Espesor corneal y variables epidemiológicas y fisiológicas en población de riesgo de glaucoma Corneal thickness and the epidemiological and physiological variables seen in the glaucoma risk population

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Idalia Triana Casado

2012-12-01

Full Text Available Objetivo: caracterizar el espesor corneal central en pacientes con factores de riesgo de glaucoma crónico simple. Métodos: se realizó un estudio epidemiológico, observacional, descriptivo y longitudinal prospectivo, en el Servicio de Glaucoma del Hospital "Dr. Salvador Allende" durante el año 2010. El universo estuvo constituido por 1 238 pacientes que acudieron a la consulta de oftalmología por síntomas astenópicos. La muestra, aplicados los criterios de inclusión y exclusión, quedó conformada por 656 pacientes con factores de riesgo de la enfermedad, de estos se desecharon 19 por una diferencia entre los ojos de 10 µm o más de espesor corneal. Las variables analizadas fueron: espesor corneal, edad, sexo, color de la piel y presión intraocular. Resultados: de los pacientes con factores de riesgo de glaucoma, predominaron aquellos entre 50 y 59 años de edad (22,76 %, masculinos (60,28 % y de piel no blanca (57,29 %. El espesor corneal estuvo disminuido (61,85 % y la presión intraocular aumentada (55,41 %, aún con ajuste (46,93 %. Conclusiones: la disminución del espesor corneal estuvo relacionada con la edad, el sexo femenino, la piel no blanca y el aumento de la presión intraocular en aquellos pacientes sospechosos de glaucoma.Objective: to characterize the central corneal thickness seen in patients with simple chronic glaucoma risk factors. Methods: a prospective longitudinal, descriptive, observational, and epidemiological study was conducted in the Glaucoma Service of “Dr. Salvador Allende” hospital during 2010. The universe of study was made up of 1 238 patients that went to the ophthalmological service due to asthenopic symptoms. Taking the inclusion and exclusion criteria into account, the final sample was composed by 656 patients with glaucoma risk factors, 19 of whom were excluded because of 10 µm and over difference in the corneal thickness between the eyes. The analyzed variables were corneal thickness, age

Interleukin-17A Promotes Parietal Cell Atrophy by Inducing ApoptosisSummary

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Kevin A. Bockerstett

Full Text Available Background & Aims: Atrophic gastritis caused by chronic inflammation in the gastric mucosa leads to the loss of gastric glandular cells, including acid-secreting parietal cells. Parietal cell atrophy in a setting of chronic inflammation induces spasmolytic polypeptide expressing metaplasia, a critical step in gastric carcinogenesis. However, the mechanisms by which inflammation causes parietal cell atrophy and spasmolytic polypeptide expressing metaplasia are not well defined. We investigated the role of interleukin-17A (IL-17A in causing parietal cell atrophy. Methods: A mouse model of autoimmune atrophic gastritis was used to examine IL-17A production during early and late stages of disease. Organoids derived from corpus glands were used to determine the direct effects of IL-17A on gastric epithelial cells. Immunofluorescent staining was used to examine IL-17A receptors and the direct effect of signaling on parietal cells. Mice were infected with an IL-17A-producing adenovirus to determine the effects of IL-17A on parietal cells in vivo. Finally, IL-17A neutralizing antibodies were administered to mice with active atrophic gastritis to evaluate the effects on parietal cell atrophy and metaplasia. Results: Increased IL-17A correlated with disease severity in mice with chronic atrophic gastritis. IL-17A caused caspase-dependent gastric organoid degeneration, which could not be rescued with a necroptosis inhibitor. Parietal cells expressed IL-17A receptors and IL-17A treatment induced apoptosis in parietal cells. Overexpressing IL-17A in vivo induced caspase-3 activation and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling staining in parietal cells. Finally, IL-17A neutralizing antibody decreased parietal cell atrophy and metaplasia in mice with chronic atrophic gastritis. Conclusions: These data identify IL-17A as a cytokine that promotes parietal cell apoptosis during atrophic gastritis, a

Xenomelia: a new right parietal lobe syndrome.

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McGeoch, Paul D; Brang, David; Song, Tao; Lee, Roland R; Huang, Mingxiong; Ramachandran, V S

2011-12-01

Damage to the right parietal lobe has long been associated with various disorders of body image. The authors have recently suggested that an unusual behavioural condition in which otherwise rational individuals desire the amputation of a healthy limb might also arise from right parietal dysfunction. Four subjects who desired the amputation of healthy legs (two right, one left and one, at first, bilateral and then left only) were recruited and underwent magnetoencephalography (MEG) scans during tactile stimulation of sites above and below the desired amputation line. Regions of interest (ROIs) in each hemisphere (superior parietal lobule (SPL), inferior parietal lobule, S1, M1, insula, premotor cortex and precuneus) were defined using FreeSurfer software. Analysis of average MEG activity across the 40-140 ms post-stimulation timeframe was carried out using an unpaired t test. This revealed significantly reduced activation only in the right SPL ROI for the subjects' affected legs when compared with both subjects' unaffected legs and that of controls. The right SPL is a cortical area that appears ideally placed to unify disparate sensory inputs to create a coherent sense of having a body. The authors propose that inadequate activation of the right SPL leads to the unnatural situation in which the sufferers can feel the limb in question being touched without it actually incorporating into their body image, with a resulting desire for amputation. The authors introduce the term 'xenomelia' as a more appropriate name than apotemnophilia or body integrity identity disorder, for what appears to be an unrecognised right parietal lobe syndrome.

Reduced parietal activation in cervical dystonia after parietal TMS interleaved with fMRI

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de Vries, Paulien M.; de Jong, Bauke M.; Bohning, Daryl E.; Hinson, Vanessa K.; George, Mark S.; Leenders, Klaus L.

Objective: Clinically normal hand movement with altered cerebral activation patterns in cervical dystonia (CD) may imply cerebral adaptation. Since impaired sensorimotor integration appears to play a role in dystonia, left superior parietal cortex modulation with repetitive transcranial magnetic

Functional segregation and integration within fronto-parietal networks.

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Parlatini, Valeria; Radua, Joaquim; Dell'Acqua, Flavio; Leslie, Anoushka; Simmons, Andy; Murphy, Declan G; Catani, Marco; Thiebaut de Schotten, Michel

2017-02-01

Experimental data on monkeys and functional studies in humans support the existence of a complex fronto-parietal system activating for cognitive and motor tasks, which may be anatomically supported by the superior longitudinal fasciculus (SLF). Advanced tractography methods have recently allowed the separation of the three branches of the SLF but are not suitable for their functional investigation. In order to gather comprehensive information about the functional organisation of these fronto-parietal connections, we used an innovative method, which combined tractography of the SLF in the largest dataset so far (129 participants) with 14 meta-analyses of functional magnetic resonance imaging (fMRI) studies. We found that frontal and parietal functions can be clustered into a dorsal spatial/motor network associated with the SLF I, and a ventral non-spatial/motor network associated with the SLF III. Further, all the investigated functions activated a middle network mostly associated with the SLF II. Our findings suggest that dorsal and ventral fronto-parietal networks are segregated but also share regions of activation, which may support flexible response properties or conscious processing. In sum, our novel combined approach provided novel findings on the functional organisation of fronto-parietal networks, and may be successfully applied to other brain connections. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Motor role of parietal cortex in a monkey model of hemispatial neglect.

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Kubanek, Jan; Li, Jingfeng M; Snyder, Lawrence H

2015-04-21

Parietal cortex is central to spatial cognition. Lesions of parietal cortex often lead to hemispatial neglect, an impairment of choices of targets in space. It has been unclear whether parietal cortex implements target choice at the general cognitive level, or whether parietal cortex subserves the choice of targets of particular actions. To address this question, monkeys engaged in choice tasks in two distinct action contexts--eye movements and arm movements. We placed focused reversible lesions into specific parietal circuits using the GABAA receptor agonist muscimol and validated the lesion placement using MRI. We found that lesions on the lateral bank of the intraparietal sulcus [lateral intraparietal area (LIP)] specifically biased choices made using eye movements, whereas lesions on the medial bank of the intraparietal sulcus [parietal reach region (PRR)] specifically biased choices made using arm movements. This double dissociation suggests that target choice is implemented in dedicated parietal circuits in the context of specific actions. This finding emphasizes a motor role of parietal cortex in spatial choice making and contributes to our understanding of hemispatial neglect.

VALORES RELATIVOS AO TRABALHO EM UMA INSTITUIÇÃO PÚBLICA DE ENSINO SUPERIOR.

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Simone Alves Pacheco de Campos

2017-08-01

Full Text Available Este estudo teve como objetivo identificar a estrutura de valores relativos ao trabalho em uma instituição pública de ensino superior. Para tanto, realizou-se uma pesquisa descritiva, de caráter quantitativo, cujos resultados demonstraram que os valores encontram-se hierarquizados segundo a seguinte estrutura: Estabilidade e Realização no Trabalho, Relações Sociais e Prestígio. As mulheres diferiram dos homens em relação à ênfase na busca por realização e estabilidade. Indivíduos com idade superior à idade média buscam sucesso profissional e poder de influência, concomitantemente com a manutenção de relações sociais positivas no trabalho. Servidores com mais tempo de cargo buscam a realização no trabalho. Por fim, a realização desta pesquisa forneceu importantes contribuições à gestão considerando que, a partir da compreensão dos valores relativos ao trabalho as organizações podem direcionar seus esforços e práticas à manutenção de um ambiente de trabalho voltado à realização das metas dos seus funcionários.

Intrinsic connections and architectonics of posterior parietal cortex in the rhesus monkey

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Pandya, D.N.; Seltzer, B.

1982-01-01

By means of autoradiographic and ablation-degeneration techniques, the intrinsic cortical connections of the posterior parietal cortex in the rhesus monkey were traced and correlated with a reappraisal of cerebral architectonics. Two major rostral-to-caudal connectional sequences exist. One begins in the dorsal postcentral gyrus (area 2) and proceeds, through architectonic divisions of the superior parietal lobule (areas PE and PEc), to a cortical region on the medial surface of the parietal lobe (area PGm). This area has architectonic features similar to those of the caudal inferior parietal lobule (area PG). The second sequence begins in the ventral post/central gyrus (area 2) and passes through the rostral inferior parietal lobule (areas PG and PFG) to reach the caudal inferior parietal lobule (area PG). Both the superior parietal lobule and the rostral inferior parietal lobule also send projections to various other zones located in the parietal opercular region, the intraparietal sulcus, and the caudalmost portion of the cingulate sulcus. Areas PGm and PG, on the other hand, project to each other, to the cingulate region, to the caudalmost portion of the superior temporal gyrus, and to the upper bank of the superior temporal sulcus. Finally, a reciprocal sequence of connections, directed from caudal to rostral, links together many of the above-mentioned parietal zones. With regard to the laminar pattern of termination, the rostral-to-caudal connections are primarily distributed in the form of cortical ''columns'' while the caudal-to-rostral connections are found mainly over the first cortical cell layer

Parietal lesion effects on cued recall following pair associate learning.

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Ben-Zvi, Shir; Soroker, Nachum; Levy, Daniel A

2015-07-01

We investigated the involvement of the posterior parietal cortex in episodic memory in a lesion-effects study of cued recall following pair-associate learning. Groups of patients who had experienced first-incident stroke, generally in middle cerebral artery territory, and exhibited damage that included lateral posterior parietal regions, were tested within an early post-stroke time window. In three experiments, patients and matched healthy comparison groups executed repeated study and cued recall test blocks of pairs of words (Experiment 1), pairs of object pictures (Experiment 2), or pairs of object pictures and environmental sounds (Experiment 3). Patients' brain CT scans were subjected to quantitative analysis of lesion volumes. Behavioral and lesion data were used to compute correlations between area lesion extent and memory deficits, and to conduct voxel-based lesion-symptom mapping. These analyses implicated lateral ventral parietal cortex, especially the angular gyrus, in cued recall deficits, most pronouncedly in the cross-modal picture-sound pairs task, though significant parietal lesion effects were also found in the unimodal word pairs and picture pairs tasks. In contrast to an earlier study in which comparable parietal lesions did not cause deficits in item recognition, these results indicate that lateral posterior parietal areas make a substantive contribution to demanding forms of recollective retrieval as represented by cued recall, especially for complex associative representations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bilateral, posterior parietal polymicrogyria as part of speech therapy ...

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SA Journal of Radiology ... Magnetic resonance imaging (MRI) has been associated with either diffuse polymicrogyria around the entire extent of the sylvian fissure or in the posterior aspects of the parietal regions, in which case it is called posterior parietal ... This article discusses the possible embryological origin of these

Isolation, culture and adenoviral transduction of parietal cells from mouse gastric mucosa

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Gliddon, Briony L; Nguyen, Nhung V; Gunn, Priscilla A; Gleeson, Paul A; Driel, Ian R van

2008-01-01

Here we describe a method for the isolation of intact gastric glands from mice and primary culture and transfection of mouse gastric epithelial cells. Collagenase digestion of PBS-perfused mouse stomachs released large intact gastric glands that were plated on a basement membrane matrix. The heterogeneous gland cell cultures typically contain ∼60% parietal cells. Isolated mouse parietal cells remain viable in culture for up to 5 days and react strongly with an antibody specific to the gastric H + /K + ATPase. Isolated intact mouse gastric glands and primary cultures of mouse parietal cells respond to the secretagogue, histamine. Typical morphological changes from a resting to an acid-secreting active parietal cell were observed. In resting cultures of mouse parietal cells, the H + /K + ATPase displayed a cytoplasmic punctate staining pattern consistent with tubulovesicle element structures. Following histamine stimulation, an expansion of internal apical vacuole structures was observed together with a pronounced redistribution of the H + /K + ATPase from the cytoplasm to the apical vacuoles. A reproducible procedure to express genes of interest exogenously in these cultures of mouse parietal cells was also established. This method combines recombinant adenoviral transduction with magnetic field-assisted transfection resulting in ∼30% transduced parietal cells. Adenoviral-transduced parietal cells maintain their ability to undergo agonist-induced activation. This protocol will be useful for the isolation, culture and expression of genes in parietal cells from genetically modified mice and as such will be an invaluable tool for studying the complex exocytic and endocytic trafficking events of the H + /K + ATPase which underpin the regulation of acid secretion

Origin of parietal podocytes in atubular glomeruli mapped by lineage tracing.

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Schulte, Kevin; Berger, Katja; Boor, Peter; Jirak, Peggy; Gelman, Irwin H; Arkill, Kenton P; Neal, Christopher R; Kriz, Wilhelm; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J

2014-01-01

Parietal podocytes are fully differentiated podocytes lining Bowman's capsule where normally only parietal epithelial cells (PECs) are found. Parietal podocytes form throughout life and are regularly observed in human biopsies, particularly in atubular glomeruli of diseased kidneys; however, the origin of parietal podocytes is unresolved. To assess the capacity of PECs to transdifferentiate into parietal podocytes, we developed and characterized a novel method for creating atubular glomeruli by electrocoagulation of the renal cortex in mice. Electrocoagulation produced multiple atubular glomeruli containing PECs as well as parietal podocytes that projected from the vascular pole and lined Bowman's capsule. Notably, induction of cell death was evident in some PECs. In contrast, Bowman's capsules of control animals and normal glomeruli of electrocoagulated kidneys rarely contained podocytes. PECs and podocytes were traced by inducible and irreversible genetic tagging using triple transgenic mice (PEC- or Pod-rtTA/LC1/R26R). Examination of serial cryosections indicated that visceral podocytes migrated onto Bowman's capsule via the vascular stalk; direct transdifferentiation from PECs to podocytes was not observed. Similar results were obtained in a unilateral ureter obstruction model and in human diseased kidney biopsies, in which overlap of PEC- or podocyte-specific antibody staining indicative of gradual differentiation did not occur. These results suggest that induction of atubular glomeruli leads to ablation of PECs and subsequent migration of visceral podocytes onto Bowman's capsule, rather than transdifferentiation from PECs to parietal podocytes.

Bertrand Russell: pacifismo político relativo

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Francisco A. Laca-Arocena

2011-01-01

Full Text Available Siguiendo la biografía de Bertrand Russell (1872-1970, lógico matemático, filósofo, premio Nobel de Literatura 1950 y militante pacifista a lo largo de gran parte del conflictivo siglo XX, se analiza el doble conflicto que afronta un pacifista: de desobediencia civil a un gobierno que ha declarado una guerra y de relativa marginación social con una opinión pública cuando ésta es mayoritariamente favorable a esa guerra. Tras un breve análisis del pacifismo contrastándolo con una doble tradición en el pensamiento político anglosajón, el utilitarismo y la teoría del contrato social, se incide en la distinción personal de Russell entre guerras ¿de prestigio¿ y ¿de valores¿. Fue pacifista en la Primera Guerra Mundial considerándola una guerra de prestigio, pero fue partidario de oponerse al nazismo en la Segunda Guerra entendiendo que se trataba de un combate de valores. Volvería a un activismo pacifista en su oposición a la guerra de Vietnam. Estas diferentes posiciones ante la guerra en relación con lo que en cada caso esté en juego, se conoce como ¿pacifismo político relativo¿, cuyo representante más genuino fue el propio Russell.

Intradiploic encephalocele of the left parietal bone: A case report

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Kim, Hyung Sock; Huh, Choon Woong; Kim, Dal Soo; Mok, Jin Ho; Kim, In Soo; Yang, Geun Seok [Myongji St. Mary' s Hospital, Seoul (Korea, Republic of)

2015-06-15

Encephaloceles are generally regarded as midline abnormalities. A 50-year-old man presented with a parietal intradiploic encephalocele manifesting as intermittent headache for the past 6 months. Computed tomography (CT) showed bone destruction associated with a left parietal lesion. Magnetic resonance imaging (MRI) demonstrated brain herniation within the intradiploic space. Cerebral angiographic imaging showed a normal cerebral vessel pattern within the herniated brain lesion. In this case, surgical treatment may not be necessary in the absence of concurrent symptoms and neurologic deficit. We report the CT, MRI, and angiographic findings of an extremely rare case of parietal intradiploic encephalocele in adulthood.

Intradiploic encephalocele of the left parietal bone: A case report

International Nuclear Information System (INIS)

Kim, Hyung Sock; Huh, Choon Woong; Kim, Dal Soo; Mok, Jin Ho; Kim, In Soo; Yang, Geun Seok

2015-01-01

Encephaloceles are generally regarded as midline abnormalities. A 50-year-old man presented with a parietal intradiploic encephalocele manifesting as intermittent headache for the past 6 months. Computed tomography (CT) showed bone destruction associated with a left parietal lesion. Magnetic resonance imaging (MRI) demonstrated brain herniation within the intradiploic space. Cerebral angiographic imaging showed a normal cerebral vessel pattern within the herniated brain lesion. In this case, surgical treatment may not be necessary in the absence of concurrent symptoms and neurologic deficit. We report the CT, MRI, and angiographic findings of an extremely rare case of parietal intradiploic encephalocele in adulthood

Temporal order processing of syllables in the left parietal lobe.

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Moser, Dana; Baker, Julie M; Sanchez, Carmen E; Rorden, Chris; Fridriksson, Julius

2009-10-07

Speech processing requires the temporal parsing of syllable order. Individuals suffering from posterior left hemisphere brain injury often exhibit temporal processing deficits as well as language deficits. Although the right posterior inferior parietal lobe has been implicated in temporal order judgments (TOJs) of visual information, there is limited evidence to support the role of the left inferior parietal lobe (IPL) in processing syllable order. The purpose of this study was to examine whether the left inferior parietal lobe is recruited during temporal order judgments of speech stimuli. Functional magnetic resonance imaging data were collected on 14 normal participants while they completed the following forced-choice tasks: (1) syllable order of multisyllabic pseudowords, (2) syllable identification of single syllables, and (3) gender identification of both multisyllabic and monosyllabic speech stimuli. Results revealed increased neural recruitment in the left inferior parietal lobe when participants made judgments about syllable order compared with both syllable identification and gender identification. These findings suggest that the left inferior parietal lobe plays an important role in processing syllable order and support the hypothesized role of this region as an interface between auditory speech and the articulatory code. Furthermore, a breakdown in this interface may explain some components of the speech deficits observed after posterior damage to the left hemisphere.

Aspirin induces morphological transformation to the secretory state in isolated rabbit parietal cells.

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Murthy, U K; Levine, R A

1991-08-01

The morphological response of rabbit parietal cells to aspirin was evaluated by grading several ultra-structural features including the extent of the tubulovesicular system, intracellular secretory canaliculi, and microvilli. After exposure of isolated parietal cells and gastric glands to aspirin or histamine, there was an approximately twofold increase in the ratio of secretory to nonsecretory parietal cells, and depletion of extracellular Ca2+ abolished the aspirin-induced morphological changes. Morphometry in parietal cells showed that aspirin induced a sixfold increase in secretory canalicular membrane elaboration. Aspirin potentiated histamine-induced parietal cell respiration and aminopyrine uptake ratio but did not increase basal respiration or aminopyrine uptake, suggesting an apparent dissociation from aspirin-induced morphological changes.

Parietal epithelial cells: their role in health and disease.

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Romagnani, Paola

2011-01-01

Parietal epithelial cells of Bowman's capsules were first described by Sir William Bowman in 1842 in his paper On the Structure and Use of the Malpighian Bodies of the Kidney [London, Taylor, 1842], but since then their functions have remained poorly understood. A large body of evidence has recently suggested that parietal epithelial cells represent a reservoir of renal progenitors in adult human kidney which generate novel podocytes during childhood and adolescence, and can regenerate injured podocytes. The discovery that parietal epithelial cells represent a potential source for podocyte regeneration suggests that podocyte injury can be repaired. However, recent results also suggest that an abnormal proliferative response of renal progenitors to podocyte injury can generate hyperplastic glomerular lesions that are observed in crescentic glomerulonephritis and other types of glomerular disorders. Taken together, these results establish an entirely novel view that changes the way of thinking about renal physiology and pathophysiology, and suggest that understanding how self-renewal and fate decision of parietal epithelial cells in response to podocyte injury may be perturbed or modulated will be crucial for obtaining novel tools for prevention and treatment of glomerulosclerosis. Copyright © 2011 S. Karger AG, Basel.

Visuo-spatial construction in patients with frontal and parietal lobe lesions

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Himani Kashyap

2011-04-01

Full Text Available Visuospatial construction, traditionally viewed as a putative parietal function, also requires sustained attention, planning, organization strategies and error correction, and hence frontal lobe mediation. The relative contributions of the frontal and parietal lobes are poorly understood. To examine the contributions of parietal, frontal lobes, as well as right and left cerebral hemispheres to visuospatial construction. The Stick Construction Test for two-dimensional construction and the Block Construction Test for three-dimensional construction were administered pre-surgically to patients with lesions in the parietal lobe (n =9 and the frontal lobe (n=11, along with normal control subjects (n =20 matched to the patients on age (+/- 3 years, gender, education (+/- 3 years and handedness. The patients were significantly slower than the controls on both two-dimensional and three-dimensional tests. Patients with parietal lesions were slower than those with frontal lesions on the test of three-dimensional construction. Within each lobe patients with right and left sided lesions did not differ significantly. It appears that tests of three-dimensional construction might be most sensitive to visuospatial construction deficits. Visuospatial construction involves the mediation of both frontal and parietal lobes. The function does not appear to be lateralized. The networks arising from the parieto-occipital areas and projecting to the frontal cortices (e.g., occipito-frontal fasciculus may be the basis of the mediation of both lobes in visuospatial construction. The present findings need replication from studies with larger sample sizes.

Functional connectivity of parietal cortex during temporal selective attention.

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Tyler, Sarah C; Dasgupta, Samhita; Agosta, Sara; Battelli, Lorella; Grossman, Emily D

2015-04-01

Perception of natural experiences requires allocation of attention towards features, objects, and events that are moving and changing over time. This allocation of attention is controlled by large-scale brain networks that, when damaged, cause widespread cognitive deficits. In particular, damage to ventral parietal cortex (right lateralized TPJ, STS, supramarginal and angular gyri) is associated with failures to selectively attend to and isolate features embedded within rapidly changing visual sequences (Battelli, Pascual-Leone, & Cavanagh, 2007; Husain, Shapiro, Martin, & Kennard, 1997). In this study, we used fMRI to investigate the neural activity and functional connectivity of intact parietal cortex while typical subjects judged the relative onsets and offsets of rapidly flickering tokens (a phase discrimination task in which right parietal patients are impaired). We found two regions in parietal cortex correlated with task performance: a bilateral posterior TPJ (pTPJ) and an anterior right-lateralized TPJ (R aTPJ). Both regions were deactivated when subjects engaged in the task but showed different patterns of functional connectivity. The bilateral pTPJ was strongly connected to nodes within the default mode network (DMN) and the R aTPJ was connected to the attention network. Accurate phase discriminations were associated with increased functional correlations between sensory cortex (hMT+) and the bilateral pTPJ, whereas accuracy on a control task was associated with yoked activity in the hMT+ and the R aTPJ. We conclude that temporal selective attention is particularly sensitive for revealing information pathways between sensory and core cognitive control networks that, when damaged, can lead to nonspatial attention impairments in right parietal stroke patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

Elasticidade-preço da demanda por etanol no Brasil: como renda e preços relativos explicam diferenças entre estados

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Veronica Fernandez Orellano

2013-12-01

Full Text Available Este artigo estuda a demanda por etanol no Brasil no período 2001-2009, considerando as características regionais de renda e de preços relativos. Essas características explicam variação relevante na elasticidade-preço da demanda, aspecto até então desconsiderado em estudos anteriores. Foi estimado um modelo econométrico a partir de um painel de dados estaduais mensais, no qual variáveis instrumentais foram usadas para controlar a endogeneidade na análise da demanda. Conclui-se que a demanda é mais elástica em estados mais pobres e em que o preço relativo está próximo a 70%, a taxa técnica de substituição entre etanol e gasolina, parâmetro relevante para as decisões de consumo de proprietários de veículos flex-fuel. Essas regiões apresentam maiores elasticidades-preço da demanda, em última análise, por conta de diferenças logísticas e tributárias, as quais definem o preço relativo. Esses resultados diferem daqueles obtidos por Salvo e Huse (2013, pois identificam diferenças regionais que independem da heterogeneidade das preferências dos consumidores, mas decorrem da configuração logística e de renda. Os resultados sugerem implicações para as políticas tributária e de infraestrutura logística, as quais, ao afetarem o nível de preços relativos de etanol e gasolina, afetam a sensibilidade da demanda com relação às variações de preço.

Distinct Oscillatory Frequencies Underlie Excitability of Human Occipital and Parietal Cortex.

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Samaha, Jason; Gosseries, Olivia; Postle, Bradley R

2017-03-15

Transcranial magnetic stimulation (TMS) of human occipital and posterior parietal cortex can give rise to visual sensations called phosphenes. We used near-threshold TMS with concurrent EEG recordings to measure how oscillatory brain dynamics covary, on single trials, with the perception of phosphenes after occipital and parietal TMS. Prestimulus power and phase, predominantly in the alpha band (8-13 Hz), predicted occipital TMS phosphenes, whereas higher-frequency beta-band (13-20 Hz) power (but not phase) predicted parietal TMS phosphenes. TMS-evoked responses related to phosphene perception were similar across stimulation sites and were characterized by an early (200 ms) posterior negativity and a later (>300 ms) parietal positivity in the time domain and an increase in low-frequency (∼5-7 Hz) power followed by a broadband decrease in alpha/beta power in the time-frequency domain. These correlates of phosphene perception closely resemble known electrophysiological correlates of conscious perception of near-threshold visual stimuli. The regionally differential pattern of prestimulus predictors of phosphene perception suggests that distinct frequencies may reflect cortical excitability in occipital versus posterior parietal cortex, calling into question the broader assumption that the alpha rhythm may serve as a general index of cortical excitability. SIGNIFICANCE STATEMENT Alpha-band oscillations are thought to reflect cortical excitability and are therefore ascribed an important role in gating information transmission across cortex. We probed cortical excitability directly in human occipital and parietal cortex and observed that, whereas alpha-band dynamics indeed reflect excitability of occipital areas, beta-band activity was most predictive of parietal cortex excitability. Differences in the state of cortical excitability predicted perceptual outcomes (phosphenes), which were manifest in both early and late patterns of evoked activity, revealing the time

Comparación de los valores del espesor corneal central según los equipos Lenstar, Galilei y Pentacam Comparative study of the central corneal thickness measurements taken by Lenstar, Gallilei and Pentacam equipment

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Iramis Miranda Hernández

2012-06-01

Full Text Available Objetivo: Comparar valores del espesor corneal central obtenidos mediante la paquimetría con el sistema de interferometria de coherencia parcial (Lenstar con los sistemas Scheimpflug (Pentacam; Oculus y Galilei (Ziemer, Suiza. Métodos: Se realizó un estudio prospectivo, comparativo en 120 ojos de 60 pacientes. Para la comparación se tomaron varias mediciones recomendadas por los fabricantes para probar la eficacia del equipo con el nuevo biómetro Lenstar LS 900 (Haag Streit AG y con los equipos Pentacam y Galilei. La comparación de los valores se realizó mediante el análisis de regresión lineal y correlación de Pearson. Resultados: El análisis reveló que existe una alta correspondencia en los valores del espesor corneal central entre Lenstar y los topógrafos Galilei y Pentacam. Conclusiones: Existe una alta correspondencia entre los valores del espesor corneal central obtenidos por los equipos Lenstar, Pentacam y Galilei. Por esto el equipo Lenstar es útil en la cirugía de catarata y la cirugía refractiva.Objective: To compare the central corneal thickness measurements taken by pachimetry with the partial coherence interferometry, Lenstar and with Scheimpflug systems (Pentacam; Oculus and Galilei (Ziemer, Switzerland. Methods: Comparative and prospective study of 120 eyes from 60 patients. Several recommended measurements were taken with the optical biometers LenstarLS 900 (Haag Streit AG and with Pentacam y Galilei topographers. The results were evaluated using the linear regresión analysis and Pearson´s correlation. Results: There is high correlation among the central corneal thickness measurements taken by the Lenstar equipment and topographers Pentacam and Galilei. Conclusion: The new biometer LENSTAR provided results that correlated very well with those of the Pentacam and Galilei systems. The Lenstar is a precise device that will be helpful for any cataract or refractive surgery.

Modelo gravimétrico del espesor de la corteza terrestre en Colombia

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Leuro Parra Erick

2000-08-01

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The gravimetric model of the crustal thickness of the earth in Colombia was made from Total Bouguer Anomaly and topographic height given by the Instituto Geográfico Agustín Codazzi. They were transformed to bidimensional series of Fourier, that combined with mathematics expressions of the gravitational potential, both, they made possible to find the crustal thickness starting from observable values across the earth's surface (gravity and topography. The results of several points were converted to surface through Minime Curvature algorithm. In order to obtain reliability of the results, seismic control was applied from another works.

La determinación del espesor de la corteza terrestre en Colombia, a partir de datos gravimétricos, se hizo utilizando datos de Anomalia Total de Bouguer y altura topográfica suministrados por el Instituto Geográfico Agustin Codazzi. Estos fueron representados mediante series bidimensionales de Fourier, que al ser combinadas con expresiones matemáticas del potencial gravitacional terrestre, permitieron plantear el grosor cortical en términos observables (gravedad y altura sobre la superficie terrestre. Los resultados han sido dispuestos en una malla de puntos que se interpolan a una superficie utilizando el algoritmo de mínima curvatura. Para la estimación de la confiabilidad de los resultados se ha realizado una confrontación con las deducciones geológicas obtenidas de algunas interpretaciones sismicas realizadas en el pais.

Short parietal lobe connections of the human and monkey brain

DEFF Research Database (Denmark)

Catani, Marco; Robertsson, Naianna; Beyh, Ahmad

2017-01-01

projections were reconstructed for both species and results compared to identify similarities or differences in tract anatomy (i.e., trajectories and cortical projections). In addition, post-mortem dissections were performed in a human brain. The largest tract identified in both human and monkey brains...... and angular gyri of the inferior parietal lobule in humans but only to the supramarginal gyrus in the monkey brain. The third tract connects the postcentral gyrus to the anterior region of the superior parietal lobule and is more prominent in monkeys compared to humans. Finally, short U-shaped fibres...... and monkeys with some differences for those areas that have cytoarchitectonically distinct features in humans. The overall pattern of intraparietal connectivity supports the special role of the inferior parietal lobule in cognitive functions characteristic of humans....

Modulation of fronto-parietal connections during the rubber hand illusion

DEFF Research Database (Denmark)

Karabanov, Anke Ninija; Ritterband-Rosenbaum, Anina; Christensen, Mark Schram

2017-01-01

Accumulating evidence suggests that parieto-frontal connections play a role in adjusting body ownership during the Rubber Hand Illusion (RHI). Using a motor version of the rubber hand illusion paradigm, we applied single-site and dual-site transcranial magnetic stimulation (TMS) to investigate...... and during three RHI conditions: a) agency and ownership, b) agency but no ownership and c) neither agency nor ownership. Parietal-motor communication differed among experimental conditions. The induction of action ownership was associated with an inhibitory parietal-to-motor connectivity, which...... cortico-spinal and parietal-frontal connectivity during perceived rubber hand ownership. Healthy volunteers received a conditioning TMS pulse over left anterior intraparietal sulcus (aIPS) and a test TMS pulse over left primary motor cortex (M1). Motor Evoked Potentials (MEPs) were recorded at rest...

Overlapping Parietal Activity in Memory and Perception: Evidence for the Attention to Memory Model

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Cabeza, Roberto; Mazuz, Yonatan S.; Stokes, Jared; Kragel, James E.; Woldorff, Marty G.; Ciaramelli, Elisa; Olson, Ingrid R.; Moscovitch, Morris

2011-01-01

The specific role of different parietal regions to episodic retrieval is a topic of intense debate. According to the Attention to Memory (AtoM) model, dorsal parietal cortex (DPC) mediates top-down attention processes guided by retrieval goals, whereas ventral parietal cortex (VPC) mediates bottom-up attention processes captured by the retrieval…

Differentiated parietal connectivity of frontal regions for "what" and "where" memory.

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Rottschy, C; Caspers, S; Roski, C; Reetz, K; Dogan, I; Schulz, J B; Zilles, K; Laird, A R; Fox, P T; Eickhoff, S B

2013-11-01

In a previous meta-analysis across almost 200 neuroimaging experiments, working memory for object location showed significantly stronger convergence on the posterior superior frontal gyrus, whereas working memory for identity showed stronger convergence on the posterior inferior frontal gyrus (dorsal to, but overlapping with Brodmann's area BA 44). As similar locations have been discussed as part of a dorsal frontal-superior parietal reach system and an inferior frontal grasp system, the aim of the present study was to test whether the regions of working-memory related "what" and "where" processing show a similar distinction in parietal connectivity. The regions that were found in the previous meta-analysis were used as seeds for functional connectivity analyses using task-based meta-analytic connectivity modelling and task-independent resting state correlations. While the ventral seed showed significantly stronger connectivity with the bilateral intraparietal sulcus (IPS), the dorsal seed showed stronger connectivity with the bilateral posterior inferior parietal and the medial superior parietal lobule. The observed connections of regions involved in memory for object location and identity thus clearly demonstrate a distinction into separate pathways that resemble the parietal connectivity patterns of the dorsal and ventral premotor cortex in non-human primates and humans. It may hence be speculated that memory for a particular location and reaching towards it as well as object memory and finger positioning for manipulation may rely on shared neural systems. Moreover, the ensuing regions, in turn, featured differential connectivity with the bilateral ventral and dorsal extrastriate cortex, suggesting largely segregated bilateral connectivity pathways from the dorsal visual cortex via the superior and inferior parietal lobules to the dorsal posterior frontal cortex and from the ventral visual cortex via the IPS to the ventral posterior frontal cortex that may

Significance of parietal projection in radiosotope scintigraphy of the brain

International Nuclear Information System (INIS)

Fomchenkov, E.P.

1978-01-01

The diagnostic value of the isotope scintigraphy of the brain in the parieal projection with the change of the dip angle of the gamma-chamber detector to the plane of the physiological horizontal was revealed. The observation was made on 100 patients with suspected presence of the volumetric process of the brain. Three variants of placing were studied: the parietal projection - standard (collimator plane parallel to the plane of physiological horizontal and strictly perpendicular to the sagittal plane); the placing with an angle of 30 deg between the detector plane and the physiological horizontal, opened at the front (posterio-parietal); placing with an angle of 30 deg between the detector plane and the physiological horizontal opened at the back (anterio-parietal). A comparative analysis of scintigrams with focal processes of the brain showed the largest informativeness of the proposed modification of the parietal projection in the form of a change of the dip angle of the gamma-chamber detector plane to the plane of the physiological horizontal opened at the back; this makes it possible to reveal more thoroughly the focus of the increased, pathological accumulation of the isotope in different parts of the skull, where the use of as standard placing is of small informativeness

Predicting oculomotor behaviour from correlated populations of posterior parietal neurons.

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Graf, Arnulf B A; Andersen, Richard A

2015-01-23

Oculomotor function critically depends on how signals representing saccade direction and eye position are combined across neurons in the lateral intraparietal (LIP) area of the posterior parietal cortex. Here we show that populations of parietal neurons exhibit correlated variability, and that using these interneuronal correlations yields oculomotor predictions that are more accurate and also less uncertain. The structure of LIP population responses is therefore essential for reliable read-out of oculomotor behaviour.

The structure of the parietal pleura and its relationship to pleural liquid dynamics in sheep.

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Albertine, K H; Wiener-Kronish, J P; Staub, N C

1984-03-01

We studied the parietal pleura of six sheep to obtain information on pleural structure, blood supply, and lymphatic drainage. In the strict sense, the parietal pleura is composed of a single layer of mesothelial cells and a uniform layer of loose, irregular connective tissue (about 23 micron in width) subjacent to the mesothelial cells. The parietal pleural blood vessels are 10-15 micron from the pleural space. Tracer substances put in the pleural space are removed at specific locations. Colloidal carbon and chick red blood cells are cleared by the parietal pleural lymphatics located over the intercostal spaces at the caudal end of the thoracic wall and over the lateral sides of the pericardial sac. In these areas the mesothelial cells have specialized openings, the stomata, that directly communicate with the underlying lymphatic lacunae. Cells and particulate matter in the pleural space are cleared only by the parietal pleural lymphatics. Compared to the visceral pleura, we believe the thinness of the parietal pleura, the closeness of its blood vessels to the pleural space, and its specialized lymphatic clearance pathways, together indicate that the parietal pleura plays a major role in pleural liquid and protein dynamics in sheep.

Abstract Representations of Object-Directed Action in the Left Inferior Parietal Lobule.

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Chen, Quanjing; Garcea, Frank E; Jacobs, Robert A; Mahon, Bradford Z

2018-06-01

Prior neuroimaging and neuropsychological research indicates that the left inferior parietal lobule in the human brain is a critical substrate for representing object manipulation knowledge. In the present functional MRI study we used multivoxel pattern analyses to test whether action similarity among objects can be decoded in the inferior parietal lobule independent of the task applied to objects (identification or pantomime) and stimulus format in which stimuli are presented (pictures or printed words). Participants pantomimed the use of objects, cued by printed words, or identified pictures of objects. Classifiers were trained and tested across task (e.g., training data: pantomime; testing data: identification), stimulus format (e.g., training data: word format; testing format: picture) and specific objects (e.g., training data: scissors vs. corkscrew; testing data: pliers vs. screwdriver). The only brain region in which action relations among objects could be decoded across task, stimulus format and objects was the inferior parietal lobule. By contrast, medial aspects of the ventral surface of the left temporal lobe represented object function, albeit not at the same level of abstractness as actions in the inferior parietal lobule. These results suggest compulsory access to abstract action information in the inferior parietal lobe even when simply identifying objects.

Patterns of morphological integration between parietal and temporal areas in the human skull.

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Bruner, Emiliano; Pereira-Pedro, Ana Sofia; Bastir, Markus

2017-10-01

Modern humans have evolved bulging parietal areas and large, projecting temporal lobes. Both changes, largely due to a longitudinal expansion of these cranial and cerebral elements, were hypothesized to be the result of brain evolution and cognitive variations. Nonetheless, the independence of these two morphological characters has not been evaluated. Because of structural and functional integration among cranial elements, changes in the position of the temporal poles can be a secondary consequence of parietal bulging and reorientation of the head axis. In this study, we use geometric morphometrics to test the correlation between parietal shape and the morphology of the endocranial base in a sample of adult modern humans. Our results suggest that parietal proportions show no correlation with the relative position of the temporal poles within the spatial organization of the endocranial base. The vault and endocranial base are likely to be involved in distinct morphogenetic processes, with scarce or no integration between these two districts. Therefore, the current evidence rejects the hypothesis of reciprocal morphological influences between parietal and temporal morphology, suggesting that evolutionary spatial changes in these two areas may have been independent. However, parietal bulging exerts a visible effect on the rotation of the cranial base, influencing head position and orientation. This change can have had a major relevance in the reorganization of the head functional axis. © 2017 Wiley Periodicals, Inc.

Brain activity dynamics in human parietal regions during spontaneous switches in bistable perception.

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Megumi, Fukuda; Bahrami, Bahador; Kanai, Ryota; Rees, Geraint

2015-02-15

The neural mechanisms underlying conscious visual perception have been extensively investigated using bistable perception paradigms. Previous functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) studies suggest that the right anterior superior parietal (r-aSPL) and the right posterior superior parietal lobule (r-pSPL) have opposite roles in triggering perceptual reversals. It has been proposed that these two areas are part of a hierarchical network whose dynamics determine perceptual switches. However, how these two parietal regions interact with each other and with the rest of the brain during bistable perception is not known. Here, we investigated such a model by recording brain activity using fMRI while participants viewed a bistable structure-from-motion stimulus. Using dynamic causal modeling (DCM), we found that resolving such perceptual ambiguity was specifically associated with reciprocal interactions between these parietal regions and V5/MT. Strikingly, the strength of bottom-up coupling between V5/MT to r-pSPL and from r-pSPL to r-aSPL predicted individual mean dominance duration. Our findings are consistent with a hierarchical predictive coding model of parietal involvement in bistable perception and suggest that visual information processing underlying spontaneous perceptual switches can be described as changes in connectivity strength between parietal and visual cortical regions. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Sex-dependent age modulation of frontostriatal and temporo-parietal activation during cognitive control.

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Christakou, Anastasia; Halari, Rozmin; Smith, Anna B; Ifkovits, Eve; Brammer, Mick; Rubia, Katya

2009-10-15

Developmental functional imaging studies of cognitive control show progressive age-related increase in task-relevant fronto-striatal activation in male development from childhood to adulthood. Little is known, however, about how gender affects this functional development. In this study, we used event related functional magnetic resonance imaging to examine effects of sex, age, and their interaction on brain activation during attentional switching and interference inhibition, in 63 male and female adolescents and adults, aged 13 to 38. Linear age correlations were observed across all subjects in task-specific frontal, striatal and temporo-parietal activation. Gender analysis revealed increased activation in females relative to males in fronto-striatal areas during the Switch task, and laterality effects in the Simon task, with females showing increased left inferior prefrontal and temporal activation, and males showing increased right inferior prefrontal and parietal activation. Increased prefrontal activation clusters in females and increased parietal activation clusters in males furthermore overlapped with clusters that were age-correlated across the whole group, potentially reflecting more mature prefrontal brain activation patterns for females, and more mature parietal activation patterns for males. Gender by age interactions further supported this dissociation, revealing exclusive female-specific age correlations in inferior and medial prefrontal brain regions during both tasks, and exclusive male-specific age correlations in superior parietal (Switch task) and temporal regions (Simon task). These findings show increased recruitment of age-correlated prefrontal activation in females, and of age-correlated parietal activation in males, during tasks of cognitive control. Gender differences in frontal and parietal recruitment may thus be related to gender differences in the neurofunctional maturation of these brain regions.

Dissociation of Subtraction and Multiplication in the Right Parietal Cortex: Evidence from Intraoperative Cortical Electrostimulation

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Yu, Xiaodan; Chen, Chuansheng; Pu, Song; Wu, Chenxing; Li, Yongnian; Jiang, Tao; Zhou, Xinlin

2011-01-01

Previous research has consistently shown that the left parietal cortex is critical for numerical processing, but the role of the right parietal lobe has been much less clear. This study used the intraoperative cortical electrical stimulation approach to investigate neural dissociation in the right parietal cortex for subtraction and…

Estudios de series temporales de energía solar UV-B de 305 nm y espesor de la capa de ozono estratosférico en Arica, norte de Chile

OpenAIRE

Rivas,Miguel; Leiva,Carlos; Rojas,Elisa

2011-01-01

En este trabajo se muestran los resultados del análisis de las series temporales de la energía solar medida a nivel del suelo, en la banda de 305 nm, y el espesor de la capa de ozono estratosférico. El rasgo más importante es la independencia de los valores de energía a nivel del suelo respecto de la variabilidad de corto periodo de la capa de ozono, siendo probablemente efectos meteorológicos locales los que llevan el mayor peso de la varianza.

Attenuating illusory binding with TMS of the right parietal cortex

OpenAIRE

Esterman, Michael; Verstynen, Timothy; Robertson, Lynn C.

2007-01-01

A number of neuroimaging and neuropsychology studies have implicated various regions of parietal cortex as playing a critical role in the binding of color and form into conjunctions. The current study investigates the role of two such regions by examining how parietal transcranial magnetic stimulation (TMS) influences binding errors known as ‘illusory conjunctions.’ Participants made fewer binding errors after 1 Hz rTMS of the right intraparietal sulcus (IPS), while basic perception of featur...

Investigating the effects of nitrous oxide sedation on frontal-parietal interactions.

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Ryu, Ji-Ho; Kim, Pil-Jong; Kim, Hong-Gee; Koo, Yong-Seo; Shin, Teo Jeon

2017-06-09

Although functional connectivity has received considerable attention in the study of consciousness, few studies have investigated functional connectivity limited to the sedated state where consciousness is maintained but impaired. The aim of the present study was to investigate changes in functional connectivity of the parietal-frontal network resulting from nitrous oxide-induced sedation, and to determine the neural correlates of cognitive impairment during consciousness transition states. Electroencephalography was acquired from healthy adult patients who underwent nitrous oxide inhalation to induce cognitive impairment, and was analyzed using Granger causality (GC). Periods of awake, sedation and recovery for GC between frontal and parietal areas in the delta, theta, alpha, beta, gamma and total frequency bands were obtained. The Friedman test with post-hoc analysis was conducted for GC values of each period for comparison. As a sedated state was induced by nitrous oxide inhalation, power in the low frequency band showed increased activity in frontal regions that was reversed with discontinuation of nitrous oxide. Feedback and feedforward connections analyzed in spectral GC were changed differently in accordance with EEG frequency bands in the sedated state by nitrous oxide administration. Calculated spectral GC of the theta, alpha, and beta frequency regions in the parietal-to-frontal direction was significantly decreased in the sedated state while spectral GC in the reverse direction did not show significant change. Frontal-parietal functional connectivity is significantly affected by nitrous oxide inhalation. Significantly decreased parietal-to-frontal interaction may induce a sedated state. Copyright © 2017 Elsevier B.V. All rights reserved.

The mirror mechanism in the parietal lobe.

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Rizzolatti, Giacomo; Rozzi, Stefano

2018-01-01

The mirror mechanism is a basic mechanism that transforms sensory representations of others' actions into motor representations of the same actions in the brain of the observer. The mirror mechanism plays an important role in understanding actions of others. In the present chapter we discuss first the basic organization of the posterior parietal lobe in the monkey, stressing that it is best characterized as a motor scaffold, on the top of which sensory information is organized. We then describe the location of the mirror mechanism in the posterior parietal cortex of the monkey, and its functional role in areas PFG, and anterior, ventral, and lateral intraparietal areas. We will then present evidence that a similar functional organization is present in humans. We will conclude by discussing the role of the mirror mechanism in the recognition of action performed with tools. Copyright © 2018 Elsevier B.V. All rights reserved.

Medidas ultrasonográficas del espesor conjunto de la unión útero-placentaria en yeguas criollas colombianas

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Fernando Emilio Vega Díaz

2013-04-01

Full Text Available En el trabajo se determinaron los valores ultrasonográficos del espesor conjunto de la unión úteroplacentaria (ECUP, desde el cuarto mes hasta el final de la gestación, en 20 yeguas criollas colombianas, con edades entre 4 y 8 años y un promedio de peso de 348 kg, para un total de 640 mediciones en cada examen. Para el efecto se hicieron exámenes transrectal y transabdominal con transductor lineal de 6.0 MHz y transductor convexo R40 de 3.5 MHz, respectivamente. Durante el periodo de gestación se encontraron diferencias (P £ 0.05 entre los parámetros ECUP y divergencias cuando se compararon con los resultados reportados en hembras equinas de otras razas. La media de los valores ECUP incrementó con la edad gestacional; para la transrectal se encontró un mínimo de 3.1 ± 1.28 mm y un máximo de 7.3 ± 2.22 mm, y para transabdominal estos valores fueron de 6.3 ± 1.28 mm y 14.3 ± 2.22 mm.

The contribution of the human posterior parietal cortex to episodic memory

OpenAIRE

Sestieri, Carlo; Shulman, Gordon L.; Corbetta, Maurizio

2017-01-01

The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional–anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push–pull relationship, poten...

Optimized gamma synchronization enhances functional binding of fronto-parietal cortices in mathematically gifted adolescents during deductive reasoning

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Li eZhang

2014-06-01

Full Text Available As enhanced fronto-parietal network has been suggested to support reasoning ability of math-gifted adolescents, the main goal of this EEG source analysis is to investigate the temporal binding of the gamma-band (30-60Hz synchronization between frontal and parietal cortices in adolescents with exceptional mathematical ability, including the functional connectivity of gamma neurocognitive network, the temporal dynamics of fronto-parietal network (phase-locking durations and network lability in time domain, and the self-organized criticality of synchronizing oscillation. Compared with the average-ability subjects, the math-gifted adolescents show a highly integrated fronto-parietal network due to distant gamma phase-locking oscillations, which is indicated by lower modularity of the global network topology, more connector bridges between the frontal and parietal cortices and less connector hubs in the sensorimotor cortex. The time-domain analysis finds that, while maintaining more stable phase dynamics of the fronto-parietal coupling, the math-gifted adolescents are characterized by more extensive fronto-parietal connection reconfiguration. The results from sample fitting in the power-law model further find that the phase-locking durations in the math-gifted brain abides by a wider interval of the power-law distribution. This phase-lock distribution mechanism could represent a relatively optimized pattern for the functional binding of frontal-parietal network, which underlies stable fronto-parietal connectivity and increases flexibility of timely network reconfiguration.

The Oft-Neglected Role of Parietal EEG Asymmetry and Risk for Major Depressive Disorder

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Stewart, Jennifer L.; Towers, David N.; Coan, James A.; Allen, John J.B.

2010-01-01

Relatively less right parietal activity may reflect reduced arousal and signify risk for major depressive disorder (MDD). Inconsistent findings with parietal electroencephalographic (EEG) asymmetry, however, suggest issues such as anxiety comorbidity and sex differences have yet to be resolved. Resting parietal EEG asymmetry was assessed in 306 individuals (31% male) with (n = 143) and without (n = 163) a DSM-IV diagnosis of lifetime MDD and no comorbid anxiety disorders. Past MDD+ women displayed relatively less right parietal activity than current MDD+ and MDD- women, replicating prior work. Recent caffeine intake, an index of arousal, moderated the relationship between depression and EEG asymmetry for women and men. Findings suggest that sex differences and arousal should be examined in studies of depression and regional brain activity. PMID:20525011

Phosphene-guided transcranial magnetic stimulation of occipital but not parietal cortex suppresses stimulus visibility

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Tapia, Evelina; Mazzi, Chiara; Savazzi, Silvia; Beck, Diane M.

2014-01-01

Transcranial magnetic stimulation (TMS) applied over the occipital lobe approximately 100 ms after the onset of a stimulus decreases its visibility if it appears in the location of the phosphene. Because phosphenes can also be elicited by stimulation of the parietal regions, we asked if the same procedure that is used to reduce visibility of stimuli with occipital TMS will lead to decreased stimulus visibility when TMS is applied to parietal regions. TMS was randomly applied at 0 to 130 ms after the onset of the stimulus (SOA) in steps of 10 ms in occipital and parietal regions. Participants responded to the orientation of the line stimulus and rated its visibility. We replicate previous reports of phosphenes from both occipital and parietal TMS. As previously reported, we also observed visual suppression around the classical 100 ms window both in the objective line orientation and subjective visibility responses with occipital TMS. Parietal stimulation, on the other hand, did not consistently reduce stimulus visibility in any time window. PMID:24584900

Parietal cells-new perspectives in glomerular disease

NARCIS (Netherlands)

Miesen, L.; Steenbergen, E.; Smeets, B.

2017-01-01

In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman's capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and

Visual perception is dependent on visuospatial working memory and thus on the posterior parietal cortex.

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Pisella, Laure

2017-06-01

Visual perception involves complex and active processes. We will start by explaining why visual perception is dependent on visuospatial working memory, especially the spatiotemporal integration of the perceived elements through the ocular exploration of visual scenes. Then we will present neuropsychology, transcranial magnetic stimulation and neuroimaging data yielding information on the specific role of the posterior parietal cortex of the right hemisphere in visuospatial working memory. Within the posterior parietal cortex, neuropsychology data also suggest that there might be dissociated neural substrates for deployment of attention (superior parietal lobules) and spatiotemporal integration (right inferior parietal lobule). Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Evolution of posterior parietal cortex and parietal-frontal networks for specific actions in primates.

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Kaas, Jon H; Stepniewska, Iwona

2016-02-15

Posterior parietal cortex (PPC) is an extensive region of the human brain that develops relatively late and is proportionally large compared with that of monkeys and prosimian primates. Our ongoing comparative studies have led to several conclusions about the evolution of this posterior parietal region. In early placental mammals, PPC likely was a small multisensory region much like PPC of extant rodents and tree shrews. In early primates, PPC likely resembled that of prosimian galagos, in which caudal PPC (PPCc) is visual and rostral PPC (PPCr) has eight or more multisensory domains where electrical stimulation evokes different complex motor behaviors, including reaching, hand-to-mouth, looking, protecting the face or body, and grasping. These evoked behaviors depend on connections with functionally matched domains in premotor cortex (PMC) and motor cortex (M1). Domains in each region compete with each other, and a serial arrangement of domains allows different factors to influence motor outcomes successively. Similar arrangements of domains have been retained in New and Old World monkeys, and humans appear to have at least some of these domains. The great expansion and prolonged development of PPC in humans suggest the addition of functionally distinct territories. We propose that, across primates, PMC and M1 domains are second and third levels in a number of parallel, interacting networks for mediating and selecting one type of action over others. © 2015 Wiley Periodicals, Inc.

Estudios de series temporales de energía solar UV-B de 305 nm y espesor de la capa de ozono estratosférico en Arica, norte de Chile

OpenAIRE

Rivas, Miguel; Leiva, Carlos; Rojas, Elisa

2011-01-01

En este trabajo se muestran los resultados del análisis de las series temporales de la energía solar medida a nivel del suelo, en la banda de 305 nm, y el espesor de la capa de ozono estratosférico. El rasgo más importante es la independencia de los valores de energía a nivel del suelo respecto de la variabilidad de corto periodo de la capa de ozono, siendo probablemente efectos meteorológicos locales los que llevan el mayor peso de la varianza. In this paper, the results obtained by analy...

Nuclear Glycogen Inclusions in Canine Parietal Cells.

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Silvestri, S; Lepri, E; Dall'Aglio, C; Marchesi, M C; Vitellozzi, G

2017-05-01

Nuclear glycogen inclusions occur infrequently in pathologic conditions but also in normal human and animal tissues. Their function or significance is unclear. To the best of the authors' knowledge, no reports of nuclear glycogen inclusions in canine parietal cells exist. After initial observations of nuclear inclusions/pseudoinclusions during routine histopathology, the authors retrospectively examined samples of gastric mucosa from dogs presenting with gastrointestinal signs for the presence of intranuclear inclusions/pseudoinclusions and determined their composition using histologic and electron-microscopic methods. In 24 of 108 cases (22%), the authors observed various numbers of intranuclear inclusions/pseudoinclusions within scattered parietal cells. Nuclei were characterized by marked karyomegaly and chromatin margination around a central optically empty or slightly eosinophilic area. The intranuclear inclusions/pseudoinclusions stained positive with periodic acid-Schiff (PAS) and were diastase sensitive, consistent with glycogen. Several PAS-positive/diastase-sensitive sections were further examined by transmission electron microscopy, also using periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining to identify polysaccharides. Ultrastructurally, the nuclear inclusions were composed of electron-dense particles that were not membrane bound, without evidence of nuclear membrane invaginations or cytoplasmic organelles in the nuclei, and positive staining with PA-TCH-SP, confirming a glycogen composition. No cytoplasmic glycogen deposits were observed, suggesting that the intranuclear glycogen inclusions were probably synthesized in loco. Nuclear glycogen inclusions were not associated with gastritis or colonization by Helicobacter-like organisms ( P > .05). Our findings suggest that nuclear glycogen inclusions in canine parietal cells could be an incidental finding. Nevertheless, since nuclear glycogen is present in several pathologic

Neuronal oscillations form parietal/frontal networks during contour integration.

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Castellano, Marta; Plöchl, Michael; Vicente, Raul; Pipa, Gordon

2014-01-01

The ability to integrate visual features into a global coherent percept that can be further categorized and manipulated are fundamental abilities of the neural system. While the processing of visual information involves activation of early visual cortices, the recruitment of parietal and frontal cortices has been shown to be crucial for perceptual processes. Yet is it not clear how both cortical and long-range oscillatory activity leads to the integration of visual features into a coherent percept. Here, we will investigate perceptual grouping through the analysis of a contour categorization task, where the local elements that form contour must be linked into a coherent structure, which is then further processed and manipulated to perform the categorization task. The contour formation in our visual stimulus is a dynamic process where, for the first time, visual perception of contours is disentangled from the onset of visual stimulation or from motor preparation, cognitive processes that until now have been behaviorally attached to perceptual processes. Our main finding is that, while local and long-range synchronization at several frequencies seem to be an ongoing phenomena, categorization of a contour could only be predicted through local oscillatory activity within parietal/frontal sources, which in turn, would synchronize at gamma (>30 Hz) frequency. Simultaneously, fronto-parietal beta (13-30 Hz) phase locking forms a network spanning across neural sources that are not category specific. Both long range networks, i.e., the gamma network that is category specific, and the beta network that is not category specific, are functionally distinct but spatially overlapping. Altogether, we show that a critical mechanism underlying contour categorization involves oscillatory activity within parietal/frontal cortices, as well as its synchronization across distal cortical sites.

Counteracting fatigue in multiple sclerosis with right parietal anodal transcranial direct current stimulation

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Katrin Hanken

2016-09-01

Full Text Available Background: Fatigue in multiple sclerosis (MS patients appears to correlate with vigilance decrement as reflected in an increase in reaction time and errors with prolonged time-on-task. Objectives: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. Methods: In study I, a randomized double-blind placebo-controlled study, anodal tDCS (1,5mA was delivered to the right parietal cortex or the right frontal cortex of 52 healthy participants during the first 20min of a 40min lasting visual vigilance task. Study II, also a randomized double-blind placebo-controlled study, investigated the effect of anodal tDCS (1.5mA over the right parietal cortex in 46 MS patients experiencing cognitive fatigue. TDCS was delivered for 20min before patients performed a 20min lasting visual vigilance task.Results: Study I showed that right parietal stimulation, but not right frontal stimulation, counteracts the increase in reaction time associated with vigilance decrement. Hence, only right parietal stimulation was applied to the MS patients in study II. Stimulation had a significant effect on vigilance decrement in mildly to moderately cognitively fatigued MS patients. Vigilance testing significantly increased the feeling of fatigue independent of stimulation.Conclusions: Anodal tDCS over the right parietal cortex can counteract the increase in reaction times during vigilance performance but not the increase in subjective fatigue. This finding is compatible with our model of fatigue in MS, suggesting a dissociation between the feeling and the behavioral characteristics of fatigue.

Counteracting Fatigue in Multiple Sclerosis with Right Parietal Anodal Transcranial Direct Current Stimulation.

Science.gov (United States)

Hanken, Katrin; Bosse, Mona; Möhrke, Kim; Eling, Paul; Kastrup, Andreas; Antal, Andrea; Hildebrandt, Helmut

2016-01-01

Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time (RT) and errors with prolonged time-on-task. The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. In study I, a randomized double-blind placebo-controlled study, anodal tDCS (1.5 mA) was delivered to the right parietal cortex or the right frontal cortex of 52 healthy participants during the first 20 min of a 40-min lasting visual vigilance task. Study II, also a randomized double-blind placebo-controlled study, investigated the effect of anodal tDCS (1.5 mA) over the right parietal cortex in 46 MS patients experiencing cognitive fatigue. tDCS was delivered for 20 min before patients performed a 20-min lasting visual vigilance task. Study I showed that right parietal stimulation, but not right frontal stimulation, counteracts the increase in RT associated with vigilance decrement. Hence, only right parietal stimulation was applied to the MS patients in study II. Stimulation had a significant effect on vigilance decrement in mildly to moderately cognitively fatigued MS patients. Vigilance testing significantly increased the feeling of fatigue independent of stimulation. Anodal tDCS over the right parietal cortex can counteract the increase in RTs during vigilance performance, but not the increase in subjective fatigue. This finding is compatible with our model of fatigue in MS, suggesting a dissociation between the feeling and the behavioral characteristics of fatigue.

Muscarinic responses of gastric parietal cells

International Nuclear Information System (INIS)

Wilkes, J.M.; Kajimura, M.; Scott, D.R.; Hersey, S.J.; Sachs, G.

1991-01-01

Isolated rabbit gastric glands were used to study the nature of the muscarinic cholinergic responses of parietal cells. Carbachol stimulation of acid secretion, as measured by the accumulation of aminopyrine, was inhibited by the M1 antagonist, pirenzepine, with an IC50 of 13 microM; by the M2 antagonist, 11,2-(diethylamino)methyl-1 piperidinyl acetyl-5,11-dihydro-6H-pyrido 2,3-b 1,4 benzodiazepin-6-one (AF-DX 116), with an IC50 of 110 microM; and by the M1/M3 antagonist, diphenyl-acetoxy-4-methylpiperidinemethiodide, with an IC50 of 35 nM. The three antagonists displayed equivalent IC50 values for the inhibition of carbachol-stimulated production of 14CO2 from radiolabeled glucose, which is a measure of the turnover of the H,K-ATPase, the final step of acid secretion. Intracellular calcium levels were measured in gastric glands loaded with FURA 2. Carbachol was shown to both release calcium from an intracellular pool and to promote calcium entry across the plasma membrane. The calcium entry was inhibitable by 20 microM La3+. The relative potency of the three muscarinic antagonists for inhibition of calcium entry was essentially the same as for inhibition of acid secretion or pump related glucose oxidation. Image analysis of the glands showed the effects of carbachol, and of the antagonists, on intracellular calcium were occurring largely in the parietal cell. The rise in cell calcium due to release of calcium from intracellular stores was inhibited by 4-DAMP with an IC50 of 1.7 nM, suggesting that the release pathway was regulated by a low affinity M3 muscarinic receptor or state; Ca entry and acid secretion are regulated by a high affinity M3 muscarinic receptor or state, inhibited by higher 4-DAMP concentrations, suggesting that it is the steady-state elevation of Ca that is related to parietal cell function rather than the [Ca]i transient

Visual Short-Term Memory Activity in Parietal Lobe Reflects Cognitive Processes beyond Attentional Selection.

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Sheremata, Summer L; Somers, David C; Shomstein, Sarah

2018-02-07

Visual short-term memory (VSTM) and attention are distinct yet interrelated processes. While both require selection of information across the visual field, memory additionally requires the maintenance of information across time and distraction. VSTM recruits areas within human (male and female) dorsal and ventral parietal cortex that are also implicated in spatial selection; therefore, it is important to determine whether overlapping activation might reflect shared attentional demands. Here, identical stimuli and controlled sustained attention across both tasks were used to ask whether fMRI signal amplitude, functional connectivity, and contralateral visual field bias reflect memory-specific task demands. While attention and VSTM activated similar cortical areas, BOLD amplitude and functional connectivity in parietal cortex differentiated the two tasks. Relative to attention, VSTM increased BOLD amplitude in dorsal parietal cortex and decreased BOLD amplitude in the angular gyrus. Additionally, the tasks differentially modulated parietal functional connectivity. Contrasting VSTM and attention, intraparietal sulcus (IPS) 1-2 were more strongly connected with anterior frontoparietal areas and more weakly connected with posterior regions. This divergence between tasks demonstrates that parietal activation reflects memory-specific functions and consequently modulates functional connectivity across the cortex. In contrast, both tasks demonstrated hemispheric asymmetries for spatial processing, exhibiting a stronger contralateral visual field bias in the left versus the right hemisphere across tasks, suggesting that asymmetries are characteristic of a shared selection process in IPS. These results demonstrate that parietal activity and patterns of functional connectivity distinguish VSTM from more general attention processes, establishing a central role of the parietal cortex in maintaining visual information. SIGNIFICANCE STATEMENT Visual short-term memory (VSTM) and

Differential frontal-parietal phase synchrony during hypnosis as a function of hypnotic suggestibility.

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Terhune, Devin Blair; Cardeña, Etzel; Lindgren, Magnus

2011-10-01

Spontaneous dissociative alterations in awareness and perception among highly suggestible individuals following a hypnotic induction may result from disruptions in the functional coordination of the frontal-parietal network. We recorded EEG and self-reported state dissociation in control and hypnosis conditions in two sessions with low and highly suggestible participants. Highly suggestible participants reliably experienced greater state dissociation and exhibited lower frontal-parietal phase synchrony in the alpha2 frequency band during hypnosis than low suggestible participants. These findings suggest that highly suggestible individuals exhibit a disruption of the frontal-parietal network that is only observable following a hypnotic induction. Copyright © 2011 Society for Psychophysiological Research.

The inferior parietal lobule and recognition memory : expectancy violation or successful retrieval?

OpenAIRE

O'Connor, Akira R.; Han, Sanghoon; Dobbins, Ian G.

2010-01-01

Functional neuroimaging studies of episodic recognition demonstrate an increased lateral parietal response for studied versus new materials, often termed a retrieval success effect. Using a novel memory analog of attentional cueing, we manipulated the correspondence between anticipated and actual recognition evidence by presenting valid or invalid anticipatory cues (e. g., "likely old") before recognition judgments. Although a superior parietal region demonstrated the retrieval success patter...

Parietal epithelial cells and podocytes in glomerular diseases

NARCIS (Netherlands)

Smeets, B.; Moeller, M.J.

2012-01-01

In recent years, it has become apparent that parietal epithelial cells (PECs) play an important role within the renal glomerulus, in particular in diseased conditions. In this review, we examine current knowledge about the role of PECs and their interactions with podocytes in development and under

Multimodal responses induced by cortical stimulation of the parietal lobe: a stereo-electroencephalography study.

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Balestrini, Simona; Francione, Stefano; Mai, Roberto; Castana, Laura; Casaceli, Giuseppe; Marino, Daniela; Provinciali, Leandro; Cardinale, Francesco; Tassi, Laura

2015-09-01

The functional complexity of the parietal lobe still represents a challenge for neurophysiological and functional neuroimaging studies. While the somatosensory functions of the anterior parietal cortex are well established, the posterior parietal cortex has a relevant role in processing the sensory information, including visuo-spatial perception, visual attention, visuo-motor transformations and other complex and not completely understood functions. We retrospectively analysed all the clinical manifestations induced by intracerebral bipolar electrical stimulation in 172 patients suffering from drug-resistant focal epilepsy (mean age 25.6, standard deviation 11.6; 44% females and 56% males) with at least one electrode stereotactically implanted in the parietal cortex. A total of 1186 electrical stimulations were included in the analysis, of which 88 were subsequently excluded because of eliciting pathological electric activity or inducing ictal symptomatology. In the dominant parietal lobe, clinical responses were observed for 56 (25%) of the low-frequency stimulations and for 76 (50%) of the high-frequency stimulations. In the non-dominant parietal lobe, 111 (27%) low-frequency and 176 (55%) high-frequency stimulations were associated with a clinical response. Body scheme alteration was the only clinical effect showing a lateralization, as they were evoked only in the non-dominant hemisphere. The occurrence of somatosensory sensations, motor symptoms, dysarthria and multimodal responses were significantly associated with stimulation of the postcentral gyrus (odds ratio: 5.83, P < 0.001; odds ratio: 8.77, P < 0.001; odds ratio: 5.44, P = 0.011; odds ratio: 8.33, P = 0.006; respectively). Stimulation of the intraparietal sulcus was associated with the occurrence of sensory illusions or hallucinations (odds ratio: 8.68, P < 0.001) and eyeball/eyelid movements or sensations (odds ratio: 4.35, P = 0.047). To our knowledge, this is the only currently available complete

Kinesthetic alexia due to left parietal lobe lesions.

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Ihori, Nami; Kawamura, Mitsuru; Araki, Shigeo; Kawachi, Juro

2002-01-01

To investigate the neuropsychological mechanisms of kinesthetic alexia, we asked 7 patients who showed kinesthetic alexia with preserved visual reading after damage to the left parietal region to perform tasks consisting of kinesthetic written reproduction (writing down the same letter as the kinesthetic stimulus), kinesthetic reading aloud, visual written reproduction (copying letters), and visual reading aloud of hiragana (Japanese phonograms). We compared the performance in these tasks and the lesion sites in each patient. The results suggested that deficits in any one of the following functions might cause kinesthetic alexia: (1) the retrieval of kinesthetic images (motor engrams) of characters from kinesthetic stimuli, (2) kinesthetic images themselves, (3) access to cross-modal association from kinesthetic images, and (4) cross-modal association itself (retrieval of auditory and visual images from kinesthetic images of characters). Each of these factors seemed to be related to different lesion sites in the left parietal lobe. Copyright 2002 S. Karger AG, Basel

Enhanced Working Memory Binding by Direct Electrical Stimulation of the Parietal Cortex

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Agustina Birba

2017-06-01

Full Text Available Recent works evince the critical role of visual short-term memory (STM binding deficits as a clinical and preclinical marker of Alzheimer’s disease (AD. These studies suggest a potential role of posterior brain regions in both the neurocognitive deficits of Alzheimer’s patients and STM binding in general. Thereupon, we surmised that stimulation of the posterior parietal cortex (PPC might be a successful approach to tackle working memory deficits in this condition, especially at early stages. To date, no causal evidence exists of the role of the parietal cortex in STM binding. A unique approach to assess this issue is afforded by single-subject direct intracranial electrical stimulation of specific brain regions during a relevant cognitive task. Electrical stimulation has been used both for clinical purposes and to causally probe brain mechanisms. Previous evidence of electrical currents spreading through white matter along well defined functional circuits indicates that visual working memory mechanisms are subserved by a specific widely distributed network. Here, we stimulated the parietal cortex of a subject with intracranial electrodes as he performed the visual STM task. We compared the ensuing results to those from a non-stimulated condition and to the performance of a matched control group. In brief, direct stimulation of the parietal cortex induced a selective improvement in STM. These results, together with previous studies, provide very preliminary but promising ground to examine behavioral changes upon parietal stimulation in AD. We discuss our results regarding: (a the usefulness of the task to target prodromal stages of AD; (b the role of a posterior network in STM binding and in AD; and (c the potential opportunity to improve STM binding through brain stimulation.

Fronto-parietal coding of goal-directed actions performed by artificial agents.

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Kupferberg, Aleksandra; Iacoboni, Marco; Flanagin, Virginia; Huber, Markus; Kasparbauer, Anna; Baumgartner, Thomas; Hasler, Gregor; Schmidt, Florian; Borst, Christoph; Glasauer, Stefan

2018-03-01

With advances in technology, artificial agents such as humanoid robots will soon become a part of our daily lives. For safe and intuitive collaboration, it is important to understand the goals behind their motor actions. In humans, this process is mediated by changes in activity in fronto-parietal brain areas. The extent to which these areas are activated when observing artificial agents indicates the naturalness and easiness of interaction. Previous studies indicated that fronto-parietal activity does not depend on whether the agent is human or artificial. However, it is unknown whether this activity is modulated by observing grasping (self-related action) and pointing actions (other-related action) performed by an artificial agent depending on the action goal. Therefore, we designed an experiment in which subjects observed human and artificial agents perform pointing and grasping actions aimed at two different object categories suggesting different goals. We found a signal increase in the bilateral inferior parietal lobule and the premotor cortex when tool versus food items were pointed to or grasped by both agents, probably reflecting the association of hand actions with the functional use of tools. Our results show that goal attribution engages the fronto-parietal network not only for observing a human but also a robotic agent for both self-related and social actions. The debriefing after the experiment has shown that actions of human-like artificial agents can be perceived as being goal-directed. Therefore, humans will be able to interact with service robots intuitively in various domains such as education, healthcare, public service, and entertainment. © 2017 Wiley Periodicals, Inc.

The contribution of the human posterior parietal cortex to episodic memory.

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Sestieri, Carlo; Shulman, Gordon L; Corbetta, Maurizio

2017-02-17

The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional-anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push-pull relationship, potentially mediated by prefrontal regions. Moreover, different PPC regions carry out specific functions during retrieval - for example, representing retrieved information, recoding this information based on task demands, or accumulating evidence for memory decisions.

The role of parietal cortex in the formation of colour and motion based concepts

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Samuel William Cheadle

2014-07-01

Full Text Available Imaging evidence shows that separate subdivisions of parietal cortex, in and around the intraparietal sulcus (IPS, are engaged when stimuli are grouped according to colour and to motion (Zeki and Stutters 2013. Since grouping is an essential step in the formation of concepts, we wanted to learn whether parietal cortex is also engaged in the formation of concepts according to these two attributes. Using functional magnetic resonance imaging (fMRI, and choosing the recognition of concept-based colour or motion stimuli as our paradigm, we found that there was strong concept-related activity in and around the intraparietal sulcus (IPS, a region whose homologue in the macaque monkey is known to receive direct but segregated anatomical inputs from V4 and V5. Parietal activity related to colour concepts was juxtaposed but did not overlap with activity related to motion concepts, thus emphasizing the continuation of the segregation of colour and motion into the conceptual system. Concurrent retinotopic mapping experiments showed that within the parietal cortex, concept-related activity increases within later stage IPS areas.

Investigation of Parietal Polysaccharides from Retama raetam Roots ...

African Journals Online (AJOL)

These results indicate the presence of the homogalacturonans and rhamnogalacturonans in pectin. This study constitutes the preliminary data obtained in the biochemical analysis of the parietal compounds of the roots of a species which grows in an arid area in comparison with those of its aerial parts. Keywords: Retama ...

Fractionation of parietal function in bistable perception probed with concurrent TMS-EEG.

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Schauer, Georg; Chang, Acer; Schwartzman, David; Rae, Charlotte L; Iriye, Heather; Seth, Anil K; Kanai, Ryota

2016-08-16

When visual input has conflicting interpretations, conscious perception can alternate spontaneously between these possible interpretations. This is called bistable perception. Previous neuroimaging studies have indicated the involvement of two right parietal areas in resolving perceptual ambiguity (ant-SPLr and post-SPLr). Transcranial magnetic stimulation (TMS) studies that selectively interfered with the normal function of these regions suggest that they play opposing roles in this type of perceptual switch. In the present study, we investigated this fractionation of parietal function by use of combined TMS with electroencephalography (EEG). Specifically, while participants viewed either a bistable stimulus, a replay stimulus, or resting-state fixation, we applied single pulse TMS to either location independently while simultaneously recording EEG. Combined with participant's individual structural magnetic resonance imaging (MRI) scans, this dataset allows for complex analyses of the effect of TMS on neural time series data, which may further elucidate the causal role of the parietal cortex in ambiguous perception.

Parietal seeding of unsuspected gallbladder carcinoma after laparoscopic cholecystectomy.

Science.gov (United States)

Marmorale, C; Scibé, R; Siquini, W; Massa, M; Brunelli, A; Landi, E

1998-01-01

Laparoscopic cholecystectomy (VALC) represents the treatment of choice for the symptomatic gallstones. However the occurrence of an adenocarcinoma of the gallbladder results a controindication for this surgical technique. We present a case of a 52 years old woman who underwent a VALC; histology revealed a gallbladder adenocarcinoma. For this reason the patient underwent a second operation that is right hepatic trisegmentectomy. Six months later the patient presented with a parietal recurrence at the extraction site of the gallbladder. We discuss the possible mechanism responsible for carcinomatous dissemination during laparoscopic surgery and we raccommend the use of some procedures in order to limit the risk and eventually to treat a neoplastic parietal seeding. These complications suggest the problem about the utility and the future played by video assisted laparoscopic surgery in the diagnosis and treatment of intraabdominal malignancies.

Neuronal synchronization in human parietal cortex during saccade planning

NARCIS (Netherlands)

Werf, J. van der; Buchholz, V.N.; Jensen, O.; Medendorp, W.P.

2009-01-01

Neuropsychological and neuroimaging studies have implicated the human posterior parietal cortex (PPC) in sensorimotor integration and saccade planning However, the temporal dynamics of the underlying physiology and its relationship to observations in non-human primates have been difficult to pin

The Neuroanatomical Basis for Posterior Superior Parietal Lobule Control Lateralization of visuospatial Attention

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Yan eWu

2016-03-01

Full Text Available The right hemispheric dominance in visuospatial attention in human brain has been well established. Converging evidence has documented that ventral posterior parietal cortex (PPC plays an important role in visuospatial attention. The role of dorsal PPC subregions, especially the superior parietal lobule (SPL in visuospatial attention is still controversial. In the current study, we used repetitive transcranial magnetic stimulation (rTMS and diffusion magnetic resonance imaging (MRI techniques to test the role of posterior SPL in visuospatial attention and to investigate the potential neuroanatomical basis for right hemisphere dominance in visuospatial function. TMS results unraveled that the right SPL predominantly mediated visuospatial attention compared to left SPL. Anatomical connections analyses between the posterior SPL and the intrahemispheric frontal subregions and the contralateral PPC revealed that right posterior SPL has stronger anatomical connections with the ipsilateral middle frontal gyrus, with the ipsilateral inferior frontal gyrus, and with contralateral PPC than that of the left posterior SPL. Furthermore, these asymmetric anatomical connections were closely related to behavioral performances. Our findings indicate that SPL plays a crucial role in regulating visuospatial attention, and dominance of visuospatial attention results from unbalanced interactions between the bilateral fronto-parietal networks and the interhemispheric parietal network.

Exogenous vs. endogenous attention: Shifting the balance of fronto-parietal activity.

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Meyer, Kristin N; Du, Feng; Parks, Emily; Hopfinger, Joseph B

2018-03-01

Despite behavioral and electrophysiological evidence for dissociations between endogenous (voluntary) and exogenous (reflexive) attention, fMRI results have yet to consistently and clearly differentiate neural activation patterns between these two types of attention. This study specifically aimed to determine whether activity in the dorsal fronto-parietal network differed between endogenous and exogenous conditions. Participants performed a visual discrimination task in endogenous and exogenous attention conditions while undergoing fMRI scanning. Analyses revealed robust and bilateral activation throughout the dorsal fronto-parietal network for each condition, in line with many previous results. In order to investigate possible differences in the balance of neural activity within this network with greater sensitivity, a priori regions of interest (ROIs) were selected for analysis, centered on the frontal eye fields (FEF) and intraparietal sulcus (IPS) regions identified in previous studies. The results revealed a significant interaction between region, condition, and hemisphere. Specifically, in the left hemisphere, frontal areas were more active than parietal areas, but only during endogenous attention. Activity in the right hemisphere, in contrast, remained relatively consistent for these regions across conditions. Analysis of this activity over time indicates that this left-hemispheric regional imbalance is present within the FEF early, at 3-6.5 s post-stimulus presentation, whereas a regional imbalance in the exogenous condition is not evident until 6.5-8 s post-stimulus presentation. Overall, our results provide new evidence that although the dorsal fronto-parietal network is indeed associated with both types of attentional orienting, regions of the network are differentially engaged over time and across hemispheres depending on the type of attention. Copyright © 2018 Elsevier Ltd. All rights reserved.

Differential Recruitment of Parietal Cortex during Spatial and Non-spatial Reach Planning

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Pierre-Michel Bernier

2017-05-01

Full Text Available The planning of goal-directed arm reaching movements is associated with activity in the dorsal parieto-frontal cortex, within which multiple regions subserve the integration of arm- and target-related sensory signals to encode a motor goal. Surprisingly, many of these regions show sustained activity during reach preparation even when target location is not specified, i.e., when a motor goal cannot be unambiguously formed. The functional role of these non-spatial preparatory signals remains unresolved. Here this process was investigated in humans by comparing reach preparatory activity in the presence or absence of information regarding upcoming target location. In order to isolate the processes specific to reaching and to control for visuospatial attentional factors, the reaching task was contrasted to a finger movement task. Functional MRI and electroencephalography (EEG were used to characterize the spatio-temporal pattern of reach-related activity in the parieto-frontal cortex. Reach planning with advance knowledge of target location induced robust blood oxygenated level dependent and EEG responses across parietal and premotor regions contralateral to the reaching arm. In contrast, reach preparation without knowledge of target location was associated with a significant BOLD response bilaterally in the parietal cortex. Furthermore, EEG alpha- and beta-band activity was restricted to parietal scalp sites, the magnitude of the latter being correlated with reach reaction times. These results suggest an intermediate stage of sensorimotor transformations in bilateral parietal cortex when target location is not specified.

Bilateral parietal extradural metastatic ewing's sarcoma simulating acute epidural hematoma

International Nuclear Information System (INIS)

Aslam, E.; Imran, M.; Faridi, N.M.

2006-01-01

Sarcomas usually metastasize to lugs. The following case report describes an unusual metastasis of Ewing's sarcoma to extradural parietal region bilaterally. The primary was found at lower end of ulna. (author)

Clinical evidence of parietal cortex dysfunction and correlation with extent of allodynia in CRPS type 1.

Science.gov (United States)

Cohen, H; McCabe, C; Harris, N; Hall, J; Lewis, J; Blake, D R

2013-04-01

Unusual symptoms such as digit misidentification and neglect-like phenomena have been reported in complex regional pain syndrome (CRPS), which we hypothesized could be explained by parietal lobe dysfunction. Twenty-two patients with chronic CRPS attending an in-patient rehabilitation programme underwent standard neurological examination followed by clinical assessment of parietal lobe function and detailed sensory testing. Fifteen (68%) patients had evidence of parietal lobe dysfunction. Six (27%) subjects failed six or more test categories and demonstrated new clinical signs consistent with their parietal testing impairments, which were impacting significantly on activities of daily living. A higher incidence was noted in subjects with >1 limb involvement, CRPS affecting the dominant side and in left-handed subjects. Eighteen patients (82%) had mechanical allodynia covering 3-57.5% of the body surface area. Allochiria (unilateral tactile stimulation perceived only in the analogous location on the opposite limb), sensory extinction (concurrent bilateral tactile stimulation perceived only in one limb), referred sensations (unilateral tactile stimulation perceived concurrently in another discrete body area) and dysynchiria (unilateral non-noxious tactile stimulation perceived bilaterally as noxious) were present in some patients. Greater extent of body surface allodynia was correlated with worse parietal function (Spearman's rho = -0.674, p = 0.001). In patients with chronic CRPS, detailed clinical examination may reveal parietal dysfunction, with severity relating to the extent of allodynia. © 2012 European Federation of International Association for the Study of Pain Chapters.

Does shape discrimination by the mouth activate the parietal and occipital lobes? - near-infrared spectroscopy study.

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Tomonori Kagawa

Full Text Available A cross-modal association between somatosensory tactile sensation and parietal and occipital activities during Braille reading was initially discovered in tests with blind subjects, with sighted and blindfolded healthy subjects used as controls. However, the neural background of oral stereognosis remains unclear. In the present study, we investigated whether the parietal and occipital cortices are activated during shape discrimination by the mouth using functional near-infrared spectroscopy (fNIRS. Following presentation of the test piece shape, a sham discrimination trial without the test pieces induced posterior parietal lobe (BA7, extrastriate cortex (BA18, BA19, and striate cortex (BA17 activation as compared with the rest session, while shape discrimination of the test pieces markedly activated those areas as compared with the rest session. Furthermore, shape discrimination of the test pieces specifically activated the posterior parietal cortex (precuneus/BA7, extrastriate cortex (BA18, 19, and striate cortex (BA17, as compared with sham sessions without a test piece. We concluded that oral tactile sensation is recognized through tactile/visual cross-modal substrates in the parietal and occipital cortices during shape discrimination by the mouth.

Multicenter prospective randomized study comparing the technique of using a bovine pericardium biological prosthesis reinforcement in parietal herniorrhaphy (Tutomesh TUTOGEN) with simple parietal herniorrhaphy, in a potentially contaminated setting.

Science.gov (United States)

Nedelcu, Marius; Verhaeghe, Pierre; Skalli, Mehdi; Champault, Gerard; Barrat, Christophe; Sebbag, Hugues; Reche, Fabian; Passebois, Laurent; Beyrne, Daniel; Gugenheim, Jean; Berdah, Stephane; Bouayed, Amine; Michel Fabre, Jean; Nocca, David

2016-03-01

The use of parietal synthetic prosthetic reinforcement material in potentially contaminated settings is not recommended, as there is a risk that the prosthesis may become infected. Thus, simple parietal herniorrhaphy, is the conventional treatment, even though there is a significant risk that the hernia may recur. Using new biomaterials of animal origin presently appears to offer a new therapeutic solution, but their effectiveness has yet to be demonstrated. The purpose of this multicenter prospective randomized single-blind study was to compare the surgical treatment of inguinal hernia or abdominal incisional hernia by simple parietal herniorrhaphy without prosthetic reinforcement (Group A), with Tutomesh TUTOGEN biological prosthesis reinforcement parietal herniorrhaphy (Group B), in a potentially contaminated setting. We examined early postoperative complications in the first month after the operation, performed an assessment after one year of survival without recurrence and analyzed the quality of life and pain of the patients (using SF-12 health status questionnaire and Visual Analog Pain Scale) at 1, 6, and 12 months, together with an economic impact study. Hundred and thirty four patients were enrolled between January 2009 and October 2010 in 20 French hospitals. The groups were comparable with respect to their enrollment characteristics, their history, types of operative indications and procedures carried out. At one month post-op, the rate of infectious complications (n(A) = 11(18.33%) vs. n(B) = 12(19.05%), p = 0.919) was not significantly different between the two groups. The assessment after one year of survival without recurrence revealed that survival was significantly greater in Group B (Group A recurrence: 10, Group B: 3; p = 0.0475). No difference in the patients' quality of life was demonstrated at 1, 6, or 12 months. However, at the 1 month follow-up, the "perceived health" rating seemed better in the group with Tutomesh (p�

Fronto-Parietal Network Reconfiguration Supports the Development of Reasoning Ability.

Science.gov (United States)

Wendelken, Carter; Ferrer, Emilio; Whitaker, Kirstie J; Bunge, Silvia A

2016-05-01

The goal of this fMRI study was to examine how well developmental improvements in reasoning ability can be explained by changes in functional connectivity between specific nodes in prefrontal and parietal cortices. To this end, we examined connectivity within the lateral fronto-parietal network (LFPN) and its relation to reasoning ability in 132 children and adolescents aged 6-18 years, 56 of whom were scanned twice over the course of 1.5 years. Developmental changes in strength of connections within the LFPN were most prominent in late childhood and early adolescence. Reasoning ability was related to functional connectivity between left rostrolateral prefrontal cortex (RLPFC) and inferior parietal lobule (IPL), but only among 12-18-year olds. For 9-11-year olds, reasoning ability was most strongly related to connectivity between left and right RLPFC; this relationship was mediated by working memory. For 6-8-year olds, significant relationships between connectivity and performance were not observed; in this group, processing speed was the primary mediator of improvement in reasoning ability. We conclude that different connections best support reasoning at different points in development and that RLPFC-IPL connectivity becomes an important predictor of reasoning during adolescence. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The fMRI study on the front-parietal activation in abacus mental calculation trained children

International Nuclear Information System (INIS)

Zhao Kunyuan; Wang Bin; Long Jinfeng; Li Lixin; Shen Xiaojun

2010-01-01

Objective: To investigate the difference in front-parietal activation between the trained and untrained children engaged in addition and multiplication with functional magnetic resonance imaging (fMRI), and to explore the role of abacus mental calculation in brain development. Methods: Twenty-four children trained with abacus mental calculation and twelve untrained children performed mental calculation tasks including addition, multiplication and number-object control judging tasks. Blood oxygenation level dependence (BOLD) fMRI was performed when they were calculating. All data were analyzed by SPM2 (statistical parametric mapping 2) to generate the brain activation map. Results: The performance of the trained group had better correctness and shorter reaction time than that of the untrained group. The front-parietal activation between two groups had obvious difference. The activation involved less prefrontal cortex in the trained group than in the untrained group (P<0.05). The parietal activation in the trained group was mainly in the posterior superior parietal lobe/ precuneus, whereas the activation areas focused on the inferior parietal lobule in the untrained group. Conclusion: Abacus mental calculation involves multiple functional areas. and these areas may work together as a whole in processing arithmetic problems. Abacus mental calculation not only enhances the information processing in some brain areas and improves the utilization efficiency of neural resources, but also plays an important role in developing brain. (authors)

Subtotal ablation of parietal epithelial cells induces crescent formation.

NARCIS (Netherlands)

Sicking, E.M.; Fuss, A.; Uhlig, S.; Jirak, P.; Dijkman, H.; Wetzels, J.; Engel, D.R.; Urzynicok, T.; Heidenreich, S.; Kriz, W.; Kurts, C.; Ostendorf, T.; Floege, J.; Smeets, B.; Moeller, M.J.

2012-01-01

Parietal epithelial cells (PECs) of the renal glomerulus contribute to the formation of both cellular crescents in rapidly progressive GN and sclerotic lesions in FSGS. Subtotal transgenic ablation of podocytes induces FSGS but the effect of specific ablation of PECs is unknown. Here, we established

Regional intercostal bulging of the parietal pleura

International Nuclear Information System (INIS)

Jantsch, H.; Greene, R.; Lechner, G.; Mavritz, W.; Pichler, W.; Winkler, M.; Zadrobilek, E.

1989-01-01

This paper describes bedside radiographs with localized intercostal bulging as the sole indication of tension pneumothorax in six patients with acute deterioration in gas exchange. Relief of the pneumothorax was followed by a rush of gas from the tension space and a prompt improvement in gas exchange. The authors concluded the regional intercostal bulging of the parietal pleura may be the sole indicator of life-threatening tension pneumothorax in patients on mechanical ventilation

Parietal cells?new perspectives in glomerular disease

OpenAIRE

Miesen, Laura; Steenbergen, Eric; Smeets, Bart

2017-01-01

In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman?s capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and podocytes have a common mesenchymal origin and are the result of divergent differentiation during embryogenesis. Podocytes and PTECs are highly differentiated cells with well-established functions pertain...

Visual processing of multiple elements in the dyslexic brain: evidence for a superior parietal dysfunction

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Muriel Anne Lobier

2014-07-01

Full Text Available The visual attention (VA span deficit hypothesis of developmental dyslexia posits that impaired multiple element processing can be responsible for poor reading outcomes. In VA span impaired dyslexic children, poor performance on letter report tasks is associated with reduced parietal activations for multiple letter processing. While this hints towards a non-specific, attention-based dysfunction, it is still unclear whether reduced parietal activity generalizes to other types of stimuli. Furthermore, putative links between reduced parietal activity and reduced ventral occipito-temporal (vOT in dyslexia have yet to be explored. Using fMRI, we measured brain activity in 12 VA span impaired dyslexic adults and 12 adult skilled readers while they carried out a categorization task on single or multiple alphanumeric or non-alphanumeric characters. While healthy readers activated parietal areas more strongly for multiple than single element processing (right-sided for alphanumeric and bilateral for non-alphanumeric, similar stronger multiple element right parietal activations were absent for dyslexic participants. Contrasts between skilled and dyslexic readers revealed significantly reduced right superior parietal lobule (SPL activity for dyslexic readers regardless of stimuli type. Using a priori anatomically defined ROI, we showed that neural activity was reduced for dyslexic participants in both SPL and vOT bilaterally. Finally, we used multiple regressions to test whether SPL activity could predict vOT activity in each group. In the left hemisphere, SPL activity modulated vOT activity for both normal and dyslexic readers. In contrast, in the right hemisphere, SPL activity modulated vOT activity only for dyslexic readers. These results bring critical support to the visual attention interpretation of the VA Span deficit. In addition, they offer a new insight on how deficits in automatic vOT based word recognition could arise in developmental dyslexia.

Choline acetyltransferase-containing neurons in the human parietal neocortex

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V Benagiano

2009-06-01

Full Text Available A number of immunocytochemical studies have indicated the presence of cholinergic neurons in the cerebral cortex of various species of mammals. Whether such cholinergic neurons in the human cerebral cortex are exclusively of subcortical origin is still debated. In this immunocytochemical study, the existence of cortical cholinergic neurons was investigated on surgical samples of human parietal association neocortex using a highly specific monoclonal antibody against choline acetyltransferase (ChAT, the acetylcholine biosynthesising enzyme. ChAT immunoreactivity was detected in a subpopulation of neurons located in layers II and III. These were small or medium-sized pyramidal neurons which showed cytoplasmic immunoreactivity in the perikarya and processes, often in close association to blood microvessels. This study, providing demonstration of ChAT neurons in the human parietal neocortex, strongly supports the existence of intrinsic cholinergic innervation of the human neocortex. It is likely that these neurons contribute to the cholinergic innervation of the intracortical microvessels.

Percent wall thickness evaluated by Gd-DTPA enhanced cine MRI as an indicator of local parietal movement in hypertrophic cardiomyopathy

International Nuclear Information System (INIS)

Hirano, Masaharu

1998-01-01

Hypertrophic cardiomyopathy (HCM) is a cardiac disease, the basic pathology of which consists of a decrease in left ventricular dilation compliance due to uneven hypertrophy of the left ventricular wall. Magnetic resonance imaging (MRI) is useful in monitoring uneven parietal hypertrophy and kinetics in HCM patients. The present study was undertaken in 47 HCM patients who showed asymmetrical septal hypertrophy to determine if percent thickness can be an indicator of left ventricular local movement using cine MRI. Longest and shortest axis images were acquired by the ECG synchronization method using a 1.5 T MR imager. Cardiac function was analyzed based on longest axis cine images, and telediastolic and telesystolic parietal thickness were measured based on shorter axis cine images at the papillary muscle level. Parietal movement index and percent thickness were used as indicators of local parietal movement. The correlation between these indicators and parietal thickness was evaluated. The percent thickness changed at an earlier stage of hypertrophy than the parietal movement index, thus it is thought to be useful in detecting left ventricular parietal movement disorders at an early stage of HCM. (author)

Percent wall thickness evaluated by Gd-DTPA enhanced cine MRI as an indicator of local parietal movement in hypertrophic cardiomyopathy

Energy Technology Data Exchange (ETDEWEB)

Hirano, Masaharu [Tokyo Medical Coll. (Japan)

1998-11-01

Hypertrophic cardiomyopathy (HCM) is a cardiac disease, the basic pathology of which consists of a decrease in left ventricular dilation compliance due to uneven hypertrophy of the left ventricular wall. Magnetic resonance imaging (MRI) is useful in monitoring uneven parietal hypertrophy and kinetics in HCM patients. The present study was undertaken in 47 HCM patients who showed asymmetrical septal hypertrophy to determine if percent thickness can be an indicator of left ventricular local movement using cine MRI. Longest and shortest axis images were acquired by the ECG synchronization method using a 1.5 T MR imager. Cardiac function was analyzed based on longest axis cine images, and telediastolic and telesystolic parietal thickness were measured based on shorter axis cine images at the papillary muscle level. Parietal movement index and percent thickness were used as indicators of local parietal movement. The correlation between these indicators and parietal thickness was evaluated. The percent thickness changed at an earlier stage of hypertrophy than the parietal movement index, thus it is thought to be useful in detecting left ventricular parietal movement disorders at an early stage of HCM. (author)

Metabolic Hyperactivity of the Medial Posterior Parietal Lobes in Psychogenic Tremor

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Peter Hedera

2012-05-01

Full Text Available Background: The pathophysiology of psychogenic movement disorders, including psychogenic tremor (PT, is only emerging. Case Report: This is a single case report of a patient who met diagnostic criteria for PT. He underwent positron emission tomography (PET of brain with 18F-deoxyglucose at resting state. His PET study showed symmetrically increased 18F-deoxyglucose uptake in both posterior medial parietal lobes. There was no corresponding abnormality on structural imaging. Discussion: Hypermetabolism of the medial aspects of posterior parietal lobes bilaterally may reflect abnormal activity of sensory integration that is important in the pathogenesis of PT. This further supports the idea that non-organic movement disorders may be associated with detectable functional brain abnormalities.

Induction of motor associative plasticity in the posterior parietal cortex-primary motor network

DEFF Research Database (Denmark)

Chao, Chi-Chao; Karabanov, Anke Ninija; Paine, Rainer

2015-01-01

There is anatomical and functional connectivity between the primary motor cortex (M1) and posterior parietal cortex (PPC) that plays a role in sensorimotor integration. In this study, we applied corticocortical paired-associative stimuli to ipsilateral PPC and M1 (parietal ccPAS) in healthy right......-handed subjects to test if this procedure could modulate M1 excitability and PPC–M1 connectivity. One hundred and eighty paired transcranial magnetic stimuli to the PPC and M1 at an interstimulus interval (ISI) of 8 ms were delivered at 0.2 Hz. We found that parietal ccPAS in the left hemisphere increased...... the excitability of conditioned left M1 assessed by motor evoked potentials (MEPs) and the input–output curve. Motor behavior assessed by the Purdue pegboard task was unchanged compared with controls. At baseline, conditioning stimuli over the left PPC potentiated MEPs from left M1 when ISI was 8 ms...

Sensory-parietal cortical stimulation improves motor recovery in severe capsular infarct.

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Kim, Ra Gyung; Cho, Jongwook; Ree, Jinkyue; Kim, Hyung-Sun; Rosa-Neto, Pedro; Kim, Jin-Myung; Lee, Min-Cheol; Kim, Hyoung-Ihl

2016-12-01

The prevalence of subcortical white matter strokes in elderly patients is on the rise, but these patients show mixed responses to conventional rehabilitative interventions. To examine whether cortical electrical stimulation can promote motor recovery after white matter stroke, we delivered stimulation to a small or wide region of sensory-parietal cortex for two weeks in a rodent model of circumscribed subcortical capsular infarct. The sham-operated group (SOG) showed persistent and severe motor impairments together with decreased activation in bilateral sensorimotor cortices and striatum. In contrast, sensory-parietal cortex stimulation significantly improved motor recovery: final recovery levels were 72.9% of prelesion levels in the wide stimulation group (WSG) and 37% of prelesion levels in the small stimulation group (SSG). The microPET imaging showed reversal of cortical diaschisis in both groups: in both hemispheres for the WSG, and in the hemisphere ipsilateral to stimulation in the SSG. In addition, we observed activation of the corpus callosum and subcortical corticostriatal structures after stimulation. The results from the c-Fos mapping study were grossly consistent with the microPET imaging. Sensory-parietal cortex stimulation may therefore be a useful strategy for overcoming the limits of rehabilitative training in patients with severe forms of subcortical capsular infarct. © The Author(s) 2015.

Characterization of visual percepts evoked by noninvasive stimulation of the human posterior parietal cortex.

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Peter J Fried

Full Text Available Phosphenes are commonly evoked by transcranial magnetic stimulation (TMS to study the functional organization, connectivity, and excitability of the human visual brain. For years, phosphenes have been documented only from stimulating early visual areas (V1-V3 and a handful of specialized visual regions (V4, V5/MT+ in occipital cortex. Recently, phosphenes were reported after applying TMS to a region of posterior parietal cortex involved in the top-down modulation of visuo-spatial processing. In the present study, we systematically characterized parietal phosphenes to determine if they are generated directly by local mechanisms or emerge through indirect activation of other visual areas. Using technology developed in-house to record the subjective features of phosphenes, we found no systematic differences in the size, shape, location, or frame-of-reference of parietal phosphenes when compared to their occipital counterparts. In a second experiment, discrete deactivation by 1 Hz repetitive TMS yielded a double dissociation: phosphene thresholds increased at the deactivated site without producing a corresponding change at the non-deactivated location. Overall, the commonalities of parietal and occipital phosphenes, and our ability to independently modulate their excitability thresholds, lead us to conclude that they share a common neural basis that is separate from either of the stimulated regions.

Neural representations of social status hierarchy in human inferior parietal cortex.

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Chiao, Joan Y; Harada, Tokiko; Oby, Emily R; Li, Zhang; Parrish, Todd; Bridge, Donna J

2009-01-01

Mental representations of social status hierarchy share properties with that of numbers. Previous neuroimaging studies have shown that the neural representation of numerical magnitude lies within a network of regions within inferior parietal cortex. However the neural basis of social status hierarchy remains unknown. Using fMRI, we studied subjects while they compared social status magnitude of people, objects and symbols, as well as numerical magnitude. Both social status and number comparisons recruited bilateral intraparietal sulci. We also observed a semantic distance effect whereby neural activity within bilateral intraparietal sulci increased for semantically close relative to far numerical and social status comparisons. These results demonstrate that social status and number comparisons recruit distinct and overlapping neuronal representations within human inferior parietal cortex.

An enlarged parietal foramen in the late archaic Xujiayao 11 neurocranium from Northern China, and rare anomalies among Pleistocene Homo.

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Wu, Xiu-Jie; Xing, Song; Trinkaus, Erik

2013-01-01

We report here a neurocranial abnormality previously undescribed in Pleistocene human fossils, an enlarged parietal foramen (EPF) in the early Late Pleistocene Xujiayao 11 parietal bones from the Xujiayao (Houjiayao) site, northern China. Xujiayao 11 is a pair of partial posteromedial parietal bones from an adult. It exhibits thick cranial vault bones, arachnoid granulations, a deviated posterior sagittal suture, and a unilateral (right) parietal lacuna with a posteriorly-directed and enlarged endocranial vascular sulcus. Differential diagnosis indicates that the perforation is a congenital defect, an enlarged parietal foramen, commonly associated with cerebral venous and cranial vault anomalies. It was not lethal given the individual's age-at-death, but it may have been associated with secondary neurological deficiencies. The fossil constitutes the oldest evidence in human evolution of this very rare condition (a single enlarged parietal foramen). In combination with developmental and degenerative abnormalities in other Pleistocene human remains, it suggests demographic and survival patterns among Pleistocene Homo that led to an elevated frequency of conditions unknown or rare among recent humans.

An enlarged parietal foramen in the late archaic Xujiayao 11 neurocranium from Northern China, and rare anomalies among Pleistocene Homo.

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Xiu-Jie Wu

Full Text Available We report here a neurocranial abnormality previously undescribed in Pleistocene human fossils, an enlarged parietal foramen (EPF in the early Late Pleistocene Xujiayao 11 parietal bones from the Xujiayao (Houjiayao site, northern China. Xujiayao 11 is a pair of partial posteromedial parietal bones from an adult. It exhibits thick cranial vault bones, arachnoid granulations, a deviated posterior sagittal suture, and a unilateral (right parietal lacuna with a posteriorly-directed and enlarged endocranial vascular sulcus. Differential diagnosis indicates that the perforation is a congenital defect, an enlarged parietal foramen, commonly associated with cerebral venous and cranial vault anomalies. It was not lethal given the individual's age-at-death, but it may have been associated with secondary neurological deficiencies. The fossil constitutes the oldest evidence in human evolution of this very rare condition (a single enlarged parietal foramen. In combination with developmental and degenerative abnormalities in other Pleistocene human remains, it suggests demographic and survival patterns among Pleistocene Homo that led to an elevated frequency of conditions unknown or rare among recent humans.

Neural sources of visual working memory maintenance in human parietal and ventral extrastriate visual cortex.

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Becke, Andreas; Müller, Notger; Vellage, Anne; Schoenfeld, Mircea Ariel; Hopf, Jens-Max

2015-04-15

Maintaining information in visual working memory is reliably indexed by the contralateral delay activity (CDA) - a sustained modulation of the event-related potential (ERP) with a topographical maximum over posterior scalp regions contralateral to the memorized input. Based on scalp topography, it is hypothesized that the CDA reflects neural activity in the parietal cortex, but the precise cortical origin of underlying electric activity was never determined. Here we combine ERP recordings with magnetoencephalography based source localization to characterize the cortical current sources generating the CDA. Observers performed a cued delayed match to sample task where either the color or the relative position of colored dots had to be maintained in memory. A detailed source-localization analysis of the magnetic activity in the retention interval revealed that the magnetic analog of the CDA (mCDA) is generated by current sources in the parietal cortex. Importantly, we find that the mCDA also receives contribution from current sources in the ventral extrastriate cortex that display a time-course similar to the parietal sources. On the basis of the magnetic responses, forward modeling of ERP data reveals that the ventral sources have non-optimal projections and that these sources are therefore concealed in the ERP by overlapping fields with parietal projections. The present observations indicate that visual working memory maintenance, as indexed by the CDA, involves the parietal cortical regions as well as the ventral extrastriate regions, which code the sensory representation of the memorized content. Copyright © 2015 Elsevier Inc. All rights reserved.

Examining the role of the temporo-parietal network in memory, imagery and viewpoint transformations

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Kiret eDhindsa

2014-09-01

Full Text Available The traditional view of the medial temporal lobe (MTL focuses on its role in episodic memory. However, some of the underlying functions of the MTL can be ascertained from its wider role in supporting spatial cognition in concert with parietal and prefrontal regions. The MTL is strongly implicated in the formation of enduring allocentric representations (e.g. O’Keefe (1976; Ekstrom et al. (2003; King et al. (2002. According to our BBB model (Byrne et al. (2007, these representations must interact with head-centered and body-centered representations in posterior parietal cortex via a transformation circuit involving retrosplenial areas. Egocentric sensory representations in parietal areas can then cue the recall of allocentric spatial representations in long-term memory and, conversely, the products of retrieval in MTL can generate mental imagery within a parietal ’window’. Such imagery is necessarily egocentric and forms part of visuospatial working memory, where it can be manipulated for the purpose of planning/imagining the future. Recent fMRI evidence (Lambrey et al. (2012; Zhang et al. (2012 supports the BBB model. To further test the model, we had participants learn the locations of objects in a virtual scene and tested their spatial memory under conditions that impose varying demands on the transformation circuit. We analyzed how brain activity correlated with accuracy in judging the direction of an object 1 from visuospatial working memory (we assume working memory due to the order of tasks and the consistency viewpoint, but long-term memory is also possible, 2 after a rotation of viewpoint, or 3 after a rotation and translation (judgement of relative direction. We found performance-related activity in both tasks requiring viewpoint rotation in the core medial temporal to medial parietal. These results are consistent with the BBB model and shed further light on the mechanisms underlying spatial memory, mental imagery and viewpoint

The regenerative potential of parietal epithelial cells in adult mice

NARCIS (Netherlands)

Berger, K.; Schulte, K.; Boor, P.; Kuppe, C.; Kuppevelt, T.H. van; Floege, J.; Smeets, B.; Moeller, M.J.

2014-01-01

Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman's capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically

[Successive subcortical hemorrhages in the superior parietal lobule and postcentral gyrus in a 23-year-old female].

Science.gov (United States)

Sato, K; Yoshikawa, H; Komai, K; Takamori, M

1998-04-01

We report a non-hypertensive 23-year-old female with successive hemorrhages in parietal subcortical regions. She had first experienced a transient pain in the left upper extremity one month before admission. She noticed dysesthesia in the same limb and weakness on her left hand, and, five days after, visited our hospital because of suddenly developed convulsion in the limb and loss of consciousness for a few minutes. Neurological examination revealed distal dominant flaccid paresis, positive pathological reflex and touch and position sense disturbances in the affected limb. Brain CT detected two high-density areas in the parietal lobe. Brain MRI demonstrated an acute phase subcortical hematoma in the left postcentral gyrus and a subacute phase one in the left superior parietal lobule. SPECT indicated hypoperfusion in the left frontal and parietal cortex. Cerebral angiography showed no abnormal findings. Her symptoms gradually improved, but left ulnar-type pseudoradicular sensory impairment remained on discharge. We considered the hemorrhage in this patient have arisen from rupture of cavernous hemangioma, because she was relatively young, the hematomas were oval in shape and successively developed in the left parietal lobe. Our patient suggests that a subcortical hemorrhage in the post-central gyrus causes flaccid paresis and pyramidal tract involvement.

Seeing is not feeling: posterior parietal but not somatosensory cortex engagement during touch observation.

Science.gov (United States)

Chan, Annie W-Y; Baker, Chris I

2015-01-28

Observing touch has been reported to elicit activation in human primary and secondary somatosensory cortices and is suggested to underlie our ability to interpret other's behavior and potentially empathy. However, despite these reports, there are a large number of inconsistencies in terms of the precise topography of activation, the extent of hemispheric lateralization, and what aspects of the stimulus are necessary to drive responses. To address these issues, we investigated the localization and functional properties of regions responsive to observed touch in a large group of participants (n = 40). Surprisingly, even with a lenient contrast of hand brushing versus brushing alone, we did not find any selective activation for observed touch in the hand regions of somatosensory cortex but rather in superior and inferior portions of neighboring posterior parietal cortex, predominantly in the left hemisphere. These regions in the posterior parietal cortex required the presence of both brush and hand to elicit strong responses and showed some selectivity for the form of the object or agent of touch. Furthermore, the inferior parietal region showed nonspecific tactile and motor responses, suggesting some similarity to area PFG in the monkey. Collectively, our findings challenge the automatic engagement of somatosensory cortex when observing touch, suggest mislocalization in previous studies, and instead highlight the role of posterior parietal cortex. Copyright © 2015 the authors 0270-6474/15/351468-13$15.00/0.

Observing complex action sequences: The role of the fronto-parietal mirror neuron system.

Science.gov (United States)

Molnar-Szakacs, Istvan; Kaplan, Jonas; Greenfield, Patricia M; Iacoboni, Marco

2006-11-15

A fronto-parietal mirror neuron network in the human brain supports the ability to represent and understand observed actions allowing us to successfully interact with others and our environment. Using functional magnetic resonance imaging (fMRI), we wanted to investigate the response of this network in adults during observation of hierarchically organized action sequences of varying complexity that emerge at different developmental stages. We hypothesized that fronto-parietal systems may play a role in coding the hierarchical structure of object-directed actions. The observation of all action sequences recruited a common bilateral network including the fronto-parietal mirror neuron system and occipito-temporal visual motion areas. Activity in mirror neuron areas varied according to the motoric complexity of the observed actions, but not according to the developmental sequence of action structures, possibly due to the fact that our subjects were all adults. These results suggest that the mirror neuron system provides a fairly accurate simulation process of observed actions, mimicking internally the level of motoric complexity. We also discuss the results in terms of the links between mirror neurons, language development and evolution.

Right hemisphere dominance during spatial selective attention and target detection occurs outside the dorsal fronto-parietal network

Science.gov (United States)

Shulman, Gordon L.; Pope, Daniel L. W.; Astafiev, Serguei V.; McAvoy, Mark P.; Snyder, Abraham Z.; Corbetta, Maurizio

2010-01-01

Spatial selective attention is widely considered to be right hemisphere dominant. Previous functional magnetic resonance imaging (fMRI) studies, however, have reported bilateral blood-oxygenation-level-dependent (BOLD) responses in dorsal fronto-parietal regions during anticipatory shifts of attention to a location (Kastner et al., 1999; Corbetta et al., 2000; Hopfinger et al., 2000). Right-lateralized activity has mainly been reported in ventral fronto-parietal regions for shifts of attention to an unattended target stimulus (Arrington et al., 2000; Corbetta et al., 2000). However, clear conclusions cannot be drawn from these studies because hemispheric asymmetries were not assessed using direct voxel-wise comparisons of activity in left and right hemispheres. Here, we used this technique to measure hemispheric asymmetries during shifts of spatial attention evoked by a peripheral cue stimulus and during target detection at the cued location. Stimulus-driven shifts of spatial attention in both visual fields evoked right-hemisphere dominant activity in temporo-parietal junction (TPJ). Target detection at the attended location produced a more widespread right hemisphere dominance in frontal, parietal, and temporal cortex, including the TPJ region asymmetrically activated during shifts of spatial attention. However, hemispheric asymmetries were not observed during either shifts of attention or target detection in the dorsal fronto-parietal regions (anterior precuneus, medial intraparietal sulcus, frontal eye fields) that showed the most robust activations for shifts of attention. Therefore, right hemisphere dominance during stimulus-driven shifts of spatial attention and target detection reflects asymmetries in cortical regions that are largely distinct from the dorsal fronto-parietal network involved in the control of selective attention. PMID:20219998

Gastrin receptor characterization: affinity cross-linking of the gastrin receptor on canine gastric parietal cells

International Nuclear Information System (INIS)

Matsumoto, M.; Park, J.; Yamada, T.

1987-01-01

The authors applied affinity cross-linking methods to label the gastrin receptor on isolated canine gastric parietal cells in order to elucidate the nature of its chemical structure. 125 I-labeled Leu 15 -gastrin and 125 I-labeled gastrin/sub 2-17/ bound to intact parietal cells and their membranes with equal affinity, and half-maximal inhibition of binding was obtained at an incubation concentration of 3.2 x 10 -10 M unlabeled gastrin. 125 I-gastrin/sub 2-17/ was cross-linked to plasma membranes or intact parietal cells by incubation in disuccinimidyl suberate. The membrane pellets were solubilized with or without dithiothreitol and applied to electrophoresis on 7.5% sodium dodecyl sulfate polyacrylamide gels. Autoradiograms revealed a band of labeling at M/sub r/ 76,000 and labeling of this band was inhibited in a dose-dependent fashion by addition of unlabeled gastrin to the incubation mixture. Dithiothreitol in concentrations as high as 100 mM did not later the electrophoretic mobility of the labeled band. After taking into account the molecular weight of 125 I-gastrin/sub 2-17/, the results suggest that the gastrin receptor on parietal cells is a single protein of M/sub r/ 74,000 without disulfide-linked subunits

Unique and shared roles of the posterior parietal and dorsolateral prefrontal cortex in cognitive functions

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Fumi eKatsuki

2012-05-01

Full Text Available The dorsolateral prefrontal and posterior parietal cortex are two parts of a broader brain network involved in the control of cognitive functions such as working memory, spatial attention, and decision making. The two areas share many functional properties and exhibit similar patterns of activation during the execution of mental operations. However, neurophysiological experiments in non-human primates have also documented subtle differences, revealing functional specialization within the fronto-parietal network. These differences include the ability of the dorsolateral prefrontal cortex to influence memory performance, attention allocation and motor responses to a greater extent, and to resist interference by distracting stimuli. In recent years, distinct cellular and anatomical differences have been identified, offering insights into how functional specialization is achieved. This article reviews the common functions and functional differences between the dorsolateral prefrontal and posterior parietal cortex, and their underlying mechanisms.

Prediction of Reach Goals in Depth and Direction from the Parietal Cortex

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Matteo Filippini

2018-04-01

Full Text Available Summary: The posterior parietal cortex is well known to mediate sensorimotor transformations during the generation of movement plans, but its ability to control prosthetic limbs in 3D environments has not yet been fully demonstrated. With this aim, we trained monkeys to perform reaches to targets located at various depths and directions and tested whether the reach goal position can be extracted from parietal signals. The reach goal location was reliably decoded with accuracy close to optimal (>90%, and this occurred also well before movement onset. These results, together with recent work showing a reliable decoding of hand grip in the same area, suggest that this is a suitable site to decode the entire prehension action, to be considered in the development of brain-computer interfaces. : Filippini et al. show that it is possible to use parietal cortex activity to predict in which direction the arm will move and how far it will reach. This opens up the possibility of neural prostheses that can accurately guide reach and grasp using signals from this part of the brain. Keywords: neuroprosthetics, offline neural decoding, reaching in depth, monkey, V6A, machine learning, visuomotor transformations, hand guidance, prehension, robotics

Influencia del tratamiento térmico sobre el espesor y porosidad de películas delgadas de ZrO2 obtenidas por la ruta sol-gel

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Caruso, R.

2004-04-01

Full Text Available The present work is aimed to investigate the thermal densification mechanisms of sol-gel zirconia thin films deposited by dip coating, with particular emphasis on thickness and porosity evolution at different firing treatments (100-1100ºC. For this purpose, we have only used data from transmission spectrum. Implications for controlled design of sol-gel zirconia films will be considered.El este trabajo se investigan los mecanismos de densificación de películas delgadas de zirconia obtenidas por vía sol-gel y depositadas mediante la técnica dip-coating. Nuestro interés se centra en la determinación del espesor y porosidad de películas tratadas a temperaturas en el rango 100-1100 ºC. Para ello, se ha utilizado exclusivamente la técnica de espectrofotometría. Los resultados de este trabajo tienen interés para el diseño controlado de recubrimientos sol-gel de ZrO2.

Transcranial direct current stimulation over the parietal cortex alters bias in item and source memory tasks.

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Pergolizzi, Denise; Chua, Elizabeth F

2016-10-01

Neuroimaging data have shown that activity in the lateral posterior parietal cortex (PPC) correlates with item recognition and source recollection, but there is considerable debate about its specific contributions. Performance on both item and source memory tasks were compared between participants who were given bilateral transcranial direct current stimulation (tDCS) over the parietal cortex to those given prefrontal or sham tDCS. The parietal tDCS group, but not the prefrontal group, showed decreased false recognition, and less bias in item and source discrimination tasks compared to sham stimulation. These results are consistent with a causal role of the PPC in item and source memory retrieval, likely based on attentional and decision-making biases. Copyright © 2016 Elsevier Inc. All rights reserved.

Vulnerability of the frontal and parietal regions in hypertensive patients during working memory task.

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Li, Xin; Wang, Wenxiao; Wang, Ailin; Li, Peng; Zhang, Junying; Tao, Wuhai; Zhang, Zhanjun

2017-05-01

Hypertension is related with cognitive decline in the elderly. The frontal-parietal executive system plays an important role in cognitive aging and is also vulnerable to damage in elderly patients with hypertension. Examination of the brain's functional characteristics in frontal-parietal regions of hypertension is likely to be important for understanding the neural mechanisms of hypertension's effect on cognitive aging. We address this issue by comparing hypertension and control-performers in a functional MRI study. Twenty-eight hypertensive patients and 32 elderly controls were tested with n-back task with two load levels. The hypertensive patients exhibited worse executive and memory abilities than control subjects. The patterns of brain activation changed under different working memory loads in the hypertensive patients, who exhibited reduced activation only in the precentral gyrus under low loads and reduced activation in the middle frontal gyrus, left medial superior frontal gyrus and right precuneus under high loads. Thus, more regions of diminished activation were observed in the frontal and parietal regions with increasing task difficulty. More importantly, we found that lower activation in changed frontal and parietal regions was associated with worse cognitive function in high loads. The results demonstrate the relationship between cognitive function and frontoparietal functional activation in hypertension and their relevance to cognitive aging risk. Our findings provide a better understanding of the mechanism of cognitive decline in hypertension and highlight the importance of brain protection in hypertension.

Connections of the medial posterior parietal cortex (area 7m) in the monkey.

Science.gov (United States)

Leichnetz, G R

2001-06-01

The afferent and efferent cortical and subcortical connections of the medial posterior parietal cortex (area 7m) were studied in cebus (Cebus apella) and macaque (Macaca fascicularis) monkeys using the retrograde and anterograde capabilities of the horseradish peroxidase (HRP) technique. The principal intraparietal corticocortical connections of area 7m in both cebus and macaque cases were with the ipsilateral medial bank of the intraparietal sulcus (MIP) and adjacent superior parietal lobule (area 5), inferior parietal lobule (area 7a), lateral bank of the IPS (area 7ip), caudal parietal operculum (PGop), dorsal bank of the caudal superior temporal sulcus (visual area MST), and medial prestriate cortex (including visual area PO and caudal medial lobule). Its principal frontal corticocortical connections were with the prefrontal cortex in the shoulder above the principal sulcus and the cortex in the shoulder above the superior ramus of the arcuate sulcus (SAS), the area purported to contain the smooth eye movement-related frontal eye field (FEFsem) in the cebus monkey by other investigators. There were moderate connections with the cortex in the rostral bank of the arcuate sulcus (purported to contain the saccade-related frontal eye field; FEFsac), supplementary eye field (SEF), and rostral dorsal premotor area (PMDr). Area 7m also had major connections with the cingulate cortex (area 23), particularly the ventral bank of the cingulate sulcus. The principal subcortical connections of area 7m were with the dorsal portion of the ventrolateral thalamic (VLc) nucleus, lateral posterior thalamic nucleus, lateral pulvinar, caudal mediodorsal thalamic nucleus and medial pulvinar, central lateral, central superior lateral, and central inferior intralaminar thalamic nuclei, dorsolateral caudate nucleus and putamen, middle region of the claustrum, nucleus of the diagonal band, zona incerta, pregeniculate nucleus, anterior and posterior pretectal nuclei, intermediate layer of

Automatic and Intentional Number Processing Both Rely on Intact Right Parietal Cortex: A Combined fMRI and Neuronavigated TMS Study

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Cohen Kadosh, Roi; Bien, Nina; Sack, Alexander T.

2012-01-01

Practice and training usually lead to performance increase in a given task. In addition, a shift from intentional toward more automatic processing mechanisms is often observed. It is currently debated whether automatic and intentional processing is subserved by the same or by different mechanism(s), and whether the same or different regions in the brain are recruited. Previous correlational evidence provided by behavioral, neuroimaging, modeling, and neuropsychological studies addressing this question yielded conflicting results. Here we used transcranial magnetic stimulation (TMS) to compare the causal influence of disrupting either left or right parietal cortex during automatic and intentional numerical processing, as reflected by the size congruity effect and the numerical distance effect, respectively. We found a functional hemispheric asymmetry within parietal cortex with only the TMS-induced right parietal disruption impairing both automatic and intentional numerical processing. In contrast, disrupting the left parietal lobe with TMS, or applying sham stimulation, did not affect performance during automatic or intentional numerical processing. The current results provide causal evidence for the functional relevance of right, but not left, parietal cortex for intentional, and automatic numerical processing, implying that at least within the parietal cortices, automatic, and intentional numerical processing rely on the same underlying hemispheric lateralization. PMID:22347175

Examining the role of the temporo-parietal network in memory, imagery, and viewpoint transformations.

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Dhindsa, Kiret; Drobinin, Vladislav; King, John; Hall, Geoffrey B; Burgess, Neil; Becker, Suzanna

2014-01-01

The traditional view of the medial temporal lobe (MTL) focuses on its role in episodic memory. However, some of the underlying functions of the MTL can be ascertained from its wider role in supporting spatial cognition in concert with parietal and prefrontal regions. The MTL is strongly implicated in the formation of enduring allocentric representations (e.g., O'Keefe, 1976; King et al., 2002; Ekstrom et al., 2003). According to our BBB model (Byrne et al., 2007), these representations must interact with head-centered and body-centered representations in posterior parietal cortex via a transformation circuit involving retrosplenial areas. Egocentric sensory representations in parietal areas can then cue the recall of allocentric spatial representations in long-term memory and, conversely, the products of retrieval in MTL can generate mental imagery within a parietal "window." Such imagery is necessarily egocentric and forms part of visuospatial working memory, in which it can be manipulated for the purpose of planning/imagining the future. Recent fMRI evidence (Lambrey et al., 2012; Zhang et al., 2012) supports the BBB model. To further test the model, we had participants learn the locations of objects in a virtual scene and tested their spatial memory under conditions that impose varying demands on the transformation circuit. We analyzed how brain activity correlated with accuracy in judging the direction of an object (1) from visuospatial working memory (we assume transient working memory due to the order of tasks and the absence of change in viewpoint, but long-term memory retrieval is also possible), (2) after a rotation of viewpoint, or (3) after a rotation and translation of viewpoint (judgment of relative direction). We found performance-related activity in both tasks requiring viewpoint rotation (ROT and JRD, i.e., conditions 2 and 3) in the core medial temporal to medial parietal circuit identified by the BBB model. These results are consistent with the

Haptically guided grasping. FMRI shows right-hemisphere parietal stimulus encoding, and bilateral dorso-ventral parietal gradients of object- and action-related processing during grasp execution

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Mattia eMarangon

2016-01-01

Full Text Available The neural bases of haptically-guided grasp planning and execution are largely unknown, especially for stimuli having no visual representations. Therefore, we used functional magnetic resonance imaging (fMRI to monitor brain activity during haptic exploration of novel 3D complex objects, subsequent grasp planning, and the execution of the pre-planned grasps. Haptic object exploration, involving extraction of shape, orientation and length of the to-be-grasped targets, was associated with the fronto-parietal, temporo-occipital, and insular cortex activity. Yet, only the anterior divisions of the posterior parietal cortex (PPC of the right hemisphere were significantly more engaged in exploration of complex objects (vs. simple control disks. None of these regions were re-recruited during the planning phase. Even more surprisingly, the left-hemisphere intraparietal, temporal, and occipital areas that were significantly invoked for grasp planning did not show sensitivity to object features. Finally, grasp execution, involving the re-recruitment of the critical right-hemisphere PPC clusters, was also significantly associated with two kinds of bilateral parieto-frontal processes. The first represents transformations of grasp-relevant target features and is linked to the dorso-dorsal (lateral and medial parieto-frontal networks. The second monitors grasp kinematics and belongs to the ventro-dorsal networks. Indeed, signal modulations associated with these distinct functions follow dorso-ventral gradients, with left aIPS showing significant sensitivity to both target features and the characteristics of the required grasp. Thus, our results from the haptic domain are consistent with the notion that the parietal processing for action guidance reflects primarily transformations from object-related to effector-related coding, and these mechanisms are rather independent of sensory input modality.

Right parietal cortex and calculation processing: intraoperative functional mapping of multiplication and addition in patients affected by a brain tumor.

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Della Puppa, Alessandro; De Pellegrin, Serena; d'Avella, Elena; Gioffrè, Giorgio; Munari, Marina; Saladini, Marina; Salillas, Elena; Scienza, Renato; Semenza, Carlo

2013-11-01

The role of parietal areas in number processing is well known. The significance of intraoperative functional mapping of these areas has been only partially explored, however, and only a few discordant data are available in the surgical literature with regard to the right parietal lobe. The purpose of this study was to evaluate the clinical impact of simple calculation in cortical electrostimulation of right-handed patients affected by a right parietal brain tumor. Calculation mapping in awake surgery was performed in 3 right-handed patients affected by high-grade gliomas located in the right parietal lobe. Preoperatively, none of the patients presented with calculation deficits. In all 3 cases, after sensorimotor and language mapping, cortical and intraparietal sulcus areas involved in single-digit multiplication and addition calculations were mapped using bipolar electrostimulation. In all patients, different sites of the right parietal cortex, mainly in the inferior lobule, were detected as being specifically related to calculation (multiplication or addition). In 2 patients the intraparietal sulcus was functionally specific for multiplication. No functional sites for language were detected. All sites functional for calculation were spared during tumor resection, which was complete in all cases without postoperative neurological deficits. These findings provide intraoperative data in support of an anatomofunctional organization for multiplication and addition within the right parietal area. Furthermore, the study shows the potential clinical relevance of intraoperative mapping of calculation in patients undergoing surgery in the right parietal area. Further and larger studies are needed to confirm these data and assess whether mapped areas are effectively essential for function.

Tracing the origin of glomerular extracapillary lesions from parietal epithelial cells.

NARCIS (Netherlands)

Smeets, B.; Uhlig, S.; Fuss, A.; Mooren, F.; Wetzels, J.F.M.; Floege, J.; Moeller, M.J.

2009-01-01

Cellular lesions form in Bowman's space in both crescentic glomerulonephritis and collapsing glomerulopathy. The pathomechanism and origin of the proliferating cells in these lesions are unknown. In this study, we examined proliferating cells by lineage tracing of either podocytes or parietal

The role of frontal and parietal brain areas in bistable perception

NARCIS (Netherlands)

Knapen, T.; Brascamp, J.; Pearson, J.; van Ee, R.; Blake, R.

2011-01-01

When sensory input allows for multiple, competing perceptual interpretations, observers' perception can fluctuate over time, which is called bistable perception. Imaging studies in humans have revealed transient responses in a right-lateralized network in the frontal-parietal cortex (rFPC) around

Potential role of monkey inferior parietal neurons coding action semantic equivalences as precursors of parts of speech.

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Yamazaki, Yumiko; Yokochi, Hiroko; Tanaka, Michio; Okanoya, Kazuo; Iriki, Atsushi

2010-01-01

The anterior portion of the inferior parietal cortex possesses comprehensive representations of actions embedded in behavioural contexts. Mirror neurons, which respond to both self-executed and observed actions, exist in this brain region in addition to those originally found in the premotor cortex. We found that parietal mirror neurons responded differentially to identical actions embedded in different contexts. Another type of parietal mirror neuron represents an inverse and complementary property of responding equally to dissimilar actions made by itself and others for an identical purpose. Here, we propose a hypothesis that these sets of inferior parietal neurons constitute a neural basis for encoding the semantic equivalence of various actions across different agents and contexts. The neurons have mirror neuron properties, and they encoded generalization of agents, differentiation of outcomes, and categorization of actions that led to common functions. By integrating the activities of these mirror neurons with various codings, we further suggest that in the ancestral primates' brains, these various representations of meaningful action led to the gradual establishment of equivalence relations among the different types of actions, by sharing common action semantics. Such differential codings of the components of actions might represent precursors to the parts of protolanguage, such as gestural communication, which are shared among various members of a society. Finally, we suggest that the inferior parietal cortex serves as an interface between this action semantics system and other higher semantic systems, through common structures of action representation that mimic language syntax.

Modelo predictivo del espesor de la capa de óxido y microdureza en aluminio Al3003-B14 y Al6063-T6 anodizado usando análisis multifactorial Oxide film thickness and microhardness prediction model of Al3003-B14 and Al6063-T6 anodized aluminum using multifactorial analysis

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Leonardo Eladio Vergara Guillén

2011-08-01

Full Text Available En esta investigación se modela a partir de los parámetros del proceso el espesor de la capa de óxido y la microdureza de los aluminios Al3003 y Al6063 anodizados. Para ello se realizaron estudios de la microdureza y espesor de capa de la superficie anodizada, utilizando técnicas de análisis multifactorial y diseño robusto. Se establecieron los siguientes niveles de los parámetros del proceso: temperatura [15 °C, 25 °C], tiempo [30 min; 60 min], concentración de electrolito [1,2 M; 2 M], densidad de corriente [1 Amp/dm²; 3 Amp/dm²], aluminio [Al3003,Al6063] y como variable de ruido, la deformación plástica [0%, 10%, 20%, 30%]. Se propuso un diseño fraccionado 2(7-2 mixto, con el cual se efectuó un total de 48 pruebas usando soluciones electrolíticas de ácido sulfúrico. La medición de microdureza se realizó con un indentador Vickers con carga de 400 g; el espesor de la capa de óxido se captó mediante microscopia electrónica. A los resultados se les realizó un análisis de varianza (ANOVA, para determinar los factores significativos y la robustez de los efectos. Se encontraron resultados de microdureza [HV] [85,74-308,87]; y espesor de óxido [µm] [12,82- 94,69]. Finalmente, se muestran los modelos de predicción de cada una de las respuestas en función de los factores significativos estas ecuaciones permitirán seleccionar la microdureza y espesor de la capa de óxido para cumplir los requerimientos de un producto particular mediante una selección apropiada de los parámetros del proceso.In this research, the thickness of the oxide layer and the microhardness of anodized aluminum Al3003 and Al6063 are modeled based on process parameters. To this end, studies of the microhardness and the thickness layer of the anodized surface were made, via techniques of multifactorial analysis and robust design. The following levels of the process parameters were established: temperature [15°C, 25°C], time [30min; 60min

Right parietal cortex mediates recognition memory for melodies.

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Schaal, Nora K; Javadi, Amir-Homayoun; Halpern, Andrea R; Pollok, Bettina; Banissy, Michael J

2015-07-01

Functional brain imaging studies have highlighted the significance of right-lateralized temporal, frontal and parietal brain areas for memory for melodies. The present study investigated the involvement of bilateral posterior parietal cortices (PPCs) for the recognition memory of melodies using transcranial direct current stimulation (tDCS). Participants performed a recognition task before and after tDCS. The task included an encoding phase (12 melodies), a retention period, as well as a recognition phase (24 melodies). Experiment 1 revealed that anodal tDCS over the right PPC led to a deterioration of overall memory performance compared with sham. Experiment 2 confirmed the results of Experiment 1 and further showed that anodal tDCS over the left PPC did not show a modulatory effect on memory task performance, indicating a right lateralization for musical memory. Furthermore, both experiments revealed that the decline in memory for melodies can be traced back to an interference of anodal stimulation on the recollection process (remember judgements) rather than to familiarity judgements. Taken together, this study revealed a causal involvement of the right PPC for memory for melodies and demonstrated a key role for this brain region in the recollection process of the memory task. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Parietal theta burst TMS: Functional fractionation observed during bistable perception not evident in attention tasks.

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Schauer, Georg; Kanai, Ryota; Brascamp, Jan W

2016-02-01

When visual input is ambiguous, perception spontaneously alternates between interpretations: bistable perception. Studies have identified two distinct sites near the right intraparietal sulcus where inhibitory transcranial magnetic stimulation (TMS) affects the frequency of occurrence of these alternations, but strikingly with opposite directions of effect for the two sites. Lesion and TMS studies on spatial and sustained attention have also indicated a parcellation of right parietal cortex, into areas serving distinct attentional functions. We used the exact TMS procedure previously employed to affect bistable perception, yet measured its effect on spatial and sustained attention tasks. Although there was a trend for TMS to affect performance, trends were consistently similar for both parietal sites, with no indication of opposite effects. We interpret this as signifying that the previously observed parietal fractionation of function regarding the perception of ambiguous stimuli is not due to TMS-induced modification of spatial or sustained attention. Copyright © 2016 Elsevier Inc. All rights reserved.

Cifras del retroceso: el deterioro relativo de la tasa de mortalidad infantil de Argentina en la segunda mitad del siglo XX

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José Carlos Escudero

2006-01-01

Full Text Available Se compara la evolución histórica de la tasa de mortalidad infantil de Argentina con la de otros países americanos en la segunda mitad del siglo XX. También se compara la evolución histórica de la tasa de mortalidad infantil de la Ciudad Autónoma de Buenos Aires y la del Gran Buenos Aires con la de otras ciudades de América y del mundo. Esto muestra el deterioro relativo de la posición de Argentina con respecto a su nivel de mortalidad infantil.

Transcriptional landscape of glomerular parietal epithelial cells.

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Sina A Gharib

Full Text Available Very little is known about the function of glomerular parietal epithelial cells (PECs. In this study, we performed genome-wide expression analysis on PEC-enriched capsulated vs. PEC-deprived decapsulated rat glomeruli to determine the transcriptional state of PECs under normal conditions. We identified hundreds of differentially expressed genes that mapped to distinct biologic modules including development, tight junction, ion transport, and metabolic processes. Since developmental programs were highly enriched in PECs, we characterized several of their candidate members at the protein level. Collectively, our findings confirm that PECs are multifaceted cells and help define their diverse functional repertoire.

Interlaminar differences in the pyramidal cell phenotype in parietal cortex of an Indian bat, cynopterus sphinx.

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Srivastava, U C; Pathak, S V

2010-10-30

To study interlaminar phenotypic variations in the pyramidal neurons of parietal isocortex in bat (Cynopterus sphinx), Golgi and Nissl methods have been employed. The parietal isocortex is relatively thin in the bat as compared to prototheria with layer III, V and VI accounting for more than two—thirds of total cortical thickness. Thick cell free layer I and thinnest accentuated layer II are quite in connotation with other chiropterids. Poor demarcation of layer III/IV in the present study is also in connotation with primitive eutherian mammal (i.e. prototherian) and other chiropterids. Most of the pyramidal cells in the different layers of the parietal isocortex are of typical type as seen in other eutherians but differ significantly in terms of soma shape and size, extent of dendritic arbor, diameter of dendrites and spine density. Percentage of pyramidal neurons, diameter of apical dendrite and spine density on apical dendrite appear to follow an increasing trend from primitive to advanced mammals; but extent of dendrites are probably governed by the specific life patterns of these mammals. It is thus concluded that 'typical' pyramidal neurons in parietal isocortex are similar in therians but different from those in prototherians. It is possible that these cells might have arisen among early eutherians after divergence from prototherian stock.

Fronto-parietal contributions to phonological processes in successful artificial grammar learning

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Dariya Goranskaya

2016-11-01

Full Text Available Sensitivity to regularities plays a crucial role in the acquisition of various linguistic features from spoken language input. Artificial grammar (AG learning paradigms explore pattern recognition abilities in a set of structured sequences (i.e. of syllables or letters. In the present study, we investigated the functional underpinnings of learning phonological regularities in auditorily presented syllable sequences. While previous neuroimaging studies either focused on functional differences between the processing of correct vs. incorrect sequences or between different levels of sequence complexity, here the focus is on the neural foundation of the actual learning success. During functional magnetic resonance imaging (fMRI, participants were exposed to a set of syllable sequences with an underlying phonological rule system, known to ensure performance differences between participants. We expected that successful learning and rule application would require phonological segmentation and phoneme comparison. As an outcome of four alternating learning and test fMRI sessions, participants split into successful learners and non-learners. Relative to non-learners, successful learners showed increased task-related activity in a fronto-parietal network of brain areas encompassing the left lateral premotor cortex as well as bilateral superior and inferior parietal cortices during both learning and rule application. These areas were previously associated with phonological segmentation, phoneme comparison and verbal working memory. Based on these activity patterns and the phonological strategies for rule acquisition and application, we argue that successful learning and processing of complex phonological rules in our paradigm is mediated via a fronto-parietal network for phonological processes.

Body-centred map in parietal eye fields - functional MRI study

International Nuclear Information System (INIS)

Brotchie, P.; Chen, D.Y.; Bradley, W.G.

2002-01-01

Full text: In order for us to interact with our environment we need to know where objects are around us, relative to our body. In monkeys, a body-centred map of visual space is known to exist within the parietal eye fields. This map is formed by the modulation of neuronal activity by eye and head position (Brotchie et al, Nature 1995; Synder et al, Nature 1998). In humans no map of body centred space has been demonstrated. By using functional MRI we have localised a region along the intraparietal sulcus which has properties similar to the parietal eye fields of monkeys (Brotchie et al, ISMRM, 2000). The aim of this study was to determine if activity in this region is modulated by head position, consistent with a body centered representation of visual space. Functional MRI was performed on 6 subjects performing simple visually guided saccades using a 1.5 Tesla GE Echospeed scanner. 10 scans were performed on the 6 subjects at left and right body orientations. Regions of interest were selected around the intraparietal sulcus proper (IPSP) of both hemispheres and voxels with BOLD signal which correlated with the paradigm (r>0.35) were selected for further analysis. Comparisons of percentage signal change were made between the left and right IPSP using Student t test. Of the 10 MRI examinations, 6 demonstrated statistically significant differences in the amount of signal change between left and right IPSP. In each of these 6 cases, the signal change was greater within the IPSP contralateral to the direction of head position relative to the body. This indicates a modulation of activity within the IPSP related to head position, most likely reflecting modulation of the underlying neuronal activity and suggests the existence of a body-centred encoding of space within the parietal eye fields of humans. Copyright (2002) Blackwell Science Pty Ltd

Temporo-Parietal and Fronto-Parietal Lobe Contributions to Theory of Mind and Executive Control: An fMRI Study of Verbal Jokes

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Yu-Chen eChan

2015-09-01

Full Text Available ‘Getting a joke’ always requires resolving an apparent incongruity but the particular cognitive operations called upon vary depending on the nature of the joke itself. Previous research has identified the primary neural correlates of the cognitive and affective processes called upon to respond to humor generally, but little work has been done on the substrates underlying the distinct cognitive operations required to comprehend particular joke types. This study explored the neural correlates of the cognitive processes required to successfully comprehend three joke types: bridging-inference jokes, exaggeration jokes and ambiguity jokes. For all joke types, the left dlPFC appeared to support common cognitive mechanisms, such as script-shifting, while the vACC was associated with affective appreciation. The temporo-parietal lobe (TPJ and MTG was associated with bridging-inference jokes, suggesting involvement of these regions with ‘theory of mind’ processing. The ventral fronto-parietal lobe (IPL and IFG was associated with both exaggeration and ambiguity jokes, suggesting that it supports executive control processes such as retrieval from episodic memory, self-awareness, and language-based decoding. The social-affective appreciation of verbal jokes was associated with activity in the orbitofrontal cortex, amygdala, ventral anterior cingulate cortex (vACC, and parahippocampal gyrus. These results allow a more precise account of the neural

Parietal intradiploic encephalocele: Report of a case and review of the literature.

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Arevalo-Perez, Julio; Millán-Juncos, José M

2015-06-01

Encephaloceles consist of brain tissue and meninges that has herniated through a skull defect, usually located in the midline. They are seen more commonly in children and very rarely in adults. We present a case of an 84-year-old patient who was incidentally diagnosed with a lytic bone lesion in the right parietal intradiploic space, after computed tomography of the head was performed. A magnetic resonance imaging scan of the brain showed herniation of brain tissue through the defect. Magnetic resonance imaging was crucial in demonstrating the presence of parenchyma and its continuity with the rest of the brain, consequently distinguishing it from other entities. We report the imaging findings of a parietal indradiploic encephalocele with its differential diagnosis and a review of the relevant literature. © The Author(s) 2015.

El contexto del arte parietal. La tecnología de los artistas en la Cueva de Tito Bustillo (Asturias

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Moure Romanillo, Alfonso

1988-12-01

Full Text Available This study overlaps in part with a communication presented to the «Colloque International d'Art Parietal Paléolithique» held at Perigueux-Le Thot in december 1984. The technological responses contained in a decorated zone of the cave of Tito Bustillo are analyzed, as well as the activities carried out on living floors related to the preparation and completion of the parietal art.

El trabajo coincide parcialmente con la comunicación presentada al «Colloque International d'Art Parietal Paléolithique» celebrado en Perigueux-Le Thot, en diciembre de 1984. Se analizan las respuestas tecnológicas contenidas en un área de decoración de la cueva de Tito Bustillo (Asturias, así como las actividades en áreas de estancia relacionadas con la preparación y ejecución del arte parietal.

LEVANTAMENTO, SELEÇÃO E SISTEMATIZAÇÃO DE TERMOS RELATIVOS AOS MEIOS DE HOSPEDAGEM

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Júlia Moreira de Deus

2016-12-01

Full Text Available Está sendo realizado um projeto de pesquisa com a finalidade de elaborar um dicionário trilíngue (PortuguêsInglês-Espanhol com termos relacionados ao turismo. O dicionário visa contribuir com a comunicação no campo do turismo e disponibilizar uma fonte de consulta para profissionais e estudantes. A esta pesquisa coube levantar, selecionar e sistematizar os termos relativos aos meios de hospedagem. Para isso, foi feito um levantamento em cinco dicionários especializados e três obras que tratavam do assunto; foram selecionados os termos que designam meios de hospedagem;as definições e contextos foram inseridos em fichas e foram identificadas as principais características dos termos; foi organizado um mapa conceitual dos meios de hospedagem. Por fim, um especialista foi consultado para validar os termos. Os dados coletados nessa primeira etapa da pesquisa foram usados na redação das definições dos termos selecionados. Palavras-chave: Dicionário. Meios de Hospedagem. Terminologia.

Haptically Guided Grasping. fMRI Shows Right-Hemisphere Parietal Stimulus Encoding, and Bilateral Dorso-Ventral Parietal Gradients of Object- and Action-Related Processing during Grasp Execution.

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Marangon, Mattia; Kubiak, Agnieszka; Króliczak, Gregory

2015-01-01

The neural bases of haptically-guided grasp planning and execution are largely unknown, especially for stimuli having no visual representations. Therefore, we used functional magnetic resonance imaging (fMRI) to monitor brain activity during haptic exploration of novel 3D complex objects, subsequent grasp planning, and the execution of the pre-planned grasps. Haptic object exploration, involving extraction of shape, orientation, and length of the to-be-grasped targets, was associated with the fronto-parietal, temporo-occipital, and insular cortex activity. Yet, only the anterior divisions of the posterior parietal cortex (PPC) of the right hemisphere were significantly more engaged in exploration of complex objects (vs. simple control disks). None of these regions were re-recruited during the planning phase. Even more surprisingly, the left-hemisphere intraparietal, temporal, and occipital areas that were significantly invoked for grasp planning did not show sensitivity to object features. Finally, grasp execution, involving the re-recruitment of the critical right-hemisphere PPC clusters, was also significantly associated with two kinds of bilateral parieto-frontal processes. The first represents transformations of grasp-relevant target features and is linked to the dorso-dorsal (lateral and medial) parieto-frontal networks. The second monitors grasp kinematics and belongs to the ventro-dorsal networks. Indeed, signal modulations associated with these distinct functions follow dorso-ventral gradients, with left aIPS showing significant sensitivity to both target features and the characteristics of the required grasp. Thus, our results from the haptic domain are consistent with the notion that the parietal processing for action guidance reflects primarily transformations from object-related to effector-related coding, and these mechanisms are rather independent of sensory input modality.

The impact of top-down spatial attention on laterality and hemispheric asymmetry in the human parietal cortex.

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Jeong, Su Keun; Xu, Yaoda

2016-08-01

The human parietal cortex exhibits a preference to contralaterally presented visual stimuli (i.e., laterality) as well as an asymmetry between the two hemispheres with the left parietal cortex showing greater laterality than the right. Using visual short-term memory and perceptual tasks and varying target location predictability, this study examined whether hemispheric laterality and asymmetry are fixed characteristics of the human parietal cortex or whether they are dynamic and modulated by the deployment of top-down attention to the target present hemifield. Two parietal regions were examined here that have previously been shown to be involved in visual object individuation and identification and are located in the inferior and superior intraparietal sulcus (IPS), respectively. Across three experiments, significant laterality was found in both parietal regions regardless of attentional modulation with laterality being greater in the inferior than superior IPS, consistent with their roles in object individuation and identification, respectively. Although the deployment of top-down attention had no effect on the superior IPS, it significantly increased laterality in the inferior IPS. The deployment of top-down spatial attention can thus amplify the strength of laterality in the inferior IPS. Hemispheric asymmetry, on the other hand, was absent in both brain regions and only emerged in the inferior but not the superior IPS with the deployment of top-down attention. Interestingly, the strength of hemispheric asymmetry significantly correlated with the strength of laterality in the inferior IPS. Hemispheric asymmetry thus seems to only emerge when there is a sufficient amount of laterality present in a brain region.

The organization of the posterior parietal cortex devoted to upper limb actions: An fMRI study

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Ferri, Stefania; Rizzolatti, Giacomo

2015-01-01

Abstract The present fMRI study examined whether upper‐limb action classes differing in their motor goal are encoded by different PPC sectors. Action observation was used as a proxy for action execution. Subjects viewed actors performing object‐related (e.g., grasping), skin‐displacing (e.g., rubbing the skin), and interpersonal upper limb actions (e.g., pushing someone). Observation of the three action classes activated a three‐level network including occipito‐temporal, parietal, and premotor cortex. The parietal region common to observing all three action classes was located dorsally to the left intraparietal sulcus (DIPSM/DIPSA border). Regions specific for observing an action class were obtained by combining the interaction between observing action classes and stimulus types with exclusive masking for observing the other classes, while for regions considered preferentially active for a class the interaction was exclusively masked with the regions common to all observed actions. Left putative human anterior intraparietal was specific for observing manipulative actions, and left parietal operculum including putative human SII region, specific for observing skin‐displacing actions. Control experiments demonstrated that this latter activation depended on seeing the skin being moved and not simply on seeing touch. Psychophysiological interactions showed that the two specific parietal regions had similar connectivities. Finally, observing interpersonal actions preferentially activated a dorsal sector of left DIPSA, possibly the homologue of ventral intraparietal coding the impingement of the target person's body into the peripersonal space of the actor. These results support the importance of segregation according to the action class as principle of posterior parietal cortex organization for action observation and by implication for action execution. Hum Brain Mapp 36:3845–3866, 2015. © 2015 The Authors Human Brain Mapping Published by Wiley

Sustained attention is associated with right superior longitudinal fasciculus and superior parietal white matter microstructure in children

DEFF Research Database (Denmark)

Klarborg, Brith; Skak Madsen, Kathrine; Vestergaard, Martin

2013-01-01

Sustained attention develops during childhood and has been linked to the right fronto-parietal cortices in functional imaging studies; however, less is known about its relation to white matter (WM) characteristics. Here we investigated whether the microstructure of the WM underlying and connecting...... the right fronto-parietal cortices was associated with sustained attention performance in a group of 76 typically developing children aged 7-13 years. Sustained attention was assessed using a rapid visual information processing paradigm. The two behavioral measures of interest were the sensitivity index d......' and the coefficient of variation in reaction times (RT(CV) ). Diffusion-weighted imaging was performed. Mean fractional anisotropy (FA) was extracted from the WM underlying right dorsolateral prefrontal (DLPFC) and parietal cortex (PC), and the right superior longitudinal fasciculus (SLF), as well as equivalent...

La desambiguación de oraciones de relativo en gallego: Nueva evidencia de adjunción alta en lenguas romances

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Juan Carlos Acuña

2005-01-01

Full Text Available La investigación sobre el procesamiento de oraciones ha puesto de manifiesto la importancia de obtener datos de lenguas diferentes al inglés (e.g., Cuetos y Mitchell, 1988. En el marco de la desambiguación de oraciones de relativo como Alguien disparó al criado de la actriz que estaba en el balcón, en la que tanto “la actriz” como “el criado” podrían ser los que “estaban en el balcón”, se han encontrado preferencias dispares en distintos idiomas. Así, en inglés parecen preferirse adjunciones bajas hacia el sintagma nominal más cercano (SN2, mientras que en lenguas como el español o el francés se prefieren adjunciones altas, es decir, hacia el sintagma nominal más lejano (SN1. En el caso de otras lenguas romances, portugués e italiano, los resultados son inciertos, pues algunos autores han encontrado preferencias por la adjunción baja mientras que otros lo han hecho por la adjunción alta. En la presente investigación se evalúan, a partir de un estudio de cuestionario y un experimento de lectura autoadministrada mediante ventana móvil, las preferencias estructurales de hablantes de gallego, una lengua con un estrecho parecido al espa��ol (preferencia hacia SN1 y al portugués (preferencia incierta. Los datos, los primeros en lengua gallega, indican, tanto en el estudio de cuestionario como en el estudio on-line, preferencias por las estructuras en las que la cláusula de relativo ambigua se adjunta alto en el marco sintagmático. Estos resultados son discutidos en relación con los principales modelos de procesamiento de oraciones y las preferencias encontradas en distintas lenguas.

Caracterización del injerto parietal

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José Manuel Díaz Fernández

1996-12-01

Full Text Available Se realizó un estudio descriptivo, longitudinal y prospectivo de 22 pacientes en los que se utilizó el injerto parietal autógeno para reconstruir defectos del cráneo, en los servicios de Cirugía Maxilofacial y Neurocirugía del Hospital Clinicoquirúrgico Docente "Saturnino Lora", de Santiago de Cuba, desde 1988 hasta 1991. El método de extracción del injerto con división in situ resultó el más empleado y el que ofreció las mejores posibilidades de reconstrucción en cuanto a forma, volumen y flexibilidad, por lo que se recomienda en los defectos pequeños y medianos, sobre todo de la región frontal y áreas adyacentes, donde el contorno y la simetría son los 2 aspectos fundamentales que se deben conseguir. El método de división, in vitro se utilizó en las reconstrucciones de las deformidades de grandes dimensiones, particularmente en aquellas que no incluían la frente. El índice de complicaciones fue bajoIt was carried out a descriptive, longitudinal and prospective study of 22 patients in whom an autogenous parietal graft was used to reconstruct cranial defects at the Maxillofacial Surgery and Neurosurgery Department of the "Saturnino Lora" Clinical and Surgical Teaching Hospital, in Santiago de Cuba, from 1988 to 1991. The graft extraction method with division in situ was the most used and offered the best possibilities for reconstruction as regards form, volume and flexibility. Therefore, it is recommended for small and medium defects, particularly of the frontal region and adjacent areas, where contour and symmetry are the two fundamental aspects to be taken into consideration. The method of division in vitro was used to reconstruct large deformities, specially those in which the forehead was not included. The complications index was low

COMPARACIÓN HISTOLÓGICA Y MORFOMÉTRICA ENTRE EL OJO DE Eremophilus mutisii (TRICHOMYCTERIDAE Y EL DE Oncorhynchus mykiss (SALMONIDAE

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MARIO OSWALDO TOVAR BOHÓRQUEZ

2008-05-01

Full Text Available La visión es de importancia variable dependiendo de la relación de los peces con su hábitat, siendo clave en algunas especies y secundaria en otras. El objetivo de este estudio fue realizar una comparación entre el ojo de capitán de la sabana y trucha arco iris. La primera, nativa del altiplano cundiboyacence. La segunda es una especie introducida al país y con alta importancia en la piscicultura. Se obtuvieron cortes de ojo a 5 µm de espesor en ambas especies. Las dos presentan la estructura ocular típica de teleósteos conformada por una retina con ocho capas y dos membranas, células fotorreceptoras (conos y bastones, así como los otros tipos de células neuronales características (bipolares, horizontales, amacrinas y ganglionares, y un cristalino casi esférico. La trucha presenta cartílago en la esclerótica y en capitán de la sabana está ausente. El espesor promedio de las estructuras en capitán de la sabana es: retina de 183,5 +/-41,2 µm, córnea de 20,6 +/-5,4 µm e iris de 31,2 +/-6,4 µm; trucha arco iris presentó una retina de 389,5 +/-65,2 µm, una córnea de 300,4 +/-101,8 µm y un iris de 41,2 +/-13,7 µm. Los resultados obtenidos en este estudio muestran diferencias en el espesor de la retina, cornea, esclerótica, tamaño relativo del ojo y diámetro horizontal del cristalino; para los cuales trucha arco iris presenta un valor mayor. Estas diferencias posiblemente se relacionan con diferencias en sensibilidad y resolución visual entre las dos especies y podrían reflejar adaptaciones del sistema visual al medio.

Posterior parietal cortex and episodic encoding: insights from fMRI subsequent memory effects and dual-attention theory.

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Uncapher, Melina R; Wagner, Anthony D

2009-02-01

The formation of episodic memories--memories for life events--is affected by attention during event processing. A leading neurobiological model of attention posits two separate yet interacting systems that depend on distinct regions in lateral posterior parietal cortex (PPC). From this dual-attention perspective, dorsal PPC is thought to support the goal-directed allocation of attention, whereas ventral PPC is thought to support reflexive orienting to information that automatically captures attention. To advance understanding of how parietal mechanisms may impact event encoding, we review functional MRI studies that document the relationship between lateral PPC activation during encoding and subsequent memory performance (e.g., later remembering or forgetting). This review reveals that (a) encoding-related activity is frequently observed in human lateral PPC, (b) increased activation in dorsal PPC is associated with later memory success, and (c) increased activation in ventral PPC predominantly correlates with later memory failure. From a dual-attention perspective, these findings suggest that allocating goal-directed attention during event processing increases the probability that the event will be remembered later, whereas the capture of reflexive attention during event processing may have negative consequences for event encoding. The prevalence of encoding-related activation in parietal cortex suggests that neurobiological models of episodic memory should consider how parietal-mediated attentional mechanisms regulate encoding.

Frontal and parietal cortical interactions with distributed visual representations during selective attention and action selection.

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Nelissen, Natalie; Stokes, Mark; Nobre, Anna C; Rushworth, Matthew F S

2013-10-16

Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity.

Frontal and Parietal Cortical Interactions with Distributed Visual Representations during Selective Attention and Action Selection

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Stokes, Mark; Nobre, Anna C.; Rushworth, Matthew F. S.

2013-01-01

Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity. PMID:24133250

Primary cultures of glomerular parietal epithelial cells or podocytes with proven origin.

NARCIS (Netherlands)

Kabgani, N.; Grigoleit, T.; Schulte, K.; Sechi, A.; Sauer-Lehnen, S.; Tag, C.; Boor, P.; Kuppe, C.; Warsow, G.; Schordan, S.; Mostertz, J.; Chilukoti, R.K.; Homuth, G.; Endlich, N.; Tacke, F.; Weiskirchen, R.; Fuellen, G.; Endlich, K.; Floege, J.; Smeets, B.; Moeller, M.J.

2012-01-01

Parietal epithelial cells (PECs) are crucially involved in the pathogenesis of rapidly progressive glomerulonephritis (RPGN) as well as in focal and segmental glomerulosclerosis (FSGS). In this study, transgenic mouse lines were used to isolate pure, genetically tagged primary cultures of PECs or

Individual structural differences in left inferior parietal area are associated with schoolchildrens’ arithmetic scores

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Yongxin eLi

2013-12-01

Full Text Available Arithmetic skill is of critical importance for academic achievement, professional success and everyday life, and childhood is the key period to acquire this skill. Neuroimaging studies have identified that left parietal regions are a key neural substrate for representing arithmetic skill. Although the relationship between functional brain activity in left parietal regions and arithmetic skill has been studied in detail, it remains unclear about the relationship between arithmetic achievement and structural properties in left inferior parietal area in schoolchildren. The current study employed a combination of voxel-based morphometry (VBM for high-resolution T1-weighted images and fiber tracking on diffusion tensor imaging (DTI to examine the relationship between structural properties in the inferior parietal area and arithmetic achievement in 10-year-old schoolchildren. VBM of the T1-weighted images revealed that individual differences in arithmetic scores were significantly and positively correlated with the grey matter (GM volume in the left intraparietal sulcus (IPS. Fiber tracking analysis revealed that the forceps major, left superior longitudinal fasciculus (SLF, bilateral inferior longitudinal fasciculus (ILF and inferior fronto-occipital fasciculus (IFOF were the primary pathways connecting the left IPS with other brain areas. Furthermore, the regression analysis of the probabilistic pathways revealed a significant and positive correlation between the fractional anisotropy (FA values in the left SLF, ILF and bilateral IFOF and arithmetic scores. The brain structure-behavior correlation analyses indicated that the GM volumes in the left IPS and the FA values in the tract pathways connecting left IPS were both related to children’s arithmetic achievement. The present findings provide evidence that individual structural differences in the left IPS are associated with arithmetic scores in schoolchildren.

An atretic parietal cephalocele associated with multiple intracranial and eye anomalies

International Nuclear Information System (INIS)

Saatci, I.; Yelgec, S.; Aydin, K.; Akalan, N.

1998-01-01

We present the cranial MRI findings in a 4-month-old girl with an atretic parietal cephalocele associated with multiple cerebral and ocular anomalies including lobar holoprosencephaly, a Dandy-Walker malformation, agenesis of the corpus callosum, grey-matter heterotopia, extra-axial cysts in various locations, bilateral microphthalmia and a retroocular cyst. (orig.)

Lateralization of Egocentric and Allocentric Spatial Processing after Parietal Brain Lesions

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Iachini, Tina; Ruggiero, Gennaro; Conson, Massimiliano; Trojano, Luigi

2009-01-01

The purpose of this paper was to verify whether left and right parietal brain lesions may selectively impair egocentric and allocentric processing of spatial information in near/far spaces. Two Right-Brain-Damaged (RBD), 2 Left-Brain-Damaged (LBD) patients (not affected by neglect or language disturbances) and eight normal controls were submitted…

Central and peripheral components of writing critically depend on a defined area of the dominant superior parietal gyrus.

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Magrassi, Lorenzo; Bongetta, Daniele; Bianchini, Simonetta; Berardesca, Marta; Arienta, Cesare

2010-07-30

Classical neuropsychological models of writing separate central (linguistic) processes common to oral spelling, writing and typing from peripheral (motor) processes that are modality specific. Damage to the left superior parietal gyrus, an area of the cortex involved in peripheral processes specific to handwriting, should generate distorted graphemes but not misspelled words, while damage to other areas of the cortex like the frontal lobe should produce alterations in written and oral spelling without distorted graphemes. We describe the clinical and neuropsychological features of a patient with combined agraphia for handwriting and typewriting bearing a small glioblastoma in the left parietal lobe. His agraphia resolved after antiedema therapy and we tested by bipolar cortical stimulation his handwriting abilities during an awake neurosurgical procedure. We found that we could reversibly re-induce the same defects of writing by stimulating during surgery a limited area of the superior parietal gyrus in the same patient and in an independent patient that was never agraphic before the operation. In those patients stimulation caused spelling errors, poorly formed letters and in some cases a complete cessation of writing with minimal or no effects on oral spelling. Our results suggest that stimulating a specific area in the superior parietal gyrus we can generate different patterns of agraphia. Moreover, our findings also suggest that some of the central processes specific for typing and handwriting converge with motor processes at least in the limited portion of the superior parietal gyrus we mapped in our patients. Copyright 2010 Elsevier B.V. All rights reserved.

Syndecan-1 in the mouse parietal peritoneum microcirculation in inflammation.

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Paulina M Kowalewska

Full Text Available BACKGROUND: The heparan sulfate proteoglycan syndecan-1 (CD138 was shown to regulate inflammatory responses by binding chemokines and cytokines and interacting with adhesion molecules, thereby modulating leukocyte trafficking to tissues. The objectives of this study were to examine the expression of syndecan-1 and its role in leukocyte recruitment and chemokine presentation in the microcirculation underlying the parietal peritoneum. METHODS: Wild-type BALB/c and syndecan-1 null mice were stimulated with an intraperitoneal injection of Staphylococcus aureus LTA, Escherichia coli LPS or TNFα and the microcirculation of the parietal peritoneum was examined by intravital microscopy after 4 hours. Fluorescence confocal microscopy was used to examine syndecan-1 expression in the peritoneal microcirculation using fluorescent antibodies. Blocking antibodies to adhesion molecules were used to examine the role of these molecules in leukocyte-endothelial cell interactions in response to LTA. To determine whether syndecan-1 co-localizes with chemokines in vivo, fluorescent antibodies to syndecan-1 were co-injected intravenously with anti-MIP-2 (CXCL2, anti-KC (CXCL1 or anti-MCP-1 (CCL2. RESULTS AND CONCLUSION: Syndecan-1 was localized to the subendothelial region of peritoneal venules and the mesothelial layer. Leukocyte rolling was significantly decreased with LPS treatment while LTA and TNFα significantly increased leukocyte adhesion compared with saline control. Leukocyte-endothelial cell interactions were not different in syndecan-1 null mice. Antibody blockade of β2 integrin (CD18, ICAM-1 (CD54 and VCAM-1 (CD106 did not decrease leukocyte adhesion in response to LTA challenge while blockade of P-selectin (CD62P abrogated leukocyte rolling. Lastly, MIP-2 expression in the peritoneal venules was not dependent on syndecan-1 in vivo. Our data suggest that syndecan-1 is expressed in the parietal peritoneum microvasculature but does not regulate leukocyte

Bilateral fronto-parietal integrity in young chronic cigarette smokers: a diffusion tensor imaging study.

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Yanhui Liao

Full Text Available Cigarette smoking continues to be the leading cause of preventable morbidity and mortality in China and other countries. Previous studies have demonstrated gray matter loss in chronic smokers. However, only a few studies assessed the changes of white matter integrity in this group. Based on those previous reports of alterations in white matter integrity in smokers, the aim of this study was to examine the alteration of white matter integrity in a large, well-matched sample of chronic smokers and non-smokers.Using in vivo diffusion tensor imaging (DTI to measure the differences of whole-brain white matter integrity between 44 chronic smoking subjects (mean age, 28.0±5.6 years and 44 healthy age- and sex-matched comparison non-smoking volunteers (mean age, 26.3±5.8 years. DTI was performed on a 3-Tesla Siemens scanner (Allegra; Siemens Medical System. The data revealed that smokers had higher fractional anisotropy (FA than healthy non-smokers in almost symmetrically bilateral fronto-parietal tracts consisting of a major white matter pathway, the superior longitudinal fasciculus (SLF.We found the almost symmetrically bilateral fronto-parietal whiter matter changes in a relatively large sample of chronic smokers. These findings support the hypothesis that chronic cigarette smoking involves alterations of bilateral fronto-parietal connectivity.

Noninvasive brain stimulation of the parietal lobe for improving neurologic, neuropsychologic, and neuropsychiatric deficits.

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Bolognini, Nadia; Miniussi, Carlo

2018-01-01

Transcranial magnetic stimulation (TMS) and transcranial electric stimulation (tES) are noninvasive brain stimulation (NIBS) tools that are now widely used in neuroscientific research in humans. The fact that both TMS and tES are able to modulate brain plasticity and, in turn, affect behavior is opening up new horizons in the treatment of brain circuit and plasticity disorders. In the present chapter, we will first provide the reader with a brief background on the basic principles of NIBS, describing the electromagnetic and physical foundations of TMS and tES, as well as the current knowledge of the neurophysiologic basis of their effects on brain activity and plasticity. In the main part, we will outline studies aimed at improving persistent symptoms and deficits in patients suffering from neurologic and neuropsychiatric disorders featured by dysfunction of the parietal lobe. The emerging view is that NIBS of parietal areas holds the promise to overcome various sensory, motor, and cognitive disorders that are often refractory to standard medical or behavioral therapies. The chapter closes with an outlook on further developments in this realm, discussing novel therapeutic approaches that could lead to more effective rehabilitation procedures, better suited for the specific parietal lobe dysfunction. Copyright © 2018 Elsevier B.V. All rights reserved.

Thalamic and parietal brain morphology predicts auditory category learning.

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Scharinger, Mathias; Henry, Molly J; Erb, Julia; Meyer, Lars; Obleser, Jonas

2014-01-01

Auditory categorization is a vital skill involving the attribution of meaning to acoustic events, engaging domain-specific (i.e., auditory) as well as domain-general (e.g., executive) brain networks. A listener's ability to categorize novel acoustic stimuli should therefore depend on both, with the domain-general network being particularly relevant for adaptively changing listening strategies and directing attention to relevant acoustic cues. Here we assessed adaptive listening behavior, using complex acoustic stimuli with an initially salient (but later degraded) spectral cue and a secondary, duration cue that remained nondegraded. We employed voxel-based morphometry (VBM) to identify cortical and subcortical brain structures whose individual neuroanatomy predicted task performance and the ability to optimally switch to making use of temporal cues after spectral degradation. Behavioral listening strategies were assessed by logistic regression and revealed mainly strategy switches in the expected direction, with considerable individual differences. Gray-matter probability in the left inferior parietal lobule (BA 40) and left precentral gyrus was predictive of "optimal" strategy switch, while gray-matter probability in thalamic areas, comprising the medial geniculate body, co-varied with overall performance. Taken together, our findings suggest that successful auditory categorization relies on domain-specific neural circuits in the ascending auditory pathway, while adaptive listening behavior depends more on brain structure in parietal cortex, enabling the (re)direction of attention to salient stimulus properties. © 2013 Published by Elsevier Ltd.

Recency Effects in the Inferior Parietal Lobe during Verbal Recognition Memory

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Bradley Russell Buchsbaum

2011-07-01

Full Text Available The most recently encountered information is often most easily remembered in psychological tests of memory. Recent investigations of the neural basis of such recency effects have shown that activation in the lateral inferior parietal cortex (LIPC tracks the recency of a probe item when subjects make recognition memory judgments. A key question regarding recency effects in the LIPC is whether they fundamentally reflect the storage (and strength of information in memory, or whether such effects are a consequence of task difficulty or an upswing in resting state network activity. Using functional magnetic resonance imaging (fMRI we show that recency effects in the LIPC are independent of the difficulty of recognition memory decisions, that they are not a by-product of an increase in resting state network activity, and that they appear to dissociate from regions known to be involved in verbal working memory maintenance. We conclude with a discussion of two alternative explanations – the memory strength and expectancy hypotheses, respectively -- of the parietal lobe recency effect.

Parietal pleural invasion/adhesion of subpleural lung cancer: Quantitative 4-dimensional CT analysis using dynamic-ventilatory scanning

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Sakuma, Kotaro, E-mail: ksakuma@ohara-hp.or.jp [Department of Radiology, Ohara General Hospital, 6-11 Omachi, Fukushima City, Fukushima 960-8611 (Japan); Department of Radiology and Nuclear Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima City, Fukushima 960-1295 (Japan); Yamashiro, Tsuneo, E-mail: clatsune@yahoo.co.jp [Department of Radiology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215 (Japan); Moriya, Hiroshi, E-mail: hrshmoriya@gmail.com [Department of Radiology, Ohara General Hospital, 6-11 Omachi, Fukushima City, Fukushima 960-8611 (Japan); Murayama, Sadayuki, E-mail: sadayuki@med.u-ryukyu.ac.jp [Department of Radiology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215 (Japan); Ito, Hiroshi, E-mail: h-ito@fmu.ac.jp [Department of Radiology and Nuclear Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima City, Fukushima 960-1295 (Japan)

2017-02-15

Highlights: • 4DCT can be used for assessment of pleural invasion/adhesion by lung cancer. • Quantitative 4DCT indices of lung cancer and adjacent structures are described. • An automatic analysis of pleural invasion/adhesion would be developed in the future. - Abstract: Purpose: Using 4-dimensional dynamic-ventilatory scanning by a 320-row computed tomography (CT) scanner, we performed a quantitative assessment of parietal pleural invasion and adhesion by peripheral (subpleural) lung cancers. Methods: Sixteen patients with subpleural lung cancer underwent dynamic-ventilation CT during free breathing. Neither parietal pleural invasion nor adhesion was subsequently confirmed by surgery in 10 patients, whereas the other 6 patients were judged to have parietal pleural invasion or adhesion. Using research software, we tracked the movements of the cancer and of an adjacent structure such as the rib or aorta, and converted the data to 3-dimensional loci. The following quantitative indices were compared by the Mann-Whitney test: cross-correlation coefficient between time curves for the distances moved from the inspiratory frame by the cancer and the adjacent structure, the ratio of the total movement distances (cancer/adjacent structure), and the cosine similarities between the inspiratory and expiratory vectors (from the cancer to the adjacent structure) and between vectors of the cancer and of the adjacent structure (from inspiratory to expiratory frames). Results: Generally, the movements of the loci of the lung cancer and the adjacent structure were similar in patients with parietal pleural invasion/adhesion, while they were independent in patients without. There were significant differences in all the parameters between the two patient groups (cross-correlation coefficient and the movement distance ratio, P < 0.01; cosine similarities, P < 0.05). Conclusion: These observations suggest that quantitative indices by dynamic-ventilation CT can be utilized as a

Gyri of the human parietal lobe: Volumes, spatial extents, automatic labelling, and probabilistic atlases.

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Heather M Wild

Full Text Available Accurately describing the anatomy of individual brains enables interlaboratory communication of functional and developmental studies and is crucial for possible surgical interventions. The human parietal lobe participates in multimodal sensory integration including language processing and also contains the primary somatosensory area. We describe detailed protocols to subdivide the parietal lobe, analyze morphological and volumetric characteristics, and create probabilistic atlases in MNI152 stereotaxic space. The parietal lobe was manually delineated on 3D T1 MR images of 30 healthy subjects and divided into four regions: supramarginal gyrus (SMG, angular gyrus (AG, superior parietal lobe (supPL and postcentral gyrus (postCG. There was the expected correlation of male gender with larger brain and intracranial volume. We examined a wide range of anatomical features of the gyri and the sulci separating them. At least a rudimentary primary intermediate sulcus of Jensen (PISJ separating SMG and AG was identified in nearly all (59/60 hemispheres. Presence of additional gyri in SMG and AG was related to sulcal features and volumetric characteristics. The parietal lobe was slightly (2% larger on the left, driven by leftward asymmetries of the postCG and SMG. Intersubject variability was highest for SMG and AG, and lowest for postCG. Overall the morphological characteristics tended to be symmetrical, and volumes also tended to covary between hemispheres. This may reflect developmental as well as maturation factors. To assess the accuracy with which the labels can be used to segment newly acquired (unlabelled T1-weighted brain images, we applied multi-atlas label propagation software (MAPER in a leave-one-out experiment and compared the resulting automatic labels with the manually prepared ones. The results showed strong agreement (mean Jaccard index 0.69, corresponding to a mean Dice index of 0.82, average mean volume error of 0.6%. Stereotaxic

Multimodal FMRI resting-state functional connectivity in granulin mutations: the case of fronto-parietal dementia.

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Enrico Premi

Full Text Available BACKGROUND: Monogenic dementias represent a great opportunity to trace disease progression from preclinical to symptomatic stages. Frontotemporal Dementia related to Granulin (GRN mutations presents a specific framework of brain damage, involving fronto-temporal regions and long inter-hemispheric white matter bundles. Multimodal resting-state functional MRI (rs-fMRI is a promising tool to carefully describe disease signature from the earliest disease phase. OBJECTIVE: To define local connectivity alterations in GRN related pathology moving from the presymptomatic (asymptomatic GRN mutation carriers to the clinical phase of the disease (GRN- related Frontotemporal Dementia. METHODS: Thirty-one GRN Thr272fs mutation carriers (14 patients with Frontotemporal Dementia and 17 asymptomatic carriers and 38 healthy controls were recruited. Local connectivity measures (Regional Homogeneity (ReHo, Fractional Amplitude of Low Frequency Fluctuation (fALFF and Degree Centrality (DC were computed, considering age and gender as nuisance variables as well as the influence of voxel-level gray matter atrophy. RESULTS: Asymptomatic GRN carriers had selective reduced ReHo in the left parietal region and increased ReHo in frontal regions compared to healthy controls. Considering Frontotemporal Dementia patients, all measures (ReHo, fALFF and DC were reduced in inferior parietal, frontal lobes and posterior cingulate cortex. Considering GRN mutation carriers, an inverse correlation with age in the posterior cingulate cortex, inferior parietal lobule and orbitofrontal cortex was found. CONCLUSIONS: GRN pathology is characterized by functional brain network alterations even decades before the clinical onset; they involve the parietal region primarily and then spread to the anterior regions of the brain, supporting the concept of molecular nexopathies.

Posterior Parietal Cortex and Episodic Encoding: Insights from fMRI Subsequent Memory Effects and Dual Attention Theory

Science.gov (United States)

Uncapher, Melina; Wagner, Anthony D.

2010-01-01

The formation of episodic memories –– memories for life events –– is affected by attention during event processing. A leading neurobiological model of attention posits two separate yet interacting systems that depend on distinct regions in lateral posterior parietal cortex (PPC). From this dual-attention perspective, dorsal PPC is thought to support the goal-directed allocation of attention, whereas ventral PPC is thought to support reflexive orienting to information that automatically captures attention. To advance understanding of how parietal mechanisms may impact event encoding, we review functional MRI studies that document the relationship between lateral PPC activation during encoding and subsequent memory performance (e.g., later remembering or forgetting). This review reveals that (a) encoding-related activity is frequently observed in human lateral PPC, (b) increased activation in dorsal PPC is associated with later memory success, and (c) increased activation in ventral PPC predominantly correlates with later memory failure. From a dual-attention perspective, these findings suggest that allocating goal-directed attention during event processing increases the probability that the event will be remembered later, whereas the capture of reflexive attention during event processing may have negative consequences for event encoding. The prevalence of encoding-related activation in parietal cortex suggests that neurobiological models of episodic memory should consider how parietal-mediated attentional mechanisms regulate encoding. PMID:19028591

Glomerular parietal epithelial cells in kidney physiology, pathology, and repair

OpenAIRE

Shankland, Stuart J.; Anders, Hans-Joachim; Romagnani, Paola

2013-01-01

Purpose of review We have summarized recently published glomerular parietal epithelial cell (PEC) research, focusing on their roles in glomerular development and physiology, and in certain glomerular diseases. The rationale is that PECs have been largely ignored until the recent availability of cell lineage tracing studies, human and murine PEC culture systems, and potential therapeutic interventions of PECs. Recent findings Several new paradigms involving PECs have emerged demonstrating thei...

Gas1 expression in parietal cells of Bowman's capsule in experimental diabetic nephropathy.

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Luna-Antonio, Brenda I; Rodriguez-Muñoz, Rafael; Namorado-Tonix, Carmen; Vergara, Paula; Segovia, Jose; Reyes, Jose L

2017-07-01

Gas1 (Growth Arrest-Specific 1) is a pleiotropic protein with novel functions including anti-proliferative and proapoptotic activities. In the kidney, the expression of Gas1 has been described in mesangial cells. In this study, we described that renal parietal cells of Bowman's capsule (BC) and the distal nephron cells also express Gas1. The role of Gas1 in the kidney is not yet known. There is a subpopulation of progenitor cells in Bowman's capsule with self-renewal properties which can eventually differentiate into podocytes as a possible mechanism of regeneration in the early stages of diabetic nephropathy. We analyzed the expression of Gas1 in the parietal cells of Bowman's capsule in murine experimental diabetes. We found that diabetes reduced the expression of Gas1 and increased the expression of progenitor markers like NCAM, CD24, and SIX1/2, and mesenchymal markers like PAX2 in the Bowman's capsule. We also analyzed the expression of WT1 (a podocyte-specific marker) on BC and observed an increase in the number of WT1 positive cells in diabetes. In contrast, nephrin, another podocyte-specific protein, decreases its expression in the first week of diabetes in the glomerular tuft, which is gradually restored during the second and third weeks of diabetes. These results suggest that in diabetes the decrease of Gas1 promotes the activation of parietal progenitor cells of Bowman's capsule that might differentiate into podocytes and compensate their loss observed in this pathology.

Frontal and parietal theta burst TMS impairs working memory for visual-spatial conjunctions.

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Morgan, Helen M; Jackson, Margaret C; van Koningsbruggen, Martijn G; Shapiro, Kimron L; Linden, David E J

2013-03-01

In tasks that selectively probe visual or spatial working memory (WM) frontal and posterior cortical areas show a segregation, with dorsal areas preferentially involved in spatial (e.g. location) WM and ventral areas in visual (e.g. object identity) WM. In a previous fMRI study [1], we showed that right parietal cortex (PC) was more active during WM for orientation, whereas left inferior frontal gyrus (IFG) was more active during colour WM. During WM for colour-orientation conjunctions, activity in these areas was intermediate to the level of activity for the single task preferred and non-preferred information. To examine whether these specialised areas play a critical role in coordinating visual and spatial WM to perform a conjunction task, we used theta burst transcranial magnetic stimulation (TMS) to induce a functional deficit. Compared to sham stimulation, TMS to right PC or left IFG selectively impaired WM for conjunctions but not single features. This is consistent with findings from visual search paradigms, in which frontal and parietal TMS selectively affects search for conjunctions compared to single features, and with combined TMS and functional imaging work suggesting that parietal and frontal regions are functionally coupled in tasks requiring integration of visual and spatial information. Our results thus elucidate mechanisms by which the brain coordinates spatially segregated processing streams and have implications beyond the field of working memory. Copyright © 2013 Elsevier Inc. All rights reserved.

Activity in the fronto-parietal network indicates numerical inductive reasoning beyond calculation: An fMRI study combined with a cognitive model.

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Liang, Peipeng; Jia, Xiuqin; Taatgen, Niels A; Borst, Jelmer P; Li, Kuncheng

2016-05-19

Numerical inductive reasoning refers to the process of identifying and extrapolating the rule involved in numeric materials. It is associated with calculation, and shares the common activation of the fronto-parietal regions with calculation, which suggests that numerical inductive reasoning may correspond to a general calculation process. However, compared with calculation, rule identification is critical and unique to reasoning. Previous studies have established the central role of the fronto-parietal network for relational integration during rule identification in numerical inductive reasoning. The current question of interest is whether numerical inductive reasoning exclusively corresponds to calculation or operates beyond calculation, and whether it is possible to distinguish between them based on the activity pattern in the fronto-parietal network. To directly address this issue, three types of problems were created: numerical inductive reasoning, calculation, and perceptual judgment. Our results showed that the fronto-parietal network was more active in numerical inductive reasoning which requires more exchanges between intermediate representations and long-term declarative knowledge during rule identification. These results survived even after controlling for the covariates of response time and error rate. A computational cognitive model was developed using the cognitive architecture ACT-R to account for the behavioral results and brain activity in the fronto-parietal network.

A parietal biomarker for ADHD liability:As predicted by The Distributed Effects Perspective Model of ADHD

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T. Sigi eHale

2015-05-01

Full Text Available Background: We previously hypothesized that poor task-directed sensory information processing should be indexed by increased weighting of right hemisphere (RH biased attention and visuo-perceptual brain functions during task operations, and have demonstrated this phenotype in ADHD across multiple studies, using multiple methodologies. However, in our recent Distributed Effects Model of ADHD, we surmised that this phenotype is not ADHD specific, but rather more broadly reflective of any circumstance that disrupts the induction and maintenance of an emergent task-directed neural architecture. Under this view, increased weighting of RH biased attention and visuo-perceptual brain functions is expected to generally index neurocognitive sets that are not optimized for task-directed thought and action, and when durable expressed, liability for ADHD. Method: The current study tested this view by examining whether previously identified rightward parietal EEG asymmetry in ADHD was associated with common ADHD characteristics and comorbidities (i.e., ADHD risk factors. Results: Barring one exception (non-right handedness, we found that it was. Rightward parietal asymmetry was associated with carrying the DRD4-7R risk allele, being male, having mood disorder, and having anxiety disorder. However, differences in the specific expression of rightward parietal asymmetry were observed, which are discussed in relation to possible unique mechanisms underlying ADHD liability in different ADHD RFs. Conclusion: Rightward parietal asymmetry appears to be a durable feature of ADHD liability, as predicted by the Distributed Effects Perspective Model of ADHD. Moreover, variability in the expression of this phenotype may shed light on different sources of ADHD liability.

Distinct parietal sites mediate the influences of mood, arousal, and their interaction on human recognition memory.

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Greene, Ciara M; Flannery, Oliver; Soto, David

2014-12-01

The two dimensions of emotion, mood valence and arousal, have independent effects on recognition memory. At present, however, it is not clear how those effects are reflected in the human brain. Previous research in this area has generally dealt with memory for emotionally valenced or arousing stimuli, but the manner in which interacting mood and arousal states modulate responses in memory substrates remains poorly understood. We investigated memory for emotionally neutral items while independently manipulating mood valence and arousal state by means of music exposure. Four emotional conditions were created: positive mood/high arousal, positive mood/low arousal, negative mood/high arousal, and negative mood/low arousal. We observed distinct effects of mood valence and arousal in parietal substrates of recognition memory. Positive mood increased activity in ventral posterior parietal cortex (PPC) and orbitofrontal cortex, whereas arousal condition modulated activity in dorsal PPC and the posterior cingulate. An interaction between valence and arousal was observed in left ventral PPC, notably in a parietal area distinct from the those identified for the main effects, with a stronger effect of mood on recognition memory responses here under conditions of relative high versus low arousal. We interpreted the PPC activations in terms of the attention-to-memory hypothesis: Increased arousal may lead to increased top-down control of memory, and hence dorsal PPC activation, whereas positive mood valence may result in increased activity in ventral PPC regions associated with bottom-up attention to memory. These findings indicate that distinct parietal sites mediate the influences of mood, arousal, and their interplay during recognition memory.

Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional prosody perception.

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Marjolijn Hoekert

Full Text Available In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms. Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction, revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become

Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional prosody perception.

Science.gov (United States)

Hoekert, Marjolijn; Bais, Leonie; Kahn, René S; Aleman, André

2008-05-21

In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody) conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS) to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms). Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction), revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become more apparent half

Autoimmune gastritis and parietal cell reactivity in two children with abnormal intestinal permeability

NARCIS (Netherlands)

Greenwood, Deanne L. V.; Crock, Patricia; Braye, Stephen; Davidson, Patricia; Sentry, John W.

Autoimmune gastritis is characterised by lymphocytic infiltration of the gastric submucosa, with loss of parietal and chief cells and achlorhydria. Often, gastritis is expressed clinically as cobalamin deficiency with megaloblastic anaemia, which is generally described as a disease of the elderly.

Parietal scalp is another affected area in female pattern hair loss: an analysis of hair density and hair diameter

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Rojhirunsakool S

2017-12-01

Full Text Available Salinee Rojhirunsakool, Poonkiat Suchonwanit Department of Medicine, Division of Dermatology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Purpose: Female pattern hair loss (FPHL is a common hair disease. However, studies of the quantitative measurement of FPHL are still limited. The aim of this study was to investigate the characteristics of hair density and hair diameter in normal women and FPHL patients, and further correlate the quantitative measurement with the clinical presentation of FPHL.Patients and methods: An evaluation of 471 FPHL patients and 236 normal women was carried out according to the Ludwig classification, and analysis was performed by using a computerized handheld USB camera with computer-assisted software. Various areas of the scalp, including frontal, parietal, midscalp, and occipital, were analyzed for hair density, non-vellus hair diameter, and percentage of miniaturized hair.Results: The hair density in normal women was the highest and the lowest in the midscalp and parietal areas, respectively. The FPHL group revealed the lowest hair density in the parietal area. Significant differences in hair density, non-vellus hair diameter, and percentage of miniaturized hair between the normal and FPHL groups were observed, especially in the midscalp and parietal areas.Conclusion: The parietal area is another important affected area in FPHL in addition to the midscalp area. This finding provides novel important information of FPHL and will be useful for hair transplant surgeons choosing the optimal donor sites for hair transplantation in women. Keywords: androgenetic alopecia, alopecia, phototrichogram, miniaturization

The Regenerative Potential of Parietal Epithelial Cells in Adult Mice

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Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H.; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J.

2014-01-01

Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman’s capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glo...

Distributed patterns of occipito-parietal functional connectivity predict the precision of visual working memory.

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Galeano Weber, Elena M; Hahn, Tim; Hilger, Kirsten; Fiebach, Christian J

2017-02-01

Limitations in visual working memory (WM) quality (i.e., WM precision) may depend on perceptual and attentional limitations during stimulus encoding, thereby affecting WM capacity. WM encoding relies on the interaction between sensory processing systems and fronto-parietal 'control' regions, and differences in the quality of this interaction are a plausible source of individual differences in WM capacity. Accordingly, we hypothesized that the coupling between perceptual and attentional systems affects the quality of WM encoding. We combined fMRI connectivity analysis with behavioral modeling by fitting a variable precision and fixed capacity model to the performance data obtained while participants performed a visual delayed continuous response WM task. We quantified functional connectivity during WM encoding between occipital and parietal brain regions activated during both perception and WM encoding, as determined using a conjunction of two independent experiments. The multivariate pattern of voxel-wise inter-areal functional connectivity significantly predicted WM performance, most specifically the mean of WM precision but not the individual number of items that could be stored in memory. In particular, higher occipito-parietal connectivity was associated with higher behavioral mean precision. These results are consistent with a network perspective of WM capacity, suggesting that the efficiency of information flow between perceptual and attentional neural systems is a critical determinant of limitations in WM quality. Copyright © 2016 Elsevier Inc. All rights reserved.

Endoplasmic reticulum stress responses differ in meninges and associated vasculature, striatum, and parietal cortex after a neurotoxic amphetamine exposure.

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Thomas, Monzy; George, Nysia I; Saini, Upasana T; Patterson, Tucker A; Hanig, Joseph P; Bowyer, John F

2010-08-01

Amphetamine (AMPH) is used to treat attention deficit and hyperactivity disorders, but it can produce neurotoxicity and adverse vascular effects at high doses. The endoplasmic reticulum (ER) stress response (ERSR) entails the unfolded protein response, which helps to avoid or minimize ER dysfunction. ERSR is often associated with toxicities resulting from the accumulation of unfolded or misfolded proteins and has been associated with methamphetamine toxicity in the striatum. The present study evaluates the effect of AMPH on several ERSR elements in meninges and associated vasculature (MAV), parietal cortex, and striatum. Adult, male Sprague-Dawley rats were exposed to saline, environmentally induced hyperthermia (EIH) or four consecutive doses of AMPH that produce hyperthermia. Expression changes (mRNA and protein levels) of key ERSR-related genes in MAV, striatum, and parietal cortex at 3 h or 1 day postdosing were monitored. AMPH increased the expression of some ERSR-related genes in all tissues. Atf4 (activating transcription factor 4, an indicator of Perk pathway activation), Hspa5/Grp78 (Glucose regulated protein 78, master regulator of ERSR), Pdia4 (protein disulfide isomerase, protein-folding enzyme), and Nfkb1 (nuclear factor of kappa b, ERSR sensor) mRNA increased significantly in MAV and parietal cortex 3 h after AMPH. In striatum, Atf4 and Hspa5/Grp78 mRNA significantly increased 3 h after AMPH, but Pdia4 and Nfkb11 did not. Thus, AMPH caused a robust activation of the Perk pathway in all tissues, but significant Ire1 pathway activation occurred only after AMPH treatment in the parietal cortex and striatum. Ddit3/Chop, a downstream effector of the ERSR pathway related to the neurotoxicity, was only increased in striatum and parietal cortex. Conversely, Pdia4, an enzyme protective in the ERSR, was only increased in MAV. The overall ERSR manifestation varied significantly between MAV, striatum, and parietal cortex after a neurotoxic exposure to AMPH.

Parietal and occipital encephalocele in same child: A rarest variety of double encephalocele.

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Sharma, Somnath; Ojha, Bal Krishan; Chandra, Anil; Singh, Sunil Kumar; Srivastava, Chhitij

2016-05-01

An encephalocele is a protrusion of the brain and/or meninges through a defect in the skull. Based on the location of the skull defect they are classified into sincipital, basal, occipital or parietal varieties. Occurrence of more than one Encephalocele in a patient is very rare and very few cases of double encephalocele are reported. We report an interesting case where a parietal and an occipital encephalocele were present together. The patient was a 2 months boy who was brought to us with complaints of two swelling on the scalp since birth. Neuroimaging studies confirmed it to be a case of double encephalocele. The rarity of the findings prompted us to report this case. The presentation and management of the case along with and review of the relevant literature is presented. Copyright © 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

EEG source reconstruction reveals frontal-parietal dynamics of spatial conflict processing.

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Cohen, Michael X; Ridderinkhof, K Richard

2013-01-01

Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus) conflict modulation in stimulus-contralateral parietal gamma (30-50 Hz), followed by a later alpha-band (8-12 Hz) conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4-8 Hz), alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials) had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions.

EEG source reconstruction reveals frontal-parietal dynamics of spatial conflict processing.

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Michael X Cohen

Full Text Available Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus conflict modulation in stimulus-contralateral parietal gamma (30-50 Hz, followed by a later alpha-band (8-12 Hz conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4-8 Hz, alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions.

EEG Source Reconstruction Reveals Frontal-Parietal Dynamics of Spatial Conflict Processing

Science.gov (United States)

Cohen, Michael X; Ridderinkhof, K. Richard

2013-01-01

Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus) conflict modulation in stimulus-contralateral parietal gamma (30–50 Hz), followed by a later alpha-band (8–12 Hz) conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4–8 Hz), alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials) had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions. PMID:23451201

Parietal disruption alters audiovisual binding in the sound-induced flash illusion.

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Kamke, Marc R; Vieth, Harrison E; Cottrell, David; Mattingley, Jason B

2012-09-01

Selective attention and multisensory integration are fundamental to perception, but little is known about whether, or under what circumstances, these processes interact to shape conscious awareness. Here, we used transcranial magnetic stimulation (TMS) to investigate the causal role of attention-related brain networks in multisensory integration between visual and auditory stimuli in the sound-induced flash illusion. The flash illusion is a widely studied multisensory phenomenon in which a single flash of light is falsely perceived as multiple flashes in the presence of irrelevant sounds. We investigated the hypothesis that extrastriate regions involved in selective attention, specifically within the right parietal cortex, exert an influence on the multisensory integrative processes that cause the flash illusion. We found that disruption of the right angular gyrus, but not of the adjacent supramarginal gyrus or of a sensory control site, enhanced participants' veridical perception of the multisensory events, thereby reducing their susceptibility to the illusion. Our findings suggest that the same parietal networks that normally act to enhance perception of attended events also play a role in the binding of auditory and visual stimuli in the sound-induced flash illusion. Copyright © 2012 Elsevier Inc. All rights reserved.

Acute parietal lobe infarction presenting as Gerstmann’s syndrome and cognitive decline mimicking senile dementia

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Chen TY

2013-07-01

Full Text Available Tien-Yu Chen,1 Chun-Yen Chen,1,3 Che-Hung Yen,2,3 Shin-Chang Kuo,1,3 Yi-Wei Yeh,1,3 Serena Chang,1 San-Yuan Huang1,31Department of Psychiatry, 2Department of Neurology, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, 3Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of ChinaAbstract: Gerstmann’s syndrome encompasses the tetrad of finger agnosia, agraphia, acalculia, and right-left confusion. An elderly man with a history of several cardiovascular diseases was initially brought to the psychiatric outpatient department by his family because of worsening of recent memory, executive function, and mixed anxious-depressive mood. Gerstmann’s syndrome without obvious motor function impairment and dementia-like features could be observed at first. Emergent brain computed tomography scan revealed new left-middle cerebral artery infarction over the left posterior parietal lobe. This case reminds us that acute cerebral infarction involving the parietal lobe may present as Gerstmann’s syndrome accompanied by cognitive decline mimicking dementia. As a result, emergent organic workups should be arranged, especially for elderly patients at high risk for cerebral vascular accident.Keywords: Gerstmann’s syndrome, dementia, parietal lobe infarction

Investigating the Functional Utility of the Left Parietal ERP Old/New Effect: Brain Activity Predicts within But Not between Participant Variance in Episodic Recollection

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Catherine A. MacLeod

2017-12-01

Full Text Available A success story within neuroimaging has been the discovery of distinct neural correlates of episodic retrieval, providing insight into the processes that support memory for past life events. Here we focus on one commonly reported neural correlate, the left parietal old/new effect, a positive going modulation seen in event-related potential (ERP data that is widely considered to index episodic recollection. Substantial evidence links changes in the size of the left parietal effect to changes in remembering, but the precise functional utility of the effect remains unclear. Here, using forced choice recognition of verbal stimuli, we present a novel population level test of the hypothesis that the magnitude of the left parietal effect correlates with memory performance. We recorded ERPs during old/new recognition, source accuracy and Remember/Know/Guess tasks in two large samples of healthy young adults, and successfully replicated existing within participant modulations of the magnitude of the left parietal effect with recollection. Critically, however, both datasets also show that across participants the magnitude of the left parietal effect does not correlate with behavioral measures of memory – including both subjective and objective estimates of recollection. We conclude that in these tasks, and across this healthy young adult population, the generators of the left parietal ERP effect do not index performance as expected. Taken together, these novel findings provide important constraints on the functional interpretation of the left parietal effect, suggesting that between group differences in the magnitude of old/new effects cannot always safely be used to infer differences in recollection.

Pneumothorax simulated by detachment of parietal pleura associated with pneumomediastinum

International Nuclear Information System (INIS)

Rozeik, C.; Kotterer, O.; Deininger, H.K.

1994-01-01

We report a case of blunt chest trauma, where findings on repeated conventional chest radiographs were compatible with pneumothorax developing after 2 days of mechanical high-pressure ventilation. CT showed that the appearance was due to a detachment of the parietal pleura along the lateral, mediastinal and diaphragmatic boundaries of the lungs, imitating a pneumothorax. The case report illustrates the key role of CT in the differential diagnosis of epipleural interstitial air collection versus pneumothorax. (orig./MG)

Pneumothorax simulated by detachment of parietal pleura associated with pneumomediastinum

Energy Technology Data Exchange (ETDEWEB)

Rozeik, C. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany); Kotterer, O. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany); Deininger, H.K. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany)

1994-10-01

We report a case of blunt chest trauma, where findings on repeated conventional chest radiographs were compatible with pneumothorax developing after 2 days of mechanical high-pressure ventilation. CT showed that the appearance was due to a detachment of the parietal pleura along the lateral, mediastinal and diaphragmatic boundaries of the lungs, imitating a pneumothorax. The case report illustrates the key role of CT in the differential diagnosis of epipleural interstitial air collection versus pneumothorax. (orig./MG)

Posterior parietal cortex mediates encoding and maintenance processes in change blindness.

Science.gov (United States)

Tseng, Philip; Hsu, Tzu-Yu; Muggleton, Neil G; Tzeng, Ovid J L; Hung, Daisy L; Juan, Chi-Hung

2010-03-01

It is commonly accepted that right posterior parietal cortex (PPC) plays an important role in updating spatial representations, directing visuospatial attention, and planning actions. However, recent studies suggest that right PPC may also be involved in processes that are more closely associated with our visual awareness as its activation level positively correlates with successful conscious change detection (Beck, D.M., Rees, G., Frith, C.D., & Lavie, N. (2001). Neural correlates of change detection and change blindness. Nature Neuroscience, 4, 645-650.). Furthermore, disruption of its activity increases the occurrences of change blindness, thus suggesting a causal role for right PPC in change detection (Beck, D.M., Muggleton, N., Walsh, V., & Lavie, N. (2006). Right parietal cortex plays a critical role in change blindness. Cerebral Cortex, 16, 712-717.). In the context of a 1-shot change detection paradigm, we applied transcranial magnetic stimulation (TMS) during different time intervals to elucidate the temporally precise involvement of PPC in change detection. While subjects attempted to detect changes between two image sets separated by a brief time interval, TMS was applied either during the presentation of picture 1 when subjects were encoding and maintaining information into visual short-term memory, or picture 2 when subjects were retrieving information relating to picture 1 and comparing it to picture 2. Our results show that change blindness occurred more often when TMS was applied during the viewing of picture 1, which implies that right PPC plays a crucial role in the processes of encoding and maintaining information in visual short-term memory. In addition, since our stimuli did not involve changes in spatial locations, our findings also support previous studies suggesting that PPC may be involved in the processes of encoding non-spatial visual information (Todd, J.J. & Marois, R. (2004). Capacity limit of visual short-term memory in human

Inhibition of partially purified K+/H+-ATPase from guinea-pig isolated and enriched parietal cells by substituted benzimidazoles.

Science.gov (United States)

Beil, W.; Sewing, K. F.

1984-01-01

The cellular and subcellular distributions of adenosinetriphosphatases (ATPases) were examined in guinea-pig gastric mucosal cells. All cell types displayed Mg2+-ATPase and bicarbonate (HCO3-)-stimulated ATPase activity. K+-ATPase was located only in fractions derived from parietal cells. Differential and density-gradient centrifugation of material prepared from parietal cells revealed that K+-ATPase activity was located in a tubulo-vesicular membrane fraction. Enzyme activity was ten fold greater in this fraction than in a crude parietal cell homogenate. The substituted benzimidazoles, omeprazole and picoprazole, inhibited K+-ATPase (IC50 1.8 +/- 0.5 mumol l-1 and 3.1 +/- 0.4 mumol l-1, respectively). Detailed kinetic analysis indicated that these compounds were non-competitive and reversible inhibitors of the enzyme. In contrast cimetidine and verapamil were without effect on the enzyme. The relevance of the inhibition of K+-ATPase to the antisecretory activity of the benzimidazoles, in experimental animals and man, is discussed. PMID:6146367

Low-frequency rTMS in the superior parietal cortex affects the working memory in horizontal axis during the spatial task performance.

Science.gov (United States)

Ribeiro, Jéssica Alves; Marinho, Francisco Victor Costa; Rocha, Kaline; Magalhães, Francisco; Baptista, Abrahão Fontes; Velasques, Bruna; Ribeiro, Pedro; Cagy, Mauricio; Bastos, Victor Hugo; Gupta, Daya; Teixeira, Silmar

2018-03-01

Spatial working memory has been extensively investigated with different tasks, treatments, and analysis tools. Several studies suggest that low frequency of the repetitive transcranial magnetic stimulation (rTMS) applied to the parietal cortex may influence spatial working memory (SWM). However, it is not yet known if after low-frequency rTMS applied to the superior parietal cortex, according to Pz electroencephalography (EEG) electrode, would change the orientation interpretation about the vertical and horizontal axes coordinates in an SWM task. The current study aims at filling this gap and obtains a better understanding of the low-frequency rTMS effect in SWM. In this crossover study, we select 20 healthy subjects in two conditions (control and 1-Hz rTMS). The subjects performed an SWM task with two random coordinates. Our results presented that low-frequency rTMS applied over the superior parietal cortex may influence the SWM to lead to a larger distance of axes interception point (p low-frequency rTMS over the superior parietal cortex (SPC) changes the SWM performance, and it has more predominance in horizontal axis.

Attentional Demands Predict Short-Term Memory Load Response in Posterior Parietal Cortex

Science.gov (United States)

Magen, Hagit; Emmanouil, Tatiana-Aloi; McMains, Stephanie A.; Kastner, Sabine; Treisman, Anne

2009-01-01

Limits to the capacity of visual short-term memory (VSTM) indicate a maximum storage of only 3 or 4 items. Recently, it has been suggested that activity in a specific part of the brain, the posterior parietal cortex (PPC), is correlated with behavioral estimates of VSTM capacity and might reflect a capacity-limited store. In three experiments that…

Distinct antigenic characteristics of murine parietal yolk sac laminin

DEFF Research Database (Denmark)

Wewer, U M; Tichy, D; Damjanov, A

1987-01-01

Two monoclonal antibodies (LAM-A and LAM-B) specific for laminin from normal and neoplastic parietal yolk sac (PYS) cells were produced in rats immunized with a mouse yolk sac carcinoma cell line. Both antibodies immunoprecipitated the 400,000- and 200,000-Da chains of laminin and reacted...... with purified PYS laminin in ELISA. LAM-A reacted with mouse and rat PYS laminin, whereas LAM-B reacted only with mouse PYS laminin. Formaldehyde- and methanol-fixed adult and fetal somatic tissues were immunohistochemically unreactive with either of the two antibodies. In acetone-fixed tissue sections, both...

Anatomical substrates of the alerting, orienting and executive control components of attention: focus on the posterior parietal lobe.

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Xuntao Yin

Full Text Available Both neuropsychological and functional neuroimaging studies have identified that the posterior parietal lobe (PPL is critical for the attention function. However, the unique role of distinct parietal cortical subregions and their underlying white matter (WM remains in question. In this study, we collected both magnetic resonance imaging and diffusion tensor imaging (DTI data in normal participants, and evaluated their attention performance using attention network test (ANT, which could isolate three different attention components: alerting, orienting and executive control. Cortical thickness, surface area and DTI parameters were extracted from predefined PPL subregions and correlated with behavioural performance. Tract-based spatial statistics (TBSS was used for the voxel-wise statistical analysis. Results indicated structure-behaviour relationships on multiple levels. First, a link between the cortical thickness and WM integrity of the right inferior parietal regions and orienting performance was observed. Specifically, probabilistic tractography demonstrated that the integrity of WM connectivity between the bilateral inferior parietal lobules mediated the orienting performance. Second, the scores of executive control were significantly associated with the WM diffusion metrics of the right supramarginal gyrus. Finally, TBSS analysis revealed that alerting performance was significant correlated with the fractional anisotropy of local WM connecting the right thalamus and supplementary motor area. We conclude that distinct areas and features within PPL are associated with different components of attention. These findings could yield a more complete understanding of the nature of the PPL contribution to visuospatial attention.

Parietal and premotor cortices: activation reflects imitation accuracy during observation, delayed imitation and concurrent imitation.

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Krüger, Britta; Bischoff, Matthias; Blecker, Carlo; Langhanns, Christine; Kindermann, Stefan; Sauerbier, Isabell; Reiser, Mathias; Stark, Rudolf; Munzert, Jörn; Pilgramm, Sebastian

2014-10-15

This study investigated whether activation within areas belonging to the action observation and imitation network reveals a linear relation to the subsequent accuracy of imitating a bimanual rhythmic movement measured via a motion capturing system. 20 participants were scanned with functional magnetic resonance imaging (fMRI) when asked to imitate observed bimanual movements either concurrently versus with a delay (2s) or simply to observe the movements without imitation. Results showed that action observation relates to activation within classic mirror-related areas. Activation patterns were more widespread when participants were asked to imitate the movement. During observation with concurrent imitation, activation in the left inferior parietal lobe (IPL) was associated negatively with imitation accuracy. During observation in the delayed imitation condition, higher subsequent imitation accuracy was coupled with higher activation in the right superior parietal lobe (SPL) and the left parietal operculum (POp). During the delayed imitation itself, a negative association between imitation accuracy and brain activation was revealed in the right ventral premotor cortex (vPMC). We conclude that the IPL is involved in online comparison and visuospatial attention processes during imitation, the SPL provides a kinesthetic blueprint during movement observation, the POp preserves body identity, and the vPMC recruits motor representations--especially when no concurrent visual guidance is possible. Copyright © 2014 Elsevier Inc. All rights reserved.

Inactivation of Parietal Reach Region Affects Reaching But Not Saccade Choices in Internally Guided Decisions.

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Christopoulos, Vassilios N; Bonaiuto, James; Kagan, Igor; Andersen, Richard A

2015-08-19

The posterior parietal cortex (PPC) has traditionally been considered important for awareness, spatial perception, and attention. However, recent findings provide evidence that the PPC also encodes information important for making decisions. These findings have initiated a running argument of whether the PPC is critically involved in decision making. To examine this issue, we reversibly inactivated the parietal reach region (PRR), the area of the PPC that is specialized for reaching movements, while two monkeys performed a memory-guided reaching or saccade task. The task included choices between two equally rewarded targets presented simultaneously in opposite visual fields. Free-choice trials were interleaved with instructed trials, in which a single cue presented in the peripheral visual field defined the reach and saccade target unequivocally. We found that PRR inactivation led to a strong reduction of contralesional choices, but only for reaches. On the other hand, saccade choices were not affected by PRR inactivation. Importantly, reaching and saccade movements to single instructed targets remained largely intact. These results cannot be explained as an effector-nonspecific deficit in spatial attention or awareness, since the temporary "lesion" had an impact only on reach choices. Hence, the PPR is a part of a network for reach decisions and not just reach planning. There has been an ongoing debate on whether the posterior parietal cortex (PPC) represents only spatial awareness, perception, and attention or whether it is also involved in decision making for actions. In this study we explore whether the parietal reach region (PRR), the region of the PPC that is specialized for reaches, is involved in the decision process. We inactivated the PRR while two monkeys performed reach and saccade choices between two targets presented simultaneously in both hemifields. We found that inactivation affected only the reach choices, while leaving saccade choices intact

Altered Parietal Activation during Non-symbolic Number Comparison in Children with Prenatal Alcohol Exposure

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Keri J. Woods

2018-01-01

Full Text Available Number processing is a cognitive domain particularly sensitive to prenatal alcohol exposure, which relies on intact parietal functioning. Alcohol-related alterations in brain activation have been found in the parietal lobe during symbolic number processing. However, the effects of prenatal alcohol exposure on the neural correlates of non-symbolic number comparison and the numerical distance effect have not been investigated. Using functional magnetic resonance imaging (fMRI, we examined differences in brain activation associated with prenatal alcohol exposure in five parietal regions involved in number processing during a non-symbolic number comparison task with varying degrees of difficulty. fMRI results are presented for 27 Cape Colored children (6 fetal alcohol syndome (FAS/partial FAS, 5 heavily exposed (HE non-sydromal, 16 controls; mean age ± SD = 11.7 ± 1.1 years. Fetal alcohol exposure was assessed by interviewing mothers using a timeline follow-back approach. Separate subject analyses were performed in each of five regions of interest, bilateral horizontal intraparietal sulci (IPS, bilateral posterior superior parietal lobules (PSPL, and left angular gyrus (left AG, using the general linear model with predictors for number comparison and difficulty level. Mean percent signal change for each predictor was extracted for each subject for each region to examine group differences and associations with continuous measures of alcohol exposure. Although groups did not differ in performance, controls activated the right PSPL more during non-symbolic number comparison than exposed children, but this was not significant after controlling for maternal smoking, and the right IPS more than children with fetal alcohol syndrome (FAS or partial FAS. More heavily exposed children recruited the left AG to a greater extent as task difficulty increased, possibly to compensate, in part, for impairments in function in the PSPL and IPS. Notably, in non

Matrix metalloproteinase-9 expression is enhanced in renal parietal epithelial cells of zucker diabetic Fatty rats and is induced by albumin in in vitro primary parietal cell culture.

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Yuanyuan Zhang

Full Text Available As a subfamily of matrix metalloproteinases (MMPs, gelatinases including MMP-2 and MMP-9 play an important role in remodeling and homeostasis of the extracellular matrix. However, conflicting results have been reported regarding their expression level and activity in the diabetic kidney. This study investigated whether and how MMP-9 expression and activity were changed in glomerular epithelial cells upon albumin overload. In situ zymography, immunostaining and Western blot for renal MMP gelatinolytic activity and MMP-9 protein expression were performed in Zucker lean and Zucker diabetic rats. Confocal microscopy revealed a focal increase in gelatinase activity and MMP-9 protein in the glomeruli of diabetic rats. Increased glomerular MMP-9 staining was mainly observed in hyperplastic parietal epithelial cells (PECs expressing claudin-1 in the diabetic kidneys. Interestingly, increased parietal MMP-9 was often accompanied by decreased staining for podocyte markers (nephrin and podocalyxin in the sclerotic area of affected glomeruli in diabetic rats. Additionally, urinary excretion of podocyte marker proteins was significantly increased in association with the levels of MMP-9 and albumin in the urine of diabetic animals. To evaluate the direct effect of albumin on expression and activity of MMP-9, primary cultured rat glomerular PECs were incubated with rat serum albumin (0.25 - 1 mg/ml for 24 - 48 hrs. MMP-9 mRNA levels were significantly increased following albumin treatment. Meanwhile, albumin administration resulted in a dose-dependent increase in MMP-9 protein and activity in culture supernatants of PECs. Moreover, albumin activated p44/42 mitogen-activated protein kinase (MAPK in PECs. Inhibition of p44/42 MAPK suppressed albumin-induced MMP-9 secretion from glomerular PECs. Taken together, we have demonstrated that an up-regulation of MMP-9 in activated parietal epithelium is associated with a loss of adjacent podocytes in progressive

Matrix Metalloproteinase-9 Expression Is Enhanced in Renal Parietal Epithelial Cells of Zucker Diabetic Fatty Rats and Is Induced by Albumin in In Vitro Primary Parietal Cell Culture

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Zhang, Yuanyuan; George, Jasmine; Li, Yun; Olufade, Rebecca; Zhao, Xueying

2015-01-01

As a subfamily of matrix metalloproteinases (MMPs), gelatinases including MMP-2 and MMP-9 play an important role in remodeling and homeostasis of the extracellular matrix. However, conflicting results have been reported regarding their expression level and activity in the diabetic kidney. This study investigated whether and how MMP-9 expression and activity were changed in glomerular epithelial cells upon albumin overload. In situ zymography, immunostaining and Western blot for renal MMP gelatinolytic activity and MMP-9 protein expression were performed in Zucker lean and Zucker diabetic rats. Confocal microscopy revealed a focal increase in gelatinase activity and MMP-9 protein in the glomeruli of diabetic rats. Increased glomerular MMP-9 staining was mainly observed in hyperplastic parietal epithelial cells (PECs) expressing claudin-1 in the diabetic kidneys. Interestingly, increased parietal MMP-9 was often accompanied by decreased staining for podocyte markers (nephrin and podocalyxin) in the sclerotic area of affected glomeruli in diabetic rats. Additionally, urinary excretion of podocyte marker proteins was significantly increased in association with the levels of MMP-9 and albumin in the urine of diabetic animals. To evaluate the direct effect of albumin on expression and activity of MMP-9, primary cultured rat glomerular PECs were incubated with rat serum albumin (0.25 - 1 mg/ml) for 24 - 48 hrs. MMP-9 mRNA levels were significantly increased following albumin treatment. Meanwhile, albumin administration resulted in a dose-dependent increase in MMP-9 protein and activity in culture supernatants of PECs. Moreover, albumin activated p44/42 mitogen-activated protein kinase (MAPK) in PECs. Inhibition of p44/42 MAPK suppressed albumin-induced MMP-9 secretion from glomerular PECs. Taken together, we have demonstrated that an up-regulation of MMP-9 in activated parietal epithelium is associated with a loss of adjacent podocytes in progressive diabetic nephropathy

Expression of UV-sensitive parapinopsin in the iguana parietal eyes and its implication in UV-sensitivity in vertebrate pineal-related organs.

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Wada, Seiji; Kawano-Yamashita, Emi; Koyanagi, Mitsumasa; Terakita, Akihisa

2012-01-01

The pineal-related organs of lower vertebrates have the ability to discriminate different wavelengths of light. This wavelength discrimination is achieved through antagonistic light responses to UV or blue and visible light. Previously, we demonstrated that parapinopsin underlies the UV reception in the lamprey pineal organ and identified parapinopsin genes in teleosts and frogs of which the pineal-related organs were reported to discriminate light. In this study, we report the first identification of parapinopsin in the reptile lineage and show its expression in the parietal eye of the green iguana. Spectroscopic analysis revealed that iguana parapinopsin is a UV-sensitive pigment, similar to lamprey parapinopsin. Interestingly, immunohistochemical analyses using antibodies specific to parapinopsin and parietopsin, a parietal eye green-sensitive pigment, revealed that parapinopsin and parietopsin are colocalized in the outer segments of the parietal eye photoreceptor cells in iguanas. These results strongly suggest that parapinopsin underlies the wavelength discrimination involving UV reception in the iguana parietal eye. The current findings support the idea that parapinopsin is a common photopigment underlying the UV-sensitivity in wavelength discrimination of the pineal-related organs found from lampreys to reptiles.

Expression of UV-Sensitive Parapinopsin in the Iguana Parietal Eyes and Its Implication in UV-Sensitivity in Vertebrate Pineal-Related Organs

Science.gov (United States)

Wada, Seiji; Kawano-Yamashita, Emi; Koyanagi, Mitsumasa; Terakita, Akihisa

2012-01-01

The pineal-related organs of lower vertebrates have the ability to discriminate different wavelengths of light. This wavelength discrimination is achieved through antagonistic light responses to UV or blue and visible light. Previously, we demonstrated that parapinopsin underlies the UV reception in the lamprey pineal organ and identified parapinopsin genes in teleosts and frogs of which the pineal-related organs were reported to discriminate light. In this study, we report the first identification of parapinopsin in the reptile lineage and show its expression in the parietal eye of the green iguana. Spectroscopic analysis revealed that iguana parapinopsin is a UV-sensitive pigment, similar to lamprey parapinopsin. Interestingly, immunohistochemical analyses using antibodies specific to parapinopsin and parietopsin, a parietal eye green-sensitive pigment, revealed that parapinopsin and parietopsin are colocalized in the outer segments of the parietal eye photoreceptor cells in iguanas. These results strongly suggest that parapinopsin underlies the wavelength discrimination involving UV reception in the iguana parietal eye. The current findings support the idea that parapinopsin is a common photopigment underlying the UV-sensitivity in wavelength discrimination of the pineal-related organs found from lampreys to reptiles. PMID:22720013

Expression of UV-sensitive parapinopsin in the iguana parietal eyes and its implication in UV-sensitivity in vertebrate pineal-related organs.

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Seiji Wada

Full Text Available The pineal-related organs of lower vertebrates have the ability to discriminate different wavelengths of light. This wavelength discrimination is achieved through antagonistic light responses to UV or blue and visible light. Previously, we demonstrated that parapinopsin underlies the UV reception in the lamprey pineal organ and identified parapinopsin genes in teleosts and frogs of which the pineal-related organs were reported to discriminate light. In this study, we report the first identification of parapinopsin in the reptile lineage and show its expression in the parietal eye of the green iguana. Spectroscopic analysis revealed that iguana parapinopsin is a UV-sensitive pigment, similar to lamprey parapinopsin. Interestingly, immunohistochemical analyses using antibodies specific to parapinopsin and parietopsin, a parietal eye green-sensitive pigment, revealed that parapinopsin and parietopsin are colocalized in the outer segments of the parietal eye photoreceptor cells in iguanas. These results strongly suggest that parapinopsin underlies the wavelength discrimination involving UV reception in the iguana parietal eye. The current findings support the idea that parapinopsin is a common photopigment underlying the UV-sensitivity in wavelength discrimination of the pineal-related organs found from lampreys to reptiles.

Modelos e instrumentos para estudios sobre espesor óptico de aerosoles y su relación con el forzamiento radiativo terrestre

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Pamela Piñas Sumalave

2015-12-01

Full Text Available El objetivo fue dar a conocer sobre los modelos e instrumentos necesarios para recabar, procesar e interpretar datos de los aerosoles atmosféricos y sub variables necesarias para su estudio. Así mismo del posible forzamiento radiativo que debido a las propiedades ópticas de los aerosoles generaría en la ciudad de Huancayo. Los aerosoles generados por la quema de biomasa en el Perú en un alto porcentaje provienen de la Amazonía, a esto se añade los provenientes de otros países. Entre los instrumentos disponibles en la ciudad de Huancayo para estos estudios se tiene el Fotómetro Solar CIMEL CE318 de la Red AERONET, red que cuenta con más de 450 fotómetros alrededor del mundo; este instrumento recaba información de variables como el espesor óptico de aerosoles, coeficiente de angstrom y otros. Para corroborar esta información se tiene acceso a datos proporcionados por el espectroradiómetro MODIS a bordo de los satélites Terra y Aqua. Los modelos atmosféricos utilizados para el procesamiento de datos de aerosoles y el forzamiento radiativo son el HYSPLIT y el SBDART. En conclusión es necesario tener consolidada la información, acerca de las variables como de los instrumentos y modelos que son necesarios e indispensables para la investigación de esta problemática que tiene su punto de origen en las quemas de biomasa, con consecuencia en la contaminación atmosférica y que finalmente perjudica a todo un entorno social y medioambiental.

Spatial summation in macaque parietal area 7a follows a winner-take-all rule

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Oleksiak, Anna; Klink, P. Christiaan; Postma, Albert; van der Ham, Ineke J.M.; Lankheet, Martin J.M.; van Wezel, Richard Jack Anton

2011-01-01

While neurons in posterior parietal cortex have been found to signal the presence of a salient stimulus among multiple items in a display, spatial summation within their receptive field in the absence of an attentional bias has never been investigated. This information, however, is indispensable

Improving ideomotor limb apraxia by electrical stimulation of the left posterior parietal cortex.

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Bolognini, Nadia; Convento, Silvia; Banco, Elisabetta; Mattioli, Flavia; Tesio, Luigi; Vallar, Giuseppe

2015-02-01

Limb apraxia, a deficit of planning voluntary gestures, is most frequently caused by damage to the left hemisphere, where, according to an influential neurofunctional model, gestures are planned, before being executed through the motor cortex of the hemisphere contralateral to the acting hand. We used anodal transcranial direct current stimulation delivered to the left posterior parietal cortex (PPC), the right motor cortex (M1), and a sham stimulation condition, to modulate the ability of six left-brain-damaged patients with ideomotor apraxia, and six healthy control subjects, to imitate hand gestures, and to perform skilled hand movements using the left hand. Transcranial direct current stimulation delivered to the left PPC reduced the time required to perform skilled movements, and planning, but not execution, times in imitating gestures, in both patients and controls. In patients, the amount of decrease of planning times brought about by left PPC transcranial direct current stimulation was influenced by the size of the parietal lobe damage, with a larger parietal damage being associated with a smaller improvement. Of interest from a clinical perspective, left PPC stimulation also ameliorated accuracy in imitating hand gestures in patients. Instead, transcranial direct current stimulation to the right M1 diminished execution, but not planning, times in both patients and healthy controls. In conclusion, by using a transcranial stimulation approach, we temporarily improved ideomotor apraxia in the left hand of left-brain-damaged patients, showing a role of the left PPC in planning gestures. This evidence opens up novel perspectives for the use of transcranial direct current stimulation in the rehabilitation of limb apraxia. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Observational learning of new movement sequences is reflected in fronto-parietal coherence.

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Jurjen van der Helden

Full Text Available Mankind is unique in her ability for observational learning, i.e. the transmission of acquired knowledge and behavioral repertoire through observation of others' actions. In the present study we used electrophysiological measures to investigate brain mechanisms of observational learning. Analysis investigated the possible functional coupling between occipital (alpha and motor (mu rhythms operating in the 10 Hz frequency range for translating "seeing" into "doing". Subjects observed movement sequences consisting of six consecutive left or right hand button presses directed at one of two target-buttons for subsequent imitation. Each movement sequence was presented four times, intervened by short pause intervals for sequence rehearsal. During a control task subjects observed the same movement sequences without a requirement for subsequent reproduction. Although both alpha and mu rhythms desynchronized during the imitation task relative to the control task, modulations in alpha and mu power were found to be largely independent from each other over time, arguing against a functional coupling of alpha and mu generators during observational learning. This independence was furthermore reflected in the absence of coherence between occipital and motor electrodes overlaying alpha and mu generators. Instead, coherence analysis revealed a pair of symmetric fronto-parietal networks, one over the left and one over the right hemisphere, reflecting stronger coherence during observation of movements than during pauses. Individual differences in fronto-parietal coherence were furthermore found to predict imitation accuracy. The properties of these networks, i.e. their fronto-parietal distribution, their ipsilateral organization and their sensitivity to the observation of movements, match closely with the known properties of the mirror neuron system (MNS as studied in the macaque brain. These results indicate a functional dissociation between higher order areas for

El arte parietal, espejo de las sociedades paleolíticas

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Georges SAUVET

2009-12-01

Full Text Available RESUMEN: El presente trabajo aboga por un estudio del arte parietal como instrumento del conocimiento de la geografía humana de las sociedades de cazadores y de la evolución de sus redes de alianza, durante el Paleolítico superior. Tomando como ejemplo el componente figurativo de este arte y un amplio corpus de 3981 figuras procedentes de 154 yacimientos franceses y españoles, se demuestra que las asociaciones entre especies animales diferentes obedecen a reglas simples y coherentes, que se dejan fácilmente exprimir por un modelo formal. El análisis de doce sub-conjuntos sincrónicos y diacrónicos evidencia la movilidad de las connexiones interregionales (por ejemplo el desarrollo del Solutrense cantábrico en relación con los centros peninsulares y con escaso contacto con el sudoeste francés, al contrario de la situación que prevalece durante el Magdaleniense medio-superior. Sin embargo conforta la idea que las variaciones regionales operan dentro de un sistema de pensamiento religioso relativamente estable. Una segunda fase del trabajo se propone describir la estructuración del arte parietal a un nivel mucho más fino, teniendo en cuenta la diversidad formal de cada figura y sus relaciones topológicas con las demás. Una larga base de datos está en curso de elaboración para su tratamiento con las técnicas de "extracción de conocimiento" (Knowledge Discovery in Databases. Unos resultados preliminares dejan esperar que una base de datos de este tipo servirá el objetivo y proporcionará une visión más precisa y segura de la historia de los pueblos paleolíticos, dado que la fuente del estilo propio de cada grupo debe buscarse en la construcción gráfica de paneles complejos.ABSTRACT: This paper pleads in favour of the study of parietal art as a means to investigate the human geography of palaeolithic hunter-gatherers in Europe and the evolution of their alliance networks. Taking the example of the figurative component of Rock

Parietal Lobe Volume Deficits in Adolescents with Schizophrenia and Adolescents with Cannabis Use Disorders

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Kumra, Sanjiv; Robinson, Paul; Tambyraja, Rabindra; Jensen, Daniel; Schimunek, Caroline; Houri, Alaa; Reis, Tiffany; Lim, Kelvin

2012-01-01

Objective: In early-onset schizophrenia (EOS), the earliest structural brain volumetric abnormalities appear in the parietal cortices. Early exposure to cannabis may represent an environmental risk factor for developing schizophrenia. This study characterized cerebral cortical gray matter structure in adolescents in regions of interest (ROIs) that…

Deficits in visual search for conjunctions of motion and form after parietal damage but with spared hMT+/V5.

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Dent, Kevin; Lestou, Vaia; Humphreys, Glyn W

2010-02-01

It has been argued that area hMT+/V5 in humans acts as a motion filter, enabling targets defined by a conjunction of motion and form to be efficiently selected. We present data indicating that (a) damage to parietal cortex leads to a selective problem in processing motion-form conjunctions, and (b) that the presence of a structurally and functional intact hMT+/V5 is not sufficient for efficient search for motion-form conjunctions. We suggest that, in addition to motion-processing areas (e.g., hMT+/V5), the posterior parietal cortex is necessary for efficient search with motion-form conjunctions, so that damage to either brain region may bring about deficits in search. We discuss the results in terms of the involvement of the posterior parietal cortex in the top-down guidance of search or in the binding of motion and form information.

Timing-dependent modulation of the posterior parietal cortex-primary motor cortex pathway by sensorimotor training

DEFF Research Database (Denmark)

Karabanov, Anke Ninija; Jin, Seung-Hyun; Joutsen, Atte

2012-01-01

at baseline and at four time points (0, 30, 60, and 180 min) after training. For EEG, task-related power and coherence were calculated for early and late training phases. The conditioned MEP was facilitated at a 2-ms conditioning-test interval before training. However, facilitation was abolished immediately...... following training, but returned to baseline at subsequent time points. Regional EEG activity and interregional connectivity between PPC and M1 showed an initial increase during early training followed by a significant decrease in the late phases. The findings indicate that parietal-motor interactions......Interplay between posterior parietal cortex (PPC) and ipsilateral primary motor cortex (M1) is crucial during execution of movements. The purpose of the study was to determine whether functional PPC-M1 connectivity in humans can be modulated by sensorimotor training. Seventeen participants...

Hippocampal and posterior parietal contributions to developmental increases in visual short-term memory capacity.

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von Allmen, David Yoh; Wurmitzer, Karoline; Klaver, Peter

2014-10-01

Developmental increases in visual short-term memory (VSTM) capacity have been associated with changes in attention processing limitations and changes in neural activity within neural networks including the posterior parietal cortex (PPC). A growing body of evidence suggests that the hippocampus plays a role in VSTM, but it is unknown whether the hippocampus contributes to the capacity increase across development. We investigated the functional development of the hippocampus and PPC in 57 children, adolescents and adults (age 8-27 years) who performed a visuo-spatial change detection task. A negative relationship between age and VSTM related activity was found in the right posterior hippocampus that was paralleled by a positive age-activity relationship in the right PPC. In the posterior hippocampus, VSTM related activity predicted individual capacity in children, whereas neural activity in the right anterior hippocampus predicted individual capacity in adults. The findings provide first evidence that VSTM development is supported by an integrated neural network that involves hippocampal and posterior parietal regions.

Emotion unfolded by motion: a role for parietal lobe in decoding dynamic facial expressions.

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Sarkheil, Pegah; Goebel, Rainer; Schneider, Frank; Mathiak, Klaus

2013-12-01

Facial expressions convey important emotional and social information and are frequently applied in investigations of human affective processing. Dynamic faces may provide higher ecological validity to examine perceptual and cognitive processing of facial expressions. Higher order processing of emotional faces was addressed by varying the task and virtual face models systematically. Blood oxygenation level-dependent activation was assessed using functional magnetic resonance imaging in 20 healthy volunteers while viewing and evaluating either emotion or gender intensity of dynamic face stimuli. A general linear model analysis revealed that high valence activated a network of motion-responsive areas, indicating that visual motion areas support perceptual coding for the motion-based intensity of facial expressions. The comparison of emotion with gender discrimination task revealed increased activation of inferior parietal lobule, which highlights the involvement of parietal areas in processing of high level features of faces. Dynamic emotional stimuli may help to emphasize functions of the hypothesized 'extended' over the 'core' system for face processing.

Temporo-Parietal Junction Activity in Theory-of-Mind Tasks: Falseness, Beliefs, or Attention

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Aichhorn, Markus; Perner, Josef; Weiss, Benjamin; Kronbichler, Martin; Staffen, Wolfgang; Ladurner, Gunther

2009-01-01

By combining the false belief (FB) and photo (PH) vignettes to identify theory-of-mind areas with the false sign (FS) vignettes, we re-establish the functional asymmetry between the left and right temporo-parietal junction (TPJ). The right TPJ (TPJ-R) is specially sensitive to processing belief information, whereas the left TPJ (TPJ-L) is equally…

Asymmetric multisensory interactions of visual and somatosensory responses in a region of the rat parietal cortex.

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Michael T Lippert

Full Text Available Perception greatly benefits from integrating multiple sensory cues into a unified percept. To study the neural mechanisms of sensory integration, model systems are required that allow the simultaneous assessment of activity and the use of techniques to affect individual neural processes in behaving animals. While rodents qualify for these requirements, little is known about multisensory integration and areas involved for this purpose in the rodent. Using optical imaging combined with laminar electrophysiological recordings, the rat parietal cortex was identified as an area where visual and somatosensory inputs converge and interact. Our results reveal similar response patterns to visual and somatosensory stimuli at the level of current source density (CSD responses and multi-unit responses within a strip in parietal cortex. Surprisingly, a selective asymmetry was observed in multisensory interactions: when the somatosensory response preceded the visual response, supra-linear summation of CSD was observed, but the reverse stimulus order resulted in sub-linear effects in the CSD. This asymmetry was not present in multi-unit activity however, which showed consistently sub-linear interactions. These interactions were restricted to a specific temporal window, and pharmacological tests revealed significant local intra-cortical contributions to this phenomenon. Our results highlight the rodent parietal cortex as a system to model the neural underpinnings of multisensory processing in behaving animals and at the cellular level.

ANALISIS DEL COMPORTAMIENTO DE LA INMIGRACIÓN EN LO RELATIVO AL USO DEL SISTEMA PÚBLICO DE SALUD, EN TRES COMUNAS DE LA REGIÓN METROPOLITANA

OpenAIRE

OPAZO GALAZ, HUMBERTO; REYES RUIZ, MONICA

2011-01-01

La inmigración es un fenómeno complejo, que involucra múltiples aspectos, y por tanto debe ser estudiado desde todas sus perspectivas. El propósito de este caso de estudio, es analizar el comportamiento del colectivo inmigrante en las comunas de Santiago, Independencia y Recoleta de la Región Metropolitana de Santiago de Chile, en lo relativo al uso del sistema de salud público, en condiciones de pre y post programa de regularización migratoria, acontecida en el país en el año 2007. A fin ...

High Frequency rTMS over the Left Parietal Lobule Increases Non-Word Reading Accuracy

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Costanzo, Floriana; Menghini, Deny; Caltagirone, Carlo; Oliveri, Massimiliano; Vicari, Stefano

2012-01-01

Increasing evidence in the literature supports the usefulness of Transcranial Magnetic Stimulation (TMS) in studying reading processes. Two brain regions are primarily involved in phonological decoding: the left superior temporal gyrus (STG), which is associated with the auditory representation of spoken words, and the left inferior parietal lobe…

Self-face recognition shares brain regions active during proprioceptive illusion in the right inferior fronto-parietal superior longitudinal fasciculus III network.

Science.gov (United States)

Morita, Tomoyo; Saito, Daisuke N; Ban, Midori; Shimada, Koji; Okamoto, Yuko; Kosaka, Hirotaka; Okazawa, Hidehiko; Asada, Minoru; Naito, Eiichi

2017-04-21

Proprioception is somatic sensation that allows us to sense and recognize position, posture, and their changes in our body parts. It pertains directly to oneself and may contribute to bodily awareness. Likewise, one's face is a symbol of oneself, so that visual self-face recognition directly contributes to the awareness of self as distinct from others. Recently, we showed that right-hemispheric dominant activity in the inferior fronto-parietal cortices, which are connected by the inferior branch of the superior longitudinal fasciculus (SLF III), is associated with proprioceptive illusion (awareness), in concert with sensorimotor activity. Herein, we tested the hypothesis that visual self-face recognition shares brain regions active during proprioceptive illusion in the right inferior fronto-parietal SLF III network. We scanned brain activity using functional magnetic resonance imaging while twenty-two right-handed healthy adults performed two tasks. One was a proprioceptive illusion task, where blindfolded participants experienced a proprioceptive illusion of right hand movement. The other was a visual self-face recognition task, where the participants judged whether an observed face was their own. We examined whether the self-face recognition and the proprioceptive illusion commonly activated the inferior fronto-parietal cortices connected by the SLF III in a right-hemispheric dominant manner. Despite the difference in sensory modality and in the body parts involved in the two tasks, both tasks activated the right inferior fronto-parietal cortices, which are likely connected by the SLF III, in a right-side dominant manner. Here we discuss possible roles for right inferior fronto-parietal activity in bodily awareness and self-awareness. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Trepanation and enlarged parietal foramen on skulls from the Loyalty Islands (Melanesia).

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Vasilyev, Sergey V; Sviridov, Alexey A

2017-06-01

The goal of this study is a comprehensive examination of openings discovered on two skulls in the collection of skeletal remains from the Loyalty Islands (Melanesia). The skull No. 1524 displayed an evidence of successful trepanation, and the skull No. 7985 revealed openings that were reminiscent of a trepanation, however, we are inclined to believe that in the latter case we are dealing with a rare genetic anomaly - enlarged parietal foramen.

Differential Medial Temporal Lobe and Parietal Cortical Contributions to Real-world Autobiographical Episodic and Autobiographical Semantic Memory.

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Brown, Thackery I; Rissman, Jesse; Chow, Tiffany E; Uncapher, Melina R; Wagner, Anthony D

2018-04-18

Autobiographical remembering can depend on two forms of memory: episodic (event) memory and autobiographical semantic memory (remembering personally relevant semantic knowledge, independent of recalling a specific experience). There is debate about the degree to which the neural signals that support episodic recollection relate to or build upon autobiographical semantic remembering. Pooling data from two fMRI studies of memory for real-world personal events, we investigated whether medial temporal lobe (MTL) and parietal subregions contribute to autobiographical episodic and semantic remembering. During scanning, participants made memory judgments about photograph sequences depicting past events from their life or from others' lives, and indicated whether memory was based on episodic or semantic knowledge. Results revealed several distinct functional patterns: activity in most MTL subregions was selectively associated with autobiographical episodic memory; the hippocampal tail, superior parietal lobule, and intraparietal sulcus were similarly engaged when memory was based on retrieval of an autobiographical episode or autobiographical semantic knowledge; and angular gyrus demonstrated a graded pattern, with activity declining from autobiographical recollection to autobiographical semantic remembering to correct rejections of novel events. Collectively, our data offer insights into MTL and parietal cortex functional organization, and elucidate circuitry that supports different forms of real-world autobiographical memory.

The parietal memory network activates similarly for true and associative false recognition elicited via the DRM procedure.

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McDermott, Kathleen B; Gilmore, Adrian W; Nelson, Steven M; Watson, Jason M; Ojemann, Jeffrey G

2017-02-01

Neuroimaging investigations of human memory encoding and retrieval have revealed that multiple regions of parietal cortex contribute to memory. Recently, a sparse network of regions within parietal cortex has been identified using resting state functional connectivity (MRI techniques). The regions within this network exhibit consistent task-related responses during memory formation and retrieval, leading to its being called the parietal memory network (PMN). Among its signature patterns are: deactivation during initial experience with an item (e.g., encoding); activation during subsequent repetitions (e.g., at retrieval); greater activation for successfully retrieved familiar words than novel words (e.g., hits relative to correctly-rejected lures). The question of interest here is whether novel words that are subjectively experienced as having been recently studied would elicit PMN activation similar to that of hits. That is, we compared old items correctly recognized to two types of novel items on a recognition test: those correctly identified as new and those incorrectly labeled as old due to their strong associative relation to the studied words (in the DRM false memory protocol). Subjective oldness plays a strong role in driving activation, as hits and false alarms activated similarly (and greater than correctly-rejected lures). Copyright © 2016 Elsevier Ltd. All rights reserved.

Repair of large frontal temporal parietal skull defect with digitally reconstructed titanium mesh: a report of 20 cases

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Gang-ge CHENG

2013-09-01

Full Text Available Objective　To explore the clinical effect and surgical technique of the repair of large defect involving frontal, temporal, and parietal regions using digitally reconstructed titanium mesh. Methods　Twenty patients with large frontal, temporal, and parietal skull defect hospitalized in Air Force General Hospital from November 2006 to May 2012 were involved in this study. In these 20 patients, there were 13 males and 7 females, aged 18-58 years (mean 39 years, and the defect size measured from 7.0cm×9.0cm to 11.5cm×14.0cm (mean 8.5cm×12.0cm. Spiral CT head scan and digital three-dimensional reconstruction of skull were performed in all the patients. The shape and geometric size of skull defect was traced based on the symmetry principle, and then the data were transferred into digital precision lathe to reconstruct a titanium mesh slightly larger (1.0-1.5cm than the skull defect, and the finally the prosthesis was perfected after pruning the border. Cranioplasty was performed 6-12 months after craniotomy using the digitally reconstructed titanium mesh. Results　The digitally reconstructed titanium mesh was used in 20 patients with large frontal, temporal, parietal skull defect. The surgical technique was relatively simple, and the surgical duration was shorter than before. The titanium mesh fit to the defect of skull accurately with satisfactory molding effect, good appearance and symmetrical in shape. No related complication was found in all the patients. Conclusion　Repair of large frontal, temporal, parietal skull defect with digitally reconstructed titanium mesh is more advantageous than traditional manual reconstruction, and it can improve the life quality of patients.

The Role of the Parietal Lobe in Visual Extinction Studied with Transcranial Magnetic Stimulation

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Battelli, Lorella; Alvarez, George A.; Carlson, Thomas; Pascual-Leone, Alvaro

2009-01-01

Interhemispheric competition between homologous areas in the human brain is believed to be involved in a wide variety of human behaviors from motor activity to visual perception and particularly attention. For example, patients with lesions in the posterior parietal cortex are unable to selectively track objects in the contralesional side of…

Estudos sobre thrombose cardiaca e endocardite parietal de origem não valvular On thrombosis of heart and on mural endocarditis of non-valvular origin

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C. Magarinos Torres

1928-01-01

Full Text Available 1.-Since the parietal endocarditis represents a chapter generally neglected, owing to the relative lack of cases, and somewhat confused because there various terms have been applied to a very same morbid condition, it justifies the work which previously we tried to accomplish, of nosographic classification. Taking into account the functional disturbances and the anatomical changes, all cases of parietal endocarditis referred to in the litterature were distributed by the following groups: A-Group-Valvulo-parietal endocarditis. 1st . type-Valvulo-parietal endocarditis per continuum. 2nd. type-Metastatic valvulo-parietal endocarditis. 3rd. type-Valvulo-parietal endocarditis of the mitral stenosis. B-Group-Genuine parietal endocarditis. a with primary lesions in the myocardium. b with primary lesions in the endocardium. 4th type-Fibrous chronic parietal endocarditis (B A Ü M L E R, « endocarditis parietalis simplex». 5th type-Septic acute parietal endocarditis (LESCHKE, «endocarditis parietalis septica». 6th type-Subacute parietal endocarditis (MAGARINOS TORRES, «endocarditis muralis lenta». 2.-Studying a group of 14 cases of fibrous endomyocarditis with formation of thrombi, and carrying together pathological and bacteriological examinations it has been found that some of such cases represent an infectious parietal endocarditis, sometimes post-puerperal, of subacute or slow course, the endocardic vegetations being contamined by pathogenic microörganisms of which the most frequent is the Diplococcus pneumoniae, in most cases of attenuated virulence. Along with the infectious parietal endocarditis, there occur arterial and venous thromboses (abdominal aorta, common illiac and femural arteries and external jugular veins. The case 5,120 is a typical one of this condition which we name subacute parietal endocarditis (endocarditis parietalis s. muralis lenta. 3.-The endocarditis muralis lenta encloses an affection reputed to be of rare occurrence

The sixth sense in mammalian forerunners: Variability of the parietal foramen and the evolution of the pineal eye in South African Permo-Triassic eutheriodont therapsids

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Julien Benoit

2016-12-01

Full Text Available In some extant ectotherms, the third eye (or pineal eye is a photosensitive organ located in the parietal foramen on the midline of the skull roof. The pineal eye sends information regarding exposure to sunlight to the pineal complex, a region of the brain devoted to the regulation of body temperature, reproductive synchrony, and biological rhythms. The parietal foramen is absent in mammals but present in most of the closest extinct relatives of mammals, the Therapsida. A broad ranging survey of the occurrence and size of the parietal foramen in different South African therapsid taxa demonstrates that through time the parietal foramen tends, in a convergent manner, to become smaller and is absent more frequently in eutherocephalians (Akidnognathiidae, Whaitsiidae, and Baurioidea and non-mammaliaform eucynodonts. Among the latter, the Probainognathia, the lineage leading to mammaliaforms, are the only one to achieve the complete loss of the parietal foramen. These results suggest a gradual and convergent loss of the photoreceptive function of the pineal organ and degeneration of the third eye. Given the role of the pineal organ to achieve fine-tuned thermoregulation in ectotherms (i.e., “cold-blooded” vertebrates, the gradual loss of the parietal foramen through time in the Karoo stratigraphic succession may be correlated with the transition from a mesothermic metabolism to a high metabolic rate (endothermy in mammalian ancestry. The appearance in the eye of melanopsin-containing retinal ganglion cells replacing the photoreceptive role of the pineal eye could also have accompanied its loss.

ESTUDIO TOPOGRÁFICO DE PELÍCULAS DELGADAS DE ORO SOBRE MICA MEDIANTE EVAPORACIÓN POR MÉTODO FÍSICO

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Sebastián Bahamondes

2012-01-01

Full Text Available Se presenta un estudio topográfico de la formación de películas delgadas de oro sobre mica moscovita. La caracterización de las muestras fue hecha con microscopio de efecto túnel (STM y microscopio de fuerza atómica (AFM. Se realizó un conjunto de muestras del mismo espesor, evaporadas a distintas temperaturas del sustrato (entre -160 y 260 °C y otro conjunto de muestras evaporadas a temperatura ambiente variando su espesor (ente 1,5 y 33 nm. Los resultados muestran que el oro presenta un crecimiento tridimensional a través de la formación de granos; estos se presentan aislados o formando nanohilos hasta los 6 nm de espesor, los cuales recubren completamente el sustrato sobre 8 nm de espesor. El diámetro promedio de grano es constante hasta espesores de 8 nm y aumenta con el espesor para deposiciones mayores. El diámetro promedio de grano es similar para películas de igual espesor sin importar la temperatura del sustrato.

Proliferating cells in HIV and pamidronate-associated collapsing focal segmental glomerulosclerosis are parietal epithelial cells.

NARCIS (Netherlands)

Dijkman, H.B.P.M.; Weening, J.J.; Smeets, B.; Verrijp, K.; Kuppevelt, A.H.M.S.M. van; Assmann, K.K.; Steenbergen, E.; Wetzels, J.F.M.

2006-01-01

Collapsing focal segmental glomerulosclerosis (cFSGS) is characterized by hyperplasia of glomerular epithelial cells. In a mouse model of FSGS and in a patient with recurrent idiopathic FSGS, we identified the proliferating cells as parietal epithelial cells (PECs). In the present study, we have

Proliferating cells in HIV and pamidronate-associated collapsing focal segmental glomerulosclerosis are parietal epithelial cells

NARCIS (Netherlands)

Dijkman, H. B. P. M.; Weening, J. J.; Smeets, B.; Verrijp, K. C. N.; van Kuppevelt, T. H.; Assmann, K. K. J. M.; Steenbergen, E. J.; Wetzels, J. F. M.

2006-01-01

Collapsing focal segmental glomerulosclerosis (cFSGS) is characterized by hyperplasia of glomerular epithelial cells. In a mouse model of FSGS and in a patient with recurrent idiopathic FSGS, we identified the proliferating cells as parietal epithelial cells (PECs). In the present study, we have

Single-cell analysis of peptide expression and electrophysiology of right parietal neurons involved in male copulation behavior of a simultaneous hermaphrodite.

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El Filali, Z; de Boer, P A C M; Pieneman, A W; de Lange, R P J; Jansen, R F; Ter Maat, A; van der Schors, R C; Li, K W; van Straalen, N M; Koene, J M

2015-12-01

Male copulation is a complex behavior that requires coordinated communication between the nervous system and the peripheral reproductive organs involved in mating. In hermaphroditic animals, such as the freshwater snail Lymnaea stagnalis, this complexity increases since the animal can behave both as male and female. The performance of the sexual role as a male is coordinated via a neuronal communication regulated by many peptidergic neurons, clustered in the cerebral and pedal ganglia and dispersed in the pleural and parietal ganglia. By combining single-cell matrix-assisted laser mass spectrometry with retrograde staining and electrophysiology, we analyzed neuropeptide expression of single neurons of the right parietal ganglion and their axonal projections into the penial nerve. Based on the neuropeptide profile of these neurons, we were able to reconstruct a chemical map of the right parietal ganglion revealing a striking correlation with the earlier electrophysiological and neuroanatomical studies. Neurons can be divided into two main groups: (i) neurons that express heptapeptides and (ii) neurons that do not. The neuronal projection of the different neurons into the penial nerve reveals a pattern where (spontaneous) activity is related to branching pattern. This heterogeneity in both neurochemical anatomy and branching pattern of the parietal neurons reflects the complexity of the peptidergic neurotransmission involved in the regulation of male mating behavior in this simultaneous hermaphrodite.

The Effects of Maternal Hyperthyroidism on Histologic Changes in Parietal Lobe in Rat Embryos

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Fatemeh Mirsafi

2017-05-01

Full Text Available Background Maternal hyperthyroidism causes developmental defects on the nervous system of fetuses. Objectives The present study was designed to study the effects of maternal hyperthyroidism on the development of the parietal lobe in the brain of rat embryos. Methods In this experimental study, thirty Sprague-Dawley rats were randomly divided into three groups. The control group received no injections, the sham group received intraperitoneal injections of distilled water solution containing salt and polysorbate (solvent of levothyroxine, and the experimental group received once-daily, intraperitoneal injections of 0.5 mg/kg levothyroxine for a 10-day period to become hyperthyroid rats. The hyperthyroid rats were then mated, and all pregnant rats were killed on the 20th day of gestation. Fetuses were removed, fixed, and processed for histological procedures. The fetuses were sagitally sectioned at 5 µ thickness and stained with hematoxylin-eosin (H and E technique. The sections were examined using a light microscope and Motic software. Results The results showed no significant difference in the studied variables between the sham and control groups. A significantly increase in body weight and a significant decrease in crown-rump length of embryos was observed in the experimental group when compared to the control group. The mean total thickness of the parietal cortex, ventricular layer, and intermediate layer of embryos showed a significant decrease in the experimental group compared to the control and sham groups. The mean number of cells also showed a significant decrease in the intermediate and ventricular layers in the experimental group compared to the control and sham groups. Conclusions This study showed that maternal hyperthyroidism leads to a reduction in development of the parietal cortex in embryos. Maternal hyperthyroidism can disturb the growth and development of embryos.

Posterior parietal cortex and long-term memory: some data from laboratory animals

OpenAIRE

Myskiw, Jociane C.; Izquierdo, Iván

2012-01-01

The posterior parietal cortex (PPC) was long viewed as just involved in the perception of spatial relationships between the body and its surroundings and of movements related to them. In recent years the PPC has been shown to participate in many other cognitive processes, among which working memory and the consolidation and retrieval of episodic memory. The neurotransmitter and other molecular processes involved have been determined to a degree in rodents. More research will no doubt determin...

The Effects of Maternal Hyperthyroidism on Histologic Changes in Parietal Lobe in Rat Embryos

OpenAIRE

Fatemeh Mirsafi; Gholamreza Kaka; Mahnaz Azarnia

2017-01-01

Background Maternal hyperthyroidism causes developmental defects on the nervous system of fetuses. Objectives The present study was designed to study the effects of maternal hyperthyroidism on the development of the parietal lobe in the brain of rat embryos. Methods In this experimental study, thirty Sprague-Dawley rats were randomly divided into three groups. The control group rec...

Thickness calculation software of the thermal insulation in facilities using thermal solar energy; Software para el calculo de espesores del aislante termico en instalaciones de aprovechamiento de energia solar termica

Energy Technology Data Exchange (ETDEWEB)

Portillo Jimenez, Canek [Universidad Autonoma de Sinaloa, Culiacan, Sinaloa (Mexico)]. E-mail: cnk@uas.uasnet.mx

2010-11-15

It is presented a software application for calculating the thickness of the thermal insulation used in various facilities where there are thermal systems using solar energy. The software facilitates the calculation of the thermal cover thickness over components such as pipes (flat or round), storage and other devices that require thermal protection, installed in outdoors or indoors. The software was programmed in Visual Basic by following the technical specifications of the current regulations in the field. Application examples are performed, obtaining certain results that are discussed briefly. [Spanish] Se presenta un software de aplicacion para el calculo de los espesores de los aislantes termicos, utilizados en diferentes instalaciones donde existen sistemas de aprovechamiento termico de energia solar. El software facilita el calculo del grosor del recubrimiento termico en componentes tales como: tuberias (planas o circulares), depositos acumuladores y otros aparatos que necesiten proteccion termica, instalados en exteriores o en interiores. El software fue programado en Visual Basic siguiendo las especificaciones tecnicas de la normatividad vigente en la materia. Se realizan ejemplos de aplicacion, donde se obtienen ciertos resultados de los cuales se hace una breve discusion.

Collaborative activity between parietal and dorso-lateral prefrontal cortex in dynamic spatial working memory revealed by fMRI.

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Diwadkar, V A; Carpenter, P A; Just, M A

2000-07-01

Functional MRI was used to determine how the constituents of the cortical network subserving dynamic spatial working memory respond to two types of increases in task complexity. Participants mentally maintained the most recent location of either one or three objects as the three objects moved discretely in either a two- or three-dimensional array. Cortical activation in the dorsolateral prefrontal (DLPFC) and the parietal cortex increased as a function of the number of object locations to be maintained and the dimensionality of the display. An analysis of the response characteristics of the individual voxels showed that a large proportion were activated only when both the variables imposed the higher level of demand. A smaller proportion were activated specifically in response to increases in task demand associated with each of the independent variables. A second experiment revealed the same effect of dimensionality in the parietal cortex when the movement of objects was signaled auditorily rather than visually, indicating that the additional representational demands induced by 3-D space are independent of input modality. The comodulation of activation in the prefrontal and parietal areas by the amount of computational demand suggests that the collaboration between areas is a basic feature underlying much of the functionality of spatial working memory. Copyright 2000 Academic Press.

Symptomatic Parietal Intradiploic Encephalocele—A Case Report and Literature Review

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Shi, Chen; Flores, Bruno; Fisher, Stephen; Barnett, Samuel L

2017-01-01

Encephalocele is a rare condition that consists of herniation of cerebral matter through openings of dura and skull. A majority of encephaloceles are congenital and manifest in childhood. We present a case of a 45-year-old man presenting with contralateral hemiparesis and found to have an extremely rare phenomenon of a symptomatic posttraumatic parietal intradiploic encephalocele (IE) manifesting 36 years following pediatric traumatic head injury. Computed tomography and magnetic resonance imaging confirmed herniation of brain tissue into the intradiploic space. Surgical treatment with reduction of the encephalocele achieved near resolution of preoperative hemiparesis on follow-up. The pathogenesis and a literature review of IE are discussed. PMID:28316901

Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory.

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Kawasaki, Masahiro; Kitajo, Keiichi; Yamaguchi, Yoko

2014-01-01

In humans, theta phase (4-8 Hz) synchronization observed on electroencephalography (EEG) plays an important role in the manipulation of mental representations during working memory (WM) tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

Inferior parietal and right frontal contributions to trial-by-trial adaptations of attention to memory.

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Kizilirmak, Jasmin M; Rösler, Frank; Bien, Siegfried; Khader, Patrick H

2015-07-21

The attention to memory theory (AtoM) proposes that the same brain regions might be involved in selective processing of perceived stimuli (selective attention) and memory representations (selective retrieval). Although this idea is compelling, given consistently found neural overlap between perceiving and remembering stimuli, recent comparisons brought evidence for overlap as well as considerable differences. Here, we present a paradigm that enables the investigation of the AtoM hypothesis from a novel perspective to gain further insight into the neural resources involved in AtoM. Selective attention in perception is often investigated as a control process that shows lingering effects on immediately following trials. Here, we employed a paradigm capable of modulating selective retrieval in a similarly dynamic manner as in such selective-attention paradigms by inducing trial-to-trial shifts between relevant and irrelevant memory representations as well as changes of the width of the internal focus on memory. We found evidence for an involvement of bilateral inferior parietal lobe and right inferior frontal gyrus in reorienting the attentional focus on previously accessed memory representations. Moreover, we could dissociate the right inferior from the parietal activation in separate contrasts, suggesting that the right inferior frontal gyrus plays a role in facilitating attentional reorienting to memory representations when competing representations have been activated in the preceding trial, potentially by resolving this competition. Our results support the AtoM theory, i.e. that ventral frontal and parietal regions are involved in automatic attentional reorienting in memory, and highlight the importance of further investigations of the overlap and differences between regions involved in internal (memory) and external (perceptual) attentional selection. Copyright © 2015 Elsevier B.V. All rights reserved.

Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory

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Masahiro eKawasaki

2014-03-01

Full Text Available In humans, theta phase (4–8 Hz synchronization observed on electroencephalography (EEG plays an important role in the manipulation of mental representations during working memory (WM tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

Ultrasonographic analysis in vitro of parietal thickness of lower limb varicose veins.

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Bruschi, E; Como, G; Zuiani, C; Segatto, E; Rocco, M; Biasi, G; Bazzocchi, M

2006-09-01

The aim of this study was to evaluate the ability of ultrasound (US) to measure the parietal thickness of varicose veins. In a blind in vitro analysis, 28 great saphenous veins, obtained after stripping surgery from 28 patients with chronic venous insufficiency, were examined with a digital US scanner ATL-HDI5000, linear 5-1 to 2-MHz broadband probe, compound imaging technique and analogic-digital zooming. We obtained one to three progressive measurements for each vein wall (total 67 parietal thicknesses). The samples, fixed in formalin, were sent to the pathology laboratory: sections were obtained at the same level of the sonographic planes, and images were obtained by digital camera mounted on an optical microscope. Measurements obtained at histology were considered as the gold standard. K-statistic was applied to compare sonographic and histologic measurements. Considering only the hypoechoic wall portion, 29/29 (100%) diagnoses of hypotrophy (K=0.91), 19/22 (86%) diagnoses of normotrophy (K=0,47) and 12/16 (75%) diagnoses of hypertrophy (K=0.7) were obtained by sonography. In our preliminary experience, the in vitro study of varicose veins allows precise, at least morphological, detection of hypotrophic walls. If these preliminary data are confirmed in vivo, sonography could be used to discriminate patients eligible for conservative treatment instead of surgery.

Functional Heterogeneity in Posterior Parietal Cortex Across Attention and Episodic Memory Retrieval

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Hutchinson, J. Benjamin; Uncapher, Melina R.; Weiner, Kevin S.; Bressler, David W.; Silver, Michael A.; Preston, Alison R.; Wagner, Anthony D.

2014-01-01

While attention is critical for event memory, debate has arisen regarding the extent to which posterior parietal cortex (PPC) activation during episodic retrieval reflects engagement of PPC-mediated mechanisms of attention. Here, we directly examined the relationship between attention and memory, within and across subjects, using functional magnetic resonance imaging attention-mapping and episodic retrieval paradigms. During retrieval, 4 functionally dissociable PPC regions were identified. Specifically, 2 PPC regions positively tracked retrieval outcomes: lateral intraparietal sulcus (latIPS) indexed graded item memory strength, whereas angular gyrus (AnG) tracked recollection. By contrast, 2 other PPC regions demonstrated nonmonotonic relationships with retrieval: superior parietal lobule (SPL) tracked retrieval reaction time, consistent with a graded engagement of top-down attention, whereas temporoparietal junction displayed a complex pattern of below-baseline retrieval activity, perhaps reflecting disengagement of bottom-up attention. Analyses of retrieval effects in PPC topographic spatial attention maps (IPS0-IPS5; SPL1) revealed that IPS5 and SPL1 exhibited a nonmonotonic relationship with retrieval outcomes resembling that in the SPL region, further suggesting that SPL activation during retrieval reflects top-down attention. While demands on PPC attention mechanisms vary during retrieval attempts, the present functional parcellation of PPC indicates that 2 additional mechanisms (mediated by latIPS and AnG) positively track retrieval outcomes. PMID:23019246

Estudios de series temporales de energía solar UV-B de 305 nm y espesor de la capa de ozono estratosférico en Arica, norte de Chile Study of time series for 305 nm solar energy UV-B and stratospheric ozone layer thickness Arica in the north of Chile

OpenAIRE

Miguel Rivas; Carlos Leiva; Elisa Rojas

2011-01-01

En este trabajo se muestran los resultados del análisis de las series temporales de la energía solar medida a nivel del suelo, en la banda de 305 nm, y el espesor de la capa de ozono estratosférico. El rasgo más importante es la independencia de los valores de energía a nivel del suelo respecto de la variabilidad de corto periodo de la capa de ozono, siendo probablemente efectos meteorológicos locales los que llevan el mayor peso de la varianza.In this paper, the results obtained by analyzing...

Counteracting Fatigue in Multiple Sclerosis with Right Parietal Anodal Transcranial Direct Current Stimulation

OpenAIRE

Hanken, Katrin; Bosse, Mona; M?hrke, Kim; Eling, Paul; Kastrup, Andreas; Antal, Andrea; Hildebrandt, Helmut

2016-01-01

BACKGROUND: Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time (RT) and errors with prolonged time-on-task. OBJECTIVES: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. METHODS: In study I, a randomized double-blind placebo-controll...

Contribución al estudio de espesores de soleras de hormigón para cargas de estanterías mediante elementos finitos

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Ferrer Gisbert, C.

2016-09-01

Full Text Available In the current paper, comparative analyses between three procedures of calculation have been developed, in order to obtain slab on grade thicknesses when the slabs are loaded with racking posts. For this case, the classical expression of Westergaard cannot be applied directly because of the influence of the remainder posts and their proximity. Firstly, the comparative analysis has been done by means of bibliographical design abacus; in the second place, the slab is discretized with finite elements resting above the soil modelled with soil reaction springs; and in third place, a three dimensional solid finite element model represents the base and subgrade set. In the paper some innovative issues regarding the thickness performance and the grade slab interaction are developed. Finally, a series of graphical results are obtained allowing for the pre-design.En el presente artículo se realiza un estudio comparativo entre tres procedimientos de cálculo para obtener espesores en soleras de hormigón ligeramente armadas por retracción, con cargas debidas a estanterías. Las fórmulas para cargas aisladas de Westergaard no tienen para este caso una aplicación directa debido a la influencia del resto de soportes y su cercanía. El estudio comparativo se realiza en primer lugar mediante nomogramas de cálculo de la bibliografía; en segundo lugar, la solera se discretiza con elementos finitos y apoya sobre el terreno modelizado con coeficiente de balasto, y en tercer lugar, mediante elementos finitos tridimensionales sólidos que representan la base y la explanada, desarrollándose aspectos novedosos en el tratamiento del conjunto solera-terreno tanto en sus expresiones como en su interacción. Asimismo, se obtienen una serie de gráficas que permiten realizar predimensionados.

Uncertain relational reasoning in the parietal cortex.

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Ragni, Marco; Franzmeier, Imke; Maier, Simon; Knauff, Markus

2016-04-01

The psychology of reasoning is currently transitioning from the study of deductive inferences under certainty to inferences that have degrees of uncertainty in both their premises and conclusions; however, only a few studies have explored the cortical basis of uncertain reasoning. Using transcranial magnetic stimulation (TMS), we show that areas in the right superior parietal lobe (rSPL) are necessary for solving spatial relational reasoning problems under conditions of uncertainty. Twenty-four participants had to decide whether a single presented order of objects agreed with a given set of indeterminate premises that could be interpreted in more than one way. During the presentation of the order, 10-Hz TMS was applied over the rSPL or a sham control site. Right SPL TMS during the inference phase disrupted performance in uncertain relational reasoning. Moreover, we found differences in the error rates between preferred mental models, alternative models, and inconsistent models. Our results suggest that different mechanisms are involved when people reason spatially and evaluate different kinds of uncertain conclusions. Copyright © 2016 Elsevier Inc. All rights reserved.

A INFLUÊNCIA DOS VALORES RELATIVOS AO TRABALHO NAS DECISÕES DE CARREIRA: UM ESTUDO SOBRE AS PERSPECTIVAS DE DISCENTES DE INSTITUIÇÕES DE ENSINO SUPERIOR

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Taís de Andrade

Full Text Available Este estudo tem como objetivo analisar a influência dos Valores Relativos ao Trabalho sobre as Âncoras de Carreira, a partir da perspectiva de discentes de instituições de ensino superior. Para o alcance deste objetivo, partiu-se de duas perspectivas teóricas: a abordagem de Valores do Trabalho proposta por Ros, Schwartz e Surkis (1999 e Porto e Pilati (2010 e as Âncoras de Carreira propostas por Schein (1993. Visando atingir o objetivo do estudo, realizou-se uma pesquisa quantitativa, de caráter descritivo do tipo survey. O instrumento preenchido por 958 discentes foi baseado na Escala Revisada de Valores Relativos ao Trabalho (EVT-R, de Porto e Pilati (2010, e no Inventário de Âncoras de Carreira, desenvolvido por Schein (1993. Considerando o modelo proposto, optou-se por trabalhar com modelagem de equações estruturais. Os principais resultados encontrados expõem que os valores prioritários entre os discentes investigados, foram Segurança e Realização. Em relação à carreira, houve o predomínio das âncoras Segurança/estabilidade e Desafio Puro. Ainda, a análise do modelo estrutural permitiu identificar que o construto Valores do Trabalho explica 30,5% (R2 da variância do construto Âncoras de Carreira. De maneira geral, tal achado sustenta a importância das demandas internas, representadas pelos valores que os indivíduos atribuem ao trabalho, sobre as decisões de carreira, pressuposto esse com poucas evidências empíricas, até então.

Abnormal parietal function in conversion paresis.

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Marije van Beilen

Full Text Available The etiology of medically unexplained symptoms such as conversion disorder is poorly understood. This is partly because the interpretation of neuroimaging results in conversion paresis has been complicated by the use of different control groups, tasks and statistical comparisons. The present study includes these different aspects in a single data set. In our study we included both normal controls and feigners to control for conversion paresis. We studied both movement execution and imagery, and we contrasted both within-group and between-group activation. Moreover, to reveal hemisphere-specific effects that have not been reported before, we performed these analyses using both flipped and unflipped data. This approach resulted in the identification of abnormal parietal activation which was specific for conversion paresis patients. Patients also showed reduced activity in the prefrontal cortex, supramarginal gyrus and precuneus, including hemisphere-specific activation that is lateralized in the same hemisphere, regardless of right- or left-sided paresis. We propose that these regions are candidates for an interface between psychological mechanisms and disturbed higher-order motor control. Our study presents an integrative neurophysiological view of the mechanisms that contribute to the etiology of this puzzling psychological disorder, which can be further investigated with other types of conversion symptoms.

Meta-analysis: how does posterior parietal cortex contribute to reasoning?

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Wendelken, Carter

2015-01-01

Reasoning depends on the contribution of posterior parietal cortex (PPC). But PPC is involved in many basic operations—including spatial attention, mathematical cognition, working memory, long-term memory, and language—and the nature of its contribution to reasoning is unclear. Psychological theories of the processes underlying reasoning make divergent claims about the neural systems that are likely to be involved, and better understanding the specific contribution of PPC can help to inform these theories. We set out to address several competing hypotheses, concerning the role of PPC in reasoning: (1) reasoning involves application of formal logic and is dependent on language, with PPC activation for reasoning mainly reflective of linguistic processing; (2) reasoning involves probabilistic computation and is thus dependent on numerical processing mechanisms in PPC; and (3) reasoning is built upon the representation and processing of spatial relations, and PPC activation associated with reasoning reflects spatial processing. We conducted two separate meta-analyses. First, we pooled data from our own studies of reasoning in adults, and examined activation in PPC regions of interest (ROI). Second, we conducted an automated meta-analysis using Neurosynth, in which we examined overlap between activation maps associated with reasoning and maps associated with other key functions of PPC. In both analyses, we observed reasoning-related activation concentrated in the left Inferior Parietal Lobe (IPL). Reasoning maps demonstrated the greatest overlap with mathematical cognition. Maintenance, visuospatial, and phonological processing also demonstrated some overlap with reasoning, but a large portion of the reasoning map did not overlap with the map for any other function. This evidence suggests that the PPC’s contribution to reasoning may be most closely related to its role in mathematical cognition, but that a core component of this contribution may be specific to

Meta-analysis: How does posterior parietal cortex contribute to reasoning?

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Carter eWendelken

2015-01-01

Full Text Available Reasoning depends on the contribution of posterior parietal cortex (PPC. But PPC is involved in many basic operations -- including spatial attention, mathematical cognition, working memory, long-term memory, and language -- and the nature of its contribution to reasoning is unclear. Psychological theories of the processes underlying reasoning make divergent claims about the neural systems that are likely to be involved, and better understanding the specific contribution of PPC can help to inform these theories. We set out to address several competing hypotheses, concerning the role of PPC in reasoning: 1 reasoning involves application of formal logic and is dependent on language, with PPC activation for reasoning mainly reflective of linguistic processing, 2 reasoning involves probabilistic computation and is thus dependent on numerical processing mechanisms in PPC, and 3 reasoning is built upon the representation and processing of spatial relations, and PPC activation associated with reasoning reflects spatial processing. We conducted two separate meta-analyses. First, we pooled data from our own studies of reasoning in adults, and examined activation in PPC regions of interest. Second, we conducted an automated meta-analysis using Neurosynth, in which we examined overlap between activation maps associated with reasoning and maps associated with other key functions of PPC. In both analyses, we observed reasoning-related activation concentrated in the left Inferior Parietal Lobe (IPL. Reasoning maps demonstrated the greatest overlap with mathematical cognition. Maintenance, visuospatial, and phonological processing also demonstrated some overlap with reasoning, but a large portion of the reasoning map did not overlap with the map for any other function. This evidence suggests that the PPC’s contribution to reasoning may be most closely related to its role in mathematical cognition, but that a core component of this contribution may be specific

Frontal Parietal Control Network Regulates the Anti-Correlated Default and Dorsal Attention Networks

OpenAIRE

Gao, Wei; Lin, Weili

2011-01-01

Recent reports demonstrate the anti-correlated behaviors between the default and the dorsal attention (DA) networks. We aimed to investigate the roles of the frontal parietal control (FPC) network in regulating the two anti-correlated networks through three experimental conditions, including resting, continuous self-paced/attended sequential finger tapping (FT), and natural movie watching (MW), respectively. The two goal-directed tasks were chosen to engage either one of the two competing net...

Counteracting fatigue in multiple sclerosis with right parietal anodal transcranial direct current stimulation

OpenAIRE

Katrin Hanken; Katrin Hanken; Mona Bosse; Kim Möhrke; Paul Eling; Andreas Kastrup; Andrea Antal; Helmut Hildebrandt; Helmut Hildebrandt

2016-01-01

Background: Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time and errors with prolonged time-on-task. Objectives: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. Methods: In study I, a randomized double-blind placebo-controlled study, anoda...

Dominant lymph drainage patterns in the occipital and parietal regions: evaluation of lymph nodes in patients with skin cancer of the head.

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Maeda, Taku; Yamamoto, Yuhei; Furukawa, Hiroshi; Oyama, Akihiko; Funayama, Emi; Murao, Naoki; Hayashi, Toshihiko

2017-08-01

The purpose of this study was to evaluate the superficial lymph drainage patterns of primary skin cancers of the head arising from the occipital or parietal region. The dominant patterns of lymph drainage were retrospectively reviewed in eight patients aged 36-85 years with skin cancers in the occipital or parietal region in whom sentinel lymph node biopsy or lymph node dissection had been performed at Hokkaido University Hospital between January 1981 and December 2015. Lymph drainage was mainly to the occipital (6/8, 75%), level II (5/8, 63%), and level V lymph nodes (5/8, 63%). Of the six patients with drainage to the occipital lymph nodes, four (67%) also had drainage to level V nodes. The dominant lymph drainage pattern in patients with skin cancer arising from the occipital or parietal region was to the occipital, level II, and level V lymph nodes. Further, lymph tended to drain directly from the occipital region to the level V lymph nodes.

Midfrontal Theta and Posterior Parietal Alpha Band Oscillations Support Conflict Resolution in a Masked Affective Priming Task.

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Jiang, Jun; Bailey, Kira; Xiao, Xiao

2018-01-01

Past attempts to characterize the neural mechanisms of affective priming have conceptualized it in terms of classic cognitive conflict, but have not examined the neural oscillatory mechanisms of subliminal affective priming. Using behavioral and electroencephalogram (EEG) time frequency (TF) analysis, the current study examines the oscillatory dynamics of unconsciously triggered conflict in an emotional facial expressions version of the masked affective priming task. The results demonstrate that the power dynamics of conflict are characterized by increased midfrontal theta activity and suppressed parieto-occipital alpha activity. Across-subject and within-trial correlation analyses further confirmed this pattern. Phase synchrony and Granger causality analyses (GCAs) revealed that the fronto-parietal network was involved in unconscious conflict detection and resolution. Our findings support a response conflict account of affective priming, and reveal the role of the fronto-parietal network in unconscious conflict control.

Midfrontal Theta and Posterior Parietal Alpha Band Oscillations Support Conflict Resolution in a Masked Affective Priming Task

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Jun Jiang

2018-05-01

Full Text Available Past attempts to characterize the neural mechanisms of affective priming have conceptualized it in terms of classic cognitive conflict, but have not examined the neural oscillatory mechanisms of subliminal affective priming. Using behavioral and electroencephalogram (EEG time frequency (TF analysis, the current study examines the oscillatory dynamics of unconsciously triggered conflict in an emotional facial expressions version of the masked affective priming task. The results demonstrate that the power dynamics of conflict are characterized by increased midfrontal theta activity and suppressed parieto-occipital alpha activity. Across-subject and within-trial correlation analyses further confirmed this pattern. Phase synchrony and Granger causality analyses (GCAs revealed that the fronto-parietal network was involved in unconscious conflict detection and resolution. Our findings support a response conflict account of affective priming, and reveal the role of the fronto-parietal network in unconscious conflict control.

It's how you get there: Walking down a virtual alley activates premotor and parietal areas

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Johanna eWagner

2014-02-01

Full Text Available Voluntary drive is crucial for motor learning, therefore we are interested in the role that motor planning plays in gait movements. In this study we examined the impact of an interactive Virtual Environment (VE feedback task on the EEG patterns during robot assisted walking. We compared walking in the VE modality to two control conditions: walking with a visual attention paradigm, in which visual stimuli were unrelated to the motor task; and walking with mirror feedback, in which participants observed their own movements. Eleven healthy participants were considered. Application of independent component analysis to the EEG revealed three independent component clusters in premotor and parietal areas showing increased activity during walking with the adaptive VE training paradigm compared to the control conditions. During the interactive VE walking task spectral power in frequency ranges 8-12Hz, 15-20Hz and 23-40Hz was significantly (p ≤ 0.05 decreased. This power decrease is interpreted as a correlate of an active cortical area. Furthermore activity in the premotor cortex revealed gait cycle related modulations significantly different (p ≤ 0.05 from baseline in the frequency range 23-40Hz during walking. These modulations were significantly (p ≤ 0.05 reduced depending on gait cycle phases in the interactive VE walking task compared to the control conditions.We demonstrate that premotor and parietal areas show increased activity during walking with the adaptive VE training paradigm, when compared to walking with mirror- and movement unrelated feedback. Previous research has related a premotor-parietal network to motor planning and motor intention. We argue that movement related interactive feedback enhances motor planning and motor intention. We hypothesize that this might improve gait recovery during rehabilitation.

The Acid-Secreting Parietal Cell as an Endocrine Source of Sonic Hedgehog During Gastric Repair

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Engevik, Amy C.; Feng, Rui; Yang, Li

2013-01-01

Sonic Hedgehog (Shh) has been shown to regulate wound healing in various tissues. Despite its known function in tissue regeneration, the role of Shh secreted from the gastric epithelium during tissue repair in the stomach remains unknown. Here we tested the hypothesis that Shh secreted from the acid-secreting parietal cell is a fundamental circulating factor that drives gastric repair. A mouse model expressing a parietal cell-specific deletion of Shh (PC-ShhKO) was generated using animals bearing loxP sites flanking exon 2 of the Shh gene (Shhflx/flx) and mice expressing a Cre transgene under the control of the H+,K+-ATPase β-subunit promoter. Shhflx/flx, the H+,K+-ATPase β-subunit promoter, and C57BL/6 mice served as controls. Ulcers were induced via acetic acid injury. At 1, 2, 3, 4, 5, and 7 days after the ulcer induction, gastric tissue and blood samples were collected. Parabiosis experiments were used to establish the effect of circulating Shh on ulcer repair. Control mice exhibited an increased expression of Shh in the gastric tissue and plasma that correlated with the repair of injury within 7 days after surgery. PC-ShhKO mice showed a loss of ulcer repair and reduced Shh tissue and plasma concentrations. In a parabiosis experiment whereby a control mouse was paired with a PC-ShhKO littermate and both animals subjected to gastric injury, a significant increase in the circulating Shh was measured in both parabionts. Elevated circulating Shh concentrations correlated with the repair of gastric ulcers in the PC-ShhKO parabionts. Therefore, the acid-secreting parietal cell within the stomach acts as an endocrine source of Shh during repair. PMID:24092639

Role of the right inferior parietal cortex in auditory selective attention: An rTMS study.

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Bareham, Corinne A; Georgieva, Stanimira D; Kamke, Marc R; Lloyd, David; Bekinschtein, Tristan A; Mattingley, Jason B

2018-02-01

Selective attention is the process of directing limited capacity resources to behaviourally relevant stimuli while ignoring competing stimuli that are currently irrelevant. Studies in healthy human participants and in individuals with focal brain lesions have suggested that the right parietal cortex is crucial for resolving competition for attention. Following right-hemisphere damage, for example, patients may have difficulty reporting a brief, left-sided stimulus if it occurs with a competitor on the right, even though the same left stimulus is reported normally when it occurs alone. Such "extinction" of contralesional stimuli has been documented for all the major sense modalities, but it remains unclear whether its occurrence reflects involvement of one or more specific subregions of the temporo-parietal cortex. Here we employed repetitive transcranial magnetic stimulation (rTMS) over the right hemisphere to examine the effect of disruption of two candidate regions - the supramarginal gyrus (SMG) and the superior temporal gyrus (STG) - on auditory selective attention. Eighteen neurologically normal, right-handed participants performed an auditory task, in which they had to detect target digits presented within simultaneous dichotic streams of spoken distractor letters in the left and right channels, both before and after 20 min of 1 Hz rTMS over the SMG, STG or a somatosensory control site (S1). Across blocks, participants were asked to report on auditory streams in the left, right, or both channels, which yielded focused and divided attention conditions. Performance was unchanged for the two focused attention conditions, regardless of stimulation site, but was selectively impaired for contralateral left-sided targets in the divided attention condition following stimulation of the right SMG, but not the STG or S1. Our findings suggest a causal role for the right inferior parietal cortex in auditory selective attention. Copyright © 2017 Elsevier Ltd. All rights

Comparing TMS perturbations to occipital and parietal cortices in concurrent TMS-fMRI studies-Methodological considerations

DEFF Research Database (Denmark)

Leitao, Joana; Thielscher, Axel; Tuennerhoff, Johannes

2017-01-01

the effect of transient perturbations on functional brain organization. This concurrent TMS-fMRI study applied TMS perturbation to occipital and parietal cortices with the aim to 'mimick' neglect and hemianopia. Based on the challenges and interpretational limitations of our own study we aim to provide...

Visual feature integration indicated by pHase-locked frontal-parietal EEG signals.

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Phillips, Steven; Takeda, Yuji; Singh, Archana

2012-01-01

The capacity to integrate multiple sources of information is a prerequisite for complex cognitive ability, such as finding a target uniquely identifiable by the conjunction of two or more features. Recent studies identified greater frontal-parietal synchrony during conjunctive than non-conjunctive (feature) search. Whether this difference also reflects greater information integration, rather than just differences in cognitive strategy (e.g., top-down versus bottom-up control of attention), or task difficulty is uncertain. Here, we examine the first possibility by parametrically varying the number of integrated sources from one to three and measuring phase-locking values (PLV) of frontal-parietal EEG electrode signals, as indicators of synchrony. Linear regressions, under hierarchical false-discovery rate control, indicated significant positive slopes for number of sources on PLV in the 30-38 Hz, 175-250 ms post-stimulus frequency-time band for pairs in the sagittal plane (i.e., F3-P3, Fz-Pz, F4-P4), after equating conditions for behavioural performance (to exclude effects due to task difficulty). No such effects were observed for pairs in the transverse plane (i.e., F3-F4, C3-C4, P3-P4). These results provide support for the idea that anterior-posterior phase-locking in the lower gamma-band mediates integration of visual information. They also provide a potential window into cognitive development, seen as developing the capacity to integrate more sources of information.

Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size.

Science.gov (United States)

Song, Chen; Sandberg, Kristian; Andersen, Lau Møller; Blicher, Jakob Udby; Rees, Geraint

2017-09-13

GABA is the primary inhibitory neurotransmitter in human brain. The level of GABA varies substantially across individuals, and this variability is associated with interindividual differences in visual perception. However, it remains unclear whether the association between GABA level and visual perception reflects a general influence of visual inhibition or whether the GABA levels of different cortical regions selectively influence perception of different visual features. To address this, we studied how the GABA levels of parietal and occipital cortices related to interindividual differences in size, orientation, and brightness perception. We used visual contextual illusion as a perceptual assay since the illusion dissociates perceptual content from stimulus content and the magnitude of the illusion reflects the effect of visual inhibition. Across individuals, we observed selective correlations between the level of GABA and the magnitude of contextual illusion. Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size and orientation preference in which neural responses to stimulus sizes and stimulus orientations are modulated by intraregional lateral connections. We propose that these lateral connections may underlie the selective influence of GABA on visual perception. SIGNIFICANCE STATEMENT GABA, the primary inhibitory neurotransmitter in human visual system, varies substantially across individuals. This interindividual variability in GABA level is linked to interindividual differences in many aspects of visual perception. However, the widespread influence of GABA raises the

Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size

Science.gov (United States)

Andersen, Lau Møller; Blicher, Jakob Udby

2017-01-01

GABA is the primary inhibitory neurotransmitter in human brain. The level of GABA varies substantially across individuals, and this variability is associated with interindividual differences in visual perception. However, it remains unclear whether the association between GABA level and visual perception reflects a general influence of visual inhibition or whether the GABA levels of different cortical regions selectively influence perception of different visual features. To address this, we studied how the GABA levels of parietal and occipital cortices related to interindividual differences in size, orientation, and brightness perception. We used visual contextual illusion as a perceptual assay since the illusion dissociates perceptual content from stimulus content and the magnitude of the illusion reflects the effect of visual inhibition. Across individuals, we observed selective correlations between the level of GABA and the magnitude of contextual illusion. Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size and orientation preference in which neural responses to stimulus sizes and stimulus orientations are modulated by intraregional lateral connections. We propose that these lateral connections may underlie the selective influence of GABA on visual perception. SIGNIFICANCE STATEMENT GABA, the primary inhibitory neurotransmitter in human visual system, varies substantially across individuals. This interindividual variability in GABA level is linked to interindividual differences in many aspects of visual perception. However, the widespread influence of GABA raises the

Separating recognition processes of declarative memory via anodal tDCS: boosting old item recognition by temporal and new item detection by parietal stimulation.

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Pisoni, Alberto; Turi, Zsolt; Raithel, Almuth; Ambrus, Géza Gergely; Alekseichuk, Ivan; Schacht, Annekathrin; Paulus, Walter; Antal, Andrea

2015-01-01

There is emerging evidence from imaging studies that parietal and temporal cortices act together to achieve successful recognition of declarative information; nevertheless, the precise role of these regions remains elusive. To evaluate the role of these brain areas in declarative memory retrieval, we applied bilateral tDCS, with anode over the left and cathode over the right parietal or temporal cortices separately, during the recognition phase of a verbal learning paradigm using a balanced old-new decision task. In a parallel group design, we tested three different groups of healthy adults, matched for demographic and neurocognitive status: two groups received bilateral active stimulation of either the parietal or the temporal cortex, while a third group received sham stimulation. Accuracy, discriminability index (d') and reaction times of recognition memory performance were measurements of interest. The d' sensitivity index and accuracy percentage improved in both active stimulation groups, as compared with the sham one, while reaction times remained unaffected. Moreover, the analysis of accuracy revealed a different effect of tDCS for old and new item recognition. While the temporal group showed enhanced performance for old item recognition, the parietal group was better at correctly recognising new ones. Our results support an active role of both of these areas in memory retrieval, possibly underpinning different stages of the recognition process.

Dissociable Changes of Frontal and Parietal Cortices in Inherent Functional Flexibility across the Human Life Span.

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Yin, Dazhi; Liu, Wenjing; Zeljic, Kristina; Wang, Zhiwei; Lv, Qian; Fan, Mingxia; Cheng, Wenhong; Wang, Zheng

2016-09-28

Extensive evidence suggests that frontoparietal regions can dynamically update their pattern of functional connectivity, supporting cognitive control and adaptive implementation of task demands. However, it is largely unknown whether this flexibly functional reconfiguration is intrinsic and occurs even in the absence of overt tasks. Based on recent advances in dynamics of resting-state functional resonance imaging (fMRI), we propose a probabilistic framework in which dynamic reconfiguration of intrinsic functional connectivity between each brain region and others can be represented as a probability distribution. A complexity measurement (i.e., entropy) was used to quantify functional flexibility, which characterizes heterogeneous connectivity between a particular region and others over time. Following this framework, we identified both functionally flexible and specialized regions over the human life span (112 healthy subjects from 13 to 76 years old). Across brainwide regions, we found regions showing high flexibility mainly in the higher-order association cortex, such as the lateral prefrontal cortex (LPFC), lateral parietal cortex, and lateral temporal lobules. In contrast, visual, auditory, and sensory areas exhibited low flexibility. Furthermore, we observed that flexibility of the right LPFC improved during maturation and reduced due to normal aging, with the opposite occurring for the left lateral parietal cortex. Our findings reveal dissociable changes of frontal and parietal cortices over the life span in terms of inherent functional flexibility. This study not only provides a new framework to quantify the spatiotemporal behavior of spontaneous brain activity, but also sheds light on the organizational principle behind changes in brain function across the human life span. Recent neuroscientific research has demonstrated that the human capability of adaptive task control is primarily the result of the flexible operation of frontal brain networks. However

The gastric acid secretagogue gastrin-releasing peptide and the inhibitor oxyntomodulin do not exert their effect directly on the parietal cell in the rat

DEFF Research Database (Denmark)

Poulsen, Steen Seier; Holst, J J

1988-01-01

in vitro by measuring [14C]-aminopyrine accumulation, a reliable index of H+ generation, in isolated rat parietal cells. However, neither gastrin-releasing peptide nor oxyntomodulin influenced basal acid secretion or histamine-stimulated gastric acid secretion. Electron-microscopic studies of unstimulated...... and histamine-stimulated parietal cells confirmed that the cells retained the normal morphology of intracellular organelles and that the cells responded to physiological stimulation by marked expansion of the intracellular canaliculi....

Rat glomerular epithelial cells in culture. Parietal or visceral epithelial origin

International Nuclear Information System (INIS)

Norgaard, J.O.

1987-01-01

Isolated glomeruli from rats were explanted under standard culture conditions and outgrowths were studied by light and electron microscopy in order to identify the cells. Rat glomerular samples contained 20 to 30% structurally well-preserved encapsulated glomeruli which had a large rate of attachment to the substrate and very constantly gave rise to cellular outgrowth. In order to label cells from which outgrowth originated the glomerular incorporation of [ 3 H]thymidine was studied in the preattachment phase. By light and electron microscope autoradiograph it was demonstrated that label was located only over visceral and parietal epithelial cells during the first 3 days of culture. Incorporation of [ 3 H]thymidine was seen in mesangial cells after 5 days, i.e., after the glomeruli had attached to the culture vessels and the initial outgrowth had appeared. Consequently the first cells to grow out were of epithelial origin. Glomeruli were then incubated with [ 3 H]thymidine for the first 2 1/2 days of culture in order to label the epithelial cells, then were allowed to attach to the substrate and induce cell outgrowth. By light microscope autoradiography performed with the outgrowths in situ two types of cells with labeled nuclei were seen: (a) a small, polyhedral ciliated cell which grew in colonies where the cells were joined by junctional complexes (type I), and (b) a second very large, often multinucleated cell (type II). Based on the structural resemblance with their counterparts in situ and on comparisons with positively identified visceral epithelial cells in outgrowths from other species it is suggested that type I cells are derived from the parietal epithelium of Bowman's capsule and type II cells from the visceral epithelium

10 Hz rTMS over right parietal cortex alters sense of agency during self-controlled movements

DEFF Research Database (Denmark)

Ritterband-Rosenbaum, Anina; Karabanov, Anke N; Christensen, Mark Schram

2014-01-01

A large body of fMRI and lesion-literature has provided evidence that the Inferior Parietal Cortex (IPC) is important for sensorimotor integration and sense of agency (SoA). We used repetitive transcranial magnetic stimulation (rTMS) to explore the role of the IPC during a validated SoA detection...

Frontal and parietal transcranial magnetic stimulation (TMS) disturbs programming of saccadic eye movements.

Science.gov (United States)

Zangemeister, W H; Canavan, A G; Hoemberg, V

1995-11-01

Transcranial magnetic stimulation (TMS) of human motor cortex typically evoked motor responses. TMS has failed to elicit eye movements in humans, whereas prolongations of saccadic latency have been reported with TMS. In previous studied we demonstrated that saccades can be abolished or saccadic trajectories can be changed through TMS in the 100 msec before saccade onset. This effect was especially marked when TMS was applied parietally. TMS never influenced a saccade in flight. Simulations of predictive experimental saccades that were impaired through TMS of the frontal or parietal cortex demonstrated especially that the dynamics of small saccades were markedly influenced, resulting in a significant decrease in acceleration and amplitude, or an almost complete inhibition. The impact of inhibition through TMS was critically dependent on timing: early TMS (-70 msec) had a much larger inhibitory effect than late TMS (-20 msec) on experimental saccades. Differential timing of TMS in influencing the cortical control signal is demonstrated through simulations of a reciprocally innervated eye movement model that paralleled empirically determined changes in eye movement dynamics after real TMS. There is a reasonable match between the model and the experimental data. We conclude that the inhibitory action of a presaccadic disturbance, such as a TMS pulse, on saccadic programming is inversely related to timing and amplitude of the predicted saccade.

Early Left Parietal Activity Elicited by Direct Gaze: A High-Density EEG Study

Science.gov (United States)

Burra, Nicolas; Kerzel, Dirk; George, Nathalie

2016-01-01

Gaze is one of the most important cues for human communication and social interaction. In particular, gaze contact is the most primary form of social contact and it is thought to capture attention. A very early-differentiated brain response to direct versus averted gaze has been hypothesized. Here, we used high-density electroencephalography to test this hypothesis. Topographical analysis allowed us to uncover a very early topographic modulation (40–80 ms) of event-related responses to faces with direct as compared to averted gaze. This modulation was obtained only in the condition where intact broadband faces–as opposed to high-pass or low-pas filtered faces–were presented. Source estimation indicated that this early modulation involved the posterior parietal region, encompassing the left precuneus and inferior parietal lobule. This supports the idea that it reflected an early orienting response to direct versus averted gaze. Accordingly, in a follow-up behavioural experiment, we found faster response times to the direct gaze than to the averted gaze broadband faces. In addition, classical evoked potential analysis showed that the N170 peak amplitude was larger for averted gaze than for direct gaze. Taken together, these results suggest that direct gaze may be detected at a very early processing stage, involving a parallel route to the ventral occipito-temporal route of face perceptual analysis. PMID:27880776

Navigating actions through the rodent parietal cortex

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Jonathan R. Whitlock

2014-05-01

Full Text Available The posterior parietal cortex (PPC participates in a manifold of cognitive functions, including visual attention, working memory, spatial processing and movement planning. Given the vast interconnectivity of PPC with sensory and motor areas, it is not surprising that neuronal recordings show that PPC often encodes mixtures of spatial information as well as the movements required to reach a goal. Recent work sought to discern the relative strength of spatial versus motor signaling in PPC by recording single unit activity in PPC of freely behaving rats during selective changes in either the spatial layout of the local environment or in the pattern of locomotor behaviors executed during navigational tasks. The results revealed unequivocally a predominant sensitivity of PPC neurons to locomotor action structure, with subsets of cells even encoding upcoming movements more than 1 second in advance. In light of these and other recent findings in the field, I propose that one of the key contributions of PPC to navigation is the synthesis of goal-directed behavioral sequences, and that the rodent PPC may serve as an apt system to investigate cellular mechanisms for spatial motor planning as traditionally studied in humans and monkeys.

Larger right posterior parietal volume in action video game experts: a behavioral and voxel-based morphometry (VBM study.

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Satoshi Tanaka

Full Text Available Recent studies suggest that action video game players exhibit superior performance in visuospatial cognitive tasks compared with non-game players. However, the neural basis underlying this visuospatial cognitive performance advantage remains largely unknown. The present human behavioral and imaging study compared gray matter volume in action video game experts and non-experts using structural magnetic resonance imaging and voxel-based morphometry analysis. The results revealed significantly larger gray matter volume in the right posterior parietal cortex in experts compared with non-experts. Furthermore, the larger gray matter volume in the right posterior parietal cortex significantly correlated with individual performance in a visual working memory task in experts. These results suggest that differences in brain structure may be linked to extensive video game play, leading to superior visuospatial cognitive performance in action video game experts.

Parietal Fast Sleep Spindle Density Decrease in Alzheimer's Disease and Amnesic Mild Cognitive Impairment

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Gorgoni, Maurizio; Lauri, Giulia; Truglia, Ilaria; Cordone, Susanna; Sarasso, Simone; Scarpelli, Serena; Mangiaruga, Anastasia; D'Atri, Aurora; Tempesta, Daniela; Ferrara, Michele; Marra, Camillo; Rossini, Paolo Maria; De Gennaro, Luigi

2016-01-01

Several studies have identified two types of sleep spindles: fast (13–15 Hz) centroparietal and slow (11–13 Hz) frontal spindles. Alterations in spindle activity have been observed in Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). Only few studies have separately assessed fast and slow spindles in these patients showing a reduction of fast spindle count, but the possible local specificity of this phenomenon and its relation to cognitive decline severity are not clear. Moreover, fast and slow spindle density have never been assessed in AD/MCI. We have assessed fast and slow spindles in 15 AD patients, 15 amnesic MCI patients, and 15 healthy elderly controls (HC). Participants underwent baseline polysomnographic recording (19 cortical derivations). Spindles during nonrapid eye movements sleep were automatically detected, and spindle densities of the three groups were compared in the derivations where fast and slow spindles exhibited their maximum expression (parietal and frontal, resp.). AD and MCI patients showed a significant parietal fast spindle density decrease, positively correlated with Minimental State Examination scores. Our results suggest that AD-related changes in spindle density are specific for frequency and location, are related to cognitive decline severity, and may have an early onset in the pathology development. PMID:27066274

A micromethod for the assay of cellular secretory physiology: Application to rabbit parietal cells

International Nuclear Information System (INIS)

Adrian, T.E.; Goldenring, J.R.; Oddsdottir, M.; Zdon, M.J.; Zucker, K.A.; Lewis, J.J.; Modlin, I.M.

1989-01-01

A micromethod for investigating secretory physiology in isolated cells was evaluated. The method utilized a specially designed polycarbonate incubation chamber to provide constant oxygenation to cells incubating in a 96-well microtiter plate. Cells were rapidly separated from media by vacuum filtration. Isolated parietal cells were utilized to demonstrate the versatility of the method for assay of intracellular accumulation of [ 14 C]-aminopyrine, secretion of intrinsic factor into the medium, and assay of intracellular cAMP. Histamine stimulated the uptake of [ 14 C]aminopyrine and intrinsic factor secretion in a sustained and linear fashion. At the end of the 2-h period uptake of aminopyrine and secretion of intrinsic factor were increased 17- and 5-fold, respectively. This response to histamine was accompanied by a rapid and sustained 3-fold rise in intracellular cyclic AMP. In contrast, carbamylcholine caused a transient increase in [ 14 C]aminopyrine accumulation and intrinsic factor secretion which was most pronounced during the first 10 min and had almost ceased by 30 min. Carbamylcholine had no effect on intracellular cAMP levels. This new method, which can handle 400 replicates using parietal cells from the fundic mucosa of a single rabbit, is suitable for studying the time course of intracellular events which accompany general secretory processes

Inconsistent Effects of Parietal α-tACS on Pseudoneglect across Two Experiments: A Failed Internal Replication

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Domenica Veniero

2017-06-01

Full Text Available Transcranial electrical stimulation (tES is being investigated as an experimental and clinical interventional technique in human participants. While promising, important limitations have been identified, including weak effect sizes and high inter- and intra-individual variability of outcomes. Here, we compared two “inhibitory” tES-techniques with supposedly different mechanisms of action as to their effects on performance in a visuospatial attention task, and report on a direct replication attempt. In two experiments, 2 × 20 healthy participants underwent tES in three separate sessions testing different protocols (10 min stimulation each with a montage targeting right parietal cortex (right parietal–left frontal, electrode-sizes: 3cm × 3cm–7 cm × 5 cm, while performing a perceptual line bisection (landmark task. The tES-protocols were compared as to their ability to modulate pseudoneglect (thought to be under right hemispheric control. In experiment 1, sham-tES was compared to transcranial alternating current stimulation at alpha frequency (10 Hz; α-tACS (expected to entrain “inhibitory” alpha oscillations and to cathodal transcranial direct current stimulation (c-tDCS (shown to suppress neuronal spiking activity. In experiment 2, we attempted to replicate the findings of experiment 1, and establish frequency-specificity by adding a 45 Hz-tACS condition to α-tACS and sham. In experiment 1, right parietal α-tACS led to the expected changes in spatial attention bias, namely a rightward shift in subjective midpoint estimation (relative to sham. However, this was not confirmed in experiment 2 and in the complete sample. Right parietal c-tDCS and 45 Hz-tACS had no effect. These results highlight the importance of replication studies, adequate statistical power and optimizing tES-interventions for establishing the robustness and reliability of electrical stimulation effects, and best practice.

Activation in the Right Inferior Parietal Lobule Reflects the Representation of Musical Structure beyond Simple Pitch Discrimination

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Royal, Isabelle; Vuvan, Dominique T.; Zendel, Benjamin Rich; Robitaille, Nicolas; Schönwiesner, Marc; Peretz, Isabelle

2016-01-01

Pitch discrimination tasks typically engage the superior temporal gyrus and the right inferior frontal gyrus. It is currently unclear whether these regions are equally involved in the processing of incongruous notes in melodies, which requires the representation of musical structure (tonality) in addition to pitch discrimination. To this aim, 14 participants completed two tasks while undergoing functional magnetic resonance imaging, one in which they had to identify a pitch change in a series of non-melodic repeating tones and a second in which they had to identify an incongruous note in a tonal melody. In both tasks, the deviants activated the right superior temporal gyrus. A contrast between deviants in the melodic task and deviants in the non-melodic task (melodic > non-melodic) revealed additional activity in the right inferior parietal lobule. Activation in the inferior parietal lobule likely represents processes related to the maintenance of tonal pitch structure in working memory during pitch discrimination. PMID:27195523

Mechanisms within the Parietal Cortex Correlate with the Benefits of Random Practice in Motor Adaptation

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Benjamin Thürer

2017-08-01

Full Text Available The motor learning literature shows an increased retest or transfer performance after practicing under unstable (random conditions. This random practice effect (also known as contextual interference effect is frequently investigated on the behavioral level and discussed in the context of mechanisms of the dorsolateral prefrontal cortex and increased cognitive efforts during movement planning. However, there is a lack of studies examining the random practice effect in motor adaptation tasks and, in general, the underlying neural processes of the random practice effect are not fully understood. We tested 24 right-handed human subjects performing a reaching task using a robotic manipulandum. Subjects learned to adapt either to a blocked or a random schedule of different force field perturbations while subjects’ electroencephalography (EEG was recorded. The behavioral results showed a distinct random practice effect in terms of a more stabilized retest performance of the random compared to the blocked practicing group. Further analyses showed that this effect correlates with changes in the alpha band power in electrodes over parietal areas. We conclude that the random practice effect in this study is facilitated by mechanisms within the parietal cortex during movement execution which might reflect online feedback mechanisms.

Prefrontal, posterior parietal and sensorimotor network activity underlying speed control during walking

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Thomas C Bulea

2015-05-01

Full Text Available Accumulating evidence suggests cortical circuits may contribute to control of human locomotion. Here, noninvasive electroencephalography (EEG recorded from able-bodied volunteers during a novel treadmill walking paradigm was used to assess neural correlates of walking. A systematic processing method, including a recently developed subspace reconstruction algorithm, reduced movement-related EEG artifact prior to independent component analysis and dipole source localization. We quantified cortical activity while participants tracked slow and fast target speeds across two treadmill conditions: an active mode that adjusted belt speed based on user movements and a passive mode reflecting a typical treadmill. Our results reveal frequency specific, multi-focal task related changes in cortical oscillations elicited by active walking. Low γ band power, localized to the prefrontal and posterior parietal cortices, was significantly increased during double support and early swing phases, critical points in the gait cycle since the active controller adjusted speed based on pelvis position and swing foot velocity. These phasic γ band synchronizations provide evidence that prefrontal and posterior parietal networks, previously implicated in visuo-spatial and somotosensory integration, are engaged to enhance lower limb control during gait. Sustained μ and β band desynchronization within sensorimotor cortex, a neural correlate for movement, was observed during walking thereby validating our methods for isolating cortical activity. Our results also demonstrate the utility of EEG recorded during locomotion for probing the multi-regional cortical networks which underpin its execution. For example, the cortical network engagement elicited by the active treadmill suggests that it may enhance neuroplasticity for more effective motor training.

Object integration requires attention: Visual search for Kanizsa figures in parietal extinction.

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Gögler, Nadine; Finke, Kathrin; Keller, Ingo; Müller, Hermann J; Conci, Markus

2016-11-01

The contribution of selective attention to object integration is a topic of debate: integration of parts into coherent wholes, such as in Kanizsa figures, is thought to arise either from pre-attentive, automatic coding processes or from higher-order processes involving selective attention. Previous studies have attempted to examine the role of selective attention in object integration either by employing visual search paradigms or by studying patients with unilateral deficits in selective attention. Here, we combined these two approaches to investigate object integration in visual search in a group of five patients with left-sided parietal extinction. Our search paradigm was designed to assess the effect of left- and right-grouped nontargets on detecting a Kanizsa target square. The results revealed comparable reaction time (RT) performance in patients and controls when they were presented with displays consisting of a single to-be-grouped item that had to be classified as target vs. nontarget. However, when display size increased to two items, patients showed an extinction-specific pattern of enhanced RT costs for nontargets that induced a partial shape grouping on the right, i.e., in the attended hemifield (relative to the ungrouped baseline). Together, these findings demonstrate a competitive advantage for right-grouped objects, which in turn indicates that in parietal extinction, attentional competition between objects particularly limits integration processes in the contralesional, i.e., left hemifield. These findings imply a crucial contribution of selective attentional resources to visual object integration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differential roles of polar orbital prefrontal cortex and parietal lobes in logical reasoning with neutral and negative emotional content.

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Eimontaite, Iveta; Goel, Vinod; Raymont, Vanessa; Krueger, Frank; Schindler, Igor; Grafman, Jordan

2018-05-14

To answer the question of how brain pathology affects reasoning about negative emotional content, we administered a disjunctive logical reasoning task involving arguments with neutral content (e.g. Either there are tigers or women in NYC, but not both; There are no tigers in NYC; There are women in NYC) and emotionally laden content (e.g. Either there are pedophiles or politicians in Texas, but not both; There are politicians in Texas; There are no pedophiles in Texas) to 92 neurological patients with focal lesions to various parts of the brain. A Voxel Lesion Symptom Mapping (VLSM) analysis identified 16 patients, all with lesions to the orbital polar prefrontal cortex (BA 10 & 11), as being selectively impaired in the emotional reasoning condition. Another 17 patients, all with lesions to the parietal cortex, were identified as being impaired in the neutral content condition. The reasoning scores of these two patient groups, along with 23 matched normal controls, underwent additional analysis to explore the effect of belief bias. This analysis revealed that the differences identified above were largely driven by trials where there was an incongruency between the believability of the conclusion and the validity of the argument (i.e. valid argument /false conclusion or invalid argument /true conclusion). Patients with lesions to polar orbital prefrontal cortex underperformed in incongruent emotional content trials and over performed in incongruent neutral content trials (compared to both normal controls and patients with parietal lobe lesions). Patients with lesions to parietal lobes underperformed normal controls (at a trend level) in neutral trials where there was a congruency between the believability of the conclusion and the validity of the argument (i.e. valid argument/true conclusion or invalid argument/false conclusion). We conclude that lesions to the polar orbital prefrontal cortex (i) prevent these patients from enjoying any emotionally induced cognitive

Effect of transcranial magnetic stimulation (TMS on parietal and premotor cortex during planning of reaching movements.

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Pierpaolo Busan

Full Text Available BACKGROUND: Cerebral activation during planning of reaching movements occurs both in the superior parietal lobule (SPL and premotor cortex (PM, and their activation seems to take place in parallel. METHODOLOGY: The activation of the SPL and PM has been investigated using transcranial magnetic stimulation (TMS during planning of reaching movements under visual guidance. PRINCIPAL FINDINGS: A facilitory effect was found when TMS was delivered on the parietal cortex at about half of the time from sight of the target to hand movement, independently of target location in space. Furthermore, at the same stimulation time, a similar facilitory effect was found in PM, which is probably related to movement preparation. CONCLUSIONS: This data contributes to the understanding of cortical dynamics in the parieto-frontal network, and suggests that it is possible to interfere with the planning of reaching movements at different cortical points within a particular time window. Since similar effects may be produced at similar times on both the SPL and PM, parallel processing of visuomotor information is likely to take place in these regions.

Changes in cerebral activations during movement execution and imagery after parietal cortex TMS interleaved with 3T MRI

NARCIS (Netherlands)

de Vries, Paulien M.; de Jong, Bauke M.; Bohning, Daryl E.; Walker, John A.; George, Mark S.; Leenders, Klaus L.

2009-01-01

The left parietal cortex contributes to goal-directed hand movement. In this study, we targeted this region with transcranial magnetic stimulation (TMS) to assess the effects on a wider distributed circuitry related to motor control. Ten healthy subjects underwent 3 Tesla functional magnetic

Elaboration versus suppression of cued memories: influence of memory recall instruction and success on parietal lobe, default network, and hippocampal activity.

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Gimbel, Sarah I; Brewer, James B

2014-01-01

Functional imaging studies of episodic memory retrieval consistently report task-evoked and memory-related activity in the medial temporal lobe, default network and parietal lobe subregions. Associated components of memory retrieval, such as attention-shifts, search, retrieval success, and post-retrieval processing also influence regional activity, but these influences remain ill-defined. To better understand how top-down control affects the neural bases of memory retrieval, we examined how regional activity responses were modulated by task goals during recall success or failure. Specifically, activity was examined during memory suppression, recall, and elaborative recall of paired-associates. Parietal lobe was subdivided into dorsal (BA 7), posterior ventral (BA 39), and anterior ventral (BA 40) regions, which were investigated separately to examine hypothesized distinctions in sub-regional functional responses related to differential attention-to-memory and memory strength. Top-down suppression of recall abolished memory strength effects in BA 39, which showed a task-negative response, and BA 40, which showed a task-positive response. The task-negative response in default network showed greater negatively-deflected signal for forgotten pairs when task goals required recall. Hippocampal activity was task-positive and was influenced by memory strength only when task goals required recall. As in previous studies, we show a memory strength effect in parietal lobe and hippocampus, but we show that this effect is top-down controlled and sensitive to whether the subject is trying to suppress or retrieve a memory. These regions are all implicated in memory recall, but their individual activity patterns show distinct memory-strength-related responses when task goals are varied. In parietal lobe, default network, and hippocampus, top-down control can override the commonly identified effects of memory strength.

Elaboration versus suppression of cued memories: influence of memory recall instruction and success on parietal lobe, default network, and hippocampal activity.

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Sarah I Gimbel

Full Text Available Functional imaging studies of episodic memory retrieval consistently report task-evoked and memory-related activity in the medial temporal lobe, default network and parietal lobe subregions. Associated components of memory retrieval, such as attention-shifts, search, retrieval success, and post-retrieval processing also influence regional activity, but these influences remain ill-defined. To better understand how top-down control affects the neural bases of memory retrieval, we examined how regional activity responses were modulated by task goals during recall success or failure. Specifically, activity was examined during memory suppression, recall, and elaborative recall of paired-associates. Parietal lobe was subdivided into dorsal (BA 7, posterior ventral (BA 39, and anterior ventral (BA 40 regions, which were investigated separately to examine hypothesized distinctions in sub-regional functional responses related to differential attention-to-memory and memory strength. Top-down suppression of recall abolished memory strength effects in BA 39, which showed a task-negative response, and BA 40, which showed a task-positive response. The task-negative response in default network showed greater negatively-deflected signal for forgotten pairs when task goals required recall. Hippocampal activity was task-positive and was influenced by memory strength only when task goals required recall. As in previous studies, we show a memory strength effect in parietal lobe and hippocampus, but we show that this effect is top-down controlled and sensitive to whether the subject is trying to suppress or retrieve a memory. These regions are all implicated in memory recall, but their individual activity patterns show distinct memory-strength-related responses when task goals are varied. In parietal lobe, default network, and hippocampus, top-down control can override the commonly identified effects of memory strength.

Metaplasia of the parietal layer of Bowman's capsule. A histopathological survey of the human kidney

OpenAIRE

Haensly, William E.; Lee, J.C.

1986-01-01

Human kidney sections taken at autopsy were examined to determine the incidence of metaplasia of the Bowman's parietal epithelium. Autopsy records were consulted to determine if there was any correlation between clinical disease, histopathological changes in organ systems and metaplasia of Bowman's capsule. The sections represented both sexes in 9 age groups from 2 to 87 years. The sections were fixed in neutral formalin, embedded in paraffin, sectioned at 6 pm...

Diffusion Tensor Magnetic Resonance Imaging Finding of Discrepant Fractional Anisotropy Between the Frontal and Parietal Lobes After Whole-Brain Irradiation in Childhood Medulloblastoma Survivors: Reflection of Regional White Matter Radiosensitivity?

International Nuclear Information System (INIS)

Qiu Deqiang; Kwong, Dora; Chan, Godfrey; Leung, Lucullus; Khong, P.-L.

2007-01-01

Purpose: To test the hypothesis that fractional anisotropy (FA) is more severely reduced in white matter of the frontal lobe compared with the parietal lobe after receiving the same whole-brain irradiation dose in a cohort of childhood medulloblastoma survivors. Methods and Materials: Twenty-two medulloblastoma survivors (15 male, mean [± SD] age = 12.1 ± 4.6 years) and the same number of control subjects (15 male, aged 12.0 ± 4.2 years) were recruited for diffusion tensor magnetic resonance imaging scans. Using an automated tissue classification method and the Talairach Daemon atlas, FA values of frontal and parietal lobes receiving the same radiation dose, and the ratio between them were quantified and denoted as FFA, PFA, and FA f/p , respectively. The Mann-Whitney U test was used to test for significant differences of FFA, PFA, and FA f/p between medulloblastoma survivors and control subjects. Results: Frontal lobe and parietal lobe white matter FA were found to be significantly less in medulloblastoma survivors compared with control subjects (frontal p = 0.001, parietal p = 0.026). Moreover, these differences were found to be discrepant, with the frontal lobe having a significantly larger difference in FA compared with the parietal lobe. The FA f/p of control and medulloblastoma survivors was 1.110 and 1.082, respectively (p = 0.029). Conclusion: Discrepant FA changes after the same irradiation dose suggest radiosensitivity of the frontal lobe white matter compared with the parietal lobe. Special efforts to address the potentially vulnerable frontal lobe after treatment with whole-brain radiation may be needed so as to balance disease control and treatment-related morbidity

The role of prefrontal and parietal cortices in esthetic appreciation of representational and abstract art: a TMS study.

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Cattaneo, Zaira; Lega, Carlotta; Gardelli, Chiara; Merabet, Lotfi B; Cela-Conde, Camilo J; Nadal, Marcos

2014-10-01

To explain the biological foundations of art appreciation is to explain one of our species' distinctive traits. Previous neuroimaging and electrophysiological studies have pointed to the prefrontal and the parietal cortex as two critical regions mediating esthetic appreciation of visual art. In this study, we applied transcranial magnetic stimulation (TMS) over the left prefrontal cortex and the right posterior parietal cortex while participants were evaluating whether they liked, and by how much, a particular painting. By depolarizing cell membranes in the targeted regions, TMS transiently interferes with the activity of specific cortical areas, which allows clarifying their role in a given task. Our results show that both regions play a fundamental role in mediating esthetic appreciation. Critically though, the effects of TMS varied depending on the type of art considered (i.e. representational vs. abstract) and on participants' a-priori inclination toward one or the other. Copyright © 2014 Elsevier Inc. All rights reserved.

Increased gray matter density in the parietal cortex of mathematicians: a voxel-based morphometry study.

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Aydin, K; Ucar, A; Oguz, K K; Okur, O O; Agayev, A; Unal, Z; Yilmaz, S; Ozturk, C

2007-01-01

The training to acquire or practicing to perform a skill, which may lead to structural changes in the brain, is called experience-dependent structural plasticity. The main purpose of this cross-sectional study was to investigate the presence of experience-dependent structural plasticity in mathematicians' brains, which may develop after long-term practice of mathematic thinking. Twenty-six volunteer mathematicians, who have been working as academicians, were enrolled in the study. We applied an optimized method of voxel-based morphometry in the mathematicians and the age- and sex-matched control subjects. We assessed the gray and white matter density differences in mathematicians and the control subjects. Moreover, the correlation between the cortical density and the time spent as an academician was investigated. We found that cortical gray matter density in the left inferior frontal and bilateral inferior parietal lobules of the mathematicians were significantly increased compared with the control subjects. Furthermore, increase in gray matter density in the right inferior parietal lobule of the mathematicians was strongly correlated with the time spent as an academician (r = 0.84; P mathematicians' brains revealed increased gray matter density in the cortical regions related to mathematic thinking. The correlation between cortical density increase and the time spent as an academician suggests experience-dependent structural plasticity in mathematicians' brains.

Tamaño relativo encefálico e índices cerebrales en Vanellus c. chilensis (Aves: Charadriidae Relative encephalic size and cerebral indices of Vanellus c. chilensis (Aves: Charadriidae

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ESTELA PISTONE

2002-09-01

Full Text Available Se analizó la composición cuantitativa encefálica y se estimaron índices cerebrales en Vanellus c. chilensis (tero o queltehue. Se estimó el volumen porcentual e índices cerebrales del encéfalo total y de siete de sus componentes, como así también los núcleos de relevo de las vías trigeminal, visual y acústica. El telencéfalo es el componente de mayor volumen relativo, siendo el neoestriado la estructura telencefálica de tamaño superior. El desarrollo del estriado propiamente dicho, tecto óptico y los núcleos de relevo de las vías visual y trigeminal concuerdan con la dieta carnívora de Vanellus c. chilensis. El tamaño relativo del Wulst y de los núcleos de la vía acústica se asocia a las complicadas tácticas que utiliza esta especie en la defensa del nido. Los índices cerebrales de las estructuras encefálicas analizadas indican que Vanellus c. chilensis es un ave progresivaThe quantitative encephalic composition and cerebral indices of Vanellus c. chilensis (southern lapwing were analyzed. The percentual volumes and cerebral indices for the whole encephalon and for seven components were calculated as well as relevous nuclei of the trigeminal, visual and acoustic pathways. The component of greater relative volume is the telencephalon. The neostriatum is the most developed encephalic structure. Developing of bulbus olfactorius, striatum, tectum opticum and relevous nuclei of visual and trigeminal pathways are according with the carnivorous diet of Vanellus c. chilensis. The relative size of Wulst and relevous nuclei of acoustic pathway appears associated with the complex tactics used by this species in the defense of nest. Cerebral indices of all the analyzed structures suggest that Vanellus c. chilensis is a progresive bird

Right Fronto-Parietal Dysfunction in Children with ADHD and Developmental Dyslexia as Determined by Line Bisection Judgements

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Waldie, Karen E.; Hausmann, Markus

2010-01-01

Visual line bisection is a reliable and valid laterality task that is typically used with patients with acquired brain damage to assess right hemisphere functioning. Neurologically normal individuals tend to bisect lines to the left of the objective midline whereas those with right parietal damage bisect lines to the right. In this study children…

Posterior parietal cortex role in a sensorimotor task performance Papel do córtex parietal posterior na realização de uma tarefa sensório-motora

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Sergio Nader

2008-06-01

Full Text Available This study aimed to elucidate electrophysiological and cortical mechanisms involved in anticipatory actions when individuals had to catch balls in free drop; specifically through quantitative electroencephalography (qEEG alpha absolute power changes. The sample was composed for 23 health subjects, both sexes, with ages varying between 25 and 40 years, absence of mental and physical illness, right handed and don't make use of any psychoactive or psychotropic substance at the time of the study. The experiment consisted of a task of catching balls in free drop. The three-way ANOVA analysis demonstrated an interaction between moment and position factors in left parietal posterior cortex (PPC (p=0.001. Through the experimental task employed, this area demonstrated a differentiated activity involving expectation, planning and preparedness in the ball's drop task.O estudo tentou elucidar mecanismos eletrofisiológicos e corticais envolvidos em ações antecipatórias quando os sujeitos testados tiveram que apreender bolas em queda livre; especificamente através de mudanças na potência absoluta na banda alfa da eletrencefalografia quantitativa (EEGq. A amostra foi composta por 23 sujeitos sadios, ambos os sexos, idade entre variando entre 25 e 40 anos, sem comprometimento físico e mental, destros, e não fazer uso de nenhuma substância psicoativa ou psicotrópicos até o momento do estudo. O experimento consistiu de uma tarefa de apreensão de bolas em queda livre. A análise three-way ANOVA demonstrou uma interação entre os fatores momento e posição no córtex parietal posterior (CPP esquerdo (p=0,001. Através da tarefa experimental empregada, esta área demonstrou uma atividade diferenciada envolvendo expectativa, planejamento e prontidão na tarefa de queda de bolas.

Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory

OpenAIRE

Masahiro eKawasaki; Masahiro eKawasaki; Masahiro eKawasaki; Keiichi eKitajo; Keiichi eKitajo; Yoko eYamaguchi

2014-01-01

In humans, theta phase (4–8 Hz) synchronization observed on electroencephalography (EEG) plays an important role in the manipulation of mental representations during working memory (WM) tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from...

Desarrollo de efectos cerámicos como acabados superficiales, mediante tecnología de inyección digital

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Spain S.A., Ferro

2012-04-01

Full Text Available Ferro Spain SA has tackled the practical viability of tile surfaces decoration by means of applying layers of reduced thickness by means of the use of digital injection technology by inkjet and, specifically, relating to effects and superficial finishes different from colouring. It has been studied several mechanisms which allow to get those effects and the influence of the main variables. It has also been assessed the obtained results dealing with the current regulations as in the case of non-slip effect.

Ferro Spain, S.A. ha abordado la viabilidad práctica de la decoración de superficies cerámicas mediante la aplicación de capas de muy reducido espesor mediante el uso de la tecnología de inyección digital por chorro de tinta y, específicamente en lo relativo a efectos y acabados superficiales distintos de la coloración. Se han estudiado los diversos mecanismos que permiten obtener dichos efectos y la influencia de las principales variables. También ha evaluado los resultados obtenidos atendiendo a las normativas vigentes como es el caso del efecto antideslizante.

Dysregulated left inferior parietal activity in schizophrenia and depression: functional connectivity and characterization

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Veronika I. Müller

2013-06-01

Full Text Available The inferior parietal cortex (IPC is a heterogeneous region that is known to be involved in a multitude of diverse different tasks and processes, though its contribution to these often-complex functions is yet poorly understood. In a previous study we demonstrated that patients with depression failed to deactivate the left IPC during processing of congruent audiovisual information. We now found the same dysregulation (same region and condition in schizophrenia. By using task-independent (resting state and task-dependent (MACM analyses we aimed at characterizing this particular region with regard to its connectivity and function. Across both approaches, results revealed functional connectivity of the left inferior parietal seed region with bilateral IPC, precuneus and posterior cingulate cortex (PrC/PCC, medial orbitofrontal cortex (mOFC, left middle frontal (MFG as well as inferior frontal (IFG gyrus. Network-level functional characterization further revealed that on the one hand, all interconnected regions are part of a network involved in memory processes. On the other hand, sub-networks are formed when emotion, language, social cognition and reasoning processes are required. Thus, the IPC-region that is dysregulated in both depression and schizophrenia is functionally connected to a network of regions which, depending on task demands may form sub-networks. These results therefore indicate that dysregulation of left IPC in depression and schizophrenia might not only be connected to deficits in audiovisual integration, but is possibly also associated to impaired memory and deficits in emotion processing in these patient groups.

Integration of Visual and Proprioceptive Limb Position Information in Human Posterior Parietal, Premotor, and Extrastriate Cortex.

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Limanowski, Jakub; Blankenburg, Felix

2016-03-02

The brain constructs a flexible representation of the body from multisensory information. Previous work on monkeys suggests that the posterior parietal cortex (PPC) and ventral premotor cortex (PMv) represent the position of the upper limbs based on visual and proprioceptive information. Human experiments on the rubber hand illusion implicate similar regions, but since such experiments rely on additional visuo-tactile interactions, they cannot isolate visuo-proprioceptive integration. Here, we independently manipulated the position (palm or back facing) of passive human participants' unseen arm and of a photorealistic virtual 3D arm. Functional magnetic resonance imaging (fMRI) revealed that matching visual and proprioceptive information about arm position engaged the PPC, PMv, and the body-selective extrastriate body area (EBA); activity in the PMv moreover reflected interindividual differences in congruent arm ownership. Further, the PPC, PMv, and EBA increased their coupling with the primary visual cortex during congruent visuo-proprioceptive position information. These results suggest that human PPC, PMv, and EBA evaluate visual and proprioceptive position information and, under sufficient cross-modal congruence, integrate it into a multisensory representation of the upper limb in space. The position of our limbs in space constantly changes, yet the brain manages to represent limb position accurately by combining information from vision and proprioception. Electrophysiological recordings in monkeys have revealed neurons in the posterior parietal and premotor cortices that seem to implement and update such a multisensory limb representation, but this has been difficult to demonstrate in humans. Our fMRI experiment shows that human posterior parietal, premotor, and body-selective visual brain areas respond preferentially to a virtual arm seen in a position corresponding to one's unseen hidden arm, while increasing their communication with regions conveying visual

Study of the paleolithic parietal art from the archaeological perspective: old ghosts / new approaches

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Clara Hernando Álvarez

2010-03-01

Full Text Available This paper aims to analyse the parietal palaeolithic graphic designs from an archaeological perspective, leaving aside the aesthetic ties of traditional historiography. Traditional European analysis techniques of palaeolithic rock art will be contrasted with new interdisciplinary applications, looking for an archaeological knowledge about the artistic graphic expression of prehistoric societies. Finally, a methodological trial will be suggestedapplying the Harris Matrix in the reading and arrangement (ordination of the palaeolithic graphic designs of the central panel of Llonin's cave (Peñamellera Alta, Asturias.

Parietal cells-new perspectives in glomerular disease.

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Miesen, Laura; Steenbergen, Eric; Smeets, Bart

2017-07-01

In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman's capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and podocytes have a common mesenchymal origin and are the result of divergent differentiation during embryogenesis. Podocytes and PTECs are highly differentiated cells with well-established functions pertaining to the maintenance of the filtration barrier and transport, respectively. For PECs, no specific function other than a structural one has been known until recently. Possible important functions for PECs in the fate of the glomerulus in glomerular disease have now become apparent: (1) PECs may be involved in the replacement of lost podocytes; (2) PECs form the basis of extracapillary proliferative lesions and subsequent sclerosis in glomerular disease. In addition to the acknowledgement that PECs are crucial in glomerular disease, knowledge has been gained regarding the molecular processes driving the phenotypic changes and behavior of PECs. Understanding these molecular processes is important for the development of specific therapeutic approaches aimed at either stimulation of the regenerative function of PECs or inhibition of the pro-sclerotic action of PECs. In this review, we discuss recent advances pertaining to the role of PECs in glomerular regeneration and disease and address the major molecular processes involved.

Functional Clustering of the Human Inferior Parietal Lobule by Whole-Brain Connectivity Mapping of Resting-State Functional Magnetic Resonance Imaging Signals

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Li, Chiang-Shan R.

2014-01-01

Abstract The human inferior parietal lobule (IPL) comprised the lateral bank of the intraparietal sulcus, angular gyrus, and supramarginal gyrus, defined on the basis of anatomical landmarks and cytoarchitectural organization of neurons. However, it is not clear as to whether the three areas represent functional subregions within the IPL. For instance, imaging studies frequently identified clusters of activities that cut across areal boundaries. Here, we used resting-state functional magnetic resonance imaging (fMRI) data to examine how individual voxels within the IPL are best clustered according to their connectivity to the whole brain. The results identified a best estimate of seven clusters that are hierarchically arranged as the anterior, middle, and posterior subregions. The anterior, middle, and posterior IPL are each significantly connected to the somatomotor areas, superior/middle/inferior frontal gyri, and regions of the default mode network. This functional segregation is supported by recent cytoarchitechtonics and tractography studies. IPL showed hemispheric differences in connectivity that accord with a predominantly left parietal role in tool use and language processing and a right parietal role in spatial attention and mathematical cognition. The functional clusters may also provide a more parsimonious and perhaps even accurate account of regional activations of the IPL during a variety of cognitive challenges, as reported in earlier fMRI studies. PMID:24308753

Influence of beta blockade on gastric acid secretion and changes in gastric mucosal blood flow before and after parietal cell vagotomy in dogs and man

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Hovendal, C P; Bech, K; Bekker, C

1983-01-01

The aim of the present study was, in paired experiments in dogs, to examine the effect of beta-receptor blockade on gastric acid secretion and mucosal blood flow before and after parietal cell vagotomy (PCV). The secretory response to pentagastrin was reduced after vagotomy. beta-Adrenergic block......The aim of the present study was, in paired experiments in dogs, to examine the effect of beta-receptor blockade on gastric acid secretion and mucosal blood flow before and after parietal cell vagotomy (PCV). The secretory response to pentagastrin was reduced after vagotomy. beta...

Perceptual difficulty in source memory encoding and retrieval: prefrontal versus parietal electrical brain activity.

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Kuo, Trudy Y; Van Petten, Cyma

2008-01-01

It is well established that source memory retrieval--remembering relationships between a core item and some additional attribute of an event--engages prefrontal cortex (PFC) more than simple item memory. In event-related potentials (ERPs), this is manifest in a late-onset difference over PFC between studied items which mandate retrieval of a second attribute, and unstudied items which can be immediately rejected. Although some sorts of attribute conjunctions are easier to remember than others, the role of source retrieval difficulty on prefrontal activity has received little attention. We examined memory for conjunctions of object shape and color when color was an integral part of the depicted object, and when monochrome objects were surrounded by colored frames. Source accuracy was reliably worse when shape and color were spatially separated, but prefrontal activity did not vary across the object-color and frame-color conditions. The insensitivity of prefrontal ERPs to this perceptual manipulation of difficulty stands in contrast to their sensitivity to encoding task: deliberate voluntary effort to integrate objects and colors during encoding reduced prefrontal activity during retrieval, but perceptual organization of stimuli did not. The amplitudes of ERPs over parietal cortex were larger for frame-color than object-color stimuli during both study and test phases of the memory task. Individual variability in parietal ERPs was strongly correlated with memory accuracy, which we suggest reflects a contribution of visual working memory to long-term memory. We discuss multiple bottlenecks for source memory performance.

What is said or how it is said makes a difference: role of the right fronto-parietal operculum in emotional prosody as revealed by repetitive TMS.

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van Rijn, Sophie; Aleman, André; van Diessen, Eric; Berckmoes, Celine; Vingerhoets, Guy; Kahn, René S

2005-06-01

Emotional signals in spoken language can be conveyed by semantic as well as prosodic cues. We investigated the role of the fronto-parietal operculum, a somatosensory area where the lips, tongue and jaw are represented, in the right hemisphere to detection of emotion in prosody vs. semantics. A total of 14 healthy volunteers participated in the present experiment, which involved transcranial magnetic stimulation (TMS) in combination with frameless stereotaxy. As predicted, compared with sham stimulation, TMS over the right fronto-parietal operculum differentially affected the reaction times for detection of emotional prosody vs. emotional semantics, showing that there is a dissociation at a neuroanatomical level. Detection of withdrawal emotions (fear and sadness) in prosody was delayed significantly by TMS. No effects of TMS were observed for approach emotions (happiness and anger). We propose that the right fronto-parietal operculum is not globally involved in emotion evaluation, but sensitive to specific forms of emotional discrimination and emotion types.

The role of human parietal area 7A as a link between sequencing in hand actions and in overt speech production

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Stefan eHeim

2012-12-01

Full Text Available Research on the evolutionary basis of the human language faculty has proposed the mirror neuron system as a link between motor processing and speech development. Consequently, most work has focussed on the left inferior frontal cortex, in particular Broca's region, and the left inferior parietal cortex. However, the direct link between planning of hand motor and speech actions remains to be elucidated. Thus, the present study investigated whether sequencing of hand motor actions vs. speech motor actions has a common neural denominator. For the hand motor task, 25 subjects performed single, repeated, or sequenced button presses with either the left or right hand. The speech task was in analogy; the same subjects produced the syllable "po" once or repeatedly, or a sequence of different syllables (po-pi-po. Speech motor vs. hand motor effectors resulted in increased perisylvian activation including Broca's region (left area 44 and areas medially adjacent to left area 45. In contrast, common activation for sequenced vs. repeated production of button presses and syllables revealed the effector-independent involvement of left area 7A in the superior parietal lobule (SPL in sequencing. These data demonstrate that sequencing of vocal gestures, an important precondition for ordered utterances and ultimately human speech, shares area 7A, rather than inferior parietal regions, as a common cortical module with hand motor sequencing. Interestingly, area 7A has previously also been shown to be involved in the observation of hand and non-hand actions. In combination with the literature, the present data thus suggest a distinction between area 44, which is specifically recruited for (cognitive aspects of speech, and SPL area 7A for general aspects of motor sequencing. In sum, the study demonstrates a yet little considered role of the superior parietal lobule in the origins of speech, and may be discussed in the light of embodiment of speech and language in the

Multi-Tasking and Choice of Training Data Influencing Parietal ERP Expression and Single-Trial Detection—Relevance for Neuroscience and Clinical Applications

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Kirchner, Elsa A.; Kim, Su Kyoung

2018-01-01

Event-related potentials (ERPs) are often used in brain-computer interfaces (BCIs) for communication or system control for enhancing or regaining control for motor-disabled persons. Especially results from single-trial EEG classification approaches for BCIs support correlations between single-trial ERP detection performance and ERP expression. Hence, BCIs can be considered as a paradigm shift contributing to new methods with strong influence on both neuroscience and clinical applications. Here, we investigate the relevance of the choice of training data and classifier transfer for the interpretability of results from single-trial ERP detection. In our experiments, subjects performed a visual-motor oddball task with motor-task relevant infrequent (targets), motor-task irrelevant infrequent (deviants), and motor-task irrelevant frequent (standards) stimuli. Under dual-task condition, a secondary senso-motor task was performed, compared to the simple-task condition. For evaluation, average ERP analysis and single-trial detection analysis with different numbers of electrodes were performed. Further, classifier transfer was investigated between simple and dual task. Parietal positive ERPs evoked by target stimuli (but not by deviants) were expressed stronger under dual-task condition, which is discussed as an increase of task emphasis and brain processes involved in task coordination and change of task set. Highest classification performance was found for targets irrespective whether all 62, 6 or 2 parietal electrodes were used. Further, higher detection performance of targets compared to standards was achieved under dual-task compared to simple-task condition in case of training on data from 2 parietal electrodes corresponding to results of ERP average analysis. Classifier transfer between tasks improves classification performance in case that training took place on more varying examples (from dual task). In summary, we showed that P300 and overlaying parietal positive

Cingulate, Frontal and Parietal Cortical Dysfunction in Attention-Deficit/Hyperactivity Disorder

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Bush, George

2011-01-01

Functional and structural neuroimaging have identified abnormalities of the brain that are likely to contribute to the neuropathophysiology of attention-deficit/hyperactivity disorder (ADHD). In particular, hypofunction of the brain regions comprising the cingulo-frontal-parietal (CFP) cognitive-attention network have been consistently observed across studies. These are major components of neural systems that are relevant to ADHD, including cognitive/attention networks, motor systems and reward/feedback-based processing systems. Moreover, these areas interact with other brain circuits that have been implicated in ADHD, such as the “default mode” resting state network. ADHD imaging data related to CFP network dysfunction will be selectively highlighted here to help facilitate its integration with the other information presented in this special issue. Together, these reviews will help shed light on the neurobiology of ADHD. PMID:21489409

Visual short-term memory load suppresses temporo-parietal junction activity and induces inattentional blindness.

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Todd, J Jay; Fougnie, Daryl; Marois, René

2005-12-01

The right temporo-parietal junction (TPJ) is critical for stimulus-driven attention and visual awareness. Here we show that as the visual short-term memory (VSTM) load of a task increases, activity in this region is increasingly suppressed. Correspondingly, increasing VSTM load impairs the ability of subjects to consciously detect the presence of a novel, unexpected object in the visual field. These results not only demonstrate that VSTM load suppresses TPJ activity and induces inattentional blindness, but also offer a plausible neural mechanism for this perceptual deficit: suppression of the stimulus-driven attentional network.

Differential contributions of the superior and inferior parietal cortex to feedback versus feedforward control of tools.

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Macuga, Kristen L; Frey, Scott H

2014-05-15

Damage to the superior and/or inferior parietal lobules (SPL, IPL) (Sirigu et al., 1996) or cerebellum (Grealy and Lee, 2011) can selectively disrupt motor imagery, motivating the hypothesis that these regions participate in predictive (i.e., feedforward) control. If so, then the SPL, IPL, and cerebellum should show greater activity as the demands on feedforward control increase from visually-guided execution (closed-loop) to execution without visual feedback (open-loop) to motor imagery. Using fMRI and a Fitts' reciprocal aiming task with tools directed at targets in far space, we found that the SPL and cerebellum exhibited greater activity during closed-loop control. Conversely, open-loop and imagery conditions were associated with increased activity within the IPL and prefrontal areas. These results are consistent with a superior-to-inferior gradient in the representation of feedback-to-feedforward control within the posterior parietal cortex. Additionally, the anterior SPL displayed greater activity when aiming movements were performed with a stick vs. laser pointer. This may suggest that it is involved in the remapping of far into near (reachable) space (Maravita and Iriki, 2004), or in distalization of the end-effector from hand to stick (Arbib et al., 2009). Copyright © 2014 Elsevier Inc. All rights reserved.

Subtle gray matter changes in temporo-parietal cortex associated with cardiovascular risk factors.

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de Toledo Ferraz Alves, Tânia Corrêa; Scazufca, Márcia; Squarzoni, Paula; de Souza Duran, Fábio Luiz; Tamashiro-Duran, Jaqueline Hatsuko; Vallada, Homero P; Andrei, Anna; Wajngarten, Mauricio; Menezes, Paulo R; Busatto, Geraldo F

2011-01-01

Vascular risk factors may play an important role in the pathophysiology of Alzheimer's disease (AD). While there is consistent evidence of gray matter (GM) abnormalities in earlier stages of AD, the presence of more subtle GM changes associated with vascular risk factors in the absence of clinically significant vascular events has been scarcely investigated. This study aimed to examine GM changes in elderly subjects with cardiovascular risk factors. We predicted that the presence of cardiovascular risk would be associated with GM abnormalities involving the temporal-parietal cortices and limbic structures. We recruited 248 dementia-free subjects, age range 66-75 years, from the population-based "São Paulo Ageing and Health Study", classified in accordance to their Framingham Coronary Heart Disease Risk (FCHDR) score to undergo an MRI scan. We performed an overall analysis of covariance, controlled to total GM and APOE4 status, to investigate the presence of regional GM abnormalities in association with FCHDR subgroups (high-risk, medium-risk, and low-risk), and followed by post hoc t-test. We also applied a co-relational design in order to investigate the presence of linear progression of the GM vulnerability in association with cardiovascular risk factor. Voxel-based morphometry showed that the presence of cardiovascular risk factors were associated with regional GM loss involving the temporal cortices bilaterally. Those results retained statistical significance after including APOE4 as a covariate of interest. We also observed that there was a negative correlation between FCHDR scores and rGM distribution in the parietal cortex. Subclinical cerebrovascular abnormalities involving GM loss may provide an important link between cardiovascular risk factors and AD.

Surfaceome and Proteosurfaceome in Parietal Monoderm Bacteria: Focus on Protein Cell-Surface Display

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Mickaël Desvaux

2018-02-01

Full Text Available The cell envelope of parietal monoderm bacteria (archetypal Gram-positive bacteria is formed of a cytoplasmic membrane (CM and a cell wall (CW. While the CM is composed of phospholipids, the CW is composed at least of peptidoglycan (PG covalently linked to other biopolymers, such as teichoic acids, polysaccharides, and/or polyglutamate. Considering the CW is a porous structure with low selective permeability contrary to the CM, the bacterial cell surface hugs the molecular figure of the CW components as a well of the external side of the CM. While the surfaceome corresponds to the totality of the molecules found at the bacterial cell surface, the proteinaceous complement of the surfaceome is the proteosurfaceome. Once translocated across the CM, secreted proteins can either be released in the extracellular milieu or exposed at the cell surface by associating to the CM or the CW. Following the gene ontology (GO for cellular components, cell-surface proteins at the CM can either be integral (GO: 0031226, i.e., the integral membrane proteins, or anchored to the membrane (GO: 0046658, i.e., the lipoproteins. At the CW (GO: 0009275, cell-surface proteins can be covalently bound, i.e., the LPXTG-proteins, or bound through weak interactions to the PG or wall polysaccharides, i.e., the cell wall binding proteins. Besides monopolypeptides, some proteins can associate to each other to form supramolecular protein structures of high molecular weight, namely the S-layer, pili, flagella, and cellulosomes. After reviewing the cell envelope components and the different molecular mechanisms involved in protein attachment to the cell envelope, perspectives in investigating the proteosurfaceome in parietal monoderm bacteria are further discussed.

Individual Differences in Reasoning and Visuospatial Attention are Associated with Prefrontal and Parietal White Matter Tracts in Healthy Older Adults

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Monge, Zachary A.; Greenwood, Pamela M.; Parasuraman, Raja; Strenziok, Maren

2016-01-01

Objective Although reasoning and attention are two cognitive processes necessary for ensuring the efficiency of many everyday activities in older adults, the role of white matter integrity in these processes has been little studied. This is an important question due to the role of white matter integrity as a neural substrate of cognitive aging. Here, we sought to examine the white matter tracts subserving reasoning and visuospatial attention in healthy older adults. Method Sixty-one adults aged 60 and older completed a battery of cognitive tests to assess reasoning and visuospatial attention. In addition, diffusion tensor images were collected to assess Fractional Anisotropy (FA) – a measure of white matter integrity. A principle component analysis of the test scores yielded two components: reasoning and visuospatial attention. Whole-brain correlations between FA and the cognitive components were submitted to probabilistic tractography analyses for visualization of cortical targets of tracts. Results For reasoning, bilateral thalamo-anterior prefrontal, anterior corpus callosum, and corpus callosum body tracts interconnecting the superior frontal cortices and right cingulum bundle were found. For visuospatial attention, a right inferior fronto-parietal tract, and bilateral parietal and temporal connections were found. Conclusions We conclude that in older adults, prefrontal cortex white matter tracts and interhemispheric communication are important in higher order cognitive functioning. On the other hand, right-sided fronto-parietal tracts appear to be critical for supporting control of cognitive processes, such as redirecting attention. Researchers may use our results to develop neuroscience-based interventions for older adults targeting brain mechanisms involved in cognitive plasticity. PMID:26986750

Prefrontal and parietal correlates of cognitive control related to the adult outcome of attention-deficit/hyperactivity disorder diagnosed in childhood.

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Schulz, Kurt P; Li, Xiaobo; Clerkin, Suzanne M; Fan, Jin; Berwid, Olga G; Newcorn, Jeffrey H; Halperin, Jeffrey M

2017-05-01

The protracted and highly variable development of prefrontal cortex regions that support cognitive control has been purported to shape the adult outcome of attention-deficit/hyperactivity disorder (ADHD). This neurodevelopmental model was tested in a prospectively followed sample of 27 adult probands who were diagnosed with ADHD in childhood and 28 carefully matched comparison subjects aged 21-28 years. Probands were classified with persistent ADHD or remitted ADHD. Behavioral and neural responses to the Stimulus and Response Conflict Task (SRCT) performed during functional magnetic resonance imaging (fMRI) were compared in probands and comparison subjects and in probands with persistent and remitted ADHD. Response speed and accuracy for stimulus, response, and combined conflicts did not differ across groups. Orbitofrontal, inferior frontal and parietal activation was lower in probands than comparison subjects, but only for combined conflicts, when demand for cognitive control was highest. Reduced activation for combined conflicts in probands was almost wholly attributable to the persistence of ADHD; orbitofrontal, inferior frontal, anterior cingulate and parietal activation was lower in probands with persistent ADHD than both probands with remitted ADHD and comparison subjects, but did not differ between probands with remitted ADHD and comparison subjects. These data provide the first evidence that prefrontal and parietal activation during cognitive control parallels the adult outcome of ADHD diagnosed in childhood, with persistence of symptoms linked to reduced activation and symptom recovery associated with activation indistinguishable from adults with no history of ADHD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transient contribution of left posterior parietal cortex to cognitive restructuring.

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Sutoh, Chihiro; Matsuzawa, Daisuke; Hirano, Yoshiyuki; Yamada, Makiko; Nagaoka, Sawako; Chakraborty, Sudesna; Ishii, Daisuke; Matsuda, Shingo; Tomizawa, Haruna; Ito, Hiroshi; Tsuji, Hiroshi; Obata, Takayuki; Shimizu, Eiji

2015-03-17

Cognitive restructuring is a fundamental method within cognitive behavioural therapy of changing dysfunctional beliefs into flexible beliefs and learning to react appropriately to the reality of an anxiety-causing situation. To clarify the neural mechanisms of cognitive restructuring, we designed a unique task that replicated psychotherapy during a brain scan. The brain activities of healthy male participants were analysed using functional magnetic resonance imaging. During the brain scan, participants underwent Socratic questioning aimed at cognitive restructuring regarding the necessity of handwashing after using the restroom. The behavioural result indicated that the Socratic questioning effectively decreased the participants' degree of belief (DOB) that they must wash their hands. Alterations in the DOB showed a positive correlation with activity in the left posterior parietal cortex (PPC) while the subject thought about and rated own belief. The involvement of the left PPC not only in planning and decision-making but also in conceptualization may play a pivotal role in cognitive restructuring.

Prefrontal and parietal activity is modulated by the rule complexity of inductive reasoning and can be predicted by a cognitive model.

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Jia, Xiuqin; Liang, Peipeng; Shi, Lin; Wang, Defeng; Li, Kuncheng

2015-01-01

In neuroimaging studies, increased task complexity can lead to increased activation in task-specific regions or to activation of additional regions. How the brain adapts to increased rule complexity during inductive reasoning remains unclear. In the current study, three types of problems were created: simple rule induction (i.e., SI, with rule complexity of 1), complex rule induction (i.e., CI, with rule complexity of 2), and perceptual control. Our findings revealed that increased activations accompany increased rule complexity in the right dorsal lateral prefrontal cortex (DLPFC) and medial posterior parietal cortex (precuneus). A cognitive model predicted both the behavioral and brain imaging results. The current findings suggest that neural activity in frontal and parietal regions is modulated by rule complexity, which may shed light on the neural mechanisms of inductive reasoning. Copyright © 2014. Published by Elsevier Ltd.

Activation of right parietal cortex during memory retrieval of nonlinguistic auditory stimuli.

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Klostermann, Ellen C; Loui, Psyche; Shimamura, Arthur P

2009-09-01

In neuroimaging studies, the left ventral posterior parietal cortex (PPC) is particularly active during memory retrieval. However, most studies have used verbal or verbalizable stimuli. We investigated neural activations associated with the retrieval of short, agrammatical music stimuli (Blackwood, 2004), which have been largely associated with right hemisphere processing. At study, participants listened to music stimuli and rated them on pleasantness. At test, participants made old/new recognition judgments with high/low confidence ratings. Right, but not left, ventral PPC activity was observed during the retrieval of these music stimuli. Thus, rather than indicating a special status of left PPC in retrieval, both right and left ventral PPC participate in memory retrieval, depending on the type of information that is to be remembered.

Effects of marijuana use on prefrontal and parietal volumes and cognition in emerging adults.

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Price, Jenessa S; McQueeny, Tim; Shollenbarger, Skyler; Browning, Erin L; Wieser, Jon; Lisdahl, Krista M

2015-08-01

Chronic marijuana (MJ) use among adolescents has been associated with structural and functional abnormalities, particularly in developing regions responsible for higher order cognition. This study investigated prefrontal (PFC) and parietal volumes and executive function in emerging adult MJ users and explored potential gender differences. Participants (ages 18-25) were 27 MJ users and 32 controls without neurologic or psychiatric disorders or heavy other drug use. A series of multiple regressions examined whether group status, past year MJ use, and their interactions with gender predicted ROI volumes. Post hoc analyses consisted of brain-behavior correlations between volumes and cognitive variables and Fisher's z tests to assess group differences. MJ users demonstrated significantly smaller medial orbitofrontal (mOFC; p = 0.004, FDR p = 0.024) and inferior parietal volumes (p = 0.04, FDR p = 0.12); follow-up regressions found that increased past year MJ use did not significantly dose-dependently predict smaller mOFC volume in a sub-sample of individuals with at least one past year MJ use. There were no significant gender interactions. There was a significant brain-behavior difference by group, such that smaller mOFC volumes were associated with poorer complex attention for MJ users (p < 0.05). Smaller mOFC volumes among MJ users suggest disruption of typical neurodevelopmental processes associated with regular MJ use for both genders. These results highlight the need for longitudinal, multi-modal imaging studies providing clearer information on timing of neurodevelopmental processes and neurocognitive impacts of youth MJ initiation.

Attention enhances multi-voxel representation of novel objects in frontal, parietal and visual cortices.

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Woolgar, Alexandra; Williams, Mark A; Rich, Anina N

2015-04-01

Selective attention is fundamental for human activity, but the details of its neural implementation remain elusive. One influential theory, the adaptive coding hypothesis (Duncan, 2001, An adaptive coding model of neural function in prefrontal cortex, Nature Reviews Neuroscience 2:820-829), proposes that single neurons in certain frontal and parietal regions dynamically adjust their responses to selectively encode relevant information. This selective representation may in turn support selective processing in more specialized brain regions such as the visual cortices. Here, we use multi-voxel decoding of functional magnetic resonance images to demonstrate selective representation of attended--and not distractor--objects in frontal, parietal, and visual cortices. In addition, we highlight a critical role for task demands in determining which brain regions exhibit selective coding. Strikingly, representation of attended objects in frontoparietal cortex was highest under conditions of high perceptual demand, when stimuli were hard to perceive and coding in early visual cortex was weak. Coding in early visual cortex varied as a function of attention and perceptual demand, while coding in higher visual areas was sensitive to the allocation of attention but robust to changes in perceptual difficulty. Consistent with high-profile reports, peripherally presented objects could also be decoded from activity at the occipital pole, a region which corresponds to the fovea. Our results emphasize the flexibility of frontoparietal and visual systems. They support the hypothesis that attention enhances the multi-voxel representation of information in the brain, and suggest that the engagement of this attentional mechanism depends critically on current task demands. Copyright © 2015 Elsevier Inc. All rights reserved.

Activity in the fronto-parietal network indicates numerical inductive reasoning beyond calculation : An fMRI study combined with a cognitive model

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Liang, Peipeng; Jia, Xiuqin; Taatgen, Niels A; Borst, Jelmer P; Li, Kuncheng

2016-01-01

Numerical inductive reasoning refers to the process of identifying and extrapolating the rule involved in numeric materials. It is associated with calculation, and shares the common activation of the fronto-parietal regions with calculation, which suggests that numerical inductive reasoning may

Efectos de las tolerancias de construcción en el desempeño de los pavimentos flexibles

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Cesar Sandoval

2013-01-01

Full Text Available La consistencia entre el diseño y construcción es un factor importante para el desempeño de los pavimentos, el espesor de las capas juega un papel importante en el comportamiento los pavimentos flexibles en servicio, las diferencias en espesor de las capas entre el diseño y el pavimento construido, son determinantes en el desempeño de la estructura. Las especificaciones técnicas colombianas de construcción de carreteras permiten unas tolerancias constructivas en el espesor de las capas de los pavimentos, que podrían incidir en la disminución de la vida útil de los pavimentos en servicio. Se realizó un estudio para determinar si las tolerancias permitidas, tienen efecto significativo en el desempeño de los pavimentos flexibles, se analizaron dos estructuras de pavimento, una de las cuales incluía una capa estabilizada con cemento. Utilizando técnicas estadísticas de simulación, para cada estructura se variaron de manera simultánea los espesores de todas sus capas dentro de las tolerancias permitidas, se realizaron 100 variaciones para cada estructura, y posteriormente se evaluó el desempeño de cada combinación de espesores utilizando el software de la Guía Mecanicista - Empírica para el diseño de pavimentos (MEPDG, los parámetros estudiados fueron rugosidad, fisuras piel de cocodrilo y ahuellamiento. Los resultados muestran que reducciones de espesor de la carpeta asfáltica y la capa estabilizada con cemento dentro de las tolerancias permitidas, tienen una incidencia significativa en el deterioro prematuro de los pavimentos. Las variaciones de espesor dentro de las tolerancias permitidas de las capas base y subbase, no tienen incidencia significativa en el desempeño de estas estructuras.

Pericardial Parietal Mesothelial Cells: Source of the Angiotensin-Converting-Enzyme of the Bovine Pericardial Fluid

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Ilsione Ribeiro de Sousa Filho

Full Text Available Abstract Background: Angiotensin II (Ang II, the primary effector hormone of the renin-angiotensin system (RAS, acts systemically or locally, being produced by the action of angiotensin-converting-enzyme (ACE on angiotensin I. Although several tissue RASs, such as cardiac RAS, have been described, little is known about the presence of an RAS in the pericardial fluid and its possible sources. Locally produced Ang II has paracrine and autocrine effects, inducing left ventricular hypertrophy, fibrosis, heart failure and cardiac dysfunction. Because of the difficulties inherent in human pericardial fluid collection, appropriate experimental models are useful to obtain data regarding the characteristics of the pericardial fluid and surrounding tissues. Objectives: To evidence the presence of constituents of the Ang II production paths in bovine pericardial fluid and parietal pericardium. Methods: Albumin-free crude extracts of bovine pericardial fluid, immunoprecipitated with anti-ACE antibody, were submitted to electrophoresis (SDS-PAGE and gels stained with coomassie blue. Duplicates of gels were probed with anti-ACE antibody. In the pericardial membranes, ACE was detected by use of immunofluorescence. Results: Immunodetection on nitrocellulose membranes showed a 146-KDa ACE isoform in the bovine pericardial fluid. On the pericardial membrane sections, ACE was immunolocalized in the mesothelial layer. Conclusions: The ACE isoform in the bovine pericardial fluid and parietal pericardium should account at least partially for the production of Ang II in the pericardial space, and should be considered when assessing the cardiac RAS.

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject.

Science.gov (United States)

Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe; Saridis, George A; Gjedde, Albert; Ptito, Maurice; Kupers, Ron

2013-01-01

Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA) 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong, and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI) revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

Transcranial magnetic stimulation of right inferior parietal cortex causally influences prefrontal activation for visual detection

DEFF Research Database (Denmark)

Leitao, Joana; Thielscher, Axel; Lee, Hweeling

2017-01-01

-parietal areas integrating the evidence into a decision variable that is compared to a decisional threshold. This concurrent transcranial magnetic stimulation (TMS)-fMRI study applied 10 Hz bursts of four TMS (or Sham) pulses to the intraparietal sulcus (IPS) to investigate the causal influence of IPS...... affect participants' performance accuracy, it affected how observers adjusted their response times after making an error. We therefore suggest that activation increases in superior frontal gyri for misses relative to correct responses may not be critical for signal detection performance, but rather...

Effect of pharmacological interventions on the fronto-cingulo-parietal cognitive control network in psychiatric disorders: a transdiagnostic systematic review of fMRI studies

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Therese eVan Amelsvoort

2016-05-01

Full Text Available Executive function deficits such as working memory, decision-making, and attention problems are a common feature of several psychiatric disorders for which no satisfactory treatment exists. Here, we transdiagnostically investigate the effects of pharmacological interventions (other than methylphenidate on the fronto-cingulo-parietal cognitive control network, in order to identify functional brain markers for future pro-cognitive pharmacological interventions. 29 manuscripts investigated the effect of pharmacological treatment on executive function-related brain correlates in psychotic disorders (n=11, depression (n=4, bipolar disorder (n=4, ADHD (n=4, OCD (n=2, smoking dependence (n=2, alcohol dependence (n=1 and pathological gambling (n=1. In terms of impact on the fronto-cingulo-parietal networks, the preliminary evidence for catechol-o-methyl-transferase inhibitors, nicotinic receptor agonists and atomoxetine suggested was relatively consistent, the data for atypical antipsychotics and anticonvulsants moderate, and interpretation of the data for antidepressants was hampered by the employed study designs. Increased activity in task-relevant areas and decreased activity in task-irrelevant areas were the most common transdiagnostic effects of pharmacological treatment. These markers showed good positive and moderate negative predictive value. It is concluded that fronto-cingulo-parietal activity changes can serve as a marker for future pro-cognitive interventions. Future recommendations include the use of randomized double-blind designs and selective cholinergic and glutamatergic compounds.

Surface Reconstruction from Parallel Curves with Application to Parietal Bone Fracture Reconstruction.

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Abdul Majeed

Full Text Available Maxillofacial trauma are common, secondary to road traffic accident, sports injury, falls and require sophisticated radiological imaging to precisely diagnose. A direct surgical reconstruction is complex and require clinical expertise. Bio-modelling helps in reconstructing surface model from 2D contours. In this manuscript we have constructed the 3D surface using 2D Computerized Tomography (CT scan contours. The fracture part of the cranial vault are reconstructed using GC1 rational cubic Ball curve with three free parameters, later the 2D contours are flipped into 3D with equidistant z component. The constructed surface is represented by contours blending interpolant. At the end of this manuscript a case report of parietal bone fracture is also illustrated by employing this method with a Graphical User Interface (GUI illustration.

Partial clinical response to 2 weeks of 2 Hz repetitive transcranial magnetic stimulation to the right parietal cortex in depression

NARCIS (Netherlands)

Schutter, D.J.L.G.; Laman, D.M.; Honk, E.J. van; Vergouwen, A.C.M.; Koerselman, F.

2009-01-01

The aim of this treatment study was to evaluate the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) over the right parietal cortex in depression. In a double-blind, sham-controlled design ten consecutive sessions of 2 Hz rTMS (inter-pulse interval 0.5 s) at 90% motor

Effects of Preweaning Polysensorial Enrichment upon Development of the Parietal Cortical Plate of Undernourished Rats: A Stereological Study

OpenAIRE

González, Héctor; Adaro, Luis; Hernández, Alejandro; Fernández, Víctor

2014-01-01

This investigation was undertaken in order to quantify the effects of early polysensorial enrichment on the development of cortical pyramids, located in the parietal cortex of rats simultaneously submitted to protein-energy undernutrition. A short period of stimulation during suckling significantly decreases the cellular density in the cortical plate (phylogenetic-ontogenetic evolutionary index). Results suggest that the cerebral cortex develops according to a sophisticated neuronal network, ...

Metodología para el cálculo de espesores límite libres de fase sigma durante el hipertemple en piezas de aceros dúplex de gran sección

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Jimbert, P.

2013-04-01

embargo, al aumentar la profundidad a la que se encuentran los yacimientos actuales, los espesores para este tipo de canalizaciones se han visto incrementados, lo que se traduce en mayores niveles de exigencia sobre todo su proceso de fabricación, incluyendo el tratamiento térmico. Para evitar la precipitación de estas fases intermetálicas, como la fase sigma, es necesario conocer el perfil de enfriamiento en el centro de la pieza y para ello, conocer el valor del Coeficiente de Transferencia de Calor Superficial (h es fundamental. Dicho coeficiente varía durante el hipertemple y su valor se determina experimentalmente ya que depende de varios parámetros del proceso. Diversos estudios demuestran que su valor se estabiliza a los pocos segundos, por lo que para conocer el perfil de enfriamiento en el centro de grandes secciones bastaría con conocer el valor estabilizado de h. Sin embargo, los estudios existentes en la literatura se refieren a diámetros menores de 100 mm. En el presente trabajo se ha desarrollado una metodología para predecir la precipitación de fases intermetálicas en piezas de acero dúplex con grandes espesores en instalaciones industriales a partir del cálculo de h. Esta metodología nos permite calcular los perfiles de enfriamiento sin sacrificar ninguna pieza, utilizando una o varias piezas patrón sensorizadas con termopares y una simulación posterior mediante ANSYS.

Development of rostral inferior parietal lobule area functional connectivity from late childhood to early adulthood.

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Wang, Mengxing; Zhang, Jilei; Dong, Guangheng; Zhang, Hui; Lu, Haifeng; Du, Xiaoxia

2017-06-01

Although the mirror neuron system (MNS) has been extensively studied in monkeys and adult humans, very little is known about its development. Previous studies suggest that the MNS is present by infancy and that the brain and MNS-related cognitive abilities (such as language, empathy, and imitation learning) continue to develop after childhood. In humans, the PFt area of the inferior parietal lobule (IPL) seems to particularly correlate with the functional properties of the PF area in primates, which contains mirror neurons. However, little is known about the functional connectivity (FC) of the PFt area with other brain areas and whether these networks change over time. Here, we investigated the FC development of the PFt area-based network in 59 healthy subjects aged 7-26 years at resting-state to study brain development from late childhood through adolescence to early adulthood. The bilateral PFt showed similar core FC networks, which included the frontal lobe, the cingulate gyri, the insula, the somatosensory cortex, the precuneus, the superior and inferior parietal lobules, the temporal lobe, and the cerebellum posterior lobes. Furthermore, the FC between the left PFt and the left IPL exhibited a significantly positive correlation with age, and the FC between the left PFt and the right postcentral gyrus exhibited a significantly negative correlation with age. In addition, the FC between the right PFt and the right putamen exhibited a significantly negative correlation with age. Our findings suggest that the PFt area-based network develops and is reorganized with age. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

Tracing the origin of glomerular extracapillary lesions from parietal epithelial cells.

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Smeets, Bart; Uhlig, Sandra; Fuss, Astrid; Mooren, Fieke; Wetzels, Jack F M; Floege, Jürgen; Moeller, Marcus J

2009-12-01

Cellular lesions form in Bowman's space in both crescentic glomerulonephritis and collapsing glomerulopathy. The pathomechanism and origin of the proliferating cells in these lesions are unknown. In this study, we examined proliferating cells by lineage tracing of either podocytes or parietal epithelial cells (PECs) in the nephrotoxic nephritis model of inflammatory crescentic glomerulonephritis. In addition, we traced the fate of genetically labeled PECs in the Thy-1.1 transgenic mouse model of collapsing glomerulopathy. In both models, cellular bridges composed of PECs were observed between Bowman's capsule and the glomerular tuft. Genetically labeled PECs also populated larger, more advanced cellular lesions. In these lesions, we detected de novo expression of CD44 in activated PECs. In contrast, we rarely identified genetically labeled podocytes within the cellular lesions of crescentic glomerulonephritis. In conclusion, PECs constitute the majority of cells that compose early extracapillary proliferative lesions in both crescentic glomerulonephritis and collapsing glomerulopathy, suggesting similar pathomechanisms in both diseases.

Temporary interference over the posterior parietal cortices disrupts thermoregulatory control in humans.

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Alberto Gallace

Full Text Available The suggestion has recently been made that certain higher-order cortical areas involved in supporting multisensory representations of the body, and of the space around it, might also play a role in controlling thermoregulatory functions. Here we demonstrate that temporary interference with the function of one of these areas, the posterior parietal cortex, by repetitive transcranial magnetic stimulation, results in a decrease in limb temperature. By contrast, interference with the activity of a sensory-specific area (the primary somatosensory cortex had no effect on temperature. The results of this experiment suggest that associative multisensory brain areas might exert a top-down modulation over basic physiological control. Such a function might be part of a larger neural circuit responsible for maintaining the integrity of the body at both a homeostatic and a psychological level.

No evidence for enhancements to visual working memory with transcranial direct current stimulation to prefrontal or posterior parietal cortices.

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Robison, Matthew K; McGuirk, William P; Unsworth, Nash

2017-08-01

The present study examined the relative contributions of the prefrontal cortex (PFC) and posterior parietal cortex (PPC) to visual working memory. Evidence from a number of different techniques has led to the theory that the PFC controls access to working memory (i.e., filtering), determining which information is encoded and maintained for later use whereas the parietal cortex determines how much information is held at 1 given time, regardless of relevance (i.e., capacity; McNab & Klingberg, 2008; Vogel, McCollough, & Machizawa, 2005). To test this theory, we delivered transcranial DC stimulation (tDCS) to the right PFC and right PPC and measured visual working memory capacity and filtering abilities both during and immediately following stimulation. We observed no evidence that tDCS to either the PFC or PPC significantly improved visual working memory. Although the present results did not allow us to make firm theoretical conclusions about the roles of the PFC and PPC in working memory, the results add to the growing body of literature surrounding tDCS and its associated behavioral and neurophysiological effects. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Normal variation of focal T2 Hyperintensities in anterior parietal periventricular white matter: Another 'Terminal Zones of Myelination'

International Nuclear Information System (INIS)

Park, Jong Oag; Woo, Je Ho; Ki, Tae Sung; Lee, Jong Hwa; Chung, Jin Woo; Lee, Don Young

1994-01-01

It has been known that there are several areas of T2 hyperintensity in normal white matter of brain, such as terminal zones of myelination, ependymitis granularis, ones of posterior internal capsule, and perivascular space. The aim of our study is to demonstrate another region of T2 hyperintensities in normal pediatric age group. We have studied brain MR for 10 normal volunteers and 35 patients without having intracranial lesions in pediatric age group(3-19 years). In 5 among 45 cases, focal T2 hyperintensities were seen in the parietal periventricular white matter beneath the postcentral gyri. They were noted as poorly defined, 5-10 mm sized areas of increased signal intensities on T2-weighted axial images. They were also characterized by bilateral, posteromedially oriented, short band-like or oval areas. Interestingly, they were directly continuous with the T2 hyperintensity of posterior internal capsule. In spite of the relatively highly frequency in the pediatric population as in our study, this finding has not been reported in the asymptomatic adults. The results show that the bilateral anterior parietal hyperintense areas may be another terminal zones of delayed myelination affecting the parietopontine tract. They should be differentiated from pathologic T2 hyperintensities by their characteristic findings

Subtotal Ablation of Parietal Epithelial Cells Induces Crescent Formation

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Sicking, Eva-Maria; Fuss, Astrid; Uhlig, Sandra; Jirak, Peggy; Dijkman, Henry; Wetzels, Jack; Engel, Daniel R.; Urzynicok, Torsten; Heidenreich, Stefan; Kriz, Wilhelm; Kurts, Christian; Ostendorf, Tammo; Floege, Jürgen; Smeets, Bart

2012-01-01

Parietal epithelial cells (PECs) of the renal glomerulus contribute to the formation of both cellular crescents in rapidly progressive GN and sclerotic lesions in FSGS. Subtotal transgenic ablation of podocytes induces FSGS but the effect of specific ablation of PECs is unknown. Here, we established an inducible transgenic mouse to allow subtotal ablation of PECs. Proteinuria developed during doxycycline-induced cellular ablation but fully reversed 26 days after termination of doxycycline administration. The ablation of PECs was focal, with only 30% of glomeruli exhibiting histologic changes; however, the number of PECs was reduced up to 90% within affected glomeruli. Ultrastructural analysis revealed disruption of PEC plasma membranes with cytoplasm shedding into Bowman’s space. Podocytes showed focal foot process effacement, which was the most likely cause for transient proteinuria. After >9 days of cellular ablation, the remaining PECs formed cellular extensions to cover the denuded Bowman’s capsule and expressed the activation marker CD44 de novo. The induced proliferation of PECs persisted throughout the observation period, resulting in the formation of typical cellular crescents with periglomerular infiltrate, albeit without accompanying proteinuria. In summary, subtotal ablation of PECs leads the remaining PECs to react with cellular activation and proliferation, which ultimately forms cellular crescents. PMID:22282596

SATISFAÇÃO E VALORES RELATIVOS AO TRABALHO: estudo realizado com os colaboradores Beltrame Comércio de Materiais de Construção

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Aline Mortari Machado

2016-12-01

Full Text Available Desde as últimas décadas, no contexto organizacional, os colaboradores passaram a receber maior atenção de pesquisadores com o intuito de conhecer mais sobre os aspectos peculiares dos indivíduos e sobre o comportamento humano.  Assim, tendo em vista a importância da temática, o objetivo principal deste estudo foi analisar a satisfação no trabalho e os valores relativos ao trabalho dos colaboradores da empresa Beltrame Comércio de Materiais de Construção. Para atingir o objetivo proposto, foi realizada uma pesquisa quantitativa através da aplicação de um questionário na força de trabalho contendo a Escala de Satisfação no Trabalho (EST, proposta por Siqueira (1995 e a Escala de Valores do Trabalho Revisada (EVT-R, de Porto e Pilati (2010, juntamente com questões para caracterizar o perfil sociodemográfico dos colaboradores. Como principais resultados, obteve-se que os colaboradores sentem-se, no geral, satisfeitos com a empresa e o principal valor orientador no trabalho é Segurança.

Visuospatial information processing load and the ratio between parietal cue and target P3 amplitudes in the Attentional Network Test.

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Abramov, Dimitri M; Pontes, Monique; Pontes, Adailton T; Mourao-Junior, Carlos A; Vieira, Juliana; Quero Cunha, Carla; Tamborino, Tiago; Galhanone, Paulo R; deAzevedo, Leonardo C; Lazarev, Vladimir V

2017-04-24

In ERP studies of cognitive processes during attentional tasks, the cue signals containing information about the target can increase the amplitude of the parietal cue P3 in relation to the 'neutral' temporal cue, and reduce the subsequent target P3 when this information is valid, i.e. corresponds to the target's attributes. The present study compared the cue-to-target P3 ratios in neutral and visuospatial cueing, in order to estimate the contribution of valid visuospatial information from the cue to target stages of the task performance, in terms of cognitive load. The P3 characteristics were also correlated with the results of individuals' performance of the visuospatial tasks, in order to estimate the relationship of the observed ERP with spatial reasoning. In 20 typically developing boys, aged 10-13 years (11.3±0.86), the intelligence quotient (I.Q.) was estimated by the Block Design and Vocabulary subtests from the WISC-III. The subjects performed the Attentional Network Test (ANT) accompanied by EEG recording. The cued two-choice task had three equiprobable cue conditions: No cue, with no information about the target; Neutral (temporal) cue, with an asterisk in the center of the visual field, predicting the target onset; and Spatial cues, with an asterisk in the upper or lower hemifield, predicting the onset and corresponding location of the target. The ERPs were estimated for the mid-frontal (Fz) and mid-parietal (Pz) scalp derivations. In the Pz, the Neutral cue P3 had a lower amplitude than the Spatial cue P3; whereas for the target ERPs, the P3 of the Neutral cue condition was larger than that of the Spatial cue condition. However, the sums of the magnitudes of the cue and target P3 were equal in the spatial and neutral cueing, probably indicating that in both cases the equivalent information processing load is included in either the cue or the target reaction, respectively. Meantime, in the Fz, the analog ERP components for both the cue and target

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

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Andreas A Ioannides

2013-08-01

Full Text Available Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1 and motor (M1 cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45 to 70 Hz activity at latencies of 20 to 50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occured in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

Specifying the brain anatomy underlying temporo-parietal junction activations for theory of mind: A review using probabilistic atlases from different imaging modalities

NARCIS (Netherlands)

Schurz, M.; Tholen, M.G.; Perner, J.; Mars, R.B.; Sallet, J.

2017-01-01

In this quantitative review, we specified the anatomical basis of brain activity reported in the Temporo-Parietal Junction (TPJ) in Theory of Mind (ToM) research. Using probabilistic brain atlases, we labeled TPJ peak coordinates reported in the literature. This was carried out for four different

Projections to early visual areas V1 and V2 in the calcarine fissure from parietal association areas in the macaque.

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Elena eBorra

2011-06-01

Full Text Available Non-extrastriate projections to area V1 in monkeys, now demonstrated by several anatomical studies, are potential substrates of physiologically documented multisensory effects in primary sensory areas. The full network of projections among association and primary areas, however, is likely to be complex and is still only partially understood. In the present report, we used the anterograde tracer biotinylated dextran amine to investigate projections to areas V1 and V2 from subdivisions of the parietal association cortex in macaque. Parietal cortex was chosen to allow comparisons between projections from this higher association area and from other previously reported areas. In addition, we were interested in further elucidating pathways to areas V1 and V2 from parietal areas, as potentially contributing to attention and active vision. Of eight cases, three brains had projections only to area V2, and the five others projected to both areas V1 and V2. Terminations in area V1 were sparse. These were located in supragranular layers I, II, upper III; occasionally in IVB; and in layer VI. Terminations in V2 were denser, and slightly more prevalent in the supragranular layers. For both areas, terminations were in the calcarine region, corresponding to the representation of the peripheral visual field. By reconstructions of single axons, we demonstrated that four of nine axons had collaterals, either to V1 and V2 (n=1 or to area V1 and a ventral area likely to be TEO (n=3. In area V1, axons extended divergently in layer VI as well as layer I. Overall, these and previous results suggest a nested connectivity architecture, consisting of multiple direct and indirect recurrent projections from association areas to area V1. Terminations in area V1 are not abundant, but could be potentiated by the network of indirect connections.

New Insights into Glomerular Parietal Epithelial Cell Activation and Its Signaling Pathways in Glomerular Diseases

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Hua Su

2015-01-01

Full Text Available The glomerular parietal epithelial cells (PECs have aroused an increasing attention recently. The proliferation of PECs is the main feature of crescentic glomerulonephritis; besides that, in the past decade, PEC activation has been identified in several types of noninflammatory glomerulonephropathies, such as focal segmental glomerulosclerosis, diabetic glomerulopathy, and membranous nephropathy. The pathogenesis of PEC activation is poorly understood; however, a few studies delicately elucidate the potential mechanisms and signaling pathways implicated in these processes. In this review we will focus on the latest observations and concepts about PEC activation in glomerular diseases and the newest identified signaling pathways in PEC activation.

Seeing without the Occipito-Parietal Cortex: Simultagnosia as a Shrinkage of the Attentional Visual Field

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François Michel

2004-01-01

Full Text Available Following bi-parietal lesions patient AT showed a severe inability to relocate her attention within a visual field which perimetry proved to be near-normal. An experimental approach with tasks testing visuo-spatial attention demonstrated a shrinkage of A.T.’s attentional visual field. With her visual attention narrowed to a kind of functional tunnel vision, the patient exhibited simultanagnosia (Wolpert, 1924, a symptom previously described in 1909 by Balint under the label of Psychic paralysis of “Gaze”. In striking contrast AT showed an efficient and effortless perception of complex natural scenes, which, according to recent work in normal subjects, necessitate few if any attentional resources.

Metaplasia of the parietal layer of Bowman's capsule in the human kidney. Incidence in alcoholic liver disease and hypertension

OpenAIRE

Haensly, William E.

1988-01-01

This report is the second of two surveys to determine the incidence of metaplasia of Bowman's parietal epithelium in the human kidney. Human kidney sections obtained at autopsy at the Department of Pathology, University of Texas Medical Branch, Galveston, Texas, were examined with the light microscope. The kidneys were fixed in neutral formalin, sectioned at 6 pm and stained with hematoxylin and eosin. Autopsy records were consulted after kidney section exa...

[Signal transudation pathways in parietal cells of the gastric mucosa in experimental stomach ulcer].

Science.gov (United States)

Ostapchenko, L I; Drobins'ka, O V; Chaĭka, V O; Bohun, L I; Bohdanova, O V; Kot, L I; Haĭda, L M

2009-01-01

The goal of the presented work was the research of signal transduction mechanism in the rat gastric parietal cells under stomach ulcer conditions. In these cells activation of adenylate cyclase (increase of cAMP level and proteinkinase A activity) and phosphoinositide (increases [Ca2+]i; cGMP and phoshatidylinocitole levels; proteinkinase C, proteinkinase G, and calmodulin-dependent-proteinkinase activity) of signals pathway was shown. An increase of plasma membrane phospholipids (PC, PS, PE, PI, LPC) level was shown. Under conditions of influence of the stress factor the membran enzymes activity (H+, K+ -ATPase, 5'-AMPase, Na+, K+ -ATPase, Ca2+, Mg2+ -ATPase and H+, K+ -ATPase) was considerably increased. The intensification of lipid peroxidation processes in rats was demonstrated.

Altered resting-state effective connectivity of fronto-parietal motor control systems on the primary motor network following stroke

Science.gov (United States)

Inman, Cory S.; James, G. Andrew; Hamann, Stephan; Rajendra, Justin K.; Pagnoni, Giuseppe; Butler, Andrew J.

2011-01-01

Previous brain imaging work suggests that stroke alters the effective connectivity (the influence neural regions exert upon each other) of motor execution networks. The present study examines the intrinsic effective connectivity of top-down motor control in stroke survivors (n=13) relative to healthy participants (n=12). Stroke survivors exhibited significant deficits in motor function, as assessed by the Fugl-Meyer Motor Assessment. We used structural equation modeling (SEM) of resting-state fMRI data to investigate the relationship between motor deficits and the intrinsic effective connectivity between brain regions involved in motor control and motor execution. An exploratory adaptation of SEM determined the optimal model of motor execution effective connectivity in healthy participants, and confirmatory SEM assessed stroke survivors’ fit to that model. We observed alterations in spontaneous resting-state effective connectivity from fronto-parietal guidance systems to the motor network in stroke survivors. More specifically, diminished connectivity was found in connections from the superior parietal cortex to primary motor cortex and supplementary motor cortex. Furthermore, the paths demonstrated large individual variance in stroke survivors but less variance in healthy participants. These findings suggest that characterizing the deficits in resting-state connectivity of top-down processes in stroke survivors may help optimize cognitive and physical rehabilitation therapies by individually targeting specific neural pathway. PMID:21839174

High-alpha band synchronization across frontal, parietal and visual cortex mediates behavioral and neuronal effects of visuospatial attention.

Science.gov (United States)

Lobier, Muriel; Palva, J Matias; Palva, Satu

2018-01-15

Visuospatial attention prioritizes processing of attended visual stimuli. It is characterized by lateralized alpha-band (8-14 Hz) amplitude suppression in visual cortex and increased neuronal activity in a network of frontal and parietal areas. It has remained unknown what mechanisms coordinate neuronal processing among frontoparietal network and visual cortices and implement the attention-related modulations of alpha-band amplitudes and behavior. We investigated whether large-scale network synchronization could be such a mechanism. We recorded human cortical activity with magnetoencephalography (MEG) during a visuospatial attention task. We then identified the frequencies and anatomical networks of inter-areal phase synchronization from source localized MEG data. We found that visuospatial attention is associated with robust and sustained long-range synchronization of cortical oscillations exclusively in the high-alpha (10-14 Hz) frequency band. This synchronization connected frontal, parietal and visual regions and was observed concurrently with amplitude suppression of low-alpha (6-9 Hz) band oscillations in visual cortex. Furthermore, stronger high-alpha phase synchronization was associated with decreased reaction times to attended stimuli and larger suppression of alpha-band amplitudes. These results thus show that high-alpha band phase synchronization is functionally significant and could coordinate the neuronal communication underlying the implementation of visuospatial attention. Copyright © 2017 Elsevier Inc. All rights reserved.

The parietal cell gastric H, K-ATPase also functions as the Na, K-ATPase and Ca-ATPase in altered states.

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Ray, Tushar

2013-01-01

This article offers an explanation for the apparent lack of Na, K-ATPase activity in parietal cells although ouabain has been known to inhibit gastric acid secretion since 1962. The gastric H, K-ATPase (proton-pump) seems to be acting in altered states, thus behaving like a Na, K-ATPase (Na-pump) and/or Ca-ATPase (Ca-pump) depending on cellular needs.  This conclusion is based on the following findings. First, parietal cell fractions do not exhibit Na, K-ATPase activity at pH 7.0 but do at pH 8.5. Second, the apical plasma membrane (APM) fraction exhibits a (Ca or Mg)-ATPase activity with negligible H, K-ATPase activity. However, when assayed with Mg alone in presence of the 80 k Da cytosolic proton-pump activator (HAF), the APM fraction reveals remarkably high H, K-ATPase activity, suggesting the observed low affinity of Ca (or Mg)-ATPase is an altered state of the latter. Third, calcium (between 1 and 4 µM) shows both stimulation and inhibition of the HAF-stimulated H, K-ATPase depending on its concentration, revealing a close interaction between the  proton-pump activator and local Ca concentration in gastric H, K-ATPase function. Such interactions suggest that Ca is acting as a terminal member of the intracellular signaling system for the HAF-regulated proton-pump. It appears that during resting state, the HAF-associated H, K-ATPase remains inhibited by Ca (>1 µM) and, prior to resumption of acid secretion the gastric H, K-ATPase acts temporarily as a Ca-pump for removing excess Ca from its immediate environment. This conclusion is consistent with the recent reports of immunochemical co-localization of the gastric H, K-ATPase and Ca-ATPase by superimposition in parietal cells, and a transitory efflux of Ca immediately preceding the onset of acid secretion. These new perspectives on proton-pump function would open new avenues for a fuller understanding of the intracellular regulation of the ubiquitous Na-pump.

Parietal and early visual cortices encode working memory content across mental transformations.

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Christophel, Thomas B; Cichy, Radoslaw M; Hebart, Martin N; Haynes, John-Dylan

2015-02-01

Active and flexible manipulations of memory contents "in the mind's eye" are believed to occur in a dedicated neural workspace, frequently referred to as visual working memory. Such a neural workspace should have two important properties: The ability to store sensory information across delay periods and the ability to flexibly transform sensory information. Here we used a combination of functional MRI and multivariate decoding to indentify such neural representations. Subjects were required to memorize a complex artificial pattern for an extended delay, then rotate the mental image as instructed by a cue and memorize this transformed pattern. We found that patterns of brain activity already in early visual areas and posterior parietal cortex encode not only the initially remembered image, but also the transformed contents after mental rotation. Our results thus suggest that the flexible and general neural workspace supporting visual working memory can be realized within posterior brain regions. Copyright © 2014 Elsevier Inc. All rights reserved.

Temporal structure in neuronal activity during working memory in Macaque parietal cortex

CERN Document Server

Pesaran, B; Sahami, M; Mitra, P; Andersen, R A

2000-01-01

A number of cortical structures are reported to have elevated single unit firing rates sustained throughout the memory period of a working memory task. How the nervous system forms and maintains these memories is unknown but reverberating neuronal network activity is thought to be important. We studied the temporal structure of single unit (SU) activity and simultaneously recorded local field potential (LFP) activity from area LIP in the inferior parietal lobe of two awake macaques during a memory-saccade task. Using multitaper techniques for spectral analysis, which play an important role in obtaining the present results, we find elevations in spectral power in a 50--90 Hz (gamma) frequency band during the memory period in both SU and LFP activity. The activity is tuned to the direction of the saccade providing evidence for temporal structure that codes for movement plans during working memory. We also find SU and LFP activity are coherent during the memory period in the 50--90 Hz gamma band and no consisten...

Resting-state functional connectivity of ventral parietal regions associated with attention reorienting and episodic recollection

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Sander M Daselaar

2013-02-01

Full Text Available In functional neuroimaging studies, ventral parietal cortex (VPC is recruited by very different cognitive tasks. Explaining the contributions VPC to these tasks has become a topic of intense study and lively debate. Perception studies frequently find VPC activations during tasks involving attention-reorienting, and memory studies frequently find them during tasks involving episodic recollection. According to the Attention to Memory (AtoM model, both phenomena can be explained by the same VPC function: bottom-up attention. Yet, a recent functional MRI (fMRI meta-analysis suggested that attention-reorienting activations are more frequent in anterior VPC, whereas recollection activations are more frequent in posterior VPC. Also, there is evidence that anterior and posterior VPC regions have different functional connectivity patterns. To investigate these issues, we conducted a resting-state functional connectivity analysis using as seeds the center-of-mass of attention-reorienting and recollection activations in the meta-analysis, which were located in the supramarginal gyrus (SMG, around the temporo-parietal junction—TPJ and in the angular gyrus (AG, respectively. The SMG seed showed stronger connectivity with ventrolateral prefrontal cortex (VLPFC and occipito-temporal cortex, whereas the AG seed showed stronger connectivity with the hippocampus and default network regions. To investigate whether these connectivity differences were graded or sharp, VLPFC and hippocampal connectivity was measured in VPC regions traversing through the SMG and AG seeds. The results showed a graded pattern: VLPFC connectivity gradually decreases from SMG to AG, whereas hippocampal connectivity gradually increases from SMG to AG. Importantly, both gradients showed an abrupt break when extended beyond VPC borders. This finding suggests that functional differences between SMG and AG are more subtle than previously thought. These connectivity differences can be

La opinión consultiva del Tribunal Internacional del Derecho del Mar: Aspectos relativos a la determinación del vínculo efectivo entre los Estados y las personas jurídicas a las que patrocinan para llevar a cabo actividades en la Zona

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Juan Nicolás Guerrero Peniche

2012-12-01

Full Text Available No obstante la existencia de un instrumento convencional en la ma­teria, el derecho del mar en general, y lo relativo a la explotación de minerales en la Zona, se encuentra aún en una fase de puesta en práctica y de definición fina de los derechos y obligaciones de los Estados. Uno de los ejemplos que se ha hecho patente es lo relativo a las obligaciones de aquellos Estados que pa­trocinan a particulares a fin de llevar actividades de exploración y explotación de los recursos de la Zona. Esta cuestión fue remitida en 2010 por la Autoridad Internacional de Fondos Marinos al Tribunal Internacional de Derecho del Mar a fin de que este la dilucidara. La Opinión Consultiva que emitió el Tribunal presenta conclusiones de particular relevancia en materia de la de­terminación de un vínculo efectivo entre las personas jurídicas y los Estados que las patrocinan. Esta cuestión, que juega un papel determinante a fin de lograr una eficaz protección del medio marino en el marco del mecanismo de patrocinio para la exploración y explotación de los recursos en la Zona, conlleva importantes consecuencias para las actividades en áreas reservadas.

Evaluación del espesor corneal central y su influencia en la presión intraocular en pacientes del Hospital "Dr. Miguel Enríquez" Evaluation of the central corneal thickness and its impact on the intraocular pressure of patients in "Dr. Miguel Enriquez" hospital

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María Teresa Arrronte Alarcón

2012-01-01

Full Text Available Objetivo: evaluar el espesor corneal central en sujetos sanos, hipertensos oculares, sospechosos de glaucoma y glaucomatosos, y su influencia en la presión intraocular. Métodos: se realizó un estudio descriptivo y transversal que incluyó 708 ojos de 356 sujetos que acudieron al servicio de oftalmología del Hospital Universitario "Dr. Miguel Enríquez" entre enero y diciembre de 2010. A los pacientes se les midió el espesor corneal central con paquimetría ultrasónica (paquímetro US 4000. El resto de la información se obtuvo a partir de las historias clínicas de los pacientes. Resultados: Los hipertensos oculares presentaron córneas gruesas (p=0,07; el mayor número de casos que tenían diagnóstico de sospecha de glaucoma y de glaucoma primario de ángulo abierto presentaron un grosor corneal delgado (p=0,62 y p=0,08 respectivamente. Si no se hubiese tenido en cuenta el factor de corrección para evaluar la presión intraocular se encontraría 48,1 % de los glaucomatosos y 31,5 % de los hipertensos oculares con diagnóstico inadecuado (pObjective: to evaluate the central corneal thickness in healthy individuals, in persons with ocular hypertension, and in suspected glaucoma and glaucomatous people, and its influence in intraocular pressure. Methods: a cross-sectional and descriptive study was performed in 708 eyes from 356 people who had been seen at ophthalmology service of “Dr. Miguel Enríquez”, university hospital from January to December, 2010. Their central corneal thickness was measured with ultrasonic pachymetry (pachymeter US 4000. The rest of the information came from the clinical histories of the patients. Results: Most of the ocular hypertensives presented thick corneas (p=0,07; a high number of cases that had diagnosis of glaucoma suspicion and primary open-angle glaucoma showed thin corneas (p=0,62 and (p=0,08 respectively. If the correction factor to evaluate the IOP had not been considered, then 48,1 % of the

Bilateral front-parietal polymicrogyria accompanied by cobblestone lissencephaly: 3T MR imaging findings of a case

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Bozkurt, Y.; Battal, B.; Ozcan, E.; Kocaoglu, M.

2012-01-01

Full text: Background: The cerebral cortex develops in three overlapping stages: cell proliferation, neuronal migration, and cortical organization. Lissencephaly (smooth brain) is a severe malformation of the cerebral cortex that results from impaired neuronal migration. Polymicrogyria is a disorder of late migration or cortical organization, and supposed to reflect a disruption of normal neuronal migration with subsequent disordered cortical organization. A combination of cobblestone lissencephaly and polymicrogyria is very rare in the same patient's brain. Objective: To present clinical and 3T magnetic resonance (MR) imaging findings of a 17-year-old male with bilateral fronto-parietal polimicrogyria accompanied by cobblestone lissencaphaly. Materials and methods: A 17-year-old male who had seizures and involuntary muscular spasm from birth, was referred to our Hospital. The patient was evaluated by a complete history, physical examination, a laboratory work-up, and cranial MR examination for evaluate the central nervous system. Results: A sharp wave paroxysm in the left temporal area was observed in the electroencephalogram (EEG). The neurological examination of our patient was normal. A slight increase have seen in the aspartate aminotransferase (SGOT) levels. The other biochemical tests were found to be normal. Cranial MR imaging showed an irregular nodular cortex with hypomyelination of the white matter at the lateral and posterior part of the right occipital lobe. We also observed the changes compatible with polymicrogyria in a large area of the medial parts of the bilateral temporal and parietal lobes. Conclusion: The role of radiological modalities for diagnosis of cortical formation disorders are very important. MR imaging are fairly useful for evaluation of these anomalies

Estudios de series temporales de energía solar UV-B de 305 nm y espesor de la capa de ozono estratosférico en Arica, norte de Chile Study of time series for 305 nm solar energy UV-B and stratospheric ozone layer thickness Arica in the north of Chile

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Miguel Rivas

2011-08-01

Full Text Available En este trabajo se muestran los resultados del análisis de las series temporales de la energía solar medida a nivel del suelo, en la banda de 305 nm, y el espesor de la capa de ozono estratosférico. El rasgo más importante es la independencia de los valores de energía a nivel del suelo respecto de la variabilidad de corto periodo de la capa de ozono, siendo probablemente efectos meteorológicos locales los que llevan el mayor peso de la varianza.In this paper, the results obtained by analyzing time series of ground level energy of the solar radiation in the 305 nm band and stratospheric ozone layer thickness are shown. The most relevant feature found is the independence of the variability of the ground level energy with respect to the short period variations of the ozone layer, being the meteorological local effects those which more heavily affect the variability.

Contrasting effects of vocabulary knowledge on temporal and parietal brain structure across lifespan.

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Richardson, Fiona M; Thomas, Michael S C; Filippi, Roberto; Harth, Helen; Price, Cathy J

2010-05-01

Using behavioral, structural, and functional imaging techniques, we demonstrate contrasting effects of vocabulary knowledge on temporal and parietal brain structure in 47 healthy volunteers who ranged in age from 7 to 73 years. In the left posterior supramarginal gyrus, vocabulary knowledge was positively correlated with gray matter density in teenagers but not adults. This region was not activated during auditory or visual sentence processing, and activation was unrelated to vocabulary skills. Its gray matter density may reflect the use of an explicit learning strategy that links new words to lexical or conceptual equivalents, as used in formal education and second language acquisition. By contrast, in left posterior temporal regions, gray matter as well as auditory and visual sentence activation correlated with vocabulary knowledge throughout lifespan. We propose that these effects reflect the acquisition of vocabulary through context, when new words are learnt within the context of semantically and syntactically related words.

Dureza knoop de resinas compostas em função do número relativo de radicais livres Relative number of free radicals and knoop hardness of composites

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Marco Aurélio de MENEZES

1998-07-01

Full Text Available A pesquisa teve a finalidade de determinar o número relativo de radicais livres e a dureza Knoop de três resinas compostas (Z100, Silux Plus e Heliomolar RO. Para o ensaio dos radicais livres, as irradiações foram: 110, 180, 300, 580 mW/cm2, pelos tempos de 10, 20, 30, 40, 50, 60, 80 e 90 segundos. As durezas foram determinadas com as cores claras com irradiação de 110 e 300 mW/cm2, por 20, 40, 60 e 80 segundos, nas faces da frente e do fundo, nas idades de 5 minutos, 1 hora, 1 dia, 1 semana e 1 mês. As conclusões foram: a resina Z100 apresentou cerca de 3 vezes mais radicais livres do que as outras; o número relativo de radicais livres aumenta com a intensidade e tempo de exposição; maior intensidade de luz aumentou a dureza; maior tempo de exposição aumentou as durezas das resinas Silux Plus e Heliomolar, mas não da Z100; a dureza aumentou com a idade até 1 mês; o lado da irradiação apresentou maior dureza do que o do fundo; a resina Z100 foi bem mais dura e sofreu menos a influência da irradiação.The present study had the purpose of determining the relative number of free radicals of three composites with clear and dark colors. Intensities of irradiation were: 110, 180, 300, and 580 mW/cm2, for 10, 20, 30, 40, 50, 60, 80 and 90 seconds. Hardness was determined for the clear colors of the composites, using 110 and 300 mW/cm2 irradiation intensities, for 20, 40, 60, and 80 seconds, on front and deep surfaces, at the ages of 5 minutes, 1 hour, 1 day, 1 week, and 1 month. The conclusions were that: depending on the resin, clear colors present more free radicals; the number of free radicals increases with higher intensity and longer irradiation time; composite Z100 is much richer in free radicals than Silux Plus and Heliomolar RO; higher intensity of irradiation leads to increasing hardness; longer irradiation time increases hardness of Silux Plus and Heliomolar RO, but not that of Z100; hardness increases with age; in depth

An impaired attentional dwell time after parietal and frontal lesions related to impaired selective attention not unilateral neglect.

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Correani, Alessia; Humphreys, Glyn W

2011-07-01

The attentional blink, a measure of the temporal dynamics of visual processing, has been documented to be more pronounced following brain lesions that are associated with visual neglect. This suggests that, in addition to their spatial bias in attention, neglect patients may have a prolonged dwell time for attention. Here the attentional dwell time was examined in patients with damage focused on either posterior parietal or frontal cortices. In three experiments, we show that there is an abnormally pronounced attentional dwell time, which does not differ in patients with posterior parietal and with frontal lobe lesions, and this is associated with a measure of selective attention but not with measures of spatial bias in selection. These data occurred both when we attempted to match patients and controls for overall differences in performance and when a single set stimulus exposure was used across participants. In Experiments 1 and 2, requiring report of colour-form conjunctions, there was evidence that the patients were also impaired at temporal binding, showing errors in feature combination across stimuli and in reporting in the correct temporal order. In Experiment 3, requiring only the report of features but introducing task switching led to similar results. The data suggest that damage to a frontoparietal network can compromise temporal selection of visual stimuli; however, this is not necessarily related to a deficit in hemispatial visual attention but it is to impaired target selection. We discuss the implications for understanding visual selection.

Glucose phosphorylation rate in rat parietal cortex during normoglycemia, hypoglycemia, acute hyperglycemia, and in diabetes-prone rats

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Broendsted, H.E.; Gjedde, A. (Department of General Physiology and Biophysics, Panum Institute, University of Copenhagen (Denmark))

1990-01-01

Cerebral metabolic rate for glucose (CMRglc) was studied in rats using (6-{sup 14}C)glucose. After intravenous injection the radioactivity of the parietal cortex was corrected for loss of labeled CO{sub 2} and divided by the integral of the arterial plasma glucose concentration, determined during tracer circulation. Treatment with insulin, resulting in plasma glucose concentrations less than 2.6 mmol/l, reduced CMRglc to 64% of the values found in control animals. CMRglc did not change in animals with acute hyper-glycemia produced by intraperiotoneal injection of a glucose solution or in diabetes-prone rats with or withour insulin treatment. (author).

Spatial imagery relies on a sensory independent, though sensory sensitive, functional organization within the parietal cortex: a fMRI study of angle discrimination in sighted and congenitally blind individuals.

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Bonino, Daniela; Ricciardi, Emiliano; Bernardi, Giulio; Sani, Lorenzo; Gentili, Claudio; Vecchi, Tomaso; Pietrini, Pietro

2015-02-01

Although vision offers distinctive information to space representation, individuals who lack vision since birth often show perceptual and representational skills comparable to those found in sighted individuals. However, congenitally blind individuals may result in impaired spatial analysis, when engaging in 'visual' spatial features (e.g., perspective or angle representation) or complex spatial mental abilities. In the present study, we measured behavioral and brain responses using functional magnetic resonance imaging in sighted and congenitally blind individuals during spatial imagery based on a modified version of the mental clock task (e.g., angle discrimination) and a simple recognition control condition, as conveyed across distinct sensory modalities: visual (sighted individuals only), tactile and auditory. Blind individuals were significantly less accurate during the auditory task, but comparable-to-sighted during the tactile task. As expected, both groups showed common neural activations in intraparietal and superior parietal regions across visual and non-visual spatial perception and imagery conditions, indicating the more abstract, sensory independent functional organization of these cortical areas, a property that we named supramodality. At the same time, however, comparisons in brain responses and functional connectivity patterns across experimental conditions demonstrated also a functional lateralization, in a way that correlated with the distinct behavioral performance in blind and sighted individuals. Specifically, blind individuals relied more on right parietal regions, mainly in the tactile and less in the auditory spatial processing. In sighted, spatial representation across modalities relied more on left parietal regions. In conclusions, intraparietal and superior parietal regions subserve supramodal spatial representations in sighted and congenitally blind individuals. Differences in their recruitment across non-visual spatial processing in

Human middle longitudinal fascicle: segregation and behavioral-clinical implications of two distinct fiber connections linking temporal pole and superior temporal gyrus with the angular gyrus or superior parietal lobule using multi-tensor tractography.

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Makris, N; Preti, M G; Wassermann, D; Rathi, Y; Papadimitriou, G M; Yergatian, C; Dickerson, B C; Shenton, M E; Kubicki, M

2013-09-01

The middle longitudinal fascicle (MdLF) is a major fiber connection running principally between the superior temporal gyrus and the parietal lobe, neocortical regions of great biological and clinical interest. Although one of the most prominent cerebral association fiber tracts, it has only recently been discovered in humans. In this high angular resolution diffusion imaging (HARDI) MRI study, we delineated the two major fiber connections of the human MdLF, by examining morphology, topography, cortical connections, biophysical measures, volume and length in seventy-four brains. These two fiber connections course together through the dorsal temporal pole and the superior temporal gyrus maintaining a characteristic topographic relationship in the mediolateral and ventrodorsal dimensions. As these pathways course towards the parietal lobe, they split to form separate fiber pathways, one following a ventrolateral trajectory and connecting with the angular gyrus and the other following a dorsomedial route and connecting with the superior parietal lobule. Based on the functions of their cortical affiliations, we suggest that the superior temporal-angular connection of the MdLF, i.e., STG(MdLF)AG plays a role in language and attention, whereas the superior temporal-superior parietal connection of the MdLF, i.e., STG(MdLF)SPL is involved in visuospatial and integrative audiovisual functions. Furthermore, the MdLF may have clinical implications in neurodegenerative disorders such as primary progressive aphasia, frontotemporal dementia, posterior cortical atrophy, corticobulbar degeneration and Alzheimer's disease as well as attention-deficit/hyperactivity disorder and schizophrenia.

Evaluación ultrasonográfica del espesor conjunto útero placentario en yeguas de raza de tiro Ardenés, Región de Valparaíso, Chile

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Jorge Lohse

2016-03-01

Full Text Available El presente estudio se realizó con el objetivo de estandarizar medidas de espesor conjunto útero placentario (ECUP, en yeguas de raza Ardenes entre el 5° y último mes de gestación siendo el primer estudio de esta medición en esta raza de tipo de tiro, éste fue desarrollado en un haras de la región de Valparaiso, Chile. Un total de 61 yeguas gestantes, clínicamente sanas de raza Ardenés, escogidas al azar y con edades que fluctuaron entre 4 a 18 años, fueron ecografiadas por vía transrectal, para determinar el ECUP, lo cual fue realizado por un solo examinador durante la temporada de parición 2009-2010. La medición de dicho parámetro se realizó con equipo de ultrasonografía análogo, con un transductor lineal de frecuencia 6.0/8.0 MHz. Este procedimiento se repitió 3 veces y con estas medidas se obtuvo un promedio individual. Los resultados fueron descritos en promedios y desviación estándar. Los valores obtenidos en promedio para cada mes son los siguientes: 3,75 mm al 5° mes (121 a 150 días; 3,98 mm al 6° mes (151 a 180 días; 4,02 mm al 7° mes (181 a 210 días; 4,50 mm al 8° mes (211 a 240 días; 4,71 mm al 9° mes (241 a 270 días; 5,02 mm al 10° mes (271 a 300 días; 8,10 mm al 11er mes (301-330 días; 9,73 mm al 12° mes (331 a 360 días. Se concluye que no hubo una variación significativa en el grosor del ECUP en los distintos meses del segundo tercio de gestación, y tampoco hay mayor diferencia comparando estas mediciones con otras razas equinas mencionado en la literatura.

Lower Choline and Myo-Inositol in Temporo-Parietal Cortex Is Associated With Apathy in Amnestic MCI.

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Tumati, Shankar; Opmeer, Esther M; Marsman, Jan-Bernard C; Martens, Sander; Reesink, Fransje E; De Deyn, Peter P; Aleman, André

2018-01-01

Apathy is a common symptom in patients with amnestic mild cognitive impairment (aMCI) and is associated with an increased risk of progression to Alzheimer's disease (AD). The neural substrates underlying apathy in aMCI may involve multiple brain regions, including the anterior cingulate cortex and the temporo-parietal region. Here we investigated neurometabolites in brain regions that may underlie apathy in aMCI patients using proton magnetic resonance spectroscopy ( 1 H-MRS). Twenty-eight aMCI patients with varying degrees of apathy and 20 matched controls underwent 1 H-MRS. Spectra were acquired from single voxels in the posterior cingulate cortex (PCC), dorsal anterior cingulate cortex (DACC), right dorsolateral prefrontal cortex (DLPFC), and right temporo-parietal cortex (TPC). Apathy was measured with the Apathy Evaluation Scale (AES). Spearman partial correlations between metabolite concentrations in each region and severity of apathy were determined. Additionally, analyses of covariance (ANCOVA) were performed to determine whether metabolite changes differed between patients with or without clinically-diagnosed apathy. The degree of apathy was found to be negatively correlated with choline and myo-inositol (mI) in the TPC. Additional exploratory analyses suggested that N-acetylaspartate (NAA)/mI ratio was reduced in aMCI without clinical apathy but not in aMCI with clinical apathy. In the DACC, glutamate and glutamine (Glx) levels tended to be higher in the aMCI with apathy group compared to controls and reduced in association with depression scores. In conclusion, apathy in aMCI patients was associated with neurometabolite changes indicative of altered membranal integrity and glial function in the right TPC. Findings also indicated that in a clinically-diagnosed aMCI cohort, apathy symptoms may be suggestive of neural changes that are distinct from aMCI without apathy.

Crossmodal semantic congruence can affect visuo-spatial processing and activity of the fronto-parietal attention networks

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Serena eMastroberardino

2015-07-01

Full Text Available Previous studies have shown that multisensory stimuli can contribute to attention control. Here we investigate whether irrelevant audio-visual stimuli can affect the processing of subsequent visual targets, in the absence of any direct bottom-up signals generated by low-level sensory changes and any goal-related associations between the multisensory stimuli and the visual targets. Each trial included two pictures (cat/dog, one in each visual hemifield, and a central sound that was semantically congruent with one of the two pictures (i.e. either meow or woof sound. These irrelevant audio-visual stimuli were followed by a visual target that appeared either where the congruent or the incongruent picture had been presented (valid/invalid trials. The visual target was a Gabor patch requiring an orientation discrimination judgment, allowing us to uncouple the visual task from the audio-visual stimuli. Behaviourally we found lower performance for invalid than valid trials, but only when the task demands were high (Gabor target presented together with a Gabor distractor vs. Gabor target alone. The fMRI analyses revealed greater activity for invalid than for valid trials in the dorsal and the ventral fronto-parietal attention networks. The dorsal network was recruited irrespective of task demands, while the ventral network was recruited only when task demands were high and target discrimination required additional top-down control. We propose that crossmodal semantic congruence generates a processing bias associated with the location of congruent picture, and that the presentation of the visual target on the opposite side required updating these processing priorities. We relate the activation of the attention networks to these updating operations. We conclude that the fronto-parietal networks mediate the influence of crossmodal semantic congruence on visuo-spatial processing, even in the absence of any low-level sensory cue and any goal-driven task

Distinct contribution of the parietal and temporal cortex to hand configuration and contextual judgements about tools.

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Andres, Michael; Pelgrims, Barbara; Olivier, Etienne

2013-09-01

Neuropsychological studies showed that manipulatory and semantic knowledge can be independently impaired in patients with upper-limb apraxia, leading to different tool use disorders. The present study aimed to dissociate the brain regions involved in judging the hand configuration or the context associated to tool use. We focussed on the left supramarginalis gyrus (SMG) and left middle temporal gyrus (MTG), whose activation, as evidenced by functional magnetic resonance imaging (fMRI) studies, suggests that they may play a critical role in tool use. The distinctive location of SMG in the dorsal visual stream led us to postulate that this parietal region could play a role in processing incoming information about tools to shape hand posture. In contrast, we hypothesized that MTG, because of its interconnections with several cortical areas involved in semantic memory, could contribute to retrieving semantic information necessary to create a contextual representation of tool use. To test these hypotheses, we used neuronavigated transcranial magnetic stimulation (TMS) to interfere transiently with the function of either left SMG or left MTG in healthy participants performing judgement tasks about either hand configuration or context of tool use. We found that SMG virtual lesions impaired hand configuration but not contextual judgements, whereas MTG lesions selectively interfered with judgements about the context of tool use while leaving hand configuration judgements unaffected. This double dissociation demonstrates that the ability to infer a context of use or a hand posture from tool perception relies on distinct processes, performed in the temporal and parietal regions. The present findings suggest that tool use disorders caused by SMG lesions will be characterized by difficulties in selecting the appropriate hand posture for tool use, whereas MTG lesions will yield difficulties in using tools in the appropriate context. Copyright © 2012. Published by Elsevier Ltd.

Lower Choline and Myo-Inositol in Temporo-Parietal Cortex Is Associated With Apathy in Amnestic MCI

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Shankar Tumati

2018-04-01

Full Text Available Apathy is a common symptom in patients with amnestic mild cognitive impairment (aMCI and is associated with an increased risk of progression to Alzheimer’s disease (AD. The neural substrates underlying apathy in aMCI may involve multiple brain regions, including the anterior cingulate cortex and the temporo-parietal region. Here we investigated neurometabolites in brain regions that may underlie apathy in aMCI patients using proton magnetic resonance spectroscopy (1H-MRS. Twenty-eight aMCI patients with varying degrees of apathy and 20 matched controls underwent 1H-MRS. Spectra were acquired from single voxels in the posterior cingulate cortex (PCC, dorsal anterior cingulate cortex (DACC, right dorsolateral prefrontal cortex (DLPFC, and right temporo-parietal cortex (TPC. Apathy was measured with the Apathy Evaluation Scale (AES. Spearman partial correlations between metabolite concentrations in each region and severity of apathy were determined. Additionally, analyses of covariance (ANCOVA were performed to determine whether metabolite changes differed between patients with or without clinically-diagnosed apathy. The degree of apathy was found to be negatively correlated with choline and myo-inositol (mI in the TPC. Additional exploratory analyses suggested that N-acetylaspartate (NAA/mI ratio was reduced in aMCI without clinical apathy but not in aMCI with clinical apathy. In the DACC, glutamate and glutamine (Glx levels tended to be higher in the aMCI with apathy group compared to controls and reduced in association with depression scores. In conclusion, apathy in aMCI patients was associated with neurometabolite changes indicative of altered membranal integrity and glial function in the right TPC. Findings also indicated that in a clinically-diagnosed aMCI cohort, apathy symptoms may be suggestive of neural changes that are distinct from aMCI without apathy.

MicroRNA-193a Regulates the Transdifferentiation of Human Parietal Epithelial Cells toward a Podocyte Phenotype.

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Kietzmann, Leonie; Guhr, Sebastian S O; Meyer, Tobias N; Ni, Lan; Sachs, Marlies; Panzer, Ulf; Stahl, Rolf A K; Saleem, Moin A; Kerjaschki, Dontscho; Gebeshuber, Christoph A; Meyer-Schwesinger, Catherine

2015-06-01

Parietal epithelial cells have been identified as potential progenitor cells in glomerular regeneration, but the molecular mechanisms underlying this process are not fully defined. Here, we established an immortalized polyclonal human parietal epithelial cell (hPEC) line from naive human Bowman's capsule cells isolated by mechanical microdissection. These hPECs expressed high levels of PEC-specific proteins and microRNA-193a (miR-193a), a suppressor of podocyte differentiation through downregulation of Wilms' tumor 1 in mice. We then investigated the function of miR-193a in the establishment of podocyte and PEC identity and determined whether inhibition of miR-193a influences the behavior of PECs in glomerular disease. After stable knockdown of miR-193a, hPECs adopted a podocyte-like morphology and marker expression, with decreased expression levels of PEC markers. In mice, inhibition of miR-193a by complementary locked nucleic acids resulted in an upregulation of the podocyte proteins synaptopodin and Wilms' tumor 1. Conversely, overexpression of miR-193a in vivo resulted in the upregulation of PEC markers and the loss of podocyte markers in isolated glomeruli. Inhibition of miR-193a in a mouse model of nephrotoxic nephritis resulted in reduced crescent formation and decreased proteinuria. Together, these results show the establishment of a human PEC line and suggest that miR-193a functions as a master switch, such that glomerular epithelial cells with high levels of miR-193a adopt a PEC phenotype and cells with low levels of miR-193a adopt a podocyte phenotype. miR-193a-mediated maintenance of PECs in an undifferentiated reactive state might be a prerequisite for PEC proliferation and migration in crescent formation. Copyright © 2015 by the American Society of Nephrology.

Diminishing parochialism in intergroup conflict by disrupting the right temporo-parietal junction.

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Baumgartner, Thomas; Schiller, Bastian; Rieskamp, Jörg; Gianotti, Lorena R R; Knoch, Daria

2014-05-01

Individuals react to violation of social norms by outgroup members differently than to transgressions of those same norms by ingroup members: namely outgroup perpetrators are punished much more harshly than ingroup perpetrators. This parochial punishment pattern has been observed and extensively studied in social psychology and behavioral economics. Despite progress in recent years, however, little is known about the neural underpinnings of this intergroup bias. Here, we demonstrate by means of transcranial magnetic stimulation (TMS) that the transient disruption of the right, but not the left temporo-parietal junction (TPJ), reduces parochial punishment in a third-party punishment paradigm with real social groups. Moreover, we show that this observed TMS effect on parochial punishment is mediated by a classical punishment motive, i.e. retaliation. Finally, our data suggests that a change in perspective-taking might be the underlying mechanism that explains the impact of right TPJ disruption on retaliation motivation and parochial punishment. These findings provide the first causal evidence that the right TPJ plays a pivotal role in the implementation of parochial behaviors.

Perception of Upright: Multisensory Convergence and the Role of Temporo-Parietal Cortex

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Amir Kheradmand

2017-10-01

Full Text Available We inherently maintain a stable perception of the world despite frequent changes in the head, eye, and body positions. Such “orientation constancy” is a prerequisite for coherent spatial perception and sensorimotor planning. As a multimodal sensory reference, perception of upright represents neural processes that subserve orientation constancy through integration of sensory information encoding the eye, head, and body positions. Although perception of upright is distinct from perception of body orientation, they share similar neural substrates within the cerebral cortical networks involved in perception of spatial orientation. These cortical networks, mainly within the temporo-parietal junction, are crucial for multisensory processing and integration that generate sensory reference frames for coherent perception of self-position and extrapersonal space transformations. In this review, we focus on these neural mechanisms and discuss (i neurobehavioral aspects of orientation constancy, (ii sensory models that address the neurophysiology underlying perception of upright, and (iii the current evidence for the role of cerebral cortex in perception of upright and orientation constancy, including findings from the neurological disorders that affect cortical function.

Histología y morfometría del ojo del pez dulceacuícola Paracheirodon axelrodi (Characiformes: Characidae

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Mario O Tovar

2009-12-01

Full Text Available El pez dulceacuícola P. axelrodi es de gran importancia comercial en la Orinoquía Colombiana y a nivel mundial, pero carece de estudios acerca de su visión. Se utilizaron diez individuos, con longitud total promedio de 2.7 cm (SD= 0.2, n= 20. Se realizaron cortes a 8 μm y se tiρeron con H-E. El tamaρo relativo del ojo es 9.8% (SD= 1.1, n= 20; el cristalino tiene un tamaρo relativo de 64.3% (SD= 4.9, n=20. Una esclerótica con tejido cartilaginoso. La retina está constituida por ocho capas y dos membranas, hay areae centrales en la zona posterior, por lo tanto tiene mayor espesor que la zona lateral. El espesor promedio de las estructuras es: retina lateral: 144.5 μm (SD= 5.4, n= 20, retina temporal: 210.4 μm (SD= 14.8, n= 20; cristalino (esfιrico: dorso-ventral 759.6 μm (SD= 31.7, n= 20 y antero- posterior 763.4 μm (SD= 30.7, n= 20 y cσrnea: 27.6 μm (SD= 4.3, n= 20. El tamaρo relativo del ojo, relacionado con la presencia de areae centrales y una córnea delgada, muestra las necesidades visuales del neón cardenal (cazador para adaptarse al hábitat, lo que hace necesario tener un sistema visual desarrollado que le permita tener mejor sensibilidad y resolución visual.Histology and morphometry of the eye in the freshwater Paracheirodon axelrodi (Characiformes: Characidae. The visual system of Teleost fishes has a wide range of adaptations. The eye has suffered modifications, mainly towards better sensitivity and visual resolution according to specific environmental conditions. In that way, this organ is so important for survival. In spite of being the most commercialized Orinoquía species, and one of the most important ornamental fish worldwide, there are almost no studies on the communication systems of P. axelrodi (including vision. We studied the eye in ten individuals of P. axelrodi, with a mean total length of 2.7 cm (SD= 0.2, n= 20. We measured eye relative size (TRO after sacrifice. Heads were processed for hematoxylin

Dissociable parietal regions facilitate successful retrieval of recently learned and personally familiar information.

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Elman, Jeremy A; Cohn-Sheehy, Brendan I; Shimamura, Arthur P

2013-03-01

In fMRI analyses, the posterior parietal cortex (PPC) is particularly active during the successful retrieval of episodic memory. To delineate the neural correlates of episodic retrieval more succinctly, we compared retrieval of recently learned spatial locations (photographs of buildings) with retrieval of previously familiar locations (photographs of familiar campus buildings). Episodic retrieval of recently learned locations activated a circumscribed region within the ventral PPC (anterior angular gyrus and adjacent regions in the supramarginal gyrus) as well as medial PPC regions (posterior cingulated gyrus and posterior precuneus). Retrieval of familiar locations activated more posterior regions in the ventral PPC (posterior angular gyrus, LOC) and more anterior regions in the medial PPC (anterior precuneus and retrosplenial cortex). These dissociable effects define more precisely PPC regions involved in the retrieval of recent, contextually bound information as opposed to regions involved in other processes, such as visual imagery, scene reconstruction, and self-referential processing. Copyright © 2012 Elsevier Ltd. All rights reserved.

Agnosia for mirror stimuli: a new case report with a small parietal lesion.

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Martinaud, Olivier; Mirlink, Nicolas; Bioux, Sandrine; Bliaux, Evangéline; Lebas, Axel; Gerardin, Emmanuel; Hannequin, Didier

2014-11-01

Only seven cases of agnosia for mirror stimuli have been reported, always with an extensive lesion. We report a new case of an agnosia for mirror stimuli due to a circumscribed lesion. An extensive battery of neuropsychological tests and a new experimental procedure to assess visual object mirror and orientation discrimination were assessed 10 days after the onset of clinical symptoms, and 5 years later. The performances of our patient were compared with those of four healthy control subjects matched for age. This test revealed an agnosia for mirror stimuli. Brain imaging showed a small right occipitoparietal hematoma, encompassing the extrastriate cortex adjoining the inferior parietal lobe. This new case suggests that: (i) agnosia for mirror stimuli can persist for 5 years after onset and (ii) the posterior part of the right intraparietal sulcus could be critical in the cognitive process of mirror stimuli discrimination. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

[Brodmann Areas 39 and 40: Human Parietal Association Area and Higher Cortical Function].

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Sakurai, Yasuhisa

2017-04-01

The anatomy and function of the angular gyrus (Brodmann Area 39) and supramarginal gyrus (Brodmann Area 40) are described here. Both gyri constitute the inferior part of the parietal lobe. Association fibers from the angular gyrus project to the dorsolateral prefrontal cortex via the superior longitudinal fasciculus (SLF) II/arcuate fasciculus (AF), whereas those from the supramarginal gyrus project to the ventrolateral prefrontal cortex via SLF III/AF. Damage to the left angular gyrus causes kanji agraphia (lexical agraphia) and mild anomia, whereas damage to the left supramarginal gyrus causes kana alexia (phonological dyslexia) and kana agraphia (phonological agraphia). Damage to either gyrus causes Gerstmann's syndrome (finger agnosia, left-right disorientation, agraphia and acalculia) and verbal short-term memory impairment. "Angular alexia with agraphia" results from damage to the middle occipital gyrus posterior to the angular gyrus. Alexia and agraphia, with lesions in the angular or supramarginal gyrus, are characterized by kana transposition errors in reading words, which suggests the impairment of sequential phonological processing.

A Model of Self-Organizing Head-Centered Visual Responses in Primate Parietal Areas

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Mender, Bedeho M. W.; Stringer, Simon M.

2013-01-01

We present a hypothesis for how head-centered visual representations in primate parietal areas could self-organize through visually-guided learning, and test this hypothesis using a neural network model. The model consists of a competitive output layer of neurons that receives afferent synaptic connections from a population of input neurons with eye position gain modulated retinal receptive fields. The synaptic connections in the model are trained with an associative trace learning rule which has the effect of encouraging output neurons to learn to respond to subsets of input patterns that tend to occur close together in time. This network architecture and synaptic learning rule is hypothesized to promote the development of head-centered output neurons during periods of time when the head remains fixed while the eyes move. This hypothesis is demonstrated to be feasible, and each of the core model components described is tested and found to be individually necessary for successful self-organization. PMID:24349064

Enhancing creative cognition with a rapid right-parietal neurofeedback procedure.

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Agnoli, Sergio; Zanon, Marco; Mastria, Serena; Avenanti, Alessio; Corazza, Giovanni Emanuele

2018-02-14

The present article describes an innovative neurofeedback training (NFT) procedure aimed at increasing creative cognition through the enhancement of specific brain activities previously associated with divergent thinking. We designed and tested two NFT protocols based on training alpha and beta EEG oscillations selectively measured over the right parietal region. A total of 80 participants were involved, 40 in the alpha NFT protocol and 40 in the beta NFT protocol. The NFT loop was closed on a video stream that would advance only when oscillation power exceeded a normalized threshold. The total duration of the protocol was two hours in a single day, hence its classification as rapid. Changes in ideational fluency and originality, measured with a divergent thinking task, were compared between participants receiving real video feedback and participants receiving sham feedback. We controlled for individual differences in creative achievement level. Results showed that the protocols were effective at enhancing alpha and beta activities in the targeted area. Differences between the two protocols emerged in their effectiveness at promoting divergent thinking. While no significant changes in originality resulted from the rapid alpha NFT, increases in both originality and fluency emerged as a consequence of the rapid beta NFT. These results were particularly evident in participants starting with a low creative achievement level. Possible interpretations and future directions are proposed and discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Attention as the 'glue' for object integration in parietal extinction.

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Conci, Markus; Groß, Julia; Keller, Ingo; Müller, Hermann J; Finke, Kathrin

2018-04-01

Patients with unilateral, parietal brain damage frequently show visual extinction, which manifests in a failure to identify contralesional stimuli when presented simultaneously with other, ipsilesional stimuli (but full awareness for single stimulus presentations). Extinction reflects an impairment of spatial selective attention, leaving basic preattentive processing unaffected. For instance, access to bilaterally grouped objects is usually spared in extinction, suggesting that grouping occurs at a stage preceding (in the patients: abnormally biased) spatial-attentional selection. Here, we reinvestigated this notion by comparing (largely between participants, but also within a single-case participant) conditions with objects that varied in their dominant direction of grouping: from the attended to the non-attended hemifield (data from Conci et al., 2009) versus from the non-attended to the attended hemifield (new data). We observe complete absence of extinction when shape completion extended from the attended hemifield. By contrast, extinction was not diminished when object groupings propagate from the unattended hemifield. Moreover, we found the individual severity of the attentional impairment (assessed by a standard "inattention" test) to be directly related to the degree of completion in the unattended hemifield. This pattern indicates that grouping can overcome visual extinction only when object integration departs from the attended visual field, implying, contrary to many previous accounts, that attention is crucial for grouping to be initiated. Copyright © 2018 Elsevier Ltd. All rights reserved.

Modeling of effusion in the presence of a turbulent parietal flow. Application to the thermal protection of walls; Modelisation de l`effusion en presence d`un ecoulement parietal turbulent. Application a la protection thermique des parois

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Belletre, J.; Bataille, F.; Lallemaned, A. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France)

1997-12-31

The effusion of a cold gas through a porous wall submitted to a hot turbulent parietal flow is studied in order to reduce the convective heat fluxes between the wall and the hot fluid. A modeling of the turbulent dynamical and thermal boundary layer is obtained using a RNG k-{epsilon} model. The cold gas injection through the porous plate and the fluid-wall friction are taken into account using a discrete succession of pores and solid elements. For a 1% injection rate, the modeling results agree with experiments performed in a test-duct. On the other hand, convective heat fluxes on the porous plate are calculated using semi-empirical correlations and different injection rates and temperatures of the hot flow. (J.S.) 23 refs.

Liderazgo: un poder relativo

OpenAIRE

Huaylupo Alcázar, Juan Alberto

2007-01-01

Se analiza los implícitos epistemológicos, teóricos e históricos de la concepción y práctica del liderazgo, en la política cotidiana y en el quehacer la administración pública y empresarial. La interpretación predominantemente individualista del liderazgo, se encuentra asociado con formas particulares de interpretación de la historia y la sociedad, así como, con la conservación y reproducción del poder en las organizaciones, la sociedad y el Estado. El liderazgo, es una relación social que ex...

Coeficiente de pesimismo relativo

OpenAIRE

Ángel Samaniego; Gerardo Reyes Ruiz; Jordi Bachs Ferrer

2008-01-01

Las empresas de hoy se están dando cuenta de que el éxito no depende sólo de la obtención de utilidades, sino que se requiere contribuir con todos los que participan en ellas para hacerlas más competitivas y enfrentar un mundo cada vez más globalizado. Para lograr esto deben emprender acciones de responsabilidad social empresarial (RSE); sin embargo, existe confusión sobre el concepto y algunas empresas que dicen ser socialmente responsables no lo son totalmente. Se estudiar...

Parietal Epithelial Cells Participate in the Formation of Sclerotic Lesions in Focal Segmental Glomerulosclerosis

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Smeets, Bart; Kuppe, Christoph; Sicking, Eva-Maria; Fuss, Astrid; Jirak, Peggy; van Kuppevelt, Toin H.; Endlich, Karlhans; Wetzels, Jack F.M.; Gröne, Hermann-Josef; Floege, Jürgen

2011-01-01

The pathogenesis of the development of sclerotic lesions in focal segmental glomerulosclerosis (FSGS) remains unknown. Here, we selectively tagged podocytes or parietal epithelial cells (PECs) to determine whether PECs contribute to sclerosis. In three distinct models of FSGS (5/6-nephrectomy + DOCA-salt; the murine transgenic chronic Thy1.1 model; or the MWF rat) and in human biopsies, the primary injury to induce FSGS associated with focal activation of PECs and the formation of cellular adhesions to the capillary tuft. From this entry site, activated PECs invaded the affected segment of the glomerular tuft and deposited extracellular matrix. Within the affected segment, podocytes were lost and mesangial sclerosis developed within the endocapillary compartment. In conclusion, these results demonstrate that PECs contribute to the development and progression of the sclerotic lesions that define FSGS, but this pathogenesis may be relevant to all etiologies of glomerulosclerosis. PMID:21719782

Functional specialization of the left ventral parietal cortex in working memory

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Jennifer Lou Langel

2014-06-01

Full Text Available The function of the ventral parietal cortex (VPC is subject to much debate. Many studies suggest a lateralization of function in the VPC, with the left hemisphere facilitating verbal working memory and the right subserving stimulus-driven attention. However, many attentional tasks elicit activity in the VPC bilaterally. To elucidate the potential divides across the VPC in function, we assessed the pattern of activity in the VPC bilaterally across two tasks that require different demands, an oddball attentional task with low working memory demands and a working memory task. An anterior region of the VPC was bilaterally active during novel targets in the oddball task and during retrieval in WM, while more posterior regions of the VPC displayed dissociable functions in the left and right hemisphere, with the left being active during the encoding and retrieval of WM, but not during the oddball task and the right showing the reverse pattern. These results suggest that bilateral regions of the anterior VPC subserve non-mnemonic processes, such as stimulus-driven attention during WM retrieval and oddball detection. The left posterior VPC may be important for speech-related processing important for both working memory and perception, while the right hemisphere is more lateralized for attention.

Influencia de los esfuerzos residuales en la adherencia de recubrimientos de Al2O3-40% TiO2 depositados mediante proyección térmica por combustión

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Edward Restrepo

2016-11-01

Los resultados obtenidos indican que, en todas las muestras, el esfuerzo residual fue de tipo compresivo y que su magnitud se incrementa con el aumento del espesor de la capa y con la disminución de la temperatura del sustrato, lo que hizo que los recubrimientos depositados sobre sustratos precalentados a 250 °C y con un bajo espesor de la capa fuesen los de mayor resistencia.

The role of inferior parietal and inferior frontal cortex in working memory.

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Baldo, Juliana V; Dronkers, Nina F

2006-09-01

Verbal working memory involves two major components: a phonological store that holds auditory-verbal information very briefly and an articulatory rehearsal process that allows that information to be refreshed and thus held longer in short-term memory (A. Baddeley, 1996, 2000; A. Baddeley & G. Hitch, 1974). In the current study, the authors tested two groups of patients who were chosen on the basis of their relatively focal lesions in the inferior parietal (IP) cortex or inferior frontal (IF) cortex. Patients were tested on a series of tasks that have been previously shown to tap phonological storage (span, auditory rhyming, and repetition) and articulatory rehearsal (visual rhyming and a 2-back task). As predicted, IP patients were disproportionately impaired on the span, rhyming, and repetition tasks and thus demonstrated a phonological storage deficit. IF patients, however, did not show impairment on these storage tasks but did exhibit impairment on the visual rhyming task, which requires articulatory rehearsal. These findings lend further support to the working memory model and provide evidence of the roles of IP and IF cortex in separable working memory processes. ((c) 2006 APA, all rights reserved).

The role of the right temporo-parietal junction in social decision-making.

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Bitsch, Florian; Berger, Philipp; Nagels, Arne; Falkenberg, Irina; Straube, Benjamin

2018-03-26

Identifying someone else's noncooperative intentions can prevent exploitation in social interactions. Hence, the inference of another person's mental state might be most pronounced in order to improve social decision-making. Here, we tested the hypothesis that brain regions associated with Theory of Mind (ToM), particularly the right temporo-parietal junction (rTPJ), show higher neural responses when interacting with a selfish person and that the rTPJ-activity as well as cooperative tendencies will change over time. We used functional magnetic resonance imaging (fMRI) and a modified prisoner's dilemma game in which 20 participants interacted with three fictive playing partners who behaved according to stable strategies either competitively, cooperatively or randomly during seven interaction blocks. The rTPJ and the posterior-medial prefrontal cortex showed higher activity during the interaction with a competitive compared with a cooperative playing partner. Only the rTPJ showed a high response during an early interaction phase, which preceded participants increase in defective decisions. Enhanced functional connectivity between the rTPJ and the left hippocampus suggests that social cognition and learning processes co-occur when behavioral adaptation seems beneficial. © 2018 Wiley Periodicals, Inc.

What is said or how it is said makes a difference : role of the right fronto-parietal operculum in emotional prosody as revealed by repetitive TMS

NARCIS (Netherlands)

van Rijn, S; Aleman, A; van Diessen, E; Berckmoes, C; Vingerhoets, G; Kahn, RS

Emotional signals in spoken language can be conveyed by semantic as well as prosodic cues. We investigated the role of the fronto-parietal operculum, a somatosensory area where the lips, tongue and jaw are represented, in the right hemisphere to detection of emotion in prosody vs. semantics. A total

The flexible use of multiple cue relationships in spatial navigation : A comparison of water maze performance following hippocampal, medial septal, prefrontal cortex, or posterior parietal cortex lesions

NARCIS (Netherlands)

Compton, DM; Griffith, HR; McDaniel, WF; Foster, RA; Davis, BK

Rats prepared with lesions of the prefrontal cortex, posterior parietal cortex, hippocampus, or medial septal area were tested for acquisition of a number of variations of the open-field water maze using a version of place learning assessment described by Eichenbaum, Stewart, and Morris (1991).

Reglamento (UE n.º 611/2013 de la Comisión, de 24 de junio de 2013, relativo a las medidas aplicables a la notificación de casos de violación de datos personales en el marco de la Directiva 2002/58/CE del Parlamento Europeo y del Consejo sobre la privaci

Directory of Open Access Journals (Sweden)

M.ª Teresa HEREDERO CAMPO

2013-12-01

Full Text Available Reglamento (UE n.º 611/2013 de la Comisión, de 24 de junio de 2013, relativo a las medidas aplicables a la notificación de casos de violación de datos personales en el marco de la Directiva 2002/58/CE del Parlamento Europeo y del Consejo sobre la privacidad y las comunicaciones electrónicas [DOUE L 173, de 26-VI-2013

The parietal epithelial cell is crucially involved in human idiopathic focal segmental glomerulosclerosis.

Science.gov (United States)

Dijkman, Henry; Smeets, Bart; van der Laak, Jeroen; Steenbergen, Eric; Wetzels, Jack

2005-10-01

Focal segmental glomerulosclerosis (FSGS) is one of the most common patterns of glomerular injury encountered in human renal biopsies. Epithelial hyperplasia, which can be prominent in FSGS, has been attributed to dedifferentiation and proliferation of podocytes. Based on observations in a mouse model of FSGS, we pointed to the role of parietal epithelial cells (PECs). In the present study we investigated the relative role of PECs and podocytes in human idiopathic FSGS. We performed a detailed study of lesions from a patient with recurrent idiopathic FSGS by serial sectioning, marker analysis and three-dimensional reconstruction of glomeruli. We have studied the expression of markers for podocytes, PECs, mesangial cells, endothelium, and myofibroblasts. We also looked at proliferation and composition of the deposited extracellular matrix (ECM). We found that proliferating epithelial cells in FSGS lesions are negative for podocyte and macrophage markers, but stain for PEC markers. The composition of the matrix deposited by these cells is identical to Bowman's capsule. Our study demonstrates that PECs are crucially involved in the pathogenesis of FSGS lesions.

Influencia de la configuración del medio filtrante sobre el proceso de filtración a tasa constante del agua clarificada del río Cauca

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Lina M. Perea-Torres

2013-08-01

Full Text Available Se evaluó a escala piloto el efecto de la configuración del medio filtrante sobre el proceso de filtración del agua clarificada de la planta de potabilización Puerto Mallarino, Cali – Colombia. Se analizaron cuatro configuraciones, una con características similares a los filtros existentes y las restantes con diferente tamaño efectivo y espesor de antracita. Se analizó turbiedad, duración de carrera, producción de agua y pérdida de carga. La filtración fue más eficaz al reducir el tamaño efectivo e incrementar el espesor. La configuración que mostró un mejor desempeño incluso operando con turbiedades de agua clarificada mayores a 10,0 UTN, fue la del filtro con un espesor de 700 mm.

Distinct roles of visual, parietal, and frontal motor cortices in memory-guided sensorimotor decisions.

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Goard, Michael J; Pho, Gerald N; Woodson, Jonathan; Sur, Mriganka

2016-08-04

Mapping specific sensory features to future motor actions is a crucial capability of mammalian nervous systems. We investigated the role of visual (V1), posterior parietal (PPC), and frontal motor (fMC) cortices for sensorimotor mapping in mice during performance of a memory-guided visual discrimination task. Large-scale calcium imaging revealed that V1, PPC, and fMC neurons exhibited heterogeneous responses spanning all task epochs (stimulus, delay, response). Population analyses demonstrated unique encoding of stimulus identity and behavioral choice information across regions, with V1 encoding stimulus, fMC encoding choice even early in the trial, and PPC multiplexing the two variables. Optogenetic inhibition during behavior revealed that all regions were necessary during the stimulus epoch, but only fMC was required during the delay and response epochs. Stimulus identity can thus be rapidly transformed into behavioral choice, requiring V1, PPC, and fMC during the transformation period, but only fMC for maintaining the choice in memory prior to execution.

Atypical Balance between Occipital and Fronto-Parietal Activation for Visual Shape Extraction in Dyslexia

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Zhang, Ying; Whitfield-Gabrieli, Susan; Christodoulou, Joanna A.; Gabrieli, John D. E.

2013-01-01

Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI) to examine brain activation while adults with or without dyslexia responded to the change of an arrow’s direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading. PMID:23825653

Posterior parietal cortex is critical for the encoding, consolidation, and retrieval of a memory that guides attention for learning.

Science.gov (United States)

Schiffino, Felipe L; Zhou, Vivian; Holland, Peter C

2014-02-01

Within most contemporary learning theories, reinforcement prediction error, the difference between the obtained and expected reinforcer value, critically influences associative learning. In some theories, this prediction error determines the momentary effectiveness of the reinforcer itself, such that the same physical event produces more learning when its presentation is surprising than when it is expected. In other theories, prediction error enhances attention to potential cues for that reinforcer by adjusting cue-specific associability parameters, biasing the processing of those stimuli so that they more readily enter into new associations in the future. A unique feature of these latter theories is that such alterations in stimulus associability must be represented in memory in an enduring fashion. Indeed, considerable data indicate that altered associability may be expressed days after its induction. Previous research from our laboratory identified brain circuit elements critical to the enhancement of stimulus associability by the omission of an expected event, and to the subsequent expression of that altered associability in more rapid learning. Here, for the first time, we identified a brain region, the posterior parietal cortex, as a potential site for a memorial representation of altered stimulus associability. In three experiments using rats and a serial prediction task, we found that intact posterior parietal cortex function was essential during the encoding, consolidation, and retrieval of an associability memory enhanced by surprising omissions. We discuss these new results in the context of our previous findings and additional plausible frontoparietal and subcortical networks. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Parietal lesions produce illusory conjunction errors in rats

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Raymond PIERRE Kesner

2012-05-01

Full Text Available When several different objects are presented, visual objects are perceived correctly only if their features are identified and then bound together. Illusory-conjunction errors result when an object is correctly identified but is combined incorrectly. The parietal cortex (PPC has been shown repeatedly to play an important role in feature binding. The present study builds on a series of recent studies that have made use of visual search paradigms to elucidate the neural system involved in feature binding. This experiment attempts to define the role the PPC plays in binding the properties of a visual object that varies on the features of color and size in rats. Rats with PPC lesions or control surgery were exposed to three blocks of 20 trials administered over a 1-week period, with each block containing ten-one feature and ten-two feature trials. The target object consisted of one color object (e.g. black and white and one size object (e.g. short and tall. Of the ten one feature trials, five of the trials were tailored specifically for size discrimination and five for color discrimination. In the two-feature condition, the animal was required to locate the targeted object among four objects with two objects differing in size and two objects differing in color. The results showed a significant decrease in learning the task for the PPC lesioned rats compared to controls, especially for the two-feature condition. Based on a subsequent error analysis for color and size, the results showed a significant increase in illusory conjunction errors for the PPC lesioned rats relative to controls for color and relative to color discrimination, suggesting that the PPC may support feature binding as it relates to color. There was an increase in illusory conjunctions errors for both the PPC lesioned and control animals for size, but this appeared to be due to a difficulty with size discrimination.

Task-irrelevant memory load induces inattentional blindness without temporo-parietal suppression.

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Matsuyoshi, Daisuke; Ikeda, Takashi; Sawamoto, Nobukatsu; Kakigi, Ryusuke; Fukuyama, Hidenao; Osaka, Naoyuki

2010-08-01

We often fail to consciously detect an unexpected object when we are engaged in an attention-demanding task (inattentional blindness). The inattentional blindness which is induced by visual short-term memory (VSTM) load has been proposed to result from a suppression of temporo-parietal junction (TPJ) activity that involves stimulus-driven attention. However, the fact that, inversely proportional to TPJ activity, intraparietal sulcus (IPS) activity correlates with VSTM load renders questionable the account of inattentional blindness based only on TPJ activity. Here, we investigated whether the TPJ is solely responsible for inattentional blindness by decoupling IPS and TPJ responses to VSTM load and then using the same manipulation to test the behavioral inattentional blindness performance. Experiment 1 showed that TPJ activity was not suppressed by task-irrelevant load while the IPS responded to both task-relevant and task-irrelevant load. Although the TPJ account of inattentional blindness predicts that the degree of inattentional blindness should track TPJ activity, we found in Experiment 2 that inattentional blindness was induced not only by task-relevant load but also by task-irrelevant load, showing inconsistency between the extent of inattentional blindness and TPJ response. These findings suggest that inattentional blindness can be induced without suppression of TPJ activity and seem to offer the possibility that the IPS contributes to conscious perception. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

The Regenerative Potential of Parietal Epithelial Cells in Adult Mice

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Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H.; Floege, Jürgen; Smeets, Bart

2014-01-01

Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman’s capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glomerular hypertrophy was induced by progressive partial nephrectomies. Again, no significant podocyte replenishment was observed. Rather, labeled PECs exclusively invaded segments of the tuft affected by glomerulosclerosis, consistent with our previous findings. We next reassessed PEC recruitment in juvenile mice using a different reporter mouse and confirmed significant recruitment of labeled PECs onto the glomerular tuft. Moreover, some labeled cells on Bowman’s capsule expressed podocyte markers, and cells on Bowman’s capsule were also directly labeled in juvenile podocyte-specific Pod-rtTA transgenic mice. In 6-week-old mice, however, cells on Bowman’s capsule no longer expressed podocyte-specific markers. Similarly, in human kidneys, some cells on Bowman’s capsule expressed the podocyte marker synaptopodin from 2 weeks to 2 years of age but not at 7 years of age. In summary, podocyte regeneration from PECs could not be detected in aging mice or models of glomerular hypertrophy. We propose that a small fraction of committed podocytes reside on Bowman’s capsule close to the vascular stalk and are recruited onto the glomerular tuft during infancy to adolescence in mice and humans. PMID:24408873

The regenerative potential of parietal epithelial cells in adult mice.

Science.gov (United States)

Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J

2014-04-01

Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman's capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glomerular hypertrophy was induced by progressive partial nephrectomies. Again, no significant podocyte replenishment was observed. Rather, labeled PECs exclusively invaded segments of the tuft affected by glomerulosclerosis, consistent with our previous findings. We next reassessed PEC recruitment in juvenile mice using a different reporter mouse and confirmed significant recruitment of labeled PECs onto the glomerular tuft. Moreover, some labeled cells on Bowman's capsule expressed podocyte markers, and cells on Bowman's capsule were also directly labeled in juvenile podocyte-specific Pod-rtTA transgenic mice. In 6-week-old mice, however, cells on Bowman's capsule no longer expressed podocyte-specific markers. Similarly, in human kidneys, some cells on Bowman's capsule expressed the podocyte marker synaptopodin from 2 weeks to 2 years of age but not at 7 years of age. In summary, podocyte regeneration from PECs could not be detected in aging mice or models of glomerular hypertrophy. We propose that a small fraction of committed podocytes reside on Bowman's capsule close to the vascular stalk and are recruited onto the glomerular tuft during infancy to adolescence in mice and humans.

Estado nutricional relativo ao zinco de crianças que frequentam creches do estado da Paraíba Zinc nutritional status in children attending public daycare centers in the state of Paraíba, Brazil

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Dixis Figueroa Pedraza

2011-08-01

Full Text Available OBJETIVO: Avaliar o estado nutricional relativo ao zinco de crianças assistidas em creches do Estado da Paraíba. MÉTODOS: O estado nutricional relativo ao zinco de 235 crianças pré-escolares foi avaliado através de sua concentração no soro, da ingestão dietética de zinco e da estatura para idade, como recomendado pelo International Zinc Consultative Group. As concentrações séricas de zinco foram determinadas por espectrofotometria de absorção atômica de chama, considerando deficiência de zinco valores OBJECTIVE: This study assessed the zinc levels of children attending public daycare centers in the state of Paraíba. Brazil. METHODS: The zinc levels of 235 preschool children were evaluated through serum zinc concentration, dietary zinc intake and height-for-age, as recommended by the International Zinc Nutrition Consultative Group. Baseline zinc levels in the serum were measured by flame atomic absorption spectrophotometry, considering values <65µmol/L indicative of zinc deficiency. The 24-hour recall method was used to record food consumption, considering the food consumption of the child the day before and in the daycare center. Zinc inadequacy was analyzed according to the estimated average zinc requirement by life stage and diet type recommended by the International Zinc Nutrition Consultative Group. The World Health Organization Growth Reference was used as the reference for the height-for-age indices. Children with indices two z-scores below the median value of the reference population were considered stunted. Statistical analysis was performed by the t-test or analysis of variance by the software Statistical Package for the Social Sciences -16.0. RESULTS: The prevalence of inadequate serum zinc concentration, inadequate zinc intakes and stunting were 16.2%, 16.6% and 7.7%, respectively. Mean serum zinc was lower in children of underweight mothers than in children of normal weight mothers. CONCLUSION: The studied children

Fronto-Parietal Brain Responses to Visuotactile Congruence in an Anatomical Reference Frame

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Jakub Limanowski

2018-03-01

Full Text Available Spatially and temporally congruent visuotactile stimulation of a fake hand together with one’s real hand may result in an illusory self-attribution of the fake hand. Although this illusion relies on a representation of the two touched body parts in external space, there is tentative evidence that, for the illusion to occur, the seen and felt touches also need to be congruent in an anatomical reference frame. We used functional magnetic resonance imaging and a somatotopical, virtual reality-based setup to isolate the neuronal basis of such a comparison. Participants’ index or little finger was synchronously touched with the index or little finger of a virtual hand, under congruent or incongruent orientations of the real and virtual hands. The left ventral premotor cortex responded significantly more strongly to visuotactile co-stimulation of the same versus different fingers of the virtual and real hand. Conversely, the left anterior intraparietal sulcus responded significantly more strongly to co-stimulation of different versus same fingers. Both responses were independent of hand orientation congruence and of spatial congruence of the visuotactile stimuli. Our results suggest that fronto-parietal areas previously associated with multisensory processing within peripersonal space and with tactile remapping evaluate the congruence of visuotactile stimulation on the body according to an anatomical reference frame.

Fronto-Parietal Brain Responses to Visuotactile Congruence in an Anatomical Reference Frame.

Science.gov (United States)

Limanowski, Jakub; Blankenburg, Felix

2018-01-01

Spatially and temporally congruent visuotactile stimulation of a fake hand together with one's real hand may result in an illusory self-attribution of the fake hand. Although this illusion relies on a representation of the two touched body parts in external space, there is tentative evidence that, for the illusion to occur, the seen and felt touches also need to be congruent in an anatomical reference frame. We used functional magnetic resonance imaging and a somatotopical, virtual reality-based setup to isolate the neuronal basis of such a comparison. Participants' index or little finger was synchronously touched with the index or little finger of a virtual hand, under congruent or incongruent orientations of the real and virtual hands. The left ventral premotor cortex responded significantly more strongly to visuotactile co-stimulation of the same versus different fingers of the virtual and real hand. Conversely, the left anterior intraparietal sulcus responded significantly more strongly to co-stimulation of different versus same fingers. Both responses were independent of hand orientation congruence and of spatial congruence of the visuotactile stimuli. Our results suggest that fronto-parietal areas previously associated with multisensory processing within peripersonal space and with tactile remapping evaluate the congruence of visuotactile stimulation on the body according to an anatomical reference frame.

The effect of different EEG derivations on sleep staging in rats: the frontal midline–parietal bipolar electrode for sleep scoring

International Nuclear Information System (INIS)

Fang, Guangzhan; Zhang, Chunpeng; Xia, Yang; Lai, Yongxiu; Liu, Tiejun; You, Zili; Yao, Dezhong

2009-01-01

Most sleep-staging research has focused on developing and optimizing algorithms for sleep scoring, but little attention has been paid to the effect of different electroencephalogram (EEG) derivations on sleep staging. To explore the possible effects of EEG derivations, an automatic computer method was established and confirmed by agreement analysis between the computer and two independent raters, and four fronto-parietal bipolar leads were compared for sleep scoring in rats. The results demonstrated that different bipolar electrodes have significantly different sleep-staging accuracies, and that the optimal frontal electrode for sleep scoring is located at the anterior midline

Experienced Mindfulness Meditators Exhibit Higher Parietal-Occipital EEG Gamma Activity during NREM Sleep

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Ferrarelli, Fabio; Smith, Richard; Dentico, Daniela; Riedner, Brady A.; Zennig, Corinna; Benca, Ruth M.; Lutz, Antoine; Davidson, Richard J.; Tononi, Giulio

2013-01-01

Over the past several years meditation practice has gained increasing attention as a non-pharmacological intervention to provide health related benefits, from promoting general wellness to alleviating the symptoms of a variety of medical conditions. However, the effects of meditation training on brain activity still need to be fully characterized. Sleep provides a unique approach to explore the meditation-related plastic changes in brain function. In this study we performed sleep high-density electroencephalographic (hdEEG) recordings in long-term meditators (LTM) of Buddhist meditation practices (approximately 8700 mean hours of life practice) and meditation naive individuals. We found that LTM had increased parietal-occipital EEG gamma power during NREM sleep. This increase was specific for the gamma range (25–40 Hz), was not related to the level of spontaneous arousal during NREM and was positively correlated with the length of lifetime daily meditation practice. Altogether, these findings indicate that meditation practice produces measurable changes in spontaneous brain activity, and suggest that EEG gamma activity during sleep represents a sensitive measure of the long-lasting, plastic effects of meditative training on brain function. PMID:24015304

Fronto-parietal network oscillations reveal relationship between working memory capacity and cognitive control

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Rasa eGulbinaite

2014-09-01

Full Text Available Executive-attention theory proposes a close relationship between working memory capacity (WMC and cognitive control abilities. However, conflicting results are documented in the literature, with some studies reporting that individual variations in WMC predict differences in cognitive control and trial-to-trial control adjustments (operationalized as the size of the congruency effect and congruency sequence effects, respectively, while others report no WMC-related differences. We hypothesized that brain network dynamics might be a more sensitive measure of WMC-related differences in cognitive control abilities. Thus, in the present study, we measured human EEG during the Simon task to characterize WMC-related differences in the neural dynamics of conflict processing and adaptation to conflict. Although high- and low-WMC individuals did not differ behaviorally, there were substantial WMC-related differences in theta (4-8 Hz and delta (1-3 Hz connectivity in fronto-parietal networks. Group differences in local theta and delta power were relatively less pronounced. These results suggest that the relationship between WMC and cognitive control abilities is more strongly reflected in large-scale oscillatory network dynamics than in spatially localized activity or in behavioral task performance.

The significance of caveolin-1 expression in parietal epithelial cells of Bowman's capsule.

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Ostalska-Nowicka, D; Nowicki, M; Zachwieja, J; Kasper, M; Witt, M

2007-11-01

To analyse the expression of caveolin-1 in normal human kidney and during diseases leading to nephrotic syndrome in children and to compare its pattern with those observed in control samples, both human and animal. The study group was composed of 104 children diagnosed with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), lupus glomerulonephritis (LGN) and Schönlein-Henoch glomerulopathy (SH). The research protocol employed direct immunohistochemical assay with the use of mono- and polyclonal antibodies against caveolins. Kidney samples of Wistar rats, wild-type mice and caveolin-1-deficient mice were also analysed. In the control human samples, caveolin-1 was most abundant in the muscle layer of blood vessels and parietal epithelial cells (PECs). Its expression in PECs was significantly lower in children diagnosed with FSGS and LGN than in those with MCD, SH or in controls. In the control animal tissues, except for knock-out mice, caveolin-1 was present in distal convoluted tubules, PECs, endothelial cells and muscle. Caveolae are extremely stable elements of PECs and can be excluded from their cell membrane only in response to the dramatic cell reconstruction observed in FSGS and LGN.

Effect of substituted benzimidazoles on acid secretion in isolated and enriched guinea pig parietal cells.

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Sewing, K F; Harms, P; Schulz, G; Hannemann, H

1983-01-01

The inhibitory effect of the three benzimidazole derivatives timoprazole, picoprazole, and omeprazole on histamine and dbcAMP stimulated 14C-aminopyrine accumulation (= H+ secretion) has been studied in isolated and enriched guinea-pig parietal cells. All compounds tested inhibited H+ secretion in a concentration dependent manner with IC50 values of 8.5 +/- 1.9 mumol/l for timoprazole, 3.9 +/- 0.7 mumol/l for picoprazole, and 0.13 +/- 0.03 mumol/l for omeprazole. The IC50 of timoprazole, when dbcAMP was used as a stimulus, did not differ significantly from that of histamine stimulation. The type of inhibition was of a non-competitive nature. The full acid response to histamine after temporary exposure of the cells to the benzimidazoles could be restored by washing the cells twice; this suggests that the inhibition is reversible. The data - among others - indicate that the properties of the benzimidazoles described here would allow these compounds to be used as effective antisecretagogues. PMID:6303916

Conhecimentos e práticas de trabalhadoras de creches universitárias relativos às infecções respiratórias agudas na infância Conocimientos y prácticas de trabajadoras de guarderías universitarias relativos a las infecciones respiratorias agudas en la infancia Knowledge and practices of university day care center workers relative to acute respiratory infections in childhood

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Roberta Cristiane P. Alves

2006-03-01

Full Text Available Dada a elevada freqüência de infecções respiratórias agudas em creches, o objetivo deste trabalho foi identificar conhecimentos e práticas de trabalhadoras de creches relativos à prevenção, detecção precoce e manejo desses agravos. Mediante quatorze entrevistas estruturadas em duas creches universitárias da cidade de São Paulo, verificou-se que as trabalhadoras: demonstram familiaridade com diversos agravos; apontam febre e respiração ruidosa como sinais de gravidade; consideram poluição e transmissão como principais causas; referem o cuidado com o ambiente como melhor forma de controle; cuidam mantendo observação contínua da criança e intervenções de higiene e conforto e maior cuidado emocional; consideram educação e cuidado interligados no atendimento infantil, manifestando necessidade de maior preparo para cuidar; têm na prática diária a fonte de seus conhecimentos.Dada la elevada frecuencia de infecciones respiratorias agudas en guarderías, el objetivo en este trabajo fue identificar conocimientos y prácticas de trabajadoras de guarderías relativos a la prevención, detección precoz y manejo de esas afecciones. Mediante catorce entrevistas estructuradas en dos guarderías universitarias de la ciudad de São Paulo, se verificó que las trabajadoras: demuestran familiaridad con las diversas afecciones; señalan fiebre y respiración ruidosa como signos de gravedad; consideran a la polución y transmisión como sus principales causas; refieren al cuidado del ambiente como la mejor forma de control; se preocupan con la observación continua del niño y con acciones de higiene, confort y cuidado emocional; consideran que la educación y el cuidado son necesarios para atender a los niños y desean mayor preparación para cuidar; tienen en la práctica diaria la fuente de sus conocimientos.Given the increasing frequency of acute respiratory infections in day care centers, the objective of this work was to identify

Virtual lesions of the inferior parietal cortex induce fast changes of implicit religiousness/spirituality.

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Crescentini, Cristiano; Aglioti, Salvatore M; Fabbro, Franco; Urgesi, Cosimo

2014-05-01

Religiousness and spirituality (RS) are two ubiquitous aspects of human experience typically considered impervious to scientific investigation. Nevertheless, associations between RS and frontoparietal neural activity have been recently reported. However, much less is known about whether such activity is causally involved in modulating RS or just epiphenomenal to them. Here we combined two-pulse (10 Hz) Transcranial Magnetic Stimulation (TMS) with a novel, ad-hoc developed RS-related, Implicit Association Test (IAT) to investigate whether implicit RS representations, although supposedly rather stable, can be rapidly modified by a virtual lesion of inferior parietal lobe (IPL) and dorsolateral prefrontal cortex (DLPFC). A self-esteem (SE) IAT, focused on self-concepts nonrelated to RS representations, was developed as control. A specific increase of RS followed inhibition of IPL demonstrating its causative role in inducing fast plastic changes of religiousness/spirituality. In contrast, DLPFC inhibition had more widespread effects probably reflecting a general role in the acquisition or maintenance of task-rules or in controlling the expression of self-related representations not specific to RS. Copyright © 2014 Elsevier Ltd. All rights reserved.

DESIGN AND CHARACTERIZATION OF THERMALLY ACTUATED BIMETALLIC MEMBRANES BY MICHELSON INTERFEROMETRY

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JULIO ENRIQUE DUARTE

2011-01-01

Full Text Available En el presente trabajo se describen el diseño y la caracterización de membranas bimetálicas de Al-Si, con actuación térmica. El diseño se realizó empleando el método de los Elementos Finitos y se concentró en optimizar la relación de los espesores de las capas de aluminio y silicio. La defl exión de las membranas se determinó aplicando la técnica del Interferómetro de Michelson. En la etapa experimental se utilizaron membranas cuadradas de 5 mm de lado, con un espesor de 10 mm para el silicio y espesores de 4 y 1 mm para el aluminio. La caracterización entregó un desplazamiento máximo de 14 mm para la membrana con 4 mm de Al, lo cual es consistente con los resultados obtenidos numéricamente.

Podocyte and Parietal Epithelial Cell Interactions in Health and Disease.

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Al Hussain, Turki; Al Mana, Hadeel; Hussein, Maged H; Akhtar, Mohammed

2017-01-01

The glomerulus has 3 resident cells namely mesangial cells that produce the mesangial matrix, endothelial cells that line the glomerular capillaries, and podocytes that cover the outer surface of the glomerular basement membrane. Parietal epithelial cells (PrECs), which line the Bowman's capsule are not part of the glomerular tuft but may have an important role in the normal function of the glomerulus. A significant progress has been made in recent years regarding our understanding of the role and function of these cells in normal kidney and in kidneys with various types of glomerulopathy. In crescentic glomerulonephritis necrotizing injury of the glomerular tuft results in activation and leakage of fibrinogen which provides the trigger for excessive proliferation of PrECs giving rise to glomerular crescents. In cases of collapsing glomerulopathy, podocyte injury causes collapse of the glomerular capillaries and activation and proliferation of PrECs, which accumulate within the urinary space in the form of pseudocrescents. Many of the noninflammatory glomerular lesions such as focal segmental glomerulosclerosis and global glomerulosclerosis also result from podocyte injury which causes variable loss of podocytes. In these cases podocyte injury leads to activation of PrECs that extend on to the glomerular tuft where they cause segmental and/or global sclerosis by producing excess matrix, resulting in obliteration of the capillary lumina. In diabetic nephropathy, in addition to increased matrix production in the mesangium and glomerular basement membranes, increased loss of podocytes is an important determinant of long-term prognosis. Contrary to prior belief there is no convincing evidence for an active podocyte proliferation in any of the above mentioned glomerulopathies.

Controversies over the mechanisms underlying the crucial role of the left fronto-parietal areas in the representation of tools

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Guido eGainotti

2013-10-01

Full Text Available Anatomo-clinical and neuroimaging data show that the left fronto-parietal areas play an important role in representing tools. As manipulation is an important source of knowledge about tools, it has been assumed that motor activity explains the link between tool knowledge and the left fronto-parietal areas. However, controversies exist over the exact mechanisms underlying this relationship. According to a strong version of the ‘embodied cognition theory’, activation of a tool concept necessarily involves re-enactment of the corresponding kind of action. Impairment of the ability to use tools should, therefore, lead to impairment of tool knowledge. Both the ‘domains of knowledge hypothesis’ and the ‘sensory-motor model of conceptual knowledge’ refute the strong version of the ‘embodied cognition hypothesis’ but acknowledge that manipulation and other action schemata play an important role in our knowledge of tools. The basic difference between these two models is that the former is based on an innatist model and the latter holds that the brain’s organization of categories is experience dependent. Data supporting and arguing against each of these models are briefly reviewed. In particular, the following lines of research, which argue against the innate nature of the brain’s categorical organization, are discussed: (1 the observation that in patients with category-specific disorders the semantic impairment does not respect the boundaries between biological entities and artefact items; (2 data showing that experience-driven neuroplasticity in musicians is not confined to alterations of perceptual and motor maps but also leads to the establishment of higher-level semantic representations for musical instruments; (3 results of experiments using previously unfamiliar materials showing that the history of our sensory-motor experience with an object significantly affects its neural representation.

Refuerzo de pavimentos sobre arcillas expansivas

OpenAIRE

Zornberg, Jorge

2012-01-01

El refuerzo de la capa base de pavimentos se ha utilizado a los efectos de: (i) aumentar la vida útil de un pavimento manteniendo el espesor de la capa base, o (ii) disminuir el espesor de la capa base manteniendo la vida útil del pavimento. Este artículo describe una tercera aplicación del refuerzo basal de pavimentos, a saber, la mitigación de grietas longitudinales inducidas en pavimentos construidos sobre subrasantes compuestas de arcillas expansivas. Aunque todavía existe la necesidad de...

Excitatory stimulation of the right inferior parietal cortex lessens implicit religiousness/spirituality.

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Crescentini, Cristiano; Di Bucchianico, Marilena; Fabbro, Franco; Urgesi, Cosimo

2015-04-01

Although religiousness and spirituality (RS) are considered two fundamental constituents of human life, neuroscientific investigation has long avoided the study of their neurocognitive basis. Nevertheless, recent investigations with brain imaging and brain damaged patients, and more recently with brain stimulation methods, have documented important associations between RS beliefs and experiences and frontoparietal neural activity. In this study, we further investigated how individuals' implicit RS self-representations can be modulated by changes in right inferior parietal lobe (IPL) excitability, a key region associated to RS. To this end, we combined continuous theta burst stimulation (cTBS), intermittent TBS (iTBS), and sham TBS with RS-related, Implicit Association Test (IAT) and with a control self-esteem (SE) IAT in a group of fourteen healthy adult individuals. A specific decrease of implicit RS, as measured with the IAT effect, was induced by increasing IPL excitability with iTBS; conversely cTBS, which is supposedly inhibitory, left participants' implicit RS unchanged. The performance in the control SE-IAT was left unchanged by any TBS stimulation. These data showed the causative role of right IPL functional state in mediating plastic changes of implicit RS. Implications of these results are also discussed in the light of the variability of behavioral effects associated with TBS. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prospective relations between resting-state connectivity of parietal subdivisions and arithmetic competence.

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Price, Gavin R; Yeo, Darren J; Wilkey, Eric D; Cutting, Laurie E

2018-04-01

The present study investigates the relation between resting-state functional connectivity (rsFC) of cytoarchitectonically defined subdivisions of the parietal cortex at the end of 1st grade and arithmetic performance at the end of 2nd grade. Results revealed a dissociable pattern of relations between rsFC and arithmetic competence among subdivisions of intraparietal sulcus (IPS) and angular gyrus (AG). rsFC between right hemisphere IPS subdivisions and contralateral IPS subdivisions positively correlated with arithmetic competence. In contrast, rsFC between the left hIP1 and the right medial temporal lobe, and rsFC between the left AG and left superior frontal gyrus, were negatively correlated with arithmetic competence. These results suggest that strong inter-hemispheric IPS connectivity is important for math development, reflecting either neurocognitive mechanisms specific to arithmetic processing, domain-general mechanisms that are particularly relevant to arithmetic competence, or structural 'cortical maturity'. Stronger connectivity between IPS, and AG, subdivisions and frontal and temporal cortices, however, appears to be negatively associated with math development, possibly reflecting the ability to disengage suboptimal problem-solving strategies during mathematical processing, or to flexibly reorient task-based networks. Importantly, the reported results pertain even when controlling for reading, spatial attention, and working memory, suggesting that the observed rsFC-behavior relations are specific to arithmetic competence. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Mental reversal of imagined melodies: a role for the posterior parietal cortex.

Science.gov (United States)

Zatorre, Robert J; Halpern, Andrea R; Bouffard, Marc

2010-04-01

Two fMRI experiments explored the neural substrates of a musical imagery task that required manipulation of the imagined sounds: temporal reversal of a melody. Musicians were presented with the first few notes of a familiar tune (Experiment 1) or its title (Experiment 2), followed by a string of notes that was either an exact or an inexact reversal. The task was to judge whether the second string was correct or not by mentally reversing all its notes, thus requiring both maintenance and manipulation of the represented string. Both experiments showed considerable activation of the superior parietal lobe (intraparietal sulcus) during the reversal process. Ventrolateral and dorsolateral frontal cortices were also activated, consistent with the memory load required during the task. We also found weaker evidence for some activation of right auditory cortex in both studies, congruent with results from previous simpler music imagery tasks. We interpret these results in the context of other mental transformation tasks, such as mental rotation in the visual domain, which are known to recruit the intraparietal sulcus region, and we propose that this region subserves general computations that require transformations of a sensory input. Mental imagery tasks may thus have both task or modality-specific components as well as components that supersede any specific codes and instead represent amodal mental manipulation.

Influence of the type of lightweight clay brick on the equivalent thermal transmittance of different types of façades on buildings

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Morales, M. P.

2016-09-01

Full Text Available This paper compares the equivalent thermal transmittances of different façades built using commercial clay bricks with three different thicknesses and façades made using the same method but with ceramic bricks with optimized rhomboidal interior geometry. Equivalent thermal transmittances of 0.300 W/m2·K were recorded for the rhomboidal brick with a thickness of 0.290 m and a façade with thermo-acoustic insulation and a large format brick on the interior, but the final thickness of the façade was 0.445 m. For ventilated façades made of the proposed rhomboidal brick with thicknesses of 0.290 and 0.240 m an 8–9% improvement was found, with values of 0.312 W/m2·K and 0.339 W/m2·K, respectively. It can be concluded that in view of the small difference in thermal terms, the best option is to use a brick 0.240 m thick, as the overall thickness of the façade will not then exceed 0.300 m.En el presente trabajo se comparan las transmitancias térmicas equivalentes de diferentes fachadas ejecutadas con bloques comerciales de tres espesores 0,290 m, 0,240 m y 0,190 m, con el mismo montaje pero con un bloque cerámico optimizado con geometría interior romboidal. Se ha obtenido una transmitancia térmica equivalente de 0,300 W/m2·K para el ladrillo con geometría romboidal de 0,290 m de espesor y pared con aislamiento termoacústico y gran formato en el interior, con un espesor total de fachada de 0,445 m. Para fachadas ventiladas con el ladrillo romboidal propuesto con espesores de 0,290 y 0,240 m, se obtiene una mejora de un 8%–9%, con valores de 0,312 W/m2·K y 0,339 W/m2·K, respectivamente. Podemos concluir que, dada la pequeña diferencia en términos térmicos, la mejor opción es el uso de ladrillos de 0,240 m de espesor, siempre y cuando el espesor total de fachada no exceda los 0,300 m.

The effect of dual-hemisphere transcranial direct current stimulation over the parietal operculum on tactile orientation discrimination

DEFF Research Database (Denmark)

Fujimoto, Shuhei; Tanaka, Satoshi; Laakso, Ilkka

2017-01-01

The parietal operculum (PO) often shows ipsilateral activation during tactile object perception in neuroimaging experiments. However, the relative contribution of the PO to tactile judgment remains unclear. Here, we examined the effect of transcranial direct current stimulation (tDCS) over...... bilateral PO to test the relative contributions of the ipsilateral PO to tactile object processing. Ten healthy adults participated in this study, which had a double-blind, sham-controlled, cross-over design. Participants discriminated grating orientation during three tDCS and sham conditions. In the dual......-hemisphere tDCS conditions, anodal and cathodal electrodes were placed over the left and right PO. In the uni-hemisphere tDCS condition, anodal and cathodal electrodes were applied over the left PO and contralateral orbit, respectively. In the tDCS and sham conditions, we applied 2 mA for 15 min and for 15 s...

EL LIDERAZGO: UN PODER RELATIVO

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Juan Huaylupo Alcázar

2011-07-01

Full Text Available RESUMENSe analiza los implícitos epistemológicos, teóricos e históricos de la concepción y práctica del liderazgo, en la política cotidiana y en el quehacer la administración pública y empresarial. La interpretación predominantemente individualista del liderazgo, se encuentra asociado con formas particulares de interpretación de la historia y la sociedad, así como, con la conservación y reproducción del poder en las organizaciones, la sociedad y el Estado. El liderazgo, es una relación social que expresa y representa los sentimientos y aspiraciones de específicascolectividades, de ningún modo desarraigado del devenir de la organización, ni del medio social e histórico de las sociedades.SUMMARYThis article analyzes the epistemological, theoretical and  historical implicit of the conception and practice of the leadership, in the public and also in the private administration. The mainlyindividualistic interpretation of the leadership is associated with peculiar forms of the interpretation of the history and the society, as well as, the conservation and reproduction of the power in the organizations, the society and the State. The leadership is a social relationship that expresses and represents the feelings and the aspirations of specific collectives, at all eradicated of becoming of the organization, neither of the social and historical contexts of the societies.

Development of Right-hemispheric Dominance of Inferior Parietal Lobule in Proprioceptive Illusion Task

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Naito, Eiichi; Morita, Tomoyo; Saito, Daisuke N; Ban, Midori; Shimada, Koji; Okamoto, Yuko; Kosaka, Hirotaka; Okazawa, Hidehiko; Asada, Minoru

2017-01-01

Abstract Functional lateralization can be an indicator of brain maturation. We have consistently shown that, in the adult brain, proprioceptive processing of muscle spindle afferents generating illusory movement of the right hand activates inferior frontoparietal cortical regions in a right-side dominant manner in addition to the cerebrocerebellar motor network. Here we provide novel evidence regarding the development of the right-dominant use of the inferior frontoparietal cortical regions in humans using this task. We studied brain activity using functional magnetic resonance imaging while 60 right-handed blindfolded healthy children (8–11 years), adolescents (12–15 years), and young adults (18–23 years) (20 per group) experienced the illusion. Adult-like right-dominant use of the inferior parietal lobule (IPL) was observed in adolescents, while children used the IPL bilaterally. In contrast, adult-like lateralized cerebrocerebellar motor activation patterns were already observable in children. The right-side dominance progresses during adolescence along with the suppression of the left-sided IPL activity that emerges during childhood. Therefore, the neuronal processing implemented in the adult's right IPL during the proprioceptive illusion task is likely mediated bilaterally during childhood, and then becomes right-lateralized during adolescence at a substantially later time than the lateralized use of the cerebrocerebellar motor system for kinesthetic processing. PMID:28968653

Functional development of fronto-striato-parietal networks associated with time perception

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Anna eSmith

2011-11-01

Full Text Available Compared to our understanding of the functional maturation of executive functions, little is known about the neurofunctional development of perceptive functions. Time perception develops during late adolescence, underpinning many functions including motor and verbal processing, as well as late maturing higher order cognitive skills such as forward planning and future-related decision-making. Nothing, however, is known about the neurofunctional changes associated with time perception from childhood to adulthood. Using functional magnetic resonance imaging we explored the effects of age on the brain activation and functional connectivity of 32 male participants from 10 to 53 years of age during a time discrimination task that required the discrimination of temporal intervals of seconds differing by several hundred milliseconds. Increasing development was associated with progressive activation increases within left lateralised dorsolateral and inferior fronto-parieto-striato-thalamic brain regions. Furthermore, despite comparable task performance, adults showed increased functional connectivity between inferior/dorsolateral interhemispheric fronto-frontal activation as well as between inferior fronto-parietal regions compared with adolescents. Activation in caudate, specifically, was associated with both increasing age and better temporal discrimination. Progressive decreases in activation with age were observed in ventromedial prefrontal cortex, limbic regions and cerebellum. The findings demonstrate age-dependent developmentally dissociated neural networks for time discrimination. With increasing age there is progressive recruitment of later maturing left hemispheric and lateralised fronto-parieto-striato-thalamic networks, known to mediate time discrimination in adults, while earlier developing brain regions such as ventromedial prefrontal cortex, limbic and paralimbic areas and cerebellum subserve fine-temporal processing functions in children

Mapping human temporal and parietal neuronal population activity and functional coupling during mathematical cognition

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Daitch, Amy L.; Foster, Brett L.; Schrouff, Jessica; Rangarajan, Vinitha; Kaşikçi, Itır; Gattas, Sandra; Parvizi, Josef

2016-01-01

Brain areas within the lateral parietal cortex (LPC) and ventral temporal cortex (VTC) have been shown to code for abstract quantity representations and for symbolic numerical representations, respectively. To explore the fast dynamics of activity within each region and the interaction between them, we used electrocorticography recordings from 16 neurosurgical subjects implanted with grids of electrodes over these two regions and tracked the activity within and between the regions as subjects performed three different numerical tasks. Although our results reconfirm the presence of math-selective hubs within the VTC and LPC, we report here a remarkable heterogeneity of neural responses within each region at both millimeter and millisecond scales. Moreover, we show that the heterogeneity of response profiles within each hub mirrors the distinct patterns of functional coupling between them. Our results support the existence of multiple bidirectional functional loops operating between discrete populations of neurons within the VTC and LPC during the visual processing of numerals and the performance of arithmetic functions. These findings reveal information about the dynamics of numerical processing in the brain and also provide insight into the fine-grained functional architecture and connectivity within the human brain. PMID:27821758

Parietal and temporal activity during a multimodal dance video game: an fNIRS study.

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Tachibana, Atsumichi; Noah, J Adam; Bronner, Shaw; Ono, Yumie; Onozuka, Minoru

2011-10-03

Using functional near infrared spectroscopy (fNIRS) we studied how playing a dance video game employs coordinated activation of sensory-motor integration centers of the superior parietal lobe (SPL) and superior temporal gyrus (STG). Subjects played a dance video game, in a block design with 30s of activity alternating with 30s of rest, while changes in oxy-hemoglobin (oxy-Hb) levels were continuously measured. The game was modified to compare difficult (4-arrow), simple (2-arrow), and stepping conditions. Oxy-Hb levels were greatest with increased task difficulty. The quick-onset, trapezoidal time-course increase in SPL oxy-Hb levels reflected the on-off neuronal response of spatial orienting and rhythmic motor timing that were required during the activity. Slow-onset, bell-shaped increases in oxy-Hb levels observed in STG suggested the gradually increasing load of directing multisensory information to downstream processing centers associated with motor behavior and control. Differences in temporal relationships of SPL and STG oxy-Hb concentration levels may reflect the functional roles of these brain structures during the task period. NIRS permits insights into temporal relationships of cortical hemodynamics during real motor tasks. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Lateralization of the posterior parietal cortex for internal monitoring of self- versus externally generated movements.

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Ogawa, Kenji; Inui, Toshio

2007-11-01

Internal monitoring or state estimation of movements is essential for human motor control to compensate for inherent delays and noise in sensorimotor loops. Two types of internal estimation of movements exist: self-generated movements, and externally generated movements. We used functional magnetic resonance imaging to investigate differences in brain activity for internal monitoring of self- versus externally generated movements during visual occlusion. Participants tracked a sinusoidally moving target with a mouse cursor. On some trials, vision of either target (externally generated) or cursor (self-generated) movement was transiently occluded, during which subjects continued tracking by estimating current position of either the invisible target or cursor on screen. Analysis revealed that both occlusion conditions were associated with increased activity in the presupplementary motor area and decreased activity in the right lateral occipital cortex compared to a control condition with no occlusion. Moreover, the right and left posterior parietal cortex (PPC) showed greater activation during occlusion of target and cursor movements, respectively. This study suggests lateralization of the PPC for internal monitoring of internally versus externally generated movements, fully consistent with previously reported clinical findings.

Functional connectivity between prefrontal and parietal cortex drives visuo-spatial attention shifts.

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Heinen, Klaartje; Feredoes, Eva; Ruff, Christian C; Driver, Jon

2017-05-01

It is well established that the frontal eye-fields (FEF) in the dorsal attention network (DAN) guide top-down selective attention. In addition, converging evidence implies a causal role for the FEF in attention shifting, which is also known to recruit the ventral attention network (VAN) and fronto-striatal regions. To investigate the causal influence of the FEF as (part of) a central hub between these networks, we applied thetaburst transcranial magnetic stimulation (TBS) off-line, combined with functional magnetic resonance (fMRI) during a cued visuo-spatial attention shifting paradigm. We found that TBS over the right FEF impaired performance on a visual discrimination task in both hemifields following attention shifts, while only left hemifield performance was affected when participants were cued to maintain the focus of attention. These effects recovered ca. 20min post stimulation. Furthermore, particularly following attention shifts, TBS suppressed the neural signal in bilateral FEF, right inferior and superior parietal lobule (IPL/SPL) and bilateral supramarginal gyri (SMG). Immediately post stimulation, functional connectivity was impaired between right FEF and right SMG as well as right putamen. Importantly, the extent of decreased connectivity between right FEF and right SMG correlated with behavioural impairment following attention shifts. The main finding of this study demonstrates that influences from right FEF on SMG in the ventral attention network causally underly attention shifts, presumably by enabling disengagement from the current focus of attention. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Lower Parietal Encoding Activation Is Associated with Sharper Information and Better Memory.

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Lee, Hongmi; Chun, Marvin M; Kuhl, Brice A

2017-04-01

Mean fMRI activation in ventral posterior parietal cortex (vPPC) during memory encoding often negatively predicts successful remembering. A popular interpretation of this phenomenon is that vPPC reflects "off-task" processing. However, recent fMRI studies considering distributed patterns of activity suggest that vPPC actively represents encoded material. Here, we assessed the relationships between pattern-based content representations in vPPC, mean activation in vPPC, and subsequent remembering. We analyzed data from two fMRI experiments where subjects studied then recalled word-face or word-scene associations. For each encoding trial, we measured 1) mean univariate activation within vPPC and 2) the strength of face/scene information as indexed by pattern analysis. Mean activation in vPPC negatively predicted subsequent remembering, but the strength of pattern-based information in the same vPPC voxels positively predicted later memory. Indeed, univariate amplitude averaged across vPPC voxels negatively correlated with pattern-based information strength. This dissociation reflected a tendency for univariate reductions to maximally occur in voxels that were not strongly tuned for the category of encoded stimuli. These results indicate that vPPC activity patterns reflect the content and quality of memory encoding and constitute a striking example of lower univariate activity corresponding to stronger pattern-based information. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Filmes de ficção científica como mediadores de conceitos relativos ao meio ambiente Science fiction movies and environmental education: is it possible?

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Carlos Alberto Machado

2008-01-01

Full Text Available Muito se fala sobre o meio ambiente nos meios de comunicação e nas escolas, mas pouco se sabe sobre toda sua gama e envergadura. Confundem-se princípios ecológicos com o ensino generalizado do meio ambiente que cobre uma gama muito maior de conceitos e uma complexidade de relações urgentes e esquece-se que o estudo do meio ambiente deve tratar do todo envolvido pelo homem, do todo ao redor. Visões utópicas e distópicas a respeito desse tema estão presentes em alguns filmes de ficção científica feitos para cinema e televisão. Este texto analisa relações entre esses filmes e conceitos científicos relativos ao meio ambiente e aponta possibilidades de uso dos mesmos no ensino de ciência.The environment is one of the most important scientific subjects in the XXI century. Schools and the media talk about it all the time but they do not have enough knowledge. They forget that environmental studies must embrace the human beings and the whole world around them. Utopian and non-utopian conceptions about this subject are often presented in science fictions movies made for the cinema or for the television. This text discusses the relation between science fiction movies and scientific environmental concepts. In addition, it suggests a way to use the science in these kinds of films at school to develop science teaching.

Secado de lúcuma (Pouteria obovata empleando la técnica de Ventana RefractanteTM

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Diego Gamboa

2014-01-01

Full Text Available La lúcuma es una fruta que experimenta una tendencia creciente a nivel comercial en forma de harina para su empleo en la industria alimentaria. Este estudio tuvo como objetivo obtener harina de lúcuma utilizando el método de secado por ventana refractante y evaluar el efecto del espesor de la pulpa de lúcuma y el tiempo de secado en la humedad y el color de la harina. Fue utilizado un Diseño Compuesto Central Rotable (DCCR con el tiempo entre 10 y 50 min y el espesor entre 1 y 3 mm. Se empleó una temperatura fija de 95°C y lámina mylar (polietileno de tereftalato metalizado como película refractante de 0,1 mm. Se determinó que las condiciones ideales para obtener harina de lúcuma (9,8% de humedad con esta técnica se da cuando el espesor fue 1,3 mm y con un tiempo de 15 minutos; a estas condiciones la difusividad efectiva del agua es de 2,53E-7 m2/s.

INFLUENCE OF THICKNESS ON THE DRYING OF PAPAYA PUREE (Carica papaya L. THROUGH REFRACTANCE WINDOWTM TECHNOLOGY

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MARÍA U. OCORÓ-ZAMORA

2013-01-01

Full Text Available El objetivo de este trabajo fue evaluar la influencia del espesor de las muestras (2, 3 y 4 mm sobre las cinéticas de secado, actividad de agua (aw y color (∆E de rodajas de puré de papaya procesadas por tecnología de ventana de refractanciaTM (RWTM. Adicionalmente se evaluó la difusividad del agua (Deff teniendo en cuenta el encogimiento. Los datos de humedad se ajustaron mediante los modelos de Newton y Midilli. Los resultados mostraron que a menor espesor el secado fue más rápido, los valores de aw fueron menores y los ∆E superiores. Las muestras alcanzaron 0.0652, 0.1132 y 0.2624 g agua/ g sólido seco en 60 min para rodajas de 2, 3 y 4 mm, respectivamente. El Modelo de Midilli fue el más apropiado para predecir las curvas de secado de papaya por RWTM. Deff disminuyó a menor espesor y su orden de magnitud fue de 10-10 m2/s.

Development of Right-hemispheric Dominance of Inferior Parietal Lobule in Proprioceptive Illusion Task.

Science.gov (United States)

Naito, Eiichi; Morita, Tomoyo; Saito, Daisuke N; Ban, Midori; Shimada, Koji; Okamoto, Yuko; Kosaka, Hirotaka; Okazawa, Hidehiko; Asada, Minoru

2017-11-01

Functional lateralization can be an indicator of brain maturation. We have consistently shown that, in the adult brain, proprioceptive processing of muscle spindle afferents generating illusory movement of the right hand activates inferior frontoparietal cortical regions in a right-side dominant manner in addition to the cerebrocerebellar motor network. Here we provide novel evidence regarding the development of the right-dominant use of the inferior frontoparietal cortical regions in humans using this task. We studied brain activity using functional magnetic resonance imaging while 60 right-handed blindfolded healthy children (8-11 years), adolescents (12-15 years), and young adults (18-23 years) (20 per group) experienced the illusion. Adult-like right-dominant use of the inferior parietal lobule (IPL) was observed in adolescents, while children used the IPL bilaterally. In contrast, adult-like lateralized cerebrocerebellar motor activation patterns were already observable in children. The right-side dominance progresses during adolescence along with the suppression of the left-sided IPL activity that emerges during childhood. Therefore, the neuronal processing implemented in the adult's right IPL during the proprioceptive illusion task is likely mediated bilaterally during childhood, and then becomes right-lateralized during adolescence at a substantially later time than the lateralized use of the cerebrocerebellar motor system for kinesthetic processing. © The Author 2017. Published by Oxford University Press.

Theta, mental flexibility, and post-traumatic stress disorder: connecting in the parietal cortex.

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Benjamin T Dunkley

Full Text Available Post-traumatic stress disorder (PTSD is a mental health injury characterised by re-experiencing, avoidance, numbing and hyperarousal. Whilst the aetiology of the disorder is relatively well understood, there is debate about the prevalence of cognitive sequelae that manifest in PTSD. In particular, there are conflicting reports about deficits in executive function and mental flexibility. Even less is known about the neural changes that underlie such deficits. Here, we used magnetoencephalography to study differences in functional connectivity during a mental flexibility task in combat-related PTSD (all males, mean age = 37.4, n = 18 versus a military control (all males, mean age = 33.05, n = 19 group. We observed large-scale increases in theta connectivity in the PTSD group compared to controls. The PTSD group performance was compromised in the more attentionally-demanding task and this was characterised by 'late-stage' theta hyperconnectivity, concentrated in network connections involving right parietal cortex. Furthermore, we observed significant correlations with the connectivity strength in this region with a number of cognitive-behavioural outcomes, including measures of attention, depression and anxiety. These findings suggest atypical coordination of neural synchronisation in large scale networks contributes to deficits in mental flexibility for PTSD populations in timed, attentionally-demanding tasks, and this propensity toward network hyperconnectivity may play a more general role in the cognitive sequelae evident in this disorder.

The phenotypes of podocytes and parietal epithelial cells may overlap in diabetic nephropathy.

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Andeen, Nicole K; Nguyen, Tri Q; Steegh, Floor; Hudkins, Kelly L; Najafian, Behzad; Alpers, Charles E

2015-11-01

Reversal of diabetic nephropathy (DN) has been achieved in humans and mice, but only rarely and under special circumstances. As progression of DN is related to podocyte loss, reversal of DN requires restoration of podocytes. Here, we identified and quantified potential glomerular progenitor cells that could be a source for restored podocytes. DN was identified in 31 human renal biopsy cases and separated into morphologically early or advanced lesions. Markers of podocytes (WT-1, p57), parietal epithelial cells (PECs) (claudin-1), and cell proliferation (Ki-67) were identified by immunohistochemistry. Podocyte density was progressively reduced with DN. Cells marking as podocytes (p57) were present infrequently on Bowman's capsule in controls, but significantly increased in histologically early DN. Ki-67-expressing cells were identified on the glomerular tuft and Bowman's capsule in DN, but rarely in controls. Cells marking as PECs were present on the glomerular tuft, particularly in morphologically advanced DN. These findings show evidence of phenotypic plasticity in podocyte and PEC populations and are consistent with studies in the BTBR ob/ob murine model in which reversibility of DN occurs with podocytes potentially regenerating from PEC precursors. Thus, our findings support, but do not prove, that podocytes may regenerate from PEC progenitors in human DN. If so, progression of DN may represent a modifiable net balance between podocyte loss and regeneration.

Dissociated roles of the parietal and frontal cortices in the scope and control of attention during visual working memory.

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Li, Siyao; Cai, Ying; Liu, Jing; Li, Dawei; Feng, Zifang; Chen, Chuansheng; Xue, Gui

2017-04-01

Mounting evidence suggests that multiple mechanisms underlie working memory capacity. Using transcranial direct current stimulation (tDCS), the current study aimed to provide causal evidence for the neural dissociation of two mechanisms underlying visual working memory (WM) capacity, namely, the scope and control of attention. A change detection task with distractors was used, where a number of colored bars (i.e., two red bars, four red bars, or two red plus two blue bars) were presented on both sides (Experiment 1) or the center (Experiment 2) of the screen for 100ms, and participants were instructed to remember the red bars and to ignore the blue bars (in both Experiments), as well as to ignore the stimuli on the un-cued side (Experiment 1 only). In both experiments, participants finished three sessions of the task after 15min of 1.5mA anodal tDCS administered on the right prefrontal cortex (PFC), the right posterior parietal cortex (PPC), and the primary visual cortex (VC), respectively. The VC stimulation served as an active control condition. We found that compared to stimulation on the VC, stimulation on the right PPC specifically increased the visual WM capacity under the no-distractor condition (i.e., 4 red bars), whereas stimulation on the right PFC specifically increased the visual WM capacity under the distractor condition (i.e., 2 red bars plus 2 blue bars). These results suggest that the PPC and PFC are involved in the scope and control of attention, respectively. We further showed that compared to central presentation of the stimuli (Experiment 2), bilateral presentation of the stimuli (on both sides of the fixation in Experiment 1) led to an additional demand for attention control. Our results emphasize the dissociated roles of the frontal and parietal lobes in visual WM capacity, and provide a deeper understanding of the neural mechanisms of WM. Copyright © 2017 Elsevier Inc. All rights reserved.

experimental

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Andrés Felipe Rojas G.

2008-01-01

Full Text Available Durante el proceso de desvolatilización, las partículas de carbón cambian su estructura debido a la liberación de su materia volátil, obteniéndose un sólido poroso rico en carbono fijo (Carbonizado con diferentes morfologías. Se obtuvieron carbonizados a partir de tres carbones bituminosos (La Yolanda, El Cerrejón y Thoresby en un reactor tubular, a tres temperaturas (900, 1000 y 1100ºC y tres tiempos (100, 150 y 300 ms de desvolatilización. Estas morfologías se identificaron usando una técnica automática de análisis de imagen. Por medio de esta técnica de análisis de imagen se determinó el área promedio de partícula de cada muestra de carbonizado, el espesor medio de pared, el porcentaje de espesor de pared menor a 3 y 5 µm, la porosidad y el porcentaje de cada uno de los morfotipos del carbonizado. Se encontró que tanto la porosidad como el espesor de pared menor a 3 y 5 µm, disminuyen con el aumento de la temperatura y el tiempo de desvolatilización, mientras que el espesor medio de pared aumenta con el incremento en estos mismos parámetros. También se encontró que el carbón El Cerrejón produce carbonizados tenuisphere en mayor proporción, mientras que el carbón La Yolanda genera principalmente carbonizados crassinetwork.

Sequential inference as a mode of cognition and its correlates in fronto-parietal and hippocampal brain regions.

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Thomas H B FitzGerald

2017-05-01

Full Text Available Normative models of human cognition often appeal to Bayesian filtering, which provides optimal online estimates of unknown or hidden states of the world, based on previous observations. However, in many cases it is necessary to optimise beliefs about sequences of states rather than just the current state. Importantly, Bayesian filtering and sequential inference strategies make different predictions about beliefs and subsequent choices, rendering them behaviourally dissociable. Taking data from a probabilistic reversal task we show that subjects' choices provide strong evidence that they are representing short sequences of states. Between-subject measures of this implicit sequential inference strategy had a neurobiological underpinning and correlated with grey matter density in prefrontal and parietal cortex, as well as the hippocampus. Our findings provide, to our knowledge, the first evidence for sequential inference in human cognition, and by exploiting between-subject variation in this measure we provide pointers to its neuronal substrates.

Secado de lúcuma (Pouteria obovata) empleando la técnica de Ventana RefractanteTM

OpenAIRE

Diego Gamboa; Deiner Ibáñez; Marcela Meléndez; Edgar Paredes; Raúl Siche

2014-01-01

La lúcuma es una fruta que experimenta una tendencia creciente a nivel comercial en forma de harina para su empleo en la industria alimentaria. Este estudio tuvo como objetivo obtener harina de lúcuma utilizando el método de secado por ventana refractante y evaluar el efecto del espesor de la pulpa de lúcuma y el tiempo de secado en la humedad y el color de la harina. Fue utilizado un Diseño Compuesto Central Rotable (DCCR) con el tiempo entre 10 y 50 min y el espesor entre 1 y 3 mm. Se emple...

Ischemia-induced glomerular parietal epithelial cells hyperplasia: Commonly misdiagnosed cellular crescent in renal biopsy.

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Zeng, Yeting; Wang, Xinrui; Xie, Feilai; Zheng, Zhiyong

2017-08-01

Ischemic pseudo-cellular crescent (IPCC) that is induced by ischemia and composed of hyperplastic glomerular parietal epithelial cells resembles cellular crescent. In this study, we aimed to assess the clinical and pathological features of IPCC in renal biopsy to avoid over-diagnosis and to determine the diagnostic basis. 4 IPCC cases diagnosed over a 4-year period (2012-2015) were evaluated for the study. Meanwhile, 5 cases of ANCA-associated glomerulonephritis and 5 cases of lupus nephritis (LN) were selected as control. Appropriate clinical data, morphology, and immunohistochemical features of all cases were retrieved. Results showed that the basement membrane of glomerulus with IPCC appeared as a concentric twisted ball, and glomerular cells of the lesion were reduced even entirely absent, and the adjacent afferent arterioles showed sclerosis or luminal stenosis. Furthermore, immune globulin deposition, vasculitis, and fibrinous exudate have not been observed in IPCC. While the cellular crescents showed diverse characteristics in both morphology and immunostaining in the control group. Therefore, these results indicated that IPCC is a sort of ischemic reactive hyperplasia and associated with sclerosis, stenosis, or obstruction of adjacent afferent arterioles, which is clearly different from cellular crescents result from glomerulonephritis. Copyright © 2017 Elsevier GmbH. All rights reserved.

De novo expression of sodium-glucose cotransporter SGLT2 in Bowman’s capsule coincides with replacement of parietal epithelial cell layer with proximal tubule-like epithelium

OpenAIRE

Tabatabai, Niloofar M.; North, Paula E.; Regner, Kevin R.; Kumar, Suresh N.; Duris, Christine B.; Blodgett, Amy B.

2014-01-01

In kidney nephron, parietal epithelial cells line the Bowman’s capsule and function as a permeability barrier for the glomerular filtrate. Bowman’s capsule cells with proximal tubule epithelial morphology have been found. However, the effects of tubular metaplasia in Bowman’s capsule on kidney function remain poorly understood. Sodium-glucose cotransporter 2 (SGLT2) plays a major role in reabsorption of glucose in the kidney and is expressed on brush border membrane of epithelial cells in the...

The rehabilitative effects on written language of a combined language and parietal dual-tDCS treatment in a stroke case.

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De Tommaso, Barbara; Piedimonte, Alessandro; Caglio, Marcella M; D'Agata, Federico; Campagnoli, Marcello; Orsi, Laura; Raimondo, Simona; Vighetti, Sergio; Mortara, Paolo; Massazza, Giuseppe; Pinessi, Lorenzo

2017-09-01

In this paper we report the effect of a combined transcranial direct current stimulation (tDCS) and speech language therapy on linguistic deficits following left brain damage in a stroke case. We show that simultaneous electrical excitatory stimulation to the left and inhibitory stimulation to the right parietal regions (dual-tDCS) affected writing and reading rehabilitation, enhancing speech therapy outcomes. The results of a comparison with healthy controls showed that application of dual-tDCS could improve, in particular, sub-lexical transcoding and, specifically, the reading of non-words with increasing length and complexity. Positive repercussions on patient's quality of functional communication were also ascertained. Significant changes were also found in other language and cognitive tasks not directly treated (comprehension and constructive apraxia).

Glomerular parietal epithelial cell activation induces collagen secretion and thickening of Bowman's capsule in diabetes.

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Holderied, Alexander; Romoli, Simone; Eberhard, Jonathan; Konrad, Lukas A; Devarapu, Satish K; Marschner, Julian A; Müller, Susanna; Anders, Hans-Joachim

2015-03-01

The metabolic and hemodynamic alterations in diabetes activate podocytes to increase extracellular matrix (ECM) production, leading to thickening of the glomerular basement membrane (GBM). We hypothesized that diabetes would activate parietal epithelial cells (PECs) in a similar manner and cause thickening of Bowman's capsules. Periodic acid Schiff staining of human kidney biopsies of 30 patients with diabetic nephropathy (DN) revealed a significantly thicker Bowman's capsule as compared with 20 non-diabetic controls. The average thickness was 4.55±0.21 μm in the group of patients with DN compared with 2.92±0.21 μm in the group of non-diabetic controls (PBowman's capsule showed strong association with CD44-positive PECs. In summary, metabolic alterations in diabetes activate PECs to increase the expression and secretion of Bowman's capsule proteins. This process may contribute to the thickening of the Bowman's capsule, similar to the thickening of the GBM that is driven by activated podocytes. These data may also imply that activated PECs contribute to ECM production once they migrate to the glomerular tuft, a process resulting in glomerular scaring, for example, in diabetic glomerulosclerosis.

Motor imagery training: Kinesthetic imagery strategy and inferior parietal fMRI activation.

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Lebon, Florent; Horn, Ulrike; Domin, Martin; Lotze, Martin

2018-04-01

Motor imagery (MI) is the mental simulation of action frequently used by professionals in different fields. However, with respect to performance, well-controlled functional imaging studies on MI training are sparse. We investigated changes in fMRI representation going along with performance changes of a finger sequence (error and velocity) after MI training in 48 healthy young volunteers. Before training, we tested the vividness of kinesthetic and visual imagery. During tests, participants were instructed to move or to imagine moving the fingers of the right hand in a specific order. During MI training, participants repeatedly imagined the sequence for 15 min. Imaging analysis was performed using a full-factorial design to assess brain changes due to imagery training. We also used regression analyses to identify those who profited from training (performance outcome and gain) with initial imagery scores (vividness) and fMRI activation magnitude during MI at pre-test (MI pre ). After training, error rate decreased and velocity increased. We combined both parameters into a common performance index. FMRI activation in the left inferior parietal lobe (IPL) was associated with MI and increased over time. In addition, fMRI activation in the right IPL during MI pre was associated with high initial kinesthetic vividness. High kinesthetic imagery vividness predicted a high performance after training. In contrast, occipital activation, associated with visual imagery strategies, showed a negative predictive value for performance. Our data echo the importance of high kinesthetic vividness for MI training outcome and consider IPL as a key area during MI and through MI training. © 2018 Wiley Periodicals, Inc.

Changes in glomerular parietal epithelial cells in mouse kidneys with advanced age

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Roeder, Sebastian S.; Stefanska, Ania; Eng, Diana G.; Kaverina, Natalya; Sunseri, Maria W.; McNicholas, Bairbre A.; Rabinovitch, Peter; Engel, Felix B.; Daniel, Christoph; Amann, Kerstin; Lichtnekert, Julia; Pippin, Jeffrey W.

2015-01-01

Kidney aging is accompanied by characteristic changes in the glomerulus, but little is known about the effect of aging on glomerular parietal epithelial cells (PECs), nor if the characteristic glomerular changes in humans and rats also occur in very old mice. Accordingly, a descriptive analysis was undertaken in 27-mo-old C57B6 mice, considered advanced age. PEC density was significantly lower in older mice compared with young mice (aged 3 mo), and the decrease was more pronounced in juxtamedullary glomeruli compared with outer cortical glomeruli. In addition to segmental and global glomerulosclerosis in older mice, staining for matrix proteins collagen type IV and heparan sulfate proteoglycan were markedly increased in Bowman's capsules of older mouse glomeruli, consistent with increased extracellular matrix production by PECs. De novo staining for CD44, a marker of activated and profibrotic PECs, was significantly increased in aged glomeruli. CD44 staining was more pronounced in the juxtamedullary region and colocalized with phosphorylated ERK. Additionally, a subset of aged PECs de novo expressed the epithelial-to-mesenchymal transition markers α-smooth muscle and vimentin, with no changes in epithelial-to-mesenchymal transition markers E-cadherin and β-catenin. The mural cell markers neural/glial antigen 2, PDGF receptor-β, and CD146 as well as Notch 3 were also substantially increased in aged PECs. These data show that mice can be used to better understand the aging kidney and that PECs undergo substantial changes, especially in juxtamedullary glomeruli, that may participate in the overall decline in glomerular structure and function with advancing age. PMID:26017974

New developments in the analysis and measurement of thicknesses by {beta}-particle excitation of X fluorescent rays; Nouveaux developpements de l'analyse et de la mesure des epaisseurs par excitation des raies de fluorescence X au moyen de particules {beta}; Novye usovershenstvovaniya analiza i izmereniya plotnosti putem vozbuzhdeniya fluorestsiruyushchikh spektrov rentgenovskogo lucha beta-chastitsami; Nuevos adelantos en el analisis y la medicion de espesores mediante la excitacion de rayos X por particulas beta

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Martinelli, P [Commissariat a l' Energie Atomique, Saclay (France); Seibel, G [Institut de Recherches de la Siderurgie, St-Germain-en-Laye (France)

1962-01-15

The method of analysing and measuring the thickness of deposits by {beta}-X fluorescence which we previously described has been further developed. Using Pm{sup 147} and Kr{sup 85} sources, it is possible to reduce the background observed with Sr{sup 90}. We quote the results obtained for various thickness measurements of metal deposits, an analysis of the solutions, and the continuous measurement of calcium and iron in core samples. We describe experiments made for analysis of the X-radiation by crystal. (author) [French] Le procede d'analyse et de mesure des epaisseurs de depots par fluorescence {beta}-X que nous avons precedemment decrit a fait l'objet de nouveaux developpements. L'emploi de sources de {sup 147}Pm et de {sup 85}Kr permet de reduire le bruit de fond que l'on observe avec le {sup 90}Sr. Nous donnons les resultats obtenus pour diverses mesures d'epaisseurs de depots metalliques, l'analyse des solutions et la mesure en continu du calcium et du fer dans les carottes de minerais. Nous decrivons les essais effectues en vue d'analyser le rayonnement X au moyen d'un cristal. (author) [Spanish] Los autores han introducido nuevos perfeccionamientos en su procedimiento de analisis y de medicion de espesores de depositos por fluorescencia de rayos X excitada por particulas beta. La utilizacion de fuentes de {sup 147}Pm y de {sup 85}Kr permite reducir la actividad de fondo que se observa empleando {sup 90}Sr. Los autores exponen los resultados obtenidos en materia de mediciones de espesores de depositos metalicos, analisis de soluciones y medicion continua del calcio y del hierro en muestras de minerales extraidas por sondeo. Tambien describen los ensayos realizados con miras a analizar los rayos X por medio de un cristal. (author) [Russian] Protsess analiza i izmereniya plotnosti sloev putem fluorestsiruyushchikh beta- i rentgenovskikh luchej, kotoryj opisyvalsya nami ran'she, byl predmetom novykh usovershenstvovanij. Ispol'zovanie istochnikov prometeya-147 i

NEURAL CORRELATES FOR APATHY: FRONTAL - PREFRONTAL AND PARIETAL CORTICAL - SUBCORTICAL CIRCUITS

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Rita Moretti

2016-12-01

Full Text Available Apathy is an uncertain nosographical entity, which includes reduced motivation, abulia, decreased empathy, and lack of emotional invovlement; it is an important and heavy-burden clinical condition which strongly impacts in every day life events, affects the common daily living abilities, reduced the inner goal directed behavior, and gives the heaviest burden on caregivers. Is a quite common comorbidity of many neurological disease, However, there is no definite consensus on the role of apathy in clinical practice, no definite data on anatomical circuits involved in its development, and no definite instrument to detect it at bedside. As a general observation, the occurrence of apathy is connected to damage of prefrontal cortex (PFC and basal ganglia; emotional affective apathy may be related to the orbitomedial PFC and ventral striatum; cognitive apathy may be associated with dysfunction of lateral PFC and dorsal caudate nuclei; deficit of autoactivation may be due to bilateral lesions of the internal portion of globus pallidus, bilateral paramedian thalamic lesions, or the dorsomedial portion of PFC. On the other hand, apathy severity has been connected to neurofibrillary tangles density in the anterior cingulate gyrus and to grey matter atrophy in the anterior cingulate (ACC and in the left medial frontal cortex, confirmed by functional imaging studies. These neural networks are linked to projects, judjing and planning, execution and selection common actions, and through the basolateral amygdala and nucleus accumbens projects to the frontostriatal and to the dorsolateral prefrontal cortex. Therefore, an alteration of these circuitry caused a lack of insight, a reduction of decision-making strategies and a reduced speedness in action decsion, major resposnible for apathy. Emergent role concerns also the parietal cortex, with its direct action motivation control.We will discuss the importance of these circuits in different pathologies

Antigastric parietal cell and antithyroid autoantibodies in patients with desquamative gingivitis.

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Chang, Julia Yu-Fong; Chiang, Chun-Pin; Wang, Yi-Ping; Wu, Yang-Che; Chen, Hsin-Ming; Sun, Andy

2017-04-01

Desquamative gingivitis (DG) is principally associated with erosive oral lichen planus (EOLP), mucous membrane pemphigoid (MMP), and pemphigus vulgaris (PV). Serum autoantibodies including antigastric parietal cell antibody (GPCA), antithyroglobulin antibody (TGA), and antithyroid microsomal antibody (TMA) were measured in 500 patients with DG, 287 EOLP without DG (EOLP/DG - ) patients, and 100 healthy control subjects. The 500 patients with DG were diagnosed as having EOLP in 455 (91%), PV in 40 (8%), and MMP in five (1%) patients. We found that 37.0%, 43.6%, and 42.6% of 500 patients with DG, 39.6%, 46.4%, and 45.1% of 455 EOLP with DG (EOLP/DG) patients, and 18.5%, 27.5%, and 30.3% of 287 EOLP/DG - patients had the presence of GPCA, TGA, and TMA in their sera, respectively. DG, EOLP/DG, and EOLP/DG - patients all had a significantly higher frequency of GPCA, TGA, or TMA positivity than healthy control subjects (all P-values < 0.001). Moreover, 455 EOLP/DG patients had a significantly higher frequency of GPCA, TGA, or TMA positivity than 287 EOLP/DG - patients (all P-values < 0.001). Of 210 TGA/TMA-positive patients with DG whose serum thyroid-stimulating hormone (TSH) levels were measured, 84.3%, 6.7%, and 9.0% patients had normal, lower, and higher serum TSH levels, respectively. We conclude that 73.4% DG, 77.1% EOLP/DG, and 47.4% EOLP/DG - patients may have GPCA/TGA/TMA positivity in their sera. Because part of GPCA-positive patients may develop pernicious anemia, autoimmune atrophic gastritis, and gastric carcinoma, and part of TGA/TMA-positive patients may have thyroid dysfunction, these patients should be referred to medical department for further management. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Ontogenia dos estratos parietais da antera de Tabebuia pulcherrima Sandw. (Bignoniaceae Ontogeny of the anther parietal layers of Tabebuia pulcherrima Sandw. (Bignoniaceae

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Nelson S Bittencourt Jr

1997-07-01

Full Text Available A ontogenia do tapete e dos demais estratos parietais, bem como o desenvolvimento do estômio e deiscência da antera de Tabebuia pulcherrima, foram presentemente estudados. O padrão de formação da parede do androsporângio é do tipo Dicotiledôneo. A camada parietal primária, a camada esporogênica e o tapete interno derivam-se diretamente do meristema fundamental. O tecido esporogênico, em cada androsporângio, visto em secção transversal, organiza-se numa fileira celular em forma de ferradura. O tapete é do tipo secretor e possui origem dual. O tapete interno diferencia-se precocemente em relação ao tapete externo. As duas camadas tapetais são discretamente dimórficas, mas tal dimorfismo é perdido no fim do estádio meiótico do esporângio. O dimorfismo tapetai e a precoce diferenciação do tapete interno são interpretados como expressão de um lapso ontogenético entre as duas camadas. Nas regiões dorso-laterais das tecas desenvolve-se um endotécio multiestratificado com espessamentos anelados ou helicoidais nas paredes celulares. A deiscência é precedida pela degeneração dos tecidos placentóides e ruptura dos septos interesporangiais. Apenas as células epidérmicas dos dois lados do sítio de ruptura do estômio (células estomiais estão envolvidas com a ruptura do mesmo.The ontogeny of the tapetum and parietal layers, as well as the stomium development and the dehiscence of the anther of Tabebuia pulcherima was studied. The anther wall formation follows the Dicotyledoneous type. The primary parietal layer, the sporogenous tissue, and the inner tapetum are differentiated directly from the ground meristem. The sporogenous tissue, as seeing in a transverse section, is organized in one cellular strip with a horseshoe outline. The tapetum is secretory and shows a distinct dual origin. The inner tapetai layer differentiates earlier than the outher. The two tapetai layers are moderately dimorphic. However, even such a

Mice lacking the conserved transcription factor Grainyhead-like 3 (Grhl3) display increased apposition of the frontal and parietal bones during embryonic development.

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Goldie, Stephen J; Arhatari, Benedicta D; Anderson, Peter; Auden, Alana; Partridge, Darren D; Jane, Stephen M; Dworkin, Sebastian

2016-10-18

Increased apposition of the frontal and parietal bones of the skull during embryogenesis may be a risk factor for the subsequent development of premature skull fusion, or craniosynostosis. Human craniosynostosis is a prevalent, and often serious embryological and neonatal pathology. Other than known mutations in a small number of contributing genes, the aetiology of craniosynostosis is largely unknown. Therefore, the identification of novel genes which contribute to normal skull patterning, morphology and premature suture apposition is imperative, in order to fully understand the genetic regulation of cranial development. Using advanced imaging techniques and quantitative measurement, we show that genetic deletion of the highly-conserved transcription factor Grainyhead-like 3 (Grhl3) in mice (Grhl3 -/- ) leads to decreased skull size, aberrant skull morphology and premature apposition of the coronal sutures during embryogenesis. Furthermore, Grhl3 -/- mice also present with premature collagen deposition and osteoblast alignment at the sutures, and the physical interaction between the developing skull, and outermost covering of the brain (the dura mater), as well as the overlying dermis and subcutaneous tissue, appears compromised in embryos lacking Grhl3. Although Grhl3 -/- mice die at birth, we investigated skull morphology and size in adult animals lacking one Grhl3 allele (heterozygous; Grhl3 +/- ), which are viable and fertile. We found that these adult mice also present with a smaller cranial cavity, suggestive of post-natal haploinsufficiency in the context of cranial development. Our findings show that our Grhl3 mice present with increased apposition of the frontal and parietal bones, suggesting that Grhl3 may be involved in the developmental pathogenesis of craniosynostosis.

Transcranial direct current stimulation of the posterior parietal cortex modulates arithmetic learning.

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Grabner, Roland H; Rütsche, Bruno; Ruff, Christian C; Hauser, Tobias U

2015-07-01

The successful acquisition of arithmetic skills is an essential step in the development of mathematical competencies and has been associated with neural activity in the left posterior parietal cortex (PPC). It is unclear, however, whether this brain region plays a causal role in arithmetic skill acquisition and whether arithmetic learning can be modulated by means of non-invasive brain stimulation of this key region. In the present study we addressed these questions by applying transcranial direct current stimulation (tDCS) over the left PPC during a short-term training that simulates the typical path of arithmetic skill acquisition (specifically the transition from effortful procedural to memory-based problem-solving strategies). Sixty participants received either anodal, cathodal or sham tDCS while practising complex multiplication and subtraction problems. The stability of the stimulation-induced learning effects was assessed in a follow-up test 24 h after the training. Learning progress was modulated by tDCS. Cathodal tDCS (compared with sham) decreased learning rates during training and resulted in poorer performance which lasted over 24 h after stimulation. Anodal tDCS showed an operation-specific improvement for subtraction learning. Our findings extend previous studies by demonstrating that the left PPC is causally involved in arithmetic learning (and not only in arithmetic performance) and that even a short-term tDCS application can modulate the success of arithmetic knowledge acquisition. Moreover, our finding of operation-specific anodal stimulation effects suggests that the enhancing effects of tDCS on learning can selectively affect just one of several cognitive processes mediated by the stimulated area. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Changes in glomerular parietal epithelial cells in mouse kidneys with advanced age.

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Roeder, Sebastian S; Stefanska, Ania; Eng, Diana G; Kaverina, Natalya; Sunseri, Maria W; McNicholas, Bairbre A; Rabinovitch, Peter; Engel, Felix B; Daniel, Christoph; Amann, Kerstin; Lichtnekert, Julia; Pippin, Jeffrey W; Shankland, Stuart J

2015-07-15

Kidney aging is accompanied by characteristic changes in the glomerulus, but little is known about the effect of aging on glomerular parietal epithelial cells (PECs), nor if the characteristic glomerular changes in humans and rats also occur in very old mice. Accordingly, a descriptive analysis was undertaken in 27-mo-old C57B6 mice, considered advanced age. PEC density was significantly lower in older mice compared with young mice (aged 3 mo), and the decrease was more pronounced in juxtamedullary glomeruli compared with outer cortical glomeruli. In addition to segmental and global glomerulosclerosis in older mice, staining for matrix proteins collagen type IV and heparan sulfate proteoglycan were markedly increased in Bowman's capsules of older mouse glomeruli, consistent with increased extracellular matrix production by PECs. De novo staining for CD44, a marker of activated and profibrotic PECs, was significantly increased in aged glomeruli. CD44 staining was more pronounced in the juxtamedullary region and colocalized with phosphorylated ERK. Additionally, a subset of aged PECs de novo expressed the epithelial-to-mesenchymal transition markers α-smooth muscle and vimentin, with no changes in epithelial-to-mesenchymal transition markers E-cadherin and β-catenin. The mural cell markers neural/glial antigen 2, PDGF receptor-β, and CD146 as well as Notch 3 were also substantially increased in aged PECs. These data show that mice can be used to better understand the aging kidney and that PECs undergo substantial changes, especially in juxtamedullary glomeruli, that may participate in the overall decline in glomerular structure and function with advancing age. Copyright © 2015 the American Physiological Society.

Glomerular parietal epithelial cells contribute to adult podocyte regeneration in experimental focal segmental glomerulosclerosis

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Eng, Diana G.; Sunseri, Maria W.; Kaverina, Natalya; Roeder, Sebastian S.; Pippin, Jeffrey W.; Shankland, Stuart J.

2015-01-01

Since adult podocytes cannot adequately proliferate following depletion in disease states there has been interest in the potential role of progenitors in podocyte repair and regeneration. To determine if parietal epithelial cells (PECs) can serve as adult podocyte progenitors following disease-induced podocyte depletion, PECs were permanently labeled in adult PECrtTA/LC1/R26 reporter mice. In normal mice, labeled PECs were confined to Bowman's capsule, while in disease (cytotoxic sheep anti-podocyte antibody), labeled PECs were found in the glomerular tuft in progressively higher numbers by days 7, 14 and 28. Early in disease, the majority of PECs in the tuft co-expressed CD44. By day 28, when podocyte numbers were significantly higher and disease severity was significantly lower, the majority of labeled PECs co-expressed podocyte proteins but not CD44. Neither labeled PECs on the tuft, nor podocytes stained for the proliferation marker BrdU. The de novo expression of phospho-ERK colocalized to CD44 expressing PECs, but not to PECs expressing podocyte markers. Thus, in a mouse model of focal segmental glomerulosclerosis typified by abrupt podocyte depletion followed by regeneration, PECs undergo two phenotypic changes once they migrate to the glomerular tuft. Initially these cells are predominantly activated CD44 expressing cells coinciding with glomerulosclerosis, and later they predominantly exhibit a podocyte phenotype which is likely reparative. PMID:25993321

Glomerular parietal epithelial cells contribute to adult podocyte regeneration in experimental focal segmental glomerulosclerosis.

Science.gov (United States)

Eng, Diana G; Sunseri, Maria W; Kaverina, Natalya V; Roeder, Sebastian S; Pippin, Jeffrey W; Shankland, Stuart J

2015-11-01

As adult podocytes cannot adequately proliferate following depletion in disease states, there has been interest in the potential role of progenitors in podocyte repair and regeneration. To determine whether parietal epithelial cells (PECs) can serve as adult podocyte progenitors following disease-induced podocyte depletion, PECs were permanently labeled in adult PEC-rtTA/LC1/R26 reporter mice. In normal mice, labeled PECs were confined to Bowman's capsule, whereas in disease (cytotoxic sheep anti-podocyte antibody) labeled PECs were found in the glomerular tuft in progressively higher numbers by days 7, 14, and 28. Early in disease, the majority of PECs in the tuft coexpressed CD44. By day 28, when podocyte numbers were significantly higher and disease severity was significantly lower, the majority of labeled PECs coexpressed podocyte proteins but not CD44. Neither labeled PECs on the tuft nor podocytes stained for the proliferation marker BrdU. The de novo expression of phospho-ERK colocalized to CD44 expressing PECs, but not to PECs expressing podocyte markers. Thus, in a mouse model of focal segmental glomerulosclerosis typified by abrupt podocyte depletion followed by regeneration, PECs undergo two phenotypic changes once they migrate to the glomerular tuft. Initially these cells are predominantly activated CD44 expressing cells coinciding with glomerulosclerosis, and later they predominantly exhibit a podocyte phenotype, which is likely reparative.

Functional network-based statistics in depression: Theory of mind subnetwork and importance of parietal region.

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Lai, Chien-Han; Wu, Yu-Te; Hou, Yuh-Ming

2017-08-01

The functional network analysis of whole brain is an emerging field for research in depression. We initiated this study to investigate which subnetwork is significantly altered within the functional connectome in major depressive disorder (MDD). The study enrolled 52 first-episode medication-naïve patients with MDD and 40 controls for functional network analysis. All participants received the resting-state functional imaging using a 3-Tesla magnetic resonance scanner. After preprocessing, we calculated the connectivity matrix of functional connectivity in whole brain for each subject. The network-based statistics of connectome was used to perform group comparisons between patients and controls. The correlations between functional connectivity and clinical parameters were also performed. MDD patients had significant alterations in the network involving "theory of mind" regions, such as the left precentral gyrus, left angular gyrus, bilateral rolandic operculums and left inferior frontal gyrus. The center node of significant network was the left angular gyrus. No significant correlations of functional connectivity within the subnetwork and clinical parameters were noted. Functional connectivity of "theory of mind" subnetwork may be the core issue for pathophysiology in MDD. In addition, the center role of parietal region should be emphasized in future study. Copyright © 2017. Published by Elsevier B.V.

The left visual-field advantage in rapid visual presentation is amplified rather than reduced by posterior-parietal rTMS

DEFF Research Database (Denmark)

Verleger, Rolf; Möller, Friderike; Kuniecki, Michal

2010-01-01

) either as effective or as sham stimulation. In two experiments, either one of these two factors, hemisphere and effectiveness of rTMS, was varied within or between participants. Again, T2 was much better identified in the left than in the right visual field. This advantage of the left visual field......In the present task, series of visual stimuli are rapidly presented left and right, containing two target stimuli, T1 and T2. In previous studies, T2 was better identified in the left than in the right visual field. This advantage of the left visual field might reflect dominance exerted...... by the right over the left hemisphere. If so, then repetitive transcranial magnetic stimulation (rTMS) to the right parietal cortex might release the left hemisphere from right-hemispheric control, thereby improving T2 identification in the right visual field. Alternatively or additionally, the asymmetry in T2...

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

DEFF Research Database (Denmark)

Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe

2013-01-01

magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified...... reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann...... of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first...

De novo expression of sodium-glucose cotransporter SGLT2 in Bowman's capsule coincides with replacement of parietal epithelial cell layer with proximal tubule-like epithelium.

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Tabatabai, Niloofar M; North, Paula E; Regner, Kevin R; Kumar, Suresh N; Duris, Christine B; Blodgett, Amy B

2014-08-01

In kidney nephron, parietal epithelial cells line the Bowman's capsule and function as a permeability barrier for the glomerular filtrate. Bowman's capsule cells with proximal tubule epithelial morphology have been found. However, the effects of tubular metaplasia in Bowman's capsule on kidney function remain poorly understood. Sodium-glucose cotransporter 2 (SGLT2) plays a major role in reabsorption of glucose in the kidney and is expressed on brush border membrane (BBM) of epithelial cells in the early segment of the proximal tubule. We hypothesized that SGLT2 is expressed in tubularized Bowman's capsule and used our novel antibody to test this hypothesis. Immunohistochemical analysis was performed with our SGLT2 antibody on C57BL/6 mouse kidney prone to have tubularized Bowman's capsules. Cell membrane was examined with periodic acid-Schiff (PAS) stain. The results showed that SGLT2 was localized on BBM of the proximal tubules in young and adult mice. Bowman's capsules were lined mostly with normal brush border-less parietal epithelial cells in young mice, while they were almost completely covered with proximal tubule-like cells in adult mice. Regardless of age, SGLT2 was expressed on BBM of the tubularized Bowman's capsule but did not co-localize with nephrin in the glomerulus. SGLT2-expressing tubular cells expanded from the urinary pole toward the vascular pole of the Bowman's capsule. This study identified the localization of SGLT2 in the Bowman's capsule. Bowman's capsules with tubular metaplasia may acquire roles in reabsorption of filtered glucose and sodium.

Convergent functional architecture of the superior parietal lobule unraveled with multimodal neuroimaging approaches.

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Wang, Jiaojian; Yang, Yong; Fan, Lingzhong; Xu, Jinping; Li, Changhai; Liu, Yong; Fox, Peter T; Eickhoff, Simon B; Yu, Chunshui; Jiang, Tianzi

2015-01-01

The superior parietal lobule (SPL) plays a pivotal role in many cognitive, perceptive, and motor-related processes. This implies that a mosaic of distinct functional and structural subregions may exist in this area. Recent studies have demonstrated that the ongoing spontaneous fluctuations in the brain at rest are highly structured and, like coactivation patterns, reflect the integration of cortical locations into long-distance networks. This suggests that the internal differentiation of a complex brain region may be revealed by interaction patterns that are reflected in different neuroimaging modalities. On the basis of this perspective, we aimed to identify a convergent functional organization of the SPL using multimodal neuroimaging approaches. The SPL was first parcellated based on its structural connections as well as on its resting-state connectivity and coactivation patterns. Then, post hoc functional characterizations and connectivity analyses were performed for each subregion. The three types of connectivity-based parcellations consistently identified five subregions in the SPL of each hemisphere. The two anterior subregions were found to be primarily involved in action processes and in visually guided visuomotor functions, whereas the three posterior subregions were primarily associated with visual perception, spatial cognition, reasoning, working memory, and attention. This parcellation scheme for the SPL was further supported by revealing distinct connectivity patterns for each subregion in all the used modalities. These results thus indicate a convergent functional architecture of the SPL that can be revealed based on different types of connectivity and is reflected by different functions and interactions. © 2014 Wiley Periodicals, Inc.

Frontal parietal control network regulates the anti-correlated default and dorsal attention networks.

Science.gov (United States)

Gao, Wei; Lin, Weili

2012-01-01

Recent reports demonstrate the anti-correlated behaviors between the default (DF) and the dorsal attention (DA) networks. We aimed to investigate the roles of the frontal parietal control (FPC) network in regulating the two anti-correlated networks through three experimental conditions, including resting, continuous self-paced/attended sequential finger tapping (FT), and natural movie watching (MW), respectively. The two goal-directed tasks were chosen to engage either one of the two competing networks-FT for DA whereas MW for default. We hypothesized that FPC will selectively augment/suppress either network depending on how the task targets the specific network; FPC will positively correlate with the target network, but negatively correlate with the network anti-correlated with the target network. We further hypothesized that significant causal links from FPC to both DA and DF are present during all three experimental conditions, supporting the initiative regulating role of FPC over the two opposing systems. Consistent with our hypotheses, FPC exhibited a significantly higher positive correlation with DA (P = 0.0095) whereas significantly more negative correlation with default (P = 0.0025) during FT when compared to resting. Completely opposite to that observed during FT, the FPC was significantly anti-correlated with DA (P = 2.1e-6) whereas positively correlated with default (P = 0.0035) during MW. Furthermore, extensive causal links from FPC to both DA and DF were observed across all three experimental states. Together, our results strongly support the notion that the FPC regulates the anti-correlated default and DA networks. Copyright © 2011 Wiley Periodicals, Inc.

Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia.

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Iuculano, Teresa; Cohen Kadosh, Roi

2014-01-01

Nearly 7% of the population exhibit difficulties in dealing with numbers and performing arithmetic, a condition named Developmental Dyscalculia (DD), which significantly affects the educational and professional outcomes of these individuals, as it often persists into adulthood. Research has mainly focused on behavioral rehabilitation, while little is known about performance changes and neuroplasticity induced by the concurrent application of brain-behavioral approaches. It has been shown that numerical proficiency can be enhanced by applying a small-yet constant-current through the brain, a non-invasive technique named transcranial electrical stimulation (tES). Here we combined a numerical learning paradigm with transcranial direct current stimulation (tDCS) in two adults with DD to assess the potential benefits of this methodology to remediate their numerical difficulties. Subjects learned to associate artificial symbols to numerical quantities within the context of a trial and error paradigm, while tDCS was applied to the posterior parietal cortex (PPC). The first subject (DD1) received anodal stimulation to the right PPC and cathodal stimulation to the left PPC, which has been associated with numerical performance's improvements in healthy subjects. The second subject (DD2) received anodal stimulation to the left PPC and cathodal stimulation to the right PPC, which has been shown to impair numerical performance in healthy subjects. We examined two indices of numerical proficiency: (i) automaticity of number processing; and (ii) mapping of numbers onto space. Our results are opposite to previous findings with non-dyscalculic subjects. Only anodal stimulation to the left PPC improved both indices of numerical proficiency. These initial results represent an important step to inform the rehabilitation of developmental learning disabilities, and have relevant applications for basic and applied research in cognitive neuroscience, rehabilitation, and education.

Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia

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Teresa eIuculano

2014-02-01

Full Text Available Nearly 7% of the population exhibit difficulties in dealing with numbers and performing arithmetic, a condition named Developmental Dyscalculia (DD, which significantly affects the educational and professional outcomes of these individuals, as it often persists into adulthood. Research has mainly focused on behavioral rehabilitation, while little is known about performance changes and neuroplasticity induced by the concurrent application of brain-behavioral approaches. It has been shown that numerical proficiency can be enhanced by applying a small – yet constant – current through the brain, a non-invasive technique named transcranial electrical stimulation (tES. Here we combined a numerical learning paradigm with transcranial direct current stimulation (tDCS in two adults with DD to assess the potential benefits of this methodology to remediate their numerical difficulties. Subjects learned to associate artificial symbols to numerical quantities within the context of a trial and error paradigm, while tDCS was applied to the posterior parietal cortex (PPC. The first subject (DD1 received anodal stimulation to the right PPC and cathodal stimulation to the left PPC, which has been associated with numerical performance’s improvements in healthy subjects. The second subject (DD2 received anodal stimulation to the left PPC and cathodal stimulation to the right PPC, which has been shown to impair numerical performance in healthy subjects. We examined two indices of numerical proficiency: (i automaticity of number processing; and (ii mapping of numbers onto space. Our results are opposite to previous findings with non-dyscalculic subjects. Only anodal stimulation to the left PPC improved both indices of numerical proficiency. These initial results represent an important step to inform the rehabilitation of developmental learning disabilities, and have relevant applications for basic and applied research in cognitive neuroscience, rehabilitation

Descripción histológica del ojo de Panaque nigrolineatus (Siluriformes: Loricariidae y sus implicaciones ecomorfológicas Histological structure of the eye of Panaque nigrolineatus (Siluriformes: Loricariidae, ecomorphological implications

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SHERYLL CORCHUELO

2012-06-01

Full Text Available La cucha real (Panaque nigrolineatus es endémica de las cuencas del Orinoco y Amazonas. La información relacionada con el sistema visual de esta especie es muy escasa, a pesar de ser un sentido fundamental en la interacción del individuo con su ambiente. Los especímenes se clasificaron en dos grupos en base a su tamano corporal: pequenos (longitud estándar (media ± DE de 5.92 ± 1.43 cm y peso promedio de 8.50 ± 6.8 g y grandes (longitud estándar (media ± DE de 15.9 ± 0.69 cm y peso promedio de 142.48 ± 18.71 g. En los ejemplares pequenos, el ojo presentó una morfología redondeada, y en los de mayor tamano presentó una morfología ligeramente alargada. Se obtuvieron cortes histológicos de 7 μηι que fueron coloreados con las técnicas H&E y Orceína. El tamano relativo del ojo fue mayor en los ejemplares pequenos (6.46 % que en los de mayor tamano (4.55 %. El espesor de la córnea de los grupos evaluados, presentó variaciones morfométricas significativas, entre su espesor central y periférico. La esclera presentó tejido conectivo denso. Los individuos de mayor tamano corporal tienen una esclera significativamente más gruesa tanto en la región lateral como en la región posterior. Algo similar ocurre con el espesor del iris. La pupila presentó morfología omega. En el cristalino fueron evidenciadas interdigitaciones celulares ubicadas en las regiones laterales. La retina de P. nigrolineatus está compuesta por siete capas. No existen diferencias significativas entre el espesor de la retina de los dos grupos evaluados de P! nigrolineatus. Se observaron de 10 a 12 papilas del nervio óptico en la retina de P. nigrolineatus cuyo diámetro oscila entre 24.57 y 131.90 μηι. Teniendo en cuenta el análisis histológico y morfométrico del ojo de P. nigrolineatus, esta especie presenta adaptaciones orientadas a suplir los requerimientos visuales de organismos bentónicos que habitan ecosistemas con cuerpos de agua turbios, de

Activity in human visual and parietal cortex reveals object-based attention in working memory.

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Peters, Benjamin; Kaiser, Jochen; Rahm, Benjamin; Bledowski, Christoph

2015-02-25

Visual attention enables observers to select behaviorally relevant information based on spatial locations, features, or objects. Attentional selection is not limited to physically present visual information, but can also operate on internal representations maintained in working memory (WM) in service of higher-order cognition. However, only little is known about whether attention to WM contents follows the same principles as attention to sensory stimuli. To address this question, we investigated in humans whether the typically observed effects of object-based attention in perception are also evident for object-based attentional selection of internal object representations in WM. In full accordance with effects in visual perception, the key behavioral and neuronal characteristics of object-based attention were observed in WM. Specifically, we found that reaction times were shorter when shifting attention to memory positions located on the currently attended object compared with equidistant positions on a different object. Furthermore, functional magnetic resonance imaging and multivariate pattern analysis of visuotopic activity in visual (areas V1-V4) and parietal cortex revealed that directing attention to one position of an object held in WM also enhanced brain activation for other positions on the same object, suggesting that attentional selection in WM activates the entire object. This study demonstrated that all characteristic features of object-based attention are present in WM and thus follows the same principles as in perception. Copyright © 2015 the authors 0270-6474/15/353360-10$15.00/0.

Endogenous BDNF is required for long-term memory formation in the rat parietal cortex.

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Alonso, Mariana; Bekinschtein, Pedro; Cammarota, Martín; Vianna, Monica R M; Izquierdo, Iván; Medina, Jorge H

2005-01-01

Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory consolidation in the neocortex. Brain-derived neurotrophic factor (BDNF) modulates both short-term synaptic function and activity-dependent synaptic plasticity in hippocampal and cortical neurons. We have recently demonstrated that endogenous BDNF in the hippocampus is involved in memory formation. Here we examined the role of BDNF in the parietal cortex (PCx) in short-term (STM) and long-term memory (LTM) formation of a one-trial fear-motivated learning task in rats. Bilateral infusions of function-blocking anti-BDNF antibody into the PCx impaired both STM and LTM retention scores and decreased the phosphorylation state of cAMP response element-binding protein (CREB). In contrast, intracortical administration of recombinant human BDNF facilitated LTM and increased CREB activation. Moreover, inhibitory avoidance training is associated with a rapid and transient increase in phospho-CREB/total CREB ratio in the PCx. Thus, our results indicate that endogenous BDNF is required for both STM and LTM formation of inhibitory avoidance learning, possibly involving CREB activation-dependent mechanisms. The present data support the idea that early sensory areas constitute important components of the networks subserving memory formation and that information processing in neocortex plays an important role in memory formation.

Medial Position and Counterclockwise Rotation of the Parietal Scalp Hair-Whorl as a Possible Indicator for Non-Right-Handedness

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Heinrich Schmidt

2008-01-01

Full Text Available The objective of our study was to assess the association between position and swirling direction of the parietal whorl (PW and handedness. In 519 patients of a pediatric practice, PWs were located and the swirling direction determined. Of those patients, handedness could be specified in 217. The right-sided PW (n = 347; 70.8% and the clockwise (CW swirling type (n = 411; 83.9% of all participants were predominant in children with one PW. Non-right-handedness (NRH was found in 40 (18.4%. Medial position of the whorl per se increases the chance for NRH, indifferent of the swirling direction. In patients with counterclockwise (CCW swirling, the chance of NRH increased 3.5-fold for the right-sided, 5.4-fold for the left-sided, and 12.9-fold for the medial-positioned whorl. We conclude that NRH is associated with the position (medial! and the swirling direction (CCW! of the PW.

Expression of a novel stress-inducible protein, sestrin 2, in rat glomerular parietal epithelial cells

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Hamatani, Hiroko; Sakairi, Toru; Takahashi, Satoshi; Watanabe, Mitsuharu; Maeshima, Akito; Ohse, Takamoto; Pippin, Jeffery W.; Shankland, Stuart J.; Nojima, Yoshihisa

2014-01-01

Sestrin 2, initially identified as a p53 target protein, accumulates in cells exposed to stress and inhibits mammalian target of rapamycin (mTOR) signaling. In normal rat kidneys, sestrin 2 was selectively expressed in parietal epithelial cells (PECs), identified by the marker protein gene product 9.5. In adriamycin nephropathy, sestrin 2 expression decreased in PECs on day 14, together with increased expression of phosphorylated S6 ribosomal protein (P-S6RP), a downstream target of mTOR. Sestrin 2 expression was markedly decreased on day 42, coinciding with glomerulosclerosis and severe periglomerular fibrosis. In puromycin aminonucleoside nephropathy, decreased sestrin 2 expression, increased P-S6RP expression, and periglomerular fibrosis were observed on day 9, when massive proteinuria developed. These changes were transient and nearly normalized by day 28. In crescentic glomerulonephritis, sestrin 2 expression was not detected in cellular crescents, whereas P-S6RP increased. In conditionally immortalized cultured PECs, the forced downregulation of sestrin 2 by short hairpin RNA resulted in increased expression of P-S6RP and increased apoptosis. These data suggest that sestrin 2 is involved in PEC homeostasis by regulating the activity of mTOR. In addition, sestrin 2 could be a novel marker of PECs, and decreased expression of sestrin 2 might be a marker of PEC injury. PMID:25056347

Abnormal prefrontal and parietal activity linked to deficient active binding in working memory in schizophrenia.

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Grot, Stéphanie; Légaré, Virginie Petel; Lipp, Olivier; Soulières, Isabelle; Dolcos, Florin; Luck, David

2017-10-01

Working memory deficits have been widely reported in schizophrenia, and may result from inefficient binding processes. These processes, and their neural correlates, remain understudied in schizophrenia. Thus, we designed an FMRI study aimed at investigating the neural correlates of both passive and active binding in working memory in schizophrenia. Nineteen patients with schizophrenia and 23 matched controls were recruited to perform a working memory binding task, in which they were instructed to memorize three letters and three spatial locations. In the passive binding condition, letters and spatial locations were directly presented as bound. Conversely, in the active binding condition, words and spatial locations were presented as separated, and participants were instructed to intentionally create associations between them. Patients exhibited a similar performance to the controls for the passive binding condition, but a significantly lower performance for the active binding. FMRI analyses revealed that this active binding deficit was related to aberrant activity in the posterior parietal cortex and the ventrolateral prefrontal cortex. This study provides initial evidence of a specific deficit for actively binding information in schizophrenia, which is linked to dysfunctions in the neural networks underlying attention, manipulation of information, and encoding strategies. Together, our results suggest that all these dysfunctions may be targets for neuromodulation interventions known to improve cognitive deficits in schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

Interpersonal brain synchronization in the right temporo-parietal junction during face-to-face economic exchange.

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Tang, Honghong; Mai, Xiaoqin; Wang, Shun; Zhu, Chaozhe; Krueger, Frank; Liu, Chao

2016-01-01

In daily life, interpersonal interactions are influenced by uncertainty about other people's intentions. Face-to-face (FF) interaction reduces such uncertainty by providing external visible cues such as facial expression or body gestures and facilitates shared intentionality to promote belief of cooperative decisions and actual cooperative behaviors in interaction. However, so far little is known about interpersonal brain synchronization between two people engaged in naturally occurring FF interactions. In this study, we combined an adapted ultimatum game with functional near-infrared spectroscopy (fNIRS) hyperscanning to investigate how FF interaction impacts interpersonal brain synchronization during economic exchange. Pairs of strangers interacted repeatedly either FF or face-blocked (FB), while their activation was simultaneously measured in the right temporo-parietal junction (rTPJ) and the control region, right dorsolateral prefrontal cortex (rDLPFC). Behaviorally, FF interactions increased shared intentionality between strangers, leading more positive belief of cooperative decisions and more actual gains in the game. FNIRS results indicated increased interpersonal brain synchronizations during FF interactions in rTPJ (but not in rDLPFC) with greater shared intentionality between partners. These results highlighted the importance of rTPJ in collaborative social interactions during FF economic exchange and warrant future research that combines FF interactions with fNIRS hyperscanning to study social brain disorders such as autism. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

El factor de constreñimiento y su dependencia de las dimensiones en probetas de fractura DC(T

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Donoso, J. R.

2002-10-01

Full Text Available The Common Format Equation constraint factor, Ω*, introduced by Donoso and Landes, is analyzed in terms of its dependence on crack length and thickness, in disk-shaped compact specimens, DC(T. Numerical analysis of the load-displacement behavior of blunt-notched DC(T specimens, and experimental evaluation of pre-cracked DC(T specimens of various thickness, allows one to obtain the values of Ω* in terms of the thickness-to-ligament ratio, B/b, as a measure of the degree of size-induced constraint in this geometry.

El factor de constreñimiento de la Ecuación del Formato Común, Ω*, desarrollado por Donoso y Landes, se analiza en términos de su dependencia de la longitud de grieta y el espesor, en probetas de geometría disco-compacta, DC(T. El análisis numérico del comportamiento carga-desplazamiento de probetas DC(T, con entalla roma, y la evaluación experimental de probetas DC(T prefisuradas, con diferentes espesores, permite obtener los valores de Ω*, en función del cociente espesor/ligamento, B/b, como una medida del grado de constreñimiento inducido por la relación de tamaños en esta geometría.

Using tDCS to Explore the Role of the Right Temporo-Parietal Junction in Theory of Mind and Cognitive Empathy.

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Mai, Xiaoqin; Zhang, Wenli; Hu, Xinmu; Zhen, Zhen; Xu, Zhenhua; Zhang, Jing; Liu, Chao

2016-01-01

The right temporo-parietal junction (rTPJ) is thought to be closely related to theory of mind (ToM) and cognitive empathy. In the present study, we investigated whether these socio-cognitive abilities could be modulated with non-invasive transcranial direct current stimulation (tDCS) of the rTPJ. Participants received anodal (excitatory), cathodal (inhibitory), or sham stimulation before performing a social cognitive task which included inferring other's intention (the ToM condition) and inferring other's emotion (the cognitive empathy condition). Our results showed that the accuracy of both ToM and cognitive empathy decreased after receiving the cathodal stimulation, suggesting that altering the cortical excitability in the rTPJ could influence human's socio-cognitive abilities. The results of this study emphasize the critical role of the rTPJ in ToM and cognitive empathy and demonstrate that these socio-cognitive abilities could be modulated by the tDCS.

Effect of visual feedback on the occipito-parietal-motor network in Parkinson's disease patients with freezing of gait

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Priya D Velu

2014-01-01

Full Text Available Freezing of gait (FOG is an elusive phenomenon that debilitates a large number of Parkinson’s disease (PD patients regardless of stage of disease, medication status, or DBS implantation. Sensory cues, especially visual feedback cues, have been shown to alleviate FOG episodes or prevent episodes from even occurring. Here, we examine cortical information flow between occipital, parietal, and motor areas during the pre-movement stage of gait in a PD-with-FOG patient that had a strong positive behavioral response to visual cues, a PD-with-FOG patient without any behavioral response to visual cues, and an age-matched healthy control, before and after training with visual feedback. Results for this case study show differences in cortical information flow between the responding PD-with-FOG patient and the other two subjects, notably, an increased information flow in the beta range. Tentatively suggesting the formation of an alternative cortical sensory-motor pathway during training with visual feedback, these results are proposed as subject for further verification employing larger cohorts of patients.

The parietal cell gastric H, K-ATPase also functions as the Na, K-ATPase and Ca-ATPase in altered states [v2; ref status: indexed, http://f1000r.es/1tc

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Tushar Ray

2013-09-01

Full Text Available This article offers an explanation for the apparent lack of Na, K-ATPase activity in parietal cells although ouabain has been known to inhibit gastric acid secretion since 1962. The gastric H, K-ATPase (proton-pump seems to be acting in altered states, thus behaving like a Na, K-ATPase (Na-pump and/or Ca-ATPase (Ca-pump depending on cellular needs.  This conclusion is based on the following findings. First, parietal cell fractions do not exhibit Na, K-ATPase activity at pH 7.0 but do at pH 8.5. Second, the apical plasma membrane (APM fraction exhibits a (Ca or Mg-ATPase activity with negligible H, K-ATPase activity. However, when assayed with Mg alone in presence of the 80 k Da cytosolic proton-pump activator (HAF, the APM fraction reveals remarkably high H, K-ATPase activity, suggesting the observed low affinity of Ca (or Mg-ATPase is an altered state of the latter. Third, calcium (between 1 and 4 µM shows both stimulation and inhibition of the HAF-stimulated H, K-ATPase depending on its concentration, revealing a close interaction between the  proton-pump activator and local Ca concentration in gastric H, K-ATPase function. Such interactions suggest that Ca is acting as a terminal member of the intracellular signaling system for the HAF-regulated proton-pump. It appears that during resting state, the HAF-associated H, K-ATPase remains inhibited by Ca (>1 µM and, prior to resumption of acid secretion the gastric H, K-ATPase acts temporarily as a Ca-pump for removing excess Ca from its immediate environment. This conclusion is consistent with the recent reports of immunochemical co-localization of the gastric H, K-ATPase and Ca-ATPase by superimposition in parietal cells, and a transitory efflux of Ca immediately preceding the onset of acid secretion. These new perspectives on proton-pump function would open new avenues for a fuller understanding of the intracellular regulation of the ubiquitous Na-pump.

Distinct regions of right temporo-parietal junction are selective for theory of mind and exogenous attention.

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Scholz, Jonathan; Triantafyllou, Christina; Whitfield-Gabrieli, Susan; Brown, Emery N; Saxe, Rebecca

2009-01-01

In functional magnetic resonance imaging (fMRI) studies, a cortical region in the right temporo-parietal junction (RTPJ) is recruited when participants read stories about people's thoughts ('Theory of Mind'). Both fMRI and lesion studies suggest that a region near the RTPJ is associated with attentional reorienting in response to an unexpected stimulus. Do Theory of Mind and attentional reorienting recruit a single population of neurons, or are there two neighboring but distinct neural populations in the RTPJ? One recent study compared these activations, and found evidence consistent with a single common region. However, the apparent overlap may have been due to the low resolution of the previous technique. We tested this hypothesis using a high-resolution protocol, within-subjects analyses, and more powerful statistical methods. Strict conjunction analyses revealed that the area of overlap was small and on the periphery of each activation. In addition, a bootstrap analysis identified a reliable 6-10 mm spatial displacement between the peak activations of the two tasks; the same magnitude and direction of displacement was observed in within-subjects comparisons. In all, these results suggest that there are neighboring but distinct regions within the RTPJ implicated in Theory of Mind and orienting attention.

Parietal cortex integrates contextual and saliency signals during the encoding of natural scenes in working memory.

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Santangelo, Valerio; Di Francesco, Simona Arianna; Mastroberardino, Serena; Macaluso, Emiliano

2015-12-01

The Brief presentation of a complex scene entails that only a few objects can be selected, processed indepth, and stored in memory. Both low-level sensory salience and high-level context-related factors (e.g., the conceptual match/mismatch between objects and scene context) contribute to this selection process, but how the interplay between these factors affects memory encoding is largely unexplored. Here, during fMRI we presented participants with pictures of everyday scenes. After a short retention interval, participants judged the position of a target object extracted from the initial scene. The target object could be either congruent or incongruent with the context of the scene, and could be located in a region of the image with maximal or minimal salience. Behaviourally, we found a reduced impact of saliency on visuospatial working memory performance when the target was out-of-context. Encoding-related fMRI results showed that context-congruent targets activated dorsoparietal regions, while context-incongruent targets de-activated the ventroparietal cortex. Saliency modulated activity both in dorsal and ventral regions, with larger context-related effects for salient targets. These findings demonstrate the joint contribution of knowledge-based and saliency-driven attention for memory encoding, highlighting a dissociation between dorsal and ventral parietal regions. © 2015 Wiley Periodicals, Inc.

10 Hz rTMS over right parietal cortex alters sense of agency during self-generated movements

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Anina eRitterband-Rosenbaum

2014-06-01

Full Text Available A large body of fMRI and lesion-literature has provided evidence that the Inferior Parietal Cortex (IPC is important for sensorimotor integration and sense of agency (SoA. We used repetitive transcranial magnetic stimulation (rTMS to explore the role of the IPC during a validated SoA detection task. 12 healthy, right-handed adults were included. The effects of rTMS on subjects’ SoA during self-generated movements were explored. The experiment consisted of 1/3 self-generated movements and 2/3 computer manipulated movements that introduced uncertainty as to whether the subjects were agents of an observed movement. Subjects completed three sessions, in which subjects received online rTMS over the right IPC (active condition, over the vertex (CZ (sham condition or no TMS but a sound-matched control. We found that rTMS over right IPC significantly altered SoA of the non-perturbed movements. Following IPC stimulation subjects were more likely to experience self-generated movements as being externally perturbed compared to the control site (P=0.002 and the stimulation-free control (P=0.042. The data support the importance of IPC activation during sensorimotor comparison in order to correctly determine the agent of movements.

The Importance of Lateral Connections in the Parietal Cortex for Generating Motor Plans.

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Derrik E Asher

Full Text Available Substantial evidence has highlighted the significant role of associative brain areas, such as the posterior parietal cortex (PPC in transforming multimodal sensory information into motor plans. However, little is known about how different sensory information, which can have different delays or be absent, combines to produce a motor plan, such as executing a reaching movement. To address these issues, we constructed four biologically plausible network architectures to simulate PPC: 1 feedforward from sensory input to the PPC to a motor output area, 2 feedforward with the addition of an efference copy from the motor area, 3 feedforward with the addition of lateral or recurrent connectivity across PPC neurons, and 4 feedforward plus efference copy, and lateral connections. Using an evolutionary strategy, the connectivity of these network architectures was evolved to execute visually guided movements, where the target stimulus provided visual input for the entirety of each trial. The models were then tested on a memory guided motor task, where the visual target disappeared after a short duration. Sensory input to the neural networks had sensory delays consistent with results from monkey studies. We found that lateral connections within the PPC resulted in smoother movements and were necessary for accurate movements in the absence of visual input. The addition of lateral connections resulted in velocity profiles consistent with those observed in human and non-human primate visually guided studies of reaching, and allowed for smooth, rapid, and accurate movements under all conditions. In contrast, Feedforward or Feedback architectures were insufficient to overcome these challenges. Our results suggest that intrinsic lateral connections are critical for executing accurate, smooth motor plans.

Amygdala, Pulvinar & Inferior Parietal Cortex Contribute to Early Processing of Faces without Awareness

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Vanessa eTroiani

2013-06-01

Full Text Available The goals of the present study were twofold. First, we wished to investigate the neural correlates of stimulus-driven processing of stimuli strongly suppressed from awareness and in the absence of top-down influences. We accomplished this using a novel approach in which participants performed an orthogonal task atop a flash suppression noise image to prevent top-down search. Second, we wished to investigate the extent to which amygdala responses differentiate between suppressed stimuli (fearful faces and houses based on their motivational relevance. Using continuous flash suppression in conjunction with fMRI, we presented fearful faces, houses, and a no stimulus control to one eye while participants performed an orthogonal task that appeared atop the flashing Mondrian image presented to the opposite eye. In 29 adolescents, we show activation in subcortical regions, including the superior colliculus, amygdala, thalamus, and hippocampus for suppressed objects (fearful faces and houses compared to a no stimulus control. Suppressed stimuli showed less activation compared to a no stimulus control in early visual cortex, indicating that object information was being suppressed from this region. Additionally, we find no activation in regions associated with conscious processing of these percepts (fusiform gyrus and/or parahippocampal cortex as assessed by mean activations and multi-voxel patterns. A psychophysiological interaction analysis that seeded the amygdala showed task-specific (fearful faces greater than houses modulation of right pulvinar and left inferior parietal cortex. Taken together, our results support a role for the amygdala in stimulus-driven attentional guidance towards objects of relevance and a potential mechanism for successful suppression of rivalrous stimuli.

Parietal EEG alpha suppression time of memory retrieval reflects memory load while the alpha power of memory maintenance is a composite of the visual process according to simultaneous and successive Sternberg memory tasks.

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Okuhata, Shiho; Kusanagi, Takuya; Kobayashi, Tetsuo

2013-10-25

The present study investigated EEG alpha activity during visual Sternberg memory tasks using two different stimulus presentation modes to elucidate how the presentation mode affected parietal alpha activity. EEGs were recorded from 10 healthy adults during the Sternberg tasks in which memory items were presented simultaneously and successively. EEG power and suppression time (ST) in the alpha band (8-13Hz) were computed for the memory maintenance and retrieval phases. The alpha activity differed according to the presentation mode during the maintenance phase but not during the retrieval phase. Results indicated that parietal alpha power recorded during the maintenance phase did not reflect the memory load alone. In contrast, ST during the retrieval phase increased with the memory load for both presentation modes, indicating a serial memory scanning process, regardless of the presentation mode. These results indicate that there was a dynamic transition in the memory process from the maintenance phase, which was sensitive to external factors, toward the retrieval phase, during which the process converged on the sequential scanning process, the Sternberg task essentially required. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Ligereza y espesor en la arquitectura contemporánea

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Juan Antonio Cortés

2011-05-01

Full Text Available

The modern architect tried to achieve complete immateriality, translucency and lightness fading in the air strength and weight of ancient architecture. Wright, Le Corbusier and Mies proposed by the clearness and transparency of the envelope to shift from mass to volume. The thickness of recent architecture calls us different shades on their quality: The level geometry and the physical level (density. The thickness is not a measurable quantity, but a noticeable appearance. In the works of Herzog and de Meuron is found that thick will look to the facades designed as flat planes with no depth. But this thickness there is no loss of lightness and translucency, but a nuanced treatment, non-compacted solid, undergoing a self-consistent intermediate state of matter in which the solid becomes soft and liquid evaporates, the fluid thickens and ethereal changes to dense. Sejima's research, Sanaa in their projects, is about the thickness as a superposition of transparencies and reflections by the use of transparent materials, through a series of layers arranged in parallel vertical space and using the curvature of the walls in the corners or all the walls to contribute to the emergence of multiple reflections and opacity unexpected. In fact, her main interests in the reflection and not in the transparency. The substance of architecture becomes an issue linked to the changing situation of the subject, although governed by the formal organization of the building.

Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study

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Andrew D. Robertson

2017-09-01

Full Text Available Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL magnetic resonance imaging (MRI in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF and the spatial coefficient of variation of CBF (sCoV were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73 and excellent reliability for sCoV (ICC = 0.94. In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036. The greatest change occurred in the parietal lobe (+18 ± 12%. Gray matter sCoV, however, did not change following training (P = 0.31. This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries.

Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study

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Robertson, Andrew D.; Marzolini, Susan; Middleton, Laura E.; Basile, Vincenzo S.; Oh, Paul I.; MacIntosh, Bradley J.

2017-01-01

Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL) magnetic resonance imaging (MRI) in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF) and the spatial coefficient of variation of CBF (sCoV) were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC) indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73) and excellent reliability for sCoV (ICC = 0.94). In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036). The greatest change occurred in the parietal lobe (+18 ± 12%). Gray matter sCoV, however, did not change following training (P = 0.31). This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries. PMID:29033829

Anodal transcranial direct current stimulation of parietal cortex enhances action naming in Corticobasal Syndrome

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Rosa eManenti

2015-04-01

Full Text Available Background: Corticobasal Syndrome (CBS is a neurodegenerative disorder that overlaps both clinically and neuropathologically with Frontotemporal dementia and is characterized by apraxia, alien limb phenomena, cortical sensory loss, cognitive impairment, behavioural changes and aphasia. It has been recently demonstrated that transcranial direct current stimulation (tDCS improves naming in healthy subjects and in subjects with language deficits.Objective: The aim of the present study was to explore the extent to which anodal transcranial direct current stimulation (anodal tDCS over the parietal cortex (PARC could facilitate naming performance in CBS subjects. Methods: Anodal tDCS was applied to the left and right PARC during object and action naming in seventeen patients with a diagnosis of possible CBS. Participants underwent two sessions of anodal tDCS (left and right and one session of placebo tDCS. Vocal responses were recorded and analyzed for accuracy and vocal Reaction Times (vRTs. Results: A shortening of naming latency for actions was observed only after active anodal stimulation over the left PARC, as compared to placebo and right stimulations. No effects have been reported for accuracy.Conclusions: Our preliminary finding demonstrated that tDCS decreased vocal reaction time during action naming in a sample of patients with CBS. A possible explanation of our results is that anodal tDCS over the left PARC effects the brain network implicated in action observation and representation. Further studies, based on larger patient samples, should be conducted to investigate the usefulness of tDCS as an additional treatment of linguistic deficits in CBS patients.

EEG UPPER/LOW ALPHA FREQUENCY POWER RATIO RELATES TO TEMPORO-PARIETAL BRAIN ATROPHY AND MEMORY PERFORMANCES IN MILD COGNITIVE IMPAIRMENT

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Davide Vito Moretti

2013-10-01

Full Text Available Objective: temporo-parietal cortex thinning is associated to mild cognitive impairment (MCI due to Alzheimer disease (AD. The increase of EEG upper/low alpha power ratio has been associated with AD-converter MCI subjects. We investigated the association of alpha3/alpha2 ratio with patterns of cortical thickness in MCI.Methods: 74 adult subjects with MCI underwent clinical and neuropsychological evaluation, electroencephalogram (EEG recording and high resolution 3D magnetic resonance imaging (MRI. Alpha3/alpha2 power ratio as well as cortical thickness was computed for each subject. Three MCI groups were detected according to increasing tertile values of upper/low alpha power ratio . Difference of cortical thikness among the groups was estimated. Pearson’s r was used to assess the topography of the correlation between cortical thinning and memory impairment.Results: High upper/low alpha power ratio group had total cortical grey matter (CGM volume reduction of 471 mm2 than low upper/low alpha power ratio group (p

Alteraciones de la mucosa bucal causadas por la asociación entre el tabaco y los colutorios bucales con una concentración de alcohol del 26,9 %

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Anna Christina Medeiros Fossati

Full Text Available Se analizaron el epitelio y la capa de queratina de la mucosa oral de 15 ratas que durante 45 días fueron sometidas a una aplicación tópica de picadura de tabaco y de colutorio bucal con una concentración de alcohol del 26,9 %. Tras ese período, se extrajeron las mucosas y se les realizó un análisis histológico. Se observó una significativa disminución del espesor del epitelio y de la capa de queratina, lo que indica que la picadura asociada con colutorios bucales con alta concentración de alcohol, provoca la reducción del espesor de la capa de queratina y del epitelio de la boca.

Consciousness and the prefrontal parietal network: insights from attention, working memory, and chunking.

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Bor, Daniel; Seth, Anil K

2012-01-01

Consciousness has of late become a "hot topic" in neuroscience. Empirical work has centered on identifying potential neural correlates of consciousness (NCCs), with a converging view that the prefrontal parietal network (PPN) is closely associated with this process. Theoretical work has primarily sought to explain how informational properties of this cortical network could account for phenomenal properties of consciousness. However, both empirical and theoretical research has given less focus to the psychological features that may account for the NCCs. The PPN has also been heavily linked with cognitive processes, such as attention. We describe how this literature is under-appreciated in consciousness science, in part due to the increasingly entrenched assumption of a strong dissociation between attention and consciousness. We argue instead that there is more common ground between attention and consciousness than is usually emphasized: although objects can under certain circumstances be attended to in the absence of conscious access, attention as a content selection and boosting mechanism is an important and necessary aspect of consciousness. Like attention, working memory and executive control involve the interlinking of multiple mental objects and have also been closely associated with the PPN. We propose that this set of cognitive functions, in concert with attention, make up the core psychological components of consciousness. One related process, chunking, exploits logical or mnemonic redundancies in a dataset so that it can be recoded and a given task optimized. Chunking has been shown to activate PPN particularly robustly, even compared with other cognitively demanding tasks, such as working memory or mental arithmetic. It is therefore possible that chunking, as a tool to detect useful patterns within an integrated set of intensely processed (attended) information, has a central role to play in consciousness. Following on from this, we suggest that a key

The glomerular parietal epithelial cell's responses are influenced by SM22 alpha levels.

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Naito, Shokichi; Pippin, Jeffrey W; Shankland, Stuart J

2014-11-06

Studies have shown in several diseases initially affecting podocytes, that the neighboring glomerular parietal epithelial cells (PECs) are secondarily involved. The PEC response might be reparative under certain circumstances, yet injurious under others. The factors governing these are not well understood. We have shown that SM22α, an actin-binding protein considered a marker of smooth muscle differentiation, is upregulated in podocytes and PECs in several models of podocyte disease. However, the impact of SM22α levels on PECs is not known. Experimental glomerular disease, characterized by primary podocyte injury, was induced in aged-matched SM22α+/+ and SM22α-/-mice by intraperitoneal injection of sheep anti-rabbit glomeruli antibody. Immunostaining methods were employed on days 7 and 14 of disease. The number of PEC transition cells, defined as cells co-expressing a PEC protein (PAX2) and podocyte protein (Synaptopodin) was higher in diseased SM22α-/-mice compared with SM22α+/+mice. WT1 staining along Bowman's capsule is higher in diseased SM22α-/-mice. This was accompanied by increased PEC proliferation (measured by ki-67 staining), and an increase in immunostaining for the progenitor marker NCAM, in a subpopulation of PECs in diseased SM22α-/-mice. In addition, immunostaining for vimentin and alpha smooth muscle actin, markers of epithelial-to-mesenchymal transition (EMT), was lower in diseased SM22α-/-mice compared to diseased SM22α+/+mice. SM22α levels may impact how PECs respond following a primary podocyte injury in experimental glomerular disease. Absent/lower levels favor an increase in PEC transition cells and PECs expressing a progenitor marker, and a lower EMT rate compared to SM22α+/+mice, where SM22 levels are markedly increased in PECs.

Consciousness and the prefrontal parietal network: Insights from attention, working memory and chunking

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Daniel eBor

2012-03-01

Full Text Available Consciousness has of late become a hot topic in neuroscience. Empirical work has centred on identifying potential neural correlates of consciousness (NCCs, with a converging view that the prefrontal parietal network (PPN is closely associated with this process. Theoretical work has primarily sought to explain how informational properties of this cortical network could account for phenomenal properties of consciousness. However, both empirical and theoretical research has given less focus to the psychological features that may account for the NCCs. The PPN has also been heavily linked with cognitive processes, such as attention. We describe how this literature is under-appreciated in consciousness science, in part due to the increasingly entrenched assumption of a strong dissociation between attention and consciousness. We argue instead that there is more common ground between attention and consciousness than is usually emphasized: although objects can under certain circumstances be attended to in the absence of conscious access, attention as a content selection and boosting mechanism is an important and necessary aspect of consciousness. Like attention, working memory and executive control involve the interlinking of multiple mental objects and have also been closely associated with the PPN. We propose that this set of cognitive functions, in concert with attention, make up the core psychological components of consciousness. One related process, chunking, has been shown to activate PPN particularly robustly, even compared with other cognitively demanding tasks, such as working memory or mental arithmetic. It is therefore possible that chunking, as a tool to detect useful patterns within an integrated set of intensely processed (attended information, has a central role to play in consciousness. Following on from this, we suggest that the main evolutionary purpose of consciousness may be to provide innovative solutions to complex or novel problems.

Increased density of DISC1-immunoreactive oligodendroglial cells in fronto-parietal white matter of patients with paranoid schizophrenia.

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Bernstein, Hans-Gert; Jauch, Esther; Dobrowolny, Henrik; Mawrin, Christian; Steiner, Johann; Bogerts, Bernhard

2016-09-01

Profound white matter abnormalities have repeatedly been described in schizophrenia, which involve the altered expression of numerous oligodendrocyte-associated genes. Transcripts of the disrupted-in-schizophrenia 1 (DISC1) gene, a key susceptibility factor in schizophrenia, have recently been shown to be expressed by oligodendroglial cells and to negatively regulate oligodendrocyte differentiation and maturation. To learn more about the putative role(s) of oligodendroglia-associated DISC1 in schizophrenia, we analyzed the density of DISC1-immunoreactive oligodendrocytes in the fronto-parietal white matter in postmortem brains of patients with schizophrenia. Compared with controls (N = 12) and cases with undifferentiated/residual schizophrenia (N = 6), there was a significantly increased density of DISC1-expressing glial cells in paranoid schizophrenia (N = 12), which unlikely resulted from neuroleptic treatment. Pathophysiologically, over-expression of DISC1 protein(s) in white matter oligodendrocytes might add to the reduced levels of two myelin markers, 2',3'-cyclic-nucleotide 3'-phosphodiesterase and myelin basic protein in schizophrenia. Moreover, it might significantly contribute to cell cycle abnormalities as well as to deficits in oligodendroglial cell differentiation and maturation found in schizophrenia.

Activity in inferior parietal and medial prefrontal cortex signals the accumulation of evidence in a probability learning task.

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Mathieu d'Acremont

Full Text Available In an uncertain environment, probabilities are key to predicting future events and making adaptive choices. However, little is known about how humans learn such probabilities and where and how they are encoded in the brain, especially when they concern more than two outcomes. During functional magnetic resonance imaging (fMRI, young adults learned the probabilities of uncertain stimuli through repetitive sampling. Stimuli represented payoffs and participants had to predict their occurrence to maximize their earnings. Choices indicated loss and risk aversion but unbiased estimation of probabilities. BOLD response in medial prefrontal cortex and angular gyri increased linearly with the probability of the currently observed stimulus, untainted by its value. Connectivity analyses during rest and task revealed that these regions belonged to the default mode network. The activation of past outcomes in memory is evoked as a possible mechanism to explain the engagement of the default mode network in probability learning. A BOLD response relating to value was detected only at decision time, mainly in striatum. It is concluded that activity in inferior parietal and medial prefrontal cortex reflects the amount of evidence accumulated in favor of competing and uncertain outcomes.

The impact of auditory working memory training on the fronto-parietal working memory network.

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Schneiders, Julia A; Opitz, Bertram; Tang, Huijun; Deng, Yuan; Xie, Chaoxiang; Li, Hong; Mecklinger, Axel

2012-01-01

Working memory training has been widely used to investigate working memory processes. We have shown previously that visual working memory benefits only from intra-modal visual but not from across-modal auditory working memory training. In the present functional magnetic resonance imaging study we examined whether auditory working memory processes can also be trained specifically and which training-induced activation changes accompany theses effects. It was investigated whether working memory training with strongly distinct auditory materials transfers exclusively to an auditory (intra-modal) working memory task or whether it generalizes to a (across-modal) visual working memory task. We used adaptive n-back training with tonal sequences and a passive control condition. The memory training led to a reliable training gain. Transfer effects were found for the (intra-modal) auditory but not for the (across-modal) visual transfer task. Training-induced activation decreases in the auditory transfer task were found in two regions in the right inferior frontal gyrus. These effects confirm our previous findings in the visual modality and extents intra-modal effects in the prefrontal cortex to the auditory modality. As the right inferior frontal gyrus is frequently found in maintaining modality-specific auditory information, these results might reflect increased neural efficiency in auditory working memory processes. Furthermore, task-unspecific (amodal) activation decreases in the visual and auditory transfer task were found in the right inferior parietal lobule and the superior portion of the right middle frontal gyrus reflecting less demand on general attentional control processes. These data are in good agreement with amodal activation decreases within the same brain regions on a visual transfer task reported previously.

The impact of auditory working memory training on the fronto-parietal working memory network

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Schneiders, Julia A.; Opitz, Bertram; Tang, Huijun; Deng, Yuan; Xie, Chaoxiang; Li, Hong; Mecklinger, Axel

2012-01-01

Working memory training has been widely used to investigate working memory processes. We have shown previously that visual working memory benefits only from intra-modal visual but not from across-modal auditory working memory training. In the present functional magnetic resonance imaging study we examined whether auditory working memory processes can also be trained specifically and which training-induced activation changes accompany theses effects. It was investigated whether working memory training with strongly distinct auditory materials transfers exclusively to an auditory (intra-modal) working memory task or whether it generalizes to a (across-modal) visual working memory task. We used adaptive n-back training with tonal sequences and a passive control condition. The memory training led to a reliable training gain. Transfer effects were found for the (intra-modal) auditory but not for the (across-modal) visual transfer task. Training-induced activation decreases in the auditory transfer task were found in two regions in the right inferior frontal gyrus. These effects confirm our previous findings in the visual modality and extents intra-modal effects in the prefrontal cortex to the auditory modality. As the right inferior frontal gyrus is frequently found in maintaining modality-specific auditory information, these results might reflect increased neural efficiency in auditory working memory processes. Furthermore, task-unspecific (amodal) activation decreases in the visual and auditory transfer task were found in the right inferior parietal lobule and the superior portion of the right middle frontal gyrus reflecting less demand on general attentional control processes. These data are in good agreement with amodal activation decreases within the same brain regions on a visual transfer task reported previously. PMID:22701418

VARIAÇÕES DO NÍVEL RELATIVO DO MAR DURANTE O HOLOCENO NA BACIA HIDROGRÁFICA DO RIO UNA, REGIÃO DE CABO FRIO - RIO DE JANEIRO: ASPECTOS SEDIMENTOLÓGICOS, FACIOLÓGICOS E GEOCRONOLÓGICOS

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Aline Meneguci Cunha

2017-03-01

Full Text Available As Flutuações do nível do mar e mudanças climáticas durante o Holoceno foram importante para construção e evolução das paisagens sedimentares costeiras. As  variações do nível relativo do mar são identificadas através de indicadores geológicos, biológicos e arqueológicos. Objetiva-se identificar indicadores geológicos dessas variações na bacia hidrográfica do rio Una, região dos Lagos Fluminenses, Rio de Janeiro. Como procedimento metodológico elaborou-se seis perfis estratigráficos em diferentes pontos, envolvendo, análises sedimentológicas e faciológicos, combinadas, em todas as fases da pesquisa, a um controle sistemático de campo. Em laboratório elaborou-se tabelas de fácies sedimentares, contendo atributos referente a diagnose, cor, geometria, contato, estrutura sedimentar e conteúdo fossilífero. As idade obtidas ao radiocarbono variam entre 6330 a 4.800 cal anos A.P. Resultados sugerem que o processo sedimentar mais representativo em termos de conteúdo fossilífero foram deposições de conchas de moluscos no optimum climático holocênico, definido como periodo interglacial.  

Electrochemical noise evaluation of anodized aluminum. Comparative study against corrosion behaviour in the atmosphere

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Betancourt, N.

2003-12-01

Full Text Available The present work reports the evaluation of aluminum and anodized aluminum by electrochemical noise, as a part of the PATINA/CYTED project of the working group Nº 5. A visual examination is also made. The samples were exposed at several Ibero-American atmospheres up to 2 years of exposure. Different thickness of anodized aluminum were evaluated. The electrochemical potential noise of the 5 μm unexposed sample (pattern showed a different behaviour to that showed by the other anodized specimens. This could be due to a slower sealed of the samples of higher thickness. The same behaviour was observed on the samples exposed at the rural station El Pardo. According to the visual examination, the samples of bare aluminum and those of anodized 5 μm thickness were the most affected by pitting corrosion in the highly polluted atmospheres. A good correlation between corrosion behaviour determined by visual examination and EN was obtained.

Como parte de las investigaciones de la Red PATINA el grupo de trabajo Nº 5 dedicó su atención al comportamiento del aluminio desnudo y anodizado con diferentes espesores en diferentes atmósferas de Iberoamérica. En el presente trabajo se presenta una evaluación de patrones de aluminio 99,5 % de pureza desnudo y anodizado con espesores de 15 y 25 μm, mediante ruido electroquímico. Los resultados obtenidos se comparan con el comportamiento determinado en diferentes atmósferas durante un período de 2 años. El ruido de voltaje del patrón de 5 μm de espesor presenta un comportamiento diferente al de los restantes espesores, lo que coincide con una mayor susceptibilidad a la corrosión picadura de este primer anodizado. Se reportan también algunas diferencias en el ruido de corriente. Se concluye que mediante la utilización del ruido electroquímico es posible caracterizar el aluminio con respecto a su sensibilidad a la corrosión picadura en condiciones atmosféricas.

The Role of Angiotensin II in Parietal Epithelial Cell Proliferation and Crescent Formation in Glomerular Diseases.

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Rizzo, Paola; Novelli, Rubina; Rota, Cinzia; Gagliardini, Elena; Ruggiero, Barbara; Rottoli, Daniela; Benigni, Ariela; Remuzzi, Giuseppe

2017-11-01

Crescentic glomerulonephritis (GN) is a devastating disease with rapidly progressive deterioration in kidney function, which, histologically, manifests as crescent formation in most glomeruli. We previously found that crescents derive from the aberrant proliferation and migration of parietal epithelial cells (PECs)/progenitor cells, and that the angiotensin (ang) II/ang II type-1 (AT 1 ) receptor pathway may participate, together with the stromal cell-derived factor-1 (SDF-1)/C-X-C chemokine receptor 4 axis, in the development of those lesions. Herein, we elucidated sequential events and cellular and molecular interactions occurring during crescentic lesion onset and evolution. By analyzing kidney biopsy specimens of patients with extracapillary GN, divided according to the grade of glomerular lesions, we found that the accumulation of macrophages expressing matrix metalloproteinase-12 started manifesting in glomeruli affected by early-stage lesions, whereas AT 1 receptor expression could not be detected. In glomeruli with advanced lesions, AT 1 receptor expression increased markedly, and the up-regulation of SDF-1, and its receptor C-X-C chemokine receptor 7, was documented on podocytes and PECs, respectively. In vitro studies were instrumental to demonstrating the role of ang II in inducing podocyte SDF-1 production, which ultimately activates PECs. The present findings support the possibility that angiotensin-converting enzyme inhibitor treatment might limit PEC activation and reduce the frequency and extension of crescents in extracapillary GN. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Modulation of motor control in saccadic behaviors by TMS over the posterior parietal cortex.

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Liang, Wei-Kuang; Juan, Chi-Hung

2012-08-01

The right posterior parietal cortex (rPPC) has been found to be critical in shaping visual selection and distractor-induced saccade curvature in the context of predictive as well as nonpredictive visual cues by means of transcranial magnetic stimulation (TMS) interference. However, the dynamic details of how distractor-induced saccade curvatures are affected by rPPC TMS have not yet been investigated. This study aimed to elucidate the key dynamic properties that cause saccades to curve away from distractors with different degrees of curvature in various TMS and target predictability conditions. Stochastic optimal feedback control theory was used to model the dynamics of the TMS saccade data. This allowed estimation of torques, which was used to identify the critical dynamic mechanisms producing saccade curvature. The critical mechanisms of distractor-induced saccade curvatures were found to be the motor commands and torques in the transverse direction. When an unpredictable saccade target occurred with rPPC TMS, there was an initial period of greater distractor-induced torque toward the side opposite the distractor in the transverse direction, immediately followed by a relatively long period of recovery torque that brought the deviated trace back toward the target. The results imply that the mechanisms of distractor-induced saccade curvature may be comprised of two mechanisms: the first causing the initial deviation and the second bringing the deviated trace back toward the target. The pattern of the initial torque in the transverse direction revealed the former mechanism. Conversely, the later mechanism could be well explained as a consequence of the control policy in this model. To summarize, rPPC TMS increased the initial torque away from the distractor as well as the recovery torque toward the target.

The Impact of Auditory Working Memory Training on the Fronto-Parietal Working Memory Network

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Julia eSchneiders

2012-06-01

Full Text Available Working memory training has been widely used to investigate working memory processes. We have shown previously that visual working memory benefits only from intra-modal visual but not from across-modal auditory working memory training. In the present functional magnetic resonance imaging study we examined whether auditory working memory processes can also be trained specifically and which training-induced activation changes accompany theses effects. It was investigated whether working memory training with strongly distinct auditory materials transfers exclusively to an auditory (intra-modal working memory task or whether it generalizes to an (across-modal visual working memory task. We used an adaptive n-back training with tonal sequences and a passive control condition. The memory training led to a reliable training gain. Transfer effects were found for the (intra-modal auditory but not for the (across-modal visual 2-back task. Training-induced activation changes in the auditory 2-back task were found in two regions in the right inferior frontal gyrus. These effects confirm our previous findings in the visual modality and extends intra-modal effects to the auditory modality. These results might reflect increased neural efficiency in auditory working memory processes as in the right inferior frontal gyrus is frequently found in maintaining modality-specific auditory information. By this, these effects are analogical to the activation decreases in the right middle frontal gyrus for the visual modality in our previous study. Furthermore, task-unspecific (across-modal activation decreases in the visual and auditory 2-back task were found in the right inferior parietal lobule and the superior portion of the right middle frontal gyrus reflecting less demands on general attentional control processes. These data are in good agreement with across-modal activation decreases within the same brain regions on a visual 2-back task reported previously.

Body integrity identity disorder: deranged body processing, right fronto-parietal dysfunction, and phenomenological experience of body incongruity.

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Giummarra, Melita J; Bradshaw, John L; Nicholls, Michael E R; Hilti, Leonie M; Brugger, Peter

2011-12-01

Body integrity identity disorder (BIID) is characterised by profound experience of incongruity between the biological and desired body structure. The condition manifests in "non-belonging" of body parts, and the subsequent desire to amputate, paralyse or disable a limb. Little is known about BIID; however, a neuropsychological model implicating right fronto-parietal and insular networks is emerging, with potential disruption to body representation. We argue that, as there is scant systematic research on BIID published to date and much of the research is methodologically weak, it is premature to assume that the only process underlying bodily experience that is compromised is body representation. The present review systematically investigates which aspects of neurological processing of the body, and sense of self, may be compromised in BIID. We argue that the disorder most likely reflects dysregulation in multiple levels of body processing. That is, the disunity between self and the body could arguably come about through congenital and/or developmental disruption of body representations, which, together with altered multisensory integration, may preclude the experience of self-attribution and embodiment of affected body parts. Ulimately, there is a need for official diagnostic criteria to facilitate epidemiological characterisation of BIID, and for further research to systematically investigate which aspects of body representation and processing are truly compromised in the disorder.

At the intersection of attention and memory: the mechanistic role of the posterior parietal lobe in working memory

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Berryhill, Marian E.; Chein, Jason; Olson, Ingrid R.

2011-01-01

Portions of the posterior parietal cortex (PPC) play a role in working memory (WM) yet the precise mechanistic function of this region remains poorly understood. The pure storage hypothesis proposes that this region functions as a short-lived modality-specific memory store. Alternatively, the internal attention hypothesis proposes that the PPC functions as an attention-based storage and refreshing mechanism deployable as an alternative to material-specific rehearsal. These models were tested in patients with bilateral PPC lesions. Our findings discount the pure storage hypothesis because variables indexing storage capacity and longevity were not disproportionately affected by PPC damage. Instead, our data support the internal attention account by showing that (a) normal participants tend to use a rehearsal-based WM maintenance strategy for recall tasks but not for recognition tasks; (b) patients with PPC lesions performed normally on WM tasks that relied on material-specific rehearsal strategies but poorly on WM tasks that relied on attention-based maintenance strategies and patient strategy usage could be shifted by task or instructions; (c) patients’ memory deficits extended into the long-term domain. These findings suggest that the PPC maintains or shifts internal attention among the representations of items in WM. PMID:21345344

At the intersection of attention and memory: the mechanistic role of the posterior parietal lobe in working memory.

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Berryhill, Marian E; Chein, Jason; Olson, Ingrid R

2011-04-01

Portions of the posterior parietal cortex (PPC) play a role in working memory (WM) yet the precise mechanistic function of this region remains poorly understood. The pure storage hypothesis proposes that this region functions as a short-lived modality-specific memory store. Alternatively, the internal attention hypothesis proposes that the PPC functions as an attention-based storage and refreshing mechanism deployable as an alternative to material-specific rehearsal. These models were tested in patients with bilateral PPC lesions. Our findings discount the pure storage hypothesis because variables indexing storage capacity and longevity were not disproportionately affected by PPC damage. Instead, our data support the internal attention account by showing that (a) normal participants tend to use a rehearsal-based WM maintenance strategy for recall tasks but not for recognition tasks; (b) patients with PPC lesions performed normally on WM tasks that relied on material-specific rehearsal strategies but poorly on WM tasks that relied on attention-based maintenance strategies and patient strategy usage could be shifted by task or instructions; (c) patients' memory deficits extended into the long-term domain. These findings suggest that the PPC maintains or shifts internal attention among the representations of items in WM. Copyright © 2011 Elsevier Ltd. All rights reserved.

ANÁLISIS Y ESTUDIO DEL DESEMPEÑO DE LOS ENTRELAZADORES DE BITS DE BLOQUE, DORADO Y DORADO RELATIVO EN UN CANAL DE LÍNEA ELÉCTRICA DE BAJA TENSIÓN ANALYSIS OF THE PERFORMANCE OF THE INTERLEAVERS OF BLOCK, GOLDEN AND RELATIVE GOLDEN IN A OF LOW VOLTAGE POWER LINE CHANNEL

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Washington Fernández R

2008-09-01

Full Text Available En este trabajo se analizan y se estudian tres tipos de entrelazadores de bit: bloque, dorado y dorado relativo, y se determina su desempeño en un canal de línea eléctrica de baja tensión. Se utiliza el modelo de ruido dado por Middleton, para la simulación del canal de línea eléctrica de baja tensión y el algoritmo que se utiliza para generar ruido gaussiano es el método de Box-Muller. Se compara el desempeño de los entrelazadores de bits de bloque, dorado y dorado relativo, en relación al largo de la palabra versus la razón de señal a ruido y bits erróneos por palabras versus la razón de señal a ruido. La codificación de línea que se utiliza es no retorno a cero. El entrelazador de bit dorado es el que tiene el mejor desempeño, por lo tanto, se puede emplear en la transmisión por línea eléctrica de baja tensión para disminuir los errores de bits consecutivos producido por el ruido impulsivo.This paper analyzes three types of interleavers: block, golden and golden relative to determine their performance in of low voltage power line channel. The model of noise given by Middleton is used for the simulation of the low voltage power line channel and the algorithm used to generate Gaussian noise is based on the Box-Muller method. The performance of interleavers block, golden and golden relative is compared in relationship to the length of the words versus the signal to noise ratio. The error bit by word versus signal to noise ratio is compared also. The codification of line used is no return to zero. It is concluded that the interleavers of golden has the best performance, thus it can be used in data transmission in low-voltage power line, reducing errors consecutive bits produced by impulse noise.

Morfología de la semilla y anatomía de la cubierta seminal de cinco especies de Calliandra (Leguminosae-Mimosoideae de Venezuela

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Sirli Leython

2008-09-01

Full Text Available Se estudió la morfología de las semillas y la anatomía de la cubierta seminal en cinco especies venezolanas del género Calliandra, con la finalidad de establecer similitudes y diferencias entre estos taxa, para su utilización como criterio taxonómico. Se analizaron caracteres morfológicos de valor taxonómico; entre ellos la forma y el tamaño de la semilla, así como anatómicos tales como espesor de las diferentes regiones, la ubicación de la línea lúcida y el tamaño relativo de los espacios intercelulares en la hipodermis. Con los resultados se realizaron análisis de agrupamiento por medio de la función de análisis discriminante. Diez caracteres cuantitativos, y tres caracteres cualitativos, resultaron informativos para la separación de especies.Seed morphology and anatomy of the seed coat in five species of Calliandra (Leguminosae-Mimosoideae from Venezuela. Calliandra is an exclusively Neotropoical genus with 135 described species. There are 30 species in Venezuela. We studied seed morphology and the seed coat anatomy of five species: Calliandra riparia Pittier, Calliandra glomerulata Karsten var. glomerulata, Calliandra magdalenae (DC. Benth. var. magdalenae, Calliandra surinamensis Benth. and Calliandra falcata Benth., to establish simililarities and differences amongst taxa for taxonomic characterization. Of the evaluated characters, 10 quantitative characters and 3 qualitative characters were selected as the most informative for the separation of species. Seed morphological characters of taxonomic value are form and size. Thickness of the light line, number of layers and space between the osteosclereids constitute distinctive characters. Rev. Biol. Trop. 56 (3: 1075-1086. Epub 2008 September 30.

Medida de los pesos relativos del coste de la asistencia como efecto de la aplicación retrospectiva de los adjusted clinical groups en atención primaria Measurement of relative cost weights as an effect of the retrospective application of adjusted clinical groups in primary care

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Antoni Sicras-Mainar

2006-03-01

Full Text Available Objetivo: El objeto del estudio es obtener los pesos relativos medios de los costes de la asistencia con la aplicación retrospectiva de los adjusted clinical groups (ACG en población atendida por equipos de atención primaria en situación de práctica clínica habitual. Métodos: Estudio descriptivo de carácter retrospectivo. Fueron incluidos en el estudio todos los pacientes atendidos por 4 equipos de atención primaria durante el año 2003. Las principales mediciones fueron: variables universales (edad y sexo, dependientes (visitas y costes y de casuística o comorbilidad. El modelo de costes para cada paciente se estableció diferenciando los costes fijos y los variables. Se efectuó un análisis de regresión lineal múltiple para la predicción de los modelos. El coste relativo de cada ACG se obtuvo dividiendo el coste medio de cada categoría entre el coste medio de toda la población de referencia. Resultados: El número total de pacientes estudiados fue de 62.311 (intensidad de uso del 76,7%, con una media de 4,8 ± 3,2 episodios y 7,8 ± 7,5 visitas/paciente/año. La distribución de los costes fue de 24.135.236,41 €, el 28,9% fijos. El coste unitario total por visita/año fue de 49,62 ± 24,71 € y el promedio paciente/año de 387,34 ± 145,87 € (pesos relativos de referencia. El poder explicativo de la clasificación ACG fue del 50,1% en las visitas y del 54,9% para los costes totales. Conclusiones: Los ACG se muestran como un aceptable sistema de clasificación de pacientes en situación de práctica clínica habitual. De confirmarse los resultados posibilitarían una mejora en la aplicación práctica de los ACG como una posible herramienta para la gestión clínica en los centros de atención primaria.Objective: The objective of the study is to obtain the cost's relative average weights of the assistance with the retrospective application of the Adjusted Clinical Groups (ACG's in four teams of Primary Care with an attended

Crescimento absoluto e relativo de mudas de maracujazeiro sob biofertilizante e águas salinas Absolute and relative growth of yellow passion seedlings over salines waters and bovine biofertilizer

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Francisco de Oliveira Mesquita

2012-06-01

Full Text Available Um experimento foi conduzido em abrigo telado no DSER/CCA/UFPB, no período de Maio/Julho de 2008, para avaliar os efeitos da salinidade da água de irrigação e do biofertilizante bovino no crescimento das mudas de maracujazeiro-amarelo (Passiflora edulis Sims. Os tratamentos foram distribuídos no DIC e 12 plantas por parcela, com três repetições, usando o arranjo fatorial 5 x 2 x 2, referente aos níveis de salinidade da água de irrigação: 0.5; 1,0; 2,0; 3,0 e 4,0 dS m-1, no solo sem e com biofertilizante bovino, avaliando aos 25 e 65 dias após emergência das plântulas. Determinando a altura de plantas, diâmetro do caule, massa seca da parte aérea, raiz e total. O aumento da salinidade das águas inibiu o crescimento absoluto e relativo das plantas avaliado pela altura, diâmetro do caule, matéria seca da parte aérea, raízes e total, mas, em qualquer situação, com menor intensidade nos tratamentos com o biofertilizante.An experiment was carried out under greenhouse in DSER/CCA/UFPB, in period May-July 2008, Paraiba state, Brazil, in order to evaluate the effects of salinity water irrigation and bovine biofertilizer on inittial growth of passion fruit Passiflora edulis Sims seedlings. The treatments were distributed competed randomized design, with three repetitions, in factorial arrangement 5 x 2 x 2, refering at levels of irrigation water salinity: 0.5; 1.0; 2.0; 3.0 and 4.0 dS m-1, in soil without and with bovine biofertilizer and evaluations made at ages of 25 and 65 days after seedling emergence. For assessing growth the plants’s height, stem diameter, dry matter of the part aerea, roots and dry matter total of the yellow passion fruit plants, but in every condition with low intensity in treatment with bovine biofertilizer.

Laser melting treatment of Ni-P surface alloys on mild steel. Influence of initial coating thickness and laser scanning rate

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García-Alonso, M. C.

1997-08-01

Full Text Available Different thickness Ni-P coatings deposited on mild steel are submitted to laser surface melting at different scanning rates. The microstructure of the alloys is characterized by optical and scanning electron microscopy and microprobe analysis. It is shown that both the initial coating thickness and the laser scanning rate have an influence on the shape, extent and size of the different structures resulting from the solidification process. Thus, when the laser scanning rate increases a progressive refinement of the structure takes place that could even totally block the dendritic growth produced during solidification for a high initial coating thickness.

Recubrimientos de Ni-P, con distinto espesor, depositados sobre un acero microaleado fueron tratados con láser a diferentes velocidades de barrido. La microestructura, tanto del recubrimiento como del acero base, ha sido caracterizada por microscopía óptica y electrónica y por microanálisis. En el proceso de solidificación se han obtenido distintas estructuras que varían en cuanto a la forma, extensión y tamaño dependiendo del espesor inicial de recubrimiento y de la velocidad de barrido del haz láser. A medida que la velocidad del haz aumenta, se produce un refinamiento progresivo de la microestructura dendrítica y, en casos extremos de alto espesor de recubrimiento y velocidades grandes, este crecimiento dendrítico se bloquea.

The temporo-parietal junction contributes to global gestalt perception—evidence from studies in chess experts

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Rennig, Johannes; Bilalić, Merim; Huberle, Elisabeth; Karnath, Hans-Otto; Himmelbach, Marc

2013-01-01

In a recent neuroimaging study the comparison of intact vs. disturbed perception of global gestalt indicated a significant role of the temporo-parietal junction (TPJ) in the intact perception of global gestalt (Huberle and Karnath, 2012). This location corresponded well with the areas known to be damaged or impaired in patients with simultanagnosia after stroke or due to neurodegenerative diseases. It was concluded that the TPJ plays an important role in the integration of individual items to a holistic percept. Thus, increased BOLD signals should be found in this region whenever a task calls for the integration of multiple visual items. Behavioral experiments in chess experts suggested that their superior skills in comparison to chess novices are partly based on fast holistic processing of chess positions with multiple pieces. We thus analyzed BOLD data from four fMRI studies that compared chess experts with chess novices during the presentation of complex chess-related visual stimuli (Bilalić et al., 2010, 2011a,b, 2012). Three regions of interests were defined by significant TPJ clusters in the abovementioned study of global gestalt perception (Huberle and Karnath, 2012) and BOLD signal amplitudes in these regions were compared between chess experts and novices. These cross-paradigm ROI analyses revealed higher signals at the TPJ in chess experts in comparison to novices during presentations of complex chess positions. This difference was consistent across the different tasks in five independent experiments. Our results confirm the assumption that the TPJ region identified in previous work on global gestalt perception plays an important role in the processing of complex visual stimulus configurations. PMID:24009574

The temporo-parietal junction contributes to global gestalt perception-evidence from studies in chess experts.

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Rennig, Johannes; Bilalić, Merim; Huberle, Elisabeth; Karnath, Hans-Otto; Himmelbach, Marc

2013-01-01

In a recent neuroimaging study the comparison of intact vs. disturbed perception of global gestalt indicated a significant role of the temporo-parietal junction (TPJ) in the intact perception of global gestalt (Huberle and Karnath, 2012). This location corresponded well with the areas known to be damaged or impaired in patients with simultanagnosia after stroke or due to neurodegenerative diseases. It was concluded that the TPJ plays an important role in the integration of individual items to a holistic percept. Thus, increased BOLD signals should be found in this region whenever a task calls for the integration of multiple visual items. Behavioral experiments in chess experts suggested that their superior skills in comparison to chess novices are partly based on fast holistic processing of chess positions with multiple pieces. We thus analyzed BOLD data from four fMRI studies that compared chess experts with chess novices during the presentation of complex chess-related visual stimuli (Bilalić et al., 2010, 2011a,b, 2012). Three regions of interests were defined by significant TPJ clusters in the abovementioned study of global gestalt perception (Huberle and Karnath, 2012) and BOLD signal amplitudes in these regions were compared between chess experts and novices. These cross-paradigm ROI analyses revealed higher signals at the TPJ in chess experts in comparison to novices during presentations of complex chess positions. This difference was consistent across the different tasks in five independent experiments. Our results confirm the assumption that the TPJ region identified in previous work on global gestalt perception plays an important role in the processing of complex visual stimulus configurations.

Attention and alcohol cues: a role for medial parietal cortex and shifting away from alcohol features?

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Thomas Edward Gladwin

2013-12-01

Full Text Available Attention plays a central role in theories of alcohol dependence; however, its precise role in alcohol-related biases is not yet clear. In the current study, social drinkers performed a spatial cueing task designed to evoke conflict between automatic processes due to incentive salience and control exerted to follow task-related goals. Such conflict is a potentially important task feature from the perspective of dual-process models of addiction. Subjects received instructions either to direct their attention towards pictures of alcoholic beverages, and away from non-alcohol beverages; or to direct their attention towards pictures of non-alcoholic beverages, and away from alcohol beverages. A probe stimulus was likely to appear at the attended location, so that both spatial and non-spatial interference was possible. Activation in medial parietal cortex was found during Approach Alcohol versus Avoid Alcohol blocks. This region is associated with the, possibly automatic, shifting of attention between stimulus features, suggesting that subjects may have shifted attention away from certain features of alcoholic cues when attention had to be directed towards an upcoming stimulus at their location. Further, activation in voxels close to this region was negatively correlated with riskier drinking behavior. A tentative interpretation of the results is that risky drinking may be associated with a reduced tendency to shift attention away from potentially distracting task-irrelevant alcohol cues. The results suggest novel hypotheses and directions for future study, in particular towards the potential therapeutic use of training the ability to shifting attention away from alcohol-related stimulus features.

Temporo-parietal dysfunction in Tourette syndrome: Insights from an fMRI study of Theory of Mind.

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Eddy, Clare M; Cavanna, Andrea E; Rickards, Hugh E; Hansen, Peter C

2016-10-01

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by tics, repetitive movements and vocalizations which are prompted by a sensory-cognitive premonitory urge. Complex tics include environmentally dependent social behaviors such as echoing of other people's speech and actions. Recent studies have suggested that adults with TS can show differences to controls in Theory of Mind (ToM): reasoning about mental states (e.g. beliefs, emotions). In this study, twenty-five adults with uncomplicated TS (no co-morbid disorders, moderate tic severity), and twenty-five healthy age and gender matched controls were scanned with fMRI during an established ToM task. Neural activity was contrasted across ToM trials involving reasoning about false-belief, and matched trials requiring judgments about physical states rather than mental states. Contrasting task conditions uncovered differential fMRI activation in TS during ToM involving the right temporo-parietal junction (TPJ), right amygdala and posterior cingulate. Further analysis revealed that activity within the right TPJ as localised by this task covaried with the severity of symptoms including echophenomena, impulse control problems and premonitory urges in TS. Amygdala activation was also linked to premonitory urges, while activity in the left TPJ during ToM was linked to ratings of non-obscene socially inappropriate symptoms. These findings indicate that patients with TS exhibit atypical functional activation within key neural substrates involved in ToM. More generally, our data could highlight an important role for TPJ dysfunction in driving compulsive behaviors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Laminar thickness alterations in the fronto-parietal cortical mantle of patients with attention-deficit/hyperactivity disorder.

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Elseline Hoekzema

Full Text Available Although Attention-Deficit/Hyperactivity Disorder (ADHD was initially regarded as a disorder exclusive to childhood, nowadays its prevalence in adulthood is well established. The development of novel techniques for quantifying the thickness of the cerebral mantle allows the further exploration of the neuroanatomical profiles underlying the child and adult form of the disorder. To examine the cortical mantle in children and adults with ADHD, we applied a vertex-wise analysis of cortical thickness to anatomical brain MRI scans acquired from children with (n = 43 and without ADHD (n = 41, as well as a group of adult neurotypical individuals (n = 31, adult patients with a history of stimulant treatment (n = 31 and medication-naïve adults with ADHD (n = 24. We observed several clusters of reduced laminar cortical thickness in ADHD patients in comparison to neurotypical individuals. These differences were primarily located in the dorsal attention network, including the bilateral inferior and superior parietal cortex and a section of the frontal cortex (centered on the superior frontal and precentral gyrus bilaterally. Further laminar thickness deficits were observed in the bilateral orbitofrontal cortex and medial occipital cortex. The deficits in the cortical surface were especially pronounced in the child sample, while adult patients showed a more typical laminar thickness across the cerebral mantle. These findings show that the neuroanatomical profile of ADHD, especially the childhood form of the disorder, involves robust alterations in the cortical mantle, which are most prominent in brain regions subserving attentional processing.

[Functional mapping using subdural electrodes combined with monitoring during awake craniotomy enabled preservation of function and extensive resection of a glioma adjacent to the parietal lobe language sites: a case report].

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Takebayashi, Kento; Saito, Taiichi; Nitta, Masayuki; Tamura, Manabu; Maruyama, Takashi; Muragaki, Yoshihiro; Okada, Yoshikazu

2015-01-01

Surgical resection of gliomas located in the dominant parietal lobe is difficult because this lesion is surrounded by multiple functional areas. Although functional mapping during awake craniotomy is very useful for resection of gliomas adjacent to eloquent areas, the limited time available makes it difficult to sufficiently evaluate multiple functions, such as language, calculative ability, distinction of right and left sides, and finger recognition. Here, we report a case of anaplastic oligodendroglioma, which was successfully treated with a combination of functional mapping using subdural electrodes and monitoring under awake craniotomy for glioma. A 32-year-old man presented with generalized seizure. Magnetic resonance imaging revealed a non-enhanced tumor in the left angular and supramarginal gyri. In addition, the tumor showed high accumulation on 11C-methionine positron emission tomography(PET)(tumor/normal brain tissue ratio=3.20). Preparatory mapping using subdural electrodes showed absence of brain function on the tumor lesion. Surgical removal was performed using cortical mapping during awake craniotomy with an updated navigation system using intraoperative magnetic resonance imaging(MRI). The tumor was resected until aphasia was detected by functional monitoring, and the extent of tumor resection was 93%. The patient showed transient transcortical aphasia and Gerstmann's syndrome after surgery but eventually recovered. The pathological diagnosis was anaplastic oligodendroglioma, and the patient was administered chemo-radiotherapy. The patient has been progression free for more than 2 years. The combination of subdural electrode mapping and monitoring during awake craniotomy is useful in order to achieve preservation of function and extensive resection for gliomas in the dominant parietal lobe.

Relação entre fator de condição relativo (Kn e abundância de ectoparasitos de brânquias, em duas espécies de ciclídeos da bacia do rio Paraná, Brasil = Relation between the relative condition factor (Kn and the abundance of gill ectoparasites in two species of cichlids from the Paraná river basin, Brazil

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Fábio Hideki Yamada

2008-04-01

Full Text Available Foram analisados 33 espécimes de Satanoperca pappaterra, capturados entre março de 2004 e junho de 2005, na planície de inundação do alto rio Paraná e 33 espécimes de Crenicichla niederleinii, capturados entre novembro de 2005 e novembro de 2006, no reservatório de Itaipu. Ambos estavam parasitados por monogenéticos, pertencentes ao gênero Sciadicleithrum e por metacercárias de Ascocotyle sp. O fator de condição relativo (Kn não diferiu significativamente entre indivíduos parasitados e não-parasitados das duas espécies de hospedeiros. Apenas Sciadicleithrum sp.1 parasito de S. pappaterra apresentou correlação positiva e significativa entre o fator de condição relativo (Kn e a abundância de parasitismo. Por outro lado, Ascocotyle sp. de ambos os hospedeiros e Sciadicleithrum sp.2parasito de C. niederleinii não apresentaram correlações entre o Kn e a abundância de parasitismo.The study analyzed 33 specimens of Satanoperca pappaterra, captured from the Upper Paraná River floodplain between March 2004 and June of 2005, and 33 specimens of Crenicichla niederleinii captured from the Itaipu Reservoir between November 2005 and November 2006. Both were parasitized by monogeneans pertaining to the genus Sciadicleithrum and by metacercariae of Ascocotyle sp. The relative condition factor (Kn did not differ significantly between parasitized and unparasitized individuals from the two host species. Only Sciadicleithrum sp.1, parasite of S. pappaterra, presented positive and significant correlation between the relative condition factor (Kn and the abundance of parasitism. On the other hand, Ascocotyle sp. in both hosts and Sciadicleithrum sp.2 parasite of C. niederleiniidid not present correlations between the Kn and the abundance of parasitism.

Disturbance of visual search by stimulating to posterior parietal cortex in the brain using transcranial magnetic stimulation

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Iramina, Keiji; Ge, Sheng; Hyodo, Akira; Hayami, Takehito; Ueno, Shoogo

2009-04-01

In this study, we applied a transcranial magnetic stimulation (TMS) to investigate the temporal aspect for the functional processing of visual attention. Although it has been known that right posterior parietal cortex (PPC) in the brain has a role in certain visual search tasks, there is little knowledge about the temporal aspect of this area. Three visual search tasks that have different difficulties of task execution individually were carried out. These three visual search tasks are the "easy feature task," the "hard feature task," and the "conjunction task." To investigate the temporal aspect of the PPC involved in the visual search, we applied various stimulus onset asynchronies (SOAs) and measured the reaction time of the visual search. The magnetic stimulation was applied on the right PPC or the left PPC by the figure-eight coil. The results show that the reaction times of the hard feature task are longer than those of the easy feature task. When SOA=150 ms, compared with no-TMS condition, there was a significant increase in target-present reaction time when TMS pulses were applied. We considered that the right PPC was involved in the visual search at about SOA=150 ms after visual stimulus presentation. The magnetic stimulation to the right PPC disturbed the processing of the visual search. However, the magnetic stimulation to the left PPC gives no effect on the processing of the visual search.