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Sample records for cortex multiple forms

  1. Medial prefrontal cortex subserves diverse forms of self-reflection.

    Science.gov (United States)

    Jenkins, Adrianna C; Mitchell, Jason P

    2011-01-01

    The ability to think about oneself--to self--reflect--is one of the defining features of the human mind. Recent research has suggested that this ability may be subserved by a particular brain region: the medial prefrontal cortex (MPFC). However, although humans can contemplate a variety of different aspects of themselves, including their stable personality traits, current feelings, and physical attributes, no research has directly examined the extent to which these different forms of self-reflection are subserved by common mechanisms. To address this question, participants were scanned using functional magnetic resonance imaging (fMRI) while making judgments about their own personality traits, current mental states, and physical attributes as well as those of another person. Whereas some brain regions responded preferentially during only one form of self-reflection, a robust region of MPFC was engaged preferentially during self-reflection across all three types of judgment. These results suggest that--although dissociable--diverse forms of self-referential thought draw on a shared cognitive process subserved by MPFC.

  2. Multiple time scales of adaptation in auditory cortex neurons.

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    Ulanovsky, Nachum; Las, Liora; Farkas, Dina; Nelken, Israel

    2004-11-17

    Neurons in primary auditory cortex (A1) of cats show strong stimulus-specific adaptation (SSA). In probabilistic settings, in which one stimulus is common and another is rare, responses to common sounds adapt more strongly than responses to rare sounds. This SSA could be a correlate of auditory sensory memory at the level of single A1 neurons. Here we studied adaptation in A1 neurons, using three different probabilistic designs. We showed that SSA has several time scales concurrently, spanning many orders of magnitude, from hundreds of milliseconds to tens of seconds. Similar time scales are known for the auditory memory span of humans, as measured both psychophysically and using evoked potentials. A simple model, with linear dependence on both short-term and long-term stimulus history, provided a good fit to A1 responses. Auditory thalamus neurons did not show SSA, and their responses were poorly fitted by the same model. In addition, SSA increased the proportion of failures in the responses of A1 neurons to the adapting stimulus. Finally, SSA caused a bias in the neuronal responses to unbiased stimuli, enhancing the responses to eccentric stimuli. Therefore, we propose that a major function of SSA in A1 neurons is to encode auditory sensory memory on multiple time scales. This SSA might play a role in stream segregation and in binding of auditory objects over many time scales, a property that is crucial for processing of natural auditory scenes in cats and of speech and music in humans.

  3. Multiple running speed signals in medial entorhinal cortex

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    Hinman, James R.; Brandon, Mark P.; Climer, Jason R.; Chapman, G. William; Hasselmo, Michael E.

    2016-01-01

    Grid cells in medial entorhinal cortex (MEC) can be modeled using oscillatory interference or attractor dynamic mechanisms that perform path integration, a computation requiring information about running direction and speed. The two classes of computational models often use either an oscillatory frequency or a firing rate that increases as a function of running speed. Yet it is currently not known whether these are two manifestations of the same speed signal or dissociable signals with potentially different anatomical substrates. We examined coding of running speed in MEC and identified these two speed signals to be independent of each other within individual neurons. The medial septum (MS) is strongly linked to locomotor behavior and removal of MS input resulted in strengthening of the firing rate speed signal, while decreasing the strength of the oscillatory speed signal. Thus two speed signals are present in MEC that are differentially affected by disrupted MS input. PMID:27427460

  4. A precise form of divisive suppression supports population coding in the primary visual cortex.

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    MacEvoy, Sean P; Tucker, Thomas R; Fitzpatrick, David

    2009-05-01

    The responses of neurons in the primary visual cortex (V1) to an optimally oriented grating are suppressed when a non-optimal grating is superimposed. Although cross-orientation suppression is thought to reflect mechanisms that maintain a distributed code for orientation, the effect of superimposed gratings on V1 population responses is unknown. Using intrinsic signal optical imaging, we found that patterns of tree shrew V1 activity evoked by superimposed equal-contrast gratings were predicted by the averages of patterns evoked by individual component gratings. This prediction held across contrasts, for summed sinusoidal gratings or nonsumming square-wave gratings, and was evident in single-unit extracellular recordings. Intracellular recordings revealed consistent levels of suppression throughout the time course of subthreshold responses. These results indicate that divisive suppression powerfully governs population responses to multiple orientations. Moreover, the specific form of suppression that we observed appears to support independent population codes for stimulus orientation and strength and calls for a reassessment of mechanisms that underlie cross-orientation suppression.

  5. Structural and functional changes across the visual cortex of a patient with visual form agnosia.

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    Bridge, Holly; Thomas, Owen M; Minini, Loredana; Cavina-Pratesi, Cristiana; Milner, A David; Parker, Andrew J

    2013-07-31

    Loss of shape recognition in visual-form agnosia occurs without equivalent losses in the use of vision to guide actions, providing support for the hypothesis of two visual systems (for "perception" and "action"). The human individual DF received a toxic exposure to carbon monoxide some years ago, which resulted in a persisting visual-form agnosia that has been extensively characterized at the behavioral level. We conducted a detailed high-resolution MRI study of DF's cortex, combining structural and functional measurements. We present the first accurate quantification of the changes in thickness across DF's occipital cortex, finding the most substantial loss in the lateral occipital cortex (LOC). There are reduced white matter connections between LOC and other areas. Functional measures show pockets of activity that survive within structurally damaged areas. The topographic mapping of visual areas showed that ordered retinotopic maps were evident for DF in the ventral portions of visual cortical areas V1, V2, V3, and hV4. Although V1 shows evidence of topographic order in its dorsal portion, such maps could not be found in the dorsal parts of V2 and V3. We conclude that it is not possible to understand fully the deficits in object perception in visual-form agnosia without the exploitation of both structural and functional measurements. Our results also highlight for DF the cortical routes through which visual information is able to pass to support her well-documented abilities to use visual information to guide actions.

  6. Auditory Cortex tACS and tRNS for Tinnitus: Single versus Multiple Sessions

    Directory of Open Access Journals (Sweden)

    Laura Claes

    2014-01-01

    Full Text Available Tinnitus is the perception of a sound in the absence of an external acoustic source, which often exerts a significant impact on the quality of life. Currently there is evidence that neuroplastic changes in both neural pathways are involved in the generation and maintaining of tinnitus. Neuromodulation has been suggested to interfere with these neuroplastic alterations. In this study we aimed to compare the effect of two upcoming forms of transcranial electrical neuromodulation: alternating current stimulation (tACS and random noise stimulation (tRNS, both applied on the auditory cortex. A database with 228 patients with chronic tinnitus who underwent noninvasive neuromodulation was retrospectively analyzed. The results of this study show that a single session of tRNS induces a significant suppressive effect on tinnitus loudness and distress, in contrast to tACS. Multiple sessions of tRNS augment the suppressive effect on tinnitus loudness but have no effect on tinnitus distress. In conclusion this preliminary study shows a possibly beneficial effect of tRNS on tinnitus and can be a motivation for future randomized placebo-controlled clinical studies with auditory tRNS for tinnitus. Auditory alpha-modulated tACS does not seem to be contributing to the treatment of tinnitus.

  7. Manifold free multiple sheet superplastic forming

    Science.gov (United States)

    Elmer, John W.; Bridges, Robert L.

    2004-01-13

    Fluid-forming compositions in a container attached to enclosed adjacent sheets are heated to relatively high temperatures to generate fluids (gases) that effect inflation of the sheets. Fluid rates to the enclosed space between the sheets can be regulated by the canal from the container. Inflated articles can be produced by a continuous, rather than batch-type, process.

  8. Temporal Sequence of Visuo-Auditory Interaction in Multiple Areas of the Guinea Pig Visual Cortex

    Science.gov (United States)

    Nishimura, Masataka; Song, Wen-Jie

    2012-01-01

    Recent studies in humans and monkeys have reported that acoustic stimulation influences visual responses in the primary visual cortex (V1). Such influences can be generated in V1, either by direct auditory projections or by feedback projections from extrastriate cortices. To test these hypotheses, cortical activities were recorded using optical imaging at a high spatiotemporal resolution from multiple areas of the guinea pig visual cortex, to visual and/or acoustic stimulations. Visuo-auditory interactions were evaluated according to differences between responses evoked by combined auditory and visual stimulation, and the sum of responses evoked by separate visual and auditory stimulations. Simultaneous presentation of visual and acoustic stimulations resulted in significant interactions in V1, which occurred earlier than in other visual areas. When acoustic stimulation preceded visual stimulation, significant visuo-auditory interactions were detected only in V1. These results suggest that V1 is a cortical origin of visuo-auditory interaction. PMID:23029483

  9. Multiple functional attributes of glucose-monitoring neurons in the medial orbitofrontal (ventrolateral prefrontal) cortex.

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    Szabó, István; Hormay, Edina; Csetényi, Bettina; Nagy, Bernadett; Lénárd, László; Karádi, Zoltán

    2018-02-01

    Multiple functional attributes of glucose-monitoring neurons in the medial orbitofrontal (ventrolateral prefrontal) cortex. NEUROSCI BIOBEHAV REV 73(1) XXX-XXX, 2017.- Special chemosensory cells, the glucose-monitoring (GM) neurons, reportedly involved in the central feeding control, exist in the medial orbitofrontal (ventrolateral prefrontal) cortex (mVLPFC). Electrophysiological, metabolic and behavioral studies reveal complex functional attributes of these cells and raise their homeostatic significance. Single neuron recordings, by means of the multibarreled microelectrophoretic technique, elucidate differential sensitivities of limbic forebrain neurons in the rat and the rhesus monkey to glucose and other chemicals, whereas gustatory stimulations demonstrate their distinct taste responsiveness. Metabolic examinations provide evidence for alteration of blood glucose level in glucose tolerance test and elevation of plasma triglyceride concentration after destruction of the local GM cells by streptozotocin (STZ). In behavioral studies, STZ microinjection into the mVLPFC fails to interfere with the acquisition of saccharin conditioned taste avoidance, does cause, however, taste perception deficit in taste reactivity tests. Multiple functional attributes of GM neurons in the mVLPFC, within the frame of the hierarchically organized central GM neuronal network, appear to play important role in the maintenance of the homeostatic balance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Resting‐state connectivity of pre‐motor cortex reflects disability in multiple sclerosis

    DEFF Research Database (Denmark)

    Dogonowski, Anne-Marie; Siebner, Hartwig Roman; Soelberg Sørensen, P.

    2013-01-01

    Objective To characterize the relationship between motor resting-state connectivity of the dorsal pre-motor cortex (PMd) and clinical disability in patients with multiple sclerosis (MS). Materials and methods A total of 27 patients with relapsing–remitting MS (RR-MS) and 15 patients with secondary...... progressive MS (SP-MS) underwent functional resting-state magnetic resonance imaging. Clinical disability was assessed using the Expanded Disability Status Scale (EDSS). Independent component analysis was used to characterize motor resting-state connectivity. Multiple regression analysis was performed in SPM8...... between the individual expression of motor resting-state connectivity in PMd and EDSS scores including age as covariate. Separate post hoc analyses were performed for patients with RR-MS and SP-MS. Results The EDSS scores ranged from 0 to 7 with a median score of 4.3. Motor resting-state connectivity...

  11. Blocking the eIF2α kinase (PKR) enhances positive and negative forms of cortex-dependent taste memory.

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    Stern, Elad; Chinnakkaruppan, Adaikkan; David, Orit; Sonenberg, Nahum; Rosenblum, Kobi

    2013-02-06

    Age-associated memory deterioration (and the decline in ability to acquire new information) is one of the major diseases of our era. Cognitive enhancement can be achieved by using psycho-stimulants, such as caffeine or nicotine, but very little is known about drugs that can enhance the consolidation phase of memories in the cortex, the brain structure considered to store, at least partially, long-term memories. We used cortex-dependent taste-learning paradigms to test the hypothesis that pharmacological manipulation of the translation initiation eIF2α, which plays a role in hippocampus-dependent memory, can enhance positive or negative forms of taste memories. We found that dephosphorylation (Ser51) of eIF2α, specifically in the cortex, is both correlated with and necessary for normal memory consolidation. To reduce eIF2α phosphorylation and improve memory consolidation, we pharmacologically inhibited one of the eIF2α kinases, PKR, which is known to be involved in brain aging and Alzheimer's disease. Systemic or local microinjection of PKR inhibitor to the gustatory cortex enhanced both positive and negative forms of taste memory in rats and mice. Our results provide clear evidence that PKR plays a major role in cortex-dependent memory consolidation and, therefore, that pharmacological inhibition of PKR is a potential target for drugs to enhance cognition.

  12. Acute form of multiple sclerosis in a child simulation encephalitis

    International Nuclear Information System (INIS)

    Niagolova, S.; Karapasheva, V.; Nikolova, M.

    2007-01-01

    Multiple sclerosis (MS) is considered the most common demyelinating process involving the CNS. Although usually considered an adult disease multiple sclerosis can begin to manifest during childhood. The clinical presentation of the disease in early childhood can range from paraesthesias to dramatic presentations, suggesting diffuse encephalopathy with cerebral oedema, meningismus and impaired consciousness. Multiple sclerosis is usually characterized by a typical relapsing-remitting clinical course. But there are acute, clinically fulminant forms with atypical. neurologic symptoms and death in months. MRI has become increasingly relevant in the diagnosis of multiple sclerosis in the past years. Yet, the specificity is limited. Atypical forms of MS and other diseases of CNS may show similar patterns on MRI. We report a case of 7 years old boy with clinically fulminant Marburg type of multiple sclerosis that ended with death in two months. The patient was a diagnostic problem despite the certain degree of clinical and radiological suspicion. The postmortem diagnosis is based on pathomorphologic changes (gross pathologic and microscopic features) in CNS.The present case is of clinical, radiological and pathomorphologic interest because of its early onset in childhood, unusual clinical course and acute progression. Awareness of the MRI features of multiple sclerosis and MS-variants (subtypes) may help in such atypical presentations in childhood. (authors)

  13. Multiple forms of tropoelastin produced by RNA from bovine ligament

    International Nuclear Information System (INIS)

    Parks, W.C.; Wrenn, D.S.; Mecham, R.P.

    1986-01-01

    Tropoelastin is the monomeric precursor protein of elastin, a major connective tissue component. Whether elastin is the product of one of multiple forms of tropoelastin is unknown. Here they provide evidence for three forms of tropoelastin that are the products of unique RNAs. Total RNA was isolated from fetal bovine ligamentum nuchae and used as substrate for cell-free translation in a reticulocyte lysate system. Translated products were immunoprecipitated by a specific monoclonal antibody. Immunoprepitates were analyzed by PAGE-SDS electrophoresis followed by fluorography. When ligament RNA was translated with either [ 3 H] leucine or [ 35 S] cysteine three bands that migrated at 71, 68.7 and 65.2 KD, respectively, were detected. These observations suggest that there are multiple forms of tropoelastin mRNA. Whether these RNA, are the products of different genes or the result of gene splicing remains to be demonstrated

  14. Performance effect of multiple control forms in a Lean organization

    DEFF Research Database (Denmark)

    Kristensen, Thomas Borup; Israelsen, Poul

    2012-01-01

    Over the last decades Lean has developed into a prominent management philosophy reaching beyond shop floor tools. However, substantial support of performance effects from Lean is still scarce and at best with mixed results. Recently, research has turned its focus towards perceiving Lean...... as a control package. In this paper we present statistical support for enhanced performance coming from Lean. Furthermore, our results strongly support the perception of Lean as a set of multiple control forms (output, behavioral, and social controls) that complement each other. Therefore, performance...... is increased if the average level of control forms is increased, and performance is further increased if the control forms are balanced at the same level representing a complementary effect between them. Our data are archival data spanning multiple years in a strong Lean organization. The dependent performance...

  15. [Neuroanatomy of Frontal Association Cortex].

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    Takada, Masahiko

    2016-11-01

    The frontal association cortex is composed of the prefrontal cortex and the motor-related areas except the primary motor cortex (i.e., the so-called higher motor areas), and is well-developed in primates, including humans. The prefrontal cortex receives and integrates large bits of diverse information from the parietal, temporal, and occipital association cortical areas (termed the posterior association cortex), and paralimbic association cortical areas. This information is then transmitted to the primary motor cortex via multiple motor-related areas. Given these facts, it is likely that the prefrontal cortex exerts executive functions for behavioral control. The functional input pathways from the posterior and paralimbic association cortical areas to the prefrontal cortex are classified primarily into six groups. Cognitive signals derived from the prefrontal cortex are conveyed to the rostral motor-related areas to transform them into motor signals, which finally enter the primary motor cortex via the caudal motor-related areas. Furthermore, it has been shown that, similar to the primary motor cortex, areas of the frontal association cortex form individual networks (known as "loop circuits") with the basal ganglia and cerebellum via the thalamus, and hence are extensively involved in the expression and control of behavioral actions.

  16. Enhanced peripheral visual processing in congenitally deaf humans is supported by multiple brain regions, including primary auditory cortex

    Directory of Open Access Journals (Sweden)

    Gregory D. Scott

    2014-03-01

    Full Text Available Brain reorganization associated with altered sensory experience clarifies the critical role of neuroplasticity in development. An example is enhanced peripheral visual processing associated with congenital deafness, but the neural systems supporting this have not been fully characterized. A gap in our understanding of deafness-enhanced peripheral vision is the contribution of primary auditory cortex. Previous studies of auditory cortex that use anatomical normalization across participants were limited by inter-subject variability of Heschl’s gyrus. In addition to reorganized auditory cortex (cross-modal plasticity, a second gap in our understanding is the contribution of altered modality-specific cortices (visual intramodal plasticity in this case, as well as supramodal and multisensory cortices, especially when target detection is required across contrasts. Here we address these gaps by comparing fMRI signal change for peripheral versus perifoveal visual stimulation (11-15° vs. 2°-7° in congenitally deaf and hearing participants in a blocked experimental design with two analytical approaches: a Heschl’s gyrus region of interest analysis and a whole brain analysis. Our results using individually-defined primary auditory cortex (Heschl’s gyrus indicate that fMRI signal change for more peripheral stimuli was greater than perifoveal in deaf but not in hearing participants. Whole-brain analyses revealed differences between deaf and hearing participants for peripheral versus perifoveal visual processing in extrastriate visual cortex including primary auditory cortex, MT+/V5, superior-temporal auditory and multisensory and/or supramodal regions, such as posterior parietal cortex, frontal eye fields, anterior cingulate, and supplementary eye fields. Overall, these data demonstrate the contribution of neuroplasticity in multiple systems including primary auditory cortex, supramodal and multisensory regions, to altered visual processing in

  17. Effect of multiple forming tools on geometrical and mechanical properties in incremental sheet forming

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    Wernicke, S.; Dang, T.; Gies, S.; Tekkaya, A. E.

    2018-05-01

    The tendency to a higher variety of products requires economical manufacturing processes suitable for the production of prototypes and small batches. In the case of complex hollow-shaped parts, single point incremental forming (SPIF) represents a highly flexible process. The flexibility of this process comes along with a very long process time. To decrease the process time, a new incremental forming approach with multiple forming tools is investigated. The influence of two incremental forming tools on the resulting mechanical and geometrical component properties compared to SPIF is presented. Sheets made of EN AW-1050A were formed to frustums of a pyramid using different tool-path strategies. Furthermore, several variations of the tool-path strategy are analyzed. A time saving between 40% and 60% was observed depending on the tool-path and the radii of the forming tools while the mechanical properties remained unchanged. This knowledge can increase the cost efficiency of incremental forming processes.

  18. Resting-state connectivity of pre-motor cortex reflects disability in multiple sclerosis.

    Science.gov (United States)

    Dogonowski, A-M; Siebner, H R; Soelberg Sørensen, P; Paulson, O B; Dyrby, T B; Blinkenberg, M; Madsen, K H

    2013-11-01

    To characterize the relationship between motor resting-state connectivity of the dorsal pre-motor cortex (PMd) and clinical disability in patients with multiple sclerosis (MS). A total of 27 patients with relapsing-remitting MS (RR-MS) and 15 patients with secondary progressive MS (SP-MS) underwent functional resting-state magnetic resonance imaging. Clinical disability was assessed using the Expanded Disability Status Scale (EDSS). Independent component analysis was used to characterize motor resting-state connectivity. Multiple regression analysis was performed in SPM8 between the individual expression of motor resting-state connectivity in PMd and EDSS scores including age as covariate. Separate post hoc analyses were performed for patients with RR-MS and SP-MS. The EDSS scores ranged from 0 to 7 with a median score of 4.3. Motor resting-state connectivity of left PMd showed a positive linear relation with clinical disability in patients with MS. This effect was stronger when considering the group of patients with RR-MS alone, whereas patients with SP-MS showed no increase in coupling strength between left PMd and the motor resting-state network with increasing clinical disability. No significant relation between motor resting-state connectivity of the right PMd and clinical disability was detected in MS. The increase in functional coupling between left PMd and the motor resting-state network with increasing clinical disability can be interpreted as adaptive reorganization of the motor system to maintain motor function, which appears to be limited to the relapsing-remitting stage of the disease. © 2013 John Wiley & Sons A/S.

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

    Science.gov (United States)

    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…

  20. Plasma Biomarkers Discriminate Clinical Forms of Multiple Sclerosis

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    Tejera-Alhambra, Marta; Casrouge, Armanda; de Andrés, Clara; Seyfferth, Ansgar; Ramos-Medina, Rocío; Alonso, Bárbara; Vega, Janet; Fernández-Paredes, Lidia; Albert, Matthew L.; Sánchez-Ramón, Silvia

    2015-01-01

    Multiple sclerosis, the most common cause of neurological disability in young population after trauma, represents a significant public health burden. Current challenges associated with management of multiple sclerosis (MS) patients stem from the lack of biomarkers that might enable stratification of the different clinical forms of MS and thus prompt treatment for those patients with progressive MS, for whom there is currently no therapy available. In the present work we analyzed a set of thirty different plasma cytokines, chemokines and growth factors present in circulation of 129 MS patients with different clinical forms (relapsing remitting, secondary progressive and primary progressive MS) and 53 healthy controls, across two independent cohorts. The set of plasma analytes was quantified with Luminex xMAP technology and their predictive power regarding clinical outcome was evaluated both individually using ROC curves and in combination using logistic regression analysis. Our results from two independent cohorts of MS patients demonstrate that the divergent clinical and histology-based MS forms are associated with distinct profiles of circulating plasma protein biomarkers, with distinct signatures being composed of chemokines and growth/angiogenic factors. With this work, we propose that an evaluation of a set of 4 circulating biomarkers (HGF, Eotaxin/CCL11, EGF and MIP-1β/CCL4) in MS patients might serve as an effective tool in the diagnosis and more personalized therapeutic targeting of MS patients. PMID:26039252

  1. Managing Multiple Forms of Employment in the Construction Sector

    DEFF Research Database (Denmark)

    Raja, Jawwad; D. Green, Stuart; Leiringer, Roine

    2013-01-01

    different contracting arrangements impinge on attempts to reposition human resource management (HRM) as a strategic function along the business partnering model. Elevating the role of the HR function is found to be difficult to reconcile with the concurrent demands of managing multiple forms of employment......The construction industry is one of the largest and most complex industrial sectors in the UK. The industry's failure to adopt progressive human resource (HR) practices is routinely blamed on the challenges of operating in a fragmented, project-based environment reliant on subcontracting...

  2. Expressions of multiple neuronal dynamics during sensorimotor learning in the motor cortex of behaving monkeys.

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    Yael Mandelblat-Cerf

    Full Text Available Previous studies support the notion that sensorimotor learning involves multiple processes. We investigated the neuronal basis of these processes by recording single-unit activity in motor cortex of non-human primates (Macaca fascicularis, during adaptation to force-field perturbations. Perturbed trials (reaching to one direction were practiced along with unperturbed trials (to other directions. The number of perturbed trials relative to the unperturbed ones was either low or high, in two separate practice schedules. Unsurprisingly, practice under high-rate resulted in faster learning with more pronounced generalization, as compared to the low-rate practice. However, generalization and retention of behavioral and neuronal effects following practice in high-rate were less stable; namely, the faster learning was forgotten faster. We examined two subgroups of cells and showed that, during learning, the changes in firing-rate in one subgroup depended on the number of practiced trials, but not on time. In contrast, changes in the second subgroup depended on time and practice; the changes in firing-rate, following the same number of perturbed trials, were larger under high-rate than low-rate learning. After learning, the neuronal changes gradually decayed. In the first subgroup, the decay pace did not depend on the practice rate, whereas in the second subgroup, the decay pace was greater following high-rate practice. This group shows neuronal representation that mirrors the behavioral performance, evolving faster but also decaying faster at learning under high-rate, as compared to low-rate. The results suggest that the stability of a new learned skill and its neuronal representation are affected by the acquisition schedule.

  3. Cytokine profiling in the prefrontal cortex of Parkinson's Disease and Multiple System Atrophy patients.

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    Rydbirk, Rasmus; Elfving, Betina; Andersen, Mille Dahl; Langbøl, Mia Aggergaard; Folke, Jonas; Winge, Kristian; Pakkenberg, Bente; Brudek, Tomasz; Aznar, Susana

    2017-10-01

    Parkinson's Disease (PD) and Multiple System Atrophy (MSA) are neurodegenerative diseases characterized neuropathologically by alpha-synuclein accumulation in brain cells. This accumulation is hypothesized to contribute to constitutive neuroinflammation, and to participate in the neurodegeneration. Cytokines, which are the main inflammatory signalling molecules, have been identified in blood and cerebrospinal fluid of PD patients, but studies investigating the human brain levels are scarce. It is documented that neurotrophins, necessary for survival of brain cells and known to interact with cytokines, are altered in the basal ganglia of PD patients. In regards to MSA, no major study has investigated brain cytokine or neurotrophin protein expression. Here, we measured protein levels of 18 cytokines (IL-2, 4-8, 10, 12, 13, 17, G-CSF, GM-CSF, IFN-γ, MCP-1, MIP-1α and 1β, TNF-α) and 5 neurotrophins (BDNF, GDNF, bFGF, PDGF-BB, VEGF) in the dorsomedial prefrontal cortex in brains of MSA and PD patients and control subjects. We found altered expression of IL-2, IL-13, and G-CSF, but no differences in neurotrophin levels. Further, in MSA patients we identified increased mRNA levels of GSK3β that is involved in neuroinflammatory pathways. Lastly, we identified increased expression of the neurodegenerative marker S100B, but not CRP, in PD and MSA patients, indicating local rather than systemic inflammation. Supporting this, in both diseases we observed increased MHC class II + and CD45 + positive cells, and low numbers of infiltrating CD3 + cells. In conclusion, we identified neuroinflammatory responses in PD and MSA which seems more widespread in the brain than neurotrophic changes. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Metabolic Changes in the Visual Cortex Are Linked to Retinal Nerve Fiber Layer Thinning in Multiple Sclerosis

    Science.gov (United States)

    Schubert, Florian; Bock, Markus; Walaszek, Bernadeta; Waiczies, Helmar; Schwenteck, Thomas; Dörr, Jan; Bellmann-Strobl, Judith; Mohr, Christian; Weinges-Evers, Nicholetta; Ittermann, Bernd; Wuerfel, Jens T.; Paul, Friedemann

    2011-01-01

    Objective To investigate the damage to the retinal nerve fiber layer as part of the anterior visual pathway as well as an impairment of the neuronal and axonal integrity in the visual cortex as part of the posterior visual pathway with complementary neuroimaging techniques, and to correlate our results to patients' clinical symptoms concerning the visual pathway. Design, Subjects and Methods Survey of 86 patients with relapsing-remitting multiple sclerosis that were subjected to retinal nerve fiber layer thickness (RNFLT) measurement by optical coherence tomography, to a routine MRI scan including the calculation of the brain parenchymal fraction (BPF), and to magnetic resonance spectroscopy at 3 tesla, quantifying N-acetyl aspartate (NAA) concentrations in the visual cortex and normal-appearing white matter. Results RNFLT correlated significantly with BPF and visual cortex NAA, but not with normal-appearing white matter NAA. This was connected with the patients' history of a previous optic neuritis. In a combined model, both BPF and visual cortex NAA were independently associated with RNFLT. Conclusions Our data suggest the existence of functional pathway-specific damage patterns exceeding global neurodegeneration. They suggest a strong interrelationship between damage to the anterior and the posterior visual pathway. PMID:21494672

  5. Megascale rhythmic shoreline forms on a beach with multiple bars

    Directory of Open Access Journals (Sweden)

    Zbigniew Pruszak

    2008-06-01

    Full Text Available The study, carried out in 2003 and 2006 at the Lubiatowo Coastal ResearchStation (Poland, located on the non-tidal southern Baltic coast(tidal range < 0.06 m, focused on larger rhythmic forms (mega-cusps withwavelengths in the interval 500 m > Lc > 20 m. Statistical analyses of detailed shoreline configurations were performed mostly with the Discrete Wavelet Transformmethod (DWT. The beach is composed of fine sand with grain diameter D50 ≈ 0.22 mm, which produces 4 longshore sandbars and a gently sloping seabed with β = 0.015. The analysis confirms the key role of bars in hydro- and morphodynamic surf zone processes.The hypothesis was therefore set up that, in a surf zone with multiple bars, the bars and mega-scale shoreline rhythmic forms form one integrated physical system; experimental evidence to substantiate this hypothesis was also sought.In such a system not only do self-regulation processes include swash zone phenomena, they also incorporate processes in offshore surf zone locations.The longshore dimensions of large cusps are thus related to the distances between periodically active large bed forms (bars. The spatial dimension of bar system activity (number of active bars depends, at a given time scale, on the associated hydrodynamic conditions. It was assumed that such a time scale could include either the development and duration of a storm, or a period of stable, yet distinct waves, capable of remodelling the beach configuration.The indentation to wavelength ratio of mega-cusps for the studied non-tidal dissipative environment may be one order of magnitude greater than for mesotidal, reflective beaches.

  6. Distributed patterns of activity in sensory cortex reflect the precision of multiple items maintained in visual short-term memory.

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    Emrich, Stephen M; Riggall, Adam C; Larocque, Joshua J; Postle, Bradley R

    2013-04-10

    Traditionally, load sensitivity of sustained, elevated activity has been taken as an index of storage for a limited number of items in visual short-term memory (VSTM). Recently, studies have demonstrated that the contents of a single item held in VSTM can be decoded from early visual cortex, despite the fact that these areas do not exhibit elevated, sustained activity. It is unknown, however, whether the patterns of neural activity decoded from sensory cortex change as a function of load, as one would expect from a region storing multiple representations. Here, we use multivoxel pattern analysis to examine the neural representations of VSTM in humans across multiple memory loads. In an important extension of previous findings, our results demonstrate that the contents of VSTM can be decoded from areas that exhibit a transient response to visual stimuli, but not from regions that exhibit elevated, sustained load-sensitive delay-period activity. Moreover, the neural information present in these transiently activated areas decreases significantly with increasing load, indicating load sensitivity of the patterns of activity that support VSTM maintenance. Importantly, the decrease in classification performance as a function of load is correlated with within-subject changes in mnemonic resolution. These findings indicate that distributed patterns of neural activity in putatively sensory visual cortex support the representation and precision of information in VSTM.

  7. Modulation of the Left Prefrontal Cortex with High Frequency Repetitive Transcranial Magnetic Stimulation Facilitates Gait in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Amer M. Burhan

    2015-01-01

    Full Text Available Multiple Sclerosis (MS is a chronic central nervous system (CNS demyelinating disease. Gait abnormalities are common and disabling in patients with MS with limited treatment options available. Emerging evidence suggests a role of prefrontal attention networks in modulating gait. High-frequency repetitive transcranial magnetic stimulation (rTMS is known to enhance cortical excitability in stimulated cortex and its correlates. We investigated the effect of high-frequency left prefrontal rTMS on gait parameters in a 51-year-old Caucasian male with chronic relapsing/remitting MS with residual disabling attention and gait symptoms. Patient received 6 Hz, rTMS at 90% motor threshold using figure of eight coil centered on F3 location (using 10-20 electroencephalography (EEG lead localization system. GAITRite gait analysis system was used to collect objective gait measures before and after one session and in another occasion three consecutive daily sessions of rTMS. Two-tailed within subject repeated measure t-test showed significant enhancement in ambulation time, gait velocity, and cadence after three consecutive daily sessions of rTMS. Modulating left prefrontal cortex excitability using rTMS resulted in significant change in gait parameters after three sessions. To our knowledge, this is the first report that demonstrates the effect of rTMS applied to the prefrontal cortex on gait in MS patients.

  8. Multiple distinct subtypes of GABAergic neurons in mouse visual cortex identified by triple immunostaining

    Directory of Open Access Journals (Sweden)

    Yuri Gonchar

    2008-03-01

    Full Text Available The majority of cortical interneurons use GABA (gamma amino butyric acid as inhibitory neurotransmitter. GABAergic neurons are morphologically, connectionally, electrically and chemically heterogeneous. In rat cerebral cortex three distinct groups of GABAergic interneurons have been identifi ed by the expression of parvalbumin (PV, calretinin (CR and somatostatin (SOM. Recent studies in mouse cerebral cortex have revealed a different organization in which the CR and SOM populations are partially overlapping. Because CR and SOM neurons derive from different progenitors located in different embryonic structures, the coexpression of CR + SOM suggests that the chemical differentiation of interneurons is regulated postmitotically. Here, we have taken an important fi rst step towards understanding this process by triple immunostaining mouse visual cortex with a panel of antibodies, which has been used extensively for classifying developing interneurons. We have found at least 13 distinct groups of GABAergic neurons which include PV, CR, SOM, CCK (cholecystokinin, CR + SOM, CR + NPY (neuropeptide Y, CR + VIP (vasointestinal polypeptide, SOM + NPY, SOM + VIP, VIP + ChAT (choline acetyltransferase, CCK + NPY, CR + SOM + NPY and CR + SOM + VIP expressing cells. Triple immunostaining with PV, CR and SOM antibodies during postnatal development further showed that PV is never colocalized with CR and SOM. Importantly, expression of SOM and CR + SOM developed after the percentage of CR cells that do not express SOM has reached the mature level, suggesting that the chemical differentiation of SOM and CR + SOM neurons is a postnatal event, which may be controlled by transcriptional regulation.

  9. 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).

  10. Seven years of recording from monkey cortex with a chronically implanted multiple microelectrode

    Directory of Open Access Journals (Sweden)

    Jürgen Krüger

    2010-05-01

    Full Text Available A brush of 64 microwires was chronically implanted in the ventral premotor cortex of a macaque monkey. Contrary to common approaches, the wires were inserted from the white matter side. This approach, by avoiding mechanical pressure on the dura and pia mater during penetration, disturbed only minimally the cortical recording site. With this approach isolated potentials and multiunit activity were recorded for more than seven years in about one third of electrodes. The indirect insertion method also provided an excellent stability within each recording session, and in some cases even allowed recording from the same neurons for several years. Histological examination of the implanted brain region shows only a very marginal damage the recording area. Advantages and problems related to long-term recording are discussed.

  11. Multiple molecular forms of pyridinoline crosslinks generated by the ...

    African Journals Online (AJOL)

    molecular forms of pyridinoline crosslinks from insoluble bone type I collagen, and we studied ... resorbed in a dynamic process during ... proteins at 4 C for 24H in 4 mol/L .... fragments was merely due to interactions ... completely elucidated.

  12. Cytokine profiling in the prefrontal cortex of Parkinson's Disease and Multiple System Atrophy patients

    DEFF Research Database (Denmark)

    Rydbirk, Rasmus; Elfving, Betina; Andersen, Mille Dahl

    2017-01-01

    . Cytokines, which are the main inflammatory signalling molecules, have been identified in blood and cerebrospinal fluid of PD patients, but studies investigating the human brain levels are scarce. It is documented that neurotrophins, necessary for survival of brain cells and known to interact with cytokines......, are altered in the basal ganglia of PD patients. In regards to MSA, no major study has investigated brain cytokine or neurotrophin protein expression. Here, we measured protein levels of 18 cytokines (IL-2, 4-8, 10, 12, 13, 17, G-CSF, GM-CSF, IFN-γ, MCP-1, MIP-1α and 1β, TNF-α) and 5 neurotrophins (BDNF, GDNF......, bFGF, PDGF-BB, VEGF) in the dorsomedial prefrontal cortex in brains of MSA and PD patients and control subjects. We found altered expression of IL-2, IL-13, and G-CSF, but no differences in neurotrophin levels. Further, in MSA patients we identified increased mRNA levels of GSK3β that is involved...

  13. Spatial Correlation of Pathology and Perfusion Changes within the Cortex and White Matter in Multiple Sclerosis.

    Science.gov (United States)

    Mulholland, A D; Vitorino, R; Hojjat, S-P; Ma, A Y; Zhang, L; Lee, L; Carroll, T J; Cantrell, C G; Figley, C R; Aviv, R I

    2018-01-01

    The spatial correlation between WM and cortical GM disease in multiple sclerosis is controversial and has not been previously assessed with perfusion MR imaging. We sought to determine the nature of association between lobar WM, cortical GM, volume and perfusion. Nineteen individuals with secondary-progressive multiple sclerosis, 19 with relapsing-remitting multiple sclerosis, and 19 age-matched healthy controls were recruited. Quantitative MR perfusion imaging was used to derive CBF, CBV, and MTT within cortical GM, WM, and T2-hyperintense lesions. A 2-step multivariate linear regression (corrected for age, disease duration, and Expanded Disability Status Scale) was used to assess correlations between perfusion and volume measures in global and lobar normal-appearing WM, cortical GM, and T2-hyperintense lesions. The Bonferroni adjustment was applied as appropriate. Global cortical GM and WM volume was significantly reduced for each group comparison, except cortical GM volume of those with relapsing-remitting multiple sclerosis versus controls. Global and lobar cortical GM CBF and CBV were reduced in secondary-progressive multiple sclerosis compared with other groups but not for relapsing-remitting multiple sclerosis versus controls. Global and lobar WM CBF and CBV were not significantly different across groups. The distribution of lobar cortical GM and WM volume reduction was disparate, except for the occipital lobes in patients with secondary-progressive multiple sclerosis versus those with relapsing-remitting multiple sclerosis. Moderate associations were identified between lobar cortical GM and lobar normal-appearing WM volume in controls and in the left temporal lobe in relapsing-remitting multiple sclerosis. No significant associations occurred between cortical GM and WM perfusion or volume. Strong correlations were observed between cortical-GM perfusion, normal appearing WM and lesional perfusion, with respect to each global and lobar region within HC, and

  14. Posterior Inferotemporal Cortex Cells Use Multiple Input Pathways for Shape Encoding.

    Science.gov (United States)

    Ponce, Carlos R; Lomber, Stephen G; Livingstone, Margaret S

    2017-05-10

    In the macaque monkey brain, posterior inferior temporal (PIT) cortex cells contribute to visual object recognition. They receive concurrent inputs from visual areas V4, V3, and V2. We asked how these different anatomical pathways shape PIT response properties by deactivating them while monitoring PIT activity in two male macaques. We found that cooling of V4 or V2|3 did not lead to consistent changes in population excitatory drive; however, population pattern analyses showed that V4-based pathways were more important than V2|3-based pathways. We did not find any image features that predicted decoding accuracy differences between both interventions. Using the HMAX hierarchical model of visual recognition, we found that different groups of simulated "PIT" units with different input histories (lacking "V2|3" or "V4" input) allowed for comparable levels of object-decoding performance and that removing a large fraction of "PIT" activity resulted in similar drops in performance as in the cooling experiments. We conclude that distinct input pathways to PIT relay similar types of shape information, with V1-dependent V4 cells providing more quantitatively useful information for overall encoding than cells in V2 projecting directly to PIT. SIGNIFICANCE STATEMENT Convolutional neural networks are the best models of the visual system, but most emphasize input transformations across a serial hierarchy akin to the primary "ventral stream" (V1 → V2 → V4 → IT). However, the ventral stream also comprises parallel "bypass" pathways: V1 also connects to V4, and V2 to IT. To explore the advantages of mixing long and short pathways in the macaque brain, we used cortical cooling to silence inputs to posterior IT and compared the findings with an HMAX model with parallel pathways. Copyright © 2017 the authors 0270-6474/17/375019-16$15.00/0.

  15. Maps of the Auditory Cortex.

    Science.gov (United States)

    Brewer, Alyssa A; Barton, Brian

    2016-07-08

    One of the fundamental properties of the mammalian brain is that sensory regions of cortex are formed of multiple, functionally specialized cortical field maps (CFMs). Each CFM comprises two orthogonal topographical representations, reflecting two essential aspects of sensory space. In auditory cortex, auditory field maps (AFMs) are defined by the combination of tonotopic gradients, representing the spectral aspects of sound (i.e., tones), with orthogonal periodotopic gradients, representing the temporal aspects of sound (i.e., period or temporal envelope). Converging evidence from cytoarchitectural and neuroimaging measurements underlies the definition of 11 AFMs across core and belt regions of human auditory cortex, with likely homology to those of macaque. On a macrostructural level, AFMs are grouped into cloverleaf clusters, an organizational structure also seen in visual cortex. Future research can now use these AFMs to investigate specific stages of auditory processing, key for understanding behaviors such as speech perception and multimodal sensory integration.

  16. Multiple vitamin K forms exist in dairy foods

    Science.gov (United States)

    Background: The plant-based form of vitamin K (phylloquinone, vitamin K-1) has been well quantified in the US diet. Menaquinones (vitamin K-2) are another class of vitamin K compounds that differ from phylloquinone in the length and saturation of their side chain, but they have not been well charact...

  17. Missed cases of multiple forms of child abuse and neglect.

    Science.gov (United States)

    Koc, Feyza; Oral, Resmiye; Butteris, Regina

    2014-01-01

    Child abuse and neglect is a public health problem and usually associated with family dysfunction due to multiple psychosocial, individual, and environmental factors. The diagnosis of child abuse may be difficult and require a high index of suspicion on the part of the practitioners encountering the child and the family. System-related factors may also enable abuse or prevent the early recognition of abuse. Child abuse and neglect that goes undiagnosed may give rise to chronic abuse and increased morbidity-mortality. In this report, we present two siblings who missed early diagnosis and we emphasize the importance of systems issues to allow early recognition of child abuse and neglect.

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

    Science.gov (United States)

    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.

  19. Multiple D3-Instantons and Mock Modular Forms I

    Science.gov (United States)

    Alexandrov, Sergei; Banerjee, Sibasish; Manschot, Jan; Pioline, Boris

    2017-07-01

    We study D3-instanton corrections to the hypermultiplet moduli space in type IIB string theory compactified on a Calabi-Yau threefold. In a previous work, consistency of D3-instantons with S-duality was established at first order in the instanton expansion, using the modular properties of the M5-brane elliptic genus. We extend this analysis to the two-instanton level, where wall-crossing phenomena start playing a role. We focus on the contact potential, an analogue of the Kähler potential which must transform as a modular form under S-duality. We show that it can be expressed in terms of a suitable modification of the partition function of D4-D2-D0 BPS black holes, constructed out of the generating function of MSW invariants (the latter coincide with Donaldson-Thomas invariants in a particular chamber). Modular invariance of the contact potential then requires that, in the case where the D3-brane wraps a reducible divisor, the generating function of MSW invariants must transform as a vector-valued mock modular form, with a specific modular completion built from the MSW invariants of the constituents. Physically, this gives a powerful constraint on the degeneracies of BPS black holes. Mathematically, our result gives a universal prediction for the modular properties of Donaldson-Thomas invariants of pure two-dimensional sheaves.

  20. Individual mediodorsal thalamic neurons project to multiple areas of the rat prefrontal cortex: A single neuron-tracing study using virus vectors.

    Science.gov (United States)

    Kuramoto, Eriko; Pan, Shixiu; Furuta, Takahiro; Tanaka, Yasuhiro R; Iwai, Haruki; Yamanaka, Atsushi; Ohno, Sachi; Kaneko, Takeshi; Goto, Tetsuya; Hioki, Hiroyuki

    2017-01-01

    The prefrontal cortex has an important role in a variety of cognitive and executive processes, and is generally defined by its reciprocal connections with the mediodorsal thalamic nucleus (MD). The rat MD is mainly subdivided into three segments, the medial (MDm), central (MDc), and lateral (MDl) divisions, on the basis of the cytoarchitecture and chemoarchitecture. The MD segments are known to topographically project to multiple prefrontal areas at the population level: the MDm mainly to the prelimbic, infralimbic, and agranular insular areas; the MDc to the orbital and agranular insular areas; and the MDl to the prelimbic and anterior cingulate areas. However, it is unknown whether individual MD neurons project to single or multiple prefrontal cortical areas. In the present study, we visualized individual MD neurons with Sindbis virus vectors, and reconstructed whole structures of MD neurons. While the main cortical projection targets of MDm, MDc, and MDl neurons were generally consistent with those of previous results, it was found that individual MD neurons sent their axon fibers to multiple prefrontal areas, and displayed various projection patterns in the target areas. Furthermore, the axons of single MD neurons were not homogeneously spread, but were rather distributed to form patchy axon arbors approximately 1 mm in diameter. The multiple-area projections and patchy axon arbors of single MD neurons might be able to coactivate cortical neuron groups in distant prefrontal areas simultaneously. Furthermore, considerable heterogeneity of the projection patterns is likely, to recruit the different sets of cortical neurons, and thus contributes to a variety of prefrontal functions. J. Comp. Neurol. 525:166-185, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. Multiple D3-Instantons and Mock Modular Forms II

    Science.gov (United States)

    Alexandrov, Sergei; Banerjee, Sibasish; Manschot, Jan; Pioline, Boris

    2018-03-01

    We analyze the modular properties of D3-brane instanton corrections to the hypermultiplet moduli space in type IIB string theory compactified on a Calabi-Yau threefold. In Part I, we found a necessary condition for the existence of an isometric action of S-duality on this moduli space: the generating function of DT invariants in the large volume attractor chamber must be a vector-valued mock modular form with specified modular properties. In this work, we prove that this condition is also sufficient at two-instanton order. This is achieved by producing a holomorphic action of {SL(2,Z)} on the twistor space which preserves the holomorphic contact structure. The key step is to cancel the anomalous modular variation of the Darboux coordinates by a local holomorphic contact transformation, which is generated by a suitable indefinite theta series. For this purpose we introduce a new family of theta series of signature (2, n - 2), find their modular completion, and conjecture sufficient conditions for their convergence, which may be of independent mathematical interest.

  2. Multiple D3-instantons and mock modular forms I

    CERN Document Server

    Alexandrov, Sergei; Manschot, Jan; Pioline, Boris

    2017-01-01

    We study D3-instanton corrections to the hypermultiplet moduli space in type IIB string theory compactified on a Calabi-Yau threefold. In a previous work, consistency of D3-instantons with S-duality was established at first order in the instanton expansion, using the modular properties of the M5-brane elliptic genus. We extend this analysis to the two-instanton level, where wall-crossing phenomena start playing a role. We focus on the contact potential, an analogue of the Kahler potential which must transform as a modular form under S-duality. We show that it can be expressed in terms of a suitable modification of the partition function of D4-D2-D0 BPS black holes, constructed out of the generating function of MSW invariants (the latter coincide with Donaldson-Thomas invariants in a particular chamber). Modular invariance of the contact potential then requires that, in case where the D3-brane wraps a reducible divisor, the generating function of MSW invariants must transform as a vector-valued mock modular fo...

  3. Multiple active forms of thrombin. IV. Relative activities of meizothrombins

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, M.F.; Mann, K.G. (Univ. of Vermont College of Medicine, Burlington (USA))

    1990-06-25

    The prothrombin activation intermediates meizothrombin and meizothrombin(desF1) (meizothrombin that has been autoproteolyzed to remove fragment 1) have been obtained in a relatively pure, active form with minimal autolysis, making them suitable for enzymatic characterization. When compared at equimolar concentrations, alpha-thrombin, fragment 1.2+ alpha-thrombin, meizothrombin(desF1), and meizothrombin have approximately 100, 100, 10, and 1% activity, respectively, toward the macromolecular substrates factor V, fibrinogen, and platelets. The difference in activity of these four enzymes cannot be attributed to alterations in the catalytic triad, as all four enzymes have nearly identical catalytic efficiency toward the chromogenic substrate S2238. Further, the ability of meizothrombin and meizothrombin(desF1) to activate protein C was 75% of the activity exhibited by alpha-thrombin or fragment 1.2+ alpha-thrombin. All four enzymes bind to thrombomodulin, as judged by the enhanced rate of protein C activation upon preincubation of the enzymes with thrombomodulin. The extent of rate enhancement varied, with meizothrombin/thrombomodulin exhibiting only 50% of the alpha-thrombin/thrombomodulin rate. This difference in rate is not due to a decreased affinity of the meizothrombin for thrombomodulin since the apparent dissociation constants for the alpha-thrombin-thrombomodulin complex and the meizothrombin-thrombomodulin complex are virtually identical. The difference in the observed rate is due in part to the higher Km for protein C exhibited by the meizothrombin-thrombomodulin complex. Incubation of the thrombomodulin-enzyme complex with phospholipid vesicles caused an increase in the protein C activation rates. The kinetic constants for protein C activation in the presence of phospholipid are virtually identical for these enzyme-thrombomodulin complexes.

  4. Multiple active forms of thrombin. IV. Relative activities of meizothrombins

    International Nuclear Information System (INIS)

    Doyle, M.F.; Mann, K.G.

    1990-01-01

    The prothrombin activation intermediates meizothrombin and meizothrombin(desF1) (meizothrombin that has been autoproteolyzed to remove fragment 1) have been obtained in a relatively pure, active form with minimal autolysis, making them suitable for enzymatic characterization. When compared at equimolar concentrations, alpha-thrombin, fragment 1.2+ alpha-thrombin, meizothrombin(desF1), and meizothrombin have approximately 100, 100, 10, and 1% activity, respectively, toward the macromolecular substrates factor V, fibrinogen, and platelets. The difference in activity of these four enzymes cannot be attributed to alterations in the catalytic triad, as all four enzymes have nearly identical catalytic efficiency toward the chromogenic substrate S2238. Further, the ability of meizothrombin and meizothrombin(desF1) to activate protein C was 75% of the activity exhibited by alpha-thrombin or fragment 1.2+ alpha-thrombin. All four enzymes bind to thrombomodulin, as judged by the enhanced rate of protein C activation upon preincubation of the enzymes with thrombomodulin. The extent of rate enhancement varied, with meizothrombin/thrombomodulin exhibiting only 50% of the alpha-thrombin/thrombomodulin rate. This difference in rate is not due to a decreased affinity of the meizothrombin for thrombomodulin since the apparent dissociation constants for the alpha-thrombin-thrombomodulin complex and the meizothrombin-thrombomodulin complex are virtually identical. The difference in the observed rate is due in part to the higher Km for protein C exhibited by the meizothrombin-thrombomodulin complex. Incubation of the thrombomodulin-enzyme complex with phospholipid vesicles caused an increase in the protein C activation rates. The kinetic constants for protein C activation in the presence of phospholipid are virtually identical for these enzyme-thrombomodulin complexes

  5. Decreased NAA in gray matter is correlated with decreased availability of acetate in white matter in postmortem multiple sclerosis cortex.

    Science.gov (United States)

    Li, S; Clements, R; Sulak, M; Gregory, R; Freeman, E; McDonough, J

    2013-11-01

    Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the central nervous system (CNS) which leads to progressive neurological disability. Our previous studies have demonstrated mitochondrial involvement in MS cortical pathology and others have documented decreased levels of the neuronal mitochondrial metabolite N-acetyl aspartate (NAA) in the MS brain. While NAA is synthesized in neurons, it is broken down in oligodendrocytes into aspartate and acetate. The resulting acetate is incorporated into myelin lipids, linking neuronal mitochondrial function to oligodendrocyte-mediated elaboration of myelin lipids in the CNS. In the present study we show that treating human SH-SY5Y neuroblastoma cells with the electron transport chain inhibitor antimycin A decreased levels of NAA as measured by HPLC. To better understand the significance of the relationship between mitochondrial function and levels of NAA and its breakdown product acetate on MS pathology we then quantitated the levels of NAA and acetate in MS and control postmortem tissue blocks. Regardless of lesion status, we observed that levels of NAA were decreased 25 and 32 % in gray matter from parietal and motor cortex in MS, respectively, compared to controls. Acetate levels in adjacent white matter mirrored these decreases as evidenced by the 36 and 45 % reduction in acetate obtained from parietal and motor cortices. These data suggest a novel mechanism whereby mitochondrial dysfunction and reduced NAA levels in neurons may result in compromised myelination by oligodendrocytes due to decreased availability of acetate necessary for the synthesis of myelin lipids.

  6. Enhanced peripheral visual processing in congenitally deaf humans is supported by multiple brain regions, including primary auditory cortex

    OpenAIRE

    Scott, Gregory D.; Karns, Christina M.; Dow, Mark W.; Stevens, Courtney; Neville, Helen J.

    2014-01-01

    Brain reorganization associated with altered sensory experience clarifies the critical role of neuroplasticity in development. An example is enhanced peripheral visual processing associated with congenital deafness, but the neural systems supporting this have not been fully characterized. A gap in our understanding of deafness-enhanced peripheral vision is the contribution of primary auditory cortex. Previous studies of auditory cortex that use anatomical normalization across participants wer...

  7. FormScanner: Open-Source Solution for Grading Multiple-Choice Exams

    Science.gov (United States)

    Young, Chadwick; Lo, Glenn; Young, Kaisa; Borsetta, Alberto

    2016-01-01

    The multiple-choice exam remains a staple for many introductory physics courses. In the past, people have graded these by hand or even flaming needles. Today, one usually grades the exams with a form scanner that utilizes optical mark recognition (OMR). Several companies provide these scanners and particular forms, such as the eponymous…

  8. Bees Algorithm for Construction of Multiple Test Forms in E-Testing

    Science.gov (United States)

    Songmuang, Pokpong; Ueno, Maomi

    2011-01-01

    The purpose of this research is to automatically construct multiple equivalent test forms that have equivalent qualities indicated by test information functions based on item response theory. There has been a trade-off in previous studies between the computational costs and the equivalent qualities of test forms. To alleviate this problem, we…

  9. Use of diffusion tensor imaging to identify similarities and differences between cerebellar and Parkinsonism forms of multiple system atrophy

    International Nuclear Information System (INIS)

    Wang, Po-Shan; Wu, Hsiu-Mei; Lin, Ching-Po; Soong, Bing-Wen

    2011-01-01

    We performed diffusion tensor imaging to determine if multiple system atrophy (MSA)-cerebellar (C) and MSA-Parkinsonism (P) show similar changes, as shown in pathological studies. Nineteen patients with MSA-C, 12 patients with MSA-P, 20 patients with Parkinson disease, and 20 healthy controls were evaluated with the use of voxel-based morphometry analysis of diffusion tensor imaging. There was an increase in apparent diffusion coefficient values in the middle cerebellar peduncles and cerebellum and a decrease in fractional anisotropy in the pyramidal tract, middle cerebellar peduncles, and white matter of the cerebellum in patients with MSA-C and MSA-P compared to the controls (P<0.001). In addition, isotropic diffusion-weighted image values were reduced in the cerebellar cortex and deep cerebellar nuclei in patients with MSA-C and increased in the basal ganglia in patients with MSA-P. These results indicate that despite their disparate clinical manifestations, patients with MSA-C and MSA-P share similar diffusion tensor imaging features in the infratentorial region. Further, the combination of FA, ADC and iDWI images can be used to distinguish between MSA (either form) and Parkinson disease, which has potential therapeutic implications. (orig.)

  10. Use of diffusion tensor imaging to identify similarities and differences between cerebellar and Parkinsonism forms of multiple system atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Po-Shan [National Yang-Ming University, Department of Neurology, School of Medicine, Taipei (China); Taipei Veterans General Hospital, Neurological Institute, Taipei (China); Taipei Municipal Gan-Dau Hospital, Neurological Institute, Taipei (China); National Yang-Ming University, Institute of Brain Science, Taipei (China); Wu, Hsiu-Mei [National Yang-Ming University, Department of Neurology, School of Medicine, Taipei (China); Taipei Veterans General Hospital, Department of Radiology, Taipei (China); Lin, Ching-Po [National Yang-Ming University, Institute of Brain Science, Taipei (China); Soong, Bing-Wen [National Yang-Ming University, Department of Neurology, School of Medicine, Taipei (China); Taipei Veterans General Hospital, Neurological Institute, Taipei (China)

    2011-07-15

    We performed diffusion tensor imaging to determine if multiple system atrophy (MSA)-cerebellar (C) and MSA-Parkinsonism (P) show similar changes, as shown in pathological studies. Nineteen patients with MSA-C, 12 patients with MSA-P, 20 patients with Parkinson disease, and 20 healthy controls were evaluated with the use of voxel-based morphometry analysis of diffusion tensor imaging. There was an increase in apparent diffusion coefficient values in the middle cerebellar peduncles and cerebellum and a decrease in fractional anisotropy in the pyramidal tract, middle cerebellar peduncles, and white matter of the cerebellum in patients with MSA-C and MSA-P compared to the controls (P<0.001). In addition, isotropic diffusion-weighted image values were reduced in the cerebellar cortex and deep cerebellar nuclei in patients with MSA-C and increased in the basal ganglia in patients with MSA-P. These results indicate that despite their disparate clinical manifestations, patients with MSA-C and MSA-P share similar diffusion tensor imaging features in the infratentorial region. Further, the combination of FA, ADC and iDWI images can be used to distinguish between MSA (either form) and Parkinson disease, which has potential therapeutic implications. (orig.)

  11. Use of diffusion tensor imaging to identify similarities and differences between cerebellar and Parkinsonism forms of multiple system atrophy.

    Science.gov (United States)

    Wang, Po-Shan; Wu, Hsiu-Mei; Lin, Ching-Po; Soong, Bing-Wen

    2011-07-01

    We performed diffusion tensor imaging to determine if multiple system atrophy (MSA)-cerebellar (C) and MSA-Parkinsonism (P) show similar changes, as shown in pathological studies. Nineteen patients with MSA-C, 12 patients with MSA-P, 20 patients with Parkinson disease, and 20 healthy controls were evaluated with the use of voxel-based morphometry analysis of diffusion tensor imaging. There was an increase in apparent diffusion coefficient values in the middle cerebellar peduncles and cerebellum and a decrease in fractional anisotropy in the pyramidal tract, middle cerebellar peduncles, and white matter of the cerebellum in patients with MSA-C and MSA-P compared to the controls (P < 0.001). In addition, isotropic diffusion-weighted image values were reduced in the cerebellar cortex and deep cerebellar nuclei in patients with MSA-C and increased in the basal ganglia in patients with MSA-P. These results indicate that despite their disparate clinical manifestations, patients with MSA-C and MSA-P share similar diffusion tensor imaging features in the infratentorial region. Further, the combination of FA, ADC and iDWI images can be used to distinguish between MSA (either form) and Parkinson disease, which has potential therapeutic implications.

  12. Encephalic magnetic resonance imaging in spinal clinical forms of multiple sclerosis

    International Nuclear Information System (INIS)

    Lubetzki, C.; Lyon-Caen, O.; Lhermitte, F.; Iba-Zizen, M.T.

    1988-01-01

    The diagnosis of multiple sclerosis (MS) in patients presenting with signs and symptoms of pure spinal cord involvement is always difficult. Previous studies have shown the usefulness of encephalic magnetic resonance imaging (MRI) of the brain in those cases. The aim was to evaluate the diagnosis value of brain MRI in medullar forms of MS. 3 refs

  13. Erythrocyte membrane fatty acids in benign and progressive forms of multiple sclerosis

    NARCIS (Netherlands)

    Koch, M; Ramsaransing, GSM; Fokkema, MR; Heersema, DJ; De Keyser, J

    2006-01-01

    BACKGROUND: There is no good explanation why a proportion of patients with multiple sclerosis (MS) have a relatively benign form of the disease. An imbalance between saturated and unsaturated fatty acids (FA) might influence the disease course of MS. AIM: To assess whether the erythrocyte membrane

  14. Legitimating New Forms of Organizing and New International Activities in the Eyes of Multiple Stakeholders

    DEFF Research Database (Denmark)

    Turcan, Romeo V.

    The research on new venture legitimation strategies is emerging; although, it is yet to form a central line of enquiry in entrepreneurship research. To contribute to this development, this paper explores the process of legitimation in a non-for-profit venture (hereafter as NGO, non-governmental...... organization). The paper explores (1) how this NGO acquired cognitive legitimacy, defined as knowledge about the new form of organizing and new activity and what is needed to succeed in respective sector, and socio-political legitimacy, defined as the value placed on the new form of organizing and new activity...... by its multiple stakeholders; and (2) what legitimation strategies it developed and adopted to legitimate itself in the eyes of its multiple stakeholders. Theoretically, the paper is grounded within legitimation theory. The empirical context is defined by a new, international NGO entering an established...

  15. The temporal dynamics of implicit processing of non-letter, letter, and word-forms in the human visual cortex

    Directory of Open Access Journals (Sweden)

    Lawrence Gregory Appelbaum

    2009-11-01

    Full Text Available The decoding of visually presented line segments into letters, and letters into words, is critical to fluent reading abilities. Here we investigate the temporal dynamics of visual orthographic processes, focusing specifically on right hemisphere contributions and interactions between the hemispheres involved in the implicit processing of visually presented words, consonants, false fonts, and symbolic strings. High-density EEG was recorded while participants detected infrequent, simple, perceptual targets (dot strings embedded amongst a of character strings. Beginning at 130ms, orthographic and non-orthographic stimuli were distinguished by a sequence of ERP effects over occipital recording sites. These early latency occipital effects were dominated by enhanced right-sided negative-polarity activation for non-orthographic stimuli that peaked at around 180ms. This right-sided effect was followed by bilateral positive occipital activity for false-fonts, but not symbol strings. Moreover the size of components of this later positive occipital wave was inversely correlated with the right-sided ROcc180 wave, suggesting that subjects who had larger early right-sided activation for non-orthographic stimuli had less need for more extended bilateral (e.g. interhemispheric processing of those stimuli shortly later. Additional early (130-150ms negative-polarity activity over left occipital cortex and longer-latency centrally distributed responses (>300ms were present, likely reflecting implicit activation of the previously reported ‘visual-word-form’ area and N400-related responses, respectively. Collectively, these results provide a close look at some relatively unexplored portions of the temporal flow of information processing in the brain related to the implicit processing of potentially linguistic information and provide valuable information about the interactions between hemispheres supporting visual orthographic processing.

  16. Not all effort is equal: the role of the anterior cingulate cortex in different forms of effort-reward decisions

    Directory of Open Access Journals (Sweden)

    Victoria eHolec

    2014-01-01

    Full Text Available The rat anterior cingulate cortex (ACC mediates effort-based decision making when the task requires the physical effort of climbing a ramp. Normal rats will readily climb a barrier leading to high reward whereas rats with ACC lesions will opt instead for an easily obtained small reward. The present study explored whether the role of ACC in cost-benefit decisions extends beyond climbing by testing its role in ramp climbing as well as two novel cost-benefit decision tasks, one involving the physical effort of lifting weights and the other the emotional cost of overcoming fear (i.e., courage. As expected, rats with extensive ACC lesions tested on a ramp-climbing task were less likely to choose a high-reward/high-effort arm than sham controls. However, during the first few trials, lesioned rats were as likely as controls to initially turn into the high-reward arm but far less likely to actually climb the barrier, suggesting that the role of the ACC is not in deciding which course of action to pursue, but rather in maintaining a course of action in the face of countervailing forces. In the effort-reward decision task involving weight lifting, some lesion animals behaved like controls while others avoided the high reward arm. However, the results were not statistically significant and a follow-up study using incremental increasing effort failed to show any difference between lesion and control groups. The results suggest that the ACC is not needed for effort-reward decisions involving weight lifting but may affect motor abilities. Finally, a courage task explored the willingness of rats to overcome the fear of crossing an open, exposed arm to obtain a high reward. Both sham and ACC-lesioned animals exhibited equal tendencies to enter the open arm. However, whereas sham animals gradually improved on the task, ACC-lesioned rats did not. Taken together, the results suggest that the role of the ACC in effort-reward decisions may be limited to certain

  17. Alignment engineering in liquid crystalline elastomers: Free-form microstructures with multiple functionalities

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Hao; Cerretti, Giacomo; Wiersma, Diederik S., E-mail: camilla.parmeggiani@lens.unifi.it, E-mail: wiersma@lens.unifi.it [European Laboratory for Non Linear Spectroscopy (LENS), University of Florence, via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Wasylczyk, Piotr [European Laboratory for Non Linear Spectroscopy (LENS), University of Florence, via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Faculty of Physics, Institute of Experimental Physics, University of Warsaw, ul. Hoza 69, Warszawa 00-681 (Poland); Martella, Daniele [European Laboratory for Non Linear Spectroscopy (LENS), University of Florence, via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Dipartimento di Chimica “Ugo Schiff,” University of Florence, via della Lastruccia 3-13, 50019 Sesto Fiorentino (Italy); Parmeggiani, Camilla, E-mail: camilla.parmeggiani@lens.unifi.it, E-mail: wiersma@lens.unifi.it [European Laboratory for Non Linear Spectroscopy (LENS), University of Florence, via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); CNR-INO, via Nello Carrara 1, 50019 Sesto Fiorentino (Italy)

    2015-03-16

    We report a method to fabricate polymer microstructures with local control over the molecular orientation. Alignment control is achieved on molecular level in a structure of arbitrary form that can be from 1 to 100 μm in size, by fixing the local boundary conditions with micro-grating patterns. The method makes use of two-photon polymerization (Direct Laser Writing) and is demonstrated specifically in liquid-crystalline elastomers. This concept allows for the realization of free-form polymeric structures with multiple functionalities which are not possible to realize with existing techniques and which can be locally controlled by light in the micrometer scale.

  18. Prevalence of multiple forms of sexting behavior among youth : a systematic review and meta-analysis

    OpenAIRE

    Madigan, Sheri; Ly, Ahn; Rash, Christina L.; Ouytsel, Van, Joris; Temple, Jeff R.

    2018-01-01

    Abstract: Importance The existing literature on sexting among youth shows that sexting is a predictor of sexual behavior and may be associated with other health outcomes and risky behaviors. However, there remains a lack of consensus on the prevalence of sexting, which is needed to inform future research, intervention, and policy development. Objective To provide a meta-analytic synthesis of studies examining the prevalence of multiple forms of sexting behavior, analyzed by age, sex, geograph...

  19. Neural Priming in Human Frontal Cortex: Multiple Forms of Learning Reduce Demands on the Prefrontal Executive System

    Science.gov (United States)

    Race, Elizabeth A.; Shanker, Shanti; Wagner, Anthony D.

    2009-01-01

    Past experience is hypothesized to reduce computational demands in PFC by providing bottom-up predictive information that informs subsequent stimulus-action mapping. The present fMRI study measured cortical activity reductions ("neural priming"/"repetition suppression") during repeated stimulus classification to investigate the mechanisms through…

  20. Metabolic gene expression changes in astrocytes in Multiple Sclerosis cerebral cortex are indicative of immune-mediated signaling

    KAUST Repository

    Zeis, T.; Allaman, I.; Gentner, M.; Schroder, K.; Tschopp, J.; Magistretti, Pierre J.; Schaeren-Wiemers, N.

    2015-01-01

    Emerging as an important correlate of neurological dysfunction in Multiple Sclerosis (MS), extended focal and diffuse gray matter abnormalities have been found and linked to clinical manifestations such as seizures, fatigue and cognitive dysfunction

  1. Low level postnatal methylmercury exposure in vivo alters developmental forms of short-term synaptic plasticity in the visual cortex of rat

    International Nuclear Information System (INIS)

    Dasari, Sameera; Yuan, Yukun

    2009-01-01

    Methylmercury (MeHg) has been previously shown to affect neurotransmitter release. Short-term synaptic plasticity (STP) is primarily related to changes in the probability of neurotransmitter release. To determine if MeHg affects STP development, we examined STP forms in the visual cortex of rat following in vivo MeHg exposure. Neonatal rats received 0 (0.9% NaCl), 0.75 or 1.5 mg/kg/day MeHg subcutaneously for 15 or 30 days beginning on postnatal day 5, after which visual cortical slices were prepared for field potential recordings. In slices prepared from rats treated with vehicle, field excitatory postsynaptic potentials (fEPSPs) evoked by paired-pulse stimulation at 20-200 ms inter-stimulus intervals showed a depression (PPD) of the second fEPSP (fEPSP2). PPD was also seen in slices prepared from rats after 15 day treatment with 0.75 or 1.5 mg/kg/day MeHg. However, longer duration treatment (30 days) with either dose of MeHg resulted in paired-pulse facilitation (PPF) of fEPSP2 in the majority of slices examined. PPF remained observable in slices prepared from animals in which MeHg exposure had been terminated for 30 days after completion of the initial 30 day MeHg treatment, whereas slices from control animals still showed PPD. MeHg did not cause any frequency- or region-preferential effect on STP. Manipulations of [Ca 2+ ] e or application of the GABA A receptor antagonist bicuculline could alter the strength and polarity of MeHg-induced changes in STP. Thus, these data suggest that low level postnatal MeHg exposure interferes with the developmental transformation of STP in the visual cortex, which is a long-lasting effect.

  2. The Continental Margin of East Asia: a collage of multiple plates formed by convergence and extension from multiple directions

    Science.gov (United States)

    Mao, J.; Wang, T.; Ludington, S.; Qiu, Z.; Li, Z.

    2017-12-01

    East Asia is one of the most complex regions in the world. Its margin was divided into 4 parts: Northeast Asia, North China, South China and Southeast Asia. During the Phanerozoic, continental plates of East Asia have interacted successively with a) the Paleo Tethyan Ocean, b) the Tethyan and Paleo Pacific Oceans and c) the Pacific and Indian. In the Early Mesozoic, the Indosinian orogeny is characterized by the convergence and extension within multiple continental plates, whereas the Late Mesozoic Yanshanian orogeny is characterized by both convergence and compression due to oceanic subduction and by widespread extension. We propose this combination as "East Asia Continental Margin type." Except in Northeast Asia, where Jurassic and Cretaeous accretionary complexes are common, most magmatic rocks are the result of reworking of ancient margins of small continental plates; and oceanic island arc basalts and continental margin arc andesites are largely absent. Because South China is adjacent to the western margin of the Pacific Plate, some effects of its westward subduction must be unavoidable, but juvenile arc-related crust has not been identified. The East Asian Continental Margin is characterized by magmatic rocks that are the result of post-convergent tectonics, which differs markedly from the active continental margins of both South and North America. In summary, the chief characteristics of the East Asian Continental Margin are: 1) In Mesozoic, the periphery of multiple blocks experienced magmatism caused by lithospheric delamination and thinning in response to extension punctuated by shorter periods of convergence. 2) The main mechanism of magma generation was the partial melting of crustal rocks, due to underplating by upwelling mafic magma associated with the collapse of orogenic belts and both extension and compression between small continental blocks. 3) During orogeny, mostly high Sr/Y arc-related granitoids formed, whereas during post-orogenic times, A

  3. Rod microglia: elongation, alignment, and coupling to form trains across the somatosensory cortex after experimental diffuse brain injury

    Directory of Open Access Journals (Sweden)

    Ziebell Jenna M

    2012-10-01

    Full Text Available Abstract Background Since their discovery, the morphology of microglia has been interpreted to mirror their function, with ramified microglia constantly surveying the micro-environment and rapidly activating when changes occur. In 1899, Franz Nissl discovered what we now recognize as a distinct microglial activation state, microglial rod cells (Stäbchenzellen, which he observed adjacent to neurons. These rod-shaped microglia are typically found in human autopsy cases of paralysis of the insane, a disease of the pre-penicillin era, and best known today from HIV-1-infected brains. Microglial rod cells have been implicated in cortical ‘synaptic stripping’ but their exact role has remained unclear. This is due at least in part to a scarcity of experimental models. Now we have noted these rod microglia after experimental diffuse brain injury in brain regions that have an associated sensory sensitivity. Here, we describe the time course, location, and surrounding architecture associated with rod microglia following experimental diffuse traumatic brain injury (TBI. Methods Rats were subjected to a moderate midline fluid percussion injury (mFPI, which resulted in transient suppression of their righting reflex (6 to 10 min. Multiple immunohistochemistry protocols targeting microglia with Iba1 and other known microglia markers were undertaken to identify the morphological activation of microglia. Additionally, labeling with Iba1 and cell markers for neurons and astrocytes identified the architecture that surrounds these rod cells. Results We identified an abundance of Iba1-positive microglia with rod morphology in the primary sensory barrel fields (S1BF. Although present for at least 4 weeks post mFPI, they developed over the first week, peaking at 7 days post-injury. In the absence of contusion, Iba1-positive microglia appear to elongate with their processes extending from the apical and basal ends. These cells then abut one another and lay adjacent

  4. What do children with specific language impairment do with multiple forms of DO?

    Science.gov (United States)

    Rice, Mabel L; Blossom, Megan

    2013-02-01

    This study was designed to examine the early usage patterns of multiple grammatical functions of DO in children with and without specific language impairment (SLI). Children's use of this plurifunctional form is informative for evaluation of theoretical accounts of the deficit in SLI. Spontaneous uses of multiple functions of DO were analyzed in language samples from 89 children: 37 children with SLI, ages 5;0-5;6 (years;months); 37 age-equivalent children; and 15 language-equivalent children, ages 2;8-4;10. Proportion correct and types of errors produced were analyzed for each function of DO. Children with SLI had significantly lower levels of proportion correct auxiliary DO use compared to both control groups, with omissions of the DO form as the primary error type. Children with SLI had near-ceiling performance on lexical DO and elliptical DO, similar to both control groups. Plurifunctionality is not problematic: Children acquire each function of DO separately. Grammatical properties of the function, rather than surface properties of the form, dictate whether children with SLI will have difficulty using the word. Overall, these results support the extended optional infinitive account of SLI and the use of auxiliary DO omissions as part of a clinical marker for SLI.

  5. Multiple isoelectric forms of poliovirus RNA-dependent RNA polymerase: Evidence for phosphorylation

    International Nuclear Information System (INIS)

    Ransone, L.J.; Dasgupta, A.

    1989-01-01

    Poliovirus-specific RNA-dependent RNA polymerase (3Dpol) was purified to apparent homogeneity. A single polypeptide of an apparent molecular weight of 63,000 catalyzes the synthesis of dimeric and monomeric RNA products in response to the poliovirion RNA template. Analysis of purified 3Dpol by two-dimensional electrophoresis showed multiple forms of 3Dpol, suggesting posttranslational modification of the protein in virus-infected cells. The two major forms of 3Dpol appear to have approximate pI values of 7.1 and 7.4. Incubation of purified 3Dpol with calf intestinal phosphatase resulted in almost complete disappearance of the pI 7.1 form and a concomitant increase in the intensity of the pI 7.4 form of 3Dpol. Addition of 32P-labeled Pi during infection of HeLa cells with poliovirus resulted in specific labeling of 3Dpol and 3CD, a viral protein which contains the entire 3Dpol sequence. Both 3Dpol and 3CD appear to be phosphorylated at serine residues. Ribosomal salt washes prepared from both mock- and poliovirus-infected cells contain phosphatases capable of dephosphorylating quantitatively the phosphorylated form (pI 7.1) of 3Dpol

  6. Does early-onset multiple sclerosis differ from adult-onset form in Iranian people

    Directory of Open Access Journals (Sweden)

    Fereshteh Ashtari

    2010-01-01

    Full Text Available Background: Few studies have attempted to delineate the clinical profile of multiple Sclerosis (MS among people of Asia. This study sought to identify the characteristics of early-onset Multiple Sclerosis (EOMS comparison to adult-onset form (AOMS in Isfahan, IRAN. Methods: This prospective study was conducted on 104 youths with multiple sclerosis beginning before the age of 16 years and 123 patients with adult-onset multiple sclerosis. Patients were observed for a mean period of 5 years. The common presenting symptoms, MRI finding, course of disease and disability score were compared between the two groups. Results: The mean onset age of disease in youths and adults were 14 ± 1.9 and 27.7 ± 8.06 years, respectively. Female/male ratio was 4.47:1 in EOMS and 3.92:1 in AOMS, this ratio was 7:1 in early childhood MS (≤ 10 year. The most common presenting symptom was optic neuritis in the EOMS group and paresthesia in AOMS. Optic neuritis was common in AOMS too, but brainstem/cerebellar signs were more common in EOMS than AOMS. Seizure occurred more frequently in EOMS than in the AOMS group (12.6% vs. 1.6%, respectively, p < 0.001. MRI showed that brainstem plaques were more prevalent in the EOMS compared with the AOMS group. Conclusions: It was concluded that early-onset MS does not significantly differ from adult form in terms of major clinical manifestation and course of disease, however Seizure is more common in EOMS, and brainstem and cerebellar symptoms as presenting symptom are more common.

  7. The Multiple Correspondence Analysis Method and Brain Functional Connectivity: Its Application to the Study of the Non-linear Relationships of Motor Cortex and Basal Ganglia.

    Science.gov (United States)

    Rodriguez-Sabate, Clara; Morales, Ingrid; Sanchez, Alberto; Rodriguez, Manuel

    2017-01-01

    The complexity of basal ganglia (BG) interactions is often condensed into simple models mainly based on animal data and that present BG in closed-loop cortico-subcortical circuits of excitatory/inhibitory pathways which analyze the incoming cortical data and return the processed information to the cortex. This study was aimed at identifying functional relationships in the BG motor-loop of 24 healthy-subjects who provided written, informed consent and whose BOLD-activity was recorded by MRI methods. The analysis of the functional interaction between these centers by correlation techniques and multiple linear regression showed non-linear relationships which cannot be suitably addressed with these methods. The multiple correspondence analysis (MCA), an unsupervised multivariable procedure which can identify non-linear interactions, was used to study the functional connectivity of BG when subjects were at rest. Linear methods showed different functional interactions expected according to current BG models. MCA showed additional functional interactions which were not evident when using lineal methods. Seven functional configurations of BG were identified with MCA, two involving the primary motor and somatosensory cortex, one involving the deepest BG (external-internal globus pallidum, subthalamic nucleus and substantia nigral), one with the input-output BG centers (putamen and motor thalamus), two linking the input-output centers with other BG (external pallidum and subthalamic nucleus), and one linking the external pallidum and the substantia nigral. The results provide evidence that the non-linear MCA and linear methods are complementary and should be best used in conjunction to more fully understand the nature of functional connectivity of brain centers.

  8. Teriflunomide: a once-daily oral medication for the treatment of relapsing forms of multiple sclerosis.

    Science.gov (United States)

    Miller, Aaron E

    2015-10-01

    The purpose was to summarize US prescribing information for teriflunomide in the treatment of patients with relapsing forms of multiple sclerosis (RMS), with reference to clinical efficacy and safety outcomes. In September 2012, the US Food and Drug Administration granted approval for the use of teriflunomide, 14 mg and 7 mg once daily, to treat RMS on the basis of the results of a Phase II study and the Phase III TEMSO (Teriflunomide Multiple Sclerosis Oral) trial. After recent updates to the prescribing information (October 2014), key findings from these and 2 other Phase III clinical trials, TOWER (Teriflunomide Oral in People With Relapsing Multiple Sclerosis) and TOPIC (Oral Teriflunomide for Patients with a First Clinical Episode Suggestive of Multiple Sclerosis), and practical considerations for physicians are summarized. Teriflunomide, 14 mg and 7 mg, significantly reduced mean number of unique active lesions on magnetic resonance imaging (MRI; P treatment was also associated with significant efficacy on MRI measures of disease activity in TEMSO; both doses significantly reduced total lesion volume and number of gadolinium-enhancing T1 lesions. TOPIC evaluated patients with a first clinical event consistent with acute demyelination and brain MRI lesions characteristic of multiple sclerosis. More patients were free of relapse in the teriflunomide 14-mg and 7-mg groups than in the placebo group (P treatment are recommended to assess potential safety issues. Women of childbearing potential must use effective contraception and, in the event of pregnancy, undergo an accelerated elimination procedure to reduce plasma concentrations of teriflunomide. Clinical evidence suggests that teriflunomide is an effective therapeutic choice for patients with RMS, both as an initial treatment and as an alternative for patients who may have experienced intolerance or inadequate response to a previous or current disease-modifying therapy. Copyright © 2015 The Authors

  9. PSEUDOTUMORAL FORM OF MULTIPLE SCLEROSIS WITH SYMPTOMATIC CONVULSIVE SEIZURES (A CLINICAL CASE

    Directory of Open Access Journals (Sweden)

    Yu. A. Belova

    2015-01-01

    Full Text Available Multiple sclerosis (MS is prominent among central nervous system diseases. It affects chiefly young people and almost inevitably results in disability. In the past decade, there has been an upward trend for the prevalence of MS worldwide; in particular, the higher prevalence of this disease has been registered in the Moscow Region, which is associated with both an objective increase in its morbidity and improvement of specialized care to the population in the region. MS is characterized by a variety of clinical manifestations. However, paroxysmal disturbances are referred to as the rare symptoms of MS: the incidence of epileptic seizures in this condition is 0.89 to 7.5% according to the literature data. In addition to the clinical form of MS, there are its rare malignant atypical forms that also include its pseudotumoral form characterized by intrinsic neuroimaging and clinical signs that are different from the classical form of MS and another abnormality of the central nervous system. The pseudotumoral form of MS is characterized by the development of acute focal demyelination that appears as a large focus of an increased magnetic resonance signal with perifocal edema as evidenced by magnetic resonance imaging. A pseudotumoral focus of demyelination can occur both at the onset of MS and during its recurrent course. The atypical onset of MS is a special challenge because of diagnostic problems, which may lead to erroneous therapeutic policy and have a negative impact on the late prognosis of the disease. The authors provide a clinical case of the pseudotumoral form of MS with convulsive seizures at the onset of demyelinating disease. The problems of diagnosis and therapeutic approaches are discussed.

  10. Unprecedented multiplicity of Ig transmembrane and secretory mRNA forms in the cartilaginous fish.

    Science.gov (United States)

    Rumfelt, Lynn L; Diaz, Marilyn; Lohr, Rebecca L; Mochon, Evonne; Flajnik, Martin F

    2004-07-15

    In most jawed vertebrates including cartilaginous fish, membrane-bound IgM is expressed as a five Ig superfamily (Igsf)-domain H chain attached to a transmembrane (Tm) region. Heretofore, bony fish IgM was the one exception with IgM mRNA spliced to produce a four-domain Tm H chain. We now demonstrate that the Tm and secretory (Sec) mRNAs of the novel cartilaginous fish Ig isotypes, IgW and IgNAR, are present in multiple forms, most likely generated by alternative splicing. In the nurse shark, Ginglymostoma cirratum, and horn shark, Heterodontus francisci, alternative splicing of Tm exons to the second or the fourth constant (C(H)) exons produces two distinct IgW Tm cDNAs. Although the seven-domain IgW Sec cDNA form contains a canonical secretory tail shared with IgM, IgNAR, and IgA, we report a three-domain cDNA form of shark IgW (IgW(short)) having an unusual Sec tail, which is orthologous to skate IgX(short) cDNA. The IgW and IgW(short) Sec transcripts are restricted in their tissue distribution and expression levels vary among individual sharks, with all forms expressed early in ontogeny. IgNAR mRNA is alternatively spliced to produce a truncated four-domain Tm cDNA and a second Tm cDNA is expressed identical in Igsf domains as the Sec form. PBL is enriched in the Tm cDNA of these Igs. These molecular data suggest that cartilaginous fish have augmented their humoral immune repertoire by diversifying the sizes of their Ig isotypes. Furthermore, these Tm cDNAs are prototypical and the truncated variants may translate as more stable protein at the cell surface.

  11. On the road to invariant recognition: explaining tradeoff and morph properties of cells in inferotemporal cortex using multiple-scale task-sensitive attentive learning.

    Science.gov (United States)

    Grossberg, Stephen; Markowitz, Jeffrey; Cao, Yongqiang

    2011-12-01

    Visual object recognition is an essential accomplishment of advanced brains. Object recognition needs to be tolerant, or invariant, with respect to changes in object position, size, and view. In monkeys and humans, a key area for recognition is the anterior inferotemporal cortex (ITa). Recent neurophysiological data show that ITa cells with high object selectivity often have low position tolerance. We propose a neural model whose cells learn to simulate this tradeoff, as well as ITa responses to image morphs, while explaining how invariant recognition properties may arise in stages due to processes across multiple cortical areas. These processes include the cortical magnification factor, multiple receptive field sizes, and top-down attentive matching and learning properties that may be tuned by task requirements to attend to either concrete or abstract visual features with different levels of vigilance. The model predicts that data from the tradeoff and image morph tasks emerge from different levels of vigilance in the animals performing them. This result illustrates how different vigilance requirements of a task may change the course of category learning, notably the critical features that are attended and incorporated into learned category prototypes. The model outlines a path for developing an animal model of how defective vigilance control can lead to symptoms of various mental disorders, such as autism and amnesia. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Combining Multiple Forms Of Visual Information To Specify Contact Relations In Spatial Layout

    Science.gov (United States)

    Sedgwick, Hal A.

    1990-03-01

    An expert system, called Layout2, has been described, which models a subset of available visual information for spatial layout. The system is used to examine detailed interactions between multiple, partially redundant forms of information in an environment-centered geometrical model of an environment obeying certain rather general constraints. This paper discusses the extension of Layout2 to include generalized contact relations between surfaces. In an environment-centered model, the representation of viewer-centered distance is replaced by the representation of environmental location. This location information is propagated through the representation of the environment by a network of contact relations between contiguous surfaces. Perspective information interacts with other forms of information to specify these contact relations. The experimental study of human perception of contact relations in extended spatial layouts is also discussed. Differences between human results and Layout2 results reveal limitations in the human ability to register available information; they also point to the existence of certain forms of information not yet formalized in Layout2.

  13. How Do Multiple-Star Systems Form? VLA Study Reveals "Smoking Gun"

    Science.gov (United States)

    2006-12-01

    Astronomers have used the National Science Foundation's Very Large Array (VLA) radio telescope to image a young, multiple-star system with unprecedented detail, yielding important clues about how such systems are formed. Most Sun-sized or larger stars in the Universe are not single, like our Sun, but are members of multiple-star systems. Astronomers have been divided on how such systems can form, producing competing theoretical models for this process. Multiple Star Formation Graphic Proposed Formation Process for L1551 IRS5 CREDIT: Bill Saxton, NRAO/AUI/NSF Click on image for page of graphics and full information The new VLA study produced a "smoking gun" supporting one of the competing models, said Jeremy Lim, of the Institute of Astronomy & Astrophysics, Academia Sinica, in Taipei, Taiwan, whose study, done with Shigehisa Takakuwa of the National Astronomical Observatory of Japan, is published in the December 10 issue of the Astrophysical Journal. Ironically, their discovery of a third, previously-unknown, young star in the system may support a second theoretical model. "There may be more than one way to make a multiple-star system," Lim explained. The astronomers observed an object called L1551 IRS5, young, still-forming protostars enshrouded in a cloud of gas and dust, some 450 light-years from Earth in the direction of the constellation Taurus. Invisible to optical telescopes because of the gas and dust, this object was discovered in 1976 by astronomers using infrared telescopes. A VLA study in 1998 showed two young stars orbiting each other, each surrounded by a disk of dust that may, in time, congeal into a system of planets. Lim and Takakuwa re-examined the system, using improved technical capabilities that greatly boosted the quality of their images. "In the earlier VLA study, only half of the VLA's 27 antennas had receivers that could collect the radio waves, at a frequency of 43 GigaHertz (GHz), coming from the dusty disks. When we re-observed this

  14. SUB-STELLAR COMPANIONS AND STELLAR MULTIPLICITY IN THE TAURUS STAR-FORMING REGION

    International Nuclear Information System (INIS)

    Daemgen, Sebastian; Bonavita, Mariangela; Jayawardhana, Ray; Lafrenière, David; Janson, Markus

    2015-01-01

    We present results from a large, high-spatial-resolution near-infrared imaging search for stellar and sub-stellar companions in the Taurus-Auriga star-forming region. The sample covers 64 stars with masses between those of the most massive Taurus members at ∼3 M ☉ and low-mass stars at ∼0.2 M ☉ . We detected 74 companion candidates, 34 of these reported for the first time. Twenty-five companions are likely physically bound, partly confirmed by follow-up observations. Four candidate companions are likely unrelated field stars. Assuming physical association with their host star, estimated companion masses are as low as ∼2 M Jup . The inferred multiplicity frequency within our sensitivity limits between ∼10-1500 AU is 26.3 −4.9 +6.6 %. Applying a completeness correction, 62% ± 14% of all Taurus stars between 0.7 and 1.4 M ☉ appear to be multiple. Higher order multiples were found in 1.8 −1.5 +4.2 % of the cases, in agreement with previous observations of the field. We estimate a sub-stellar companion frequency of ∼3.5%-8.8% within our sensitivity limits from the discovery of two likely bound and three other tentative very low-mass companions. This frequency appears to be in agreement with what is expected from the tail of the stellar companion mass ratio distribution, suggesting that stellar and brown dwarf companions share the same dominant formation mechanism. Further, we find evidence for possible evolution of binary parameters between two identified sub-populations in Taurus with ages of ∼2 Myr and ∼20 Myr, respectively

  15. SUB-STELLAR COMPANIONS AND STELLAR MULTIPLICITY IN THE TAURUS STAR-FORMING REGION

    Energy Technology Data Exchange (ETDEWEB)

    Daemgen, Sebastian [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5H 3H4 (Canada); Bonavita, Mariangela [The University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Jayawardhana, Ray [Physics and Astronomy, York University, Toronto, Ontario L3T 3R1 (Canada); Lafrenière, David [Department of Physics, University of Montréal, Montréal, QC (Canada); Janson, Markus, E-mail: daemgen@astro.utoronto.ca [Department of Astronomy, Stockholm University, Stockholm (Sweden)

    2015-02-01

    We present results from a large, high-spatial-resolution near-infrared imaging search for stellar and sub-stellar companions in the Taurus-Auriga star-forming region. The sample covers 64 stars with masses between those of the most massive Taurus members at ∼3 M {sub ☉} and low-mass stars at ∼0.2 M {sub ☉}. We detected 74 companion candidates, 34 of these reported for the first time. Twenty-five companions are likely physically bound, partly confirmed by follow-up observations. Four candidate companions are likely unrelated field stars. Assuming physical association with their host star, estimated companion masses are as low as ∼2 M {sub Jup}. The inferred multiplicity frequency within our sensitivity limits between ∼10-1500 AU is 26.3{sub −4.9}{sup +6.6}%. Applying a completeness correction, 62% ± 14% of all Taurus stars between 0.7 and 1.4 M {sub ☉} appear to be multiple. Higher order multiples were found in 1.8{sub −1.5}{sup +4.2}% of the cases, in agreement with previous observations of the field. We estimate a sub-stellar companion frequency of ∼3.5%-8.8% within our sensitivity limits from the discovery of two likely bound and three other tentative very low-mass companions. This frequency appears to be in agreement with what is expected from the tail of the stellar companion mass ratio distribution, suggesting that stellar and brown dwarf companions share the same dominant formation mechanism. Further, we find evidence for possible evolution of binary parameters between two identified sub-populations in Taurus with ages of ∼2 Myr and ∼20 Myr, respectively.

  16. Development of particle multiplicity distributions using a general form of the grand canonical partition function

    International Nuclear Information System (INIS)

    Lee, S.J.; Mekjian, A.Z.

    2004-01-01

    Various phenomenological models of particle multiplicity distributions are discussed using a general form of a unified model which is based on the grand canonical partition function and Feynman's path integral approach to statistical processes. These models can be written as special cases of a more general distribution which has three control parameters which are a,x,z. The relation to these parameters to various physical quantities are discussed. A connection of the parameter a with Fisher's critical exponent τ is developed. Using this grand canonical approach, moments, cumulants and combinants are discussed and a physical interpretation of the combinants are given and their behavior connected to the critical exponent τ. Various physical phenomena such as hierarchical structure, void scaling relations, Koba-Nielson-Olesen or KNO scaling features, clan variables, and branching laws are shown in terms of this general approach. Several of these features which were previously developed in terms of the negative binomial distribution are found to be more general. Both hierarchical structure and void scaling relations depend on the Fisher exponent τ. Applications of our approach to the charged particle multiplicity distribution in jets of L3 and H1 data are given

  17. Numerical and Experimental Study on the Formation and Dispersion Patterns of Multiple Explosively Formed Penetrators

    Directory of Open Access Journals (Sweden)

    Jian Feng Liu

    Full Text Available Abstract Three-dimensional numerical simulations and experiments were performed to examine the formation and spatial dispersion patterns of integral multiple explosively formed penetrators (MEFP warhead with seven hemispherical liners. Numerical results had successfully described the formation process and distribution pattern of MEFP. A group of penetrators consisting of a central penetrator surrounded by 6 penetrators is formed during the formation process of MEFP and moves in the direction of aiming position. The maximum divergence angle of the surrounding penetrator group was 7.8°, and the damage area could reach 0.16 m2 at 1.2 m. The laws of perforation dispersion patterns of MEFP were also obtained through a nonlinear fitting of the perforation information on the target at different standoffs. The terminal effects of the MEFP warhead were performed on three #45 steel targets with a dimension of 160cm ( 160cm ( 1.5cm at various standoffs (60, 80, and 120 cm. The simulation results were validated through penetration experiments at different standoffs. It has shown excellent agreement between simulation and experiment results.

  18. Do Multiple Forms of Social Capital Mediate the Relationship Between Parental Violence and Children's Maladaptive Behaviors?

    Science.gov (United States)

    Kim, Sangwon; Lee, Yanghee

    2018-03-01

    Many things can harm children's well-being. Among them, exposure to parental violence makes children vulnerable and often leads to aggression and/or depression. However, not all children who have suffered parental violence show aggressive behavior or depressive mood. Social capital, defined as resources accruing from interpersonal relationships, was proposed to significantly mediate the relationships among adverse experiences and their negative impacts. In previous studies, social capital accrued from parents played a positive role for children in violent situations, but children exposed to parental violence need alternative sources of social capital. This study targeted fourth-grade Korean children and aimed to identify and test the role of various forms of social capital to help children overcome negative consequences from parental violence. Siblings, friends, teachers, neighbors, and online acquaintances were sources of social capital, and the results showed that social capital from siblings, teachers, neighbors, or online acquaintances mediated in the relationships between parental violence and aggressive behavior. In addition, social capital from siblings and online acquaintances mediated in the relationships between parental violence and depressive mood. The findings have implications in terms of intervention. It is suggested that multiple forms of social capital from children's immediate environments are helpful in their adaptation from exposure to parental violence, and thus, relationship-based interventions are recommended.

  19. Cortical thinning in the anterior cingulate cortex predicts multiple sclerosis patients' fluency performance in a lateralised manner

    Directory of Open Access Journals (Sweden)

    Olivia Geisseler

    2016-01-01

    Full Text Available Cognitive impairment is as an important feature of Multiple Sclerosis (MS, and might be even more relevant to patients than mobility restrictions. Compared to the multitude of studies investigating memory deficits or basic cognitive slowing, executive dysfunction is a rarely studied cognitive domain in MS, and its neural correlates remain largely unexplored. Even rarer are topological studies on specific cognitive functions in MS. Here we used several structural MRI parameters – including cortical thinning and T2 lesion load – to investigate neural correlates of executive dysfunction, both on a global and a regional level by means of voxel- and vertex-wise analyses. Forty-eight patients with relapsing-remitting MS and 48 healthy controls participated in the study. Five executive functions were assessed, i.e. verbal and figural fluency, working memory, interference control and set shifting. Patients scored lower than controls in verbal and figural fluency only, and displayed widespread cortical thinning. On a global level, cortical thickness independently predicted verbal fluency performance, when controlling for lesion volume and central brain atrophy estimates. On a regional level, cortical thinning in the anterior cingulate region correlated with deficits in verbal and figural fluency and did so in a lateralised manner: Left-sided thinning was related to reduced verbal – but not figural – fluency, whereas the opposite pattern was observed for right-sided thinning. We conclude that executive dysfunction in MS patients can specifically affect verbal and figural fluency. The observed lateralised clinico-anatomical correlation has previously been described in brain-damaged patients with large focal lesions only, for example after stroke. Based on focal grey matter atrophy, we here show for the first time comparable lateralised findings in a white matter disease with widespread pathology.

  20. Metabolic gene expression changes in astrocytes in Multiple Sclerosis cerebral cortex are indicative of immune-mediated signaling

    KAUST Repository

    Zeis, T.

    2015-04-01

    Emerging as an important correlate of neurological dysfunction in Multiple Sclerosis (MS), extended focal and diffuse gray matter abnormalities have been found and linked to clinical manifestations such as seizures, fatigue and cognitive dysfunction. To investigate possible underlying mechanisms we analyzed the molecular alterations in histopathological normal appearing cortical gray matter (NAGM) in MS. By performing a differential gene expression analysis of NAGM of control and MS cases we identified reduced transcription of astrocyte specific genes involved in the astrocyte–neuron lactate shuttle (ANLS) and the glutamate–glutamine cycle (GGC). Additional quantitative immunohistochemical analysis demonstrating a CX43 loss in MS NAGM confirmed a crucial involvement of astrocytes and emphasizes their importance in MS pathogenesis. Concurrently, a Toll-like/IL-1β signaling expression signature was detected in MS NAGM, indicating that immune-related signaling might be responsible for the downregulation of ANLS and GGC gene expression in MS NAGM. Indeed, challenging astrocytes with immune stimuli such as IL-1β and LPS reduced their ANLS and GGC gene expression in vitro. The detected upregulation of IL1B in MS NAGM suggests inflammasome priming. For this reason, astrocyte cultures were treated with ATP and ATP/LPS as for inflammasome activation. This treatment led to a reduction of ANLS and GGC gene expression in a comparable manner. To investigate potential sources for ANLS and GGC downregulation in MS NAGM, we first performed an adjuvant-driven stimulation of the peripheral immune system in C57Bl/6 mice in vivo. This led to similar gene expression changes in spinal cord demonstrating that peripheral immune signals might be one source for astrocytic gene expression changes in the brain. IL1B upregulation in MS NAGM itself points to a possible endogenous signaling process leading to ANLS and GGC downregulation. This is supported by our findings that, among others

  1. Multiple pyogenic liver abscesses formed after appendectomy: The role of percutaneous drainage in a critically ill patient

    Directory of Open Access Journals (Sweden)

    Enver Zerem

    2012-11-01

    Full Text Available Multiple pyogenic liver abscesses formed after appendectomy andtheir percutaneous treatment with multiple catheters have been rarelydescribed. We report a case of multiple pyogenic liver abscesses in acritically ill patient, formed after appendectomy and treated successfully by antibiotics and drainage with six catheters that were introduced simultaneously under ultrasound control. Even though this was a case of liver abscess secondary to appendicitis, today very rare in Western countries, but still a serious complication in developing countries, it was successfully resolved by percutaneous drainage, along with antibiotic therapy. Conclusion. We emphasize the advantages of percutaneous treatment compared with surgery regarding the avoidance of perioperative complications and the risks of general anesthesia.

  2. Correlation of Diffusion and Metabolic Alterations in Different Clinical Forms of Multiple Sclerosis

    Science.gov (United States)

    Hannoun, Salem; Bagory, Matthieu; Durand-Dubief, Francoise; Ibarrola, Danielle; Comte, Jean-Christophe; Confavreux, Christian; Cotton, Francois; Sappey-Marinier, Dominique

    2012-01-01

    Diffusion tensor imaging (DTI) and MR spectroscopic imaging (MRSI) provide greater sensitivity than conventional MRI to detect diffuse alterations in normal appearing white matter (NAWM) of Multiple Sclerosis (MS) patients with different clinical forms. Therefore, the goal of this study is to combine DTI and MRSI measurements to analyze the relation between diffusion and metabolic markers, T2-weighted lesion load (T2-LL) and the patients clinical status. The sensitivity and specificity of both methods were then compared in terms of MS clinical forms differentiation. MR examination was performed on 71 MS patients (27 relapsing remitting (RR), 26 secondary progressive (SP) and 18 primary progressive (PP)) and 24 control subjects. DTI and MRSI measurements were obtained from two identical regions of interest selected in left and right centrum semioval (CSO) WM. DTI metrics and metabolic contents were significantly altered in MS patients with the exception of N-acetyl-aspartate (NAA) and NAA/Choline (Cho) ratio in RR patients. Significant correlations were observed between diffusion and metabolic measures to various degrees in every MS patients group. Most DTI metrics were significantly correlated with the T2-LL while only NAA/Cr ratio was correlated in RR patients. A comparison analysis of MR methods efficiency demonstrated a better sensitivity/specificity of DTI over MRSI. Nevertheless, NAA/Cr ratio could distinguish all MS and SP patients groups from controls, while NAA/Cho ratio differentiated PP patients from controls. This study demonstrated that diffusivity changes related to microstructural alterations were correlated with metabolic changes and provided a better sensitivity to detect early changes, particularly in RR patients who are more subject to inflammatory processes. In contrast, the better specificity of metabolic ratios to detect axonal damage and demyelination may provide a better index for identification of PP patients. PMID:22479330

  3. The computational form of craving is a selective multiplication of economic value.

    Science.gov (United States)

    Konova, Anna B; Louie, Kenway; Glimcher, Paul W

    2018-04-17

    Craving is thought to be a specific desire state that biases choice toward the desired object, be it chocolate or drugs. A vast majority of people report having experienced craving of some kind. In its pathological form craving contributes to health outcomes in addiction and obesity. Yet despite its ubiquity and clinical relevance we still lack a basic neurocomputational understanding of craving. Here, using an instantaneous measure of subjective valuation and selective cue exposure, we identify a behavioral signature of a food craving-like state and advance a computational framework for understanding how this state might transform valuation to bias choice. We find desire induced by exposure to a specific high-calorie, high-fat/sugar snack good is expressed in subjects' momentary willingness to pay for this good. This effect is selective but not exclusive to the exposed good; rather, we find it generalizes to nonexposed goods in proportion to their subjective attribute similarity to the exposed ones. A second manipulation of reward size (number of snack units available for purchase) further suggested that a multiplicative gain mechanism supports the transformation of valuation during laboratory craving. These findings help explain how real-world food craving can result in behaviors inconsistent with preferences expressed in the absence of craving and open a path for the computational modeling of craving-like phenomena using a simple and repeatable experimental tool for assessing subjective states in economic terms. Copyright © 2018 the Author(s). Published by PNAS.

  4. Prevalence of Multiple Forms of Sexting Behavior Among Youth: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Madigan, Sheri; Ly, Anh; Rash, Christina L; Van Ouytsel, Joris; Temple, Jeff R

    2018-04-01

    The existing literature on sexting among youth shows that sexting is a predictor of sexual behavior and may be associated with other health outcomes and risky behaviors. However, there remains a lack of consensus on the prevalence of sexting, which is needed to inform future research, intervention, and policy development. To provide a meta-analytic synthesis of studies examining the prevalence of multiple forms of sexting behavior, analyzed by age, sex, geography, and method of sexting. In an academic setting, electronic searches in MEDLINE, PsycINFO, EMBASE, and Web of Science were conducted for the period January 1990 to June 2016, yielding 1147 nonduplicate records. Studies were included if participants were younger than 18 years and the prevalence of sexting explicit images, videos, or messages was reported. Literature review and data extraction followed established PRISMA guidelines. Two independent reviewers extracted all relevant data. Random-effects meta-analyses were used to derive the mean prevalence rates. Thirty-nine studies met final inclusion criteria. Meta-analyses of the prevalence of sending, receiving, and forwarding without consent, as well as having one's sext forwarded without consent. Among 39 included studies, there were 110 380 participants; the mean age was 15.16 years (age range, 11.9-17.0 years), and on average 47.2% were male. Studies were available for sending (n = 34), receiving (n = 20), forwarding without consent (n = 5), and having a sext forwarded without consent (n = 4). The mean prevalences for sending and receiving sexts were 14.8% (95% CI, 12.8%-16.8%) and 27.4% (95% CI, 23.1%-31.7%), respectively. Moderator analyses revealed that effect sizes varied as a function of child age (prevalence increased with age), year of data collection (prevalence increased over time), and sexting method (higher prevalence on mobile devices compared with computers). The prevalence of forwarding a sext without consent was 12

  5. One-step isothermal detection of multiple KRAS mutations by forming SNP specific hairpins on a gold nanoshell.

    Science.gov (United States)

    Chung, Chan Ho; Kim, Joong Hyun

    2018-04-24

    We developed a one-step isothermal method for typing multiple KRAS mutations using a designed set of primers to form a hairpin on a gold nanoshell upon being ligated by a SNP specific DNA ligase after binding of targets. As a result, we could detect as low as 20 attomoles of KRAS mutations within 1 h.

  6. Multiple dimensions of relatedness among words: Conjoint effects of form and meaning in word recognition★

    OpenAIRE

    Pastizzo, Matthew John; Feldman, Laurie Beth

    2009-01-01

    Words can be similar with respect to form (viz., spelling, pronunciation), meaning, or both form and meaning. In three lexical decision experiments (48 ms forward masked, 116 ms, and 250 ms SOAs), targets (e.g., FLOAT) followed prime words related by form only (e.g., COAT), meaning only (e.g., SWIM), or form and meaning (e.g., BOAT). BOAT–FLOAT and SWIM–FLOAT type pairs showed reduced target decision latencies relative to unrelated controls when primes were unmasked, but not when they were ma...

  7. Multiple blocks of intermittent and continuous theta-burst stimulation applied via transcranial magnetic stimulation differently affect sensory responses in rat barrel cortex.

    Science.gov (United States)

    Thimm, Andreas; Funke, Klaus

    2015-02-15

    Theta-burst stimulation (TBS) applied via transcranial magnetic stimulation is able to modulate human cortical excitability. Here we investigated in a rat model how two different forms of TBS, intermittent (iTBS) and continuous (cTBS), affect sensory responses in rat barrel cortex. We found that iTBS but less cTBS promoted late (>18 ms) sensory response components while not affecting the earliest response (8-18 ms). The effect increased with each of the five iTBS blocks applied. cTBS somewhat reduced the early response component after the first block but had a similar effect as iTBS after four to five blocks. We conclude that iTBS primarly modulates the activity of (inhibitory) cortical interneurons while cTBS may first reduce general neuronal excitability with a single block but reverse to iTBS-like effects with application of several blocks. Cortical sensory processing varies with cortical state and the balance of inhibition to excitation. Repetitive transcranial magnetic stimulation (rTMS) has been shown to modulate human cortical excitability. In a rat model, we recently showed that intermittent theta-burst stimulation (iTBS) applied to the corpus callosum, to activate primarily supragranular cortical pyramidal cells but fewer subcortical neurons, strongly reduced the cortical expression of parvalbumin (PV), indicating reduced activity of fast-spiking interneurons. Here, we used the well-studied rodent barrel cortex system to test how iTBS and continuous TBS (cTBS) modulate sensory responses evoked by either single or double stimuli applied to the principal (PW) and/or adjacent whisker (AW) in urethane-anaesthetized rats. Compared to sham stimulation, iTBS but not cTBS particularly enhanced late (>18 ms) response components of multi-unit spiking and local field potential responses in layer 4 but not the very early response (iTBS diminished the suppression of the second response evoked by paired PW or AW-PW stimulation at 20 ms intervals. The effects

  8. Cerebral cortex modulation of pain

    Institute of Scientific and Technical Information of China (English)

    Yu-feng XIE; Fu-quan HUO; Jing-shi TANG

    2009-01-01

    Pain is a complex experience encompassing sensory-discriminative, affective-motivational and cognitiv e-emotional com-ponents mediated by different mechanisms. Contrary to the traditional view that the cerebral cortex is not involved in pain perception, an extensive cortical network associated with pain processing has been revealed using multiple methods over the past decades. This network consistently includes, at least, the anterior cingulate cortex, the agranular insular cortex, the primary (SⅠ) and secondary somatosensory (SⅡ) cortices, the ventrolateral orbital cortex and the motor cortex. These corti-cal structures constitute the medial and lateral pain systems, the nucleus submedius-ventrolateral orbital cortex-periaque-ductal gray system and motor cortex system, respectively. Multiple neurotransmitters, including opioid, glutamate, GABA and dopamine, are involved in the modulation of pain by these cortical structures. In addition, glial cells may also be in-volved in cortical modulation of pain and serve as one target for pain management research. This review discusses recent studies of pain modulation by these cerebral cortical structures in animals and human.

  9. Acid protease and formation of multiple forms of glycoamylase in batch and continuous cultures of Aspergillus niger

    DEFF Research Database (Denmark)

    Aalbæk, Thomas; Reeslev, Morten; Jensen, Bo

    2002-01-01

    In order to identify factors responsible for production of multiple forms of glucoamylase (GA) by Aspergillus niger Bo-1, the fungus was cultured in both complex and defined media in pH-controlled batch fermenters and chemostats. At all culture conditions three forms of GA were produced...... degradation of the GA forms at low pH. It was concluded that the observed modifications of the extracellular profile of GA isoforms in A. niger Bo-1 are due to changes in pH and medium composition....

  10. Added value of multiple versus single sessions of repetitive transcranial magnetic stimulation in predicting motor cortex stimulation efficacy for refractory neuropathic pain.

    Science.gov (United States)

    Pommier, Benjamin; Quesada, Charles; Fauchon, Camille; Nuti, Christophe; Vassal, François; Peyron, Roland

    2018-05-18

    OBJECTIVE Selection criteria for offering patients motor cortex stimulation (MCS) for refractory neuropathic pain are a critical topic of research. A single session of repetitive transcranial magnetic stimulation (rTMS) has been advocated for selecting MCS candidates, but it has a low negative predictive value. Here the authors investigated whether multiple rTMS sessions would more accurately predict MCS efficacy. METHODS Patients included in this longitudinal study could access MCS after at least four rTMS sessions performed 3-4 weeks apart. The positive (PPV) and negative (NPV) predictive values of the four rTMS sessions and the correlation between the analgesic effects of the two treatments were assessed. RESULTS Twelve MCS patients underwent an average of 15.9 rTMS sessions prior to surgery; nine of the patients were rTMS responders. Postoperative follow-up was 57.8 ± 15.6 months (mean ± standard deviation). Mean percentage of pain relief (%R) was 21% and 40% after the first and fourth rTMS sessions, respectively. The corresponding mean durations of pain relief were respectively 2.4 and 12.9 days. A cumulative effect of the rTMS sessions was observed on both %R and duration of pain relief (p < 0.01). The %R value obtained with MCS was 35% after 6 months and 43% at the last follow-up. Both the PPV and NPV of rTMS were 100% after the fourth rTMS session (p = 0.0045). A significant correlation was found between %R or duration of pain relief after the fourth rTMS session and %R at the last MCS follow-up (R 2 = 0.83, p = 0.0003). CONCLUSIONS Four rTMS sessions predicted MCS efficacy better than a single session in neuropathic pain patients. Taking into account the cumulative effects of rTMS, the authors found a high-level correlation between the analgesic effects of rTMS and MCS.

  11. Importance of magnesium depletion with hypofunction of the biological clock in the pathophysiology of headhaches with photophobia, sudden infant death and some clinical forms of multiple sclerosis.

    Science.gov (United States)

    Durlach, J; Pagès, N; Bac, P; Bara, M; Guiet-Bara, A

    2004-12-01

    Mg depletion is a type of Mg deficit due to a dysregulation of the Mg status. It cannot be corrected through nutritional supplementation only, but requires the most specific correction of the dysregulating mechanism. Among those, Biological Clock (BC) dysrhythmias are to be considered. The aim of this study is to analyze the clinical forms of Mg depletion with hypofunction of the Biological Clock (hBC). hBC may be due to either Primary disorders of BC [Suprachiasmatic Nuclei (SCN) and pineal gland (PG)] or Secondary with homeostatic response [reactive Photophobia (Pphi] to light neurostimulating effects [Nervous Hyper Excitability (NHE)]. The symptomatology is mainly diurnal and observed during fair weather (Spring,Summer). The elective marker of hBC is represented by a decrease in melatonin and in its metabolites in various fluids. The clinical forms of NHE due to Mg depletion with hBC are central and peripheral. The central forms associate anxiety, headaches and dyssomnia. The peripheral manifestations are neuromuscular: photosensitive epilepsia mainly. Three chronopathological forms of Mg depletion with hBC have been highlighted: 1. Headaches with Pphi: mainly migraine; 2. Sudden Infant Death Syndrome (SIDS); 3. Multiple Sclerosis (MS).- Headaches with Pphi, migraine particularly. These cephalalgias are diurnal with Pphi and are aggravated during the fair seasons (particularly during midnight sun-summer). Migraine is their typical form with its dishabituation to visual stimuli and its occipital cortex hyperexcitability. Comorbidity with anxiety is frequent. In 2/3 of the cases, it appears first.- SIDS might be linked to an impaired maturation of both photoendocrine system and brown adipose tissue. MS may be associated with primary disorders of BC Clinical forms of Mg depletion with hBC in MS present diurnal exacerbations and relapses during fair seasons. They have been underestimated because they disagree with the dogma of the , presently questioned

  12. The proteolytic system of pineapple stems revisited: Purification and characterization of multiple catalytically active forms.

    Science.gov (United States)

    Matagne, André; Bolle, Laetitia; El Mahyaoui, Rachida; Baeyens-Volant, Danielle; Azarkan, Mohamed

    2017-06-01

    Crude pineapple proteases extract (aka stem bromelain; EC 3.4.22.4) is an important proteolytic mixture that contains enzymes belonging to the cysteine proteases of the papain family. Numerous studies have been reported aiming at the fractionation and characterization of the many molecular species present in the extract, but more efforts are still required to obtain sufficient quantities of the various purified protease forms for detailed physicochemical, enzymatic and structural characterization. In this work, we describe an efficient strategy towards the purification of at least eight enzymatic forms. Thus, following rapid fractionation on a SP-Sepharose FF column, two sub-populations with proteolytic activity were obtained: the unbound (termed acidic) and bound (termed basic) bromelain fractions. Following reversible modification with monomethoxypolyethylene glycol (mPEG), both fractions were further separated on Q-Sepharose FF and SP-Sepharose FF, respectively. This procedure yielded highly purified molecular species, all titrating ca. 1 mol of thiol group per mole of enzyme, with distinct biochemical properties. N-terminal sequencing allowed identifying at least eight forms with proteolytic activity. The basic fraction contained previously identified species, i.e. basic bromelain forms 1 and 2, ananain forms 1 and 2, and comosain (MEROPS identifier: C01.027). Furthermore, a new proteolytic species, showing similarities with basic bomelain forms 1 and 2, was discovered and termed bromelain form 3. The two remaining species were found in the acidic bromelain fraction and were arbitrarily named acidic bromelain forms 1 and 2. Both, acidic bromelain forms 1, 2 and basic bromelain forms 1, 2 and 3 are glycosylated, while ananain forms 1 and 2, and comosain are not. The eight protease forms display different amidase activities against the various substrates tested, namely small synthetic chromogenic compounds (DL-BAPNA and Boc-Ala-Ala-Gly-pNA), fluorogenic compounds

  13. Primes of the form x2+ny2 Fermat, class field theory, and complex multiplication

    CERN Document Server

    Cox, David A

    2014-01-01

    An exciting approach to the history and mathematics of number theory ". . . the author's style is totally lucid and very easy to read . . .the result is indeed a wonderful story." -Mathematical ReviewsWritten in a unique and accessible style for readers of varied mathematical backgrounds, the Second Edition of Primes of the Form p = x2+ ny2 details the history behind how Pierre de Fermat's work ultimately gave birth to quadratic reciprocity and the genus theory of quadratic forms. The book also illustrates how results of Euler and Gauss can be fully understood only in the context of class fi

  14. Modeling Multiple Human-Automation Distributed Systems using Network-form Games

    Science.gov (United States)

    Brat, Guillaume

    2012-01-01

    The paper describes at a high-level the network-form game framework (based on Bayes net and game theory), which can be used to model and analyze safety issues in large, distributed, mixed human-automation systems such as NextGen.

  15. Relationship between Multiple Forms of Maltreatment by a Parent or Guardian and Adolescent Alcohol Use.

    Science.gov (United States)

    Shin, Sunny Hyucksun; Edwards, Erika; Heeren, Timothy; Amodeo, Maryann

    2009-01-01

    This study examined the effect of the co-occurrence of multiple categories of maltreatment on adolescent alcohol use. Data were from the National Longitudinal Study of Adolescent Health which used a nationally representative sample of adolescents (n = 14,078). Among those reporting any maltreatment, over one-third had experienced more than one type of maltreatment. Logistic regression models found that all types or combinations of types of maltreatment except physical-abuse-only were strongly associated with adolescent alcohol use, controlling for age, gender, race, and parental alcoholism. These results add to accumulating evidence that child maltreatment has a deleterious impact on adolescent alcohol use.

  16. Morphology and solubility of multiple crystal forms of Taka-amylase A

    Science.gov (United States)

    Ninomiya, Kumiko; Yamamoto, Tenyu; Oheda, Tadashi; Sato, Kiyotaka; Sazaki, Gen; Matsuura, Yoshiki

    2001-01-01

    An α-amylase originating from a mold Aspergillus oryzae, Taka-amylase A (Mr of 52 kDa, pI of 3.8), has been purified to an electrophoretically single band grade. Crystallization behaviors were investigated using ammonium sulfate and polyethleneglycol 8000 as precipitants. The variations in the morphology of the crystals obtained with changing crystallization parameters are described. Five apparently different crystal forms were obtained, and their morphology and crystallographic data have been determined. Solubility values of four typical forms were measured using a Michelson-type two-beam interferometer. The results of these experiments showed that this protein can be a potentially interesting and useful model for crystal growth study with a gram-amount availability of pure protein sample.

  17. Reliability and equivalence of alternate forms for the Symbol Digit Modalities Test: implications for multiple sclerosis clinical trials.

    Science.gov (United States)

    Benedict, Ralph H B; Smerbeck, Audrey; Parikh, Rajavi; Rodgers, Jonathan; Cadavid, Diego; Erlanger, David

    2012-09-01

    Cognitive impairment is common in multiple sclerosis (MS), but is seldom assessed in clinical trials investigating the effects of disease-modifying therapies. The Symbol Digit Modalities Test (SDMT) is a particularly promising tool due to its sensitivity and robust correlation with brain magnetic resonance imaging (MRI) and vocational disability. Unfortunately, there are no validated alternate SDMT forms, which are needed to mitigate practice effects. The aim of the study was to assess the reliability and equivalence of SDMT alternate forms. Twenty-five healthy participants completed each of five alternate versions of the SDMT - the standard form, two versions from the Rao Brief Repeatable Battery, and two forms specifically designed for this study. Order effects were controlled using a Latin-square research design. All five versions of the SDMT produced mean values within 3 raw score points of one another. Three forms were very consistent, and not different by conservative statistical tests. The SDMT test-retest reliability using these forms was good to excellent, with all r values exceeding 0.80. For the first time, we find good evidence that at least three alternate versions of the SDMT are of equivalent difficulty in healthy adults. The forms are reliable, and can be implemented in clinical trials emphasizing cognitive outcomes.

  18. Multimodal Nonlinear Optical Imaging for Sensitive Detection of Multiple Pharmaceutical Solid-State Forms and Surface Transformations.

    Science.gov (United States)

    Novakovic, Dunja; Saarinen, Jukka; Rojalin, Tatu; Antikainen, Osmo; Fraser-Miller, Sara J; Laaksonen, Timo; Peltonen, Leena; Isomäki, Antti; Strachan, Clare J

    2017-11-07

    Two nonlinear imaging modalities, coherent anti-Stokes Raman scattering (CARS) and sum-frequency generation (SFG), were successfully combined for sensitive multimodal imaging of multiple solid-state forms and their changes on drug tablet surfaces. Two imaging approaches were used and compared: (i) hyperspectral CARS combined with principal component analysis (PCA) and SFG imaging and (ii) simultaneous narrowband CARS and SFG imaging. Three different solid-state forms of indomethacin-the crystalline gamma and alpha forms, as well as the amorphous form-were clearly distinguished using both approaches. Simultaneous narrowband CARS and SFG imaging was faster, but hyperspectral CARS and SFG imaging has the potential to be applied to a wider variety of more complex samples. These methodologies were further used to follow crystallization of indomethacin on tablet surfaces under two storage conditions: 30 °C/23% RH and 30 °C/75% RH. Imaging with (sub)micron resolution showed that the approach allowed detection of very early stage surface crystallization. The surfaces progressively crystallized to predominantly (but not exclusively) the gamma form at lower humidity and the alpha form at higher humidity. Overall, this study suggests that multimodal nonlinear imaging is a highly sensitive, solid-state (and chemically) specific, rapid, and versatile imaging technique for understanding and hence controlling (surface) solid-state forms and their complex changes in pharmaceuticals.

  19. LED surgical lighting system with multiple free-form surfaces for highly sterile operating theater application.

    Science.gov (United States)

    Liu, Peng; Zhang, Yaqin; Zheng, Zhenrong; Li, Haifeng; Liu, Xu

    2014-06-01

    Although the ventilation system is widely employed in the operating theater, a strictly sterile surgical environment still cannot be ensured because of laminar disturbance, which is mainly caused by the surgical lighting system. Abandoning traditional products, we propose an LED surgical lighting system, which can alleviate the laminar disturbance and provide an appropriate lighting condition for surgery. It contains a certain amount of LED lens units, which are embedded in the ceiling and arranged around the air supply smallpox. The LED lens unit integrated with an LED light source and a free-form lens is required to produce a uniform circular illumination with a large tolerance to the change of lighting distance. To achieve such a dedicated lens, two free-form refractive surfaces, which are converted into two ordinary differential equations by the design method presented in this paper, are used to deflect the rays. The results show that the LED surgical lighting system can provide an excellent illumination environment for surgery, and, apparently, the laminar disturbance also can be relieved.

  20. Monoclonal antibodies reveal multiple forms of expression of human microsomal epoxide hydrolase

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Hongying; Takagi, Akira [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Kayano, Hidekazu [Department of Pathology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan); Koyama, Isamu [Department of Digestive and General Surgery, Saitama International Medical Center, Faculty of Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1298 (Japan); Morisseau, Christophe; Hammock, Bruce D. [Department of Entomology and Cancer Center, University of California, Davis, One Shields Avenue, Davis, CA 95616-8584 (United States); Akatsuka, Toshitaka, E-mail: akatsuka@saitama-med.ac.jp [Department of Microbiology, Faculty of Medicine, Saitama Medical University, Moroyama-cho, Iruma-gun, Saitama 350-0495 (Japan)

    2012-04-01

    In a previous study, we developed five kinds of monoclonal antibodies against different portions of human mEH: three, anti-N-terminal; one, anti-C-terminal; one, anti-conformational epitope. Using them, we stained the intact and the permeabilized human cells of various kinds and performed flow cytometric analysis. Primary hepatocytes and peripheral blood mononuclear cells (PBMC) showed remarkable differences. On the surface, hepatocytes exhibited 4 out of 5 epitopes whereas PBMC did not show any of the epitopes. mEH was detected inside both cell types, but the most prominent expression was observed for the conformational epitope in the hepatocytes and the two N-terminal epitopes in PBMC. These differences were also observed between hepatocyte-derived cell lines and mononuclear cell-derived cell lines. In addition, among each group, there were several differences which may be related to the cultivation, the degree of differentiation, or the original cell subsets. We also noted that two glioblastoma cell lines reveal marked expression of the conformational epitope on the surface which seemed to correlate with the brain tumor-associated antigen reported elsewhere. Several cell lines also underwent selective permeabilization before flow cytometric analysis, and we noticed that the topological orientation of mEH on the ER membrane in those cells was in accordance with the previous report. However, the orientation on the cell surface was inconsistent with the report and had a great variation between the cells. These findings show the multiple mode of expression of mEH which may be possibly related to the multiple roles that mEH plays in different cells. -- Highlights: ► We examine expression of five mEH epitopes in human cells. ► Remarkable differences exist between hepatocytes and PBMC. ► mEH expression in cell lines differs depending on several factors. ► Some glioblastoma cell lines reveal marked surface expression of mEH. ► Topology of mEH on the cell

  1. Injectable interferon beta-1b for the treatment of relapsing forms of multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Slobodan M Jankovic

    2010-03-01

    Full Text Available Slobodan M JankovicPharmacology Department, Medical Faculty, University of Kragujevac, Kragujevac, SerbiaAbstract: Multiple sclerosis (MS is chronic inflammatory and demyelinating disease with either a progressive (10%–15% or relapsing-remitting (85%–90% course. The pathological hallmarks of MS are lesions of both white and grey matter in the central nervous system. The onset of the disease is usually around 30 years of age. The patients experience an acute focal neurologic dysfunction which is not characteristic, followed by partial or complete recovery. Acute episodes of neurologic dysfunction with diverse signs and symptoms will then recur throughout the life of a patient, with periods of partial or complete remission and clinical stability in between. Currently, there are several therapeutic options for MS with disease-modifying properties. Immunomodulatory therapy with interferon beta-1b (IFN-β1b or -1a, glatiramer and natalizumab shows similar efficacy; in a resistant or intolerant patient, the most recently approved therapeutic option is mitoxantrone. IFN-β1b in patients with MS binds to specific receptors on surface of immune cells, changing the expression of several genes and leading to a decrease in quantity of cell-associated adhesion molecules, inhibition of major histocompatibility complex class II expression and reduction in inflammatory cells migration into the central nervous system. After 2 years of treatment, IFN-β1b reduces the risk of development of clinically defined MS from 45% (with placebo to 28% (with IFN-β1b. It also reduces relapses for 34% (1.31 exacerbations annually with placebo and 0.9 with higher dose of IFN-β1b and makes 31% more patients relapse-free. In secondary-progressive disease annual rate of progression is 3% lower with IFN-β1b. In recommended doses IFN-β1b causes the following frequent adverse effects: injection site reactions (redness, discoloration, inflammation, pain, necrosis and non

  2. [Living with a chronic progressive form of multiple sclerosis--a balance act].

    Science.gov (United States)

    Hellige, Barbara

    2002-12-01

    There are only a few studies in the German speaking countries available which address the subject of the experience of chronically ill people during the course of their illness. Therefore it was the intent of this present study to find answers for central nurse science issues: How do people who suffer from a chronically progressive course of multiple sclerosis experience the downward trajectory? Which strategies do they develop in order to integrate the disease into their lives? In what ways does the scientific paradigm of medicine influence the perceptions of the illness and the life with it? After an analysis of the national and international state of nursing research follows a description of the methodology of the Grounded Theory and the individual examination steps of the study. The second part examines some essentials of the study. The results show that the trajectory is characterized by four phases. At first the ill person concentrates on the social discussion of the pathogenesis and the medical paradigma. But with physical experiences, exchange with other affected people and acquired information, those concerned develop a very case-specific knowledge. Often disillusioned by the medication strategies, based on the experience that their subjectivity and their individuality are not taken into account, they increasingly disapprove the deficit-oriented perspective of the professionals. They develop distinctly self-caring potentialities. To identify and support this self-care potentialities should be the very core of nursing.

  3. Development and evaluation of new multiple-unit levodopa sustained-release floating dosage forms.

    Science.gov (United States)

    Goole, J; Vanderbist, F; Amighi, K

    2007-04-04

    This work relates to the development and the in vitro evaluation of sustained-release minitablets (MT), prepared by melt granulation and subsequent compression, which are designed to float over an extended period of time. Levodopa was used as a model drug. The importance of the composition and manufacturing parameters of the MT on their floating and dissolution properties was then examined. The investigation showed that MT composition and MT diameter had the greatest influence on drug release, which was sustained for more than 8h. By using the same formulation, the best floating properties were obtained with 3mm MT prepared at low compression forces ranging between 50 and 100N. Their resultant-weight (RW) values were always higher than those obtained with a marketed HBS dosage form within 13h. When they were filled into gelatin capsules, no sticking was observed. By evaluating the dissolution profiles of levodopa at different pH values, it was found that dissolution profiles depend more on the prolonged-release ability of Methocel K15M than on the pH-dependent solubility of levodopa. Finally, the robustness of the floating MT was assessed by testing the drug release variability in function of the stirring conditions during dissolution tests.

  4. Astrophysics. Multiple images of a highly magnified supernova formed by an early-type cluster galaxy lens.

    Science.gov (United States)

    Kelly, Patrick L; Rodney, Steven A; Treu, Tommaso; Foley, Ryan J; Brammer, Gabriel; Schmidt, Kasper B; Zitrin, Adi; Sonnenfeld, Alessandro; Strolger, Louis-Gregory; Graur, Or; Filippenko, Alexei V; Jha, Saurabh W; Riess, Adam G; Bradac, Marusa; Weiner, Benjamin J; Scolnic, Daniel; Malkan, Matthew A; von der Linden, Anja; Trenti, Michele; Hjorth, Jens; Gavazzi, Raphael; Fontana, Adriano; Merten, Julian C; McCully, Curtis; Jones, Tucker; Postman, Marc; Dressler, Alan; Patel, Brandon; Cenko, S Bradley; Graham, Melissa L; Tucker, Bradley E

    2015-03-06

    In 1964, Refsdal hypothesized that a supernova whose light traversed multiple paths around a strong gravitational lens could be used to measure the rate of cosmic expansion. We report the discovery of such a system. In Hubble Space Telescope imaging, we have found four images of a single supernova forming an Einstein cross configuration around a redshift z = 0.54 elliptical galaxy in the MACS J1149.6+2223 cluster. The cluster's gravitational potential also creates multiple images of the z = 1.49 spiral supernova host galaxy, and a future appearance of the supernova elsewhere in the cluster field is expected. The magnifications and staggered arrivals of the supernova images probe the cosmic expansion rate, as well as the distribution of matter in the galaxy and cluster lenses. Copyright © 2015, American Association for the Advancement of Science.

  5. Design and synthesis of an amphiphilic graft hydrogel having a hydrophobic domain formed by multiple interactions

    Energy Technology Data Exchange (ETDEWEB)

    Nitta, Kyohei [Department of Life and Functional Material Science, Graduate School of Natural Science, Konan University, 8-9-1 Okamoto, Higashinada, Kobe 658-8501 (Japan); Japan Society for the Promotion of Science (DC1), Ichibancho, Chiyoda, Tokyo 102-8471 (Japan); Kimoto, Atsushi [Department of Chemistry of Functional Molecules, Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Higashinada, Kobe 658-8501 (Japan); Watanabe, Junji, E-mail: junjiknd@konan-u.ac.jp [Department of Chemistry of Functional Molecules, Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Higashinada, Kobe 658-8501 (Japan)

    2016-11-01

    A novel hydrogel having hydrophobic oligo segments and hydrophilic poly(acrylamidoglycolic acid) (PAGA) as pH responsive polymer segments was designed and synthesized to be used as a soft biomaterial. Poly(trimethylene carbonate) (PTMC) as the side chain, for which the degrees of polymerization were 9, 19, and 49, and the composition ratios were 1, 5, and 10 mol%, was used as the oligo segment in the hydrogel. The swelling ratio of the hydrogel was investigated under various changes in conditions such as pH, temperature, and hydrogen bonding upon urea addition. Under pH 2–11 conditions, the graft gel reversibly swelled and shrank due to the effect of PAGA main chain. The interior morphology and skin layer of the hydrogel was observed by a scanning electron microscope. The hydrogel composed of PAGA as the hydrophilic polymer backbone had a sponge-like structure, with a pore size of approximately 100 μm. On the other hand, upon increasing the ratio of trimethylene carbonate (TMC) units in the hydrogel, the pores became smaller or disappeared. Moreover, thickness of the skin layer significantly increased with the swelling ratio depended on the incorporation ratios of the PTMC macromonomer. Molecular incorporation in the hydrogel was evaluated using a dye as a model drug molecule. These features would play an important role in drug loading. Increasing the ratio of TMC units favored the adsorption of the dye and activation of the incorporation behavior. - Highlights: • Hydrogen bonding and hydrophobic interaction are dominant factor for forming hydrogels. • Hydrogel properties were tuned by changing in graft length and macromonomer content in feed. • The resulting graft gel could encapsulate and retain organic dye in the hydrogel. • Poly(trimethylene carbonate) segment in the hydrogel was dominant unit for hydrogel.

  6. Only two sex forms but multiple gender variants: How to explain?

    Science.gov (United States)

    De Loof, Arnold

    2018-01-01

    ABSTRACT Are sex and gender interchangeable terms? In classical biology, both are sometimes but not always used on an equal basis for some groups of animals. However, for our own species the Homo sapiens, they are not. A major question is why are there only two types of gametes (sperm- and egg cells), two types of sex steroids, (androgens and estrogens in vertebrates, and two types of ecdysteroids in insects), while the reproduction-related behaviour of the gamete producers displays a much greater variability than just two prominent forms, namely heterosexual males and heterosexual females? It indicates that in addition to a few sex-determining genes ( = the first pillar), other factors play a role. A second possible pillar is the still poorly understood cognitive memory system in which electrical phenomena and its association with the plasma membrane membrane-cytoskeletal complex of cells play a major role (learning, imitation and imprinting). This paper advances a third pillar, that hitherto has been almost completely ignored, namely the cellular Ca2+-homeostasis system, more specifically its sex-specific differences. Differential male-female genetics- and hormone-based Ca2+-homeostasis with effects on gender-related processes has been named Calcigender before. It will be argued that it follows from the principles of Ca2+- physiology and homeostasis that all individuals of a sexually reproducing animal population have a personalized gender behaviour. Thus, subdividing gender-behaviours in hetero-, homo-, bi-, trans- etc. which all result from a differential use of the very same basic physiological principles, is too primitive a system that may yield false sociological interpretations. PMID:29497472

  7. Design and synthesis of an amphiphilic graft hydrogel having a hydrophobic domain formed by multiple interactions

    International Nuclear Information System (INIS)

    Nitta, Kyohei; Kimoto, Atsushi; Watanabe, Junji

    2016-01-01

    A novel hydrogel having hydrophobic oligo segments and hydrophilic poly(acrylamidoglycolic acid) (PAGA) as pH responsive polymer segments was designed and synthesized to be used as a soft biomaterial. Poly(trimethylene carbonate) (PTMC) as the side chain, for which the degrees of polymerization were 9, 19, and 49, and the composition ratios were 1, 5, and 10 mol%, was used as the oligo segment in the hydrogel. The swelling ratio of the hydrogel was investigated under various changes in conditions such as pH, temperature, and hydrogen bonding upon urea addition. Under pH 2–11 conditions, the graft gel reversibly swelled and shrank due to the effect of PAGA main chain. The interior morphology and skin layer of the hydrogel was observed by a scanning electron microscope. The hydrogel composed of PAGA as the hydrophilic polymer backbone had a sponge-like structure, with a pore size of approximately 100 μm. On the other hand, upon increasing the ratio of trimethylene carbonate (TMC) units in the hydrogel, the pores became smaller or disappeared. Moreover, thickness of the skin layer significantly increased with the swelling ratio depended on the incorporation ratios of the PTMC macromonomer. Molecular incorporation in the hydrogel was evaluated using a dye as a model drug molecule. These features would play an important role in drug loading. Increasing the ratio of TMC units favored the adsorption of the dye and activation of the incorporation behavior. - Highlights: • Hydrogen bonding and hydrophobic interaction are dominant factor for forming hydrogels. • Hydrogel properties were tuned by changing in graft length and macromonomer content in feed. • The resulting graft gel could encapsulate and retain organic dye in the hydrogel. • Poly(trimethylene carbonate) segment in the hydrogel was dominant unit for hydrogel.

  8. MULTIPLICITY, DISKS, AND JETS IN THE NGC 2071 STAR-FORMING REGION

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco-Gonzalez, Carlos [Max-Planck-Institut fuer Radioastronomie (MPIfR), Auf dem Huegel 69, 53121 Bonn (Germany); Osorio, Mayra; Anglada, Guillem; Gomez, Jose F. [Instituto de Astrofisica de Andalucia, CSIC, Camino Bajo de Huetor 50, E-18008 Granada (Spain); D' Alessio, Paola; Rodriguez, Luis F. [Centro de Radioastronomia y Astrofisica UNAM, Apartado Postal 3-72 (Xangari), 58089 Morelia, Michoacan (Mexico); Torrelles, Jose M., E-mail: carrasco@mpifr-bonn.mpg.de [Instituto de Ciencias del Espacio (CSIC)-UB/IEEC, Universitat de Barcelona, Marti i Franques 1, E-08028 Barcelona (Spain)

    2012-02-10

    We present centimeter (cm) and millimeter (mm) observations of the NGC 2071 star-forming region performed with the Very Large Array (VLA) and Combined Array for Research in Millimeter-wave Astronomy (CARMA). We detected counterparts at 3.6 cm and 3 mm for the previously known sources IRS 1, IRS 2, IRS 3, and VLA 1. All these sources show spectral energy distributions (SEDs) dominated by free-free thermal emission at cm wavelengths and thermal dust emission at mm wavelengths, suggesting that all of them are associated with young stellar objects (YSOs). IRS 1 shows a complex morphology at 3.6 cm, with changes in the direction of its elongation. We discuss two possible explanations to this morphology: the result of changes in the direction of a jet due to interactions with a dense ambient medium, or that we are actually observing the superposition of two jets arising from two components of a binary system. Higher angular resolution observations at 1.3 cm support the second possibility, since a double source is inferred at this wavelength. IRS 3 shows a clear jet-like morphology at 3.6 cm. Over a timespan of four years, we observed changes in the morphology of this source that we interpret as due to ejection of ionized material in a jet. The emission at 3 mm of IRS 3 is angularly resolved, with a deconvolved size (FWHM) of {approx}120 AU, and seems to be tracing a dusty circumstellar disk perpendicular to the radio jet. An irradiated accretion disk model around an intermediate-mass YSO can account for the observed SED and spatial intensity profile at 3 mm, supporting this interpretation.

  9. MULTIPLICITY, DISKS, AND JETS IN THE NGC 2071 STAR-FORMING REGION

    International Nuclear Information System (INIS)

    Carrasco-González, Carlos; Osorio, Mayra; Anglada, Guillem; Gómez, José F.; D'Alessio, Paola; Rodríguez, Luis F.; Torrelles, José M.

    2012-01-01

    We present centimeter (cm) and millimeter (mm) observations of the NGC 2071 star-forming region performed with the Very Large Array (VLA) and Combined Array for Research in Millimeter-wave Astronomy (CARMA). We detected counterparts at 3.6 cm and 3 mm for the previously known sources IRS 1, IRS 2, IRS 3, and VLA 1. All these sources show spectral energy distributions (SEDs) dominated by free-free thermal emission at cm wavelengths and thermal dust emission at mm wavelengths, suggesting that all of them are associated with young stellar objects (YSOs). IRS 1 shows a complex morphology at 3.6 cm, with changes in the direction of its elongation. We discuss two possible explanations to this morphology: the result of changes in the direction of a jet due to interactions with a dense ambient medium, or that we are actually observing the superposition of two jets arising from two components of a binary system. Higher angular resolution observations at 1.3 cm support the second possibility, since a double source is inferred at this wavelength. IRS 3 shows a clear jet-like morphology at 3.6 cm. Over a timespan of four years, we observed changes in the morphology of this source that we interpret as due to ejection of ionized material in a jet. The emission at 3 mm of IRS 3 is angularly resolved, with a deconvolved size (FWHM) of ∼120 AU, and seems to be tracing a dusty circumstellar disk perpendicular to the radio jet. An irradiated accretion disk model around an intermediate-mass YSO can account for the observed SED and spatial intensity profile at 3 mm, supporting this interpretation.

  10. Conformational changes induced by Mg2+ on the multiple forms of glutamine synthetase from Bacillus brevis Bb G1

    Directory of Open Access Journals (Sweden)

    Suja Abraham

    2013-01-01

    Full Text Available Conformational changes play an important role in the function of proteins. Glutamine synthetase, an important enzyme of nitrogen metabolism, was purified under sporulating (GSala and non-sporulating (GSpyr conditions and the effect of Mg2+ on these multiple forms was studied by fluorescence spectroscopy to detect possible conformational changes that occur in the presenceof Mg2+. The substantial changes in the fluorescence emission maximum, fluorescence intensity and lifetime that occur in the presence of different concentrations of Mg2+, indicated major changes in molecular conformations in both forms of this enzyme. The fluorescent changes produced by the effect of Mg2+ in GSala was much more prominent than in GSpyr. These observations strongly support the possibility that GSala and GSpyr undergoes a conformational change on binding with Mg2+.

  11. Connecting the Dots: State Health Department Approaches to Addressing Shared Risk and Protective Factors Across Multiple Forms of Violence

    Science.gov (United States)

    Wilkins, Natalie; Myers, Lindsey; Kuehl, Tomei; Bauman, Alice; Hertz, Marci

    2018-01-01

    Violence takes many forms, including intimate partner violence, sexual violence, child abuse and neglect, bullying, suicidal behavior, and elder abuse and neglect. These forms of violence are interconnected and often share the same root causes. They can also co-occur together in families and communities and can happen at the same time or at different stages of life. Often, due to a variety of factors, separate, “siloed” approaches are used to address each form of violence. However, understanding and implementing approaches that prevent and address the overlapping root causes of violence (risk factors) and promote factors that increase the resilience of people and communities (protective factors) can help practitioners more effectively and efficiently use limited resources to prevent multiple forms of violence and save lives. This article presents approaches used by 2 state health departments, the Maryland Department of Health and Mental Hygiene and the Colorado Department of Public Health and Environment, to integrate a shared risk and protective factor approach into their violence prevention work and identifies key lessons learned that may serve to inform crosscutting violence prevention efforts in other states. PMID:29189502

  12. Connecting the Dots: State Health Department Approaches to Addressing Shared Risk and Protective Factors Across Multiple Forms of Violence.

    Science.gov (United States)

    Wilkins, Natalie; Myers, Lindsey; Kuehl, Tomei; Bauman, Alice; Hertz, Marci

    Violence takes many forms, including intimate partner violence, sexual violence, child abuse and neglect, bullying, suicidal behavior, and elder abuse and neglect. These forms of violence are interconnected and often share the same root causes. They can also co-occur together in families and communities and can happen at the same time or at different stages of life. Often, due to a variety of factors, separate, "siloed" approaches are used to address each form of violence. However, understanding and implementing approaches that prevent and address the overlapping root causes of violence (risk factors) and promote factors that increase the resilience of people and communities (protective factors) can help practitioners more effectively and efficiently use limited resources to prevent multiple forms of violence and save lives. This article presents approaches used by 2 state health departments, the Maryland Department of Health and Mental Hygiene and the Colorado Department of Public Health and Environment, to integrate a shared risk and protective factor approach into their violence prevention work and identifies key lessons learned that may serve to inform crosscutting violence prevention efforts in other states.

  13. Structural relationships among the multiple forms of DNA-dependent RNA polymerase II from cultured parsley cells

    International Nuclear Information System (INIS)

    Link, G.; Bogorad, L.; Kidd, G.H.; Richter, G.

    1978-01-01

    DNA-dependent RNA polymerase II (or B) was purified from cultured parsley cells, and its molecular structure was examined in detail. Upon centrifugation through glycerol gradients, RNA polymerase II sediments as a single band with an apparent sedimentation constant of 15S. No contamination with RNA polymerases I or III could be detected when the activity of purified RNA polymerase II was assayed in the presence of high concentrations of α-amanitin. Analysis of purified RNA polymerase II be nondenaturing and denaturing polyacrylamide gel electrophoresis revealed that this enzyme exists in multiple forms. They were designated II(O), II(A), and II(B). It is suggested that each form has a subunit of Mr = 140000 as well as smaller polypeptides in common. They differ, however, in the molecular weights of their largest subunits which is 220000 in form II(O), 200000 in form II(A), and 180000 in form II(B). These large subunits were labelled with 125 I, digested with trypsin, and tryptic digests were compared by two-dimensional analysis on thin-layer plates (Elder et al. (1977) J. Biol. Chem. 252, 6510-6515). Fingerprints of tryptic digests from the polypeptides with Mr = 220000, Mr = 200000, and Mr = 180000 were similar. It is, therefore, suggested that these subunits are stucturally related. A tryptic digest was also produced from the subunit with Mr = 140000. Its fingerprint was found to yield a considerably different distribution of peptides as compared to those from the three large subunits. (orig.) [de

  14. The Social Attribution Task-Multiple Choice (SAT-MC): A Psychometric and Equivalence Study of an Alternate Form.

    Science.gov (United States)

    Johannesen, Jason K; Lurie, Jessica B; Fiszdon, Joanna M; Bell, Morris D

    2013-01-01

    The Social Attribution Task-Multiple Choice (SAT-MC) uses a 64-second video of geometric shapes set in motion to portray themes of social relatedness and intentions. Considered a test of "Theory of Mind," the SAT-MC assesses implicit social attribution formation while reducing verbal and basic cognitive demands required of other common measures. We present a comparability analysis of the SAT-MC and the new SAT-MC-II, an alternate form created for repeat testing, in a university sample (n = 92). Score distributions and patterns of association with external validation measures were nearly identical between the two forms, with convergent and discriminant validity supported by association with affect recognition ability and lack of association with basic visual reasoning. Internal consistency of the SAT-MC-II was superior (alpha = .81) to the SAT-MC (alpha = .56). Results support the use of SAT-MC and new SAT-MC-II as equivalent test forms. Demonstrating relatively higher association to social cognitive than basic cognitive abilities, the SAT-MC may provide enhanced sensitivity as an outcome measure of social cognitive intervention trials.

  15. The Kinematics of Multiple-peaked Lyα Emission in Star-forming Galaxies at z ~ 2-3

    Science.gov (United States)

    Kulas, Kristin R.; Shapley, Alice E.; Kollmeier, Juna A.; Zheng, Zheng; Steidel, Charles C.; Hainline, Kevin N.

    2012-01-01

    We present new results on the Lyα emission-line kinematics of 18 z ~ 2-3 star-forming galaxies with multiple-peaked Lyα profiles. With our large spectroscopic database of UV-selected star-forming galaxies at these redshifts, we have determined that ~30% of such objects with detectable Lyα emission display multiple-peaked emission profiles. These profiles provide additional constraints on the escape of Lyα photons due to the rich velocity structure in the emergent line. Despite recent advances in modeling the escape of Lyα from star-forming galaxies at high redshifts, comparisons between models and data are often missing crucial observational information. Using Keck II NIRSPEC spectra of Hα (z ~ 2) and [O III]λ5007 (z ~ 3), we have measured accurate systemic redshifts, rest-frame optical nebular velocity dispersions, and emission-line fluxes for the objects in the sample. In addition, rest-frame UV luminosities and colors provide estimates of star formation rates and the degree of dust extinction. In concert with the profile sub-structure, these measurements provide critical constraints on the geometry and kinematics of interstellar gas in high-redshift galaxies. Accurate systemic redshifts allow us to translate the multiple-peaked Lyα profiles into velocity space, revealing that the majority (11/18) display double-peaked emission straddling the velocity-field zero point with stronger red-side emission. Interstellar absorption-line kinematics suggest the presence of large-scale outflows for the majority of objects in our sample, with an average measured interstellar absorption velocity offset of langΔv absrang = -230 km s-1. A comparison of the interstellar absorption kinematics for objects with multiple- and single-peaked Lyα profiles indicate that the multiple-peaked objects are characterized by significantly narrower absorption line widths. We compare our data with the predictions of simple models for outflowing and infalling gas distributions around

  16. Evaluation of Shear Strength of RC Beams with Multiple Interfaces Formed before Initial Setting Using 3D Printing Technology

    Directory of Open Access Journals (Sweden)

    Kyeongjin Kim

    2017-11-01

    Full Text Available With the recent development of 3D printing technology, concrete materials are sometimes used in 3D printing. Concrete structures based on 3D printing have been characterized to have the form of multiple layer build-up. Unlike general concrete structures, therefore, the 3D-printed concrete can be regarded as an orthotropic material. The material property of the 3D-printed concrete’s interface between layers is expected to be far different from that of general concrete bodies since there are no aggregate interlocks and weak chemical bonding. Such a difference finally affects the structural performance of concrete structures even though the interfaces are formed before initial setting of the concrete. The current study mainly reviewed the changes in fracture energy (toughness with respect to various environmental conditions of such interface. Changes in fracture energies of interfaces between concrete layers were measured using low-speed Crack Mouth Opening Displacement (CMOD closed loop concrete fracture test. The experimental results indicated reduction in fracture energy as well as tensile strengths. To improve the tensile strength of interfaces, the use of bridging materials is suggested. Since it was assumed that reduction in fracture energy could be a cause of shear strength, to evaluate the reduced structural performance of concrete structure constructed with multiple interfaces by 3D printing technology, the shear strength of RC beam by 3D printing technology was predicted and compared with that of plain RC beam. Based on the fracture energy measured in this study, Modified Compression Field Theory (MCFT theory-applied Vector 2 program was employed to predict the degree of reduction in shear strength without considering stirrups. Reduction factors were presented based on the obtained results to predict the reduction in shear strength due to interfaces before initial setting of the concrete.

  17. A method for determining the analytical form of a radionuclide depth distribution using multiple gamma spectrometry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Steven Clifford, E-mail: sdewey001@gmail.com [United States Air Force School of Aerospace Medicine, Occupational Environmental Health Division, Health Physics Branch, Radiation Analysis Laboratories, 2350 Gillingham Drive, Brooks City-Base, TX 78235 (United States); Whetstone, Zachary David, E-mail: zacwhets@umich.edu [Radiological Health Engineering Laboratory, Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, 1906 Cooley Building, Ann Arbor, MI 48109-2104 (United States); Kearfott, Kimberlee Jane, E-mail: kearfott@umich.edu [Radiological Health Engineering Laboratory, Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, 1906 Cooley Building, Ann Arbor, MI 48109-2104 (United States)

    2011-06-15

    When characterizing environmental radioactivity, whether in the soil or within concrete building structures undergoing remediation or decommissioning, it is highly desirable to know the radionuclide depth distribution. This is typically modeled using continuous analytical expressions, whose forms are believed to best represent the true source distributions. In situ gamma ray spectroscopic measurements are combined with these models to fully describe the source. Currently, the choice of analytical expressions is based upon prior experimental core sampling results at similar locations, any known site history, or radionuclide transport models. This paper presents a method, employing multiple in situ measurements at a single site, for determining the analytical form that best represents the true depth distribution present. The measurements can be made using a variety of geometries, each of which has a different sensitivity variation with source spatial distribution. Using non-linear least squares numerical optimization methods, the results can be fit to a collection of analytical models and the parameters of each model determined. The analytical expression that results in the fit with the lowest residual is selected as the most accurate representation. A cursory examination is made of the effects of measurement errors on the method. - Highlights: > A new method for determining radionuclide distribution as a function of depth is presented. > Multiple measurements are used, with enough measurements to determine the unknowns in analytical functions that might describe the distribution. > The measurements must be as independent as possible, which is achieved through special collimation of the detector. > Although the effects of measurements errors may be significant on the results, an improvement over other methods is anticipated.

  18. Multiple Forms and Settings of Exposure to Violence and Values: Unique and Interactive Relationships With Antisocial Behavior in Adolescence.

    Science.gov (United States)

    Bacchini, Dario; Affuso, Gaetana; Aquilar, Serena

    2015-10-01

    The general purpose of this study was to investigate the relationships between multiple forms and settings of exposure to violence (ETV) as well as personal values and antisocial behavior (ASB) in adolescence. The association of ETV as witness or victim in different contexts (family, school, or neighborhood) and the association of the selected values of power, universalism, and conformity with ASB were analyzed. In addition, the role of ETV in moderating the relationship between values and ASB was tested. A total of 369 adolescents participated in the study. Hierarchical multiple regression analysis was performed. Results revealed that ASB was independently affected by exposure to family violence as a victim, exposure to school violence as a witness, exposure to neighborhood violence as a witness, and by all three selected values. The associations of ASB with universalism and conformity were negative. Conversely, the association of ASB with power was positive. One interaction had statistically significant effects. Results revealed that exposure to school violence as a witness moderates the relationship between universalism and ASB. The results highlight a high percentage of explained variance by ETV and values on ASB and suggest the importance of adopting a socio-ecological framework in interpreting adolescent behavior. © The Author(s) 2014.

  19. Visual Categorization and the Parietal Cortex

    Directory of Open Access Journals (Sweden)

    Jamie K Fitzgerald

    2012-05-01

    Full Text Available The primate brain is adept at rapidly grouping items and events into functional classes, or categories, in order to recognize the significance of stimuli and guide behavior. Higher cognitive functions have traditionally been considered the domain of frontal areas. However, increasing evidence suggests that parietal cortex is also involved in categorical and associative processes. Previous work showed that the parietal cortex is highly involved in spatial processing, attention and saccadic eye movement planning, and more recent studies have found decision-making signals in LIP. We recently found that a subdivision of parietal cortex, the lateral intraparietal area (LIP, reflects learned categories for multiple types of visual stimuli. Additionally, a comparison of categorization signals in parietal and frontal areas found stronger and earlier categorization signals in parietal cortex, arguing that parietal abstract association or category signals are unlikely to arise via feedback from prefrontal cortex (PFC.

  20. Fadiga na forma remitente recorrente da esclerose múltipla Fatigue in multiple sclerosis relapsing-remitting form

    Directory of Open Access Journals (Sweden)

    MARIA FERNANDA MENDES

    2000-06-01

    Full Text Available Foram avaliados 95 pacientes com forma remitente-recorrente da esclerose múltipla quanto à presença de fadiga. A Escala de Severidade de Fadiga foi aplicada em todos os pacientes. Em 64 pacientes (67,4% a fadiga foi encontrada. Não observamos diferenças clínicas quanto ao gênero, idade, grau de incapacidade funcional e depressão, nos pacientes com e sem fadiga. Foi encontrada correlação entre ansiedade e tempo de doença com a presença de fadiga. Ao analisarmos estas variáveis quanto à intensidade da fadiga, observamos haver associação entre fadiga grave e maior incapacidade funcional.In 95 patients with the remitting-relapsing form of multiple sclerosis we investigated fatigue. All of them were evaluated with the Fatigue Severity Scale and we found it in 64 patients (67.4%. Gender, age, depression and fuctional incapacity was not predictive of fatigue occurrence, while anxiety and time of disease seems to be correlated with it. When we analysed the fatigue severity, a correlation between the EDSS and the increasing fatigue severity was found.

  1. ODMSummary: A Tool for Automatic Structured Comparison of Multiple Medical Forms Based on Semantic Annotation with the Unified Medical Language System.

    Science.gov (United States)

    Storck, Michael; Krumm, Rainer; Dugas, Martin

    2016-01-01

    Medical documentation is applied in various settings including patient care and clinical research. Since procedures of medical documentation are heterogeneous and developed further, secondary use of medical data is complicated. Development of medical forms, merging of data from different sources and meta-analyses of different data sets are currently a predominantly manual process and therefore difficult and cumbersome. Available applications to automate these processes are limited. In particular, tools to compare multiple documentation forms are missing. The objective of this work is to design, implement and evaluate the new system ODMSummary for comparison of multiple forms with a high number of semantically annotated data elements and a high level of usability. System requirements are the capability to summarize and compare a set of forms, enable to estimate the documentation effort, track changes in different versions of forms and find comparable items in different forms. Forms are provided in Operational Data Model format with semantic annotations from the Unified Medical Language System. 12 medical experts were invited to participate in a 3-phase evaluation of the tool regarding usability. ODMSummary (available at https://odmtoolbox.uni-muenster.de/summary/summary.html) provides a structured overview of multiple forms and their documentation fields. This comparison enables medical experts to assess multiple forms or whole datasets for secondary use. System usability was optimized based on expert feedback. The evaluation demonstrates that feedback from domain experts is needed to identify usability issues. In conclusion, this work shows that automatic comparison of multiple forms is feasible and the results are usable for medical experts.

  2. Predicting the oral pharmacokinetic profiles of multiple-unit (pellet) dosage forms using a modeling and simulation approach coupled with biorelevant dissolution testing: case example diclofenac sodium.

    Science.gov (United States)

    Kambayashi, Atsushi; Blume, Henning; Dressman, Jennifer B

    2014-07-01

    The objective of this research was to characterize the dissolution profile of a poorly soluble drug, diclofenac, from a commercially available multiple-unit enteric coated dosage form, Diclo-Puren® capsules, and to develop a predictive model for its oral pharmacokinetic profile. The paddle method was used to obtain the dissolution profiles of this dosage form in biorelevant media, with the exposure to simulated gastric conditions being varied in order to simulate the gastric emptying behavior of pellets. A modified Noyes-Whitney theory was subsequently fitted to the dissolution data. A physiologically-based pharmacokinetic (PBPK) model for multiple-unit dosage forms was designed using STELLA® software and coupled with the biorelevant dissolution profiles in order to simulate the plasma concentration profiles of diclofenac from Diclo-Puren® capsule in both the fasted and fed state in humans. Gastric emptying kinetics relevant to multiple-units pellets were incorporated into the PBPK model by setting up a virtual patient population to account for physiological variations in emptying kinetics. Using in vitro biorelevant dissolution coupled with in silico PBPK modeling and simulation it was possible to predict the plasma profile of this multiple-unit formulation of diclofenac after oral administration in both the fasted and fed state. This approach might be useful to predict variability in the plasma profiles for other drugs housed in multiple-unit dosage forms. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Functional inactivation of hypocretin 1 receptors in the medial prefrontal cortex affects the pyramidal neuron activity and gamma oscillations: An in vivo multiple-channel single-unit recording study.

    Science.gov (United States)

    He, C; Chen, Q-H; Ye, J-N; Li, C; Yang, L; Zhang, J; Xia, J-X; Hu, Z-A

    2015-06-25

    The hypocretin signaling is thought to play a critical role in maintaining wakefulness via stimulating the subcortical arousal pathways. Although the cortical areas, including the medial prefrontal cortex (mPFC), receive dense hypocretinergic fibers and express its receptors, it remains unclear whether the hypocretins can directly regulate the neural activity of the mPFC in vivo. In the present study, using multiple-channel single-unit recording study, we found that infusion of the SB-334867, a blocker for the Hcrtr1, beside the recording sites within the mPFC substantially exerted an inhibitory effect on the putative pyramidal neuron (PPN) activity in naturally behaving rats. In addition, functional blockade of the Hcrtr1 also selectively reduced the power of the gamma oscillations. The PPN activity and the power of the neural oscillations were not affected after microinjection of the TCS-OX2-29, a blocker for the Hcrtr2, within the mPFC. Together, these data indicate that endogenous hypocretins acting on the Hcrtr1 are required for the normal neural activity in the mPFC in vivo, and thus might directly contribute cortical arousal and mPFC-dependent cognitive processes. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Plasma biomarkers of decreased vesicular storage distinguish Parkinson disease with orthostatic hypotension from the parkinsonian form of multiple system atrophy.

    Science.gov (United States)

    Goldstein, David S; Kopin, Irwin J; Sharabi, Yehonatan; Holmes, Courtney

    2015-02-01

    Parkinson disease with orthostatic hypotension (PD + OH) and the parkinsonian form of multiple system atrophy (MSA-P) can be difficult to distinguish clinically. Recent studies indicate that PD entails a vesicular storage defect in catecholaminergic neurons. Although cardiac sympathetic neuroimaging by (18)F-dopamine positron emission tomography can identify decreased vesicular storage, this testing is not generally available. We assessed whether plasma biomarkers of a vesicular storage defect can separate PD + OH from MSA-P. We conceptualized that after F-dopamine injection, augmented production of F-dihydroxyphenylacetic acid (F-DOPAC) indicates decreased vesicular storage, and we therefore predicted that arterial plasma F-DOPAC would be elevated in PD + OH but not in MSA-P. We measured arterial plasma F-DOPAC after (18)F-dopamine administration (infused i.v. over 3 min) in patients with PD + OH (N = 12) or MSA-P (N = 21) and in healthy control subjects (N = 26). Peak F-DOPAC:dihydroxyphenylglycol (DHPG) was also calculated to adjust for effects of denervation on F-DOPAC production. Plasma F-DOPAC accumulated rapidly after initiation of (18)F-dopamine infusion. Peak F-DOPAC (5-10 min) in PD + OH averaged three times that in MSA-P (P 300 nCi-kg/cc-mCi, in contrast with 7 of 12 PD + OH patients (χ(2) = 16.6, P < 0.0001). DHPG was lower in PD + OH (3.83 ± 0.36 nmol/L) than in MSA-P (5.20 ± 0.29 nmol/L, P = 0.007). All MSA-P patients had peak F-DOPAC:DHPG < 60, in contrast with 9 of 12 PD + OH patients (χ(2) = 17.5, P < 0.0001). Adjustment of peak F-DOPAC for DHPG increased test sensitivity from 58 to 81% at similar high specificity. After F-dopamine injection, plasma F-DOPAC and F-DOPAC:DHPG distinguish PD + OH from MSA-P.

  5. Monitoring of multiple solvent induced form changes during high shear wet granulation and drying processes using online Raman spectroscopy.

    Science.gov (United States)

    Reddy, Jay Poorna; Jones, John W; Wray, Patrick S; Dennis, Andrew B; Brown, Jonathan; Timmins, Peter

    2018-04-25

    Form changes during drug product processing can be a risk to the final product quality in terms of chemical stability and bioavailability. In this study, online Raman spectroscopy was used to monitor the form changes in real time during high shear wet granulation of Compound A, a highly soluble drug present at a high drug load in an extended release formulation. The effect of water content, temperature, wet massing time and drying technique on the degree of drug transformation were examined. A designed set of calibration standards were employed to develop quantitative partial least square regression models to predict the concentration of each drug form during both wet granulation and the drying process. Throughout all our experiments we observed complex changes of the drug form during granulation, manifest as conversions between the initial non-solvated form of Compound A, the hemi-hydrate form and the "apparent" amorphous form (dissolved drug). The online Raman data demonstrate that the non-solvated form converts to an "apparent" amorphous form (dissolved drug) due to drug dissolution with no appearance of the hemi-hydrate form during water addition stage. The extent of conversion of the non-solvated form was governed by the amount of water added and the rate of conversion was accelerated at higher temperatures. Interestingly, in the wet massing zone, the formation of the hemi-hydrate form was observed at a rate equivalent to the rate of depletion of the non-solvated form with no change in the level of the "apparent amorphous" form generated. The level of hemi-hydrate increased with an increase in wet massing time. The drying process had a significant effect on the proportion of each form. During tray drying, changes in drug form continued for hours. In contrast fluid bed drying appeared to lock the final proportions of drug form product attained during granulation, with comparatively small changes observed during drying. In conclusion, it was possible to

  6. Multiple-Choice Testing Using Immediate Feedback--Assessment Technique (IF AT®) Forms: Second-Chance Guessing vs. Second-Chance Learning?

    Science.gov (United States)

    Merrel, Jeremy D.; Cirillo, Pier F.; Schwartz, Pauline M.; Webb, Jeffrey A.

    2015-01-01

    Multiple choice testing is a common but often ineffective method for evaluating learning. A newer approach, however, using Immediate Feedback Assessment Technique (IF AT®, Epstein Educational Enterprise, Inc.) forms, offers several advantages. In particular, a student learns immediately if his or her answer is correct and, in the case of an…

  7. Tumor necrosis factor-alfa and interleukin-4 in cerbrospinal fluid and plasma in different clinical forms of multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Obradović Dragana

    2012-01-01

    Full Text Available Background/Aim. Multiple sclerosis (MS is an immunemediated central nervous system disease characterized by inflammation, demyelination and axonal degeneration. Cytokines are proven mediators of immunological process in MS. The aim of this study was to investigate whether there is a difference in the production of the tumor necrosis factor alpha (TNF-alpha and interleukin-4 (IL-4 in cerebrospinal fluid (CSF and plasma in the MS patients and the controls (other neurological non-inflammatory diseases and to determine a possible difference in these cytokines in plasma and CSF in different clinical forms of MS. Methods. This study involved 60 consecutive MS patients - 48 patients with relapsing-remitting MS (RRMS and 12 patients with secondary progressive MS (SPMS. The control group consisted of 20, age and sex matched, nonimmunological, neurological patients. According to the clinical presentation of MS at the time of this investigation, 34 (56.7% patients had relapse (RRMS, 14 (23.3% were in remission (RRMS, while the rest of the patients, 12 (20.0%, were SPMS. TNF-alpha and IL-4 concentrations were measured in the same time in CSF and plasma in the MS patients and the controls. Extended disability status score (EDSS, albumin ratio and IgG index were determined in all MS patients. Results. The MS patients had significantly higher CSF and plasma levels of TNF-alpha than the controls (p < 0.001 for both samples. IL-4 CSF levels were significantly lower in the MS patients than in the controls (p < 0.001, however plasma levels were similar. The patients in relapse (RRMS and with progressive disease (SPMS had higher concentrations of CSF TNF-alpha levels than the patients in remission (p < 0.001. IL-4 CSF levels in relapse (RRMS and SPMS groups were lower than in the patients in remission. The patients in remission had an unmeasurable plasma TNF-alpha level and the patients with SPMS had significantly lower IL-4 levels in plasma than the patients in

  8. DNA-based prenatal diagnosis for severe and variant forms of multiple acyl-CoA dehydrogenation deficiency

    DEFF Research Database (Denmark)

    Olsen, Rikke K J; Andresen, Brage S; Christensen, Ernst

    2005-01-01

    OBJECTIVES: Multiple acyl-CoA dehydrogenation deficiency (MADD) is a clinically heterogeneous disorder of mitochondrial fatty acid, amino acid, and choline oxidation due to mutations in the genes encoding electron transfer flavoprotein (ETF) or ETF ubiquinone oxidoreductase (ETFQO). So far...

  9. What Form of Mathematics Are Assessments Assessing? The Case of Multiplication and Division in Fourth Grade NAEP Items

    Science.gov (United States)

    Kosko Karl W.; Singh, Rashmi

    2018-01-01

    Multiplicative reasoning is a key concept in elementary school mathematics. Item statistics reported by the National Assessment of Educational Progress (NAEP) assessment provide the best current indicator for how well elementary students across the U.S. understand this, and other concepts. However, beyond expert reviews and statistical analysis,…

  10. The Inclusion of Multiple Exceptional Gifted Students in Talent Development Programmes: Interaction Synthesis of Both Provision Form and Content

    Science.gov (United States)

    Gyarmathy, Éva; Senior, John

    2018-01-01

    Models of giftedness in the 21st century tend to describe talent as a social construct. Research now indicates that certain talented populations that are composed of multiple exceptional individuals are excluded from talent development programmes. Recognizing how well the environment best fits individual needs at particular key developmental…

  11. Photonic Crystal Waveguide Weakly Interacting with Multiple Off-Channel Resonant Features Formed of Kerr Nonlinear Dielectric Media

    Directory of Open Access Journals (Sweden)

    A. R. McGurn

    2007-01-01

    a number of analytical results are presented providing simple explanations of the quantitative behaviors of the systems. A relationship of these systems to forms of electromagnetic-induced transparency and modifications of waveguide dispersion relations is discussed.

  12. A New Approach in the Simplification of a Multiple-Beam Forming Network Based on CORPS Using Compressive Arrays

    Directory of Open Access Journals (Sweden)

    Armando Arce

    2012-01-01

    Full Text Available This research paper deals with a innovative way to simplify the design of beam-forming networks (BFNs for multibeam steerable antenna arrays based on coherently radiating periodic structures (CORPS technology using the noniterative matrix pencil method (MPM. This design approach is based on the application of the MPM to linear arrays fed by CORPS-BFN configurations to further reduce the complexity of the beam-forming network. Two 2-beam design configurations of CORPS-BFN for a steerable linear array are analyzed and compared using this compressive method. Simulation results show the effectiveness and advantages of applying the MPM on BFNs based on CORPS exploiting the nonuniformity of the antenna elements. Furthermore, final results show that the integration of CORPS-BFN and MPM reduces the entire antenna system including the antenna array and the beam-forming network subsystem resulting in a substantial simplification in such systems.

  13. Acid protease and formation of multiple forms of glucoamylase in batch and continuous cultures of Aspergillus niger

    DEFF Research Database (Denmark)

    Aalbæk, Thomas; Reeslev, Morten; Jensen, Bo

    2002-01-01

    with molecular weights of approx. 91 (GAI), 73 (GAII), and 59 kDa (GAIII). Data from batch fermentations with constant pH 3.0 and 5.0 showed a uniform distribution of extracellular GA forms throughout the fermentations and independent of culture growth phases. Furthermore, steady-state data from chemostat...

  14. Child Sexual Abuse and Women's Sexual Health: The Contribution of CSA Severity and Exposure to Multiple Forms of Childhood Victimization

    Science.gov (United States)

    Lacelle, Celine; Hebert, Martine; Lavoie, Francine; Vitaro, Frank; Tremblay, Richard E.

    2012-01-01

    Research studies have provided increasing evidence for the potential adverse impact of child sexual abuse on women's sexual health. The present study examined the association between child sexual abuse and sexual health while controlling for various forms of childhood victimization. Self-report questionnaires were administered to 889 young women…

  15. Columns formed by multiple twinning in nickel layers—An approach of grain boundary engineering by electrodeposition

    DEFF Research Database (Denmark)

    Alimadadi, Hossein; da Silva Fanta, Alice Bastos; Somers, Marcel A. J.

    2013-01-01

    grain boundaries. A peculiar arrangement of Σ3 boundaries forming five-fold junctions is observed. The resulting microstructure meets the requirements for grain boundary engineering. Twinning induced effects on the crystallographic orientation of grains result in one major texture component being a ⟨210......⟩ fiber axis and additional minor orientations originating from first and second generation twins of ⟨210⟩, i.e., ⟨542⟩ and ⟨20 2 1⟩....

  16. [[Method of forming a multiple attrition life table and its application to the study of nuptiality among women in China

    Science.gov (United States)

    Zeng, Y

    1987-01-01

    Trends in marital status among women in China for the period 1950-1970 and for 1981 are analyzed using the multiple decrement life table method. The results confirm those obtained with traditional methods of data analysis. It is found that over the past 30 years, Chinese women have experienced a high rate of marriage and a low divorce rate. The significant increase in age at marriage and the lowering of the death rate have affected marital status at all ages. The development of a marital status life table permits the author to estimate current numbers of women in the four marital statuses of unmarried, currently married, widowed, and divorced by age and their future likelihood of changing marital status.

  17. The mitochondrial genomes of sponges provide evidence for multiple invasions by Repetitive Hairpin-forming Elements (RHE

    Directory of Open Access Journals (Sweden)

    Lavrov Dennis V

    2009-12-01

    Full Text Available Abstract Background The mitochondrial (mt genomes of sponges possess a variety of features, which appear to be intermediate between those of Eumetazoa and non-metazoan opisthokonts. Among these features is the presence of long intergenic regions, which are common in other eukaryotes, but generally absent in Eumetazoa. Here we analyse poriferan mitochondrial intergenic regions, paying particular attention to repetitive sequences within them. In this context we introduce the mitochondrial genome of Ircinia strobilina (Lamarck, 1816; Demospongiae: Dictyoceratida and compare it with mtDNA of other sponges. Results Mt genomes of dictyoceratid sponges are identical in gene order and content but display major differences in size and organization of intergenic regions. An even higher degree of diversity in the structure of intergenic regions was found among different orders of demosponges. One interesting observation made from such comparisons was of what appears to be recurrent invasions of sponge mitochondrial genomes by repetitive hairpin-forming elements, which cause large genome size differences even among closely related taxa. These repetitive hairpin-forming elements are structurally and compositionally divergent and display a scattered distribution throughout various groups of demosponges. Conclusion Large intergenic regions of poriferan mt genomes are targets for insertions of repetitive hairpin- forming elements, similar to the ones found in non-metazoan opisthokonts. Such elements were likely present in some lineages early in animal mitochondrial genome evolution but were subsequently lost during the reduction of intergenic regions, which occurred in the Eumetazoa lineage after the split of Porifera. Porifera acquired their elements in several independent events. Patterns of their intra-genomic dispersal can be seen in the mt genome of Vaceletia sp.

  18. Tomographic and analog 3-D simulations using NORA. [Non-Overlapping Redundant Image Array formed by multiple pinholes

    Science.gov (United States)

    Yin, L. I.; Trombka, J. I.; Bielefeld, M. J.; Seltzer, S. M.

    1984-01-01

    The results of two computer simulations demonstrate the feasibility of using the nonoverlapping redundant array (NORA) to form three-dimensional images of objects with X-rays. Pinholes admit the X-rays to nonoverlapping points on a detector. The object is reconstructed in the analog mode by optical correlation and in the digital mode by tomographic computations. Trials were run with a stick-figure pyramid and extended objects with out-of-focus backgrounds. Substitution of spherical optical lenses for the pinholes increased the light transmission sufficiently that objects could be easily viewed in a dark room. Out-of-focus aberrations in tomographic reconstruction could be eliminated using Chang's (1976) algorithm.

  19. National Register of Historic Places multiple property documentation form -- Historic, archaeological, and traditional cultural properties of the Hanford Site, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Nickens, P.R.

    1997-08-01

    The US Department of Energy`s Hanford Site encompasses an area of 560 square miles on the Columbia River in southeastern Washington. Since 1943, the Hanford Site has existed as a protected area for activities primarily related to the production of radioactive materials for national defense uses. For cultural resources on the Hanford Site, establishment of the nuclear reservation as a high security area, with public access restricted, has resulted in a well-protected status, although no deliberate resource protection measures were in effect to mitigate effects of facilities construction and associated activities. Thus, the Hanford Site contains an extensive record of aboriginal archaeological sites and Native American cultural properties, along with pre-Hanford Euro-American sites (primarily archaeological in nature with the removal of most pre-1943 structures), and a considerable number of Manhattan Project/Cold War era buildings and structures. The recent mission change from production to clean up and disposal of DOE lands created a critical need for development and implementation of new and different cultural resource management strategies. DOE-RL has undertaken a preservation planning effort for the Hanford Site. The intent of this Plan is to enable DOE-RL to organize data and develop goals, objectives, and priorities for the identification, evaluation, registration, protection, preservation, and enhancement of the Site`s historical and cultural properties. Decisions made about the identification, evaluation, registration and treatment of historic properties are most aptly made when relationships between individual properties and other similar properties are considered. The historic context and the multiple property documentation (NTD) process provides DOE-RL the organizational framework for these decisions. Once significant patterns are identified, contexts developed, and expected properties are defined, the NTD process provides the foundation for future

  20. Effects of a radiation-induced α-thalassemia on the production of multiple forms of hemoglobins in fetal mice

    International Nuclear Information System (INIS)

    Popp, R.A.; Bradshaw, B.S.; Hirsch, G.P.

    1978-01-01

    Embryonic hemoglobins in α-thalassemic heterozygotes and normal fetuses were compared to study the effects of the deficient α chain on the synthesis of hemoglobins in the nucleated embryonic erythrocytes derived from the fetal yolk sac. Acrylamide gel electrophoresis showed that less hemoglobin Ell (α 2 y 2 ) was formed in α-thalassemic heterozygotes between 12 1 / 2 and 14 1 / 2 days of gestation. Quantitation of in vitro synthesis between 11 1 / 2 and 13 1 / 2 days of gestation also showed that Ell was synthesized less rapidly in α-thalassemic fetuses. In contrast, the synthesis of Elll (α 2 z 2 ) was higher in α-thalassemic than in normal fetuses at 12 1 / 2 and 13 1 / 2 days of gestation. Measurements of the synthesis of individual chains in El (x 2 y 2 ) and Ell showed that x chain synthesis was normal and that α chain synthesis was deficient in α-thalassemic fetuses at 11 1 / 2 and 12 1 / 2 days of gestation. Thus, there is still no proof for close linkage of x- and α-chain genes in chromosome 11. Differences in the electrophoretic patterns of embryonic hemoglobins of α-thalassemic and normal fetuses can be explained by normal synthesis of x chains, deficient synthesis of α chains, and a higher affinity of z than y for the reduced amount of α chain present in the nucleated embryonic erythrocytes of α-thalassemic mice

  1. Bifurcation and category learning in network models of oscillating cortex

    Science.gov (United States)

    Baird, Bill

    1990-06-01

    A genetic model of oscillating cortex, which assumes “minimal” coupling justified by known anatomy, is shown to function as an associative memory, using previously developed theory. The network has explicit excitatory neurons with local inhibitory interneuron feedback that forms a set of nonlinear oscillators coupled only by long-range excitatory connections. Using a local Hebb-like learning rule for primary and higher-order synapses at the ends of the long-range connections, the system learns to store the kinds of oscillation amplitude patterns observed in olfactory and visual cortex. In olfaction, these patterns “emerge” during respiration by a pattern forming phase transition which we characterize in the model as a multiple Hopf bifurcation. We argue that these bifurcations play an important role in the operation of real digital computers and neural networks, and we use bifurcation theory to derive learning rules which analytically guarantee CAM storage of continuous periodic sequences-capacity: N/2 Fourier components for an N-node network-no “spurious” attractors.

  2. Multiple novel alternative splicing forms of FBXW7α have a translational modulatory function and show specific alteration in human cancer.

    Directory of Open Access Journals (Sweden)

    Yueyong Liu

    Full Text Available FBXW7 acts as a tumor suppressor through ubiquitination and degradation of multiple oncoproteins. Loss of FBXW7 expression, which could be partially attributed by the genomic deletion or mutation of FBXW7 locus, is frequently observed in various human cancers. However, the mechanisms regulating FBXW7 expression still remain poorly understood. Here we examined the 5' region of FBXW7 gene to investigate the regulation of FBXW7 expression. We identified seven alternative splicing (AS 5'-UTR forms of FBXW7α that are composed of multiple novel non-coding exons. A significant difference in translational efficiency among these 5'-UTRs variants was observed by in vivo Luciferase reporter assay and Western blot. Furthermore, we found that the mRNA level of the AS form with high translational efficiency was specifically reduced in more than 80% of breast cancer cell lines and in more than 50% of human primary cancers from various tissues. In addition, we also identified mutations of FBXW7 in prostate cancers (5.6%, kidney cancers (16.7%, and bladder cancers (18.8%. Our results suggest that in addition to mutation, differential expression of FBXW7α AS forms with different translational properties may serve as a novel mechanism for inactivation of FBXW7 in human cancer.

  3. Spatial-area selective retrieval of multiple object-place associations in a hierarchical cognitive map formed by theta phase coding.

    Science.gov (United States)

    Sato, Naoyuki; Yamaguchi, Yoko

    2009-06-01

    The human cognitive map is known to be hierarchically organized consisting of a set of perceptually clustered landmarks. Patient studies have demonstrated that these cognitive maps are maintained by the hippocampus, while the neural dynamics are still poorly understood. The authors have shown that the neural dynamic "theta phase precession" observed in the rodent hippocampus may be capable of forming hierarchical cognitive maps in humans. In the model, a visual input sequence consisting of object and scene features in the central and peripheral visual fields, respectively, results in the formation of a hierarchical cognitive map for object-place associations. Surprisingly, it is possible for such a complex memory structure to be formed in a few seconds. In this paper, we evaluate the memory retrieval of object-place associations in the hierarchical network formed by theta phase precession. The results show that multiple object-place associations can be retrieved with the initial cue of a scene input. Importantly, according to the wide-to-narrow unidirectional connections among scene units, the spatial area for object-place retrieval can be controlled by the spatial area of the initial cue input. These results indicate that the hierarchical cognitive maps have computational advantages on a spatial-area selective retrieval of multiple object-place associations. Theta phase precession dynamics is suggested as a fundamental neural mechanism of the human cognitive map.

  4. An absorptive single-pole four-throw switch using multiple-contact MEMS switches and its application to a monolithic millimeter-wave beam-forming network

    International Nuclear Information System (INIS)

    Lee, Sanghyo; Kim, Jong-Man; Kim, Yong-Kweon; Kwon, Youngwoo

    2009-01-01

    In this paper, a new absorptive single-pole four-throw (SP4T) switch based on multiple-contact switching is proposed and integrated with a Butler matrix to demonstrate a monolithic beam-forming network at millimeter waves (mm waves). In order to simplify the switching driving circuit and reduce the number of unit switches in an absorptive SP4T switch, the individual switches were replaced with long-span multiple-contact switches using stress-free single-crystalline-silicon MEMS technology. This approach improves the mechanical stability as well as the manufacturing yield, thereby allowing successful integration into a monolithic beam former. The fabricated absorptive SP4T MEMS switch shows insertion loss less than 1.3 dB, return losses better than 11 dB at 30 GHz and wideband isolation performance higher than 39 dB from 20 to 40 GHz. The absorptive SP4T MEMS switch is integrated with a 4 × 4 Butler matrix on a single chip to implement a monolithic beam-forming network, directing beam into four distinct angles. Array factors from the measured data show that the proposed absorptive SPnT MEMS switch can be effectively used for high-performance mm-wave beam-switching systems. This work corresponds to the first demonstration of a monolithic beam-forming network using switched beams

  5. Holocene evolution of the Liaohe Delta, a tide-dominated delta formed by multiple rivers in Northeast China

    Science.gov (United States)

    He, Lei; Xue, Chunting; Ye, Siyuan; Laws, Edward Allen; Yuan, Hongming; Yang, Shixiong; Du, Xiaolei

    2018-02-01

    The Liaohe Delta in Northeast China is one of the ecologically important estuarine deltas in China. It has been formed via the accumulation of sediment discharged by four rivers in the Liaohe Plain that enter Liaodong Bay. Twenty-seven 30-40 m long cores recovered from the Liaohe Plain and Liaodong Bay were analyzed for sedimentary characteristics, grain size, foraminifera species, and ages determined by accelerator mass spectrometry (AMS) 14C to document the stratigraphical sequence and the spatio-temporal evolution of the Liaohe Delta. Our results revealed that the sedimentary environments have evolved from fluvial, tidal flat/estuarine, to neritic and finally to a deltaic environment since the Late Pleistocene. The Holocene transgression arrived at the present coastline at ∼8500 cal a BP and flooded the maximum area of land at ∼7000 cal a BP. A deltaic environment prevailed in this area after 7000 cal a BP. Bounded by the modern Liaohe River mouth, the present deltaic sedimentary system can be divided into the eastern and western components. The rate of seaward progradation of the eastern paleocoastline was estimated to be ∼8.6 m/a since 7000 cal a BP; the eastern cores in the present coastline began receiving the deltaic sediments at ∼5000 cal a BP. The rate of seaward progradation of the western paleocoastline was estimated to be only ∼2.8 m/a since 7000 cal a BP. The coastline on the western side began accumulating deltaic sediments about 2000 years later than the eastern coastline. Depocenter shifting was hypothesized to be the reason for the spatial differences in the sedimentary processes. However, the change of sediment fluxes of the western rivers due to climate changes and ancient human impacts might be the reason for the differences of the temporal evolution of the eastern and western sedimentary systems in the Liaohe Delta.

  6. Vibration of an Offshore Structure Having the Form of a Hollow Column Partially Filled with Multiple Fluids and Immersed in Water

    OpenAIRE

    Lin, Hsien-Yuan; Lee, Jeng-Nan; Sung, Wen-Hao

    2012-01-01

    This paper employs the numerical assembly method (NAM) to determine the exact frequency-response amplitudes of an offshore structure such as piles or towers having the form of a hollow column filled with multiple fluids, immersed in water, carrying an eccentric tip mass supported by a translational spring and/or a rotational spring, and subjected to a harmonic force. The hollow column is modeled as a Bernoulli-Euler cantilever beam fixed at the bottom. For the case of zero harmonic force, the...

  7. Laparoscopic adrenal cortex

    International Nuclear Information System (INIS)

    Peyrolou, A.; Salom, A.; Harguindeguy; Taroco, L.; Ardao, G.; Broli, F. . E mail: andresssss@adinet.com.uy

    2005-01-01

    The paper presents the case of a female patient who carried an aldosterone-secreting tumor of adrenal cortex.In the analysis of diagnosis and para clinical examinations there is particular reference to the laparoscopic surgery mode of treatment.Diagnosis should be established on the basis of clinical and laboratory tests (hypopotassemia and hyperaldosteronism).Tumor topography was confirmed through CT scan, MRI and Scintiscan in left adrenal cortex.Resection was consequently made through laparoscopic surgery.The patients evolution was excellent from the surgical viewpoint,with I levels of blood pressure, potassium and aldosterone returned to normal

  8. Neural computation of visual imaging based on Kronecker product in the primary visual cortex

    Directory of Open Access Journals (Sweden)

    Guozheng Yao

    2010-03-01

    Full Text Available Abstract Background What kind of neural computation is actually performed by the primary visual cortex and how is this represented mathematically at the system level? It is an important problem in the visual information processing, but has not been well answered. In this paper, according to our understanding of retinal organization and parallel multi-channel topographical mapping between retina and primary visual cortex V1, we divide an image into orthogonal and orderly array of image primitives (or patches, in which each patch will evoke activities of simple cells in V1. From viewpoint of information processing, this activated process, essentially, involves optimal detection and optimal matching of receptive fields of simple cells with features contained in image patches. For the reconstruction of the visual image in the visual cortex V1 based on the principle of minimum mean squares error, it is natural to use the inner product expression in neural computation, which then is transformed into matrix form. Results The inner product is carried out by using Kronecker product between patches and function architecture (or functional column in localized and oriented neural computing. Compared with Fourier Transform, the mathematical description of Kronecker product is simple and intuitive, so is the algorithm more suitable for neural computation of visual cortex V1. Results of computer simulation based on two-dimensional Gabor pyramid wavelets show that the theoretical analysis and the proposed model are reasonable. Conclusions Our results are: 1. The neural computation of the retinal image in cortex V1 can be expressed to Kronecker product operation and its matrix form, this algorithm is implemented by the inner operation between retinal image primitives and primary visual cortex's column. It has simple, efficient and robust features, which is, therefore, such a neural algorithm, which can be completed by biological vision. 2. It is more suitable

  9. Late emergence of the vibrissa direction selectivity map in the rat barrel cortex.

    Science.gov (United States)

    Kremer, Yves; Léger, Jean-François; Goodman, Dan; Brette, Romain; Bourdieu, Laurent

    2011-07-20

    In the neocortex, neuronal selectivities for multiple sensorimotor modalities are often distributed in topographical maps thought to emerge during a restricted period in early postnatal development. Rodent barrel cortex contains a somatotopic map for vibrissa identity, but the existence of maps representing other tactile features has not been clearly demonstrated. We addressed the issue of the existence in the rat cortex of an intrabarrel map for vibrissa movement direction using in vivo two-photon imaging. We discovered that the emergence of a direction map in rat barrel cortex occurs long after all known critical periods in the somatosensory system. This map is remarkably specific, taking a pinwheel-like form centered near the barrel center and aligned to the barrel cortex somatotopy. We suggest that this map may arise from intracortical mechanisms and demonstrate by simulation that the combination of spike-timing-dependent plasticity at synapses between layer 4 and layer 2/3 and realistic pad stimulation is sufficient to produce such a map. Its late emergence long after other classical maps suggests that experience-dependent map formation and refinement continue throughout adult life.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Diffuse nitrogen loss simulation and impact assessment of stereoscopic agriculture pattern by integrated water system model and consideration of multiple existence forms

    Science.gov (United States)

    Zhang, Yongyong; Gao, Yang; Yu, Qiang

    2017-09-01

    Agricultural nitrogen loss becomes an increasingly important source of water quality deterioration and eutrophication, even threatens water safety for humanity. Nitrogen dynamic mechanism is still too complicated to be well captured at watershed scale due to its multiple existence forms and instability, disturbance of agricultural management practices. Stereoscopic agriculture is a novel agricultural planting pattern to efficiently use local natural resources (e.g., water, land, sunshine, heat and fertilizer). It is widely promoted as a high yield system and can obtain considerable economic benefits, particularly in China. However, its environmental quality implication is not clear. In our study, Qianyanzhou station is famous for its stereoscopic agriculture pattern of Southern China, and an experimental watershed was selected as our study area. Regional characteristics of runoff and nitrogen losses were simulated by an integrated water system model (HEQM) with multi-objective calibration, and multiple agriculture practices were assessed to find the effective approach for the reduction of diffuse nitrogen losses. Results showed that daily variations of runoff and nitrogen forms were well reproduced throughout watershed, i.e., satisfactory performances for ammonium and nitrate nitrogen (NH4-N and NO3-N) loads, good performances for runoff and organic nitrogen (ON) load, and very good performance for total nitrogen (TN) load. The average loss coefficient was 62.74 kg/ha for NH4-N, 0.98 kg/ha for NO3-N, 0.0004 kg/ha for ON and 63.80 kg/ha for TN. The dominating form of nitrogen losses was NH4-N due to the applied fertilizers, and the most dramatic zones aggregated in the middle and downstream regions covered by paddy and orange orchard. In order to control diffuse nitrogen losses, the most effective practices for Qianyanzhou stereoscopic agriculture pattern were to reduce farmland planting scale in the valley by afforestation, particularly for orchard in the

  12. Radial oxygen gradients over rat cortex arterioles

    OpenAIRE

    Galler, Michael

    2011-01-01

    Purpose: We present the results of the visualisation of radial oxygen gradients in rats’ cortices and their use in neurocritical management. Methods: PO2 maps of the cortex of 10 wistar rats were obtained with a camera (SensiMOD, PCO, Kehlheim, Germany). Those pictures were analyzed and edited by a custom-made software. We chose a vessel for examination. A matrix, designed to evaluate the cortical O2 partial pressure, was placed vertically to the artery and afterwards multiple regio...

  13. A hierarchy for relational reasoning in the prefrontal cortex.

    Science.gov (United States)

    Krawczyk, Daniel C; Michelle McClelland, M; Donovan, Colin M

    2011-05-01

    The human brain possesses a unique capacity to reason about abstract relationships among items in our environment. The neural organization of reasoning abilities has remained elusive. Two approaches toward investigating human reasoning have involved studying visuo-spatial reasoning abilities and studying analogical reasoning. These approaches have both revealed anterior prefrontal cortex (PFC) involvement, but no prior studies have jointly investigated these two forms of reasoning to understand any potential convergence of activation within the PFC. Using fMRI, we tested the extent to which these two forms of reasoning (visuo-spatial and analogical) overlap in PFC activation. We conducted a visuo-spatial reasoning task that required processing multiple changes across three abstract pictures. This task activated a progressively anterior series of PFC regions when multiple relations had to be integrated. We also conducted a four-term analogy task in a stage-wise manner and compared results from this task to semantic and perceptual control conditions that did not require integrating relations across the problems. We found greater activation for analogical reasoning in the series of PFC regions that were sequentially involved in the visuo-spatial reasoning task. These findings indicate that stages of neural processing overlap for different domains within human reasoning. The pattern of differences across the analogy task suggests a hierarchical organization for relational reasoning across domains in which posterior frontal cortex is active across concrete reasoning tasks, while progressively more anterior regions are recruited to process increasingly abstract representations in reasoning. Copyright © 2010 Elsevier Srl. All rights reserved.

  14. Effects of Arousal on Mouse Sensory Cortex Depend on Modality

    Directory of Open Access Journals (Sweden)

    Daisuke Shimaoka

    2018-03-01

    Full Text Available Summary: Changes in arousal modulate the activity of mouse sensory cortex, but studies in different mice and different sensory areas disagree on whether this modulation enhances or suppresses activity. We measured this modulation simultaneously in multiple cortical areas by imaging mice expressing voltage-sensitive fluorescent proteins (VSFP. VSFP imaging estimates local membrane potential across large portions of cortex. We used temporal filters to predict local potential from running speed or from pupil dilation, two measures of arousal. The filters provided good fits and revealed that the effects of arousal depend on modality. In the primary visual cortex (V1 and auditory cortex (Au, arousal caused depolarization followed by hyperpolarization. In the barrel cortex (S1b and a secondary visual area (LM, it caused only hyperpolarization. In all areas, nonetheless, arousal reduced the phasic responses to trains of sensory stimuli. These results demonstrate diverse effects of arousal across sensory cortex but similar effects on sensory responses. : Shimaoka et al. use voltage-sensitive imaging to show that the effects of arousal on the mouse cortex are markedly different across areas and over time. In all the sensory areas studied, nonetheless, arousal reduced the phasic voltage responses to trains of sensory stimuli. Keywords: cerebral cortex, cortical state, locomotion, sensory processing, widefield imaging

  15. An unusual form of spondyloepiphyseal dysplasia, with advanced carpal and spinal end-plate ossification mimicking COMP-mutation-like multiple epiphyseal dysplasia

    Energy Technology Data Exchange (ETDEWEB)

    Pazzaglia, Ugo E.; Zarattini, Guido [University of Brescia Medical School, Department of Orthopaedics and Traumatology, Brescia (Italy); Beluffi, Giampiero [Fondazione IRCCS Policlinico S. Matteo, Section of Paediatric Radiology, Department of Radiodiagnosis, Pavia (Italy)

    2008-07-15

    We present a child with irregular ossification of tubular bone epiphyses, short bones, and spine. The radiographic evolution of bones undergoing endochondral ossification was followed from the age of 1 year 9 months to 6 years. The unusual features demonstrated in this child made classification difficult: pseudoachondroplasia was excluded because no mutations of the COMP gene were found. Considering the evolution of the radiographic appearances, the most likely diagnosis would seem to be an unusual form of spondyloepiphyseal dysplasia, mimicking some aspects of multiple epiphyseal dysplasia. Endochondral ossification was diffusely altered with a mixture of epiphyseal ossification delay associated with acceleration and early fusion. This case was a unique presentation within the family, suggesting a mutation in the affected child. (orig.)

  16. Vibration of an Offshore Structure Having the Form of a Hollow Column Partially Filled with Multiple Fluids and Immersed in Water

    Directory of Open Access Journals (Sweden)

    Hsien-Yuan Lin

    2012-01-01

    Full Text Available This paper employs the numerical assembly method (NAM to determine the exact frequency-response amplitudes of an offshore structure such as piles or towers having the form of a hollow column filled with multiple fluids, immersed in water, carrying an eccentric tip mass supported by a translational spring and/or a rotational spring, and subjected to a harmonic force. The hollow column is modeled as a Bernoulli-Euler cantilever beam fixed at the bottom. For the case of zero harmonic force, the simultaneous equations of the vibration system reduce to an eigenvalue problem so that the natural frequencies and mode shapes of the beam can also be obtained. The effect of height of filled fluids on the characteristics of free vibration is also presented.

  17. An unusual form of spondyloepiphyseal dysplasia, with advanced carpal and spinal end-plate ossification mimicking COMP-mutation-like multiple epiphyseal dysplasia

    International Nuclear Information System (INIS)

    Pazzaglia, Ugo E.; Zarattini, Guido; Beluffi, Giampiero

    2008-01-01

    We present a child with irregular ossification of tubular bone epiphyses, short bones, and spine. The radiographic evolution of bones undergoing endochondral ossification was followed from the age of 1 year 9 months to 6 years. The unusual features demonstrated in this child made classification difficult: pseudoachondroplasia was excluded because no mutations of the COMP gene were found. Considering the evolution of the radiographic appearances, the most likely diagnosis would seem to be an unusual form of spondyloepiphyseal dysplasia, mimicking some aspects of multiple epiphyseal dysplasia. Endochondral ossification was diffusely altered with a mixture of epiphyseal ossification delay associated with acceleration and early fusion. This case was a unique presentation within the family, suggesting a mutation in the affected child. (orig.)

  18. The anterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Pavlović D.M.

    2009-01-01

    Full Text Available The anterior cingulate cortex (ACC has a role in attention, analysis of sensory information, error recognition, problem solving, detection of novelty, behavior, emotions, social relations, cognitive control, and regulation of visceral functions. This area is active whenever the individual feels some emotions, solves a problem, or analyzes the pros and cons of an action (if it is a right decision. Analogous areas are also found in higher mammals, especially whales, and they contain spindle neurons that enable complex social interactions. Disturbance of ACC activity is found in dementias, schizophrenia, depression, the obsessive-compulsive syndrome, and other neuropsychiatric diseases.

  19. Regulating prefrontal cortex activation

    DEFF Research Database (Denmark)

    Aznar, Susana; Klein, Anders Bue

    2013-01-01

    The prefrontal cortex (PFC) is involved in mediating important higher-order cognitive processes such as decision making, prompting thereby our actions. At the same time, PFC activation is strongly influenced by emotional reactions through its functional interaction with the amygdala...... of emotion-based actions, such as addiction and other impulse-related behaviors. In this review, we give an overview of the 5-HT2A receptor distribution (neuronal, intracellular, and anatomical) along with its functional and physiological effect on PFC activation, and how that relates to more recent findings...... of a regulatory effect of the PFC on the emotional control of our actions....

  20. Pharmacokinetic Properties of Three Forms of Vaginal Progesterone Administered in Either Single Or Multiple Dose Regimen in Healthy Post-menopausal Chinese Women

    Directory of Open Access Journals (Sweden)

    Jianzhong Shentu

    2017-04-01

    Full Text Available Objective: A generic vaginal progesterone gel has recently been developed in China. Little is known about its pharmacokinetic properties in Chinese subjects. The purpose of our study was to investigate the pharmacokinetics of three forms of vaginal progesterone gel (test formulations at 4 and 8% strength vs. a reference formulation: Crinone 8% in Chinese healthy post-menopausal women.Methods: This study consisted of two parts study. The part 1 study was a single-center, open-label, 3-period study. Twelve healthy post-menopausal women were to evaluate the safety and pharmacokinetics of 45 mg vaginal progesterone gel (Test 4% following single dose and multiple doses administered once every other day (q.o.d. for six times or once daily (q.d. for 6 days. The part 2 study was a randomized, open-label, 3-stage crossover study. Twelve post-menopausal women received 90 mg vaginal progesterone gel (Test 8% or 90 mg Crinone (Reference 8% following single dose and multiple doses (q.o.d. or q.d.. Plasma concentrations of progesterone were measured up to 72 h by using a validated liquid chromatography tandem-mass spectrometry method. The primary pharmacokinetic parameters, maximum plasma concentration (Cmax and area under the plasma concentration–time curve (AUC from time zero to last measurable concentration (AUC0-t and extrapolated to infinity (AUC0-∞ were compared by an analysis of variance using log-transformed data.Results: Totally 24 subjects were enrolled in and completed the study. Following single dose, The geometric mean Cmax values for Test 4%, Test 8%, and Crinone 8% were 6.35, 10.34, 10.45 ng/mL, and their geometric mean AUC0-t (AUC0-∞ were 113.73 (118.00, 169.39 (173.98, and 190.07 (201.13 ng⋅h/mL, respectively. The mean T1/2 values of progesterone were 11.00, 10.92, and 11.40 h, respectively. For 8% test formulation vs. reference, the 90% CIs of the least squares mean test/reference ratios of Cmax, AUC0-t, and AUC0-∞ were 78.32–124

  1. Optimization of a multi-gene HIV-1 recombinant subtype CRF02AG DNA vaccine for expression of multiple immunogenic forms

    International Nuclear Information System (INIS)

    Ellenberger, Dennis; Li Bin; Smith, James; Yi Hong; Folks, Thomas; Robinson, Harriet; Butera, Salvatore

    2004-01-01

    We developed an AIDS vaccine for Western and West-Central Africa based on a DNA plasmid vector expressing HIV-1 recombinant subtype CRF02 A G gag, pol, and env genes. To optimize the production of noninfectious HIV-like particles (VLPs) and potentially improve the effectiveness of the vaccine, we generated four potential vaccine constructs: the parental (IC2) and three modifications (IC25, IC48, and IC90) containing mutations within the HIV protease. While the parental construct IC2 expressed aggregates of Gag proteins, the IC25 construct resulted in the production of immature VLPs (the core comprises unprocessed Pr 55Gag ). The remaining two constructs (IC48 and IC90) produced mature VLPs (the core comprises processed capsid p24) in addition to immature VLPs and aggregates of Gag proteins. VLPs incorporated significant levels of mature gp120 envelope glycoprotein. Importantly, the mature VLPs were fusion competent and entered coreceptor-specific target cells. The production of multiple antigenic forms, including fusion-competent VLPs, by candidate DNA vaccine constructs may provide immunologic advantages for induction of protective cellular and humoral responses against HIV-1 proteins

  2. Multiple, Distinct Intercontinental Lineages but Isolation of Australian Populations in a Cosmopolitan Lichen-Forming Fungal Taxon, Psora decipiens (Psoraceae, Ascomycota

    Directory of Open Access Journals (Sweden)

    Steven D. Leavitt

    2018-02-01

    Full Text Available Multiple drivers shape the spatial distribution of species, including dispersal capacity, niche incumbency, climate variability, orographic barriers, and plate tectonics. However, biogeographic patterns of fungi commonly do not fit conventional expectations based on studies of animals and plants. Fungi, in general, are known to occur across exceedingly broad, intercontinental distributions, including some important components of biological soil crust communities (BSCs. However, molecular data often reveal unexpected biogeographic patterns in lichenized fungal species that are assumed to have cosmopolitan distributions. The lichen-forming fungal species Psora decipiens is found on all continents, except Antarctica and occurs in BSCs across diverse habitats, ranging from hot, arid deserts to alpine habitats. In order to better understand factors that shape population structure in cosmopolitan lichen-forming fungal species, we investigated biogeographic patterns in the cosmopolitan taxon P. decipiens, along with the closely related taxa P. crenata and P. saviczii. We generated a multi-locus sequence dataset based on a worldwide sampling of these taxa in order to reconstruct evolutionary relationships and explore phylogeographic patterns. Both P. crenata and P. decipiens were not recovered as monophyletic; and P. saviczii specimens were recovered as a monophyletic clade closely related to a number of lineages comprised of specimens representing P. decipiens. Striking phylogeographic patterns were observed for P. crenata, with populations from distinct geographic regions belonging to well-separated, monophyletic lineages. South African populations of P. crenata were further divided into well-supported sub-clades. While well-supported phylogenetic substructure was also observed for the nominal taxon P. decipiens, nearly all lineages were comprised of specimens collected from intercontinental populations. However, all Australian specimens representing

  3. Preparatory attention in visual cortex.

    Science.gov (United States)

    Battistoni, Elisa; Stein, Timo; Peelen, Marius V

    2017-05-01

    Top-down attention is the mechanism that allows us to selectively process goal-relevant aspects of a scene while ignoring irrelevant aspects. A large body of research has characterized the effects of attention on neural activity evoked by a visual stimulus. However, attention also includes a preparatory phase before stimulus onset in which the attended dimension is internally represented. Here, we review neurophysiological, functional magnetic resonance imaging, magnetoencephalography, electroencephalography, and transcranial magnetic stimulation (TMS) studies investigating the neural basis of preparatory attention, both when attention is directed to a location in space and when it is directed to nonspatial stimulus attributes (content-based attention) ranging from low-level features to object categories. Results show that both spatial and content-based attention lead to increased baseline activity in neural populations that selectively code for the attended attribute. TMS studies provide evidence that this preparatory activity is causally related to subsequent attentional selection and behavioral performance. Attention thus acts by preactivating selective neurons in the visual cortex before stimulus onset. This appears to be a general mechanism that can operate on multiple levels of representation. We discuss the functional relevance of this mechanism, its limitations, and its relation to working memory, imagery, and expectation. We conclude by outlining open questions and future directions. © 2017 New York Academy of Sciences.

  4. Word Recognition in Auditory Cortex

    Science.gov (United States)

    DeWitt, Iain D. J.

    2013-01-01

    Although spoken word recognition is more fundamental to human communication than text recognition, knowledge of word-processing in auditory cortex is comparatively impoverished. This dissertation synthesizes current models of auditory cortex, models of cortical pattern recognition, models of single-word reading, results in phonetics and results in…

  5. Discriminability of Single and Multichannel Intracortical Microstimulation within Somatosensory Cortex

    Directory of Open Access Journals (Sweden)

    Cynthia Kay Overstreet

    2016-12-01

    Full Text Available The addition of tactile and proprioceptive feedback to neuroprosthetic limbs is expected to significantly improve the control of these devices. Intracortical microstimulation (ICMS of somatosensory cortex is a promising method of delivering this sensory feedback. To date, the main focus of somatosensory ICMS studies has been to deliver discriminable signals, corresponding to varying intensity, to a single location in cortex. However, multiple independent and simultaneous streams of sensory information will need to be encoded by ICMS to provide functionally relevant feedback for a neuroprosthetic limb (e.g. encoding contact events and pressure on multiple digits.In this study, we evaluated the ability of an awake, behaving non-human primate (Macaca mulatta to discriminate ICMS stimuli delivered on multiple electrodes spaced within somatosensory cortex. We delivered serial stimulation on single electrodes to evaluate the discriminability of sensations corresponding to ICMS of distinct cortical locations. Additionally, we delivered trains of multichannel stimulation, derived from a tactile sensor, synchronously across multiple electrodes. Our results indicate that discrimination of multiple ICMS stimuli is a challenging task, but that discriminable sensory percepts can be elicited by both single and multichannel ICMS on electrodes spaced within somatosensory cortex.

  6. Morphology and distribution of chandelier cell axon terminals in the mouse cerebral cortex and claustroamygdaloid complex.

    Science.gov (United States)

    Inda, M C; DeFelipe, J; Muñoz, A

    2009-01-01

    Chandelier cells represent a unique type of cortical gamma-aminobutityric acidergic interneuron whose axon terminals (Ch-terminals) only form synapses with the axon initial segments of some pyramidal cells. Here, we have used immunocytochemistry for the high-affinity plasma membrane transporter GAT-1 and the calcium-binding protein parvalbumin to analyze the morphology and distribution of Ch-terminals in the mouse cerebral cortex and claustroamygdaloid complex. In general, 2 types of Ch-terminals were distinguished on the basis of their size and the density of the axonal boutons that made up the terminal. Simple Ch-terminals were made up of 1 or 2 rows of labeled boutons, each row consisting of only 3-5 boutons. In contrast, complex Ch-terminals were tight cylinder-like structures made up of multiple rows of boutons. Simple Ch-terminals were detected throughout the cerebral cortex and claustroamygdaloid complex, the complex type was only occasionally found in certain regions, whereas in others they were very abundant. These results indicate that there are substantial differences in the morphology and distribution of Ch-terminals between different areas and layers of the mouse cerebral cortex. Furthermore, we suggest that the distribution of complex Ch-terminals may be related to the developmental origin of the different brain regions analyzed.

  7. Sample size requirements for one-year treatment effects using deep gray matter volume from 3T MRI in progressive forms of multiple sclerosis.

    Science.gov (United States)

    Kim, Gloria; Chu, Renxin; Yousuf, Fawad; Tauhid, Shahamat; Stazzone, Lynn; Houtchens, Maria K; Stankiewicz, James M; Severson, Christopher; Kimbrough, Dorlan; Quintana, Francisco J; Chitnis, Tanuja; Weiner, Howard L; Healy, Brian C; Bakshi, Rohit

    2017-11-01

    The subcortical deep gray matter (DGM) develops selective, progressive, and clinically relevant atrophy in progressive forms of multiple sclerosis (PMS). This patient population is the target of active neurotherapeutic development, requiring the availability of outcome measures. We tested a fully automated MRI analysis pipeline to assess DGM atrophy in PMS. Consistent 3D T1-weighted high-resolution 3T brain MRI was obtained over one year in 19 consecutive patients with PMS [15 secondary progressive, 4 primary progressive, 53% women, age (mean±SD) 50.8±8.0 years, Expanded Disability Status Scale (median, range) 5.0, 2.0-6.5)]. DGM segmentation applied the fully automated FSL-FIRST pipeline ( http://fsl.fmrib.ox.ac.uk ). Total DGM volume was the sum of the caudate, putamen, globus pallidus, and thalamus. On-study change was calculated using a random-effects linear regression model. We detected one-year decreases in raw [mean (95% confidence interval): -0.749 ml (-1.455, -0.043), p = 0.039] and annualized [-0.754 ml/year (-1.492, -0.016), p = 0.046] total DGM volumes. A treatment trial for an intervention that would show a 50% reduction in DGM brain atrophy would require a sample size of 123 patients for a single-arm study (one-year run-in followed by one-year on-treatment). For a two-arm placebo-controlled one-year study, 242 patients would be required per arm. The use of DGM fraction required more patients. The thalamus, putamen, and globus pallidus, showed smaller effect sizes in their on-study changes than the total DGM; however, for the caudate, the effect sizes were somewhat larger. DGM atrophy may prove efficient as a short-term outcome for proof-of-concept neurotherapeutic trials in PMS.

  8. Computer modeling of Motor Cortex Stimulation: Effects of Anodal, Cathodal and Bipolar Stimulation

    NARCIS (Netherlands)

    Manola, L.; Holsheimer, J.; Buitenweg, Jan R.; Veltink, Petrus H.

    2007-01-01

    Motor cortex stimulation (MCS) is a promising clinical technique for treatment of chronic pain. However, optimization of the therapeutic efficacy is hampered since it is not known how electrically activated neural structures in the motor cortex can induce pain relief. Furthermore, multiple neural

  9. Teaching Form as Form

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2012-01-01

    understanding of form per se, or, to use an expression from this text, of form as form. This challenge can be reduced to one question: how can design teaching support students in achieving not only the ability to recognize and describe different form-related concepts in existing design (i.e. analytical...

  10. Visual Information Present in Infragranular Layers of Mouse Auditory Cortex.

    Science.gov (United States)

    Morrill, Ryan J; Hasenstaub, Andrea R

    2018-03-14

    The cerebral cortex is a major hub for the convergence and integration of signals from across the sensory modalities; sensory cortices, including primary regions, are no exception. Here we show that visual stimuli influence neural firing in the auditory cortex of awake male and female mice, using multisite probes to sample single units across multiple cortical layers. We demonstrate that visual stimuli influence firing in both primary and secondary auditory cortex. We then determine the laminar location of recording sites through electrode track tracing with fluorescent dye and optogenetic identification using layer-specific markers. Spiking responses to visual stimulation occur deep in auditory cortex and are particularly prominent in layer 6. Visual modulation of firing rate occurs more frequently at areas with secondary-like auditory responses than those with primary-like responses. Auditory cortical responses to drifting visual gratings are not orientation-tuned, unlike visual cortex responses. The deepest cortical layers thus appear to be an important locus for cross-modal integration in auditory cortex. SIGNIFICANCE STATEMENT The deepest layers of the auditory cortex are often considered its most enigmatic, possessing a wide range of cell morphologies and atypical sensory responses. Here we show that, in mouse auditory cortex, these layers represent a locus of cross-modal convergence, containing many units responsive to visual stimuli. Our results suggest that this visual signal conveys the presence and timing of a stimulus rather than specifics about that stimulus, such as its orientation. These results shed light on both how and what types of cross-modal information is integrated at the earliest stages of sensory cortical processing. Copyright © 2018 the authors 0270-6474/18/382854-09$15.00/0.

  11. Chemosensory Learning in the Cortex

    Directory of Open Access Journals (Sweden)

    Edmund eRolls

    2011-09-01

    Full Text Available Taste is a primary reinforcer. Olfactory-taste and visual-taste association learning takes place in the primate including human orbitofrontal cortex to build representations of flavour. Rapid reversal of this learning can occur using a rule-based learning system that can be reset when an expected taste or flavour reward is not obtained, that is by negative reward prediction error, to which a population of neurons in the orbitofrontal cortex responds. The representation in the orbitofrontal cortex but not the primary taste or olfactory cortex is of the reward value of the visual / olfactory / taste / input as shown by devaluation experiments in which food is fed to satiety, and by correlations with the activations with subjective pleasantness ratings in humans. Sensory-specific satiety for taste, olfactory, visual, and oral somatosensory inputs produced by feeding a particular food to satiety are implemented it is proposed by medium-term synaptic adaptation in the orbitofrontal cortex. Cognitive factors, including word-level descriptions, modulate the representation of the reward value of food in the orbitofrontal cortex, and this effect is learned it is proposed by associative modification of top-down synapses onto neurons activated by bottom-up taste and olfactory inputs when both are active in the orbitofrontal cortex. A similar associative synaptic learning process is proposed to be part of the mechanism for the top-down attentional control to the reward value vs the sensory properties such as intensity of taste and olfactory inputs in the orbitofrontal cortex, as part of a biased activation theory of selective attention.

  12. Dopamine-dependent changes in the functional connectivity between basal ganglia and cerebral cortex in humans

    NARCIS (Netherlands)

    Williams, D; Tijssen, M; van Bruggen, G; Bosch, A; Insola, A; Di Lazzaro, V; Mazzone, P; Oliviero, A; Quartarone, A; Speelman, H; Brown, P

    2002-01-01

    We test the hypothesis that interaction between the human basal ganglia and cerebral cortex involves activity in multiple functional circuits characterized by their frequency of oscillation, phase characteristics, dopamine dependency and topography. To this end we took recordings from

  13. Combined array-comparative genomic hybridization and single-nucleotide polymorphism-loss of heterozygosity analysis reveals complex changes and multiple forms of chromosomal instability in colorectal cancers

    DEFF Research Database (Denmark)

    Gaasenbeek, Michelle; Howarth, Kimberley; Rowan, Andrew J

    2006-01-01

    Cancers with chromosomal instability (CIN) are held to be aneuploid/polyploid with multiple large-scale gains/deletions, but the processes underlying CIN are unclear and different types of CIN might exist. We investigated colorectal cancer cell lines using array-comparative genomic hybridization...

  14. Higher Order Spike Synchrony in Prefrontal Cortex during visual memory

    Directory of Open Access Journals (Sweden)

    Gordon ePipa

    2011-06-01

    Full Text Available Precise temporal synchrony of spike firing has been postulated as an important neuronal mechanism for signal integration and the induction of plasticity in neocortex. As prefrontal cortex plays an important role in organizing memory and executive functions, the convergence of multiple visual pathways onto PFC predicts that neurons should preferentially synchronize their spiking when stimulus information is processed. Furthermore, synchronous spike firing should intensify if memory processes require the induction of neuronal plasticity, even if this is only for short-term. Here we show with multiple simultaneously recorded units in ventral prefrontal cortex that neurons participate in 3 ms precise synchronous discharges distributed across multiple sites separated by at least 500 µm. The frequency of synchronous firing is modulated by behavioral performance and is specific for the memorized visual stimuli. In particular, during the memory period in which activity is not stimulus driven, larger groups of up to 7 sites exhibit performance dependent modulation of their spike synchronization.

  15. 3-D vision and figure-ground separation by visual cortex.

    Science.gov (United States)

    Grossberg, S

    1994-01-01

    A neural network theory of three-dimensional (3-D) vision, called FACADE theory, is described. The theory proposes a solution of the classical figure-ground problem for biological vision. It does so by suggesting how boundary representations and surface representations are formed within a boundary contour system (BCS) and a feature contour system (FCS). The BCS and FCS interact reciprocally to form 3-D boundary and surface representations that are mutually consistent. Their interactions generate 3-D percepts wherein occluding and occluded object parts are separated, completed, and grouped. The theory clarifies how preattentive processes of 3-D perception and figure-ground separation interact reciprocally with attentive processes of spatial localization, object recognition, and visual search. A new theory of stereopsis is proposed that predicts how cells sensitive to multiple spatial frequencies, disparities, and orientations are combined by context-sensitive filtering, competition, and cooperation to form coherent BCS boundary segmentations. Several factors contribute to figure-ground pop-out, including: boundary contrast between spatially contiguous boundaries, whether due to scenic differences in luminance, color, spatial frequency, or disparity; partially ordered interactions from larger spatial scales and disparities to smaller scales and disparities; and surface filling-in restricted to regions surrounded by a connected boundary. Phenomena such as 3-D pop-out from a 2-D picture, Da Vinci stereopsis, 3-D neon color spreading, completion of partially occluded objects, and figure-ground reversals are analyzed. The BCS and FCS subsystems model aspects of how the two parvocellular cortical processing streams that join the lateral geniculate nucleus to prestriate cortical area V4 interact to generate a multiplexed representation of Form-And-Color-And-DEpth, or FACADE, within area V4. Area V4 is suggested to support figure-ground separation and to interact with

  16. Topography and collateralization of dopaminergic projections to primary motor cortex in rats.

    Science.gov (United States)

    Hosp, Jonas A; Nolan, Helen E; Luft, Andreas R

    2015-05-01

    Dopaminergic signaling within the primary motor cortex (M1) is necessary for successful motor skill learning. Dopaminergic neurons projecting to M1 are located in the ventral tegmental area (VTA, nucleus A10) of the midbrain. It is unknown which behavioral correlates are encoded by these neurons. The objective here is to investigate whether VTA-M1 fibers are collaterals of projections to prefrontal cortex (PFC) or nucleus accumbens (NAc) or if they form a distinct pathway. In rats, multiple-site retrograde fluorescent tracers were injected into M1, PFC and the core region of the NAc and VTA sections investigated for concomitant labeling of different tracers. Dopaminergic neurons projecting to M1, PFC and NAc were found in nucleus A10 and to a lesser degree in the medial nucleus A9. Neurons show high target specificity, minimal collateral branching to other than their target area and hardly cross the midline. Whereas PFC- and NAc-projecting neurons are indistinguishably intermingled within the ventral portion of dopaminergic nuclei in middle and caudal midbrain, M1-projecting neurons are only located within the dorsal part of the rostral midbrain. Within M1, the forelimb representation receives sevenfold more dopaminergic projections than the hindlimb representation. This strong rostro-caudal gradient as well as the topographical preference to dorsal structures suggest that projections to M1 emerged late in the development of the dopaminergic systems in and form a functionally distinct system.

  17. Modulation of brain activity by multiple lexical and word form variables in visual word recognition: A parametric fMRI study.

    Science.gov (United States)

    Hauk, Olaf; Davis, Matthew H; Pulvermüller, Friedemann

    2008-09-01

    Psycholinguistic research has documented a range of variables that influence visual word recognition performance. Many of these variables are highly intercorrelated. Most previous studies have used factorial designs, which do not exploit the full range of values available for continuous variables, and are prone to skewed stimulus selection as well as to effects of the baseline (e.g. when contrasting words with pseudowords). In our study, we used a parametric approach to study the effects of several psycholinguistic variables on brain activation. We focussed on the variable word frequency, which has been used in numerous previous behavioural, electrophysiological and neuroimaging studies, in order to investigate the neuronal network underlying visual word processing. Furthermore, we investigated the variable orthographic typicality as well as a combined variable for word length and orthographic neighbourhood size (N), for which neuroimaging results are still either scarce or inconsistent. Data were analysed using multiple linear regression analysis of event-related fMRI data acquired from 21 subjects in a silent reading paradigm. The frequency variable correlated negatively with activation in left fusiform gyrus, bilateral inferior frontal gyri and bilateral insulae, indicating that word frequency can affect multiple aspects of word processing. N correlated positively with brain activity in left and right middle temporal gyri as well as right inferior frontal gyrus. Thus, our analysis revealed multiple distinct brain areas involved in visual word processing within one data set.

  18. Unveiling multiple solid-state transitions in pharmaceutical solid dosage forms using multi-series hyperspectral imaging and different curve resolution approaches

    DEFF Research Database (Denmark)

    Alexandrino, Guilherme L; Amigo Rubio, Jose Manuel; Khorasani, Milad Rouhi

    2017-01-01

    Solid-state transitions at the surface of pharmaceutical solid dosage forms (SDF) were monitored using multi-series hyperspectral imaging (HSI) along with Multivariate Curve Resolution – Alternating Least Squares (MCR-ALS) and Parallel Factor Analysis (PARAFAC and PARAFAC2). First, the solid-stat...

  19. Orbitofrontal cortex function and structure in depression.

    Science.gov (United States)

    Drevets, Wayne C

    2007-12-01

    The orbitofrontal cortex (OFC) has been implicated in the pathophysiology of major depression by evidence obtained using neuroimaging, neuropathologic, and lesion analysis techniques. The abnormalities revealed by these techniques show a regional specificity, and suggest that some OFC regions which appear cytoarchitectonically distinct also are functionally distinct with respect to mood regulation. For example, the severity of depression correlates inversely with physiological activity in parts of the posterior lateral and medial OFC, consistent with evidence that dysfunction of the OFC associated with cerebrovascular lesions increases the vulnerability for developing the major depressive syndrome. The posterior lateral and medial OFC function may also be impaired in individuals who develop primary mood disorders, as these patients show grey-matter volumetric reductions, histopathologic abnormalities, and altered hemodynamic responses to emotionally valenced stimuli, probabilistic reversal learning, and reward processing. In contrast, physiological activity in the anteromedial OFC situated in the ventromedial frontal polar cortex increases during the depressed versus the remitted phases of major depressive disorder to an extent that is positively correlated with the severity of depression. Effective antidepressant treatment is associated with a reduction in activity in this region. Taken together these data are compatible with evidence from studies in experimental animals indicating that some orbitofrontal and medial prefrontal cortex regions function to inhibit, while others function to enhance, emotional expression. Alterations in the functional balance between these regions and the circuits they form with anatomically related areas of the temporal lobe, striatum, thalamus, and brain stem thus may underlie the pathophysiology of mood disorders, such as major depression.

  20. Non-uniform 3He polarization formed by multiple collisions of a fast 3He+ ion with polarized Rb vapor in a strong magnetic field

    International Nuclear Information System (INIS)

    Arimoto, Y.; Yonehara, K.; Yamagata, T.; Tanaka, M.

    2001-01-01

    We investigated the spatial distribution of a polarization in 3 He beam expected from a novel polarized 3 He ion source based on electron pumping, i.e., multiple electron capture and stripping collisions of an incident fast 3 He + ion with a polarized Rb vapor in a strong axial magnetic field. For this purpose, a Monte Carlo simulation was carried out for 19 keV 3 He + ions with varying Rb vapor thickness, magnetic field, and beam emittance. The calculated results showed a distribution of the 3 He polarization that we call a 'polarization hole', which has a low polarization area around the beam axis. The parameters characterizing the polarization hole, i.e., the polarization and radius of the hole, were found to depend on the Rb vapor thickness, the magnetic field, the beam size, and the angular divergence of the initial beam. These parameters were successfully reproduced with analytical functions deduced from a probability density function prescription. This provides a powerful tool to treat complex phenomena of multiple collisions in strong magnetic fields without performing time-consuming Monte Carlo calculations

  1. An assessment in rodents of the pathological and immunopathological consequence of multiple vaccinations and challenge with radiation-attenuated malaria parasites (blood forms and sporozoites)

    International Nuclear Information System (INIS)

    Boonpucknavig, S.

    1982-06-01

    Multiple vaccination with irradiated merozoites of Plasmodium berghei resulted in high levels of circulating antibody but a low degree of protection to challenge with normal merozoites. On the other hand, the multiple vaccinations and the challenge resulted in severe immunopathological reactions shortly after the immunization or challenge. These reactions were seen in the liver, kidneys and spleen and included the accumulation of mononuclear cells, severe coagulative necrosis of liver cells and proliferative changes in the splenic white pulp and in the glomeruli. The pathological reactions were more severe than in non-immunized animals but the parasitemia was lower and less malarial antigen was detected in Kupfer Cells of the liver, the sinusoidal cells of the spleen and the reticuloendothelial cells in the interstitial tissue of the kidney. Vaccination with irradiated sporozoites of P. berghei resulted in good protection to challenge with normal sporozoites even before circulating anti-sporozoite antibody could be detected. Only mild pathological changes were associated with up to 4 immunizations followed by challenge and these were largely limited to the liver, and were reversible. Sporozoite antigens were detected in the spleen and immune complexes in the glomeruli for 2-4 weeks following challenge but not later. Immunized mice however often developed some lobular pneumonia of the lung but the severity of this did not increase with challenge

  2. Hydrogen Generation using non-polar coaxial InGaN/GaN Multiple Quantum Well Structure Formed on Hollow n-GaN Nanowires.

    Science.gov (United States)

    Park, Ji-Hyeon; Mandal, Arjun; Kang, San; Chatterjee, Uddipta; Kim, Jin Soo; Park, Byung-Guon; Kim, Moon-Deock; Jeong, Kwang-Un; Lee, Cheul-Ro

    2016-08-24

    This article demonstrates for the first time to the best of our knowledge, the merits of InGaN/GaN multiple quantum wells (MQWs) grown on hollow n-GaN nanowires (NWs) as a plausible alternative for stable photoelectrochemical water splitting and efficient hydrogen generation. These hollow nanowires are achieved by a growth method rather not by conventional etching process. Therefore this approach becomes simplistic yet most effective. We believe relatively low Ga flux during the selective area growth (SAG) aids the hollow nanowire to grow. To compare the optoelectronic properties, simultaneously solid nanowires are also studied. In this present communication, we exhibit that lower thermal conductivity of hollow n-GaN NWs affects the material quality of InGaN/GaN MQWs by limiting In diffusion. As a result of this improvement in material quality and structural properties, photocurrent and photosensitivity are enhanced compared to the structures grown on solid n-GaN NWs. An incident photon-to-current efficiency (IPCE) of around ~33.3% is recorded at 365 nm wavelength for hollow NWs. We believe that multiple reflections of incident light inside the hollow n-GaN NWs assists in producing a larger amount of electron hole pairs in the active region. As a result the rate of hydrogen generation is also increased.

  3. MRI volumetry of prefrontal cortex

    Science.gov (United States)

    Sheline, Yvette I.; Black, Kevin J.; Lin, Daniel Y.; Pimmel, Joseph; Wang, Po; Haller, John W.; Csernansky, John G.; Gado, Mokhtar; Walkup, Ronald K.; Brunsden, Barry S.; Vannier, Michael W.

    1995-05-01

    Prefrontal cortex volumetry by brain magnetic resonance (MR) is required to estimate changes postulated to occur in certain psychiatric and neurologic disorders. A semiautomated method with quantitative characterization of its performance is sought to reliably distinguish small prefrontal cortex volume changes within individuals and between groups. Stereological methods were tested by a blinded comparison of measurements applied to 3D MR scans obtained using an MPRAGE protocol. Fixed grid stereologic methods were used to estimate prefrontal cortex volumes on a graphic workstation, after the images are scaled from 16 to 8 bits using a histogram method. In addition images were resliced into coronal sections perpendicular to the bicommissural plane. Prefrontal cortex volumes were defined as all sections of the frontal lobe anterior to the anterior commissure. Ventricular volumes were excluded. Stereological measurement yielded high repeatability and precision, and was time efficient for the raters. The coefficient of error was volumetry by stereology can yield accurate and repeatable measurements. Small frontal lobe volume reductions in patients with brain disorders such as depression and schizophrenia can be efficiently assessed using this method.

  4. Interplay of hippocampus and prefrontal cortex in memory

    Science.gov (United States)

    Preston, Alison R.; Eichenbaum, Howard

    2013-01-01

    Recent studies on the hippocampus and the prefrontal cortex have considerably advanced our understanding of the distinct roles of these brain areas in the encoding and retrieval of memories, and of how they interact in the prolonged process by which new memories are consolidated into our permanent storehouse of knowledge. These studies have led to a new model of how the hippocampus forms and replays memories and how the prefrontal cortex engages representations of the meaningful contexts in which related memories occur, as well as how these areas interact during memory retrieval. Furthermore, they have provided new insights into how interactions between the hippocampus and prefrontal cortex support the assimilation of new memories into pre-existing networks of knowledge, called schemas, and how schemas are modified in this process as the foundation of memory consolidation. PMID:24028960

  5. Crystal Structures of Apo and Metal-Bound Forms of the UreE Protein from Helicobacter pylori: Role of Multiple Metal Binding Sites

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Rong; Munger, Christine; Asinas, Abdalin; Benoit, Stephane L.; Miller, Erica; Matte, Allan; Maier, Robert J.; Cygler, Miroslaw (McGill); (Georgia); (Biotech Res.)

    2010-10-22

    The crystal structure of the urease maturation protein UreE from Helicobacter pylori has been determined in its apo form at 2.1 {angstrom} resolution, bound to Cu{sup 2+} at 2.7 {angstrom} resolution, and bound to Ni{sup 2+} at 3.1 {angstrom} resolution. Apo UreE forms dimers, while the metal-bound enzymes are arranged as tetramers that consist of a dimer of dimers associated around the metal ion through coordination by His102 residues from each subunit of the tetramer. Comparison of independent subunits from different crystal forms indicates changes in the relative arrangement of the N- and C-terminal domains in response to metal binding. The improved ability of engineered versions of UreE containing hexahistidine sequences at either the N-terminal or C-terminal end to provide Ni{sup 2+} for the final metal sink (urease) is eliminated in the H102A version. Therefore, the ability of the improved Ni{sup 2+}-binding versions to deliver more nickel is likely an effect of an increased local concentration of metal ions that can rapidly replenish transferred ions bound to His102.

  6. Interpretation of the function of the striate cortex

    Science.gov (United States)

    Garner, Bernardette M.; Paplinski, Andrew P.

    2000-04-01

    Biological neural networks do not require retraining every time objects move in the visual field. Conventional computer neural networks do not share this shift-invariance. The brain compensates for movements in the head, body, eyes and objects by allowing the sensory data to be tracked across the visual field. The neurons in the striate cortex respond to objects moving across the field of vision as is seen in many experiments. It is proposed, that the neurons in the striate cortex allow continuous angle changes needed to compensate for changes in orientation of the head, eyes and the motion of objects in the field of vision. It is hypothesized that the neurons in the striate cortex form a system that allows for the translation, some rotation and scaling of objects and provides a continuity of objects as they move relative to other objects. The neurons in the striate cortex respond to features which are fundamental to sight, such as orientation of lines, direction of motion, color and contrast. The neurons that respond to these features are arranged on the cortex in a way that depends on the features they are responding to and on the area of the retina from which they receive their inputs.

  7. Integrative proteomics, genomics, and translational immunology approaches reveal mutated forms of Proteolipid Protein 1 (PLP1) and mutant-specific immune response in multiple sclerosis.

    Science.gov (United States)

    Qendro, Veneta; Bugos, Grace A; Lundgren, Debbie H; Glynn, John; Han, May H; Han, David K

    2017-03-01

    In order to gain mechanistic insights into multiple sclerosis (MS) pathogenesis, we utilized a multi-dimensional approach to test the hypothesis that mutations in myelin proteins lead to immune activation and central nervous system autoimmunity in MS. Mass spectrometry-based proteomic analysis of human MS brain lesions revealed seven unique mutations of PLP1; a key myelin protein that is known to be destroyed in MS. Surprisingly, in-depth genomic analysis of two MS patients at the genomic DNA and mRNA confirmed mutated PLP1 in RNA, but not in the genomic DNA. Quantification of wild type and mutant PLP RNA levels by qPCR further validated the presence of mutant PLP RNA in the MS patients. To seek evidence linking mutations in abundant myelin proteins and immune-mediated destruction of myelin, specific immune response against mutant PLP1 in MS patients was examined. Thus, we have designed paired, wild type and mutant peptide microarrays, and examined antibody response to multiple mutated PLP1 in sera from MS patients. Consistent with the idea of different patients exhibiting unique mutation profiles, we found that 13 out of 20 MS patients showed antibody responses against specific but not against all the mutant-PLP1 peptides. Interestingly, we found mutant PLP-directed antibody response against specific mutant peptides in the sera of pre-MS controls. The results from integrative proteomic, genomic, and immune analyses reveal a possible mechanism of mutation-driven pathogenesis in human MS. The study also highlights the need for integrative genomic and proteomic analyses for uncovering pathogenic mechanisms of human diseases. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Mapping visual cortex in monkeys and humans using surface-based atlases

    Science.gov (United States)

    Van Essen, D. C.; Lewis, J. W.; Drury, H. A.; Hadjikhani, N.; Tootell, R. B.; Bakircioglu, M.; Miller, M. I.

    2001-01-01

    We have used surface-based atlases of the cerebral cortex to analyze the functional organization of visual cortex in humans and macaque monkeys. The macaque atlas contains multiple partitioning schemes for visual cortex, including a probabilistic atlas of visual areas derived from a recent architectonic study, plus summary schemes that reflect a combination of physiological and anatomical evidence. The human atlas includes a probabilistic map of eight topographically organized visual areas recently mapped using functional MRI. To facilitate comparisons between species, we used surface-based warping to bring functional and geographic landmarks on the macaque map into register with corresponding landmarks on the human map. The results suggest that extrastriate visual cortex outside the known topographically organized areas is dramatically expanded in human compared to macaque cortex, particularly in the parietal lobe.

  9. Phasic and tonic neuron ensemble codes for stimulus-environment conjunctions in the lateral entorhinal cortex.

    Science.gov (United States)

    Pilkiw, Maryna; Insel, Nathan; Cui, Younghua; Finney, Caitlin; Morrissey, Mark D; Takehara-Nishiuchi, Kaori

    2017-07-06

    The lateral entorhinal cortex (LEC) is thought to bind sensory events with the environment where they took place. To compare the relative influence of transient events and temporally stable environmental stimuli on the firing of LEC cells, we recorded neuron spiking patterns in the region during blocks of a trace eyeblink conditioning paradigm performed in two environments and with different conditioning stimuli. Firing rates of some neurons were phasically selective for conditioned stimuli in a way that depended on which room the rat was in; nearly all neurons were tonically selective for environments in a way that depended on which stimuli had been presented in those environments. As rats moved from one environment to another, tonic neuron ensemble activity exhibited prospective information about the conditioned stimulus associated with the environment. Thus, the LEC formed phasic and tonic codes for event-environment associations, thereby accurately differentiating multiple experiences with overlapping features.

  10. The Functions of the Orbitofrontal Cortex

    Science.gov (United States)

    Rolls, Edmund T.

    2004-01-01

    The orbitofrontal cortex contains the secondary taste cortex, in which the reward value of taste is represented. It also contains the secondary and tertiary olfactory cortical areas, in which information about the identity and also about the reward value of odours is represented. The orbitofrontal cortex also receives information about the sight…

  11. A hierarchy of intrinsic timescales across primate cortex.

    Science.gov (United States)

    Murray, John D; Bernacchia, Alberto; Freedman, David J; Romo, Ranulfo; Wallis, Jonathan D; Cai, Xinying; Padoa-Schioppa, Camillo; Pasternak, Tatiana; Seo, Hyojung; Lee, Daeyeol; Wang, Xiao-Jing

    2014-12-01

    Specialization and hierarchy are organizing principles for primate cortex, yet there is little direct evidence for how cortical areas are specialized in the temporal domain. We measured timescales of intrinsic fluctuations in spiking activity across areas and found a hierarchical ordering, with sensory and prefrontal areas exhibiting shorter and longer timescales, respectively. On the basis of our findings, we suggest that intrinsic timescales reflect areal specialization for task-relevant computations over multiple temporal ranges.

  12. High hydrogen desorption properties of Mg-based nanocomposite at moderate temperatures: The effects of multiple catalysts in situ formed by adding nickel sulfides/graphene

    Science.gov (United States)

    Xie, Xiubo; Chen, Ming; Liu, Peng; Shang, Jiaxiang; Liu, Tong

    2017-12-01

    Nickel sulfides decorated reduced graphene oxide (rGO) has been produced by co-reducing Ni2+ and graphene oxide (GO), and is subsequently ball milled with Mg nanoparticles (NPs) produced by hydrogen plasma metal reaction (HPMR). The nickel sulfides of about 800 nm completely in situ change to MgS, Mg2Ni and Ni multiple catalysts after first hydrogenation/dehydrogenation process at 673 K. The Mg-5wt%NiS/rGO nanocomposite shows the highest hydrogen desorption kinetics and capacity properties, and the catalytic effect order of the additives is NiS/rGO, NiS and rGO. At 573 K, the Mg-NiS/rGO nanocomposite can quickly desorb 3.7 wt% H2 in 10 min and 4.5 wt% H2 in 60 min. The apparent hydrogen absorption and desorption activation energies of the Mg-5wt%NiS/rGO nanocomposite are decreased to 44.47 and 63.02 kJ mol-1, smaller than those of the Mg-5wt%rGO and Mg-5wt%NiS samples. The best hydrogen desorption properties of the Mg-5wt%NiS/rGO nanocomposite can be explained by the synergistic catalytic effects of the highly dispersed MgS, Mg2Ni and Ni catalysts on the rGO sheets, and the more nucleation sites between the catalysts, rGO sheets and Mg matrix.

  13. Race, Ethnicity and Ancestry in Unrelated Transplant Matching for the National Marrow Donor Program: A Comparison of Multiple Forms of Self-Identification with Genetics

    Science.gov (United States)

    Hollenbach, Jill A.; Saperstein, Aliya; Albrecht, Mark; Vierra-Green, Cynthia; Parham, Peter; Norman, Paul J.; Maiers, Martin

    2015-01-01

    We conducted a nationwide study comparing self-identification to genetic ancestry classifications in a large cohort (n = 1752) from the National Marrow Donor Program. We sought to determine how various measures of self-identification intersect with genetic ancestry, with the aim of improving matching algorithms for unrelated bone marrow transplant. Multiple dimensions of self-identification, including race/ethnicity and geographic ancestry were compared to classifications based on ancestry informative markers (AIMs), and the human leukocyte antigen (HLA) genes, which are required for transplant matching. Nearly 20% of responses were inconsistent between reporting race/ethnicity versus geographic ancestry. Despite strong concordance between AIMs and HLA, no measure of self-identification shows complete correspondence with genetic ancestry. In certain cases geographic ancestry reporting matches genetic ancestry not reflected in race/ethnicity identification, but in other cases geographic ancestries show little correspondence to genetic measures, with important differences by gender. However, when respondents assign ancestry to grandparents, we observe sub-groups of individuals with well- defined genetic ancestries, including important differences in HLA frequencies, with implications for transplant matching. While we advocate for tailored questioning to improve accuracy of ancestry ascertainment, collection of donor grandparents’ information will improve the chances of finding matches for many patients, particularly for mixed-ancestry individuals. PMID:26287376

  14. Race, Ethnicity and Ancestry in Unrelated Transplant Matching for the National Marrow Donor Program: A Comparison of Multiple Forms of Self-Identification with Genetics.

    Directory of Open Access Journals (Sweden)

    Jill A Hollenbach

    Full Text Available We conducted a nationwide study comparing self-identification to genetic ancestry classifications in a large cohort (n = 1752 from the National Marrow Donor Program. We sought to determine how various measures of self-identification intersect with genetic ancestry, with the aim of improving matching algorithms for unrelated bone marrow transplant. Multiple dimensions of self-identification, including race/ethnicity and geographic ancestry were compared to classifications based on ancestry informative markers (AIMs, and the human leukocyte antigen (HLA genes, which are required for transplant matching. Nearly 20% of responses were inconsistent between reporting race/ethnicity versus geographic ancestry. Despite strong concordance between AIMs and HLA, no measure of self-identification shows complete correspondence with genetic ancestry. In certain cases geographic ancestry reporting matches genetic ancestry not reflected in race/ethnicity identification, but in other cases geographic ancestries show little correspondence to genetic measures, with important differences by gender. However, when respondents assign ancestry to grandparents, we observe sub-groups of individuals with well- defined genetic ancestries, including important differences in HLA frequencies, with implications for transplant matching. While we advocate for tailored questioning to improve accuracy of ancestry ascertainment, collection of donor grandparents' information will improve the chances of finding matches for many patients, particularly for mixed-ancestry individuals.

  15. Lesion-to-ventricle distance and other risk factors for the persistence of newly formed black holes in relapsing-remitting multiple sclerosis.

    Science.gov (United States)

    Papadopoulou, Athina; Menegola, Milena; Kuhle, Jens; Ramagopalan, Sreeram V; D'Souza, Marcus; Sprenger, Till; Radue, Ernst-Wilhelm; Kappos, Ludwig; Yaldizli, Özgür

    2014-03-01

    Progenitor cells from the subventricular zone (SVZ) of the lateral ventricles are assumed to contribute to remyelination and resolution of black holes (BHs) in multiple sclerosis (MS). This process may depend on the distance between the lesion and the SVZ. The objective of this paper is to investigate the relationship between lesion-to-ventricle (LV) distance and persistence of new BHs. We analysed the magnetic resonance images (MRIs) of 289 relapsing-remitting (RR) MS patients, obtained during a multi-centre, placebo-controlled phase II trial over one year. Overall, 112/289 patients showed 367 new BHs at the beginning of the trial. Of these, 225 were located in 94/112 patients at the level of the lateral ventricles on axial MRIs and included in this analysis. In total, 86/225 (38%) BHs persisted at month 12. LV distance in persistent BHs (PBHs) was not longer than in transient BHs. In fact PBHs tended to be closer to the SVZ than transient BHs. A generalised linear mixed multivariate model adjusted for BHs clustered within a patient and including patient- as well as lesion-specific factors revealed size, ring contrast enhancement, and shorter LV distance as independent predictors for BH persistence. Location of BHs close to the lateral ventricles does not appear to favourably influence the resolution of new BHs in RRMS.

  16. Spontaneous high-gamma band activity reflects functional organization of auditory cortex in the awake macaque.

    Science.gov (United States)

    Fukushima, Makoto; Saunders, Richard C; Leopold, David A; Mishkin, Mortimer; Averbeck, Bruno B

    2012-06-07

    In the absence of sensory stimuli, spontaneous activity in the brain has been shown to exhibit organization at multiple spatiotemporal scales. In the macaque auditory cortex, responses to acoustic stimuli are tonotopically organized within multiple, adjacent frequency maps aligned in a caudorostral direction on the supratemporal plane (STP) of the lateral sulcus. Here, we used chronic microelectrocorticography to investigate the correspondence between sensory maps and spontaneous neural fluctuations in the auditory cortex. We first mapped tonotopic organization across 96 electrodes spanning approximately two centimeters along the primary and higher auditory cortex. In separate sessions, we then observed that spontaneous activity at the same sites exhibited spatial covariation that reflected the tonotopic map of the STP. This observation demonstrates a close relationship between functional organization and spontaneous neural activity in the sensory cortex of the awake monkey. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Cerebellar modulation of frontal cortex dopamine efflux in mice: relevance to autism and schizophrenia.

    Science.gov (United States)

    Mittleman, Guy; Goldowitz, Daniel; Heck, Detlef H; Blaha, Charles D

    2008-07-01

    Cerebellar and frontal cortical pathologies have been commonly reported in schizophrenia, autism, and other developmental disorders. Whether there is a relationship between prefrontal and cerebellar pathologies is unknown. Using fixed potential amperometry, dopamine (DA) efflux evoked by cerebellar or, dentate nucleus electrical stimulation (50 Hz, 200 muA) was recorded in prefrontal cortex of urethane anesthetized lurcher (Lc/+) mice with 100% loss of cerebellar Purkinje cells and wildtype (+/+) control mice. Cerebellar stimulation with 25 and 100 pulses evoked prefrontal cortex DA efflux in +/+ mice that persisted for 12 and 25 s poststimulation, respectively. In contrast, 25 pulse cerebellar stimulation failed to evoke prefrontal cortex DA efflux in Lc/+ mice indicating a dependency on cerebellar Purkinje cell outputs. Dentate nucleus stimulation (25 pulses) evoked a comparable but briefer (baseline recovery within 7 s) increase in prefrontal cortex DA efflux compared to similar cerebellar stimulation in +/+ mice. However, in Lc/+ mice 25 pulse dentate nucleus evoked prefrontal cortex DA efflux was attenuated by 60% with baseline recovery within 4 s suggesting that dentate nucleus outputs to prefrontal cortex remain partially functional. DA reuptake blockade enhanced 100 pulse stimulation evoked prefrontal cortex responses, while serotonin or norepinephrine reuptake blockade were without effect indicating the specificity of the amperometric recordings to DA. Results provide neurochemical evidence that the cerebellum can modulate DA efflux in the prefrontal cortex. Together, these findings may explain why cerebellar and frontal cortical pathologies co-occur, and may provide a mechanism that accounts for the diversity of symptoms common to multiple developmental disorders.

  18. Measurement of Multiple Vitamin K Forms in Processed and Fresh-Cut Pork Products in the U.S. Food Supply.

    Science.gov (United States)

    Fu, Xueyan; Shen, Xiaohua; Finnan, Emily G; Haytowitz, David B; Booth, Sarah L

    2016-06-08

    Vitamin K food composition data have historically been limited to plant-based phylloquinone (vitamin K1). The purpose of this study was to expand analysis of vitamin K to animal products and to measure phylloquinone and 10 forms of menaquinones (vitamin K2) in processed and fresh-cut pork products. Nationally representative samples of processed pork products (n = 28) were obtained through USDA's National Food and Nutrition Analysis Program, and fresh pork (six cuts; n = 5 per cut) and bacon (n = 4) were purchased from local retail outlets. All samples were analyzed by high-performance liquid chromatography (phylloquinone and menaquinone-4) and atmospheric-pressure chemical ionization-liquid chromatography-mass spectrometry (menaquinone-5 to menaquinone-13). Although low in phylloquinone (processed pork products and fresh pork cuts contained menaquinone-4, menaquinone-10, and menaquinone-11 (range: [35.1 ± 11.0]-[534 ± 89.0] μg of menaquinones per 100 g). The total menaquinone contents of processed pork products were correlated with fat contents (r = 0.935). In summary, processed and fresh-cut pork products are a rich dietary source of menaquinones that are currently unaccounted for in assessment of vitamin K in the food supply.

  19. Distinct timescales of population coding across cortex.

    Science.gov (United States)

    Runyan, Caroline A; Piasini, Eugenio; Panzeri, Stefano; Harvey, Christopher D

    2017-08-03

    The cortex represents information across widely varying timescales. For instance, sensory cortex encodes stimuli that fluctuate over few tens of milliseconds, whereas in association cortex behavioural choices can require the maintenance of information over seconds. However, it remains poorly understood whether diverse timescales result mostly from features intrinsic to individual neurons or from neuronal population activity. This question remains unanswered, because the timescales of coding in populations of neurons have not been studied extensively, and population codes have not been compared systematically across cortical regions. Here we show that population codes can be essential to achieve long coding timescales. Furthermore, we find that the properties of population codes differ between sensory and association cortices. We compared coding for sensory stimuli and behavioural choices in auditory cortex and posterior parietal cortex as mice performed a sound localization task. Auditory stimulus information was stronger in auditory cortex than in posterior parietal cortex, and both regions contained choice information. Although auditory cortex and posterior parietal cortex coded information by tiling in time neurons that were transiently informative for approximately 200 milliseconds, the areas had major differences in functional coupling between neurons, measured as activity correlations that could not be explained by task events. Coupling among posterior parietal cortex neurons was strong and extended over long time lags, whereas coupling among auditory cortex neurons was weak and short-lived. Stronger coupling in posterior parietal cortex led to a population code with long timescales and a representation of choice that remained consistent for approximately 1 second. In contrast, auditory cortex had a code with rapid fluctuations in stimulus and choice information over hundreds of milliseconds. Our results reveal that population codes differ across cortex

  20. Estimates of segregation and overlap of functional connectivity networks in the human cerebral cortex.

    Science.gov (United States)

    Yeo, B T Thomas; Krienen, Fenna M; Chee, Michael W L; Buckner, Randy L

    2014-03-01

    The organization of the human cerebral cortex has recently been explored using techniques for parcellating the cortex into distinct functionally coupled networks. The divergent and convergent nature of cortico-cortical anatomic connections suggests the need to consider the possibility of regions belonging to multiple networks and hierarchies among networks. Here we applied the Latent Dirichlet Allocation (LDA) model and spatial independent component analysis (ICA) to solve for functionally coupled cerebral networks without assuming that cortical regions belong to a single network. Data analyzed included 1000 subjects from the Brain Genomics Superstruct Project (GSP) and 12 high quality individual subjects from the Human Connectome Project (HCP). The organization of the cerebral cortex was similar regardless of whether a winner-take-all approach or the more relaxed constraints of LDA (or ICA) were imposed. This suggests that large-scale networks may function as partially isolated modules. Several notable interactions among networks were uncovered by the LDA analysis. Many association regions belong to at least two networks, while somatomotor and early visual cortices are especially isolated. As examples of interaction, the precuneus, lateral temporal cortex, medial prefrontal cortex and posterior parietal cortex participate in multiple paralimbic networks that together comprise subsystems of the default network. In addition, regions at or near the frontal eye field and human lateral intraparietal area homologue participate in multiple hierarchically organized networks. These observations were replicated in both datasets and could be detected (and replicated) in individual subjects from the HCP. © 2013.

  1. Motor cortex is required for learning but not for executing a motor skill.

    Science.gov (United States)

    Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu L; Dhawale, Ashesh K; Kampff, Adam R; Ölveczky, Bence P

    2015-05-06

    Motor cortex is widely believed to underlie the acquisition and execution of motor skills, but its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex's established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in "tutoring" these circuits during learning. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Relationship between multiple forms of childhood maltreatment and adult mental health in community respondents: results from the adverse childhood experiences study.

    Science.gov (United States)

    Edwards, Valerie J; Holden, George W; Felitti, Vincent J; Anda, Robert F

    2003-08-01

    This study examined the prevalence of a history of various combinations of childhood maltreatment types (physical abuse, sexual abuse, and witnessing of maternal battering) among adult members of a health maintenance organization (HMO) and explored the relationship with adult mental health of the combinations of types of childhood maltreatment and emotional abuse in the childhood family environment. A total of 8,667 adult members of an HMO completed measures of childhood exposure to family dysfunction, which included items on physical and sexual abuse, witnessing of maternal battering, and emotional abuse in the childhood family environment. The adults' current mental health was assessed by using the mental health scale of the Medical Outcomes Study 36-item Short-Form Health Survey. The prevalences of sexual abuse, physical abuse, and witnessing of maternal violence were 21.6%, 20.6%, and 14.0%, respectively, when the maltreatment types were considered separately. Among respondents reporting any of the maltreatment types, 34.6% reported more than one type of maltreatment. Lower mean mental health scores were associated with higher numbers of abuse categories (mean=78.5, 75.5, 72.8, and 69.9 for respondents with no, one, two, and three abuse types, respectively). Both an emotionally abusive family environment and the interaction of an emotionally abusive family environment with the various maltreatment types had a significant effect on mental health scores. Childhood physical and sexual abuse, as well as witnessing of maternal battering, were common among the adult members of an HMO in this study. Among those reporting any maltreatment, more than one-third had experienced more than one type of maltreatment. A dose-response relation was found between the number of types of maltreatment reported and mental health scores. In addition, an emotionally abusive family environment accentuated the decrements in mental health scores. Future research examining the effects of

  3. Demonstration of two-user, 10-Gbits/s optical code-division multiple-access system implemented by using cascaded longperiod fiber gratings formed in dispersion-compensating fiber with inner-cladding structure

    DEFF Research Database (Denmark)

    Kim, Sun-Jong; Eom, T.J.; Kim, T.Y.

    2005-01-01

    A two-user, 10-Gbits/s optical code-division multiple-access system implemented by using cascaded long-period fiber gratings formed in a dispersion-compensating fiber (DCF) is demonstrated. Our results show that the sensitivity of cladding modes to the refractive index change on the cladding...... surface is greatly reduced by utilizing the inner-cladding mode of the DCF. Two pairs of encoder/decoder are constructed and the performance is evaluated by measuring bit error rate (BER). With an interferer, a BER of 1.5 X 10(-12) is measured at a received optical power of -6 dBm....

  4. Demonstration of two-user, 10-Gbits/s optical code-division multiple-access system implemented by using cascaded long-period fiber gratings formed in dispersion-compensating fiber with inner-cladding structure

    Science.gov (United States)

    Kim, Sun-Jong; Eom, Tae-Jung; Kim, Tae-Young; Lee, Byeong Ha; Park, Chang-Soo

    2005-09-01

    A two-user, 10-Gbits/s optical code-division multiple-access system implemented by using cascaded long-period fiber gratings formed in a dispersion-compensating fiber (DCF) is demonstrated. Our results show that the sensitivity of cladding modes to the refractive index change on the cladding surface is greatly reduced by utilizing the inner-cladding mode of the DCF. Two pairs of encoder/decoder are constructed and the performance is evaluated by measuring bit error rate (BER). With an interferer, a BER of 1.5×10-12 is measured at a received optical power of -6 dBm.

  5. Spatial attention improves the quality of population codes in human visual cortex.

    Science.gov (United States)

    Saproo, Sameer; Serences, John T

    2010-08-01

    Selective attention enables sensory input from behaviorally relevant stimuli to be processed in greater detail, so that these stimuli can more accurately influence thoughts, actions, and future goals. Attention has been shown to modulate the spiking activity of single feature-selective neurons that encode basic stimulus properties (color, orientation, etc.). However, the combined output from many such neurons is required to form stable representations of relevant objects and little empirical work has formally investigated the relationship between attentional modulations on population responses and improvements in encoding precision. Here, we used functional MRI and voxel-based feature tuning functions to show that spatial attention induces a multiplicative scaling in orientation-selective population response profiles in early visual cortex. In turn, this multiplicative scaling correlates with an improvement in encoding precision, as evidenced by a concurrent increase in the mutual information between population responses and the orientation of attended stimuli. These data therefore demonstrate how multiplicative scaling of neural responses provides at least one mechanism by which spatial attention may improve the encoding precision of population codes. Increased encoding precision in early visual areas may then enhance the speed and accuracy of perceptual decisions computed by higher-order neural mechanisms.

  6. Responses of primate frontal cortex neurons during natural vocal communication.

    Science.gov (United States)

    Miller, Cory T; Thomas, A Wren; Nummela, Samuel U; de la Mothe, Lisa A

    2015-08-01

    The role of primate frontal cortex in vocal communication and its significance in language evolution have a controversial history. While evidence indicates that vocalization processing occurs in ventrolateral prefrontal cortex neurons, vocal-motor activity has been conjectured to be primarily subcortical and suggestive of a distinctly different neural architecture from humans. Direct evidence of neural activity during natural vocal communication is limited, as previous studies were performed in chair-restrained animals. Here we recorded the activity of single neurons across multiple regions of prefrontal and premotor cortex while freely moving marmosets engaged in a natural vocal behavior known as antiphonal calling. Our aim was to test whether neurons in marmoset frontal cortex exhibited responses during vocal-signal processing and/or vocal-motor production in the context of active, natural communication. We observed motor-related changes in single neuron activity during vocal production, but relatively weak sensory responses for vocalization processing during this natural behavior. Vocal-motor responses occurred both prior to and during call production and were typically coupled to the timing of each vocalization pulse. Despite the relatively weak sensory responses a population classifier was able to distinguish between neural activity that occurred during presentations of vocalization stimuli that elicited an antiphonal response and those that did not. These findings are suggestive of the role that nonhuman primate frontal cortex neurons play in natural communication and provide an important foundation for more explicit tests of the functional contributions of these neocortical areas during vocal behaviors. Copyright © 2015 the American Physiological Society.

  7. 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...

  8. Normal and abnormal neuronal migration in the developing cerebral cortex

    OpenAIRE

    Sun, Xue-Zhi; Takahashi, Sentaro; Cui, Chun; Zhang, Rui; Sakata-Haga, Hiromi; Sawada, Kazuhiko; Fukui, Yoshihiro

    2002-01-01

    Neuronal migration is the critical cellular process which initiates histogenesis of cerebral cortex. Migration involves a series of complex cell interactions and transformation. After completing their final mitosis, neurons migrate from the ventricular zone into the cortical plate, and then establish neuronal lamina and settle onto the outermost layer, forming an “inside-out” gradient of maturation. This process is guided by radial glial fibers, requires proper receptors, ligands, other unkno...

  9. Reduced dorso-lateral prefrontal cortex in treatment resistant schizophrenia.

    Science.gov (United States)

    Zugman, André; Gadelha, Ary; Assunção, Idaiane; Sato, João; Ota, Vanessa K; Rocha, Deyvis L; Mari, Jair J; Belangero, Sintia I; Bressan, Rodrigo A; Brietzke, Elisa; Jackowski, Andrea P

    2013-08-01

    Treatment resistance affects up to one third of patients with schizophrenia (SCZ). A better understanding of its biological underlying processes could improve treatment. The aim of this study was to compare cortical thickness between non-resistant SCZ (NR-SCZ), treatment-resistant SCZ (TR-SCZ) patients and healthy controls (HC). Structural MRI scans were obtained from 3 groups of individuals: 61 treatment resistant SCZ individuals, 67 non-resistant SCZ and 80 healthy controls. Images were analyzed using cortical surface modelling (implemented in freesurfer package) to identify group differences in cortical thickness. Statistical significant differences were identified using Monte-Carlo simulation method with a corrected p-cluster<0.01. Patients in the TR-SCZ group showed a widespread reduction in cortical thickness in frontal, parietal, temporal and occipital regions bilaterally. NR-SCZ group had reduced cortex in two regions (left superior frontal cortex and left caudal middle frontal cortex). TR-SCZ group also showed decreased thickness in the left dorsolateral prefrontal cortex (DLPFC) when compared with patients from NR-SCZ group. The reduction in cortical thickness in DLPFC indicates a more severe form of the disease or a specific finding for this group. Alterations in this region should be explored as a putative marker for treatment resistance. Prospective studies, with individuals being followed from first episode psychosis until refractoriness is diagnosed, are needed to clarify these hypotheses. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Metabolic activity in striate and extrastriate cortex in the hooded rat: contralateral and ipsilateral eye input

    International Nuclear Information System (INIS)

    Thurlow, G.A.; Cooper, R.M.

    1988-01-01

    The extent of changes in glucose metabolism resulting from ipsilateral and contralateral eye activity in the posterior cortex of the hooded rat was demonstrated by means of the C-14 2-deoxyglucose autoradiographic technique. By stimulating one eye with square wave gratings and eliminating efferent activation from the other by means of enucleation or intraocular TTX injection, differences between ipsilaterally and contralaterally based visual activity in the two hemispheres were maximized. Carbon-14 levels in layer IV of autoradiographs of coronal sections were measured and combined across sections to form right and left matrices of posterior cortex metabolic activity. A difference matrix, formed by subtracting the metabolic activity matrix of cortex contralateral to the stimulated eye from the ipsilateral depressed matrix, emphasized those parts of the visual cortex that received monocular visual input. The demarcation of striate cortex by means of cholinesterase stain and the examination of autoradiographs from sections cut tangential to the cortical surface aided in the interpretation of the difference matrices. In striate cortex, differences were maximal in the medial monocular portion, and the lateral or binocular portion was shown to be divided metabolically into a far lateral contralaterally dominant strip along the cortical representation of the vertical meridian, and a more medial region of patches of more or less contralaterally dominant binocular input. Lateral peristriate differences were less than those of striate cortex, and regions of greater and lesser monocular input could be distinguished. We did not detect differences between the two hemispheres in either anterior or medial peristriate areas

  11. Hierarchical representation of shapes in visual cortex-from localized features to figural shape segregation.

    Science.gov (United States)

    Tschechne, Stephan; Neumann, Heiko

    2014-01-01

    Visual structures in the environment are segmented into image regions and those combined to a representation of surfaces and prototypical objects. Such a perceptual organization is performed by complex neural mechanisms in the visual cortex of primates. Multiple mutually connected areas in the ventral cortical pathway receive visual input and extract local form features that are subsequently grouped into increasingly complex, more meaningful image elements. Such a distributed network of processing must be capable to make accessible highly articulated changes in shape boundary as well as very subtle curvature changes that contribute to the perception of an object. We propose a recurrent computational network architecture that utilizes hierarchical distributed representations of shape features to encode surface and object boundary over different scales of resolution. Our model makes use of neural mechanisms that model the processing capabilities of early and intermediate stages in visual cortex, namely areas V1-V4 and IT. We suggest that multiple specialized component representations interact by feedforward hierarchical processing that is combined with feedback signals driven by representations generated at higher stages. Based on this, global configurational as well as local information is made available to distinguish changes in the object's contour. Once the outline of a shape has been established, contextual contour configurations are used to assign border ownership directions and thus achieve segregation of figure and ground. The model, thus, proposes how separate mechanisms contribute to distributed hierarchical cortical shape representation and combine with processes of figure-ground segregation. Our model is probed with a selection of stimuli to illustrate processing results at different processing stages. We especially highlight how modulatory feedback connections contribute to the processing of visual input at various stages in the processing hierarchy.

  12. Hierarchical representation of shapes in visual cortex - from localized features to figural shape segregation

    Directory of Open Access Journals (Sweden)

    Stephan eTschechne

    2014-08-01

    Full Text Available Visual structures in the environment are effortlessly segmented into image regions and those combined to a representation of surfaces and prototypical objects. Such a perceptual organization is performed by complex neural mechanisms in the visual cortex of primates. Multiple mutually connected areas in the ventral cortical pathway receive visual input and extract local form features that are subsequently grouped into increasingly complex, more meaningful image elements. At this stage, highly articulated changes in shape boundary as well as very subtle curvature changes contribute to the perception of an object.We propose a recurrent computational network architecture that utilizes a hierarchical distributed representation of shape features to encode boundary features over different scales of resolution. Our model makes use of neural mechanisms that model the processing capabilities of early and intermediate stages in visual cortex, namely areas V1-V4 and IT. We suggest that multiple specialized component representations interact by feedforward hierarchical processing that is combined with feedback from representations generated at higher stages. In so doing, global configurational as well as local information is available to distinguish changes in the object's contour. Once the outline of a shape has been established, contextual contour configurations are used to assign border ownership directions and thus achieve segregation of figure and ground. This combines separate findings about the generation of cortical shape representation using hierarchical representations with figure-ground segregation mechanisms.Our model is probed with a selection of artificial and real world images to illustrate processing results at different processing stages. We especially highlight how modulatory feedback connections contribute to the processing of visual input at various stages in the processing hierarchy.

  13. The Significance of Memory in Sensory Cortex.

    Science.gov (United States)

    Muckli, Lars; Petro, Lucy S

    2017-05-01

    Early sensory cortex is typically investigated in response to sensory stimulation, masking the contribution of internal signals. Recently, van Kerkoerle and colleagues reported that attention and memory signals segregate from sensory signals within specific layers of primary visual cortex, providing insight into the role of internal signals in sensory processing. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. The significance of memory in sensory cortex

    OpenAIRE

    Muckli, Lars; Petro, Lucy S.

    2017-01-01

    Early sensory cortex is typically investigated in response to sensory stimulation, masking the contribution of internal signals. Recently, van Kerkoerle and colleagues reported that attention and memory signals segregate from sensory signals within specific layers of primary visual cortex, providing insight into the role of internal signals in sensory processing.

  15. Efficacy of a Film-Forming Medical Device Containing Piroxicam and Sun Filters in the Treatment of Multiple Actinic Keratosis Lesions in a Subject with a History of Kaposi Sarcoma

    Directory of Open Access Journals (Sweden)

    Elisabetta Scotti

    2016-10-01

    Full Text Available Actinic keratosis (AK is considered a premalignant form of skin cancer due to chronic sun exposure. In addition, human papilloma virus (HPV has been advocated a role in the pathogenesis of this clinical condition. HPV proteins (mainly E6 and E7 seem to act synergistically with ultraviolet (UV radiation in reducing the defensive mechanisms of keratinocyte apoptosis after UV damage. Data regarding the involvement of other viruses, i.e. human herpes viruses (HHV, in the pathogenesis of AK are so far controversial. HHV8 is considered the infective agent involved in the development of Kaposi sarcoma. Some experimental data have shown that AK lesions carry HHV8 in more than 30% of the bioptic samples. Topical piroxicam was shown to be effective in the treatment of AK. In addition, the molecule shows antiviral action against HPV and HHV8. Here, we report the efficacy of a medical device containing a film-forming substance (polyvinyl alcohol, chemical and physical sun filters (SPF 50+, and 0.8% piroxicam (ActixicamTM, Difa Cooper; ACTX in the treatment of multiple scalp AK lesions, unresponsive to other treatments, in a subject with Kaposi sarcoma and a history of severe contact dermatitis. The subject presented with severe involvement of the scalp, with multiple hypertrophic AK lesions. Previous lesion-directed and field-targeted treatments have not been effective. The subject was treated with ACTX applied twice daily on the affected scalp. Relevant clinical improvement was observed as soon as 1 month of therapy. Complete clinical resolution of all scalp lesions was observed after 3 months of treatment. The product was well tolerated.

  16. A slow-releasing form of prostacyclin agonist (ONO1301SR) enhances endogenous secretion of multiple cardiotherapeutic cytokines and improves cardiac function in a rapid-pacing-induced model of canine heart failure.

    Science.gov (United States)

    Shirasaka, Tomonori; Miyagawa, Shigeru; Fukushima, Satsuki; Saito, Atsuhiro; Shiozaki, Motoko; Kawaguchi, Naomasa; Matsuura, Nariaki; Nakatani, Satoshi; Sakai, Yoshiki; Daimon, Takashi; Okita, Yutaka; Sawa, Yoshiki

    2013-08-01

    Cardiac functional deterioration in dilated cardiomyopathy (DCM) is known to be reversed by intramyocardial up-regulation of multiple cardioprotective factors, whereas a prostacyclin analog, ONO1301, has been shown to paracrinally activate interstitial cells to release a variety of protective factors. We here hypothesized that intramyocardial delivery of a slow-releasing form of ONO1301 (ONO1301SR) might activate regional myocardium to up-regulate cardiotherapeutic factors, leading to regional and global functional recovery in DCM. ONO1301 elevated messenger RNA and protein level of hepatocyte growth factor, vascular endothelial growth factor, and stromal-derived factor-1 of normal human dermal fibroblasts in a dose-dependent manner in vitro. Intramyocardial delivery of ONO1301SR, which is ONO1301 mixed with polylactic and glycolic acid polymer (PLGA), but not that of PLGA only, yielded significant global functional recovery in a canine rapid pacing-induced DCM model, assessed by echocardiography and cardiac catheterization (n = 5 each). Importantly, speckle-tracking echocardiography unveiled significant regional functional recovery in the ONO1301-delivered territory, consistent to significantly increased vascular density, reduced interstitial collagen accumulation, attenuated myocyte hypertrophy, and reversed mitochondrial structure in the corresponding area. Intramyocardial delivery of ONO1301SR, which is a PLGA-coated slow-releasing form of ONO1301, up-regulated multiple cardiotherapeutic factors in the injected territory, leading to region-specific reverse left ventricular remodeling and consequently a global functional recovery in a rapid-pacing-induced canine DCM model, warranting a further preclinical study to optimize this novel drug-delivery system to treat DCM. Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  17. Seasonal distribution and evolving forms of multiple sclerosis patients diagnosed from April 2004 to November 2007 Distribución estacional y formas evolutivas de esclerosis múltiple en pacientes diagnosticados entre Abril del 2004 y Noviembre del 2007

    Directory of Open Access Journals (Sweden)

    Hermes Fundora-Hernández

    2009-09-01

    Full Text Available BACKGROUND: Multiple sclerosis (MS was first reported in Cuba in 1965. The most frequent appearance is observed in the first six months of the year. OBJECTIVE: To determine the seasonal distribution and evolving forms of MS patients diagnosed with the disease between April 2004 and November 2007. METHOD: Twenty-one patients with suspected MS and 42 outbreaks were studied. Patients were classified according to Lublin and Revingold's criteria for clinical forms and according to McDonald. RESULTS: Most patients were classified in outbreak and remission and only two patients classified as primary-progressive multiple sclerosis. The higher number of outbreaks occurred in the first two quarters of the year. CONCLUSION: It is recommended to study further weather variables that may be related to the emergence of these outbreaks in our environment.INTRODUCCIÓN: La esclerosis múltiple (EM fue reportada en Cuba por primera vez en 1965. Se ha venido observando la aparición más frecuente en los primeros seis meses del año. OBJETIVO: Determinar la distribución estacional y formas evolutivas de EM en pacientes con diagnóstico de esta enfermedad entre abril 2004 y noviembre 2007. MÉTODO: Se estudiaron 21 pacientes con sospecha de EM y un total de 42 brotes. Los pacientes fueron clasificados según los criterios de Lublin y Revingold para las formas evolutivas y según los criterios de McDonald. RESULTADOS: Solo dos pacientes clasificaron en la forma evolutiva progresiva primaria; los primeros dos trimestres del año fueron los de mayor número de brotes. CONCLUSIÓN: Se recomienda profundizar en las variables climatológicas que pudieran tener vínculo con la aparición de estos brotes en nuestro medio.

  18. Applying Multiple Intelligences

    Science.gov (United States)

    Christodoulou, Joanna A.

    2009-01-01

    The ideas of multiple intelligences introduced by Howard Gardner of Harvard University more than 25 years ago have taken form in many ways, both in schools and in other sometimes-surprising settings. The silver anniversary of Gardner's learning theory provides an opportunity to reflect on the ways multiple intelligences theory has taken form and…

  19. The Functioning of a Cortex without Layers

    Directory of Open Access Journals (Sweden)

    Julien Guy

    2017-07-01

    Full Text Available A major hallmark of cortical organization is the existence of a variable number of layers, i.e., sheets of neurons stacked on top of each other, in which neurons have certain commonalities. However, even for the neocortex, variable numbers of layers have been described and it is just a convention to distinguish six layers from each other. Whether cortical layers are a structural epiphenomenon caused by developmental dynamics or represent a functionally important modularization of cortical computation is still unknown. Here we present our insights from the reeler mutant mouse, a model for a developmental, “molecular lesion”-induced loss of cortical layering that could serve as ground truth of what an intact layering adds to the cortex in terms of functionality. We could demonstrate that the reeler neocortex shows no inversion of cortical layers but rather a severe disorganization that in the primary somatosensory cortex leads to the complete loss of layers. Nevertheless, the somatosensory system is well organized. When exploring an enriched environment with specific sets of whiskers, activity-dependent gene expression takes place in the corresponding modules. Precise whisker stimuli lead to the functional activation of somatotopically organized barrel columns as visualized by intrinsic signal optical imaging. Similar results were obtained in the reeler visual system. When analyzing pathways that could be responsible for preservation of tactile perception, lemniscal thalamic projections were found to be largely intact, despite the smearing of target neurons across the cortical mantle. However, with optogenetic experiments we found evidence for a mild dispersion of thalamic synapse targeting on layer IV-spiny stellate cells, together with a general weakening in thalamocortical input strength. This weakening of thalamic inputs was compensated by intracortical mechanisms involving increased recurrent excitation and/or reduced feedforward

  20. Subplate in the developing cortex of mouse and human

    DEFF Research Database (Denmark)

    Wang, Wei Zhi; Hoerder-Suabedissen, Anna; Oeschger, Franziska M

    2010-01-01

    Abstract The subplate is a largely transient zone containing precocious neurons involved in several key steps of cortical development. The majority of subplate neurons form a compact layer in mouse, but are dispersed throughout a much larger zone in the human. In rodent, subplate neurons are among...... several genes that are specifically expressed in the subplate layer of the rodent dorsal cortex. Here we examined the human subplate for some of these markers. In the human dorsal cortex, connective tissue growth factor-positive neurons can be seen in the ventricular zone at 15-22 postconceptional weeks...... growth factor- and nuclear receptor-related 1-positive cells are two distinct cell populations of the human subplate. Furthermore, our microarray analysis in rodent suggested that subplate neurons produce plasma proteins. Here we demonstrate that the human subplate also expresses alpha2zinc...

  1. Targeting Aurora B to the equatorial cortex by MKlp2 is required for cytokinesis.

    Directory of Open Access Journals (Sweden)

    Mayumi Kitagawa

    Full Text Available Although Aurora B is important in cleavage furrow ingression and completion during cytokinesis, the mechanism by which kinase activity is targeted to the cleavage furrow and the molecule(s responsible for this process have remained elusive. Here, we demonstrate that an essential mitotic kinesin MKlp2 requires myosin-II for its localization to the equatorial cortex, and this event is required to recruit Aurora B to the equatorial cortex in mammalian cells. This recruitment event is also required to promote the highly focused accumulation of active RhoA at the equatorial cortex and stable ingression of the cleavage furrow in bipolar cytokinesis. Specifically, in drug-induced monopolar cytokinesis, targeting Aurora B to the cell cortex by MKlp2 is essential for cell polarization and furrow formation. Once the furrow has formed, MKlp2 further recruits Aurora B to the growing furrow. This process together with continuous Aurora B kinase activity at the growing furrow is essential for stable furrow propagation and completion. In contrast, a MKlp2 mutant defective in binding myosin-II does not recruit Aurora B to the cell cortex and does not promote furrow formation during monopolar cytokinesis. This mutant is also defective in maintaining the ingressing furrow during bipolar cytokinesis. Together, these findings reveal that targeting Aurora B to the cell cortex (or the equatorial cortex by MKlp2 is essential for the maintenance of the ingressing furrow for successful cytokinesis.

  2. Decoding bipedal locomotion from the rat sensorimotor cortex

    Science.gov (United States)

    Rigosa, J.; Panarese, A.; Dominici, N.; Friedli, L.; van den Brand, R.; Carpaneto, J.; DiGiovanna, J.; Courtine, G.; Micera, S.

    2015-10-01

    Objective. Decoding forelimb movements from the firing activity of cortical neurons has been interfaced with robotic and prosthetic systems to replace lost upper limb functions in humans. Despite the potential of this approach to improve locomotion and facilitate gait rehabilitation, decoding lower limb movement from the motor cortex has received comparatively little attention. Here, we performed experiments to identify the type and amount of information that can be decoded from neuronal ensemble activity in the hindlimb area of the rat motor cortex during bipedal locomotor tasks. Approach. Rats were trained to stand, step on a treadmill, walk overground and climb staircases in a bipedal posture. To impose this gait, the rats were secured in a robotic interface that provided support against the direction of gravity and in the mediolateral direction, but behaved transparently in the forward direction. After completion of training, rats were chronically implanted with a micro-wire array spanning the left hindlimb motor cortex to record single and multi-unit activity, and bipolar electrodes into 10 muscles of the right hindlimb to monitor electromyographic signals. Whole-body kinematics, muscle activity, and neural signals were simultaneously recorded during execution of the trained tasks over multiple days of testing. Hindlimb kinematics, muscle activity, gait phases, and locomotor tasks were decoded using offline classification algorithms. Main results. We found that the stance and swing phases of gait and the locomotor tasks were detected with accuracies as robust as 90% in all rats. Decoded hindlimb kinematics and muscle activity exhibited a larger variability across rats and tasks. Significance. Our study shows that the rodent motor cortex contains useful information for lower limb neuroprosthetic development. However, brain-machine interfaces estimating gait phases or locomotor behaviors, instead of continuous variables such as limb joint positions or speeds

  3. Inhibition in the Human Auditory Cortex.

    Directory of Open Access Journals (Sweden)

    Koji Inui

    Full Text Available Despite their indispensable roles in sensory processing, little is known about inhibitory interneurons in humans. Inhibitory postsynaptic potentials cannot be recorded non-invasively, at least in a pure form, in humans. We herein sought to clarify whether prepulse inhibition (PPI in the auditory cortex reflected inhibition via interneurons using magnetoencephalography. An abrupt increase in sound pressure by 10 dB in a continuous sound was used to evoke the test response, and PPI was observed by inserting a weak (5 dB increase for 1 ms prepulse. The time course of the inhibition evaluated by prepulses presented at 10-800 ms before the test stimulus showed at least two temporally distinct inhibitions peaking at approximately 20-60 and 600 ms that presumably reflected IPSPs by fast spiking, parvalbumin-positive cells and somatostatin-positive, Martinotti cells, respectively. In another experiment, we confirmed that the degree of the inhibition depended on the strength of the prepulse, but not on the amplitude of the prepulse-evoked cortical response, indicating that the prepulse-evoked excitatory response and prepulse-evoked inhibition reflected activation in two different pathways. Although many diseases such as schizophrenia may involve deficits in the inhibitory system, we do not have appropriate methods to evaluate them; therefore, the easy and non-invasive method described herein may be clinically useful.

  4. Motor cortex is required for learning but not executing a motor skill

    Science.gov (United States)

    Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu; Dhawale, Ashesh; Kampff, Adam R.; Ölveczky, Bence P.

    2018-01-01

    Motor cortex is widely believed to underlie the acquisition and execution of motor skills, yet its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex’s established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in ‘tutoring’ these circuits during learning. PMID:25892304

  5. Enlargement of Axo-Somatic Contacts Formed by GAD-Immunoreactive Axon Terminals onto Layer V Pyramidal Neurons in the Medial Prefrontal Cortex of Adolescent Female Mice Is Associated with Suppression of Food Restriction-Evoked Hyperactivity and Resilience to Activity-Based Anorexia.

    Science.gov (United States)

    Chen, Yi-Wen; Wable, Gauri Satish; Chowdhury, Tara Gunkali; Aoki, Chiye

    2016-06-01

    Many, but not all, adolescent female mice that are exposed to a running wheel while food restricted (FR) become excessive wheel runners, choosing to run even during the hours of food availability, to the point of death. This phenomenon is called activity-based anorexia (ABA). We used electron microscopic immunocytochemistry to ask whether individual differences in ABA resilience may correlate with the lengths of axo-somatic contacts made by GABAergic axon terminals onto layer 5 pyramidal neurons (L5P) in the prefrontal cortex. Contact lengths were, on average, 40% greater for the ABA-induced mice, relative to controls. Correspondingly, the proportion of L5P perikaryal plasma membrane contacted by GABAergic terminals was 45% greater for the ABA mice. Contact lengths in the anterior cingulate cortex correlated negatively and strongly with the overall wheel activity after FR (R = -0.87, P resilience through suppression of wheel running, a behavior that is intrinsically rewarding and helpful for foraging but maladaptive within a cage. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  6. The effect of age and disease on the MR imaging T2 low signal intensity area in the cerebral cortex

    Energy Technology Data Exchange (ETDEWEB)

    Imon, Yukari; Yamaguchi, Shinya; Katayama, Sadao; Harada, Akira; Yamamura, Yasuhiro; Nakamura, Shigenobu [Hiroshima Univ. (Japan). School of Medicine

    1994-09-01

    We retrospectively studied magnetic resonance (MR) images of the brain in 139 patients (16 cases of Alzheimer's disease, 8 cases of Parkinson's disease, 53 cases of multiple cerebral infarct, 33 cases of other central nervous diseases, and 29 cases of peripheral neuropathy) between the age of 6 and 85 years old with a mean age of 60.6[+-]18.5 to examine the appearance of T2 low signal intensity areas (T[sub 2]-CLIA) in the cerebral cortex. Motor, occipital, sensory or other cortices were evaluated with long repetition time/echo time (TR/TE) spin-echo sequences and staged into three grades in the motor cortex: none, partial, and whole; and two grades in the other: none or present. In general, T[sub 2]-CLIA was not seen in any cortex in patients less than 50 years old, then after 50 years old T[sub 2]-CLIA increased with age. Over 70 years of age T[sub 2]-CLIA appeared in 50.9% of patients in the whole motor cortex, 88.7% in either whole or partial motor cortex, 47.2% in the occipital cortex, and 20.8% in the sensory cortex. T[sub 2]-CLIA was not observed in other cortices. The incidence of T[sub 2]-CLIA appearance in the motor cortex was significantly higher in all central nervous diseases than in cases of peripheral neuropathy over 70. T[sub 2]-CLIA showed a correlation with temporal lobe atrophy and white matter lesions in the motor cortex. In the sensory cortex, T[sub 2]-CLIA correlated with white matter lesions. These results suggest that T[sub 2]-CLIA may correlate with age or accumulation of nonheme iron in the cortex associated with central nervous diseases. (author).

  7. The effect of age and disease on the MR imaging T2 low signal intensity area in the cerebral cortex

    International Nuclear Information System (INIS)

    Imon, Yukari; Yamaguchi, Shinya; Katayama, Sadao; Harada, Akira; Yamamura, Yasuhiro; Nakamura, Shigenobu

    1994-01-01

    We retrospectively studied magnetic resonance (MR) images of the brain in 139 patients (16 cases of Alzheimer's disease, 8 cases of Parkinson's disease, 53 cases of multiple cerebral infarct, 33 cases of other central nervous diseases, and 29 cases of peripheral neuropathy) between the age of 6 and 85 years old with a mean age of 60.6±18.5 to examine the appearance of T2 low signal intensity areas (T 2 -CLIA) in the cerebral cortex. Motor, occipital, sensory or other cortices were evaluated with long repetition time/echo time (TR/TE) spin-echo sequences and staged into three grades in the motor cortex: none, partial, and whole; and two grades in the other: none or present. In general, T 2 -CLIA was not seen in any cortex in patients less than 50 years old, then after 50 years old T 2 -CLIA increased with age. Over 70 years of age T 2 -CLIA appeared in 50.9% of patients in the whole motor cortex, 88.7% in either whole or partial motor cortex, 47.2% in the occipital cortex, and 20.8% in the sensory cortex. T 2 -CLIA was not observed in other cortices. The incidence of T 2 -CLIA appearance in the motor cortex was significantly higher in all central nervous diseases than in cases of peripheral neuropathy over 70. T 2 -CLIA showed a correlation with temporal lobe atrophy and white matter lesions in the motor cortex. In the sensory cortex, T 2 -CLIA correlated with white matter lesions. These results suggest that T 2 -CLIA may correlate with age or accumulation of nonheme iron in the cortex associated with central nervous diseases. (author)

  8. The effect of age and disease on the MR imaging T2 low signal intensity area in the cerebral cortex

    Energy Technology Data Exchange (ETDEWEB)

    Imon, Yukari; Yamaguchi, Shinya; Katayama, Sadao; Harada, Akira; Yamamura, Yasuhiro; Nakamura, Shigenobu (Hiroshima Univ. (Japan). School of Medicine)

    1994-09-01

    We retrospectively studied magnetic resonance (MR) images of the brain in 139 patients (16 cases of Alzheimer's disease, 8 cases of Parkinson's disease, 53 cases of multiple cerebral infarct, 33 cases of other central nervous diseases, and 29 cases of peripheral neuropathy) between the age of 6 and 85 years old with a mean age of 60.6[+-]18.5 to examine the appearance of T2 low signal intensity areas (T[sub 2]-CLIA) in the cerebral cortex. Motor, occipital, sensory or other cortices were evaluated with long repetition time/echo time (TR/TE) spin-echo sequences and staged into three grades in the motor cortex: none, partial, and whole; and two grades in the other: none or present. In general, T[sub 2]-CLIA was not seen in any cortex in patients less than 50 years old, then after 50 years old T[sub 2]-CLIA increased with age. Over 70 years of age T[sub 2]-CLIA appeared in 50.9% of patients in the whole motor cortex, 88.7% in either whole or partial motor cortex, 47.2% in the occipital cortex, and 20.8% in the sensory cortex. T[sub 2]-CLIA was not observed in other cortices. The incidence of T[sub 2]-CLIA appearance in the motor cortex was significantly higher in all central nervous diseases than in cases of peripheral neuropathy over 70. T[sub 2]-CLIA showed a correlation with temporal lobe atrophy and white matter lesions in the motor cortex. In the sensory cortex, T[sub 2]-CLIA correlated with white matter lesions. These results suggest that T[sub 2]-CLIA may correlate with age or accumulation of nonheme iron in the cortex associated with central nervous diseases. (author).

  9. Different processing phases for features, figures, and selective attention in the primary visual cortex

    NARCIS (Netherlands)

    Roelfsema, P.R.; Tolboom, M.; Khayat, P.S.

    2007-01-01

    Our visual system imposes structure onto images that usually contain a diversity of surfaces, contours, and colors. Psychological theories propose that there are multiple steps in this process that occur in hierarchically organized regions of the cortex: early visual areas register basic features,

  10. (EOI) Form

    International Development Research Centre (IDRC) Digital Library (Canada)

    Dorine Odongo

    COLLABORATING TECHNICAL AGENCIES: EXPRESSION OF INTEREST FORM. • Please read the information provided about the initiative and the eligibility requirements in the Prospectus before completing this application form. • Ensure all the sections of the form are accurately completed and saved in PDF format.

  11. Modular forms

    NARCIS (Netherlands)

    Edixhoven, B.; van der Geer, G.; Moonen, B.; Edixhoven, B.; van der Geer, G.; Moonen, B.

    2008-01-01

    Modular forms are functions with an enormous amount of symmetry that play a central role in number theory, connecting it with analysis and geometry. They have played a prominent role in mathematics since the 19th century and their study continues to flourish today. Modular forms formed the

  12. Location coding by opponent neural populations in the auditory cortex.

    Directory of Open Access Journals (Sweden)

    G Christopher Stecker

    2005-03-01

    Full Text Available Although the auditory cortex plays a necessary role in sound localization, physiological investigations in the cortex reveal inhomogeneous sampling of auditory space that is difficult to reconcile with localization behavior under the assumption of local spatial coding. Most neurons respond maximally to sounds located far to the left or right side, with few neurons tuned to the frontal midline. Paradoxically, psychophysical studies show optimal spatial acuity across the frontal midline. In this paper, we revisit the problem of inhomogeneous spatial sampling in three fields of cat auditory cortex. In each field, we confirm that neural responses tend to be greatest for lateral positions, but show the greatest modulation for near-midline source locations. Moreover, identification of source locations based on cortical responses shows sharp discrimination of left from right but relatively inaccurate discrimination of locations within each half of space. Motivated by these findings, we explore an opponent-process theory in which sound-source locations are represented by differences in the activity of two broadly tuned channels formed by contra- and ipsilaterally preferring neurons. Finally, we demonstrate a simple model, based on spike-count differences across cortical populations, that provides bias-free, level-invariant localization-and thus also a solution to the "binding problem" of associating spatial information with other nonspatial attributes of sounds.

  13. Visual attentional load influences plasticity in the human motor cortex.

    Science.gov (United States)

    Kamke, Marc R; Hall, Michelle G; Lye, Hayley F; Sale, Martin V; Fenlon, Laura R; Carroll, Timothy J; Riek, Stephan; Mattingley, Jason B

    2012-05-16

    Neural plasticity plays a critical role in learning, memory, and recovery from injury to the nervous system. Although much is known about the physical and physiological determinants of plasticity, little is known about the influence of cognitive factors. In this study, we investigated whether selective attention plays a role in modifying changes in neural excitability reflecting long-term potentiation (LTP)-like plasticity. We induced LTP-like effects in the hand area of the human motor cortex using transcranial magnetic stimulation (TMS). During the induction of plasticity, participants engaged in a visual detection task with either low or high attentional demands. Changes in neural excitability were assessed by measuring motor-evoked potentials in a small hand muscle before and after the TMS procedures. In separate experiments plasticity was induced either by paired associative stimulation (PAS) or intermittent theta-burst stimulation (iTBS). Because these procedures induce different forms of LTP-like effects, they allowed us to investigate the generality of any attentional influence on plasticity. In both experiments reliable changes in motor cortex excitability were evident under low-load conditions, but this effect was eliminated under high-attentional load. In a third experiment we investigated whether the attentional task was associated with ongoing changes in the excitability of motor cortex, but found no difference in evoked potentials across the levels of attentional load. Our findings indicate that in addition to their role in modifying sensory processing, mechanisms of attention can also be a potent modulator of cortical plasticity.

  14. Differential effects of insular and ventromedial prefrontal cortex lesions on risky decision-making.

    Science.gov (United States)

    Clark, L; Bechara, A; Damasio, H; Aitken, M R F; Sahakian, B J; Robbins, T W

    2008-05-01

    The ventromedial prefrontal cortex (vmPFC) and insular cortex are implicated in distributed neural circuitry that supports emotional decision-making. Previous studies of patients with vmPFC lesions have focused primarily on decision-making under uncertainty, when outcome probabilities are ambiguous (e.g. the Iowa Gambling Task). It remains unclear whether vmPFC is also necessary for decision-making under risk, when outcome probabilities are explicit. It is not known whether the effect of insular damage is analogous to the effect of vmPFC damage, or whether these regions contribute differentially to choice behaviour. Four groups of participants were compared on the Cambridge Gamble Task, a well-characterized measure of risky decision-making where outcome probabilities are presented explicitly, thus minimizing additional learning and working memory demands. Patients with focal, stable lesions to the vmPFC (n = 20) and the insular cortex (n = 13) were compared against healthy subjects (n = 41) and a group of lesion controls (n = 12) with damage predominantly affecting the dorsal and lateral frontal cortex. The vmPFC and insular cortex patients showed selective and distinctive disruptions of betting behaviour. VmPFC damage was associated with increased betting regardless of the odds of winning, consistent with a role of vmPFC in biasing healthy individuals towards conservative options under risk. In contrast, patients with insular cortex lesions failed to adjust their bets by the odds of winning, consistent with a role of the insular cortex in signalling the probability of aversive outcomes. The insular group attained a lower point score on the task and experienced more 'bankruptcies'. There were no group differences in probability judgement. These data confirm the necessary role of the vmPFC and insular regions in decision-making under risk. Poor decision-making in clinical populations can arise via multiple routes, with functionally dissociable effects of vmPFC and

  15. Evidence for unlimited capacity processing of simple features in visual cortex.

    Science.gov (United States)

    White, Alex L; Runeson, Erik; Palmer, John; Ernst, Zachary R; Boynton, Geoffrey M

    2017-06-01

    Performance in many visual tasks is impaired when observers attempt to divide spatial attention across multiple visual field locations. Correspondingly, neuronal response magnitudes in visual cortex are often reduced during divided compared with focused spatial attention. This suggests that early visual cortex is the site of capacity limits, where finite processing resources must be divided among attended stimuli. However, behavioral research demonstrates that not all visual tasks suffer such capacity limits: The costs of divided attention are minimal when the task and stimulus are simple, such as when searching for a target defined by orientation or contrast. To date, however, every neuroimaging study of divided attention has used more complex tasks and found large reductions in response magnitude. We bridged that gap by using functional magnetic resonance imaging to measure responses in the human visual cortex during simple feature detection. The first experiment used a visual search task: Observers detected a low-contrast Gabor patch within one or four potentially relevant locations. The second experiment used a dual-task design, in which observers made independent judgments of Gabor presence in patches of dynamic noise at two locations. In both experiments, blood-oxygen level-dependent (BOLD) signals in the retinotopic cortex were significantly lower for ignored than attended stimuli. However, when observers divided attention between multiple stimuli, BOLD signals were not reliably reduced and behavioral performance was unimpaired. These results suggest that processing of simple features in early visual cortex has unlimited capacity.

  16. Acute pharmacogenetic activation of medial prefrontal cortex ...

    Indian Academy of Sciences (India)

    Sthitapranjya Pati

    2018-01-24

    Jan 24, 2018 ... Exclusively Activated by Designer Drugs (DREADDs) have provided novel ... ad libitum access to food and water. ... testing. 2.3 Drug treatment and behavioural tests .... IL cortex (figure 3E, two-way ANOVA: interaction effect,.

  17. CEREBRAL CORTEX DAMAGE INDUCED BY ACUTE ORAL ...

    African Journals Online (AJOL)

    2018-02-28

    Feb 28, 2018 ... This study examines alcohol-induced cerebral cortex damage and the association with oxidative ... alcohol has profound effects on the function ... Chronic use of ..... Alcohol induced brain damage and liver damage in young.

  18. Food related processes in the insular cortex

    Directory of Open Access Journals (Sweden)

    Sabine eFrank

    2013-08-01

    Full Text Available The insular cortex is a multimodal brain region with regional cytoarchitectonic differences indicating various functional specializations. As a multisensory neural node, the insular cortex integrates perception, emotion, interoceptive awareness, cognition, and gustation. Regarding the latter, predominantly the anterior part of the insular cortex is regarded as the primary taste cortex.In this review, we will specifically focus on the involvement of the insula in food processing and on multimodal integration of food-related items. Influencing factors of insular activation elicited by various foods range from calorie-content to the internal physiologic state, body mass index or eating behavior. Sensory perception of food-related stimuli including seeing, smelling, and tasting elicits increased activation in the anterior and mid-dorsal part of the insular cortex. Apart from the pure sensory gustatory processing, there is also a strong association with the rewarding/hedonic aspects of food items, which is reflected in higher insular activity and stronger connections to other reward-related areas. Interestingly, the processing of food items has been found to elicit different insular activation in lean compared to obese subjects and in patients suffering from an eating disorder (anorexia nervosa, bulimia nervosa. The knowledge of functional differences in the insular cortex opens up the opportunity for possible noninvasive treatment approaches for obesity and eating disorders. To target brain functions directly, real-time functional magnetic resonance imaging neurofeedback offers a state-of-the-art tool to learn to control the anterior insular cortex activity voluntarily. First evidence indicates that obese adults have an enhanced ability to regulate the anterior insular cortex.

  19. High-resolution slab gel isoelectric focusing: methods for quantitative electrophoretic transfer and immunodetection of proteins as applied to the study of the multiple isoelectric forms of ornithine decarboxylase.

    Science.gov (United States)

    Reddy, S G; Cochran, B J; Worth, L L; Knutson, V P; Haddox, M K

    1994-04-01

    A high-resolution isoelectric focusing vertical slab gel method which can resolve proteins which differ by a single charge was developed and this method was applied to the study of the multiple isoelectric forms of ornithine decarboxylase. Separation of proteins at this high level of resolution was achieved by increasing the ampholyte concentration in the gels to 6%. Various lots of ampholytes, from the same or different commercial sources, differed significantly in their protein binding capacity. Ampholytes bound to proteins interfered both with the electrophoretic transfer of proteins from the gel to immunoblotting membranes and with the ability of antibodies to interact with proteins on the immunoblotting membranes. Increasing the amount of protein loaded into a gel lane also decreased the efficiency of the electrophoretic transfer and immunodetection. To overcome these problems, both gel washing and gel electrophoretic transfer protocols for disrupting the ampholyte-protein binding and enabling a quantitative electrophoretic transfer of proteins were developed. Two gel washing procedures, with either thiocyanate or borate buffers, and a two-step electrophoretic transfer method are described. The choice of which method to use to optimally disrupt the ampholyte-protein binding was found to vary with each lot of ampholytes employed.

  20. TECHNO-ECONOMIC ANALYSIS IN A SUPERSTRUCTURE OF A MULTIPLE FLOORS BUILDING (THREE, FIVE, SEVEN AND NINE FLOORS IN REINFORCED CONCRETE AND RIBBED SLABS WITH RECTANGULAR FORM AND DIFFERENT COMPRESSIVE STRENGTH VALUES

    Directory of Open Access Journals (Sweden)

    E. F. S. Moraes

    2017-12-01

    Full Text Available Adapting “fck" values between 25 MPa to 40 MPa, in three, five, seven and nine floor buildings for places under winds of up to 30 m/s, this research calculated the cost and inputs of these variations. The results have as a goal to improve multiple floors building design in reinforced concrete and ribbed slabs, and to contribute to economic gains. The results were analysed in five stages. (I Architectural design definition in a 1:1 proportion, (II structural conception, (III structural design, (IV cost composition and (V techno economic parameters. To sum up, the results showed that lower “fck” has presented more viability to few flooring. In addition, with the increase of floors also the “fck” raised, causing higher cost around 16,54% in the beams and 11,16% in the slabs. Moreover, the pillars showed a saving of 28,89% in the cost, ranging by up to 11,93% in the average thickness and 6,29% in the concrete form expenditure per m³. Therefore, the research showed an economic achievement of 5,14% in the overall cost between the number of floor.

  1. Intrinsic frequency biases and profiles across human cortex.

    Science.gov (United States)

    Mellem, Monika S; Wohltjen, Sophie; Gotts, Stephen J; Ghuman, Avniel Singh; Martin, Alex

    2017-11-01

    Recent findings in monkeys suggest that intrinsic periodic spiking activity in selective cortical areas occurs at timescales that follow a sensory or lower order-to-higher order processing hierarchy (Murray JD, Bernacchia A, Freedman DJ, Romo R, Wallis JD, Cai X, Padoa-Schioppa C, Pasternak T, Seo H, Lee D, Wang XJ. Nat Neurosci 17: 1661-1663, 2014). It has not yet been fully explored if a similar timescale hierarchy is present in humans. Additionally, these measures in the monkey studies have not addressed findings that rhythmic activity within a brain area can occur at multiple frequencies. In this study we investigate in humans if regions may be biased toward particular frequencies of intrinsic activity and if a full cortical mapping still reveals an organization that follows this hierarchy. We examined the spectral power in multiple frequency bands (0.5-150 Hz) from task-independent data using magnetoencephalography (MEG). We compared standardized power across bands to find regional frequency biases. Our results demonstrate a mix of lower and higher frequency biases across sensory and higher order regions. Thus they suggest a more complex cortical organization that does not simply follow this hierarchy. Additionally, some regions do not display a bias for a single band, and a data-driven clustering analysis reveals a regional organization with high standardized power in multiple bands. Specifically, theta and beta are both high in dorsal frontal cortex, whereas delta and gamma are high in ventral frontal cortex and temporal cortex. Occipital and parietal regions are biased more narrowly toward alpha power, and ventral temporal lobe displays specific biases toward gamma. Thus intrinsic rhythmic neural activity displays a regional organization but one that is not necessarily hierarchical. NEW & NOTEWORTHY The organization of rhythmic neural activity is not well understood. Whereas it has been postulated that rhythms are organized in a hierarchical manner across

  2. Auditory Connections and Functions of Prefrontal Cortex

    Directory of Open Access Journals (Sweden)

    Bethany ePlakke

    2014-07-01

    Full Text Available The functional auditory system extends from the ears to the frontal lobes with successively more complex functions occurring as one ascends the hierarchy of the nervous system. Several areas of the frontal lobe receive afferents from both early and late auditory processing regions within the temporal lobe. Afferents from the early part of the cortical auditory system, the auditory belt cortex, which are presumed to carry information regarding auditory features of sounds, project to only a few prefrontal regions and are most dense in the ventrolateral prefrontal cortex (VLPFC. In contrast, projections from the parabelt and the rostral superior temporal gyrus (STG most likely convey more complex information and target a larger, widespread region of the prefrontal cortex. Neuronal responses reflect these anatomical projections as some prefrontal neurons exhibit responses to features in acoustic stimuli, while other neurons display task-related responses. For example, recording studies in non-human primates indicate that VLPFC is responsive to complex sounds including vocalizations and that VLPFC neurons in area 12/47 respond to sounds with similar acoustic morphology. In contrast, neuronal responses during auditory working memory involve a wider region of the prefrontal cortex. In humans, the frontal lobe is involved in auditory detection, discrimination, and working memory. Past research suggests that dorsal and ventral subregions of the prefrontal cortex process different types of information with dorsal cortex processing spatial/visual information and ventral cortex processing non-spatial/auditory information. While this is apparent in the non-human primate and in some neuroimaging studies, most research in humans indicates that specific task conditions, stimuli or previous experience may bias the recruitment of specific prefrontal regions, suggesting a more flexible role for the frontal lobe during auditory cognition.

  3. Auditory connections and functions of prefrontal cortex

    Science.gov (United States)

    Plakke, Bethany; Romanski, Lizabeth M.

    2014-01-01

    The functional auditory system extends from the ears to the frontal lobes with successively more complex functions occurring as one ascends the hierarchy of the nervous system. Several areas of the frontal lobe receive afferents from both early and late auditory processing regions within the temporal lobe. Afferents from the early part of the cortical auditory system, the auditory belt cortex, which are presumed to carry information regarding auditory features of sounds, project to only a few prefrontal regions and are most dense in the ventrolateral prefrontal cortex (VLPFC). In contrast, projections from the parabelt and the rostral superior temporal gyrus (STG) most likely convey more complex information and target a larger, widespread region of the prefrontal cortex. Neuronal responses reflect these anatomical projections as some prefrontal neurons exhibit responses to features in acoustic stimuli, while other neurons display task-related responses. For example, recording studies in non-human primates indicate that VLPFC is responsive to complex sounds including vocalizations and that VLPFC neurons in area 12/47 respond to sounds with similar acoustic morphology. In contrast, neuronal responses during auditory working memory involve a wider region of the prefrontal cortex. In humans, the frontal lobe is involved in auditory detection, discrimination, and working memory. Past research suggests that dorsal and ventral subregions of the prefrontal cortex process different types of information with dorsal cortex processing spatial/visual information and ventral cortex processing non-spatial/auditory information. While this is apparent in the non-human primate and in some neuroimaging studies, most research in humans indicates that specific task conditions, stimuli or previous experience may bias the recruitment of specific prefrontal regions, suggesting a more flexible role for the frontal lobe during auditory cognition. PMID:25100931

  4. Multiple inflation

    International Nuclear Information System (INIS)

    Murphy, P.J.

    1987-01-01

    The Theory of Inflation, namely, that at some point the entropy content of the universe was greatly increased, has much promise. It may solve the puzzles of homogeneity and the creation of structure. However, no particle physics model has yet been found that can successfully drive inflation. The difficulty in satisfying the constraint that the isotropy of the microwave background places on the effective potential of prospective models is immense. In this work we have codified the requirements of such models in a most general form. We have carefully calculated the amounts of inflation the various problems of the Standard Model need for their solution. We have derived a completely model independent upper bond on the inflationary Hubble parameter. We have developed a general notation with which to probe the possibilities of Multiple Inflation. We have shown that only in very unlikely circumstances will any evidence of an earlier inflation, survive the de Sitter period of its successor. In particular, it is demonstrated that it is most unlikely that two bouts of inflation will yield high amplitudes of density perturbations on small scales and low amplitudes on large. We conclude that, while multiple inflation will be of great theoretical interest, it is unlikely to have any observational impact

  5. Cellular properties of principal neurons in the rat entorhinal cortex. I. The lateral entorhinal cortex

    NARCIS (Netherlands)

    Canto, C.B.; Witter, M.P.

    2012-01-01

    The lateral entorhinal cortex (LEC) provides a major cortical input to the hippocampal formation, equaling that of the medial entorhinal cortex (MEC). To understand the functional contributions made by LEC, basic knowledge of individual neurons, in the context of the intrinsic network, is needed.

  6. Encoding and retrieval of artificial visuoauditory memory traces in the auditory cortex requires the entorhinal cortex.

    Science.gov (United States)

    Chen, Xi; Guo, Yiping; Feng, Jingyu; Liao, Zhengli; Li, Xinjian; Wang, Haitao; Li, Xiao; He, Jufang

    2013-06-12

    Damage to the medial temporal lobe impairs the encoding of new memories and the retrieval of memories acquired immediately before the damage in human. In this study, we demonstrated that artificial visuoauditory memory traces can be established in the rat auditory cortex and that their encoding and retrieval depend on the entorhinal cortex of the medial temporal lobe in the rat. We trained rats to associate a visual stimulus with electrical stimulation of the auditory cortex using a classical conditioning protocol. After conditioning, we examined the associative memory traces electrophysiologically (i.e., visual stimulus-evoked responses of auditory cortical neurons) and behaviorally (i.e., visual stimulus-induced freezing and visual stimulus-guided reward retrieval). The establishment of a visuoauditory memory trace in the auditory cortex, which was detectable by electrophysiological recordings, was achieved over 20-30 conditioning trials and was blocked by unilateral, temporary inactivation of the entorhinal cortex. Retrieval of a previously established visuoauditory memory was also affected by unilateral entorhinal cortex inactivation. These findings suggest that the entorhinal cortex is necessary for the encoding and involved in the retrieval of artificial visuoauditory memory in the auditory cortex, at least during the early stages of memory consolidation.

  7. Molecular Diversity of HIV-1 among People Who Inject Drugs in Kuala Lumpur, Malaysia: Massive Expansion of Circulating Recombinant Form (CRF) 33_01B and Emergence of Multiple Unique Recombinant Clusters

    Science.gov (United States)

    Chow, Wei Zhen; Ng, Kim Tien; Yong, Yean Kong; Azmel, Azureen; Takebe, Yutaka; Al-Darraji, Haider Abdulrazzaq Abed; Kamarulzaman, Adeeba; Tee, Kok Keng

    2013-01-01

    Since the discovery of HIV-1 circulating recombinant form (CRF) 33_01B in Malaysia in the early 2000 s, continuous genetic diversification and active recombination involving CRF33_01B and other circulating genotypes in the region including CRF01_AE and subtype B′ of Thai origin, have led to the emergence of novel CRFs and unique recombinant forms. The history and magnitude of CRF33_01B transmission among various risk groups including people who inject drugs (PWID) however have not been investigated despite the high epidemiological impact of CRF33_01B in the region. We update the most recent molecular epidemiology of HIV-1 among PWIDs recruited in Malaysia between 2010 and 2011 by population sequencing and phylogenetic analysis of 128 gag-pol sequences. HIV-1 CRF33_01B was circulating among 71% of PWIDs whilst a lower prevalence of other previously dominant HIV-1 genotypes [subtype B′ (11%) and CRF01_AE (5%)] and CRF01_AE/B′ unique recombinants (13%) were detected, indicating a significant shift in genotype replacement in this population. Three clusters of CRF01_AE/B′ recombinants displaying divergent yet phylogenetically-related mosaic genomes to CRF33_01B were identified and characterized, suggestive of an abrupt emergence of multiple novel CRF clades. Using rigorous maximum likelihood approach and the Bayesian Markov chain Monte Carlo (MCMC) sampling of CRF33_01Bpol sequences to elucidate the past population dynamics, we found that the founder lineages of CRF33_01B were likely to have first emerged among PWIDs in the early 1990 s before spreading exponentially to various high and low-risk populations (including children who acquired infections from their mothers) and later on became endemic around the early 2000 s. Taken together, our findings provide notable genetic evidence indicating the widespread expansion of CRF33_01B among PWIDs and into the general population. The emergence of numerous previously unknown recombinant clades highlights the

  8. Molecular diversity of HIV-1 among people who inject drugs in Kuala Lumpur, Malaysia: massive expansion of circulating recombinant form (CRF) 33_01B and emergence of multiple unique recombinant clusters.

    Science.gov (United States)

    Chow, Wei Zhen; Ong, Lai Yee; Razak, Siti Humaira; Lee, Yeat Mei; Ng, Kim Tien; Yong, Yean Kong; Azmel, Azureen; Takebe, Yutaka; Al-Darraji, Haider Abdulrazzaq Abed; Kamarulzaman, Adeeba; Tee, Kok Keng

    2013-01-01

    Since the discovery of HIV-1 circulating recombinant form (CRF) 33_01B in Malaysia in the early 2000 s, continuous genetic diversification and active recombination involving CRF33_01B and other circulating genotypes in the region including CRF01_AE and subtype B' of Thai origin, have led to the emergence of novel CRFs and unique recombinant forms. The history and magnitude of CRF33_01B transmission among various risk groups including people who inject drugs (PWID) however have not been investigated despite the high epidemiological impact of CRF33_01B in the region. We update the most recent molecular epidemiology of HIV-1 among PWIDs recruited in Malaysia between 2010 and 2011 by population sequencing and phylogenetic analysis of 128 gag-pol sequences. HIV-1 CRF33_01B was circulating among 71% of PWIDs whilst a lower prevalence of other previously dominant HIV-1 genotypes [subtype B' (11%) and CRF01_AE (5%)] and CRF01_AE/B' unique recombinants (13%) were detected, indicating a significant shift in genotype replacement in this population. Three clusters of CRF01_AE/B' recombinants displaying divergent yet phylogenetically-related mosaic genomes to CRF33_01B were identified and characterized, suggestive of an abrupt emergence of multiple novel CRF clades. Using rigorous maximum likelihood approach and the Bayesian Markov chain Monte Carlo (MCMC) sampling of CRF33_01Bpol sequences to elucidate the past population dynamics, we found that the founder lineages of CRF33_01B were likely to have first emerged among PWIDs in the early 1990 s before spreading exponentially to various high and low-risk populations (including children who acquired infections from their mothers) and later on became endemic around the early 2000 s. Taken together, our findings provide notable genetic evidence indicating the widespread expansion of CRF33_01B among PWIDs and into the general population. The emergence of numerous previously unknown recombinant clades highlights the escalating

  9. Molecular diversity of HIV-1 among people who inject drugs in Kuala Lumpur, Malaysia: massive expansion of circulating recombinant form (CRF 33_01B and emergence of multiple unique recombinant clusters.

    Directory of Open Access Journals (Sweden)

    Wei Zhen Chow

    Full Text Available Since the discovery of HIV-1 circulating recombinant form (CRF 33_01B in Malaysia in the early 2000 s, continuous genetic diversification and active recombination involving CRF33_01B and other circulating genotypes in the region including CRF01_AE and subtype B' of Thai origin, have led to the emergence of novel CRFs and unique recombinant forms. The history and magnitude of CRF33_01B transmission among various risk groups including people who inject drugs (PWID however have not been investigated despite the high epidemiological impact of CRF33_01B in the region. We update the most recent molecular epidemiology of HIV-1 among PWIDs recruited in Malaysia between 2010 and 2011 by population sequencing and phylogenetic analysis of 128 gag-pol sequences. HIV-1 CRF33_01B was circulating among 71% of PWIDs whilst a lower prevalence of other previously dominant HIV-1 genotypes [subtype B' (11% and CRF01_AE (5%] and CRF01_AE/B' unique recombinants (13% were detected, indicating a significant shift in genotype replacement in this population. Three clusters of CRF01_AE/B' recombinants displaying divergent yet phylogenetically-related mosaic genomes to CRF33_01B were identified and characterized, suggestive of an abrupt emergence of multiple novel CRF clades. Using rigorous maximum likelihood approach and the Bayesian Markov chain Monte Carlo (MCMC sampling of CRF33_01Bpol sequences to elucidate the past population dynamics, we found that the founder lineages of CRF33_01B were likely to have first emerged among PWIDs in the early 1990 s before spreading exponentially to various high and low-risk populations (including children who acquired infections from their mothers and later on became endemic around the early 2000 s. Taken together, our findings provide notable genetic evidence indicating the widespread expansion of CRF33_01B among PWIDs and into the general population. The emergence of numerous previously unknown recombinant clades highlights the

  10. Fast voltage-sensitive dye imaging of excitatory and inhibitory synaptic transmission in the rat granular retrosplenial cortex.

    Science.gov (United States)

    Nixima, Ken'ichi; Okanoya, Kazuo; Ichinohe, Noritaka; Kurotani, Tohru

    2017-09-01

    Rodent granular retrosplenial cortex (GRS) has dense connections between the anterior thalamic nuclei (ATN) and hippocampal formation. GRS superficial pyramidal neurons exhibit distinctive late spiking (LS) firing property and form patchy clusters with prominent apical dendritic bundles. The aim of this study was to investigate spatiotemporal dynamics of signal transduction in the GRS induced by ATN afferent stimulation by using fast voltage-sensitive dye imaging in rat brain slices. In coronal slices, layer 1a stimulation, which presumably activated thalamic fibers, evoked propagation of excitatory synaptic signals from layers 2-4 to layers 5-6 in a direction perpendicular to the layer axis, followed by transverse signal propagation within each layer. In the presence of ionotropic glutamate receptor antagonists, inhibitory responses were observed in superficial layers, induced by direct activation of inhibitory interneurons in layer 1. In horizontal slices, excitatory signals in deep layers propagated transversely mainly from posterior to anterior via superficial layers. Cortical inhibitory responses upon layer 1a stimulation in horizontal slices were weaker than those in the coronal slices. Observed differences between coronal and horizontal planes suggest anisotropy of the intracortical circuitry. In conclusion, ATN inputs are processed differently in coronal and horizontal planes of the GRS and then conveyed to other cortical areas. In both planes, GRS superficial layers play an important role in signal propagation, which suggests that superficial neuronal cascade is crucial in the integration of multiple information sources. NEW & NOTEWORTHY Superficial neurons in the rat granular retrosplenial cortex (GRS) show distinctive late-spiking (LS) firing property. However, little is known about spatiotemporal dynamics of signal transduction in the GRS. We demonstrated LS neuron network relaying thalamic inputs to deep layers and anisotropic distribution of

  11. Auditory attention activates peripheral visual cortex.

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    Anthony D Cate

    Full Text Available BACKGROUND: Recent neuroimaging studies have revealed that putatively unimodal regions of visual cortex can be activated during auditory tasks in sighted as well as in blind subjects. However, the task determinants and functional significance of auditory occipital activations (AOAs remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: We examined AOAs in an intermodal selective attention task to distinguish whether they were stimulus-bound or recruited by higher-level cognitive operations associated with auditory attention. Cortical surface mapping showed that auditory occipital activations were localized to retinotopic visual cortex subserving the far peripheral visual field. AOAs depended strictly on the sustained engagement of auditory attention and were enhanced in more difficult listening conditions. In contrast, unattended sounds produced no AOAs regardless of their intensity, spatial location, or frequency. CONCLUSIONS/SIGNIFICANCE: Auditory attention, but not passive exposure to sounds, routinely activated peripheral regions of visual cortex when subjects attended to sound sources outside the visual field. Functional connections between auditory cortex and visual cortex subserving the peripheral visual field appear to underlie the generation of AOAs, which may reflect the priming of visual regions to process soon-to-appear objects associated with unseen sound sources.

  12. Lower layers in the motor cortex are more effective targets for penetrating microelectrodes in cortical prostheses

    Science.gov (United States)

    Parikh, Hirak; Marzullo, Timothy C.; Kipke, Daryl R.

    2009-04-01

    Improving cortical prostheses requires the development of recording neural interfaces that are efficient in terms of providing maximal control information with minimal interface complexity. While the typical approaches have targeted neurons in the motor cortex with multiple penetrating shanks, an alternative approach is to determine an efficient distribution of electrode sites within the layers of the cortex with fewer penetrating shanks. The objective of this study was to compare unit activity in the upper and lower layers of the cortex with respect to movement and direction in order to inform the design of penetrating microelectrodes. Four rats were implanted bilaterally with multi-site single-shank silicon microelectrode arrays in the neck/shoulder region of the motor cortex. We simultaneously recorded unit activity across all layers of the motor cortex while the animal was engaged in a movement direction task. Localization of the electrode array within the different layers of the cortex was determined by histology. We denoted units from layers 2 and 3 and units as upper layer units, and units from layers 5 and 6 as lower layer units. Analysis of unit spiking activity demonstrated that both the upper and lower layers encode movement and direction information. Unit responses in either cortical layer of the cortex were not preferentially associated with contralateral or ipsilateral movement. Aggregate analysis (633 neurons) and best session analysis (75 neurons) indicated that units in the lower layers (layers 5, 6) are more likely to encode direction information when compared to units in the upper layers (layers 2, 3) (p< 0.05). These results suggest that electrode sites clustered in the lower layers provide access to more salient control information for cortical neuroprostheses.

  13. Multiple Hierarchies and Organizational Control

    Science.gov (United States)

    Evans, Peter B.

    1975-01-01

    Uses a control-loss model to explore the effects of multiple channels in formal organizations, and presents an argument for the superior control properties of dual hierarchies. Two variant forms of multiple hierarchies are considered. (Author)

  14. Alterations of the cerebral cortex in sporadic small vessel disease: A systematic review of in vivo MRI data.

    Science.gov (United States)

    Peres, Roxane; De Guio, François; Chabriat, Hugues; Jouvent, Eric

    2016-04-01

    Cerebral small vessel diseases of the brain are a major determinant of cognitive impairment in the elderly. In small vessel diseases, the most easily identifiable lesions, both at post-mortem evaluation and magnetic resonance imaging, lie in subcortical areas. However, recent results obtained post-mortem, particularly in severe cases, have highlighted the burden of cortex lesions such as microinfarcts and diffuse neuronal loss. The recent development of image post-processing methods allows now assessing in vivo multiple aspects of the cerebral cortex. This systematic review aimed to analyze in vivo magnetic resonance imaging studies evaluating cortex alterations at different stages of small vessel diseases. Studies assessing the relationships between small vessel disease magnetic resonance imaging markers obtained at the subcortical level and cortex estimates were reviewed both in community-dwelling elderly and in patients with symptomatic small vessel diseases. Thereafter, studies analyzing cortex estimates in small vessel disease patients compared with healthy subjects were evaluated. The results support that important cortex alterations develop along the course of small vessel diseases independently of concomitant neurodegenerative processes. Easy detection and quantification of cortex changes in small vessel diseases as well as understanding their underlying mechanisms are challenging tasks for better understanding cognitive decline in small vessel diseases. © The Author(s) 2016.

  15. The role of the medial prefrontal cortex in trace fear extinction

    Science.gov (United States)

    Kwapis, Janine L.; Jarome, Timothy J.

    2015-01-01

    The extinction of delay fear conditioning relies on a neural circuit that has received much attention and is relatively well defined. Whether this established circuit also supports the extinction of more complex associations, however, is unclear. Trace fear conditioning is a better model of complex relational learning, yet the circuit that supports extinction of this memory has received very little attention. Recent research has indicated that trace fear extinction requires a different neural circuit than delay extinction; trace extinction requires the participation of the retrosplenial cortex, but not the amygdala, as noted in a previous study. Here, we tested the roles of the prelimbic and infralimbic regions of the medial prefrontal cortex in trace and delay fear extinction by blocking NMDA receptors during extinction learning. We found that the prelimbic cortex is necessary for trace, but not for delay fear extinction, whereas the infralimbic cortex is involved in both types of extinction. These results are consistent with the idea that trace fear associations require plasticity in multiple cortical areas for successful extinction. Further, the infralimbic cortex appears to play a role in extinction regardless of whether the animal was initially trained in trace or delay conditioning. Together, our results provide new information about how the neural circuits supporting trace and delay fear extinction differ. PMID:25512576

  16. Novel experience induces persistent sleep-dependent plasticity in the cortex but not in the hippocampus

    Directory of Open Access Journals (Sweden)

    Sidarta Ribeiro

    2007-10-01

    Full Text Available Episodic and spatial memories engage the hippocampus during acquisition but migrate to the cerebral cortex over time. We have recently proposed that the interplay between slow-wave (SWS and rapid eye movement (REM sleep propagates recent synaptic changes from the hippocampus to the cortex. To test this theory, we jointly assessed extracellular neuronal activity, local field potentials (LFP, and expression levels of plasticity-related immediate-early genes (IEG arc and zif-268 in rats exposed to novel spatio-tactile experience. Post-experience firing rate increases were strongest in SWS and lasted much longer in the cortex (hours than in the hippocampus (minutes. During REM sleep, firing rates showed strong temporal dependence across brain areas: cortical activation during experience predicted hippocampal activity in the first post-experience hour, while hippocampal activation during experience predicted cortical activity in the third post-experience hour. Four hours after experience, IEG expression was specifically upregulated during REM sleep in the cortex, but not in the hippocampus. Arc gene expression in the cortex was proportional to LFP amplitude in the spindle-range (10-14 Hz but not to firing rates, as expected from signals more related to dendritic input than to somatic output. The results indicate that hippocampo-cortical activation during waking is followed by multiple waves of cortical plasticity as full sleep cycles recur. The absence of equivalent changes in the hippocampus may explain its mnemonic disengagement over time.

  17. Specific metabolomics adaptations define a differential regional vulnerability in the adult human cerebral cortex

    Directory of Open Access Journals (Sweden)

    Rosanna Cabré

    2016-12-01

    Full Text Available Brain neurons offer diverse responses to stresses and detrimental factors during development and aging, and as a result of both neurodegenerative and neuropsychiatric disorders. This multiplicity of responses can be ascribed to the great diversity among neuronal populations. Here we have determined the metabolomic profile of three healthy adult human brain regions—entorhinal cortex, hippocampus, and frontal cortex—using mass spectrometry-based technologies. Our results show the existence of a lessened energy demand, mitochondrial stress, and lower one-carbon metabolism (particularly restricted to the methionine cycle specifically in frontal cortex. These findings, along with the better antioxidant capacity and lower mTOR signaling also seen in frontal cortex, suggest that this brain region is especially resistant to stress compared to the entorhinal cortex and hippocampus, which are more vulnerable regions. Globally, our results show the presence of specific metabolomics adaptations in three mature, healthy human brain regions, confirming the existence of cross-regional differences in cell vulnerability in the human cerebral cortex.

  18. Abstract memory representations in the ventromedial prefrontal cortex and hippocampus support concept generalization.

    Science.gov (United States)

    Bowman, Caitlin R; Zeithamova, Dagmar

    2018-02-07

    Memory function involves both the ability to remember details of individual experiences and the ability to link information across events to create new knowledge. Prior research has identified the ventromedial prefrontal cortex (VMPFC) and the hippocampus as important for integrating across events in service of generalization in episodic memory. The degree to which these memory integration mechanisms contribute to other forms of generalization, such as concept learning, is unclear. The present study used a concept-learning task in humans (both sexes) coupled with model-based fMRI to test whether VMPFC and hippocampus contribute to concept generalization, and whether they do so by maintaining specific category exemplars or abstract category representations. Two formal categorization models were fit to individual subject data: a prototype model that posits abstract category representations and an exemplar model that posits category representations based on individual category members. Latent variables from each of these models were entered into neuroimaging analyses to determine whether VMPFC and the hippocampus track prototype or exemplar information during concept generalization. Behavioral model fits indicated that almost three quarters of the subjects relied on prototype information when making judgments about new category members. Paralleling prototype dominance in behavior, correlates of the prototype model were identified in VMPFC and the anterior hippocampus with no significant exemplar correlates. These results indicate that the VMPFC and portions of the hippocampus play a broad role in memory generalization and that they do so by representing abstract information integrated from multiple events. SIGNIFICANCE STATEMENT Whether people represent concepts as a set of individual category members or by deriving generalized concept representations abstracted across exemplars has been debated. In episodic memory, generalized memory representations have been shown

  19. Cortical chemoarchitecture shapes macroscale effective functional connectivity patterns in macaque cerebral cortex

    NARCIS (Netherlands)

    Turk, Elise; Scholtens, Lianne H.; van den Heuvel, Martijn P.

    The mammalian cortex is a complex system of-at the microscale level-interconnected neurons and-at the macroscale level-interconnected areas, forming the infrastructure for local and global neural processing and information integration. While the effects of regional chemoarchitecture on local

  20. Multiple Perspectives / Multiple Readings

    Directory of Open Access Journals (Sweden)

    Simon Biggs

    2005-01-01

    Full Text Available People experience things from their own physical point of view. What they see is usually a function of where they are and what physical attitude they adopt relative to the subject. With augmented vision (periscopes, mirrors, remote cameras, etc we are able to see things from places where we are not present. With time-shifting technologies, such as the video recorder, we can also see things from the past; a time and a place we may never have visited.In recent artistic work I have been exploring the implications of digital technology, interactivity and internet connectivity that allow people to not so much space/time-shift their visual experience of things but rather see what happens when everybody is simultaneously able to see what everybody else can see. This is extrapolated through the remote networking of sites that are actual installation spaces; where the physical movements of viewers in the space generate multiple perspectives, linked to other similar sites at remote locations or to other viewers entering the shared data-space through a web based version of the work.This text explores the processes involved in such a practice and reflects on related questions regarding the non-singularity of being and the sense of self as linked to time and place.

  1. [Pain information pathways from the periphery to the cerebral cortex].

    Science.gov (United States)

    Kuroda, Ryotaro; Kawabata, Atsufumi

    2003-07-01

    A recent PET study revealed that the first and second somatosensory cortices (SI, SII), and the anterior cingulate cortex are activated by painful peripheral stimulation in humans. It has become clear that painful signals (nociceptive information) evoked at the periphery are transmitted via various circuits to the multiple cerebral cortices where pain signals are processed and perceived. Human or clinical pain is not merely a modality of somatic sensation, but associated with the affect that accompanies sensation. Consequently, pain has a somatosensory-discriminative aspect and an affective-cognitive aspect that are processed in different but correlated brain structures in the ascending circuits. Considering the physiologic characteristics and fiber connections, the SI and SII cortices appear to be involved in somatosensory-discriminative pain, and the anterior cingulate cortex (area 24) in the affective-cognitive aspect of pain. This paper deals with the ascending pain pathways from the periphery to these cortices and their interconnections. Our recent findings on the protease-activated receptors 1 and 2 (PAR-1, and -2), which are confirmed to exist in the dorsal root ganglion cells, are also described. Activation of PAR-2 during inflammation or tissue injury at the periphery is pronociceptive, while PAR-1 appears to be antinociceptive. Based on the these findings, PAR-1 and PAR-2 are attracting interest as target molecules for new drug development.

  2. Prefrontal cortex and somatosensory cortex in tactile crossmodal association: an independent component analysis of ERP recordings.

    Directory of Open Access Journals (Sweden)

    Yixuan Ku

    2007-08-01

    Full Text Available Our previous studies on scalp-recorded event-related potentials (ERPs showed that somatosensory N140 evoked by a tactile vibration in working memory tasks was enhanced when human subjects expected a coming visual stimulus that had been paired with the tactile stimulus. The results suggested that such enhancement represented the cortical activities involved in tactile-visual crossmodal association. In the present study, we further hypothesized that the enhancement represented the neural activities in somatosensory and frontal cortices in the crossmodal association. By applying independent component analysis (ICA to the ERP data, we found independent components (ICs located in the medial prefrontal cortex (around the anterior cingulate cortex, ACC and the primary somatosensory cortex (SI. The activity represented by the IC in SI cortex showed enhancement in expectation of the visual stimulus. Such differential activity thus suggested the participation of SI cortex in the task-related crossmodal association. Further, the coherence analysis and the Granger causality spectral analysis of the ICs showed that SI cortex appeared to cooperate with ACC in attention and perception of the tactile stimulus in crossmodal association. The results of our study support with new evidence an important idea in cortical neurophysiology: higher cognitive operations develop from the modality-specific sensory cortices (in the present study, SI cortex that are involved in sensation and perception of various stimuli.

  3. Functional magnetic resonance imaging of the human primary visual cortex during visual stimulation

    International Nuclear Information System (INIS)

    Miki, Atsushi; Abe, Haruki; Nakajima, Takashi; Fujita, Motoi; Watanabe, Hiroyuki; Kuwabara, Takeo; Naruse, Shoji; Takagi, Mineo.

    1995-01-01

    Signal changes in the human primary visual cortex during visual stimulation were evaluated using non-invasive functional magnetic resonance imaging (fMRI). The experiments were performed on 10 normal human volunteers and 2 patients with homonymous hemianopsia, including one who was recovering from the exacerbation of multiple sclerosis. The visual stimuli were provided by a pattern generator using the checkerboard pattern for determining the visual evoked potential of full-field and hemifield stimulation. In normal volunteers, a signal increase was observed on the bilateral primary visual cortex during the full-field stimulation and on the contra-lateral cortex during hemifield stimulation. In the patient with homonymous hemianopsia after cerebral infarction, the signal change was clearly decreased on the affected side. In the other patient, the one recovering from multiple sclerosis with an almost normal visual field, the fMRI was within normal limits. These results suggest that it is possible to visualize the activation of the visual cortex during visual stimulation, and that there is a possibility of using this test as an objective method of visual field examination. (author)

  4. Category-specific responses to faces and objects in primate auditory cortex

    Directory of Open Access Journals (Sweden)

    Kari L Hoffman

    2008-03-01

    Full Text Available Auditory and visual signals often occur together, and the two sensory channels are known to infl uence each other to facilitate perception. The neural basis of this integration is not well understood, although other forms of multisensory infl uences have been shown to occur at surprisingly early stages of processing in cortex. Primary visual cortex neurons can show frequency-tuning to auditory stimuli, and auditory cortex responds selectively to certain somatosensory stimuli, supporting the possibility that complex visual signals may modulate early stages of auditory processing. To elucidate which auditory regions, if any, are responsive to complex visual stimuli, we recorded from auditory cortex and the superior temporal sulcus while presenting visual stimuli consisting of various objects, neutral faces, and facial expressions generated during vocalization. Both objects and conspecifi c faces elicited robust fi eld potential responses in auditory cortex sites, but the responses varied by category: both neutral and vocalizing faces had a highly consistent negative component (N100 followed by a broader positive component (P180 whereas object responses were more variable in time and shape, but could be discriminated consistently from the responses to faces. The face response did not vary within the face category, i.e., for expressive vs. neutral face stimuli. The presence of responses for both objects and neutral faces suggests that auditory cortex receives highly informative visual input that is not restricted to those stimuli associated with auditory components. These results reveal selectivity for complex visual stimuli in a brain region conventionally described as non-visual unisensory cortex.

  5. Callosal connections of dorso-lateral premotor cortex.

    Science.gov (United States)

    Marconi, B; Genovesio, A; Giannetti, S; Molinari, M; Caminiti, R

    2003-08-01

    This study investigated the organization of the callosal connections of the two subdivisions of the monkey dorsal premotor cortex (PMd), dorso-rostral (F7) and dorso-caudal (F2). In one animal, Fast blue and Diamidino yellow were injected in F7 and F2, respectively; in a second animal, the pattern of injections was reversed. F7 and F2 receive a major callosal input from their homotopic counterpart. The heterotopic connections of F7 originate mainly from F2, with smaller contingent from pre-supplementary motor area (pre-SMA, F6), area 8 (frontal eye fields), and prefrontal cortex (area 46), while those of F2 originate from F7, with smaller contributions from ventral premotor areas (F5, F4), SMA-proper (F3), and primary motor cortex (M1). Callosal cells projecting homotopically are mostly located in layers II-III, those projecting heterotopically occupy layers II-III and V-VI. A spectral analysis was used to characterize the spatial fluctuations of the distribution of callosal neurons, in both F7 and F2, as well as in adjacent cortical areas. The results revealed two main periodic components. The first, in the domain of the low spatial frequencies, corresponds to periodicities of cell density with peak-to-peak distances of approximately 10 mm, and suggests an arrangement of callosal cells in the form of 5-mm wide bands. The second corresponds to periodicities of approximately 2 mm, and probably reflects a 1-mm columnar-like arrangement. Coherency and phase analyses showed that, although similar in their spatial arrangements, callosal cells projecting to dorsal premotor areas are segregated in the tangential cortical domain.

  6. Retrosplenial Cortex and Long-Term Memory: Molecules to Behavior

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    Travis P. Todd

    2015-01-01

    Full Text Available The retrosplenial cortex (RSC is reciprocally connected with the hippocampus and various parahippocampal cortical regions, suggesting that RSC is well-positioned to contribute to hippocampal-dependent memory. Consistent with this, substantial behavioral evidence indicates that RSC is essential for consolidating and/or retrieving contextual and spatial memories. In addition, there is growing evidence that RSC neurons undergo activity-dependent plastic changes during memory formation and retrieval. In this paper we review both the behavioral and cellular/molecular data and posit that the RSC has a particularly important role in the storage and retrieval of spatial and contextual memories perhaps due its involvement in binding together multiple cues in the environment. We identify remaining questions and avenues for future research that take advantage of emerging methods to selectively manipulate RSC neurons both spatially and temporally and to image the RSC in awake, behaving animals.

  7. [Subcortical laminar heterotopia 'double cortex syndrome'].

    Science.gov (United States)

    Teplyshova, A M; Gaskin, V V; Kustov, G V; Gudkova, A A; Luzin, R V; Trifonov, I S; Lebedeva, A V

    2017-01-01

    This article presents a clinical case of a 29-year-old patient with 'Double cortex syndrome' with epilepsy, intellectual and mental disorders. Subcortical band heterotopia is a rare disorder of neuronal migration. Such patients typically present with epilepsy and variable degrees of mental retardation and behavioral and intellectual disturbances. The main diagnostic method is magnetic resonance imaging (MRI).

  8. Motor cortex stimulation: role of computer modeling

    NARCIS (Netherlands)

    Manola, L.; Holsheimer, J.; Sakas, D.E.; Simpson, B.A

    Motor cortex stimulation (MCS) is a promising clinical technique used to treat chronic, otherwise intractable pain. However, the mechanisms by which the neural elements that are stimulated during MCS induce pain relief are not understood. Neither is it known which neural elements (fibers (parallel

  9. Postictal inhibition of the somatosensory cortex

    DEFF Research Database (Denmark)

    Beniczky, Sándor; Jovanovic, Marina; Atkins, Mary Doreen

    2011-01-01

    Transient suppression of the motor cortex and of the speech areas cause well-described postictal phenomena following seizures involving the respective cortical areas. Pain is a rare symptom in epileptic seizures. We present a patient with painful tonic seizures in the left leg. The amplitude...

  10. Primary Auditory Cortex Regulates Threat Memory Specificity

    Science.gov (United States)

    Wigestrand, Mattis B.; Schiff, Hillary C.; Fyhn, Marianne; LeDoux, Joseph E.; Sears, Robert M.

    2017-01-01

    Distinguishing threatening from nonthreatening stimuli is essential for survival and stimulus generalization is a hallmark of anxiety disorders. While auditory threat learning produces long-lasting plasticity in primary auditory cortex (Au1), it is not clear whether such Au1 plasticity regulates memory specificity or generalization. We used…

  11. Excessive oral intake caffeine altered cerebral cortex ...

    African Journals Online (AJOL)

    Caffeine is commonly consumed in an effort to enhance speed in performance and wakefulness. However, little is known about the deleterious effects it can produce on the brain, this study aimed at determining the extents of effects and damage that can be caused by excessive consumption of caffeine on the cerebral cortex ...

  12. PACAP decides neuronal laminar fate via PKA signaling in the developing cerebral cortex

    International Nuclear Information System (INIS)

    Ohtsuka, Masanari; Fukumitsu, Hidefumi; Furukawa, Shoei

    2008-01-01

    Laminar formation in the developing cerebral cortex requires the precisely regulated generation of phenotype-specified neurons. To test the possible involvement of pituitary adenylate cyclase-activating polypeptide (PACAP) in this formation, we investigated the effects of PACAP administered into the telencephalic ventricular space of 13.5-day-old mouse embryos. PACAP partially inhibited the proliferation of cortical progenitors and altered the position and gene-expression profiles of newly generated neurons otherwise expected for layer IV to those of neurons for the deeper layers, V and VI, of the cerebral cortex. The former and latter effects were seen only when the parent progenitor cells were exposed to PACAP in the later and in earlier G1 phase, respectively; and these effects were suppressed by co-treatment with a protein kinase A (PKA) inhibitor. These observations suggest that PACAP participates in the processes forming the neuronal laminas in the developing cortex via the intracellular PKA pathway

  13. A radial map of multi-whisker correlation selectivity in the rat barrel cortex.

    Science.gov (United States)

    Estebanez, Luc; Bertherat, Julien; Shulz, Daniel E; Bourdieu, Laurent; Léger, Jean-François

    2016-11-21

    In the barrel cortex, several features of single-whisker stimuli are organized in functional maps. The barrel cortex also encodes spatio-temporal correlation patterns of multi-whisker inputs, but so far the cortical mapping of neurons tuned to such input statistics is unknown. Here we report that layer 2/3 of the rat barrel cortex contains an additional functional map based on neuronal tuning to correlated versus uncorrelated multi-whisker stimuli: neuron responses to uncorrelated multi-whisker stimulation are strongest above barrel centres, whereas neuron responses to correlated and anti-correlated multi-whisker stimulation peak above the barrel-septal borders, forming rings of multi-whisker synchrony-preferring cells.

  14. Differential microstructural alterations in rat cerebral cortex in a model of chronic mild stress depression

    DEFF Research Database (Denmark)

    Khan, Ahmad Raza; Kroenke, Christopher D; Wiborg, Ove

    2018-01-01

    , hypothalamus, prefrontal cortex, and amygdala, which form an interconnected system known as the stress circuit. Most studies have focused only on this circuit, however, some studies indicate that manipulation of sensory and motor systems may impact genesis and therapy of mood disorders and therefore...... anisotropy in the resilient group. Neurite density was not found to be significantly higher in any cortical ROIs in the stress group compared to control, although axonal density is higher in the stress groups. We also report significant thinning of motor cortex (MC) in both stress groups......-MRI) to assess cortical microstructure in stressed (anhedonic and resilient) and control animals. MRI is followed by immunohistochemistry to substantiate the d-MRI findings. We find significantly lower extracellular diffusivity in auditory cortex (AC) of stress groups and a significantly higher fractional...

  15. Structural and functional analyses of human cerebral cortex using a surface-based atlas

    Science.gov (United States)

    Van Essen, D. C.; Drury, H. A.

    1997-01-01

    We have analyzed the geometry, geography, and functional organization of human cerebral cortex using surface reconstructions and cortical flat maps of the left and right hemispheres generated from a digital atlas (the Visible Man). The total surface area of the reconstructed Visible Man neocortex is 1570 cm2 (both hemispheres), approximately 70% of which is buried in sulci. By linking the Visible Man cerebrum to the Talairach stereotaxic coordinate space, the locations of activation foci reported in neuroimaging studies can be readily visualized in relation to the cortical surface. The associated spatial uncertainty was empirically shown to have a radius in three dimensions of approximately 10 mm. Application of this approach to studies of visual cortex reveals the overall patterns of activation associated with different aspects of visual function and the relationship of these patterns to topographically organized visual areas. Our analysis supports a distinction between an anterior region in ventral occipito-temporal cortex that is selectively involved in form processing and a more posterior region (in or near areas VP and V4v) involved in both form and color processing. Foci associated with motion processing are mainly concentrated in a region along the occipito-temporal junction, the ventral portion of which overlaps with foci also implicated in form processing. Comparisons between flat maps of human and macaque monkey cerebral cortex indicate significant differences as well as many similarities in the relative sizes and positions of cortical regions known or suspected to be homologous in the two species.

  16. Maps of space in human frontoparietal cortex.

    Science.gov (United States)

    Jerde, Trenton A; Curtis, Clayton E

    2013-12-01

    Prefrontal cortex (PFC) and posterior parietal cortex (PPC) are neural substrates for spatial cognition. We here review studies in which we tested the hypothesis that human frontoparietal cortex may function as a priority map. According to priority map theory, objects or locations in the visual world are represented by neural activity that is proportional to their attentional priority. Using functional magnetic resonance imaging (fMRI), we first identified topographic maps in PFC and PPC as candidate priority maps of space. We then measured fMRI activity in candidate priority maps during the delay periods of a covert attention task, a spatial working memory task, and a motor planning task to test whether the activity depended on the particular spatial cognition. Our hypothesis was that some, but not all, candidate priority maps in PFC and PPC would be agnostic with regard to what was being prioritized, in that their activity would reflect the location in space across tasks rather than a particular kind of spatial cognition (e.g., covert attention). To test whether patterns of delay period activity were interchangeable during the spatial cognitive tasks, we used multivariate classifiers. We found that decoders trained to predict the locations on one task (e.g., working memory) cross-predicted the locations on the other tasks (e.g., covert attention and motor planning) in superior precentral sulcus (sPCS) and in a region of intraparietal sulcus (IPS2), suggesting that these patterns of maintenance activity may be interchangeable across the tasks. Such properties make sPCS in frontal cortex and IPS2 in parietal cortex viable priority map candidates, and suggest that these areas may be the human homologs of the monkey frontal eye field (FEF) and lateral intraparietal area (LIP). Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. [Raman spectra of monkey cerebral cortex tissue].

    Science.gov (United States)

    Zhu, Ji-chun; Guo, Jian-yu; Cai, Wei-ying; Wang, Zu-geng; Sun, Zhen-rong

    2010-01-01

    Monkey cerebral cortex, an important part in the brain to control action and thought activities, is mainly composed of grey matter and nerve cell. In the present paper, the in situ Raman spectra of the cerebral cortex of the birth, teenage and aged monkeys were achieved for the first time. The results show that the Raman spectra for the different age monkey cerebral cortex exhibit most obvious changes in the regions of 1000-1400 and 2800-3000 cm(-1). With monkey growing up, the relative intensities of the Raman bands at 1313 and 2885 cm(-1) mainly assigned to CH2 chain vibrational mode of lipid become stronger and stronger whereas the relative intensities of the Raman bands at 1338 and 2932 cm(-1) mainly assigned to CH3 chain vibrational mode of protein become weaker and weaker. In addition, the two new Raman bands at 1296 and 2850 cm(-1) are only observed in the aged monkey cerebral cortex, therefore, the two bands can be considered as a character or "marker" to differentiate the caducity degree with monkey growth In order to further explore the changes, the relative intensity ratios of the Raman band at 1313 cm(-1) to that at 1338 cm(-1) and the Raman band at 2885 cm(-1) to that at 2 932 cm(-1), I1313/I1338 and I2885/I2932, which are the lipid-to-protein ratios, are introduced to denote the degree of the lipid content. The results show that the relative intensity ratios increase significantly with monkey growth, namely, the lipid content in the cerebral cortex increases greatly with monkey growth. So, the authors can deduce that the overmuch lipid is an important cause to induce the caducity. Therefore, the results will be a powerful assistance and valuable parameter to study the order of life growth and diagnose diseases.

  18. Excitatory Neuronal Hubs Configure Multisensory Integration of Slow Waves in Association Cortex

    Directory of Open Access Journals (Sweden)

    Satoshi Kuroki

    2018-03-01

    Full Text Available Summary: Multisensory integration (MSI is a fundamental emergent property of the mammalian brain. During MSI, perceptual information encoded in patterned activity is processed in multimodal association cortex. The systems-level neuronal dynamics that coordinate MSI, however, are unknown. Here, we demonstrate intrinsic hub-like network activity in the association cortex that regulates MSI. We engineered calcium reporter mouse lines based on the fluorescence resonance energy transfer sensor yellow cameleon (YC2.60 expressed in excitatory or inhibitory neurons. In medial and parietal association cortex, we observed spontaneous slow waves that self-organized into hubs defined by long-range excitatory and local inhibitory circuits. Unlike directional source/sink-like flows in sensory areas, medial/parietal excitatory and inhibitory hubs had net-zero balanced inputs. Remarkably, multisensory stimulation triggered rapid phase-locking mainly of excitatory hub activity persisting for seconds after the stimulus offset. Therefore, association cortex tends to form balanced excitatory networks that configure slow-wave phase-locking for MSI. Video Abstract: : Kuroki et al. performed cell-type-specific, wide-field FRET-based calcium imaging to visualize cortical network activity induced by multisensory inputs. They observed phase-locking of cortical slow waves in excitatory neuronal hubs in association cortical areas that may underlie multisensory integration. Keywords: wide-field calcium imaging, multisensory integration, cortical slow waves, association cortex, phase locking, fluorescence resonance energy transfer, spontaneous activity, excitatory neuron, inhibitory neuron, mouse

  19. Motor cortex stimulation in the treatment of central and neuropathic pain.

    Science.gov (United States)

    Nguyen, J P; Lefaucher, J P; Le Guerinel, C; Eizenbaum, J F; Nakano, N; Carpentier, A; Brugières, P; Pollin, B; Rostaing, S; Keravel, Y

    2000-01-01

    Motor cortex stimulation has been proposed for the treatment of central pain. Thirty-two patients with refractory central and neuropathic pain of peripheral origin were treated by chronic stimulation of the motor cortex between May 1993 and January 1997. The mean follow-up was 27.3 months. The first 24 patients were operated on according to the technique described by Tsubokawa. The last 13 cases (8 new patients and 5 reinterventions) were operated on by a technique including localization by superficial CT reconstruction of the central region and neuronavigator guidance. The position of the central sulcus was confirmed by the use of intraoperative somatosensory evoked potentials. The somatotopic organization of the motor cortex was established preoperatively by studying the motor responses at stimulation of the motor cortex through the dura. Ten of the 13 patients with central pain (77%) and 10 of the 12 patients with neuropathic facial pain experienced substantial pain relief (83.3%). One of the three patients with post-paraplegia pain was clearly improved. A satisfactory result was obtained in one patient with pain related to plexus avulsion and in one patient with pain related to intercostal herpes zoster. None of the patients developed epileptic seizures. Our results confirm that chronic stimulation of the motor cortex is an effective method in treating certain forms of refractory pain.

  20. 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.

  1. Medial frontal cortex and response conflict: Evidence from human intracranial EEG and medial frontal cortex lesion

    NARCIS (Netherlands)

    Cohen, M.X.; Ridderinkhof, K.R.; Haupt, S.; Elger, C.E.; Fell, J.

    2008-01-01

    The medial frontal cortex (MFC) has been implicated in the monitoring and selection of actions in the face of competing alternatives, but much remains unknown about its functional properties, including electrophysiological oscillations, during response conflict tasks. Here, we recorded intracranial

  2. Adolescent changes in dopamine D1 receptor expression in orbitofrontal cortex and piriform cortex accompany an associative learning deficit.

    Directory of Open Access Journals (Sweden)

    Anna K Garske

    Full Text Available The orbitofrontal cortex (OFC and piriform cortex are involved in encoding the predictive value of olfactory stimuli in rats, and neural responses to olfactory stimuli in these areas change as associations are learned. This experience-dependent plasticity mirrors task-related changes previously observed in mesocortical dopamine neurons, which have been implicated in learning the predictive value of cues. Although forms of associative learning can be found at all ages, cortical dopamine projections do not mature until after postnatal day 35 in the rat. We hypothesized that these changes in dopamine circuitry during the juvenile and adolescent periods would result in age-dependent differences in learning the predictive value of environmental cues. Using an odor-guided associative learning task, we found that adolescent rats learn the association between an odor and a palatable reward significantly more slowly than either juvenile or adult rats. Further, adolescent rats displayed greater distractibility during the task than either juvenile or adult rats. Using real-time quantitative PCR and immunohistochemical methods, we observed that the behavioral deficit in adolescence coincides with a significant increase in D1 dopamine receptor expression compared to juvenile rats in both the OFC and piriform cortex. Further, we found that both the slower learning and increased distractibility exhibited in adolescence could be alleviated by experience with the association task as a juvenile, or by an acute administration of a low dose of either the dopamine D1 receptor agonist SKF-38393 or the D2 receptor antagonist eticlopride. These results suggest that dopaminergic modulation of cortical function may be important for learning the predictive value of environmental stimuli, and that developmental changes in cortical dopaminergic circuitry may underlie age-related differences in associative learning.

  3. Multiple sclerosis

    Science.gov (United States)

    ... indwelling catheter Osteoporosis or thinning of the bones Pressure sores Side effects of medicines used to treat the ... Daily bowel care program Multiple sclerosis - discharge Preventing pressure ulcers Swallowing problems Images Multiple sclerosis MRI of the ...

  4. Radial Structure Scaffolds Convolution Patterns of Developing Cerebral Cortex

    Directory of Open Access Journals (Sweden)

    Mir Jalil Razavi

    2017-08-01

    Full Text Available Commonly-preserved radial convolution is a prominent characteristic of the mammalian cerebral cortex. Endeavors from multiple disciplines have been devoted for decades to explore the causes for this enigmatic structure. However, the underlying mechanisms that lead to consistent cortical convolution patterns still remain poorly understood. In this work, inspired by prior studies, we propose and evaluate a plausible theory that radial convolution during the early development of the brain is sculptured by radial structures consisting of radial glial cells (RGCs and maturing axons. Specifically, the regionally heterogeneous development and distribution of RGCs controlled by Trnp1 regulate the convex and concave convolution patterns (gyri and sulci in the radial direction, while the interplay of RGCs' effects on convolution and axons regulates the convex (gyral convolution patterns. This theory is assessed by observations and measurements in literature from multiple disciplines such as neurobiology, genetics, biomechanics, etc., at multiple scales to date. Particularly, this theory is further validated by multimodal imaging data analysis and computational simulations in this study. We offer a versatile and descriptive study model that can provide reasonable explanations of observations, experiments, and simulations of the characteristic mammalian cortical folding.

  5. The logic of single-cell projections from visual cortex.

    Science.gov (United States)

    Han, Yunyun; Kebschull, Justus M; Campbell, Robert A A; Cowan, Devon; Imhof, Fabia; Zador, Anthony M; Mrsic-Flogel, Thomas D

    2018-04-05

    Neocortical areas communicate through extensive axonal projections, but the logic of information transfer remains poorly understood, because the projections of individual neurons have not been systematically characterized. It is not known whether individual neurons send projections only to single cortical areas or distribute signals across multiple targets. Here we determine the projection patterns of 591 individual neurons in the mouse primary visual cortex using whole-brain fluorescence-based axonal tracing and high-throughput DNA sequencing of genetically barcoded neurons (MAPseq). Projections were highly diverse and divergent, collectively targeting at least 18 cortical and subcortical areas. Most neurons targeted multiple cortical areas, often in non-random combinations, suggesting that sub-classes of intracortical projection neurons exist. Our results indicate that the dominant mode of intracortical information transfer is not based on 'one neuron-one target area' mapping. Instead, signals carried by individual cortical neurons are shared across subsets of target areas, and thus concurrently contribute to multiple functional pathways.

  6. 3D topology of orientation columns in visual cortex revealed by functional optical coherence tomography.

    Science.gov (United States)

    Nakamichi, Yu; Kalatsky, Valery A; Watanabe, Hideyuki; Sato, Takayuki; Rajagopalan, Uma Maheswari; Tanifuji, Manabu

    2018-04-01

    Orientation tuning is a canonical neuronal response property of six-layer visual cortex that is encoded in pinwheel structures with center orientation singularities. Optical imaging of intrinsic signals enables us to map these surface two-dimensional (2D) structures, whereas lack of appropriate techniques has not allowed us to visualize depth structures of orientation coding. In the present study, we performed functional optical coherence tomography (fOCT), a technique capable of acquiring a 3D map of the intrinsic signals, to study the topology of orientation coding inside the cat visual cortex. With this technique, for the first time, we visualized columnar assemblies in orientation coding that had been predicted from electrophysiological recordings. In addition, we found that the columnar structures were largely distorted around pinwheel centers: center singularities were not rigid straight lines running perpendicularly to the cortical surface but formed twisted string-like structures inside the cortex that turned and extended horizontally through the cortex. Looping singularities were observed with their respective termini accessing the same cortical surface via clockwise and counterclockwise orientation pinwheels. These results suggest that a 3D topology of orientation coding cannot be fully anticipated from 2D surface measurements. Moreover, the findings demonstrate the utility of fOCT as an in vivo mesoscale imaging method for mapping functional response properties of cortex in the depth axis. NEW & NOTEWORTHY We used functional optical coherence tomography (fOCT) to visualize three-dimensional structure of the orientation columns with millimeter range and micrometer spatial resolution. We validated vertically elongated columnar structure in iso-orientation domains. The columnar structure was distorted around pinwheel centers. An orientation singularity formed a string with tortuous trajectories inside the cortex and connected clockwise and counterclockwise

  7. Medial prefrontal cortex role in recognition memory in rodents.

    Science.gov (United States)

    Morici, Juan Facundo; Bekinschtein, Pedro; Weisstaub, Noelia V

    2015-10-01

    The study of the neurobiology of recognition memory, defined by the integration of the different components of experiences that support recollection of past experiences have been a challenge for memory researches for many years. In the last twenty years, with the development of the spontaneous novel object recognition task and all its variants this has started to change. The features of recognition memory include a particular object or person ("what"), the context in which the experience took place, which can be the arena itself or the location within a particular arena ("where") and the particular time at which the event occurred ("when"). This definition instead of the historical anthropocentric one allows the study of this type of episodic memory in animal models. Some forms of recognition memory that require integration of different features recruit the medial prefrontal cortex. Focusing on findings from spontaneous recognition memory tasks performed by rodents, this review concentrates on the description of previous works that have examined the role that the medial prefrontal cortex has on the different steps of recognition memory. We conclude that this structure, independently of the task used, is required at different memory stages when the task cannot be solved by a single item strategy. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Normal and abnormal neuronal migration in the developing cerebral cortex.

    Science.gov (United States)

    Sun, Xue-Zhi; Takahashi, Sentaro; Cui, Chun; Zhang, Rui; Sakata-Haga, Hiromi; Sawada, Kazuhiko; Fukui, Yoshihiro

    2002-08-01

    Neuronal migration is the critical cellular process which initiates histogenesis of cerebral cortex. Migration involves a series of complex cell interactions and transformation. After completing their final mitosis, neurons migrate from the ventricular zone into the cortical plate, and then establish neuronal lamina and settle onto the outermost layer, forming an "inside-out" gradient of maturation. This process is guided by radial glial fibers, requires proper receptors, ligands, other unknown extracellular factors, and local signaling to stop neuronal migration. This process is also highly sensitive to various physical, chemical and biological agents as well as to genetic mutations. Any disturbance of the normal process may result in neuronal migration disorder. Such neuronal migration disorder is believed as major cause of both gross brain malformation and more special cerebral structural and functional abnormalities in experimental animals and in humans. An increasing number of instructive studies on experimental models and several genetic model systems of neuronal migration disorder have established the foundation of cortex formation and provided deeper insights into the genetic and molecular mechanisms underlying normal and abnormal neuronal migration.

  9. Evoked potentials in large-scale cortical networks elicited by TMS of the visual cortex

    Science.gov (United States)

    Grossman, Emily D.; Srinivasan, Ramesh

    2011-01-01

    Single pulses of transcranial magnetic stimulation (TMS) result in distal and long-lasting oscillations, a finding directly challenging the virtual lesion hypothesis. Previous research supporting this finding has primarily come from stimulation of the motor cortex. We have used single-pulse TMS with simultaneous EEG to target seven brain regions, six of which belong to the visual system [left and right primary visual area V1, motion-sensitive human middle temporal cortex, and a ventral temporal region], as determined with functional MRI-guided neuronavigation, and a vertex “control” site to measure the network effects of the TMS pulse. We found the TMS-evoked potential (TMS-EP) over visual cortex consists mostly of site-dependent theta- and alphaband oscillations. These site-dependent oscillations extended beyond the stimulation site to functionally connected cortical regions and correspond to time windows where the EEG responses maximally diverge (40, 200, and 385 ms). Correlations revealed two site-independent oscillations ∼350 ms after the TMS pulse: a theta-band oscillation carried by the frontal cortex, and an alpha-band oscillation over parietal and frontal cortical regions. A manipulation of stimulation intensity at one stimulation site (right hemisphere V1-V3) revealed sensitivity to the stimulation intensity at different regions of cortex, evidence of intensity tuning in regions distal to the site of stimulation. Together these results suggest that a TMS pulse applied to the visual cortex has a complex effect on brain function, engaging multiple brain networks functionally connected to the visual system with both invariant and site-specific spatiotemporal dynamics. With this characterization of TMS, we propose an alternative to the virtual lesion hypothesis. Rather than a technique that simulates lesions, we propose TMS generates natural brain signals and engages functional networks. PMID:21715670

  10. Functions of delay-period activity in the prefrontal cortex and mnemonic scotomas revisited

    Directory of Open Access Journals (Sweden)

    Shintaro eFunahashi

    2015-02-01

    Full Text Available Working memory is one of key concepts to understand functions of the prefrontal cortex. Delay-period activity is an important neural correlate to understand the role of working memory in prefrontal functions. The importance of delay-period activity is that this activity can encode not only visuospatial information but also a variety of information including non-spatial visual features, auditory and tactile stimuli, task rules, expected reward, and numerical quantity. This activity also participates in a variety of information processing including sensory-to-motor information transformation. These mnemonic features of delay-period activity enable to perform various important operations that the prefrontal cortex participates in, such as executive controls, and therefore, support the notion that working memory is an important function to understand prefrontal functions. On the other hand, although experiments using manual versions of the delayed-response task had revealed many important findings, an oculomotor version of this task enabled us to use multiple cue positions, exclude postural orientation during the delay period, and further prove the importance of mnemonic functions of the prefrontal cortex. In addition, monkeys with unilateral lesions exhibited specific impairment only in the performance of memory-guided saccades directed toward visual cues in the visual field contralateral to the lesioned hemisphere. This result indicates that memories for visuospatial coordinates in each hemifield are processed primarily in the contralateral prefrontal cortex. This result further strengthened the idea of mnemonic functions of the prefrontal cortex. Thus, the mnemonic functions of the prefrontal cortex and delay-period activity may not need to be reconsidered, but should be emphasized.

  11. Misconceptions about mirror-induced motor cortex activation.

    NARCIS (Netherlands)

    Praamstra, P.; Torney, L.; Rawle, C.J.; Miall, R.C.

    2011-01-01

    Observation of self-produced hand movements through a mirror, creating an illusion of the opposite hand moving, was recently reported to induce ipsilateral motor cortex activation, that is, motor cortex activation for the hand in rest. The reported work goes far beyond earlier work on motor cortex

  12. Asymmetric Temporal Integration of Layer 4 and Layer 2/3 Inputs in Visual Cortex

    OpenAIRE

    Hang, Giao B.; Dan, Yang

    2010-01-01

    Neocortical neurons in vivo receive concurrent synaptic inputs from multiple sources, including feedforward, horizontal, and feedback pathways. Layer 2/3 of the visual cortex receives feedforward input from layer 4 and horizontal input from layer 2/3. Firing of the pyramidal neurons, which carries the output to higher cortical areas, depends critically on the interaction of these pathways. Here we examined synaptic integration of inputs from layer 4 and layer 2/3 in rat visual cortical slices...

  13. Differences between Neural Activity in Prefrontal Cortex and Striatum during Learning of Novel Abstract Categories

    OpenAIRE

    Antzoulatos, Evan G.; Miller, Earl K.

    2011-01-01

    Learning to classify diverse experiences into meaningful groups, like categories, is fundamental to normal cognition. To understand its neural basis, we simultaneously recorded from multiple electrodes in the lateral prefrontal cortex and dorsal striatum, two interconnected brain structures critical for learning. Each day, monkeys learned to associate novel, abstract dot-based categories with a right vs. left saccade. Early on, when they could acquire specific stimulus-response associations, ...

  14. MULTIPLE OBJECTS

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    A. A. Bosov

    2015-04-01

    Full Text Available Purpose. The development of complicated techniques of production and management processes, information systems, computer science, applied objects of systems theory and others requires improvement of mathematical methods, new approaches for researches of application systems. And the variety and diversity of subject systems makes necessary the development of a model that generalizes the classical sets and their development – sets of sets. Multiple objects unlike sets are constructed by multiple structures and represented by the structure and content. The aim of the work is the analysis of multiple structures, generating multiple objects, the further development of operations on these objects in application systems. Methodology. To achieve the objectives of the researches, the structure of multiple objects represents as constructive trio, consisting of media, signatures and axiomatic. Multiple object is determined by the structure and content, as well as represented by hybrid superposition, composed of sets, multi-sets, ordered sets (lists and heterogeneous sets (sequences, corteges. Findings. In this paper we study the properties and characteristics of the components of hybrid multiple objects of complex systems, proposed assessments of their complexity, shown the rules of internal and external operations on objects of implementation. We introduce the relation of arbitrary order over multiple objects, we define the description of functions and display on objects of multiple structures. Originality.In this paper we consider the development of multiple structures, generating multiple objects.Practical value. The transition from the abstract to the subject of multiple structures requires the transformation of the system and multiple objects. Transformation involves three successive stages: specification (binding to the domain, interpretation (multiple sites and particularization (goals. The proposed describe systems approach based on hybrid sets

  15. Dyslexic children lack word selectivity gradients in occipito-temporal and inferior frontal cortex

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    O.A. Olulade

    2015-01-01

    Full Text Available fMRI studies using a region-of-interest approach have revealed that the ventral portion of the left occipito-temporal cortex, which is specialized for orthographic processing of visually presented words (and includes the so-called “visual word form area”, VWFA, is characterized by a posterior-to-anterior gradient of increasing selectivity for words in typically reading adults, adolescents, and children (e.g. Brem et al., 2006, 2009. Similarly, the left inferior frontal cortex (IFC has been shown to exhibit a medial-to-lateral gradient of print selectivity in typically reading adults (Vinckier et al., 2007. Functional brain imaging studies of dyslexia have reported relative underactivity in left hemisphere occipito-temporal and inferior frontal regions using whole-brain analyses during word processing tasks. Hence, the question arises whether gradient sensitivities in these regions are altered in dyslexia. Indeed, a region-of-interest analysis revealed the gradient-specific functional specialization in the occipito-temporal cortex to be disrupted in dyslexic children (van der Mark et al., 2009. Building on these studies, we here (1 investigate if a word-selective gradient exists in the inferior frontal cortex in addition to the occipito-temporal cortex in normally reading children, (2 compare typically reading with dyslexic children, and (3 examine functional connections between these regions in both groups. We replicated the previously reported anterior-to-posterior gradient of increasing selectivity for words in the left occipito-temporal cortex in typically reading children, and its absence in the dyslexic children. Our novel finding is the detection of a pattern of increasing selectivity for words along the medial-to-lateral axis of the left inferior frontal cortex in typically reading children and evidence of functional connectivity between the most lateral aspect of this area and the anterior aspects of the occipito-temporal cortex. We

  16. Low intensity areas observed T2-weighted magnetic resonance imaging of the cerebral cortex in various neurological diseases

    Energy Technology Data Exchange (ETDEWEB)

    Imon, Yukari [Hiroshima Univ. (Japan). School of Medicine

    1996-02-01

    We retrospectively studied magnetic resonance images of the brain in 158 patients (8 cases of amyotrophic lateral sclerosis, 16 cases of Alzheimer`s disease, 8 cases of Parkinson`s disease, 53 cases of multiple cerebral infarct, 20 cases of other central nervous system (CNS) diseases, and 53 cases without any CNS disease) to examine the appearance of T2-weighted low signal intensity areas (LIA) in the cerebral cortex. The age of subjects ranged from 36 to 85 years with the mean 65.0 and SD 9.9 years. LIA in the motor and sensory cortices, and brain atrophy were evaluated visually on axial images of the spin-echo sequence obtained with a 1.5 tesla system. The incidence of LIA in the motor cortex was significantly higher in all CNS diseases than in cases without any CNS disease, but not significantly different among CNS diseases. LIA in the motor cortex showed a correlation with age, temporal and parietal atrophy. The appearance of LIA in the sensory cortex correlated with that of LIA in the motor cortex, and parietal atrophy. These results suggest that LIA may appear according to age and be associated with the accumulation of nonheme iron in the cortex, especially in patients with CNS diseases. (author)

  17. Spontaneous Up states in vitro: a single-metric index of the functional maturation and regional differentiation of the cerebral cortex

    Directory of Open Access Journals (Sweden)

    Pavlos eRigas

    2015-10-01

    Full Text Available Understanding the development and differentiation of the neocortex remains a central focus of neuroscience. While previous studies have examined isolated aspects of cellular and synaptic organization, an integrated functional index of the cortical microcircuit is still lacking. Here we aimed to provide such an index, in the form of spontaneously recurring periods of persistent network activity -or Up states- recorded in mouse cortical slices. These coordinated network dynamics emerge through the orchestrated regulation of multiple cellular and synaptic elements and represent the default activity of the cortical microcircuit. To explore whether spontaneous Up states can capture developmental changes in intracortical networks we obtained local field potential recordings throughout the mouse lifespan. Two independent and complementary methodologies revealed that Up state activity is systematically modified by age, with the largest changes occurring during early development and adolescence. To explore possible regional heterogeneities we also compared the development of Up states in two distinct cortical areas and show that primary somatosensory cortex develops at a faster pace than primary motor cortex. Our findings suggest that in vitro Up states can serve as a functional index of cortical development and differentiation and can provide a baseline for comparing experimental and/or genetic mouse models.

  18. Spontaneous Up states in vitro: a single-metric index of the functional maturation and regional differentiation of the cerebral cortex.

    Science.gov (United States)

    Rigas, Pavlos; Adamos, Dimitrios A; Sigalas, Charalambos; Tsakanikas, Panagiotis; Laskaris, Nikolaos A; Skaliora, Irini

    2015-01-01

    Understanding the development and differentiation of the neocortex remains a central focus of neuroscience. While previous studies have examined isolated aspects of cellular and synaptic organization, an integrated functional index of the cortical microcircuit is still lacking. Here we aimed to provide such an index, in the form of spontaneously recurring periods of persistent network activity -or Up states- recorded in mouse cortical slices. These coordinated network dynamics emerge through the orchestrated regulation of multiple cellular and synaptic elements and represent the default activity of the cortical microcircuit. To explore whether spontaneous Up states can capture developmental changes in intracortical networks we obtained local field potential recordings throughout the mouse lifespan. Two independent and complementary methodologies revealed that Up state activity is systematically modified by age, with the largest changes occurring during early development and adolescence. To explore possible regional heterogeneities we also compared the development of Up states in two distinct cortical areas and show that primary somatosensory cortex develops at a faster pace than primary motor cortex. Our findings suggest that in vitro Up states can serve as a functional index of cortical development and differentiation and can provide a baseline for comparing experimental and/or genetic mouse models.

  19. Grammatical distinctions in the left frontal cortex.

    Science.gov (United States)

    Shapiro, K A; Pascual-Leone, A; Mottaghy, F M; Gangitano, M; Caramazza, A

    2001-08-15

    Selective deficits in producing verbs relative to nouns in speech are well documented in neuropsychology and have been associated with left hemisphere frontal cortical lesions resulting from stroke and other neurological disorders. The basis for these impairments is unresolved: Do they arise because of differences in the way grammatical categories of words are organized in the brain, or because of differences in the neural representation of actions and objects? We used repetitive transcranial magnetic stimulation (rTMS) to suppress the excitability of a portion of left prefrontal cortex and to assess its role in producing nouns and verbs. In one experiment subjects generated real words; in a second, they produced pseudowords as nouns or verbs. In both experiments, response latencies increased for verbs but were unaffected for nouns following rTMS. These results demonstrate that grammatical categories have a neuroanatomical basis and that the left prefrontal cortex is selectively engaged in processing verbs as grammatical objects.

  20. An integrative theory of prefrontal cortex function.

    Science.gov (United States)

    Miller, E K; Cohen, J D

    2001-01-01

    The prefrontal cortex has long been suspected to play an important role in cognitive control, in the ability to orchestrate thought and action in accordance with internal goals. Its neural basis, however, has remained a mystery. Here, we propose that cognitive control stems from the active maintenance of patterns of activity in the prefrontal cortex that represent goals and the means to achieve them. They provide bias signals to other brain structures whose net effect is to guide the flow of activity along neural pathways that establish the proper mappings between inputs, internal states, and outputs needed to perform a given task. We review neurophysiological, neurobiological, neuroimaging, and computational studies that support this theory and discuss its implications as well as further issues to be addressed

  1. The role of prefrontal cortex in psychopathy

    Science.gov (United States)

    Koenigs, Michael

    2014-01-01

    Psychopathy is a personality disorder characterized by remorseless and impulsive antisocial behavior. Given the significant societal costs of the recidivistic criminal activity associated with the disorder, there is a pressing need for more effective treatment strategies, and hence, a better understanding of the psychobiological mechanisms underlying the disorder. The prefrontal cortex (PFC) is likely to play an important role in psychopathy. In particular, the ventromedial and anterior cingulate sectors of PFC are theorized to mediate a number of social and affective decision-making functions that appear to be disrupted in psychopathy. This article provides a critical summary of human neuroimaging data implicating prefrontal dysfunction in psychopathy. A growing body of evidence associates psychopathy with structural and functional abnormalities in ventromedial PFC and anterior cingulate cortex. Although this burgeoning field still faces a number of methodological challenges and outstanding questions that will need to be resolved by future studies, the research to date has established a link between psychopathy and PFC. PMID:22752782

  2. Monkey cortex through fMRI glasses.

    Science.gov (United States)

    Vanduffel, Wim; Zhu, Qi; Orban, Guy A

    2014-08-06

    In 1998 several groups reported the feasibility of fMRI experiments in monkeys, with the goal to bridge the gap between invasive nonhuman primate studies and human functional imaging. These studies yielded critical insights in the neuronal underpinnings of the BOLD signal. Furthermore, the technology has been successful in guiding electrophysiological recordings and identifying focal perturbation targets. Finally, invaluable information was obtained concerning human brain evolution. We here provide a comprehensive overview of awake monkey fMRI studies mainly confined to the visual system. We review the latest insights about the topographic organization of monkey visual cortex and discuss the spatial relationships between retinotopy and category- and feature-selective clusters. We briefly discuss the functional layout of parietal and frontal cortex and continue with a summary of some fascinating functional and effective connectivity studies. Finally, we review recent comparative fMRI experiments and speculate about the future of nonhuman primate imaging. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Working Memory in the Prefrontal Cortex

    Science.gov (United States)

    Funahashi, Shintaro

    2017-01-01

    The prefrontal cortex participates in a variety of higher cognitive functions. The concept of working memory is now widely used to understand prefrontal functions. Neurophysiological studies have revealed that stimulus-selective delay-period activity is a neural correlate of the mechanism for temporarily maintaining information in working memory processes. The central executive, which is the master component of Baddeley’s working memory model and is thought to be a function of the prefrontal cortex, controls the performance of other components by allocating a limited capacity of memory resource to each component based on its demand. Recent neurophysiological studies have attempted to reveal how prefrontal neurons achieve the functions of the central executive. For example, the neural mechanisms of memory control have been examined using the interference effect in a dual-task paradigm. It has been shown that this interference effect is caused by the competitive and overloaded recruitment of overlapping neural populations in the prefrontal cortex by two concurrent tasks and that the information-processing capacity of a single neuron is limited to a fixed level, can be flexibly allocated or reallocated between two concurrent tasks based on their needs, and enhances behavioral performance when its allocation to one task is increased. Further, a metamemory task requiring spatial information has been used to understand the neural mechanism for monitoring its own operations, and it has been shown that monitoring the quality of spatial information represented by prefrontal activity is an important factor in the subject's choice and that the strength of spatially selective delay-period activity reflects confidence in decision-making. Although further studies are needed to elucidate how the prefrontal cortex controls memory resource and supervises other systems, some important mechanisms related to the central executive have been identified. PMID:28448453

  4. Spatial integration in mouse primary visual cortex

    OpenAIRE

    Vaiceliunaite, Agne; Erisken, Sinem; Franzen, Florian; Katzner, Steffen; Busse, Laura

    2013-01-01

    Responses of many neurons in primary visual cortex (V1) are suppressed by stimuli exceeding the classical receptive field (RF), an important property that might underlie the computation of visual saliency. Traditionally, it has proven difficult to disentangle the underlying neural circuits, including feedforward, horizontal intracortical, and feedback connectivity. Since circuit-level analysis is particularly feasible in the mouse, we asked whether neural signatures of spatial integration in ...

  5. Approach motivation in human cerebral cortex

    OpenAIRE

    Casasanto, Daniel; Brookshire, Geoffrey

    2018-01-01

    Different regions of the human cerebral cortex are specialized for different emotions, but the principles underlying this specialization have remained unknown. According to the sword and shield hypothesis, hemispheric specialization for affective motivation, a basic dimension of human emotion, varies across individuals according to the way they use their hands to perform approach- and avoidance-related actions. In a test of this hypothesis, here we measured approach motivation before and afte...

  6. Bioacoustic Signal Classification in Cat Auditory Cortex

    Science.gov (United States)

    1994-01-01

    of the cat’s WINER. 1. A. Anatomy of layer IV in cat primary auditory cortex t4,1). J miedial geniculate body Ideintified by projections to binaural...34language" (see for example Tartter, 1986, chapter 8; and Lieberman, 1984). Attempts have been made to train animals (mainly apes, gorillas , _ _ ___I 3...gestures of a gorilla : Language acquisition in another Pongid. Brain and Language, 1978a, 5, 72-97. Patterson, F. Conversations with a gorilla

  7. Orbitofrontal cortex as a cognitive map of task space.

    Science.gov (United States)

    Wilson, Robert C; Takahashi, Yuji K; Schoenbaum, G; Niv, Yael

    2014-01-22

    Orbitofrontal cortex (OFC) has long been known to play an important role in decision making. However, the exact nature of that role has remained elusive. Here, we propose a unifying theory of OFC function. We hypothesize that OFC provides an abstraction of currently available information in the form of a labeling of the current task state, which is used for reinforcement learning (RL) elsewhere in the brain. This function is especially critical when task states include unobservable information, for instance, from working memory. We use this framework to explain classic findings in reversal learning, delayed alternation, extinction, and devaluation as well as more recent findings showing the effect of OFC lesions on the firing of dopaminergic neurons in ventral tegmental area (VTA) in rodents performing an RL task. In addition, we generate a number of testable experimental predictions that can distinguish our theory from other accounts of OFC function. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Properties of doublecortin-(DCX-expressing cells in the piriform cortex compared to the neurogenic dentate gyrus of adult mice.

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    Friederike Klempin

    Full Text Available The piriform cortex receives input from the olfactory bulb and (via the entorhinal cortex sends efferents to the hippocampus, thereby connecting the two canonical neurogenic regions of the adult rodent brain. Doublecortin (DCX is a cytoskeleton-associated protein that is expressed transiently in the course of adult neurogenesis. Interestingly, the adult piriform cortex, which is usually considered non-neurogenic (even though some reports exist that state otherwise, also contains an abundant population of DCX-positive cells. We asked how similar these cells would be to DCX-positive cells in the course of adult hippocampal neurogenesis. Using BAC-generated transgenic mice that express GFP under the DCX promoter, we studied DCX-expression and electrophysiological properties of DCX-positive cells in the mouse piriform cortex in comparison with the dentate gyrus. While one class of cells in the piriform cortex indeed showed features similar to newly generated immature granule neurons, the majority of DCX cells in the piriform cortex was mature and revealed large Na+ currents and multiple action potentials. Furthermore, when proliferative activity was assessed, we found that all DCX-expressing cells in the piriform cortex were strictly postmitotic, suggesting that no DCX-positive "neuroblasts" exist here as they do in the dentate gyrus. We conclude that DCX in the piriform cortex marks a unique population of postmitotic neurons with a subpopulation that retains immature characteristics associated with synaptic plasticity. DCX is thus, per se, no marker of neurogenesis but might be associated more broadly with plasticity.

  9. Visual cortex entrains to sign language.

    Science.gov (United States)

    Brookshire, Geoffrey; Lu, Jenny; Nusbaum, Howard C; Goldin-Meadow, Susan; Casasanto, Daniel

    2017-06-13

    Despite immense variability across languages, people can learn to understand any human language, spoken or signed. What neural mechanisms allow people to comprehend language across sensory modalities? When people listen to speech, electrophysiological oscillations in auditory cortex entrain to slow ([Formula: see text]8 Hz) fluctuations in the acoustic envelope. Entrainment to the speech envelope may reflect mechanisms specialized for auditory perception. Alternatively, flexible entrainment may be a general-purpose cortical mechanism that optimizes sensitivity to rhythmic information regardless of modality. Here, we test these proposals by examining cortical coherence to visual information in sign language. First, we develop a metric to quantify visual change over time. We find quasiperiodic fluctuations in sign language, characterized by lower frequencies than fluctuations in speech. Next, we test for entrainment of neural oscillations to visual change in sign language, using electroencephalography (EEG) in fluent speakers of American Sign Language (ASL) as they watch videos in ASL. We find significant cortical entrainment to visual oscillations in sign language sign is strongest over occipital and parietal cortex, in contrast to speech, where coherence is strongest over the auditory cortex. Nonsigners also show coherence to sign language, but entrainment at frontal sites is reduced relative to fluent signers. These results demonstrate that flexible cortical entrainment to language does not depend on neural processes that are specific to auditory speech perception. Low-frequency oscillatory entrainment may reflect a general cortical mechanism that maximizes sensitivity to informational peaks in time-varying signals.

  10. Does intrinsic motivation enhance motor cortex excitability?

    Science.gov (United States)

    Radel, Rémi; Pjevac, Dusan; Davranche, Karen; d'Arripe-Longueville, Fabienne; Colson, Serge S; Lapole, Thomas; Gruet, Mathieu

    2016-11-01

    Intrinsic motivation (IM) is often viewed as a spontaneous tendency for action. Recent behavioral and neuroimaging evidence indicate that IM, in comparison to extrinsic motivation (EM), solicits the motor system. Accordingly, we tested whether IM leads to greater excitability of the motor cortex than EM. To test this hypothesis, we used two different tasks to induce the motivational orientation using either words representing each motivational orientation or pictures previously linked to each motivational orientation through associative learning. Single-pulse transcranial magnetic stimulation over the motor cortex was applied when viewing the stimuli. Electromyographic activity was recorded on the contracted first dorsal interosseous muscle. Two indexes of corticospinal excitability (the amplitude of motor-evoked potential and the length of cortical silent period) were obtained through unbiased automatic detection and analyzed using a mixed model that provided both statistical power and a high level of control over all important individual, task, and stimuli characteristics. Across the two tasks and the two indices of corticospinal excitability, the exposure to IM-related stimuli did not lead to a greater corticospinal excitability than EM-related stimuli or than stimuli with no motivational valence (ps > .20). While these results tend to dismiss the advantage of IM at activating the motor cortex, we suggest alternative hypotheses to explain this lack of effect, which deserves further research. © 2016 Society for Psychophysiological Research.

  11. Amodal processing in human prefrontal cortex.

    Science.gov (United States)

    Tamber-Rosenau, Benjamin J; Dux, Paul E; Tombu, Michael N; Asplund, Christopher L; Marois, René

    2013-07-10

    Information enters the cortex via modality-specific sensory regions, whereas actions are produced by modality-specific motor regions. Intervening central stages of information processing map sensation to behavior. Humans perform this central processing in a flexible, abstract manner such that sensory information in any modality can lead to response via any motor system. Cognitive theories account for such flexible behavior by positing amodal central information processing (e.g., "central executive," Baddeley and Hitch, 1974; "supervisory attentional system," Norman and Shallice, 1986; "response selection bottleneck," Pashler, 1994). However, the extent to which brain regions embodying central mechanisms of information processing are amodal remains unclear. Here we apply multivariate pattern analysis to functional magnetic resonance imaging (fMRI) data to compare response selection, a cognitive process widely believed to recruit an amodal central resource across sensory and motor modalities. We show that most frontal and parietal cortical areas known to activate across a wide variety of tasks code modality, casting doubt on the notion that these regions embody a central processor devoid of modality representation. Importantly, regions of anterior insula and dorsolateral prefrontal cortex consistently failed to code modality across four experiments. However, these areas code at least one other task dimension, process (instantiated as response selection vs response execution), ensuring that failure to find coding of modality is not driven by insensitivity of multivariate pattern analysis in these regions. We conclude that abstract encoding of information modality is primarily a property of subregions of the prefrontal cortex.

  12. Hemodynamic Responses on Prefrontal Cortex Related to Meditation and Attentional Task

    Directory of Open Access Journals (Sweden)

    Singh eDeepeshwar

    2015-02-01

    Full Text Available Recent neuroimaging studies state that meditation increases regional cerebral blood flow (rCBF in the prefrontal cortex (PFC. The present study employed functional near infrared spectroscopy (fNIRS to evaluate the relative hemodynamic changes in prefrontal cortex during a cognitive task. Twenty-two healthy male volunteers with ages between 18 and 30 years (group mean age ± SD; 22.9 ± 4.6 years performed a color-word stroop task before and after 20 minutes of meditation and random thinking. Repeated measures ANOVA was performed followed by a post-hoc analysis with Bonferroni adjustment for multiple comparisons between the mean values of ‘During’ and ‘Post’ with ‘Pre’ state. During meditation there was an increased in oxy-hemoglobin (∆HbO and total hemoglobin (∆THC concentration with reduced deoxy-hemoglobin (∆HbR concentration over the right prefrontal cortex (rPFC, whereas in random thinking there was increased ∆HbR with reduced total hemoglobin concentration on the rPFC. The mean reaction time was shorter in stroop color word task with reduced ∆THC after meditation, suggestive of improved performance and efficiency in task related to attention. Our findings demonstrated that meditation increased cerebral oxygenation and enhanced performance, which was associated with prefrontal cortex activation.

  13. Impairment in judgement of the moral emotion guilt following orbitofrontal cortex damage.

    Science.gov (United States)

    Funayama, Michitaka; Koreki, Akihiro; Muramatsu, Taro; Mimura, Masaru; Kato, Motoichiro; Abe, Takayuki

    2018-04-19

    Although neuroimaging studies have provided evidence for an association between moral emotions and the orbitofrontal cortex, studies on patients with focal lesions using experimental probes of moral emotions are scarce. Here, we addressed this topic by presenting a moral emotion judgement task to patients with focal brain damage. Four judgement tasks in a simple pairwise choice paradigm were given to 72 patients with cerebrovascular disease. These tasks consisted of a perceptual line judgement task as a control task; the objects' preference task as a basic preference judgement task; and two types of moral emotion judgement task, an anger task and a guilt task. A multiple linear regression analysis was performed on each set of task performance scores to take into account potential confounders. Performance on the guilt emotion judgement task negatively correlated with the orbitofrontal cortex damage, but not with the other variables. Results for the other judgement tasks did not reach statistical significance. The close association between orbitofrontal cortex damage and a decrease in guilt emotion judgement consistency might suggest that the orbitofrontal cortex plays a key role in the sense of guilt, a hallmark of morality. © 2018 The British Psychological Society.

  14. Occipital cortex of blind individuals is functionally coupled with executive control areas of frontal cortex.

    Science.gov (United States)

    Deen, Ben; Saxe, Rebecca; Bedny, Marina

    2015-08-01

    In congenital blindness, the occipital cortex responds to a range of nonvisual inputs, including tactile, auditory, and linguistic stimuli. Are these changes in functional responses to stimuli accompanied by altered interactions with nonvisual functional networks? To answer this question, we introduce a data-driven method that searches across cortex for functional connectivity differences across groups. Replicating prior work, we find increased fronto-occipital functional connectivity in congenitally blind relative to blindfolded sighted participants. We demonstrate that this heightened connectivity extends over most of occipital cortex but is specific to a subset of regions in the inferior, dorsal, and medial frontal lobe. To assess the functional profile of these frontal areas, we used an n-back working memory task and a sentence comprehension task. We find that, among prefrontal areas with overconnectivity to occipital cortex, one left inferior frontal region responds to language over music. By contrast, the majority of these regions responded to working memory load but not language. These results suggest that in blindness occipital cortex interacts more with working memory systems and raise new questions about the function and mechanism of occipital plasticity.

  15. Comparative density of CCK- and PV-GABA cells within the cortex and hippocampus

    Directory of Open Access Journals (Sweden)

    Paul David Whissell

    2015-09-01

    Full Text Available Cholecystokinin (CCK- and parvalbumin (PV-expressing neurons constitute the two major populations of perisomatic GABAergic neurons in the cortex and the hippocampus. As CCK- and PV-GABA neurons differ in an array of morphological, biochemical and electrophysiological features, it has been proposed that they form distinct inhibitory ensembles which differentially contribute to network oscillations and behaviour. However, the relationship and balance between CCK- and PV-GABA neurons in the inhibitory networks of the brain is currently unclear as the distribution of these cells has never been compared on a large scale. Here, we systemically investigated the distribution of CCK- and PV-GABA cells across a wide number of discrete forebrain regions using an intersectional genetic approach. Our analysis revealed several novel trends in the distribution of these cells. While PV-GABA cells were more abundant overall, CCK-GABA cells outnumbered PV-GABA cells in several subregions of the hippocampus, medial prefrontal cortex and ventrolateral temporal cortex. Interestingly, CCK-GABA cells were relatively more abundant in secondary/association areas of the cortex (V2, S2, M2, and AudD/AudV than they were in corresponding primary areas (V1, S1, M1 and Aud1. The reverse trend was observed for PV-GABA cells. Our findings suggest that the balance between CCK- and PV-GABA cells in a given cortical region is related to the type of processing that area performs; inhibitory networks in the secondary cortex tend to favour the inclusion of CCK-GABA cells more than networks in the primary cortex. The intersectional genetic labelling approach employed in the current study expands upon the ability to study molecularly defined subsets of GABAergic neurons. This technique can be applied to the investigation of neuropathologies which involve disruptions to the GABAergic system, including schizophrenia, stress, maternal immune activation and autism.

  16. Anisotropy of ongoing neural activity in the primate visual cortex

    Directory of Open Access Journals (Sweden)

    Maier A

    2014-09-01

    Full Text Available Alexander Maier,1 Michele A Cox,1 Kacie Dougherty,1 Brandon Moore,1 David A Leopold2 1Department of Psychology, College of Arts and Science, Vanderbilt University, Nashville, TN, USA; 2Section on Cognitive Neurophysiology and Imaging, National Institute of Mental Health, National Institute of Health, Bethesda, MD, USA Abstract: The mammalian neocortex features distinct anatomical variation in its tangential and radial extents. This review consolidates previously published findings from our group in order to compare and contrast the spatial profile of neural activity coherence across these distinct cortical dimensions. We focus on studies of ongoing local field potential (LFP data obtained simultaneously from multiple sites in the primary visual cortex in two types of experiments in which electrode contacts were spaced either along the cortical surface or at different laminar positions. These studies demonstrate that across both dimensions the coherence of ongoing LFP fluctuations diminishes as a function of interelectrode distance, although the nature and spatial scale of this falloff is very different. Along the cortical surface, the overall LFP coherence declines gradually and continuously away from a given position. In contrast, across the cortical layers, LFP coherence is discontinuous and compartmentalized as a function of depth. Specifically, regions of high LFP coherence fall into discrete superficial and deep laminar zones, with an abrupt discontinuity between the granular and infragranular layers. This spatial pattern of ongoing LFP coherence is similar when animals are at rest and when they are engaged in a behavioral task. These results point to the existence of partially segregated laminar zones of cortical processing that extend tangentially within the laminar compartments and are thus oriented orthogonal to the cortical columns. We interpret these electrophysiological observations in light of the known anatomical organization of

  17. Encoding of temporal intervals in the rat hindlimb sensorimotor cortex

    Directory of Open Access Journals (Sweden)

    Eric Bean Knudsen

    2012-09-01

    Full Text Available The gradual buildup of neural activity over experimentally imposed delay periods, termed climbing activity, is well documented and is a potential mechanism by which interval time is encoded by distributed cortico-thalamico-striatal networks in the brain. Additionally, when multiple delay periods are incorporated, this activity has been shown to scale its rate of climbing proportional to the delay period. However, it remains unclear whether these patterns of activity occur within areas of motor cortex dedicated to hindlimb movement. Moreover, the effects of behavioral training (e.g. motor tasks under different reward conditions but with similar behavioral output are not well addressed. To address this, we recorded activity from the hindlimb sensorimotor cortex (HLSMC of two groups of rats performing a skilled hindlimb press task. In one group, rats were trained only to a make a valid press within a finite window after cue presentation for reward (non-interval trained, nIT; n=5, while rats in the second group were given duration-specific cues in which they had to make presses of either short or long duration to receive reward (interval trained, IT; n=6. Using PETH analyses, we show that cells recorded from both groups showed climbing activity during the task in similar proportions (35% IT and 47% nIT, however only climbing activity from IT rats was temporally scaled to press duration. Furthermore, using single trial decoding techniques (Wiener filter, we show that press duration can be inferred using climbing activity from IT animals (R=0.61 significantly better than nIT animals (R=0.507, p<0.01, suggesting IT animals encode press duration through temporally scaled climbing activity. Thus, if temporal intervals are behaviorally relevant then the activity of climbing neurons is temporally scaled to encode the passage of time.

  18. Multiple sclerosis

    International Nuclear Information System (INIS)

    Grunwald, I.Q.; Kuehn, A.L.; Backens, M.; Papanagiotou, P.; Shariat, K.; Kostopoulos, P.

    2008-01-01

    Multiple sclerosis is the most common chronic inflammatory disease of myelin with interspersed lesions in the white matter of the central nervous system. Magnetic resonance imaging (MRI) plays a key role in the diagnosis and monitoring of white matter diseases. This article focuses on key findings in multiple sclerosis as detected by MRI. (orig.) [de

  19. Treatment of Multiple Sclerosis

    OpenAIRE

    Bošnjak-Pašić, Marija; Vidrih, Branka; Miškov, Snježana; Demarin, Vida

    2009-01-01

    Multiple sclerosis is an autoimmune inflammatory demyelinating disease of the central nervous system, characterized by multifocal inflammatory destruction of myelin, axonal damage and loss of oligodendrocytes. The disease is carried through two stages: inflammatory and degenerative. The most common form of disease in approximately 85% of the cases is RRMS (relapsing-remitting form). The treatment of MS is divided into: treatment of the acute phase of illness, prevention of new relapses and di...

  20. The role of human ventral visual cortex in motion perception

    Science.gov (United States)

    Saygin, Ayse P.; Lorenzi, Lauren J.; Egan, Ryan; Rees, Geraint; Behrmann, Marlene

    2013-01-01

    Visual motion perception is fundamental to many aspects of visual perception. Visual motion perception has long been associated with the dorsal (parietal) pathway and the involvement of the ventral ‘form’ (temporal) visual pathway has not been considered critical for normal motion perception. Here, we evaluated this view by examining whether circumscribed damage to ventral visual cortex impaired motion perception. The perception of motion in basic, non-form tasks (motion coherence and motion detection) and complex structure-from-motion, for a wide range of motion speeds, all centrally displayed, was assessed in five patients with a circumscribed lesion to either the right or left ventral visual pathway. Patients with a right, but not with a left, ventral visual lesion displayed widespread impairments in central motion perception even for non-form motion, for both slow and for fast speeds, and this held true independent of the integrity of areas MT/V5, V3A or parietal regions. In contrast with the traditional view in which only the dorsal visual stream is critical for motion perception, these novel findings implicate a more distributed circuit in which the integrity of the right ventral visual pathway is also necessary even for the perception of non-form motion. PMID:23983030

  1. Contributor Form

    Directory of Open Access Journals (Sweden)

    Chief Editor

    2014-09-01

    to produce preprints or reprints and translate into languages other than English for sale or free distribution; and 4 the right to republish the work in a collection of articles in any other mechanical or electronic format. We give the rights to the corresponding author to make necessary changes as per the request of the journal, do the rest of the correspondence on our behalf and he/she will act as the guarantor for the manuscript on our behalf. All persons who have made substantial contributions to the work reported in the manuscript, but who are not contributors, are named in the Acknowledgment and have given me/us their written permission to be named. If I/we do not include an Acknowledgment that means I/we have not received substantial contributions from non-contributors and no contributor has been omitted.S NoAuthors' NamesContribution (IJCME Guidelines{1 substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; 2 drafting the article or revising it critically for important intellectual content; and 3 final approval of the version to be published. Authors should meet conditions 1, 2, and 3}.SignatureDate                              Note: All the authors are required to sign independently in this form in the sequence given above. In case an author has left the institution/country and whose whereabouts are not known, the senior author may sign on his/her behalf taking the responsibility.No addition/deletion/ or any change in the sequence of the authorship will be permissible at a later stage, without valid reasons and permission of the Editor.If the authorship is contested at any stage, the article will be either returned or will not be processed for publication till the issue is solved.Maximum up to 4 authors for short communication and up to 6 authors for original article.

  2. Contributors Form

    Directory of Open Access Journals (Sweden)

    Chief Editor

    2016-06-01

    to produce preprints or reprints and translate into languages other than English for sale or free distribution; and 4 the right to republish the work in a collection of articles in any other mechanical or electronic format. We give the rights to the corresponding author to make necessary changes as per the request of the journal, do the rest of the correspondence on our behalf and he/she will act as the guarantor for the manuscript on our behalf. All persons who have made substantial contributions to the work reported in the manuscript, but who are not contributors, are named in the Acknowledgment and have given me/us their written permission to be named. If I/we do not include an Acknowledgment that means I/we have not received substantial contributions from non-contributors and no contributor has been omitted.S NoAuthors' NamesContribution (IJCME Guidelines{1 substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; 2 drafting the article or revising it critically for important intellectual content; and 3 final approval of the version to be published. Authors should meet conditions 1, 2, and 3}.SignatureDate                              Note: All the authors are required to sign independently in this form in the sequence given above. In case an author has left the institution/country and whose whereabouts are not known, the senior author may sign on his/her behalf taking the responsibility.No addition/deletion/ or any change in the sequence of the authorship will be permissible at a later stage, without valid reasons and permission of the Editor.If the authorship is contested at any stage, the article will be either returned or will not be processed for publication till the issue is solved.Maximum up to 4 authors for short communication and up to 6 authors for original article.

  3. Saturation in Phosphene Size with Increasing Current Levels Delivered to Human Visual Cortex.

    Science.gov (United States)

    Bosking, William H; Sun, Ping; Ozker, Muge; Pei, Xiaomei; Foster, Brett L; Beauchamp, Michael S; Yoshor, Daniel

    2017-07-26

    Electrically stimulating early visual cortex results in a visual percept known as a phosphene. Although phosphenes can be evoked by a wide range of electrode sizes and current amplitudes, they are invariably described as small. To better understand this observation, we electrically stimulated 93 electrodes implanted in the visual cortex of 13 human subjects who reported phosphene size while stimulation current was varied. Phosphene size increased as the stimulation current was initially raised above threshold, but then rapidly reached saturation. Phosphene size also depended on the location of the stimulated site, with size increasing with distance from the foveal representation. We developed a model relating phosphene size to the amount of activated cortex and its location within the retinotopic map. First, a sigmoidal curve was used to predict the amount of activated cortex at a given current. Second, the amount of active cortex was converted to degrees of visual angle by multiplying by the inverse cortical magnification factor for that retinotopic location. This simple model accurately predicted phosphene size for a broad range of stimulation currents and cortical locations. The unexpected saturation in phosphene sizes suggests that the functional architecture of cerebral cortex may impose fundamental restrictions on the spread of artificially evoked activity and this may be an important consideration in the design of cortical prosthetic devices. SIGNIFICANCE STATEMENT Understanding the neural basis for phosphenes, the visual percepts created by electrical stimulation of visual cortex, is fundamental to the development of a visual cortical prosthetic. Our experiments in human subjects implanted with electrodes over visual cortex show that it is the activity of a large population of cells spread out across several millimeters of tissue that supports the perception of a phosphene. In addition, we describe an important feature of the production of phosphenes by

  4. Exposure to Inorganic Mercury Causes Oxidative Stress, Cell Death, and Functional Deficits in the Motor Cortex.

    Science.gov (United States)

    Teixeira, Francisco B; de Oliveira, Ana C A; Leão, Luana K R; Fagundes, Nathália C F; Fernandes, Rafael M; Fernandes, Luanna M P; da Silva, Márcia C F; Amado, Lilian L; Sagica, Fernanda E S; de Oliveira, Edivaldo H C; Crespo-Lopez, Maria E; Maia, Cristiane S F; Lima, Rafael R

    2018-01-01

    Mercury is a toxic metal that can be found in the environment in three different forms - elemental, organic and inorganic. Inorganic mercury has a lower liposolubility, which results in a lower organism absorption and reduced passage through the blood-brain barrier. For this reason, exposure models that use inorganic mercury in rats in order to evaluate its effects on the central nervous system are rare, especially in adult subjects. This study investigated if a chronic exposure to low doses of mercury chloride (HgCl2), an inorganic form of mercury, is capable of promoting motor alterations and neurodegenerative in the motor cortex of adult rats. Forty animals were exposed to a dose of 0.375 mg/kg/day, for 45 days. They were then submitted to motor evaluation and euthanized to collect the motor cortex. Measurement of mercury deposited in the brain parenchyma, evaluation of oxidative balance, quantification of cellular cytotoxicity and apoptosis and density of mature neurons and astrocytes of the motor cortex were performed. It was observed that chronic exposure to inorganic mercury caused a decrease in balance and fine motor coordination, formation of mercury deposits and oxidative stress verified by the increase of lipoperoxidation and nitrite concentration and a decrease of the total antioxidant capacity. In addition, we found that this model of exposure to inorganic mercury caused cell death by cytotoxicity and induction of apoptosis with a decreased number of neurons and astrocytes in the motor cortex. Our results provide evidence that exposure to inorganic mercury in low doses, even in spite of its poor ability to cross biological barriers, is still capable of inducing motor deficits, cell death by cytotoxicity and apoptosis, and oxidative stress in the motor cortex of adult rats.

  5. Exposure to Inorganic Mercury Causes Oxidative Stress, Cell Death, and Functional Deficits in the Motor Cortex

    Directory of Open Access Journals (Sweden)

    Francisco B. Teixeira

    2018-05-01

    Full Text Available Mercury is a toxic metal that can be found in the environment in three different forms – elemental, organic and inorganic. Inorganic mercury has a lower liposolubility, which results in a lower organism absorption and reduced passage through the blood–brain barrier. For this reason, exposure models that use inorganic mercury in rats in order to evaluate its effects on the central nervous system are rare, especially in adult subjects. This study investigated if a chronic exposure to low doses of mercury chloride (HgCl2, an inorganic form of mercury, is capable of promoting motor alterations and neurodegenerative in the motor cortex of adult rats. Forty animals were exposed to a dose of 0.375 mg/kg/day, for 45 days. They were then submitted to motor evaluation and euthanized to collect the motor cortex. Measurement of mercury deposited in the brain parenchyma, evaluation of oxidative balance, quantification of cellular cytotoxicity and apoptosis and density of mature neurons and astrocytes of the motor cortex were performed. It was observed that chronic exposure to inorganic mercury caused a decrease in balance and fine motor coordination, formation of mercury deposits and oxidative stress verified by the increase of lipoperoxidation and nitrite concentration and a decrease of the total antioxidant capacity. In addition, we found that this model of exposure to inorganic mercury caused cell death by cytotoxicity and induction of apoptosis with a decreased number of neurons and astrocytes in the motor cortex. Our results provide evidence that exposure to inorganic mercury in low doses, even in spite of its poor ability to cross biological barriers, is still capable of inducing motor deficits, cell death by cytotoxicity and apoptosis, and oxidative stress in the motor cortex of adult rats.

  6. Origins of the specialization for letters and numbers in ventral occipitotemporal cortex.

    Science.gov (United States)

    Hannagan, Thomas; Amedi, Amir; Cohen, Laurent; Dehaene-Lambertz, Ghislaine; Dehaene, Stanislas

    2015-07-01

    Deep in the occipitotemporal cortex lie two functional regions, the visual word form area (VWFA) and the number form area (NFA), which are thought to play a special role in letter and number recognition, respectively. We review recent progress made in characterizing the origins of these symbol form areas in children or adults, sighted or blind subjects, and humans or monkeys. We propose two non-mutually-exclusive hypotheses on the origins of the VWFA and NFA: the presence of a connectivity bias, and a sensitivity to shape features. We assess the explanatory power of these hypotheses, describe their consequences, and offer several experimental tests. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Linear summation of outputs in a balanced network model of motor cortex.

    Science.gov (United States)

    Capaday, Charles; van Vreeswijk, Carl

    2015-01-01

    Given the non-linearities of the neural circuitry's elements, we would expect cortical circuits to respond non-linearly when activated. Surprisingly, when two points in the motor cortex are activated simultaneously, the EMG responses are the linear sum of the responses evoked by each of the points activated separately. Additionally, the corticospinal transfer function is close to linear, implying that the synaptic interactions in motor cortex must be effectively linear. To account for this, here we develop a model of motor cortex composed of multiple interconnected points, each comprised of reciprocally connected excitatory and inhibitory neurons. We show how non-linearities in neuronal transfer functions are eschewed by strong synaptic interactions within each point. Consequently, the simultaneous activation of multiple points results in a linear summation of their respective outputs. We also consider the effects of reduction of inhibition at a cortical point when one or more surrounding points are active. The network response in this condition is linear over an approximately two- to three-fold decrease of inhibitory feedback strength. This result supports the idea that focal disinhibition allows linear coupling of motor cortical points to generate movement related muscle activation patterns; albeit with a limitation on gain control. The model also explains why neural activity does not spread as far out as the axonal connectivity allows, whilst also explaining why distant cortical points can be, nonetheless, functionally coupled by focal disinhibition. Finally, we discuss the advantages that linear interactions at the cortical level afford to motor command synthesis.

  8. Multiple homicides.

    Science.gov (United States)

    Copeland, A R

    1989-09-01

    A study of multiple homicides or multiple deaths involving a solitary incident of violence by another individual was performed on the case files of the Office of the Medical Examiner of Metropolitan Dade County in Miami, Florida, during 1983-1987. A total of 107 multiple homicides were studied: 88 double, 17 triple, one quadruple, and one quintuple. The 236 victims were analyzed regarding age, race, sex, cause of death, toxicologic data, perpetrator, locale of the incident, and reason for the incident. This article compares this type of slaying with other types of homicide including those perpetrated by serial killers. Suggestions for future research in this field are offered.

  9. Contextual Learning Induces Dendritic Spine Clustering in Retrosplenial Cortex

    Directory of Open Access Journals (Sweden)

    Adam C Frank

    2014-03-01

    Full Text Available Molecular and electrophysiological studies find convergent evidence suggesting that plasticity within a dendritic tree is not randomly dispersed, but rather clustered into functional groups. Further, results from in silico neuronal modeling show that clustered plasticity is able to increase storage capacity 45 times compared to dispersed plasticity. Recent in vivo work utilizing chronic 2-photon microscopy tested the clustering hypothesis and showed that repetitive motor learning is able to induce clustered addition of new dendritic spines on apical dendrites of L5 neurons in primary motor cortex; moreover, clustered spines were found to be more stable than non-clustered spines, suggesting a physiological role for spine clustering. To further test this hypothesis we used in vivo 2-photon imaging in Thy1-YFP-H mice to chronically examine dendritic spine dynamics in retrosplenial cortex (RSC during spatial learning. RSC is a key component of an extended spatial learning and memory circuit that includes hippocampus and entorhinal cortex. Importantly, RSC is known from both lesion and immediate early gene studies to be critically involved in spatial learning and more specifically in contextual fear conditioning. We utilized a modified contextual fear conditioning protocol wherein animals received a mild foot shock each day for five days; this protocol induces gradual increases in context freezing over several days before the animals reach a behavioral plateau. We coupled behavioral training with four separate in vivo imaging sessions, two before training begins, one early in training, and a final session after training is complete. This allowed us to image spine dynamics before training as well as early in learning and after animals had reached behavioral asymptote. We find that this contextual learning protocol induces a statistically significant increase in the formation of clusters of new dendritic spines in trained animals when compared to home

  10. Resolving the organization of the third tier visual cortex in primates: a hypothesis-based approach.

    Science.gov (United States)

    Angelucci, Alessandra; Rosa, Marcello G P

    2015-01-01

    As highlighted by several contributions to this special issue, there is still ongoing debate about the number, exact location, and boundaries of the visual areas located in cortex immediately rostral to the second visual area (V2), i.e., the "third tier" visual cortex, in primates. In this review, we provide a historical overview of the main ideas that have led to four models of third tier cortex organization, which are at the center of today's debate. We formulate specific predictions of these models, and compare these predictions with experimental evidence obtained primarily in New World primates. From this analysis, we conclude that only one of these models (the "multiple-areas" model) can accommodate the breadth of available experimental evidence. According to this model, most of the third tier cortex in New World primates is occupied by two distinct areas, both representing the full contralateral visual quadrant: the dorsomedial area (DM), restricted to the dorsal half of the third visual complex, and the ventrolateral posterior area (VLP), occupying its ventral half and a substantial fraction of its dorsal half. DM belongs to the dorsal stream of visual processing, and overlaps with macaque parietooccipital (PO) area (or V6), whereas VLP belongs to the ventral stream and overlaps considerably with area V3 proposed by others. In contrast, there is substantial evidence that is inconsistent with the concept of a single elongated area V3 lining much of V2. We also review the experimental evidence from macaque monkey and humans, and propose that, once the data are interpreted within an evolutionary-developmental context, these species share a homologous (but not necessarily identical) organization of the third tier cortex as that observed in New World monkeys. Finally, we identify outstanding issues, and propose experiments to resolve them, highlighting in particular the need for more extensive, hypothesis-driven investigations in macaque and humans.

  11. Effect of prenatal exposure to ethanol on the development of cerebral cortex: I. Neuronal generation

    International Nuclear Information System (INIS)

    Miller, M.W.

    1988-01-01

    Prenatal exposure to ethanol causes profound disruptions in the development of the cerebral cortex. Therefore, the effect of in utero ethanol exposure on the generation of neurons was determined. Pregnant rats were fed a liquid diet in which ethanol constituted 37.5% of the total caloric content (Et) or pair-fed an isocaloric control diet (Ct) from gestational day (GD) 6 to the day of birth. The time of origin of cortical neurons was determined in the mature pups of females injected with [3H]thymidine on one day during the period from GD 10 to the day of birth. The brains were processed by standard autoradiographic techniques. Ethanol exposure produced multiple defects in neuronal ontogeny. The period of generation was 1-2 days later for Et-treated rats than for rats exposed prenatally to either control diet. Moreover, the generation period was 1-2 days longer in Et-treated rats. The numbers of neurons generated on a specific day was altered; from GD 12-19 significantly fewer neurons were generated in Et-treated rats than in Ct-treated rats, whereas after GD 19 more neurons were born. The distribution of neurons generated on a specific day was disrupted; most notable was the distribution of late-generated neurons in deep cortex of Et-treated rats rather than in superficial cortex as they are in controls. Cortical neurons in Et-treated rats tended to be smaller than in Ct-treated rats, particularly early generated neurons in deep cortex. The late-generated neurons in Et-treated rats were of similar size to those in Ct-treated rats despite their abnormal position in deep cortex. Neurons in Ct-treated rats tended to be rounder than those in Et-treated rats which were more polarized in the radial orientation

  12. Developmental changes in GABAergic mechanisms in human visual cortex across the lifespan

    Directory of Open Access Journals (Sweden)

    Joshua G A Pinto

    2010-06-01

    Full Text Available Functional maturation of visual cortex is linked with dynamic changes in synaptic expression of GABAergic mechanisms. These include setting the excitation-inhibition balance required for experience-dependent plasticity, as well as, intracortical inhibition underlying development and aging of receptive field properties. Animal studies have shown developmental regulation of GABAergic mechanisms in visual cortex. In this study, we show for the first time how these mechanisms develop in the human visual cortex across the lifespan. We used Western blot analysis of postmortem tissue from human primary visual cortex (n=30, range: 20 days to 80 years to quantify expression of 8 pre- and post-synaptic GABAergic markers. We quantified the inhibitory modulating cannabinoid receptor (CB1, GABA vesicular transporter (VGAT, GABA synthesizing enzymes (GAD65/GAD67, GABAA receptor anchoring protein (Gephyrin, and GABAA receptor subunits (GABAA∝1, GABAA∝2, GABAA∝3. We found a complex pattern of changes, many of which were prolonged and continued well into into the teen, young adult, and even older adult years. These included a monotonic increase or decrease (GABAA∝1, GABAA∝2, a biphasic increase then decrease (GAD65, Gephyrin, or multiple increases and decreases (VGAT, CB1 across the lifespan. Comparing the balances between the pre- and post-synaptic markers we found 3 main transitions (early childhood, early teen years, aging when there were rapid switches in the composition of the GABAergic signaling system, indicating that functioning of the GABAergic system must change as the visual cortex develops and ages. Furthermore, these results provide key information for translating therapies developed in animal models into effective treatments for amblyopia in humans.

  13. Early sensitivity of left perisylvian cortex to relationality in nouns and verbs.

    Science.gov (United States)

    Williams, Adina; Reddigari, Samir; Pylkkänen, Liina

    2017-06-01

    The ability to track the relationality of concepts, i.e., their capacity to encode a relationship between entities, is one of the core semantic abilities humans possess. In language processing, we systematically leverage this ability when computing verbal argument structure, in order to link participants to the events they participate in. Previous work has converged on a large region of left posterior perisylvian cortex as a locus for such processing, but the wide range of experimental stimuli and manipulations has yielded an unclear picture of the region's exact role(s). Importantly, there is a tendency for effects of relationality in single-word studies to localize to posterior temporo-parietal cortex, while argument structure effects in sentences appear in left superior temporal cortex. To characterize these sensitivities, we designed two MEG experiments that cross the factors relationality and eventivity. The first used minimal noun phrases and tested for an effect of semantic composition, while the second employed full sentences and a manipulation of grammatical category. The former identified a region of the left inferior parietal lobe sensitive to relationality, but not eventivity or combination, beginning at 170ms. The latter revealed a similarly-timed effect of relationality in left mid-superior temporal cortex, independent of eventivity and category. The results suggest that i) multiple sub-regions of perisylvian cortex are sensitive to the relationality carried by concepts even in the absence of arguments, ii) linguistic context modulates the locus of this sensitivity, consistent with prior studies, and iii) relationality information is accessed early - before 200ms - regardless of the concept's event status or syntactic category. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Fluid consumption and taste novelty determines transcription temporal dynamics in the gustatory cortex

    OpenAIRE

    Inberg, Sharon; Jacob, Eyal; Elkobi, Alina; Edry, Efrat; Rappaport, Akiva; Simpson, T. Ian; Armstrong, J. Douglas; Shomron, Noam; Pasmanik-Chor, Metsada; Rosenblum, Kobi

    2016-01-01

    Background Novel taste memories, critical for animal survival, are consolidated to form long term memories which are dependent on translation regulation in the gustatory cortex (GC) hours following acquisition. However, the role of transcription regulation in the process is unknown. Results Here, we report that transcription in the GC is necessary for taste learning in rats, and that drinking and its consequences, as well as the novel taste experience, affect transcription in the GC during ta...

  15. The Parahippocampal Cortex Mediates Contextual Associative Memory: Evidence from an fMRI Study

    OpenAIRE

    Li, Mi; Lu, Shengfu; Zhong, Ning

    2016-01-01

    The parahippocampal cortex (PHC) plays a key role in episodic memory, spatial processing, and the encoding of novel stimuli. Recent studies proposed that the PHC is largely involved in contextual associative processing. Consequently, the function of this region has been a hot debate in cognitive neuroscience. To test this assumption, we used two types of experimental materials to form the contextual associative memory: visual objects in reality and meaningless visual shapes. New associations ...

  16. Congenital Deafness Reduces, But Does Not Eliminate Auditory Responsiveness in Cat Extrastriate Visual Cortex.

    Science.gov (United States)

    Land, Rüdiger; Radecke, Jan-Ole; Kral, Andrej

    2018-04-01

    Congenital deafness not only affects the development of the auditory cortex, but also the interrelation between the visual and auditory system. For example, congenital deafness leads to visual modulation of the deaf auditory cortex in the form of cross-modal plasticity. Here we asked, whether congenital deafness additionally affects auditory modulation in the visual cortex. We demonstrate that auditory activity, which is normally present in the lateral suprasylvian visual areas in normal hearing cats, can also be elicited by electrical activation of the auditory system with cochlear implants. We then show that in adult congenitally deaf cats auditory activity in this region was reduced when tested with cochlear implant stimulation. However, the change in this area was small and auditory activity was not completely abolished despite years of congenital deafness. The results document that congenital deafness leads not only to changes in the auditory cortex but also affects auditory modulation of visual areas. However, the results further show a persistence of fundamental cortical sensory functional organization despite congenital deafness. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Multiple Sclerosis

    Science.gov (United States)

    Multiple sclerosis (MS) is a nervous system disease that affects your brain and spinal cord. It damages the myelin sheath, the material that surrounds and protects your nerve cells. This damage slows down ...

  18. Multiple myeloma.

    LENUS (Irish Health Repository)

    Collins, Conor D

    2012-02-01

    Advances in the imaging and treatment of multiple myeloma have occurred over the past decade. This article summarises the current status and highlights how an understanding of both is necessary for optimum management.

  19. Multiple mononeuropathy

    Science.gov (United States)

    ... with multiple mononeuropathy are prone to new nerve injuries at pressure points such as the knees and elbows. They should avoid putting pressure on these areas, for example, by not leaning on the elbows, crossing the knees, ...

  20. Predicting Spike Occurrence and Neuronal Responsiveness from LFPs in Primary Somatosensory Cortex

    Science.gov (United States)

    Storchi, Riccardo; Zippo, Antonio G.; Caramenti, Gian Carlo; Valente, Maurizio; Biella, Gabriele E. M.

    2012-01-01

    Local Field Potentials (LFPs) integrate multiple neuronal events like synaptic inputs and intracellular potentials. LFP spatiotemporal features are particularly relevant in view of their applications both in research (e.g. for understanding brain rhythms, inter-areal neural communication and neronal coding) and in the clinics (e.g. for improving invasive Brain-Machine Interface devices). However the relation between LFPs and spikes is complex and not fully understood. As spikes represent the fundamental currency of neuronal communication this gap in knowledge strongly limits our comprehension of neuronal phenomena underlying LFPs. We investigated the LFP-spike relation during tactile stimulation in primary somatosensory (S-I) cortex in the rat. First we quantified how reliably LFPs and spikes code for a stimulus occurrence. Then we used the information obtained from our analyses to design a predictive model for spike occurrence based on LFP inputs. The model was endowed with a flexible meta-structure whose exact form, both in parameters and structure, was estimated by using a multi-objective optimization strategy. Our method provided a set of nonlinear simple equations that maximized the match between models and true neurons in terms of spike timings and Peri Stimulus Time Histograms. We found that both LFPs and spikes can code for stimulus occurrence with millisecond precision, showing, however, high variability. Spike patterns were predicted significantly above chance for 75% of the neurons analysed. Crucially, the level of prediction accuracy depended on the reliability in coding for the stimulus occurrence. The best predictions were obtained when both spikes and LFPs were highly responsive to the stimuli. Spike reliability is known to depend on neuron intrinsic properties (i.e. on channel noise) and on spontaneous local network fluctuations. Our results suggest that the latter, measured through the LFP response variability, play a dominant role. PMID:22586452

  1. Monocular Visual Deprivation Suppresses Excitability in Adult Human Visual Cortex

    DEFF Research Database (Denmark)

    Lou, Astrid Rosenstand; Madsen, Kristoffer Hougaard; Paulson, Olaf Bjarne

    2011-01-01

    The adult visual cortex maintains a substantial potential for plasticity in response to a change in visual input. For instance, transcranial magnetic stimulation (TMS) studies have shown that binocular deprivation (BD) increases the cortical excitability for inducing phosphenes with TMS. Here, we...... of visual deprivation has a substantial impact on experience-dependent plasticity of the human visual cortex.......The adult visual cortex maintains a substantial potential for plasticity in response to a change in visual input. For instance, transcranial magnetic stimulation (TMS) studies have shown that binocular deprivation (BD) increases the cortical excitability for inducing phosphenes with TMS. Here, we...... employed TMS to trace plastic changes in adult visual cortex before, during, and after 48 h of monocular deprivation (MD) of the right dominant eye. In healthy adult volunteers, MD-induced changes in visual cortex excitability were probed with paired-pulse TMS applied to the left and right occipital cortex...

  2. Connectivity changes underlying neurofeedback training of visual cortex activity.

    Directory of Open Access Journals (Sweden)

    Frank Scharnowski

    Full Text Available Neurofeedback based on real-time functional magnetic resonance imaging (fMRI is a new approach that allows training of voluntary control over regionally specific brain activity. However, the neural basis of successful neurofeedback learning remains poorly understood. Here, we assessed changes in effective brain connectivity associated with neurofeedback training of visual cortex activity. Using dynamic causal modeling (DCM, we found that training participants to increase visual cortex activity was associated with increased effective connectivity between the visual cortex and the superior parietal lobe. Specifically, participants who learned to control activity in their visual cortex showed increased top-down control of the superior parietal lobe over the visual cortex, and at the same time reduced bottom-up processing. These results are consistent with efficient employment of top-down visual attention and imagery, which were the cognitive strategies used by participants to increase their visual cortex activity.

  3. Long-Term Potentiation in the Motor Cortex

    Science.gov (United States)

    Iriki, Atsushi; Pavlides, Constantine; Keller, Asaf; Asanuma, Hiroshi

    1989-09-01

    Long-term potentiation (LTP) is a model for learning and memory processes. Tetanic stimulation of the sensory cortex produces LTP in motor cortical neurons, whereas tetanization of the ventrolateral nucleus of the thalamus, which also projects to the motor cortex, does not. However, after simultaneous high-frequency stimulation of both the sensory cortex and the ventrolateral nucleus of the thalamus, LTP of thalamic input to motor cortical neurons is induced. This associative LTP occurs only in neurons in the superficial layers of the motor cortex that receive monosynaptic input from both the sensory cortex and the ventrolateral nucleus of the thalamus. Associative LTP in the motor cortex may constitute a basis for the retention of motor skills.

  4. Double Cortex Syndrome (Subcortical Band Heterotopia): A Case Report.

    Science.gov (United States)

    Momen, Ali Akbar; Momen, Mehdi

    2015-01-01

    Objective Approximately 5-10% of preschool age children are considered developmentally disabled. Brain Magnetic Resonance Imaging (MRI) plays a key role in the diagnostic evaluation in these children. Many congenital or acquired brain anomalies are revealed with MRIs. Although the majority of these abnormalities are sporadic but patients with subcortical band heterotopia or double cortex syndrome have sex-linked inheritance. We are going to present the first case in Iran from Ahvaz city, which was presented with status epilepticus associated with developmental delay and finally diagnosed as double cortex syndrome, because band heterotopia cases especially for continuous or generalized form is rare. A 4.5-year-old developmentally delayed girl was admitted for generalized tonic clonic seizure attack of 1 hr, upward gaze, locked mouth, and urinary incontinence (status epilepticus) in the child neurology ward. She had a history of recurrent seizures that started as febrile seizures since she was 12 months of age and had frequent admissions for having recurrent seizure attacks. She was the only child of consanguineous parents with negative family history of any neurologic problems. She was a product of uneventful term pregnancy, vaginal delivery with a low Apgar score at birth who was admitted for six days in the neonatal ward for hypotonia and cyanosis. At 4.5 years of age, she had HC: 45cm (spike-wave discharges. A brain MRI showed corpus callosal dysplasia, generalized band heterotopia, and polymicrogyria. She was discharged home with oral valproate and regular outpatient follow-ups. In the diagnostic evaluation of developmentally delayed and epileptic children, a brain MRI is strongly recommended for accurate diagnosis of anomalies such as neuronal migration disorders (band heterotopia) and others, because appropriate therapeutic management, prognosis, prevention, and genetic counseling for prenatal diagnosis are dependent on definite diagnosis of the proband case.

  5. Inhibitory Gating of Basolateral Amygdala Inputs to the Prefrontal Cortex.

    Science.gov (United States)

    McGarry, Laura M; Carter, Adam G

    2016-09-07

    Interactions between the prefrontal cortex (PFC) and basolateral amygdala (BLA) regulate emotional behaviors. However, a circuit-level understanding of functional connections between these brain regions remains incomplete. The BLA sends prominent glutamatergic projections to the PFC, but the overall influence of these inputs is predominantly inhibitory. Here we combine targeted recordings and optogenetics to examine the synaptic underpinnings of this inhibition in the mouse infralimbic PFC. We find that BLA inputs preferentially target layer 2 corticoamygdala over neighboring corticostriatal neurons. However, these inputs make even stronger connections onto neighboring parvalbumin and somatostatin expressing interneurons. Inhibitory connections from these two populations of interneurons are also much stronger onto corticoamygdala neurons. Consequently, BLA inputs are able to drive robust feedforward inhibition via two parallel interneuron pathways. Moreover, the contributions of these interneurons shift during repetitive activity, due to differences in short-term synaptic dynamics. Thus, parvalbumin interneurons are activated at the start of stimulus trains, whereas somatostatin interneuron activation builds during these trains. Together, these results reveal how the BLA impacts the PFC through a complex interplay of direct excitation and feedforward inhibition. They also highlight the roles of targeted connections onto multiple projection neurons and interneurons in this cortical circuit. Our findings provide a mechanistic understanding for how the BLA can influence the PFC circuit, with important implications for how this circuit participates in the regulation of emotion. The prefrontal cortex (PFC) and basolateral amygdala (BLA) interact to control emotional behaviors. Here we show that BLA inputs elicit direct excitation and feedforward inhibition of layer 2 projection neurons in infralimbic PFC. BLA inputs are much stronger at corticoamygdala neurons compared

  6. Theta coupling between V4 and prefrontal cortex predicts visual short-term memory performance.

    Science.gov (United States)

    Liebe, Stefanie; Hoerzer, Gregor M; Logothetis, Nikos K; Rainer, Gregor

    2012-01-29

    Short-term memory requires communication between multiple brain regions that collectively mediate the encoding and maintenance of sensory information. It has been suggested that oscillatory synchronization underlies intercortical communication. Yet, whether and how distant cortical areas cooperate during visual memory remains elusive. We examined neural interactions between visual area V4 and the lateral prefrontal cortex using simultaneous local field potential (LFP) recordings and single-unit activity (SUA) in monkeys performing a visual short-term memory task. During the memory period, we observed enhanced between-area phase synchronization in theta frequencies (3-9 Hz) of LFPs together with elevated phase locking of SUA to theta oscillations across regions. In addition, we found that the strength of intercortical locking was predictive of the animals' behavioral performance. This suggests that theta-band synchronization coordinates action potential communication between V4 and prefrontal cortex that may contribute to the maintenance of visual short-term memories.

  7. Synchronous activity in cat visual cortex encodes collinear and cocircular contours.

    Science.gov (United States)

    Samonds, Jason M; Zhou, Zhiyi; Bernard, Melanie R; Bonds, A B

    2006-04-01

    We explored how contour information in primary visual cortex might be embedded in the simultaneous activity of multiple cells recorded with a 100-electrode array. Synchronous activity in cat visual cortex was more selective and predictable in discriminating between drifting grating and concentric ring stimuli than changes in firing rate. Synchrony was found even between cells with wholly different orientation preferences when their receptive fields were circularly aligned, and membership in synchronous groups was orientation and curvature dependent. The existence of synchrony between cocircular cells reinforces its role as a general mechanism for contour integration and shape detection as predicted by association field concepts. Our data suggest that cortical synchrony results from common and synchronous input from earlier visual areas and that it could serve to shape extrastriate response selectivity.

  8. Cellular properties of principal neurons in the rat entorhinal cortex. II. The medial entorhinal cortex

    NARCIS (Netherlands)

    Canto, C.B.; Witter, M.P.

    2012-01-01

    Principal neurons in different medial entorhinal cortex (MEC) layers show variations in spatial modulation that stabilize between 15 and 30 days postnatally. These in vivo variations are likely due to differences in intrinsic membrane properties and integrative capacities of neurons. The latter

  9. Pharmacokinetics of Maleic Acid as a Food Adulterant Determined by Microdialysis in Rat Blood and Kidney Cortex

    Directory of Open Access Journals (Sweden)

    Mei-Ling Hou

    2016-03-01

    Full Text Available Maleic acid has been shown to be used as a food adulterant in the production of modified starch by the Taiwan Food and Drug Administration. Due to the potential toxicity of maleic acid to the kidneys, this study aimed to develop an analytical method to investigate the pharmacokinetics of maleic acid in rat blood and kidney cortex. Multiple microdialysis probes were simultaneously inserted into the jugular vein and the kidney cortex for sampling after maleic acid administration (10 or 30 mg/kg, i.v., respectively. The pharmacokinetic results demonstrated that maleic acid produced a linear pharmacokinetic phenomenon within the doses of 10 and 30 mg/kg. The area under concentration versus time curve (AUC of the maleic acid in kidney cortex was 5-fold higher than that in the blood after maleic acid administration (10 and 30 mg/kg, i.v., respectively, indicating that greater accumulation of maleic acid occurred in the rat kidney.

  10. On the estimate of deviations of partial sums of a multiple Fourier-Walsh series of the form S2j,⋯,2jf (x ) of a function in the metric L1(Qk)

    Science.gov (United States)

    Igenberlina, Alua; Matin, Dauren; Turgumbayev, Mendybay

    2017-09-01

    In this paper, deviations of the partial sums of a multiple Fourier-Walsh series of a function in the metric L1(Qk) on a dyadic group are investigated. This estimate plays an important role in the study of equivalent normalizations in this space by means of a difference, oscillation, and best approximation by polynomials in the Walsh system. The classical classical Besov space and its equivalent normalizations are set forth in the well-known monographs of Nikolsky S.M., Besov O.V., Ilyin V.P., Triebel H.; in the works of Kazakh scientists such as Amanov T.I., Mynbaev K.T., Otelbaev M.O., Smailov E.S.. The Besov spaces on the dyadic group and the Vilenkin groups in the one-dimensional case are considered in works by Ombe H., Bloom Walter R, Fournier J., Onneweer C.W., Weyi S., Jun Tateoka.

  11. Olfactocentric paralimbic cortex morphology in adolescents with bipolar disorder

    OpenAIRE

    Wang, Fei; Kalmar, Jessica H.; Womer, Fay Y.; Edmiston, Erin E.; Chepenik, Lara G.; Chen, Rachel; Spencer, Linda; Blumberg, Hilary P.

    2011-01-01

    The olfactocentric paralimbic cortex plays a critical role in the regulation of emotional and neurovegetative functions that are disrupted in core features of bipolar disorder. Adolescence is thought to be a critical period in both the maturation of the olfactocentric paralimbic cortex and in the emergence of bipolar disorder pathology. Together, these factors implicate a central role for the olfactocentric paralimbic cortex in the development of bipolar disorder and suggest that abnormalitie...

  12. Frequency specific modulation of human somatosensory cortex

    Directory of Open Access Journals (Sweden)

    Matteo eFeurra

    2011-02-01

    Full Text Available Oscillatory neuronal activities are commonly observed in response to sensory stimulation. However, their functional roles are still the subject of debate. One way to probe the roles of oscillatory neural activities is to deliver alternating current to the cortex at biologically relevant frequencies and examine whether such stimulation influences perception and cognition. In this study, we tested whether transcranial alternating current stimulation (tACS over the primary somatosensory cortex (SI could elicit tactile sensations in humans in a frequency dependent manner. We tested the effectiveness of tACS over SI at frequency bands ranging from 2 to 70 Hz. Our results show that stimulation in alpha (10-14 Hz and high gamma (52-70 Hz frequency range produces a tactile sensation in the contralateral hand. A weaker effect was also observed for beta (16-20 Hz stimulation. These findings highlight the frequency-dependency of effective tACS over SI with the effective frequencies corresponding to those observed in previous EEG/MEG studies of tactile perception. Our present study suggests that tACS could be used as a powerful online stimulation technique to reveal the causal roles of oscillatory brain activities.

  13. Cognitive Control Signals in Posterior Cingulate Cortex

    Directory of Open Access Journals (Sweden)

    Benjamin eHayden

    2010-12-01

    Full Text Available Efficiently shifting between tasks is a central function of cognitive control. The role of the default network—a constellation of areas with high baseline activity that declines during task performance—in cognitive control remains poorly understood. We hypothesized that task switching demands cognitive control to shift the balance of processing towards the external world, and therefore predicted that switching between the two tasks would require suppression of activity of neurons within the CGp. To test this idea, we recorded the activity of single neurons in posterior cingulate cortex (CGp, a central node in the default network, in monkeys performing two interleaved tasks. As predicted, we found that basal levels of neuronal activity were reduced following a switch from one task to another and gradually returned to pre-switch baseline on subsequent trials. We failed to observe these effects in lateral intraparietal cortex (LIP, part of the dorsal fronto-parietal cortical attention network directly connected to CGp. These findings indicate that suppression of neuronal activity in CGp facilitates cognitive control, and suggest that activity in the default network reflects processes that directly compete with control processes elsewhere in the brain..

  14. Role of the hippocampus and orbitofrontal cortex during the disambiguation of social cues in working memory

    Science.gov (United States)

    Ross, Robert S.; LoPresti, Matthew L.; Schon, Karin; Stern, Chantal E.

    2013-01-01

    Human social interactions are complex behaviors requiring the concerted effort of multiple neural systems to track and monitor the individuals around us. Cognitively, adjusting our behavior based on changing social cues such as facial expressions relies on working memory and the ability to disambiguate, or separate, representations of overlapping stimuli resulting from viewing the same individual with different facial expressions. We conducted an fMRI experiment examining brain regions contributing to the encoding, maintenance and retrieval of overlapping identity information during working memory using a delayed match-to-sample (DMS) task. In the overlapping condition, two faces from the same individual with different facial expressions were presented at sample. In the non-overlapping condition, the two sample faces were from two different individuals with different expressions. fMRI activity was assessed by contrasting the overlapping and non-overlapping condition at sample, delay, and test. The lateral orbitofrontal cortex showed increased fMRI signal in the overlapping condition in all three phases of the DMS task and increased functional connectivity with the hippocampus when encoding overlapping stimuli. The hippocampus showed increased fMRI signal at test. These data suggest lateral orbitofrontal cortex helps encode and maintain representations of overlapping stimuli in working memory while the orbitofrontal cortex and hippocampus contribute to the successful retrieval of overlapping stimuli. We suggest the lateral orbitofrontal cortex and hippocampus play a role in encoding, maintaining, and retrieving social cues, especially when multiple interactions with an individual need to be disambiguated in a rapidly changing social context in order to make appropriate social responses. PMID:23640112

  15. Feature diagnosticity and task context shape activity in human scene-selective cortex.

    Science.gov (United States)

    Lowe, Matthew X; Gallivan, Jason P; Ferber, Susanne; Cant, Jonathan S

    2016-01-15

    Scenes are constructed from multiple visual features, yet previous research investigating scene processing has often focused on the contributions of single features in isolation. In the real world, features rarely exist independently of one another and likely converge to inform scene identity in unique ways. Here, we utilize fMRI and pattern classification techniques to examine the interactions between task context (i.e., attend to diagnostic global scene features; texture or layout) and high-level scene attributes (content and spatial boundary) to test the novel hypothesis that scene-selective cortex represents multiple visual features, the importance of which varies according to their diagnostic relevance across scene categories and task demands. Our results show for the first time that scene representations are driven by interactions between multiple visual features and high-level scene attributes. Specifically, univariate analysis of scene-selective cortex revealed that task context and feature diagnosticity shape activity differentially across scene categories. Examination using multivariate decoding methods revealed results consistent with univariate findings, but also evidence for an interaction between high-level scene attributes and diagnostic visual features within scene categories. Critically, these findings suggest visual feature representations are not distributed uniformly across scene categories but are shaped by task context and feature diagnosticity. Thus, we propose that scene-selective cortex constructs a flexible representation of the environment by integrating multiple diagnostically relevant visual features, the nature of which varies according to the particular scene being perceived and the goals of the observer. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Activation of cannabinoid system in anterior cingulate cortex and orbitofrontal cortex modulates cost-benefit decision making.

    Science.gov (United States)

    Khani, Abbas; Kermani, Mojtaba; Hesam, Soghra; Haghparast, Abbas; Argandoña, Enrike G; Rainer, Gregor

    2015-06-01

    Despite the evidence for altered decision making in cannabis abusers, the role of the cannabinoid system in decision-making circuits has not been studied. Here, we examined the effects of cannabinoid modulation during cost-benefit decision making in the anterior cingulate cortex (ACC) and orbitofrontal cortex (OFC), key brain areas involved in decision making. We trained different groups of rats in a delay-based and an effort-based form of cost-benefit T-maze decision-making task. During test days, the rats received local injections of either vehicle or ACEA, a cannabinoid type-1 receptor (CB1R) agonist in the ACC or OFC. We measured spontaneous locomotor activity following the same treatments and characterized CB1Rs localization on different neuronal populations within these regions using immunohistochemistry. We showed that CB1R activation in the ACC impaired decision making such that rats were less willing to invest physical effort to gain high reward. Similarly, CB1R activation in the OFC induced impulsive pattern of choice such that rats preferred small immediate rewards to large delayed rewards. Control tasks ensured that the effects were specific for differential cost-benefit tasks. Furthermore, we characterized widespread colocalizations of CB1Rs on GABAergic axonal ends but few colocalizations on glutamatergic, dopaminergic, and serotonergic neuronal ends. These results provide first direct evidence that the cannabinoid system plays a critical role in regulating cost-benefit decision making in the ACC and OFC and implicate cannabinoid modulation of synaptic ends of predominantly interneurons and to a lesser degree other neuronal populations in these two frontal regions.

  17. [Multiple meningiomas].

    Science.gov (United States)

    Terrier, L-M; François, P

    2016-06-01

    Multiple meningiomas (MMs) or meningiomatosis are defined by the presence of at least 2 lesions that appear simultaneously or not, at different intracranial locations, without the association of neurofibromatosis. They present 1-9 % of meningiomas with a female predominance. The occurrence of multiple meningiomas is not clear. There are 2 main hypotheses for their development, one that supports the independent evolution of these tumors and the other, completely opposite, that suggests the propagation of tumor cells of a unique clone transformation, through cerebrospinal fluid. NF2 gene mutation is an important intrinsic risk factor in the etiology of multiple meningiomas and some exogenous risk factors have been suspected but only ionizing radiation exposure has been proven. These tumors can grow anywhere in the skull but they are more frequently observed in supratentorial locations. Their histologic types are similar to unique meningiomas of psammomatous, fibroblastic, meningothelial or transitional type and in most cases are benign tumors. The prognosis of these tumors is eventually good and does not differ from the unique tumors except for the cases of radiation-induced multiple meningiomas, in the context of NF2 or when diagnosed in children where the outcome is less favorable. Each meningioma lesion should be dealt with individually and their multiple character should not justify their resection at all costs. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  18. Higher media multi-tasking activity is associated with smaller gray-matter density in the anterior cingulate cortex.

    Directory of Open Access Journals (Sweden)

    Kep Kee Loh

    Full Text Available Media multitasking, or the concurrent consumption of multiple media forms, is increasingly prevalent in today's society and has been associated with negative psychosocial and cognitive impacts. Individuals who engage in heavier media-multitasking are found to perform worse on cognitive control tasks and exhibit more socio-emotional difficulties. However, the neural processes associated with media multi-tasking remain unexplored. The present study investigated relationships between media multitasking activity and brain structure. Research has demonstrated that brain structure can be altered upon prolonged exposure to novel environments and experience. Thus, we expected differential engagements in media multitasking to correlate with brain structure variability. This was confirmed via Voxel-Based Morphometry (VBM analyses: Individuals with higher Media Multitasking Index (MMI scores had smaller gray matter density in the anterior cingulate cortex (ACC. Functional connectivity between this ACC region and the precuneus was negatively associated with MMI. Our findings suggest a possible structural correlate for the observed decreased cognitive control performance and socio-emotional regulation in heavy media-multitaskers. While the cross-sectional nature of our study does not allow us to specify the direction of causality, our results brought to light novel associations between individual media multitasking behaviors and ACC structure differences.

  19. Severe form of hemolytic-uremic syndrome with multiple organ failure in a child: a case report [v1; ref status: indexed, http://f1000r.es/24q

    Directory of Open Access Journals (Sweden)

    Dino Mijatovic

    2014-03-01

    Full Text Available Introduction: Hemolytic-uremic syndrome (HUS is a leading cause of acute renal failure in infants and young children. It is traditionally defined as a triad of acute renal failure, hemolytic anemia and thrombocytopenia that occur within a week after prodromal hemorrhagic enterocolitis. Severe cases can also be presented by acute respiratory distress syndrome (ARDS, toxic megacolon with ileus, pancreatitis, central nervous system (CNS disorders and multiple organ failure (MOF. Case presentation: A previously healthy 4-year old Caucasian girl developed acute renal failure, thrombocytopenia and hemolytic anemia following a short episode of abdominal pain and bloody diarrhea. In the next week of, what initially appeared as typical HUS, she developed MOF, including ileus, pancreatitis, hepatitis, coma and ARDS, accompanied by hemodynamic instability and extreme leukocytosis. Nonetheless, the girl made a complete recovery after one month of the disease. She was successfully treated in the intensive care unit and significant improvement was noticed after plasmapheresis and continuous veno-venous hemodialysis. Conclusions: Early start of plasmapheresis and meticulous supportive treatment in the intensive care unit, including renal placement therapy, may be the therapy of choice in severe cases of HUS presented by MOF. Monitoring of prognostic factors is important for early performance of appropriate diagnostic and therapeutical interventions.

  20. Improving of effectivity and feasibility of secondary ventilation in branches with multiple forms; Mejoras de la efectividad y fiabilidad de la ventilacion secundaria en tajos con sutiraje en fondo de saco

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    The extension of sublevels caving method in the Spanish mining industry for the exploitation of vertical and thick seams has introduced and additional risk factor in terms of the ventilation systems. In fact, this mining system requires that production faces are ventilated by secondary ventilation system, and in many cases these systems have a complicated structure (with multiple fans and branches of variable length), due to the complex configuration of the method itself and also to the very dynamic character of this kind of faces. In these conditions, the ventilation networks become difficult to design, and also to control in a routine basis. Furthermore, the type of seams to which the method is best applicable are usually very gassy and with a high methane emission rate. As a consequence of all this, the project has been focused to a number of different activities which are complementary between themselves and which try to provide to the users technical tools and clear criteria for the design, installation and maintenance of these kind of ventilation networks. As starting point, the situation and normal practice in other European countries was studied, and those cases which had common points with the project aims (for example Wistow mine in Selby Group, U.K.) were analysed in more detail. (Author)

  1. Effects of the Bee Venom Herbal Acupuncture on the Neurotransmitters of the Rat Brain Cortex

    Directory of Open Access Journals (Sweden)

    Hyoung-Seok Yun

    2001-02-01

    Full Text Available In order to study the effects of bee venom Herbal Acupuncture on neurotransmitters in the rat brain cortex, herbal acupuncture with bee venom group and normal saline group was performed at LI4 bilaterally of the rat. the average optical density of neurotransmitters from the cerebral cortex was analysed 30 minutes after the herbal aqupuncture, by the immunohistochemistry. The results were as follows: 1. The density of NADPH-diaphorase in bee venom group was increased significantly at the motor cortex, visual cortex, auditory cortex, cingulate cortex, retrosplenial cortex and perirhinal cortex compared to the normal saline group. 2. The average optical density of vasoactive intestinal peptide in bee venom group had significant changes at the insular cortex, retrosplenial cortex and perirhinal cortex, compared to the normal saline group. 3. The average optical density of neuropeptide-Y in bee venom group increased significantly at the visual cortex and cingulate cortex, compared to the normal saline group.

  2. Multiple sclerosis

    DEFF Research Database (Denmark)

    Stenager, Egon; Stenager, E N; Knudsen, Lone

    1994-01-01

    In a cross-sectional study of 117 randomly selected patients (52 men, 65 women) with definite multiple sclerosis, it was found that 76 percent were married or cohabitant, 8 percent divorced. Social contacts remained unchanged for 70 percent, but outgoing social contacts were reduced for 45 percent......, need for structural changes in home and need for pension became greater with increasing physical handicap. No significant differences between gender were found. It is concluded that patients and relatives are under increased social strain, when multiple sclerosis progresses to a moderate handicap...

  3. Architecture of the Entorhinal Cortex A Review of Entorhinal Anatomy in Rodents with Some Comparative Notes

    Directory of Open Access Journals (Sweden)

    Menno P. Witter

    2017-06-01

    Full Text Available The entorhinal cortex (EC is the major input and output structure of the hippocampal formation, forming the nodal point in cortico-hippocampal circuits. Different division schemes including two or many more subdivisions have been proposed, but here we will argue that subdividing EC into two components, the lateral EC (LEC and medial EC (MEC might suffice to describe the functional architecture of EC. This subdivision then leads to an anatomical interpretation of the different phenotypes of LEC and MEC. First, we will briefly summarize the cytoarchitectonic differences and differences in hippocampal projection patterns on which the subdivision between LEC and MEC traditionally is based and provide a short comparative perspective. Second, we focus on main differences in cortical connectivity, leading to the conclusion that the apparent differences may well correlate with the functional differences. Cortical connectivity of MEC is features interactions with areas such as the presubiculum, parasubiculum, retrosplenial cortex (RSC and postrhinal cortex, all areas that are considered to belong to the “spatial processing domain” of the cortex. In contrast, LEC is strongly connected with olfactory areas, insular, medial- and orbitofrontal areas and perirhinal cortex. These areas are likely more involved in processing of object information, attention and motivation. Third, we will compare the intrinsic networks involving principal- and inter-neurons in LEC and MEC. Together, these observations suggest that the different phenotypes of both EC subdivisions likely depend on the combination of intrinsic organization and specific sets of inputs. We further suggest a reappraisal of the notion of EC as a layered input-output structure for the hippocampal formation.

  4. Altered SPECT 123I-iomazenil Binding in the Cingulate Cortex of Children with Anorexia Nervosa

    Science.gov (United States)

    Nagamitsu, Shinichiro; Sakurai, Rieko; Matsuoka, Michiko; Chiba, Hiromi; Ozono, Shuichi; Tanigawa, Hitoshi; Yamashita, Yushiro; Kaida, Hayato; Ishibashi, Masatoshi; Kakuma, Tatsuki; Croarkin, Paul E.; Matsuishi, Toyojiro

    2016-01-01

    Several lines of evidence suggest that anxiety plays a key role in the development and maintenance of anorexia nervosa (AN) in children. The purpose of this study was to examine cortical GABA(A)-benzodiazepine receptor binding before and after treatment in children beginning intensive AN treatment. Brain single-photon emission computed tomography (SPECT) measurements using 123I-iomazenil, which binds to GABA(A)-benzodiazepine receptors, was performed in 26 participants with AN who were enrolled in a multimodal treatment program. Sixteen of the 26 participants underwent a repeat SPECT scan immediately before discharge at conclusion of the intensive treatment program. Eating behavior and mood disturbances were assessed using Eating Attitudes Test with 26 items (EAT-26) and the short form of the Profile of Mood States (POMS). Clinical outcome scores were evaluated after a 1-year period. We examined association between relative iomazenil-binding activity in cortical regions of interest and psychometric profiles and determined which psychometric profiles show interaction effects with brain regions. Further, we determined if binding activity could predict clinical outcome and treatment changes. Higher EAT-26 scores were significantly associated with lower iomazenil-binding activity in the anterior and posterior cingulate cortex. Higher POMS subscale scores were significantly associated with lower iomazenil-binding activity in the left frontal, parietal cortex, and posterior cingulate cortex (PCC). “Depression–Dejection” and “Confusion” POMS subscale scores, and total POMS score showed interaction effects with brain regions in iomazenil-binding activity. Decreased binding in the anterior cingulate cortex and left parietal cortex was associated with poor clinical outcomes. Relative binding increases throughout the PCC and occipital gyrus were observed after weight gain in children with AN. These findings suggest that cortical GABAergic receptor binding is altered

  5. Simultaneous analysis of multiple T helper subsets in leprosy reveals distinct patterns of Th1, Th2, Th17 and Tregs markers expression in clinical forms and reactional events.

    Science.gov (United States)

    Azevedo, Michelle de Campos Soriani; Marques, Heloisa; Binelli, Larissa Sarri; Malange, Mariana Silva Vieira; Devides, Amanda Carreira; Silva, Eliane Aparecida; Fachin, Luciana Raquel Vincenzi; Ghidella, Cassio Cesar; Soares, Cleverson Teixeira; Garlet, Gustavo Pompermaier; Rosa, Patrícia Sammarco; Belone, Andrea de Farias Fernandes; Trombone, Ana Paula Favaro

    2017-12-01

    Leprosy is a chronic infectious disease caused by Mycobacterium leprae. Previous studies have demonstrated that the difference among clinical forms of leprosy can be associated with the immune response of patients, mainly by T helper (Th) and regulatory T cells (Tregs). Then, aiming at clarifying the immune response, the expression of cytokines related to Th1, Th2, Th17 and Tregs profiles were evaluated by qPCR in 87 skin biopsies from leprosy patients. Additionally, cytokines and anti-PGL-1 antibodies were determined in serum by ELISA. The results showed that the expression of various targets (mRNA) related to Th1, Th2, Th17 and Tregs were significantly modulated in leprosy when compared with healthy individuals, suggesting the presence of a mixed profile. In addition, the targets related to Th1 predominated in the tuberculoid pole and side and Th2 and Tregs predominated in the lepromatous pole and side; however, Th17 targets showed a mixed profile. Concerning reactional events, Tregs markers were decreased and IL-15 was increased in reversal reaction and IL-17F, CCL20 and IL-8 in erythema nodosum leprosum, when compared with the respective non-reactional leprosy patients. Additionally, ELISA analysis demonstrated that IL-22, IL-6, IL-10 and anti-PGL-1 antibody levels were significantly higher in the serum of patients when compared with healthy individuals, and IL-10 and anti-PGL-1 antibodies were also increased in the lepromatous pole and side. Together, these results indicate that Th1, Th2 and Th17 are involved in the determination of clinical forms of leprosy and suggest that decreased Tregs activity may be involved in the pathogenesis of reactional events.

  6. Visual Stimuli Induce Waves of Electrical Activity in Turtle Cortex

    Science.gov (United States)

    Prechtl, J. C.; Cohen, L. B.; Pesaran, B.; Mitra, P. P.; Kleinfeld, D.

    1997-07-01

    The computations involved in the processing of a visual scene invariably involve the interactions among neurons throughout all of visual cortex. One hypothesis is that the timing of neuronal activity, as well as the amplitude of activity, provides a means to encode features of objects. The experimental data from studies on cat [Gray, C. M., Konig, P., Engel, A. K. & Singer, W. (1989) Nature (London) 338, 334-337] support a view in which only synchronous (no phase lags) activity carries information about the visual scene. In contrast, theoretical studies suggest, on the one hand, the utility of multiple phases within a population of neurons as a means to encode independent visual features and, on the other hand, the likely existence of timing differences solely on the basis of network dynamics. Here we use widefield imaging in conjunction with voltage-sensitive dyes to record electrical activity from the virtually intact, unanesthetized turtle brain. Our data consist of single-trial measurements. We analyze our data in the frequency domain to isolate coherent events that lie in different frequency bands. Low frequency oscillations (scale differences in neuronal timing are present and persistent during visual processing.

  7. Language networks in anophthalmia: maintained hierarchy of processing in 'visual' cortex.

    Science.gov (United States)

    Watkins, Kate E; Cowey, Alan; Alexander, Iona; Filippini, Nicola; Kennedy, James M; Smith, Stephen M; Ragge, Nicola; Bridge, Holly

    2012-05-01

    normally seen for vision. The differences in cortical organization between bilateral anophthalmia and other forms of congenital blindness are considered to be due to the total absence of stimulation in 'visual' cortex by light or retinal activity in the former condition, and suggests development of subcortical auditory input to the geniculo-striate pathway.

  8. Two-Photon Functional Imaging of the Auditory Cortex in Behaving Mice: From Neural Networks to Single Spines

    Directory of Open Access Journals (Sweden)

    Ruijie Li

    2018-04-01

    Full Text Available In vivo two-photon Ca2+ imaging is a powerful tool for recording neuronal activities during perceptual tasks and has been increasingly applied to behaving animals for acute or chronic experiments. However, the auditory cortex is not easily accessible to imaging because of the abundant temporal muscles, arteries around the ears and their lateral locations. Here, we report a protocol for two-photon Ca2+ imaging in the auditory cortex of head-fixed behaving mice. By using a custom-made head fixation apparatus and a head-rotated fixation procedure, we achieved two-photon imaging and in combination with targeted cell-attached recordings of auditory cortical neurons in behaving mice. Using synthetic Ca2+ indicators, we recorded the Ca2+ transients at multiple scales, including neuronal populations, single neurons, dendrites and single spines, in auditory cortex during behavior. Furthermore, using genetically encoded Ca2+ indicators (GECIs, we monitored the neuronal dynamics over days throughout the process of associative learning. Therefore, we achieved two-photon functional imaging at multiple scales in auditory cortex of behaving mice, which extends the tool box for investigating the neural basis of audition-related behaviors.

  9. Multiple myeloma

    International Nuclear Information System (INIS)

    Sohn, Jeong Ick; Ha, Choon Ho; Choi, Karp Shik

    1994-01-01

    Multiple myeloma is a malignant plasma cell tumor that is thought to originate proliferation of a single clone of abnormal plasma cell resulting production of a whole monoclonal paraprotein. The authors experienced a case of multiple myeloma with severe mandibular osteolytic lesions in 46-year-old female. As a result of careful analysis of clinical, radiological, histopathological features, and laboratory findings, we diagnosed it as multiple myeloma, and the following results were obtained. 1. Main clinical symptoms were intermittent dull pain on the mandibular body area, abnormal sensation of lip and pain due to the fracture on the right clavicle. 2. Laboratory findings revealed M-spike, reversed serum albumin-globulin ratio, markedly elevated ESR and hypercalcemia. 3. Radiographically, multiple osteolytic punched-out radiolucencies were evident on the skull, zygoma, jaw bones, ribs, clavicle and upper extremities. Enlarged liver and increased uptakes on the lesional sites in RN scan were also observed. 4. Histopathologically, markedly hypercellular marrow with sheets of plasmoblasts and megakaryocytes were also observed.

  10. Multiple sclerosis

    DEFF Research Database (Denmark)

    Stenager, E; Jensen, K

    1988-01-01

    Forty-two (12%) of a total of 366 patients with multiple sclerosis (MS) had psychiatric admissions. Of these, 34 (81%) had their first psychiatric admission in conjunction with or after the onset of MS. Classification by psychiatric diagnosis showed that there was a significant positive correlation...

  11. Multiple sclerosis

    DEFF Research Database (Denmark)

    Stenager, E; Knudsen, L; Jensen, K

    1991-01-01

    In a cross-sectional investigation of 116 patients with multiple sclerosis, the social and sparetime activities of the patient were assessed by both patient and his/her family. The assessments were correlated to physical disability which showed that particularly those who were moderately disabled...

  12. Multiple sclerosis

    DEFF Research Database (Denmark)

    Stenager, E; Jensen, K

    1990-01-01

    An investigation on the correlation between ability to read TV subtitles and the duration of visual evoked potential (VEP) latency in 14 patients with definite multiple sclerosis (MS), indicated that VEP latency in patients unable to read the TV subtitles was significantly delayed in comparison...

  13. Multiple sclerosis

    DEFF Research Database (Denmark)

    Stenager, E; Knudsen, L; Jensen, K

    1994-01-01

    In a cross-sectional study of 94 patients (42 males, 52 females) with definite multiple sclerosis (MS) in the age range 25-55 years, the correlation of neuropsychological tests with the ability to read TV-subtitles and with the use of sedatives is examined. A logistic regression analysis reveals...

  14. Multiple Sclerosis.

    Science.gov (United States)

    Plummer, Nancy; Michael, Nancy, Ed.

    This module on multiple sclerosis is intended for use in inservice or continuing education programs for persons who administer medications in long-term care facilities. Instructor information, including teaching suggestions, and a listing of recommended audiovisual materials and their sources appear first. The module goal and objectives are then…

  15. Parenting Multiples

    Science.gov (United States)

    ... when your babies do. Though it can be hard to let go of the thousand other things you need to do, remember that your well-being is key to your ability to take care of your babies. What Problems Can Happen? It may be hard to tell multiple babies apart when they first ...

  16. Cortex and amygdala morphology in psychopathy.

    Science.gov (United States)

    Boccardi, Marina; Frisoni, Giovanni B; Hare, Robert D; Cavedo, Enrica; Najt, Pablo; Pievani, Michela; Rasser, Paul E; Laakso, Mikko P; Aronen, Hannu J; Repo-Tiihonen, Eila; Vaurio, Olli; Thompson, Paul M; Tiihonen, Jari

    2011-08-30

    Psychopathy is characterized by abnormal emotional processes, but only recent neuroimaging studies have investigated its cerebral correlates. The study aim was to map local differences of cortical and amygdalar morphology. Cortical pattern matching and radial distance mapping techniques were used to analyze the magnetic resonance images of 26 violent male offenders (age: 32±8) with psychopathy diagnosed using the Psychopathy Checklist-Revised (PCL-R) and no schizophrenia spectrum disorders, and in matched controls (age: 35± sp="0.12"/>11). The cortex displayed up to 20% reduction in the orbitofrontal and midline structures (corrected pamygdala (corrected p=0.05 on the right; and symmetrical pattern on the left). Psychopathy features specific morphology of the main cerebral structures involved in cognitive and emotional processing, consistent with clinical and functional data, and with a hypothesis of an alternative evolutionary brain development. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Densified waste form and method for forming

    Science.gov (United States)

    Garino, Terry J.; Nenoff, Tina M.; Sava Gallis, Dorina Florentina

    2015-08-25

    Materials and methods of making densified waste forms for temperature sensitive waste material, such as nuclear waste, formed with low temperature processing using metallic powder that forms the matrix that encapsulates the temperature sensitive waste material. The densified waste form includes a temperature sensitive waste material in a physically densified matrix, the matrix is a compacted metallic powder. The method for forming the densified waste form includes mixing a metallic powder and a temperature sensitive waste material to form a waste form precursor. The waste form precursor is compacted with sufficient pressure to densify the waste precursor and encapsulate the temperature sensitive waste material in a physically densified matrix.

  18. Prefrontal cortex and sensory cortices during working memory: quantity and quality.

    Science.gov (United States)

    Ku, Yixuan; Bodner, Mark; Zhou, Yong-Di

    2015-04-01

    The activity in sensory cortices and the prefrontal cortex (PFC) throughout the delay interval of working memory (WM) tasks reflect two aspects of WM-quality and quantity, respectively. The delay activity in sensory cortices is fine-tuned to sensory information and forms the neural basis of the precision of WM storage, while the delay activity in the PFC appears to represent behavioral goals and filters out irrelevant distractions, forming the neural basis of the quantity of task-relevant information in WM. The PFC and sensory cortices interact through different frequency bands of neuronal oscillation (theta, alpha, and gamma) to fulfill goal-directed behaviors.

  19. Olfactocentric Paralimbic Cortex Morphology in Adolescents with Bipolar Disorder

    Science.gov (United States)

    Wang, Fei; Kalmar, Jessica H.; Womer, Fay Y.; Edmiston, Erin E.; Chepenik, Lara G.; Chen, Rachel; Spencer, Linda; Blumberg, Hilary P.

    2011-01-01

    The olfactocentric paralimbic cortex plays a critical role in the regulation of emotional and neurovegetative functions that are disrupted in core features of bipolar disorder. Adolescence is thought to be a critical period in both the maturation of the olfactocentric paralimbic cortex and in the emergence of bipolar disorder pathology. Together,…

  20. Anodal vs cathodal stimulation of motor cortex: a modeling study

    NARCIS (Netherlands)

    Manola, L.; Holsheimer, J.; Veltink, Petrus H.; Buitenweg, Jan R.

    Objective. To explore the effects of electrical stimulation performed by an anode, a cathode or a bipole positioned over the motor cortex for chronic pain management. Methods. A realistic 3D volume conductor model of the human precentral gyrus (motor cortex) was used to calculate the

  1. Insular Cortex Is Involved in Consolidation of Object Recognition Memory

    Science.gov (United States)

    Bermudez-Rattoni, Federico; Okuda, Shoki; Roozendaal, Benno; McGaugh, James L.

    2005-01-01

    Extensive evidence indicates that the insular cortex (IC), also termed gustatory cortex, is critically involved in conditioned taste aversion and taste recognition memory. Although most studies of the involvement of the IC in memory have investigated taste, there is some evidence that the IC is involved in memory that is not based on taste. In…

  2. Genetic influences on thinning of the cerebral cortex during development

    NARCIS (Netherlands)

    van Soelen, I.L.C.; Brouwer, R.M.; van Baal, G.C.M.; Schnack, H.G.; Peper, J.S.; Collins, D.L.; Evans, A.C.; Kahn, R.S.; Boomsma, D.I.; Hulshoff Pol, H.E.

    2012-01-01

    During development from childhood to adulthood the human brain undergoes considerable thinning of the cerebral cortex. Whether developmental cortical thinning is influenced by genes and if independent genetic factors influence different parts of the cortex is not known. Magnetic resonance brain

  3. Khat distorts the prefrontal cortex histology and function of adult ...

    African Journals Online (AJOL)

    Khat is a psychoactive herbal drug of pronounced ethno-pharmacological significance often abused due to its unregulated use. It affects many brain centers including the prefrontal cortex which is the anterior most part of the frontal lobe. The prefrontal cortex modulates working memory, planning complex cognitive ...

  4. Modality-specific involvement of occipital cortex in Early Blind?

    NARCIS (Netherlands)

    van der Lubbe, Robert Henricus Johannes; van Mierlo, C.M.; Postma, A.

    2008-01-01

    What happens in occipital cortex when neuronal activity is no longer evoked by regular visual stimulation? Studying brain activity induced by tactile and auditory stimuli in the blind may provide an answer. Several studies indicate that occipital cortex in the blind is recruited in simple tasks,

  5. Parallel, multi-stage processing of colors, faces and shapes in macaque inferior temporal cortex

    Science.gov (United States)

    Lafer-Sousa, Rosa; Conway, Bevil R.

    2014-01-01

    Visual-object processing culminates in inferior temporal (IT) cortex. To assess the organization of IT, we measured fMRI responses in alert monkey to achromatic images (faces, fruit, bodies, places) and colored gratings. IT contained multiple color-biased regions, which were typically ventral to face patches and, remarkably, yoked to them, spaced regularly at four locations predicted by known anatomy. Color and face selectivity increased for more anterior regions, indicative of a broad hierarchical arrangement. Responses to non-face shapes were found across IT, but were stronger outside color-biased regions and face patches, consistent with multiple parallel streams. IT also contained multiple coarse eccentricity maps: face patches overlapped central representations; color-biased regions spanned mid-peripheral representations; and place-biased regions overlapped peripheral representations. These results suggest that IT comprises parallel, multi-stage processing networks subject to one organizing principle. PMID:24141314

  6. Study of physiology of visual cortex activated by rotating grating with functional MRI

    International Nuclear Information System (INIS)

    Liang Ping; Shao Qing; Zhang Zhiqiang; Lu Guangming

    2004-01-01

    Objective: To research the physiology of visual cortex activated by rotating grating with functional-MRI (fMRI), and to identify the components of the activation. Methods: Functional MRI was performed in 9 healthy volunteers by using GRE-EPI sequences on a 1.5 T MR scanner. In the block designing, rotating grating, static grating, and luminance were plotted as task states, while static grating, luminance, and darkness were set as control states. The stimuli tasks included six steps. Imaging processing and statistical analysis was carried out off-line using SPM99 in single-subject method. Results: Some respective areas of visual cortex were activated by the various stimuli information supplied by rotating grating. The strong activation in the middle of occipital lobe located at primary vision area was related to the stimuli of white luminance. Its average maximum points were at 13, -98, -2 and 11, -100, -41 The bilateral activations of Brodmann 19th area located at MT area were related to visual motion perception. Its average maximum points were at 46, -72, -2 and -44, -74, 0. The mild activation in the middle of occipital lobe was related to form perception. Its average maximum points were at -12, -98, -6 and -16, -96, -6. Conclusion: The plotting of control state is important in bock design. The effective visual information of rotating grating includes components of luminance, visual motion perception, and form perception. FMRI has potential as a tool for studying the basic physiology of visual cortex. (authors)

  7. Functional connectivity of visual cortex in the blind follows retinotopic organization principles.

    Science.gov (United States)

    Striem-Amit, Ella; Ovadia-Caro, Smadar; Caramazza, Alfonso; Margulies, Daniel S; Villringer, Arno; Amedi, Amir

    2015-06-01

    Is visual input during critical periods of development crucial for the emergence of the fundamental topographical mapping of the visual cortex? And would this structure be retained throughout life-long blindness or would it fade as a result of plastic, use-based reorganization? We used functional connectivity magnetic resonance imaging based on intrinsic blood oxygen level-dependent fluctuations to investigate whether significant traces of topographical mapping of the visual scene in the form of retinotopic organization, could be found in congenitally blind adults. A group of 11 fully and congenitally blind subjects and 18 sighted controls were studied. The blind demonstrated an intact functional connectivity network structural organization of the three main retinotopic mapping axes: eccentricity (centre-periphery), laterality (left-right), and elevation (upper-lower) throughout the retinotopic cortex extending to high-level ventral and dorsal streams, including characteristic eccentricity biases in face- and house-selective areas. Functional connectivity-based topographic organization in the visual cortex was indistinguishable from the normally sighted retinotopic functional connectivity structure as indicated by clustering analysis, and was found even in participants who did not have a typical retinal development in utero (microphthalmics). While the internal structural organization of the visual cortex was strikingly similar, the blind exhibited profound differences in functional connectivity to other (non-visual) brain regions as compared to the sighted, which were specific to portions of V1. Central V1 was more connected to language areas but peripheral V1 to spatial attention and control networks. These findings suggest that current accounts of critical periods and experience-dependent development should be revisited even for primary sensory areas, in that the connectivity basis for visual cortex large-scale topographical organization can develop without any

  8. Object Representations in Human Visual Cortex Formed Through Temporal Integration of Dynamic Partial Shape Views.

    Science.gov (United States)

    Orlov, Tanya; Zohary, Ehud

    2018-01-17

    We typically recognize visual objects using the spatial layout of their parts, which are present simultaneously on the retina. Therefore, shape extraction is based on integration of the relevant retinal information over space. The lateral occipital complex (LOC) can represent shape faithfully in such conditions. However, integration over time is sometimes required to determine object shape. To study shape extraction through temporal integration of successive partial shape views, we presented human participants (both men and women) with artificial shapes that moved behind a narrow vertical or horizontal slit. Only a tiny fraction of the shape was visible at any instant at the same retinal location. However, observers perceived a coherent whole shape instead of a jumbled pattern. Using fMRI and multivoxel pattern analysis, we searched for brain regions that encode temporally integrated shape identity. We further required that the representation of shape should be invariant to changes in the slit orientation. We show that slit-invariant shape information is most accurate in the LOC. Importantly, the slit-invariant shape representations matched the conventional whole-shape representations assessed during full-image runs. Moreover, when the same slit-dependent shape slivers were shuffled, thereby preventing their spatiotemporal integration, slit-invariant shape information was reduced dramatically. The slit-invariant representation of the various shapes also mirrored the structure of shape perceptual space as assessed by perceptual similarity judgment tests. Therefore, the LOC is likely to mediate temporal integration of slit-dependent shape views, generating a slit-invariant whole-shape percept. These findings provide strong evidence for a global encoding of shape in the LOC regardless of integration processes required to generate the shape percept. SIGNIFICANCE STATEMENT Visual objects are recognized through spatial integration of features available simultaneously on the retina. The lateral occipital complex (LOC) represents shape faithfully in such conditions even if the object is partially occluded. However, shape must sometimes be reconstructed over both space and time. Such is the case in anorthoscopic perception, when an object is moving behind a narrow slit. In this scenario, spatial information is limited at any moment so the whole-shape percept can only be inferred by integration of successive shape views over time. We find that LOC carries shape-specific information recovered using such temporal integration processes. The shape representation is invariant to slit orientation and is similar to that evoked by a fully viewed image. Existing models of object recognition lack such capabilities. Copyright © 2018 the authors 0270-6474/18/380659-20$15.00/0.

  9. Neurogenic Radial Glia-like Cells in Meninges Migrate and Differentiate into Functionally Integrated Neurons in the Neonatal Cortex.

    Science.gov (United States)

    Bifari, Francesco; Decimo, Ilaria; Pino, Annachiara; Llorens-Bobadilla, Enric; Zhao, Sheng; Lange, Christian; Panuccio, Gabriella; Boeckx, Bram; Thienpont, Bernard; Vinckier, Stefan; Wyns, Sabine; Bouché, Ann; Lambrechts, Diether; Giugliano, Michele; Dewerchin, Mieke; Martin-Villalba, Ana; Carmeliet, Peter

    2017-03-02

    Whether new neurons are added in the postnatal cerebral cortex is still debated. Here, we report that the meninges of perinatal mice contain a population of neurogenic progenitors formed during embryonic development that migrate to the caudal cortex and differentiate into Satb2 + neurons in cortical layers II-IV. The resulting neurons are electrically functional and integrated into local microcircuits. Single-cell RNA sequencing identified meningeal cells with distinct transcriptome signatures characteristic of (1) neurogenic radial glia-like cells (resembling neural stem cells in the SVZ), (2) neuronal cells, and (3) a cell type with an intermediate phenotype, possibly representing radial glia-like meningeal cells differentiating to neuronal cells. Thus, we have identified a pool of embryonically derived radial glia-like cells present in the meninges that migrate and differentiate into functional neurons in the neonatal cerebral cortex. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Role of the ventrolateral orbital cortex and medial prefrontal cortex in incentive downshift situations.

    Science.gov (United States)

    Ortega, Leonardo A; Glueck, Amanda C; Uhelski, Megan; Fuchs, Perry N; Papini, Mauricio R

    2013-05-01

    The present research evaluated the role of two prefrontal cortex areas, the ventrolateral orbital cortex (VLO) and the medial prefrontal cortex (mPFC), on two situations involving incentive downshifts, consummatory successive negative contrast (cSNC) with sucrose solutions and Pavlovian autoshaping following continuous vs. partial reinforcement with food pellets. Animals received electrolytic lesions and then were tested on cSNC, autoshaping, open-field activity, and sucrose sensitivity. Lesions of the VLO reduced suppression of consummatory behavior after the incentive downshift, but only during the first downshift trial, and also eliminated the enhancement of anticipatory behavior during partial reinforcement, relative to continuous reinforcement, in autoshaping. There was no evidence of specific effects of mPFC lesions on incentive downshifts. Open-field activity was also reduced by VLO lesions, but only in the central area, whereas mPFC lesions had no observable effects on activity. Animals with mPFC lesions exhibited decreased consumption of the lowest sucrose concentration, whereas no effects were observed in animals with VLO lesions. These results suggest that the VLO may exert nonassociative (i.e., motivational, emotional) influences on behavior in situations involving incentive downshifts. No clear role on incentive downshift was revealed by mPFC lesions. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Reduced frontal cortex thickness and cortical volume associated with pathological narcissism.

    Science.gov (United States)

    Mao, Yu; Sang, Na; Wang, Yongchao; Hou, Xin; Huang, Hui; Wei, Dongtao; Zhang, Jinfu; Qiu, Jiang

    2016-07-22

    Pathological narcissism is often characterized by arrogant behavior, a lack of empathy, and willingness to exploit other individuals. Generally, individuals with high levels of narcissism are more likely to suffer mental disorders. However, the brain structural basis of individual pathological narcissism trait among healthy people has not yet been investigated with surface-based morphometry. Thus, in this study, we investigated the relationship between cortical thickness (CT), cortical volume (CV), and individual pathological narcissism in a large healthy sample of 176 college students. Multiple regression was used to analyze the correlation between regional CT, CV, and the total Pathological Narcissism Inventory (PNI) score, adjusting for age, sex, and total intracranial volume. The results showed that the PNI score was significantly negatively associated with CT and CV in the right dorsolateral prefrontal cortex (DLPFC, key region of the central executive network, CEN), which might be associated with impaired emotion regulation processes. Furthermore, the PNI score showed significant negative associations with CV in the right postcentral gyrus, left medial prefrontal cortex (MPFC), and the CT in the right inferior frontal cortex (IFG, overlap with social brain network), which may be related to impairments in social cognition. Together, these findings suggest a unique structural basis for individual differences in pathological narcissism, distributed across different gray matter regions of the social brain network and CEN. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  12. Prefrontal Cortex Networks Shift from External to Internal Modes during Learning

    Science.gov (United States)

    Brincat, Scott L.

    2016-01-01

    As we learn about items in our environment, their neural representations become increasingly enriched with our acquired knowledge. But there is little understanding of how network dynamics and neural processing related to external information changes as it becomes laden with “internal” memories. We sampled spiking and local field potential activity simultaneously from multiple sites in the lateral prefrontal cortex (PFC) and the hippocampus (HPC)—regions critical for sensory associations—of monkeys performing an object paired-associate learning task. We found that in the PFC, evoked potentials to, and neural information about, external sensory stimulation decreased while induced beta-band (∼11–27 Hz) oscillatory power and synchrony associated with “top-down” or internal processing increased. By contrast, the HPC showed little evidence of learning-related changes in either spiking activity or network dynamics. The results suggest that during associative learning, PFC networks shift their resources from external to internal processing. SIGNIFICANCE STATEMENT As we learn about items in our environment, their representations in our brain become increasingly enriched with our acquired “top-down” knowledge. We found that in the prefrontal cortex, but not the hippocampus, processing of external sensory inputs decreased while internal network dynamics related to top-down processing increased. The results suggest that during learning, prefrontal cortex networks shift their resources from external (sensory) to internal (memory) processing. PMID:27629722

  13. 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.

  14. Complex neural codes in rat prelimbic cortex are stable across days on a spatial decision task

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    Nathaniel J. Powell

    2014-04-01

    Full Text Available The rodent prelimbic cortex has been shown to play an important role in cognitive processing, and has been implicated in encoding many different parameters relevant to solving decision-making tasks. However, it is not known how the prelimbic cortex represents all these disparate variables, and if they are simultaneously represented when the task requires it. In order to investigate this question, we trained rats to run the Multiple-T Left Right Alternate (MT-LRA task and recorded multi-unit ensembles from their prelimbic regions. Significant populations of cells in the prelimbic cortex represented the strategy controlling reward receipt on a given lap, whether the animal chose to go right or left on a given lap, and whether the animal made a correct decision or an error on a given lap. These populations overlapped in the cells recorded, with several cells demonstrating differential firing to all three variables. The spatial and strategic firing patterns of individual prelimbic cells were highly conserved across several days of running this task, indicating that each cell encoded the same information across days.

  15. Basic level category structure emerges gradually across human ventral visual cortex.

    Science.gov (United States)

    Iordan, Marius Cătălin; Greene, Michelle R; Beck, Diane M; Fei-Fei, Li

    2015-07-01

    Objects can be simultaneously categorized at multiple levels of specificity ranging from very broad ("natural object") to very distinct ("Mr. Woof"), with a mid-level of generality (basic level: "dog") often providing the most cognitively useful distinction between categories. It is unknown, however, how this hierarchical representation is achieved in the brain. Using multivoxel pattern analyses, we examined how well each taxonomic level (superordinate, basic, and subordinate) of real-world object categories is represented across occipitotemporal cortex. We found that, although in early visual cortex objects are best represented at the subordinate level (an effect mostly driven by low-level feature overlap between objects in the same category), this advantage diminishes compared to the basic level as we move up the visual hierarchy, disappearing in object-selective regions of occipitotemporal cortex. This pattern stems from a combined increase in within-category similarity (category cohesion) and between-category dissimilarity (category distinctiveness) of neural activity patterns at the basic level, relative to both subordinate and superordinate levels, suggesting that successive visual areas may be optimizing basic level representations.

  16. Mirror therapy in lower limb amputees. A look beyond primary motor cortex reorganization

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    Seidel, S.; Essmeister, M.; Sycha, T.; Auff, E. [Vienna Medical Univ. (Austria). Dept. of Neurology; Kasprian, G.; Furtner, J.; Schoepf, V.; Prayer, D. [Vienna Medical Univ. (Austria). Dept. of Neuroradiology

    2011-11-15

    Phantom pain in upper limb amputees is associated with the extent of reorganization in the primary sensorimotor cortex. Mirror visual feedback therapy has been shown to improve phantom pain. We investigated the extent of cortical reorganization in lower limb amputees and changes in neural activity induced by mirror therapy. Eight lower limb amputees underwent 12 sessions of MVFT and functional magnetic resonance imaging (fMRI) of the brain before the first and after the last MVFT session. FMRI sessions consisted of two runs in which subjects were instructed to perform repetitive movement of the healthy and phantom ankle. Before MVFT, the mean phantom pain intensity was 4.6 {+-} 3.1 on a visual analog scale and decreased to 1.8 {+-} 1.7 (p = 0.04). We did not observe a consistent pattern of cortical activation in primary sensorimotor areas during phantom limb movements. Following MVFT, increased activity was obtained in the right orbitofrontal cortex during phantom ankle movements. Comparison of cortical activity during movements of the phantom ankle and the intact ankle showed significantly higher activity in the left inferior frontal cortex (pars triangularis). These results question the known association between phantom pain and primary sensorimotor reorganization and propose reorganizational changes involving multiple cortical areas in lower limb amputees. Finally, reduction of phantom pain after mirror visual feedback therapy was associated with increased prefrontal cortical activity during phantom ankle movements. (orig.)

  17. Cortical oscillations in auditory perception and speech: evidence for two temporal windows in human auditory cortex

    Directory of Open Access Journals (Sweden)

    Huan eLuo

    2012-05-01

    Full Text Available Natural sounds, including vocal communication sounds, contain critical information at multiple time scales. Two essential temporal modulation rates in speech have been argued to be in the low gamma band (~20-80 ms duration information and the theta band (~150-300 ms, corresponding to segmental and syllabic modulation rates, respectively. On one hypothesis, auditory cortex implements temporal integration using time constants closely related to these values. The neural correlates of a proposed dual temporal window mechanism in human auditory cortex remain poorly understood. We recorded MEG responses from participants listening to non-speech auditory stimuli with different temporal structures, created by concatenating frequency-modulated segments of varied segment durations. We show that these non-speech stimuli with temporal structure matching speech-relevant scales (~25 ms and ~200 ms elicit reliable phase tracking in the corresponding associated oscillatory frequencies (low gamma and theta bands. In contrast, stimuli with non-matching temporal structure do not. Furthermore, the topography of theta band phase tracking shows rightward lateralization while gamma band phase tracking occurs bilaterally. The results support the hypothesis that there exists multi-time resolution processing in cortex on discontinuous scales and provide evidence for an asymmetric organization of temporal analysis (asymmetrical sampling in time, AST. The data argue for a macroscopic-level neural mechanism underlying multi-time resolution processing: the sliding and resetting of intrinsic temporal windows on privileged time scales.

  18. Mirror therapy in lower limb amputees. A look beyond primary motor cortex reorganization

    International Nuclear Information System (INIS)

    Seidel, S.; Essmeister, M.; Sycha, T.; Auff, E.; Kasprian, G.; Furtner, J.; Schoepf, V.; Prayer, D.

    2011-01-01

    Phantom pain in upper limb amputees is associated with the extent of reorganization in the primary sensorimotor cortex. Mirror visual feedback therapy has been shown to improve phantom pain. We investigated the extent of cortical reorganization in lower limb amputees and changes in neural activity induced by mirror therapy. Eight lower limb amputees underwent 12 sessions of MVFT and functional magnetic resonance imaging (fMRI) of the brain before the first and after the last MVFT session. FMRI sessions consisted of two runs in which subjects were instructed to perform repetitive movement of the healthy and phantom ankle. Before MVFT, the mean phantom pain intensity was 4.6 ± 3.1 on a visual analog scale and decreased to 1.8 ± 1.7 (p = 0.04). We did not observe a consistent pattern of cortical activation in primary sensorimotor areas during phantom limb movements. Following MVFT, increased activity was obtained in the right orbitofrontal cortex during phantom ankle movements. Comparison of cortical activity during movements of the phantom ankle and the intact ankle showed significantly higher activity in the left inferior frontal cortex (pars triangularis). These results question the known association between phantom pain and primary sensorimotor reorganization and propose reorganizational changes involving multiple cortical areas in lower limb amputees. Finally, reduction of phantom pain after mirror visual feedback therapy was associated with increased prefrontal cortical activity during phantom ankle movements. (orig.)

  19. Voltage Imaging of Waking Mouse Cortex Reveals Emergence of Critical Neuronal Dynamics

    Science.gov (United States)

    Scott, Gregory; Fagerholm, Erik D.; Mutoh, Hiroki; Leech, Robert; Sharp, David J.; Shew, Woodrow L.

    2014-01-01

    Complex cognitive processes require neuronal activity to be coordinated across multiple scales, ranging from local microcircuits to cortex-wide networks. However, multiscale cortical dynamics are not well understood because few experimental approaches have provided sufficient support for hypotheses involving multiscale interactions. To address these limitations, we used, in experiments involving mice, genetically encoded voltage indicator imaging, which measures cortex-wide electrical activity at high spatiotemporal resolution. Here we show that, as mice recovered from anesthesia, scale-invariant spatiotemporal patterns of neuronal activity gradually emerge. We show for the first time that this scale-invariant activity spans four orders of magnitude in awake mice. In contrast, we found that the cortical dynamics of anesthetized mice were not scale invariant. Our results bridge empirical evidence from disparate scales and support theoretical predictions that the awake cortex operates in a dynamical regime known as criticality. The criticality hypothesis predicts that small-scale cortical dynamics are governed by the same principles as those governing larger-scale dynamics. Importantly, these scale-invariant principles also optimize certain aspects of information processing. Our results suggest that during the emergence from anesthesia, criticality arises as information processing demands increase. We expect that, as measurement tools advance toward larger scales and greater resolution, the multiscale framework offered by criticality will continue to provide quantitative predictions and insight on how neurons, microcircuits, and large-scale networks are dynamically coordinated in the brain. PMID:25505314

  20. Functional heterogeneity of conflict, error, task-switching, and unexpectedness effects within medial prefrontal cortex.

    Science.gov (United States)

    Nee, Derek Evan; Kastner, Sabine; Brown, Joshua W

    2011-01-01

    The last decade has seen considerable discussion regarding a theoretical account of medial prefrontal cortex (mPFC) function with particular focus on the anterior cingulate cortex. The proposed theories have included conflict detection, error likelihood prediction, volatility monitoring, and several distinct theories of error detection. Arguments for and against particular theories often treat mPFC as functionally homogeneous, or at least nearly so, despite some evidence for distinct functional subregions. Here we used functional magnetic resonance imaging (fMRI) to simultaneously contrast multiple effects of error, conflict, and task-switching that have been individually construed in support of various theories. We found overlapping yet functionally distinct subregions of mPFC, with activations related to dominant error, conflict, and task-switching effects successively found along a rostral-ventral to caudal-dorsal gradient within medial prefrontal cortex. Activations in the rostral cingulate zone (RCZ) were strongly correlated with the unexpectedness of outcomes suggesting a role in outcome prediction and preparing control systems to deal with anticipated outcomes. The results as a whole support a resolution of some ongoing debates in that distinct theories may each pertain to corresponding distinct yet overlapping subregions of mPFC. Copyright © 2010 Elsevier Inc. All rights reserved.

  1. The gene cortex controls mimicry and crypsis in butterflies and moths.

    Science.gov (United States)

    Nadeau, Nicola J; Pardo-Diaz, Carolina; Whibley, Annabel; Supple, Megan A; Saenko, Suzanne V; Wallbank, Richard W R; Wu, Grace C; Maroja, Luana; Ferguson, Laura; Hanly, Joseph J; Hines, Heather; Salazar, Camilo; Merrill, Richard M; Dowling, Andrea J; ffrench-Constant, Richard H; Llaurens, Violaine; Joron, Mathieu; McMillan, W Owen; Jiggins, Chris D

    2016-06-02

    The wing patterns of butterflies and moths (Lepidoptera) are diverse and striking examples of evolutionary diversification by natural selection. Lepidopteran wing colour patterns are a key innovation, consisting of arrays of coloured scales. We still lack a general understanding of how these patterns are controlled and whether this control shows any commonality across the 160,000 moth and 17,000 butterfly species. Here, we use fine-scale mapping with population genomics and gene expression analyses to identify a gene, cortex, that regulates pattern switches in multiple species across the mimetic radiation in Heliconius butterflies. cortex belongs to a fast-evolving subfamily of the otherwise highly conserved fizzy family of cell-cycle regulators, suggesting that it probably regulates pigmentation patterning by regulating scale cell development. In parallel with findings in the peppered moth (Biston betularia), our results suggest that this mechanism is common within Lepidoptera and that cortex has become a major target for natural selection acting on colour and pattern variation in this group of insects.

  2. Attention to Color Sharpens Neural Population Tuning via Feedback Processing in the Human Visual Cortex Hierarchy.

    Science.gov (United States)

    Bartsch, Mandy V; Loewe, Kristian; Merkel, Christian; Heinze, Hans-Jochen; Schoenfeld, Mircea A; Tsotsos, John K; Hopf, Jens-Max

    2017-10-25

    Attention can facilitate the selection of elementary object features such as color, orientation, or motion. This is referred to as feature-based attention and it is commonly attributed to a modulation of the gain and tuning of feature-selective units in visual cortex. Although gain mechanisms are well characterized, little is known about the cortical processes underlying the sharpening of feature selectivity. Here, we show with high-resolution magnetoencephalography in human observers (men and women) that sharpened selectivity for a particular color arises from feedback processing in the human visual cortex hierarchy. To assess color selectivity, we analyze the response to a color probe that varies in color distance from an attended color target. We find that attention causes an initial gain enhancement in anterior ventral extrastriate cortex that is coarsely selective for the target color and transitions within ∼100 ms into a sharper tuned profile in more posterior ventral occipital cortex. We conclude that attention sharpens selectivity over time by attenuating the response at lower levels of the cortical hierarchy to color values neighboring the target in color space. These observations support computational models proposing that attention tunes feature selectivity in visual cortex through backward-propagating attenuation of units less tuned to the target. SIGNIFICANCE STATEMENT Whether searching for your car, a particular item of clothing, or just obeying traffic lights, in everyday life, we must select items based on color. But how does attention allow us to select a specific color? Here, we use high spatiotemporal resolution neuromagnetic recordings to examine how color selectivity emerges in the human brain. We find that color selectivity evolves as a coarse to fine process from higher to lower levels within the visual cortex hierarchy. Our observations support computational models proposing that feature selectivity increases over time by attenuating the

  3. Multiple sclerosis

    International Nuclear Information System (INIS)

    Sadashima, Hiromichi; Kusaka, Hirofumi; Imai, Terukuni; Takahashi, Ryosuke; Matsumoto, Sadayuki; Yamamoto, Toru; Yamasaki, Masahiro; Maya, Kiyomi

    1986-01-01

    Eleven patients with a definite diagnosis of multiple sclerosis were examined in terms of correlations between the clinical features and the results of cranial computed tomography (CT), and magnetic resonance imaging (MRI). Results: In 5 of the 11 patients, both CT and MRI demonstrated lesions consistent with a finding of multiple sclerosis. In 3 patients, only MRI demonstrated lesions. In the remaining 3 patients, neither CT nor MRI revealed any lesion in the brain. All 5 patients who showed abnormal findings on both CT and MRI had clinical signs either of cerebral or brainstem - cerebellar lesions. On the other hand, two of the 3 patients with normal CT and MRI findings had optic-nerve and spinal-cord signs. Therefore, our results suggested relatively good correlations between the clinical features, CT, and MRI. MRI revealed cerebral lesions in two of the four patients with clinical signs of only optic-nerve and spinal-cord lesions. MRI demonstrated sclerotic lesions in 3 of the 6 patients whose plaques were not detected by CT. In conclusion, MRI proved to be more helpful in the demonstration of lesions attributable to chronic multiple sclerosis. (author)

  4. Effect of camphor essential oil on rat cerebral cortex activity as manifested by fractal dimension changes

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    Grbić G.

    2008-01-01

    Full Text Available The aim of our study was to investigate the effect of camphor essential oil on rat cerebral cortex activity by fractal analysis. Fractal dimension (FD values of the parietal electrocortical activity were calculated before and after intra-peritoneal administration of camphor essential oil (450-675 μl/kg in anesthetized rats. Camphor oil induced seizure-like activity with single and multiple spiking of high amplitudes in the parietal electrocorticogram and occasional clonic limb convulsions. The FD values of cortical activity after camphor oil administration increased on the average. Only FD values of cortical ECoG sequences were lower than those before camphor oil administration.

  5. TMS-induced neural noise in sensory cortex interferes with short-term memory storage in prefrontal cortex.

    Science.gov (United States)

    Bancroft, Tyler D; Hogeveen, Jeremy; Hockley, William E; Servos, Philip

    2014-01-01

    In a previous study, Harris et al. (2002) found disruption of vibrotactile short-term memory after applying single-pulse transcranial magnetic stimulation (TMS) to primary somatosensory cortex (SI) early in the maintenance period, and suggested that this demonstrated a role for SI in vibrotactile memory storage. While such a role is compatible with recent suggestions that sensory cortex is the storage substrate for working memory, it stands in contrast to a relatively large body of evidence from human EEG and single-cell recording in primates that instead points to prefrontal cortex as the storage substrate for vibrotactile memory. In the present study, we use computational methods to demonstrate how Harris et al.'s results can be reproduced by TMS-induced activity in sensory cortex and subsequent feedforward interference with memory traces stored in prefrontal cortex, thereby reconciling discordant findings in the tactile memory literature.

  6. Fetal frontal cortex transplant (14C) 2-deoxyglucose uptake and histology: survival in cavities of host rat brain motor cortex

    International Nuclear Information System (INIS)

    Sharp, F.R.; Gonzalez, M.F.

    1984-01-01

    Fetal frontal neocortex from 18-day-old rat embryonic brain was transplanted into cavities in 30-day-old host motor cortex. Sixty days after transplantation, 5 of 15 transplanted rats had surviving fetal transplants. The fetal cortex transplants were physically attached to the host brain, completely filled the original cavity, and had numerous surviving cells including pyramidal neurons. Cell lamination within the fetal transplant was abnormal. The ( 14 C) 2-deoxyglucose uptake of all five of the fetal neocortex transplants was less than adjacent cortex and contralateral host motor-sensory cortex, but more than adjacent corpus callosum white matter. The results indicate that fetal frontal neocortex can be transplanted into damaged rat motor cortex. The metabolic rate of the transplants suggests they could be partially functional

  7. Intracellular responses to frequency modulated tones in the dorsal cortex of the mouse inferior colliculus

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    Ruediger eGeis

    2013-01-01

    Full Text Available Frequency modulations occur in many natural sounds, including vocalizations. The neuronal response to frequency modulated (FM stimuli has been studied extensively in different brain areas, with an emphasis on the auditory cortex and the central nucleus of the inferior colliculus. Here, we measured the responses to FM sweeps in whole-cell recordings from neurons in the dorsal cortex of the mouse inferior colliculus. Both up- and downward logarithmic FM sweeps were presented at two different speeds to both the ipsi- and the contralateral ear. Based on the number of action potentials that were fired, between 10-24% of cells were selective for rate or direction of the FM sweeps. A somewhat lower percentage of cells, 6-21%, showed selectivity based on EPSP size. To study the mechanisms underlying the generation of FM selectivity, we compared FM responses with responses to simple tones in the same cells. We found that if pairs of neurons responded in a similar way to simple tones, they generally also responded in a similar way to FM sweeps. Further evidence that FM selectivity can be generated within the dorsal cortex was obtained by reconstructing FM sweeps from the response to simple tones using three different models. In about half of the direction selective neurons the selectivity was generated by spectrally asymmetric synaptic inhibition. In addition, evidence for direction selectivity based on the timing of excitatory responses was also obtained in some cells. No clear evidence for the local generation of rate selectivity was obtained. We conclude that FM direction selectivity can be generated within the dorsal cortex of the mouse inferior colliculus by multiple mechanisms.

  8. Serial pathways from primate prefrontal cortex to autonomic areas may influence emotional expression

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    Saha Subhash

    2003-10-01

    Full Text Available Abstract Background Experiencing emotions engages high-order orbitofrontal and medial prefrontal areas, and expressing emotions involves low-level autonomic structures and peripheral organs. How is information from the cortex transmitted to the periphery? We used two parallel approaches to map simultaneously multiple pathways to determine if hypothalamic autonomic centres are a key link for orbitofrontal areas and medial prefrontal areas, which have been associated with emotional processes, as well as low-level spinal and brainstem autonomic structures. The latter innervate peripheral autonomic organs, whose activity is markedly increased during emotional arousal. Results We first determined if pathways linking the orbitofrontal cortex with the hypothalamus overlapped with projection neurons directed to the intermediolateral column of the spinal cord, with the aid of neural tracers injected in these disparate structures. We found that axons from orbitofrontal and medial prefrontal cortices converged in the hypothalamus with neurons projecting to brainstem and spinal autonomic centers, linking the highest with the lowest levels of the neuraxis. Using a parallel approach, we injected bidirectional tracers in the lateral hypothalamic area, an autonomic center, to label simultaneously cortical pathways leading to the hypothalamus, as well as hypothalamic axons projecting to low-level brainstem and spinal autonomic centers. We found densely distributed projection neurons in medial prefrontal and orbitofrontal cortices leading to the hypothalamus, as well as hypothalamic axonal terminations in several brainstem structures and the intermediolateral column of the spinal cord, which innervate peripheral autonomic organs. We then provided direct evidence that axons from medial prefrontal cortex synapse with hypothalamic neurons, terminating as large boutons, comparable in size to the highly efficient thalamocortical system. The interlinked orbitofrontal

  9. Estradiol and the Development of the Cerebral Cortex: An Unexpected Role?

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    Matthew C. S. Denley

    2018-05-01

    Full Text Available The cerebral cortex undergoes rapid folding in an “inside-outside” manner during embryonic development resulting in the establishment of six discrete cortical layers. This unique cytoarchitecture occurs via the coordinated processes of neurogenesis and cell migration. In addition, these processes are fine-tuned by a number of extracellular cues, which exert their effects by regulating intracellular signaling pathways. Interestingly, multiple brain regions have been shown to develop in a sexually dimorphic manner. In many cases, estrogens have been demonstrated to play an integral role in mediating these sexual dimorphisms in both males and females. Indeed, 17β-estradiol, the main biologically active estrogen, plays a critical organizational role during early brain development and has been shown to be pivotal in the sexually dimorphic development and regulation of the neural circuitry underlying sex-typical and socio-aggressive behaviors in males and females. However, whether and how estrogens, and 17β-estradiol in particular, regulate the development of the cerebral cortex is less well understood. In this review, we outline the evidence that estrogens are not only present but are engaged and regulate molecular machinery required for the fine-tuning of processes central to the cortex. We discuss how estrogens are thought to regulate the function of key molecular players and signaling pathways involved in corticogenesis, and where possible, highlight if these processes are sexually dimorphic. Collectively, we hope this review highlights the need to consider how estrogens may influence the development of brain regions directly involved in the sex-typical and socio-aggressive behaviors as well as development of sexually dimorphic regions such as the cerebral cortex.

  10. Decoding sound level in the marmoset primary auditory cortex.

    Science.gov (United States)

    Sun, Wensheng; Marongelli, Ellisha N; Watkins, Paul V; Barbour, Dennis L

    2017-10-01

    Neurons that respond favorably to a particular sound level have been observed throughout the central auditory system, becoming steadily more common at higher processing areas. One theory about the role of these level-tuned or nonmonotonic neurons is the level-invariant encoding of sounds. To investigate this theory, we simulated various subpopulations of neurons by drawing from real primary auditory cortex (A1) neuron responses and surveyed their performance in forming different sound level representations. Pure nonmonotonic subpopulations did not provide the best level-invariant decoding; instead, mixtures of monotonic and nonmonotonic neurons provided the most accurate decoding. For level-fidelity decoding, the inclusion of nonmonotonic neurons slightly improved or did not change decoding accuracy until they constituted a high proportion. These results indicate that nonmonotonic neurons fill an encoding role complementary to, rather than alternate to, monotonic neurons. NEW & NOTEWORTHY Neurons with nonmonotonic rate-level functions are unique to the central auditory system. These level-tuned neurons have been proposed to account for invariant sound perception across sound levels. Through systematic simulations based on real neuron responses, this study shows that neuron populations perform sound encoding optimally when containing both monotonic and nonmonotonic neurons. The results indicate that instead of working independently, nonmonotonic neurons complement the function of monotonic neurons in different sound-encoding contexts. Copyright © 2017 the American Physiological Society.

  11. Spatial organization of astrocytes in ferret visual cortex

    Science.gov (United States)

    López‐Hidalgo, Mónica; Hoover, Walter B.

    2016-01-01

    ABSTRACT Astrocytes form an intricate partnership with neural circuits to influence numerous cellular and synaptic processes. One prominent organizational feature of astrocytes is the “tiling” of the brain with non‐overlapping territories. There are some documented species and brain region–specific astrocyte specializations, but the extent of astrocyte diversity and circuit specificity are still unknown. We quantitatively defined the rules that govern the spatial arrangement of astrocyte somata and territory overlap in ferret visual cortex using a combination of in vivo two‐photon imaging, morphological reconstruction, immunostaining, and model simulations. We found that ferret astrocytes share, on average, half of their territory with other astrocytes. However, a specific class of astrocytes, abundant in thalamo‐recipient cortical layers (“kissing” astrocytes), overlap markedly less. Together, these results demonstrate novel features of astrocyte organization indicating that different classes of astrocytes are arranged in a circuit‐specific manner and that tiling does not apply universally across brain regions and species. J. Comp. Neurol. 524:3561–3576, 2016. © 2016 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. PMID:27072916

  12. Stereoscopic vision in the absence of the lateral occipital cortex.

    Directory of Open Access Journals (Sweden)

    Jenny C A Read

    2010-09-01

    Full Text Available Both dorsal and ventral cortical visual streams contain neurons sensitive to binocular disparities, but the two streams may underlie different aspects of stereoscopic vision. Here we investigate stereopsis in the neurological patient D.F., whose ventral stream, specifically lateral occipital cortex, has been damaged bilaterally, causing profound visual form agnosia. Despite her severe damage to cortical visual areas, we report that DF's stereo vision is strikingly unimpaired. She is better than many control observers at using binocular disparity to judge whether an isolated object appears near or far, and to resolve ambiguous structure-from-motion. DF is, however, poor at using relative disparity between features at different locations across the visual field. This may stem from a difficulty in identifying the surface boundaries where relative disparity is available. We suggest that the ventral processing stream may play a critical role in enabling healthy observers to extract fine depth information from relative disparities within one surface or between surfaces located in different parts of the visual field.

  13. Electrical stimulation of the dorsolateral prefrontal cortex improves memory monitoring.

    Science.gov (United States)

    Chua, Elizabeth F; Ahmed, Rifat

    2016-05-01

    The ability to accurately monitor one's own memory is an important feature of normal memory function. Converging evidence from neuroimaging and lesion studies have implicated the dorsolateral prefrontal cortex (DLPFC) in memory monitoring. Here we used high definition transcranial direct stimulation (HD-tDCS), a non-invasive form of brain stimulation, to test whether the DLPFC has a causal role in memory monitoring, and the nature of that role. We used a metamemory monitoring task, in which participants first attempted to recall the answer to a general knowledge question, then gave a feeling-of-knowing (FOK) judgment, followed by a forced choice recognition task. When participants received DLPFC stimulation, their feeling-of-knowing judgments were better predictors of memory performance, i.e., they had better memory monitoring accuracy, compared to stimulation of a control site, the anterior temporal lobe (ATL). Effects of DLPFC stimulation were specific to monitoring accuracy, as there was no significant increase in memory performance, and if anything, there was poorer memory performance with DLPFC stimulation. Thus we have demonstrated a causal role for the DLPFC in memory monitoring, and showed that electrically stimulating the left DLPFC led people to more accurately monitor and judge their own memory. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Task-Relevant and Accessory Items in Working Memory Have Opposite Effects on Activity in Extrastriate Cortex

    OpenAIRE

    Peters, J.C.; Roelfsema, P.R.; Goebel, R.

    2012-01-01

    During visual search, the working memory (WM) representation of the search target guides attention to matching items in the visual scene. However, we can hold multiple items in WM. Do all these items guide attention at the same time? Using a new functional magnetic resonance imaging visual search paradigm, we found that items in WM can attain two different states that influence activity in extrastriate visual cortex in opposite directions: whereas the target item in WM enhanced processing of ...

  15. The spatiotopic 'visual' cortex of the blind

    Science.gov (United States)

    Likova, Lora

    2012-03-01

    Visual cortex activity in the blind has been shown in sensory tasks. Can it be activated in memory tasks? If so, are inherent features of its organization meaningfully employed? Our recent results in short-term blindfolded subjects imply that human primary visual cortex (V1) may operate as a modality-independent 'sketchpad' for working memory (Likova, 2010a). Interestingly, the spread of the V1 activation approximately corresponded to the spatial extent of the images in terms of their angle of projection to the subject. We now raise the questions of whether under long-term visual deprivation V1 is also employed in non-visual memory task, in particular in congenitally blind individuals, who have never had visual stimulation to guide the development of the visual area organization, and whether such spatial organization is still valid for the same paradigm that was used in blindfolded individuals. The outcome has implications for an emerging reconceptualization of the principles of brain architecture and its reorganization under sensory deprivation. Methods: We used a novel fMRI drawing paradigm in congenitally and late-onset blind, compared with sighted and blindfolded subjects in three conditions of 20s duration, separated by 20s rest-intervals, (i) Tactile Exploration: raised-line images explored and memorized; (ii) Tactile Memory Drawing: drawing the explored image from memory; (iii) Scribble: mindless drawing movements with no memory component. Results and Conclusions: V1 was strongly activated for Tactile Memory Drawing and Tactile Exploration in these totally blind subjects. Remarkably, after training, even in the memory task, the mapping of V1 activation largely corresponded to the angular projection of the tactile stimuli relative to the ego-center (i.e., the effective visual angle at the head); beyond this projective boundary, peripheral V1 signals were dramatically reduced or even suppressed. The matching extent of the activation in the congenitally blind

  16. Auditory cortex involvement in emotional learning and memory.

    Science.gov (United States)

    Grosso, A; Cambiaghi, M; Concina, G; Sacco, T; Sacchetti, B

    2015-07-23

    Emotional memories represent the core of human and animal life and drive future choices and behaviors. Early research involving brain lesion studies in animals lead to the idea that the auditory cortex participates in emotional learning by processing the sensory features of auditory stimuli paired with emotional consequences and by transmitting this information to the amygdala. Nevertheless, electrophysiological and imaging studies revealed that, following emotional experiences, the auditory cortex undergoes learning-induced changes that are highly specific, associative and long lasting. These studies suggested that the role played by the auditory cortex goes beyond stimulus elaboration and transmission. Here, we discuss three major perspectives created by these data. In particular, we analyze the possible roles of the auditory cortex in emotional learning, we examine the recruitment of the auditory cortex during early and late memory trace encoding, and finally we consider the functional interplay between the auditory cortex and subcortical nuclei, such as the amygdala, that process affective information. We conclude that, starting from the early phase of memory encoding, the auditory cortex has a more prominent role in emotional learning, through its connections with subcortical nuclei, than is typically acknowledged. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Distribution of catecholamines and serotonin in the rat cerebral cortex:

    International Nuclear Information System (INIS)

    Reader, T.A.

    1981-01-01

    The rat cerebral cortex was dissected in five regions and analyzed for the catecholamines noradrenaline, adrenaline and dopamine, and for the indoleamine seroton in using sensitive radioenzymatic assay methods with thin-layer-chromatography. The noradrenaline concentration was highest in the ventral cortex, lateral to the hypothalamus, had intermediate values for the prefrontal, frontal and parietal cortical areas and was lowest in the occipital cortex. Dopamine levels were also highest in the cortex lateral to the hypothalamus, and moderate in the prefrontal and frontal cortical areas, with the lowest values measured for the occipital cortex. The ratios dopamine/noradrenaline further support the hypothesis that they are independent transmitters. Traces of adrenaline were measured in all regions examined. The serotonin distribution was found to be non-homogeneous, with the highest values for the prefrontal cortex and ventral cortex lateral to the hypothalamus. The functional significance of these amines and their ratios are discussed in relation to their role as putative modulators of cortical neuronal excitability. (author)

  18. Forelimb training drives transient map reorganization in ipsilateral motor cortex.

    Science.gov (United States)

    Pruitt, David T; Schmid, Ariel N; Danaphongse, Tanya T; Flanagan, Kate E; Morrison, Robert A; Kilgard, Michael P; Rennaker, Robert L; Hays, Seth A

    2016-10-15

    Skilled motor training results in reorganization of contralateral motor cortex movement representations. The ipsilateral motor cortex is believed to play a role in skilled motor control, but little is known about how training influences reorganization of ipsilateral motor representations of the trained limb. To determine whether training results in reorganization of ipsilateral motor cortex maps, rats were trained to perform the isometric pull task, an automated motor task that requires skilled forelimb use. After either 3 or 6 months of training, intracortical microstimulation (ICMS) mapping was performed to document motor representations of the trained forelimb in the hemisphere ipsilateral to that limb. Motor training for 3 months resulted in a robust expansion of right forelimb representation in the right motor cortex, demonstrating that skilled motor training drives map plasticity ipsilateral to the trained limb. After 6 months of training, the right forelimb representation in the right motor cortex was significantly smaller than the representation observed in rats trained for 3 months and similar to untrained controls, consistent with a normalization of motor cortex maps. Forelimb map area was not correlated with performance on the trained task, suggesting that task performance is maintained despite normalization of cortical maps. This study provides new insights into how the ipsilateral cortex changes in response to skilled learning and may inform rehabilitative strategies to enhance cortical plasticity to support recovery after brain injury. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Multiple sclerosis

    DEFF Research Database (Denmark)

    Stenager, E; Knudsen, L; Jensen, K

    1994-01-01

    The aim of the study was to examine the correlation between anxiety and physical impairment and to discover whether anxiety correlated with specific forms of cognitive dysfunction. Ninety-four patients (42 females, 52 males) with definite MS entered the study. Anxiety was measured using the State...

  20. Decision salience signals in posterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Sarah eHeilbronner

    2011-04-01

    Full Text Available Despite its phylogenetic antiquity and clinical importance, the posterior cingulate cortex (CGp remains an enigmatic nexus of attention, memory, motivation, and decision making. Here we show that CGp neurons track decision salience—the degree to which an option differs from a standard—but not the subjective value of a decision. To do this, we recorded the spiking activity of CGp neurons in monkeys choosing between options varying in reward-related risk, delay to reward, and social outcomes, each of which varied in level of decision salience. Firing rates were higher when monkeys chose the risky option, consistent with their risk-seeking preferences, but were also higher when monkeys chose the delayed and social options, contradicting their preferences. Thus, across decision contexts, neuronal activity was uncorrelated with how much monkeys valued a given option, as inferred from choice. Instead, neuronal activity signaled the deviation of the chosen option from the standard, independently of how it differed. The observed decision salience signals suggest a role for CGp in the flexible allocation of neural resources to motivationally significant information, akin to the role of attention in selective processing of sensory inputs.

  1. Frontopolar cortex mediates abstract integration in analogy.

    Science.gov (United States)

    Green, Adam E; Fugelsang, Jonathan A; Kraemer, David J M; Shamosh, Noah A; Dunbar, Kevin N

    2006-06-22

    Integration of abstractly similar relations during analogical reasoning was investigated using functional magnetic resonance imaging. Activation elicited by an analogical reasoning task that required both complex working memory and integration of abstractly similar relations was compared to activation elicited by a non-analogical task that required complex working memory in the absence of abstract relational integration. A left-sided region of the frontal pole of the brain (BA 9/10) was selectively active for the abstract relational integration component of analogical reasoning. Analogical reasoning also engaged a left-sided network of parieto-frontal regions. Activity in this network during analogical reasoning is hypothesized to reflect categorical alignment of individual component terms that make up analogies. This parieto-frontal network was also engaged by the complex control task, which involved explicit categorization, but not by a simpler control task, which did not involve categorization. We hypothesize that frontopolar cortex mediates abstract relational integration in complex reasoning while parieto-frontal regions mediate working memory processes, including manipulation of terms for the purpose of categorical alignment, that facilitate this integration.

  2. Retinal oscillations carry visual information to cortex

    Directory of Open Access Journals (Sweden)

    Kilian Koepsell

    2009-04-01

    Full Text Available Thalamic relay cells fire action potentials that transmit information from retina to cortex. The amount of information that spike trains encode is usually estimated from the precision of spike timing with respect to the stimulus. Sensory input, however, is only one factor that influences neural activity. For example, intrinsic dynamics, such as oscillations of networks of neurons, also modulate firing pattern. Here, we asked if retinal oscillations might help to convey information to neurons downstream. Specifically, we made whole-cell recordings from relay cells to reveal retinal inputs (EPSPs and thalamic outputs (spikes and then analyzed these events with information theory. Our results show that thalamic spike trains operate as two multiplexed channels. One channel, which occupies a low frequency band (<30 Hz, is encoded by average firing rate with respect to the stimulus and carries information about local changes in the visual field over time. The other operates in the gamma frequency band (40-80 Hz and is encoded by spike timing relative to retinal oscillations. At times, the second channel conveyed even more information than the first. Because retinal oscillations involve extensive networks of ganglion cells, it is likely that the second channel transmits information about global features of the visual scene.

  3. Navigating actions through the rodent parietal cortex

    Directory of Open Access Journals (Sweden)

    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.

  4. Development of rat female genital cortex and control of female puberty by sexual touch.

    Directory of Open Access Journals (Sweden)

    Constanze Lenschow

    2017-09-01

    Full Text Available Rat somatosensory cortex contains a large sexually monomorphic genital representation. Genital cortex undergoes an unusual 2-fold expansion during puberty. Here, we investigate genital cortex development and female rat sexual maturation. Ovariectomies and estradiol injections suggested sex hormones cause the pubertal genital cortex expansion but not its maintenance at adult size. Genital cortex expanded by thalamic afferents invading surrounding dysgranular cortex. Genital touch was a dominant factor driving female sexual maturation. Raising female rats in contact with adult males promoted genital cortex expansion, whereas contact to adult females or nontactile (audio-visual-olfactory male cues did not. Genital touch imposed by human experimenters powerfully advanced female genital cortex development and sexual maturation. Long-term blocking of genital cortex by tetrodotoxin in pubescent females housed with males prevented genital cortex expansion and decelerated vaginal opening. Sex hormones, sexual experience, and neural activity shape genital cortex, which contributes to the puberty promoting effects of sexual touch.

  5. Development of rat female genital cortex and control of female puberty by sexual touch.

    Science.gov (United States)

    Lenschow, Constanze; Sigl-Glöckner, Johanna; Brecht, Michael

    2017-09-01

    Rat somatosensory cortex contains a large sexually monomorphic genital representation. Genital cortex undergoes an unusual 2-fold expansion during puberty. Here, we investigate genital cortex development and female rat sexual maturation. Ovariectomies and estradiol injections suggested sex hormones cause the pubertal genital cortex expansion but not its maintenance at adult size. Genital cortex expanded by thalamic afferents invading surrounding dysgranular cortex. Genital touch was a dominant factor driving female sexual maturation. Raising female rats in contact with adult males promoted genital cortex expansion, whereas contact to adult females or nontactile (audio-visual-olfactory) male cues did not. Genital touch imposed by human experimenters powerfully advanced female genital cortex development and sexual maturation. Long-term blocking of genital cortex by tetrodotoxin in pubescent females housed with males prevented genital cortex expansion and decelerated vaginal opening. Sex hormones, sexual experience, and neural activity shape genital cortex, which contributes to the puberty promoting effects of sexual touch.

  6. Reciprocal neural response within lateral and ventral medial prefrontal cortex during hot and cold reasoning.

    Science.gov (United States)

    Goel, Vinod; Dolan, Raymond J

    2003-12-01

    Logic is widely considered the basis of rationality. Logical choices, however, are often influenced by emotional responses, sometimes to our detriment, sometimes to our advantage. To understand the neural basis of emotionally neutral ("cold") and emotionally salient ("hot") reasoning we studied 19 volunteers using event-related fMRI, as they made logical judgments about arguments that varied in emotional saliency. Despite identical logical form and content categories across "hot" and "cold" reasoning conditions, lateral and ventral medial prefrontal cortex showed reciprocal response patterns as a function of emotional saliency of content. "Cold" reasoning trials resulted in enhanced activity in lateral/dorsal lateral prefrontal cortex (L/DLPFC) and suppression of activity in ventral medial prefrontal cortex (VMPFC). By contrast, "hot" reasoning trials resulted in enhanced activation in VMPFC and suppression of activation in L/DLPFC. This reciprocal engagement of L/DLPFC and VMPFC provides evidence for a dynamic neural system for reasoning, the configuration of which is strongly influenced by emotional saliency.

  7. Emotion regulation in spider phobia: role of the medial prefrontal cortex

    Science.gov (United States)

    Schäfer, Axel; Walter, Bertram; Stark, Rudolf; Vaitl, Dieter; Schienle, Anne

    2009-01-01

    Phobic responses are strong emotional reactions towards phobic objects, which can be described as a deficit in the automatic regulation of emotions. Difficulties in the voluntary cognitive control of these emotions suggest a further phobia-specific deficit in effortful emotion regulation mechanisms. The actual study is based on this emotion regulation conceptualization of specific phobias. The aim is to investigate the neural correlates of these two emotion regulation deficits in spider phobics. Sixteen spider phobic females participated in a functional magnetic resonance imaging (fMRI) study in which they were asked to voluntarily up- and down-regulate their emotions elicited by spider and generally aversive pictures with a reappraisal strategy. In line with the hypothesis concerning an automatic emotion regulation deficit, increased activity in the insula and reduced activity in the ventromedial prefrontal cortex was observed. Furthermore, phobia-specific effortful regulation within phobics was associated with altered activity in medial prefrontal cortex areas. Altogether, these results suggest that spider phobic subjects are indeed characterized by a deficit in the automatic as well as the effortful regulation of emotions elicited by phobic compared with aversive stimuli. These two forms of phobic emotion regulation deficits are associated with altered activity in different medial prefrontal cortex subregions. PMID:19398537

  8. The role of the medial prefrontal cortex in the conditioning and extinction of fear

    Directory of Open Access Journals (Sweden)

    Thomas Francis Giustino

    2015-11-01

    Full Text Available Once acquired, a fearful memory can persist for a lifetime. Although learned fear can be extinguished, extinction memories are fragile. The resilience of fear memories to extinction may contribute to the maintenance of disorders of fear and anxiety, including post-traumatic stress disorder (PTSD. As such, considerable effort has been placed on understanding the neural circuitry underlying the acquisition, expression, and extinction of emotional memories in rodent models as well as in humans. A triad of brain regions, including the prefrontal cortex, hippocampus, and amygdala, form an essential brain circuit involved in fear conditioning and extinction. Within this circuit, the prefrontal cortex is thought to exert top-down control over subcortical structures to regulate appropriate behavioral responses. Importantly, a division of labor has been proposed in which the prelimbic (PL and infralimbic (IL subdivisions of the medial prefrontal cortex (mPFC regulate the expression and suppression of fear in rodents, respectively. Here we critically review the anatomical and physiological evidence that has led to this proposed dichotomy of function within mPFC. We propose that under some conditions, the PL and IL act in concert, exhibiting similar patterns of neural activity in response to aversive conditioned stimuli and during the expression or inhibition of conditioned fear. This may stem from common synaptic inputs, parallel downstream outputs, or cortico-cortical interactions. Despite this functional covariation, these mPFC subdivisions may still be coding for largely opposing behavioral outcomes, with PL biased towards fear expression and IL towards suppression.

  9. Dynamics of dendritic spines in the mouse auditory cortex during memory formation and memory recall.

    Science.gov (United States)

    Moczulska, Kaja Ewa; Tinter-Thiede, Juliane; Peter, Manuel; Ushakova, Lyubov; Wernle, Tanja; Bathellier, Brice; Rumpel, Simon

    2013-11-05

    Long-lasting changes in synaptic connections induced by relevant experiences are believed to represent the physical correlate of memories. Here, we combined chronic in vivo two-photon imaging of dendritic spines with auditory-cued classical conditioning to test if the formation of a fear memory is associated with structural changes of synapses in the mouse auditory cortex. We find that paired conditioning and unpaired conditioning induce a transient increase in spine formation or spine elimination, respectively. A fraction of spines formed during paired conditioning persists and leaves a long-lasting trace in the network. Memory recall triggered by the reexposure of mice to the sound cue did not lead to changes in spine dynamics. Our findings provide a synaptic mechanism for plasticity in sound responses of auditory cortex neurons induced by auditory-cued fear conditioning; they also show that retrieval of an auditory fear memory does not lead to a recapitulation of structural plasticity in the auditory cortex as observed during initial memory consolidation.

  10. Gating of hippocampal activity, plasticity, and memory by entorhinal cortex long-range inhibition.

    Science.gov (United States)

    Basu, Jayeeta; Zaremba, Jeffrey D; Cheung, Stephanie K; Hitti, Frederick L; Zemelman, Boris V; Losonczy, Attila; Siegelbaum, Steven A

    2016-01-08

    The cortico-hippocampal circuit is critical for storage of associational memories. Most studies have focused on the role in memory storage of the excitatory projections from entorhinal cortex to hippocampus. However, entorhinal cortex also sends inhibitory projections, whose role in memory storage and cortico-hippocampal activity remains largely unexplored. We found that these long-range inhibitory projections enhance the specificity of contextual and object memory encoding. At the circuit level, these γ-aminobutyric acid (GABA)-releasing projections target hippocampal inhibitory neurons and thus act as a disinhibitory gate that transiently promotes the excitation of hippocampal CA1 pyramidal neurons by suppressing feedforward inhibition. This enhances the ability of CA1 pyramidal neurons to fire synaptically evoked dendritic spikes and to generate a temporally precise form of heterosynaptic plasticity. Long-range inhibition from entorhinal cortex may thus increase the precision of hippocampal-based long-term memory associations by assessing the salience of mnemonormation to the immediate sensory input. Copyright © 2016, American Association for the Advancement of Science.

  11. Development and function of human cerebral cortex neural networks from pluripotent stem cells in vitro.

    Science.gov (United States)

    Kirwan, Peter; Turner-Bridger, Benita; Peter, Manuel; Momoh, Ayiba; Arambepola, Devika; Robinson, Hugh P C; Livesey, Frederick J

    2015-09-15

    A key aspect of nervous system development, including that of the cerebral cortex, is the formation of higher-order neural networks. Developing neural networks undergo several phases with distinct activity patterns in vivo, which are thought to prune and fine-tune network connectivity. We report here that human pluripotent stem cell (hPSC)-derived cerebral cortex neurons form large-scale networks that reflect those found in the developing cerebral cortex in vivo. Synchronised oscillatory networks develop in a highly stereotyped pattern over several weeks in culture. An initial phase of increasing frequency of oscillations is followed by a phase of decreasing frequency, before giving rise to non-synchronous, ordered activity patterns. hPSC-derived cortical neural networks are excitatory, driven by activation of AMPA- and NMDA-type glutamate receptors, and can undergo NMDA-receptor-mediated plasticity. Investigating single neuron connectivity within PSC-derived cultures, using rabies-based trans-synaptic tracing, we found two broad classes of neuronal connectivity: most neurons have small numbers (40). These data demonstrate that the formation of hPSC-derived cortical networks mimics in vivo cortical network development and function, demonstrating the utility of in vitro systems for mechanistic studies of human forebrain neural network biology. © 2015. Published by The Company of Biologists Ltd.

  12. Coding the presence of visual objects in a recurrent neural network of visual cortex.

    Science.gov (United States)

    Zwickel, Timm; Wachtler, Thomas; Eckhorn, Reinhard

    2007-01-01

    Before we can recognize a visual object, our visual system has to segregate it from its background. This requires a fast mechanism for establishing the presence and location of objects independently of their identity. Recently, border-ownership neurons were recorded in monkey visual cortex which might be involved in this task [Zhou, H., Friedmann, H., von der Heydt, R., 2000. Coding of border ownership in monkey visual cortex. J. Neurosci. 20 (17), 6594-6611]. In order to explain the basic mechanisms required for fast coding of object presence, we have developed a neural network model of visual cortex consisting of three stages. Feed-forward and lateral connections support coding of Gestalt properties, including similarity, good continuation, and convexity. Neurons of the highest area respond to the presence of an object and encode its position, invariant of its form. Feedback connections to the lowest area facilitate orientation detectors activated by contours belonging to potential objects, and thus generate the experimentally observed border-ownership property. This feedback control acts fast and significantly improves the figure-ground segregation required for the consecutive task of object recognition.

  13. Activation of the basolateral amygdala induces long-term enhancement of specific memory representations in the cerebral cortex.

    Science.gov (United States)

    Chavez, Candice M; McGaugh, James L; Weinberger, Norman M

    2013-03-01

    The basolateral amygdala (BLA) modulates memory, particularly for arousing or emotional events, during post-training periods of consolidation. It strengthens memories whose substrates in part or whole are stored remotely, in structures such as the hippocampus, striatum and cerebral cortex. However, the mechanisms by which the BLA influences distant memory traces are unknown, largely because of the need for identifiable target mnemonic representations. Associative tuning plasticity in the primary auditory cortex (A1) constitutes a well-characterized candidate specific memory substrate that is ubiquitous across species, tasks and motivational states. When tone predicts reinforcement, the tuning of cells in A1 shifts toward or to the signal frequency within its tonotopic map, producing an over-representation of behaviorally important sounds. Tuning shifts have the cardinal attributes of forms of memory, including associativity, specificity, rapid induction, consolidation and long-term retention and are therefore likely memory representations. We hypothesized that the BLA strengthens memories by increasing their cortical representations. We recorded multiple unit activity from A1 of rats that received a single discrimination training session in which two tones (2.0 s) separated by 1.25 octaves were either paired with brief electrical stimulation (400 ms) of the BLA (CS+) or not (CS-). Frequency response areas generated by presenting a matrix of test tones (0.5-53.82 kHz, 0-70 dB) were obtained before training and daily for 3 weeks post-training. Tuning both at threshold and above threshold shifted predominantly toward the CS+ beginning on day 1. Tuning shifts were maintained for the entire 3 weeks. Absolute threshold and bandwidth decreased, producing less enduring increases in sensitivity and selectivity. BLA-induced tuning shifts were associative, highly specific and long-lasting. We propose that the BLA strengthens memory for important experiences by increasing the

  14. Multi-sensory integration in brainstem and auditory cortex.

    Science.gov (United States)

    Basura, Gregory J; Koehler, Seth D; Shore, Susan E

    2012-11-16

    Tinnitus is the perception of sound in the absence of a physical sound stimulus. It is thought to arise from aberrant neural activity within central auditory pathways that may be influenced by multiple brain centers, including the somatosensory system. Auditory-somatosensory (bimodal) integration occurs in the dorsal cochlear nucleus (DCN), where electrical activation of somatosensory regions alters pyramidal cell spike timing and rates of sound stimuli. Moreover, in conditions of tinnitus, bimodal integration in DCN is enhanced, producing greater spontaneous and sound-driven neural activity, which are neural correlates of tinnitus. In primary auditory cortex (A1), a similar auditory-somatosensory integration has been described in the normal system (Lakatos et al., 2007), where sub-threshold multisensory modulation may be a direct reflection of subcortical multisensory responses (Tyll et al., 2011). The present work utilized simultaneous recordings from both DCN and A1 to directly compare bimodal integration across these separate brain stations of the intact auditory pathway. Four-shank, 32-channel electrodes were placed in DCN and A1 to simultaneously record tone-evoked unit activity in the presence and absence of spinal trigeminal nucleus (Sp5) electrical activation. Bimodal stimulation led to long-lasting facilitation or suppression of single and multi-unit responses to subsequent sound in both DCN and A1. Immediate (bimodal response) and long-lasting (bimodal plasticity) effects of Sp5-tone stimulation were facilitation or suppression of tone-evoked firing rates in DCN and A1 at all Sp5-tone pairing intervals (10, 20, and 40 ms), and greater suppression at 20 ms pairing-intervals for single unit responses. Understanding the complex relationships between DCN and A1 bimodal processing in the normal animal provides the basis for studying its disruption in hearing loss and tinnitus models. This article is part of a Special Issue entitled: Tinnitus Neuroscience

  15. Functional organization of the face-sensitive areas in human occipital-temporal cortex.

    Science.gov (United States)

    Shao, Hanyu; Weng, Xuchu; He, Sheng

    2017-08-15

    Human occipital-temporal cortex features several areas sensitive to faces, presumably forming the biological substrate for face perception. To date, there are piecemeal insights regarding the functional organization of these regions. They have come, however, from studies that are far from homogeneous with regard to the regions involved, the experimental design, and the data analysis approach. In order to provide an overall view of the functional organization of the face-sensitive areas, it is necessary to conduct a comprehensive study that taps into the pivotal functional properties of all the face-sensitive areas, within the context of the same experimental design, and uses multiple data analysis approaches. In this study, we identified the most robustly activated face-sensitive areas in bilateral occipital-temporal cortices (i.e., AFP, aFFA, pFFA, OFA, pcSTS, pSTS) and systemically compared their regionally averaged activation and multivoxel activation patterns to 96 images from 16 object categories, including faces and non-faces. This condition-rich and single-image analysis approach critically samples the functional properties of a brain region, allowing us to test how two basic functional properties, namely face-category selectivity and face-exemplar sensitivity are distributed among these regions. Moreover, by examining the correlational structure of neural responses to the 96 images, we characterize their interactions in the greater face-processing network. We found that (1) r-pFFA showed the highest face-category selectivity, followed by l-pFFA, bilateral aFFA and OFA, and then bilateral pcSTS. In contrast, bilateral AFP and pSTS showed low face-category selectivity; (2) l-aFFA, l-pcSTS and bilateral AFP showed evidence of face-exemplar sensitivity; (3) r-OFA showed high overall response similarities with bilateral LOC and r-pFFA, suggesting it might be a transitional stage between general and face-selective information processing; (4) r-aFFA showed high

  16. Cortex Matures Faster in Youths With Highest IQ

    Science.gov (United States)

    ... NIH Cortex Matures Faster in Youths With Highest IQ Past Issues / Summer 2006 Table of Contents For ... on. Photo: Getty image (StockDisc) Youths with superior IQ are distinguished by how fast the thinking part ...

  17. Effects of entorhinal cortex lesions on memory in different tasks

    Directory of Open Access Journals (Sweden)

    G.P. Gutierrez-Figueroa

    1997-06-01

    Full Text Available Lesions of the entorhinal cortex produce retrograde memory impairment in both animals and humans. Here we report the effects of bilateral entorhinal cortex lesions caused by the stereotaxic infusion of N-methyl-D-aspartate (NMDA in rats at two different moments, before or after the training session, on memory of different tasks: two-way shuttle avoidance, inhibitory avoidance and habituation to an open field. Pre- or post-training entorhinal cortex lesions caused an impairment of performance in the shuttle avoidance task, which agrees with the previously described role of this area in the processing of memories acquired in successive sessions. In the inhibitory avoidance task, only the post-training lesions had an effect (amnesia. No effect was observed on the open field task. The findings suggest that the role of the entorhinal cortex in memory processing is task-dependent, perhaps related to the complexity of each task

  18. Functional magnetic resonance imaging of the primary motor cortex ...

    Indian Academy of Sciences (India)

    Unknown

    brain is able to control the muscles in the body in a pre- cise and efficient ... which receives inputs from the prefrontal cortex and the ... This is based on the fact that oxygenated blood ... compared with deoxygenated blood (paramagnetic) and.

  19. Reorganization of the Human Somatosensory Cortex in Hand Dystonia

    Directory of Open Access Journals (Sweden)

    Maria Jose Catalan

    2012-05-01

    Full Text Available Background and Purpose: Abnormalities of finger representations in the somatosensory cortex have been identified in patients with focal hand dystonia. Measuring blood flow with positron emission tomography (PET can be use to demonstrate functional localization of receptive fields. Methods: A vibratory stimulus was applied to the right thumb and little finger of six healthy volunteers and six patients with focal hand dystonia to map their receptive fields using H215O PET. Results: The cortical finger representations in the primary somatosensory cortex were closer to each other in patients than in normal subjects. No abnormalities were found in secondary somatosensory cortex, but the somatotopy there is less well distinguished. Conclusions: These data confirm prior electrophysiological and functional neuroimaging observations showing abnormalities of finger representations in somatosensory cortex of patients with focal hand dystonia.

  20. I find you more attractive … after (prefrontal cortex) stimulation

    NARCIS (Netherlands)

    Ferrari, C.; Lega, C.; Tamietto, M.; Nadal, M.; Cattaneo, Z.

    2015-01-01

    Facial attractiveness seems to be perceived immediately. Neuroimaging evidence suggests that the appraisal of facial attractiveness is mediated by a network of cortical and subcortical regions, mainly encompassing the reward circuit, but also including prefrontal cortices. The prefrontal cortex is

  1. Human primary visual cortex topography imaged via positron tomography

    International Nuclear Information System (INIS)

    Schwartz, E.L.; Christman, D.R.; Wolf, A.P.

    1984-01-01

    The visuotopic structure of primary visual cortex was studied in a group of 7 human volunteers using positron emission transaxial tomography (PETT) and 18 F-labeled 2-deoxy-2-fluoro-D-glucose ([ 18 F]DG). A computer animation was constructed with a spatial structure which was matched to estimates of human cortical magnification factor and to striate cortex stimulus preferences. A lateralized cortical 'checker-board' pattern of [ 18 F]DG was stimulated in primary visual cortex by having subjects view this computer animation following i.v. injection of [ 18 F]DG. The spatial structure of the stimulus was designed to produce an easily recognizable 'signature' in a series of 9 serial PETT scans obtained from each of a group of 7 volunteers. The predicted lateralized topographic 'signature' was observed in 6 of 7 subjects. Applications of this method for further PETT studies of human visual cortex are discussed. (Auth.)

  2. Preprocessing of emotional visual information in the human piriform cortex.

    Science.gov (United States)

    Schulze, Patrick; Bestgen, Anne-Kathrin; Lech, Robert K; Kuchinke, Lars; Suchan, Boris

    2017-08-23

    This study examines the processing of visual information by the olfactory system in humans. Recent data point to the processing of visual stimuli by the piriform cortex, a region mainly known as part of the primary olfactory cortex. Moreover, the piriform cortex generates predictive templates of olfactory stimuli to facilitate olfactory processing. This study fills the gap relating to the question whether this region is also capable of preprocessing emotional visual information. To gain insight into the preprocessing and transfer of emotional visual information into olfactory processing, we recorded hemodynamic responses during affective priming using functional magnetic resonance imaging (fMRI). Odors of different valence (pleasant, neutral and unpleasant) were primed by images of emotional facial expressions (happy, neutral and disgust). Our findings are the first to demonstrate that the piriform cortex preprocesses emotional visual information prior to any olfactory stimulation and that the emotional connotation of this preprocessing is subsequently transferred and integrated into an extended olfactory network for olfactory processing.

  3. SFPQ associates to LSD1 and regulates the migration of newborn pyramidal neurons in the developing cerebral cortex.

    Science.gov (United States)

    Saud, K; Cánovas, J; Lopez, C I; Berndt, F A; López, E; Maass, J C; Barriga, A; Kukuljan, M

    2017-04-01

    The development of the cerebral cortex requires the coordination of multiple processes ranging from the proliferation of progenitors to the migration and establishment of connectivity of the newborn neurons. Epigenetic regulation carried out by the COREST/LSD1 complex has been identified as a mechanism that regulates the development of pyramidal neurons of the cerebral cortex. We now identify the association of the multifunctional RNA-binding protein SFPQ to LSD1 during the development of the cerebral cortex. In vivo reduction of SFPQ dosage by in utero electroporation of a shRNA results in impaired radial migration of newborn pyramidal neurons, in a similar way to that observed when COREST or LSD1 expressions are decreased. Diminished SFPQ expression also associates to decreased proliferation of progenitor cells, while it does not affect the acquisition of neuronal fate. These results are compatible with the idea that SFPQ, plays an important role regulating proliferation and migration during the development of the cerebral cortex. Copyright © 2016 ISDN. Published by Elsevier Ltd. All rights reserved.

  4. Altered SPECT 123I iomazenil Binding in the Cingulate Cortex of Children with Anorexia Nervosa

    Directory of Open Access Journals (Sweden)

    Shinichiro eNagamitsu

    2016-02-01

    Full Text Available Several lines of evidence suggest that anxiety plays a key role in the development and maintenance of anorexia nervosa (AN in children. The purpose of this study was to examine cortical GABA(A-benzodiazepine receptor binding before and after treatment in children beginning intensive AN treatment. Brain single photon emission computed tomography (SPECT measurements using 123I iomazenil, which binds to GABA(A-benzodiazepine receptors, was performed in 26 participants with AN who were enrolled in a multimodal treatment program. Sixteen of the 26 participants underwent a repeat SPECT scan immediately before discharge at conclusion of the intensive treatment program. Eating behavior and mood disturbances were assessed using Eating Attitudes Test with 26 items (EAT-26 and the short form of the Profile of Mood States (POMS. Clinical outcome scores were evaluated after a 1-year period. We examined association between relative iomazenil binding activity in cortical regions of interest (ROIs and psychometric profiles, and determined which psychometric profiles show interaction effects with brain regions. Further, we determined if binding activity could predict clinical outcome and treatment changes. Higher EAT-26 scores were significantly associated with lower iomazenil binding activity in the anterior posterior cingulate cortex (ACC. Higher POMS subscale scores were significantly associated with lower iomazenil binding activity in the left frontal, parietal cortex, and posterior cingulate cortex (PCC. Depression-Dejection, and Confusion POMS subscale scores, and total POMS score, showed interaction effects with brain regions in iomazenil binding activity. Decreased binding in the ACC and left parietal cortex was associated with poor clinical outcomes. Relative binding increases throughout the PCC and occipital gyrus were observed after weight gain in children with AN. These findings suggest that cortical GABAergic receptor binding is altered in children

  5. Visual short-term memory load reduces retinotopic cortex response to contrast.

    Science.gov (United States)

    Konstantinou, Nikos; Bahrami, Bahador; Rees, Geraint; Lavie, Nilli

    2012-11-01

    Load Theory of attention suggests that high perceptual load in a task leads to reduced sensory visual cortex response to task-unrelated stimuli resulting in "load-induced blindness" [e.g., Lavie, N. Attention, distraction and cognitive control under load. Current Directions in Psychological Science, 19, 143-148, 2010; Lavie, N. Distracted and confused?: Selective attention under load. Trends in Cognitive Sciences, 9, 75-82, 2005]. Consideration of the findings that visual STM (VSTM) involves sensory recruitment [e.g., Pasternak, T., & Greenlee, M. Working memory in primate sensory systems. Nature Reviews Neuroscience, 6, 97-107, 2005] within Load Theory led us to a new hypothesis regarding the effects of VSTM load on visual processing. If VSTM load draws on sensory visual capacity, then similar to perceptual load, high VSTM load should also reduce visual cortex response to incoming stimuli leading to a failure to detect them. We tested this hypothesis with fMRI and behavioral measures of visual detection sensitivity. Participants detected the presence of a contrast increment during the maintenance delay in a VSTM task requiring maintenance of color and position. Increased VSTM load (manipulated by increased set size) led to reduced retinotopic visual cortex (V1-V3) responses to contrast as well as reduced detection sensitivity, as we predicted. Additional visual detection experiments established a clear tradeoff between the amount of information maintained in VSTM and detection sensitivity, while ruling out alternative accounts for the effects of VSTM load in terms of differential spatial allocation strategies or task difficulty. These findings extend Load Theory to demonstrate a new form of competitive interactions between early visual cortex processing and visual representations held in memory under load and provide a novel line of support for the sensory recruitment hypothesis of VSTM.

  6. Analogical reasoning and prefrontal cortex: evidence for separable retrieval and integration mechanisms.

    Science.gov (United States)

    Bunge, Silvia A; Wendelken, Carter; Badre, David; Wagner, Anthony D

    2005-03-01

    The present study examined the contributions of prefrontal cortex (PFC) subregions to two component processes underlying verbal analogical reasoning: semantic retrieval and integration. Event-related functional magnetic resonance imaging data were acquired while subjects performed propositional analogy and semantic decision tasks. On each trial, subjects viewed a pair of words (pair 1), followed by an instructional cue and a second word pair (pair 2). On analogy trials, subjects evaluated whether pair 2 was semantically analogous to pair 1. On semantic trials, subjects indicated whether the pair 2 words were semantically related to each other. Thus, analogy--but not semantic--trials required integration across multiple retrieved relations. To identify regions involved in semantic retrieval, we manipulated the associative strength of pair 1 words in both tasks. Anterior left inferior PFC (aLIPC) was modulated by associative strength, consistent with a role in controlled semantic retrieval. Left frontopolar cortex was insensitive to associative strength, but was more sensitive to integration demands than was aLIPC, consistent with a role in integrating the products of semantic retrieval to evaluate whether distinct representations are analogous. Right dorsolateral PFC exhibited a profile consistent with a role in response selection rather than retrieval or integration. These findings indicate that verbal analogical reasoning depends on multiple, PFC-mediated computations.

  7. Intraoperative mapping of expressive language cortex using passive real-time electrocorticography

    Directory of Open Access Journals (Sweden)

    AmiLyn M. Taplin

    2016-01-01

    Full Text Available In this case report, we investigated the utility and practicality of passive intraoperative functional mapping of expressive language cortex using high-resolution electrocorticography (ECoG. The patient presented here experienced new-onset seizures caused by a medium-grade tumor in very close proximity to expressive language regions. In preparation of tumor resection, the patient underwent multiple functional language mapping procedures. We examined the relationship of results obtained with intraoperative high-resolution ECoG, extraoperative ECoG utilizing a conventional subdural grid, extraoperative electrical cortical stimulation (ECS mapping, and functional magnetic resonance imaging (fMRI. Our results demonstrate that intraoperative mapping using high-resolution ECoG is feasible and, within minutes, produces results that are qualitatively concordant to those achieved by extraoperative mapping modalities. They also suggest that functional language mapping of expressive language areas with ECoG may prove useful in many intraoperative conditions given its time efficiency and safety. Finally, they demonstrate that integration of results from multiple functional mapping techniques, both intraoperative and extraoperative, may serve to improve the confidence in or precision of functional localization when pathology encroaches upon eloquent language cortex.

  8. Visual cortex in aging and Alzheimer’s disease: Changes in visual field maps and population receptive fields

    Directory of Open Access Journals (Sweden)

    Alyssa A. Brewer

    2014-02-01

    Full Text Available Although several studies have suggested that cortical alterations underlie such age-related visual deficits as decreased acuity, little is known about what changes actually occur in visual cortex during healthy aging. Two recent studies showed changes in primary visual cortex (V1 during normal aging; however, no studies have characterized the effects of aging on visual cortex beyond V1, important measurements both for understanding the aging process and for comparison to changes in age-related diseases. Similarly, there is almost no information about changes in visual cortex in Alzheimer’s disease (AD, the most common form of dementia. Because visual deficits are often reported as one of the first symptoms of AD, measurements of such changes in the visual cortex of AD patients might improve our understanding of how the visual system is affected by neurodegeneration as well as aid early detection, accurate diagnosis and timely treatment of AD. Here we use fMRI to first compare the visual field map (VFM organization and population receptive fields (pRFs between young adults and healthy aging subjects for occipital VFMs V1, V2, V3, and hV4. Healthy aging subjects do not show major VFM organizational deficits, but do have reduced surface area and increased pRF sizes in the foveal representations of V1, V2, and hV4 relative to healthy young control subjects. These measurements are consistent with behavioral deficits seen in healthy aging. We then demonstrate the feasibility and first characterization of these measurements in two patients with mild AD, which reveal potential changes in visual cortex as part of the pathophysiology of AD. Our data aid in our understanding of the changes in the visual processing pathways in normal aging and provide the foundation for future research into earlier and more definitive detection of AD.

  9. Multiple forms of endopeptidase activity from jojoba seeds.

    Science.gov (United States)

    Wolf, M J; Storey, R D

    1990-01-01

    The cotyledons of 27 day post-germination jojoba seedlings (Simmondsia chinensis) contained five distinct endopeptidase activities separable by DEAE Bio-Gel and CM-cellulose ion exchange chromatography. The endopeptidases were purified 108- to 266-fold and their individuality was confirmed by activity-specific assays in native acrylamide gels along with differences in their Mr and catalytic properties. The five endopeptidases, which showed activity on model substrates and protein, were named EP Ia, EP Ib, EP II, EP III and EP IV. EP Ia was a serine proteinase with a pH optimum of ca 8 and Mr of 58,000. EP Ib, II and III were discrete cysteine proteinases showing pH optima of ca 6.8, 6.0 and 5.4 and Mr of 41,000, 47,000 and 35,000 respectively. EP IV was an aspartic acid proteinase with a ca pH optimum of 3.5 and Mr of 33,000.

  10. Preliminary characterization of multiple hyaluronidase forms in boar reproductive tract

    Czech Academy of Sciences Publication Activity Database

    Cibulková, Eva; Maňásková, Pavla; Jonáková, Věra; Tichá, M.

    2007-01-01

    Roč. 68, č. 7 (2007), s. 1047-1054 ISSN 0093-691X R&D Projects: GA ČR GA303/06/0895; GA MŠk 1M06011 Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z50520701 Keywords : hyaluronidase * boar sperm * seminal plasma * epididymis * seminal vesicle Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.911, year: 2007

  11. The meek cry or the importance of resisting multiple forms

    Directory of Open Access Journals (Sweden)

    Diego Alejandro Muñoz Gaviria

    2011-07-01

    Full Text Available First step, seeks to broadly down some of the known theories of resistance. The idea in this item will be the statement configured stress field around the idea of resistance as a political option. In a second step, seeks to identify the key ideas of Paulo Freire around the resistor, as a Latin American perspective able to shed light on the "other" ways to act politically in our territories, from a critical or resistance. Finally, some conclusions are proposed that will synthesize the above and leave open questions for further reflection exercises and thematic depth.

  12. Depth-Dependent Temporal Response Properties in Core Auditory Cortex

    OpenAIRE

    Christianson, G. Björn; Sahani, Maneesh; Linden, Jennifer F.

    2011-01-01

    The computational role of cortical layers within auditory cortex has proven difficult to establish. One hypothesis is that interlaminar cortical processing might be dedicated to analyzing temporal properties of sounds; if so, then there should be systematic depth-dependent changes in cortical sensitivity to the temporal context in which a stimulus occurs. We recorded neural responses simultaneously across cortical depth in primary auditory cortex and anterior auditory field of CBA/Ca mice, an...

  13. [Transcranial magnetic stimulation and motor cortex stimulation in neuropathic pain].

    Science.gov (United States)

    Mylius, V; Ayache, S S; Teepker, M; Kappus, C; Kolodziej, M; Rosenow, F; Nimsky, C; Oertel, W H; Lefaucheur, J P

    2012-12-01

    Non-invasive and invasive cortical stimulation allows the modulation of therapy-refractory neuropathic pain. High-frequency repetitive transcranial magnetic stimulation (rTMS) of the contralateral motor cortex yields therapeutic effects at short-term and predicts the benefits of epidural motor cortex stimulation (MCS). The present article summarizes the findings on application, mechanisms and therapeutic effects of cortical stimulation in neuropathic pain.

  14. Audiovisual Association Learning in the Absence of Primary Visual Cortex

    OpenAIRE

    Seirafi, Mehrdad; De Weerd, Peter; Pegna, Alan J.; de Gelder, Beatrice

    2016-01-01

    Learning audiovisual associations is mediated by the primary cortical areas; however, recent animal studies suggest that such learning can take place even in the absence of the primary visual cortex. Other studies have demonstrated the involvement of extra-geniculate pathways and especially the superior colliculus (SC) in audiovisual association learning. Here, we investigated such learning in a rare human patient with complete loss of the bilateral striate cortex. We carried out an implicit ...

  15. Peripheral nerve injury induces glial activation in primary motor cortex

    OpenAIRE

    Julieta Troncoso; Julieta Troncoso; Efraín Buriticá; Efraín Buriticá

    2015-01-01

    Preliminary evidence suggests that peripheral facial nerve injuries are associated with sensorimotor cortex reorganization. We have characterized facial nerve lesion-induced structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with glial cell density using a rodent facial paralysis model. First, we used adult transgenic mice expressing green fluorescent protein in microglia and yellow fluorescent protein in pyramidal neurons which were subjected to eithe...

  16. A Corticocortical Circuit Directly Links Retrosplenial Cortex to M2 in the Mouse

    Science.gov (United States)

    Radulovic, Jelena

    2016-01-01

    Retrosplenial cortex (RSC) is a dorsomedial parietal area involved in a range of cognitive functions, including episodic memory, navigation, and spatial memory. Anatomically, the RSC receives inputs from dorsal hippocampal networks and in turn projects to medial neocortical areas. A particularly prominent projection extends rostrally to the posterior secondary motor cortex (M2), suggesting a functional corticocortical link from the RSC to M2 and thus a bridge between hippocampal and neocortical networks involved in mnemonic and sensorimotor aspects of navigation. We investigated the cellular connectivity in this RSC→M2 projection in the mouse using optogenetic photostimulation, retrograde labeling, and electrophysiology. Axons from RSC formed monosynaptic excitatory connections onto M2 pyramidal neurons across layers and projection classes, including corticocortical/intratelencephalic neurons (reciprocally and callosally projecting) in layers 2–6, pyramidal tract neurons (corticocollicular, corticopontine) in layer 5B, and, to a lesser extent, corticothalamic neurons in layer 6. In addition to these direct connections, disynaptic connections were made via posterior parietal cortex (RSC→PPC→M2) and anteromedial thalamus (RSC→AM→M2). In the reverse direction, axons from M2 monosynaptically excited M2-projecting corticocortical neurons in the RSC, especially in the superficial layers of the dysgranular region. These findings establish an excitatory RSC→M2 corticocortical circuit that engages diverse types of excitatory projection neurons in the downstream area, suggesting a basis for direct communication from dorsal hippocampal networks involved in spatial memory and navigation to neocortical networks involved in diverse aspects of sensorimotor integration and motor control. SIGNIFICANCE STATEMENT Corticocortical pathways interconnect cortical areas extensively, but the cellular connectivity in these pathways remains largely uncharacterized. Here, we

  17. Spatial integration in mouse primary visual cortex.

    Science.gov (United States)

    Vaiceliunaite, Agne; Erisken, Sinem; Franzen, Florian; Katzner, Steffen; Busse, Laura

    2013-08-01

    Responses of many neurons in primary visual cortex (V1) are suppressed by stimuli exceeding the classical receptive field (RF), an important property that might underlie the computation of visual saliency. Traditionally, it has proven difficult to disentangle the underlying neural circuits, including feedforward, horizontal intracortical, and feedback connectivity. Since circuit-level analysis is particularly feasible in the mouse, we asked whether neural signatures of spatial integration in mouse V1 are similar to those of higher-order mammals and investigated the role of parvalbumin-expressing (PV+) inhibitory interneurons. Analogous to what is known from primates and carnivores, we demonstrate that, in awake mice, surround suppression is present in the majority of V1 neurons and is strongest in superficial cortical layers. Anesthesia with isoflurane-urethane, however, profoundly affects spatial integration: it reduces the laminar dependency, decreases overall suppression strength, and alters the temporal dynamics of responses. We show that these effects of brain state can be parsimoniously explained by assuming that anesthesia affects contrast normalization. Hence, the full impact of suppressive influences in mouse V1 cannot be studied under anesthesia with isoflurane-urethane. To assess the neural circuits of spatial integration, we targeted PV+ interneurons using optogenetics. Optogenetic depolarization of PV+ interneurons was associated with increased RF size and decreased suppression in the recorded population, similar to effects of lowering stimulus contrast, suggesting that PV+ interneurons contribute to spatial integration by affecting overall stimulus drive. We conclude that the mouse is a promising model for circuit-level mechanisms of spatial integration, which relies on the combined activity of different types of inhibitory interneurons.

  18. Rehabilitation in multiple sclerosis.

    Science.gov (United States)

    Kubsik-Gidlewska, Anna M; Klimkiewicz, Paulina; Klimkiewicz, Robert; Janczewska, Katarzyna; Woldańska-Okońska, Marta

    2017-07-01

    The aim of the study is to present a strategy of rehabilitation in multiple sclerosis on the basis of the latest developments in the field of physiotherapy. The publications on the problem discuss a wide range of methods of physiotherapy that can be used in order to reduce the degree of disability and alleviate the symptoms associated with the disease. The complexity of the disease, the difficulty in determining the appropriate treatment and a wide range of symptoms require a comprehensive approach to the patient, which would include both pharmacology and neurorehabilitation. Rehabilitation, which includes psychotherapy and symptomatic therapy, is regarded nowadays as the best form of treatment for multiple sclerosis. An indepth diagnostic assessment of functional status and prognosis should be carried out before the start of the rehabilitation process. The prognosis should take into account the mental state, the neurological status and the awareness of the patient. The kinesiotherapy program in multiple sclerosis is based on a gradation of physiotherapy which assumes a gradual transition from basic movements to more complex ones till global functions are obtained. The most appropriate form of treatment is functional rehabilitation combined with physical procedures. Recent reports indicate the need for aerobic training to be included in the rehabilitation program. The introduction of physical activities, regardless of the severity of the disease, will reduce the negative effects of akinesia, and thus increase the functional capabilities of all body systems.

  19. Elevated blood lactate is associated with increased motor cortex excitability.

    Science.gov (United States)

    Coco, Marinella; Alagona, Giovanna; Rapisarda, Giuseppe; Costanzo, Erminio; Calogero, Roberto Antonio; Perciavalle, Valentina; Perciavalle, Vincenzo

    2010-01-01

    No information has yet been provided about the influence of blood lactate levels on the excitability of the cerebral cortex, in particular, of the motor cortex. The aim of the present study was to examine the effects of high blood lactate levels, induced with a maximal cycling or with an intravenous infusion, on motor cortex excitability. The study was carried out on 17 male athletes; all the subjects performed a maximal cycling test on a mechanically braked cycloergometer, whereas 6 of them were submitted to the intravenous infusion of a lactate solution (3 mg/kg in 1 min). Before the exercise or the injection, at the end, as well as 5 and 10 min after the conclusion, venous blood lactate was measured and excitability of the motor cortex was evaluated by using the transcranial magnetic stimulation. In both of these experimental conditions, it was observed that an increase of blood lactate is associated with a decrease of motor threshold, that is, an enhancement of motor cortex excitability. We conclude by hypothesizing that in the motor cortex the lactate could have a protective role against fatigue.

  20. Medial cortex activity, self-reflection and depression.

    Science.gov (United States)

    Johnson, Marcia K; Nolen-Hoeksema, Susan; Mitchell, Karen J; Levin, Yael

    2009-12-01

    Using functional magnetic resonance imaging, we investigated neural activity associated with self-reflection in depressed [current major depressive episode (MDE)] and healthy control participants, focusing on medial cortex areas previously shown to be associated with self-reflection. Both the MDE and healthy control groups showed greater activity in anterior medial cortex (medial frontal gyrus, anterior cingulate gyrus) when cued to think about hopes and aspirations compared with duties and obligations, and greater activity in posterior medial cortex (precuneus, posterior cingulate) when cued to think about duties and obligations (Experiment 1). However, the MDE group showed less activity than controls in the same area of medial frontal cortex when self-referential cues were more ambiguous with respect to valence (Experiment 2), and less deactivation in a non-self-referential condition in both experiments. Furthermore, individual differences in rumination were positively correlated with activity in both anterior and posterior medial cortex during non-self-referential conditions. These results provide converging evidence for a dissociation of anterior and posterior medial cortex depending on the focus of self-relevant thought. They also provide neural evidence consistent with behavioral findings that depression is associated with disruption of positively valenced thoughts in response to ambiguous cues, and difficulty disengaging from self-reflection when it is appropriate to do so.

  1. What does spatial alternation tell us about retrosplenial cortex function?

    Directory of Open Access Journals (Sweden)

    Andrew John Dudley Nelson

    2015-05-01

    Full Text Available The retrosplenial cortex supports navigation, but there are good reasons to suppose that the retrosplenial cortex has a very different role in spatial memory from that of the hippocampus and anterior thalamic nuclei. For example, retrosplenial lesions appear to have little or no effect on standard tests of spatial alternation. To examine these differences, the current study sought to determine whether the retrosplenial cortex is important for just one spatial cue type (e.g. allocentric, directional or intra-maze cues or whether the retrosplenial cortex helps the animal switch between competing spatial strategies or competing cue types. Using T-maze alternation, retrosplenial lesion rats were challenged with situations in which the available spatial information between the sample and test phases was changed, so taxing the interaction between different cue types. Clear lesion deficits emerged when intra- and extra-maze cues were placed in conflict (by rotating the maze between the sample and choice phases, or when the animals were tested in the dark in a double-maze. Finally, temporary inactivation of the retrosplenial cortex by muscimol infusions resulted in a striking deficit on standard T-maze alternation, indicating that, over time, other sites may be able to compensate for the loss of the retrosplenial cortex. This pattern of results is consistent with the impoverished use of both allocentric and directional information, exacerbated by an impaired ability to switch between different cue types.

  2. Tinnitus intensity dependent gamma oscillations of the contralateral auditory cortex.

    Directory of Open Access Journals (Sweden)

    Elsa van der Loo

    Full Text Available BACKGROUND: Non-pulsatile tinnitus is considered a subjective auditory phantom phenomenon present in 10 to 15% of the population. Tinnitus as a phantom phenomenon is related to hyperactivity and reorganization of the auditory cortex. Magnetoencephalography studies demonstrate a correlation between gamma band activity in the contralateral auditory cortex and the presence of tinnitus. The present study aims to investigate the relation between objective gamma-band activity in the contralateral auditory cortex and subjective tinnitus loudness scores. METHODS AND FINDINGS: In unilateral tinnitus patients (N = 15; 10 right, 5 left source analysis of resting state electroencephalographic gamma band oscillations shows a strong positive correlation with Visual Analogue Scale loudness scores in the contralateral auditory cortex (max r = 0.73, p<0.05. CONCLUSION: Auditory phantom percepts thus show similar sound level dependent activation of the contralateral auditory cortex as observed in normal audition. In view of recent consciousness models and tinnitus network models these results suggest tinnitus loudness is coded by gamma band activity in the contralateral auditory cortex but might not, by itself, be responsible for tinnitus perception.

  3. Harmonic Maass forms and mock modular forms

    CERN Document Server

    Bringmann, Kathrin; Ono, Ken

    2017-01-01

    Modular forms and Jacobi forms play a central role in many areas of mathematics. Over the last 10-15 years, this theory has been extended to certain non-holomorphic functions, the so-called "harmonic Maass forms". The first glimpses of this theory appeared in Ramanujan's enigmatic last letter to G. H. Hardy written from his deathbed. Ramanujan discovered functions he called "mock theta functions" which over eighty years later were recognized as pieces of harmonic Maass forms. This book contains the essential features of the theory of harmonic Maass forms and mock modular forms, together with a wide variety of applications to algebraic number theory, combinatorics, elliptic curves, mathematical physics, quantum modular forms, and representation theory.

  4. TMS-induced neural noise in sensory cortex interferes with short-term memory storage in prefrontal cortex

    OpenAIRE

    Bancroft, Tyler D.; Hogeveen, Jeremy; Hockley, William E.; Servos, Philip

    2014-01-01

    In a previous study, Harris et al. (2002) found disruption of vibrotactile short-term memory after applying single-pulse transcranial magnetic stimulation (TMS) to primary somatosensory cortex (SI) early in the maintenance period, and suggested that this demonstrated a role for SI in vibrotactile memory storage. While such a role is compatible with recent suggestions that sensory cortex is the storage substrate for working memory, it stands in contrast to a relatively large body of evidence f...

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.

  7. On good ETOL forms

    DEFF Research Database (Denmark)

    Skyum, Sven

    1978-01-01

    This paper continues the study of ETOL forms and good EOL forms done by Maurer, Salomaa and Wood. It is proven that binary very complete ETOL forms exist, good synchronized ETOL forms exist and that no propagating or synchronized ETOL form can be very complete.......This paper continues the study of ETOL forms and good EOL forms done by Maurer, Salomaa and Wood. It is proven that binary very complete ETOL forms exist, good synchronized ETOL forms exist and that no propagating or synchronized ETOL form can be very complete....

  8. Multiple time scale dynamics

    CERN Document Server

    Kuehn, Christian

    2015-01-01

    This book provides an introduction to dynamical systems with multiple time scales. The approach it takes is to provide an overview of key areas, particularly topics that are less available in the introductory form.  The broad range of topics included makes it accessible for students and researchers new to the field to gain a quick and thorough overview. The first of its kind, this book merges a wide variety of different mathematical techniques into a more unified framework. The book is highly illustrated with many examples and exercises and an extensive bibliography. The target audience of this  book are senior undergraduates, graduate students as well as researchers interested in using the multiple time scale dynamics theory in nonlinear science, either from a theoretical or a mathematical modeling perspective. 

  9. Thermoelectric generator and method of forming same

    International Nuclear Information System (INIS)

    Wilson, K.T.

    1981-01-01

    A thermoelectric device is disclosed which comprises the formation of a multiplicity of thermocouples on a substrate in a narrow strip form, the thermocouples being formed by printing with first and second inks formed of suitable different powdered metals with a proper binder or flux. The thermocouples are formed in series and the opposed coupled areas are melted to form an intermingling of the two metals and the strips may be formed in substantial lengths and rolled onto a reel, or in relatively short strip form and disposed in a side-by-side abutting relationship in substantial numbers to define a generally rectangular panel form with opposed ends in electrical connection. The method of forming the panels includes the steps of feeding a suitable substrate, either in a continuous roll or sheet form, through first and second printers to form the series connected multiplicity of thermocouples thereon. From the printers the sheet or strip passes through a melter such as an induction furnace and from the furnace it passes through a sheeter, if the strip is in roll form. The sheets are then slit into narrow strips relative to the thermocouples, printed thereon and the strips are then formed into a bundle. A predetermined number of bundles are assembled into a panel form

  10. Reduced Synapse and Axon Numbers in the Prefrontal Cortex of Rats Subjected to a Chronic Stress Model for Depression

    Science.gov (United States)

    Csabai, Dávid; Wiborg, Ove; Czéh, Boldizsár

    2018-01-01

    to form the anatomical basis for the impaired functioning of this brain area. Indeed, impaired functioning of the prefrontal cortex, such as cognitive deficits are common in stressed individuals as well as in depressed patients. PMID:29440995

  11. Reduced Synapse and Axon Numbers in the Prefrontal Cortex of Rats Subjected to a Chronic Stress Model for Depression

    Directory of Open Access Journals (Sweden)

    Dávid Csabai

    2018-01-01

    connectivity is likely to form the anatomical basis for the impaired functioning of this brain area. Indeed, impaired functioning of the prefrontal cortex, such as cognitive deficits are common in stressed individuals as well as in depressed patients.

  12. Dynamic encoding of speech sequence probability in human temporal cortex.

    Science.gov (United States)

    Leonard, Matthew K; Bouchard, Kristofer E; Tang, Claire; Chang, Edward F

    2015-05-06

    Sensory processing involves identification of stimulus features, but also integration with the surrounding sensory and cognitive context. Previous work in animals and humans has shown fine-scale sensitivity to context in the form of learned knowledge about the statistics of the sensory environment, including relative probabilities of discrete units in a stream of sequential auditory input. These statistics are a defining characteristic of one of the most important sequential signals humans encounter: speech. For speech, extensive exposure to a language tunes listeners to the statistics of sound sequences. To address how speech sequence statistics are neurally encoded, we used high-resolution direct cortical recordings from human lateral superior temporal cortex as subjects listened to words and nonwords with varying transition probabilities between sound segments. In addition to their sensitivity to acoustic features (including contextual features, such as coarticulation), we found that neural responses dynamically encoded the language-level probability of both preceding and upcoming speech sounds. Transition probability first negatively modulated neural responses, followed by positive modulation of neural responses, consistent with coordinated predictive and retrospective recognition processes, respectively. Furthermore, transition probability encoding was different for real English words compared with nonwords, providing evidence for online interactions with high-order linguistic knowledge. These results demonstrate that sensory processing of deeply learned stimuli involves integrating physical stimulus features with their contextual sequential structure. Despite not being consciously aware of phoneme sequence statistics, listeners use this information to process spoken input and to link low-level acoustic representations with linguistic information about word identity and meaning. Copyright © 2015 the authors 0270-6474/15/357203-12$15.00/0.

  13. Neurons in primary motor cortex engaged during action observation.

    Science.gov (United States)

    Dushanova, Juliana; Donoghue, John

    2010-01-01

    Neurons in higher cortical areas appear to become active during action observation, either by mirroring observed actions (termed mirror neurons) or by eliciting mental rehearsal of observed motor acts. We report the existence of neurons in the primary motor cortex (M1), an area that is generally considered to initiate and guide movement performance, responding to viewed actions. Multielectrode recordings in monkeys performing or observing a well-learned step-tracking task showed that approximately half of the M1 neurons that were active when monkeys performed the task were also active when they observed the action being performed by a human. These 'view' neurons were spatially intermingled with 'do' neurons, which are active only during movement performance. Simultaneously recorded 'view' neurons comprised two groups: approximately 38% retained the same preferred direction (PD) and timing during performance and viewing, and the remainder (62%) changed their PDs and time lag during viewing as compared with performance. Nevertheless, population activity during viewing was sufficient to predict the direction and trajectory of viewed movements as action unfolded, although less accurately than during performance. 'View' neurons became less active and contained poorer representations of action when only subcomponents of the task were being viewed. M1 'view' neurons thus appear to reflect aspects of a learned movement when observed in others, and form part of a broadly engaged set of cortical areas routinely responding to learned behaviors. These findings suggest that viewing a learned action elicits replay of aspects of M1 activity needed to perform the observed action, and could additionally reflect processing related to understanding, learning or mentally rehearsing action.

  14. Multiple Entity Reconciliation

    OpenAIRE

    Samoila, Lavinia Andreea

    2015-01-01

    Living in the age of "Big Data" is both a blessing and a curse. On he one hand, the raw data can be analysed and then used for weather redictions, user recommendations, targeted advertising and more. On he other hand, when data is aggregated from multiple sources, there is no guarantee that each source has stored the data in a standardized or even compatible format to what is required by the application. So there is a need to parse the available data and convert it to the desired form. Here i...

  15. Contextual modulation of primary visual cortex by auditory signals.

    Science.gov (United States)

    Petro, L S; Paton, A T; Muckli, L

    2017-02-19

    Early visual cortex receives non-feedforward input from lateral and top-down connections (Muckli & Petro 2013 Curr. Opin. Neurobiol. 23, 195-201. (doi:10.1016/j.conb.2013.01.020)), including long-range projections from auditory areas. Early visual cortex can code for high-level auditory information, with neural patterns representing natural sound stimulation (Vetter et al. 2014 Curr. Biol. 24, 1256-1262. (doi:10.1016/j.cub.2014.04.020)). We discuss a number of questions arising from these findings. What is the adaptive function of bimodal representations in visual cortex? What type of information projects from auditory to visual cortex? What are the anatomical constraints of auditory information in V1, for example, periphery versus fovea, superficial versus deep cortical layers? Is there a putative neural mechanism we can infer from human neuroimaging data and recent theoretical accounts of cortex? We also present data showing we can read out high-level auditory information from the activation patterns of early visual cortex even when visual cortex receives simple visual stimulation, suggesting independent channels for visual and auditory signals in V1. We speculate which cellular mechanisms allow V1 to be contextually modulated by auditory input to facilitate perception, cognition and behaviour. Beyond cortical feedback that facilitates perception, we argue that there is also feedback serving counterfactual processing during imagery, dreaming and mind wandering, which is not relevant for immediate perception but for behaviour and cognition over a longer time frame.This article is part of the themed issue 'Auditory and visual scene analysis'. © 2017 The Authors.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Adenomatous polyposis coli is required for early events in the normal growth and differentiation of the developing cerebral cortex

    Directory of Open Access Journals (Sweden)

    Price David J

    2009-01-01

    Full Text Available Abstract Background Adenomatous polyposis coli (Apc is a large multifunctional protein known to be important for Wnt/β-catenin signalling, cytoskeletal dynamics, and cell polarity. In the developing cerebral cortex, Apc is expressed in proliferating cells and its expression increases as cells migrate to the cortical plate. We examined the consequences of loss of Apc function for the early development of the cerebral cortex. Results We used Emx1Cre to inactivate Apc specifically in proliferating cerebral cortical cells and their descendents starting from embryonic day 9.5. We observed reduction in the size of the mutant cerebral cortex, disruption to its organisation, and changes in the molecular identity of its cells. Loss of Apc leads to a decrease in the size of the proliferative pool, disrupted interkinetic nuclear migration, and increased apoptosis. β-Catenin, pericentrin, and N-cadherin proteins no longer adopt their normal high concentration at the apical surface of the cerebral cortical ventricular zone, indicating that cell polarity is disrupted. Consistent with enhanced Wnt/β-catenin signalling resulting from loss of Apc we found increased levels of TCF/LEF-dependent transcription and expression of endogenous Wnt/β-catenin target genes (Axin2 (conductin, Lef1, and c-myc in the mutant cerebral cortex. In the Apc mutant cerebral cortex the expression of transcription factors Foxg1, Pax6, Tbr1, and Tbr2 is drastically reduced compared to normal and many cells ectopically express Pax3, Wnt1, and Wt1 (but not Wnt2b, Wnt8b, Ptc, Gli1, Mash1, Olig2, or Islet1. This indicates that loss of Apc function causes cerebral cortical cells to lose their normal identity and redirect to fates normally found in more posterior-dorsal regions of the central nervous system. Conclusion Apc is required for multiple aspects of early cerebral cortical development, including the regulation of cell number, interkinetic nuclear migration, cell polarity, and

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

    Science.gov (United States)

    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.

  19. Avalanche analysis from multi-electrode ensemble recordings in cat, monkey and human cerebral cortex during wakefulness and sleep.

    Directory of Open Access Journals (Sweden)

    Nima eDehghani

    2012-08-01

    Full Text Available Self-organized critical states are found in many natural systems, from earthquakes to forest fires, they have also been observed in neural systems, particularly, in neuronal cultures. However, the presence of critical states in the awake brain remains controversial. Here, we compared avalanche analyses performed on different in vivo preparations during wakefulness, slow-wave sleep and REM sleep, using high-density electrode arrays in cat motor cortex (96 electrodes, monkey motor cortex and premotor cortex and human temporal cortex (96 electrodes in epileptic patients. In neuronal avalanches defined from units (up to 160 single units, the size of avalanches never clearly scaled as power-law, but rather scaled exponentially or displayed intermediate scaling. We also analyzed the dynamics of local field potentials (LFPs and in particular LFP negative peaks (nLFPs among the different electrodes (up to 96 sites in temporal cortex or up to 128 sites in adjacent motor and pre-motor cortices. In this case, the avalanches defined from nLFPs displayed power-law scaling in double logarithmic representations, as reported previously in monkey. However, avalanche defined as positive LFP (pLFP peaks, which are less directly related to neuronal firing, also displayed apparent power-law scaling. Closer examination of this scaling using the more reliable cumulative distribution function (CDF and other rigorous statistical measures, did not confirm power-law scaling. The same pattern was seen for cats, monkey and human, as well as for different brain states of wakefulness and sleep. We also tested other alternative distributions. Multiple exponential fitting yielded optimal fits of the avalanche dynamics with bi-exponential distributions. Collectively, these results show no clear evidence for power-law scaling or self-organized critical states in the awake and sleeping brain of mammals, from cat to man.

  20. From motor cortex to visual cortex: the application of noninvasive brain stimulation to amblyopia.

    Science.gov (United States)

    Thompson, Benjamin; Mansouri, Behzad; Koski, Lisa; Hess, Robert F

    2012-04-01

    Noninvasive brain stimulation is a technique for inducing changes in the excitability of discrete neural populations in the human brain. A current model of the underlying pathological processes contributing to the loss of motor function after stroke has motivated a number of research groups to investigate the potential therapeutic application of brain stimulation to stroke rehabilitation. The loss of motor function is modeled as resulting from a combination of reduced excitability in the lesioned motor cortex and an increased inhibitory drive from the nonlesioned hemisphere over the lesioned hemisphere. This combination of impaired neural function and pathological suppression resonates with current views on the cause of the visual impairment in amblyopia. Here, we discuss how the rationale for using noninvasive brain stimulation in stroke rehabilitation can be applied to amblyopia, review a proof-of-principle study demonstrating that brain stimulation can temporarily improve amblyopic eye function, and propose future research avenues. Copyright © 2010 Wiley Periodicals, Inc.

  1. Biphasic activation of the mTOR pathway in the gustatory cortex is correlated with and necessary for taste learning.

    Science.gov (United States)

    Belelovsky, Katya; Kaphzan, Hanoch; Elkobi, Alina; Rosenblum, Kobi

    2009-06-10

    Different forms of memories and synaptic plasticity require synthesis of new proteins at the time of acquisition or immediately after. We are interested in the role of translation regulation in the cortex, the brain structure assumed to store long-term memories. The mammalian target of rapamycin, mTOR (also known as FRAP and RAFT-1), is part of a key signal transduction mechanism known to regulate translation of specific subset of mRNAs and to affect learning and synaptic plasticity. We report here that novel taste learning induces two waves of mTOR activation in the gustatory cortex. Interestingly, the first wave can be identified both in synaptoneurosomal and cellular fractions, whereas the second wave is detected in the cellular fraction but not in the synaptic one. Inhibition of mTOR, specifically in the gustatory cortex, has two effects. First, biochemically, it modulates several known downstream proteins that control translation and reduces the expression of postsynaptic density-95 in vivo. Second, behaviorally, it attenuates long-term taste memory. The results suggest that the mTOR pathway in the cortex modulates both translation factor activity and protein expression, to enable normal taste memory consolidation.

  2. Lateral prefrontal cortex is organized into parallel dorsal and ventral streams along the rostro-caudal axis.

    Science.gov (United States)

    Blumenfeld, Robert S; Nomura, Emi M; Gratton, Caterina; D'Esposito, Mark

    2013-10-01

    Anatomical connectivity differences between the dorsal and ventral lateral prefrontal cortex (PFC) of the non-human primate strongly suggests that these regions support different functions. However, after years of study, it remains unclear whether these regions are functionally distinct. In contrast, there has been a groundswell of recent studies providing evidence for a rostro-caudal functional organization, along the lateral as well as dorsomedial frontal cortex. Thus, it is not known whether dorsal and ventral regions of lateral PFC form distinct functional networks and how to reconcile any dorso-ventral organization with the medio-lateral and rostro-caudal axes. Here, we used resting-state connectivity data to identify parallel dorsolateral and ventrolateral streams of intrinsic connectivity with the dorsomedial frontal cortex. Moreover, we show that this connectivity follows a rostro-caudal gradient. Our results provide evidence for a novel framework for the intrinsic organization of the frontal cortex that incorporates connections between medio-lateral, dorso-ventral, and rostro-caudal axes.

  3. Bacurd2 is a novel interacting partner to Rnd2 which controls radial migration within the developing mammalian cerebral cortex.

    Science.gov (United States)

    Gladwyn-Ng, Ivan Enghian; Li, Shan Shan; Qu, Zhengdong; Davis, John Michael; Ngo, Linh; Haas, Matilda; Singer, Jeffrey; Heng, Julian Ik-Tsen

    2015-03-31

    During fetal brain development in mammals, newborn neurons undergo cell migration to reach their appropriate positions and form functional circuits. We previously reported that the atypical RhoA GTPase Rnd2 promotes the radial migration of mouse cerebral cortical neurons (Nature 455(7209):114-8, 2008; Neuron 69(6):1069-84, 2011), but its downstream signalling pathway is not well understood. We have identified BTB-domain containing adaptor for Cul3-mediated RhoA degradation 2 (Bacurd2) as a novel interacting partner to Rnd2, which promotes radial migration within the developing cerebral cortex. We find that Bacurd2 binds Rnd2 at its C-terminus, and this interaction is critical to its cell migration function. We show that forced expression or knockdown of Bacurd2 impairs neuronal migration within the embryonic cortex and alters the morphology of immature neurons. Our in vivo cellular analysis reveals that Bacurd2 influences the multipolar-to-bipolar transition of radially migrating neurons in a cell autonomous fashion. When we addressed the potential signalling relationship between Bacurd2 and Rnd2 using a Bacurd2-Rnd2 chimeric construct, our results suggest that Bacurd2 and Rnd2 could interact to promote radial migration within the embryonic cortex. Our studies demonstrate that Bacurd2 is a novel player in neuronal development and influences radial migration within the embryonic cerebral cortex.

  4. Early sensory cortex is activated in the absence of explicit input during crossmodal item retrieval: evidence from MEG.

    Science.gov (United States)

    Pillai, Ajay S; Gilbert, Jessica R; Horwitz, Barry

    2013-02-01

    Crossmodal associations form a fundamental aspect of our daily lives. In this study we investigated the neural correlates of crossmodal association in early sensory cortices using magnetoencephalography (MEG). We used a paired associate recognition paradigm in which subjects were tested after multiple training sessions over a span of four weeks. Subjects had to learn 12 abstract, nonlinguistic, pairs of auditory and visual objects that consisted of crossmodal (visual-auditory, VA; auditory-visual, AV) and unimodal (visual-visual, VV; auditory-auditory, AA) paired items. Visual objects included abstract, non-nameable, fractal-like images, and auditory objects included abstract tone sequences. During scanning, subjects were shown the first item of a pair (S1), followed by a delay, then the simultaneous presentation of a visual and auditory stimulus (S2). Subjects were instructed to indicate whether either of the S2 stimuli contained the correct paired associate of S1. Synthetic aperture magnetometry (SAMspm), a minimum variance beamformer, was then used to assess source power differences between the crossmodal conditions and their corresponding unimodal conditions (i.e., AV-AA and VA-VV) in the beta (15-30 Hz) and low gamma frequencies (31-54 Hz) during the S1 period. We found greater power during S1 in the corresponding modality-specific association areas for crossmodal compared with unimodal stimuli. Thus, even in the absence of explicit sensory input, the retrieval of well-learned, crossmodal pairs activate sensory areas associated with the corresponding modality. These findings support theories which posit that modality-specific regions of cortex are involved in the storage and retrieval of sensory-specific items from long-term memory. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Treatment of Cognitive Impairment in Multiple Sclerosis

    OpenAIRE

    Pierson, Susan H.; Griffith, Nathan

    2006-01-01

    Cognitive impairment in multiple sclerosis is an increasingly recognized entity. This article reviews the cognitive impairment of multiple sclerosis, its prevalence, its relationship to different types of multiple sclerosis, and its contribution to long-term functional prognosis. The discussion also focuses on the key elements of cognitive dysfunction in multiple sclerosis which distinguish it from other forms of cognitive impairment. Therapeutic interventions potentially effective for the co...

  6. Electroweak form factors

    International Nuclear Information System (INIS)

    Singh, S.K.

    2002-01-01

    The present status of electroweak nucleon form factors and the N - Δ transition form factors is reviewed. Particularly the determination of dipole mass M A in the axial vector form factor is discussed

  7. Orosensory and Homeostatic Functions of the Insular Taste Cortex.

    Science.gov (United States)

    de Araujo, Ivan E; Geha, Paul; Small, Dana M

    2012-03-01

    The gustatory aspect of the insular cortex is part of the brain circuit that controls ingestive behaviors based on chemosensory inputs. However, the sensory properties of foods are not restricted to taste and should also include salient features such as odor, texture, temperature, and appearance. Therefore, it is reasonable to hypothesize that specialized circuits within the central taste pathways must be involved in representing several other oral sensory modalities in addition to taste. In this review, we evaluate current evidence indicating that the insular gustatory cortex functions as an integrative circuit, with taste-responsive regions also showing heightened sensitivity to olfactory, somatosensory, and even visual stimulation. We also review evidence for modulation of taste-responsive insular areas by changes in physiological state, with taste-elicited neuronal responses varying according to the nutritional state of the organism. We then examine experimental support for a functional map within the insular cortex that might reflect the various sensory and homeostatic roles associated with this region. Finally, we evaluate the potential role of the taste insular cortex in weight-gain susceptibility. Taken together, the current experimental evidence favors the view that the insular gustatory cortex functions as an orosensory integrative system that not only enables the formation of complex flavor representations but also mediates their modulation by the internal state of the body, playing therefore a central role in food intake regulation.

  8. Ventromedial prefrontal cortex mediates visual attention during facial emotion recognition.

    Science.gov (United States)

    Wolf, Richard C; Philippi, Carissa L; Motzkin, Julian C; Baskaya, Mustafa K; Koenigs, Michael

    2014-06-01

    The ventromedial prefrontal cortex is known to play a crucial role in regulating human social and emotional behaviour, yet the precise mechanisms by which it subserves this broad function remain unclear. Whereas previous neuropsychological studies have largely focused on the role of the ventromedial prefrontal cortex in higher-order deliberative processes related to valuation and decision-making, here we test whether ventromedial prefrontal cortex may also be critical for more basic aspects of orienting attention to socially and emotionally meaningful stimuli. Using eye tracking during a test of facial emotion recognition in a sample of lesion patients, we show that bilateral ventromedial prefrontal cortex damage impairs visual attention to the eye regions of faces, particularly for fearful faces. This finding demonstrates a heretofore unrecognized function of the ventromedial prefrontal cortex-the basic attentional process of controlling eye movements to faces expressing emotion. © 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.

  9. Changes in Cerebral Cortex of Children Treated for Medulloblastoma

    International Nuclear Information System (INIS)

    Liu, Arthur K.; Marcus, Karen J.; Fischl, Bruce; Grant, P. Ellen; Young Poussaint, Tina; Rivkin, Michael J.; Davis, Peter; Tarbell, Nancy J.; Yock, Torunn I.

    2007-01-01

    Purpose: Children with medulloblastoma undergo surgery, radiotherapy, and chemotherapy. After treatment, these children have numerous structural abnormalities. Using high-resolution magnetic resonance imaging, we measured the thickness of the cerebral cortex in a group of medulloblastoma patients and a group of normally developing children. Methods and Materials: We obtained magnetic resonance imaging scans and measured the cortical thickness in 9 children after treatment of medulloblastoma. The measurements from these children were compared with the measurements from age- and gender-matched normally developing children previously scanned. For additional comparison, the pattern of thickness change was compared with the cortical thickness maps from a larger group of 65 normally developing children. Results: In the left hemisphere, relatively thinner cortex was found in the perirolandic region and the parieto-occipital lobe. In the right hemisphere, relatively thinner cortex was found in the parietal lobe, posterior superior temporal gyrus, and lateral temporal lobe. These regions of cortical thinning overlapped with the regions of cortex that undergo normal age-related thinning. Conclusion: The spatial distribution of cortical thinning suggested that the areas of cortex that are undergoing development are more sensitive to the effects of treatment of medulloblastoma. Such quantitative methods may improve our understanding of the biologic effects that treatment has on the cerebral development and their neuropsychological implications

  10. An FPGA-Based Massively Parallel Neuromorphic Cortex Simulator.

    Science.gov (United States)

    Wang, Runchun M; Thakur, Chetan S; van Schaik, André

    2018-01-01

    This paper presents a massively parallel and scalable neuromorphic cortex simulator designed for simulating large and structurally connected spiking neural networks, such as complex models of various areas of the cortex. The main novelty of this work is the abstraction of a neuromorphic architecture into clusters represented by minicolumns and hypercolumns, analogously to the fundamental structural units observed in neurobiology. Without this approach, simulating large-scale fully connected networks needs prohibitively large memory to store look-up tables for point-to-point connections. Instead, we use a novel architecture, based on the structural connectivity in the neocortex, such that all the required parameters and connections can be stored in on-chip memory. The cortex simulator can be easily reconfigured for simulating different neural networks without any change in hardware structure by programming the memory. A hierarchical communication scheme allows one neuron to have a fan-out of up to 200 k neurons. As a proof-of-concept, an implementation on one Altera Stratix V FPGA was able to simulate 20 million to 2.6 billion leaky-integrate-and-fire (LIF) neurons in real time. We verified the system by emulating a simplified auditory cortex (with 100 million neurons). This cortex</