Movement-related cortical potentials in paraplegic patients: abnormal patterns and considerations for BCI-rehabilitation

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Ren eXu

2014-08-01

Full Text Available Non-invasive EEG-based Brain-Computer Interfaces (BCI can be promising for the motor neuro-rehabilitation of paraplegic patients. However, this shall require detailed knowledge of the abnormalities in the EEG signatures of paraplegic patients. The association of abnormalities in different subgroups of patients and their relation to the sensorimotor integration are relevant for the design, implementation and use of BCI systems in patient populations. This study explores the patterns of abnormalities of movement related cortical potentials (MRCP during motor imagery tasks of feet and right hand in patients with paraplegia (including the subgroups with/without central neuropathic pain and complete/incomplete injury patients and the level of distinctiveness of abnormalities in these groups using pattern classification. The most notable observed abnormalities were the amplified execution negativity and its slower rebound in the patient group. The potential underlying mechanisms behind these changes and other minor dissimilarities in patients’ subgroups, as well as the relevance to BCI applications, are discussed. The findings are of interest from a neurological perspective as well as for BCI-assisted neuro-rehabilitation and therapy.

Altered Cortical Swallowing Processing in Patients with Functional Dysphagia: A Preliminary Study

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Wollbrink, Andreas; Warnecke, Tobias; Winkels, Martin; Pantev, Christo; Dziewas, Rainer

2014-01-01

Objective Current neuroimaging research on functional disturbances provides growing evidence for objective neuronal correlates of allegedly psychogenic symptoms, thereby shifting the disease concept from a psychological towards a neurobiological model. Functional dysphagia is such a rare condition, whose pathogenetic mechanism is largely unknown. In the absence of any organic reason for a patient's persistent swallowing complaints, sensorimotor processing abnormalities involving central neural pathways constitute a potential etiology. Methods In this pilot study we measured cortical swallow-related activation in 5 patients diagnosed with functional dysphagia and a matched group of healthy subjects applying magnetoencephalography. Source localization of cortical activation was done with synthetic aperture magnetometry. To test for significant differences in cortical swallowing processing between groups, a non-parametric permutation test was afterwards performed on individual source localization maps. Results Swallowing task performance was comparable between groups. In relation to control subjects, in whom activation was symmetrically distributed in rostro-medial parts of the sensorimotor cortices of both hemispheres, patients showed prominent activation of the right insula, dorsolateral prefrontal cortex and lateral premotor, motor as well as inferolateral parietal cortex. Furthermore, activation was markedly reduced in the left medial primary sensory cortex as well as right medial sensorimotor cortex and adjacent supplementary motor area (pdysphagia - a condition with assumed normal brain function - seems to be associated with distinctive changes of the swallow-related cortical activation pattern. Alterations may reflect exaggerated activation of a widely distributed vigilance, self-monitoring and salience rating network that interferes with down-stream deglutition sensorimotor control. PMID:24586948

Abnormalities in Structural Covariance of Cortical Gyrification in Parkinson's Disease.

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Xu, Jinping; Zhang, Jiuquan; Zhang, Jinlei; Wang, Yue; Zhang, Yanling; Wang, Jian; Li, Guanglin; Hu, Qingmao; Zhang, Yuanchao

2017-01-01

Although abnormal cortical morphology and connectivity between brain regions (structural covariance) have been reported in Parkinson's disease (PD), the topological organizations of large-scale structural brain networks are still poorly understood. In this study, we investigated large-scale structural brain networks in a sample of 37 PD patients and 34 healthy controls (HC) by assessing the structural covariance of cortical gyrification with local gyrification index (lGI). We demonstrated prominent small-world properties of the structural brain networks for both groups. Compared with the HC group, PD patients showed significantly increased integrated characteristic path length and integrated clustering coefficient, as well as decreased integrated global efficiency in structural brain networks. Distinct distributions of hub regions were identified between the two groups, showing more hub regions in the frontal cortex in PD patients. Moreover, the modular analyses revealed significantly decreased integrated regional efficiency in lateral Fronto-Insula-Temporal module, and increased integrated regional efficiency in Parieto-Temporal module in the PD group as compared to the HC group. In summary, our study demonstrated altered topological properties of structural networks at a global, regional and modular level in PD patients. These findings suggests that the structural networks of PD patients have a suboptimal topological organization, resulting in less effective integration of information between brain regions.

Distinct temporal and anatomical distributions of amyloid-β and tau abnormalities following controlled cortical impact in transgenic mice.

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Hien T Tran

Full Text Available Traumatic brain injury (TBI is a major environmental risk factor for Alzheimer's disease. Intracellular accumulations of amyloid-β and tau proteins have been observed within hours following severe TBI in humans. Similar abnormalities have been recapitulated in young 3xTg-AD mice subjected to the controlled cortical impact model (CCI of TBI and sacrificed at 24 h and 7 days post injury. This study investigated the temporal and anatomical distributions of amyloid-β and tau abnormalities from 1 h to 24 h post injury in the same model. Intra-axonal amyloid-β accumulation in the fimbria was detected as early as 1 hour and increased monotonically over 24 hours following injury. Tau immunoreactivity in the fimbria and amygdala had a biphasic time course with peaks at 1 hour and 24 hours, while tau immunoreactivity in the contralateral CA1 rose in a delayed fashion starting at 12 hours after injury. Furthermore, rapid intra-axonal amyloid-β accumulation was similarly observed post controlled cortical injury in APP/PS1 mice, another transgenic Alzheimer's disease mouse model. Acute increases in total and phospho-tau immunoreactivity were also evident in single transgenic Tau(P301L mice subjected to controlled cortical injury. These data provide further evidence for the causal effects of moderately severe contusional TBI on acceleration of acute Alzheimer-related abnormalities and the independent relationship between amyloid-β and tau in this setting.

Cortical Abnormalities Associated With Pediatric and Adult Obsessive-Compulsive Disorder : Findings From the ENIGMA Obsessive-Compulsive Disorder Working Group

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Boedhoe, Premika S W; Schmaal, Lianne; Abe, Yoshinari; Alonso, Pino; Ameis, Stephanie H; Anticevic, Alan; Arnold, Paul D; Batistuzzo, Marcelo C; Benedetti, Francesco; Beucke, Jan C; Bollettini, Irene; Bose, Anushree; Brem, Silvia; Calvo, Anna; Calvo, Rosa; Cheng, Yuqi; Cho, Kang Ik K; Ciullo, Valentina; Dallaspezia, Sara; Denys, D.; Feusner, Jamie D; Fitzgerald, Kate D; Fouche, Jean-Paul; Fridgeirsson, Egill A; Gruner, Patricia; Hanna, Gregory L; Hibar, Derrek P; Hoexter, Marcelo Q; Hu, Hao; Huyser, Chaim; Jahanshad, Neda; James, Anthony; Kathmann, Norbert; Kaufmann, Christian; Koch, Kathrin; Kwon, Jun Soo; Lazaro, Luisa; Lochner, Christine; Marsh, Rachel; Martínez-Zalacaín, Ignacio; Mataix-Cols, David; Menchón, José M; Minuzzi, Luciano; Morer, Astrid; Nakamae, Takashi; Nakao, Tomohiro; Narayanaswamy, Janardhanan C; Nishida, Seiji; Nurmi, Erika; O'Neill, Joseph; Piacentini, John; Piras, Fabrizio; Piras, Federica; Reddy, Y C Janardhan; Reess, Tim J; Sakai, Yuki; Sato, Joao R; Simpson, H Blair; Soreni, Noam; Soriano-Mas, Carles; Spalletta, Gianfranco; Stevens, Michael C; Szeszko, Philip R; Tolin, David F; van Wingen, Guido A; Venkatasubramanian, Ganesan; Walitza, Susanne; Wang, Zhen; Yun, Je-Yeon; Thompson, Paul M; Stein, Dan J; van den Heuvel, Odile A

2018-01-01

OBJECTIVE: Brain imaging studies of structural abnormalities in OCD have yielded inconsistent results, partly because of limited statistical power, clinical heterogeneity, and methodological differences. The authors conducted meta- and mega-analyses comprising the largest study of cortical

Cortical Abnormalities Associated With Pediatric and Adult Obsessive-Compulsive Disorder: Findings From the ENIGMA Obsessive-Compulsive Disorder Working Group

NARCIS (Netherlands)

Boedhoe, Premika S. W.; Schmaal, Lianne; Abe, Yoshinari; Alonso, Pino; Ameis, Stephanie H.; Anticevic, Alan; Arnold, Paul D.; Batistuzzo, Marcelo C.; Benedetti, Francesco; Beucke, Jan C.; Bollettini, Irene; Bose, Anushree; Brem, Silvia; Calvo, Anna; Calvo, Rosa; Cheng, Yuqi; Cho, Kang Ik K.; Ciullo, Valentina; Dallaspezia, Sara; Denys, Damiaan; Feusner, Jamie D.; Fitzgerald, Kate D.; Fouche, Jean-Paul; Fridgeirsson, Egill A.; Gruner, Patricia; Hanna, Gregory L.; Hibar, Derrek P.; Hoexter, Marcelo Q.; Hu, Hao; Huyser, Chaim; Jahanshad, Neda; James, Anthony; Kathmann, Norbert; Kaufmann, Christian; Koch, Kathrin; Kwon, Jun Soo; Lazaro, Luisa; Lochner, Christine; Marsh, Rachel; Martínez-Zalacaín, Ignacio; Mataix-Cols, David; Menchón, José M.; Minuzzi, Luciano; Morer, Astrid; Nakamae, Takashi; Nakao, Tomohiro; Narayanaswamy, Janardhanan C.; Nishida, Seiji; van Wingen, Guido A.; Figee, Martijn

2017-01-01

Brain imaging studies of structural abnormalities in OCD have yielded inconsistent results, partly because of limited statistical power, clinical heterogeneity, and methodological differences. The authors conducted meta- and mega-analyses comprising the largest study of cortical morphometry in OCD

Abnormalities in cortical gray matter density in borderline personality disorder

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Rossi, Roberta; Lanfredi, Mariangela; Pievani, Michela; Boccardi, Marina; Rasser, Paul E; Thompson, Paul M; Cavedo, Enrica; Cotelli, Maria; Rosini, Sandra; Beneduce, Rossella; Bignotti, Stefano; Magni, Laura R; Rillosi, Luciana; Magnaldi, Silvia; Cobelli, Milena; Rossi, Giuseppe; Frisoni, Giovanni B

2015-01-01

Background Borderline personality disorder (BPD) is a chronic condition with a strong impact on patients‘ affective,cognitive and social functioning. Neuroimaging techniques offer invaluable tools to understand the biological substrate of the disease. We aimed to investigate gray matter alterations over the whole cortex in a group of Borderline Personality Disorder (BPD) patients compared to healthy controls (HC). Methods Magnetic resonance-based cortical pattern matching was used to assess cortical gray matter density (GMD) in 26 BPD patients and in their age- and sex-matched HC (age: 38±11; females: 16, 61%). Results BPD patients showed widespread lower cortical GMD compared to HC (4% difference) with peaks of lower density located in the dorsal frontal cortex, in the orbitofrontal cortex, the anterior and posterior cingulate, the right parietal lobe, the temporal lobe (medial temporal cortex and fusiform gyrus) and in the visual cortex (p<0.005). Our BPD subjects displayed a symmetric distribution of anomalies in the dorsal aspect of the cortical mantle, but a wider involvement of the left hemisphere in the mesial aspect in terms of lower density. A few restricted regions of higher density were detected in the right hemisphere. All regions remained significant after correction for multiple comparisons via permutation testing. Conclusions BPD patients feature specific morphology of the cerebral structures involved in cognitive and emotional processing and social cognition/mentalization, consistent with clinical and functional data. PMID:25561291

Multimodal surface-based morphometry reveals diffuse cortical atrophy in traumatic brain injury.

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Sorenson Donna J

2009-12-01

Full Text Available Abstract Background Patients with traumatic brain injury (TBI often present with significant cognitive deficits without corresponding evidence of cortical damage on neuroradiological examinations. One explanation for this puzzling observation is that the diffuse cortical abnormalities that characterize TBI are difficult to detect with standard imaging procedures. Here we investigated a patient with severe TBI-related cognitive impairments whose scan was interpreted as normal by a board-certified radiologist in order to determine if quantitative neuroimaging could detect cortical abnormalities not evident with standard neuroimaging procedures. Methods Cortical abnormalities were quantified using multimodal surfaced-based morphometry (MSBM that statistically combined information from high-resolution structural MRI and diffusion tensor imaging (DTI. Normal values of cortical anatomy and cortical and pericortical DTI properties were quantified in a population of 43 healthy control subjects. Corresponding measures from the patient were obtained in two independent imaging sessions. These data were quantified using both the average values for each lobe and the measurements from each point on the cortical surface. The results were statistically analyzed as z-scores from the mean with a p Results The TBI patient showed significant regional abnormalities in cortical thickness, gray matter diffusivity and pericortical white matter integrity that replicated across imaging sessions. Consistent with the patient's impaired performance on neuropsychological tests of executive function, cortical abnormalities were most pronounced in the frontal lobes. Conclusions MSBM is a promising tool for detecting subtle cortical abnormalities with high sensitivity and selectivity. MSBM may be particularly useful in evaluating cortical structure in TBI and other neurological conditions that produce diffuse abnormalities in both cortical structure and tissue properties.

Functional MRI study of the brain with malformations of cortical development

International Nuclear Information System (INIS)

Zhang Lei; Zhou Wenjing; Jin Zhen; Li Ke; Zhang Chaoli

2012-01-01

Objective: To explore the patterns of motor and linguistic activation in cortical and its correlations with abnormal gray matter in patients with malformations of cortical development (MCD) and epilepsy. Methods: Seven MCD patients with epilepsy (2 patients with focal cortical dysplasia, 2 heterotopia, 2 schizencephaly, and 1 polymicrogyria) underwent blood-oxygen-level-dependent (BOLD) functional MRI (fMRI) in a 3 T MR scanner when practicing bilateral fingers tapping,toes twisting, verb generation, and picture naming.Functional images were post-processed by using SPM 5 software based on a general linear model (GLM) to generate activations above a uniform threshold with the cluster size (≥30 voxels, P<0.001 corrected). The activations were recognized and classified by two experienced neuroradiologists, and then compared with that in abnormal gray matter. Results: The clusters and intensities of motor activations were mainly located in the sensormotor cortex (SMC) and premotor area (PMA). In linguistic tasks, activations produced by verb generation were found in language-associated cortical regions and PMA with higher activation in Wernicke area, picture naming significantly in the visual cortex, and language in Broca area. Combination of the two linguistic tasks produced significant clusters and intensities in language cortex. For MCD patients with abnormal cortical abnormalities, motor and language task could produce neuronal activities within normal as well as abnormal cortex regions. In 6 patients who underwent respective surgery, epileptic seizures decreased significantly, and the follow-up images demonstrated no new neurological dysfunctions and cognitive impairments. Conclusions: fMRI can visualize neuronal activities in patients with MCD and epilepsy and demonstrate the motor and linguistic activations occurring in normal and abnormal gray matter. It should be cautious for surgery in patient with MCD and epilepsy. (authors)

White matter abnormalities in tuberous sclerosis complex

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Griffiths, P.D. [Sheffield Univ. (United Kingdom). Academic Dept. of Radiology; Bolton, P. [Cambridge Univ. (United Kingdom). Section of Developmental Psychiatry; Verity, C. [Addenbrooke`s NHS Trust, Cambridge (United Kingdom). Dept. of Paediatric Radiology

1998-09-01

The aim of this study was to investigate and describe the range of white matter abnormalities in children with tuberous sclerosis complex by means of MR imaging. Material and Methods: A retrospective cross-sectional study was performed on the basis of MR imaging findings in 20 cases of tuberous sclerosis complex in children aged 17 years or younger. Results: White matter abnormalities were present in 19/20 (95%) cases of tuberous sclerosis complex. These were most frequently (19/20 cases) found in relation to cortical tubers in the supratentorial compartment. White matter abnormalities related to tubers were found in the cerebellum in 3/20 (15%) cases. White matter abnormalities described as radial migration lines were found in relation to 5 tubers in 3 (15%) children. In 4/20 (20%) cases, white matter abnormalities were found that were not related to cortical tubers. These areas had the appearance of white matter cysts in 3 cases and infarction in the fourth. In the latter case there was a definable event in the clinical history, supporting the diagnosis of stroke. Conclusion: A range of white matter abnormalities were found by MR imaging in tuberous sclerosis complex, the commonest being gliosis and hypomyelination related to cortical tubers. Radial migration lines were seen infrequently in relation to cortical tubers and these are thought to represent heterotopic glia and neurons along the expected path of cortical migration. (orig.)

Cortical functional connectivity decodes subconscious, task-irrelevant threat-related emotion processing

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Pantazatos, Spiro P.; Talati, Ardesheer; Pavlidis, Paul; Hirsch, Joy

2012-01-01

It is currently unclear to what extent cortical structures are required for and engaged during subconscious processing of biologically salient affective stimuli (i.e. the ‘low-road’ vs. ‘many-roads’ hypotheses). Here we show that cortical-cortical and cortical-subcortical functional connectivity (FC) contain substantially more information, relative to subcortical-subcortical FC (i.e. ‘subcortical alarm’ and other limbic regions), that predicts subliminal fearful face processing within individ...

Aberrant cortical associative plasticity associated with severe adult Tourette syndrome.

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Martín-Rodríguez, Juan Francisco; Ruiz-Rodríguez, María Adilia; Palomar, Francisco J; Cáceres-Redondo, María Teresa; Vargas, Laura; Porcacchia, Paolo; Gómez-Crespo, Mercedes; Huertas-Fernández, Ismael; Carrillo, Fátima; Madruga-Garrido, Marcos; Mir, Pablo

2015-03-01

Recent studies have shown altered cortical plasticity in adult patients with Tourette syndrome. However, the clinical significance of this finding remains elusive. Motor cortical plasticity was evaluated in 15 adult patients with severe Tourette syndrome and 16 healthy controls using the paired associative stimulation protocol by transcranial magnetic stimulation. Associations between paired associative stimulation-induced plasticity and relevant clinical variables, including cortical excitability, psychiatric comorbidities, drug treatment and tic severity, were assessed. Motor cortical plasticity was abnormally increased in patients with Tourette syndrome compared with healthy subjects. This abnormal plasticity was independently associated with tic severity. Patients with severe Tourette syndrome display abnormally increased cortical associative plasticity. This aberrant cortical plasticity was associated with tic severity, suggesting an underlying mechanism for tic pathophysiology. © 2015 International Parkinson and Movement Disorder Society.

Deafferentation-Induced Plasticity of Visual Callosal Connections: Predicting Critical Periods and Analyzing Cortical Abnormalities Using Diffusion Tensor Imaging

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Jaime F. Olavarria

2012-01-01

Full Text Available Callosal connections form elaborate patterns that bear close association with striate and extrastriate visual areas. Although it is known that retinal input is required for normal callosal development, there is little information regarding the period during which the retina is critically needed and whether this period correlates with the same developmental stage across species. Here we review the timing of this critical period, identified in rodents and ferrets by the effects that timed enucleations have on mature callosal connections, and compare it to other developmental milestones in these species. Subsequently, we compare these events to diffusion tensor imaging (DTI measurements of water diffusion anisotropy within developing cerebral cortex. We observed that the relationship between the timing of the critical period and the DTI-characterized developmental trajectory is strikingly similar in rodents and ferrets, which opens the possibility of using cortical DTI trajectories for predicting the critical period in species, such as humans, in which this period likely occurs prenatally. Last, we discuss the potential of utilizing DTI to distinguish normal from abnormal cerebral cortical development, both within the context of aberrant connectivity induced by early retinal deafferentation, and more generally as a potential tool for detecting abnormalities associated with neurodevelopmental disorders.

MR imaging of abnormal synovial processes

International Nuclear Information System (INIS)

Quinn, S.F.; Sanchez, R.; Murray, W.T.; Silbiger, M.L.; Ogden, J.; Cochran, C.

1987-01-01

MR imaging can directly image abnormal synovium. The authors reviewed over 50 cases with abnormal synovial processes. The abnormalities include Baker cysts, semimembranous bursitis, chronic shoulder bursitis, peroneal tendon ganglion cyst, periarticular abscesses, thickened synovium from rheumatoid and septic arthritis, and synovial hypertrophy secondary to Legg-Calve-Perthes disease. MR imaging has proved invaluable in identifying abnormal synovium, defining the extent and, to a limited degree, characterizing its makeup

Growth and Age-Related Abnormalities in Cortical Structure and Fracture Risk

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Ego Seeman

2015-12-01

Full Text Available Vertebral fractures and trabecular bone loss have dominated thinking and research into the pathogenesis and the structural basis of bone fragility during the last 70 years. However, 80% of all fractures are non-vertebral and occur at regions assembled using large amounts of cortical bone; only 20% of fractures are vertebral. Moreover, ~80% of the skeleton is cortical and ~70% of all bone loss is cortical even though trabecular bone is lost more rapidly than cortical bone. Bone is lost because remodelling becomes unbalanced after midlife. Most cortical bone loss occurs by intracortical, not endocortical remodelling. Each remodelling event removes more bone than deposited enlarging existing canals which eventually coalesce eroding and thinning the cortex from 'within.' Thus, there is a need to study the decay of cortical as well as trabecular bone, and to develop drugs that restore the strength of both types of bone. It is now possible to accurately quantify cortical porosity and trabecular decay in vivo. The challenges still to be met are to determine whether measurement of porosity identifies persons at risk for fracture, whether this approach is compliments information obtained using bone densitometry, and whether changes in cortical porosity and other microstructural traits have the sensitivity to serve as surrogates of treatment success or failure.

Control of Somatosensory Cortical Processing by Thalamic Posterior Medial Nucleus: A New Role of Thalamus in Cortical Function.

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Carlos Castejon

Full Text Available Current knowledge of thalamocortical interaction comes mainly from studying lemniscal thalamic systems. Less is known about paralemniscal thalamic nuclei function. In the vibrissae system, the posterior medial nucleus (POm is the corresponding paralemniscal nucleus. POm neurons project to L1 and L5A of the primary somatosensory cortex (S1 in the rat brain. It is known that L1 modifies sensory-evoked responses through control of intracortical excitability suggesting that L1 exerts an influence on whisker responses. Therefore, thalamocortical pathways targeting L1 could modulate cortical firing. Here, using a combination of electrophysiology and pharmacology in vivo, we have sought to determine how POm influences cortical processing. In our experiments, single unit recordings performed in urethane-anesthetized rats showed that POm imposes precise control on the magnitude and duration of supra- and infragranular barrel cortex whisker responses. Our findings demonstrated that L1 inputs from POm imposed a time and intensity dependent regulation on cortical sensory processing. Moreover, we found that blocking L1 GABAergic inhibition or blocking P/Q-type Ca2+ channels in L1 prevents POm adjustment of whisker responses in the barrel cortex. Additionally, we found that POm was also controlling the sensory processing in S2 and this regulation was modulated by corticofugal activity from L5 in S1. Taken together, our data demonstrate the determinant role exerted by the POm in the adjustment of somatosensory cortical processing and in the regulation of cortical processing between S1 and S2. We propose that this adjustment could be a thalamocortical gain regulation mechanism also present in the processing of information between cortical areas.

Cortical mechanics and myosin-II abnormalities associated with post-ovulatory aging: implications for functional defects in aged eggs

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Mackenzie, Amelia C.L.; Kyle, Diane D.; McGinnis, Lauren A.; Lee, Hyo J.; Aldana, Nathalia; Robinson, Douglas N.; Evans, Janice P.

2016-01-01

STUDY HYPOTHESIS Cellular aging of the egg following ovulation, also known as post-ovulatory aging, is associated with aberrant cortical mechanics and actomyosin cytoskeleton functions. STUDY FINDING Post-ovulatory aging is associated with dysfunction of non-muscle myosin-II, and pharmacologically induced myosin-II dysfunction produces some of the same deficiencies observed in aged eggs. WHAT IS KNOWN ALREADY Reproductive success is reduced with delayed fertilization and when copulation or insemination occurs at increased times after ovulation. Post-ovulatory aged eggs have several abnormalities in the plasma membrane and cortex, including reduced egg membrane receptivity to sperm, aberrant sperm-induced cortical remodeling and formation of fertilization cones at the site of sperm entry, and reduced ability to establish a membrane block to prevent polyspermic fertilization. STUDY DESIGN, SAMPLES/MATERIALS, METHODS Ovulated mouse eggs were collected at 21–22 h post-human chorionic gonadotrophin (hCG) (aged eggs) or at 13–14 h post-hCG (young eggs), or young eggs were treated with the myosin light chain kinase (MLCK) inhibitor ML-7, to test the hypothesis that disruption of myosin-II function could mimic some of the effects of post-ovulatory aging. Eggs were subjected to various analyses. Cytoskeletal proteins in eggs and parthenogenesis were assessed using fluorescence microscopy, with further analysis of cytoskeletal proteins in immunoblotting experiments. Cortical tension was measured through micropipette aspiration assays. Egg membrane receptivity to sperm was assessed in in vitro fertilization (IVF) assays. Membrane topography was examined by low-vacuum scanning electron microscopy (SEM). MAIN RESULTS AND THE ROLE OF CHANCE Aged eggs have decreased levels and abnormal localizations of phosphorylated myosin-II regulatory light chain (pMRLC; P = 0.0062). Cortical tension, which is mediated in part by myosin-II, is reduced in aged mouse eggs when compared with

Brain abnormalities in murderers indicated by positron emission tomography.

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Raine, A; Buchsbaum, M; LaCasse, L

1997-09-15

Murderers pleading not guilty by reason of insanity (NGRI) are thought to have brain dysfunction, but there have been no previous studies reporting direct measures of both cortical and subcortical brain functioning in this specific group. Positron emission tomography brain imaging using a continuous performance challenge task was conducted on 41 murderers pleading not guilty by reason of insanity and 41 age- and sex-matched controls. Murderers were characterized by reduced glucose metabolism in the prefrontal cortex, superior parietal gyrus, left angular gyrus, and the corpus callosum, while abnormal asymmetries of activity (left hemisphere lower than right) were also found in the amygdala, thalamus, and medial temporal lobe. These preliminary findings provide initial indications of a network of abnormal cortical and subcortical brain processes that may predispose to violence in murderers pleading NGRI.

Congenital malformations of the supratentorial brain. Pt. 1. Disorders of cortical development

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Ertl-Wagner, B.; Rummeny, C.; Reiser, M.F.

2003-01-01

Disorders of supratentorial cortical development are usually divided into disorders of neuronal proliferation, neuronal migration and cortical organization. Based upon molecular biologic discoveries, a modified classification has recently been proposed. The category of malformations of abnormal neuronal and glial proliferation and apoptosis now includes microlissencephalies, megalencephalies, hemimegalencephalies and cortical dysplasias with balloon cells. Malformations due to abnormal neuronal migration now subsume the lissencephaly spectrum including the subcortical band heterotopias, the cobblestone complex and the group of heterotopias. Malformations due to abnormal cortical organization include the spectrum of polymicrogyria and schizencephaly as well as cortical dysplasias without balloon cells. High-resolution magnetic resonance imaging (MRI) has led to an increasing awareness of these malformations. This article aims to illustrate the classification, MRI presentation and relevant clinical features of the most commonly encountered disorders of cortical development. (orig.) [de

Amygdalo-cortical sprouting continues into early adulthood: implications for the development of normal and abnormal function during adolescence.

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Cunningham, Miles Gregory; Bhattacharyya, Sujoy; Benes, Francine Mary

2002-11-11

Adolescence is a critical stage for the development of emotional maturity and diverse forms of psychopathology. The posterior basolateral nucleus of the amygdala is known to mediate fear and anxiety and is important in assigning emotional valence to cognitive processes. The medial prefrontal cortex, a homologue of the human anterior cingulate cortex, mediates emotional, attentional, and motivational behaviors at the cortical level. We postulate that the development of connectivity between these two corticolimbic regions contributes to an enhanced integration of emotion and cognition during the postnatal period. In order to characterize the development of this relay, injections of the anterograde tracer biocytin were stereotaxically placed within the posterior basolateral nucleus of the amygdala of rats at successive postnatal time points (postnatal days 6-120). Labeled fibers in the medial prefrontal cortex were evaluated using a combination of brightfield, confocal, and electron microscopy. We found that the density of labeled fibers originating from the posterior basolateral nucleus shows a sharp curvilinear increase within layers II and V of the anterior cingulate cortex and the infralimbic subdivisions of medial prefrontal cortex during the late postweanling period. This increase was paralleled by a linear rise in the number of axospinous and axodendritic synapses present in the neuropil. Based on these results, we propose that late maturation of amygdalo-cortical connectivity may provide an anatomical basis for the development and integration of normal and possibly abnormal emotional behavior during adolescence and early adulthood. Copyright 2002 Wiley-Liss, Inc.

Altered cortical thickness and attentional deficits in adolescent girls and women with bulimia nervosa.

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Berner, Laura A; Stefan, Mihaela; Lee, Seonjoo; Wang, Zhishun; Terranova, Kate; Attia, Evelyn; Marsh, Rachel

2018-05-01

Frontostriatal and frontoparietal abnormalities likely contribute to deficits in control and attentional processes in individuals with bulimia nervosa and to the persistence of dysregulated eating across development. This study assessed these processes and cortical thickness in a large sample of adolescent girls and women with bulimia nervosa compared with healthy controls. We collected anatomical MRI data from adolescent girls and women (ages 12-38 yr) with full or subthreshold bulimia nervosa and age-matched healthy controls who also completed the Conners Continuous Performance Test-II (CPT-II). Groups were compared on task performance and cortical thickness. Mediation analyses explored associations among cortical thickness, CPT-II variables, bulimia nervosa symptoms and age. We included 60 girls and women with bulimia nervosa and 54 controls in the analyses. Compared with healthy participants, those with bulimia nervosa showed increased impulsivity and inattention on the CPT-II, along with reduced thickness of the right pars triangularis, right superior parietal and left dorsal posterior cingulate cortices. In the bulimia nervosa group, exploratory analyses revealed that binge eating frequency correlated inversely with cortical thickness of frontoparietal and insular regions and that reduced frontoparietal thickness mediated the association between age and increased symptom severity and inattention. Binge eating frequency also mediated the association between age and lower prefrontal cortical thickness. These findings are applicable to only girls and women with bulimia nervosa, and our cross-sectional design precludes understanding of whether cortical thickness alterations precede or result from bulimia nervosa symptoms. Structural abnormalities in the frontoparietal and posterior cingulate regions comprising circuits that support control and attentional processes should be investigated as potential contributors to the maintenance of bulimia nervosa and useful

Altered cortical thickness and attentional deficits in adolescent girls and women with bulimia nervosa.

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Berner, Laura A; Stefan, Mihaela; Lee, Seonjoo; Wang, Zhishun; Terranova, Kate; Attia, Evelyn; Marsh, Rachel

2018-01-12

Frontostriatal and frontoparietal abnormalities likely contribute to deficits in control and attentional processes in individuals with bulimia nervosa and to the persistence of dysregulated eating across development. This study assessed these processes and cortical thickness in a large sample of adolescent girls and women with bulimia nervosa compared with healthy controls. We collected anatomical MRI data from adolescent girls and women (ages 12-38 yr) with full or subthreshold bulimia nervosa and age-matched healthy controls who also completed the Conners Continuous Performance Test-II (CPT-II). Groups were compared on task performance and cortical thickness. Mediation analyses explored associations among cortical thickness, CPT-II variables, bulimia nervosa symptoms and age. We included 60 girls and women with bulimia nervosa and 54 controls in the analyses. Compared with healthy participants, those with bulimia nervosa showed increased impulsivity and inattention on the CPT-II, along with reduced thickness of the right pars triangularis, right superior parietal and left dorsal posterior cingulate cortices. In the bulimia nervosa group, exploratory analyses revealed that binge eating frequency correlated inversely with cortical thickness of frontoparietal and insular regions and that reduced frontoparietal thickness mediated the association between age and increased symptom severity and inattention. Binge eating frequency also mediated the association between age and lower prefrontal cortical thickness. These findings are applicable to only girls and women with bulimia nervosa, and our cross-sectional design precludes understanding of whether cortical thickness alterations precede or result from bulimia nervosa symptoms. Structural abnormalities in the frontoparietal and posterior cingulate regions comprising circuits that support control and attentional processes should be investigated as potential contributors to the maintenance of bulimia nervosa and useful

Impaired cognitive control mediates the relationship between cortical thickness of the superior frontal gyrus and role functioning in schizophrenia.

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Tully, Laura M; Lincoln, Sarah Hope; Liyanage-Don, Nadia; Hooker, Christine I

2014-02-01

Structural abnormalities in the lateral prefrontal cortex (LPFC) are well-documented in schizophrenia and recent evidence suggests that these abnormalities relate to functional outcome. Cognitive control mechanisms, reliant on the LPFC, are impaired in schizophrenia and predict functional outcome, thus impaired cognitive control could mediate the relationship between neuroanatomical abnormalities in the LPFC and functional outcome. We used surface-based morphometry to investigate relationships between cortical surface characteristics, cognitive control, and measures of social and role functioning in 26 individuals with schizophrenia and 29 healthy controls. Results demonstrate that schizophrenia participants had thinner cortex in a region of the superior frontal gyrus (BA10). Across all participants, decreased cortical thickness in this region related to decreased cognitive control and decreased role functioning. Moreover, cognitive control fully mediated the relationship between cortical thickness in the superior frontal gyrus and role functioning, indicating that neuroanatomical abnormalities in the LPFC adversely impact role functioning via impaired cognitive control processes. Copyright © 2013 Elsevier B.V. All rights reserved.

Focal cortical dysplasia – review

International Nuclear Information System (INIS)

Kabat, Joanna; Król, Przemysław

2012-01-01

Focal cortical dysplasia is a malformation of cortical development, which is the most common cause of medically refractory epilepsy in the pediatric population and the second/third most common etiology of medically intractable seizures in adults. Both genetic and acquired factors are involved in the pathogenesis of cortical dysplasia. Numerous classifications of the complex structural abnormalities of focal cortical dysplasia have been proposed – from Taylor et al. in 1971 to the last modification of Palmini classification made by Blumcke in 2011. In general, three types of cortical dysplasia are recognized. Type I focal cortical dysplasia with mild symptomatic expression and late onset, is more often seen in adults, with changes present in the temporal lobe. Clinical symptoms are more severe in type II of cortical dysplasia usually seen in children. In this type, more extensive changes occur outside the temporal lobe with predilection for the frontal lobes. New type III is one of the above dysplasias with associated another principal lesion as hippocampal sclerosis, tumor, vascular malformation or acquired pathology during early life. Brain MRI imaging shows abnormalities in the majority of type II dysplasias and in only some of type I cortical dysplasias. The most common findings on MRI imaging include: focal cortical thickening or thinning, areas of focal brain atrophy, blurring of the gray-white junction, increased signal on T2- and FLAIR-weighted images in the gray and subcortical white matter often tapering toward the ventricle. On the basis of the MRI findings, it is possible to differentiate between type I and type II cortical dysplasia. A complete resection of the epileptogenic zone is required for seizure-free life. MRI imaging is very helpful to identify those patients who are likely to benefit from surgical treatment in a group of patients with drug-resistant epilepsy. However, in type I cortical dysplasia, MR imaging is often normal, and also in both

Temporal lobe epilepsy and focal cortical dysplasia in children: A tip to find the abnormality.

Science.gov (United States)

Bartolini, Luca; Whitehead, Matthew T; Ho, Cheng-Ying; Sepeta, Leigh N; Oluigbo, Chima O; Havens, Kathryn; Freilich, Emily R; Schreiber, John M; Gaillard, William D

2017-01-01

To demonstrate an association between magnetic resonance imaging (MRI) findings and pathologic characteristics in children who had surgery for medically refractory epilepsy due to focal cortical dysplasia (FCD). We retrospectively studied 110 children who had epilepsy surgery. Twenty-seven patients with FCD were included. Thirteen had temporal lobe epilepsy (TLE) and 14 had extra-temporal lobe epilepsy (ETLE). Three patients had associated mesial temporal sclerosis. Preoperative 3T MRIs interleaved with nine controls were blindly re-reviewed and categorized according to signal alteration. Pathologic specimens were classified according to the 2011 International League Against Epilepsy (ILAE) classification and compared to MRI studies. Rates of pathology subtypes differed between TLE and ETLE (χ 2 (3) = 8.57, p = 0.04). FCD type I was more frequent in TLE, whereas FCD type II was more frequent in ETLE. In the TLE group, nine patients had temporal tip abnormalities. They all exhibited gray-white matter blurring with decreased myelination and white matter hyperintense signal. Blurring involved the whole temporal tip, not just the area of dysplasia. These patients were less likely to demonstrate cortical thickening compared to those without temporal tip findings (χ 2 (1) = 9.55, p = 0.002). Three of them had FCD Ib, three had FCD IIa, two had FCD IIIa, and one had FCD IIb; MRI features could not entirely distinguish between FCD subtypes. TLE patients showed more pronounced findings than ETLE on MRI (χ 2 (1) = 11.95, p = 0.003, odds ratio [OR] 18.00). In all cases of FCD, isolated blurring was more likely to be associated with FCD II, whereas blurring with decreased myelination was seen with FCD I (χ 2 (6) = 13.07, p = 0.042). Our study described associations between MRI characteristics and pathology in children with FCD and offered a detailed analysis of temporal lobe tip abnormalities and FCD subtypes in children with TLE. These findings may contribute to the

Assessment of cortical maturation with prenatal MRI. Part I: normal cortical maturation

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Fogliarini, Celine [Faculte Timone, Centre de Resonance Magnetique Biologique et Medicale, Marseille (France); Chaumoitre, Katia [Hopital Nord, Department of Radiology, Marseille (France); Chapon, Frederique; Levrier, Olivier; Girard, Nadine [Hopital Timone, Department of Neuroradiology, Marseille Cedex 5 (France); Fernandez, Carla; Figarella-Branger, Dominique [Hopital Timone, Department of Pathology, Marseille (France)

2005-08-01

Cortical maturation, especially gyral formation, follows a temporospatial schedule and is a good marker of fetal maturation. Although ultrasonography is still the imaging method of choice to evaluate fetal anatomy, MRI has an increasingly important role in the detection of brain abnormalities, especially of cortical development. Knowledge of MRI techniques in utero with the advantages and disadvantages of some sequences is necessary, in order to try to optimize the different magnetic resonance sequences to be able to make an early diagnosis. The different steps of cortical maturation known from histology represent the background necessary for the understanding of maturation in order to be then able to evaluate brain maturation through neuroimaging. Illustrations of the normal cortical maturation are given for each step accessible to MRI for both the cerebral hemispheres and the posterior fossa. (orig.)

Assessment of cortical maturation with prenatal MRI. Part I: normal cortical maturation

International Nuclear Information System (INIS)

Fogliarini, Celine; Chaumoitre, Katia; Chapon, Frederique; Levrier, Olivier; Girard, Nadine; Fernandez, Carla; Figarella-Branger, Dominique

2005-01-01

Cortical maturation, especially gyral formation, follows a temporospatial schedule and is a good marker of fetal maturation. Although ultrasonography is still the imaging method of choice to evaluate fetal anatomy, MRI has an increasingly important role in the detection of brain abnormalities, especially of cortical development. Knowledge of MRI techniques in utero with the advantages and disadvantages of some sequences is necessary, in order to try to optimize the different magnetic resonance sequences to be able to make an early diagnosis. The different steps of cortical maturation known from histology represent the background necessary for the understanding of maturation in order to be then able to evaluate brain maturation through neuroimaging. Illustrations of the normal cortical maturation are given for each step accessible to MRI for both the cerebral hemispheres and the posterior fossa. (orig.)

Altered cortical thickness and attentional deficits in adolescent girls and women with bulimia nervosa

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Stefan, Mihaela; Lee, Seonjoo; Wang, Zhishun; Terranova, Kate; Attia, Evelyn; Marsh, Rachel

2018-01-01

Background Frontostriatal and frontoparietal abnormalities likely contribute to deficits in control and attentional processes in individuals with bulimia nervosa and to the persistence of dysregulated eating across development. This study assessed these processes and cortical thickness in a large sample of adolescent girls and women with bulimia nervosa compared with healthy controls. Methods We collected anatomical MRI data from adolescent girls and women (ages 12–38 yr) with full or subthreshold bulimia nervosa and age-matched healthy controls who also completed the Conners Continuous Performance Test-II (CPT-II). Groups were compared on task performance and cortical thickness. Mediation analyses explored associations among cortical thickness, CPT-II variables, bulimia nervosa symptoms and age. Results We included 60 girls and women with bulimia nervosa and 54 controls in the analyses. Compared with healthy participants, those with bulimia nervosa showed increased impulsivity and inattention on the CPT-II, along with reduced thickness of the right pars triangularis, right superior parietal and left dorsal posterior cingulate cortices. In the bulimia nervosa group, exploratory analyses revealed that binge eating frequency correlated inversely with cortical thickness of frontoparietal and insular regions and that reduced frontoparietal thickness mediated the association between age and increased symptom severity and inattention. Binge eating frequency also mediated the association between age and lower prefrontal cortical thickness. Limitations These findings are applicable to only girls and women with bulimia nervosa, and our cross-sectional design precludes understanding of whether cortical thickness alterations precede or result from bulimia nervosa symptoms. Conclusion Structural abnormalities in the frontoparietal and posterior cingulate regions comprising circuits that support control and attentional processes should be investigated as potential

Sall1 regulates cortical neurogenesis and laminar fate specification in mice: implications for neural abnormalities in Townes-Brocks syndrome

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Susan J. Harrison

2012-05-01

Progenitor cells in the cerebral cortex undergo dynamic cellular and molecular changes during development. Sall1 is a putative transcription factor that is highly expressed in progenitor cells during development. In humans, the autosomal dominant developmental disorder Townes-Brocks syndrome (TBS is associated with mutations of the SALL1 gene. TBS is characterized by renal, anal, limb and auditory abnormalities. Although neural deficits have not been recognized as a diagnostic characteristic of the disease, ∼10% of patients exhibit neural or behavioral abnormalities. We demonstrate that, in addition to being expressed in peripheral organs, Sall1 is robustly expressed in progenitor cells of the central nervous system in mice. Both classical- and conditional-knockout mouse studies indicate that the cerebral cortex is particularly sensitive to loss of Sall1. In the absence of Sall1, both the surface area and depth of the cerebral cortex were decreased at embryonic day 18.5 (E18.5. These deficiencies are associated with changes in progenitor cell properties during development. In early cortical progenitor cells, Sall1 promotes proliferative over neurogenic division, whereas, at later developmental stages, Sall1 regulates the production and differentiation of intermediate progenitor cells. Furthermore, Sall1 influences the temporal specification of cortical laminae. These findings present novel insights into the function of Sall1 in the developing mouse cortex and provide avenues for future research into potential neural deficits in individuals with TBS.

Neuregulin 3 Mediates Cortical Plate Invasion and Laminar Allocation of GABAergic Interneurons

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Giorgia Bartolini

2017-01-01

Full Text Available Neural circuits in the cerebral cortex consist of excitatory pyramidal cells and inhibitory interneurons. These two main classes of cortical neurons follow largely different genetic programs, yet they assemble into highly specialized circuits during development following a very precise choreography. Previous studies have shown that signals produced by pyramidal cells influence the migration of cortical interneurons, but the molecular nature of these factors has remained elusive. Here, we identified Neuregulin 3 (Nrg3 as a chemoattractive factor expressed by developing pyramidal cells that guides the allocation of cortical interneurons in the developing cortical plate. Gain- and loss-of-function approaches reveal that Nrg3 modulates the migration of interneurons into the cortical plate in a process that is dependent on the tyrosine kinase receptor ErbB4. Perturbation of Nrg3 signaling in conditional mutants leads to abnormal lamination of cortical interneurons. Nrg3 is therefore a critical mediator in the assembly of cortical inhibitory circuits.

Correlation analysis of findings from neuroimaging and histopathology in focal cortical dysplasia

International Nuclear Information System (INIS)

Ma Mingping; Fan Jianzhong; Jiang Zirong; Bao Qiang; Du Ruibin; Ritter, J.L.

2009-01-01

Objective: To characterize neuroimaging features of focal cortical dysplasia (FCD) retrospectively and correlate those with pathological findings, which may improve our understanding of neuroimaging characteristics of FCD. Methods: Clinical information and neuroimaging findings of 28 cases with FCD proved by pathology were retrospectively reviewed, and neuroimaging features of FCD were correlated with the pathological changes. Results: MRI revealed abnormal changes in 24 of 28 patients (85.7%) and no abnormalities were observed in 4 cases. Focal cortical thickening and blurring of the gray- white matter junction were the major features of FCD on MRI. Accompanied abnormal MR signals can also be observed in cortical or subcortical white matter in FCD. The radial band of hyperintensity in subcortical white matter tapering to the ventricle is one of the characteristic features of FCD on MRI. On FDG-PET examination, focal hypometabolism were revealed in 9 of 14 cases (64.3%). Histologically, cortical dyslamination was accompanied by various degrees of dysmorphic neurons and balloon cells in cortical and subcortical areas. Subcortical white matter dysmyelination and spongiotic necrotic changes were found in some cases with FCD. Conclusion: High resolution MRI can reveal most of the lesions in FCD, including abnormal changes of cortical and subcortical white matter, which makes MRI the best pre-operation examination for FCD. (authors)

Anterior Cortical Development During Adolescence in Bipolar Disorder.

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Najt, Pablo; Wang, Fei; Spencer, Linda; Johnston, Jennifer A Y; Cox Lippard, Elizabeth T; Pittman, Brian P; Lacadie, Cheryl; Staib, Lawrence H; Papademetris, Xenophon; Blumberg, Hilary P

2016-02-15

Increasing evidence supports a neurodevelopmental model for bipolar disorder (BD), with adolescence as a critical period in its development. Developmental abnormalities of anterior paralimbic and heteromodal frontal cortices, key structures in emotional regulation processes and central in BD, are implicated. However, few longitudinal studies have been conducted, limiting understanding of trajectory alterations in BD. In this study, we performed longitudinal neuroimaging of adolescents with and without BD and assessed volume changes over time, including changes in tissue overall and within gray and white matter. Larger decreases over time in anterior cortical volumes in the adolescents with BD were hypothesized. Gray matter decreases and white matter increases are typically observed during adolescence in anterior cortices. It was hypothesized that volume decreases over time in BD would reflect alterations in those processes, showing larger gray matter contraction and decreased white matter expansion. Two high-resolution magnetic resonance imaging scans were obtained approximately 2 years apart for 35 adolescents with bipolar I disorder (BDI) and 37 healthy adolescents. Differences over time between groups were investigated for volume overall and specifically for gray and white matter. Relative to healthy adolescents, adolescents with BDI showed greater volume contraction over time in a region including insula and orbitofrontal, rostral, and dorsolateral prefrontal cortices (p adolescence in BDI in anterior cortices, including altered developmental trajectories of anterior gray and white matter. Published by Elsevier Inc.

Cortical oscillations and entrainment in speech processing during working memory load.

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Hjortkjaer, Jens; Märcher-Rørsted, Jonatan; Fuglsang, Søren A; Dau, Torsten

2018-02-02

Neuronal oscillations are thought to play an important role in working memory (WM) and speech processing. Listening to speech in real-life situations is often cognitively demanding but it is unknown whether WM load influences how auditory cortical activity synchronizes to speech features. Here, we developed an auditory n-back paradigm to investigate cortical entrainment to speech envelope fluctuations under different degrees of WM load. We measured the electroencephalogram, pupil dilations and behavioural performance from 22 subjects listening to continuous speech with an embedded n-back task. The speech stimuli consisted of long spoken number sequences created to match natural speech in terms of sentence intonation, syllabic rate and phonetic content. To burden different WM functions during speech processing, listeners performed an n-back task on the speech sequences in different levels of background noise. Increasing WM load at higher n-back levels was associated with a decrease in posterior alpha power as well as increased pupil dilations. Frontal theta power increased at the start of the trial and increased additionally with higher n-back level. The observed alpha-theta power changes are consistent with visual n-back paradigms suggesting general oscillatory correlates of WM processing load. Speech entrainment was measured as a linear mapping between the envelope of the speech signal and low-frequency cortical activity (level) decreased cortical speech envelope entrainment. Although entrainment persisted under high load, our results suggest a top-down influence of WM processing on cortical speech entrainment. © 2018 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Dysplasia and overgrowth. Magnetic resonance imaging of pediatric brain abnormalities secondary to alterations in the mechanistic target of rapamycin pathway

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Shrot, Shai; Hwang, Misun; Huisman, Thierry A.G.M.; Soares, Bruno P.; Stafstrom, Carl E.

2018-01-01

The current classification of malformations of cortical development is based on the type of disrupted embryological process (cell proliferation, migration, or cortical organization/post-migrational development) and the resulting morphological anomalous pattern of findings. An ideal classification would include knowledge of biological pathways. It has recently been demonstrated that alterations affecting the mechanistic target of rapamycin (mTOR) signaling pathway result in diverse abnormalities such as dysplastic megalencephaly, hemimegalencephaly, ganglioglioma, dysplastic cerebellar gangliocytoma, focal cortical dysplasia type IIb, and brain lesions associated with tuberous sclerosis. We review the neuroimaging findings in brain abnormalities related to alterations in the mTOR pathway, following the emerging trend from morphology towards genetics in the classification of malformations of cortical development. This approach improves the understanding of anomalous brain development and allows precise diagnosis and potentially targeted therapies that may regulate mTOR pathway function. (orig.)

Dysplasia and overgrowth. Magnetic resonance imaging of pediatric brain abnormalities secondary to alterations in the mechanistic target of rapamycin pathway

Energy Technology Data Exchange (ETDEWEB)

Shrot, Shai [Johns Hopkins University School of Medicine, Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Sheba Medical Center, Department of Diagnostic Imaging, Ramat-Gan (Israel); Hwang, Misun; Huisman, Thierry A.G.M.; Soares, Bruno P. [Johns Hopkins University School of Medicine, Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Stafstrom, Carl E. [Johns Hopkins University School of Medicine, Division of Pediatric Neurology, Department of Neurology, Baltimore, MD (United States)

2018-02-15

The current classification of malformations of cortical development is based on the type of disrupted embryological process (cell proliferation, migration, or cortical organization/post-migrational development) and the resulting morphological anomalous pattern of findings. An ideal classification would include knowledge of biological pathways. It has recently been demonstrated that alterations affecting the mechanistic target of rapamycin (mTOR) signaling pathway result in diverse abnormalities such as dysplastic megalencephaly, hemimegalencephaly, ganglioglioma, dysplastic cerebellar gangliocytoma, focal cortical dysplasia type IIb, and brain lesions associated with tuberous sclerosis. We review the neuroimaging findings in brain abnormalities related to alterations in the mTOR pathway, following the emerging trend from morphology towards genetics in the classification of malformations of cortical development. This approach improves the understanding of anomalous brain development and allows precise diagnosis and potentially targeted therapies that may regulate mTOR pathway function. (orig.)

Left hemispheric dominance of vestibular processing indicates lateralization of cortical functions in rats.

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Best, Christoph; Lange, Elena; Buchholz, Hans-Georg; Schreckenberger, Mathias; Reuss, Stefan; Dieterich, Marianne

2014-11-01

Lateralization of cortical functions such as speech dominance, handedness and processing of vestibular information are present not only in humans but also in ontogenetic older species, e.g. rats. In human functional imaging studies, the processing of vestibular information was found to be correlated with the hemispherical dominance as determined by the handedness. It is located mainly within the right hemisphere in right handers and within the left hemisphere in left handers. Since dominance of vestibular processing is unknown in animals, our aim was to study the lateralization of cortical processing in a functional imaging study applying small-animal positron emission tomography (microPET) and galvanic vestibular stimulation in an in vivo rat model. The cortical and subcortical network processing vestibular information could be demonstrated and correlated with data from other animal studies. By calculating a lateralization index as well as flipped region of interest analyses, we found that the vestibular processing in rats follows a strong left hemispheric dominance independent from the "handedness" of the animals. These findings support the idea of an early hemispheric specialization of vestibular cortical functions in ontogenetic older species.

Basal ganglia impairments in autism spectrum disorder are related to abnormal signal gating to prefrontal cortex.

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Prat, Chantel S; Stocco, Andrea; Neuhaus, Emily; Kleinhans, Natalia M

2016-10-01

Research on the biological basis of autism spectrum disorder has yielded a list of brain abnormalities that are arguably as diverse as the set of behavioral symptoms that characterize the disorder. Among these are patterns of abnormal cortical connectivity and abnormal basal ganglia development. In attempts to integrate the existing literature, the current paper tests the hypothesis that impairments in the basal ganglia's function to flexibly select and route task-relevant neural signals to the prefrontal cortex underpins patterns of abnormal synchronization between the prefrontal cortex and other cortical processing centers observed in individuals with autism spectrum disorder (ASD). We tested this hypothesis using a Dynamic Causal Modeling analysis of neuroimaging data collected from 16 individuals with ASD (mean age=25.3 years; 6 female) and 17 age- and IQ-matched neurotypical controls (mean age=25.6, 6 female), who performed a Go/No-Go test of executive functioning. Consistent with the hypothesis tested, a random-effects Bayesian model selection procedure determined that a model of network connectivity in which basal ganglia activation modulated connectivity between the prefrontal cortex and other key cortical processing centers best fit the data of both neurotypicals and individuals with ASD. Follow-up analyses suggested that the largest group differences were observed for modulation of connectivity between prefrontal cortex and the sensory input region in the occipital lobe [t(31)=2.03, p=0.025]. Specifically, basal ganglia activation was associated with a small decrease in synchronization between the occipital region and prefrontal cortical regions in controls; however, in individuals with ASD, basal ganglia activation resulted in increased synchronization between the occipital region and the prefrontal cortex. We propose that this increased synchronization may reflect a failure in basal ganglia signal gating mechanisms, resulting in a non-selective copying

Abnormal Development of the Earliest Cortical Circuits in a Mouse Model of Autism Spectrum Disorder.

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Nagode, Daniel A; Meng, Xiangying; Winkowski, Daniel E; Smith, Ed; Khan-Tareen, Hamza; Kareddy, Vishnupriya; Kao, Joseph P Y; Kanold, Patrick O

2017-01-31

Autism spectrum disorder (ASD) involves deficits in speech and sound processing. Cortical circuit changes during early development likely contribute to such deficits. Subplate neurons (SPNs) form the earliest cortical microcircuits and are required for normal development of thalamocortical and intracortical circuits. Prenatal valproic acid (VPA) increases ASD risk, especially when present during a critical time window coinciding with SPN genesis. Using optical circuit mapping in mouse auditory cortex, we find that VPA exposure on E12 altered the functional excitatory and inhibitory connectivity of SPNs. Circuit changes manifested as "patches" of mostly increased connection probability or strength in the first postnatal week and as general hyper-connectivity after P10, shortly after ear opening. These results suggest that prenatal VPA exposure severely affects the developmental trajectory of cortical circuits and that sensory-driven activity may exacerbate earlier, subtle connectivity deficits. Our findings identify the subplate as a possible common pathophysiological substrate of deficits in ASD. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Abnormal functional connectivity and cortical integrity influence dominant hand motor disability in multiple sclerosis: a multimodal analysis.

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Zhong, Jidan; Nantes, Julia C; Holmes, Scott A; Gallant, Serge; Narayanan, Sridar; Koski, Lisa

2016-12-01

Functional reorganization and structural damage occur in the brains of people with multiple sclerosis (MS) throughout the disease course. However, the relationship between resting-state functional connectivity (FC) reorganization in the sensorimotor network and motor disability in MS is not well understood. This study used resting-state fMRI, T1-weighted and T2-weighted, and magnetization transfer (MT) imaging to investigate the relationship between abnormal FC in the sensorimotor network and upper limb motor disability in people with MS, as well as the impact of disease-related structural abnormalities within this network. Specifically, the differences in FC of the left hemisphere hand motor region between MS participants with preserved (n = 17) and impaired (n = 26) right hand function, compared with healthy controls (n = 20) was investigated. Differences in brain atrophy and MT ratio measured at the global and regional levels were also investigated between the three groups. Motor preserved MS participants had stronger FC in structurally intact visual information processing regions relative to motor impaired MS participants. Motor impaired MS participants showed weaker FC in the sensorimotor and somatosensory association cortices and more severe structural damage throughout the brain compared with the other groups. Logistic regression analysis showed that regional MTR predicted motor disability beyond the impact of global atrophy whereas regional grey matter volume did not. More importantly, as the first multimodal analysis combining resting-state fMRI, T1-weighted, T2-weighted and MTR images in MS, we demonstrate how a combination of structural and functional changes may contribute to motor impairment or preservation in MS. Hum Brain Mapp 37:4262-4275, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Widespread cortical morphologic changes in juvenile myoclonic epilepsy: evidence from structural MRI.

LENUS (Irish Health Repository)

Ronan, Lisa

2012-04-01

Atypical morphology of the surface of the cerebral cortex may be related to abnormal cortical folding (gyrification) and therefore may indicate underlying malformations of cortical development (MCDs). Using magnetic resonance imaging (MRI)-based analysis, we examined cortical morphology in patients with juvenile myoclonic epilepsy (JME).

FOCAL CORTICAL DYSPLASIAS: CLINICAL AND ELECTRO-NEUROIMAGING CHARACTERISTICS

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K. Yu. Mukhin

2016-01-01

Full Text Available In spite of a notable advance made in epileptology, resistant epilepsies account for approximately 30 % of all forms of epilepsy particularly in patients with focal seizures. One of the main causes of therapy-resistant focal epilepsies is focal cortical dysplasias (FCD. This term was first introduced by D. Taylor et al. in 1971. FCD belongs to abnormal cortical development. Among all abnormalities of cortical development, FCD in surgically treated children amounts to 75 %. FCD is the most common cause of resistant epilepsy in children and the most frequent reason for diagnosing cryptogenic focal epilepsy with intractable seizures. The author gives a detailed literature review dedicated to FCD as a cause of resistant epilepsy, including the classification and histologic characteristics of FCD, its clinical manifestations and prognosis, and approaches to medical and surgical treatments. 

MRI of a family with focal abnormalities of gyration

International Nuclear Information System (INIS)

Muntaner, L.; Perez-Ferron, J.J.; Herrera, M.; Rosell, J.; Taboada, D.; Climent, S.

1997-01-01

Focal abnormalities of gyration (FAG) are developmental disorders that may occur in isolated patients or, as in the case being reported, as part of a familial disorder. Analysis of individuals in a family spanning three generations was carried out using MRI. Abnormalities, present in all members of generations II and III, included focal cortical dysplasia (three patients), focal cortical infolding (two patients) and schizencephaly (one patient); associated minor anomalies, such as white matter abnormalities, were seen in the remaining three members of generations II and III. MRI recognition of FAG in the family being reported proved useful in defining their phenotypical expression and providing proper counselling for individual family members. (orig.). With 6 figs

Progressive posterior cortical dysfunction

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Fábio Henrique de Gobbi Porto

Full Text Available Abstract Progressive posterior cortical dysfunction (PPCD is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal and ventral (occipito-temporal pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction, complete Balint's syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right . Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD.

Progressive posterior cortical dysfunction

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Porto, Fábio Henrique de Gobbi; Machado, Gislaine Cristina Lopes; Morillo, Lilian Schafirovits; Brucki, Sonia Maria Dozzi

2010-01-01

Progressive posterior cortical dysfunction (PPCD) is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal) and ventral (occipito-temporal) pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction), complete Balint’s syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right. Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD. PMID:29213665

Basal forebrain motivational salience signal enhances cortical processing and decision speed

Directory of Open Access Journals (Sweden)

Sylvina M Raver

2015-10-01

Full Text Available The basal forebrain (BF contains major projections to the cerebral cortex, and plays a well-documented role in arousal, attention, decision-making, and in modulating cortical activity. BF neuronal degeneration is an early event in Alzheimer’s disease and dementias, and occurs in normal cognitive aging. While the BF is best known for its population of cortically projecting cholinergic neurons, the region is anatomically and neurochemically diverse, and also contains prominent populations of non-cholinergic projection neurons. In recent years, increasing attention has been dedicated to these non-cholinergic BF neurons in order to better understand how non-cholinergic BF circuits control cortical processing and behavioral performance. In this review, we focus on a unique population of putative non-cholinergic BF neurons that encodes the motivational salience of stimuli with a robust ensemble bursting response. We review recent studies that describe the specific physiological and functional characteristics of these BF salience-encoding neurons in behaving animals. These studies support the unifying hypothesis whereby BF salience-encoding neurons act as a gain modulation mechanism of the decision-making process to enhance cortical processing of behaviorally relevant stimuli, and thereby facilitate faster and more precise behavioral responses. This function of BF salience-encoding neurons represents a critical component in determining which incoming stimuli warrant an animal’s attention, and is therefore a fundamental and early requirement of behavioral flexibility.

Gamma band oscillations: a key to understanding schizophrenia symptoms and neural circuit abnormalities.

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McNally, James M; McCarley, Robert W

2016-05-01

We review our current understanding of abnormal γ band oscillations in schizophrenia, their association with symptoms and the underlying cortical circuit abnormality, with a particular focus on the role of fast-spiking parvalbumin gamma-aminobutyric acid (GABA) neurons in the disease state. Clinical electrophysiological studies of schizophrenia patients and pharmacological models of the disorder show an increase in spontaneous γ band activity (not stimulus-evoked) measures. These findings provide a crucial link between preclinical and clinical work examining the role of γ band activity in schizophrenia. MRI-based experiments measuring cortical GABA provides evidence supporting impaired GABAergic neurotransmission in schizophrenia patients, which is correlated with γ band activity level. Several studies suggest that stimulation of the cortical circuitry, directly or via subcortical structures, has the potential to modulate cortical γ activity, and improve cognitive function. Abnormal γ band activity is observed in patients with schizophrenia and disease models in animals, and is suggested to underlie the psychosis and cognitive/perceptual deficits. Convergent evidence from both clinical and preclinical studies suggest the central factor in γ band abnormalities is impaired GABAergic neurotransmission, particularly in a subclass of neurons which express parvalbumin. Rescue of γ band abnormalities presents an intriguing option for therapeutic intervention.

Abnormal global processing along the dorsal visual pathway in autism: a possible mechanism for weak visuospatial coherence?

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Pellicano, Elizabeth; Gibson, Lisa; Maybery, Murray; Durkin, Kevin; Badcock, David R

2005-01-01

Frith and Happe (Frith, U., & Happe, F. (1994). Autism: Beyond theory of mind. Cognition, 50, 115-132) argue that individuals with autism exhibit 'weak central coherence': an inability to integrate elements of information into coherent wholes. Some authors have speculated that a high-level impairment might be present in the dorsal visual pathway in autism, and furthermore, that this might account for weak central coherence, at least at the visuospatial level. We assessed the integrity of the dorsal visual pathway in children diagnosed with an autism spectrum disorder (ASD), and in typically developing children, using two visual tasks, one examining functioning at higher levels of the dorsal cortical stream (Global Dot Motion (GDM)), and the other assessing lower-level dorsal stream functioning (Flicker Contrast Sensitivity (FCS)). Central coherence was tested using the Children's Embedded Figures Test (CEFT). Relative to the typically developing children, the children with ASD had shorter CEFT latencies and higher GDM thresholds but equivalent FCS thresholds. Additionally, CEFT latencies were inversely related to GDM thresholds in the ASD group. These outcomes indicate that the elevated global motion thresholds in autism are the result of high-level impairments in dorsal cortical regions. Weak visuospatial coherence in autism may be in the form of abnormal cooperative mechanisms in extra-striate cortical areas, which might contribute to differential performance when processing stimuli as Gestalts, including both dynamic (i.e., global motion perception) and static (i.e., disembedding performance) stimuli.

Alterations of cortical GABA neurons and network oscillations in schizophrenia.

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Gonzalez-Burgos, Guillermo; Hashimoto, Takanori; Lewis, David A

2010-08-01

The hypothesis that alterations of cortical inhibitory gamma-aminobutyric acid (GABA) neurons are a central element in the pathology of schizophrenia has emerged from a series of postmortem studies. How such abnormalities may contribute to the clinical features of schizophrenia has been substantially informed by a convergence with basic neuroscience studies revealing complex details of GABA neuron function in the healthy brain. Importantly, activity of the parvalbumin-containing class of GABA neurons has been linked to the production of cortical network oscillations. Furthermore, growing knowledge supports the concept that gamma band oscillations (30-80 Hz) are an essential mechanism for cortical information transmission and processing. Herein we review recent studies further indicating that inhibition from parvalbumin-positive GABA neurons is necessary to produce gamma oscillations in cortical circuits; provide an update on postmortem studies documenting that deficits in the expression of glutamic acid decarboxylase67, which accounts for most GABA synthesis in the cortex, are widely observed in schizophrenia; and describe studies using novel, noninvasive approaches directly assessing potential relations between alterations in GABA, oscillations, and cognitive function in schizophrenia.

Dynamic cortical participation during bilateral, cyclical ankle movements: Effects of Parkinson's disease.

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Takashi Yoshida

Full Text Available Parkinson's disease (PD is known to increase asymmetry and variability of bilateral movements. However, the mechanisms of such abnormalities are not fully understood. Here, we aimed to investigate whether kinematic abnormalities are related to cortical participation during bilateral, cyclical ankle movements, which required i maintenance of a specific frequency and ii bilateral coordination of the lower limbs in an anti-phasic manner. We analyzed electroencephalographic and electromyographic signals from nine men with PD and nine aged-matched healthy men while they sat and cyclically dorsi- and plantarflexed their feet. This movement was performed at a similar cadence to normal walking under two conditions: i self-paced and ii externally paced by a metronome. Participants with PD exhibited reduced range of motion and more variable bilateral coordination. However, participants with and without PD did not differ in the magnitude of corticomuscular coherence between the midline cortical areas and tibialis anterior and medial gastrocnemius muscles. This finding suggests that either the kinematic abnormalities were related to processes outside linear corticomuscular communication or PD-related changes in neural correlates maintained corticomuscular communication but not motor performance.

Curved planar reconstruction of MR images in focal cortical dysplasia of the brain

International Nuclear Information System (INIS)

Chung, Gyung Ho; Lee, Sang Yong; Kim, Chong So; Kim, Young Kon; Lee, Young Hwan; Jeong, Su Hyun

2002-01-01

To describe curved planar reconstruction imaging (CPR) and determine its usefulness in the evaluation of focal cortical dysplasia of the brain. In 17 cases of focal cortical dysplasia (cortical dysplasia (n=9), schizencephaly (n=5), and heterotopia (n=3), CPR images were created using a multiplanar reconstruction program and imaging data obtained during T1 magnetization prepared rapid acquisition gradient-echo MR imaging. We assessed the precise configuration of abnormalities and their relation to adjacent gyri and sulci. CPRI showed the brain cortex as a 2D panoramic image, demonstrating the precise configurations and locations of dysplasia-associated abnormalities and their relation to adjacent gyri and sulci, and the precise shape of the gray-white matter interface. CPRI can provide important radiological information about the extension and configuration of focal cortical dysplasia, and its relation to neighboring cortical structures. We believe that CPRI should form an essential part of the routine investigation os suspected cases of focal cortical dysplasia

Anatomical alterations of the visual motion processing network in migraine with and without aura.

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Cristina Granziera

2006-10-01

Full Text Available Patients suffering from migraine with aura (MWA and migraine without aura (MWoA show abnormalities in visual motion perception during and between attacks. Whether this represents the consequences of structural changes in motion-processing networks in migraineurs is unknown. Moreover, the diagnosis of migraine relies on patient's history, and finding differences in the brain of migraineurs might help to contribute to basic research aimed at better understanding the pathophysiology of migraine.To investigate a common potential anatomical basis for these disturbances, we used high-resolution cortical thickness measurement and diffusion tensor imaging (DTI to examine the motion-processing network in 24 migraine patients (12 with MWA and 12 MWoA and 15 age-matched healthy controls (HCs. We found increased cortical thickness of motion-processing visual areas MT+ and V3A in migraineurs compared to HCs. Cortical thickness increases were accompanied by abnormalities of the subjacent white matter. In addition, DTI revealed that migraineurs have alterations in superior colliculus and the lateral geniculate nucleus, which are also involved in visual processing.A structural abnormality in the network of motion-processing areas could account for, or be the result of, the cortical hyperexcitability observed in migraineurs. The finding in patients with both MWA and MWoA of thickness abnormalities in area V3A, previously described as a source in spreading changes involved in visual aura, raises the question as to whether a "silent" cortical spreading depression develops as well in MWoA. In addition, these experimental data may provide clinicians and researchers with a noninvasively acquirable migraine biomarker.

No Association between Cortical Gyrification or Intrinsic Curvature and Attention-deficit/Hyperactivity Disorder in Adolescents and Young Adults

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Natalie J. Forde

2017-04-01

Full Text Available Magnetic resonance imaging (MRI studies have highlighted subcortical, cortical, and structural connectivity abnormalities associated with attention-deficit/hyperactivity disorder (ADHD. Gyrification investigations of the cortex have been inconsistent and largely negative, potentially due to a lack of sensitivity of the previously used morphological parameters. The innovative approach of applying intrinsic curvature analysis, which is predictive of gyrification pattern, to the cortical surface applied herein allowed us greater sensitivity to determine whether the structural connectivity abnormalities thus far identified at a centimeter scale also occur at a millimeter scale within the cortical surface. This could help identify neurodevelopmental processes that contribute to ADHD. Structural MRI datasets from the NeuroIMAGE project were used [n = 306 ADHD, n = 164 controls, and n = 148 healthy siblings of individuals with ADHD (age in years, mean(sd; 17.2 (3.4, 16.8 (3.2, and 17.7 (3.8, respectively]. Reconstructions of the cortical surfaces were computed with FreeSurfer. Intrinsic curvature (taken as a marker of millimeter-scale surface connectivity and local gyrification index were calculated for each point on the surface (vertex with Caret and FreeSurfer, respectively. Intrinsic curvature skew and mean local gyrification index were extracted per region; frontal, parietal, temporal, occipital, cingulate, and insula. A generalized additive model was used to compare the trajectory of these measures between groups over age, with sex, scanner site, total surface area of hemisphere, and familiality accounted for. After correcting for sex, scanner site, and total surface area no group differences were found in the developmental trajectory of intrinsic curvature or local gyrification index. Despite the increased sensitivity of intrinsic curvature, compared to gyrification measures, to subtle morphological abnormalities of the cortical surface we found

Title: Cytoskeletal proteins in cortical development and diseasesubtitle: Actin associated proteins in periventricular heterotopia

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Gewei eLian

2015-04-01

Full Text Available The actin cytoskeleton regulates many important cellular processes in the brain, including cell division and proliferation, migration, and cytokinesis and differentiation. These developmental processes can be regulated through actin dependent vesicle and organelle movement, cell signaling, and the establishment and maintenance of cell junctions and cell shape. Many of these processes are mediated by extensive and intimate interactions of actin with cellular membranes and proteins. Disruption in the actin cytoskeleton in the brain gives rise to periventricular heterotopia (PH, a malformation of cortical development, characterized by abnormal neurons clustered deep in the brain along the lateral ventricles. This disorder can give rise to seizures, dyslexia and psychiatric disturbances. Anatomically, PH is characterized by a smaller brain (impaired proliferation, heterotopia (impaired initial migration and disruption along the neuroependymal lining (impaired cell-cell adhesion. Genes causal for PH have also been implicated in actin-dependent processes. The current review provides mechanistic insight into actin cytoskeletal regulation of cortical development in the context of this malformation of cortical development.

Abnormal left and right amygdala-orbitofrontal cortical functional connectivity to emotional faces: state versus trait vulnerability markers of depression in bipolar disorder.

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Versace, Amelia; Thompson, Wesley K; Zhou, Donli; Almeida, Jorge R C; Hassel, Stefanie; Klein, Crystal R; Kupfer, David J; Phillips, Mary L

2010-03-01

Amygdala-orbitofrontal cortical (OFC) functional connectivity (FC) to emotional stimuli and relationships with white matter remain little examined in bipolar disorder individuals (BD). Thirty-one BD (type I; n = 17 remitted; n = 14 depressed) and 24 age- and gender-ratio-matched healthy individuals (HC) viewed neutral, mild, and intense happy or sad emotional faces in two experiments. The FC was computed as linear and nonlinear dependence measures between amygdala and OFC time series. Effects of group, laterality, and emotion intensity upon amygdala-OFC FC and amygdala-OFC FC white matter fractional anisotropy (FA) relationships were examined. The BD versus HC showed significantly greater right amygdala-OFC FC (p relationship (p = .001) between left amygdala-OFC FC to sad faces and FA in HC. In BD, antidepressants were associated with significantly reduced left amygdala-OFC FC to mild sad faces (p = .001). In BD, abnormally elevated right amygdala-OFC FC to sad stimuli might represent a trait vulnerability for depression, whereas abnormally elevated left amygdala-OFC FC to sad stimuli and abnormally reduced amygdala-OFC FC to intense happy stimuli might represent a depression state marker. Abnormal FC measures might normalize with antidepressant medications in BD. Nonlinear amygdala-OFC FC-FA relationships in BD and HC require further study. Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Similar cortical but not subcortical gray matter abnormalities in women with posttraumatic stress disorder with versus without dissociative identity disorder.

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Chalavi, Sima; Vissia, Eline M; Giesen, Mechteld E; Nijenhuis, Ellert R S; Draijer, Nel; Barker, Gareth J; Veltman, Dick J; Reinders, Antje A T S

2015-03-30

Neuroanatomical evidence on the relationship between posttraumatic stress disorder (PTSD) and dissociative disorders is still lacking. We acquired brain structural magnetic resonance imaging (MRI) scans from 17 patients with dissociative identity disorder (DID) and co-morbid PTSD (DID-PTSD) and 16 patients with PTSD but without DID (PTSD-only), and 32 healthy controls (HC), and compared their whole-brain cortical and subcortical gray matter (GM) morphological measurements. Associations between GM measurements and severity of dissociative and depersonalization/derealization symptoms or lifetime traumatizing events were evaluated in the patient groups. DID-PTSD and PTSD-only patients, compared with HC, had similarly smaller cortical GM volumes of the whole brain and of frontal, temporal and insular cortices. DID-PTSD patients additionally showed smaller hippocampal and larger pallidum volumes relative to HC, and larger putamen and pallidum volumes relative to PTSD-only. Severity of lifetime traumatizing events and volume of the hippocampus were negatively correlated. Severity of dissociative and depersonalization/derealization symptoms correlated positively with volume of the putamen and pallidum, and negatively with volume of the inferior parietal cortex. Shared abnormal brain structures in DID-PTSD and PTSD-only, small hippocampal volume in DID-PTSD, more severe lifetime traumatizing events in DID-PTSD compared with PTSD-only, and negative correlations between lifetime traumatizing events and hippocampal volume suggest a trauma-related etiology for DID. Our results provide neurobiological evidence for the side-by-side nosological classification of PTSD and DID in the DSM-5. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Measuring Early Cortical Visual Processing in the Clinic

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Linda Bowns

2017-05-01

Full Text Available We describe a mobile app that measures early cortical visual processing suitable for use in clinics. The app is called Component Extraction and Motion Integration Test (CEMIT. Observers are asked to respond to the direction of translating plaids that move in one of two very different directions. The plaids have been selected so that the plaid components move in one of the directions and the plaid pattern moves in the other direction. In addition to correctly responding to the pattern motion, observers demonstrate their ability to correctly extract the movement (and therefore the orientation of the underlying components at specific spatial frequencies. We wanted to test CEMIT by seeing if we could replicate the broader tuning observed at low spatial frequencies for this type of plaid. Results from CEMIT were robust and successfully replicated this result for 50 typical observers. We envisage that it will be of use to researchers and clinicians by allowing them to investigate specific deficits at this fundamental level of cortical visual processing. CEMIT may also be used for screening purposes where visual information plays an important role, for example, air traffic controllers.

Abnormal interhemispheric connectivity in male psychopathic offenders.

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Hoppenbrouwers, Sylco S; De Jesus, Danilo R; Sun, Yinming; Stirpe, Tania; Hofman, Dennis; McMaster, Jeff; Hughes, Ginny; Daskalakis, Zafiris J; Schutter, Dennis J L G

2014-01-01

Psychopathic offenders inevitably violate interpersonal norms and frequently resort to aggressive and criminal behaviour. The affective and cognitive deficits underlying these behaviours have been linked to abnormalities in functional interhemispheric connectivity. However, direct neurophysiological evidence for dysfunctional connectivity in psychopathic offenders is lacking. We used transcranial magnetic stimulation combined with electroencephalography to examine interhemispheric connectivity in the dorsolateral and motor cortex in a sample of psychopathic offenders and healthy controls. We also measured intracortical inhibition and facilitation over the left and right motor cortex to investigate the effects of local cortical processes on interhemispheric connectivity. We enrolled 17 psychopathic offenders and 14 controls in our study. Global abnormalities in right to left functional connectivity were observed in psychopathic offenders compared with controls. Furthermore, in contrast to controls, psychopathic offenders showed increased intracortical inhibition in the right, but not the left, hemisphere. The relatively small sample size limited the sensitivity to show that the abnormalities in interhemispheric connectivity were specifically related to the dorsolateral prefrontal cortex in psychopathic offenders. To our knowledge, this study provides the first neurophysiological evidence for abnormal interhemispheric connectivity in psychopathic offenders and may further our understanding of the disruptive antisocial behaviour of these offenders.

Unusual cortical bone features in a patient with gorlin-goltz syndrome: a case report.

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Tarnoki, Adam Domonkos; Tarnoki, David Laszlo; Klara Kiss, Katalin; Bata, Pal; Karlinger, Kinga; Banvolgyi, Andras; Wikonkal, Norbert; Berczi, Viktor

2014-12-01

Gorlin-Goltz syndrome (GGS) consists of ectodermal and mesodermal abnormalities. In this case report we will investigate lower extremity lesions of GGS. A 52-year-old man with GGS underwent skull and lower extremity computer tomography. Radiographic findings included cervical spondylosis, transparent areas with slurred margins, and cerebral falx calcification. Tibial and fibular specific cortical lesions (thin cortical and subcortical cystic lesions) were seen on the radiography, which was confirmed by computer tomography. To our knowledge, this is the first report of such a long lesion of the tibia and fibula. Specific lower extremity cortical lesions (thin cortical and subcortical cystic lesions) may occur and these abnormalities can be found on radiography or CT, which are most probably attributed to retinoid treatment.

Unusual Cortical Bone Features in a Patient with Gorlin-Goltz Syndrome: A Case Report

International Nuclear Information System (INIS)

Tarnoki, Adam Domonkos; Tarnoki, David Laszlo; Klara Kiss, Katalin; Bata, Pal; Karlinger, Kinga; Banvolgyi, Andras; Wikonkal, Norbert; Berczi, Viktor

2014-01-01

Gorlin-Goltz syndrome (GGS) consists of ectodermal and mesodermal abnormalities. In this case report we will investigate lower extremity lesions of GGS. A 52-year-old man with GGS underwent skull and lower extremity computer tomography. Radiographic findings included cervical spondylosis, transparent areas with slurred margins, and cerebral falx calcification. Tibial and fibular specific cortical lesions (thin cortical and subcortical cystic lesions) were seen on the radiography, which was confirmed by computer tomography. To our knowledge, this is the first report of such a long lesion of the tibia and fibula. Specific lower extremity cortical lesions (thin cortical and subcortical cystic lesions) may occur and these abnormalities can be found on radiography or CT, which are most probably attributed to retinoid treatment

Major Superficial White Matter Abnormalities in Huntington's Disease

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Phillips, Owen R.; Joshi, Shantanu H.; Squitieri, Ferdinando; Sanchez-Castaneda, Cristina; Narr, Katherine; Shattuck, David W.; Caltagirone, Carlo; Sabatini, Umberto; Di Paola, Margherita

2016-01-01

Background: The late myelinating superficial white matter at the juncture of the cortical gray and white matter comprising the intracortical myelin and short-range association fibers has not received attention in Huntington's disease. It is an area of the brain that is late myelinating and is sensitive to both normal aging and neurodegenerative disease effects. Therefore, it may be sensitive to Huntington's disease processes. Methods: Structural MRI data from 25 Pre-symptomatic subjects, 24 Huntington's disease patients and 49 healthy controls was run through a cortical pattern-matching program. The surface corresponding to the white matter directly below the cortical gray matter was then extracted. Individual subject's Diffusion Tensor Imaging (DTI) data was aligned to their structural MRI data. Diffusivity values along the white matter surface were then sampled at each vertex point. DTI measures with high spatial resolution across the superficial white matter surface were then analyzed with the General Linear Model to test for the effects of disease. Results: There was an overall increase in the axial and radial diffusivity across much of the superficial white matter (p < 0.001) in Pre-symptomatic subjects compared to controls. In Huntington's disease patients increased diffusivity covered essentially the whole brain (p < 0.001). Changes are correlated with genotype (CAG repeat number) and disease burden (p < 0.001). Conclusions: This study showed broad abnormalities in superficial white matter even before symptoms are present in Huntington's disease. Since, the superficial white matter has a unique microstructure and function these abnormalities suggest it plays an important role in the disease. PMID:27242403

Mechanical properties of bovine cortical bone based on the automated ball indentation technique and graphics processing method.

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Zhang, Airong; Zhang, Song; Bian, Cuirong

2018-02-01

Cortical bone provides the main form of support in humans and other vertebrates against various forces. Thus, capturing its mechanical properties is important. In this study, the mechanical properties of cortical bone were investigated by using automated ball indentation and graphics processing at both the macroscopic and microstructural levels under dry conditions. First, all polished samples were photographed under a metallographic microscope, and the area ratio of the circumferential lamellae and osteons was calculated through the graphics processing method. Second, fully-computer-controlled automated ball indentation (ABI) tests were performed to explore the micro-mechanical properties of the cortical bone at room temperature and a constant indenter speed. The indentation defects were examined with a scanning electron microscope. Finally, the macroscopic mechanical properties of the cortical bone were estimated with the graphics processing method and mixture rule. Combining ABI and graphics processing proved to be an effective tool to obtaining the mechanical properties of the cortical bone, and the indenter size had a significant effect on the measurement. The methods presented in this paper provide an innovative approach to acquiring the macroscopic mechanical properties of cortical bone in a nondestructive manner. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transcranial magnetic stimulation reveals cortical hyperexcitability in episodic cluster headache.

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Cosentino, Guiseppe; Brighina, Filippo; Brancato, Sara; Valentino, Francesca; Indovino, Serena; Fierro, Brigida

2015-01-01

Evidence shows involvement of the cerebral cortex in the pathophysiology of cluster headache (CH). Here we investigated cortical excitability in episodic CH patients by using transcranial magnetic stimulation. In 25 patients with episodic CH and 13 healthy subjects we evaluated the motor cortical response to single-pulse (ie, motor threshold, input-output curves, cortical silent period) and paired-pulse (ie, intracortical facilitation, short intracortical inhibition) transcranial magnetic stimulation in both hemispheres. Thirteen patients were evaluated outside bout and the remaining 12 patients inside bout. Our results showed increased slope of the input-output curves after stimulation of both hemispheres in patients outside bout and in the hemisphere contralateral to the headache side in patients inside bout. Increased intracortical facilitation was observed in the hemisphere ipsilateral to the headache side in patients evaluated both outside and inside bout; reduced short intracortical inhibition was observed in patients inside bout ipsilateral to the side of pain. In conclusion, we provide evidence of increased cortical excitability in episodic CH both outside and inside bout, especially in the hemisphere ipsilateral to the side of headache attacks. Our results suggest that an abnormal regulation of cortical excitability could be involved in the pathophysiology of CH. We investigated cortical excitability in episodic cluster headache by using transcranial magnetic stimulation, providing evidence of cortical hyperexcitability in patients both inside and outside bout. We suggest that an abnormal state of cortical excitability could be involved in the pathophysiology of the disease. Copyright © 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.

Children with dyslexia show cortical hyperactivation in response to increasing literacy processing demands

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Frøydis eMorken

2014-12-01

Full Text Available This fMRI study aimed to examine how differences in literacy processing demands may affect cortical activation patterns in 11- to 12-year-old children with dyslexia as compared to children with typical reading skills. 11 children with and 18 without dyslexia were assessed using a reading paradigm based on different stages of literacy development. In the analyses, six regions showed an interaction effect between group and condition in a factorial ANOVA. These regions were selected as regions of interest for further analyses. Overall, the dyslexia group showed cortical hyperactivation compared to the typical group. The difference between the groups tended to increase with increasing processing demands. Differences in cortical activation were not reflected in in-scanner reading performance. The six regions further grouped into three patterns, which are discussed in terms of processing demands, compensatory mechanisms, orthography and contextual facilitation. We conclude that the observed hyperactivation is chiefly a result of compensatory activity, modulated by other factors.

Disrupted cortical connectivity theory as an explanatory model for autism spectrum disorders

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Kana, Rajesh K.; Libero, Lauren E.; Moore, Marie S.

2011-12-01

such as Theory-of-Mind, cognitive flexibility, and information processing; and 2) how connection abnormalities relate to, and may determine, behavioral symptoms hallmarked by the triad of Impairments in ASD. Furthermore, we will relate the disrupted cortical connectivity model to existing cognitive and neural models of ASD.

Reduced cortical thickness in gambling disorder

DEFF Research Database (Denmark)

Grant, Jon E; Odlaug, Brian Lawrence; Chamberlain, Samuel R

2015-01-01

with significant reductions (average 15.8-19.9 %) in cortical thickness, versus controls, predominantly in right frontal cortical regions. Pronounced right frontal morphometric brain abnormalities occur in gambling disorder, supporting neurobiological overlap with substance disorders and its recent......Gambling disorder has recently been recognized as a prototype 'behavioral addiction' by virtue of its inclusion in the DSM-5 category of 'Substance-Related and Addictive Disorders.' Despite its newly acquired status and prevalence rate of 1-3 % globally, relatively little is known regarding...... the neurobiology of this disorder. The aim of this study was to explore cortical morphometry in untreated gambling disorder, for the first time. Subjects with gambling disorder (N = 16) free from current psychotropic medication or psychiatric comorbidities, and healthy controls (N = 17), were entered...

Changes in basal ganglia processing of cortical input following magnetic stimulation in Parkinsonism.

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Tischler, Hadass; Moran, Anan; Belelovsky, Katya; Bronfeld, Maya; Korngreen, Alon; Bar-Gad, Izhar

2012-12-01

Parkinsonism is associated with major changes in neuronal activity throughout the cortico-basal ganglia loop. Current measures quantify changes in baseline neuronal and network activity but do not capture alterations in information propagation throughout the system. Here, we applied a novel non-invasive magnetic stimulation approach using a custom-made mini-coil that enabled us to study transmission of neuronal activity throughout the cortico-basal ganglia loop in both normal and parkinsonian primates. By magnetically perturbing cortical activity while simultaneously recording neuronal responses along the cortico-basal ganglia loop, we were able to directly investigate modifications in descending cortical activity transmission. We found that in both the normal and parkinsonian states, cortical neurons displayed similar multi-phase firing rate modulations in response to magnetic stimulation. However, in the basal ganglia, large synaptically driven stereotypic neuronal modulation was present in the parkinsonian state that was mostly absent in the normal state. The stimulation-induced neuronal activity pattern highlights the change in information propagation along the cortico-basal ganglia loop. Our findings thus point to the role of abnormal dynamic activity transmission rather than changes in baseline activity as a major component in parkinsonian pathophysiology. Moreover, our results hint that the application of transcranial magnetic stimulation (TMS) in human patients of different disorders may result in different neuronal effects than the one induced in normal subjects. Copyright © 2012 Elsevier Inc. All rights reserved.

Basic abnormalities in visual processing affect face processing at an early age in autism spectrum disorder.

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Vlamings, Petra Hendrika Johanna Maria; Jonkman, Lisa Marthe; van Daalen, Emma; van der Gaag, Rutger Jan; Kemner, Chantal

2010-12-15

A detailed visual processing style has been noted in autism spectrum disorder (ASD); this contributes to problems in face processing and has been directly related to abnormal processing of spatial frequencies (SFs). Little is known about the early development of face processing in ASD and the relation with abnormal SF processing. We investigated whether young ASD children show abnormalities in low spatial frequency (LSF, global) and high spatial frequency (HSF, detailed) processing and explored whether these are crucially involved in the early development of face processing. Three- to 4-year-old children with ASD (n = 22) were compared with developmentally delayed children without ASD (n = 17). Spatial frequency processing was studied by recording visual evoked potentials from visual brain areas while children passively viewed gratings (HSF/LSF). In addition, children watched face stimuli with different expressions, filtered to include only HSF or LSF. Enhanced activity in visual brain areas was found in response to HSF versus LSF information in children with ASD, in contrast to control subjects. Furthermore, facial-expression processing was also primarily driven by detail in ASD. Enhanced visual processing of detailed (HSF) information is present early in ASD and occurs for neutral (gratings), as well as for socially relevant stimuli (facial expressions). These data indicate that there is a general abnormality in visual SF processing in early ASD and are in agreement with suggestions that a fast LSF subcortical face processing route might be affected in ASD. This could suggest that abnormal visual processing is causative in the development of social problems in ASD. Copyright © 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Hypoxic-Ischemic Encephalopathy With Clinical and Imaging Abnormalities Limited to Occipital Lobe.

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Parmar, Hemant A; Trobe, Jonathan D

2016-09-01

The vulnerable brain areas in hypoxic-ischemic encephalopathy (HIE) following systemic hypotension are typically the neocortex, deep cerebral gray nuclei, hippocampus, cerebellum, and the parieto-occipital arterial border zone region. The visual cortex is not commonly recognized as a target in this setting. Single-institution review from 2007 to 2015 of patients who suffered cortical visual loss as an isolated clinical manifestation following systemic hypotension and whose brain imaging showed abnormalities limited to the occipital lobe. Nine patients met inclusion criteria. Visual loss at outset ranged from hand movements to 20/20, but all patients had homonymous field loss at best. In 1 patient, imaging was initially normal but 4 months later showed encephalomalacia. In 2 patients, imaging was initially subtle enough to be recognized as abnormal only when radiologists were advised that cortical visual loss was present. The occipital lobe may be an isolated target in HIE with cortical visual loss as the only clinical manifestation. Imaging performed in the acute period may appear normal or disclose abnormalities subtle enough to be overlooked. Radiologists informed of the clinical manifestations may be more attune to these abnormalities, which will become more apparent months later when occipital volume loss develops.

Hypomelanosis of Ito and brain abnormalities: MRI findings and literature review

International Nuclear Information System (INIS)

Steiner, J.; Adamsbaum, C.; Desguerres, I.; Lalande, G.; Raynaud, F.; Ponsot, G.; Kalifa, G.

1996-01-01

We report the results of a 14-year retrospective study of brain MRI abnormalities in 12 pediatric patients presenting with hypomelanosis of Ito (HI). Miscellaneous brain abnormalities were found: one patient had a medulloblastoma, three had cortical malformations, and five demonstrated ''minor'' abnormalities such as dilated Virchow-Robin spaces or brain atrophy. We emphasize the polymorphism of brain abnormalities associated with HI. (orig.). With 5 figs., 1 tab

Clinical and imaging characteristics of localized megalencephaly: a retrospective comparison of diffuse hemimegalencephaly and multilobar cortical dysplasia

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Nakahashi, Masumi; Tsushima, Yoshito; Amanuma, Makoto; Endo, Keigo [Gunma University Graduate School of Medicine, Department of Diagnostic Radiology and Nuclear Medicine, Maebashi, Gunma (Japan); Sato, Noriko; Ota, Miho [National Center Hospital of Neurology and Psychiatry, Department of Radiology, Kodaira, Tokyo (Japan); Yagishita, Akira [Tokyo Metropolitan Neurological Hospital, Department of Neuroradiology, Kokubunji, Tokyo (Japan); Saito, Yoshiaki; Sugai, Kenji; Sasaki, Masayuki [National Center Hospital of Neurology and Psychiatry, Department of Child Neurology, Kodaira, Tokyo (Japan); Natsume, Jun [Nagoya University Graduate School of Medicine, Department of Pediatrics, Nagoya, Aichi (Japan)

2009-12-15

Hemimegalencephaly is a well-known congenital malformation. However, localized megalencephaly, which may be one of the subtypes of hemimegalencephaly, has not been separately investigated. In the present study, we attempted to characterize the clinical and magnetic resonance (MR) imaging features of localized megalencephaly in comparison with ordinary diffuse hemimegalencephaly and multilobar cortical dysplasia. MR findings for 43 patients with hemimegalencephaly and ten with multilobar cortical dysplasia, which is the differential diagnosis of localized megalencephaly, were retrospectively reviewed. Clinical findings such as the onset and severity of seizures and imaging findings including the affected area of the brain, structures outside of the hemisphere, and interval morphological changes were examined. Of the 43 patients, 11 showed signs of localized megalencephaly (25.6%). Localized megalencephaly was predominantly seen on the left side (72.7%) and had a tendency toward severe-grade seizures compared to multilobar cortical dysplasia. The frequencies of the extracerebral abnormalities in the diffuse hemimegalencephaly, localized megalencephaly, and multilobar cortical dysplasia groups were 84.4%, 36.4%, and 0.0%, respectively. There were three localized megalencephaly patients whose affected areas shrank and whose images were similar to those of multilobar cortical dysplasia. Localized megalencephaly accounts for one quarter of all hemimegalencephaly cases in this study. The incidence of extracerebral abnormalities in patients with localized hemimegalencephaly was almost half that of patients with diffuse hemimegalencephaly. Extracerebral abnormalities were absent in patients with multilobar cortical dysplasia. Associated extracerebral abnormalities may be a clue to differentiating localized megalencephaly from multilobar cortical dysplasia. (orig.)

Longitudinal changes in cortical thickness in autism and typical development.

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Zielinski, Brandon A; Prigge, Molly B D; Nielsen, Jared A; Froehlich, Alyson L; Abildskov, Tracy J; Anderson, Jeffrey S; Fletcher, P Thomas; Zygmunt, Kristen M; Travers, Brittany G; Lange, Nicholas; Alexander, Andrew L; Bigler, Erin D; Lainhart, Janet E

2014-06-01

The natural history of brain growth in autism spectrum disorders remains unclear. Cross-sectional studies have identified regional abnormalities in brain volume and cortical thickness in autism, although substantial discrepancies have been reported. Preliminary longitudinal studies using two time points and small samples have identified specific regional differences in cortical thickness in the disorder. To clarify age-related trajectories of cortical development, we examined longitudinal changes in cortical thickness within a large mixed cross-sectional and longitudinal sample of autistic subjects and age- and gender-matched typically developing controls. Three hundred and forty-five magnetic resonance imaging scans were examined from 97 males with autism (mean age = 16.8 years; range 3-36 years) and 60 males with typical development (mean age = 18 years; range 4-39 years), with an average interscan interval of 2.6 years. FreeSurfer image analysis software was used to parcellate the cortex into 34 regions of interest per hemisphere and to calculate mean cortical thickness for each region. Longitudinal linear mixed effects models were used to further characterize these findings and identify regions with between-group differences in longitudinal age-related trajectories. Using mean age at time of first scan as a reference (15 years), differences were observed in bilateral inferior frontal gyrus, pars opercularis and pars triangularis, right caudal middle frontal and left rostral middle frontal regions, and left frontal pole. However, group differences in cortical thickness varied by developmental stage, and were influenced by IQ. Differences in age-related trajectories emerged in bilateral parietal and occipital regions (postcentral gyrus, cuneus, lingual gyrus, pericalcarine cortex), left frontal regions (pars opercularis, rostral middle frontal and frontal pole), left supramarginal gyrus, and right transverse temporal gyrus, superior parietal lobule, and

Longitudinal MRI study of cortical thickness, perfusion, and metabolite levels in major depressive disorder

DEFF Research Database (Denmark)

Järnum, Hanna; Eskildsen, Simon Fristed; Steffensen, Elena G

2011-01-01

OBJECTIVE: To determine whether patients with major depressive disorder (MDD) display morphologic, functional, and metabolic brain abnormalities in limbic-cortical regions at a baseline magnetic resonance (MR) scan and whether these changes are normalized in MDD patients in remission at a follow......-acetylaspartate, myo-inositol, and glutamate levels in MDD patients compared with healthy controls at baseline. CONCLUSION: Using novel MRI techniques, we have found abnormalities in cerebral regions related to cortical-limbic pathways in MDD patients....

Cortical oscillations and entrainment in speech processing during working memory load

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Hjortkjær, Jens; Märcher-Rørsted, Jonatan; Fuglsang, Søren A

2018-01-01

Neuronal oscillations are thought to play an important role in working memory (WM) and speech processing. Listening to speech in real-life situations is often cognitively demanding but it is unknown whether WM load influences how auditory cortical activity synchronizes to speech features. Here, we...... developed an auditory n-back paradigm to investigate cortical entrainment to speech envelope fluctuations under different degrees of WM load. We measured the electroencephalogram, pupil dilations and behavioural performance from 22 subjects listening to continuous speech with an embedded n-back task....... The speech stimuli consisted of long spoken number sequences created to match natural speech in terms of sentence intonation, syllabic rate and phonetic content. To burden different WM functions during speech processing, listeners performed an n-back task on the speech sequences in different levels...

Modulation of Cortical-subcortical Networks in Parkinson’s Disease by Applied Field Effects

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Christopher William Hess

2013-09-01

Full Text Available Studies suggest that endogenous field effects may play a role in neuronal oscillations and communication. Non-invasive transcranial electrical stimulation with low-intensity currents can also have direct effects on the underlying cortex as well as distant network effects. While Parkinson's disease (PD is amenable to invasive neuromodulation in the basal ganglia by deep brain stimulation, techniques of non-invasive neuromodulation like transcranial direct current stimulation (tDCS and transcranial alternating current stimulation (tACS are being investigated as possible therapies. tDCS and tACS have the potential to influence the abnormal cortical-subcortical network activity that occurs in PD through sub-threshold changes in cortical excitability or through entrainment or disruption of ongoing rhythmic cortical activity. This may allow for the targeting of specific features of the disease involving abnormal oscillatory activity, as well as the enhancement of potential cortical compensation for basal ganglia dysfunction and modulation of cortical plasticity in neurorehabilitation. However, little is currently known about how cortical stimulation will affect subcortical structures, the size of any effect, and the factors of stimulation that will influence these effects.

Thalamocortical functional connectivity in Lennox-Gastaut syndrome is abnormally enhanced in executive-control and default-mode networks.

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Warren, Aaron E L; Abbott, David F; Jackson, Graeme D; Archer, John S

2017-12-01

To identify abnormal thalamocortical circuits in the severe epilepsy of Lennox-Gastaut syndrome (LGS) that may explain the shared electroclinical phenotype and provide potential treatment targets. Twenty patients with a diagnosis of LGS (mean age = 28.5 years) and 26 healthy controls (mean age = 27.6 years) were compared using task-free functional magnetic resonance imaging (MRI). The thalamus was parcellated according to functional connectivity with 10 cortical networks derived using group-level independent component analysis. For each cortical network, we assessed between-group differences in thalamic functional connectivity strength using nonparametric permutation-based tests. Anatomical locations were identified by quantifying spatial overlap with a histologically informed thalamic MRI atlas. In both groups, posterior thalamic regions showed functional connectivity with visual, auditory, and sensorimotor networks, whereas anterior, medial, and dorsal thalamic regions were connected with networks of distributed association cortex (including the default-mode, anterior-salience, and executive-control networks). Four cortical networks (left and right executive-control network; ventral and dorsal default-mode network) showed significantly enhanced thalamic functional connectivity strength in patients relative to controls. Abnormal connectivity was maximal in mediodorsal and ventrolateral thalamic nuclei. Specific thalamocortical circuits are affected in LGS. Functional connectivity is abnormally enhanced between the mediodorsal and ventrolateral thalamus and the default-mode and executive-control networks, thalamocortical circuits that normally support diverse cognitive processes. In contrast, thalamic regions connecting with primary and sensory cortical networks appear to be less affected. Our previous neuroimaging studies show that epileptic activity in LGS is expressed via the default-mode and executive-control networks. Results of the present study suggest that

Hearing with Two Ears: Evidence for Cortical Binaural Interaction during Auditory Processing.

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Henkin, Yael; Yaar-Soffer, Yifat; Givon, Lihi; Hildesheimer, Minka

2015-04-01

Integration of information presented to the two ears has been shown to manifest in binaural interaction components (BICs) that occur along the ascending auditory pathways. In humans, BICs have been studied predominantly at the brainstem and thalamocortical levels; however, understanding of higher cortically driven mechanisms of binaural hearing is limited. To explore whether BICs are evident in auditory event-related potentials (AERPs) during the advanced perceptual and postperceptual stages of cortical processing. The AERPs N1, P3, and a late negative component (LNC) were recorded from multiple site electrodes while participants performed an oddball discrimination task that consisted of natural speech syllables (/ka/ vs. /ta/) that differed by place-of-articulation. Participants were instructed to respond to the target stimulus (/ta/) while performing the task in three listening conditions: monaural right, monaural left, and binaural. Fifteen (21-32 yr) young adults (6 females) with normal hearing sensitivity. By subtracting the response to target stimuli elicited in the binaural condition from the sum of responses elicited in the monaural right and left conditions, the BIC waveform was derived and the latencies and amplitudes of the components were measured. The maximal interaction was calculated by dividing BIC amplitude by the summed right and left response amplitudes. In addition, the latencies and amplitudes of the AERPs to target stimuli elicited in the monaural right, monaural left, and binaural listening conditions were measured and subjected to analysis of variance with repeated measures testing the effect of listening condition and laterality. Three consecutive BICs were identified at a mean latency of 129, 406, and 554 msec, and were labeled N1-BIC, P3-BIC, and LNC-BIC, respectively. Maximal interaction increased significantly with progression of auditory processing from perceptual to postperceptual stages and amounted to 51%, 55%, and 75% of the sum of

Abnormal cortical development after premature birth shown by altered allometric scaling of brain growth.

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Olga Kapellou

2006-08-01

Full Text Available We postulated that during ontogenesis cortical surface area and cerebral volume are related by a scaling law whose exponent gives a quantitative measure of cortical development. We used this approach to investigate the hypothesis that premature termination of the intrauterine environment by preterm birth reduces cortical development in a dose-dependent manner, providing a neural substrate for functional impairment.We analyzed 274 magnetic resonance images that recorded brain growth from 23 to 48 wk of gestation in 113 extremely preterm infants born at 22 to 29 wk of gestation, 63 of whom underwent neurodevelopmental assessment at a median age of 2 y. Cortical surface area was related to cerebral volume by a scaling law with an exponent of 1.29 (95% confidence interval, 1.25-1.33, which was proportional to later neurodevelopmental impairment. Increasing prematurity and male gender were associated with a lower scaling exponent (p < 0.0001 independent of intrauterine or postnatal somatic growth.Human brain growth obeys an allometric scaling relation that is disrupted by preterm birth in a dose-dependent, sexually dimorphic fashion that directly parallels the incidence of neurodevelopmental impairments in preterm infants. This result focuses attention on brain growth and cortical development during the weeks following preterm delivery as a neural substrate for neurodevelopmental impairment after premature delivery.

Cortical spreading depression in migraine-time to reconsider?

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Alan J McComas

2015-08-01

Full Text Available New evidence concerning the pathophysiology of migraine has come from the results of therapeutic transcranial magnetic stimulation (tTMS. The instantaneous responses to single pulses applied during the aura or headache phase, together with a number of other observations, make it unlikely that cortical spreading depression is involved in migraine. tTMS is considered to act by abolishing abnormal impulse activity in cortical pyramidal neurons and a suggestion is made as to how this activity could arise.

Cortical sources of resting state EEG rhythms are related to brain hypometabolism in subjects with Alzheimer's disease: an EEG-PET study.

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Babiloni, Claudio; Del Percio, Claudio; Caroli, Anna; Salvatore, Elena; Nicolai, Emanuele; Marzano, Nicola; Lizio, Roberta; Cavedo, Enrica; Landau, Susan; Chen, Kewei; Jagust, William; Reiman, Eric; Tedeschi, Gioacchino; Montella, Patrizia; De Stefano, Manuela; Gesualdo, Loreto; Frisoni, Giovanni B; Soricelli, Andrea

2016-12-01

Cortical sources of resting state electroencephalographic (EEG) delta (2-4 Hz) and low-frequency alpha (8-10.5 Hz) rhythms show abnormal activity (i.e., current density) in patients with dementia due to Alzheimer's disease (AD). Here, we hypothesized that abnormality of this activity is related to relevant disease processes as revealed by cortical hypometabolism typically observed in AD patients by fluorodeoxyglucose positron emission tomography. Resting state eyes-closed EEG data were recorded in 19 AD patients with dementia and 40 healthy elderly (Nold) subjects. EEG frequency bands of interest were delta and low-frequency alpha. EEG sources were estimated in these bands by low-resolution brain electromagnetic tomography (LORETA). Fluorodeoxyglucose positron emission tomography images were recorded only in the AD patients, and cortical hypometabolism was indexed by the so-called Alzheimer's discrimination analysis tool (PALZ) in the frontal association, ventromedial frontal, temporoparietal association, posterior cingulate, and precuneus areas. Results showed that compared with the Nold group, the AD group pointed to higher activity of delta sources and lower activity of low-frequency alpha sources in a cortical region of interest formed by all cortical areas of the PALZ score. In the AD patients, there was a positive correlation between the PALZ score and the activity of delta sources in the cortical region of interest (p < 0.05). These results suggest a relationship between resting state cortical hypometabolism and synchronization of cortical neurons at delta rhythms in AD patients with dementia. Copyright © 2016 Elsevier Inc. All rights reserved.

Abnormal early gamma responses to emotional faces differentiate unipolar from bipolar disorder patients.

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Liu, T Y; Chen, Y S; Su, T P; Hsieh, J C; Chen, L F

2014-01-01

This study investigates the cortical abnormalities of early emotion perception in patients with major depressive disorder (MDD) and bipolar disorder (BD) using gamma oscillations. Twenty-three MDD patients, twenty-five BD patients, and twenty-four normal controls were enrolled and their event-related magnetoencephalographic responses were recorded during implicit emotional tasks. Our results demonstrated abnormal gamma activity within 100 ms in the emotion-related regions (amygdala, orbitofrontal (OFC) cortex, anterior insula (AI), and superior temporal pole) in the MDD patients, suggesting that these patients may have dysfunctions or negativity biases in perceptual binding of emotional features at very early stage. Decreased left superior medial frontal cortex (smFC) responses to happy faces in the MDD patients were correlated with their serious level of depression symptoms, indicating that decreased smFC activity perhaps underlies irregular positive emotion processing in depressed patients. In the BD patients, we showed abnormal activation in visual regions (inferior/middle occipital and middle temporal cortices) which responded to emotional faces within 100 ms, supporting that the BD patients may hyperactively respond to emotional features in perceptual binding. The discriminant function of gamma activation in the left smFC, right medial OFC, right AI/inferior OFC, and the right precentral cortex accurately classified 89.6% of patients as unipolar/bipolar disorders.

Measurement of pharyngeal sensory cortical processing: technique and physiologic implications

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Ringelstein E Bernd

2009-07-01

Full Text Available Abstract Background Dysphagia is a major complication of different diseases affecting both the central and peripheral nervous system. Pharyngeal sensory impairment is one of the main features of neurogenic dysphagia. Therefore an objective technique to examine the cortical processing of pharyngeal sensory input would be a helpful diagnostic tool in this context. We developed a simple paradigm to perform pneumatic stimulation to both sides of the pharyngeal wall. Whole-head MEG was employed to study changes in cortical activation during this pharyngeal stimulation in nine healthy subjects. Data were analyzed by means of synthetic aperture magnetometry (SAM and the group analysis of individual SAM data was performed using a permutation test. Results Our results revealed bilateral activation of the caudolateral primary somatosensory cortex following sensory pharyngeal stimulation with a slight lateralization to the side of stimulation. Conclusion The method introduced here is simple and easy to perform and might be applicable in the clinical setting. The results are in keeping with previous findings showing bihemispheric involvement in the complex task of sensory pharyngeal processing. They might also explain changes in deglutition after hemispheric strokes. The ipsilaterally lateralized processing is surprising and needs further investigation.

Radiation-induced abnormal cortical thickness in patients with nasopharyngeal carcinoma after radiotherapy

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Jiabao Lin

2017-01-01

Full Text Available Conventional MRI studies showed that radiation-induced brain necrosis in patients with nasopharyngeal carcinoma (NPC in years after radiotherapy (RT could involve brain gray matter (GM and impair brain function. However, it is still unclear the radiation-induced brain morphological changes in NPC patients with normal-appearing GM in the early period after RT. In this study, we acquired high-resolution brain structural MRI data from three groups of patients, 22 before radiotherapy (pre-RT NPC patients with newly diagnosed but not yet medically treated, 22 NPC patients in the early-delayed stage after radiotherapy (post-RT-ED, and 20 NPC patients in the late-delayed stage after radiotherapy (post-RT-LD, and then analyzed the radiation-induced cortical thickness alteration in NPC patients after RT. Using a vertex-wise surface-based morphometry (SBM approach, we detected significantly decreased cortical thickness in the precentral gyrus (PreCG in the post-RT-ED group compared to the pre-RT group. And the post-RT-LD group showed significantly increased cortical thickness in widespread brain regions, including the bilateral inferior parietal, left isthmus of the cingulate, left bank of the superior temporal sulcus and left lateral occipital regions, compared to the pre-RT group, and in the bilateral PreCG compared to the post-RT-ED group. Similar analysis with ROI-wise SBM method also found the consistent results. These results indicated that radiation-induced brain injury mainly occurred in the post-RT-LD group and the cortical thickness alterations after RT were dynamic in different periods. Our findings may reflect the pathogenesis of radiation-induced brain injury in NPC patients with normal-appearing GM and an early intervention is necessary for protecting GM during RT.

Normal and abnormal neuronal migration in the developing cerebral cortex.

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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.

Cortical stimulation evokes abnormal responses in the dopamine-depleted rat basal ganglia.

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Kita, Hitoshi; Kita, Takako

2011-07-13

The motor cortex (MC) sends massive projections to the basal ganglia. Motor disabilities in patients and animal models of Parkinson's disease (PD) may be caused by dopamine (DA)-depleted basal ganglia that abnormally process the information originating from MC. To study how DA depletion alters signal transfer in the basal ganglia, MC stimulation-induced (MC-induced) unitary responses were recorded from the basal ganglia of control and 6-hydroxydopamine-treated hemi-parkinsonian rats anesthetized with isoflurane. This report describes new findings about how DA depletion alters MC-induced responses. MC stimulation evokes an excitation in normally quiescent striatal (Str) neurons projecting to the globus pallidus external segment (GPe). After DA-depletion, the spontaneous firing of Str-GPe neurons increases, and MC stimulation evokes a shorter latency excitation followed by a long-lasting inhibition that was invisible under normal conditions. The increased firing activity and the newly exposed long inhibition generate tonic inhibition and a disfacilitation in GPe. The disfacilitation in GPe is then amplified in basal ganglia circuitry and generates a powerful long inhibition in the basal ganglia output nucleus, the globus pallidus internal segment. Intra-Str injections of a behaviorally effective dose of DA precursor l-3,4-dihydroxyphenylalanine effectively reversed these changes. These newly observed mechanisms also support the generation of pauses and burst activity commonly observed in the basal ganglia of parkinsonian subjects. These results suggest that the generation of abnormal response sequences in the basal ganglia contributes to the development of motor disabilities in PD and that intra-Str DA supplements effectively suppress abnormal signal transfer.

Disrupted cortical connectivity theory as an explanatory model for autism spectrum disorders.

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Kana, Rajesh K; Libero, Lauren E; Moore, Marie S

2011-12-01

as Theory-of-Mind, cognitive flexibility, and information processing; and 2) how connection abnormalities relate to, and may determine, behavioral symptoms hallmarked by the triad of Impairments in ASD. Furthermore, we will relate the disrupted cortical connectivity model to existing cognitive and neural models of ASD. Published by Elsevier B.V.

Bilateral Cerebellar Cortical Dysplasia without Other Malformations: A Case Report

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Oh, Jung Seok; Ahn Kook Jin; Kim, Jee Young; Lee, Sun Jin; Park, Jeong Mi [Catholic University Yeouido St. Mary' s Hospital, College of Medicine, Seoul (Korea, Republic of)

2010-06-15

Recent advances in MRI have revealed congenital brain malformations and subtle developmental abnormalities of the cerebral and cerebellar cortical architecture. Typical cerebellar cortical dysplasia as a newly categorized cerebellar malformation, has been seen in patients with Fukuyama congenital muscular dystrophy. Cerebellar cortical dysplasia occurs at the embryonic stage and is often observed in healthy newborns. It is also incidentally and initially detected in adults without symptoms. To the best of our knowledge, cerebellar dysplasia without any related disorders is very rare. We describe the MRI findings in one patient with disorganized foliation of both cerebellar hemispheres without a related disorder or syndrome

Auditory midbrain processing is differentially modulated by auditory and visual cortices: An auditory fMRI study.

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Gao, Patrick P; Zhang, Jevin W; Fan, Shu-Juan; Sanes, Dan H; Wu, Ed X

2015-12-01

The cortex contains extensive descending projections, yet the impact of cortical input on brainstem processing remains poorly understood. In the central auditory system, the auditory cortex contains direct and indirect pathways (via brainstem cholinergic cells) to nuclei of the auditory midbrain, called the inferior colliculus (IC). While these projections modulate auditory processing throughout the IC, single neuron recordings have samples from only a small fraction of cells during stimulation of the corticofugal pathway. Furthermore, assessments of cortical feedback have not been extended to sensory modalities other than audition. To address these issues, we devised blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) paradigms to measure the sound-evoked responses throughout the rat IC and investigated the effects of bilateral ablation of either auditory or visual cortices. Auditory cortex ablation increased the gain of IC responses to noise stimuli (primarily in the central nucleus of the IC) and decreased response selectivity to forward species-specific vocalizations (versus temporally reversed ones, most prominently in the external cortex of the IC). In contrast, visual cortex ablation decreased the gain and induced a much smaller effect on response selectivity. The results suggest that auditory cortical projections normally exert a large-scale and net suppressive influence on specific IC subnuclei, while visual cortical projections provide a facilitatory influence. Meanwhile, auditory cortical projections enhance the midbrain response selectivity to species-specific vocalizations. We also probed the role of the indirect cholinergic projections in the auditory system in the descending modulation process by pharmacologically blocking muscarinic cholinergic receptors. This manipulation did not affect the gain of IC responses but significantly reduced the response selectivity to vocalizations. The results imply that auditory cortical

Development of diagnostic process for abnormal conditions of Ulchin units 1 and 2

Energy Technology Data Exchange (ETDEWEB)

Choi, Hyun Soo; Kwak, Jeong Keun; Yun, Jung Hyun; Kim, Jong Hyun [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

2012-10-15

Diagnosis of abnormal conditions during operation is one of difficult tasks to nuclear power plant operators. Operators may have trouble in handling abnormal conditions due to various reasons such as 1) many alarms (around 2,000 alarms in the Ulchin units 1 and 2 each) and multi alarms occurrences, 2) the same alarms occurrences in different abnormal conditions, and 3) a number of Abnormal Operating Procedures (AOPs). For these reasons, the first diagnosis on abnormal conditions largely relies on operator's experiences and pattern recognition. Then, this difficulty may be highlighted for inexperienced operators. This paper suggests an approach to develop the optimal diagnostic process for appropriate selection of AOPs by using the Elimination by Aspect (EBA) method. The EBA method uses a heuristic followed by decision makers during a process of sequential choice and which constitutes a good balance between the cost of a decision and its quality. At each stage of decision, the individuals eliminate all the options not having an expected given attribute, until only one option remains. This approach is applied to steam generator level control system abnormal procedure for Ulchin units 1 and 2. The result indicates that the EBA method is applicable to the development of optimal process on diagnosis of abnormal conditions.

Abnormalities of cerebellar foliation and fissuration: classification, neurogenetics and clinicoradiological correlations

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Demaerel, P. [University Hospital, Department of Radiology, Herestraat 49, 3000 Leuven (Belgium)

2002-08-01

Several genes have been found to influence the different cells involved in the processes of foliation and fissuration in the mouse and rat cerebellum. In the light of these new concepts and on the basis of the imaging findings in 42 patients, a classification is proposed for abnormalities of foliation and fissuration. On the basis of recent genetic and experimental evidence on mechanisms which control the origin of the cerebellum, it is suggested that abnormalities of foliation and fissuration form a single group, with a spectrum of severity. Some patients have only abnormal fissuration of the anterior lobe (type 1a) and others additional dysplasia of the anterior and part of the posterior lobe (type 1b). Extension of abnormalities into the hemispheres is often seen in the latter group. A second group has vermian and hemisphere abnormalities (type 2). In addition to the malformation of the anterior lobe of the vermis, three different hemispheric lesions can be seen in this group: cortical dysgenesis, hypertrophy of the cerebellar cortex, and malorientation of the folia. The mild abnormalities (type 1a) can be considered an incidental observation without clinical relevance. The moderate and severe cerebellar anomalies (type 1b and 2) are always associated with cerebellar symptoms and/or signs. (orig.)

Abnormalities of cerebellar foliation and fissuration: classification, neurogenetics and clinicoradiological correlations

International Nuclear Information System (INIS)

Demaerel, P.

2002-01-01

Several genes have been found to influence the different cells involved in the processes of foliation and fissuration in the mouse and rat cerebellum. In the light of these new concepts and on the basis of the imaging findings in 42 patients, a classification is proposed for abnormalities of foliation and fissuration. On the basis of recent genetic and experimental evidence on mechanisms which control the origin of the cerebellum, it is suggested that abnormalities of foliation and fissuration form a single group, with a spectrum of severity. Some patients have only abnormal fissuration of the anterior lobe (type 1a) and others additional dysplasia of the anterior and part of the posterior lobe (type 1b). Extension of abnormalities into the hemispheres is often seen in the latter group. A second group has vermian and hemisphere abnormalities (type 2). In addition to the malformation of the anterior lobe of the vermis, three different hemispheric lesions can be seen in this group: cortical dysgenesis, hypertrophy of the cerebellar cortex, and malorientation of the folia. The mild abnormalities (type 1a) can be considered an incidental observation without clinical relevance. The moderate and severe cerebellar anomalies (type 1b and 2) are always associated with cerebellar symptoms and/or signs. (orig.)

Abnormal Structure–Function Relationship in Spasmodic Dysphonia

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Ludlow, Christy L.

2012-01-01

Spasmodic dysphonia (SD) is a primary focal dystonia characterized by involuntary spasms in the laryngeal muscles during speech production. Although recent studies have found abnormal brain function and white matter organization in SD, the extent of gray matter alterations, their structure–function relationships, and correlations with symptoms remain unknown. We compared gray matter volume (GMV) and cortical thickness (CT) in 40 SD patients and 40 controls using voxel-based morphometry and cortical distance estimates. These measures were examined for relationships with blood oxygen level–dependent signal change during symptomatic syllable production in 15 of the same patients. SD patients had increased GMV, CT, and brain activation in key structures of the speech control system, including the laryngeal sensorimotor cortex, inferior frontal gyrus (IFG), superior/middle temporal and supramarginal gyri, and in a structure commonly abnormal in other primary dystonias, the cerebellum. Among these regions, GMV, CT and activation of the IFG and cerebellum showed positive relationships with SD severity, while CT of the IFG correlated with SD duration. The left anterior insula was the only region with decreased CT, which also correlated with SD symptom severity. These findings provide evidence for coupling between structural and functional abnormalities at different levels within the speech production system in SD. PMID:21666131

Cortical-Cortical Interactions And Sensory Information Processing in Autism

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2008-04-30

significant development for disseminating the results of biomedical research in our lifetime." Sir Paul Nurse , Cancer Research UK Your research papers...of the evidence for local cortical over-connectivity is anecdotal. Belmonte and colleagues suggested the co-morbidity with epilepsy that is highly...Tomma-Halme J, Lahti-Nuuttila P, Service E, Virsu V: Rate of information segregation in developmentally dyslexic children . Brain Lang 2000, 75:66-81

Quantifying cortical development in typically developing toddlers and young children, 1-6 years of age.

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Remer, Justin; Croteau-Chonka, Elise; Dean, Douglas C; D'Arpino, Sara; Dirks, Holly; Whiley, Dannielle; Deoni, Sean C L

2017-06-01

Cortical maturation, including age-related changes in thickness, volume, surface area, and folding (gyrification), play a central role in developing brain function and plasticity. Further, abnormal cortical maturation is a suspected substrate in various behavioral, intellectual, and psychiatric disorders. However, in order to characterize the altered development associated with these disorders, appreciation of the normative patterns of cortical development in neurotypical children between 1 and 6 years of age, a period of peak brain development during which many behavioral and developmental disorders emerge, is necessary. To this end, we examined measures of cortical thickness, surface area, mean curvature, and gray matter volume across 34 bilateral regions in a cohort of 140 healthy children devoid of major risk factors for abnormal development. From these data, we observed linear, logarithmic, and quadratic patterns of change with age depending on brain region. Cortical thinning, ranging from 10% to 20%, was observed throughout most of the brain, with the exception of posterior brain structures, which showed initial cortical thinning from 1 to 5 years, followed by thickening. Cortical surface area expansion ranged from 20% to 108%, and cortical curvature varied by 1-20% across the investigated age range. Right-left hemisphere asymmetry was observed across development for each of the 4 cortical measures. Our results present new insight into the normative patterns of cortical development across an important but under studied developmental window, and provide a valuable reference to which trajectories observed in neurodevelopmental disorders may be compared. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

PET in malformations of cortical development

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Bouilleret, V.; O'Brien, T.J.; Bouilleret, V.; Bouilleret, V.; Chiron, C.; Chiron, C.

2009-01-01

Within the group of malformations of cortical development, focal cortical dysplasia (FCD) are an increasingly recognized cause of intractable epilepsy that can be cured by surgery. The success of cortical resection for intractable epilepsy is highly dependent on the accurate pre-surgical delineation of the regions responsible for generating seizures. [ 18 F]-FDG PET, which images cerebral metabolism studying brain glucose uptake, is the most established functional imaging modality in the evaluation of patients with epilepsy. The aim of this article is to review [ 18 F]-FDG PET usefulness as a pre-surgical tool in the evaluation of medically refractory partial epilepsy. It has an established place in assisting in the localisation and definition of FCD in patients with no lesion, or only a subtle abnormality, on MRI. The role of FDG-PET in defining the extent of the surgical resection is still uncertain and needs to be the focus of future research. (authors)

Value of renal cortical scintigraphy in children with acute pyelonephritis

International Nuclear Information System (INIS)

Paul, A.K.; Miah, M.S.R.; Rahman, H.A.; Hasan, M.H.

2004-01-01

Purpose: Acute pyelonephritis is a major cause of morbidity in children with urinary tract infection and can result in irreversible renal scarring leading to hypertension and end-stage renal disease. Tc-99m-dimercaptosuccinic acid (DMSA) scintigraphy is the imaging modality of choice for the detection of acute pyelonephhfis and renal scarfing. This study evaluated the importance of renal cortical scintigraphy to identify children at risk from renal damage due to acute pyelonephritis. Methods: Forty-nine children (ages 9 months to 11 years) with urinary tract infection having positive urine culture were studied. A DMSA scan was performed within 72 hours of receiving antibiotic during acute infection. Single or multiple areas of varying degrees of diminished cortical uptake or diffusely decreased uptake in an enlarged kidney was considered for the diagnosis of acute pyelonephrifis. Follow-up scintigraphy was done at 6 months of initial scan in children with acute pyelonephritis documented by DMSA scan. Renal scarring was considered if the affected kidney shows cortical thinning or focal cortical defect with loss of volume or become small kidney. Children with known renal tract abnormalities were excluded from the study. RESULTS: Twenty-seven children (55%) wine considered acute pyelonephritis by DMSA scintigraphy and the abnormality was bilateral in 17(63%) cases and unilateral in 10(37%) cases. Among these 44 abnormal kidneys, scintigraphy showed solitary defect in 29 kidneys, multiple defects in 6 kidneys and diffuse decreased uptake in 9 kidneys. Of them, twenty children were available for follow-up evaluation and scintigraphy demonstrated complete recovery in 21 of 34 (62%) kidneys and renal scarfing in 13 of 34 (38%) kidneys. Renal scarring was found in 5 of 7 kidneys (71%) with diffuse decreased uptake, 2 of 5 kidneys (40%) with multiple cortical defect and 6 of 22 (27%) with single focal detect. Conclusion: The scintigraphic pattern of acute pyelonephritis

Altered cortical processing of motor inhibition in schizophrenia.

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Lindberg, Påvel G; Térémetz, Maxime; Charron, Sylvain; Kebir, Oussama; Saby, Agathe; Bendjemaa, Narjes; Lion, Stéphanie; Crépon, Benoît; Gaillard, Raphaël; Oppenheim, Catherine; Krebs, Marie-Odile; Amado, Isabelle

2016-12-01

Inhibition is considered a key mechanism in schizophrenia. Short-latency intracortical inhibition (SICI) in the motor cortex is reduced in schizophrenia and is considered to reflect locally deficient γ-aminobutyric acid (GABA)-ergic modulation. However, it remains unclear how SICI is modulated during motor inhibition and how it relates to neural processing in other cortical areas. Here we studied motor inhibition Stop signal task (SST) in stabilized patients with schizophrenia (N = 28), healthy siblings (N = 21) and healthy controls (n = 31) matched in general cognitive status and educational level. Transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) were used to investigate neural correlates of motor inhibition. SST performance was similar in patients and controls. SICI was modulated by the task as expected in healthy controls and siblings but was reduced in patients with schizophrenia during inhibition despite equivalent motor inhibition performance. fMRI showed greater prefrontal and premotor activation during motor inhibition in schizophrenia. Task-related modulation of SICI was higher in subjects who showed less inhibition-related activity in pre-supplementary motor area (SMA) and cingulate motor area. An exploratory genetic analysis of selected markers of inhibition (GABRB2, GAD1, GRM1, and GRM3) did not explain task-related differences in SICI or cortical activation. In conclusion, this multimodal study provides direct evidence of a task-related deficiency in SICI modulation in schizophrenia likely reflecting deficient GABA-A related processing in motor cortex. Compensatory activation of premotor areas may explain similar motor inhibition in patients despite local deficits in intracortical processing. Task-related modulation of SICI may serve as a useful non-invasive GABAergic marker in development of therapeutic strategies in schizophrenia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Magnetic Resonance Perfusion Imaging in Malformations of Cortical Development

International Nuclear Information System (INIS)

Widjaja, ED.; Wilkinson, I.D.; Griffiths, P.D.

2007-01-01

Background: Malformations of cortical development vary in neuronal maturity and level of functioning. Purpose: To characterize regional relative cerebral blood volume (rCBV) and difference in first moment transit time (TTfm) in polymicrogyria and cortical tubers using magnetic resonance (MR) perfusion imaging. Material and Methods: MR imaging and dynamic T2*-weighted MR perfusion imaging were performed in 13 patients with tuberous sclerosis complex, 10 with polymicrogyria, and 18 controls with developmental delay but no macroscopic brain abnormality. Regions of interest were placed in cortical tubers or polymicrogyric cortex and in the contralateral normal-appearing side in patients with malformations. In 'control' subjects, regions of interest were placed in the frontal and parietal lobes in both hemispheres. The rCBV and TTfm of the tuber/contralateral side (rCBVRTSC and TTFMTSC) as well as those of the polymicrogyria/contralateral side (rCBVRPMG and TTFMPMG) were assessed. The right-to-left asymmetry of rCBV and TTfm in the control group was also assessed (rCBVRControls and TTFMControls). Results: There was no significant asymmetry between right and left rCBV or TTfm (P>0.05) in controls. There was significant reduction in rCBVRTSC compared to rCBVRControls (P 0.05). There were no significant differences between rCBVRPMG and rCBVRControls (P>0.05) or TTFMPMG and TTFMControls (P>0.05). Conclusion: Our findings imply that cerebral blood volume of polymicrogyria is similar to normal cortex, but there is reduced cerebral blood volume in cortical tubers. The lower rCBV ratio of cortical tubers may be related to known differences in pathogenetic timing of the underlying abnormalities during brain development or the presence of gliosis

Cortical Thinning and Altered Cortico-Cortical Structural Covariance of the Default Mode Network in Patients with Persistent Insomnia Symptoms.

Science.gov (United States)

Suh, Sooyeon; Kim, Hosung; Dang-Vu, Thien Thanh; Joo, Eunyeon; Shin, Chol

2016-01-01

Recent studies have suggested that structural abnormalities in insomnia may be linked with alterations in the default-mode network (DMN). This study compared cortical thickness and structural connectivity linked to the DMN in patients with persistent insomnia (PI) and good sleepers (GS). The current study used a clinical subsample from the longitudinal community-based Korean Genome and Epidemiology Study (KoGES). Cortical thickness and structural connectivity linked to the DMN in patients with persistent insomnia symptoms (PIS; n = 57) were compared to good sleepers (GS; n = 40). All participants underwent MRI acquisition. Based on literature review, we selected cortical regions corresponding to the DMN. A seed-based structural covariance analysis measured cortical thickness correlation between each seed region of the DMN and other cortical areas. Association of cortical thickness and covariance with sleep quality and neuropsychological assessments were further assessed. Compared to GS, cortical thinning was found in PIS in the anterior cingulate cortex, precentral cortex, and lateral prefrontal cortex. Decreased structural connectivity between anterior and posterior regions of the DMN was observed in the PIS group. Decreased structural covariance within the DMN was associated with higher PSQI scores. Cortical thinning in the lateral frontal lobe was related to poor performance in executive function in PIS. Disrupted structural covariance network in PIS might reflect malfunctioning of antero-posterior disconnection of the DMN during the wake to sleep transition that is commonly found during normal sleep. The observed structural network alteration may further implicate commonly observed sustained sleep difficulties and cognitive impairment in insomnia. © 2016 Associated Professional Sleep Societies, LLC.

Regional vulnerability of longitudinal cortical association connectivity

Directory of Open Access Journals (Sweden)

Rafael Ceschin

2015-01-01

Full Text Available Preterm born children with spastic diplegia type of cerebral palsy and white matter injury or periventricular leukomalacia (PVL, are known to have motor, visual and cognitive impairments. Most diffusion tensor imaging (DTI studies performed in this group have demonstrated widespread abnormalities using averaged deterministic tractography and voxel-based DTI measurements. Little is known about structural network correlates of white matter topography and reorganization in preterm cerebral palsy, despite the availability of new therapies and the need for brain imaging biomarkers. Here, we combined novel post-processing methodology of probabilistic tractography data in this preterm cohort to improve spatial and regional delineation of longitudinal cortical association tract abnormalities using an along-tract approach, and compared these data to structural DTI cortical network topology analysis. DTI images were acquired on 16 preterm children with cerebral palsy (mean age 5.6 ± 4 and 75 healthy controls (mean age 5.7 ± 3.4. Despite mean tract analysis, Tract-Based Spatial Statistics (TBSS and voxel-based morphometry (VBM demonstrating diffusely reduced fractional anisotropy (FA reduction in all white matter tracts, the along-tract analysis improved the detection of regional tract vulnerability. The along-tract map-structural network topology correlates revealed two associations: (1 reduced regional posterior–anterior gradient in FA of the longitudinal visual cortical association tracts (inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, optic radiation, posterior thalamic radiation correlated with reduced posterior–anterior gradient of intra-regional (nodal efficiency metrics with relative sparing of frontal and temporal regions; and (2 reduced regional FA within frontal–thalamic–striatal white matter pathways (anterior limb/anterior thalamic radiation, superior longitudinal fasciculus and cortical spinal tract

Altered brain structural networks in attention deficit/hyperactivity disorder children revealed by cortical thickness.

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Liu, Tian; Chen, Yanni; Li, Chenxi; Li, Youjun; Wang, Jue

2017-07-04

This study investigated the cortical thickness and topological features of human brain anatomical networks related to attention deficit/hyperactivity disorder. Data were collected from 40 attention deficit/hyperactivity disorder children and 40 normal control children. Interregional correlation matrices were established by calculating the correlations of cortical thickness between all pairs of cortical regions (68 regions) of the whole brain. Further thresholds were applied to create binary matrices to construct a series of undirected and unweighted graphs, and global, local, and nodal efficiencies were computed as a function of the network cost. These experimental results revealed abnormal cortical thickness and correlations in attention deficit/hyperactivity disorder, and showed that the brain structural networks of attention deficit/hyperactivity disorder subjects had inefficient small-world topological features. Furthermore, their topological properties were altered abnormally. In particular, decreased global efficiency combined with increased local efficiency in attention deficit/hyperactivity disorder children led to a disorder-related shift of the network topological structure toward regular networks. In addition, nodal efficiency, cortical thickness, and correlation analyses revealed that several brain regions were altered in attention deficit/hyperactivity disorder patients. These findings are in accordance with a hypothesis of dysfunctional integration and segregation of the brain in patients with attention deficit/hyperactivity disorder and provide further evidence of brain dysfunction in attention deficit/hyperactivity disorder patients by observing cortical thickness on magnetic resonance imaging.

Morphometric Changes in the Cortical Microvascular Network in Alzheimer's Disease

NARCIS (Netherlands)

Richard, E.; van Gool, W.A.; Hoozemans, J.J.M.; van Haastert, E.S.; Eikelenboom, P.; Rozemuller, A.J.M.; van de Berg, W.D.J.

2010-01-01

Alzheimer's disease (AD) pathology is accompanied by abnormalities of the microvasculature. Despite the potential importance of morphometric changes in the cortical capillary network on neuronal dysfunction and cognitive impairment, few autopsy studies have addressed this issue. In the present

Primary cortical folding in the human newborn: an early marker of later functional development

Science.gov (United States)

Benders, M.; Borradori-Tolsa, C.; Cachia, A.; Lazeyras, F.; Ha-Vinh Leuchter, R.; Sizonenko, S. V.; Warfield, S. K.; Mangin, J. F.; Hüppi, P. S.

2008-01-01

In the human brain, the morphology of cortical gyri and sulci is complex and variable among individuals, and it may reflect pathological functioning with specific abnormalities observed in certain developmental and neuropsychiatric disorders. Since cortical folding occurs early during brain development, these structural abnormalities might be present long before the appearance of functional symptoms. So far, the precise mechanisms responsible for such alteration in the convolution pattern during intra-uterine or post-natal development are still poorly understood. Here we compared anatomical and functional brain development in vivo among 45 premature newborns who experienced different intra-uterine environments: 22 normal singletons, 12 twins and 11 newborns with intrauterine growth restriction (IUGR). Using magnetic resonance imaging (MRI) and dedicated post-processing tools, we investigated early disturbances in cortical formation at birth, over the developmental period critical for the emergence of convolutions (26–36 weeks of gestational age), and defined early ‘endophenotypes’ of sulcal development. We demonstrated that twins have a delayed but harmonious maturation, with reduced surface and sulcation index compared to singletons, whereas the gyrification of IUGR newborns is discordant to the normal developmental trajectory, with a more pronounced reduction of surface in relation to the sulcation index compared to normal newborns. Furthermore, we showed that these structural measurements of the brain at birth are predictors of infants’ outcome at term equivalent age, for MRI-based cerebral volumes and neurobehavioural development evaluated with the assessment of preterm infant's behaviour (APIB). PMID:18587151

Principles of Temporal Processing Across the Cortical Hierarchy.

Science.gov (United States)

Himberger, Kevin D; Chien, Hsiang-Yun; Honey, Christopher J

2018-05-02

The world is richly structured on multiple spatiotemporal scales. In order to represent spatial structure, many machine-learning models repeat a set of basic operations at each layer of a hierarchical architecture. These iterated spatial operations - including pooling, normalization and pattern completion - enable these systems to recognize and predict spatial structure, while robust to changes in the spatial scale, contrast and noisiness of the input signal. Because our brains also process temporal information that is rich and occurs across multiple time scales, might the brain employ an analogous set of operations for temporal information processing? Here we define a candidate set of temporal operations, and we review evidence that they are implemented in the mammalian cerebral cortex in a hierarchical manner. We conclude that multiple consecutive stages of cortical processing can be understood to perform temporal pooling, temporal normalization and temporal pattern completion. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Diagnosis of renal perfusion abnormalities by sequential CT

Energy Technology Data Exchange (ETDEWEB)

Treugut, H; Andersson, I; Hildell, J; Nyman, U; Weibull, H

1981-10-01

Abnormalities of renal perfusion can be recognised more readily by sequential CT than by plain CT scan or after static enhancement with contrast medium. Haemodynamically significant stenoses of the renal arteries and total, or partial, infarcts can be diagnosed in this way. Intrarenal and capsular collaterals can be recognised by slow contrast accumulation in the infarcted area, or by the development of contrast in the sub-capsular portion of the cortex. Renal cortical necrosis is very well demonstrated by the absence of cortical perfusion; this is seen, for instance, in the DIC syndrome or during rejection after renal transplant.

Assessment of compressive failure process of cortical bone materials using damage-based model.

Science.gov (United States)

Ng, Theng Pin; R Koloor, S S; Djuansjah, J R P; Abdul Kadir, M R

2017-02-01

The main failure factors of cortical bone are aging or osteoporosis, accident and high energy trauma or physiological activities. However, the mechanism of damage evolution coupled with yield criterion is considered as one of the unclear subjects in failure analysis of cortical bone materials. Therefore, this study attempts to assess the structural response and progressive failure process of cortical bone using a brittle damaged plasticity model. For this reason, several compressive tests are performed on cortical bone specimens made of bovine femur, in order to obtain the structural response and mechanical properties of the material. Complementary finite element (FE) model of the sample and test is prepared to simulate the elastic-to-damage behavior of the cortical bone using the brittle damaged plasticity model. The FE model is validated in a comparative method using the predicted and measured structural response as load-compressive displacement through simulation and experiment. FE results indicated that the compressive damage initiated and propagated at central region where maximum equivalent plastic strain is computed, which coincided with the degradation of structural compressive stiffness followed by a vast amount of strain energy dissipation. The parameter of compressive damage rate, which is a function dependent on damage parameter and the plastic strain is examined for different rates. Results show that considering a similar rate to the initial slope of the damage parameter in the experiment would give a better sense for prediction of compressive failure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Magnetic Resonance Perfusion Imaging in Malformations of Cortical Development

Energy Technology Data Exchange (ETDEWEB)

Widjaja, ED.; Wilkinson, I.D.; Griffiths, P.D. [Academic Section of Radiolog y, Univ. of Sheffield, Sheffield (United Kingdom)

2007-10-15

Background: Malformations of cortical development vary in neuronal maturity and level of functioning. Purpose: To characterize regional relative cerebral blood volume (rCBV) and difference in first moment transit time (TTfm) in polymicrogyria and cortical tubers using magnetic resonance (MR) perfusion imaging. Material and Methods: MR imaging and dynamic T2*-weighted MR perfusion imaging were performed in 13 patients with tuberous sclerosis complex, 10 with polymicrogyria, and 18 controls with developmental delay but no macroscopic brain abnormality. Regions of interest were placed in cortical tubers or polymicrogyric cortex and in the contralateral normal-appearing side in patients with malformations. In 'control' subjects, regions of interest were placed in the frontal and parietal lobes in both hemispheres. The rCBV and TTfm of the tuber/contralateral side (rCBVRTSC and TTFMTSC) as well as those of the polymicrogyria/contralateral side (rCBVRPMG and TTFMPMG) were assessed. The right-to-left asymmetry of rCBV and TTfm in the control group was also assessed (rCBVRControls and TTFMControls). Results: There was no significant asymmetry between right and left rCBV or TTfm (P>0.05) in controls. There was significant reduction in rCBVRTSC compared to rCBVRControls (P<0.05), but no significant difference in TTFMTSC compared to TTFMControls (P>0.05). There were no significant differences between rCBVRPMG and rCBVRControls (P>0.05) or TTFMPMG and TTFMControls (P>0.05). Conclusion: Our findings imply that cerebral blood volume of polymicrogyria is similar to normal cortex, but there is reduced cerebral blood volume in cortical tubers. The lower rCBV ratio of cortical tubers may be related to known differences in pathogenetic timing of the underlying abnormalities during brain development or the presence of gliosis.

Cortical thickness as a contributor to abnormal oscillations in schizophrenia?

Directory of Open Access Journals (Sweden)

J. Christopher Edgar

2014-01-01

Discussion: Left STG low-frequency and steady-state gamma abnormalities distinguish SZ and HC. Disease-associated damage to STG gray matter in schizophrenia may disrupt the age-related left STG gamma-band function–structure relationships observed in controls.

Cortico-Cortical Receptive Field Estimates in Human Visual Cortex

Directory of Open Access Journals (Sweden)

Koen V Haak

2012-05-01

Full Text Available Human visual cortex comprises many visual areas that contain a map of the visual field (Wandell et al 2007, Neuron 56, 366–383. These visual field maps can be identified readily in individual subjects with functional magnetic resonance imaging (fMRI during experimental sessions that last less than an hour (Wandell and Winawer 2011, Vis Res 718–737. Hence, visual field mapping with fMRI has been, and still is, a heavily used technique to examine the organisation of both normal and abnormal human visual cortex (Haak et al 2011, ACNR, 11(3, 20–21. However, visual field mapping cannot reveal every aspect of human visual cortex organisation. For example, the information processed within a visual field map arrives from somewhere and is sent to somewhere, and visual field mapping does not derive these input/output relationships. Here, we describe a new, model-based analysis for estimating the dependence between signals in distinct cortical regions using functional magnetic resonance imaging (fMRI data. Just as a stimulus-referred receptive field predicts the neural response as a function of the stimulus contrast, the neural-referred receptive field predicts the neural response as a function of responses elsewhere in the nervous system. When applied to two cortical regions, this function can be called the cortico-cortical receptive field (CCRF. We model the CCRF as a Gaussian-weighted region on the cortical surface and apply the model to data from both stimulus-driven and resting-state experimental conditions in visual cortex.

Abnormal Cortical Plasticity in Youth with Autism Spectrum Disorder: A Transcranial Magnetic Stimulation Case-Control Pilot Study.

Science.gov (United States)

Pedapati, Ernest V; Gilbert, Donald L; Erickson, Craig A; Horn, Paul S; Shaffer, Rebecca C; Wink, Logan K; Laue, Cameron S; Wu, Steve W

2016-09-01

This case-control study investigated the use of a low-intensity repetitive transcranial magnetic stimulation (rTMS) protocol to measure motor cortex (M1) plasticity in youth with autism spectrum disorder (ASD) compared with typically developing children (TDC). We hypothesized that impairments in long-term potentiation-like properties represent a neurophysiological biomarker of abnormal cortical function in ASD. We studied youth with ASD aged 11-18 years and matched controls (TDC). Intermittent theta burst stimulation (iTBS) was delivered to the dominant M1 at an intensity of 70% of resting motor threshold. Suprathreshold single-pulse TMS was performed to compare amplitudes of motor-evoked potentials (MEP) measured from surface electromyography electrodes on a target muscle before (20 pulses) and after (10 pulses/time point) iTBS at predefined timepoints (up to 30 minutes) to measure any potentiation effects. A linear mixed model was used to examine group differences in MEP amplitudes over time following iTBS. Nine youth with ASD (mean age 15.6; 7 males; 6 right-hand dominant) and 9 TDC (mean age 14.5; 5 males; 9 right-hand dominant) participated. All subjects tolerated the procedure well. Both groups had a mean increase in excitability after iTBS for 30 minutes; however, the time course of excitability changes differed (F9,144 = 2.05; p = 0.038). Post-hoc testing identified a significant decrease in amplitude of the ASD group at 20 minutes following iTBS compared with the TDC after correcting for multiple comparisons. In this study, we demonstrate early evidence for a potential physiological biomarker of cortical plasticity in youth with ASD using a rapid low-intensity rTMS protocol with a discriminate measure at 20 minutes following stimulation. The procedure was well tolerated by all 18 participants. Future work will include modification of the protocol to improve the ability to distinguish subtypes of ASD based on behavioral and cognitive testing.

Abnormal Cortical Plasticity in Youth with Autism Spectrum Disorder: A Transcranial Magnetic Stimulation Case–Control Pilot Study

Science.gov (United States)

Gilbert, Donald L.; Erickson, Craig A.; Horn, Paul S.; Shaffer, Rebecca C.; Wink, Logan K.; Laue, Cameron S.; Wu, Steve W.

2016-01-01

Abstract Objective: This case–control study investigated the use of a low-intensity repetitive transcranial magnetic stimulation (rTMS) protocol to measure motor cortex (M1) plasticity in youth with autism spectrum disorder (ASD) compared with typically developing children (TDC). We hypothesized that impairments in long-term potentiation-like properties represent a neurophysiological biomarker of abnormal cortical function in ASD. Methods: We studied youth with ASD aged 11–18 years and matched controls (TDC). Intermittent theta burst stimulation (iTBS) was delivered to the dominant M1 at an intensity of 70% of resting motor threshold. Suprathreshold single-pulse TMS was performed to compare amplitudes of motor-evoked potentials (MEP) measured from surface electromyography electrodes on a target muscle before (20 pulses) and after (10 pulses/time point) iTBS at predefined timepoints (up to 30 minutes) to measure any potentiation effects. A linear mixed model was used to examine group differences in MEP amplitudes over time following iTBS. Results: Nine youth with ASD (mean age 15.6; 7 males; 6 right-hand dominant) and 9 TDC (mean age 14.5; 5 males; 9 right-hand dominant) participated. All subjects tolerated the procedure well. Both groups had a mean increase in excitability after iTBS for 30 minutes; however, the time course of excitability changes differed (F9,144 = 2.05; p = 0.038). Post-hoc testing identified a significant decrease in amplitude of the ASD group at 20 minutes following iTBS compared with the TDC after correcting for multiple comparisons. Conclusion: In this study, we demonstrate early evidence for a potential physiological biomarker of cortical plasticity in youth with ASD using a rapid low-intensity rTMS protocol with a discriminate measure at 20 minutes following stimulation. The procedure was well tolerated by all 18 participants. Future work will include modification of the protocol to improve the ability to distinguish subtypes of

Abnormalities of Object Visual Processing in Body Dysmorphic Disorder

Science.gov (United States)

Feusner, Jamie D.; Hembacher, Emily; Moller, Hayley; Moody, Teena D.

2013-01-01

Background Individuals with body dysmorphic disorder may have perceptual distortions for their appearance. Previous studies suggest imbalances in detailed relative to configural/holistic visual processing when viewing faces. No study has investigated the neural correlates of processing non-symptom-related stimuli. The objective of this study was to determine whether individuals with body dysmorphic disorder have abnormal patterns of brain activation when viewing non-face/non-body object stimuli. Methods Fourteen medication-free participants with DSM-IV body dysmorphic disorder and 14 healthy controls participated. We performed functional magnetic resonance imaging while participants matched photographs of houses that were unaltered, contained only high spatial frequency (high detail) information, or only low spatial frequency (low detail) information. The primary outcome was group differences in blood oxygen level-dependent signal changes. Results The body dysmorphic disorder group showed lesser activity in the parahippocampal gyrus, lingual gyrus, and precuneus for low spatial frequency images. There were greater activations in medial prefrontal regions for high spatial frequency images, although no significant differences when compared to a low-level baseline. Greater symptom severity was associated with lesser activity in dorsal occipital cortex and ventrolateral prefrontal cortex for normal and high spatial frequency images. Conclusions Individuals with body dysmorphic disorder have abnormal brain activation patterns when viewing objects. Hypoactivity in visual association areas for configural and holistic (low detail) elements and abnormal allocation of prefrontal systems for details is consistent with a model of imbalances in global vs. local processing. This may occur not only for appearance but also for general stimuli unrelated to their symptoms. PMID:21557897

The cortical signature of impaired gesturing: Findings from schizophrenia

Directory of Open Access Journals (Sweden)

Petra Verena Viher

2018-01-01

Full Text Available Schizophrenia is characterized by deficits in gesturing that is important for nonverbal communication. Research in healthy participants and brain-damaged patients revealed a left-lateralized fronto-parieto-temporal network underlying gesture performance. First evidence from structural imaging studies in schizophrenia corroborates these results. However, as of yet, it is unclear if cortical thickness abnormalities contribute to impairments in gesture performance. We hypothesized that patients with deficits in gesture production show cortical thinning in 12 regions of interest (ROIs of a gesture network relevant for gesture performance and recognition. Forty patients with schizophrenia and 41 healthy controls performed hand and finger gestures as either imitation or pantomime. Group differences in cortical thickness between patients with deficits, patients without deficits, and controls were explored using a multivariate analysis of covariance. In addition, the relationship between gesture recognition and cortical thickness was investigated. Patients with deficits in gesture production had reduced cortical thickness in eight ROIs, including the pars opercularis of the inferior frontal gyrus, the superior and inferior parietal lobes, and the superior and middle temporal gyri. Gesture recognition correlated with cortical thickness in fewer, but mainly the same, ROIs within the patient sample. In conclusion, our results show that impaired gesture production and recognition in schizophrenia is associated with cortical thinning in distinct areas of the gesture network.

Motor-related brain abnormalities in HIV-infected patients. A multimodal MRI study

Energy Technology Data Exchange (ETDEWEB)

Zhou, Yawen; Wang, Xiaoxiao; Miao, Hui; Wei, Yarui; Ali, Rizwan [University of Science and Technology of China, Centers for Biomedical Engineering, Hefei, Anhui (China); Li, Ruili; Li, Hongjun [Capital Medical University, Department of Radiology, Beijing Youan Hospital, Beijing (China); Qiu, Bensheng [University of Science and Technology of China, Centers for Biomedical Engineering, Hefei, Anhui (China); Anhui Computer Application Institute of Traditional Chinese Medicine, Hefei, Anhui (China)

2017-11-15

It is generally believed that HIV infection could cause HIV-associated neurocognitive disorders (HAND) across a broad range of functional domains. Some of the most common findings are deficits in motor control. However, to date no neuroimaging studies have evaluated basic motor control in HIV-infected patients using a multimodal approach. In this study, we utilized high-resolution structural imaging and task-state functional magnetic resonance imaging (fMRI) to assess brain structure and motor function in a homogeneous cohort of HIV-infected patients. We found that HIV-infected patients had significantly reduced gray matter (GM) volume in cortical regions, which are involved in motor control, including the bilateral posterior insula cortex, premotor cortex, and supramarginal gyrus. Increased activation in bilateral posterior insula cortices was also demonstrated by patients during hand movement tasks compared with healthy controls. More importantly, the reduced GM in bilateral posterior insula cortices was spatially coincident with abnormal brain activation in HIV-infected patients. In addition, the results of partial correlation analysis indicated that GM reduction in bilateral posterior insula cortices and premotor cortices was significantly correlated with immune system deterioration. This study is the first to demonstrate spatially coincident GM reduction and abnormal activation during motor performance in HIV-infected patients. Although it remains unknown whether the brain deficits can be recovered, our findings may yield new insights into neurologic injury underlying motor dysfunction in HAND. (orig.)

Motor-related brain abnormalities in HIV-infected patients. A multimodal MRI study

International Nuclear Information System (INIS)

Zhou, Yawen; Wang, Xiaoxiao; Miao, Hui; Wei, Yarui; Ali, Rizwan; Li, Ruili; Li, Hongjun; Qiu, Bensheng

2017-01-01

It is generally believed that HIV infection could cause HIV-associated neurocognitive disorders (HAND) across a broad range of functional domains. Some of the most common findings are deficits in motor control. However, to date no neuroimaging studies have evaluated basic motor control in HIV-infected patients using a multimodal approach. In this study, we utilized high-resolution structural imaging and task-state functional magnetic resonance imaging (fMRI) to assess brain structure and motor function in a homogeneous cohort of HIV-infected patients. We found that HIV-infected patients had significantly reduced gray matter (GM) volume in cortical regions, which are involved in motor control, including the bilateral posterior insula cortex, premotor cortex, and supramarginal gyrus. Increased activation in bilateral posterior insula cortices was also demonstrated by patients during hand movement tasks compared with healthy controls. More importantly, the reduced GM in bilateral posterior insula cortices was spatially coincident with abnormal brain activation in HIV-infected patients. In addition, the results of partial correlation analysis indicated that GM reduction in bilateral posterior insula cortices and premotor cortices was significantly correlated with immune system deterioration. This study is the first to demonstrate spatially coincident GM reduction and abnormal activation during motor performance in HIV-infected patients. Although it remains unknown whether the brain deficits can be recovered, our findings may yield new insights into neurologic injury underlying motor dysfunction in HAND. (orig.)

Visual Processing Recruits the Auditory Cortices in Prelingually Deaf Children and Influences Cochlear Implant Outcomes.

Science.gov (United States)

Liang, Maojin; Chen, Yuebo; Zhao, Fei; Zhang, Junpeng; Liu, Jiahao; Zhang, Xueyuan; Cai, Yuexin; Chen, Suijun; Li, Xianghui; Chen, Ling; Zheng, Yiqing

2017-09-01

Although visual processing recruitment of the auditory cortices has been reported previously in prelingually deaf children who have a rapidly developing brain and no auditory processing, the visual processing recruitment of auditory cortices might be different in processing different visual stimuli and may affect cochlear implant (CI) outcomes. Ten prelingually deaf children, 4 to 6 years old, were recruited for the study. Twenty prelingually deaf subjects, 4 to 6 years old with CIs for 1 year, were also recruited; 10 with well-performing CIs, 10 with poorly performing CIs. Ten age and sex-matched normal-hearing children were recruited as controls. Visual ("sound" photo [photograph with imaginative sound] and "nonsound" photo [photograph without imaginative sound]) evoked potentials were measured in all subjects. P1 at Oz and N1 at the bilateral temporal-frontal areas (FC3 and FC4) were compared. N1 amplitudes were strongest in the deaf children, followed by those with poorly performing CIs, controls and those with well-performing CIs. There was no significant difference between controls and those with well-performing CIs. "Sound" photo stimuli evoked a stronger N1 than "nonsound" photo stimuli. Further analysis showed that only at FC4 in deaf subjects and those with poorly performing CIs were the N1 responses to "sound" photo stimuli stronger than those to "nonsound" photo stimuli. No significant difference was found for the FC3 and FC4 areas. No significant difference was found in N1 latencies and P1 amplitudes or latencies. The results indicate enhanced visual recruitment of the auditory cortices in prelingually deaf children. Additionally, the decrement in visual recruitment of auditory cortices was related to good CI outcomes.

Abnormal fear conditioning and amygdala processing in an animal model of autism

DEFF Research Database (Denmark)

Markram, Kamila; Rinaldi, Tania; La Mendola, Deborah

2008-01-01

A core feature of autism spectrum disorders is the impairment in social interactions. Among other brain regions, a deficit in amygdala processing has been suggested to underlie this impairment, but whether the amygdala is processing fear abnormally in autism, is yet not clear. We used the valproic......-treated animals displayed several symptoms common to autism, among them impaired social interactions and increased repetitive behaviors. Furthermore, VPA-treated rats were more anxious and exhibited abnormally high and longer lasting fear memories, which were overgeneralized and harder to extinguish...

[Schizophrenia and cortical GABA neurotransmission].

Science.gov (United States)

Hashimoto, Takanori; Matsubara, Takuro; Lewis, David A

2010-01-01

Individuals with schizophrenia show disturbances in a number of brain functions that regulate cognitive, affective, motor, and sensory processing. The cognitive deficits associated with dysfunction of the dorsolateral prefrontal cortex result, at least in part, from abnormalities in GABA neurotransmission, as reflected in a specific pattern of altered expression of GABA-related molecules. First, mRNA levels for the 67-kilodalton isoform of glutamic acid decarboxylase (GAD67), an enzyme principally responsible for GABA synthesis, and the GABA membrane transporter GAT1, which regulates the reuptake of synaptically released GABA, are decreased in a subset of GABA neurons. Second, affected GABA neurons include those that express the calcium-binding protein parvalbumin (PV), because PV mRNA levels are decreased in the prefrontal cortex of subjects with schizophrenia and GAD67 mRNA is undetectable in almost half of PV-containing neurons. These changes are accompanied by decreased GAT1 expression in the presynaptic terminals of PV-containing neurons and by increased postsynaptic GABA-A receptor alpha2 subunit expression at the axon initial segments of pyramidal neurons. These findings indicate decreased GABA synthesis/release by PV-containing GABA neurons and compensatory changes at synapses formed by these neurons. Third, another subset of GABA neurons that express the neuropeptide somatostatin (SST) also appear to be affected because their specific markers, SST and neuropeptide Y mRNAs, are decreased in a manner highly correlated with the decreases in GAD67 mRNA. Finally, mRNA levels for GABA-A receptor subunits for synaptic (alpha1 and gamma2) and extra-synaptic (delta) receptors are decreased, indicating alterations in both synaptic and extra-synaptic GABA neurotransmission. Together, this pattern of changes indicates that the altered GABA neurotransmission is specific to PV-containing and SST-containing GABA neuron subsets and involves both synaptic and extra

Iron accumulation in deep cortical layers accounts for MRI signal abnormalities in ALS: correlating 7 tesla MRI and pathology.

Directory of Open Access Journals (Sweden)

Justin Y Kwan

Full Text Available Amyotrophic lateral sclerosis (ALS is a progressive neurodegenerative disorder characterized by cortical and spinal motor neuron dysfunction. Routine magnetic resonance imaging (MRI studies have previously shown hypointense signal in the motor cortex on T(2-weighted images in some ALS patients, however, the cause of this finding is unknown. To investigate the utility of this MR signal change as a marker of cortical motor neuron degeneration, signal abnormalities on 3T and 7T MR images of the brain were compared, and pathology was obtained in two ALS patients to determine the origin of the motor cortex hypointensity. Nineteen patients with clinically probable or definite ALS by El Escorial criteria and 19 healthy controls underwent 3T MRI. A 7T MRI scan was carried out on five ALS patients who had motor cortex hypointensity on the 3T FLAIR sequence and on three healthy controls. Postmortem 7T MRI of the brain was performed in one ALS patient and histological studies of the brains and spinal cords were obtained post-mortem in two patients. The motor cortex hypointensity on 3T FLAIR images was present in greater frequency in ALS patients. Increased hypointensity correlated with greater severity of upper motor neuron impairment. Analysis of 7T T(2(*-weighted gradient echo imaging localized the signal alteration to the deeper layers of the motor cortex in both ALS patients. Pathological studies showed increased iron accumulation in microglial cells in areas corresponding to the location of the signal changes on the 3T and 7T MRI of the motor cortex. These findings indicate that the motor cortex hypointensity on 3T MRI FLAIR images in ALS is due to increased iron accumulation by microglia.

The diagnosis of renal perfusion abnormalities by sequential CT

International Nuclear Information System (INIS)

Treugut, H.; Andersson, I.; Hildell, J.; Nyman, U.; Weibull, H.

1981-01-01

Abnormalities of renal perfusion can be recognised more readily by sequential CT than by plain CT scan or after static enhancement with contrast medium. Haemodynamically significant stenoses of the renal arteries and total, or partial, infarcts can be diagnosed in this way. Intrarenal and capsular collaterals can be recognised by slow contrast accumulation in the infarcted area, or by the development of contrast in the sub-capsular portion of the cortex. Renal cortical necrosis is very well demonstrated by the absence of cortical perfusion; this is seen, for instance, in the DIC syndrome or during rejection after renal transplant. (orig.) [de

Neural Correlates of Indicators of Sound Change in Cantonese: Evidence from Cortical and Subcortical Processes.

Science.gov (United States)

Maggu, Akshay R; Liu, Fang; Antoniou, Mark; Wong, Patrick C M

2016-01-01

Across time, languages undergo changes in phonetic, syntactic, and semantic dimensions. Social, cognitive, and cultural factors contribute to sound change, a phenomenon in which the phonetics of a language undergo changes over time. Individuals who misperceive and produce speech in a slightly divergent manner (called innovators ) contribute to variability in the society, eventually leading to sound change. However, the cause of variability in these individuals is still unknown. In this study, we examined whether such misperceptions are represented in neural processes of the auditory system. We investigated behavioral, subcortical (via FFR), and cortical (via P300) manifestations of sound change processing in Cantonese, a Chinese language in which several lexical tones are merging. Across the merging categories, we observed a similar gradation of speech perception abilities in both behavior and the brain (subcortical and cortical processes). Further, we also found that behavioral evidence of tone merging correlated with subjects' encoding at the subcortical and cortical levels. These findings indicate that tone-merger categories, that are indicators of sound change in Cantonese, are represented neurophysiologically with high fidelity. Using our results, we speculate that innovators encode speech in a slightly deviant neurophysiological manner, and thus produce speech divergently that eventually spreads across the community and contributes to sound change.

Functional neuroimaging abnormalities in idiopathic generalized epilepsy

Directory of Open Access Journals (Sweden)

Megan L. McGill

2014-01-01

Full Text Available Magnetic resonance imaging (MRI techniques have been used to quantitatively assess focal and network abnormalities. Idiopathic generalized epilepsy (IGE is characterized by bilateral synchronous spike–wave discharges on electroencephalography (EEG but normal clinical MRI. Dysfunctions involving the neocortex, particularly the prefrontal cortex, and thalamus likely contribute to seizure activity. To identify possible morphometric and functional differences in the brains of IGE patients and normal controls, we employed measures of thalamic volumes, cortical thickness, gray–white blurring, fractional anisotropy (FA measures from diffusion tensor imaging (DTI and fractional amplitude of low frequency fluctuations (fALFF in thalamic subregions from resting state functional MRI. Data from 27 patients with IGE and 27 age- and sex-matched controls showed similar thalamic volumes, cortical thickness and gray–white contrast. There were no differences in FA values on DTI in tracts connecting the thalamus and prefrontal cortex. Functional analysis revealed decreased fALFF in the prefrontal cortex (PFC subregion of the thalamus in patients with IGE. We provide minimum detectable effect sizes for each measure used in the study. Our analysis indicates that fMRI-based methods are more sensitive than quantitative structural techniques for characterizing brain abnormalities in IGE.

Cortical cholinergic innervation: Distribution and source in monkeys

International Nuclear Information System (INIS)

Struble, R.G.; Cork, L.C.; Coyle, J.T.; Lehmann, J.; Mitchell, S.J.; Price, D.L.

1986-01-01

In Alzheimer's disease (AD) and its late-life variant, senile dementia of the Alzheimer's type (SDAT), the predominant neurochemical abnormalities are marked decrements in the activities of ChAT and AChE, the high affinity uptake of tritium-choline, and synthesis of acetylcholine. Two studies are undertaken to delineate more clearly the variability of cortical cholinergic innervation and the contribution of the Ch system, particularly the Ch4, to this cholinergic innervation. In the first study, ChAT activity was assessed in multiple samples of neocortex from seven normal cynomolgus monkeys. In the second study, the nbM was lesioned in order to determine the contribution of the Ch system to cortical cholinergic innervation

Sensory migraine aura is not associated with structural grey matter abnormalities

DEFF Research Database (Denmark)

Hougaard, Anders; Amin, Faisal Mohammad; Arngrim, Nanna

2016-01-01

Migraine with aura (MA) is characterized by cortical dysfunction. Frequent aura attacks may alter cerebral cortical structure in patients, or structural grey matter abnormalities may predispose MA patients to aura attacks. In the present study we aimed to investigate cerebral grey matter structure...... sensory aura regularly. We analysed high-resolution structural MR images using two complimentary approaches and compared patients with and without sensory aura. Patients were also compared to controls. We found no differences of grey matter density or cortical thickness between patients with and without...... sensory aura and no differences for the cortical visual areas between patients and controls. The somatosensory cortex was thinner in patients (1.92 mm vs. 1.96 mm, P = 0.043) and the anterior cingulate cortex of patients had a decreased grey matter density (P = 0.039) compared to controls...

A family affair: brain abnormalities in siblings of patients with schizophrenia

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Hulshoff Pol, Hilleke; Gogtay, Nitin

2013-01-01

Schizophrenia is a severe mental disorder that has a strong genetic basis. Converging evidence suggests that schizophrenia is a progressive neurodevelopmental disorder, with earlier onset cases resulting in more profound brain abnormalities. Siblings of patients with schizophrenia provide an invaluable resource for differentiating between trait and state markers, thus highlighting possible endophenotypes for ongoing research. However, findings from sibling studies have not been systematically put together in a coherent story across the broader age span. We review here the cortical grey matter abnormalities in siblings of patients with schizophrenia from childhood to adulthood, by reviewing sibling studies from both childhood-onset schizophrenia, and the more common adult-onset schizophrenia. When reviewed together, studies suggest that siblings of patients with schizophrenia display significant brain abnormalities that highlight both similarities and differences between the adult and childhood populations, with shared developmental risk patterns, and segregating trajectories. Based on current research it appears that the cortical grey matter abnormalities in siblings are likely to be an age-dependent endophenotype, which normalize by the typical age of onset of schizophrenia unless there has been more genetic or symptom burdening. With increased genetic burdening (e.g. discordant twins of patients) the grey matter abnormalities in (twin) siblings are progressive in adulthood. This synthesis of the literature clarifies the importance of brain plasticity in the pathophysiology of the illness, indicating that probands may lack protective factors critical for healthy development. PMID:23698280

Altered cortical anatomical networks in temporal lobe epilepsy

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Lv, Bin; He, Huiguang; Lu, Jingjing; Li, Wenjing; Dai, Dai; Li, Meng; Jin, Zhengyu

2011-03-01

Temporal lobe epilepsy (TLE) is one of the most common epilepsy syndromes with focal seizures generated in the left or right temporal lobes. With the magnetic resonance imaging (MRI), many evidences have demonstrated that the abnormalities in hippocampal volume and the distributed atrophies in cortical cortex. However, few studies have investigated if TLE patients have the alternation in the structural networks. In the present study, we used the cortical thickness to establish the morphological connectivity networks, and investigated the network properties using the graph theoretical methods. We found that all the morphological networks exhibited the small-world efficiency in left TLE, right TLE and normal groups. And the betweenness centrality analysis revealed that there were statistical inter-group differences in the right uncus region. Since the right uncus located at the right temporal lobe, these preliminary evidences may suggest that there are topological alternations of the cortical anatomical networks in TLE, especially for the right TLE.

Human cerebral cortices: signal variation on diffusion-weighted MR imaging

Energy Technology Data Exchange (ETDEWEB)

Asao, Chiaki [Kumamoto Regional Medical Center, Department of Radiology, Kumamoto (Japan); National Hospital Organization Kumamoto Medical Center, Department of Radiology, Kumamoto (Japan); Hirai, Toshinori; Yamashita, Yasuyuki [Kumamoto University Graduate School of Medical Sciences, Department of Diagnostic Radiology, Kumamoto (Japan); Yoshimatsu, Shunji [National Hospital Organization Kumamoto Medical Center, Department of Radiology, Kumamoto (Japan); Matsukawa, Tetsuya; Imuta, Masanori [Kumamoto Regional Medical Center, Department of Radiology, Kumamoto (Japan); Sagara, Katsuro [Kumamoto Regional Medical Center, Department of Internal Medicine, Kumamoto (Japan)

2008-03-15

We have often encountered high signal intensity (SI) of the cingulate gyrus and insula during diffusion-weighted magnetic resonance imaging (DW-MRI) on neurologically healthy adults. To date, cortical signal heterogeneity on DW images has not been investigated systematically. The purpose of our study was to determine whether there is regional signal variation in the brain cortices of neurologically healthy adults on DW-MR images. The SI of the cerebral cortices on DW-MR images at 1.5 T was evaluated in 50 neurologically healthy subjects (34 men, 16 women; age range 33-84 years; mean age 57.6 years). The cortical SI in the cingulate gyrus, insula, and temporal, occipital, and parietal lobes was graded relative to the SI of the frontal lobe. Contrast-to-noise ratios (CNRs) on DW-MR images were compared for each cortical area. Diffusion changes were analyzed by visually assessment of the differences in appearance among the cortices on apparent diffusion coefficient (ADC) maps. Increased SI was frequently seen in the cingulate gyrus and insula regardless of patient age. There were no significant gender- or laterality-related differences. The CNR was significantly higher in the cingulate gyrus and insula than in the other cortices (p <.01), and significant differences existed among the cortical regions (p <.001). There were no apparent ADC differences among the cortices on ADC maps. Regional signal variation of the brain cortices was observed on DW-MR images of healthy subjects, and the cingulate gyrus and insula frequently manifested high SI. These findings may help in the recognition of cortical signal abnormalities as visualized on DW-MR images. (orig.)

Human cerebral cortices: signal variation on diffusion-weighted MR imaging

International Nuclear Information System (INIS)

Asao, Chiaki; Hirai, Toshinori; Yamashita, Yasuyuki; Yoshimatsu, Shunji; Matsukawa, Tetsuya; Imuta, Masanori; Sagara, Katsuro

2008-01-01

We have often encountered high signal intensity (SI) of the cingulate gyrus and insula during diffusion-weighted magnetic resonance imaging (DW-MRI) on neurologically healthy adults. To date, cortical signal heterogeneity on DW images has not been investigated systematically. The purpose of our study was to determine whether there is regional signal variation in the brain cortices of neurologically healthy adults on DW-MR images. The SI of the cerebral cortices on DW-MR images at 1.5 T was evaluated in 50 neurologically healthy subjects (34 men, 16 women; age range 33-84 years; mean age 57.6 years). The cortical SI in the cingulate gyrus, insula, and temporal, occipital, and parietal lobes was graded relative to the SI of the frontal lobe. Contrast-to-noise ratios (CNRs) on DW-MR images were compared for each cortical area. Diffusion changes were analyzed by visually assessment of the differences in appearance among the cortices on apparent diffusion coefficient (ADC) maps. Increased SI was frequently seen in the cingulate gyrus and insula regardless of patient age. There were no significant gender- or laterality-related differences. The CNR was significantly higher in the cingulate gyrus and insula than in the other cortices (p <.01), and significant differences existed among the cortical regions (p <.001). There were no apparent ADC differences among the cortices on ADC maps. Regional signal variation of the brain cortices was observed on DW-MR images of healthy subjects, and the cingulate gyrus and insula frequently manifested high SI. These findings may help in the recognition of cortical signal abnormalities as visualized on DW-MR images. (orig.)

Congenital brain abnormalities: an update on malformations of cortical development and infratentorial malformations.

Science.gov (United States)

Poretti, Andrea; Boltshauser, Eugen; Huisman, Thierry A G M

2014-07-01

In the past two decades, significant progress in neuroimaging and genetic techniques has allowed for advances in the correct definition/classification of congenital brain abnormalities, which have resulted in a better understanding of their pathogenesis. In addition, new groups of diseases, such as axonal guidance disorders or tubulinopathies, are increasingly reported. Well-defined neuroimaging diagnostic criteria have been suggested for the majority of congenital brain abnormalities. Accurate diagnoses of these complex abnormalities, including distinction between malformations and disruptions, are of paramount significance for management, prognosis, and family counseling. In the next decade, these advances will hopefully be translated into deeper understanding of these disorders and more specific treatments. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The genetic influence on the cortical processing of experimental pain and the moderating effect of pain status.

Directory of Open Access Journals (Sweden)

Helen Vossen

Full Text Available BACKGROUND: Research suggests that the COMT Val(158Met, BDNF Val(66Met and OPRM1 A(118G polymorphisms moderate the experience of pain. In order to obtain experimental confirmation and extension of findings, cortical processing of experimentally-induced pain was used. METHOD: A sample of 78 individuals with chronic low back pain complaints and 37 healthy controls underwent EEG registration. Event-Related Potentials were measured in response to electrical nociceptive stimuli and moderation by COMT Val(158Met, BDNF Val(66Met and OPRM1 A(118G polymorphisms was assessed. RESULTS: Genetic variation did not have a direct effect on cortical processing of experimental pain. However, genetic effects (COMT Val(158Met and BDNF Val(66Met on experimental pain were moderated by the presence of chronic pain. In the presence of chronic pain, the COMT Met allele and the BDNF Met allele augmented cortical pain processing, whilst reducing pain processing in pain-free controls. No significant effects were found concerning the OPRM1 A(118G polymorphism. CONCLUSIONS: The current study suggests that chronic experience of pain enhances genetic sensitivity to experimentally induced mildly painful stimuli, possibly through a process of epigenetic modification.

Mapping cortical mesoscopic networks of single spiking cortical or sub-cortical neurons.

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Xiao, Dongsheng; Vanni, Matthieu P; Mitelut, Catalin C; Chan, Allen W; LeDue, Jeffrey M; Xie, Yicheng; Chen, Andrew Cn; Swindale, Nicholas V; Murphy, Timothy H

2017-02-04

Understanding the basis of brain function requires knowledge of cortical operations over wide-spatial scales, but also within the context of single neurons. In vivo, wide-field GCaMP imaging and sub-cortical/cortical cellular electrophysiology were used in mice to investigate relationships between spontaneous single neuron spiking and mesoscopic cortical activity. We make use of a rich set of cortical activity motifs that are present in spontaneous activity in anesthetized and awake animals. A mesoscale spike-triggered averaging procedure allowed the identification of motifs that are preferentially linked to individual spiking neurons by employing genetically targeted indicators of neuronal activity. Thalamic neurons predicted and reported specific cycles of wide-scale cortical inhibition/excitation. In contrast, spike-triggered maps derived from single cortical neurons yielded spatio-temporal maps expected for regional cortical consensus function. This approach can define network relationships between any point source of neuronal spiking and mesoscale cortical maps.

System for detecting and processing abnormality in electromagnetic shielding

International Nuclear Information System (INIS)

Takahashi, T.; Nakamura, M.; Yabana, Y.; Ishikawa, T.; Nagata, K.

1991-01-01

The present invention relates to a system for detecting and processing an abnormality in electromagnetic shielding of an intelligent building which is constructed using an electromagnetic shielding material for the skeleton and openings such as windows and doorways so that the whole of the building is formed into an electromagnetic shielding structure. (author). 4 figs

Dampened hippocampal oscillations and enhanced spindle activity in an asymptomatic model of developmental cortical malformations

Directory of Open Access Journals (Sweden)

Elena eCid

2014-04-01

Full Text Available Developmental cortical malformations comprise a large spectrum of histopathological brain abnormalities and syndromes. Their genetic, developmental and clinical complexity suggests they should be better understood in terms of the complementary action of independently timed perturbations (i.e. the multiple-hit hypothesis. However, understanding the underlying biological processes remains puzzling. Here we induced developmental cortical malformations in offspring, after intraventricular injection of methylazoxymethanol (MAM in utero in mice. We combined extensive histological and electrophysiological studies to characterize the model. We found that MAM injections at E14 and E15 induced a range of cortical and hippocampal malformations resembling histological alterations of specific genetic mutations and transplacental mitotoxic agent injections. However, in contrast to most of these models, intraventricularly MAM-injected mice remained asymptomatic and showed no clear epilepsy-related phenotype as tested in long-term chronic recordings and with pharmacological manipulations. Instead, they exhibited a non-specific reduction of hippocampal-related brain oscillations (mostly in CA1; including theta, gamma and HFOs; and enhanced thalamocortical spindle activity during non-REM sleep. These data suggest that developmental cortical malformations do not necessarily correlate with epileptiform activity. We propose that the intraventricular in utero MAM approach exhibiting a range of rhythmopathies is a suitable model for multiple-hit studies of associated neurological disorders.

Qualia could arise from information processing in local cortical networks.

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Orpwood, Roger

2013-01-01

Re-entrant feedback, either within sensory cortex or arising from prefrontal areas, has been strongly linked to the emergence of consciousness, both in theoretical and experimental work. This idea, together with evidence for local micro-consciousness, suggests the generation of qualia could in some way result from local network activity under re-entrant activation. This paper explores the possibility by examining the processing of information by local cortical networks. It highlights the difference between the information structure (how the information is physically embodied), and the information message (what the information is about). It focuses on the network's ability to recognize information structures amongst its inputs under conditions of extensive local feedback, and to then assign information messages to those structures. It is shown that if the re-entrant feedback enables the network to achieve an attractor state, then the message assigned in any given pass of information through the network is a representation of the message assigned in the previous pass-through of information. Based on this ability the paper argues that as information is repeatedly cycled through the network, the information message that is assigned evolves from a recognition of what the input structure is, to what it is like, to how it appears, to how it seems. It could enable individual networks to be the site of qualia generation. The paper goes on to show networks in cortical layers 2/3 and 5a have the connectivity required for the behavior proposed, and reviews some evidence for a link between such local cortical cyclic activity and conscious percepts. It concludes with some predictions based on the theory discussed.

Thickened cortical bones in congenital neutropenia

International Nuclear Information System (INIS)

Boechat, M.I.; Gormley, L.S.; O'Laughlin, B.J.

1987-01-01

Congenital neutropenia is an uncommon entity which may be familial and has a wide spectrum of clinical expression. Three sisters with the severe form of the disease, that suffered from recurrent infections which lead to their demise are described. Review of their radiographs revealed the presence of cortical thickening of the bones. Although several syndroms with different bone abnormalities have been reported associated with neutropenia, the radiographic finding of thickened cortex in children with congenital neutropenia has not been previously described. (orig.)

Thickened cortical bones in congenital neutropenia

Energy Technology Data Exchange (ETDEWEB)

Boechat, M.I.; Gormley, L.S.; O' Laughlin, B.J.

1987-02-01

Congenital neutropenia is an uncommon entity which may be familial and has a wide spectrum of clinical expression. Three sisters with the severe form of the disease, that suffered from recurrent infections which lead to their demise are described. Review of their radiographs revealed the presence of cortical thickening of the bones. Although several syndroms with different bone abnormalities have been reported associated with neutropenia, the radiographic finding of thickened cortex in children with congenital neutropenia has not been previously described.

Evidence of functional connectivity between auditory cortical areas revealed by amplitude modulation sound processing.

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Guéguin, Marie; Le Bouquin-Jeannès, Régine; Faucon, Gérard; Chauvel, Patrick; Liégeois-Chauvel, Catherine

2007-02-01

The human auditory cortex includes several interconnected areas. A better understanding of the mechanisms involved in auditory cortical functions requires a detailed knowledge of neuronal connectivity between functional cortical regions. In human, it is difficult to track in vivo neuronal connectivity. We investigated the interarea connection in vivo in the auditory cortex using a method of directed coherence (DCOH) applied to depth auditory evoked potentials (AEPs). This paper presents simultaneous AEPs recordings from insular gyrus (IG), primary and secondary cortices (Heschl's gyrus and planum temporale), and associative areas (Brodmann area [BA] 22) with multilead intracerebral electrodes in response to sinusoidal modulated white noises in 4 epileptic patients who underwent invasive monitoring with depth electrodes for epilepsy surgery. DCOH allowed estimation of the causality between 2 signals recorded from different cortical sites. The results showed 1) a predominant auditory stream within the primary auditory cortex from the most medial region to the most lateral one whatever the modulation frequency, 2) unidirectional functional connection from the primary to secondary auditory cortex, 3) a major auditory propagation from the posterior areas to the anterior ones, particularly at 8, 16, and 32 Hz, and 4) a particular role of Heschl's sulcus dispatching information to the different auditory areas. These findings suggest that cortical processing of auditory information is performed in serial and parallel streams. Our data showed that the auditory propagation could not be associated to a unidirectional traveling wave but to a constant interaction between these areas that could reflect the large adaptive and plastic capacities of auditory cortex. The role of the IG is discussed.

Relationship between higher cortical dysfunction and the findings of magnetic resonance imaging in systemic lupus erythematosus

Energy Technology Data Exchange (ETDEWEB)

Maeshima, Etsuko; Maeshima, Shinichiro; Yamada, Yoichi; Yukawa, Susumu [Wakayama Medical Coll. (Japan)

1996-04-01

The relationship between systemic lupus erythematosus (SLE) and organic lesions was investigated by magnetic resonance imaging (MRI) to clarify the etiology of higher cortical dysfunction in SLE. The subjects were 10 patients with SLE, and higher cortical dysfunction was observed in 8 (80%) of the 10 patients. Five (82.5%) of the 8 patients showed abnormal MRI findings. The findings of higher cortical dysfunction were consistent with the MRI findings in 1 of the 5 patients, but not in the remaining four. MRI revealed no lesion despite the presence of higher cortical dysfunction in three patients. These results suggest that the association of organic changes and functional changes in cerebral nerve cells is important for etiology of higher cortical dysfunction in SLE. (author).

Relationship between higher cortical dysfunction and the findings of magnetic resonance imaging in systemic lupus erythematosus

International Nuclear Information System (INIS)

Maeshima, Etsuko; Maeshima, Shinichiro; Yamada, Yoichi; Yukawa, Susumu

1996-01-01

The relationship between systemic lupus erythematosus (SLE) and organic lesions was investigated by magnetic resonance imaging (MRI) to clarify the etiology of higher cortical dysfunction in SLE. The subjects were 10 patients with SLE, and higher cortical dysfunction was observed in 8 (80%) of the 10 patients. Five (82.5%) of the 8 patients showed abnormal MRI findings. The findings of higher cortical dysfunction were consistent with the MRI findings in 1 of the 5 patients, but not in the remaining four. MRI revealed no lesion despite the presence of higher cortical dysfunction in three patients. These results suggest that the association of organic changes and functional changes in cerebral nerve cells is important for etiology of higher cortical dysfunction in SLE. (author)

Frontal and superior temporal auditory processing abnormalities in schizophrenia.

Science.gov (United States)

Chen, Yu-Han; Edgar, J Christopher; Huang, Mingxiong; Hunter, Michael A; Epstein, Emerson; Howell, Breannan; Lu, Brett Y; Bustillo, Juan; Miller, Gregory A; Cañive, José M

2013-01-01

Although magnetoencephalography (MEG) studies show superior temporal gyrus (STG) auditory processing abnormalities in schizophrenia at 50 and 100 ms, EEG and corticography studies suggest involvement of additional brain areas (e.g., frontal areas) during this interval. Study goals were to identify 30 to 130 ms auditory encoding processes in schizophrenia (SZ) and healthy controls (HC) and group differences throughout the cortex. The standard paired-click task was administered to 19 SZ and 21 HC subjects during MEG recording. Vector-based Spatial-temporal Analysis using L1-minimum-norm (VESTAL) provided 4D maps of activity from 30 to 130 ms. Within-group t-tests compared post-stimulus 50 ms and 100 ms activity to baseline. Between-group t-tests examined 50 and 100 ms group differences. Bilateral 50 and 100 ms STG activity was observed in both groups. HC had stronger bilateral 50 and 100 ms STG activity than SZ. In addition to the STG group difference, non-STG activity was also observed in both groups. For example, whereas HC had stronger left and right inferior frontal gyrus activity than SZ, SZ had stronger right superior frontal gyrus and left supramarginal gyrus activity than HC. Less STG activity was observed in SZ than HC, indicating encoding problems in SZ. Yet auditory encoding abnormalities are not specific to STG, as group differences were observed in frontal and SMG areas. Thus, present findings indicate that individuals with SZ show abnormalities in multiple nodes of a concurrently activated auditory network.

The relationship of impulsivity and cortical thickness in depressed and non-depressed adolescents.

Science.gov (United States)

Fradkin, Yuli; Khadka, Sabin; Bessette, Katie L; Stevens, Michael C

2017-10-01

Major Depressive Disorder (MDD) is recognized to be heterogeneous in terms of brain structure abnormality findings across studies, which might reflect previously unstudied traits that confer variability to neuroimaging measurements. The purpose of this study was to examine the relationships between different types of trait impulsivity and MDD diagnosis on adolescent brain structure. We predicted that adolescents with depression who were high on trait impulsivity would have more abnormal cortical structure than depressed patients or non-MDD who were low on impulsivity. We recruited 58 subjects, including 29 adolescents (ages 12-19) with a primary DSM-IV diagnosis of MDD and a history of suicide attempt and 29 demographically-matched healthy control participants. Our GLM-based analyses sought to describe differences in the linear relationships between cortical thickness and impulsivity trait levels. As hypothesized, we found significant moderation effects in rostral middle frontal gyrus and right paracentral lobule cortical thickness for different subscales of the Barratt Impulsiveness Scale. However, although these brain-behavior relationships differed between diagnostic study groups, they were not simple additive effects as we had predicted. For the middle frontal gyrus, non-MDD participants showed a strong positive association between cortical thickness and BIS-11 Motor scores, while MDD-diagnosed participants showed a negative association. For Non-Planning Impulsiveness, paracentral lobule cortical thickness was observed with greater impulsivity in MDD, but no association was found for controls. In conclusion, the findings confirm that dimensions of impulsivity have discrete neural correlates, and show that relationships between impulsivity and brain structure are expressed differently in adolescents with MDD compared to non-MDD.

Persistent renal cortical scintigram defects in children 2 years after urinary tract infection

International Nuclear Information System (INIS)

Ditchfield, Michael R.; Cook, David J.; Campo, John F. de; Grimwood, Keith; Powell, Harley R.; Gulati, Sanjeev; Sloane, Robert

2004-01-01

Background: Renal cortical scintigraphic studies challenge the role of vesicoureteric reflux in renal scar development, emphasizing instead the part played by acute pyelonephritis. Objective: To determine the prevalence of renal cortical defects in a child cohort 2 years after the child's first diagnosed urinary tract infection and to analyze the relationship of these defects with acute illness variables, primary vesicoureteric reflux and recurrent infections. Materials and methods: In a prospective cohort study, 193 children younger than 5 years with their first proven urinary tract infection underwent renal sonography, voiding cystourethrogram, and renal cortical scintigraphy within 15 days of diagnosis. Two years later, 150 of the 193 children, or 77.7%, had a further renal cortical scintigram, including 75, or 86.2%, of the 87 children who had acute scintigraphic defects. The relationship of cortical defects to age, gender, pre-treatment symptom duration, hospitalization, presence and grade of vesicoureteric reflux, and recurrent urinary tract infections was evaluated. Results: Overall, 20 of the 150 (13.3%; 95% confidence interval (CI) 8.3, 19.8) children had persistent defects 2 years after infection. This included 20 of 75 (26.7%; 95% CI 17.1, 38.1) with initially abnormal scintigrams. No new defects were detected. Although acute defects were more common in the young, those with persistent defects were older (median ages 16.4 vs. 6.8 months, P=0.004) than those with transient abnormalities. After adjustment for age, persistent defects were no longer associated with gender and were not predicted by acute illness variables, primary vesicoureteric reflux or recurrent infections. (orig.)

Tensor-based cortical surface morphometry via weighted spherical harmonic representation.

Science.gov (United States)

Chung, Moo K; Dalton, Kim M; Davidson, Richard J

2008-08-01

We present a new tensor-based morphometric framework that quantifies cortical shape variations using a local area element. The local area element is computed from the Riemannian metric tensors, which are obtained from the smooth functional parametrization of a cortical mesh. For the smooth parametrization, we have developed a novel weighted spherical harmonic (SPHARM) representation, which generalizes the traditional SPHARM as a special case. For a specific choice of weights, the weighted-SPHARM is shown to be the least squares approximation to the solution of an isotropic heat diffusion on a unit sphere. The main aims of this paper are to present the weighted-SPHARM and to show how it can be used in the tensor-based morphometry. As an illustration, the methodology has been applied in the problem of detecting abnormal cortical regions in the group of high functioning autistic subjects.

Congenital visual pathway abnormalities : A window onto cortical stability and plasticity

NARCIS (Netherlands)

Hoffmann, Michael B.; Dumoulin, Serge O.

2015-01-01

Sensory systems project information in a highly organized manner to the brain, where it is preserved in maps of the sensory structures. These sensory projections are altered in congenital abnormalities, such as anophthalmia, albinism, achiasma, and hemihydranencephaly. Consequently, these

Basic visual function and cortical thickness patterns in posterior cortical atrophy.

Science.gov (United States)

Lehmann, Manja; Barnes, Josephine; Ridgway, Gerard R; Wattam-Bell, John; Warrington, Elizabeth K; Fox, Nick C; Crutch, Sebastian J

2011-09-01

Posterior cortical atrophy (PCA) is characterized by a progressive decline in higher-visual object and space processing, but the extent to which these deficits are underpinned by basic visual impairments is unknown. This study aimed to assess basic and higher-order visual deficits in 21 PCA patients. Basic visual skills including form detection and discrimination, color discrimination, motion coherence, and point localization were measured, and associations and dissociations between specific basic visual functions and measures of higher-order object and space perception were identified. All participants showed impairment in at least one aspect of basic visual processing. However, a number of dissociations between basic visual skills indicated a heterogeneous pattern of visual impairment among the PCA patients. Furthermore, basic visual impairments were associated with particular higher-order object and space perception deficits, but not with nonvisual parietal tasks, suggesting the specific involvement of visual networks in PCA. Cortical thickness analysis revealed trends toward lower cortical thickness in occipitotemporal (ventral) and occipitoparietal (dorsal) regions in patients with visuoperceptual and visuospatial deficits, respectively. However, there was also a lot of overlap in their patterns of cortical thinning. These findings suggest that different presentations of PCA represent points in a continuum of phenotypical variation.

Reversal of brain metabolic abnormalities following treatment of AIDS dementia complex with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine): a PET-FDG study

International Nuclear Information System (INIS)

Brunetti, A.; Berg, G.; Di Chiro, G.

1989-01-01

Brain glucose metabolism was evaluated in four patients with acquired immunodeficiency syndrome (AIDS) dementia complex using [ 18 F]fluorodeoxyglucose (FDG) and positron emission tomography (PET) scans at the beginning of therapy with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine), and later in the course of therapy. In two patients, baseline, large focal cortical abnormalities of glucose utilization were reversed during the course of therapy. In the other two patients, the initial PET study did not reveal pronounced focal alterations, while the post-treatment scans showed markedly increased cortical glucose metabolism. The improved cortical glucose utilization was accompanied in all patients by immunologic and neurologic improvement. PET-FDG studies can detect cortical metabolic abnormalities associated with AIDS dementia complex, and may be used to monitor the metabolic improvement in response to AZT treatment

Frontopolar cortical inefficiency may underpin reward and working memory dysfunction in bipolar disorder.

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Jogia, Jigar; Dima, Danai; Kumari, Veena; Frangou, Sophia

2012-12-01

Emotional dysregulation in bipolar disorder is thought to arise from dysfunction within prefrontal cortical regions involved in cognitive control coupled with increased or aberrant activation within regions engaged in emotional processing. The aim of this study was to determine the common and distinct patterns of functional brain abnormalities during reward and working memory processing in patients with bipolar disorder. Participants were 36 euthymic bipolar disorder patients and 37 healthy comparison subjects matched for age, sex and IQ. Functional magnetic resonance imaging (fMRI) was conducted during the Iowa Gambling Task (IGT) and the n-back working memory task. During both tasks, patients with bipolar disorder demonstrated a pattern of inefficient engagement within the ventral frontopolar prefrontal cortex with evidence of segregation along the medial-lateral dimension for reward and working memory processing, respectively. Moreover, patients also showed greater activation in the anterior cingulate cortex during the Iowa Gambling Task and in the insula during the n-back task. Our data implicate ventral frontopolar dysfunction as a core abnormality underpinning bipolar disorder and confirm that overactivation in regions involved in emotional arousal is present even in tasks that do not typically engage emotional systems.

Repair of Neocortex in a Model of Cortical Dysplasia

Science.gov (United States)

2007-03-27

as dyslexia, intractable epilepsy, and schizophrenia which has been linked to abnormal reelin expression (Grayson et al., 2005; Brigman et al., 2006...exposure to ethanol on glutamate and GABA immunoreactivity in macaque somatosensory and motor cortices: critical timing of exposure. Neuroscience...Rothblat LA (2006) Executive functions in the heterozygous reeler mouse model of schizophrenia . Behav Neurosci 120:984-988. Caldwell MA, He X

An optimized process flow for rapid segmentation of cortical bones of the craniofacial skeleton using the level-set method.

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Szwedowski, T D; Fialkov, J; Pakdel, A; Whyne, C M

2013-01-01

Accurate representation of skeletal structures is essential for quantifying structural integrity, for developing accurate models, for improving patient-specific implant design and in image-guided surgery applications. The complex morphology of thin cortical structures of the craniofacial skeleton (CFS) represents a significant challenge with respect to accurate bony segmentation. This technical study presents optimized processing steps to segment the three-dimensional (3D) geometry of thin cortical bone structures from CT images. In this procedure, anoisotropic filtering and a connected components scheme were utilized to isolate and enhance the internal boundaries between craniofacial cortical and trabecular bone. Subsequently, the shell-like nature of cortical bone was exploited using boundary-tracking level-set methods with optimized parameters determined from large-scale sensitivity analysis. The process was applied to clinical CT images acquired from two cadaveric CFSs. The accuracy of the automated segmentations was determined based on their volumetric concurrencies with visually optimized manual segmentations, without statistical appraisal. The full CFSs demonstrated volumetric concurrencies of 0.904 and 0.719; accuracy increased to concurrencies of 0.936 and 0.846 when considering only the maxillary region. The highly automated approach presented here is able to segment the cortical shell and trabecular boundaries of the CFS in clinical CT images. The results indicate that initial scan resolution and cortical-trabecular bone contrast may impact performance. Future application of these steps to larger data sets will enable the determination of the method's sensitivity to differences in image quality and CFS morphology.

The micro-damage process zone during transverse cortical bone fracture: No ears at crack growth initiation.

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Willett, Thomas; Josey, David; Lu, Rick Xing Ze; Minhas, Gagan; Montesano, John

2017-10-01

Apply high-resolution benchtop micro-computed tomography (micro-CT) to gain greater understanding and knowledge of the formation of the micro-damage process zone formed during traverse fracture of cortical bone. Bovine cortical bone was cut into single edge notch (bending) fracture testing specimens with the crack on the transverse plane and oriented to grow in the circumferential direction. We used a multi-specimen technique and deformed the specimens to various individual secant modulus loss levels (P-values) up to and including maximum load (Pmax). Next, the specimens were infiltrated with a BaSO 4 precipitation stain and scanned at 3.57-μm isotropic voxel size using a benchtop high resolution-micro-CT. Measurements of the micro-damage process zone volume, width and height were made. These were compared with the simple Irwin's process zone model and with finite element models. Electron and confocal microscopy confirmed the formation of BaSO 4 precipitate in micro-cracks and other porosity, and an interesting novel mechanism similar to tunneling. Measurable micro-damage was detected at low P values and the volume of the process zone increased according to a second order polynomial trend. Both width and height grew linearly up to Pmax, at which point the process zone cross-section (perpendicular to the plane of the crack) was almost circular on average with a radius of approximately 550µm (approximately one quarter of the unbroken ligament thickness) and corresponding to the shape expected for a biological composite under plane stress conditions. This study reports details of the micro-damage fracture process zone previously unreported for cortical bone. High-resolution micro-CT enables 3D visualization and measurement of the process zone and confirmation that the crack front edge and process zone are affected by microstructure. It is clear that the process zone for the specimens studied grows to be meaningfully large, confirming the need for the J

Abnormal lateralization of fine motor actions in Tourette syndrome persists into adulthood.

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D Martino

Full Text Available Youth with Tourette syndrome (TS exhibit, compared to healthy, abnormal ability to lateralize digital sequential tasks. It is unknown whether this trait is related to inter-hemispheric connections, and whether it is preserved or lost in patients with TS persisting through adult life. We studied 13 adult TS patients and 15 age-matched healthy volunteers. All participants undertook: 1 a finger opposition task, performed with the right hand (RH only or with both hands, using a sensor-engineered glove in synchrony with a metronome at 2 Hz; we calculated a lateralization index [(single RH-bimanual RH/single RH X 100 for percentage of correct movements (%CORR; 2 MRI-based diffusion tensor imaging and probabilistic tractography of inter-hemispheric corpus callosum (CC connections between supplementary motor areas (SMA and primary motor cortices (M1. We confirmed a significant increase in the %CORR in RH in the bimanual vs. single task in TS patients (p<0.001, coupled to an abnormal ability to lateralize finger movements (significantly lower lateralization index for %CORR in TS patients, p = 0.04. The %CORR lateralization index correlated positively with tic severity measured with the Yale Global Tic Severity Scale (R = 0.55;p = 0.04. We detected a significantly higher fractional anisotropy (FA in both the M1-M1 (p = 0.036 and the SMA-SMA (p = 0.018 callosal fibre tracts in TS patients. In healthy subjects, the %CORR lateralization index correlated positively with fractional anisotropy of SMA-SMA fibre tracts (R = 0.63, p = 0.02; this correlation was not significant in TS patients. TS patients exhibited an abnormal ability to lateralize finger movements in sequential tasks, which increased in accuracy when the task was performed bimanually. This abnormality persists throughout different age periods and appears dissociated from the transcallosal connectivity of motor cortical regions. The altered interhemispheric transfer of motor abilities in TS may be

Abnormal fetal cerebral laminar organization in cobblestone complex as seen on post-mortem MRI and DTI

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Widjaja, Elysa; Geibprasert, Sasikhan; Blaser, Susan; Rayner, Tammy; Shannon, Patrick

2009-01-01

We report a unique case of cobblestone complex using post-mortem MR and diffusion tensor imaging to assess the laminar organization of the fetal cerebrum. The imaging findings were correlated with autopsy findings. Abnormal cortical development in cobblestone complex resulted in disruption of normal laminar organization of the fetal brain, which was seen as interruption and nodularity of the high-signal T1 cortical band with increased anisotropy and medium diffusivity extending beyond the cortical band into the cerebral mantle on post-mortem MR and diffusion tensor imaging. (orig.)

Abnormal fetal cerebral laminar organization in cobblestone complex as seen on post-mortem MRI and DTI

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Widjaja, Elysa; Geibprasert, Sasikhan; Blaser, Susan; Rayner, Tammy [Hospital for Sick Children, Department of Diagnostic Imaging, Toronto (Canada); Shannon, Patrick [University of Toronto, Department of Pathology, Mount Sinai Hospital, Toronto (Canada)

2009-08-15

We report a unique case of cobblestone complex using post-mortem MR and diffusion tensor imaging to assess the laminar organization of the fetal cerebrum. The imaging findings were correlated with autopsy findings. Abnormal cortical development in cobblestone complex resulted in disruption of normal laminar organization of the fetal brain, which was seen as interruption and nodularity of the high-signal T1 cortical band with increased anisotropy and medium diffusivity extending beyond the cortical band into the cerebral mantle on post-mortem MR and diffusion tensor imaging. (orig.)

Time course of transient cortical scintigraphic defects associated with acute pyelonephritis

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Ditchfield, Michael R.; Summerville, Dianne; Cook, David J.; Campo, John F. de [Department of Radiology, Royal Children' s Hospital, Melbourne 3052 (Australia); Grimwood, Keith; Nolan, Terrance M. [Department of General Paediatrics, Royal Children' s Hospital, Melbourne (Australia); Department of Paediatrics, University of Melbourne, Melbourne (Australia); Powell, Harley R. [Department of Nephrology, Royal Children' s Hospital, Melbourne (Australia); Sloane, Robert [Department of General Paediatrics, Royal Children' s Hospital, Melbourne (Australia)

2002-12-01

Acute pyelonephritis is distinguished from renal scarring using repeat cortical scintigraphy. The defects of acute pyelonephritis resolve, while those of scars persist. To determine the duration of reversible cortical defects following acute pyelonephritis and the time interval required to differentiate infection from scars. Materials and methods. An observational prospective study of 193 children (386 kidneys) aged less than 5 years following their first proven urinary tract infection (UTI). Renal cortical scintigraphic defects were detected in 112 (29%) kidneys within 15 days of diagnosis. Of these, 95 underwent repeat renal cortical scans 2 years after the UTI, including 50 with additional scans performed within 2-6 months of infection. Of the 50 kidneys undergoing a second renal cortical scan within 2-6 months of the first UTI, 22 (44%) had persistent defects. A third scan was performed on 17 (77%) kidneys after 2 years, by which time defects had resolved in another 8 (47%) kidneys. The predictive value of defects detected within 2-6 months of UTI representing scars is 53% (95% CI 28, 77). Overall, nine (18%) kidneys with initial renal cortical abnormalities had permanent defects. In the 45 kidneys undergoing a second cortical scan more than 6 months after the UTI, 11 (24%) had persistent defects. None of the 95 kidneys undergoing serial scans developed new or larger defects. Renal scars may not be reliably diagnosed by cortical scintigraphy performed within 6 months of UTI because the inflammatory lesions may not have fully resolved. (orig.)

Time course of transient cortical scintigraphic defects associated with acute pyelonephritis

International Nuclear Information System (INIS)

Ditchfield, Michael R.; Summerville, Dianne; Cook, David J.; Campo, John F. de; Grimwood, Keith; Nolan, Terrance M.; Powell, Harley R.; Sloane, Robert

2002-01-01

Acute pyelonephritis is distinguished from renal scarring using repeat cortical scintigraphy. The defects of acute pyelonephritis resolve, while those of scars persist. To determine the duration of reversible cortical defects following acute pyelonephritis and the time interval required to differentiate infection from scars. Materials and methods. An observational prospective study of 193 children (386 kidneys) aged less than 5 years following their first proven urinary tract infection (UTI). Renal cortical scintigraphic defects were detected in 112 (29%) kidneys within 15 days of diagnosis. Of these, 95 underwent repeat renal cortical scans 2 years after the UTI, including 50 with additional scans performed within 2-6 months of infection. Of the 50 kidneys undergoing a second renal cortical scan within 2-6 months of the first UTI, 22 (44%) had persistent defects. A third scan was performed on 17 (77%) kidneys after 2 years, by which time defects had resolved in another 8 (47%) kidneys. The predictive value of defects detected within 2-6 months of UTI representing scars is 53% (95% CI 28, 77). Overall, nine (18%) kidneys with initial renal cortical abnormalities had permanent defects. In the 45 kidneys undergoing a second cortical scan more than 6 months after the UTI, 11 (24%) had persistent defects. None of the 95 kidneys undergoing serial scans developed new or larger defects. Renal scars may not be reliably diagnosed by cortical scintigraphy performed within 6 months of UTI because the inflammatory lesions may not have fully resolved. (orig.)

Neurochemical abnormalities in brains of renal failure patients treated by repeated hemodialysis.

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Perry, T L; Yong, V W; Kish, S J; Ito, M; Foulks, J G; Godolphin, W J; Sweeney, V P

1985-10-01

We examined autopsied brain from 10 patients with end-stage renal failure who had undergone repeated hemodialysis. Eight had classic symptoms, and two had suggestive symptoms of dialysis encephalopathy. Findings were compared with those in autopsied brain from control adults who had never been hemodialyzed. Mean gamma-aminobutyric acid (GABA) contents were significantly reduced in frontal and occipital cortex, cerebellar cortex, dentate nucleus, caudate nucleus, and medial-dorsal thalamus of the hemodialyzed patients, the reduction being greater than 40% in cerebral cortex and thalamus. Choline acetyltransferase activity was reduced by 25-35% in three cortical regions in the hemodialyzed patients. These two abnormalities were observed in the brain of each hemodialyzed patient, regardless of whether or not the patient died with unequivocal dialysis encephalopathy. Pyridoxal phosphate contents were substantially reduced in brains of the hemodialyzed patients, but metabolites of noradrenaline, 3,4-dihydroxyphenylethylamine (dopamine), and 5-hydroxytryptamine (serotonin) were present in normal amounts. Aluminum levels were abnormally high in frontal cortical gray matter in the hemodialyzed patients. Although this study does not clarify the role played by aluminum toxicity in the pathogenesis of dialysis encephalopathy, the abnormalities we found suggest the need for further neurochemical investigations in this disorder.

Quantitative Folding Pattern Analysis of Early Primary Sulci in Human Fetuses with Brain Abnormalities.

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Im, K; Guimaraes, A; Kim, Y; Cottrill, E; Gagoski, B; Rollins, C; Ortinau, C; Yang, E; Grant, P E

2017-07-01

Aberrant gyral folding is a key feature in the diagnosis of many cerebral malformations. However, in fetal life, it is particularly challenging to confidently diagnose aberrant folding because of the rapid spatiotemporal changes of gyral development. Currently, there is no resource to measure how an individual fetal brain compares with normal spatiotemporal variations. In this study, we assessed the potential for automatic analysis of early sulcal patterns to detect individual fetal brains with cerebral abnormalities. Triplane MR images were aligned to create a motion-corrected volume for each individual fetal brain, and cortical plate surfaces were extracted. Sulcal basins were automatically identified on the cortical plate surface and compared with a combined set generated from 9 normal fetal brain templates. Sulcal pattern similarities to the templates were quantified by using multivariate geometric features and intersulcal relationships for 14 normal fetal brains and 5 fetal brains that were proved to be abnormal on postnatal MR imaging. Results were compared with the gyrification index. Significantly reduced sulcal pattern similarities to normal templates were found in all abnormal individual fetuses compared with normal fetuses (mean similarity [normal, abnormal], left: 0.818, 0.752; P the primary distinguishing features. The gyrification index was not significantly different between the normal and abnormal groups. Automated analysis of interrelated patterning of early primary sulci could outperform the traditional gyrification index and has the potential to quantitatively detect individual fetuses with emerging abnormal sulcal patterns. © 2017 by American Journal of Neuroradiology.

Magnetoencephalographic Imaging of Auditory and Somatosensory Cortical Responses in Children with Autism and Sensory Processing Dysfunction

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Carly Demopoulos

2017-05-01

Full Text Available This study compared magnetoencephalographic (MEG imaging-derived indices of auditory and somatosensory cortical processing in children aged 8–12 years with autism spectrum disorder (ASD; N = 18, those with sensory processing dysfunction (SPD; N = 13 who do not meet ASD criteria, and typically developing control (TDC; N = 19 participants. The magnitude of responses to both auditory and tactile stimulation was comparable across all three groups; however, the M200 latency response from the left auditory cortex was significantly delayed in the ASD group relative to both the TDC and SPD groups, whereas the somatosensory response of the ASD group was only delayed relative to TDC participants. The SPD group did not significantly differ from either group in terms of somatosensory latency, suggesting that participants with SPD may have an intermediate phenotype between ASD and TDC with regard to somatosensory processing. For the ASD group, correlation analyses indicated that the left M200 latency delay was significantly associated with performance on the WISC-IV Verbal Comprehension Index as well as the DSTP Acoustic-Linguistic index. Further, these cortical auditory response delays were not associated with somatosensory cortical response delays or cognitive processing speed in the ASD group, suggesting that auditory delays in ASD are domain specific rather than associated with generalized processing delays. The specificity of these auditory delays to the ASD group, in addition to their correlation with verbal abilities, suggests that auditory sensory dysfunction may be implicated in communication symptoms in ASD, motivating further research aimed at understanding the impact of sensory dysfunction on the developing brain.

Structural Brain Abnormalities of Attention-Deficit/Hyperactivity Disorder With Oppositional Defiant Disorder.

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Noordermeer, Siri D S; Luman, Marjolein; Greven, Corina U; Veroude, Kim; Faraone, Stephen V; Hartman, Catharina A; Hoekstra, Pieter J; Franke, Barbara; Buitelaar, Jan K; Heslenfeld, Dirk J; Oosterlaan, Jaap

2017-11-01

Attention-deficit/hyperactivity disorder (ADHD) is associated with structural abnormalities in total gray matter, basal ganglia, and cerebellum. Findings of structural abnormalities in frontal and temporal lobes, amygdala, and insula are less consistent. Remarkably, the impact of comorbid oppositional defiant disorder (ODD) (comorbidity rates up to 60%) on these neuroanatomical differences is scarcely studied, while ODD (in combination with conduct disorder) has been associated with structural abnormalities of the frontal lobe, amygdala, and insula. The aim of this study was to investigate the effect of comorbid ODD on cerebral volume and cortical thickness in ADHD. Three groups, 16 ± 3.5 years of age (mean ± SD; range 7-29 years), were studied on volumetric and cortical thickness characteristics using structural magnetic resonance imaging (surface-based morphometry): ADHD+ODD (n = 67), ADHD-only (n = 243), and control subjects (n = 233). Analyses included the moderators age, gender, IQ, and scan site. ADHD+ODD and ADHD-only showed volumetric reductions in total gray matter and (mainly) frontal brain areas. Stepwise volumetric reductions (ADHD+ODD attention, (working) memory, and decision-making. Volumetric reductions of frontal lobes were largest in the ADHD+ODD group, possibly underlying observed larger impairments in neurocognitive functions. Previously reported striatal abnormalities in ADHD may be caused by comorbid conduct disorder rather than ODD. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Abnormalities of the axial and proximal appendicular skeleton in adults with Laron syndrome (growth hormone insensitivity).

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Kornreich, L; Konen, O; Schwarz, M; Siegel, Y; Horev, G; Hershkovitz, I; Laron, Z

2008-02-01

To investigate abnormalities in the skeleton (with the exclusion of the skull, cervical spine, hands and feet) in patients with Laron syndrome, who have an inborn growth hormone resistance and congenital insulin-like growth factor-1 (IGF-1) deficiency. The study group was composed of 15 untreated patients with Laron syndrome (seven male and eight female) aged 21-68 years. Plain films of the axial and appendicular skeleton were evaluated retrospectively for abnormalities in structure and shape. The cortical width of the long bones was evaluated qualitatively and quantitatively (in the upper humerus and mid-femur), and the cortical index was calculated and compared with published references. Measurements were taken of the mid-anteroposterior and cranio-caudal diameters of the vertebral body and spinous process at L3, the interpedicular distance at L1 and L5, and the sacral slope. Thoracic and lumbar osteophytes were graded on a 5-point scale. Values were compared with a control group of 20 healthy persons matched for age. The skeleton appeared small in all patients. No signs of osteopenia were visible. The cortex of the long bones appeared thick in the upper limbs in 11 patients and in the lower limbs in four. Compared with the reference values, the cortical width was thicker than average in the humerus and thinner in the femur. The vertebral diameters at L3 and the interpedicular distances at L1 and L5 were significantly smaller in the patients than in the control subjects (PLaron syndrome may be related to a marked retroversion of the humeral head.

Adams Oliver syndrome: Description of a new phenotype with cerebellar abnormalities in a family

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D’Amico, Alessandra; Melis, Daniela; D’Arco, Felice; Di Paolo, Nilde; Carotenuto, Barbara; D’Anna, Gennaro; Russo, Carmela; Boemio, Pasquale; Brunetti, Arturo

2013-01-01

To describe cerebellar abnormalities in a family composed by a father and two affected sibs with Adams Oliver syndrome (AOS) (OMIM 100300). Brain MRI and MR angiography were performed at 1.5T. The siblings presented cerebellar cortex dysplasia characterized by the presence of cysts. Abnormalities of CNS are an unusual manifestation of AOS. To our knowledge, this is the first report of cerebellar cortical dysplasia in a family with AOS

Abnormal processing of deontological guilt in obsessive-compulsive disorder.

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Basile, Barbara; Mancini, Francesco; Macaluso, Emiliano; Caltagirone, Carlo; Bozzali, Marco

2014-07-01

Guilt plays a significant role in the occurrence and maintenance of obsessive-compulsive disorder (OCD). Two major types of guilt have been identified: one deriving from the transgression of a moral rule (deontological guilt DG), another (altruistic guilt AG), relying on the assumption of having compromised a personal altruistic goal. Clinical evidence suggests that OCD patients are particularly sensitive to DG, but not AG. In this functional magnetic resonance imaging (fMRI) study, we investigated brain response of OCD patients while processing DG and AG stimuli. A previously validated fMRI paradigm was used to selectively evoke DG and AG, and anger and sadness, as control emotions in 13 OCD patients and 19 healthy controls. Patients' behavioral results showed a prominent attitude to experience guilt, compared to controls, while accomplishing task. fMRI results revealed that patients have reduced activation in the anterior cingulate (ACC) and frontal gyrus when experiencing guilt, regardless of its specific type (DG or AG). When separately considering each type of guilt (against each of its control), patients showed decreased activation in the ACC, the insula and the precuneus, for DG. No significant differences were observed between groups when processing AG, anger or sad stimuli. This study provides evidence for an abnormal processing of guilt, and specifically DG, in OCD patients. We suggest that decreased activation may reflect patients' cerebral efficiency, which derives from their frequent exposure to guilty feelings ("neural efficiency hypothesis"). In conclusion, our study confirms a selective abnormal processing of guilt, and specifically DG, in OCD.

Postnatal Ablation of Synaptic Retinoic Acid Signaling Impairs Cortical Information Processing and Sensory Discrimination in Mice.

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Park, Esther; Tjia, Michelle; Zuo, Yi; Chen, Lu

2018-06-06

Retinoic acid (RA) and its receptors (RARs) are well established essential transcriptional regulators during embryonic development. Recent findings in cultured neurons identified an independent and critical post-transcriptional role of RA and RARα in the homeostatic regulation of excitatory and inhibitory synaptic transmission in mature neurons. However, the functional relevance of synaptic RA signaling in vivo has not been established. Here, using somatosensory cortex as a model system and the RARα conditional knock-out mouse as a tool, we applied multiple genetic manipulations to delete RARα postnatally in specific populations of cortical neurons, and asked whether synaptic RA signaling observed in cultured neurons is involved in cortical information processing in vivo Indeed, conditional ablation of RARα in mice via a CaMKIIα-Cre or a layer 5-Cre driver line or via somatosensory cortex-specific viral expression of Cre-recombinase impaired whisker-dependent texture discrimination, suggesting a critical requirement of RARα expression in L5 pyramidal neurons of somatosensory cortex for normal tactile sensory processing. Transcranial two-photon imaging revealed a significant increase in dendritic spine elimination on apical dendrites of somatosensory cortical layer 5 pyramidal neurons in these mice. Interestingly, the enhancement of spine elimination is whisker experience-dependent as whisker trimming rescued the spine elimination phenotype. Additionally, experiencing an enriched environment improved texture discrimination in RARα-deficient mice and reduced excessive spine pruning. Thus, RA signaling is essential for normal experience-dependent cortical circuit remodeling and sensory processing. SIGNIFICANCE STATEMENT The importance of synaptic RA signaling has been demonstrated in in vitro studies. However, whether RA signaling mediated by RARα contributes to neural circuit functions in vivo remains largely unknown. In this study, using a RARα conditional

Impaired cortical processing of inspiratory loads in children with chronic respiratory defects

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Clément Annick

2007-09-01

Full Text Available Abstract Background Inspiratory occlusion evoked cortical potentials (the respiratory related-evoked potentials, RREPs bear witness of the processing of changes in respiratory mechanics by the brain. Their impairment in children having suffered near-fatal asthma supports the hypothesis that relates asthma severity with the ability of the patients to perceive respiratory changes. It is not known whether or not chronic respiratory defects are associated with an alteration in brain processing of inspiratory loads. The aim of the present study was to compare the presence, the latencies and the amplitudes of the P1, N1, P2, and N2 components of the RREPs in children with chronic lung or neuromuscular disease. Methods RREPs were recorded in patients with stable asthma (n = 21, cystic fibrosis (n = 32, and neuromuscular disease (n = 16 and in healthy controls (n = 11. Results The 4 RREP components were significantly less frequently observed in the 3 groups of patients than in the controls. Within the patient groups, the N1 and the P2 components were significantly less frequently observed in the patients with asthma (16/21 for both components and cystic fibrosis (20/32 and 14/32 than in the patients with neuromuscular disease (15/16 and 16/16. When present, the latencies and amplitudes of the 4 components were similar in the patients and controls. Conclusion Chronic ventilatory defects in children are associated with an impaired cortical processing of afferent respiratory signals.

Renal cortical involvement in children with first UTI: does it differ in the presence of primary VUR?

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Aktaş, Gül Ege; Inanir, Sabahat; Turoğlu, Halil Turgut

2008-12-01

The aim of this study was to investigate the influence of vesicoureteral reflux (VUR) on dimercaptosuccinic acid (DMSA) scintigraphic patterns in children with first symptomatic urinary tract infection (UTI). A total of 45 children with the diagnosis of first symptomatic UTI (28 girls, 17 boys, mean age 18 months, range 1 month-11 years) were reviewed. All DMSA scans were obtained within 2 months of bacteriologically proven UTI (median 21 days, mean 26 +/- 21, 14). After the exclusion of the patients with bilateral cortical lesions, 82 renal units were analyzed. The scintigraphic patterns included regional and global description of renal cortical abnormality (normal or decreased differential renal function, regional renal function (RRF), and the number and severity of cortical lesions). Vesicoureteral reflux was detected in 26 (32%) renal units (15 with grade 1-2, 11 with grade 3-4). Renal cortical abnormality was observed in 10 renal units without VUR (10/56, 17%) and 13 renal units with VUR (13/26: 50%). Of the 15 renal units, 5 with grade 1-2 VUR (5/15) and 8 of the 11 renal units with grade 3-4 VUR (8/11) had renal cortical involvement. The most common scintigraphic pattern in the patients without VUR was the preserved RRF (>or=45%) and two or fewer photon-deficient areas. On the other hand, a decreased RRF (children with first symptomatic UTI.

Cortical Plasticity Induction by Pairing Subthalamic Nucleus Deep-Brain Stimulation and Primary Motor Cortical Transcranial Magnetic Stimulation in Parkinson's Disease.

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Udupa, Kaviraja; Bahl, Nina; Ni, Zhen; Gunraj, Carolyn; Mazzella, Filomena; Moro, Elena; Hodaie, Mojgan; Lozano, Andres M; Lang, Anthony E; Chen, Robert

2016-01-13

Noninvasive brain stimulation studies have shown abnormal motor cortical plasticity in Parkinson's disease (PD). These studies used peripheral nerve stimulation paired with transcranial magnetic stimulation (TMS) to primary motor cortex (M1) at specific intervals to induce plasticity. Induction of cortical plasticity through stimulation of the basal ganglia (BG)-M1 connections has not been studied. In the present study, we used a novel technique of plasticity induction by repeated pairing of deep-brain stimulation (DBS) of the BG with M1 stimulation using TMS. We hypothesize that repeated pairing of subthalamic nucleus (STN)-DBS and M1-TMS at specific time intervals will lead to plasticity in the M1. Ten PD human patients with STN-DBS were studied in the on-medication state with DBS set to 3 Hz. The interstimulus intervals (ISIs) between STN-DBS and TMS that produced cortical facilitation were determined individually for each patient. Three plasticity induction conditions with repeated pairings (180 times) at specific ISIs (∼ 3 and ∼ 23 ms) that produced cortical facilitation and a control ISI of 167 ms were tested in random order. Repeated pairing of STN-DBS and M1-TMS at short (∼ 3 ms) and medium (∼ 23 ms) latencies increased M1 excitability that lasted for at least 45 min, whereas the control condition (fixed ISI of 167 ms) had no effect. There were no specific changes in motor thresholds, intracortical circuits, or recruitment curves. Our results indicate that paired-associative cortical plasticity can be induced by repeated STN and M1 stimulation at specific intervals. These results show that STN-DBS can modulate cortical plasticity. We introduced a new experimental paradigm to test the hypothesis that pairing subthalamic nucleus deep-brain stimulation (STN-DBS) with motor cortical transcranial magnetic stimulation (M1-TMS) at specific times can induce cortical plasticity in patients with Parkinson's disease (PD). We found that repeated pairing of STN

Cortical sensorimotor alterations classify clinical phenotype and putative genotype of spasmodic dysphonia.

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Battistella, G; Fuertinger, S; Fleysher, L; Ozelius, L J; Simonyan, K

2016-10-01

Spasmodic dysphonia (SD), or laryngeal dystonia, is a task-specific isolated focal dystonia of unknown causes and pathophysiology. Although functional and structural abnormalities have been described in this disorder, the influence of its different clinical phenotypes and genotypes remains scant, making it difficult to explain SD pathophysiology and to identify potential biomarkers. We used a combination of independent component analysis and linear discriminant analysis of resting-state functional magnetic resonance imaging data to investigate brain organization in different SD phenotypes (abductor versus adductor type) and putative genotypes (familial versus sporadic cases) and to characterize neural markers for genotype/phenotype categorization. We found abnormal functional connectivity within sensorimotor and frontoparietal networks in patients with SD compared with healthy individuals as well as phenotype- and genotype-distinct alterations of these networks, involving primary somatosensory, premotor and parietal cortices. The linear discriminant analysis achieved 71% accuracy classifying SD and healthy individuals using connectivity measures in the left inferior parietal and sensorimotor cortices. When categorizing between different forms of SD, the combination of measures from the left inferior parietal, premotor and right sensorimotor cortices achieved 81% discriminatory power between familial and sporadic SD cases, whereas the combination of measures from the right superior parietal, primary somatosensory and premotor cortices led to 71% accuracy in the classification of adductor and abductor SD forms. Our findings present the first effort to identify and categorize isolated focal dystonia based on its brain functional connectivity profile, which may have a potential impact on the future development of biomarkers for this rare disorder. © 2016 EAN.

Cortical venous disease severity in MELAS syndrome correlates with brain lesion development.

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Whitehead, M T; Wien, M; Lee, B; Bass, N; Gropman, A

2017-08-01

MELAS syndrome is a mitochondrial disorder typified by recurrent stroke-like episodes, seizures, and progressive brain injury. Abnormal mitochondria have been found in arterial walls implicating a vasculogenic etiology. We have observed abnormal cortical vein T2/FLAIR signal in MELAS patients, potentially representing wall thickening and sluggish flow. We sought to examine the relationship of hyperintense veins and brain lesions in MELAS. Imaging databases at two children's hospitals were searched for brain MRIs from MELAS patients. Artifact, sedated exams, and lack of 2D-T2/FLAIR sequences were exclusion criteria. Each exam was assigned a venous score based on number of T2/FLAIR hyperintense veins: 1 = 20. Cumulative brain lesions and venous score in MELAS and aged-matched normal exams were compared by Mann-Whitney test. A total of 106 exams from 14 unique MELAS patients (mean 16 ± 3 years) and 30 exams from normal aged-matched patients (mean 15 ± 3 years) were evaluated. Median venous score between MELAS and control patients significantly differed (3 versus 1; p MELAS group, venous score correlated with presence (median = 3) or absence (median = 1) of cumulative brain lesions. In all 8 MELAS patients who developed lesions, venous hyperintensity was present prior to, during, and after lesion onset. Venous score did not correlate with brain lesion acuity. Abnormal venous signal correlates with cumulative brain lesion severity in MELAS syndrome. Cortical venous stenosis, congestion, and venous ischemia may be mechanisms of brain injury. Identification of cortical venous pathology may aid in diagnosis and could be predictive of lesion development.

Cortical basis of communication: local computation, coordination, attention.

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Alexandre, Frederic

2009-03-01

Human communication emerges from cortical processing, known to be implemented on a regular repetitive neuronal substratum. The supposed genericity of cortical processing has elicited a series of modeling works in computational neuroscience that underline the information flows driven by the cortical circuitry. In the minimalist framework underlying the current theories for the embodiment of cognition, such a generic cortical processing is exploited for the coordination of poles of representation, as is reported in this paper for the case of visual attention. Interestingly, this case emphasizes how abstract internal referents are built to conform to memory requirements. This paper proposes that these referents are the basis for communication in humans, which is firstly a coordination and an attentional procedure with regard to their congeners.

The clinical application of 99Tcm-DMSA renal cortical scintigraphy in children with urinary tract infection

International Nuclear Information System (INIS)

Zhao Ruifang; Zeng Jihua; Xu Hong; Ji Zhiying; Yuan Hong

2002-01-01

Objective: To study the value of 99 Tc m -dimercaptosuccinic acid (DMSA) renal cortical scintigraphy in distinguishing between upper urinary tract infection (UUTI) and lower UTI (LUTI), determining renal scarring, and following-up curative effect for UTI in children. Methods: The authors reviewed 252 results of 99 Tc m -DMSA renal cortical scintigraphy in children with UTIs during a period of the past five years. The age of the patients was from 1 month to 14 years. The ratio of males: females was 94:158. A standard 99 Tc m -DMSA renal cortical scintigraphic protocol was used. The studies were scored as normal (indicating LUTI) and abnormal (indicating acute pyelonephritis or renal scarring). And differential function of renal was calculated. Results: Of 252 children with UTI, 110 cases had normal images diagnosed as with LUTI. 142 cases had abnormal images, 116 cases were diagnosed as with acute pyelonephritis, 26 cases were diagnosed as with renal cortical scars. The differential function range of LUTI was 46%-54%. Of UUTIs, the differential function of single renal involved was less than 45%. Of 142 UUTIs, 17 cases repeatedly underwent renal cortical scan after therapy. 12 of 13 cases with acute pyelonephritis completely recovered normal or obviously ameliorated after 6 months, 1 cases did not show any change after 4 months. Four cases were found with renal scarring, and showed little change on repeated images for the following 6 months. conclusions: 99 Tc m -DMSA renal cortical scintigraphy is of valuable significance in distinguishing between upper and lower UTI, and in estimating renal scarring. The sequelae of renal infection can be monitored by renal cortical scan. A follow-up of 6 months may be recommended after therapy

Cortical oscillations related to processing congruent and incongruent grapheme-phoneme pairs.

Science.gov (United States)

Herdman, Anthony T; Fujioka, Takako; Chau, Wilkin; Ross, Bernhard; Pantev, Christo; Picton, Terence W

2006-05-15

In this study, we investigated changes in cortical oscillations following congruent and incongruent grapheme-phoneme stimuli. Hiragana graphemes and phonemes were simultaneously presented as congruent or incongruent audiovisual stimuli to native Japanese-speaking participants. The discriminative reaction time was 57 ms shorter for congruent than incongruent stimuli. Analysis of MEG responses using synthetic aperture magnetometry (SAM) revealed that congruent stimuli evoked larger 2-10 Hz activity in the left auditory cortex within the first 250 ms after stimulus onset, and smaller 2-16 Hz activity in bilateral visual cortices between 250 and 500 ms. These results indicate that congruent visual input can modify cortical activity in the left auditory cortex.

Temporal lobe developmental malformations and epilepsy: dual pathology and bilateral hippocampal abnormalities.

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Ho, S S; Kuzniecky, R I; Gilliam, F; Faught, E; Morawetz, R

1998-03-01

Temporal lobe developmental malformations (TLDM) with focal cortical dysplasia and balloon cells may coexist with mesial temporal sclerosis. The true incidence of this dual pathology is unknown. Our aim was to assess the frequency of amygdala (AM)-hippocampal abnormality in a homogeneous population with this specific developmental malformation. MRI-based volumetry of the AM and hippocampal formation (HF) in 30 patients with unilateral TLDM and intractable partial epilepsy was performed. A volume normalization process defined a normal range of HF and AM volumes in control subjects, and enabled the detection of bilateral volume loss. Normalized volumes detected HF atrophy in 26 patients (nine unilateral and 17 bilateral) and AM atrophy in 18 patients (three unilateral and 15 bilateral). Visual analysis detected unilateral HF abnormality in 21 patients and bilateral abnormality in two. When compared with a group of patients with temporal lobe epilepsy and pure hippocampal sclerosis (N = 92), where volumetry revealed bilateral HF atrophy in 18%, a significant difference in the frequency of bilateral HF atrophy was found (p Dual pathology is frequent in patients with TLDM (87%), and the AM-HF abnormality is often bilateral (57%). Our data suggest that more widespread and potentially epileptogenic lesions coexist with visibly detectable unilateral TLDM. This has implications for the selection of patients for temporal lobe surgery and may influence surgical strategies.

CT abnormality in multiple sclerosis analysis based on 28 probable cases and correlation with clinical manifestations

International Nuclear Information System (INIS)

Kakigi, Ryusuke; Shibasaki, Hiroshi; Tabira, Takeshi; Kuroiwa, Yoshigoro; Numaguchi, Yuji.

1981-01-01

In order to investigate the occurrence and nature of CT abnormality and its correlation with clinical manifestations in multiple sclerosis, 34 CT records obtained from 28 consecutive patients with probable multiple sclerosis were reviewed. Forty-six percent of all cases showed abnormal CT. Dilatation of cortical sulci was found in 39%; dilatation of the lateral ventricle in 36%; dilatation of prepontine or cerebello-pontine cistern and the fourth ventricle, suggesting brainstem atrophy, in 18%; dilatation of cerebellar sulci, superior cerebellar cistern and cisterna magna, suggesting cerebellar atrophy, in 11%. Low density area was found in the cerebral hemisphere in 11% of cases. Contrast enhancement, performed on 25 CT records, did not show any change. There was no correlation between CT abnormality and duration of the illness. Although abnormal CT tended to occur more frequently during exacerbations and chronic stable state than during remissions, the difference was not statistically significant. CT abnormalities suggesting brainstem atrophy, cerebellar atrophy or plaques were found exclusively during exacerbations and chronic stable state. The occurrence of CT abnormalities was not significantly different among various clinical forms which were classified based on clinically estimated sites of lesion, except that abnormal CT tended to occur less frequently in cases classified as the optic-spinal form. It is noteworthy that cerebral cortical atrophy and/or dilatation of the lateral ventricle were found in 31% of cases who did not show any clinical sign of cerebral involvement. There was a statistically significant correlation between CT abnormalities and levels of clinical disability. Eighty percent of the bedridden or severely disabled patients showed abnormal CT, in contrast with only 29% of those with moderate, slight or no disability. (author)

CT abnormality in multiple sclerosis analysis based on 28 probable cases and correlation with clinical manifestations

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Kakigi, R.; Shibasaki, H.; Tabira, T.; Kuroiwa, Y. (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine); Numaguchi, Y.

1981-10-01

In order to investigate the occurrence and nature of CT abnormality and its correlation with clinical manifestations in multiple sclerosis, 34 CT records obtained from 28 consecutive patients with probable multiple sclerosis were reviewed. Forty-six percent of all cases showed abnormal CT. Dilatation of cortical sulci was found in 39%; dilatation of the lateral ventricle in 36%; dilatation of prepontine or cerebello-pontine cistern and the fourth ventricle, suggesting brainstem atrophy, in 18%; dilatation of cerebellar sulci, superior cerebellar cistern and cisterna magna, suggesting cerebellar atrophy, in 11%. Low density area was found in the cerebral hemisphere in 11% of cases. Contrast enhancement, performed on 25 CT records, did not show any change. There was no correlation between CT abnormality and duration of the illness. Although abnormal CT tended to occur more frequently during exacerbations and chronic stable state than during remissions, the difference was not statistically significant. CT abnormalities suggesting brainstem atrophy, cerebellar atrophy or plaques were found exclusively during exacerbations and chronic stable state. The occurrence of CT abnormalities was not significantly different among various clinical forms which were classified based on clinically estimated sites of lesion, except that abnormal CT tended to occur less frequently in cases classified as the optic-spinal form. It is noteworthy that cerebral cortical atrophy and/or dilatation of the lateral ventricle were found in 31% of cases who did not show any clinical sign of cerebral involvement. There was a statistically significant correlation between CT abnormalities and levels of clinical disability. Eighty percent of the bedridden or severely disabled patients showed abnormal CT, in contrast with only 29% of those with moderate, slight or no disability.

Neuroimaging of affect processing in schizophrenia

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Habel, U.; Kircher, T.; Schneider, F.

2005-01-01

Functional imaging of normal and dysfunctional emotional processes is an important tool for a better understanding of the pathophysiology of affective symptoms in schizophrenia patients. These symptoms are still poorly characterized with respect to their neural correlates. Comparisons of cerebral activation during emotional paradigms offered the possibility for a better characterization of cerebral dysfunctions during emotional processing in schizophrenia. Abnormal activation patterns reveal a complex dysfunctional subcortical-cortical network. This is modulated by respective genotypes as well as psycho- and pharmacotherapy. (orig.) [de

Characteristics of lesional and extra-lesional cortical grey matter in relapsing-remitting and secondary progressive multiple sclerosis: A magnetisation transfer and diffusion tensor imaging study.

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Yaldizli, Özgür; Pardini, Matteo; Sethi, Varun; Muhlert, Nils; Liu, Zheng; Tozer, Daniel J; Samson, Rebecca S; Wheeler-Kingshott, Claudia Am; Yousry, Tarek A; Miller, David H; Chard, Declan T

2016-02-01

In multiple sclerosis (MS), diffusion tensor and magnetisation transfer imaging are both abnormal in lesional and extra-lesional cortical grey matter, but differences between clinical subtypes and associations with clinical outcomes have only been partly assessed. To compare mean diffusivity, fractional anisotropy and magnetisation transfer ratio (MTR) in cortical grey matter lesions (detected using phase-sensitive inversion recovery (PSIR) imaging) and extra-lesional cortical grey matter, and assess associations with disability in relapse-onset MS. Seventy-two people with MS (46 relapsing-remitting (RR), 26 secondary progressive (SP)) and 36 healthy controls were included in this study. MTR, mean diffusivity and fractional anisotropy were measured in lesional and extra-lesional cortical grey matter. Mean fractional anisotropy was higher and MTR lower in lesional compared with extra-lesional cortical grey matter. In extra-lesional cortical grey matter mean fractional anisotropy and MTR were lower, and mean diffusivity was higher in the MS group compared with controls. Mean MTR was lower and mean diffusivity was higher in lesional and extra-lesional cortical grey matter in SPMS when compared with RRMS. These differences were independent of disease duration. In multivariate analyses, MTR in extra-lesional more so than lesional cortical grey matter was associated with disability. Magnetic resonance abnormalities in lesional and extra-lesional cortical grey matter are greater in SPMS than RRMS. Changes in extra-lesional compared with lesional cortical grey matter are more consistently associated with disability. © The Author(s), 2015.

Cortical areas involved in Arabic number reading.

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Roux, F-E; Lubrano, V; Lauwers-Cances, V; Giussani, C; Démonet, J-F

2008-01-15

Distinct functional pathways for processing words and numbers have been hypothesized from the observation of dissociated impairments of these categories in brain-damaged patients. We aimed to identify the cortical areas involved in Arabic number reading process in patients operated on for various brain lesions. Direct cortical electrostimulation was prospectively used in 60 brain mappings. We used object naming and two reading tasks: alphabetic script (sentences and number words) and Arabic number reading. Cortical areas involved in Arabic number reading were identified according to location, type of interference, and distinctness from areas associated with other language tasks. Arabic number reading was sustained by small cortical areas, often extremely well localized (area (Brodmann area 45), the anterior part of the dominant supramarginal gyrus (Brodmann area 40; p area (Brodmann area 37; p areas.

Brain perfusion abnormalities associated to drug abuse in recent abstinent patients using SPECT 99m Tc-ethylen-cysteinate-dimer (ECD)

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Massardo, Teresa [University of Chile Clinical Hospital Nuclear Medicine Section, Department of Medicine, Santiago (Chile); Pallavicini, Julio [Addiction Unit, Psychiatric Clinic. University of Chile Clinical Hospital (Chile); Gonzalez, Patricio; Jaimovich, Rodrigo [University of Chile Clinical Hospital Nuclear Medicine Section, Department of Medicine, Santiago (Chile); Servat, Monica [Addiction Unit, Psychiatric Clinic. University of Chile Clinical Hospital (Chile); Lavados, Hugo [University of Chile Clinical Hospital Nuclear Medicine Section, Department of Medicine, Santiago (Chile); Arancibia, Pablo [Addiction Unit, Psychiatric Clinic. University of Chile Clinical Hospital (Chile); Padilla, Pamela [University of Chile Clinical Hospital Nuclear Medicine Section, Department of Medicine, Santiago (Chile)

2009-04-15

Several substances may produce brain perfusion abnormalities in drug-dependent patients. Their mechanism is unclear and several causes might be involved, especially vasospasm in cocaine consumption. Goal: To characterize residual brain perfusion abnormalities in substance-dependent population. We analyzed brain perfusion in 100 dependant patients (DSM-IV criteria) following a month of strict in-hospital abstinence (age:35{+-}12 y.o.; 86% men); 55% corresponded to poly-drug dependents, mainly to cocaine, alcohol and cannabis; 44% mono-drug users, mostly to alcohol. Results: Single Photon Emission Computed Tomography (SPECT) with 99mTc-ethylen-cysteinate-dimer (ECD) was abnormal in 54% of the cases, with bilateral cortical hypo-perfusion in 89%, focal in 54% and diffuse in 46% of them, with moderate or severe intensity in 61%. The abnormal perfusion group's age was 38{+-}12 versus 31{+-}10 years in the normal SPECT group (P=0.005) with a consumption period of 16{+-}11 versus 11{+-}8 years, respectively (P=0.043). Only 29% of women had abnormal perfusion versus 58% of men (P=0.047). Abnormal brain perfusion in 64% of mono and 45% in poly-drug dependents (P=0.07). Psychometric tests performed in 25 patients demonstrated association between perfusion defects and cognitive abnormalities. Relative risk for abnormal psychometric test was 2.5 [95%;CI=1.1-5.6] for abnormal SPECT. Conclusion: Dependent population after a month of abstinence persists with cortical brain perfusion abnormalities, associated to age, sex and type of drug consumption.

Temporal envelope processing in the human auditory cortex: response and interconnections of auditory cortical areas.

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Gourévitch, Boris; Le Bouquin Jeannès, Régine; Faucon, Gérard; Liégeois-Chauvel, Catherine

2008-03-01

Temporal envelope processing in the human auditory cortex has an important role in language analysis. In this paper, depth recordings of local field potentials in response to amplitude modulated white noises were used to design maps of activation in primary, secondary and associative auditory areas and to study the propagation of the cortical activity between them. The comparison of activations between auditory areas was based on a signal-to-noise ratio associated with the response to amplitude modulation (AM). The functional connectivity between cortical areas was quantified by the directed coherence (DCOH) applied to auditory evoked potentials. This study shows the following reproducible results on twenty subjects: (1) the primary auditory cortex (PAC), the secondary cortices (secondary auditory cortex (SAC) and planum temporale (PT)), the insular gyrus, the Brodmann area (BA) 22 and the posterior part of T1 gyrus (T1Post) respond to AM in both hemispheres. (2) A stronger response to AM was observed in SAC and T1Post of the left hemisphere independent of the modulation frequency (MF), and in the left BA22 for MFs 8 and 16Hz, compared to those in the right. (3) The activation and propagation features emphasized at least four different types of temporal processing. (4) A sequential activation of PAC, SAC and BA22 areas was clearly visible at all MFs, while other auditory areas may be more involved in parallel processing upon a stream originating from primary auditory area, which thus acts as a distribution hub. These results suggest that different psychological information is carried by the temporal envelope of sounds relative to the rate of amplitude modulation.

Event-related cortical processing in neuropathic pain under long-term spinal cord stimulation.

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Weigel, Ralf; Capelle, H Holger; Flor, Herta; Krauss, Joachim K

2015-01-01

discomfort discontinuation of SCS therapy was not prolonged over a 24 hour period. Further limitations were the low number of patients who agreed to discontinue SCS therapy for research purposes. Long-term SCS for treatment of neuropathic pain influenced both pain thresholds and cortical signalling. Source localization of P1 suggests involvement of regions involved in cognitive/associative processing of pain.

Transient MRI abnormalities associated with partial status epilepticus: a case report

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Amato, Carmelo; Elia, Maurizio; Musumeci, Sebastiano A; Bisceglie, Pierluigi; Moschini, Massimo

2001-04-01

We report the case of an 18-year-old woman who presented a long-lasting cluster of partial seizures, and MRI cortical abnormalities localized in the left parietal lobe. The MRI changes correlated with the site of the epileptogenic focus, and disappeared within 2 weeks. The recognition of these reversible MRI abnormalities, which are presumably due to a temporary alteration of blood-brain barrier in the epileptogenic zone with subsequent edema, and are not associated with any underlying organic conditions, is extremely useful in the medical management of the patient and allows to avoid other invasive diagnostic procedures.

Transient MRI abnormalities associated with partial status epilepticus: a case report

International Nuclear Information System (INIS)

Amato, Carmelo; Elia, Maurizio; Musumeci, Sebastiano A.; Bisceglie, Pierluigi; Moschini, Massimo

2001-01-01

We report the case of an 18-year-old woman who presented a long-lasting cluster of partial seizures, and MRI cortical abnormalities localized in the left parietal lobe. The MRI changes correlated with the site of the epileptogenic focus, and disappeared within 2 weeks. The recognition of these reversible MRI abnormalities, which are presumably due to a temporary alteration of blood-brain barrier in the epileptogenic zone with subsequent edema, and are not associated with any underlying organic conditions, is extremely useful in the medical management of the patient and allows to avoid other invasive diagnostic procedures

Axons Pull on the Brain, But Tension Does Not Drive Cortical Folding

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Xu, Gang; Knutsen, Andrew K.; Dikranian, Krikor; Kroenke, Christopher D.; Bayly, Philip V.; Taber, Larry A.

2011-01-01

During human brain development, the cerebral cortex undergoes substantial folding, leading to its characteristic highly convoluted form. Folding is necessary to accommodate the expansion of the cerbral cortex; abnormal cortical folding is linked to various neurological disorders, including schizophrenia, epilepsy, autism and mental retardation. Although this process requires mechanical forces, the specific force-generating mechanisms that drive folding remain unclear. The two most widely accepted hypotheses are (1) folding is caused by differential growth of the cortex and (2) folding is caused by mechanical tension generated in axons. Direct evidence supporting either theory, however, is lacking. Here we show that axons are indeed under considerable tension in the developing ferret brain, but the patterns of tissue stress are not consistent with a causal role for axonal tension. In particular, microdissection assays reveal that significant tension exists along axons aligned circumferentially in subcortical white matter tracts, as well as those aligned radially inside developing gyri (outward folds). Contrary to previous speculation, however, axonal tension is not directed across developing gyri, suggesting that axon tension does not drive folding. On the other hand, using computational (finite element) models, we show that differential cortical growth accompanied by remodeling of the subplate leads to outward folds and stress fields that are consistent with our microdissection experiments, supporting a mechanism involving differential growth. Local perturbations, such as temporal differences in the initiation of cortical growth, can ensure consistent folding patterns. This study shows that a combination of experimental and computational mechanics can be used to evaluate competing hypotheses of morphogenesis, and illuminate the biomechanics of cortical folding. PMID:20590291

M-Stream Deficits and Reading-Related Visual Processes in Developmental Dyslexia

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Boden, Catherine; Giaschi, Deborah

2007-01-01

Some visual processing deficits in developmental dyslexia have been attributed to abnormalities in the subcortical M stream and/or the cortical dorsal stream of the visual pathways. The nature of the relationship between these visual deficits and reading is unknown. The purpose of the present article was to characterize reading-related perceptual…

Synchronous changes of cortical thickness and corresponding white matter microstructure during brain development accessed by diffusion MRI tractography from parcellated cortex

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Tina eJeon

2015-12-01

Full Text Available Cortical thickness (CT changes during normal brain development is associated with complicated cellular and molecular processes including synaptic pruning and apoptosis. In parallel, the microstructural enhancement of developmental white matter (WM axons with their neuronal bodies in the cerebral cortex has been widely reported with measurements of metrics derived from diffusion tensor imaging (DTI, especially fractional anisotropy (FA. We hypothesized that the changes of CT and microstructural enhancement of corresponding axons are highly interacted during development. DTI and T1-weighted images of 50 healthy children and adolescents between the ages of 7 to 25 years were acquired. With the parcellated cortical gyri transformed from T1-weighted images to DTI space as the tractography seeds, probabilistic tracking was performed to delineate the WM fibers traced from specific parcellated cortical regions. CT was measured at certain cortical regions and FA was measured from the WM fibers traced from same cortical regions. The CT of all frontal cortical gyri, includeing Brodmann areas 4, 6, 8, 9, 10, 11, 44, 45, 46 and 47, decreased significantly and heterogeneously; concurrently, significant and heterogeneous increases of FA of WM traced from corresponding regions were found. We further revealed significant correlation between the slopes of the CT decrease and the slopes of corresponding WM FA increase in all frontal cortical gyri, suggesting coherent cortical pruning and corresponding WM microstructural enhancement. Such correlation was not found in cortical regions other than frontal cortex. The molecular and cellular mechanisms of these synchronous changes may be associated with overlapping signaling pathways of axonal guidance, synaptic pruning, neuronal apoptosis and more prevalent interstitial neurons in the prefrontal cortex. Revealing the coherence of cortical and WM structural changes during development may open a new window for

Auditory verbal hallucinations are related to cortical thinning in the left middle temporal gyrus of patients with schizophrenia.

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Cui, Y; Liu, B; Song, M; Lipnicki, D M; Li, J; Xie, S; Chen, Y; Li, P; Lu, L; Lv, L; Wang, H; Yan, H; Yan, J; Zhang, H; Zhang, D; Jiang, T

2018-01-01

Auditory verbal hallucinations (AVHs) are one of the most common and severe symptoms of schizophrenia, but the neuroanatomical abnormalities underlying AVHs are not well understood. The present study aims to investigate whether AVHs are associated with cortical thinning. Participants were schizophrenia patients from four centers across China, 115 with AVHs and 93 without AVHs, as well as 261 healthy controls. All received 3 T T1-weighted brain scans, and whole brain vertex-wise cortical thickness was compared across groups. Correlations between AVH severity and cortical thickness were also determined. The left middle part of the middle temporal gyrus (MTG) was significantly thinner in schizophrenia patients with AVHs than in patients without AVHs and healthy controls. Inferences were made using a false discovery rate approach with a threshold at p < 0.05. Left MTG thickness did not differ between patients without AVHs and controls. These results were replicated by a meta-analysis showing them to be consistent across the four centers. Cortical thickness of the left MTG was also found to be inversely correlated with hallucination severity across all schizophrenia patients. The results of this multi-center study suggest that an abnormally thin left MTG could be involved in the pathogenesis of AVHs in schizophrenia.

Glial activation colocalizes with structural abnormalities in amyotrophic lateral sclerosis.

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Alshikho, Mohamad J; Zürcher, Nicole R; Loggia, Marco L; Cernasov, Paul; Chonde, Daniel B; Izquierdo Garcia, David; Yasek, Julia E; Akeju, Oluwaseun; Catana, Ciprian; Rosen, Bruce R; Cudkowicz, Merit E; Hooker, Jacob M; Atassi, Nazem

2016-12-13

In this cross-sectional study, we aimed to evaluate brain structural abnormalities in relation to glial activation in the same cohort of participants. Ten individuals with amyotrophic lateral sclerosis (ALS) and 10 matched healthy controls underwent brain imaging using integrated MR/PET and the radioligand [ 11 C]-PBR28. Diagnosis history and clinical assessments including Upper Motor Neuron Burden Scale (UMNB) were obtained from patients with ALS. Diffusion tensor imaging (DTI) analyses including tract-based spatial statistics and tractography were applied. DTI metrics including fractional anisotropy (FA) and diffusivities (mean, axial, and radial) were measured in regions of interest. Cortical thickness was assessed using surface-based analysis. The locations of structural changes, measured by DTI and the areas of cortical thinning, were compared to regional glial activation measured by relative [ 11 C]-PBR28 uptake. In this cohort of individuals with ALS, reduced FA and cortical thinning colocalized with regions demonstrating higher radioligand binding. [ 11 C]-PBR28 binding in the left motor cortex was correlated with FA (r = -0.68, p < 0.05) and cortical thickness (r = -0.75, p < 0.05). UMNB was correlated with glial activation (r = +0.75, p < 0.05), FA (r = -0.77, p < 0.05), and cortical thickness (r = -0.75, p < 0.05) in the motor cortex. Increased uptake of the glial marker [ 11 C]-PBR28 colocalizes with changes in FA and cortical thinning. This suggests a link between disease mechanisms (gliosis and inflammation) and structural changes (cortical thinning and white and gray matter changes). In this multimodal neuroimaging work, we provide an in vivo model to investigate the pathogenesis of ALS. © 2016 American Academy of Neurology.

[X-ray computed tomographic abnormalities in schizophrenia. Trial of relationship with clinical data].

Science.gov (United States)

D'Amato, T; Rochet, T; Dalery, J; Chauchat, J H; Terra, J L; Arteaga, C; Marie-Cardine, M

1992-01-01

Computerized tomography (CT-scan) studies in schizophrenia revealed that some patients have neuromorphological abnormalities. The structural changes consist mainly in lateral and third ventricle enlargement, and in cortical atrophy. The present study evaluates these three changes in 42 schizophrenics aged 18 to 50, compared to 24 healthy controls. Diagnosis were established from information gathered by personal interview with the SADS-LA. Clinical sub-types were evaluated according to the DSM III-R criteria. Moreover, detailed symptoms were rated according to the Positive And Negative Syndrome Scale (PANSS). CT scans were recorded in floppy disks and blindly analyzed. Schizophrenics shown significant higher mean size of lateral and third ventricles, and higher mean anterior cortical atrophy than healthy subjects. Significant differences were also found between subtypes, with more marked abnormalities in the disorganized group. The relationship between brain abnormalities and clinical symptoms recorded with the PANSS, were analysed using Pearson correlates. Positive correlations concerned mainly negative symptoms like blunted affect, emotional withdrawal, difficulties in abstract thinking, passive apathetic social withdrawal and lack of spontaneity of conversation. Positive correlations are also observed with some symptoms classified with the PANSS in the General Psychopathology scale such as mannerism and disorientation. Negative correlation concerned most of PANSS positive symptoms.

Dissociating Cortical Activity during Processing of Native and Non-Native Audiovisual Speech from Early to Late Infancy

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Eswen Fava

2014-08-01

Full Text Available Initially, infants are capable of discriminating phonetic contrasts across the world’s languages. Starting between seven and ten months of age, they gradually lose this ability through a process of perceptual narrowing. Although traditionally investigated with isolated speech sounds, such narrowing occurs in a variety of perceptual domains (e.g., faces, visual speech. Thus far, tracking the developmental trajectory of this tuning process has been focused primarily on auditory speech alone, and generally using isolated sounds. But infants learn from speech produced by people talking to them, meaning they learn from a complex audiovisual signal. Here, we use near-infrared spectroscopy to measure blood concentration changes in the bilateral temporal cortices of infants in three different age groups: 3-to-6 months, 7-to-10 months, and 11-to-14-months. Critically, all three groups of infants were tested with continuous audiovisual speech in both their native and another, unfamiliar language. We found that at each age range, infants showed different patterns of cortical activity in response to the native and non-native stimuli. Infants in the youngest group showed bilateral cortical activity that was greater overall in response to non-native relative to native speech; the oldest group showed left lateralized activity in response to native relative to non-native speech. These results highlight perceptual tuning as a dynamic process that happens across modalities and at different levels of stimulus complexity.

Vestibulo-cortical Hemispheric Dominance: the link between Anxiety and the Vestibular System?

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Bednarczuk, Nadja F; Casanovas Ortega, Marta; Fluri, Anne-Sophie; Arshad, Qadeer

2018-05-16

Vestibular processing and anxiety networks are functionally intertwined, as demonstrated by reports of reciprocal influences upon each other. Yet whether there is an underlying link between these two systems remains unknown Previous findings have highlighted the involvement of hemispheric lateralisation in processing of both anxiety and vestibular signals. Accordingly, we explored the interaction between vestibular cortical processing and anxiety by assessing the relationship between anxiety levels and the degree of hemispheric lateralisation of vestibulo-cortical processing in 64 right-handed, healthy individuals. Vestibulo-cortical hemispheric lateralisation was determined by gaging the degree of caloric-induced nystagmus suppression following modulation of cortical excitability using trans-cranial direct current stimulation targeted over the posterior parietal cortex, an area implicated in the processing of vestibular signals. The degree of nystagmus suppression yields an objective biomarker, allowing the quantification of the degree of right vestibulo-cortical hemisphere dominance. Anxiety levels were quantified using the Trait component of the Spielberger State-Trait Anxiety Questionnaire. Our findings demonstrate that the degree of an individual's vestibulo-cortical hemispheric dominance correlates with their anxiety levels. That is, those individuals with greater right hemispheric vestibulo-cortical dominance exhibited lower levels of anxiety. By extension, our results support the notion that hemispheric lateralisation determines an individual's emotional processing, thereby linking cortical circuits involved in processing anxiety and vestibular signals respectively. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Multidimensional analysis of the abnormal neural oscillations associated with lexical processing in schizophrenia.

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Xu, Tingting; Stephane, Massoud; Parhi, Keshab K

2013-04-01

The neural mechanisms of language abnormalities, the core symptoms in schizophrenia, remain unclear. In this study, a new experimental paradigm, combining magnetoencephalography (MEG) techniques and machine intelligence methodologies, was designed to gain knowledge about the frequency, brain location, and time of occurrence of the neural oscillations that are associated with lexical processing in schizophrenia. The 248-channel MEG recordings were obtained from 12 patients with schizophrenia and 10 healthy controls, during a lexical processing task, where the patients discriminated correct from incorrect lexical stimuli that were visually presented. Event-related desynchronization/synchronization (ERD/ERS) was computed along the frequency, time, and space dimensions combined, that resulted in a large spectral-spatial-temporal ERD/ERS feature set. Machine intelligence techniques were then applied to select a small subset of oscillation patterns that are abnormal in patients with schizophrenia, according to their discriminating power in patient and control classification. Patients with schizophrenia showed abnormal ERD/ERS patterns during both lexical encoding and post-encoding periods. The top-ranked features were located at the occipital and left frontal-temporal areas, and covered a wide frequency range, including δ (1-4 Hz), α (8-12 Hz), β (12-32 Hz), and γ (32-48 Hz) bands. These top features could discriminate the patient group from the control group with 90.91% high accuracy, which demonstrates significant brain oscillation abnormalities in patients with schizophrenia at the specific frequency, time, and brain location indicated by these top features. As neural oscillation abnormality may be due to the mechanisms of the disease, the spectral, spatial, and temporal content of the discriminating features can offer useful information for helping understand the physiological basis of the language disorder in schizophrenia, as well as the pathology of the

Abnormal prefrontal cortex resting state functional connectivity and severity of internet gaming disorder.

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Jin, Chenwang; Zhang, Ting; Cai, Chenxi; Bi, Yanzhi; Li, Yangding; Yu, Dahua; Zhang, Ming; Yuan, Kai

2016-09-01

Internet Gaming Disorder (IGD) among adolescents has become an important public concern and gained more and more attention internationally. Recent studies focused on IGD and revealed brain abnormalities in the IGD group, especially the prefrontal cortex (PFC). However, the role of PFC-striatal circuits in pathology of IGD remains unknown. Twenty-five adolescents with IGD and 21 age- and gender-matched healthy controls were recruited in our study. Voxel-based morphometric (VBM) and functional connectivity analysis were employed to investigate the abnormal structural and resting-state properties of several frontal regions in individuals with online gaming addiction. Relative to healthy comparison subjects, IGD subjects showed significant decreased gray matter volume in PFC regions including the bilateral dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), anterior cingulate cortex (ACC) and the right supplementary motor area (SMA) after controlling for age and gender effects. We chose these regions as the seeding areas for the resting-state analysis and found that IGD subjects showed decreased functional connectivity between several cortical regions and our seeds, including the insula, and temporal and occipital cortices. Moreover, significant decreased functional connectivity between some important subcortical regions, i.e., dorsal striatum, pallidum, and thalamus, and our seeds were found in the IGD group and some of those changes were associated with the severity of IGD. Our results revealed the involvement of several PFC regions and related PFC-striatal circuits in the process of IGD and suggested IGD may share similar neural mechanisms with substance dependence at the circuit level.

Molecular and phenotypic abnormalities in individuals with germline heterozygous PTEN mutations and autism.

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Frazier, T W; Embacher, R; Tilot, A K; Koenig, K; Mester, J; Eng, C

2015-09-01

PTEN is a tumor suppressor associated with an inherited cancer syndrome and an important regulator of ongoing neural connectivity and plasticity. The present study examined molecular and phenotypic characteristics of individuals with germline heterozygous PTEN mutations and autism spectrum disorder (ASD) (PTEN-ASD), with the aim of identifying pathophysiologic markers that specifically associate with PTEN-ASD and that may serve as targets for future treatment trials. PTEN-ASD patients (n=17) were compared with idiopathic (non-PTEN) ASD patients with (macro-ASD, n=16) and without macrocephaly (normo-ASD, n=38) and healthy controls (n=14). Group differences were evaluated for PTEN pathway protein expression levels, global and regional structural brain volumes and cortical thickness measures, neurocognition and adaptive behavior. RNA expression patterns and brain characteristics of a murine model of Pten mislocalization were used to further evaluate abnormalities observed in human PTEN-ASD patients. PTEN-ASD had a high proportion of missense mutations and showed reduced PTEN protein levels. Compared with the other groups, prominent white-matter and cognitive abnormalities were specifically associated with PTEN-ASD patients, with strong reductions in processing speed and working memory. White-matter abnormalities mediated the relationship between PTEN protein reductions and reduced cognitive ability. The Pten(m3m4) murine model had differential expression of genes related to myelination and increased corpus callosum. Processing speed and working memory deficits and white-matter abnormalities may serve as useful features that signal clinicians that PTEN is etiologic and prompting referral to genetic professionals for gene testing, genetic counseling and cancer risk management; and could reveal treatment targets in trials of treatments for PTEN-ASD.

Abnormal proactive and reactive cognitive control during conflict processing in major depression.

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Vanderhasselt, Marie-Anne; De Raedt, Rudi; De Paepe, Annick; Aarts, Kristien; Otte, Georges; Van Dorpe, Jan; Pourtois, Gilles

2014-02-01

According to the Dual Mechanisms of Control framework, cognitive control consists of two complementary components: proactive control refers to anticipatory maintenance of goal-relevant information, whereas reactive control acts as a correction mechanism that is activated when a conflict occurs. Possibly, the well-known diminished inhibitory control in response to negative stimuli in Major Depressive Disorder (MDD) patients stems from a breakdown in proactive control, and/or anomalies in reactive cognitive control. In our study, MDD patients specifically showed increased response latencies when actively inhibiting a dominant response to a sad compared with a happy face. This condition was associated with a longer duration of a dominant ERP topography (800-900 ms poststimulus onset) and a stronger activity in the bilateral dorsal anterior cingulate cortex, reflecting abnormal reactive control when inhibiting attention to a negative stimulus. Moreover, MDD patients showed abnormalities in proactive cognitive control when preparing for the upcoming imperative stimulus (abnormal modulation of the contingent negative variation component), accompanied by more activity in brain regions belonging to the default mode network. All together, deficits to inhibit attention to negative information in MDD might originate from an abnormal use of both proactive resources and reactive control processes. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Anorexia nervosa and body dysmorphic disorder are associated with abnormalities in processing visual information.

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Li, W; Lai, T M; Bohon, C; Loo, S K; McCurdy, D; Strober, M; Bookheimer, S; Feusner, J

2015-07-01

Anorexia nervosa (AN) and body dysmorphic disorder (BDD) are characterized by distorted body image and are frequently co-morbid with each other, although their relationship remains little studied. While there is evidence of abnormalities in visual and visuospatial processing in both disorders, no study has directly compared the two. We used two complementary modalities--event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI)--to test for abnormal activity associated with early visual signaling. We acquired fMRI and ERP data in separate sessions from 15 unmedicated individuals in each of three groups (weight-restored AN, BDD, and healthy controls) while they viewed images of faces and houses of different spatial frequencies. We used joint independent component analyses to compare activity in visual systems. AN and BDD groups demonstrated similar hypoactivity in early secondary visual processing regions and the dorsal visual stream when viewing low spatial frequency faces, linked to the N170 component, as well as in early secondary visual processing regions when viewing low spatial frequency houses, linked to the P100 component. Additionally, the BDD group exhibited hyperactivity in fusiform cortex when viewing high spatial frequency houses, linked to the N170 component. Greater activity in this component was associated with lower attractiveness ratings of faces. Results provide preliminary evidence of similar abnormal spatiotemporal activation in AN and BDD for configural/holistic information for appearance- and non-appearance-related stimuli. This suggests a common phenotype of abnormal early visual system functioning, which may contribute to perceptual distortions.

Spatio-temporal cerebral blood flow perfusion patterns in cortical spreading depression

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Verisokin, Andrey Yu.; Verveyko, Darya V.; Postnov, Dmitry E.

2017-04-01

Cortical spreading depression (CSD) is an example of one of the most common abnormalities in biophysical brain functioning. Despite the fact that there are many mathematical models describing the cortical spreading depression (CSD), most of them do not take into consideration the role of redistribution of cerebral blood flow (CBF), that results in the formation of spatio-temporal patterns. The paper presents a mathematical model, which successfully explains the CBD role in the CSD process. Numerical study of this model has revealed the formation of stationary dissipative structures, visually analogous to Turing structures. However, the mechanism of their formation is not diffusion. We show these structures occur due to another type of spatial coupling, that is related to tissue perfusion rate. The proposed model predicts that at similar state of neurons the distribution of blood flow and oxygenation may by different. Currently, this effect is not taken into account when the Blood oxygen-level dependent (BOLD) contrast imaging used in functional magnetic resonance imaging (fMRI). Thus, the diagnosis on the BOLD signal can be ambiguous. We believe that our results can be used in the future for a more correct interpretation of the data obtained with fMRI, NIRS and other similar methods for research of the brain activity.

Spatial integration and cortical dynamics.

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Gilbert, C D; Das, A; Ito, M; Kapadia, M; Westheimer, G

1996-01-23

Cells in adult primary visual cortex are capable of integrating information over much larger portions of the visual field than was originally thought. Moreover, their receptive field properties can be altered by the context within which local features are presented and by changes in visual experience. The substrate for both spatial integration and cortical plasticity is likely to be found in a plexus of long-range horizontal connections, formed by cortical pyramidal cells, which link cells within each cortical area over distances of 6-8 mm. The relationship between horizontal connections and cortical functional architecture suggests a role in visual segmentation and spatial integration. The distribution of lateral interactions within striate cortex was visualized with optical recording, and their functional consequences were explored by using comparable stimuli in human psychophysical experiments and in recordings from alert monkeys. They may represent the substrate for perceptual phenomena such as illusory contours, surface fill-in, and contour saliency. The dynamic nature of receptive field properties and cortical architecture has been seen over time scales ranging from seconds to months. One can induce a remapping of the topography of visual cortex by making focal binocular retinal lesions. Shorter-term plasticity of cortical receptive fields was observed following brief periods of visual stimulation. The mechanisms involved entailed, for the short-term changes, altering the effectiveness of existing cortical connections, and for the long-term changes, sprouting of axon collaterals and synaptogenesis. The mutability of cortical function implies a continual process of calibration and normalization of the perception of visual attributes that is dependent on sensory experience throughout adulthood and might further represent the mechanism of perceptual learning.

Early and phasic cortical metabolic changes in vestibular neuritis onset.

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Marco Alessandrini

Full Text Available Functional brain activation studies described the presence of separate cortical areas responsible for central processing of peripheral vestibular information and reported their activation and interactions with other sensory modalities and the changes of this network associated to strategic peripheral or central vestibular lesions. It is already known that cortical changes induced by acute unilateral vestibular failure (UVF are various and undergo variations over time, revealing different cortical involved areas at the onset and recovery from symptoms. The present study aimed at reporting the earliest change in cortical metabolic activity during a paradigmatic form of UVF such as vestibular neuritis (VN, that is, a purely peripheral lesion of the vestibular system, that offers the opportunity to study the cortical response to altered vestibular processing. This research reports [(18F]fluorodeoxyglucose positron emission tomography brain scan data concerning the early cortical metabolic activity associated to symptoms onset in a group of eight patients suffering from VN. VN patients' cortical metabolic activity during the first two days from symptoms onset was compared to that recorded one month later and to a control healthy group. Beside the known cortical response in the sensorimotor network associated to vestibular deafferentation, we show for the first time the involvement of Entorhinal (BAs 28, 34 and Temporal (BA 38 cortices in early phases of symptomatology onset. We interpret these findings as the cortical counterparts of the attempt to reorient oneself in space counteracting the vertigo symptom (Bas 28, 34 and of the emotional response to the new pathologic condition (BA 38 respectively. These interpretations were further supported by changes in patients' subjective ratings in balance, anxiety, and depersonalization/derealization scores when tested at illness onset and one month later. The present findings contribute in expanding

The relationship between level of processing and hippocampal-cortical functional connectivity during episodic memory formation in humans.

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Schott, Björn H; Wüstenberg, Torsten; Wimber, Maria; Fenker, Daniela B; Zierhut, Kathrin C; Seidenbecher, Constanze I; Heinze, Hans-Jochen; Walter, Henrik; Düzel, Emrah; Richardson-Klavehn, Alan

2013-02-01

New episodic memory traces represent a record of the ongoing neocortical processing engaged during memory formation (encoding). Thus, during encoding, deep (semantic) processing typically establishes more distinctive and retrievable memory traces than does shallow (perceptual) processing, as assessed by later episodic memory tests. By contrast, the hippocampus appears to play a processing-independent role in encoding, because hippocampal lesions impair encoding regardless of level of processing. Here, we clarified the neural relationship between processing and encoding by examining hippocampal-cortical connectivity during deep and shallow encoding. Participants studied words during functional magnetic resonance imaging and freely recalled these words after distraction. Deep study processing led to better recall than shallow study processing. For both levels of processing, successful encoding elicited activations of bilateral hippocampus and left prefrontal cortex, and increased functional connectivity between left hippocampus and bilateral medial prefrontal, cingulate and extrastriate cortices. Successful encoding during deep processing was additionally associated with increased functional connectivity between left hippocampus and bilateral ventrolateral prefrontal cortex and right temporoparietal junction. In the shallow encoding condition, on the other hand, pronounced functional connectivity increases were observed between the right hippocampus and the frontoparietal attention network activated during shallow study processing. Our results further specify how the hippocampus coordinates recording of ongoing neocortical activity into long-term memory, and begin to provide a neural explanation for the typical advantage of deep over shallow study processing for later episodic memory. Copyright © 2011 Wiley Periodicals, Inc.

Connections underlying the synthesis of cognition, memory, and emotion in primate prefrontal cortices.

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Barbas, H

2000-07-15

Distinct domains of the prefrontal cortex in primates have a set of connections suggesting that they have different roles in cognition, memory, and emotion. Caudal lateral prefrontal areas (areas 8 and 46) receive projections from cortices representing early stages in visual or auditory processing, and from intraparietal and posterior cingulate areas associated with oculomotor guidance and attentional processes. Cortical input to areas 46 and 8 is complemented by projections from the thalamic multiform and parvicellular sectors of the mediodorsal nucleus associated with oculomotor functions and working memory. In contrast, caudal orbitofrontal areas receive diverse input from cortices representing late stages of processing within every unimodal sensory cortical system. In addition, orbitofrontal and caudal medial (limbic) prefrontal cortices receive robust projections from the amygdala, associated with emotional memory, and from medial temporal and thalamic structures associated with long-term memory. Prefrontal cortices are linked with motor control structures related to their specific roles in central executive functions. Caudal lateral prefrontal areas project to brainstem oculomotor structures, and are connected with premotor cortices effecting head, limb and body movements. In contrast, medial prefrontal and orbitofrontal limbic cortices project to hypothalamic visceromotor centers for the expression of emotions. Lateral, orbitofrontal, and medial prefrontal cortices are robustly interconnected, suggesting that they participate in concert in central executive functions. Prefrontal limbic cortices issue widespread projections through their deep layers and terminate in the upper layers of lateral (eulaminate) cortices, suggesting a predominant role in feedback communication. In contrast, when lateral prefrontal cortices communicate with limbic areas they issue projections from their upper layers and their axons terminate in the deep layers, suggesting a role in

Abnormalities of the axial and proximal appendicular skeleton in adults with Laron syndrome (growth hormone insensitivity)

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Kornreich, L.; Konen, O.; Schwarz, M.; Horev, G. [Schneider Children' s Medical Center of Israel, Imaging Department, Petah Tiqwa (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Siegel, Y. [Rabin Medical Center, Imaging Department, Petah Tiqwa (Israel); Jackson Memorial Hospital, Department of Radiology, Thoracic Section, Miami, FL (United States); Hershkovitz, I. [Tel Aviv University, Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv (Israel); Laron, Z. [Schneider Children' s Medical Center of Israel, Endocrinology and Diabetes Research Unit, Petah Tiqwa (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel)

2008-02-15

To investigate abnormalities in the skeleton (with the exclusion of the skull, cervical spine, hands and feet) in patients with Laron syndrome, who have an inborn growth hormone resistance and congenital insulin-like growth factor-1 (IGF-1) deficiency. The study group was composed of 15 untreated patients with Laron syndrome (seven male and eight female) aged 21-68 years. Plain films of the axial and appendicular skeleton were evaluated retrospectively for abnormalities in structure and shape. The cortical width of the long bones was evaluated qualitatively and quantitatively (in the upper humerus and mid-femur), and the cortical index was calculated and compared with published references. Measurements were taken of the mid-anteroposterior and cranio-caudal diameters of the vertebral body and spinous process at L3, the interpedicular distance at L1 and L5, and the sacral slope. Thoracic and lumbar osteophytes were graded on a 5-point scale. Values were compared with a control group of 20 healthy persons matched for age. The skeleton appeared small in all patients. No signs of osteopenia were visible. The cortex of the long bones appeared thick in the upper limbs in 11 patients and in the lower limbs in four. Compared with the reference values, the cortical width was thicker than average in the humerus and thinner in the femur. The vertebral diameters at L3 and the interpedicular distances at L1 and L5 were significantly smaller in the patients than in the control subjects (P < 0.001); however, at L5 the canal was wider, relative to the vertebral body. The study group had a higher rate of anterior osteophytes in the lumbar spine than the controls had, and their osteophytes were also significantly larger. In the six patients for whom radiographs of the upper extremity in its entirety were available on one film, the ulna appeared to be rotated. In one 22-year-old man, multiple epiphyses were still open. Congenital IGF-1 deficiency leads to skeletal abnormalities

Abnormalities of the axial and proximal appendicular skeleton in adults with Laron syndrome (growth hormone insensitivity)

International Nuclear Information System (INIS)

Kornreich, L.; Konen, O.; Schwarz, M.; Horev, G.; Siegel, Y.; Hershkovitz, I.; Laron, Z.

2008-01-01

To investigate abnormalities in the skeleton (with the exclusion of the skull, cervical spine, hands and feet) in patients with Laron syndrome, who have an inborn growth hormone resistance and congenital insulin-like growth factor-1 (IGF-1) deficiency. The study group was composed of 15 untreated patients with Laron syndrome (seven male and eight female) aged 21-68 years. Plain films of the axial and appendicular skeleton were evaluated retrospectively for abnormalities in structure and shape. The cortical width of the long bones was evaluated qualitatively and quantitatively (in the upper humerus and mid-femur), and the cortical index was calculated and compared with published references. Measurements were taken of the mid-anteroposterior and cranio-caudal diameters of the vertebral body and spinous process at L3, the interpedicular distance at L1 and L5, and the sacral slope. Thoracic and lumbar osteophytes were graded on a 5-point scale. Values were compared with a control group of 20 healthy persons matched for age. The skeleton appeared small in all patients. No signs of osteopenia were visible. The cortex of the long bones appeared thick in the upper limbs in 11 patients and in the lower limbs in four. Compared with the reference values, the cortical width was thicker than average in the humerus and thinner in the femur. The vertebral diameters at L3 and the interpedicular distances at L1 and L5 were significantly smaller in the patients than in the control subjects (P < 0.001); however, at L5 the canal was wider, relative to the vertebral body. The study group had a higher rate of anterior osteophytes in the lumbar spine than the controls had, and their osteophytes were also significantly larger. In the six patients for whom radiographs of the upper extremity in its entirety were available on one film, the ulna appeared to be rotated. In one 22-year-old man, multiple epiphyses were still open. Congenital IGF-1 deficiency leads to skeletal abnormalities

A cortical–hippocampal–cortical loop of information processing during memory consolidation

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Rothschild, Gideon; Eban, Elad; Frank, Loren M

2018-01-01

Hippocampal replay during sharp-wave ripple events (SWRs) is thought to drive memory consolidation in hippocampal and cortical circuits. Changes in neocortical activity can precede SWR events, but whether and how these changes influence the content of replay remains unknown. Here we show that during sleep there is a rapid cortical–hippocampal–cortical loop of information flow around the times of SWRs. We recorded neural activity in auditory cortex (AC) and hippocampus of rats as they learned a sound-guided task and during sleep. We found that patterned activation in AC precedes and predicts the subsequent content of hippocampal activity during SWRs, while hippocampal patterns during SWRs predict subsequent AC activity. Delivering sounds during sleep biased AC activity patterns, and sound-biased AC patterns predicted subsequent hippocampal activity. These findings suggest that activation of specific cortical representations during sleep influences the identity of the memories that are consolidated into long-term stores. PMID:27941790

Predicting infant cortical surface development using a 4D varifold-based learning framework and local topography-based shape morphing.

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Rekik, Islem; Li, Gang; Lin, Weili; Shen, Dinggang

2016-02-01

Longitudinal neuroimaging analysis methods have remarkably advanced our understanding of early postnatal brain development. However, learning predictive models to trace forth the evolution trajectories of both normal and abnormal cortical shapes remains broadly absent. To fill this critical gap, we pioneered the first prediction model for longitudinal developing cortical surfaces in infants using a spatiotemporal current-based learning framework solely from the baseline cortical surface. In this paper, we detail this prediction model and even further improve its performance by introducing two key variants. First, we use the varifold metric to overcome the limitations of the current metric for surface registration that was used in our preliminary study. We also extend the conventional varifold-based surface registration model for pairwise registration to a spatiotemporal surface regression model. Second, we propose a morphing process of the baseline surface using its topographic attributes such as normal direction and principal curvature sign. Specifically, our method learns from longitudinal data both the geometric (vertices positions) and dynamic (temporal evolution trajectories) features of the infant cortical surface, comprising a training stage and a prediction stage. In the training stage, we use the proposed varifold-based shape regression model to estimate geodesic cortical shape evolution trajectories for each training subject. We then build an empirical mean spatiotemporal surface atlas. In the prediction stage, given an infant, we select the best learnt features from training subjects to simultaneously predict the cortical surface shapes at all later timepoints, based on similarity metrics between this baseline surface and the learnt baseline population average surface atlas. We used a leave-one-out cross validation method to predict the inner cortical surface shape at 3, 6, 9 and 12 months of age from the baseline cortical surface shape at birth. Our

Abnormal resting-state cortical coupling in chronic tinnitus

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Langguth Berthold

2009-02-01

Full Text Available Abstract Background Subjective tinnitus is characterized by an auditory phantom perception in the absence of any physical sound source. Consequently, in a quiet environment, tinnitus patients differ from control participants because they constantly perceive a sound whereas controls do not. We hypothesized that this difference is expressed by differential activation of distributed cortical networks. Results The analysis was based on a sample of 41 participants: 21 patients with chronic tinnitus and 20 healthy control participants. To investigate the architecture of these networks, we used phase locking analysis in the 1–90 Hz frequency range of a minute of resting-state MEG recording. We found: 1 For tinnitus patients: A significant decrease of inter-areal coupling in the alpha (9–12 Hz band and an increase of inter-areal coupling in the 48–54 Hz gamma frequency range relative to the control group. 2 For both groups: an inverse relationship (r = -.71 of the alpha and gamma network coupling. 3 A discrimination of 83% between the patient and the control group based on the alpha and gamma networks. 4 An effect of manifestation on the distribution of the gamma network: In patients with a tinnitus history of less than 4 years, the left temporal cortex was predominant in the gamma network whereas in patients with tinnitus duration of more than 4 years, the gamma network was more widely distributed including more frontal and parietal regions. Conclusion In the here presented data set we found strong support for an alteration of long-range coupling in tinnitus. Long-range coupling in the alpha frequency band was decreased for tinnitus patients while long-range gamma coupling was increased. These changes discriminate well between tinnitus and control participants. We propose a tinnitus model that integrates this finding in the current knowledge about tinnitus. Furthermore we discuss the impact of this finding to tinnitus therapies using Transcranial

Abnormal regional homogeneity in patients with essential tremor revealed by resting-state functional MRI.

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Weidong Fang

Full Text Available Essential tremor (ET is one of the most common movement disorders in human adults. It can be characterized as a progressive neurological disorder of which the most recognizable feature is a tremor of the arms or hands that is apparent during voluntary movements such as eating and writing. The pathology of ET remains unclear. Resting-state fMRI (RS-fMRI, as a non-invasive imaging technique, was employed to investigate abnormalities of functional connectivity in ET in the brain. Regional homogeneity (ReHo was used as a metric of RS-fMRI to assess the local functional connectivity abnormality in ET with 20 ET patients and 20 age- and gender-matched healthy controls (HC. The ET group showed decreased ReHo in the anterior and posterior bilateral cerebellar lobes, the bilateral thalamus and the insular lobe, and increased ReHo in the bilateral prefrontal and parietal cortices, the left primary motor cortex and left supplementary motor area. The abnormal ReHo value of ET patients in the bilateral anterior cerebellar lobes and the right posterior cerebellar lobe were negatively correlated with the tremor severity score, while positively correlated with that in the left primary motor cortex. These findings suggest that the abnormality in cerebello-thalamo-cortical motor pathway is involved in tremor generation and propagation, which may be related to motor-related symptoms in ET patients. Meanwhile, the abnormality in the prefrontal and parietal regions may be associated with non-motor symptoms in ET. These findings suggest that the ReHo could be utilized for investigations of functional-pathological mechanism of ET.

Abnormalities of white matter microstructure in unmedicated obsessive-compulsive disorder and changes after medication.

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Qing Fan

Full Text Available BACKGROUND: Abnormalities of myelin integrity have been reported in obsessive-compulsive disorder (OCD using multi-parameter maps of diffusion tensor imaging (DTI. However, it was still unknown to what degree these abnormalities might be affected by pharmacological treatment. OBJECTIVE: To investigate whether the abnormalities of white matter microstructure including myelin integrity exist in OCD and whether they are affected by medication. METHODOLOGY AND PRINCIPAL FINDINGS: Parameter maps of DTI, including fractional anisotropy (FA, axial diffusivity (AD, radial diffusivity (RD and mean diffusivity (MD, were acquired from 27 unmedicated OCD patients (including 13 drug-naïve individuals and 23 healthy controls. Voxel-based analysis was then performed to detect regions with significant group difference. We compared the DTI-derived parameters of 15 patients before and after 12-week Selective Serotonin Reuptake Inhibitor (SSRI therapies. Significant differences of DTI-derived parameters were observed between OCD and healthy groups in multiple structures, mainly within the fronto-striato-thalamo-cortical loop. An increased RD in combination with no change in AD among OCD patients was found in the left medial superior frontal gyrus, temporo-parietal lobe, occipital lobe, striatum, insula and right midbrain. There was no statistical difference in DTI-derived parameters between drug-naive and previously medicated OCD patients. After being medicated, OCD patients showed a reduction in RD of the left striatum and right midbrain, and in MD of the right midbrain. CONCLUSION: Our preliminary findings suggest that abnormalities of white matter microstructure, particularly in terms of myelin integrity, are primarily located within the fronto-striato-thalamo-cortical circuit of individuals with OCD. Some abnormalities may be partly reversed by SSRI treatment.

Adolescent cortical thickness pre- and post marijuana and alcohol initiation.

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Jacobus, Joanna; Castro, Norma; Squeglia, Lindsay M; Meloy, M J; Brumback, Ty; Huestis, Marilyn A; Tapert, Susan F

Cortical thickness abnormalities have been identified in youth using both alcohol and marijuana. However, limited studies have followed individuals pre- and post initiation of alcohol and marijuana use to help identify to what extent discrepancies in structural brain integrity are pre-existing or substance-related. Adolescents (N=69) were followed from ages 13 (pre-initiation of substance use, baseline) to ages 19 (post-initiation, follow-up). Three subgroups were identified, participants that initiated alcohol use (ALC, n=23, >20 alcohol use episodes), those that initiated both alcohol and marijuana use (ALC+MJ, n=23, >50 marijuana use episodes) and individuals that did not initiate either substance regularly by follow-up (CON, n=23, marijuana use episodes). All adolescents underwent neurocognitive testing, neuroimaging, and substance use and mental health interviews. Significant group by time interactions and main effects on cortical thickness estimates were identified for 18 cortical regions spanning the left and right hemisphere (pseffect, in cortical thickness by follow-up for individuals who have not initiated regular substance use or alcohol use only by age 19; modest between-group differences were identified at baseline in several cortical regions (ALC and CON>ALC+MJ). Minimal neurocognitive differences were observed in this sample. Findings suggest pre-existing neural differences prior to marijuana use may contribute to initiation of use and observed neural outcomes. Marijuana use may also interfere with thinning trajectories that contribute to morphological differences in young adulthood that are often observed in cross-sectional studies of heavy marijuana users. Copyright © 2016 Elsevier Inc. All rights reserved.

Competing sound sources reveal spatial effects in cortical processing.

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Ross K Maddox

Full Text Available Why is spatial tuning in auditory cortex weak, even though location is important to object recognition in natural settings? This question continues to vex neuroscientists focused on linking physiological results to auditory perception. Here we show that the spatial locations of simultaneous, competing sound sources dramatically influence how well neural spike trains recorded from the zebra finch field L (an analog of mammalian primary auditory cortex encode source identity. We find that the location of a birdsong played in quiet has little effect on the fidelity of the neural encoding of the song. However, when the song is presented along with a masker, spatial effects are pronounced. For each spatial configuration, a subset of neurons encodes song identity more robustly than others. As a result, competing sources from different locations dominate responses of different neural subpopulations, helping to separate neural responses into independent representations. These results help elucidate how cortical processing exploits spatial information to provide a substrate for selective spatial auditory attention.

Abnormal distracter processing in adults with attention-deficit-hyperactivity disorder.

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Frank Marzinzik

Full Text Available BACKGROUND: Subjects with Attention-Deficit Hyperactivity Disorder (ADHD are overdistractible by stimuli out of the intended focus of attention. This control deficit could be due to primarily reduced attentional capacities or, e. g., to overshooting orienting to unexpected events. Here, we aimed at identifying disease-related abnormalities of novelty processing and, therefore, studied event-related potentials (ERP to respective stimuli in adult ADHD patients compared to healthy subjects. METHODS: Fifteen unmedicated subjects with ADHD and fifteen matched controls engaged in a visual oddball task (OT under simultaneous EEG recordings. A target stimulus, upon which a motor response was required, and non-target stimuli, which did not demand a specific reaction, were presented in random order. Target and most non-target stimuli were presented repeatedly, but some non-target stimuli occurred only once ('novels'. These unique stimuli were either 'relative novels' with which a meaning could be associated, or 'complete novels', if no association was available. RESULTS: In frontal recordings, a positive component with a peak latency of some 400 ms became maximal after novels. In healthy subjects, this novelty-P3 (or 'orienting response' was of higher magnitude after complete than after relative novels, in contrast to the patients with an undifferentially high frontal responsivity. Instead, ADHD patients tended to smaller centro-parietal P3 responses after target signals and, on a behavioural level, responded slower than controls. CONCLUSION: The results demonstrate abnormal novelty processing in adult subjects with ADHD. In controls, the ERP pattern indicates that allocation of meaning modulates the processing of new stimuli. However, in ADHD such a modulation was not prevalent. Instead, also familiar, only context-wise new stimuli were treated as complete novels. We propose that disturbed semantic processing of new stimuli resembles a mechanism for

Parenchymal abnormalities associated with developmental venous anomalies

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San Millan Ruiz, Diego; Gailloud, Philippe [Johns Hopkins Hospital, Division of Interventional Neuroradiology, Baltimore, MD (United States); Delavelle, Jacqueline [Geneva University Hospital, Neuroradiology Section, Department of Radiology and Medical Informatics, Geneva (Switzerland); Yilmaz, Hasan; Ruefenacht, Daniel A. [Geneva University Hospital, Section of Interventional Neuroradiology, Department of Clinical Neurosciences, Geneva (Switzerland); Piovan, Enrico; Bertramello, Alberto; Pizzini, Francesca [Verona City Hospital, Service of Neuroradiology, Verona (Italy)

2007-12-15

To report a retrospective series of 84 cerebral developmental venous anomalies (DVAs), focusing on associated parenchymal abnormalities within the drainage territory of the DVA. DVAs were identified during routine diagnostic radiological work-up based on magnetic resonance imaging (MRI) (60 cases), computed tomography (CT) (62 cases) or both (36 cases). Regional parenchymal modifications within the drainage territory of the DVA, such as cortical or subcortical atrophy, white matter density or signal alterations, dystrophic calcifications, presence of haemorrhage or a cavernous-like vascular malformation (CVM), were noted. A stenosis of the collecting vein of the DVA was also sought for. Brain abnormalities within the drainage territory of a DVA were encountered in 65.4% of the cases. Locoregional brain atrophy occurred in 29.7% of the cases, followed by white matter lesions in 28.3% of MRI investigations and 19.3% of CT investigations, CVMs in 13.3% of MRI investigations and dystrophic calcification in 9.6% of CT investigations. An intracranial haemorrhage possibly related to a DVA occurred in 2.4% cases, and a stenosis on the collecting vein was documented in 13.1% of cases. Parenchymal abnormalities were identified for all DVA sizes. Brain parenchymal abnormalities were associated with DVAs in close to two thirds of the cases evaluated. These abnormalities are thought to occur secondarily, likely during post-natal life, as a result of chronic venous hypertension. Outflow obstruction, progressive thickening of the walls of the DVA and their morphological organization into a venous convergence zone are thought to contribute to the development of venous hypertension in DVA. (orig.)

Cortical sensorimotor alterations classify clinical phenotype and putative genotype of spasmodic dysphonia

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Battistella, Giovanni; Fuertinger, Stefan; Fleysher, Lazar; Ozelius, Laurie J.; Simonyan, Kristina

2017-01-01

Background Spasmodic dysphonia (SD), or laryngeal dystonia, is a task-specific isolated focal dystonia of unknown causes and pathophysiology. Although functional and structural abnormalities have been described in this disorder, the influence of its different clinical phenotypes and genotypes remains scant, making it difficult to explain SD pathophysiology and to identify potential biomarkers. Methods We used a combination of independent component analysis and linear discriminant analysis of resting-state functional MRI data to investigate brain organization in different SD phenotypes (abductor vs. adductor type) and putative genotypes (familial vs. sporadic cases) and to characterize neural markers for genotype/phenotype categorization. Results We found abnormal functional connectivity within sensorimotor and frontoparietal networks in SD patients compared to healthy individuals as well as phenotype- and genotype-distinct alterations of these networks, involving primary somatosensory, premotor and parietal cortices. The linear discriminant analysis achieved 71% accuracy classifying SD and healthy individuals using connectivity measures in the left inferior parietal and sensorimotor cortex. When categorizing between different forms of SD, the combination of measures from left inferior parietal, premotor and right sensorimotor cortices achieved 81% discriminatory power between familial and sporadic SD cases, whereas the combination of measures from the right superior parietal, primary somatosensory and premotor cortices led to 71% accuracy in the classification of adductor and abductor SD forms. Conclusions Our findings present the first effort to identify and categorize isolated focal dystonia based on its brain functional connectivity profile, which may have a potential impact on the future development of biomarkers for this rare disorder. PMID:27346568

Abnormal development of sensory-motor, visual temporal and parahippocampal cortex in children with learning disabilities and borderline intellectual functioning

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Francesca eBaglio

2014-10-01

Full Text Available Borderline intellectual functioning (BIF is a condition characterized by an intelligence quotient (IQ between 70 and 85. BIF children present with cognitive, motor, social and adaptive limitations that result in learning disabilities and are more likely to develop psychiatric disorders later in life. Aim of this study was to investigate brain morphometry and its relation to IQ level in borderline intellectual functioning children.Thirteen children with BIF and 14 age- and sex-matched typically developing children were enrolled. All children underwent a full IQ assessment (WISC-III scale and a Magnetic Resonance (MR examination including conventional sequences to assess brain structural abnormalities and high resolution 3D images for voxel based morphometry (VBM analysis. To investigate to what extent the group influenced gray matter volumes, both univariate and multivariate generalized linear model analysis of variance were used, and the varimax factor analysis was used to explore variable correlations and clusters among subjects. Results showed that BIF children, compared to controls have increased regional gray matter volume in bilateral sensori-motor and right posterior temporal cortices and decreased gray matter volume in right parahippocampal gyrus. Gray matter volumes were highly correlated with IQ indices.Our is a case study of a group of BIF children showing that BIF is associated with abnormal cortical development in brain areas that have a pivotal role in motor, learning and behavioral processes. Our findings, although allowing for little generalization to general population, contributes to the very limited knowledge in this field. Future longitudinal MR studies will be useful in verifying whether cortical features can be modified over time even in association with rehabilitative intervention.

Is cortical bone hip? What determines cortical bone properties?

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Epstein, Sol

2007-07-01

Increased bone turnover may produce a disturbance in bone structure which may result in fracture. In cortical bone, both reduction in turnover and increase in hip bone mineral density (BMD) may be necessary to decrease hip fracture risk and may require relatively greater proportionate changes than for trabecular bone. It should also be noted that increased porosity produces disproportionate reduction in bone strength, and studies have shown that increased cortical porosity and decreased cortical thickness are associated with hip fracture. Continued studies for determining the causes of bone strength and deterioration show distinct promise. Osteocyte viability has been observed to be an indicator of bone strength, with viability as the result of maintaining physiological levels of loading and osteocyte apoptosis as the result of a decrease in loading. Osteocyte apoptosis and decrease are major factors in the bone loss and fracture associated with aging. Both the osteocyte and periosteal cell layer are assuming greater importance in the process of maintaining skeletal integrity as our knowledge of these cells expand, as well being a target for pharmacological agents to reduce fracture especially in cortical bone. The bisphosphonate alendronate has been seen to have a positive effect on cortical bone by allowing customary periosteal growth, while reducing the rate of endocortical bone remodeling and slowing bone loss from the endocortical surface. Risedronate treatment effects were attributed to decrease in bone resorption and thus a decrease in fracture risk. Ibandronate has been seen to increase BMD as the spine and femur as well as a reduced incidence of new vertebral fractures and non vertebral on subset post hoc analysis. And treatment with the anabolic agent PTH(1-34) documented modeling and remodelling of quiescent and active bone surfaces. Receptor activator of nuclear factor kappa B ligand (RANKL) plays a key role in bone destruction, and the human monoclonal

Prominent microglial activation in cortical white matter is selectively associated with cortical atrophy in primary progressive aphasia.

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Ohm, Daniel T; Kim, Garam; Gefen, Tamar; Rademaker, Alfred; Weintraub, Sandra; Bigio, Eileen; Mesulam, M-Marsel; Rogalski, Emily; Geula, Changiz

2018-04-21

Primary progressive aphasia (PPA) is a clinical syndrome characterized by selective language impairments associated with focal cortical atrophy favouring the language dominant hemisphere. PPA is associated with Alzheimer's disease (AD), frontotemporal lobar degeneration (FTLD), and significant accumulation of activated microglia. Activated microglia can initiate an inflammatory cascade that may contribute to neurodegeneration, but their quantitative distribution in cortical white matter and their relationship with cortical atrophy are unknown. We investigated white matter activated microglia and their association with grey matter atrophy in 10 PPA cases with either AD or FTLD-TDP pathology. Activated microglia were quantified with optical density measures of HLA-DR immunoreactivity in two regions with peak cortical atrophy, and one non-atrophied region within the language dominant hemisphere of each PPA case. Non-atrophied contralateral homologues of the language dominant regions were examined for hemispheric asymmetry. Qualitatively, greater densities of activated microglia were observed in cortical white matter when compared to grey matter. Quantitative analyses revealed significantly greater densities of activated microglia in the white matter of atrophied regions compared to non-atrophied regions in the language dominant hemisphere (p<0.05). Atrophied regions of the language dominant hemisphere also showed significantly more activated microglia compared to contralateral homologues (p<0.05). White matter activated microglia accumulate more in atrophied regions in the language dominant hemisphere of PPA. While microglial activation may constitute a response to neurodegenerative processes in white matter, the resultant inflammatory processes may also exacerbate disease progression and contribute to cortical atrophy. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Spontaneously emerging cortical representations of visual attributes

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Kenet, Tal; Bibitchkov, Dmitri; Tsodyks, Misha; Grinvald, Amiram; Arieli, Amos

2003-10-01

Spontaneous cortical activity-ongoing activity in the absence of intentional sensory input-has been studied extensively, using methods ranging from EEG (electroencephalography), through voltage sensitive dye imaging, down to recordings from single neurons. Ongoing cortical activity has been shown to play a critical role in development, and must also be essential for processing sensory perception, because it modulates stimulus-evoked activity, and is correlated with behaviour. Yet its role in the processing of external information and its relationship to internal representations of sensory attributes remains unknown. Using voltage sensitive dye imaging, we previously established a close link between ongoing activity in the visual cortex of anaesthetized cats and the spontaneous firing of a single neuron. Here we report that such activity encompasses a set of dynamically switching cortical states, many of which correspond closely to orientation maps. When such an orientation state emerged spontaneously, it spanned several hypercolumns and was often followed by a state corresponding to a proximal orientation. We suggest that dynamically switching cortical states could represent the brain's internal context, and therefore reflect or influence memory, perception and behaviour.

Identifying Cortical Lateralization of Speech Processing in Infants Using Near-Infrared Spectroscopy

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Bortfeld, Heather; Fava, Eswen; Boas, David A.

2010-01-01

We investigate the utility of near-infrared spectroscopy (NIRS) as an alternative technique for studying infant speech processing. NIRS is an optical imaging technology that uses relative changes in total hemoglobin concentration and oxygenation as an indicator of neural activation. Procedurally, NIRS has the advantage over more common methods (e.g., fMRI) in that it can be used to study the neural responses of behaviorally active infants. Older infants (aged 6–9 months) were allowed to sit on their caretakers’ laps during stimulus presentation to determine relative differences in focal activity in the temporal region of the brain during speech processing. Results revealed a dissociation of sensory-specific processing in two cortical regions, the left and right temporal lobes. These findings are consistent with those obtained using other neurophysiological methods and point to the utility of NIRS as a means of establishing neural correlates of language development in older (and more active) infants. PMID:19142766

Pitch-Responsive Cortical Regions in Congenital Amusia.

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Norman-Haignere, Sam V; Albouy, Philippe; Caclin, Anne; McDermott, Josh H; Kanwisher, Nancy G; Tillmann, Barbara

2016-03-09

Congenital amusia is a lifelong deficit in music perception thought to reflect an underlying impairment in the perception and memory of pitch. The neural basis of amusic impairments is actively debated. Some prior studies have suggested that amusia stems from impaired connectivity between auditory and frontal cortex. However, it remains possible that impairments in pitch coding within auditory cortex also contribute to the disorder, in part because prior studies have not measured responses from the cortical regions most implicated in pitch perception in normal individuals. We addressed this question by measuring fMRI responses in 11 subjects with amusia and 11 age- and education-matched controls to a stimulus contrast that reliably identifies pitch-responsive regions in normal individuals: harmonic tones versus frequency-matched noise. Our findings demonstrate that amusic individuals with a substantial pitch perception deficit exhibit clusters of pitch-responsive voxels that are comparable in extent, selectivity, and anatomical location to those of control participants. We discuss possible explanations for why amusics might be impaired at perceiving pitch relations despite exhibiting normal fMRI responses to pitch in their auditory cortex: (1) individual neurons within the pitch-responsive region might exhibit abnormal tuning or temporal coding not detectable with fMRI, (2) anatomical tracts that link pitch-responsive regions to other brain areas (e.g., frontal cortex) might be altered, and (3) cortical regions outside of pitch-responsive cortex might be abnormal. The ability to identify pitch-responsive regions in individual amusic subjects will make it possible to ask more precise questions about their role in amusia in future work. Copyright © 2016 the authors 0270-6474/16/362986-09$15.00/0.

Responses of vibrissa-sensitive cortical neurons in normal and prenatally x-irradiated rat

International Nuclear Information System (INIS)

Ito, M.; Kawabata, M.; Shoji, R.

1979-01-01

Rats were irradiated by 200 R of x ray on day 17 of gestation through the body wall of the mother. When they underwent the following electrophysiological tests at the age of 3 to 4 month, the somatosensory cortex showed a lack of layers II, III, IV, and Va. Spike responses to quick whisker deflections were recorded from single cells in the somatosenory cortex of normal and prenatally x-irradiated rats. For the irradiated rats the response latency was prolonged when compared to the normal controls. Cortical laminar analysis of field potentials revealed that there was no difference in the latency of these potentials between the two groups, suggesting that vibrissal sensory signals reach the cortical level normally even in the irradiated rats. The prolonged latency of the irradiated cortical neuronal response could thus be ascribed to an abnormal intracortical delay, which was most likely associated with the failure of development of layer IV stellate cells in these preparations

Identification of a brainstem circuit regulating visual cortical state in parallel with locomotion.

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Lee, A Moses; Hoy, Jennifer L; Bonci, Antonello; Wilbrecht, Linda; Stryker, Michael P; Niell, Cristopher M

2014-07-16

Sensory processing is dependent upon behavioral state. In mice, locomotion is accompanied by changes in cortical state and enhanced visual responses. Although recent studies have begun to elucidate intrinsic cortical mechanisms underlying this effect, the neural circuits that initially couple locomotion to cortical processing are unknown. The mesencephalic locomotor region (MLR) has been shown to be capable of initiating running and is associated with the ascending reticular activating system. Here, we find that optogenetic stimulation of the MLR in awake, head-fixed mice can induce both locomotion and increases in the gain of cortical responses. MLR stimulation below the threshold for overt movement similarly changed cortical processing, revealing that MLR's effects on cortex are dissociable from locomotion. Likewise, stimulation of MLR projections to the basal forebrain also enhanced cortical responses, suggesting a pathway linking the MLR to cortex. These studies demonstrate that the MLR regulates cortical state in parallel with locomotion. Copyright © 2014 Elsevier Inc. All rights reserved.

Relationships between rotator cuff tear types and radiographic abnormalities

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Lee, Soo Hyun; Chun, Kyung Ah; Lee Soo Jung; Kang, Min Ho; Yi, Kyung Sik; Zhang, Ying [Dept. of Diagnostic Radiology, College of Medicine, Chungbuk National University, Cheongju (Korea, Republic of)

2014-11-15

To determine relationships between different types of rotator cuff tears and radiographic abnormalities. The shoulder radiographs of 104 patients with an arthroscopically proven rotator cuff tear were compared with similar radiographs of 54 age-matched controls with intact cuffs. Two radiologists independently interpreted all radiographs for; cortical thickening with subcortical sclerosis, subcortical cysts, osteophytes in the humeral greater tuberosity, humeral migration, degenerations of the acromioclavicular and glenohumeral joints, and subacromial spurs. Statistical analysis was performed to determine relationships between each type of rotator cuff tears and radiographic abnormalities. Inter-observer agreements with respect to radiographic findings were analyzed. Humeral migration and degenerative change of the greater tuberosity, including sclerosis, subcortical cysts, and osteophytes, were more associated with full-thickness tears (p < 0.01). Subacromial spurs were more common for full-thickness and bursal-sided tears (p < 0.01). No association was found between degeneration of the acromioclavicular or glenohumeral joint and the presence of a cuff tear. Different types of rotator cuff tears are associated with different radiographic abnormalities.

Relationships between rotator cuff tear types and radiographic abnormalities

International Nuclear Information System (INIS)

Lee, Soo Hyun; Chun, Kyung Ah; Lee Soo Jung; Kang, Min Ho; Yi, Kyung Sik; Zhang, Ying

2014-01-01

To determine relationships between different types of rotator cuff tears and radiographic abnormalities. The shoulder radiographs of 104 patients with an arthroscopically proven rotator cuff tear were compared with similar radiographs of 54 age-matched controls with intact cuffs. Two radiologists independently interpreted all radiographs for; cortical thickening with subcortical sclerosis, subcortical cysts, osteophytes in the humeral greater tuberosity, humeral migration, degenerations of the acromioclavicular and glenohumeral joints, and subacromial spurs. Statistical analysis was performed to determine relationships between each type of rotator cuff tears and radiographic abnormalities. Inter-observer agreements with respect to radiographic findings were analyzed. Humeral migration and degenerative change of the greater tuberosity, including sclerosis, subcortical cysts, and osteophytes, were more associated with full-thickness tears (p < 0.01). Subacromial spurs were more common for full-thickness and bursal-sided tears (p < 0.01). No association was found between degeneration of the acromioclavicular or glenohumeral joint and the presence of a cuff tear. Different types of rotator cuff tears are associated with different radiographic abnormalities.

Motor cortical processing is causally involved in object recognition.

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Decloe, Rebecca; Obhi, Sukhvinder S

2013-12-14

Motor activity during vicarious experience of actions is a widely reported and studied phenomenon, and motor system activity also accompanies observation of graspable objects in the absence of any actions. Such motor activity is thought to reflect simulation of the observed action, or preparation to interact with the object, respectively. Here, in an initial exploratory study, we ask whether motor activity during observation of object directed actions is involved in processes related to recognition of the object after initial exposure. Single pulse Transcranial Magnetic Stimulation (TMS) was applied over the thumb representation of the motor cortex, or over the vertex, during observation of a model thumb typing on a cell-phone, and performance on a phone recognition task at the end of the trial was assessed. Disrupting motor processing over the thumb representation 100 ms after the onset of the typing video impaired the ability to recognize the phone in the recognition test, whereas there was no such effect for TMS applied over the vertex and no TMS trials. Furthermore, this effect only manifested for videos observed from the first person perspective. In an additional control condition, there was no evidence for any effects of TMS to the thumb representation or vertex when observing and recognizing non-action related shape stimuli. Overall, these data provide evidence that motor cortical processing during observation of object-directed actions from a first person perspective is causally linked to the formation of enduring representations of objects-of-action.

Cortical Network Dynamics of Perceptual Decision-Making in the Human Brain

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Markus eSiegel

2011-02-01

Full Text Available Goal-directed behavior requires the flexible transformation of sensory evidence about our environment into motor actions. Studies of perceptual decision-making have shown that this transformation is distributed across several widely separated brain regions. Yet, little is known about how decision-making emerges from the dynamic interactions among these regions. Here, we review a series of studies, in which we characterized the cortical network interactions underlying a perceptual decision process in the human brain. We used magnetoencephalography (MEG to measure the large-scale cortical population dynamics underlying each of the sub-processes involved in this decision: the encoding of sensory evidence and action plan, the mapping between the two, and the attentional selection of task-relevant evidence. We found that these sub-processes are mediated by neuronal oscillations within specific frequency ranges. Localized gamma-band oscillations in sensory and motor cortices reflect the encoding of the sensory evidence and motor plan. Large-scale oscillations across widespread cortical networks mediate the integrative processes connecting these local networks: Gamma- and beta-band oscillations across frontal, parietal and sensory cortices serve the selection of relevant sensory evidence and its flexible mapping onto action plans. In sum, our results suggest that perceptual decisions are mediated by oscillatory interactions within overlapping local and large-scale cortical networks.

Abnormal emotional processing in maltreated children diagnosed of Complex Posttraumatic Stress Disorder.

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Bertó, Clara; Ferrin, Maite; Barberá, María; Livianos, Lorenzo; Rojo, Luis; García-Blanco, Ana

2017-11-01

Maltreated children usually show a specific pattern of emotional and behavioral symptoms that exceed those relating to posttraumatic stress disorder (PTSD). These symptoms have been defined as Complex PTSD (CPTSD). The underlying attentional mechanisms of abnormal emotional processing and their relation to the clinical presentation of CPTSD are not well understood. A visual dot-probe paradigm involving pre-attentive (i.e., 500ms) and attentive (i.e., 1500ms) presentation rates of neutral versus emotional (i.e., angry, happy or sad) facial expressions was applied. Twenty-one maltreated CPTSD children were compared with twenty-six controls. The results are as follows: an attention bias away from threatening faces and an attentional bias towards sad faces were observed in maltreated CPTSD children during pre-attentive and attentive processing. Whereas the attentional bias away from angry faces was associated with social problems, the attentional bias towards sad faces was associated with depressive and withdrawn symptoms. Therefore, CPTSD children develop maladaptive negative cognitive styles, which may underlie not only social problems (by a cognitive avoidance of threatening stimuli) but also depressive symptoms (by a cognitive approach to sad stimuli). Attention processing abnormalities should be considered as therapeutic targets for new treatment approaches in this population. Copyright © 2017 Elsevier Ltd. All rights reserved.

The signer and the sign: cortical correlates of person identity and language processing from point-light displays.

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Campbell, Ruth; Capek, Cheryl M; Gazarian, Karine; MacSweeney, Mairéad; Woll, Bencie; David, Anthony S; McGuire, Philip K; Brammer, Michael J

2011-09-01

In this study, the first to explore the cortical correlates of signed language (SL) processing under point-light display conditions, the observer identified either a signer or a lexical sign from a display in which different signers were seen producing a number of different individual signs. Many of the regions activated by point-light under these conditions replicated those previously reported for full-image displays, including regions within the inferior temporal cortex that are specialised for face and body-part identification, although such body parts were invisible in the display. Right frontal regions were also recruited - a pattern not usually seen in full-image SL processing. This activation may reflect the recruitment of information about person identity from the reduced display. A direct comparison of identify-signer and identify-sign conditions showed these tasks relied to a different extent on the posterior inferior regions. Signer identification elicited greater activation than sign identification in (bilateral) inferior temporal gyri (BA 37/19), fusiform gyri (BA 37), middle and posterior portions of the middle temporal gyri (BAs 37 and 19), and superior temporal gyri (BA 22 and 42). Right inferior frontal cortex was a further focus of differential activation (signer>sign). These findings suggest that the neural systems supporting point-light displays for the processing of SL rely on a cortical network including areas of the inferior temporal cortex specialized for face and body identification. While this might be predicted from other studies of whole body point-light actions (Vaina, Solomon, Chowdhury, Sinha, & Belliveau, 2001) it is not predicted from the perspective of spoken language processing, where voice characteristics and speech content recruit distinct cortical regions (Stevens, 2004) in addition to a common network. In this respect, our findings contrast with studies of voice/speech recognition (Von Kriegstein, Kleinschmidt, Sterzer

The enemy within: propagation of aberrant corticostriatal learning to cortical function in Parkinson's disease

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Jeff A Beeler

2013-09-01

Full Text Available Motor dysfunction in Parkinson’s disease is believed to arise primarily from pathophysiology in the dorsal striatum and its related corticostriatal and thalamostriatal circuits during progressive dopamine denervation. One function of these circuits is to provide a filter that selectively facilitates or inhibits cortical activity to optimize cortical processing, making motor responses rapid and efficient. Corticostriatal synaptic plasticity mediates the learning that underlies this performance-optimizing filter. Under dopamine denervation, corticostriatal plasticity is altered, resulting in aberrant learning that induces inappropriate basal ganglia filtering that impedes rather than optimizes cortical processing. Human imaging suggests that increased cortical activity may compensate for striatal dysfunction in PD patients. In this Perspective article, we consider how aberrant learning at corticostriatal synapses may impair cortical processing and learning and undermine potential cortical compensatory mechanisms. Blocking or remediating aberrant corticostriatal plasticity may protect cortical function and support cortical compensatory mechanisms mitigating the functional decline associated with progressive dopamine denervation.

Long-term exposure to noise impairs cortical sound processing and attention control.

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Kujala, Teija; Shtyrov, Yury; Winkler, Istvan; Saher, Marieke; Tervaniemi, Mari; Sallinen, Mikael; Teder-Sälejärvi, Wolfgang; Alho, Kimmo; Reinikainen, Kalevi; Näätänen, Risto

2004-11-01

Long-term exposure to noise impairs human health, causing pathological changes in the inner ear as well as other anatomical and physiological deficits. Numerous individuals are daily exposed to excessive noise. However, there is a lack of systematic research on the effects of noise on cortical function. Here we report data showing that long-term exposure to noise has a persistent effect on central auditory processing and leads to concurrent behavioral deficits. We found that speech-sound discrimination was impaired in noise-exposed individuals, as indicated by behavioral responses and the mismatch negativity brain response. Furthermore, irrelevant sounds increased the distractibility of the noise-exposed subjects, which was shown by increased interference in task performance and aberrant brain responses. These results demonstrate that long-term exposure to noise has long-lasting detrimental effects on central auditory processing and attention control.

Cortical visual impairment

OpenAIRE

Koželj, Urša

2013-01-01

In this thesis we discuss cortical visual impairment, diagnosis that is in the developed world in first place, since 20 percent of children with blindness or low vision are diagnosed with it. The objectives of the thesis are to define cortical visual impairment and the definition of characters suggestive of the cortical visual impairment as well as to search for causes that affect the growing diagnosis of cortical visual impairment. There are a lot of signs of cortical visual impairment. ...

Can zero-hour cortical biopsy predict early graft outcomes after living donor renal transplantation?

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Rathore, Ranjeet Singh; Mehta, Nisarg; Mehta, Sony Bhaskar; Babu, Manas; Bansal, Devesh; Pillai, Biju S; Sam, Mohan P; Krishnamoorthy, Hariharan

2017-11-01

The aim of this study was to identify relevance of subclinical pathological findings in the kidneys of living donors and correlate these with early graft renal function. This was a prospective study on 84 living donor kidney transplant recipients over a period of two years. In all the donors, cortical wedge biopsy was taken and sent for assessment of glomerular, mesangial, and tubule status. The graft function of patients with normal histology was compared with those of abnormal histological findings at one, three, and six months, and one year post-surgery. Most abnormal histological findings were of mild degree. Glomerulosclerosis (GS, 25%), interstitial fibrosis (IF, 13%), acute tubular necrosis (ATN 5%), and focal tubal atrophy (FTA, 5%) were the commonly observed pathological findings in zero-hour biopsies. Only those donors who had histological changes of IF and ATN showed progressive deterioration of renal function at one month, three months, six months, and one year post-transplantation. In donors with other histological changes, no significant effect on graft function was observed. Zero-hour cortical biopsy gave us an idea of the general status of the donor kidney and presence or absence of subclinical pathological lesions. A mild degree of subclinical and pathological findings on zero-hour biopsy did not affect early graft renal function in living donor kidney transplantation. Zero-hour cortical biopsy could also help in discriminating donor-derived lesions from de novo alterations in the kidney that could happen subsequently.

Cortical processing of swallowing in ALS patients with progressive dysphagia--a magnetoencephalographic study.

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Inga K Teismann

Full Text Available Amyotrophic lateral sclerosis (ALS is a rare disease causing degeneration of the upper and lower motor neuron. Involvement of the bulbar motor neurons often results in fast progressive dysphagia. While cortical compensation of dysphagia has been previously shown in stroke patients, this topic has not been addressed in patients suffering from ALS. In the present study, we investigated cortical activation during deglutition in two groups of ALS patients with either moderate or severe dysphagia. Whole-head MEG was employed on fourteen patients with sporadic ALS using a self-paced swallowing paradigm. Data were analyzed by means of time-frequency analysis and synthetic aperture magnetometry (SAM. Group analysis of individual SAM data was performed using a permutation test. We found a reduction of cortical swallowing related activation in ALS patients compared to healthy controls. Additionally a disease-related shift of hemispheric lateralization was observed. While healthy subjects showed bilateral cortical activation, the right sensorimotor cortex was predominantly involved in ALS patients. Both effects were even stronger in the group of patients with severe dysphagia. Our results suggest that bilateral degeneration of the upper motor neuron in the primary motor areas also impairs further adjusted motor areas, which leads to a strong reduction of 'swallowing related' cortical activation. While both hemispheres are affected by the degeneration a relatively stronger activation is seen in the right hemisphere. This right hemispheric lateralization of volitional swallowing observed in this study may be the only sign of cortical plasticity in dysphagic ALS patients. It may demonstrate compensational mechanisms in the right hemisphere which is known to predominantly coordinate the pharyngeal phase of deglutition. These results add new aspects to our understanding of the pathophysiology of dysphagia in ALS patients and beyond. The compensational

Curcuma longa L. extract improves the cortical neural connectivity during the aging process.

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Flores, Gonzalo

2017-06-01

Turmeric or Curcuma is a natural product that has anti-inflammatory, antioxidant and anti-apoptotic pharmacological properties. It can be used in the control of the aging process that involves oxidative stress, inflammation, and apoptosis. Aging is a physiological process that affects higher cortical and cognitive functions with a reduction in learning and memory, limited judgment and deficits in emotional control and social behavior. Moreover, aging is a major risk factor for the appearance of several disorders such as cerebrovascular disease, diabetes mellitus, and hypertension. At the brain level, the aging process alters the synaptic intercommunication by a reduction in the dendritic arbor as well as the number of the dendritic spine in the pyramidal neurons of the prefrontal cortex, hippocampus and basolateral amygdala, consequently reducing the size of these regions. The present review discusses the synaptic changes caused by the aging process and the neuroprotective role the Curcuma has through its anti-inflammatory, antioxidant and anti-apoptotic actions.

Curcuma longa L. extract improves the cortical neural connectivity during the aging process

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Gonzalo Flores

2017-01-01

Full Text Available Turmeric or Curcuma is a natural product that has anti-inflammatory, antioxidant and anti-apoptotic pharmacological properties. It can be used in the control of the aging process that involves oxidative stress, inflammation, and apoptosis. Aging is a physiological process that affects higher cortical and cognitive functions with a reduction in learning and memory, limited judgment and deficits in emotional control and social behavior. Moreover, aging is a major risk factor for the appearance of several disorders such as cerebrovascular disease, diabetes mellitus, and hypertension. At the brain level, the aging process alters the synaptic intercommunication by a reduction in the dendritic arbor as well as the number of the dendritic spine in the pyramidal neurons of the prefrontal cortex, hippocampus and basolateral amygdala, consequently reducing the size of these regions. The present review discusses the synaptic changes caused by the aging process and the neuroprotective role the Curcuma has through its anti-inflammatory, antioxidant and anti-apoptotic actions

Curcuma longa L. extract improves the cortical neural connectivity during the aging process

Science.gov (United States)

Flores, Gonzalo

2017-01-01

Turmeric or Curcuma is a natural product that has anti-inflammatory, antioxidant and anti-apoptotic pharmacological properties. It can be used in the control of the aging process that involves oxidative stress, inflammation, and apoptosis. Aging is a physiological process that affects higher cortical and cognitive functions with a reduction in learning and memory, limited judgment and deficits in emotional control and social behavior. Moreover, aging is a major risk factor for the appearance of several disorders such as cerebrovascular disease, diabetes mellitus, and hypertension. At the brain level, the aging process alters the synaptic intercommunication by a reduction in the dendritic arbor as well as the number of the dendritic spine in the pyramidal neurons of the prefrontal cortex, hippocampus and basolateral amygdala, consequently reducing the size of these regions. The present review discusses the synaptic changes caused by the aging process and the neuroprotective role the Curcuma has through its anti-inflammatory, antioxidant and anti-apoptotic actions PMID:28761413

Parallel changes in cortical neuron biochemistry and motor function in protein-energy malnourished adult rats.

Science.gov (United States)

Alaverdashvili, Mariam; Hackett, Mark J; Caine, Sally; Paterson, Phyllis G

2017-04-01

While protein-energy malnutrition in the adult has been reported to induce motor abnormalities and exaggerate motor deficits caused by stroke, it is not known if alterations in mature cortical neurons contribute to the functional deficits. Therefore, we explored if PEM in adult rats provoked changes in the biochemical profile of neurons in the forelimb and hindlimb regions of the motor cortex. Fourier transform infrared spectroscopic imaging using a synchrotron generated light source revealed for the first time altered lipid composition in neurons and subcellular domains (cytosol and nuclei) in a cortical layer and region-specific manner. This change measured by the area under the curve of the δ(CH 2 ) band may indicate modifications in membrane fluidity. These PEM-induced biochemical changes were associated with the development of abnormalities in forelimb use and posture. The findings of this study provide a mechanism by which PEM, if not treated, could exacerbate the course of various neurological disorders and diminish treatment efficacy. Copyright © 2017 Elsevier Inc. All rights reserved.

Cortical morphology of adolescents with bipolar disorder and with schizophrenia.

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Janssen, Joost; Alemán-Gómez, Yasser; Schnack, Hugo; Balaban, Evan; Pina-Camacho, Laura; Alfaro-Almagro, Fidel; Castro-Fornieles, Josefina; Otero, Soraya; Baeza, Inmaculada; Moreno, Dolores; Bargalló, Nuria; Parellada, Mara; Arango, Celso; Desco, Manuel

2014-09-01

Recent evidence points to overlapping decreases in cortical thickness and gyrification in the frontal lobe of patients with adult-onset schizophrenia and bipolar disorder with psychotic symptoms, but it is not clear if these findings generalize to patients with a disease onset during adolescence and what may be the mechanisms underlying a decrease in gyrification. This study analyzed cortical morphology using surface-based morphometry in 92 subjects (age range 11-18 years, 52 healthy controls and 40 adolescents with early-onset first-episode psychosis diagnosed with schizophrenia (n=20) or bipolar disorder with psychotic symptoms (n=20) based on a two year clinical follow up). Average lobar cortical thickness, surface area, gyrification index (GI) and sulcal width were compared between groups, and the relationship between the GI and sulcal width was assessed in the patient group. Both patients groups showed decreased cortical thickness and increased sulcal width in the frontal cortex when compared to healthy controls. The schizophrenia subgroup also had increased sulcal width in all other lobes. In the frontal cortex of the combined patient group sulcal width was negatively correlated (r=-0.58, padolescents with schizophrenia and bipolar disorder with psychotic symptoms there is cortical thinning, decreased GI and increased sulcal width of the frontal cortex present at the time of the first psychotic episode. Decreased frontal GI is associated with the widening of the frontal sulci which may reduce sulcal surface area. These results suggest that abnormal growth (or more pronounced shrinkage during adolescence) of the frontal cortex represents a shared endophenotype for psychosis. Copyright © 2014 Elsevier B.V. All rights reserved.

Delineation of cortical pathology in multiple sclerosis using multi-surface magnetization transfer ratio imaging

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David A. Rudko

2016-01-01

Full Text Available The purpose of our study was to evaluate the utility of measurements of cortical surface magnetization transfer ratio (csMTR on the inner, mid and outer cortical boundaries as clinically accessible biomarkers of cortical gray matter pathology in multiple sclerosis (MS. Twenty-five MS patients and 12 matched controls were recruited from the MS Clinic of the Montreal Neurological Institute. Anatomical and magnetization transfer ratio (MTR images were acquired using 3 Tesla MRI at baseline and two-year time-points. MTR maps were smoothed along meshes representing the inner, mid and outer neocortical boundaries. To evaluate csMTR reductions suggestive of sub-pial demyelination in MS patients, a mixed model analysis was carried out at both the individual vertex level and in anatomically parcellated brain regions. Our results demonstrate that focal areas of csMTR reduction are most prevalent along the outer cortical surface in the superior temporal and posterior cingulate cortices, as well as in the cuneus and precentral gyrus. Additionally, age regression analysis identified that reductions of csMTR in MS patients increase with age but appear to hit a plateau in the outer caudal anterior cingulate, as well as in the precentral and postcentral cortex. After correction for the naturally occurring gradient in cortical MTR, the difference in csMTR between the inner and outer cortex in focal areas in the brains of MS patients correlated with clinical disability. Overall, our findings support multi-surface analysis of csMTR as a sensitive marker of cortical sub-pial abnormality indicative of demyelination in MS patients.

Defective cancellous bone structure and abnormal response to PTH in cortical bone of mice lacking Cx43 cytoplasmic C-terminus domain

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Pacheco-Costa, Rafael; Davis, Hannah M.; Sorenson, Chad; Hon, Mary C.; Hassan, Iraj; Reginato, Rejane D.; Allen, Matthew R.; Bellido, Teresita; Plotkin, Lilian I.

2015-01-01

Connexin43 (Cx43) forms gap junction channels and hemichannels that allow the communication among osteocytes, osteoblasts, and osteoclasts. Cx43 carboxy-terminal (CT) domain regulates channel opening and intracellular signaling by acting as a scaffold for structural and signaling proteins. To determine the role of Cx43 CT domain in bone, mice in which one allele of full length Cx43 was replaced by a mutant lacking the CT domain (Cx43ΔCT/fl) were studied. Cx43ΔCT/fl mice exhibit lower cancellous bone volume but higher cortical thickness than Cx43fl/fl controls, indicating that the CT domain is involved in normal cancellous bone gain but opposes cortical bone acquisition. Further, Cx43ΔCT is able to exert the functions of full length osteocytic Cx43 on cortical bone geometry and mechanical properties, demonstrating that domains other than the CT are responsible for Cx43 function in cortical bone. In addition, parathyroid hormone (PTH) failed to increase endocortical bone formation or energy to failure, a mechanical property that indicates resistance to fracture, in cortical bone in Cx43ΔCT mice with or without osteocytic full length Cx43. On the other hand, bone mass and bone formation markers were increased by the hormone in all mouse models, regardless of whether full length or Cx43ΔCT were or not expressed. We conclude that Cx43 CT domain is involved in proper bone acquisition; and that Cx43 expression in osteocytes is dispensable for some but not all PTH anabolic actions. PMID:26409319

A Preliminary Transcranial Magnetic Stimulation Study of Cortical Inhibition and Excitability in High-Functioning Autism and Asperger Disorder

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Enticott, Peter G.; Rinehart, Nicole J.; Tonge, Bruce J.; Bradshaw, John L.; Fitzgerald, Paul B.

2010-01-01

Aim: Controversy surrounds the distinction between high-functioning autism (HFA) and Asperger disorder, but motor abnormalities are associated features of both conditions. This study examined motor cortical inhibition and excitability in HFA and Asperger disorder using transcranial magnetic stimulation (TMS). Method: Participants were diagnosed by…

Cortical deficits of emotional face processing in adults with ADHD: its relation to social cognition and executive function.

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Ibáñez, Agustin; Petroni, Agustin; Urquina, Hugo; Torrente, Fernando; Torralva, Teresa; Hurtado, Esteban; Guex, Raphael; Blenkmann, Alejandro; Beltrachini, Leandro; Muravchik, Carlos; Baez, Sandra; Cetkovich, Marcelo; Sigman, Mariano; Lischinsky, Alicia; Manes, Facundo

2011-01-01

Although it has been shown that adults with attention-deficit hyperactivity disorder (ADHD) have impaired social cognition, no previous study has reported the brain correlates of face valence processing. This study looked for behavioral, neuropsychological, and electrophysiological markers of emotion processing for faces (N170) in adult ADHD compared to controls matched by age, gender, educational level, and handedness. We designed an event-related potential (ERP) study based on a dual valence task (DVT), in which faces and words were presented to test the effects of stimulus type (faces, words, or face-word stimuli) and valence (positive versus negative). Individual signatures of cognitive functioning in participants with ADHD and controls were assessed with a comprehensive neuropsychological evaluation, including executive functioning (EF) and theory of mind (ToM). Compared to controls, the adult ADHD group showed deficits in N170 emotion modulation for facial stimuli. These N170 impairments were observed in the absence of any deficit in facial structural processing, suggesting a specific ADHD impairment in early facial emotion modulation. The cortical current density mapping of N170 yielded a main neural source of N170 at posterior section of fusiform gyrus (maximum at left hemisphere for words and right hemisphere for faces and simultaneous stimuli). Neural generators of N170 (fusiform gyrus) were reduced in ADHD. In those patients, N170 emotion processing was associated with performance on an emotional inference ToM task, and N170 from simultaneous stimuli was associated with EF, especially working memory. This is the first report to reveal an adult ADHD-specific impairment in the cortical modulation of emotion for faces and an association between N170 cortical measures and ToM and EF.

Increased parietal circuit-breaker activity in delta frequency band and abnormal delta/theta band connectivity in salience network in hyperacusis subjects.

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Jae Joon Han

Full Text Available Recent studies have suggested that hyperacusis, an abnormal hypersensitivity to ordinary environmental sounds, may be characterized by certain resting-state cortical oscillatory patterns, even with no sound stimulus. However, previous studies are limited in that most studied subjects with other comorbidities that may have affected cortical activity. In this regard, to assess ongoing cortical oscillatory activity in idiopathic hyperacusis patients with no comorbidities, we compared differences in resting-state cortical oscillatory patterns between five idiopathic hyperacusis subjects and five normal controls. The hyperacusis group demonstrated significantly higher electrical activity in the right auditory-related cortex for the gamma frequency band and left superior parietal lobule (SPL for the delta frequency band versus the control group. The hyperacusis group also showed significantly decreased functional connectivity between the left auditory cortex (AC and left orbitofrontal cortex (OFC, between the left AC and left subgenual anterior cingulate cortex (sgACC for the gamma band, and between the right insula and bilateral dorsal anterior cingulate cortex (dACC and between the left AC and left sgACC for the theta band versus the control group. The higher electrical activity in the SPL may indicate a readiness of "circuit-breaker" activity to shift attention to forthcoming sound stimuli. Also, because of the disrupted salience network, consisting of the dACC and insula, abnormally increased salience to all sound stimuli may emerge, as a consequence of decreased top-down control of the AC by the dACC and dysfunctional emotional weight attached to auditory stimuli by the OFC. Taken together, abnormally enhanced attention and salience to forthcoming sound stimuli may render hyperacusis subjects hyperresponsive to non-noxious auditory stimuli.

Longitudinal MRI Study of Cortical Development through Early Childhood in Autism

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Schumann, C.M.; Bloss, C.S.; Barnes, C. Carter; Wideman, G.M.; Carper, R.A.; Akshoomoff, N.; Pierce, K.; Hagler, D.; Schork, N.; Lord, C.; Courchesne, E.

2010-01-01

Cross-sectional MRI studies have long hypothesized that the brain in children with autism undergoes an abnormal growth trajectory that includes a period of early overgrowth; however this has never been confirmed by a longitudinal study. We carried out the first longitudinal study of brain growth in toddlers at the time symptoms of autism are becoming clinically apparent utilizing structural MRI scans at multiple time points beginning at 1.5 years up to 5 years of age. We collected 193 scans on 41 toddlers who received a confirmed diagnosis of Autistic Disorder at ~48 months of age and 44 typically developing controls. By 2.5 years of age, both cerebral gray and white matter was significantly enlarged in toddlers with Autistic Disorder, with the most severe enlargement occurring in frontal, temporal and cingulate cortices. In the longitudinal analyses, which we accounted for age and gender effect, we found that all regions (cerebral gray, cerebral white, frontal gray, temporal gray, cingulate gray, and parietal gray) except occipital gray developed at an abnormal growth rate in toddlers with Autistic Disorder that was mainly characterized by a quadratic age effect. Females with Autistic Disorder displayed a more pronounced abnormal growth profile in more brain regions than males with the disorder. Given that overgrowth clearly begins before 2 years of age, future longitudinal studies would benefit from inclusion of even younger populations as well as further characterization of genetic and other biomarkers in order to determine the underlying neuropathological processes causing the onset of autistic symptoms. PMID:20335478

Cortical serotonin-S2 receptor binding in Lewy body dementia, Alzheimer's and Parkinson's diseases.

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Cheng, A V; Ferrier, I N; Morris, C M; Jabeen, S; Sahgal, A; McKeith, I G; Edwardson, J A; Perry, R H; Perry, E K

1991-11-01

The binding of the selective 5-HT2 antagonist [3H]ketanserin has been investigated in the temporal cortex of patients with Alzheimer's disease (SDAT), Parkinson's disease (PD), senile dementia of Lewy body type (SDLT) and neuropathologically normal subjects (control). 5-HT2 binding was reduced in SDAT, PD with dementia and SDLT. SDAT showed a 5-HT2 receptor deficit across most of the cortical layers. A significant decrease in 5-HT2 binding in the deep cortical layers was found in those SDLT cases without hallucinations. SDLT cases with hallucinations only showed a deficit in one upper layer. There was a significant difference in cortical layers III and V between SDLT without hallucinations and SDLT with hallucinations. The results confirm an abnormality of serotonin binding in various forms of dementia and suggest that preservation of 5-HT2 receptor in the temporal cortex may differentiate hallucinating from non-hallucinating cases of SDLT.

How can the process of postnatal adaptation be changed by the presence of congenital abnormalities of lip and palate

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Brucknerová Ingrid

2017-12-01

Full Text Available Despite modern approaches in molecular biology and genetics, we are still not able to identify the actual cause in more than 50% of all congenital defects. One-half of the unidentified cases is referred to as “multifactorial”. Detailed prenatal investigation of the fetus can discover the presence of congenital abnormality, which can worsen the process of postnatal adaptation. Retrospective analysis of newborns admitted to the Neonatal Department of Intensive Medicine (NDIM in 2012-2016 with the aim to analyze how the process of postnatal adaptation can be changed by the presence of congenital abnormalities of lip and palate. During a five-year period, 13 newborns were admitted to NDIM (2 premature; 11 term newborns. Chromosomal abnormality was confirmed in one patient (Down syndrome and in one patient suspicion of Patau syndrome was found. Twelve newborns had complete cheilognathopalatoschisis. Two premature newborns and two term newborns had perinatal asphyxia. In this group of patients, 33% had respiratory insufficiency without the presence of congenital heart abnormality, 66% had congenital heart abnormality with respiratory insufficiency, and 2 patients had feeding problems. Only one patient had a positive family history. The diagnosis of complete cheilognathopalatoschisis was confirmed prenatally only in 9 patients. We confirmed that clinical consequences of congenital abnormalities of lip and palate depend on the nature, localization and range of abnormalities, as well as on the genetic background and accompanying congenital abnormalities. Prenatal confirmation of the presence of congenital abnormalities has an important influence on the postnatal management of a patient.

Motor cortical processing is causally involved in object recognition

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2013-01-01

Background Motor activity during vicarious experience of actions is a widely reported and studied phenomenon, and motor system activity also accompanies observation of graspable objects in the absence of any actions. Such motor activity is thought to reflect simulation of the observed action, or preparation to interact with the object, respectively. Results Here, in an initial exploratory study, we ask whether motor activity during observation of object directed actions is involved in processes related to recognition of the object after initial exposure. Single pulse Transcranial Magnetic Stimulation (TMS) was applied over the thumb representation of the motor cortex, or over the vertex, during observation of a model thumb typing on a cell-phone, and performance on a phone recognition task at the end of the trial was assessed. Disrupting motor processing over the thumb representation 100 ms after the onset of the typing video impaired the ability to recognize the phone in the recognition test, whereas there was no such effect for TMS applied over the vertex and no TMS trials. Furthermore, this effect only manifested for videos observed from the first person perspective. In an additional control condition, there was no evidence for any effects of TMS to the thumb representation or vertex when observing and recognizing non-action related shape stimuli. Conclusion Overall, these data provide evidence that motor cortical processing during observation of object-directed actions from a first person perspective is causally linked to the formation of enduring representations of objects-of-action. PMID:24330638

Development of cortical thickness and surface area in autism spectrum disorder

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Vincent T. Mensen

2017-01-01

Full Text Available Autism spectrum disorder (ASD is a neurodevelopmental disorder often associated with changes in cortical volume. The constituents of cortical volume – cortical thickness and surface area – have separable developmental trajectories and are related to different neurobiological processes. However, little is known about the developmental trajectories of cortical thickness and surface area in ASD. In this magnetic resonance imaging (MRI study, we used an accelerated longitudinal design to investigate the cortical development in 90 individuals with ASD and 90 typically developing controls, aged 9 to 20 years. We quantified cortical measures using the FreeSurfer software package, and then used linear mixed model analyses to estimate the developmental trajectories for each cortical measure. Our primary finding was that the development of surface area follows a linear trajectory in ASD that differs from typically developing controls. In typical development, we found a decline in cortical surface area between the ages of 9 and 20 that was absent in ASD. We found this pattern in all regions where developmental trajectories for surface area differed between groups. When we applied a more stringent correction that takes the interdependency of measures into account, this effect on cortical surface area retained significance for left banks of superior temporal sulcus, postcentral area, and right supramarginal area. These areas have previously been implicated in ASD and are involved in the interpretation and processing of audiovisual social stimuli and distinction between self and others. Although some differences in cortical volume and thickness were found, none survived the more stringent correction for multiple testing. This study underscores the importance of distinguishing between cortical surface area and thickness in investigating cortical development, and suggests the development of cortical surface area is of importance to ASD.

Bipolar disorder type I and II show distinct relationships between cortical thickness and executive function.

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Abé, C; Rolstad, S; Petrovic, P; Ekman, C-J; Sparding, T; Ingvar, M; Landén, M

2018-06-15

Frontal cortical abnormalities and executive function impairment co-occur in bipolar disorder. Recent studies have shown that bipolar subtypes differ in the degree of structural and functional impairments. The relationships between cognitive performance and cortical integrity have not been clarified and might differ across patients with bipolar disorder type I, II, and healthy subjects. Using a vertex-wise whole-brain analysis, we investigated how cortical integrity, as measured by cortical thickness, correlates with executive performance in patients with bipolar disorder type I, II, and controls (N = 160). We found focal associations between executive function and cortical thickness in the medial prefrontal cortex in bipolar II patients and controls, but not in bipolar I disorder. In bipolar II patients, we observed additional correlations in lateral prefrontal and occipital regions. Our findings suggest that bipolar disorder patients show altered structure-function relationships, and importantly that those relationships may differ between bipolar subtypes. The findings are line with studies suggesting subtype-specific neurobiological and cognitive profiles. This study contributes to a better understanding of brain structure-function relationships in bipolar disorder and gives important insights into the neuropathophysiology of diagnostic subtypes. © 2018 The Authors Acta Psychiatrica Scandinavica Published by John Wiley & Sons Ltd.

Brain perfusion abnormalities in patients with euthyroid autoimmune thyroiditis

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Piga, M.; Serra, A.; Loi, G.L.; Satta, L. [University of Cagliari, Nuclear Medicine - Department of Medical Sciences ' ' M. Aresu' ' , Cagliari (Italy); Deiana, L.; Liberto, M. Di; Mariotti, S. [University of Cagliari, Endocrinology - Department of Medical Sciences ' ' M. Aresu' ' , Cagliari (Italy)

2004-12-01

Brain perfusion abnormalities have recently been demonstrated by single-photon emission computed tomography (SPECT) in rare cases of severe Hashimoto's thyroiditis (HT) encephalopathy; moreover, some degree of subtle central nervous system (CNS) involvement has been hypothesised in HT, but no direct evidence has been provided so far. The aim of this study was to assess cortical brain perfusion in patients with euthyroid HT without any clinical evidence of CNS involvement by means of {sup 99m}Tc-ECD brain SPECT. Sixteen adult patients with HT entered this study following informed consent. The diagnosis was based on the coexistence of high titres of anti-thyroid auto-antibodies and diffuse hypoechogenicity of the thyroid on ultrasound in association with normal circulating thyroid hormone and TSH concentrations. Nine consecutive adult patients with non-toxic nodular goitre (NTNG) and ten healthy subjects matched for age and sex were included as control groups. All patients underwent {sup 99m}Tc-ECD brain SPECT. Image assessment was both qualitative and semiquantitative. Semiquantitative analysis was performed by generation of four regions of interest (ROI) for each cerebral hemisphere - frontal, temporal, parietal and occipital - and one for each cerebellar hemisphere in order to evaluate cortical perfusion asymmetry. The Asymmetry Index (AI) was calculated to provide a measurement of both magnitude and direction of perfusion asymmetry. As assessed by visual examination, {sup 99m}Tc-ECD cerebral distribution was irregular and patchy in HT patients, hypoperfusion being more frequently found in frontal lobes. AI revealed abnormalities in 12/16 HT patients, in three of the nine NTNG patients and in none of the normal controls. A significant difference in the mean AI was found between patients with HT and both patients with NTNG (p<0.003) and normal controls (p<0.001), when only frontal lobes were considered. These results show the high prevalence of brain perfusion

Persistent spatial working memory deficits in rats with bilateral cortical microgyria

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Rosen Glenn D

2008-10-01

Full Text Available Abstract Background Anomalies of cortical neuronal migration (e.g., microgyria (MG and/or ectopias are associated with a variety of language and cognitive deficits in human populations. In rodents, postnatal focal freezing lesions lead to the formation of cortical microgyria similar to those seen in human dyslexic brains, and also cause subsequent deficits in rapid auditory processing similar to those reported in human language impaired populations. Thus convergent findings support the ongoing study of disruptions in neuronal migration in rats as a putative model to provide insight on human language disability. Since deficits in working memory using both verbal and non-verbal tasks also characterize dyslexic populations, the present study examined the effects of neonatally induced bilateral cortical microgyria (MG on working memory in adult male rats. Methods A delayed match-to-sample radial water maze task, in which the goal arm was altered among eight locations on a daily basis, was used to assess working memory performance in MG (n = 8 and sham (n = 10 littermates. Results Over a period of 60 sessions of testing (each session comprising one pre-delay sample trial, and one post-delay test trial, all rats showed learning as evidenced by a significant decrease in overall test errors. However, MG rats made significantly more errors than shams during initial testing, and this memory deficit was still evident after 60 days (12 weeks of testing. Analyses performed on daily error patterns showed that over the course of testing, MG rats utilized a strategy similar to shams (but with less effectiveness, as indicated by more errors. Conclusion These results indicate persistent abnormalities in the spatial working memory system in rats with induced disruptions of neocortical neuronal migration.

Neurobiological correlates of cognitions in fear and anxiety: a cognitive-neurobiological information-processing model.

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Hofmann, Stefan G; Ellard, Kristen K; Siegle, Greg J

2012-01-01

We review likely neurobiological substrates of cognitions related to fear and anxiety. Cognitive processes are linked to abnormal early activity reflecting hypervigilance in subcortical networks involving the amygdala, hippocampus, and insular cortex, and later recruitment of cortical regulatory resources, including activation of the anterior cingulate cortex and prefrontal cortex to implement avoidant response strategies. Based on this evidence, we present a cognitive-neurobiological information-processing model of fear and anxiety, linking distinct brain structures to specific stages of information processing of perceived threat.

Social anhedonia is associated with neural abnormalities during face emotion processing.

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Germine, Laura T; Garrido, Lucia; Bruce, Lori; Hooker, Christine

2011-10-01

Human beings are social organisms with an intrinsic desire to seek and participate in social interactions. Social anhedonia is a personality trait characterized by a reduced desire for social affiliation and reduced pleasure derived from interpersonal interactions. Abnormally high levels of social anhedonia prospectively predict the development of schizophrenia and contribute to poorer outcomes for schizophrenia patients. Despite the strong association between social anhedonia and schizophrenia, the neural mechanisms that underlie individual differences in social anhedonia have not been studied and are thus poorly understood. Deficits in face emotion recognition are related to poorer social outcomes in schizophrenia, and it has been suggested that face emotion recognition deficits may be a behavioral marker for schizophrenia liability. In the current study, we used functional magnetic resonance imaging (fMRI) to see whether there are differences in the brain networks underlying basic face emotion processing in a community sample of individuals low vs. high in social anhedonia. We isolated the neural mechanisms related to face emotion processing by comparing face emotion discrimination with four other baseline conditions (identity discrimination of emotional faces, identity discrimination of neutral faces, object discrimination, and pattern discrimination). Results showed a group (high/low social anhedonia) × condition (emotion discrimination/control condition) interaction in the anterior portion of the rostral medial prefrontal cortex, right superior temporal gyrus, and left somatosensory cortex. As predicted, high (relative to low) social anhedonia participants showed less neural activity in face emotion processing regions during emotion discrimination as compared to each control condition. The findings suggest that social anhedonia is associated with abnormalities in networks responsible for basic processes associated with social cognition, and provide a

Methomyl poisoning presenting with decorticate posture and cortical blindness.

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Lin, Chih-Ming

2014-01-17

Methomyl is a potent pesticide that is widely used in the field of agriculture. The systemic toxic effects of methomyl have been well described. However, the neurological effects of methomyl intoxication are not well understood. In this study, we report a 61-year-old Taiwanese man sent to our emergency department because of altered mental status. His family stated that he had consumed liquid methomyl in a suicide attempt. He was provided cardiopulmonary resuscitation because of unstable vital signs. He was then sent to an intensive care unit for close observation. On the second day of admission, he regained consciousness but exhibited irregular limb and torso posture. On the sixth day, he started to complain of blurred vision. An ophthalmologist was consulted but no obvious abnormalities could be identified. On suspicion of cerebral disease, a neurologist was consulted. Further examination revealed cortical blindness and decorticate posture. Cerebral magnetic resonance imaging (MRI) was arranged, which identified bilateral occipital regions lesions. The patient was administered normal saline and treated with aspirin and piracetam for 3 weeks in hospital. During the treatment period, his symptom of cortical blindness resolved, whereas his decorticate posture was refractory. Follow-up brain MRI results supported our clinical observations by indicating the disappearance of the bilateral occipital lesions and symmetrical putaminal high signal abnormalities. In this article, we briefly discuss the possible mechanisms underlying the cerebral effects of methomyl poisoning. Our study can provide clinicians with information on the manifestations of methomyl intoxication and an appropriate treatment direction.

Methomyl poisoning presenting with decorticate posture and cortical blindness

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Chih-Ming Lin

2014-02-01

Full Text Available Methomyl is a potent pesticide that is widely used in the field of agriculture. The systemic toxic effects of methomyl have been well described. However, the neurological effects of methomyl intoxication are not well understood. In this study, we report a 61-year-old Taiwanese man sent to our emergency department because of altered mental status. His family stated that he had consumed liquid methomyl in a suicide attempt. He was provided cardiopulmonary resuscitation because of unstable vital signs. He was then sent to an intensive care unit for close observation. On the second day of admission, he regained consciousness but exhibited irregular limb and torso posture. On the sixth day, he started to complain of blurred vision. An ophthalmologist was consulted but no obvious abnormalities could be identified. On suspicion of cerebral disease, a neurologist was consulted. Further examination revealed cortical blindness and decorticate posture. Cerebral magnetic resonance imaging (MRI was arranged, which identified bilateral occipital regions lesions. The patient was administered normal saline and treated with aspirin and piracetam for 3 weeks in hospital. During the treatment period, his symptom of cortical blindness resolved, whereas his decorticate posture was refractory. Follow-up brain MRI results supported our clinical observations by indicating the disappearance of the bilateral occipital lesions and symmetrical putaminal high signal abnormalities. In this article, we briefly discuss the possible mechanisms underlying the cerebral effects of methomyl poisoning. Our study can provide clinicians with information on the manifestations of methomyl intoxication and an appropriate treatment direction.

Simulating cortical development as a self constructing process: a novel multi-scale approach combining molecular and physical aspects.

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Frederic Zubler

Full Text Available Current models of embryological development focus on intracellular processes such as gene expression and protein networks, rather than on the complex relationship between subcellular processes and the collective cellular organization these processes support. We have explored this collective behavior in the context of neocortical development, by modeling the expansion of a small number of progenitor cells into a laminated cortex with layer and cell type specific projections. The developmental process is steered by a formal language analogous to genomic instructions, and takes place in a physically realistic three-dimensional environment. A common genome inserted into individual cells control their individual behaviors, and thereby gives rise to collective developmental sequences in a biologically plausible manner. The simulation begins with a single progenitor cell containing the artificial genome. This progenitor then gives rise through a lineage of offspring to distinct populations of neuronal precursors that migrate to form the cortical laminae. The precursors differentiate by extending dendrites and axons, which reproduce the experimentally determined branching patterns of a number of different neuronal cell types observed in the cat visual cortex. This result is the first comprehensive demonstration of the principles of self-construction whereby the cortical architecture develops. In addition, our model makes several testable predictions concerning cell migration and branching mechanisms.

Reduction in cortical IMP-SPET tracer uptake with recent cigarette consumption in a young group of healthy males

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Rourke, S.B.; Dupont, R.M.; Grant, I.; Lehr, P.P.; Lamoureux, G.; Halpern, S.; Yeung, D.W.C.

1997-01-01

Functional brain imaging techniques are being used increasingly to infer disturbances in brain function in various neuropsychiatric disorders, but the specificity of such findings is not always clear. We retrospectively examined the effects of one possible confound - cigarette smoking - on cortical uptake of iodine-123 iodoamphetamine (IMP) using single-photon emission tomographic imaging in a young (mean age=35 years) healthy group of male controls divided according to their smoking history. Subjects who had never smoked (n=17), or those with a history of smoking but no recent smoking (n=8), had equivalent and significantly higher mean cortical uptake of IMP than subjects with a history of smoking and who were current smokers (n=8). There were no differences in the cortical distribution of IMP. Our results indicate that cigarette smoking has an acute effect on global cerebral blood flow. This potential confound must be considered before abnormalities in cortical tracer uptake are attributed to some neuropsychiatric disorder of interest. (orig.). With 2 figs., 3 tabs

De novo interstitial deletion of 9q32-34.1 with mental retardation, developmental delay, epilepsy, and cortical dysplasia

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Tos, T; Alp, M Y; Karacan, C D

2014-01-01

In this report we describe a 10 year-old female patient with interstitial deletion of 9q32-q34.1 associated with mental retardation, developmental delay, short stature, mild facial dysmorphism, epilepsy, abnormal EEG and brain MRI findings consistent with focal cortical dysplasia. Interstitial...

Neonatal Brain Abnormalities and Memory and Learning Outcomes at 7 Years in Children Born Very Preterm

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Omizzolo, Cristina; Scratch, Shannon E; Stargatt, Robyn; Kidokoro, Hiroyuki; Thompson, Deanne K; Lee, Katherine J; Cheong, Jeanie; Neil, Jeffrey; Inder, Terrie E; Doyle, Lex W; Anderson, Peter J

2014-01-01

Using prospective longitudinal data from 198 very preterm and 70 full term children, this study characterised the memory and learning abilities of very preterm children at 7 years of age in both verbal and visual domains. The relationship between the extent of brain abnormalities on neonatal magnetic resonance imaging (MRI) and memory and learning outcomes at 7 years of age in very preterm children was also investigated. Neonatal MRI scans were qualitatively assessed for global, white-matter, cortical grey-matter, deep grey-matter, and cerebellar abnormalities. Very preterm children performed less well on measures of immediate memory, working memory, long-term memory, and learning compared with term born controls. Neonatal brain abnormalities, and in particular deep grey matter abnormality, were associated with poorer memory and learning performance at 7 years in very preterm children, especially global, white-matter, grey-matter and cerebellar abnormalities. Findings support the importance of cerebral neonatal pathology for predicting later memory and learning function. PMID:23805915

Normal and abnormal growth plate

International Nuclear Information System (INIS)

Kumar, R.; Madewell, J.E.; Swischuk, L.E.

1987-01-01

Skeletal growth is a dynamic process. A knowledge of the structure and function of the normal growth plate is essential in order to understand the pathophysiology of abnormal skeletal growth in various diseases. In this well-illustrated article, the authors provide a radiographic classification of abnormal growth plates and discuss mechanisms that lead to growth plate abnormalities

Learning to see again: biological constraints on cortical plasticity and the implications for sight restoration technologies

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Beyeler, Michael; Rokem, Ariel; Boynton, Geoffrey M.; Fine, Ione

2017-10-01

The ‘bionic eye’—so long a dream of the future—is finally becoming a reality with retinal prostheses available to patients in both the US and Europe. However, clinical experience with these implants has made it apparent that the visual information provided by these devices differs substantially from normal sight. Consequently, the ability of patients to learn to make use of this abnormal retinal input plays a critical role in whether or not some functional vision is successfully regained. The goal of the present review is to summarize the vast basic science literature on developmental and adult cortical plasticity with an emphasis on how this literature might relate to the field of prosthetic vision. We begin with describing the distortion and information loss likely to be experienced by visual prosthesis users. We then define cortical plasticity and perceptual learning, and describe what is known, and what is unknown, about visual plasticity across the hierarchy of brain regions involved in visual processing, and across different stages of life. We close by discussing what is known about brain plasticity in sight restoration patients and discuss biological mechanisms that might eventually be harnessed to improve visual learning in these patients.

Verbal memory impairments in schizophrenia associated with cortical thinning

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S. Guimond

2016-01-01

Full Text Available Verbal memory (VM represents one of the most affected cognitive domains in schizophrenia. Multiple studies have shown that schizophrenia is associated with cortical abnormalities, but it remains unclear whether these are related to VM impairments. Considering the vast literature demonstrating the role of the frontal cortex, the parahippocampal cortex, and the hippocampus in VM, we examined the cortical thickness/volume of these regions. We used a categorical approach whereby 27 schizophrenia patients with ‘moderate to severe’ VM impairments were compared to 23 patients with ‘low to mild’ VM impairments and 23 healthy controls. A series of between-group vertex-wise GLM on cortical thickness were performed for specific regions of interest defining the parahippocampal gyrus and the frontal cortex. When compared to healthy controls, patients with ‘moderate to severe’ VM impairments revealed significantly thinner cortex in the left frontal lobe, and the parahippocampal gyri. When compared to patients with ‘low to mild’ VM impairments, patients with ‘moderate to severe’ VM impairments showed a trend of thinner cortex in similar regions. Virtually no differences were observed in the frontal area of patients with ‘low to mild’ VM impairments relative to controls. No significant group differences were observed in the hippocampus. Our results indicate that patients with greater VM impairments demonstrate significant cortical thinning in regions known to be important in VM performance. Treating VM deficits in schizophrenia could have a positive effect on the brain; thus, subgroups of patients with more severe VM deficits should be a prioritized target in the development of new cognitive treatments.

Toward a complex system understanding of bipolar disorder: A chaotic model of abnormal circadian activity rhythms in euthymic bipolar disorder.

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Hadaeghi, Fatemeh; Hashemi Golpayegani, Mohammad Reza; Jafari, Sajad; Murray, Greg

2016-08-01

In the absence of a comprehensive neural model to explain the underlying mechanisms of disturbed circadian function in bipolar disorder, mathematical modeling is a helpful tool. Here, circadian activity as a response to exogenous daily cycles is proposed to be the product of interactions between neuronal networks in cortical (cognitive processing) and subcortical (pacemaker) areas of the brain. To investigate the dynamical aspects of the link between disturbed circadian activity rhythms and abnormalities of neurotransmitter functioning in frontal areas of the brain, we developed a novel mathematical model of a chaotic system which represents fluctuations in circadian activity in bipolar disorder as changes in the model's parameters. A novel map-based chaotic system was developed to capture disturbances in circadian activity across the two extreme mood states of bipolar disorder. The model uses chaos theory to characterize interplay between neurotransmitter functions and rhythm generation; it aims to illuminate key activity phenomenology in bipolar disorder, including prolonged sleep intervals, decreased total activity and attenuated amplitude of the diurnal activity rhythm. To test our new cortical-circadian mathematical model of bipolar disorder, we utilized previously collected locomotor activity data recorded from normal subjects and bipolar patients by wrist-worn actigraphs. All control parameters in the proposed model have an important role in replicating the different aspects of circadian activity rhythm generation in the brain. The model can successfully replicate deviations in sleep/wake time intervals corresponding to manic and depressive episodes of bipolar disorder, in which one of the excitatory or inhibitory pathways is abnormally dominant. Although neuroimaging research has strongly implicated a reciprocal interaction between cortical and subcortical regions as pathogenic in bipolar disorder, this is the first model to mathematically represent this

The Hierarchical Cortical Organization of Human Speech Processing.

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de Heer, Wendy A; Huth, Alexander G; Griffiths, Thomas L; Gallant, Jack L; Theunissen, Frédéric E

2017-07-05

natural speech. Both cerebral hemispheres were actively involved in speech processing in large and equal amounts. Also, the transformation from spectral features to semantic elements occurs early in the cortical speech-processing stream. Our experimental and analytical approaches are important alternatives and complements to standard approaches that use segmented speech and block designs, which report more laterality in speech processing and associated semantic processing to higher levels of cortex than reported here. Copyright © 2017 the authors 0270-6474/17/376539-19$15.00/0.

Pathophysiology of somatosensory abnormalities in Parkinson disease.

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Conte, Antonella; Khan, Nashaba; Defazio, Giovanni; Rothwell, John C; Berardelli, Alfredo

2013-12-01

Changes in sensory function that have been described in patients with Parkinson disease (PD) can be either 'pure' disorders of conscious perception such as elevations in sensory threshold, or disorders of sensorimotor integration, in which the interaction between sensory input and motor output is altered. In this article, we review the extensive evidence for disrupted tactile, nociceptive, thermal and proprioceptive sensations in PD, as well as the influences exerted on these sensations by dopaminergic therapy and deep brain stimulation. We argue that abnormal spatial and temporal processing of sensory information produces incorrect signals for the preparation and execution of voluntary movement. Sensory deficits are likely to be a consequence of the dopaminergic denervation of the basal ganglia that is the hallmark of PD. A possible mechanism to account for somatosensory deficits is one in which disease-related dopaminergic denervation leads to a loss of response specificity, resulting in transmission of noisier and less-differentiated information to cortical regions. Changes in pain perception might have a different explanation, possibly involving disease-related effects outside the basal ganglia, including involvement of peripheral pain receptors, as well as structures such as the periaqueductal grey matter and non-dopaminergic neurotransmitter systems.

Porencephaly and cortical dysplasia as cause of seizures in a dog

Directory of Open Access Journals (Sweden)

Machado Gisele Fabrino

2012-12-01

Full Text Available Abstract Background Seizures are a common problem in small animal neurology and it may be related to underlying diseases. Porencephaly is an extremely rare disorder, and in Veterinary Medicine it affects more often ruminants, with only few reports in dogs. Case presentation A one-year-old intact male Shih-Tzu dog was referred to Veterinary University Hospital with history of abnormal gait and generalized tonic-clonic seizures. Signs included hypermetria, abnormal nystagmus and increased myotatic reflexes. At necropsy, during the brain analysis, a cleft was observed in the left parietal and occipital lobes, creating a communication between the subarachnoid space and the left lateral ventricle, consistent with porencephaly; and also a focal atrophy of the caudal paravermal and vermal portions of the cerebellum. Furthermore, the histological examination showed cortical and cerebellar neuronal dysplasia. Conclusions Reports of seizures due to porencephaly are rare in dogs. In this case, the dog presented a group of brain abnormalities which per se or in assemblage could result in seizure manifestation.

Cortical surface area and cortical thickness in the precuneus of adult humans.

Science.gov (United States)

Bruner, E; Román, F J; de la Cuétara, J M; Martin-Loeches, M; Colom, R

2015-02-12

The precuneus has received considerable attention in the last decade, because of its cognitive functions, its role as a central node of the brain networks, and its involvement in neurodegenerative processes. Paleoneurological studies suggested that form changes in the deep parietal areas represent a major character associated with the origin of the modern human brain morphology. A recent neuroanatomical survey based on shape analysis suggests that the proportions of the precuneus are also a determinant source of overall brain geometrical differences among adult individuals, influencing the brain spatial organization. Here, we evaluate the variation of cortical thickness and cortical surface area of the precuneus in a sample of adult humans, and their relation with geometry and cognition. Precuneal thickness and surface area are not correlated. There is a marked individual variation. The right precuneus is thinner and larger than the left one, but there are relevant fluctuating asymmetries, with only a modest correlation between the hemispheres. Males have a thicker cortex but differences in cortical area are not significant between sexes. The surface area of the precuneus shows a positive allometry with the brain surface area, although the correlation is modest. The dilation/contraction of the precuneus, described as a major factor of variability within adult humans, is associated with absolute increase/decrease of its surface, but not with variation in thickness. Precuneal thickness, precuneal surface area and precuneal morphology are not correlated with psychological factors such as intelligence, working memory, attention control, and processing speed, stressing further possible roles of this area in supporting default mode functions. Beyond gross morphology, the processes underlying the large phenotypic variation of the precuneus must be further investigated through specific cellular analyses, aimed at considering differences in cellular size, density

The biology and dynamics of mammalian cortical granules

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Liu Min

2011-11-01

Full Text Available Abstract Cortical granules are membrane bound organelles located in the cortex of unfertilized oocytes. Following fertilization, cortical granules undergo exocytosis to release their contents into the perivitelline space. This secretory process, which is calcium dependent and SNARE protein-mediated pathway, is known as the cortical reaction. After exocytosis, the released cortical granule proteins are responsible for blocking polyspermy by modifying the oocytes' extracellular matrices, such as the zona pellucida in mammals. Mammalian cortical granules range in size from 0.2 um to 0.6 um in diameter and different from most other regulatory secretory organelles in that they are not renewed once released. These granules are only synthesized in female germ cells and transform an egg upon sperm entry; therefore, this unique cellular structure has inherent interest for our understanding of the biology of fertilization. Cortical granules are long thought to be static and awaiting in the cortex of unfertilized oocytes to be stimulated undergoing exocytosis upon gamete fusion. Not till recently, the dynamic nature of cortical granules is appreciated and understood. The latest studies of mammalian cortical granules document that this organelle is not only biochemically heterogeneous, but also displays complex distribution during oocyte development. Interestingly, some cortical granules undergo exocytosis prior to fertilization; and a number of granule components function beyond the time of fertilization in regulating embryonic cleavage and preimplantation development, demonstrating their functional significance in fertilization as well as early embryonic development. The following review will present studies that investigate the biology of cortical granules and will also discuss new findings that uncover the dynamic aspect of this organelle in mammals.

Proton magnetic resonance spectroscopy in disturbances of cortical development

International Nuclear Information System (INIS)

Kaminaga, T.; Kobayashi, M.; Abe, T.

2001-01-01

Proton magnetic resonance spectroscopy( 1 H-MRS) can be used for looking at cerebral metabolites in vivo. However, measurement of concentrations of cerebral metabolites in patients with disturbances of cerebral development have not been successful. Our purpose was to measure the concentrations of cerebral metabolites in such patients. We carried out quantitative 1 H-MRS in eight patients with cortical dysplasia, four with lissencephaly and three with heterotopic grey matter and six age-matched normal controls. Regions of interest for 1 H-MRS were set over the affected cortex in the patients and the occipital cortex in controls. The calculated concentration of N-acetylaspartate (NAA) was significantly lower in the affected cortex in patients with cortical dysplasia (P < 0.05), lissencephaly (P < 0.01), and heterotopia (P < 0.05) than in controls, idnicating a decreased number and/or immaturity or dysfunction of neurones in the affected cortex. The concentration of choline (Cho) was significantly lower in patients with lissencephaly (P < 0.01) than in controls, indicating glial proliferation and/or membrane abnormality. (orig.)

Semantic word category processing in semantic dementia and posterior cortical atrophy.

Science.gov (United States)

Shebani, Zubaida; Patterson, Karalyn; Nestor, Peter J; Diaz-de-Grenu, Lara Z; Dawson, Kate; Pulvermüller, Friedemann

2017-08-01

There is general agreement that perisylvian language cortex plays a major role in lexical and semantic processing; but the contribution of additional, more widespread, brain areas in the processing of different semantic word categories remains controversial. We investigated word processing in two groups of patients whose neurodegenerative diseases preferentially affect specific parts of the brain, to determine whether their performance would vary as a function of semantic categories proposed to recruit those brain regions. Cohorts with (i) Semantic Dementia (SD), who have anterior temporal-lobe atrophy, and (ii) Posterior Cortical Atrophy (PCA), who have predominantly parieto-occipital atrophy, performed a lexical decision test on words from five different lexico-semantic categories: colour (e.g., yellow), form (oval), number (seven), spatial prepositions (under) and function words (also). Sets of pseudo-word foils matched the target words in length and bi-/tri-gram frequency. Word-frequency was matched between the two visual word categories (colour and form) and across the three other categories (number, prepositions, and function words). Age-matched healthy individuals served as controls. Although broad word processing deficits were apparent in both patient groups, the deficit was strongest for colour words in SD and for spatial prepositions in PCA. The patterns of performance on the lexical decision task demonstrate (a) general lexicosemantic processing deficits in both groups, though more prominent in SD than in PCA, and (b) differential involvement of anterior-temporal and posterior-parietal cortex in the processing of specific semantic categories of words. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Structural and functional brain abnormalities place phenocopy frontotemporal dementia (FTD in the FTD spectrum

Directory of Open Access Journals (Sweden)

Rebecca M.E. Steketee

2016-01-01

Conclusion: PhFTD and bvFTD show overlapping cortical structural abnormalities indicating a continuum of changes especially in the frontotemporal regions. Together with functional changes suggestive of a compensatory response to incipient pathology in the left prefrontal regions, these findings are the first to support a possible neuropathological etiology of phFTD and suggest that phFTD may be a neurodegenerative disease on the FTD spectrum.

The Unique Brain Anatomy of Meditation Practitioners: Alterations in Cortical Gyrification

Directory of Open Access Journals (Sweden)

Eileen eLuders

2012-02-01

Full Text Available Several cortical regions are reported to vary in meditation practitioners. However, since prior analyses were focused on examining gray matter or cortical thickness, additional effects with respect to other cortical features might have remained undetected. Gyrification (the pattern and degree of cortical folding is an important cerebral characteristic related to the geometry of the brain’s surface. Cortical folding occurs early in development and might be linked to behavioral traits. Thus, exploring cortical gyrification in long-term meditators may provide additional clues with respect to the underlying anatomical correlates of meditation. This study examined cortical gyrification in a large sample (n=100 of meditators and controls, carefully matched for sex and age. Cortical gyrification was established via calculating mean curvature across thousands of vertices on individual cortical surface models. Pronounced group differences indicating larger gyrification in meditators were evident within the left precentral gyrus, right fusiform gyrus, right cuneus, as well as left and right anterior dorsal insula (the latter representing the global significance maximum. Although the exact functional implications of larger cortical gyrification remain to be established, these findings suggest the insula to be a key structure involved in aspects of meditation. For example, variations in insular complexity could affect the regulation of well-known distractions in the process of meditation, such as daydreaming, mind-wandering, and projections into past or future. Moreover, given that meditators are masters in introspection, awareness, and emotional control, increased insular gyrification may reflect an ideal integration of autonomic, affective, and cognitive processes. Due to the cross-sectional nature of this study, further research is necessary determine the relative contribution of nature and nurture to links between cortical gyrification and meditation.

Recapitulating cortical development with organoid culture in vitro and modeling abnormal spindle-like (ASPM related primary) microcephaly disease

Institute of Scientific and Technical Information of China (English)

Rui Li; Le Sun; Ai Fang; Peng Li; Qian Wu; Xiaoqun Wang

2017-01-01

The development of a cerebral organoid culture in vitro offers an opportunity to generate human brain-like organs to investigate mechanisms of human disease that are specific to the neurogenesis of radial glial (RG) and outer radial glial (oRG) cells in the ventricular zone (VZ) and subventricular zone (SVZ) of the developing neocortex.Modeling neuronal progenitors and the organization that produces mature subcortical neuron subtypes during early stages of development is essential for studying human brain developmental diseases.Several previous efforts have shown to grow neural organoid in culture dishes successfully,however we demonstrate a new paradigm that recapitulates neocortical development process with VZ,OSVZ formation and the lamination organization of cortical layer structure.In addition,using patient-specific induced pluripotent stem cells (iPSCs) with dysfunction of the Aspm gene from a primary microcephaly patient,we demonstrate neurogenesis defects result in defective neuronal activity in patient organoids,suggesting a new strategy to study human developmental diseases in central nerve system.

Abnormal presynaptic short-term plasticity and information processing in a mouse model of fragile X syndrome.

Science.gov (United States)

Deng, Pan-Yue; Sojka, David; Klyachko, Vitaly A

2011-07-27

Fragile X syndrome (FXS) is the most common inherited form of intellectual disability and the leading genetic cause of autism. It is associated with the lack of fragile X mental retardation protein (FMRP), a regulator of protein synthesis in axons and dendrites. Studies on FXS have extensively focused on the postsynaptic changes underlying dysfunctions in long-term plasticity. In contrast, the presynaptic mechanisms of FXS have garnered relatively little attention and are poorly understood. Activity-dependent presynaptic processes give rise to several forms of short-term plasticity (STP), which is believed to control some of essential neural functions, including information processing, working memory, and decision making. The extent of STP defects and their contributions to the pathophysiology of FXS remain essentially unknown, however. Here we report marked presynaptic abnormalities at excitatory hippocampal synapses in Fmr1 knock-out (KO) mice leading to defects in STP and information processing. Loss of FMRP led to enhanced responses to high-frequency stimulation. Fmr1 KO mice also exhibited abnormal synaptic processing of natural stimulus trains, specifically excessive enhancement during the high-frequency spike discharges associated with hippocampal place fields. Analysis of individual STP components revealed strongly increased augmentation and reduced short-term depression attributable to loss of FMRP. These changes were associated with exaggerated calcium influx in presynaptic neurons during high-frequency stimulation, enhanced synaptic vesicle recycling, and enlarged readily-releasable and reserved vesicle pools. These data suggest that loss of FMRP causes abnormal STP and information processing, which may represent a novel mechanism contributing to cognitive impairments in FXS.

The impact of ADHD persistence, recent cannabis use, and age of regular cannabis use onset on subcortical volume and cortical thickness in young adults.

Science.gov (United States)

Lisdahl, Krista M; Tamm, Leanne; Epstein, Jeffery N; Jernigan, Terry; Molina, Brooke S G; Hinshaw, Stephen P; Swanson, James M; Newman, Erik; Kelly, Clare; Bjork, James M

2016-04-01

Both Attention Deficit Hyperactivity Disorder (ADHD) and chronic cannabis (CAN) use have been associated with brain structural abnormalities, although little is known about the effects of both in young adults. Participants included: those with a childhood diagnosis of ADHD who were CAN users (ADHD_CAN; n=37) and non-users (NU) (ADHD_NU; n=44) and a local normative comparison group (LNCG) who did (LNCG_CAN; n=18) and did not (LNCG_NU; n=21) use CAN regularly. Multiple regressions and MANCOVAs were used to examine the independent and interactive effects of a childhood ADHD diagnosis and CAN group status and age of onset (CUO) on subcortical volumes and cortical thickness. After controlling for age, gender, total brain volume, nicotine use, and past-year binge drinking, childhood ADHD diagnosis did not predict brain structure; however, persistence of ADHD was associated with smaller left precentral/postcentral cortical thickness. Compared to all non-users, CAN users had decreased cortical thickness in right hemisphere superior frontal sulcus, anterior cingulate, and isthmus of cingulate gyrus regions and left hemisphere superior frontal sulcus and precentral gyrus regions. Early cannabis use age of onset (CUO) in those with ADHD predicted greater right hemisphere superior frontal and postcentral cortical thickness. Young adults with persistent ADHD demonstrated brain structure abnormalities in regions underlying motor control, working memory and inhibitory control. Further, CAN use was linked with abnormal brain structure in regions with high concentrations of cannabinoid receptors. Additional large-scale longitudinal studies are needed to clarify how substance use impacts neurodevelopment in youth with and without ADHD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Super-emitters in natural gas infrastructure are caused by abnormal process conditions

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Zavala-Araiza, Daniel; Alvarez, Ramón A.; Lyon, David R.; Allen, David T.; Marchese, Anthony J.; Zimmerle, Daniel J.; Hamburg, Steven P.

2017-01-01

Effectively mitigating methane emissions from the natural gas supply chain requires addressing the disproportionate influence of high-emitting sources. Here we use a Monte Carlo simulation to aggregate methane emissions from all components on natural gas production sites in the Barnett Shale production region (Texas). Our total emission estimates are two-thirds of those derived from independent site-based measurements. Although some high-emitting operations occur by design (condensate flashing and liquid unloadings), they occur more than an order of magnitude less frequently than required to explain the reported frequency at which high site-based emissions are observed. We conclude that the occurrence of abnormal process conditions (for example, malfunctions upstream of the point of emissions; equipment issues) cause additional emissions that explain the gap between component-based and site-based emissions. Such abnormal conditions can cause a substantial proportion of a site's gas production to be emitted to the atmosphere and are the defining attribute of super-emitting sites.

Cortical abnormalities in bipolar disorder: an MRI analysis of 6503 individuals from the ENIGMA Bipolar Disorder Working Group

NARCIS (Netherlands)

Hibar, D. P.; Westlye, L. T.; Doan, N. T.; Jahanshad, N.; Cheung, J. W.; Ching, C. R. K.; Versace, A.; Bilderbeck, A. C.; Uhlmann, A.; Mwangi, B.; Krämer, B.; Overs, B.; Hartberg, C. B.; Abé, C.; Dima, D.; Grotegerd, D.; Sprooten, E.; Bøen, E.; Jimenez, E.; Howells, F. M.; Delvecchio, G.; Temmingh, H.; Starke, J.; Almeida, J. R. C.; Goikolea, J. M.; Houenou, J.; Beard, L. M.; Rauer, L.; Abramovic, L.; Bonnin, M.; Ponteduro, M. F.; Keil, M.; Rive, M. M.; Yao, N.; Yalin, N.; Najt, P.; Rosa, P. G.; Redlich, R.; Trost, S.; Hagenaars, S.; Fears, S. C.; Alonso-Lana, S.; van Erp, T. G. M.; Nickson, T.; Chaim-Avancini, T. M.; Meier, T. B.; Elvsåshagen, T.; Haukvik, U. K.; Lee, W. H.; Schene, A. H.; Lloyd, A. J.; Young, A. H.; Nugent, A.; Dale, A. M.; Pfennig, A.; McIntosh, A. M.; Lafer, B.; Baune, B. T.; Ekman, C. J.; Zarate, C. A.; Bearden, C. E.; Henry, C.; Simhandl, C.; McDonald, C.; Bourne, C.; Stein, D. J.; Wolf, D. H.; Cannon, D. M.; Glahn, D. C.; Veltman, D. J.; Pomarol-Clotet, E.; Vieta, E.; Canales-Rodriguez, E. J.; Nery, F. G.; Duran, F. L. S.; Busatto, G. F.; Roberts, G.; Pearlson, G. D.; Goodwin, G. M.; Kugel, H.; Whalley, H. C.; Ruhe, H. G.; Soares, J. C.; Fullerton, J. M.; Rybakowski, J. K.; Savitz, J.; Chaim, K. T.; Fatjó-Vilas, M.; Soeiro-de-Souza, M. G.; Boks, M. P.; Zanetti, M. V.; Otaduy, M. C. G.; Schaufelberger, M. S.; Alda, M.; Ingvar, M.; Phillips, M. L.; Kempton, M. J.; Bauer, M.; Landén, M.; Lawrence, N. S.; van Haren, N. E. M.; Horn, N. R.; Freimer, N. B.; Gruber, O.; Schofield, P. R.; Mitchell, P. B.; Kahn, R. S.; Lenroot, R.; Machado-Vieira, R.; Ophoff, R. A.; Sarró, S.; Frangou, S.; Satterthwaite, T. D.; Hajek, T.; Dannlowski, U.; Malt, U. F.; Arolt, V.; Gattaz, W. F.; Drevets, W. C.; Caseras, X.; Agartz, I.; Thompson, P. M.; Andreassen, O. A.

2017-01-01

Despite decades of research, the pathophysiology of bipolar disorder (BD) is still not well understood. Structural brain differences have been associated with BD, but results from neuroimaging studies have been inconsistent. To address this, we performed the largest study to date of cortical gray

Altered cortical hubs in functional brain networks in amyotrophic lateral sclerosis.

Science.gov (United States)

Ma, Xujing; Zhang, Jiuquan; Zhang, Youxue; Chen, Heng; Li, Rong; Wang, Jian; Chen, Huafu

2015-11-01

Cortical hubs are highly connected nodes in functional brain networks that play vital roles in the efficient transfer of information across brain regions. Although altered functional connectivity has been found in amyotrophic lateral sclerosis (ALS), the changing pattern in functional network hubs in ALS remains unknown. In this study, we applied a voxel-wise method to investigate the changing pattern of cortical hubs in ALS. Through resting-state fMRI, we constructed whole-brain voxel-wise functional networks by measuring the temporal correlations of each pair of brain voxels and identified hubs using the graph theory method. Specifically, a functional connectivity strength (FCS) map was derived from the data on 20 patients with ALS and 20 healthy controls. The brain regions with high FCS values were regarded as functional network hubs. Functional hubs were found mainly in the bilateral precuneus, parietal cortex, medial prefrontal cortex, and in several visual regions and temporal areas in both groups. Within the hub regions, the ALS patients exhibited higher FCS in the prefrontal cortex compared with the healthy controls. The FCS value in the significantly abnormal hub regions was correlated with clinical variables. Results indicated the presence of altered cortical hubs in the ALS patients and could therefore shed light on the pathophysiology mechanisms underlying ALS.

Cortical tremor: a variant of cortical reflex myoclonus.

Science.gov (United States)

Ikeda, A; Kakigi, R; Funai, N; Neshige, R; Kuroda, Y; Shibasaki, H

1990-10-01

Two patients with action tremor that was thought to originate in the cerebral cortex showed fine shivering-like finger twitching provoked mainly by action and posture. Surface EMG showed relatively rhythmic discharge at a rate of about 9 Hz, which resembled essential tremor. However, electrophysiologic studies revealed giant somatosensory evoked potentials (SEPs) with enhanced long-loop reflex and premovement cortical spike by the jerk-locked averaging method. Treatment with beta-blocker showed no effect, but anticonvulsants such as clonazepam, valproate, and primidone were effective to suppress the tremor and the amplitude of SEPs. We call this involuntary movement "cortical tremor," which is in fact a variant of cortical reflex myoclonus.

MRI of cortical dysplasia - correlation with pathological findings

Energy Technology Data Exchange (ETDEWEB)

Usui, N.; Kajita, Y.; Yoshida, J. [Dept. of Neurosurgery, Nagoya Univ. School of Medicine (Japan); Matsuda, K.; Mihara, T.; Tottori, T.; Ohtsubo, T.; Baba, K.; Matsuyama, N.; Inoue, Y.; Yagi, K. [National Epilepsy Centre, Shizuoka Higashi Hospital (Japan)

2001-10-01

Cortical dysplasia (CD) is the most epileptogenic structural lesion associated with epilepsy and patients with intractable seizures caused by this condition are good surgical candidates. MRI plays an important role in detecting the abnormalities of CD. We clarified the MRI characteristics of CD by comparing imaging and histological findings in 20 patients with intractable seizures who underwent surgical resection. There were 12 males and eight females, mean age at operation was 15 years. MRI was performed at 1.5 tesla; T1-weighted, T2- and proton density-weighted spin-echo and fluid-attenuated inversion-recovery (FLAIR) images were obtained. The lesions were in the frontal lobe in nine cases, temporal in two, occipital in another two, insular in one and multilobar in six. Blurring of the grey/white matter junction was seen in all patients, and T2 prolongation in white matter and/or at the grey/white matter junction in 19. Abnormal signal intensity was more frequent in the white matter or at the grey/white matter junction than in the grey matter. FLAIR images made this abnormal high signal easier to appreciate, and we thought them very useful in this context. In areas of T2 prolongation, we saw dysplastic neurones and/or balloon cells, dysmyelination, and ectopic neuronal clustering histologically; glial proliferation played an important role in prolonging T2. (orig.)

Jealousy increased by induced relative left frontal cortical activity.

Science.gov (United States)

Kelley, Nicholas J; Eastwick, Paul W; Harmon-Jones, Eddie; Schmeichel, Brandon J

2015-10-01

Asymmetric frontal cortical activity may be one key to the process linking social exclusion to jealous feelings. The current research examined the causal role of asymmetric frontal brain activity in modulating jealousy in response to social exclusion. Transcranial direct-current stimulation (tDCS) over the frontal cortex to manipulate asymmetric frontal cortical activity was combined with a modified version of the Cyberball paradigm designed to induce jealousy. After receiving 15 min of tDCS, participants were excluded by a desired partner and reported how jealous they felt. Among individuals who were excluded, tDCS to increase relative left frontal cortical activity caused greater levels of self-reported jealousy compared to tDCS to increase relative right frontal cortical activity or sham stimulation. Limitations concerning the specificity of this effect and implications for the role of the asymmetric prefrontal cortical activity in motivated behaviors are discussed. (c) 2015 APA, all rights reserved).

Altered cortical GABA neurotransmission in schizophrenia: insights into novel therapeutic strategies.

Science.gov (United States)

Stan, Ana D; Lewis, David A

2012-06-01

Altered markers of cortical GABA neurotransmission are among the most consistently observed abnormalities in postmortem studies of schizophrenia. The altered markers are particularly evident between the chandelier class of GABA neurons and their synaptic targets, the axon initial segment (AIS) of pyramidal neurons. For example, in the dorsolateral prefrontal cortex of subjects with schizophrenia immunoreactivity for the GABA membrane transporter is decreased in presynaptic chandelier neuron axon terminals, whereas immunoreactivity for the GABAA receptor α2 subunit is increased in postsynaptic AIS. Both of these molecular changes appear to be compensatory responses to a presynaptic deficit in GABA synthesis, and thus could represent targets for novel therapeutic strategies intended to augment the brain's own compensatory mechanisms. Recent findings that GABA inputs from neocortical chandelier neurons can be powerfully excitatory provide new ideas about the role of these neurons in the pathophysiology of cortical dysfunction in schizophrenia, and consequently in the design of pharmacological interventions.

Abnormally phosphorylated tau protein in senile dementia of Lewy body type and Alzheimer disease: evidence that the disorders are distinct.

Science.gov (United States)

Strong, C; Anderton, B H; Perry, R H; Perry, E K; Ince, P G; Lovestone, S

1995-01-01

The relationship between Alzheimer disease (AD) and dementia with Lewy bodies (senile dementia Lewy body type, or SDLT) and dementia in Parkinson's disease is unclear. AD pathology is characterised by both amyloid deposition and abnormal phosphorylation of tau in paired helical filaments (PHF-tau). In AD, abnormally phosphorylated PHF-tau is present in neurofibrillary tangles, in neuritic processes of senile plaques, and also in neuropil threads dispersed throughout the cerebral cortex. Cortical homogenates from 12 cases each of AD and SDLT, 13 cases of Parkinson's disease, and 11 normal controls were examined by Western blot analysis with antibodies that detect PHF-tau. No PHF-tau was found in Parkinson's disease or control cortex. No PHF-tau was found in SDLT cases without histological evidence of tangles. PHF-tau was detectable in SDLT cases with a low density of tangles, and large amounts of PHF-tau were present in AD cases. This study demonstrates that abnormally phosphorylated PHF-tau is only present where tangles are found and not in SDLT cases without tangles or with only occasional tangles. It is concluded that Lewy body dementias are distinct at a molecular level from AD.

Transcranial magnetic stimulation provides means to assess cortical plasticity and excitability in humans with fragile X syndrome and autism spectrum disorder

Directory of Open Access Journals (Sweden)

Lindsay M Oberman

2010-06-01

Full Text Available Fragile X Syndrome (FXS is the most common heritable cause of intellectual disability. In vitro electrophysiologic data from mouse models of FXS suggest that loss of Fragile X Mental Retardation Protein (FMRP affects intracortical excitability and synaptic plasticity. Specifically, the cortex appears hyperexcitable, and use-dependent long-term potentiation (LTP and long-term depression (LTD of synaptic strength are abnormal. Though animal models provide important information, FXS and other neurodevelopmental disorders are human diseases and as such translational research to evaluate cortical excitability and plasticity must be applied in the human. Transcranial magnetic stimulation (TMS paradigms have recently been developed to noninvasively investigate cortical excitability using paired-pulse stimulation, as well as LTP- and LTD-like synaptic plasticity in response to theta burst stimulation (TBS in vivo in the human. TBS applied on consecutive days can be used to measure metaplasticity (the ability of the synapse to undergo a second plastic change following a recent induction of plasticity. The current study investigated intracortical inhibition, plasticity and metaplasticity in full mutation females with FXS, participants with autism spectrum disorders (ASD, and neurotypical controls. Results suggest that intracortical inhibition is normal in participants with FXS, while plasticity and metaplasticity appear abnormal. ASD participants showed abnormalities in plasticity and metaplasticity, as well as heterogeneity in intracortical inhibition. Our findings highlight the utility of noninvasive neurophysiological measures to translate insights from animal models to humans with neurodevelopmental disorders, and thus provide direct confirmation of cortical dysfunction in patients with FXS and ASD.

The Unique Brain Anatomy of Meditation Practitioners: Alterations in Cortical Gyrification

Science.gov (United States)

Luders, Eileen; Kurth, Florian; Mayer, Emeran A.; Toga, Arthur W.; Narr, Katherine L.; Gaser, Christian

2012-01-01

Several cortical regions are reported to vary in meditation practitioners. However, prior analyses have focused primarily on examining gray matter or cortical thickness. Thus, additional effects with respect to other cortical features might have remained undetected. Gyrification (the pattern and degree of cortical folding) is an important cerebral characteristic related to the geometry of the brain’s surface. Thus, exploring cortical gyrification in long-term meditators may provide additional clues with respect to the underlying anatomical correlates of meditation. This study examined cortical gyrification in a large sample (n = 100) of meditators and controls, carefully matched for sex and age. Cortical gyrification was established by calculating mean curvature across thousands of vertices on individual cortical surface models. Pronounced group differences indicating larger gyrification in meditators were evident within the left precentral gyrus, right fusiform gyrus, right cuneus, as well as left and right anterior dorsal insula (the latter representing the global significance maximum). Positive correlations between gyrification and the number of meditation years were similarly pronounced in the right anterior dorsal insula. Although the exact functional implications of larger cortical gyrification remain to be established, these findings suggest the insula to be a key structure involved in aspects of meditation. For example, variations in insular complexity could affect the regulation of well-known distractions in the process of meditation, such as daydreaming, mind-wandering, and projections into past or future. Moreover, given that meditators are masters in introspection, awareness, and emotional control, increased insular gyrification may reflect an integration of autonomic, affective, and cognitive processes. Due to the cross-sectional nature of this study, further research is necessary to determine the relative contribution of nature and nurture to

Evaluation of glucose metabolic abnormality in postlingually deaf patients using F-18-FDG positron emission tomography and statistical parametric mapping

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Sung; Lee, Dong Soo; Oh, Seung Ha; Kim, Chong Sun; Park, Kwang Suk; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

2000-07-01

We have previously reported the prognostic relevance of cross-modal cortical plasticity in prelingual deaf patients revealed by F-18-FDG PET and SPM analysis. In this study, we investigated metabolic abnormality in postlingual deaf patients, whose clinical features are different from prelingual deafness. Nine postlingual deaf patients (age: 30.5 {+-}14.0) were performed on F-18-FDG brain PET. We compared their PET images with those of age-matched 20 normal controls (age: 27.1 {+-}8.6), and performed correlation analysis to investigate the relationship between glucose metabolism and deaf duration using SPM99. Glucose metabolism of deaf patients was significantly (p<0.05, corrected) decreased in both anterior cingulate, inferior frontal cortices, and superior temporal cortices, and left hippocampus. Metabolism in both superior temporal cortices and association area in inferior parietal cortices showed significant (p<0.01, uncorrected) positive correlation with deaf duration. Decreased metabolism in hippocampus accompanied with hypometabolism in auditory related areas can be explained by recent finding of anatomical connectivity between them, and may be the evidence indicating their functional connectivity. Metabolism recovery in auditory cortex after long deaf duration suggests that cortical plasticity takes place also in postlingual deafness.

Evaluation of glucose metabolic abnormality in postlingually deaf patients using F-18-FDG positron emission tomography and statistical parametric mapping

International Nuclear Information System (INIS)

Lee, Jae Sung; Lee, Dong Soo; Oh, Seung Ha; Kim, Chong Sun; Park, Kwang Suk; Chung, June Key; Lee, Myung Chul

2000-01-01

We have previously reported the prognostic relevance of cross-modal cortical plasticity in prelingual deaf patients revealed by F-18-FDG PET and SPM analysis. In this study, we investigated metabolic abnormality in postlingual deaf patients, whose clinical features are different from prelingual deafness. Nine postlingual deaf patients (age: 30.5 ±14.0) were performed on F-18-FDG brain PET. We compared their PET images with those of age-matched 20 normal controls (age: 27.1 ±8.6), and performed correlation analysis to investigate the relationship between glucose metabolism and deaf duration using SPM99. Glucose metabolism of deaf patients was significantly (p<0.05, corrected) decreased in both anterior cingulate, inferior frontal cortices, and superior temporal cortices, and left hippocampus. Metabolism in both superior temporal cortices and association area in inferior parietal cortices showed significant (p<0.01, uncorrected) positive correlation with deaf duration. Decreased metabolism in hippocampus accompanied with hypometabolism in auditory related areas can be explained by recent finding of anatomical connectivity between them, and may be the evidence indicating their functional connectivity. Metabolism recovery in auditory cortex after long deaf duration suggests that cortical plasticity takes place also in postlingual deafness

Cerebrospinal fluid flow abnormalities in patients with neoplastic meningitis. An evaluation using 111In-DTPA ventriculography

International Nuclear Information System (INIS)

Grossman, S.A.; Trump, D.L.; Chen, D.C.; Thompson, G.; Camargo, E.E.

1982-01-01

Cerebrospinal fluid flow dynamics were evaluated by 111 In-diethylenetriamine pentaacetic acid ( 111 In-DTPA) ventriculography in 27 patients with neoplastic meningitis. Nineteen patients (70 percent) had evidence of cerebrospinal fluid flow disturbances. These occurred as ventricular outlet obstructions, abnormalities of flow in the spinal canal, or flow distrubances over the cortical convexities. Tumor histology, physical examination, cerebrospinal fluid analysis, myelograms, and computerized axial tomographic scans were not sufficient to predict cerebrospinal fluid flow patterns. These data indicate that cerebrospinal fluid flow abnormalities are common in patients with neoplastic meningitis and that 111 In-DTPA cerebrospinal fluid flow imaging is useful in characterizing these abnormalities. This technique provides insight into the distribution of intraventricularly administered chemotherapy and may provide explanations for treatment failure and drug-induced neurotoxicity in patients with neoplastic meningitis

Cortical somatosensory reorganization in children with spastic cerebral palsy: a multimodal neuroimaging study

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CHRISTOS ePAPADELIS

2014-09-01

Full Text Available Although cerebral palsy (CP is among the most common causes of physical disability in early childhood, we know little about the functional and structural changes of this disorder in the developing brain. Here, we investigated with three different neuroimaging modalities (magnetoencephalography (MEG, diffusion tension imaging (DTI, and resting state fMRI whether spastic CP is associated with functional and anatomical abnormalities in the sensorimotor network. Ten children participated in the study: four with diplegic CP (DCP, three with hemiplegic CP (HCP, and three typically-developing (TD children. Somatosensory evoked fields (SEFs were recorded in response to pneumatic stimuli applied to digits D1, D3, and D5 of both hands. Several parameters of water diffusion were calculated from DTI between the thalamus and the precentral and postcentral gyri in both hemispheres. The sensorimotor resting state networks (RSNs were examined by using an independent component analysis method. Tactile stimulation of the fingers elicited the first prominent cortical response at ~50 ms, in all except one child, localized over the primary somatosensory cortex (S1. In five CP children, abnormal somatotopic organization was observed in the affected (or more affected hemisphere. Euclidean distances were markedly different between the two hemispheres in the HCP children, and between DCP and TD children for both hemispheres. DTI analysis revealed decreased fractional anisotropy and increased apparent diffusion coefficient for the thalamocortical pathways in the more affected compared to less affected hemisphere in CP children. Rs-fMRI results indicated absent and/or abnormal sensorimotor RSNs for children with HCP and DCP consistent with the severity and location of their lesions. Our findings suggest an abnormal somatosensory processing mechanism in the sensorimotor network of children with CP possibly as a result of diminished thalamocortical projections.

Cortical hubs form a module for multisensory integration on top of the hierarchy of cortical networks

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Gorka Zamora-López

2010-03-01

Full Text Available Sensory stimuli entering the nervous system follow particular paths of processing, typically separated (segregated from the paths of other modal information. However, sensory perception, awareness and cognition emerge from the combination of information (integration. The corticocortical networks of cats and macaque monkeys display three prominent characteristics: (i modular organisation (facilitating the segregation, (ii abundant alternative processing paths and (iii the presence of highly connected hubs. Here, we study in detail the organisation and potential function of the cortical hubs by graph analysis and information theoretical methods. We find that the cortical hubs form a spatially delocalised, but topologically central module with the capacity to integrate multisensory information in a collaborative manner. With this, we resolve the underlying anatomical substrate that supports the simultaneous capacity of the cortex to segregate and to integrate multisensory information.

A review of reward processing and motivational impairment in schizophrenia.

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Strauss, Gregory P; Waltz, James A; Gold, James M

2014-03-01

This article reviews and synthesizes research on reward processing in schizophrenia, which has begun to provide important insights into the cognitive and neural mechanisms associated with motivational impairments. Aberrant cortical-striatal interactions may be involved with multiple reward processing abnormalities, including: (1) dopamine-mediated basal ganglia systems that support reinforcement learning and the ability to predict cues that lead to rewarding outcomes; (2) orbitofrontal cortex-driven deficits in generating, updating, and maintaining value representations; (3) aberrant effort-value computations, which may be mediated by disrupted anterior cingulate cortex and midbrain dopamine functioning; and (4) altered activation of the prefrontal cortex, which is important for generating exploratory behaviors in environments where reward outcomes are uncertain. It will be important for psychosocial interventions targeting negative symptoms to account for abnormalities in each of these reward processes, which may also have important interactions; suggestions for novel behavioral intervention strategies that make use of external cues, reinforcers, and mobile technology are discussed.

Abnormal regional spontaneous neuronal activity associated with symptom severity in treatment-naive patients with obsessive-compulsive disorder revealed by resting-state functional MRI.

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Qiu, Linlin; Fu, Xiangshuai; Wang, Shuai; Tang, Qunfeng; Chen, Xingui; Cheng, Lin; Zhang, Fuquan; Zhou, Zhenhe; Tian, Lin

2017-02-15

A large number of neuroimaging studies have revealed the dysfunction of brain activities in obsessive-compulsive disorder (OCD) during various tasks. However, regional spontaneous activity abnormalities in OCD are gradually being revealed. In this current study, we aimed to investigate cerebral regions with abnormal spontaneous activity using resting-state functional magnetic resonance imaging (fMRI) and further explored the relationship between the spontaneous neuronal activity and symptom severity of patients with OCD. Thirty-one patients with OCD and 32 age-and sex-matched normal controls received the fMRI scans and fractional amplitude of low-frequency fluctuation (fALFF) approach was applied to identify the abnormal brain activity. We found that patients with OCD showed decreased fALFF not only in the cortical-striato-thalamo-cortical (CSTC) circuits like the thalamus, but also in other cerebral systems like the cerebellum, the parietal cortex and the temporal cortex. Additionally, OCD patients demonstrated significant associations between decreased fALFF and obsessive-compulsive symptom severity in the thalamus, the paracentral lobule and the cerebellum. Our results provide evidence for abnormal spontaneous neuronal activity in distributed cerebral areas and support the notion that brain areas outside the CSTC circuits may also play an important role in the pathophysiology of OCD. Copyright © 2017 Elsevier B.V. All rights reserved.

Abnormal GABAergic function and face processing in schizophrenia: A pharmacologic-fMRI study.

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Tso, Ivy F; Fang, Yu; Phan, K Luan; Welsh, Robert C; Taylor, Stephan F

2015-10-01

The involvement of the gamma-aminobutyric acid (GABA) system in schizophrenia is suggested by postmortem studies and the common use of GABA receptor-potentiating agents in treatment. In a recent study, we used a benzodiazepine challenge to demonstrate abnormal GABAergic function during processing of negative visual stimuli in schizophrenia. This study extended this investigation by mapping GABAergic mechanisms associated with face processing and social appraisal in schizophrenia using a benzodiazepine challenge. Fourteen stable, medicated schizophrenia/schizoaffective patients (SZ) and 13 healthy controls (HC) underwent functional MRI using the blood oxygenation level-dependent (BOLD) technique while they performed the Socio-emotional Preference Task (SePT) on emotional face stimuli ("Do you like this face?"). Participants received single-blinded intravenous saline and lorazepam (LRZ) in two separate sessions separated by 1-3weeks. Both SZ and HC recruited medial prefrontal cortex/anterior cingulate during the SePT, relative to gender identification. A significant drug by group interaction was observed in the medial occipital cortex, such that SZ showed increased BOLD signal to LRZ challenge, while HC showed an expected decrease of signal; the interaction did not vary by task. The altered BOLD response to LRZ challenge in SZ was significantly correlated with increased negative affect across multiple measures. The altered response to LRZ challenge suggests that abnormal face processing and negative affect in SZ are associated with altered GABAergic function in the visual cortex, underscoring the role of impaired visual processing in socio-emotional deficits in schizophrenia. Copyright © 2015 Elsevier B.V. All rights reserved.

Deficient cortical face-sensitive N170 responses and basic visual processing in schizophrenia.

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Maher, S; Mashhoon, Y; Ekstrom, T; Lukas, S; Chen, Y

2016-01-01

Face detection, an ability to identify a visual stimulus as a face, is impaired in patients with schizophrenia. It is unclear whether impaired face processing in this psychiatric disorder results from face-specific domains or stems from more basic visual domains. In this study, we examined cortical face-sensitive N170 response in schizophrenia, taking into account deficient basic visual contrast processing. We equalized visual contrast signals among patients (n=20) and controls (n=20) and between face and tree images, based on their individual perceptual capacities (determined using psychophysical methods). We measured N170, a putative temporal marker of face processing, during face detection and tree detection. In controls, N170 amplitudes were significantly greater for faces than trees across all three visual contrast levels tested (perceptual threshold, two times perceptual threshold and 100%). In patients, however, N170 amplitudes did not differ between faces and trees, indicating diminished face selectivity (indexed by the differential responses to face vs. tree). These results indicate a lack of face-selectivity in temporal responses of brain machinery putatively responsible for face processing in schizophrenia. This neuroimaging finding suggests that face-specific processing is compromised in this psychiatric disorder. Copyright © 2015 Elsevier B.V. All rights reserved.

Extent of cortical involvement in amyotrophic lateral sclerosis--an analysis based on cortical thickness.

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Thorns, Johannes; Jansma, Henk; Peschel, Thomas; Grosskreutz, Julian; Mohammadi, Bahram; Dengler, Reinhard; Münte, Thomas F

2013-10-18

Besides the defining involvement of upper and lower motor neurons, the involvement of extramotor structures has been increasingly acknowledged in amyotrophic lateral sclerosis (ALS). Here we investigated a group of 14 mildly to moderately affected ALS patients and 14 age-matched healthy control participants using cortical thickness analysis. Cortical thickness was determined from high resolution 3D T1 magnetic resonance images and involved semiautomatic segmentation in grey and white matter, cortical alignment and determination of thickness using the Laplace method. In addition to a whole-cortex analysis a region of interest approach was applied. ALS patients showed regions of significant cortical thinning in the pre- and postcentral gyri bilaterally. Further regions of cortical thinning included superior and inferior parietal lobule, angular and supramarginal gyrus, insula, superior frontal, temporal and occipital regions, thus further substantiating extramotor involvement in ALS. A relationship between cortical thickness of the right superior frontal cortex and clinical severity (assessed by the ALS functional rating scale) was also demonstrated. Cortical thickness is reduced in ALS not only in motor areas but in widespread non-motor cortical areas. Cortical thickness is related to clinical severity.

Dynamic Causal Modeling of the Cortical Responses to Wrist Perturbations

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Yuan Yang

2017-09-01

Full Text Available Mechanical perturbations applied to the wrist joint typically evoke a stereotypical sequence of cortical and muscle responses. The early cortical responses (<100 ms are thought be involved in the “rapid” transcortical reaction to the perturbation while the late cortical responses (>100 ms are related to the “slow” transcortical reaction. Although previous studies indicated that both responses involve the primary motor cortex, it remains unclear if both responses are engaged by the same effective connectivity in the cortical network. To answer this question, we investigated the effective connectivity cortical network after a “ramp-and-hold” mechanical perturbation, in both the early (<100 ms and late (>100 ms periods, using dynamic causal modeling. Ramp-and-hold perturbations were applied to the wrist joint while the subject maintained an isometric wrist flexion. Cortical activity was recorded using a 128-channel electroencephalogram (EEG. We investigated how the perturbation modulated the effective connectivity for the early and late periods. Bayesian model comparisons suggested that different effective connectivity networks are engaged in these two periods. For the early period, we found that only a few cortico-cortical connections were modulated, while more complicated connectivity was identified in the cortical network during the late period with multiple modulated cortico-cortical connections. The limited early cortical network likely allows for a rapid muscle response without involving high-level cognitive processes, while the complexity of the late network may facilitate coordinated responses.

MicroRNA-338 modulates cortical neuronal placement and polarity.

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Kos, Aron; de Mooij-Malsen, Annetrude J; van Bokhoven, Hans; Kaplan, Barry B; Martens, Gerard J; Kolk, Sharon M; Aschrafi, Armaz

2017-07-03

The precise spatial and temporal regulation of gene expression orchestrates the many intricate processes during brain development. In the present study we examined the role of the brain-enriched microRNA-338 (miR-338) during mouse cortical development. Reduction of miR-338 levels in the developing mouse cortex, using a sequence-specific miR-sponge, resulted in a loss of neuronal polarity in the cortical plate and significantly reduced the number of neurons within this cortical layer. Conversely, miR-338 overexpression in developing mouse cortex increased the number of neurons, which exhibited a multipolar morphology. All together, our results raise the possibility for a direct role for this non-coding RNA, which was recently associated with schizophrenia, in the regulation of cortical neuronal polarity and layer placement.

The somatotopic localisation of the descending cortical tract in the cerebral peduncle: a study using MRI of changes following Wallerian degeneration in the cerebral peduncle after a supratentorial vascular lesion

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Waragai, M.; Watanabe, H.; Iwabuchi, S.

1994-01-01

We studied the effects of Wallerian degeneration in the cerebral peduncle shown by magnetic resonance imaging (MRI) following a supratentorial vascular lesion, to identify the somatotopic localisation of the descending cortical tracts. Patients with a lesion involving a large area of a cerebral hemisphere has an area of abnormal signal intensity in the whole cerebral peduncle, suggesting Wallerian degeneration of all the whole descending cortical tracts. With a small lesion confined to the precentral gyrus, corona radiata, or posterior limb of the internal capsule there was an abnormal signal at the centre of the peduncle, suggesting degeneration of the precentrospinal tract. Those with a small lesion confined to the paracentral gyrus had an abnormal area slightly lateral to the centre of the peduncle, suggesting degeneration of the parietospinal tract. Patients with a lesion of the parietal or temporal lobes, not including the paracentral or precentral gyri, corona radiata, or the posterior limb of the internal capsule, had an abnormal area laterally in the peduncle, suggesting degeneration of the parietopontine or temporopontine tract. (orig.)

Cortical processes of speech illusions in the general population.

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Schepers, E; Bodar, L; van Os, J; Lousberg, R

2016-10-18

There is evidence that experimentally elicited auditory illusions in the general population index risk for psychotic symptoms. As little is known about underlying cortical mechanisms of auditory illusions, an experiment was conducted to analyze processing of auditory illusions in a general population sample. In a follow-up design with two measurement moments (baseline and 6 months), participants (n = 83) underwent the White Noise task under simultaneous recording with a 14-lead EEG. An auditory illusion was defined as hearing any speech in a sound fragment containing white noise. A total number of 256 speech illusions (SI) were observed over the two measurements, with a high degree of stability of SI over time. There were 7 main effects of speech illusion on the EEG alpha band-the most significant indicating a decrease in activity at T3 (t = -4.05). Other EEG frequency bands (slow beta, fast beta, gamma, delta, theta) showed no significant associations with SI. SIs are characterized by reduced alpha activity in non-clinical populations. Given the association of SIs with psychosis, follow-up research is required to examine the possibility of reduced alpha activity mediating SIs in high risk and symptomatic populations.

Formulaic language in cortical and subcortical disease: Evidence of the dual process model.

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Kelly Bridges

2014-04-01

Full Text Available Introduction: It is known that an intact cortical left hemisphere is crucial for language production. Recently, more credit is given to the right hemisphere and subcortical areas in the production of non-novel language, including formulaic language. John Hughlings Jackson (1874/1958, first described how propositional and non-propositional speech are differentially affected by neural impairment. Non-propositional language is often preserved following left hemisphere stroke even when aphasia is present (Code, 1982; Sidtis et al., 2009; Van Lancker Sidtis & Postman, 2006. With right hemisphere and subcortical stroke, formulaic language is reduced (Sidtis et al., 2009; Van Lancker Sidtis & Postman, 2006; Speedie et al., 1993. The dual process model of language competence states that propositional and non-propositional speech are processed differently in the brain, with novel speech controlled by the left hemisphere, and a right hemisphere/subcortical circuit modulating formulaic language (Van Lancker Sidtis, 2004; 2012. Two studies of formulaic language will be presented as further evidence of the dual process model: a study of formulaic language in Alzheimer’s disease, and a study of recited speech in Parkinson’s disease. Formulaic language includes overlearned words, phrases or longer linguistic units that are known to the native speaker, occur naturally in discourse, and are important for normal social interaction (Fillmore, 1979; Pawley & Syder, 1983; Van Lancker, 1988; Van Lancker Sidtis, 2004; Wray, 2002. Formulaic expressions include conversational speech formulas, idioms, proverbs, expletives, pause fillers, discourse elements, and sentence stems (stereotyped sentence-initials. Longer units of linguistic material, such as prayers, rhymes, and poems, termed recited speech, is another subtype of formulaic language that is learned in childhood and recited periodically throughout life. Cortical disease: Alzheimer’s disease and formulaic

Compressive sensing-based electrostatic sensor array signal processing and exhausted abnormal debris detecting

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Tang, Xin; Chen, Zhongsheng; Li, Yue; Yang, Yongmin

2018-05-01

When faults happen at gas path components of gas turbines, some sparsely-distributed and charged debris will be generated and released into the exhaust gas. The debris is called abnormal debris. Electrostatic sensors can detect the debris online and further indicate the faults. It is generally considered that, under a specific working condition, a more serious fault generates more and larger debris, and a piece of larger debris carries more charge. Therefore, the amount and charge of the abnormal debris are important indicators of the fault severity. However, because an electrostatic sensor can only detect the superposed effect on the electrostatic field of all the debris, it can hardly identify the amount and position of the debris. Moreover, because signals of electrostatic sensors depend on not only charge but also position of debris, and the position information is difficult to acquire, measuring debris charge accurately using the electrostatic detecting method is still a technical difficulty. To solve these problems, a hemisphere-shaped electrostatic sensors' circular array (HSESCA) is used, and an array signal processing method based on compressive sensing (CS) is proposed in this paper. To research in a theoretical framework of CS, the measurement model of the HSESCA is discretized into a sparse representation form by meshing. In this way, the amount and charge of the abnormal debris are described as a sparse vector. It is further reconstructed by constraining l1-norm when solving an underdetermined equation. In addition, a pre-processing method based on singular value decomposition and a result calibration method based on weighted-centroid algorithm are applied to ensure the accuracy of the reconstruction. The proposed method is validated by both numerical simulations and experiments. Reconstruction errors, characteristics of the results and some related factors are discussed.

From Cortical and Subcortical Grey Matter Abnormalities to Neurobehavioral Phenotype of Angelman Syndrome: A Voxel-Based Morphometry Study.

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Gayane Aghakhanyan

Full Text Available Angelman syndrome (AS is a rare neurogenetic disorder due to loss of expression of maternal ubiquitin-protein ligase E3A (UBE3A gene. It is characterized by severe developmental delay, speech impairment, movement or balance disorder and typical behavioral uniqueness. Affected individuals show normal magnetic resonance imaging (MRI findings, although mild dysmyelination may be observed. In this study, we adopted a quantitative MRI analysis with voxel-based morphometry (FSL-VBM method to investigate disease-related changes in the cortical/subcortical grey matter (GM structures. Since 2006 to 2013 twenty-six AS patients were assessed by our multidisciplinary team. From those, sixteen AS children with confirmed maternal 15q11-q13 deletions (mean age 7.7 ± 3.6 years and twenty-one age-matched controls were recruited. The developmental delay and motor dysfunction were assessed using Bayley III and Gross Motor Function Measure (GMFM. Principal component analysis (PCA was applied to the clinical and neuropsychological datasets. High-resolution T1-weighted images were acquired and FSL-VBM approach was applied to investigate differences in the local GM volume and to correlate clinical and neuropsychological changes in the regional distribution of GM. We found bilateral GM volume loss in AS compared to control children in the striatum, limbic structures, insular and orbitofrontal cortices. Voxel-wise correlation analysis with the principal components of the PCA output revealed a strong relationship with GM volume in the superior parietal lobule and precuneus on the left hemisphere. The anatomical distribution of cortical/subcortical GM changes plausibly related to several clinical features of the disease and may provide an important morphological underpinning for clinical and neurobehavioral symptoms in children with AS.

Cortical GABA markers identify a molecular subtype of psychotic and bipolar disorders.

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Volk, D W; Sampson, A R; Zhang, Y; Edelson, J R; Lewis, D A

2016-09-01

Deficits in gamma aminobutyric acid (GABA) neuron-related markers, including the GABA-synthesizing enzyme GAD67, the calcium-binding protein parvalbumin, the neuropeptide somatostatin, and the transcription factor Lhx6, are most pronounced in a subset of schizophrenia subjects identified as having a 'low GABA marker' (LGM) molecular phenotype. Furthermore, schizophrenia shares degrees of genetic liability, clinical features and cortical circuitry abnormalities with schizoaffective disorder and bipolar disorder. Therefore, we determined the extent to which a similar LGM molecular phenotype may also exist in subjects with these disorders. Transcript levels for GAD67, parvalbumin, somatostatin, and Lhx6 were quantified using quantitative PCR in prefrontal cortex area 9 of 184 subjects with a diagnosis of schizophrenia (n = 39), schizoaffective disorder (n = 23) or bipolar disorder (n = 35), or with a confirmed absence of any psychiatric diagnoses (n = 87). A blinded clustering approach was employed to determine the presence of a LGM molecular phenotype across all subjects. Approximately 49% of the subjects with schizophrenia, 48% of the subjects with schizoaffective disorder, and 29% of the subjects with bipolar disorder, but only 5% of unaffected subjects, clustered in the cortical LGM molecular phenotype. These findings support the characterization of psychotic and bipolar disorders by cortical molecular phenotype which may help elucidate more pathophysiologically informed and personalized medications.

Abnormal neural hierarchy in processing of verbal information in patients with schizophrenia.

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Lerner, Yulia; Bleich-Cohen, Maya; Solnik-Knirsh, Shimrit; Yogev-Seligmann, Galit; Eisenstein, Tamir; Madah, Waheed; Shamir, Alon; Hendler, Talma; Kremer, Ilana

2018-01-01

Previous research indicates abnormal comprehension of verbal information in patients with schizophrenia. Yet the neural mechanism underlying the breakdown of verbal information processing in schizophrenia is poorly understood. Imaging studies in healthy populations have shown a network of brain areas involved in hierarchical processing of verbal information over time. Here, we identified critical aspects of this hierarchy, examining patients with schizophrenia. Using functional magnetic resonance imaging, we examined various levels of information comprehension elicited by naturally presented verbal stimuli; from a set of randomly shuffled words to an intact story. Specifically, patients with first episode schizophrenia ( N  = 15), their non-manifesting siblings ( N  = 14) and healthy controls ( N  = 15) listened to a narrated story and randomly scrambled versions of it. To quantify the degree of dissimilarity between the groups, we adopted an inter-subject correlation (inter-SC) approach, which estimates differences in synchronization of neural responses within and between groups. The temporal topography found in healthy and siblings groups were consistent with our previous findings - high synchronization in responses from early sensory toward high order perceptual and cognitive areas. In patients with schizophrenia, stimuli with short and intermediate temporal scales evoked a typical pattern of reliable responses, whereas story condition (long temporal scale) revealed robust and widespread disruption of the inter-SCs. In addition, the more similar the neural activity of patients with schizophrenia was to the average response in the healthy group, the less severe the positive symptoms of the patients. Our findings suggest that system-level neural indication of abnormal verbal information processing in schizophrenia reflects disease manifestations.

Abnormal neural hierarchy in processing of verbal information in patients with schizophrenia

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Yulia Lerner

2018-01-01

Full Text Available Previous research indicates abnormal comprehension of verbal information in patients with schizophrenia. Yet the neural mechanism underlying the breakdown of verbal information processing in schizophrenia is poorly understood. Imaging studies in healthy populations have shown a network of brain areas involved in hierarchical processing of verbal information over time. Here, we identified critical aspects of this hierarchy, examining patients with schizophrenia. Using functional magnetic resonance imaging, we examined various levels of information comprehension elicited by naturally presented verbal stimuli; from a set of randomly shuffled words to an intact story. Specifically, patients with first episode schizophrenia (N = 15, their non-manifesting siblings (N = 14 and healthy controls (N = 15 listened to a narrated story and randomly scrambled versions of it. To quantify the degree of dissimilarity between the groups, we adopted an inter-subject correlation (inter-SC approach, which estimates differences in synchronization of neural responses within and between groups. The temporal topography found in healthy and siblings groups were consistent with our previous findings – high synchronization in responses from early sensory toward high order perceptual and cognitive areas. In patients with schizophrenia, stimuli with short and intermediate temporal scales evoked a typical pattern of reliable responses, whereas story condition (long temporal scale revealed robust and widespread disruption of the inter-SCs. In addition, the more similar the neural activity of patients with schizophrenia was to the average response in the healthy group, the less severe the positive symptoms of the patients. Our findings suggest that system-level neural indication of abnormal verbal information processing in schizophrenia reflects disease manifestations.

Cortical depth dependent population receptive field attraction by spatial attention in human V1.

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Klein, Barrie P; Fracasso, Alessio; van Dijk, Jelle A; Paffen, Chris L E; Te Pas, Susan F; Dumoulin, Serge O

2018-04-27

Visual spatial attention concentrates neural resources at the attended location. Recently, we demonstrated that voluntary spatial attention attracts population receptive fields (pRFs) toward its location throughout the visual hierarchy. Theoretically, both a feed forward or feedback mechanism could underlie pRF attraction in a given cortical area. Here, we use sub-millimeter ultra-high field functional MRI to measure pRF attraction across cortical depth and assess the contribution of feed forward and feedback signals to pRF attraction. In line with previous findings, we find consistent attraction of pRFs with voluntary spatial attention in V1. When assessed as a function of cortical depth, we find pRF attraction in every cortical portion (deep, center and superficial), although the attraction is strongest in deep cortical portions (near the gray-white matter boundary). Following the organization of feed forward and feedback processing across V1, we speculate that a mixture of feed forward and feedback processing underlies pRF attraction in V1. Specifically, we propose that feedback processing contributes to the pRF attraction in deep cortical portions. Copyright © 2018. Published by Elsevier Inc.

Cortico-cortical communication dynamics

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Per E Roland

2014-05-01

Full Text Available IIn principle, cortico-cortical communication dynamics is simple: neurons in one cortical area communicate by sending action potentials that release glutamate and excite their target neurons in other cortical areas. In practice, knowledge about cortico-cortical communication dynamics is minute. One reason is that no current technique can capture the fast spatio-temporal cortico-cortical evolution of action potential transmission and membrane conductances with sufficient spatial resolution. A combination of optogenetics and monosynaptic tracing with virus can reveal the spatio-temporal cortico-cortical dynamics of specific neurons and their targets, but does not reveal how the dynamics evolves under natural conditions. Spontaneous ongoing action potentials also spread across cortical areas and are difficult to separate from structured evoked and intrinsic brain activity such as thinking. At a certain state of evolution, the dynamics may engage larger populations of neurons to drive the brain to decisions, percepts and behaviors. For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived. As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG, and a combination of invasive measurements in animal experiments. Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.

An anterior-to-posterior shift in midline cortical activity in schizophrenia during self-reflection.

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Holt, Daphne J; Cassidy, Brittany S; Andrews-Hanna, Jessica R; Lee, Su Mei; Coombs, Garth; Goff, Donald C; Gabrieli, John D; Moran, Joseph M

2011-03-01

Deficits in social cognition, including impairments in self-awareness, contribute to the overall functional disability associated with schizophrenia. Studies in healthy subjects have shown that social cognitive functions, including self-reflection, rely on the medial prefrontal cortex (mPFC) and posterior cingulate gyrus, and these regions exhibit highly correlated activity during "resting" states. In this study, we tested the hypothesis that patients with schizophrenia show dysfunction of this network during self-reflection and that this abnormal activity is associated with changes in the strength of resting-state correlations between these regions. Activation during self-reflection and control tasks was measured with functional magnetic resonance imaging in 19 patients with schizophrenia and 20 demographically matched control subjects. In addition, the resting-state functional connectivity of midline cortical areas showing abnormal self-reflection-related activation in schizophrenia was measured. Compared with control subjects, the schizophrenia patients demonstrated lower activation of the right ventral mPFC and greater activation of the mid/posterior cingulate gyri bilaterally during self-reflection, relative to a control task. A similar pattern was seen during overall social reflection. In addition, functional connectivity between the portion of the left mid/posterior cingulate gyrus showing abnormally elevated activity during self-reflection in schizophrenia, and the dorsal anterior cingulate gyrus was lower in the schizophrenia patients compared with control subjects. Schizophrenia is associated with an anterior-to-posterior shift in introspection-related activation, as well as changes in functional connectivity, of the midline cortex. These findings provide support for the hypothesis that aberrant midline cortical function contributes to social cognitive impairment in schizophrenia. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier

Cortical Development Requires Mesodermal Expression of Tbx1, a Gene Haploinsufficient in 22q11.2 Deletion Syndrome.

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Flore, Gemma; Cioffi, Sara; Bilio, Marchesa; Illingworth, Elizabeth

2017-03-01

In mammals, proper temporal control of neurogenesis and neural migration during embryonic development ensures correct formation of the cerebral cortex. Changes in the distribution of cortical projection neurons and interneurons are associated with behavioral disorders and psychiatric diseases, including schizophrenia and autism, suggesting that disrupted cortical connectivity contributes to the brain pathology. TBX1 is the major candidate gene for 22q11.2 deletion syndrome (22q11.2DS), a chromosomal deletion disorder characterized by a greatly increased risk for schizophrenia. We have previously shown that Tbx1 heterozygous mice have reduced prepulse inhibition, a behavioral abnormality that is associated with 22q11.2DS and nonsyndromic schizophrenia. Here, we show that loss of Tbx1 disrupts corticogenesis in mice by promoting premature neuronal differentiation in the medio-lateral embryonic cortex, which gives rise to the somatosensory cortex (S1). In addition, we found altered polarity in both radially migrating excitatory neurons and tangentially migrating inhibitory interneurons. Together, these abnormalities lead to altered lamination in the S1 at the terminal stages of corticogenesis in Tbx1 null mice and similar anomalies in Tbx1 heterozygous adult mice. Finally, we show that mesoderm-specific inactivation of Tbx1 is sufficient to recapitulate the brain phenotype indicating that Tbx1 exerts a cell nonautonomous role in cortical development from the mesoderm. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Cortical representations of communication sounds.

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Heiser, Marc A; Cheung, Steven W

2008-10-01

This review summarizes recent research into cortical processing of vocalizations in animals and humans. There has been a resurgent interest in this topic accompanied by an increased number of studies using animal models with complex vocalizations and new methods in human brain imaging. Recent results from such studies are discussed. Experiments have begun to reveal the bilateral cortical fields involved in communication sound processing and the transformations of neural representations that occur among those fields. Advances have also been made in understanding the neuronal basis of interaction between developmental exposures and behavioral experiences with vocalization perception. Exposure to sounds during the developmental period produces large effects on brain responses, as do a variety of specific trained tasks in adults. Studies have also uncovered a neural link between the motor production of vocalizations and the representation of vocalizations in cortex. Parallel experiments in humans and animals are answering important questions about vocalization processing in the central nervous system. This dual approach promises to reveal microscopic, mesoscopic, and macroscopic principles of large-scale dynamic interactions between brain regions that underlie the complex phenomenon of vocalization perception. Such advances will yield a greater understanding of the causes, consequences, and treatment of disorders related to speech processing.

Transcranial Direct Current Stimulation Targeting Primary Motor Versus Dorsolateral Prefrontal Cortices: Proof-of-Concept Study Investigating Functional Connectivity of Thalamocortical Networks Specific to Sensory-Affective Information Processing.

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Sankarasubramanian, Vishwanath; Cunningham, David A; Potter-Baker, Kelsey A; Beall, Erik B; Roelle, Sarah M; Varnerin, Nicole M; Machado, Andre G; Jones, Stephen E; Lowe, Mark J; Plow, Ela B

2017-04-01

The pain matrix is comprised of an extensive network of brain structures involved in sensory and/or affective information processing. The thalamus is a key structure constituting the pain matrix. The thalamus serves as a relay center receiving information from multiple ascending pathways and relating information to and from multiple cortical areas. However, it is unknown how thalamocortical networks specific to sensory-affective information processing are functionally integrated. Here, in a proof-of-concept study in healthy humans, we aimed to understand this connectivity using transcranial direct current stimulation (tDCS) targeting primary motor (M1) or dorsolateral prefrontal cortices (DLPFC). We compared changes in functional connectivity (FC) with DLPFC tDCS to changes in FC with M1 tDCS. FC changes were also compared to further investigate its relation with individual's baseline experience of pain. We hypothesized that resting-state FC would change based on tDCS location and would represent known thalamocortical networks. Ten right-handed individuals received a single application of anodal tDCS (1 mA, 20 min) to right M1 and DLPFC in a single-blind, sham-controlled crossover study. FC changes were studied between ventroposterolateral (VPL), the sensory nucleus of thalamus, and cortical areas involved in sensory information processing and between medial dorsal (MD), the affective nucleus, and cortical areas involved in affective information processing. Individual's perception of pain at baseline was assessed using cutaneous heat pain stimuli. We found that anodal M1 tDCS and anodal DLPFC tDCS both increased FC between VPL and sensorimotor cortices, although FC effects were greater with M1 tDCS. Similarly, anodal M1 tDCS and anodal DLPFC tDCS both increased FC between MD and motor cortices, but only DLPFC tDCS modulated FC between MD and affective cortices, like DLPFC. Our findings suggest that M1 stimulation primarily modulates FC of sensory networks

Comparing the influence of crestal cortical bone and sinus floor cortical bone in posterior maxilla bi-cortical dental implantation: a three-dimensional finite element analysis.

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Yan, Xu; Zhang, Xinwen; Chi, Weichao; Ai, Hongjun; Wu, Lin

2015-05-01

This study aimed to compare the influence of alveolar ridge cortical bone and sinus floor cortical bone in sinus areabi-cortical dental implantation by means of 3D finite element analysis. Three-dimensional finite element (FE) models in a posterior maxillary region with sinus membrane and the same height of alveolar ridge of 10 mm were generated according to the anatomical data of the sinus area. They were either with fixed thickness of crestal cortical bone and variable thickness of sinus floor cortical bone or vice versa. Ten models were assumed to be under immediate loading or conventional loading. The standard implant model based on the Nobel Biocare implant system was created via computer-aided design software. All materials were assumed to be isotropic and linearly elastic. An inclined force of 129 N was applied. Von Mises stress mainly concentrated on the surface of crestal cortical bone around the implant neck. For all the models, both the axial and buccolingual resonance frequencies of conventional loading were higher than those of immediate loading; however, the difference is less than 5%. The results showed that bi-cortical implant in sinus area increased the stability of the implant, especially for immediately loading implantation. The thickness of both crestal cortical bone and sinus floor cortical bone influenced implant micromotion and stress distribution; however, crestal cortical bone may be more important than sinus floor cortical bone.

Increased Insular Cortical Thickness Associated With Symptom Severity in Male Youths With Internet Gaming Disorder: A Surface-Based Morphometric Study

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Wang, Shuai; Liu, Jing; Tian, Lin; Chen, Limin; Wang, Jun; Tang, Qunfeng; Zhang, Fuquan; Zhou, Zhenhe

2018-01-01

With the rising increase in Internet-usage, Internet gaming disorder (IGD) has gained massive attention worldwide. However, detailed cerebral morphological changes remain unclear in youths with IGD. In the current study, our aim was to investigate cortical morphology and further explore the relationship between the cortical morphology and symptom severity in male youths with IGD. Forty-eight male youths with IGD and 32 age- and education-matched normal controls received magnetic resonance imaging scans. We employed a recently proposed surface-based morphometric approach for the measurement of cortical thickness (CT). We found that youths with IGD showed increased CT in the bilateral insulae and the right inferior temporal gyrus. Moreover, significantly decreased CT were found in several brain areas in youths with IGD, including the bilateral banks of the superior temporal sulci, the right inferior parietal cortex, the right precuneus, the right precentral gyrus, and the left middle temporal gyrus. Additionally, youths with IGD demonstrated a significantly positive correlation between the left insular CT and symptom severity. Our data provide evidence for the finding of abnormal CT in distributed cerebral areas and support the notion that altered structural abnormalities observed in substance addiction are also manifested in IGD. Such information extends current knowledge about IGD-related brain reorganization and could help future efforts in identifying the role of insula in the disorder. PMID:29666588

Increased Insular Cortical Thickness Associated With Symptom Severity in Male Youths With Internet Gaming Disorder: A Surface-Based Morphometric Study

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Shuai Wang

2018-04-01

Full Text Available With the rising increase in Internet-usage, Internet gaming disorder (IGD has gained massive attention worldwide. However, detailed cerebral morphological changes remain unclear in youths with IGD. In the current study, our aim was to investigate cortical morphology and further explore the relationship between the cortical morphology and symptom severity in male youths with IGD. Forty-eight male youths with IGD and 32 age- and education-matched normal controls received magnetic resonance imaging scans. We employed a recently proposed surface-based morphometric approach for the measurement of cortical thickness (CT. We found that youths with IGD showed increased CT in the bilateral insulae and the right inferior temporal gyrus. Moreover, significantly decreased CT were found in several brain areas in youths with IGD, including the bilateral banks of the superior temporal sulci, the right inferior parietal cortex, the right precuneus, the right precentral gyrus, and the left middle temporal gyrus. Additionally, youths with IGD demonstrated a significantly positive correlation between the left insular CT and symptom severity. Our data provide evidence for the finding of abnormal CT in distributed cerebral areas and support the notion that altered structural abnormalities observed in substance addiction are also manifested in IGD. Such information extends current knowledge about IGD-related brain reorganization and could help future efforts in identifying the role of insula in the disorder.

The cortical structure of consolidated memory: a hypothesis on the role of the cingulate-entorhinal cortical connection.

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Insel, Nathan; Takehara-Nishiuchi, Kaori

2013-11-01

Daily experiences are represented by networks of neurons distributed across the neocortex, bound together for rapid storage and later retrieval by the hippocampus. While the hippocampus is necessary for retrieving recent episode-based memory associations, over time, consolidation processes take place that enable many of these associations to be expressed independent of the hippocampus. It is generally thought that mechanisms of consolidation involve synaptic weight changes between cortical regions; or, in other words, the formation of "horizontal" cortico-cortical connections. Here, we review anatomical, behavioral, and physiological data which suggest that the connections in and between the entorhinal and cingulate cortices may be uniquely important for the long-term storage of memories that initially depend on the hippocampus. We propose that current theories of consolidation that divide memory into dual systems of hippocampus and neocortex might be improved by introducing a third, middle layer of entorhinal and cingulate allocortex, the synaptic weights within which are necessary and potentially sufficient for maintaining initially hippocampus-dependent associations over long time periods. This hypothesis makes a number of still untested predictions, and future experiments designed to address these will help to fill gaps in the current understanding of the cortical structure of consolidated memory. Copyright © 2013 Elsevier Inc. All rights reserved.

Humans mimicking animals: A cortical hierarchy for human vocal communication sounds

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Talkington, William J.; Rapuano, Kristina M.; Hitt, Laura; Frum, Chris A.; Lewis, James W.

2012-01-01

Numerous species possess cortical regions that are most sensitive to vocalizations produced by their own kind (conspecifics). In humans, the superior temporal sulci (STS) putatively represent homologous voice-sensitive areas of cortex. However, STS regions have recently been reported to represent auditory experience or “expertise” in general rather than showing exclusive sensitivity to human vocalizations per se. Using functional magnetic resonance imaging and a unique non-stereotypical category of complex human non-verbal vocalizations – human-mimicked versions of animal vocalizations – we found a cortical hierarchy in humans optimized for processing meaningful conspecific utterances. This left-lateralized hierarchy originated near primary auditory cortices and progressed into traditional speech-sensitive areas. These results suggest that the cortical regions supporting vocalization perception are initially organized by sensitivity to the human vocal tract in stages prior to the STS. Additionally, these findings have implications for the developmental time course of conspecific vocalization processing in humans as well as its evolutionary origins. PMID:22674283

Abnormal sound detection device

International Nuclear Information System (INIS)

Yamada, Izumi; Matsui, Yuji.

1995-01-01

Only components synchronized with rotation of pumps are sampled from detected acoustic sounds, to judge the presence or absence of abnormality based on the magnitude of the synchronized components. A synchronized component sampling means can remove resonance sounds and other acoustic sounds generated at a synchronously with the rotation based on the knowledge that generated acoustic components in a normal state are a sort of resonance sounds and are not precisely synchronized with the number of rotation. On the other hand, abnormal sounds of a rotating body are often caused by compulsory force accompanying the rotation as a generation source, and the abnormal sounds can be detected by extracting only the rotation-synchronized components. Since components of normal acoustic sounds generated at present are discriminated from the detected sounds, reduction of the abnormal sounds due to a signal processing can be avoided and, as a result, abnormal sound detection sensitivity can be improved. Further, since it is adapted to discriminate the occurrence of the abnormal sound from the actually detected sounds, the other frequency components which are forecast but not generated actually are not removed, so that it is further effective for the improvement of detection sensitivity. (N.H.)

Disconnection mechanism and regional cortical atrophy contribute to impaired processing of facial expressions and theory of mind in multiple sclerosis: a structural MRI study.

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Andrea Mike

Full Text Available Successful socialization requires the ability of understanding of others' mental states. This ability called as mentalization (Theory of Mind may become deficient and contribute to everyday life difficulties in multiple sclerosis. We aimed to explore the impact of brain pathology on mentalization performance in multiple sclerosis. Mentalization performance of 49 patients with multiple sclerosis was compared to 24 age- and gender matched healthy controls. T1- and T2-weighted three-dimensional brain MRI images were acquired at 3Tesla from patients with multiple sclerosis and 18 gender- and age matched healthy controls. We assessed overall brain cortical thickness in patients with multiple sclerosis and the scanned healthy controls, and measured the total and regional T1 and T2 white matter lesion volumes in patients with multiple sclerosis. Performances in tests of recognition of mental states and emotions from facial expressions and eye gazes correlated with both total T1-lesion load and regional T1-lesion load of association fiber tracts interconnecting cortical regions related to visual and emotion processing (genu and splenium of corpus callosum, right inferior longitudinal fasciculus, right inferior fronto-occipital fasciculus, uncinate fasciculus. Both of these tests showed correlations with specific cortical areas involved in emotion recognition from facial expressions (right and left fusiform face area, frontal eye filed, processing of emotions (right entorhinal cortex and socially relevant information (left temporal pole. Thus, both disconnection mechanism due to white matter lesions and cortical thinning of specific brain areas may result in cognitive deficit in multiple sclerosis affecting emotion and mental state processing from facial expressions and contributing to everyday and social life difficulties of these patients.

Disconnection mechanism and regional cortical atrophy contribute to impaired processing of facial expressions and theory of mind in multiple sclerosis: a structural MRI study.

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Mike, Andrea; Strammer, Erzsebet; Aradi, Mihaly; Orsi, Gergely; Perlaki, Gabor; Hajnal, Andras; Sandor, Janos; Banati, Miklos; Illes, Eniko; Zaitsev, Alexander; Herold, Robert; Guttmann, Charles R G; Illes, Zsolt

2013-01-01

Successful socialization requires the ability of understanding of others' mental states. This ability called as mentalization (Theory of Mind) may become deficient and contribute to everyday life difficulties in multiple sclerosis. We aimed to explore the impact of brain pathology on mentalization performance in multiple sclerosis. Mentalization performance of 49 patients with multiple sclerosis was compared to 24 age- and gender matched healthy controls. T1- and T2-weighted three-dimensional brain MRI images were acquired at 3Tesla from patients with multiple sclerosis and 18 gender- and age matched healthy controls. We assessed overall brain cortical thickness in patients with multiple sclerosis and the scanned healthy controls, and measured the total and regional T1 and T2 white matter lesion volumes in patients with multiple sclerosis. Performances in tests of recognition of mental states and emotions from facial expressions and eye gazes correlated with both total T1-lesion load and regional T1-lesion load of association fiber tracts interconnecting cortical regions related to visual and emotion processing (genu and splenium of corpus callosum, right inferior longitudinal fasciculus, right inferior fronto-occipital fasciculus, uncinate fasciculus). Both of these tests showed correlations with specific cortical areas involved in emotion recognition from facial expressions (right and left fusiform face area, frontal eye filed), processing of emotions (right entorhinal cortex) and socially relevant information (left temporal pole). Thus, both disconnection mechanism due to white matter lesions and cortical thinning of specific brain areas may result in cognitive deficit in multiple sclerosis affecting emotion and mental state processing from facial expressions and contributing to everyday and social life difficulties of these patients.

Prefrontal cortical and striatal activity to happy and fear faces in bipolar disorder is associated with comorbid substance abuse and eating disorder.

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Hassel, Stefanie; Almeida, Jorge R; Frank, Ellen; Versace, Amelia; Nau, Sharon A; Klein, Crystal R; Kupfer, David J; Phillips, Mary L

2009-11-01

The spectrum approach was used to examine contributions of comorbid symptom dimensions of substance abuse and eating disorder to abnormal prefrontal-cortical and subcortical-striatal activity to happy and fear faces previously demonstrated in bipolar disorder (BD). Fourteen remitted BD-type I and sixteen healthy individuals viewed neutral, mild and intense happy and fear faces in two event-related fMRI experiments. All individuals completed Substance-Use and Eating-Disorder Spectrum measures. Region-of-Interest analyses for bilateral prefrontal and subcortical-striatal regions were performed. BD individuals scored significantly higher on these spectrum measures than healthy individuals (pright PFC activity to intense happy faces (pright caudate nucleus activity to neutral faces (pright ventral putamen activity to intense happy (pabuse and eating disorder and prefrontal-cortical and subcortical-striatal activity to facial expressions in BD. Our findings suggest that these comorbid features may contribute to observed patterns of functional abnormalities in neural systems underlying mood regulation in BD.

Cortical morphology development in patients with 22q11.2 deletion syndrome at ultra-high risk of psychosis.

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Padula, Maria Carmela; Schaer, Marie; Armando, Marco; Sandini, Corrado; Zöller, Daniela; Scariati, Elisa; Schneider, Maude; Eliez, Stephan

2018-01-17

Patients with 22q11.2 deletion syndrome (22q11DS) present a high risk of developing psychosis. While clinical and cognitive predictors for the conversion towards a full-blown psychotic disorder are well defined and largely used in practice, neural biomarkers do not yet exist. However, a number of investigations indicated an association between abnormalities in cortical morphology and higher symptoms severities in patients with 22q11DS. Nevertheless, few studies included homogeneous groups of patients differing in their psychotic symptoms profile. In this study, we included 22 patients meeting the criteria for an ultra-high-risk (UHR) psychotic state and 22 age-, gender- and IQ-matched non-UHR patients. Measures of cortical morphology, including cortical thickness, volume, surface area and gyrification, were compared between the two groups using mass-univariate and multivariate comparisons. Furthermore, the development of these measures was tested in the two groups using a mixed-model approach. Our results showed differences in cortical volume and surface area in UHR patients compared with non-UHR. In particular, we found a positive association between surface area and the rate of change of global functioning, suggesting that higher surface area is predictive of improved functioning with age. We also observed accelerated cortical thinning during adolescence in UHR patients with 22q11DS. These results, although preliminary, suggest that alterations in cortical volume and surface area as well as altered development of cortical thickness may be associated to a greater probability to develop psychosis in 22q11DS.

Regional vulnerability of longitudinal cortical association connectivity: Associated with structural network topology alterations in preterm children with cerebral palsy.

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Ceschin, Rafael; Lee, Vince K; Schmithorst, Vince; Panigrahy, Ashok

2015-01-01

Preterm born children with spastic diplegia type of cerebral palsy and white matter injury or periventricular leukomalacia (PVL), are known to have motor, visual and cognitive impairments. Most diffusion tensor imaging (DTI) studies performed in this group have demonstrated widespread abnormalities using averaged deterministic tractography and voxel-based DTI measurements. Little is known about structural network correlates of white matter topography and reorganization in preterm cerebral palsy, despite the availability of new therapies and the need for brain imaging biomarkers. Here, we combined novel post-processing methodology of probabilistic tractography data in this preterm cohort to improve spatial and regional delineation of longitudinal cortical association tract abnormalities using an along-tract approach, and compared these data to structural DTI cortical network topology analysis. DTI images were acquired on 16 preterm children with cerebral palsy (mean age 5.6 ± 4) and 75 healthy controls (mean age 5.7 ± 3.4). Despite mean tract analysis, Tract-Based Spatial Statistics (TBSS) and voxel-based morphometry (VBM) demonstrating diffusely reduced fractional anisotropy (FA) reduction in all white matter tracts, the along-tract analysis improved the detection of regional tract vulnerability. The along-tract map-structural network topology correlates revealed two associations: (1) reduced regional posterior-anterior gradient in FA of the longitudinal visual cortical association tracts (inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, optic radiation, posterior thalamic radiation) correlated with reduced posterior-anterior gradient of intra-regional (nodal efficiency) metrics with relative sparing of frontal and temporal regions; and (2) reduced regional FA within frontal-thalamic-striatal white matter pathways (anterior limb/anterior thalamic radiation, superior longitudinal fasciculus and cortical spinal tract) correlated with

Relating Cortical Wave Dynamics to Learning and Remembering

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Eduardo Mercado III

2014-12-01

Full Text Available Electrical waves propagate across sensory and motor cortices in stereotypical patterns. These waves have been described as potentially facilitating sensory processing when they travel through sensory cortex, as guiding movement preparation and performance when they travel across motor cortex, and as possibly promoting synaptic plasticity and the consolidation of memory traces, especially during sleep. Here, an alternative theoretical framework is suggested that integrates Pavlovian hypotheses about learning and cortical function with concepts from contemporary proceduralist theories of memory. The proposed framework postulates that sensory-evoked cortical waves are gradually modified across repeated experiences such that the waves more effectively differentiate sensory events, and so that the waves are more likely to reverberate. It is argued that the qualities of cortical waves—their origins, form, intensity, speed, periodicity, extent, and trajectories —are a function of both the structural organization of neural circuits and ongoing reverberations resulting from previously experienced events. It is hypothesized that experience-dependent cortical plasticity, both in the short- and long-term, modulates the qualities of cortical waves, thereby enabling individuals to make progressively more precise distinctions between complex sensory events, and to reconstruct components of previously experienced events. Unlike most current neurobiological theories of learning and memory mechanisms, this hypothesis does not assume that synaptic plasticity, or any other form of neural plasticity, serves to store physical records of previously experienced events for later reactivation. Rather, the reorganization of cortical circuits may alter the potential for certain wave patterns to arise and persist. Understanding what factors determine the spatiotemporal dynamics of cortical waves, how structural changes affect their qualities, and how wave dynamics

Striatal morphology correlates with sensory abnormalities in unaffected relatives of cervical dystonia patients.

LENUS (Irish Health Repository)

Walsh, Richard A

2012-02-01

Structural grey matter abnormalities have been described in adult-onset primary torsion dystonia (AOPTD). Altered spatial discrimination thresholds are found in familial and sporadic AOPTD and in some unaffected relatives who may be non-manifesting gene carriers. Our hypothesis was that a subset of unaffected relatives with abnormal spatial acuity would have associated structural abnormalities. Twenty-eight unaffected relatives of patients with familial cervical dystonia, 24 relatives of patients with sporadic cervical dystonia and 27 control subjects were recruited. Spatial discrimination thresholds (SDTs) were determined using a grating orientation task. High-resolution magnetic resonance imaging (MRI) images (1.5 T) were analysed using voxel-based morphometry. Unaffected familial relatives with abnormal SDTs had reduced caudate grey matter volume (GMV) bilaterally relative to those with normal SDTs (right Z = 3.45, left Z = 3.81), where there was a negative correlation between SDTs and GMV (r = -0.76, r(2) = 0.58, p < 0.0001). Familial relatives also had bilateral sensory cortical expansion relative to unrelated controls (right Z = 4.02, left Z = 3.79). Unaffected relatives of patients with sporadic cervical dystonia who had abnormal SDTs had reduced putaminal GMV bilaterally compared with those with normal SDTs (right Z = 3.96, left Z = 3.45). Sensory abnormalities in some unaffected relatives correlate with a striatal substrate and may be a marker of genetic susceptibility in these individuals. Further investigation of grey matter changes as a candidate endophenotype may assist future genetic studies of dystonia.

Increased cortical-limbic anatomical network connectivity in major depression revealed by diffusion tensor imaging.

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Peng Fang

Full Text Available Magnetic resonance imaging studies have reported significant functional and structural differences between depressed patients and controls. Little attention has been given, however, to the abnormalities in anatomical connectivity in depressed patients. In the present study, we aim to investigate the alterations in connectivity of whole-brain anatomical networks in those suffering from major depression by using machine learning approaches. Brain anatomical networks were extracted from diffusion magnetic resonance images obtained from both 22 first-episode, treatment-naive adults with major depressive disorder and 26 matched healthy controls. Using machine learning approaches, we differentiated depressed patients from healthy controls based on their whole-brain anatomical connectivity patterns and identified the most discriminating features that represent between-group differences. Classification results showed that 91.7% (patients=86.4%, controls=96.2%; permutation test, p<0.0001 of subjects were correctly classified via leave-one-out cross-validation. Moreover, the strengths of all the most discriminating connections were increased in depressed patients relative to the controls, and these connections were primarily located within the cortical-limbic network, especially the frontal-limbic network. These results not only provide initial steps toward the development of neurobiological diagnostic markers for major depressive disorder, but also suggest that abnormal cortical-limbic anatomical networks may contribute to the anatomical basis of emotional dysregulation and cognitive impairments associated with this disease.

Rab3A, a possible marker of cortical granules, participates in cortical granule exocytosis in mouse eggs

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Bello, Oscar Daniel; Cappa, Andrea Isabel; Paola, Matilde de; Zanetti, María Natalia [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Fukuda, Mitsunori [Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Fissore, Rafael A. [Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, MA 01003 (United States); Mayorga, Luis S. [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Michaut, Marcela A., E-mail: mmichaut@gmail.com [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (Argentina)

2016-09-10

Fusion of cortical granules with the oocyte plasma membrane is the most significant event to prevent polyspermy. This particular exocytosis, also known as cortical reaction, is regulated by calcium and its molecular mechanism is still not known. Rab3A, a member of the small GTP-binding protein superfamily, has been implicated in calcium-dependent exocytosis and is not yet clear whether Rab3A participates in cortical granules exocytosis. Here, we examine the involvement of Rab3A in the physiology of cortical granules, particularly, in their distribution during oocyte maturation and activation, and their participation in membrane fusion during cortical granule exocytosis. Immunofluorescence and Western blot analysis showed that Rab3A and cortical granules have a similar migration pattern during oocyte maturation, and that Rab3A is no longer detected after cortical granule exocytosis. These results suggested that Rab3A might be a marker of cortical granules. Overexpression of EGFP-Rab3A colocalized with cortical granules with a Pearson correlation coefficient of +0.967, indicating that Rab3A and cortical granules have almost a perfect colocalization in the egg cortical region. Using a functional assay, we demonstrated that microinjection of recombinant, prenylated and active GST-Rab3A triggered cortical granule exocytosis, indicating that Rab3A has an active role in this secretory pathway. To confirm this active role, we inhibited the function of endogenous Rab3A by microinjecting a polyclonal antibody raised against Rab3A prior to parthenogenetic activation. Our results showed that Rab3A antibody microinjection abolished cortical granule exocytosis in parthenogenetically activated oocytes. Altogether, our findings confirm that Rab3A might function as a marker of cortical granules and participates in cortical granule exocytosis in mouse eggs. - Highlights: • Rab3A has a similar migration pattern to cortical granules in mouse oocytes. • Rab3A can be a marker of

Stroke rehabilitation using noninvasive cortical stimulation: aphasia.

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Mylius, Veit; Zouari, Hela G; Ayache, Samar S; Farhat, Wassim H; Lefaucheur, Jean-Pascal

2012-08-01

Poststroke aphasia results from the lesion of cortical areas involved in the motor production of speech (Broca's aphasia) or in the semantic aspects of language comprehension (Wernicke's aphasia). Such lesions produce an important reorganization of speech/language-specific brain networks due to an imbalance between cortical facilitation and inhibition. In fact, functional recovery is associated with changes in the excitability of the damaged neural structures and their connections. Two main mechanisms are involved in poststroke aphasia recovery: the recruitment of perilesional regions of the left hemisphere in case of small lesion and the acquisition of language processing ability in homotopic areas of the nondominant right hemisphere when left hemispheric language abilities are permanently lost. There is some evidence that noninvasive cortical stimulation, especially when combined with language therapy or other therapeutic approaches, can promote aphasia recovery. Cortical stimulation was mainly used to either increase perilesional excitability or reduce contralesional activity based on the concept of reciprocal inhibition and maladaptive plasticity. However, recent studies also showed some positive effects of the reinforcement of neural activities in the contralateral right hemisphere, based on the potential compensatory role of the nondominant hemisphere in stroke recovery.

Cortical Visual Impairment

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... resolves by one year of life. Is “cortical blindness” the same thing as CVI? Cortical blindness is ... What visual characteristics are associated with CVI? • Distinct color preferences • Variable level of vision loss, often demonstrating ...

Visual form-processing deficits: a global clinical classification.

Science.gov (United States)

Unzueta-Arce, J; García-García, R; Ladera-Fernández, V; Perea-Bartolomé, M V; Mora-Simón, S; Cacho-Gutiérrez, J

2014-10-01

Patients who have difficulties recognising visual form stimuli are usually labelled as having visual agnosia. However, recent studies let us identify different clinical manifestations corresponding to discrete diagnostic entities which reflect a variety of deficits along the continuum of cortical visual processing. We reviewed different clinical cases published in medical literature as well as proposals for classifying deficits in order to provide a global perspective of the subject. Here, we present the main findings on the neuroanatomical basis of visual form processing and discuss the criteria for evaluating processing which may be abnormal. We also include an inclusive diagram of visual form processing deficits which represents the different clinical cases described in the literature. Lastly, we propose a boosted decision tree to serve as a guide in the process of diagnosing such cases. Although the medical community largely agrees on which cortical areas and neuronal circuits are involved in visual processing, future studies making use of new functional neuroimaging techniques will provide more in-depth information. A well-structured and exhaustive assessment of the different stages of visual processing, designed with a global view of the deficit in mind, will give a better idea of the prognosis and serve as a basis for planning personalised psychostimulation and rehabilitation strategies. Copyright © 2011 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

A Mechanistic Link from GABA to Cortical Architecture and Perception.

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Kolasinski, James; Logan, John P; Hinson, Emily L; Manners, Daniel; Divanbeighi Zand, Amir P; Makin, Tamar R; Emir, Uzay E; Stagg, Charlotte J

2017-06-05

Understanding both the organization of the human cortex and its relation to the performance of distinct functions is fundamental in neuroscience. The primary sensory cortices display topographic organization, whereby receptive fields follow a characteristic pattern, from tonotopy to retinotopy to somatotopy [1]. GABAergic signaling is vital to the maintenance of cortical receptive fields [2]; however, it is unclear how this fine-grain inhibition relates to measurable patterns of perception [3, 4]. Based on perceptual changes following perturbation of the GABAergic system, it is conceivable that the resting level of cortical GABAergic tone directly relates to the spatial specificity of activation in response to a given input [5-7]. The specificity of cortical activation can be considered in terms of cortical tuning: greater cortical tuning yields more localized recruitment of cortical territory in response to a given input. We applied a combination of fMRI, MR spectroscopy, and psychophysics to substantiate the link between the cortical neurochemical milieu, the tuning of cortical activity, and variability in perceptual acuity, using human somatosensory cortex as a model. We provide data that explain human perceptual acuity in terms of both the underlying cellular and metabolic processes. Specifically, higher concentrations of sensorimotor GABA are associated with more selective cortical tuning, which in turn is associated with enhanced perception. These results show anatomical and neurochemical specificity and are replicated in an independent cohort. The mechanistic link from neurochemistry to perception provides a vital step in understanding population variability in sensory behavior, informing metabolic therapeutic interventions to restore perceptual abilities clinically. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Large-Scale Functional Brain Network Abnormalities in Alzheimer’s Disease: Insights from Functional Neuroimaging

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Bradford C. Dickerson

2009-01-01

Full Text Available Functional MRI (fMRI studies of mild cognitive impairment (MCI and Alzheimer’s disease (AD have begun to reveal abnormalities in large-scale memory and cognitive brain networks. Since the medial temporal lobe (MTL memory system is a site of very early pathology in AD, a number of studies have focused on this region of the brain. Yet it is clear that other regions of the large-scale episodic memory network are affected early in the disease as well, and fMRI has begun to illuminate functional abnormalities in frontal, temporal, and parietal cortices as well in MCI and AD. Besides predictable hypoactivation of brain regions as they accrue pathology and undergo atrophy, there are also areas of hyperactivation in brain memory and cognitive circuits, possibly representing attempted compensatory activity. Recent fMRI data in MCI and AD are beginning to reveal relationships between abnormalities of functional activity in the MTL memory system and in functionally connected brain regions, such as the precuneus. Additional work with “resting state” fMRI data is illuminating functional-anatomic brain circuits and their disruption by disease. As this work continues to mature, it will likely contribute to our understanding of fundamental memory processes in the human brain and how these are perturbed in memory disorders. We hope these insights will translate into the incorporation of measures of task-related brain function into diagnostic assessment or therapeutic monitoring, which will hopefully one day be useful for demonstrating beneficial effects of treatments being tested in clinical trials.

Abnormality of cerebral cortical glucose metabolism in temporal lobe epilepsy with cognitive function impairment

International Nuclear Information System (INIS)

Bang-Hung Yang; Tsung-Szu Yeh; Tung-Ping Su; Jyh-Cheng Chen; Ren-Shyan Liu

2004-01-01

Objective: People with epilepsy commonly report having problems with their memory. Many indicate that memory difficulties significantly hinder their functioning at work, in school, and at home. Besides, some studies have reported that memory performance as a prognostic factor is of most value in patients with risk of refractory epilepsy and when used in a multidisciplinary setting. However, the cerebral cortical areas involving memory impairment in epilepsy is still unknown. The purpose of this study was to access changes of cerebral glucose metabolism of epilepsy patients using [F-18] fluorodeoxyglucose positron emission tomography (FDG PET). Method: Nine temporal lobe epilepsy patients were studied. Each patient was confirmed with lesions in right mesial temporal lobe by MRI, PET and EEG. Serial cognition function tests were performed. Regional cerebral glucose metabolism (rCMRglc) was measured by PET at 45 minutes after injection of 370 MBq of FDG. Parametric images were generated by grand mean scaling each scan to 50. The images were then transformed into standard stereotactic space. Statistical parametric mapping (SPM2) was applied to find the correlations between verbal memory, figure memory, perception intelligent quotation (PIQ) and rCMRglc in epilepsy patients. The changes of rCMRglc were significant if corrected p value was less than 0.05. Results: There was no significant relationship between figure memory score and verbal memory score. FDG-PET scan showed changes of rCMRglc positive related with verbal memory score in precentral gyms of right frontal lobe (Brodmann area 4, corrected p < 0.001, voxel size 240) and cingulated gyms of right limbic lobe (Brodmann area 32, corrected p=0.002, voxel size 143). No negative relationship was demonstrable between verbal memory and rCMRglc in this study. Besides, significanfiy positive correlation between figure memory was shown in cuneus of right occipital lobe (Brodmann area 18, corrected p < 0.001, voxel size

The changing roles of neurons in the cortical subplate

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Michael J Friedlander

2009-08-01

Full Text Available Neurons may serve different functions over the course of an organism’s life. Recent evidence suggests that cortical subplate neurons including those that reside in the white matter may perform longitudinal multi-tasking at different stages of development. These cells play a key role in early cortical development in coordinating thalamocortical reciprocal innervation. At later stages of development, they become integrated within the cortical microcircuitry. This type of longitudinal multi-tasking can enhance the capacity for information processing by populations of cells serving different functions over the lifespan. Subplate cells are initially derived when cells from the ventricular zone underlying the cortex migrate to the cortical preplate that is subsequently split by the differentiating neurons of the cortical plate with some neurons locating in the marginal zone and others settling below in the subplate (SP. While the cortical plate neurons form most of the cortical layers (layers 2-6, the marginal zone neurons form layer 1 and the SP neurons become interstitial cells of the white matter as well as forming a compact sublayer along the bottom of layer 6. After serving as transient innervation targets for thalamocortical axons, most of these cells die and layer 4 neurons become innervated by thalamic axons. However, 10-20% survives, remaining into adulthood along the bottom of layer 6 and as a scattered population of interstitial neurons in the white matter. Surviving subplate cells’ axons project throughout the overlying laminae, reaching layer 1 and issuing axon collaterals within white matter and in lower layer 6. This suggests that they participate in local synaptic networks, as well. Moreover, they receive excitatory and inhibitory synaptic inputs, potentially monitoring outputs from axon collaterals of cortical efferents, from cortical afferents and/or from each other. We explore our understanding of the functional connectivity of

Cortical region of interest definition on SPECT brain images using X-ray CT registration

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Tzourio, N.; Sutton, D. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot); Joliot, M. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot INSERM, Orsay (France)); Mazoyer, B.M. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot Antenne d' Information Medicale, C.H.U. Bichat, Paris (France)); Charlot, V. (Hopital Louis Mourier, Colombes (France). Service de Psychiatrie); Salamon, G. (CHU La Timone, Marseille (France). Service de Neuroradiologie)

1992-11-01

We present a method for brain single photon emission computed tomography (SPECT) analysis based on individual registration of anatomical (CT) and functional ([sup 133]Xe regional cerebral blood flow) images and on the definition of three-dimensional functional regions of interest. Registration of CT and SPECT is performed through adjustment of CT-defined cortex limits to the SPECT image. Regions are defined by sectioning a cortical ribbon on the CT images, copied over the SPECT images and pooled through slices to give 3D cortical regions of interest. The proposed method shows good intra- and interobserver reproducibility (regional intraclass correlation coefficient [approx equal]0.98), and good accuracy in terms of repositioning ([approx equal]3.5 mm) as compared to the SPECT image resolution (14 mm). The method should be particularly useful for analysing SPECT studies when variations in brain anatomy (normal or abnormal) must be accounted for. (orig.).

Dissociation of face-selective cortical responses by attention.

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Furey, Maura L; Tanskanen, Topi; Beauchamp, Michael S; Avikainen, Sari; Uutela, Kimmo; Hari, Riitta; Haxby, James V

2006-01-24

We studied attentional modulation of cortical processing of faces and houses with functional MRI and magnetoencephalography (MEG). MEG detected an early, transient face-selective response. Directing attention to houses in "double-exposure" pictures of superimposed faces and houses strongly suppressed the characteristic, face-selective functional MRI response in the fusiform gyrus. By contrast, attention had no effect on the M170, the early, face-selective response detected with MEG. Late (>190 ms) category-related MEG responses elicited by faces and houses, however, were strongly modulated by attention. These results indicate that hemodynamic and electrophysiological measures of face-selective cortical processing complement each other. The hemodynamic signals reflect primarily late responses that can be modulated by feedback connections. By contrast, the early, face-specific M170 that was not modulated by attention likely reflects a rapid, feed-forward phase of face-selective processing.

Cortical oscillations modulated by congruent and incongruent audiovisual stimuli.

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Herdman, A T; Fujioka, T; Chau, W; Ross, B; Pantev, C; Picton, T W

2004-11-30

Congruent or incongruent grapheme-phoneme stimuli are easily perceived as one or two linguistic objects. The main objective of this study was to investigate the changes in cortical oscillations that reflect the processing of congruent and incongruent audiovisual stimuli. Graphemes were Japanese Hiragana characters for four different vowels (/a/, /o/, /u/, and /i/). They were presented simultaneously with their corresponding phonemes (congruent) or non-corresponding phonemes (incongruent) to native-speaking Japanese participants. Participants' reaction times to the congruent audiovisual stimuli were significantly faster by 57 ms as compared to reaction times to incongruent stimuli. We recorded the brain responses for each condition using a whole-head magnetoencephalograph (MEG). A novel approach to analysing MEG data, called synthetic aperture magnetometry (SAM), was used to identify event-related changes in cortical oscillations involved in audiovisual processing. The SAM contrast between congruent and incongruent responses revealed greater event-related desynchonization (8-16 Hz) bilaterally in the occipital lobes and greater event-related synchronization (4-8 Hz) in the left transverse temporal gyrus. Results from this study further support the concept of interactions between the auditory and visual sensory cortices in multi-sensory processing of audiovisual objects.

Swine cortical and cancellous bone: histomorphometric and densitometric characterisation

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Maria Elena Andreis

2017-06-01

Full Text Available Introduction: Swine bone morphology, composition and remodelling are similar to humans’, therefore they are considered good models in bone-related research. They have been used for several studies involving bone growth, bone and cartilage fractures and femoral head osteonecrosis. Nevertheless, the literature about pig normal bone features is incomplete. This work aims to fill the literature gaps on the microarchitecture and Bone Mineral Density (BMD of swine femoral diaphysis and distal epiphysis and tibial plateau and diaphysis. Materials and methods: Five hind limbs were collected from slaughtered 80-100 kg pigs. Microscopic analysis of cortical and cancellous bone from middle/distal femur and proximal/middle tibia was performed to determine basic histomorphometric parameters at different sites. Dual-energy X-Rays Absorptiometry was also employed to evaluate BMD. ANOVA and correlation between BMD, bone area (BA and cortical thickness were performed. Results and discussion: Diaphyseal cortical bone was mostly plexiform both in the tibia and the femur; primary/secondary osteons without clear organization were also found. Mean values for bone area, bone perimeter, trabecular width, number and separation and BMD at different anatomical sites were defined. No significant difference was found for these values at different anatomical sites. BMD proved to be positively correlated with cortical thickness (r=0,80; p<0,01. Despite the small sample size, these results seem homogeneous. They could therefore represent reference values for normal bone parameters in pigs. Applied anatomy and regenerative medicine, in fact, demand very precise information about bone micromorphology, composition and density to provide reliable indication in bone substitutes building. Moreover, since the interpretation of bone abnormalities is based on mastering normal bone characteristics, the definition of reference parameters is mandatory to avoid misinterpretation and

Magnetization transfer imaging identifies basal ganglia abnormalities in adult ADHD that are invisible to conventional T1 weighted voxel-based morphometry

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Arjun Sethi

2017-01-01

Full Text Available In childhood, Attention Deficit Hyperactivity Disorder (ADHD is reliably associated with reduced volume of the striatum. In contrast, striatal abnormalities are infrequently detected in voxel-based morphometry (VBM neuroimaging studies of adults with ADHD. This discrepancy has been suggested to reflect normalisation of striatal morphology with age and prolonged treatment of symptoms. If so, this would indicate that while striatal abnormalities are linked to symptom expression in childhood, they cannot explain the persistence of these symptoms in adulthood. However, this may not be case. Instead, we hypothesized that the lack of evidence for striatal abnormalities in adult ADHD may reflect poor sensitivity of typical (T1-weighted neuroimaging to detect subcortical differences. To address this, we acquired both magnetisation transfer (MT saturation maps optimised for subcortical contrast, and conventional T1-weighted images in 30 adults with ADHD and 30 age, IQ, gender and handedness-matched controls. Using VBM of both datasets, we demonstrate volumetric reductions within the left ventral striatum on MT that are not observed on identically pre-processed T1-weighted images from the same participants. Nevertheless, both techniques reported similar sensitivity to cortical abnormalities in the right inferior parietal lobe. Additionally, we show that differences in striatal iron may potentially explain this reduced sensitivity of T1-weighted images in adults. Together, these findings indicate that prior VBM studies reporting no abnormalities in striatal volume in adult ADHD might have been compromised by the methodological insensitivity of T1-weighted VBM to subcortical differences, and that structural abnormalities of the striatum in ADHD do indeed persist into adulthood.

Intralaminar and medial thalamic influence on cortical synchrony, information transmission and cognition

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Yuri B Saalmann

2014-05-01

Full Text Available The intralaminar and medial thalamic nuclei are part of the higher-order thalamus, which receives little sensory input, and instead forms extensive cortico-thalamo-cortical pathways. The large mediodorsal thalamic nucleus predominantly connects with the prefrontal cortex, the adjacent intralaminar nuclei connect with fronto-parietal cortex, and the midline thalamic nuclei connect with medial prefrontal cortex and medial temporal lobe. Taking into account this connectivity pattern, it is not surprising that the intralaminar and medial thalamus has been implicated in a variety of cognitive functions, including memory processing, attention and orienting, as well as reward-based behavior. This review addresses how the intralaminar and medial thalamus may regulate information transmission in cortical circuits. A key neural mechanism may involve intralaminar and medial thalamic neurons modulating the degree of synchrony between different groups of cortical neurons according to behavioral demands. Such a thalamic-mediated synchronization mechanism may give rise to large-scale integration of information across multiple cortical circuits, consequently influencing the level of arousal and consciousness. Overall, the growing evidence supports a general role for the higher-order thalamus in the control of cortical information transmission and cognitive processing.

Altered Regional Brain Cortical Thickness in Pediatric Obstructive Sleep Apnea

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Paul M. Macey

2018-01-01

Full Text Available RationaleObstructive sleep apnea (OSA affects 2–5% of all children and is associated with cognitive and behavioral deficits, resulting in poor school performance. These psychological deficits may arise from brain injury, as seen in preliminary findings of lower gray matter volume among pediatric OSA patients. However, the psychological deficits in OSA are closely related to functions in the cortex, and such brain areas have not been specifically assessed. The objective was to determine whether cortical thickness, a marker of possible brain injury, is altered in children with OSA.MethodsWe examined regional brain cortical thicknesses using high-resolution T1-weighted magnetic resonance images in 16 pediatric OSA patients (8 males; mean age ± SD = 8.4 ± 1.2 years; mean apnea/hypopnea index ± SD = 11 ± 6 events/h and 138 controls (8.3 ± 1.1 years; 62 male; 138 subjects from the NIH Pediatric MRI database to identify cortical thickness differences in pediatric OSA subjects.ResultsCortical thinning occurred in multiple regions including the superior frontal, ventral medial prefrontal, and superior parietal cortices. The left side showed greater thinning in the superior frontal cortex. Cortical thickening was observed in bilateral precentral gyrus, mid-to-posterior insular cortices, and left central gyrus, as well as right anterior insula cortex.ConclusionChanges in cortical thickness are present in children with OSA and likely indicate disruption to neural developmental processes, including maturational patterns of cortical volume increases and synaptic pruning. Regions with thicker cortices may reflect inflammation or astrocyte activation. Both the thinning and thickening associated with OSA in children may contribute to the cognitive and behavioral dysfunction frequently found in the condition.

Cortical influences drive amyotrophic lateral sclerosis.

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Eisen, Andrew; Braak, Heiko; Del Tredici, Kelly; Lemon, Roger; Ludolph, Albert C; Kiernan, Matthew C

2017-11-01

The early motor manifestations of sporadic amyotrophic lateral sclerosis (ALS), while rarely documented, reflect failure of adaptive complex motor skills. The development of these skills correlates with progressive evolution of a direct corticomotoneuronal system that is unique to primates and markedly enhanced in humans. The failure of this system in ALS may translate into the split hand presentation, gait disturbance, split leg syndrome and bulbar symptomatology related to vocalisation and breathing, and possibly diffuse fasciculation, characteristic of ALS. Clinical neurophysiology of the brain employing transcranial magnetic stimulation has convincingly demonstrated a presymptomatic reduction or absence of short interval intracortical inhibition, accompanied by increased intracortical facilitation, indicating cortical hyperexcitability. The hallmark of the TDP-43 pathological signature of sporadic ALS is restricted to cortical areas as well as to subcortical nuclei that are under the direct control of corticofugal projections. This provides anatomical support that the origins of the TDP-43 pathology reside in the cerebral cortex itself, secondarily in corticofugal fibres and the subcortical targets with which they make monosynaptic connections. The latter feature explains the multisystem degeneration that characterises ALS. Consideration of ALS as a primary neurodegenerative disorder of the human brain may incorporate concepts of prion-like spread at synaptic terminals of corticofugal axons. Further, such a concept could explain the recognised widespread imaging abnormalities of the ALS neocortex and the accepted relationship between ALS and frontotemporal dementia. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Normal and abnormal fetal brain development during the third trimester as demonstrated by neurosonography

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Malinger, G.; Lev, D.; Lerman-Sagie, T.

2006-01-01

The multiplanar neurosonographic examination of the fetus enables superb visualization of brain anatomy during pregnancy. The examination may be performed using a transvaginal or a transfundal approach and it is indicated in patients at high risk for CNS anomalies or in those with a suspicious finding during a routine examination. The purpose of this paper is to present a description of the normal brain and of abnormal findings usually diagnosed late in pregnancy, including malformations of cortical development, infratentorial anomalies, and prenatal insults

Cortical entrainment to music and its modulation by expertise.

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Doelling, Keith B; Poeppel, David

2015-11-10

Recent studies establish that cortical oscillations track naturalistic speech in a remarkably faithful way. Here, we test whether such neural activity, particularly low-frequency (music and whether experience modifies such a cortical phenomenon. Music of varying tempi was used to test entrainment at different rates. In three magnetoencephalography experiments, we recorded from nonmusicians, as well as musicians with varying years of experience. Recordings from nonmusicians demonstrate cortical entrainment that tracks musical stimuli over a typical range of tempi, but not at tempi below 1 note per second. Importantly, the observed entrainment correlates with performance on a concurrent pitch-related behavioral task. In contrast, the data from musicians show that entrainment is enhanced by years of musical training, at all presented tempi. This suggests a bidirectional relationship between behavior and cortical entrainment, a phenomenon that has not previously been reported. Additional analyses focus on responses in the beta range (∼15-30 Hz)-often linked to delta activity in the context of temporal predictions. Our findings provide evidence that the role of beta in temporal predictions scales to the complex hierarchical rhythms in natural music and enhances processing of musical content. This study builds on important findings on brainstem plasticity and represents a compelling demonstration that cortical neural entrainment is tightly coupled to both musical training and task performance, further supporting a role for cortical oscillatory activity in music perception and cognition.

Basal Forebrain Gating by Somatostatin Neurons Drives Prefrontal Cortical Activity.

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Espinosa, Nelson; Alonso, Alejandra; Morales, Cristian; Espinosa, Pedro; Chávez, Andrés E; Fuentealba, Pablo

2017-11-17

The basal forebrain provides modulatory input to the cortex regulating brain states and cognitive processing. Somatostatin-expressing neurons constitute a heterogeneous GABAergic population known to functionally inhibit basal forebrain cortically projecting cells thus favoring sleep and cortical synchronization. However, it remains unclear if somatostatin cells can regulate population activity patterns in the basal forebrain and modulate cortical dynamics. Here, we demonstrate that somatostatin neurons regulate the corticopetal synaptic output of the basal forebrain impinging on cortical activity and behavior. Optogenetic inactivation of somatostatin neurons in vivo rapidly modified neural activity in the basal forebrain, with the consequent enhancement and desynchronization of activity in the prefrontal cortex, reflected in both neuronal spiking and network oscillations. Cortical activation was partially dependent on cholinergic transmission, suppressing slow waves and potentiating gamma oscillations. In addition, recruitment dynamics was cell type-specific, with interneurons showing similar temporal profiles, but stronger responses than pyramidal cells. Finally, optogenetic stimulation of quiescent animals during resting periods prompted locomotor activity, suggesting generalized cortical activation and increased arousal. Altogether, we provide physiological and behavioral evidence indicating that somatostatin neurons are pivotal in gating the synaptic output of the basal forebrain, thus indirectly controlling cortical operations via both cholinergic and non-cholinergic mechanisms. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Posterior Thalamic Nucleus Modulation of Tactile Stimuli Processing in Rat Motor and Primary Somatosensory Cortices

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Diana Casas-Torremocha

2017-09-01

Full Text Available Rodents move rhythmically their facial whiskers and compute differences between signals predicted and those resulting from the movement to infer information about objects near their head. These computations are carried out by a large network of forebrain structures that includes the thalamus and the primary somatosensory (S1BF and motor (M1wk cortices. Spatially and temporally precise mechanorreceptive whisker information reaches the S1BF cortex via the ventroposterior medial thalamic nucleus (VPM. Other whisker-related information may reach both M1wk and S1BF via the axons from the posterior thalamic nucleus (Po. However, Po axons may convey, in addition to direct sensory signals, the dynamic output of computations between whisker signals and descending motor commands. It has been proposed that this input may be relevant for adjusting cortical responses to predicted vs. unpredicted whisker signals, but the effects of Po input on M1wk and S1BF function have not been directly tested or compared in vivo. Here, using electrophysiology, optogenetics and pharmacological tools, we compared in adult rats M1wk and S1BF in vivo responses in the whisker areas of the motor and primary somatosensory cortices to passive multi-whisker deflection, their dependence on Po activity, and their changes after a brief intense activation of Po axons. We report that the latencies of the first component of tactile-evoked local field potentials in M1wk and S1BF are similar. The evoked potentials decrease markedly in M1wk, but not in S1BF, by injection in Po of the GABAA agonist muscimol. A brief high-frequency electrical stimulation of Po decreases the responsivity of M1wk and S1BF cells to subsequent whisker stimulation. This effect is prevented by the local application of omega-agatoxin, suggesting that it may in part depend on GABA release by fast-spiking parvalbumin (PV-expressing cortical interneurons. Local optogenetic activation of Po synapses in different

Populations of auditory cortical neurons can accurately encode acoustic space across stimulus intensity.

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Miller, Lee M; Recanzone, Gregg H

2009-04-07

The auditory cortex is critical for perceiving a sound's location. However, there is no topographic representation of acoustic space, and individual auditory cortical neurons are often broadly tuned to stimulus location. It thus remains unclear how acoustic space is represented in the mammalian cerebral cortex and how it could contribute to sound localization. This report tests whether the firing rates of populations of neurons in different auditory cortical fields in the macaque monkey carry sufficient information to account for horizontal sound localization ability. We applied an optimal neural decoding technique, based on maximum likelihood estimation, to populations of neurons from 6 different cortical fields encompassing core and belt areas. We found that the firing rate of neurons in the caudolateral area contain enough information to account for sound localization ability, but neurons in other tested core and belt cortical areas do not. These results provide a detailed and plausible population model of how acoustic space could be represented in the primate cerebral cortex and support a dual stream processing model of auditory cortical processing.

Seizure-induced brain lesions: A wide spectrum of variably reversible MRI abnormalities

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Cianfoni, A.; Caulo, M.; Cerase, A.; Della Marca, G.; Falcone, C.; Di Lella, G.M.; Gaudino, S.; Edwards, J.; Colosimo, C.

2013-01-01

Introduction MRI abnormalities in the postictal period might represent the effect of the seizure activity, rather than its structural cause. Material and Methods Retrospective review of clinical and neuroimaging charts of 26 patients diagnosed with seizure-related MR-signal changes. All patients underwent brain-MRI (1.5-Tesla, standard pre- and post-contrast brain imaging, including DWI-ADC in 19/26) within 7 days from a seizure and at least one follow-up MRI, showing partial or complete reversibility of the MR-signal changes. Extensive clinical work-up and follow-up, ranging from 3 months to 5 years, ruled out infection or other possible causes of brain damage. Seizure-induced brain-MRI abnormalities remained a diagnosis of exclusion. Site, characteristics and reversibility of MRI changes, and association with characteristics of seizures were determined. Results MRI showed unilateral (13/26) and bilateral abnormalities, with high (24/26) and low (2/26) T2-signal, leptomeningeal contrast-enhancement (2/26), restricted diffusion (9/19). Location of abnormality was cortical/subcortical, basal ganglia, white matter, corpus callosum, cerebellum. Hippocampus was involved in 10/26 patients. Reversibility of MRI changes was complete in 15, and with residual gliosis or focal atrophy in 11 patients. Reversibility was noted between 15 and 150 days (average, 62 days). Partial simple and complex seizures were associated with hippocampal involvement (p = 0.015), status epilepticus with incomplete reversibility of MRI abnormalities (p = 0.041). Conclusions Seizure or epileptic status can induce transient, variably reversible MRI brain abnormalities. Partial seizures are frequently associated with hippocampal involvement and status epilepticus with incompletely reversible lesions. These seizure-induced MRI abnormalities pose a broad differential diagnosis; increased awareness may reduce the risk of misdiagnosis and unnecessary intervention

Seizure-induced brain lesions: A wide spectrum of variably reversible MRI abnormalities

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Cianfoni, A., E-mail: acianfoni@hotmail.com [Neuroradiology, Neurocenter of Italian Switzerland–Ospedale regionale Lugano, Via Tesserete 46, Lugano, 6900, CH (Switzerland); Caulo, M., E-mail: caulo@unich.it [Department of Neuroscience and Imaging, University of Chieti, Via dei Vestini 33, 6610 Chieti. Italy (Italy); Cerase, A., E-mail: alfonsocerase@gmail.com [Unit of Neuroimaging and Neurointervention NINT, Department of Neurological and Sensorineural Sciences, Azienda Ospedaliera Universitaria Senese, Policlinico “Santa Maria alle Scotte”, V.le Bracci 16, Siena (Italy); Della Marca, G., E-mail: dellamarca@rm.unicatt.it [Neurology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Falcone, C., E-mail: carlo_falc@libero.it [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Di Lella, G.M., E-mail: gdilella@rm.unicatt.it [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Gaudino, S., E-mail: sgaudino@sirm.org [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Edwards, J., E-mail: edwardjc@musc.edu [Neuroscience Dept., Medical University of South Carolina, 96J Lucas st, 29425, Charleston, SC (United States); Colosimo, C., E-mail: colosimo@rm.unicatt.it [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy)

2013-11-01

Introduction MRI abnormalities in the postictal period might represent the effect of the seizure activity, rather than its structural cause. Material and Methods Retrospective review of clinical and neuroimaging charts of 26 patients diagnosed with seizure-related MR-signal changes. All patients underwent brain-MRI (1.5-Tesla, standard pre- and post-contrast brain imaging, including DWI-ADC in 19/26) within 7 days from a seizure and at least one follow-up MRI, showing partial or complete reversibility of the MR-signal changes. Extensive clinical work-up and follow-up, ranging from 3 months to 5 years, ruled out infection or other possible causes of brain damage. Seizure-induced brain-MRI abnormalities remained a diagnosis of exclusion. Site, characteristics and reversibility of MRI changes, and association with characteristics of seizures were determined. Results MRI showed unilateral (13/26) and bilateral abnormalities, with high (24/26) and low (2/26) T2-signal, leptomeningeal contrast-enhancement (2/26), restricted diffusion (9/19). Location of abnormality was cortical/subcortical, basal ganglia, white matter, corpus callosum, cerebellum. Hippocampus was involved in 10/26 patients. Reversibility of MRI changes was complete in 15, and with residual gliosis or focal atrophy in 11 patients. Reversibility was noted between 15 and 150 days (average, 62 days). Partial simple and complex seizures were associated with hippocampal involvement (p = 0.015), status epilepticus with incomplete reversibility of MRI abnormalities (p = 0.041). Conclusions Seizure or epileptic status can induce transient, variably reversible MRI brain abnormalities. Partial seizures are frequently associated with hippocampal involvement and status epilepticus with incompletely reversible lesions. These seizure-induced MRI abnormalities pose a broad differential diagnosis; increased awareness may reduce the risk of misdiagnosis and unnecessary intervention.

The concept of transcortical cell assemblies: a key to the understanding of cortical lateralization and interhemispheric interaction.

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Pulvermüller, F; Mohr, B

1996-01-01

According to Hebb, elements of higher cognitive processes, such as concepts, words and mental images, are realized in the brain as cortical cell assemblies, i.e. large and strongly connected neuron populations that form functional units. Neurons belonging to such assemblies may be scattered over wide cortical areas, and some cell assemblies may even comprise neurons of both hemispheres (transcortical assemblies). If full activation (ignition) of an assembly leads to fast circulation of neuronal activity in the assembly, this process should be visible in high-frequency cortical responses. Some evidence will be reviewed that cell assembly ignition indeed leads to changes in high-frequency cortical responses which can be recorded in the EEG and MEG. Within the cell assembly-framework, the question of cortical laterality translates into the question of how neurons of transcortical assemblies are balanced between the hemispheres. This approach allows for different degrees of laterality. Recent evidence is summarized that the degree of laterality indeed differs between language units. For example, the cortical representation of certain words appears to be strongly lateralized to the left hemisphere while those of others are less lateralized. If neurons of both hemispheres are part of one assembly bihemispheric processing should lead to a processing advantage compared to processing in the dominant hemisphere alone. The latter appears to be the case for lexical processing, as revealed by recent behavioral studies. In conclusion, the cell assembly-framework suggests a more fine-grained description of the issue of cortical laterality; it is not appropriate to ask whether "modules" supporting higher cortical functions are located either in the left or right hemisphere. Rather, it appears fruitful to ask how the neurons of transcortical cell assemblies are balanced between the hemispheres.

Cortical bone drilling: An experimental and numerical study.

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Alam, Khurshid; Bahadur, Issam M; Ahmed, Naseer

2014-12-16

Bone drilling is a common surgical procedure in orthopedics, dental and neurosurgeries. In conventional bone drilling process, the surgeon exerts a considerable amount of pressure to penetrate the drill into the bone tissue. Controlled penetration of drill in the bone is necessary for safe and efficient drilling. Development of a validated Finite Element (FE) model of cortical bone drilling. Drilling experiments were conducted on bovine cortical bone. The FE model of the bone drilling was based on mechanical properties obtained from literature data and additionally conducted microindentation tests on the cortical bone. The magnitude of stress in bone was found to decrease exponentially away from the lips of the drill in simulations. Feed rate was found to be the main influential factor affecting the force and torque in the numerical simulations and experiments. The drilling thrust force and torque were found to be unaffected by the drilling speed in numerical simulations. Simulated forces and torques were compared with experimental results for similar drilling conditions and were found in good agreement.CONCLUSIONS: FE schemes may be successfully applied to model complex kinematics of bone drilling process.

Retrosplenial cortical thinning as a possible major contributor for cognitive impairment in HIV patients

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Shin, Na-Young [The Catholic University of Korea, Department of Radiology, College of Medicine, Seoul (Korea, Republic of); Hong, Jinwoo; Yoon, Uicheul [Catholic University of Daegu, Department of Biomedical Engineering, College of Health and Medical Science, Gyeongsan-si, Gyeongbuk (Korea, Republic of); Choi, Jun Yong [Yonsei University College of Medicine, Department of Internal Medicine and AIDS Research Institute, Seoul (Korea, Republic of); Lee, Seung-Koo [Yonsei University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Lim, Soo Mee [Ewha Womans University, School of Medicine, Department of Radiology, Seoul (Korea, Republic of)

2017-11-15

To identify brain cortical regions relevant to HIV-associated neurocognitive disorder (HAND) in HIV patients. HIV patients with HAND (n = 10), those with intact cognition (HIV-IC; n = 12), and age-matched, seronegative controls (n = 11) were recruited. All participants were male and underwent 3-dimensional T1-weighted imaging. Both vertex-wise and region of interest (ROI) analyses were performed to analyse cortical thickness. Compared to controls, both HIV-IC and HAND showed decreased cortical thickness mainly in the bilateral primary sensorimotor areas, extending to the prefrontal and parietal cortices. When directly comparing HIV-IC and HAND, HAND showed cortical thinning in the left retrosplenial cortex, left dorsolateral prefrontal cortex, left inferior parietal lobule, bilateral superior medial prefrontal cortices, right temporoparietal junction and left hippocampus, and cortical thickening in the left middle occipital cortex. Left retrosplenial cortical thinning showed significant correlation with slower information processing, declined verbal memory and executive function, and impaired fine motor skills. This study supports previous research suggesting the selective vulnerability of the primary sensorimotor cortices and associations between cortical thinning in the prefrontal and parietal cortices and cognitive impairment in HIV-infected patients. Furthermore, for the first time, we propose retrosplenial cortical thinning as a possible major contributor to HIV-associated cognitive impairment. (orig.)

Retrosplenial cortical thinning as a possible major contributor for cognitive impairment in HIV patients

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Shin, Na-Young; Hong, Jinwoo; Yoon, Uicheul; Choi, Jun Yong; Lee, Seung-Koo; Lim, Soo Mee

2017-01-01

To identify brain cortical regions relevant to HIV-associated neurocognitive disorder (HAND) in HIV patients. HIV patients with HAND (n = 10), those with intact cognition (HIV-IC; n = 12), and age-matched, seronegative controls (n = 11) were recruited. All participants were male and underwent 3-dimensional T1-weighted imaging. Both vertex-wise and region of interest (ROI) analyses were performed to analyse cortical thickness. Compared to controls, both HIV-IC and HAND showed decreased cortical thickness mainly in the bilateral primary sensorimotor areas, extending to the prefrontal and parietal cortices. When directly comparing HIV-IC and HAND, HAND showed cortical thinning in the left retrosplenial cortex, left dorsolateral prefrontal cortex, left inferior parietal lobule, bilateral superior medial prefrontal cortices, right temporoparietal junction and left hippocampus, and cortical thickening in the left middle occipital cortex. Left retrosplenial cortical thinning showed significant correlation with slower information processing, declined verbal memory and executive function, and impaired fine motor skills. This study supports previous research suggesting the selective vulnerability of the primary sensorimotor cortices and associations between cortical thinning in the prefrontal and parietal cortices and cognitive impairment in HIV-infected patients. Furthermore, for the first time, we propose retrosplenial cortical thinning as a possible major contributor to HIV-associated cognitive impairment. (orig.)

Cortical processing of object affordances for self and others’ action

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Monica eMaranesi

2014-06-01

Full Text Available The perception of objects does not rely only on visual brain areas, but also involves cortical motor regions. In particular, different parietal and premotor areas host neurons discharging during both object observation and grasping. Most of these cells often show similar visual and motor selectivity for a specific object (or set of objects, suggesting that they might play a crucial role in representing the potential motor act afforded by the object. The existence of such a mechanism for the visuomotor transformation of object physical properties in the most appropriate motor plan for interacting with them has been convincingly demonstrated in humans as well. Interestingly, human studies have shown that visually presented objects can automatically trigger the representation of an action provided that they are located within the observer’s reaching space (peripersonal space. The affordance effect also occurs when the presented object is outside the observer’s peripersonal space, but inside the peripersonal space of an observed agent. These findings recently received direct support by single neuron studies in monkey, indicating that space-constrained processing of objects in the ventral premotor cortex might be relevant to represent objects as potential targets for one’s own or others' action.

The cortical signature of amyotrophic lateral sclerosis.

Directory of Open Access Journals (Sweden)

Federica Agosta

Full Text Available The aim of this study was to explore the pattern of regional cortical thickness in patients with non-familial amyotrophic lateral sclerosis (ALS and to investigate whether cortical thinning is associated with disease progression rate. Cortical thickness analysis was performed in 44 ALS patients and 26 healthy controls. Group differences in cortical thickness and the age-by-group effects were assessed using vertex-by-vertex and multivariate linear models. The discriminatory ability of MRI variables in distinguishing patients from controls was estimated using the Concordance Statistics (C-statistic within logistic regression analyses. Correlations between cortical thickness measures and disease progression rate were tested using the Pearson coefficient. Relative to controls, ALS patients showed a bilateral cortical thinning of the primary motor, prefrontal and ventral frontal cortices, cingulate gyrus, insula, superior and inferior temporal and parietal regions, and medial and lateral occipital areas. There was a significant age-by-group effect in the sensorimotor cortices bilaterally, suggesting a stronger association between age and cortical thinning in ALS patients compared to controls. The mean cortical thickness of the sensorimotor cortices distinguished patients with ALS from controls (C-statistic ≥ 0.74. Cortical thinning of the left sensorimotor cortices was related to a faster clinical progression (r = -0.33, p = 0.03. Cortical thickness measurements allowed the detection and quantification of motor and extramotor involvement in patients with ALS. Cortical thinning of the precentral gyrus might offer a marker of upper motor neuron involvement and disease progression.

The cortical signature of amyotrophic lateral sclerosis.

Science.gov (United States)

Agosta, Federica; Valsasina, Paola; Riva, Nilo; Copetti, Massimiliano; Messina, Maria Josè; Prelle, Alessandro; Comi, Giancarlo; Filippi, Massimo

2012-01-01

The aim of this study was to explore the pattern of regional cortical thickness in patients with non-familial amyotrophic lateral sclerosis (ALS) and to investigate whether cortical thinning is associated with disease progression rate. Cortical thickness analysis was performed in 44 ALS patients and 26 healthy controls. Group differences in cortical thickness and the age-by-group effects were assessed using vertex-by-vertex and multivariate linear models. The discriminatory ability of MRI variables in distinguishing patients from controls was estimated using the Concordance Statistics (C-statistic) within logistic regression analyses. Correlations between cortical thickness measures and disease progression rate were tested using the Pearson coefficient. Relative to controls, ALS patients showed a bilateral cortical thinning of the primary motor, prefrontal and ventral frontal cortices, cingulate gyrus, insula, superior and inferior temporal and parietal regions, and medial and lateral occipital areas. There was a significant age-by-group effect in the sensorimotor cortices bilaterally, suggesting a stronger association between age and cortical thinning in ALS patients compared to controls. The mean cortical thickness of the sensorimotor cortices distinguished patients with ALS from controls (C-statistic ≥ 0.74). Cortical thinning of the left sensorimotor cortices was related to a faster clinical progression (r = -0.33, p = 0.03). Cortical thickness measurements allowed the detection and quantification of motor and extramotor involvement in patients with ALS. Cortical thinning of the precentral gyrus might offer a marker of upper motor neuron involvement and disease progression.

Swedish Massage and Abnormal Reflexes of Children with Spastic Cerebral Palsy

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Vida Alizad

2007-09-01

Full Text Available Objectives: Massage therapy is one of the most widely used complementary and alternative medicine therapies for children. This study was conducted to determine the effect of wedish massage on abnormal reflexes in children with spastic cerebral palsy (CP. Methods: This study was a single blind clinical trial conducted on forty children with spastic CP who were recruited from clinics of the University of Social Welfare & Rehabilitation Sciences. They were randomly assigned to intervention and control groups. The routine occupational therapy (OT techniques were performed during a 3 month-period in both groups. The intervention group also received Swedish massage for 30 minutes before every OT session. Primary, spinal, brain stem, midbrain, cortical and automatic reflexes were evaluated at the beginning of the study and 3 months later. The data analysis was done by parametric and nonparametric tests. Results: Finally, thirteen subjects in the intervention group and 14 subjects in the control group were remained and studied. The average ages in the intervention and control groups were 49.5 and 42.1 months respectively. There were no statistically significant differences in abnormal reflexes in the intervention group in comparison to the control (P>0.05. Discussion: Adding Swedish massage to traditional OT techniques had no significant effects on abnormal reflexes in children with spastic cerebral palsy. Evidently more research is required in order to completely reject the effects of Swedish massage on abnormal reflexes of children with CP.

Dysregulated Expression of Neuregulin-1 by Cortical Pyramidal Neurons Disrupts Synaptic Plasticity

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Amit Agarwal

2014-08-01

Full Text Available Neuregulin-1 (NRG1 gene variants are associated with increased genetic risk for schizophrenia. It is unclear whether risk haplotypes cause elevated or decreased expression of NRG1 in the brains of schizophrenia patients, given that both findings have been reported from autopsy studies. To study NRG1 functions in vivo, we generated mouse mutants with reduced and elevated NRG1 levels and analyzed the impact on cortical functions. Loss of NRG1 from cortical projection neurons resulted in increased inhibitory neurotransmission, reduced synaptic plasticity, and hypoactivity. Neuronal overexpression of cysteine-rich domain (CRD-NRG1, the major brain isoform, caused unbalanced excitatory-inhibitory neurotransmission, reduced synaptic plasticity, abnormal spine growth, altered steady-state levels of synaptic plasticity-related proteins, and impaired sensorimotor gating. We conclude that an “optimal” level of NRG1 signaling balances excitatory and inhibitory neurotransmission in the cortex. Our data provide a potential pathomechanism for impaired synaptic plasticity and suggest that human NRG1 risk haplotypes exert a gain-of-function effect.

Dysregulated expression of neuregulin-1 by cortical pyramidal neurons disrupts synaptic plasticity.

Science.gov (United States)

Agarwal, Amit; Zhang, Mingyue; Trembak-Duff, Irina; Unterbarnscheidt, Tilmann; Radyushkin, Konstantin; Dibaj, Payam; Martins de Souza, Daniel; Boretius, Susann; Brzózka, Magdalena M; Steffens, Heinz; Berning, Sebastian; Teng, Zenghui; Gummert, Maike N; Tantra, Martesa; Guest, Peter C; Willig, Katrin I; Frahm, Jens; Hell, Stefan W; Bahn, Sabine; Rossner, Moritz J; Nave, Klaus-Armin; Ehrenreich, Hannelore; Zhang, Weiqi; Schwab, Markus H

2014-08-21

Neuregulin-1 (NRG1) gene variants are associated with increased genetic risk for schizophrenia. It is unclear whether risk haplotypes cause elevated or decreased expression of NRG1 in the brains of schizophrenia patients, given that both findings have been reported from autopsy studies. To study NRG1 functions in vivo, we generated mouse mutants with reduced and elevated NRG1 levels and analyzed the impact on cortical functions. Loss of NRG1 from cortical projection neurons resulted in increased inhibitory neurotransmission, reduced synaptic plasticity, and hypoactivity. Neuronal overexpression of cysteine-rich domain (CRD)-NRG1, the major brain isoform, caused unbalanced excitatory-inhibitory neurotransmission, reduced synaptic plasticity, abnormal spine growth, altered steady-state levels of synaptic plasticity-related proteins, and impaired sensorimotor gating. We conclude that an "optimal" level of NRG1 signaling balances excitatory and inhibitory neurotransmission in the cortex. Our data provide a potential pathomechanism for impaired synaptic plasticity and suggest that human NRG1 risk haplotypes exert a gain-of-function effect. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Cortical bone metastases

International Nuclear Information System (INIS)

Davis, T.M. Jr.; Rogers, L.F.; Hendrix, R.W.

1986-01-01

Twenty-five cases of bone metastases involving the cortex alone are reviewed. Seven patients had primary lung carcinoma, while 18 had primary tumors not previously reported to produce cortical bone metastases (tumors of the breast, kidney, pancreas, adenocarcinoma of unknown origin, multiple myeloma). Radiographically, these cortical lesions were well circumscribed, osteolytic, and produced soft-tissue swelling and occasional periosteal reaction. A recurrent pattern of metadiaphyseal involvement of the long bones of the lower extremity (particularly the femur) was noted, and is discussed. Findings reported in the literature, review, pathophysiology, and the role of skeletal radiographs, bone scans, and CT scans in evaluating cortical bone metastases are addressed

Morphostructural MRI Abnormalities Related to Neuropsychiatric Disorders Associated to Multiple Sclerosis

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Simona Bonavita

2013-01-01

Full Text Available Multiple Sclerosis associated neuropsychiatric disorders include major depression (MD, obsessive-compulsive disorder (OCD, bipolar affective disorder, euphoria, pseudobulbar affect, psychosis, and personality change. Magnetic Resonance Imaging (MRI studies focused mainly on identifying morphostructural correlates of MD; only a few anecdotal cases on OCD associated to MS (OCD-MS, euphoria, pseudobulbar affect, psychosis, personality change, and one research article on MRI abnormalities in OCD-MS have been published. Therefore, in the present review we will report mainly on neuroimaging abnormalities found in MS patients with MD and OCD. All together, the studies on MD associated to MS suggest that, in this disease, depression is linked to a damage involving mainly frontotemporal regions either with discrete lesions (with those visible in T1 weighted images playing a more significant role or subtle normal appearing white matter abnormalities. Hippocampal atrophy, as well, seems to be involved in MS related depression. It is conceivable that grey matter pathology (i.e., global and regional atrophy, cortical lesions, which occurs early in the course of disease, may involve several areas including the dorsolateral prefrontal cortex, the orbitofrontal cortex, and the anterior cingulate cortex whose disruption is currently thought to explain late-life depression. Further MRI studies are necessary to better elucidate OCD pathogenesis in MS.

Abnormal functional architecture of amygdala-centered networks in adolescent posttraumatic stress disorder.

Science.gov (United States)

Aghajani, Moji; Veer, Ilya M; van Hoof, Marie-José; Rombouts, Serge A R B; van der Wee, Nic J; Vermeiren, Robert R J M

2016-03-01

Posttraumatic stress disorder (PTSD) is a prevalent, debilitating, and difficult to treat psychiatric disorder. Very little is known of how PTSD affects neuroplasticity in the developing adolescent brain. Whereas multiple lines of research implicate amygdala-centered network dysfunction in the pathophysiology of adult PTSD, no study has yet examined the functional architecture of amygdala subregional networks in adolescent PTSD. Using intrinsic functional connectivity analysis, we investigated functional connectivity of the basolateral (BLA) and centromedial (CMA) amygdala in 19 sexually abused adolescents with PTSD relative to 23 matched controls. Additionally, we examined whether altered amygdala subregional connectivity coincides with abnormal grey matter volume of the amygdaloid complex. Our analysis revealed abnormal amygdalar connectivity and morphology in adolescent PTSD patients. More specifically, PTSD patients showed diminished right BLA connectivity with a cluster including dorsal and ventral portions of the anterior cingulate and medial prefrontal cortices (p < 0.05, corrected). In contrast, PTSD patients showed increased left CMA connectivity with a cluster including the orbitofrontal and subcallosal cortices (p < 0.05, corrected). Critically, these connectivity changes coincided with diminished grey matter volume within BLA and CMA subnuclei (p < 0.05, corrected), with CMA connectivity shifts additionally relating to more severe symptoms of PTSD. These findings provide unique insights into how perturbations in major amygdalar circuits could hamper fear regulation and drive excessive acquisition and expression of fear in PTSD. As such, they represent an important step toward characterizing the neurocircuitry of adolescent PTSD, thereby informing the development of reliable biomarkers and potential therapeutic targets. © 2016 Wiley Periodicals, Inc.

Different early rearing experiences have long-term effects on cortical organization in captive chimpanzees (Pan troglodytes)

DEFF Research Database (Denmark)

Bogart, Stephanie L; Bennett, Allyson J; Schapiro, Steve

2014-01-01

-reared chimpanzees have greater global white-to-grey matter volume, more cortical folding and thinner grey matter within the cortical folds than nursery-reared animals. The findings reported here are the first to demonstrate that differences in early rearing conditions have significant consequences on brain......Consequences of rearing history in chimpanzees (Pan troglodytes) have been explored in relation to behavioral abnormalities and cognition; however, little is known about the effects of rearing conditions on anatomical brain development. Human studies have revealed that experiences of maltreatment...... and neglect during infancy and childhood can have detrimental effects on brain development and cognition. In this study, we evaluated the effects of early rearing experience on brain morphology in 92 captive chimpanzees (ages 11-43) who were either reared by their mothers (n = 46) or in a nursery (n = 46...

Role of adult neurogenesis in hippocampal-cortical memory consolidation

Science.gov (United States)

2014-01-01

Acquired memory is initially dependent on the hippocampus (HPC) for permanent memory formation. This hippocampal dependency of memory recall progressively decays with time, a process that is associated with a gradual increase in dependency upon cortical structures. This process is commonly referred to as systems consolidation theory. In this paper, we first review how memory becomes hippocampal dependent to cortical dependent with an emphasis on the interactions that occur between the HPC and cortex during systems consolidation. We also review the mechanisms underlying the gradual decay of HPC dependency during systems consolidation from the perspective of memory erasures by adult hippocampal neurogenesis. Finally, we discuss the relationship between systems consolidation and memory precision. PMID:24552281

Developing guinea pig brain as a model for cortical folding.

Science.gov (United States)

Hatakeyama, Jun; Sato, Haruka; Shimamura, Kenji

2017-05-01

The cerebral cortex in mammals, the neocortex specifically, is highly diverse among species with respect to its size and morphology, likely reflecting the immense adaptiveness of this lineage. In particular, the pattern and number of convoluted ridges and fissures, called gyri and sulci, respectively, on the surface of the cortex are variable among species and even individuals. However, little is known about the mechanism of cortical folding, although there have been several hypotheses proposed. Recent studies on embryonic neurogenesis revealed the differences in cortical progenitors as a critical factor of the process of gyrification. Here, we investigated the gyrification processes using developing guinea pig brains that form a simple but fundamental pattern of gyri. In addition, we established an electroporation-mediated gene transfer method for guinea pig embryos. We introduce the guinea pig brain as a useful model system to understand the mechanisms and basic principle of cortical folding. © 2017 Japanese Society of Developmental Biologists.

REVERSIBLE CORTICAL BLINDNESS FOLLOWING SUCCESSFUL SURGICAL REPAIR OF TWO STAB WOUNDS IN THE HEART

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Zaiton A

2008-01-01

Full Text Available This report describes a case of cortical blindness that followed successful surgical repair of two stab wounds in the heart in a 29-year old Libyan man. The patient presented in a state of pre cardiac arrest (shock and low cardiac output status, following multiple chest stab wounds. Chest tube was immediately inserted. Surgery was urgently performed suturing the two wounds; in the root of the aorta and in the left ventricle, and haemostasis was secured. Cardiac arrest was successfully prevented. The patient recovered smoothly, but 24 hours later he declared total blindness. Ophtalmic and neurological examinations and investigations that included fundoscopy, Electroencephalograms (EEGs and Computed Tomography Scans revealed no abnormalities, apart from absence of alpha waves in the EEGs. We diagnosed the case as cortical blindness and continued caring for the patient conservatively. Three days later, the patient regained his vision gradually and was discharged on the 7th postoperative day without any remarks.

Phenotype abnormality: 35 [Arabidopsis Phenome Database[Archive

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Full Text Available 35 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u541i abnormal for trait of behavioral quality... during process named response to gravity ... abnormal ... behavioral quality

Effects of parietal TMS on visual and auditory processing at the primary cortical level -- a concurrent TMS-fMRI study

DEFF Research Database (Denmark)

Leitão, Joana; Thielscher, Axel; Werner, Sebastian

2013-01-01

cortices under 3 sensory contexts: visual, auditory, and no stimulation. IPS-TMS increased activations in auditory cortices irrespective of sensory context as a result of direct and nonspecific auditory TMS side effects. In contrast, IPS-TMS modulated activations in the visual cortex in a state...... deactivations induced by auditory activity to TMS sounds. TMS to IPS may increase the responses in visual (or auditory) cortices to visual (or auditory) stimulation via a gain control mechanism or crossmodal interactions. Collectively, our results demonstrate that understanding TMS effects on (uni......Accumulating evidence suggests that multisensory interactions emerge already at the primary cortical level. Specifically, auditory inputs were shown to suppress activations in visual cortices when presented alone but amplify the blood oxygen level-dependent (BOLD) responses to concurrent visual...

PET in malformations of cortical development; La tomographie d'emission de positons (TEP) dans les malformations corticales de developpement

Energy Technology Data Exchange (ETDEWEB)

Bouilleret, V.; O' Brien, T.J. [Department of medicine, the Royal Melbourne Hospital, Royal Parade, Parkville, 3005 Victoria (Australia); Bouilleret, V. [Unite de neurophysiologie clinique et d' epileptologie, AP-HP, CHU Bicetre, 94275 Paris (France); Bouilleret, V.; Chiron, C. [Service hospitalier Frederic-Joliot, DRM, CEA, 4, place du General-Leclerc, 91401 Orsay cedex (France); Chiron, C. [Inserm U663, AP-HP, hopital Necker, 75015 Paris (France); University Paris-Descartes, 11, rue Pierre-et-Marie-Curie, 75005 Paris (France)

2009-01-15

Within the group of malformations of cortical development, focal cortical dysplasia (FCD) are an increasingly recognized cause of intractable epilepsy that can be cured by surgery. The success of cortical resection for intractable epilepsy is highly dependent on the accurate pre-surgical delineation of the regions responsible for generating seizures. [{sup 18}F]-FDG PET, which images cerebral metabolism studying brain glucose uptake, is the most established functional imaging modality in the evaluation of patients with epilepsy. The aim of this article is to review [{sup 18}F]-FDG PET usefulness as a pre-surgical tool in the evaluation of medically refractory partial epilepsy. It has an established place in assisting in the localisation and definition of FCD in patients with no lesion, or only a subtle abnormality, on MRI. The role of FDG-PET in defining the extent of the surgical resection is still uncertain and needs to be the focus of future research. (authors)

A magnetoencephalography study of multi-modal processing of pain anticipation in primary sensory cortices.

Science.gov (United States)

Gopalakrishnan, R; Burgess, R C; Plow, E B; Floden, D P; Machado, A G

2015-09-24

Pain anticipation plays a critical role in pain chronification and results in disability due to pain avoidance. It is important to understand how different sensory modalities (auditory, visual or tactile) may influence pain anticipation as different strategies could be applied to mitigate anticipatory phenomena and chronification. In this study, using a countdown paradigm, we evaluated with magnetoencephalography the neural networks associated with pain anticipation elicited by different sensory modalities in normal volunteers. When encountered with well-established cues that signaled pain, visual and somatosensory cortices engaged the pain neuromatrix areas early during the countdown process, whereas the auditory cortex displayed delayed processing. In addition, during pain anticipation, the visual cortex displayed independent processing capabilities after learning the contextual meaning of cues from associative and limbic areas. Interestingly, cross-modal activation was also evident and strong when visual and tactile cues signaled upcoming pain. Dorsolateral prefrontal cortex and mid-cingulate cortex showed significant activity during pain anticipation regardless of modality. Our results show pain anticipation is processed with great time efficiency by a highly specialized and hierarchical network. The highest degree of higher-order processing is modulated by context (pain) rather than content (modality) and rests within the associative limbic regions, corroborating their intrinsic role in chronification. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Phenotype abnormality: 31 [Arabidopsis Phenome Database[Archive

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Full Text Available 31 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u537i abnormal for trait of behavior...al quality during process named localization of cell ... abnormal ... behavioral quality

Phenotype abnormality: 33 [Arabidopsis Phenome Database[Archive

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Full Text Available 33 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u539i abnormal for trait of behavior...al quality during process named response to auxin stimulus ... abnormal ... behavioral quality

Phenotype abnormality: 32 [Arabidopsis Phenome Database[Archive

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Full Text Available 32 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u538i abnormal for trait of behavioral quality... during process named organ development ... abnormal ... organ development ... behavioral quality

Phenotype abnormality: 34 [Arabidopsis Phenome Database[Archive

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Full Text Available 34 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u540i abnormal for trait of behavioral quality... during process named response to cytokinin stimulus ... abnormal ... behavioral quality

Syllabic discrimination in premature human infants prior to complete formation of cortical layers

OpenAIRE

Mahmoudzadeh, Mahdi; Dehaene-Lambertz, Ghislaine; Fournier, Marc; Kongolo, Guy; Goudjil, Sabrina; Dubois, Jessica; Grebe, Reinhard; Wallois, Fabrice

2013-01-01

The ontogeny of linguistic functions in the human brain remains elusive. Although some auditory capacities are described before term, whether and how such immature cortical circuits might process speech are unknown. Here we used functional optical imaging to evaluate the cerebral responses to syllables at the earliest age at which cortical responses to external stimuli can be recorded in humans (28- to 32-wk gestational age). At this age, the cortical organization in layers is not completed. ...

Disorganized Cortical Patches Suggest Prenatal Origin of Autism

Science.gov (United States)

... 2014 Disorganized cortical patches suggest prenatal origin of autism NIH-funded study shows disrupted cell layering process ... study suggests that brain irregularities in children with autism can be traced back to prenatal development. “While ...

Cortical Spreading Depression Closes Paravascular Space and Impairs Glymphatic Flow: Implications for Migraine Headache.

Science.gov (United States)

Schain, Aaron J; Melo-Carrillo, Agustin; Strassman, Andrew M; Burstein, Rami

2017-03-15

Functioning of the glymphatic system, a network of paravascular tunnels through which cortical interstitial solutes are cleared from the brain, has recently been linked to sleep and traumatic brain injury, both of which can affect the progression of migraine. This led us to investigate the connection between migraine and the glymphatic system. Taking advantage of a novel in vivo method we developed using two-photon microscopy to visualize the paravascular space (PVS) in naive uninjected mice, we show that a single wave of cortical spreading depression (CSD), an animal model of migraine aura, induces a rapid and nearly complete closure of the PVS around surface as well as penetrating cortical arteries and veins lasting several minutes, and gradually recovering over 30 min. A temporal mismatch between the constriction or dilation of the blood vessel lumen and the closure of the PVS suggests that this closure is not likely to result from changes in vessel diameter. We also show that CSD impairs glymphatic flow, as indicated by the reduced rate at which intraparenchymally injected dye was cleared from the cortex to the PVS. This is the first observation of a PVS closure in connection with an abnormal cortical event that underlies a neurological disorder. More specifically, the findings demonstrate a link between the glymphatic system and migraine, and suggest a novel mechanism for regulation of glymphatic flow. SIGNIFICANCE STATEMENT Impairment of brain solute clearance through the recently described glymphatic system has been linked with traumatic brain injury, prolonged wakefulness, and aging. This paper shows that cortical spreading depression, the neural correlate of migraine aura, closes the paravascular space and impairs glymphatic flow. This closure holds the potential to define a novel mechanism for regulation of glymphatic flow. It also implicates the glymphatic system in the altered cortical and endothelial functioning of the migraine brain. Copyright © 2017

Cognitive control dysfunction and abnormal frontal cortex activation in stimulant drug users and their biological siblings.

Science.gov (United States)

Smith, D G; Jones, P S; Bullmore, E T; Robbins, T W; Ersche, K D

2013-05-14

Cognitive and neural abnormalities are known to accompany chronic drug abuse, with impairments in cognition and changes in cortical structure seen in stimulant-dependent individuals. However, premorbid differences have also been observed in the brains and behavior of individuals at risk for substance abuse, before they develop dependence. Endophenotype research has emerged as a useful method for assessing preclinical traits that may be risk factors for pathology by studying patient populations and their undiagnosed first-degree relatives. This study used the color-word Stroop task to assess executive functioning in stimulant-dependent individuals, their unaffected biological siblings and unrelated healthy control volunteers using a functional magnetic resonance imaging paradigm. Both the stimulant-dependent and sibling participants demonstrated impairments in cognitive control and processing speed on the task, registering significantly longer response latencies. However, the two groups generated very different neural responses, with the sibling participants exhibiting a significant decrease in activation in the inferior frontal gyrus compared with both stimulant-dependent individuals and control participants. Both target groups also demonstrated a decrease in hemispheric laterality throughout the task, exhibiting a disproportionate increase in right hemispheric activation, which was associated with their behavioral inefficiencies. These findings not only suggest a possible risk factor for stimulant abuse of poor inhibitory control and cortical inefficiency but they also demonstrate possible adaptations in the brains of stimulant users.

What Can Psychiatric Disorders Tell Us about Neural Processing of the Self?

Science.gov (United States)

Zhao, Weihua; Luo, Lizhu; Li, Qin; Kendrick, Keith M

2013-01-01

Many psychiatric disorders are associated with abnormal self-processing. While these disorders also have a wide-range of complex, and often heterogeneous sets of symptoms involving different cognitive, emotional, and motor domains, an impaired sense of self can contribute to many of these. Research investigating self-processing in healthy subjects has facilitated identification of changes in specific neural circuits which may cause altered self-processing in psychiatric disorders. While there is evidence for altered self-processing in many psychiatric disorders, here we will focus on four of the most studied ones, schizophrenia, autism spectrum disorder (ASD), major depression, and borderline personality disorder (BPD). We review evidence for dysfunction in two different neural systems implicated in self-processing, namely the cortical midline system (CMS) and the mirror neuron system (MNS), as well as contributions from altered inter-hemispheric connectivity (IHC). We conclude that while abnormalities in frontal-parietal activity and/or connectivity in the CMS are common to all four disorders there is more disruption of integration between frontal and parietal regions resulting in a shift toward parietal control in schizophrenia and ASD which may contribute to the greater severity and delusional aspects of their symptoms. Abnormalities in the MNS and in IHC are also particularly evident in schizophrenia and ASD and may lead to disturbances in sense of agency and the physical self in these two disorders. A better future understanding of how changes in the neural systems sub-serving self-processing contribute to different aspects of symptom abnormality in psychiatric disorders will require that more studies carry out detailed individual assessments of altered self-processing in conjunction with measurements of neural functioning.

Cortical reaction as an egg quality indicator in artificial reproduction of pikeperch, Sander lucioperca.

Science.gov (United States)

Zarski, Daniel; Krejszeff, Sławomir; Palińska, Katarzyna; Targońska, Katarzyna; Kupren, Krzysztof; Fontaine, Pascal; Kestemont, Patrick; Kucharczyk, Dariusz

2012-01-01

The aim of this study was to investigate the process of the cortical reaction in eggs of pikeperch, Sander lucioperca (L.), as well as the application of microscopic assessment of this process in egg quality evaluation. The analysis was carried out with eggs obtained from 10 females by artificial reproduction, in which hormonal stimulation with hCG was applied. Subsequently, each sample of eggs (separately from each female fish) was analysed. The analysis included observation of the cortical reaction and the process of egg swelling, and determination of the effect of temperature (12, 14 and 16°C) and the presence of spermatozoa on the cortical reaction. The results indicate that the cortical reaction in pikeperch eggs is quite violent, resulting in visible deformation of eggs between 3 and 5 min after activation. No effect of temperature or the presence of spermatozoa on the cortical reaction was observed. A strong correlation was recorded for the percentage of egg deformations observed and embryo survival rate. The described method of determination of pikeperch egg quality (based on egg deformation rate between 3 and 5 min after activation) may be highly useful, both in scientific research (where high-quality eggs are required) and in hatchery practice.

Advantages of cortical surface reconstruction using submillimeter 7 T MEMPRAGE.

Science.gov (United States)

Zaretskaya, Natalia; Fischl, Bruce; Reuter, Martin; Renvall, Ville; Polimeni, Jonathan R

2018-01-15

Recent advances in MR technology have enabled increased spatial resolution for routine functional and anatomical imaging, which has created demand for software tools that are able to process these data. The availability of high-resolution data also raises the question of whether higher resolution leads to substantial gains in accuracy of quantitative morphometric neuroimaging procedures, in particular the cortical surface reconstruction and cortical thickness estimation. In this study we adapted the FreeSurfer cortical surface reconstruction pipeline to process structural data at native submillimeter resolution. We then quantified the differences in surface placement between meshes generated from (0.75 mm) 3 isotropic resolution data acquired in 39 volunteers and the same data downsampled to the conventional 1 mm 3 voxel size. We find that when processed at native resolution, cortex is estimated to be thinner in most areas, but thicker around the Cingulate and the Calcarine sulci as well as in the posterior bank of the Central sulcus. Thickness differences are driven by two kinds of effects. First, the gray-white surface is found closer to the white matter, especially in cortical areas with high myelin content, and thus low contrast, such as the Calcarine and the Central sulci, causing local increases in thickness estimates. Second, the gray-CSF surface is placed more interiorly, especially in the deep sulci, contributing to local decreases in thickness estimates. We suggest that both effects are due to reduced partial volume effects at higher spatial resolution. Submillimeter voxel sizes can therefore provide improved accuracy for measuring cortical thickness. Copyright © 2017 Elsevier Inc. All rights reserved.

Phenotype abnormality: 42 [Arabidopsis Phenome Database[Archive

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Full Text Available 42 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u548i abnormal for trait of behavior...al quality in organ named root during process named gravitropism ... root ... abnormal ... behavioral quality

Phenotype abnormality: 40 [Arabidopsis Phenome Database[Archive

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Full Text Available 40 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u546i abnormal for trait of behavioral quality... in organ named hypocotyl during process named gravitropism ... hypocotyl ... abnormal ... behavioral quality

Phenotype abnormality: 43 [Arabidopsis Phenome Database[Archive

Lifescience Database Archive (English)

Full Text Available 43 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u549i abnormal for trait of behavioral quality... in organ named root during process named growth ... root ... abnormal ... growth ... behavioral quality

Censoring distances based on labeled cortical distance maps in cortical morphometry.

Science.gov (United States)

Ceyhan, Elvan; Nishino, Tomoyuki; Alexopolous, Dimitrios; Todd, Richard D; Botteron, Kelly N; Miller, Michael I; Ratnanather, J Tilak

2013-01-01

It has been demonstrated that shape differences in cortical structures may be manifested in neuropsychiatric disorders. Such morphometric differences can be measured by labeled cortical distance mapping (LCDM) which characterizes the morphometry of the laminar cortical mantle of cortical structures. LCDM data consist of signed/labeled distances of gray matter (GM) voxels with respect to GM/white matter (WM) surface. Volumes and other summary measures for each subject and the pooled distances can help determine the morphometric differences between diagnostic groups, however they do not reveal all the morphometric information contained in LCDM distances. To extract more information from LCDM data, censoring of the pooled distances is introduced for each diagnostic group where the range of LCDM distances is partitioned at a fixed increment size; and at each censoring step, the distances not exceeding the censoring distance are kept. Censored LCDM distances inherit the advantages of the pooled distances but also provide information about the location of morphometric differences which cannot be obtained from the pooled distances. However, at each step, the censored distances aggregate, which might confound the results. The influence of data aggregation is investigated with an extensive Monte Carlo simulation analysis and it is demonstrated that this influence is negligible. As an illustrative example, GM of ventral medial prefrontal cortices (VMPFCs) of subjects with major depressive disorder (MDD), subjects at high risk (HR) of MDD, and healthy control (Ctrl) subjects are used. A significant reduction in laminar thickness of the VMPFC in MDD and HR subjects is observed compared to Ctrl subjects. Moreover, the GM LCDM distances (i.e., locations with respect to the GM/WM surface) for which these differences start to occur are determined. The methodology is also applicable to LCDM-based morphometric measures of other cortical structures affected by disease.

Censoring Distances Based on Labeled Cortical Distance Maps in Cortical Morphometry

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Elvan eCeyhan

2013-10-01

Full Text Available It has been demonstrated that shape differences are manifested in cortical structures due to neuropsychiatric disorders. Such morphometric differences can be measured by labeled cortical distance mapping (LCDM which characterizes the morphometry of the laminar cortical mantle of cortical structures. LCDM data consist of signed/labeled distances of gray matter (GM voxels with respect to GM/white matter (WM surface. Volumes and other summary measures for each subject and the pooled distances can help determine the morphometric differences between diagnostic groups, however they do not reveal all the morphometric information con-tained in LCDM distances. To extract more information from LCDM data, censoring of the pooled distances is introduced for each diagnostic group where the range of LCDM distances is partitioned at a fixed increment size; and at each censoring step, the distances not exceeding the censoring distance are kept. Censored LCDM distances inherit the advantages of the pooled distances but also provide information about the location of morphometric differences which cannot be obtained from the pooled distances. However, at each step, the censored distances aggregate, which might confound the results. The influence of data aggregation is investigated with an extensive Monte Carlo simulation analysis and it is demonstrated that this influence is negligible. As an illustrative example, GM of ventral medial prefrontal cortices (VMPFCs of subjects with major depressive disorder (MDD, subjects at high risk (HR of MDD, and healthy control (Ctrl subjects are used. A significant reduction in laminar thickness of the VMPFC in MDD and HR subjects is observed compared to Ctrl subjects. Moreover, the GM LCDM distances (i.e., locations with respect to the GM/WM surface for which these differences start to occur are determined. The methodology is also applicable to LCDM-based morphometric measures of other cortical structures affected by disease.

Spectral fingerprints of large-scale cortical dynamics during ambiguous motion perception.

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Helfrich, Randolph F; Knepper, Hannah; Nolte, Guido; Sengelmann, Malte; König, Peter; Schneider, Till R; Engel, Andreas K

2016-11-01

Ambiguous stimuli have been widely used to study the neuronal correlates of consciousness. Recently, it has been suggested that conscious perception might arise from the dynamic interplay of functionally specialized but widely distributed cortical areas. While previous research mainly focused on phase coupling as a correlate of cortical communication, more recent findings indicated that additional coupling modes might coexist and possibly subserve distinct cortical functions. Here, we studied two coupling modes, namely phase and envelope coupling, which might differ in their origins, putative functions and dynamics. Therefore, we recorded 128-channel EEG while participants performed a bistable motion task and utilized state-of-the-art source-space connectivity analysis techniques to study the functional relevance of different coupling modes for cortical communication. Our results indicate that gamma-band phase coupling in extrastriate visual cortex might mediate the integration of visual tokens into a moving stimulus during ambiguous visual stimulation. Furthermore, our results suggest that long-range fronto-occipital gamma-band envelope coupling sustains the horizontal percept during ambiguous motion perception. Additionally, our results support the idea that local parieto-occipital alpha-band phase coupling controls the inter-hemispheric information transfer. These findings provide correlative evidence for the notion that synchronized oscillatory brain activity reflects the processing of sensory input as well as the information integration across several spatiotemporal scales. The results indicate that distinct coupling modes are involved in different cortical computations and that the rich spatiotemporal correlation structure of the brain might constitute the functional architecture for cortical processing and specific multi-site communication. Hum Brain Mapp 37:4099-4111, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Assessment of cortical and sub-cortical function in neonates by electrophysiological monitoring

NARCIS (Netherlands)

Jennekens, W.

2012-01-01

The aim of this thesis was the assessment of cortical and sub-cortical function in neonates by electrophysiological monitoring, i.e. to evaluate the function of the neonatal cortex and brainstem through quantitative analysis of signals readily available in the NICU. These signals include

Applications of brain blood flow imaging in behavioral neurophysiology: cortical field activation hypothesis

International Nuclear Information System (INIS)

Roland, P.E.

1985-01-01

The 133 xenon intracarotid method for rCBF measurements has been a very useful method for functional mapping and functional dissection of the cerebral cortex in humans. With this method it has been shown that different types of cortical information treatment activate different cortical areas and furthermore that sensory and motor functions of the cerebral cortex could be dissected into anatomical and informational subcomponents by behavioral manipulations. The brain organizes its own activity. One of the principles of organization was that the brain could recruit in advance cortical fields that were expected to participate in a certain type of information operation. During brain work in awake human beings the cerebral cortex was activated in fields that, projected on the cerebral surface, most often had a size greater than 3 CM 2 . Such activated fields appeared no matter which type of information processing was going on in the brain: during planning and execution of voluntary movements, during preparation for sensory information processing, and during sensory information processing, as well as during cognitive brain work and retrieval of specific memories. Therefore, it was hypothesized that cortical field activation was the physiological manifestation of normal brain work in awake humans

Applications of brain blood flow imaging in behavioral neurophysiology: cortical field activation hypothesis

Energy Technology Data Exchange (ETDEWEB)

Roland, P.E.

1985-01-01

The /sup 133/xenon intracarotid method for rCBF measurements has been a very useful method for functional mapping and functional dissection of the cerebral cortex in humans. With this method it has been shown that different types of cortical information treatment activate different cortical areas and furthermore that sensory and motor functions of the cerebral cortex could be dissected into anatomical and informational subcomponents by behavioral manipulations. The brain organizes its own activity. One of the principles of organization was that the brain could recruit in advance cortical fields that were expected to participate in a certain type of information operation. During brain work in awake human beings the cerebral cortex was activated in fields that, projected on the cerebral surface, most often had a size greater than 3 CM/sup 2/. Such activated fields appeared no matter which type of information processing was going on in the brain: during planning and execution of voluntary movements, during preparation for sensory information processing, and during sensory information processing, as well as during cognitive brain work and retrieval of specific memories. Therefore, it was hypothesized that cortical field activation was the physiological manifestation of normal brain work in awake humans.

Abnormal Grain Growth Suppression in Aluminum Alloys

Science.gov (United States)

Hales, Stephen J. (Inventor); Claytor, Harold Dale (Inventor); Alexa, Joel A. (Inventor)

2015-01-01

The present invention provides a process for suppressing abnormal grain growth in friction stir welded aluminum alloys by inserting an intermediate annealing treatment ("IAT") after the welding step on the article. The IAT may be followed by a solution heat treatment (SHT) on the article under effectively high solution heat treatment conditions. In at least some embodiments, a deformation step is conducted on the article under effective spin-forming deformation conditions or under effective superplastic deformation conditions. The invention further provides a welded article having suppressed abnormal grain growth, prepared by the process above. Preferably the article is characterized with greater than about 90% reduction in area fraction abnormal grain growth in any friction-stir-welded nugget.

Functional MRI of music emotion processing in frontotemporal dementia.

Science.gov (United States)

Agustus, Jennifer L; Mahoney, Colin J; Downey, Laura E; Omar, Rohani; Cohen, Miriam; White, Mark J; Scott, Sophie K; Mancini, Laura; Warren, Jason D

2015-03-01

Frontotemporal dementia is an important neurodegenerative disorder of younger life led by profound emotional and social dysfunction. Here we used fMRI to assess brain mechanisms of music emotion processing in a cohort of patients with frontotemporal dementia (n = 15) in relation to healthy age-matched individuals (n = 11). In a passive-listening paradigm, we manipulated levels of emotion processing in simple arpeggio chords (mode versus dissonance) and emotion modality (music versus human emotional vocalizations). A complex profile of disease-associated functional alterations was identified with separable signatures of musical mode, emotion level, and emotion modality within a common, distributed brain network, including posterior and anterior superior temporal and inferior frontal cortices and dorsal brainstem effector nuclei. Separable functional signatures were identified post-hoc in patients with and without abnormal craving for music (musicophilia): a model for specific abnormal emotional behaviors in frontotemporal dementia. Our findings indicate the potential of music to delineate neural mechanisms of altered emotion processing in dementias, with implications for future disease tracking and therapeutic strategies. © 2014 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals Inc. on behalf of The New York Academy of Sciences.

What is the impact of child abuse on gray matter abnormalities in individuals with major depressive disorder: a case control study.

Science.gov (United States)

Ahn, Sung Jun; Kyeong, Sunghyon; Suh, Sang Hyun; Kim, Jae-Jin; Chung, Tae-Sub; Seok, Jeong-Ho

2016-11-14

Patients with major depressive disorder (MDD) present heterogeneous clinical symptoms, and childhood abuse is associated with deepening of psychopathology. The aim of this study was to identify structural brain abnormalities in MDD and to assess further differences in gray matter density (GMD) associated with childhood abuse in MDD. Differences in regional GMD between 34 MDD patients and 26 healthy controls were assessed using magnetic resonance imaging and optimized voxel-based morphometry. Within the MDD group, further comparisons were performed focusing on the experience of maltreatment during childhood (23 MDD with child abuse vs 11 MDD without child abuse). Compared with healthy controls, the MDD patient group showed decreased GMD in the bilateral orbitofrontal cortices, right superior frontal gyrus, right posterior cingulate gyrus, bilateral middle occipital gyri, and left cuneus. In addition, the patient group showed increased GMD in bilateral postcentral gyri, parieto-occipital cortices, putamina, thalami, and hippocampi, and left cerebellar declive and tuber of vermis. Within the MDD patient group, the subgroup with abuse showed a tendency of decreased GMD in right orbitofrontal cortex, but showed increased GMD in the left postcentral gyrus compared to the subgroup without abuse. Our findings suggest a complicated dysfunction of networks between cortical-subcortical circuits in MDD. In addition, increased GMD in postcentral gyrus and a possible reduction of GMD in the orbitofrontal cortex of MDD patients with abuse subgroup may be associated with abnormalities of body perception and emotional dysregulation.

Cortical inactivation by cooling in small animals

Directory of Open Access Journals (Sweden)

Ben eCoomber

2011-06-01

Full Text Available Reversible inactivation of the cortex by surface cooling is a powerful method for studying the function of a particular area. Implanted cooling cryoloops have been used to study the role of individual cortical areas in auditory processing of awake-behaving cats. Cryoloops have also been used in rodents for reversible inactivation of the cortex, but recently there has been a concern that the cryoloop may also cool non-cortical structures either directly or via the perfusion of blood, cooled as it passed close to the cooling loop. In this study we have confirmed that the loop can inactivate most of the auditory cortex without causing a significant reduction in temperature of the auditory thalamus or other sub-cortical structures. We placed a cryoloop on the surface of the guinea pig cortex, cooled it to 2°C and measured thermal gradients across the neocortical surface. We found that the temperature dropped to 20-24°C among cells within a radius of about 2.5mm away from the loop. This temperature drop was sufficient to reduce activity of most cortical cells and led to the inactivation of almost the entire auditory region. When the temperature of thalamus, midbrain, and middle ear were measured directly during cortical cooling, there was a small drop in temperature (about 4°C but this was not sufficient to directly reduce neural activity. In an effort to visualise the extent of neural inactivation we measured the uptake of thallium ions following an intravenous injection. This confirmed that there was a large reduction of activity across much of the ipsilateral cortex and only a small reduction in subcortical structures.

Phenotype abnormality: 47 [Arabidopsis Phenome Database[Archive

Lifescience Database Archive (English)

Full Text Available 47 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u553i abnormal for trait of behavior...al quality in organ named thylakoid membrane during process named thylakoid membrane organization ... abnormal ... behavioral quality

Phenotype abnormality: 50 [Arabidopsis Phenome Database[Archive

Lifescience Database Archive (English)

Full Text Available 50 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u556i abnormal for trait of behavioral quality... in organ named whole plant during process named photomorphogenesis ... whole plant ... abnormal ... behavioral quality

Abnormal Gray Matter Shape, Thickness, and Volume in the Motor Cortico-Subcortical Loop in Idiopathic Rapid Eye Movement Sleep Behavior Disorder: Association with Clinical and Motor Features.

Science.gov (United States)

Rahayel, Shady; Postuma, Ronald B; Montplaisir, Jacques; Bedetti, Christophe; Brambati, Simona; Carrier, Julie; Monchi, Oury; Bourgouin, Pierre-Alexandre; Gaubert, Malo; Gagnon, Jean-François

2018-02-01

Idiopathic rapid eye movement sleep behavior disorder (iRBD) is a major risk factor for Parkinson's disease and dementia with Lewy bodies. Anatomical gray matter abnormalities in the motor cortico-subcortical loop areas remain under studied in iRBD patients. We acquired T1-weighted images and administrated quantitative motor tasks in 41 patients with polysomnography-confirmed iRBD and 41 healthy subjects. Cortical thickness and voxel-based morphometry (VBM) analyses were performed to investigate local cortical thickness and gray matter volume changes, vertex-based shape analysis to investigate shape of subcortical structures, and structure-based volumetric analyses to investigate volumes of subcortical and brainstem structures. Cortical thickness analysis revealed thinning in iRBD patients in bilateral medial superior frontal, orbitofrontal, anterior cingulate cortices, and the right dorsolateral primary motor cortex. VBM results showed lower gray matter volume in iRBD patients in the frontal lobes, anterior cingulate gyri, and caudate nucleus. Shape analysis revealed extensive surface contraction in the external and internal segments of the left pallidum. Clinical and motor impaired features in iRBD were associated with anomalies of the motor cortico-subcortical loop. In summary, iRBD patients showed numerous gray matter structural abnormalities in the motor cortico-subcortical loop, which are associated with lower motor performance and clinical manifestations of iRBD. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Functional localization and effective connectivity of cortical theta and alpha oscillatory activity during an attention task

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Yuichi Kitaura

detailed level, decreased flow from right inferior frontal gyrus to anterior cingulate cortex for theta, and low and high alpha oscillations, and increased feedback (bidirectional flow between left superior temporal gyrus and left inferior frontal gyrus, were observed during the arithmetic task. Conclusions: Task related medial prefrontal increase in theta oscillations possibly corresponds to frontal midline theta, while parietal decreased alpha1 activity indicates the active role of this region in the numerical task. Task related decrease of intracortical right hemispheric connectivity support the notion that these nodes need to disengage from one another in order to not interfere with the ongoing numerical processing. The bidirectional feedback between left frontal-temporal-parietal regions in the arithmetic task is very likely to be related to attention network working memory function. Significance: The methods of analysis and the results presented here will hopefully contribute to clarify the roles of the different EEG oscillations during sustained attention, both in terms of their functional localization and in terms of how they integrate brain function by supporting information flow between different cortical regions. The methodology presented here might be clinically relevant in evaluating abnormal attention function. Keywords: Quantitative EEG, sLORETA, iCoh, Directional connectivity, Frontal midline theta, Attention network, Mental arithmetic, Fronto-parietal network, Directional flow, Attention task, Granger causality

Effect of random microstructure on crack propagation in cortical bone tissue under dynamic loading

International Nuclear Information System (INIS)

Gao, X; Li, S; Adel-Wahab, A; Silberschmidt, V

2013-01-01

A fracture process in a cortical bone tissue depends on various factors, such as bone loss, heterogeneous microstructure, variation of its material properties and accumulation of microcracks. Therefore, it is crucial to comprehend and describe the effect of microstructure and material properties of the components of cortical bone on crack propagation in a dynamic loading regime. At the microscale level, osteonal bone demonstrates a random distribution of osteons imbedded in an interstitial matrix and surrounded by a thin layer known as cement line. Such a distribution of osteons can lead to localization of deformation processes. The global mechanical behavior of bone and the crack-propagation process are affected by such localization under external loads. Hence, the random distribution of microstructural features plays a key role in the fracture process of cortical bone. The purpose of this study is two-fold: firstly, to develop two-dimensional microstructured numerical models of cortical bone tissue in order to examine the interaction between the propagating crack and bone microstructure using an extended finite-element method under both quasi-static and dynamic loading conditions; secondly, to investigate the effect of randomly distributed microstructural constituents on the crack propagation processes and crack paths. The obtained results of numerical simulations showed the influence of random microstructure on the global response of bone tissue at macroscale and on the crack-propagation process for quasi-static and dynamic loading conditions

Frontal cortical control of posterior sensory and association cortices through the claustrum.

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White, Michael G; Mathur, Brian N

2018-04-06

The claustrum is a telencephalic gray matter nucleus that is richly interconnected with the neocortex. This structure subserves top-down executive functions that require frontal cortical control of posterior cortical regions. However, functional anatomical support for the claustrum allowing for long-range intercortical communication is lacking. To test this, we performed a channelrhodopsin-assisted long-circuit mapping strategy in mouse brain slices. We find that anterior cingulate cortex input to the claustrum is transiently amplified by claustrum neurons that, in turn, project to parietal association cortex or to primary and secondary visual cortices. Additionally, we observe that claustrum drive of cortical neurons in parietal association cortex is layer-specific, eliciting action potential generation briefly in layers II/III, IV, and VI but not V. These data are the first to provide a functional anatomical substrate through claustrum that may underlie top-down functions, such as executive attention or working memory, providing critical insight to this most interconnected and enigmatic nucleus.

Altered Cortical Activation in Adolescents With Acute Migraine: A Magnetoencephalography Study

Science.gov (United States)

Xiang, Jing; deGrauw, Xinyao; Korostenskaja, Milena; Korman, Abraham M.; O’Brien, Hope L.; Kabbouche, Marielle A.; Powers, Scott W.; Hershey, Andrew D.

2013-01-01

To quantitatively assess cortical dysfunction in pediatric migraine, 31 adolescents with acute migraine and age- and gender-matched controls were studied using a magnetoencephalography (MEG) system at a sampling rate of 6,000 Hz. Neuromagnetic brain activation was elicited by a finger-tapping task. The spectral and spatial signatures of magnetoencephalography data in 5 to 2,884 Hz were analyzed using Morlet wavelet and beamformers. Compared with controls, 31 migraine subjects during their headache attack phases (ictal) showed significantly prolonged latencies of neuromagnetic activation in 5 to 30 Hz, increased spectral power in 100 to 200 Hz, and a higher likelihood of neuromagnetic activation in the supplementary motor area, the occipital and ipsilateral sensorimotor cortices, in 2,200 to 2,800 Hz. Of the 31 migraine subjects, 16 migraine subjects during their headache-free phases (interictal) showed that there were no significant differences between interictal and control MEG data except that interictal spectral power in 100 to 200 Hz was significantly decreased. The results demonstrated that migraine subjects had significantly aberrant ictal brain activation, which can normalize interictally. The spread of abnormal ictal brain activation in both low- and high-frequency ranges triggered by movements may play a key role in the cascade of migraine attacks. Perspective This is the first study focusing on the spectral and spatial signatures of cortical dysfunction in adolescents with migraine using MEG signals in a frequency range of 5 to 2,884 Hz. This analyzing aberrant brain activation may be important for developing new therapeutic interventions for migraine in the future. PMID:23792072

Leakage of decision uncertainty into movement execution in Parkinson's disease?

NARCIS (Netherlands)

Praamstra, P.; Loing, A.F.; Lange, F.P. de

2014-01-01

The concept of segregated basal ganglia–cortical loops entails that functional disturbances may result from abnormal processing within loops, but also from abnormal communication between loops. Cognitive and motor processes subserved by different basal ganglia–frontal loops may interfere with one

Focal cortical dysplasia type IIa and IIb: MRI aspects in 118 cases proven by histopathology

Energy Technology Data Exchange (ETDEWEB)

Colombo, Nadia; Citterio, Alberto [Ospedale Ca Granda Niguarda, Department of Neuroradiology, Milano (Italy); Tassi, Laura; Mai, Roberto; Sartori, Ivana; Cardinale, Francesco; Lo Russo, Giorgio [Ospedale Niguarda, Claudio Munari Epilepsy Surgery Center, Milano (Italy); Deleo, Francesco; Spreafico, Roberto [IRCCS Foundation Neurological Institute ' ' C. Besta' ' , Department of Epilepsy Clinic and Experimental Neurophysiology, Milano (Italy); Bramerio, Manuela [Ospedale Niguarda, Department of Pathology, Milano (Italy)

2012-10-15

This study aims to review the magnetic resonance imaging (MRI) aspects of a large series of patients with focal cortical dysplasia type II (FCD II) and attempt to identify distinctive features in the two histopathological subtypes IIa and IIb. We retrospectively reviewed the MRI scans of 118 patients with histological proven FCD IIa (n = 37) or IIb (n = 81) who were surgically treated for intractable epilepsy. MRI was abnormal in 93 patients (79 %) and unremarkable in 25 (21 %). A dysplastic lesion was identified in 90 cases (97 %) and classified as FCD II in 83 and FCD non-II in seven cases. In three cases, the MRI diagnosis was other than FCD. There was a significant association between the presence of cortical thickening (p = 0.002) and the ''transmantle sign'' (p < 0.001) and a correct MRI diagnosis of FCD II. MRI positivity was more frequent in the patients with FCD IIb than in those with FCD IIa (91 % vs. 51 %), and the detection rate of FCD II was also better in the patients with type IIb (88 % vs. 32 %). The transmantle sign was significantly more frequent in the IIb subgroup (p = 0.003). The rates of abnormal MRI results and correct MRI diagnoses of FCD II were significantly higher in the IIb subgroup. Although other MRI stigmata may contribute to the diagnosis, the only significant correlation was between the transmantle sign and FCD IIb. (orig.)

Trade-off of cerebello-cortical and cortico-cortical functional networks for planning in 6-year-old children.

Science.gov (United States)

Kipping, Judy A; Margulies, Daniel S; Eickhoff, Simon B; Lee, Annie; Qiu, Anqi

2018-05-03

Childhood is a critical period for the development of cognitive planning. There is a lack of knowledge on its neural mechanisms in children. This study aimed to examine cerebello-cortical and cortico-cortical functional connectivity in association with planning skills in 6-year-olds (n = 76). We identified the cerebello-cortical and cortico-cortical functional networks related to cognitive planning using activation likelihood estimation (ALE) meta-analysis on existing functional imaging studies on spatial planning, and data-driven independent component analysis (ICA) of children's resting-state functional MRI (rs-fMRI). We investigated associations of cerebello-cortical and cortico-cortical functional connectivity with planning ability in 6-year-olds, as assessed using the Stockings of Cambridge task. Long-range functional connectivity of two cerebellar networks (lobules VI and lateral VIIa) with the prefrontal and premotor cortex were greater in children with poorer planning ability. In contrast, cortico-cortical association networks were not associated with the performance of planning in children. These results highlighted the key contribution of the lateral cerebello-frontal functional connectivity, but not cortico-cortical association functional connectivity, for planning ability in 6-year-olds. Our results suggested that brain adaptation to the acquisition of planning ability during childhood is partially achieved through the engagement of the cerebello-cortical functional connectivity. Copyright © 2018 Elsevier Inc. All rights reserved.

Phenotype abnormality: 44 [Arabidopsis Phenome Database[Archive

Lifescience Database Archive (English)

Full Text Available 44 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u550i abnormal for trait of behavior...al quality in organ named root during process named organ development ... root ... abnormal ... organ development ... behavioral quality

Phenotype abnormality: 45 [Arabidopsis Phenome Database[Archive

Lifescience Database Archive (English)

Full Text Available 45 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u551i abnormal for trait of behavior...al quality in organ named stamen during process named organ development ... stamen ... abnormal ... organ development ... behavioral quality

Phenotype abnormality: 37 [Arabidopsis Phenome Database[Archive

Lifescience Database Archive (English)

Full Text Available 37 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u543i abnormal for trait of behavior...al quality in organ named cotyledon during process named organ development ... cotyledon ... abnormal ... organ development ... behavioral quality

Phenotype abnormality: 39 [Arabidopsis Phenome Database[Archive

Lifescience Database Archive (English)

Full Text Available 39 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u545i abnormal for trait of behavior...al quality in organ named flower during process named organ development ... flower ... abnormal ... organ development ... behavioral quality

Neurological evidence linguistic processes precede perceptual simulation in conceptual processing.

Science.gov (United States)

Louwerse, Max; Hutchinson, Sterling

2012-01-01

There is increasing evidence from response time experiments that language statistics and perceptual simulations both play a role in conceptual processing. In an EEG experiment we compared neural activity in cortical regions commonly associated with linguistic processing and visual perceptual processing to determine to what extent symbolic and embodied accounts of cognition applied. Participants were asked to determine the semantic relationship of word pairs (e.g., sky - ground) or to determine their iconic relationship (i.e., if the presentation of the pair matched their expected physical relationship). A linguistic bias was found toward the semantic judgment task and a perceptual bias was found toward the iconicity judgment task. More importantly, conceptual processing involved activation in brain regions associated with both linguistic and perceptual processes. When comparing the relative activation of linguistic cortical regions with perceptual cortical regions, the effect sizes for linguistic cortical regions were larger than those for the perceptual cortical regions early in a trial with the reverse being true later in a trial. These results map upon findings from other experimental literature and provide further evidence that processing of concept words relies both on language statistics and on perceptual simulations, whereby linguistic processes precede perceptual simulation processes.

Discrimination of cortical laminae using MEG.

Science.gov (United States)

Troebinger, Luzia; López, José David; Lutti, Antoine; Bestmann, Sven; Barnes, Gareth

2014-11-15

Typically MEG source reconstruction is used to estimate the distribution of current flow on a single anatomically derived cortical surface model. In this study we use two such models representing superficial and deep cortical laminae. We establish how well we can discriminate between these two different cortical layer models based on the same MEG data in the presence of different levels of co-registration noise, Signal-to-Noise Ratio (SNR) and cortical patch size. We demonstrate that it is possible to make a distinction between superficial and deep cortical laminae for levels of co-registration noise of less than 2mm translation and 2° rotation at SNR > 11 dB. We also show that an incorrect estimate of cortical patch size will tend to bias layer estimates. We then use a 3D printed head-cast (Troebinger et al., 2014) to achieve comparable levels of co-registration noise, in an auditory evoked response paradigm, and show that it is possible to discriminate between these cortical layer models in real data. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Abnormal fatty acid pattern in the superior temporal gyrus distinguishes bipolar disorder from major depression and schizophrenia and resembles multiple sclerosis.

Science.gov (United States)

McNamara, Robert K; Rider, Therese; Jandacek, Ronald; Tso, Patrick

2014-03-30

This study investigated the fatty acid composition of the postmortem superior temporal gyrus (STG), a cortical region implicated in emotional processing, from normal controls (n=15) and patients with bipolar disorder (BD, n=15), major depressive disorder (MDD, n=15), and schizophrenia (SZ, n=15). For comparative purposes, STG fatty acid composition was determined in a separate cohort of multiple sclerosis patients (MS, n=15) and normal controls (n=15). Compared with controls, patients with BD, but not MDD or SZ, exhibited abnormal elevations in the saturated fatty acids (SFA) palmitic acid (16:0), stearic acid (18:0), the polyunsaturated fatty acids (PUFA) linoleic acid (18:2n-6), arachidonic acid (20:4n-6), and docosahexaenoic acid (22:6n-3), and reductions in the monounsaturated fatty acid (MUFA) oleic acid (18:1n-9). The total MUFA/SFA and 18:1/18:0 ratios were lower in the STG of BD patients and were inversely correlated with total PUFA composition. MS patients exhibited a pattern of fatty acid abnormalities similar to that observed in BD patients including elevated PUFA and a lower 18:1/18:0 ratio. Collectively, these data demonstrate that BD patients exhibit a pattern of fatty acid abnormalities in the STG that is not observed in MDD and SZ patients and closely resembles MS patients. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Phenotype abnormality: 49 [Arabidopsis Phenome Database[Archive

Lifescience Database Archive (English)

Full Text Available 49 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u555i abnormal for trait of behavior...al quality in organ named whole plant during process named cell growth ... whole plant ... abnormal ... cell growth ... behavioral quality

Phenotype abnormality: 48 [Arabidopsis Phenome Database[Archive

Lifescience Database Archive (English)

Full Text Available 48 http://metadb.riken.jp/db/SciNetS_ria224i/cria224u1ria224u554i abnormal for trait of behavior...al quality in organ named vascular leaf during process named organ development ... vascular leaf ... abnormal ... organ development ... behavioral quality

Musical Expectations Enhance Auditory Cortical Processing in Musicians: A Magnetoencephalography Study.

Science.gov (United States)

Park, Jeong Mi; Chung, Chun Kee; Kim, June Sic; Lee, Kyung Myun; Seol, Jaeho; Yi, Suk Won

2018-01-15

The present study investigated the influence of musical expectations on auditory representations in musicians and non-musicians using magnetoencephalography (MEG). Neuroscientific studies have demonstrated that musical syntax is processed in the inferior frontal gyri, eliciting an early right anterior negativity (ERAN), and anatomical evidence has shown that interconnections occur between the frontal cortex and the belt and parabelt regions in the auditory cortex (AC). Therefore, we anticipated that musical expectations would mediate neural activities in the AC via an efferent pathway. To test this hypothesis, we measured the auditory-evoked fields (AEFs) of seven musicians and seven non-musicians while they were listening to a five-chord progression in which the expectancy of the third chord was manipulated (highly expected, less expected, and unexpected). The results revealed that highly expected chords elicited shorter N1m (negative AEF at approximately 100 ms) and P2m (positive AEF at approximately 200 ms) latencies and larger P2m amplitudes in the AC than less-expected and unexpected chords. The relations between P2m amplitudes/latencies and harmonic expectations were similar between the groups; however, musicians' results were more remarkable than those of non-musicians. These findings suggest that auditory cortical processing is enhanced by musical knowledge and long-term training in a top-down manner, which is reflected in shortened N1m and P2m latencies and enhanced P2m amplitudes in the AC. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Low-frequency hippocampal-cortical activity drives brain-wide resting-state functional MRI connectivity.

Science.gov (United States)

Chan, Russell W; Leong, Alex T L; Ho, Leon C; Gao, Patrick P; Wong, Eddie C; Dong, Celia M; Wang, Xunda; He, Jufang; Chan, Ying-Shing; Lim, Lee Wei; Wu, Ed X

2017-08-15

The hippocampus, including the dorsal dentate gyrus (dDG), and cortex engage in bidirectional communication. We propose that low-frequency activity in hippocampal-cortical pathways contributes to brain-wide resting-state connectivity to integrate sensory information. Using optogenetic stimulation and brain-wide fMRI and resting-state fMRI (rsfMRI), we determined the large-scale effects of spatiotemporal-specific downstream propagation of hippocampal activity. Low-frequency (1 Hz), but not high-frequency (40 Hz), stimulation of dDG excitatory neurons evoked robust cortical and subcortical brain-wide fMRI responses. More importantly, it enhanced interhemispheric rsfMRI connectivity in various cortices and hippocampus. Subsequent local field potential recordings revealed an increase in slow oscillations in dorsal hippocampus and visual cortex, interhemispheric visual cortical connectivity, and hippocampal-cortical connectivity. Meanwhile, pharmacological inactivation of dDG neurons decreased interhemispheric rsfMRI connectivity. Functionally, visually evoked fMRI responses in visual regions also increased during and after low-frequency dDG stimulation. Together, our results indicate that low-frequency activity robustly propagates in the dorsal hippocampal-cortical pathway, drives interhemispheric cortical rsfMRI connectivity, and mediates visual processing.