WorldWideScience

Sample records for brain cortical mapping

  1. Cortical mapping by functional magnetic resonance imaging in patients with brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Majos, Agata; Stefanczyk, Ludomir; Goraj, Bozena [Medical University of Lodz, Department of Radiology, Lodz (Poland); Tybor, Krzysztof [Medical University of Lodz, Department of Neurosurgery, Lodz (Poland)

    2005-06-01

    The aim of our study was to establish the effectiveness of the functional MRI (fMRI) technique in comparison with intraoperative cortical stimulation (ICS) in planning cortex-saving neurosurgical interventions. The combination of sensory and motor stimulation during fMRI experiments was used to improve the exactness of central sulcus localization. The study subjects were 30 volunteers and 33 patients with brain tumors in the rolandic area. Detailed topographical relations of activated areas in fMRI and intraoperative techniques were compared. The agreement in the location defined by the two methods for motor centers was found to be 84%; for sensory centers it was 83%. When both kinds of activation are taken into account this agreement increases to 98%. A significant relation was found between fMRI and ICS for the agreement of the distance both for motor and sensory centers (p=0.0021-0.0024). Also a strong dependence was found between the agreement of the location and the agreement of the distance for both kinds of stimulation. The spatial correlation between fMRI and ICS methods for the sensorimotor cortex is very high. fMRI combining functional and structural information is very helpful for preoperative neurosurgical planning. The sensitivity of the fMRI technique in brain mapping increases when using both motor and sensory paradigms in the same patient. (orig.)

  2. Quantitative map of multiple auditory cortical regions with a stereotaxic fine-scale atlas of the mouse brain

    OpenAIRE

    Hiroaki Tsukano; Masao Horie; Ryuichi Hishida; Kuniyuki Takahashi; Hirohide Takebayashi; Katsuei Shibuki

    2016-01-01

    Optical imaging studies have recently revealed the presence of multiple auditory cortical regions in the mouse brain. We have previously demonstrated, using flavoprotein fluorescence imaging, at least six regions in the mouse auditory cortex, including the anterior auditory field (AAF), primary auditory cortex (AI), the secondary auditory field (AII), dorsoanterior field (DA), dorsomedial field (DM), and dorsoposterior field (DP). While multiple regions in the visual cortex and somatosensory ...

  3. Quantitative Architectural Analysis: A New Approach to Cortical Mapping

    Science.gov (United States)

    Schleicher, Axel; Morosan, Patricia; Amunts, Katrin; Zilles, Karl

    2009-01-01

    Results from functional imaging studies are often still interpreted using the classical architectonic brain maps of Brodmann and his successors. One obvious weakness in traditional, architectural mapping is the subjective nature of localizing borders between cortical areas by means of a purely visual, microscopical examination of histological…

  4. Object recognition by artificial cortical maps.

    Science.gov (United States)

    Plebe, Alessio; Domenella, Rosaria Grazia

    2007-09-01

    Object recognition is one of the most important functions of the human visual system, yet one of the least understood, this despite the fact that vision is certainly the most studied function of the brain. We understand relatively well how several processes in the cortical visual areas that support recognition capabilities take place, such as orientation discrimination and color constancy. This paper proposes a model of the development of object recognition capability, based on two main theoretical principles. The first is that recognition does not imply any sort of geometrical reconstruction, it is instead fully driven by the two dimensional view captured by the retina. The second assumption is that all the processing functions involved in recognition are not genetically determined or hardwired in neural circuits, but are the result of interactions between epigenetic influences and basic neural plasticity mechanisms. The model is organized in modules roughly related to the main visual biological areas, and is implemented mainly using the LISSOM architecture, a recent neural self-organizing map model that simulates the effects of intercortical lateral connections. This paper shows how recognition capabilities, similar to those found in brain ventral visual areas, can develop spontaneously by exposure to natural images in an artificial cortical model.

  5. [Functional magnetic resonance imaging for cortical mapping in epilepsy].

    Science.gov (United States)

    Lajos, Rudolf Kozák; Tóth, Vivien; Barsi, Péter; Rudas, Gábor

    2011-09-30

    It is not only the total curative resection of pathological tissue or the minimization of symptoms to be considered in epilepsy surgery or other neurosurgical procedures, it is equally desirable to maintain the best possible quality of life. Cortical mapping methods can help achieve this goal by delineating eloquent areas, i.e. brain regions that are vital for providing an acceptable quality of life, albeit not prone to compensatory reorganization. These areas include among others the Broca and Wernicke regions for speech, the primary motor, sensory and visual cortices. Functional MRI gained importance in the last decade as a non-invasive clinical cortical mapping technique. This method is capable of localizing cortical areas selectively activated by a given task condition. Thus, selecting appropriate tasks can help mapping eloquent brain regions. Using functional MRI provides information that is complementary to other mapping methods. Moreover, it can replace invasive methods such as the Wada test. Here, we explain the background of functional MRI, compare it to other clinical mapping methods, explain the intricacies of paradigm selection, and show the limitations of the technique while also pointing out alternative uses.

  6. Alterations in Cortical Thickness and White Matter Integrity in Mild-to-Moderate Communicating Hydrocephalic School-Aged Children Measured by Whole-Brain Cortical Thickness Mapping and DTI

    Science.gov (United States)

    Ye, Xinjian; Bai, Guanghui; Fu, Yuchuan; Mao, Chuanwan; Wu, Aiqin

    2017-01-01

    Follow-up observation is required for mild-to-moderate hydrocephalic patients because of the potential damage to brain. However, effects of mild-to-moderate hydrocephalus on gray and white matter remain unclear in vivo. Using structural MRI and diffusion tensor imaging (DTI), current study compared the cortical thickness and white matter integrity between children with mild-to-moderate communicating hydrocephalus and healthy controls. The relationships between cortical changes and intelligence quota were also examined in patients. We found that cortical thickness in the left middle temporal and left rostral middle frontal gyrus was significantly lower in the hydrocephalus group compared with that of controls. Fractional anisotropy in the right corpus callosum body was significantly lower in the hydrocephalus group compared with that of controls. In addition, there was no association of cortical thinning or white matter fractional anisotropy with intelligence quota in either group. Thus, our findings provide clues to that mild-to-moderate hydrocephalus could lead to structural brain deficits especially in the middle temporal and middle frontal gyrus prior to the behavior changes.

  7. Cortical complexity in cetacean brains.

    Science.gov (United States)

    Hof, Patrick R; Chanis, Rebecca; Marino, Lori

    2005-11-01

    Cetaceans (dolphins, whales, and porpoises) have a long, dramatically divergent evolutionary history compared with terrestrial mammals. Throughout their 55-60 million years of evolution, cetaceans acquired a compelling set of characteristics that include echolocation ability (in odontocetes), complex auditory and communicative capacities, and complex social organization. Moreover, although cetaceans have not shared a common ancestor with primates for over 90 million years, they possess a set of cognitive attributes that are strikingly convergent with those of many primates, including great apes and humans. In contrast, cetaceans have evolved a highly unusual combination of neurobiological features different from that of primates. As such, cetacean brains offer a critical opportunity to address questions about how complex behavior can be based on very different neuroanatomical and neurobiological evolutionary products. Cetacean brains and primate brains are arguably most meaningfully conceived as alternative evolutionary routes to neurobiological and cognitive complexity. In this article, we summarize data on brain size and hemisphere surface configuration in several cetacean species and present an overview of the cytoarchitectural complexity of the cerebral cortex of the bottlenose dolphin.

  8. Curved reformat of the paediatric brain MRI into a 'flat-earth map' - standardised method for demonstrating cortical surface atrophy resulting from hypoxic-ischaemic encephalopathy.

    Science.gov (United States)

    Simpson, Ewan; Andronikou, Savvas; Vedajallam, Schadie; Chacko, Anith; Thai, Ngoc Jade

    2016-09-01

    Hypoxic-ischaemic encephalopathy is optimally imaged with brain MRI in the neonatal period. However neuroimaging is often also performed later in childhood (e.g., when parents seek compensation in cases of alleged birth asphyxia). We describe a standardised technique for creating two curved reconstructions of the cortical surface to show the characteristic surface changes of hypoxic-ischaemic encephalopathy in children imaged after the neonatal period. The technique was applied for 10 cases of hypoxic-ischaemic encephalopathy and also for age-matched healthy children to assess the visibility of characteristic features of hypoxic-ischaemic encephalopathy. In the abnormal brains, fissural or sulcal widening was seen in all cases and ulegyria was identifiable in 7/10. These images could be used as a visual aid for communicating MRI findings to clinicians and other interested parties.

  9. Primary cortical brain cells influence osteoblast activity.

    Science.gov (United States)

    Anissian, Lucas; Kirby, Michael; Stark, André

    2009-12-18

    The presence of neuropeptides and neuroreceptors in the bone have been reported in several studies. Bone turn-over seems to be controlled by the nervous system. The actual pathway or the control mechanism is still under investigation. In this study we investigate the changes in osteoblast cells if they are in co-culture with primary cortical brain cells. After seven days in co-culture with the primary fetal brain cells the osteoblast cells exhibited hypertrophic morphological changes and showed stronger ALP activity.

  10. Direct cortical mapping via solving partial differential equations on implicit surfaces.

    Science.gov (United States)

    Shi, Yonggang; Thompson, Paul M; Dinov, Ivo; Osher, Stanley; Toga, Arthur W

    2007-06-01

    In this paper, we propose a novel approach for cortical mapping that computes a direct map between two cortical surfaces while satisfying constraints on sulcal landmark curves. By computing the map directly, we can avoid conventional intermediate parameterizations and help simplify the cortical mapping process. The direct map in our method is formulated as the minimizer of a flexible variational energy under landmark constraints. The energy can include both a harmonic term to ensure smoothness of the map and general data terms for the matching of geometric features. Starting from a properly designed initial map, we compute the map iteratively by solving a partial differential equation (PDE) defined on the source cortical surface. For numerical implementation, a set of adaptive numerical schemes are developed to extend the technique of solving PDEs on implicit surfaces such that landmark constraints are enforced. In our experiments, we show the flexibility of the direct mapping approach by computing smooth maps following landmark constraints from two different energies. We also quantitatively compare the metric preserving property of the direct mapping method with a parametric mapping method on a group of 30 subjects. Finally, we demonstrate the direct mapping method in the brain mapping applications of atlas construction and variability analysis.

  11. Application of cortical mapping in the surgical treatment of brain tumors in language areas%皮层功能制图在语言功能区脑肿瘤手术治疗中的应用

    Institute of Scientific and Technical Information of China (English)

    马辉; 黄伟; 孙胜玉; 夏鹤春; 孙晓川

    2012-01-01

    目的 利用皮层功能制图进行语言功能区定位,实现语言功能区保护下肿瘤的最大程度切除.方法 对16例语言功能区脑肿瘤患者,利用血氧依赖功能磁共振(BOLD-fMRI)技术和(或)术中唤醒麻醉下皮层直接电刺激( ECS)定位技术进行脑功能制图;对所获皮层功能制图资料进行个体化评估,术中辅助保护语言功能区,在神经导航指引下切除肿瘤.结果 本组肿瘤病变全切除10例,次全切除3例,大部分切除3例.术后语言功能明显改善6例,无变化6例,短暂性感觉性失语2例,语言功能明显障碍2例.结论 BOLD-f MRI结合术中唤醒麻醉下ECS皮层功能制图定位语言功能区,可在保护语言功能的同时最大程度地切除肿瘤组织,提高患者术后生活质量.%Objective To study ihe methods of cortical mapping, preoperative localization of language areas with Bold-fMRI and(or) inlraoperative electrical cortical stimulation of language areas with awaken surgery, assist to remove brain tumors in functional areas of language. Methods Cortical mapping data from such as oxygen dependent functional magnetic resonance imaging (BOLD-fMRI) technology, using the block design and reciting task to activate broca area and paragraph comprehension task to activate wemicke area, calculated cerebral laterality index (LI) to determine the dominant hemisphere; using of the electrical cortical stimulation (ECS) to localizale language areas under awake anesthesia in patients with surgery. The data combined with neuronavigation assist microscopic remove braim tomors in the language areas. Results Functional cortical mapping was used for localizate broca or wemicke area of 16 cases, image acquisition satisfied in 16 cases. Intraoperative awake and electrical stimulation of language areas in 4 cases. Lesion total resection in 10 cases, subtotal resection in 3 cases, partial resection in 3 cases. Language function improved significantly after surgery in 6

  12. Consistent Reconstruction of Cortical Surfaces from Longitudinal Brain MR Images

    OpenAIRE

    Li, Gang; Nie, Jingxin; Wu, Guorong; Wang, Yaping; Shen, Dinggang

    2011-01-01

    Accurate and consistent reconstruction of cortical surfaces from longitudinal human brain MR images is of great importance in studying longitudinal subtle change of the cerebral cortex. This paper presents a novel deformable surface method for consistent and accurate reconstruction of inner, central and outer cortical surfaces from longitudinal brain MR images. Specifically, the cortical surfaces of the group-mean image of all aligned longitudinal images of the same subject are first reconstr...

  13. Mapping the motor and sensory cortices: a historical look and a current case study in sensorimotor localization and direct cortical motor stimulation.

    Science.gov (United States)

    Silverstein, Justin

    2012-03-01

    The utilization of cortical mapping during craniotomies for epilepsy and brain tumor resection is extremely important. Cortical mapping can guide the surgical team intraoperatively with regards to the layout of important anatomical structures and their function to prevent post-operative deficits. Electroneurophysiological methods employed include sensorimotor localization recorded directly from the surface of the brain when stimulated from a peripheral nerve and direct cortical stimulation (DCS) of the motor cortex to elicit a distal muscle response. This paper presents a case, in which a paradigm of neurophysiological modalities is utilized to assist the surgeon in creating a topographic map of the motor cortex and with localizing the sensory and motor cortices, in addition to a historical review of functional localization.

  14. Modelling Human Cortical Network in Real Brain Space

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qing-Bai; FENG Hong-Bo; TANG Yi-Yuan

    2007-01-01

    Highly specific structural organization is of great significance in the topology of cortical networks.We introduce a human cortical network model.taking the specific cortical structure into account,in which nodes are brain sites placed in the actual positions of cerebral cortex and the establishment of edges depends on the spatial path length rather than the linear distance.The resulting network exhibits the essential features of cortical connectivity,properties of small-world networks and multiple clusters structure.Additionally.assortative mixing is also found in this roodel.All of these findings may be attributed to the spedtic cortical architecture.

  15. Cortical mapping with navigated transcranial magnetic stimulation in low-grade glioma surgery

    Directory of Open Access Journals (Sweden)

    Paiva WS

    2012-05-01

    Full Text Available Wellingson S Paiva1, Erich T Fonoff1, Marco A Marcolin2, Hector N Cabrera1, Manoel J Teixeira11Division of Functional Neurosurgery, Hospital das Clinicas, 2TMS Laboratory of the Psychiatry Institute, Hospital das Clinicas, University of São Paulo School of Medicine, São Paulo, BrazilAbstract: Transcranial magnetic stimulation (TMS is a promising method for both investigation and therapeutic treatment of psychiatric and neurologic disorders and, more recently, for brain mapping. This study describes the application of navigated TMS for motor cortex mapping in patients with a brain tumor located close to the precentral gyrus.Materials and methods: In this prospective study, six patients with low-grade gliomas in or near the precentral gyrus underwent TMS, and their motor responses were correlated to locations in the cortex around the lesion, generating a functional map overlaid on three-dimensional magnetic resonance imaging (MRI scans of the brain. To determine the accuracy of this new method, we compared TMS mapping with the gold standard mapping with direct cortical electrical stimulation in surgery. The same navigation system and TMS-generated map were used during the surgical resection procedure.Results: The motor cortex could be clearly mapped using both methods. The locations corresponding to the hand and forearm, found during intraoperative mapping, showed a close spatial relationship to the homotopic areas identified by TMS mapping. The mean distance between TMS and direct cortical electrical stimulation (DES was 4.16 ± 1.02 mm (range: 2.56–5.27 mm.Conclusion: Preoperative mapping of the motor cortex with navigated TMS prior to brain tumor resection is a useful presurgical planning tool with good accuracy.Keywords: transcranial magnetic stimulation, cortical mapping, brain tumor, motor cortex

  16. Consistent Reconstruction of Cortical Surfaces from Longitudinal Brain MR Images

    OpenAIRE

    Li, Gang; Nie, Jingxin; Shen, Dinggang

    2011-01-01

    Accurate and consistent reconstruction of cortical surfaces from longitudinal human brain MR images is of great importance in studying subtle morphological changes of the cerebral cortex. This paper presents a new deformable surface method for consistent and accurate reconstruction of inner, central and outer cortical surfaces from longitudinal MR images. Specifically, the cortical surfaces of the group-mean image of all aligned longitudinal images of the same subject are first reconstructed ...

  17. Optogenetic mapping of brain circuitry

    Science.gov (United States)

    Augustine, George J.; Berglund, Ken; Gill, Harin; Hoffmann, Carolin; Katarya, Malvika; Kim, Jinsook; Kudolo, John; Lee, Li M.; Lee, Molly; Lo, Daniel; Nakajima, Ryuichi; Park, Min Yoon; Tan, Gregory; Tang, Yanxia; Teo, Peggy; Tsuda, Sachiko; Wen, Lei; Yoon, Su-In

    2012-10-01

    Studies of the brain promise to be revolutionized by new experimental strategies that harness the combined power of optical techniques and genetics. We have mapped the circuitry of the mouse brain by using both optogenetic actuators that control neuronal activity and optogenetic sensors that detect neuronal activity. Using the light-activated cation channel, channelrhodopsin-2, to locally photostimulate neurons allows high-speed mapping of local and long-range circuitry. For example, with this approach we have mapped local circuits in the cerebral cortex, cerebellum and many other brain regions. Using the fluorescent sensor for chloride ions, Clomeleon, allows imaging of the spatial and temporal dimensions of inhibitory circuits in the brain. This approach allows imaging of both conventional "phasic" synaptic inhibition as well as unconventional "tonic" inhibition. The combined use of light to both control and monitor neural activity creates unprecedented opportunities to explore brain function, screen pharmaceutical agents, and potentially to use light to ameliorate psychiatric and neurological disorders.

  18. Decoding Brain States Based on Magnetoencephalography From Prespecified Cortical Regions.

    Science.gov (United States)

    Zhang, Jinyin; Li, Xin; Foldes, Stephen T; Wang, Wei; Collinger, Jennifer L; Weber, Douglas J; Bagić, Anto

    2016-01-01

    Brain state decoding based on whole-head MEG has been extensively studied over the past decade. Recent MEG applications pose an emerging need of decoding brain states based on MEG signals originating from prespecified cortical regions. Toward this goal, we propose a novel region-of-interest-constrained discriminant analysis algorithm (RDA) in this paper. RDA integrates linear classification and beamspace transformation into a unified framework by formulating a constrained optimization problem. Our experimental results based on human subjects demonstrate that RDA can efficiently extract the discriminant pattern from prespecified cortical regions to accurately distinguish different brain states.

  19. Detection and mapping of delays in early cortical folding derived from in utero MRI

    Science.gov (United States)

    Habas, Piotr A.; Rajagopalan, Vidya; Scott, Julia A.; Kim, Kio; Roosta, Ahmad; Rousseau, Francois; Barkovich, A. James; Glenn, Orit A.; Studholme, Colin

    2011-03-01

    Understanding human brain development in utero and detecting cortical abnormalities related to specific clinical conditions is an important area of research. In this paper, we describe and evaluate methodology for detection and mapping of delays in early cortical folding from population-based studies of fetal brain anatomies imaged in utero. We use a general linear modeling framework to describe spatiotemporal changes in curvature of the developing brain and explore the ability to detect and localize delays in cortical folding in the presence of uncertainty in estimation of the fetal age. We apply permutation testing to examine which regions of the brain surface provide the most statistical power to detect a given folding delay at a given developmental stage. The presented methodology is evaluated using MR scans of fetuses with normal brain development and gestational ages ranging from 20.57 to 27.86 weeks. This period is critical in early cortical folding and the formation of the primary and secondary sulci. Finally, we demonstrate a clinical application of the framework for detection and localization of folding delays in fetuses with isolated mild ventriculomegaly.

  20. Small-world anatomical networks in the human brain revealed by cortical thickness from MRI.

    Science.gov (United States)

    He, Yong; Chen, Zhang J; Evans, Alan C

    2007-10-01

    An important issue in neuroscience is the characterization for the underlying architectures of complex brain networks. However, little is known about the network of anatomical connections in the human brain. Here, we investigated large-scale anatomical connection patterns of the human cerebral cortex using cortical thickness measurements from magnetic resonance images. Two areas were considered anatomically connected if they showed statistically significant correlations in cortical thickness and we constructed the network of such connections using 124 brains from the International Consortium for Brain Mapping database. Significant short- and long-range connections were found in both intra- and interhemispheric regions, many of which were consistent with known neuroanatomical pathways measured by human diffusion imaging. More importantly, we showed that the human brain anatomical network had robust small-world properties with cohesive neighborhoods and short mean distances between regions that were insensitive to the selection of correlation thresholds. Additionally, we also found that this network and the probability of finding a connection between 2 regions for a given anatomical distance had both exponentially truncated power-law distributions. Our results demonstrated the basic organizational principles for the anatomical network in the human brain compatible with previous functional networks studies, which provides important implications of how functional brain states originate from their structural underpinnings. To our knowledge, this study provides the first report of small-world properties and degree distribution of anatomical networks in the human brain using cortical thickness measurements.

  1. Temporal lobe cortical thickness correlations differentiate the migraine brain from the healthy brain.

    Directory of Open Access Journals (Sweden)

    Todd J Schwedt

    Full Text Available Interregional cortical thickness correlations reflect underlying brain structural connectivity and functional connectivity. A few prior studies have shown that migraine is associated with atypical cortical brain structure and atypical functional connectivity amongst cortical regions that participate in sensory processing. However, the specific brain regions that most accurately differentiate the migraine brain from the healthy brain have yet to be determined. The aim of this study was to identify the brain regions that comprised interregional cortical thickness correlations that most differed between migraineurs and healthy controls.This was a cross-sectional brain magnetic resonance imaging (MRI investigation of 64 adults with migraine and 39 healthy control subjects recruited from tertiary-care medical centers and their surrounding communities. All subjects underwent structural brain MRI imaging on a 3T scanner. Cortical thickness was determined for 70 brain regions that cover the cerebral cortex and cortical thickness correlations amongst these regions were calculated. Cortical thickness correlations that best differentiated groups of six migraineurs from controls and vice versa were identified.A model containing 15 interregional cortical thickness correlations differentiated groups of migraineurs from healthy controls with high accuracy. The right temporal pole was involved in 13 of the 15 interregional correlations while the right middle temporal cortex was involved in the other two.A model consisting of 15 interregional cortical thickness correlations accurately differentiates the brains of small groups of migraineurs from those of healthy controls. Correlations with the right temporal pole were highly represented in this classifier, suggesting that this region plays an important role in migraine pathophysiology.

  2. BrainMap `95 workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The fourth annual BrainMap workshop was held at La Mansion del Rio Hotel in San Antonio December 3--4, 1995. The conference title was ``Human Brain Mapping and Modeling.`` The meeting was attended by 137 registered participants and 30 observers from 82 institutions representing 12 countries. The meeting focused on the technical issues associated with brain mapping and modeling. A total of 23 papers were presented covering the following topics: spatial normalization and registration; functional image analysis; metanalysis and modeling; and new horizons in biological databases. The full program with abstracts was available on the Research Imaging Center`s web site. A book will be published by John Wiley and Sons prior to the end of 1998.

  3. Distinct Genetic Influences on Cortical and Subcortical Brain Structures

    Science.gov (United States)

    Wen, Wei; Thalamuthu, Anbupalam; Mather, Karen A.; Zhu, Wanlin; Jiang, Jiyang; de Micheaux, Pierre Lafaye; Wright, Margaret J.; Ames, David; Sachdev, Perminder S.

    2016-09-01

    This study examined the heritability of brain grey matter structures in a subsample of older adult twins (93 MZ and 68 DZ twin pairs; mean age 70 years) from the Older Australian Twins Study. The heritability estimates of subcortical regions ranged from 0.41 (amygdala) to 0.73 (hippocampus), and of cortical regions, from 0.55 (parietal lobe) to 0.78 (frontal lobe). Corresponding structures in the two hemispheres were influenced by the same genetic factors and high genetic correlations were observed between the two hemispheric regions. There were three genetically correlated clusters, comprising (i) the cortical lobes (frontal, temporal, parietal and occipital lobes); (ii) the basal ganglia (caudate, putamen and pallidum) with weak genetic correlations with cortical lobes, and (iii) the amygdala, hippocampus, thalamus and nucleus accumbens grouped together, which genetically correlated with both basal ganglia and cortical lobes, albeit relatively weakly. Our study demonstrates a complex but patterned and clustered genetic architecture of the human brain, with divergent genetic determinants of cortical and subcortical structures, in particular the basal ganglia.

  4. Cortical spreading depression-induced preconditioning in the brain

    Institute of Scientific and Technical Information of China (English)

    Ping-ping Shen; Shuai Hou; Di Ma; Ming-ming Zhao; Ming-qin Zhu; Jing-dian Zhang; Liang-shu Feng; Li Cui; Jia-chun Feng

    2016-01-01

    Cortical spreading depression is a technique used to depolarize neurons. During focal or global ischemia, cortical spreading depression-induced preconditioning can enhance tolerance of further injury. Howev-er, the underlying mechanism for this phenomenon remains relatively unclear. To date, numerous issues exist regarding the experimental model used to precondition the brain with cortical spreading depression, such as the administration route, concentration of potassium chloride, induction time, duration of the protection provided by the treatment, the regional distribution of the protective effect, and the types of neurons responsible for the greater tolerance. In this review, we focus on the mechanisms underlying cor-tical spreading depression-induced tolerance in the brain, considering excitatory neurotransmission and metabolism, nitric oxide, genomic reprogramming, inlfammation, neurotropic factors, and cellular stress response. Speciifcally, we clarify the procedures and detailed information regarding cortical spreading de-pression-induced preconditioning and build a foundation for more comprehensive investigations in the ifeld of neural regeneration and clinical application in the future.

  5. Curved reformat of the paediatric brain MRI into a 'flat-earth map' - standardised method for demonstrating cortical surface atrophy resulting from hypoxic-ischaemic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Ewan [Bristol Royal Hospital for Children, Department of Pediatric Radiology, Bristol (United Kingdom); Andronikou, Savvas [Bristol Royal Hospital for Children, Department of Pediatric Radiology, Bristol (United Kingdom); University of Bristol, CRICBristol, Bristol (United Kingdom); Vedajallam, Schadie; Chacko, Anith; Thai, Ngoc Jade [University of Bristol, CRICBristol, Bristol (United Kingdom)

    2016-09-15

    Hypoxic-ischaemic encephalopathy is optimally imaged with brain MRI in the neonatal period. However neuroimaging is often also performed later in childhood (e.g., when parents seek compensation in cases of alleged birth asphyxia). We describe a standardised technique for creating two curved reconstructions of the cortical surface to show the characteristic surface changes of hypoxic-ischaemic encephalopathy in children imaged after the neonatal period. The technique was applied for 10 cases of hypoxic-ischaemic encephalopathy and also for age-matched healthy children to assess the visibility of characteristic features of hypoxic-ischaemic encephalopathy. In the abnormal brains, fissural or sulcal widening was seen in all cases and ulegyria was identifiable in 7/10. These images could be used as a visual aid for communicating MRI findings to clinicians and other interested parties. (orig.)

  6. Language mapping in multilingual patients: Electrocorticography and cortical stimulation during naming

    Directory of Open Access Journals (Sweden)

    Mackenzie C Cervenka

    2011-02-01

    Full Text Available Multilingual patients pose a unique challenge when planning epilepsy surgery near language cortex because the cortical representations of each language may be distinct. These distinctions may not be evident with routine electrocortical stimulation mapping (ESM. Electrocorticography (ECoG has recently been used to detect task-related spectral perturbations associated with functional brain activation. We hypothesized that using broadband high gamma augmentation (HGA, 60-150 Hertz as an index of cortical activation, ECoG would complement ESM in discriminating the cortical representations of first (L1 and second (L2 languages. We studied four adult patients for whom English was a second language, in whom subdural electrodes (a total of 358 were implanted to guide epilepsy surgery. Patients underwent ECoG recordings and electrocortical stimulation mapping (ESM while performing the same visual object naming task in L1 and L2. In three of four patients, ECoG found sites activated during naming in one language but not the other. These language-specific sites were not identified using ESM. In addition, ECoG HGA was observed at more sites during L2 versus L1 naming in two patients, suggesting that L2 processing required additional cortical resources compared to L1 processing in these individuals. Post-operative language deficits were identified in three patients (one in L2 only. These deficits were predicted by ECoG spectral mapping but not by ESM. These results suggest that pre-surgical mapping should include evaluation of all utilized languages to avoid post-operative functional deficits. Finally, this study suggests that ECoG spectral mapping may potentially complement the results of ESM of language.

  7. Three-Dimensional Mapping of Gyral Shape and Cortical Surface Asymmetries in Schizophrenia: Gender Effects

    Science.gov (United States)

    Narr, Katherine L.; Thompson, Paul M.; Sharma, Tonmoy; Moussai, Jacob; Zoumalan, Chris; Rayman, Janice; Toga, Arthur W.

    2008-01-01

    Objective People with schizophrenia exhibit abnormalities in brain structure, often in the left hemisphere. Disturbed structural lateralization is controversial, however, and effects appear mediated by gender. The authors mapped differences between schizophrenic and normal subjects in gyral asymmetries, complexity, and variability across the entire cortex. Method Asymmetry and shape profiles for 25 schizophrenic patients (15 men) and 28 demographically similar normal subjects (15 men) were obtained for 38 gyral regions, including the sylvian fissure and temporal and postcentral gyri, by using magnetic resonance data and a novel surface-based mesh-modeling approach. Cortical complexity was examined for sex and diagnosis effects in lobar regions. Intragroup variability was quantified and visualized to assess regional group abnormalities at the cortical surface. Results The patients showed greater variability in frontal areas than the comparison subjects. They also had significant deviations in gyral complexity asymmetry in the superior frontal cortex. In temporoparietal regions, significant gyral asymmetries were present in both groups. Sex differences were apparent in superior temporal gyral measures, and cortical complexity in inferior frontal regions was significantly greater in men. Conclusions Cortical variability and complexity show regional abnormalities in the frontal cortex potentially specific to schizophrenia. The results indicate highly significant temporoparietal gyral asymmetries in both diagnostic groups, contrary to reports of less lateralization in schizophrenia. Substantially larger study groups are necessary to isolate smaller deviations in surface asymmetries, if present in schizophrenia, suggesting their diagnostic value is minimal. PMID:11156807

  8. Brain segmentation and the generation of cortical surfaces

    Science.gov (United States)

    Joshi, M.; Cui, J.; Doolittle, K.; Joshi, S.; Van Essen, D.; Wang, L.; Miller, M. I.

    1999-01-01

    This paper describes methods for white matter segmentation in brain images and the generation of cortical surfaces from the segmentations. We have developed a system that allows a user to start with a brain volume, obtained by modalities such as MRI or cryosection, and constructs a complete digital representation of the cortical surface. The methodology consists of three basic components: local parametric modeling and Bayesian segmentation; surface generation and local quadratic coordinate fitting; and surface editing. Segmentations are computed by parametrically fitting known density functions to the histogram of the image using the expectation maximization algorithm [DLR77]. The parametric fits are obtained locally rather than globally over the whole volume to overcome local variations in gray levels. To represent the boundary of the gray and white matter we use triangulated meshes generated using isosurface generation algorithms [GH95]. A complete system of local parametric quadratic charts [JWM+95] is superimposed on the triangulated graph to facilitate smoothing and geodesic curve tracking. Algorithms for surface editing include extraction of the largest closed surface. Results for several macaque brains are presented comparing automated and hand surface generation. Copyright 1999 Academic Press.

  9. Neuronal networks and mediators of cortical neurovascular coupling responses in normal and altered brain states.

    Science.gov (United States)

    Lecrux, C; Hamel, E

    2016-10-05

    Brain imaging techniques that use vascular signals to map changes in neuronal activity, such as blood oxygenation level-dependent functional magnetic resonance imaging, rely on the spatial and temporal coupling between changes in neurophysiology and haemodynamics, known as 'neurovascular coupling (NVC)'. Accordingly, NVC responses, mapped by changes in brain haemodynamics, have been validated for different stimuli under physiological conditions. In the cerebral cortex, the networks of excitatory pyramidal cells and inhibitory interneurons generating the changes in neural activity and the key mediators that signal to the vascular unit have been identified for some incoming afferent pathways. The neural circuits recruited by whisker glutamatergic-, basal forebrain cholinergic- or locus coeruleus noradrenergic pathway stimulation were found to be highly specific and discriminative, particularly when comparing the two modulatory systems to the sensory response. However, it is largely unknown whether or not NVC is still reliable when brain states are altered or in disease conditions. This lack of knowledge is surprising since brain imaging is broadly used in humans and, ultimately, in conditions that deviate from baseline brain function. Using the whisker-to-barrel pathway as a model of NVC, we can interrogate the reliability of NVC under enhanced cholinergic or noradrenergic modulation of cortical circuits that alters brain states.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'.

  10. Dynamic brain mapping methodology and application.

    Science.gov (United States)

    Itil, T M; Mucci, A; Eralp, E

    1991-01-01

    Brain mapping has opened important perspectives for the neurophysiological evaluation of patients, for the discrimination of drug effects on the brain and for the study of the relationship between the brain and behavior. Our Dynamic Brain Mapping System is the result of many years of EEG quantification. It was designed as a software-oriented system to favor the largest clinical application and simultaneously stimulate new research objectives. Data collection and analysis procedures are critically important in brain mapping for a good understanding of the results. For clinical use, the maps should answer relevant EEG questions and be interpretable with the consolidated knowledge. Therefore, we have developed a new type of brain mapping technology which is called "Field blending interpolation" mapping offered together with the conventional technology with user-selectable interpolation algorithms. In addition to diagnosis, the use of computer-analyzed EEG and brain mapping can be instrumental in drug monitoring, drug selection and drug discriminations. Prospective studies are, however, required to validate the use of brain mapping in each of these new areas. Spatial analysis is the original goal of brain mapping. The development of a new data collection procedure and analysis will be instrumental in the determination of an adequate time and space resolution.

  11. SIMULATING CORTICAL MAPS FOR ATTENTION SHIFT IN AUTISM

    Directory of Open Access Journals (Sweden)

    L.-H. Tan

    2016-07-01

    Full Text Available Autism is a pervasive neuro-developmental disorder, primarily encompassing difficulties in the social, language, and communicative domains. Because autism is a spectrum disorder, it affects each individual differently and has varying degrees. There are three core aspects of impairment based upon the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV, namely impairment in socialization, impairment in communication, and restricted repetitive activities or interests. This work describes the experiment aims at expressing autistic traits through the use of self-organizing map. Works related to simulating autism through self-organizing map is limited. This work compare and contrast the difference in attention index for normal learning and marred attention shift learning ability. It was found that the attention index of normal learning is 9 times better marred attention shift for both random and pre-fixed input data. In the marred attention shift context, neurons adapt more towards the mean of both sources combined under marred context while some neurons adapt towards mean of one source under normal context. The normal learning ability produces maps with neurons orienting towards mean values of combined stimuli source. Impairment in learning ability produces similar cortical maps compared to normal learning ability. The major difference is in the attention index.

  12. More 'mapping' in brain mapping: statistical comparison of effects

    DEFF Research Database (Denmark)

    Jernigan, Terry Lynne; Gamst, Anthony C.; Fennema-Notestine, Christine

    2003-01-01

    The term 'mapping' in the context of brain imaging conveys to most the concept of localization; that is, a brain map is meant to reveal a relationship between some condition or parameter and specific sites within the brain. However, in reality, conventional voxel-based maps of brain function......, or for that matter of brain structure, are generally constructed using analyses that yield no basis for inferences regarding the spatial nonuniformity of the effects. In the normal analysis path for functional images, for example, there is nowhere a statistical comparison of the observed effect in any voxel relative...... to that in any other voxel. Under these circumstances, strictly speaking, the presence of significant activation serves as a legitimate basis only for inferences about the brain as a unit. In their discussion of results, investigators rarely are content to confirm the brain's role, and instead generally prefer...

  13. Eloquent Brain, Ethical Challenges: Functional Brain Mapping in Neurosurgery.

    Science.gov (United States)

    Klein, Eran

    2015-06-01

    Functional brain mapping is an increasingly relied upon tool in presurgical planning and intraoperative decision making. Mapping allows personalization of structure-function relationships when surgical or other treatment of pathology puts eloquent functioning like language or vision at risk. As an innovative technology, functional brain mapping holds great promise but also raises important ethical questions. In this article, recent work in neuroethics on functional imaging and functional neurosurgery is explored and applied to functional brain mapping. Specific topics discussed in this article are incidental findings, responsible innovation, and informed consent.

  14. Theory for the alignment of cortical feature maps during development

    KAUST Repository

    Bressloff, Paul C.

    2010-08-23

    We present a developmental model of ocular dominance column formation that takes into account the existence of an array of intrinsically specified cytochrome oxidase blobs. We assume that there is some molecular substrate for the blobs early in development, which generates a spatially periodic modulation of experience-dependent plasticity. We determine the effects of such a modulation on a competitive Hebbian mechanism for the modification of the feedforward afferents from the left and right eyes. We show how alternating left and right eye dominated columns can develop, in which the blobs are aligned with the centers of the ocular dominance columns and receive a greater density of feedforward connections, thus becoming defined extrinsically. More generally, our results suggest that the presence of periodically distributed anatomical markers early in development could provide a mechanism for the alignment of cortical feature maps. © 2010 The American Physical Society.

  15. Parcellating an individual subject's cortical and subcortical brain structures using snowball sampling of resting-state correlations.

    Science.gov (United States)

    Wig, Gagan S; Laumann, Timothy O; Cohen, Alexander L; Power, Jonathan D; Nelson, Steven M; Glasser, Matthew F; Miezin, Francis M; Snyder, Abraham Z; Schlaggar, Bradley L; Petersen, Steven E

    2014-08-01

    We describe methods for parcellating an individual subject's cortical and subcortical brain structures using resting-state functional correlations (RSFCs). Inspired by approaches from social network analysis, we first describe the application of snowball sampling on RSFC data (RSFC-Snowballing) to identify the centers of cortical areas, subdivisions of subcortical nuclei, and the cerebellum. RSFC-Snowballing parcellation is then compared with parcellation derived from identifying locations where RSFC maps exhibit abrupt transitions (RSFC-Boundary Mapping). RSFC-Snowballing and RSFC-Boundary Mapping largely complement one another, but also provide unique parcellation information; together, the methods identify independent entities with distinct functional correlations across many cortical and subcortical locations in the brain. RSFC parcellation is relatively reliable within a subject scanned across multiple days, and while the locations of many area centers and boundaries appear to exhibit considerable overlap across subjects, there is also cross-subject variability-reinforcing the motivation to parcellate brains at the level of individuals. Finally, examination of a large meta-analysis of task-evoked functional magnetic resonance imaging data reveals that area centers defined by task-evoked activity exhibit correspondence with area centers defined by RSFC-Snowballing. This observation provides important evidence for the ability of RSFC to parcellate broad expanses of an individual's brain into functionally meaningful units.

  16. Mapping cortical areas associated with Chinese word processing using functiona l magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    马林; 唐一源; 王岩; 李德军; 翁旭初; 张武田; 庄建程; 胡小平

    2003-01-01

    Objectives To identify the cortical areas engaged during Chinese word processing using func tional magnetic resonance imaging (fMRI) and to examine the reliability and repr oducibility of fMRI for localization of functional areas in the human brain.Methods FMRI data were collected on 8 young, right-handed, native Chinese speakers duri ng performance of Chinese synonym and homophone judgment tasks on two different clinical MRI systems (1.5 T GE Signa Horizon and 1.5 T Siemens Vision). A cro ss correlation analysis was used to statistically generate the activation map.Results Broca's area, Wernicke's area, bilateral extrastriate, and ventral tempo ral cortex were significantly activated during both the synonym and homophone activities. There was essentially no difference between results acquired on two different MRI systems.Conclusions FMRI can be used for localizing cortical areas critical to Chinese language proc essing in the human brain. The results are reliable and well reproducible acros s different clinical MRI systems.

  17. Untangling perceptual memory: hysteresis and adaptation map into separate cortical networks.

    Science.gov (United States)

    Schwiedrzik, Caspar M; Ruff, Christian C; Lazar, Andreea; Leitner, Frauke C; Singer, Wolf; Melloni, Lucia

    2014-05-01

    Perception is an active inferential process in which prior knowledge is combined with sensory input, the result of which determines the contents of awareness. Accordingly, previous experience is known to help the brain "decide" what to perceive. However, a critical aspect that has not been addressed is that previous experience can exert 2 opposing effects on perception: An attractive effect, sensitizing the brain to perceive the same again (hysteresis), or a repulsive effect, making it more likely to perceive something else (adaptation). We used functional magnetic resonance imaging and modeling to elucidate how the brain entertains these 2 opposing processes, and what determines the direction of such experience-dependent perceptual effects. We found that although affecting our perception concurrently, hysteresis and adaptation map into distinct cortical networks: a widespread network of higher-order visual and fronto-parietal areas was involved in perceptual stabilization, while adaptation was confined to early visual areas. This areal and hierarchical segregation may explain how the brain maintains the balance between exploiting redundancies and staying sensitive to new information. We provide a Bayesian model that accounts for the coexistence of hysteresis and adaptation by separating their causes into 2 distinct terms: Hysteresis alters the prior, whereas adaptation changes the sensory evidence (the likelihood function).

  18. Analysis of a human brain transcriptome map

    Directory of Open Access Journals (Sweden)

    Greene Jonathan R

    2002-04-01

    Full Text Available Abstract Background Genome wide transcriptome maps can provide tools to identify candidate genes that are over-expressed or silenced in certain disease tissue and increase our understanding of the structure and organization of the genome. Expressed Sequence Tags (ESTs from the public dbEST and proprietary Incyte LifeSeq databases were used to derive a transcript map in conjunction with the working draft assembly of the human genome sequence. Results Examination of ESTs derived from brain tissues (excluding brain tumor tissues suggests that these genes are distributed on chromosomes in a non-random fashion. Some regions on the genome are dense with brain-enriched genes while some regions lack brain-enriched genes, suggesting a significant correlation between distribution of genes along the chromosome and tissue type. ESTs from brain tumor tissues have also been mapped to the human genome working draft. We reveal that some regions enriched in brain genes show a significant decrease in gene expression in brain tumors, and, conversely that some regions lacking in brain genes show an increased level of gene expression in brain tumors. Conclusions This report demonstrates a novel approach for tissue specific transcriptome mapping using EST-based quantitative assessment.

  19. Differentiation of motor cortical representation of hand muscles by navigated mapping of optimal TMS current directions in healthy subjects.

    Science.gov (United States)

    Bashir, Shahid; Perez, Jennifer M; Horvath, Jared C; Pascual-Leone, Alvaro

    2013-08-01

    The precision of navigated transcranial magnetic stimulation (TMS) to map the human primary motor cortex may be effected by the direction of TMS-induced current in the brain as determined by the orientation of the stimulation coil. In this study, the authors investigated the effect of current directionality on motor output mapping using navigated brain stimulation. The goal of this study was to determine the optimal coil orientation (and, thus, induced brain current) to activate hand musculature representations relative to each subject's unique neuroanatomical landmarks. The authors studied motor output maps for the first dorsal interosseous, abductor pollicis brevis, and abductor digiti minimi muscles in 10 normal volunteers. Monopolar current pulses were delivered through a figure-of-eight-shaped TMS coil, and motor evoked potentials were recorded using electromyography. At each targeted brain region, the authors systematically rotated the TMS coil to determine the direction of induced current in the brain for induction of the largest motor evoked potentials. These optimal current directions were expressed as an angle relative to each subject's central sulcus. Consistency of the optimal current direction was assessed by repeating the entire mapping procedure on two different occasions across subjects. The authors demonstrate that systematic optimization of current direction as guided by MRI-based neuronavigation improves the resolution of cortical output motor mapping with TMS.

  20. The Relation of Focal Lesions to Cortical Thickness in Pediatric Traumatic Brain Injury.

    Science.gov (United States)

    Bigler, Erin D; Zielinski, Brandon A; Goodrich-Hunsaker, Naomi; Black, Garrett M; Huff, B S Trevor; Christiansen, Zachary; Wood, Dawn-Marie; Abildskov, Tracy J; Dennis, Maureen; Taylor, H Gerry; Rubin, Kenneth; Vannatta, Kathryn; Gerhardt, Cynthia A; Stancin, Terry; Yeates, Keith Owen

    2016-10-01

    In a sample of children with traumatic brain injury, this magnetic resonance imaging (MRI)-based investigation examined whether presence of a focal lesion uniquely influenced cortical thickness in any brain region. Specifically, the study explored the relation of cortical thickness to injury severity as measured by Glasgow Coma Scale score and length of stay, along with presence of encephalomalacia, focal white matter lesions or presence of hemosiderin deposition as a marker of shear injury. For comparison, a group of children without head injury but with orthopedic injury of similar age and sex were also examined. Both traumatic brain injury and orthopedic injury children had normally reduced cortical thickness with age, assumed to reflect neuronal pruning. However, the reductions observed within the traumatic brain injury sample were similar to those in the orthopedic injury group, suggesting that in this sample traumatic brain injury, per se, did not uniquely alter cortical thickness in any brain region at the group level. Injury severity in terms of Glasgow Coma Scale or longer length of stay was associated with greater reductions in frontal and occipitoparietal cortical thickness. However, presence of focal lesions were not related to unique changes in cortical thickness despite having a prominent distribution of lesions within frontotemporal regions among children with traumatic brain injury. Because focal lesions were highly heterogeneous, their association with cortical thickness and development appeared to be idiosyncratic, and not associated with group level effects.

  1. Mapping the mosaic sequence of primate visual cortical development

    Directory of Open Access Journals (Sweden)

    Inaki-Carril eMundinano

    2015-10-01

    Full Text Available Traditional ‘textbook’ theory suggests that the development and maturation of visual cortical areas occur as a wave from V1. However, more recent evidence would suggest that this is not the case, and the emergence of extrastriate areas occurs in a non-hierarchical fashion. This proposition comes from both physiological and anatomical studies but the actual developmental sequence of extrastriate areas remains unknown. In the current study, we examined the development and maturation of the visual cortex of the marmoset monkey, a New World simian, from embryonic day 130 (15 days prior to birth through to adulthood. Utilizing the well-described expression characteristics of the calcium-binding proteins calbindin and parvalbumin, and nonphosphorylated neurofilament for the pyramidal neurons, we were able to accurately map the sequence of development and maturation of the visual cortex. To this end, we demonstrated that both V1 and middle temporal area (MT emerge first and that MT likely supports dorsal stream development while V1 supports ventral stream development. Furthermore, the emergence of the dorsal stream-associated areas was significantly earlier than ventral stream areas. The difference in the temporal development of the visual streams is likely driven by a teleological requirement for specific visual behavior in early life.

  2. Regional quantitative analysis of cortical surface maps of FDG PET images

    CERN Document Server

    Protas, H D; Hayashi, K M; Chin Lung, Yu; Bergsneider, M; Sung Cheng, Huang

    2006-01-01

    Cortical surface maps are advantageous for visualizing the 3D profile of cortical gray matter development and atrophy, and for integrating structural and functional images. In addition, cortical surface maps for PET data, when analyzed in conjunction with structural MRI data allow us to investigate, and correct for, partial volume effects. Here we compared quantitative regional PET values based on a 3D cortical surface modeling approach with values obtained directly from the 3D FDG PET images in various atlas-defined regions of interest (ROIs; temporal, parietal, frontal, and occipital lobes). FDG PET and 3D MR (SPGR) images were obtained and aligned to ICBM space for 15 normal subjects. Each image was further elastically warped in 2D parameter space of the cortical surface, to align major cortical sulci. For each point within a 15 mm distance of the cortex, the value of the PET intensity was averaged to give a cortical surface map of FDG uptake. The average PET values on the cortical surface map were calcula...

  3. Cortical sulcal atlas construction using a diffeomorphic mapping approach.

    Science.gov (United States)

    Joshi, Shantanu H; Cabeen, Ryan P; Sun, Bo; Joshi, Anand A; Gutman, Boris; Zamanyan, Alen; Chakrapani, Shruthi; Dinov, Ivo; Woods, Roger P; Toga, Arthur W

    2010-01-01

    We present a geometric approach for constructing shape atlases of sulcal curves on the human cortex. Sulci and gyri are represented as continuous open curves in R3, and their shapes are studied as elements of an infinite-dimensional sphere. This shape manifold has some nice properties--it is equipped with a Riemannian L2 metric on the tangent space and facilitates computational analyses and correspondences between sulcal shapes. Sulcal mapping is achieved by computing geodesics in the quotient space of shapes modulo rigid rotations and reparameterizations. The resulting sulcal shape atlas is shown to preserve important local geometry inherently present in the sample population. This is demonstrated in our experimental results for deep brain sulci, where we integrate the elastic shape model into surface registration framework for a population of 69 healthy young adult subjects.

  4. Incidental Diagnosis of Cerebral Cortical Venous Thrombosis in Postdural Puncture Headache on Brain Computed Tomography.

    Science.gov (United States)

    Humbertjean, Lisa; Ducrocq, Xavier; Lacour, Jean-Christophe; Mione, Gioia; Richard, Sébastien

    2015-01-01

    Diagnosis of cerebral cortical venous thrombosis in patients with postdural puncture headache (PDPH) is usually secondary to changes in headache pattern or cerebral infarctions. Nevertheless, incidental discovery of asymptomatic forms on brain imaging has never been reported before and its management thus remains ill-defined. We describe 2 cases of patients with asymptomatic cortical vein thrombosis in the context of PDPH. In both cases, brain computed tomography (CT) scans showed an isolated cortical vein thrombosis without cerebral damage. Neurological examination revealed the typical orthostatic feature of PDPH, independently of cortical vein thrombosis which was considered as a radiological incidental finding. Clinical and radiological signs resolved after bed rest, oral caffeine, and anticoagulation therapy. Asymptomatic cortical vein thrombosis may be found on radiological exploration, even basic like brain CT scan without contrast, of PDPH. Utility of anticoagulation therapy, which could increase the risk of cerebral hemorrhagic complications in this specific context, has to be assessed.

  5. Reduced cortical thickness of brain areas involved in pain processing in patients with chronic pancreatitis.

    NARCIS (Netherlands)

    Frokjaer, J.B.; Bouwense, S.A.W.; Olesen, S.S.; Lundager, F.H.; Eskildsen, S.F.; Goor, H. van; Wilder-Smith, O.H.G.; Drewes, A.M.

    2012-01-01

    BACKGROUND & AIMS: Patients with painful chronic pancreatitis (CP) might have abnormal brain function. We assessed cortical thickness in brain areas involved in visceral pain processing. METHODS: We analyzed brain morphologies of 19 patients with painful CP and compared them with 15 healthy individu

  6. Resting state brain activity and functional brain mapping

    Institute of Scientific and Technical Information of China (English)

    Zhao Xiaohu; Wang Peijun; Tang Xiaowei

    2007-01-01

    Functional brain imaging studies commonly use either resting or passive task states as their control conditions, and typically identify the activation brain region associated with a specific task by subtracting the resting from the active task conditions. Numerous studies now suggest, however, that the resting state may not reflect true mental "rest" conditions. The mental activity that occurs during"rest" might therefore greatly influence the functional neuroimaging observations that are collected through the usual subtracting analysis strategies. Exploring the ongoing mental processes that occur during resting conditions is thus of particular importance for deciphering functional brain mapping results and obtaining a more comprehensive understanding of human brain functions. In this review article, we will mainly focus on the discussion of the current research background of functional brain mapping at resting state and the physiological significance of the available neuroimaging data.

  7. Comparative proteomics of rat brain in the BCNU-induced model of cortical dysplasia

    Institute of Scientific and Technical Information of China (English)

    郭谊

    2014-01-01

    Objective To screen the differential proteins in the brain(neocortex and hippocampus)between the rats with cortical dysplasia(CD)and control ones,and investigate the role of their alteration in the development of epilepsy in CD.Methods Cortical dysplasia was induced in rat pups via in utero delivery of BCNU.A two-dimensional electrophoresis

  8. Slow cortical rhythms: from single-neuron electrophysiology to whole-brain imaging in vivo

    NARCIS (Netherlands)

    U. Olcese; U. Faraguna

    2015-01-01

    The slow cortical oscillation is the major brain rhythm occurring during sleep, and has been the object of thorough investigation for over thirty years. Despite all these efforts, the function and the neuronal mechanisms behind slow cortical rhythms remain only partially understood. In this review w

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

    Science.gov (United States)

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

    2017-01-18

    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.

  10. Whole-brain activity mapping onto a zebrafish brain atlas.

    Science.gov (United States)

    Randlett, Owen; Wee, Caroline L; Naumann, Eva A; Nnaemeka, Onyeka; Schoppik, David; Fitzgerald, James E; Portugues, Ruben; Lacoste, Alix M B; Riegler, Clemens; Engert, Florian; Schier, Alexander F

    2015-11-01

    In order to localize the neural circuits involved in generating behaviors, it is necessary to assign activity onto anatomical maps of the nervous system. Using brain registration across hundreds of larval zebrafish, we have built an expandable open-source atlas containing molecular labels and definitions of anatomical regions, the Z-Brain. Using this platform and immunohistochemical detection of phosphorylated extracellular signal–regulated kinase (ERK) as a readout of neural activity, we have developed a system to create and contextualize whole-brain maps of stimulus- and behavior-dependent neural activity. This mitogen-activated protein kinase (MAP)-mapping assay is technically simple, and data analysis is completely automated. Because MAP-mapping is performed on freely swimming fish, it is applicable to studies of nearly any stimulus or behavior. Here we demonstrate our high-throughput approach using pharmacological, visual and noxious stimuli, as well as hunting and feeding. The resultant maps outline hundreds of areas associated with behaviors.

  11. Macrostructural brain changes in patients with longstanding type 1 diabetes mellitus - a cortical thickness analysis study

    DEFF Research Database (Denmark)

    Frøkjær, J B; Brock, C; Søfteland, E;

    2013-01-01

    with longstanding (average 24.6 years) type 1 DM and 20 healthy controls were studied in a 3T magnetic resonance scanner. Using an automated surface based cortical segmentation method, cortical thickness was assessed in anatomical regions including total and lobe-wise grey and white matter volumes. Also...... peripheral neuropathy (P=0.02).Patients with longstanding type 1 diabetes showed cortical thinning involving sensory related areas, even though no overall macrostructural brain alterations were detected. This could possibly have underlying functional significance since cortical thinning was associated...

  12. eConnectome: A MATLAB toolbox for mapping and imaging of brain functional connectivity.

    Science.gov (United States)

    He, Bin; Dai, Yakang; Astolfi, Laura; Babiloni, Fabio; Yuan, Han; Yang, Lin

    2011-02-15

    We have developed a MATLAB-based toolbox, eConnectome (electrophysiological connectome), for mapping and imaging functional connectivity at both the scalp and cortical levels from the electroencephalogram (EEG), as well as from the electrocorticogram (ECoG). Graphical user interfaces were designed for interactive and intuitive use of the toolbox. Major functions of eConnectome include EEG/ECoG preprocessing, scalp spatial mapping, cortical source estimation, connectivity analysis, and visualization. Granger causality measures such as directed transfer function and adaptive directed transfer function were implemented to estimate the directional interactions of brain functional networks, over the scalp and cortical sensor spaces. Cortical current density inverse imaging was implemented using a generic realistic geometry brain-head model from scalp EEGs. Granger causality could be further estimated over the cortical source domain from the inversely reconstructed cortical source signals as derived from the scalp EEG. Users may implement other connectivity estimators in the framework of eConnectome for various applications. The toolbox package is open-source and freely available at http://econnectome.umn.edu under the GNU general public license for noncommercial and academic uses.

  13. Mapping synaptic pathology within cerebral cortical circuits in subjects with schizophrenia

    Directory of Open Access Journals (Sweden)

    Robert Sweet

    2010-06-01

    Full Text Available Converging lines of evidence indicate that schizophrenia is characterized by impairments of synaptic machinery within cerebral cortical circuits. Efforts to localize these alterations in brain tissue from subjects with schizophrenia have frequently been limited to the quantification of structures that are non-selectively identified (e.g. dendritic spines labeled in Golgi preparations, axon boutons labeled with synaptophysin, or to quantification of proteins using methods unable to resolve relevant cellular compartments. Multiple label fluorescence confocal microscopy represents a means to circumvent many of these limitations, by concurrently extracting information regarding the number, morphology, and relative protein content of synaptic structures. An important adaptation required for studies of human disease is coupling this approach to stereologic methods for systematic random sampling of relevant brain regions. In this review article we consider the application of multiple label fluorescence confocal microscopy to the mapping of synaptic alterations in subjects with schizophrenia and describe the application of a novel, readily automated, iterative intensity/morphological segmentation algorithm for the extraction of information regarding synaptic structure number, size, and relative protein level from tissue sections obtained using unbiased stereological principles of sampling. In this context, we provide examples of the examination of pre- and post-synaptic structures within excitatory and inhibitory circuits of the cerebral cortex.

  14. From perception to action: a spatiotemporal cortical map.

    Science.gov (United States)

    Crochet, Sylvain; Petersen, Carl C H

    2014-01-01

    In this issue of Neuron, Guo et al. (2014) optogenetically probe contributions of different cortical regions to tactile sensory perception, finding that somatosensory cortex is necessary for acquisition of sensory information and frontal cortex is necessary for planning motor output.

  15. Geometric Representation Of Visual Data In The Cortex Of Primates: Computer Reconstruction And Modeling Of Neo-Cortical Map And Column Systems

    Science.gov (United States)

    Schwartz, Eric

    1988-08-01

    Much of vertebrate midbrain and mammalian cortex is dedicated to two-dimensional "maps" in which two or more stimulus parameters are encoded by the position of neural activation in the map. Moreover, there are a large number of such maps which interact in an unknown fashion to yield a unified perception of the world. Our research program is based on studying the structure and function of brain maps. In the present paper, we review a recently constructed system of computer aided neuro-anatomy which allows high resolution texture mapped models of cortical surfaces in two and three dimensions to be displayed and manipulated. At the same time, this work demonstrates some of the basic geometric patterns of architecture of the primate brain, such as columnar and topographic mapping.

  16. Chronic imaging of cortical sensory map dynamics using a genetically encoded calcium indicator

    OpenAIRE

    Minderer, M; Liu, W.; Sumanovski, L. T.; Kügler, S; Helmchen, F; Margolis, D. J.

    2012-01-01

    Abstract  In vivo optical imaging can reveal the dynamics of large-scale cortical activity, but methods for chronic recording are limited. Here we present a technique for long-term investigation of cortical map dynamics using wide-field ratiometric fluorescence imaging of the genetically encoded calcium indicator (GECI) Yellow Cameleon 3.60. We find that wide-field GECI signals report sensory-evoked activity in anaesthetized mouse somatosensory cortex with high sensitivity and spatiotemporal ...

  17. Chronic imaging of cortical sensory map dynamics using a genetically encoded calcium indicator.

    Science.gov (United States)

    Minderer, Matthias; Liu, Wenrui; Sumanovski, Lazar T; Kügler, Sebastian; Helmchen, Fritjof; Margolis, David J

    2012-01-01

    In vivo optical imaging can reveal the dynamics of large-scale cortical activity, but methods for chronic recording are limited. Here we present a technique for long-term investigation of cortical map dynamics using wide-field ratiometric fluorescence imaging of the genetically encoded calcium indicator (GECI) Yellow Cameleon 3.60. We find that wide-field GECI signals report sensory-evoked activity in anaesthetized mouse somatosensory cortex with high sensitivity and spatiotemporal precision, and furthermore, can be measured repeatedly in separate imaging sessions over multiple weeks. This method opens new possibilities for the longitudinal study of stability and plasticity of cortical sensory representations.

  18. Prediction of brain maturity based on cortical thickness at different spatial resolutions.

    Science.gov (United States)

    Khundrakpam, Budhachandra S; Tohka, Jussi; Evans, Alan C

    2015-05-01

    Several studies using magnetic resonance imaging (MRI) scans have shown developmental trajectories of cortical thickness. Cognitive milestones happen concurrently with these structural changes, and a delay in such changes has been implicated in developmental disorders such as attention-deficit/hyperactivity disorder (ADHD). Accurate estimation of individuals' brain maturity, therefore, is critical in establishing a baseline for normal brain development against which neurodevelopmental disorders can be assessed. In this study, cortical thickness derived from structural magnetic resonance imaging (MRI) scans of a large longitudinal dataset of normally growing children and adolescents (n=308), were used to build a highly accurate predictive model for estimating chronological age (cross-validated correlation up to R=0.84). Unlike previous studies which used kernelized approach in building prediction models, we used an elastic net penalized linear regression model capable of producing a spatially sparse, yet accurate predictive model of chronological age. Upon investigating different scales of cortical parcellation from 78 to 10,240 brain parcels, we observed that the accuracy in estimated age improved with increased spatial scale of brain parcellation, with the best estimations obtained for spatial resolutions consisting of 2560 and 10,240 brain parcels. The top predictors of brain maturity were found in highly localized sensorimotor and association areas. The results of our study demonstrate that cortical thickness can be used to estimate individuals' brain maturity with high accuracy, and the estimated ages relate to functional and behavioural measures, underscoring the relevance and scope of the study in the understanding of biological maturity.

  19. Synapse-centric mapping of cortical models to the SpiNNaker neuromorphic architecture

    Directory of Open Access Journals (Sweden)

    James Courtney Knight

    2016-09-01

    Full Text Available While the adult human brain has approximately 8.8x10^10 neurons, this number is dwarfed by its 1x10^15 synapses. From the point of view of neuromorphic engineering and neural simulation in general this makes the simulation of these synapses a particularly complex problem. SpiNNaker is a digital, neuromorphic architecture designed for simulating large-scale spiking neural networks at speeds close to biological real-time. Current solutions for simulating spiking neural networks on SpiNNaker are heavily inspired by work on distributed high-performance computing. However, while SpiNNaker shares many characteristics with such distributed systems, its component nodes have much more limited resources and, as the system lacks global synchronization, the computation performed on each node must complete within a fixed time step. We first analyze the performance of the current SpiNNaker neural simulation software and identify several problems that occur when it is used to simulate networks of the type often used to model the cortex which contain large numbers of sparsely connected synapses. We then present a new, more flexible approach for mapping the simulation of such networks to SpiNNaker which solves many of these problems. Finally we analyze the performance of our new approach using both benchmarks, designed to represent cortical connectivity, and larger, functional cortical models. In a benchmark network where neurons receive input from 8000 STDP synapses, our new approach allows more neurons to be simulated on each SpiNNaker core than has been previously possible. We also demonstrate that the largest plastic neural network previously simulated on neuromorphic hardware can be run in real time using our new approach: double the speed that was previously achieved. Additionally this network contains two types of plastic synapse which previously had to be trained separately but, using our new approach, can be trained simultaneously.

  20. Synapse-Centric Mapping of Cortical Models to the SpiNNaker Neuromorphic Architecture.

    Science.gov (United States)

    Knight, James C; Furber, Steve B

    2016-01-01

    While the adult human brain has approximately 8.8 × 10(10) neurons, this number is dwarfed by its 1 × 10(15) synapses. From the point of view of neuromorphic engineering and neural simulation in general this makes the simulation of these synapses a particularly complex problem. SpiNNaker is a digital, neuromorphic architecture designed for simulating large-scale spiking neural networks at speeds close to biological real-time. Current solutions for simulating spiking neural networks on SpiNNaker are heavily inspired by work on distributed high-performance computing. However, while SpiNNaker shares many characteristics with such distributed systems, its component nodes have much more limited resources and, as the system lacks global synchronization, the computation performed on each node must complete within a fixed time step. We first analyze the performance of the current SpiNNaker neural simulation software and identify several problems that occur when it is used to simulate networks of the type often used to model the cortex which contain large numbers of sparsely connected synapses. We then present a new, more flexible approach for mapping the simulation of such networks to SpiNNaker which solves many of these problems. Finally we analyze the performance of our new approach using both benchmarks, designed to represent cortical connectivity, and larger, functional cortical models. In a benchmark network where neurons receive input from 8000 STDP synapses, our new approach allows 4× more neurons to be simulated on each SpiNNaker core than has been previously possible. We also demonstrate that the largest plastic neural network previously simulated on neuromorphic hardware can be run in real time using our new approach: double the speed that was previously achieved. Additionally this network contains two types of plastic synapse which previously had to be trained separately but, using our new approach, can be trained simultaneously.

  1. Adult Pilomyxoid Astrocytoma Mimicking a Cortical Brain Tumor: MR Imaging Findings

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jong Chang; Weon, Young Cheol; Suh, Jae Hee; Kim, Young; Hwang, Jae Cheol [Ulsan University Hospital, Ulsan (Korea, Republic of)

    2010-08-15

    A pilomyxoid astrocytoma (PMA) is a recently identified low-grade neoplasm that was previously classified as a pilocytic astrocytoma (PA), yet demonstrates unique histological features and more aggressive behavior. Although a PMA is generally a tumor of early childhood and typically occurs in the hypothalamic/chiasmatic region, it can mimic cortical tumors, especially in adults. We report the MR findings of a PMA presenting as a cortical brain tumor in an adult with neurofibromatosis 1 (NF1)

  2. Cortical neuron loss in post-traumatic higher brain dysfunction using (123)I-iomazenil SPECT.

    Science.gov (United States)

    Nakagawara, Jyoji; Kamiyama, Kenji; Takahashi, Masaaki; Nakamura, Hirohiko

    2013-01-01

    In patients with higher brain dysfunction (HBD) after mild traumatic brain injury (MTBI), diagnostic imaging of cortical neuron loss in the frontal lobes was studied using SPECT with (123)I-iomazenil (IMZ), as a radioligand for central benzodiazepine receptor (BZR). Statistical imaging analysis using three-dimensional stereotactic surface projections (3D-SSP) for (123)I-IMZ SPECT was performed in 17 patients. In all patients with HBD defined by neuropsychological tests, cortical neuron loss was indicated in the bilateral medial frontal lobes in 14 patients (83 %). A comparison between the group of 17 patients and the normal database demonstrated common areas of cortical neuron loss in the bilateral medial frontal lobes involving the medial frontal gyrus (MFG) and the anterior cingulate gyrus (ACG). In an assessment of cortical neuron loss in the frontal medial cortex using the stereotactic extraction estimation (SEE) method (level 3), significant cortical neuron loss was observed within bilateral MFG in 9 patients and unilateral MFG in 4, and bilateral ACG in 12 and unilateral ACG in 3. Fourteen patients showed significant cortical neuron loss in bilateral MFG or ACG. In patients with MTBI, HBD seemed to correlate with selective cortical neuron loss within the bilateral MFG or ACG where the responsible lesion could be. 3D-SSP and SEE level 3 analysis for (123)I-IMZ SPECT could be valuable for diagnostic imaging of HBD after MTBI.

  3. Modeling Pediatric Brain Trauma: Piglet Model of Controlled Cortical Impact.

    Science.gov (United States)

    Pareja, Jennifer C Munoz; Keeley, Kristen; Duhaime, Ann-Christine; Dodge, Carter P

    2016-01-01

    The brain has different responses to traumatic injury as a function of its developmental stage. As a model of injury to the immature brain, the piglet shares numerous similarities in regards to morphology and neurodevelopmental sequence compared to humans. This chapter describes a piglet scaled focal contusion model of traumatic brain injury that accounts for the changes in mass and morphology of the brain as it matures, facilitating the study of age-dependent differences in response to a comparable mechanical trauma.

  4. Brain mapping in a patient with congenital blindness – a case for multimodal approaches

    Directory of Open Access Journals (Sweden)

    Jarod L Roland

    2013-07-01

    Full Text Available Recent advances in basic neuroscience research across a wide range of methodologies have contributed significantly to our understanding of human cortical electrophysiology and functional brain imaging. Translation of this research into clinical neurosurgery has opened doors for advanced mapping of functionality that previously was prohibitively difficult, if not impossible. Here we present the case of a unique individual with congenital blindness and medically refractory epilepsy who underwent neurosurgical treatment of her seizures. Pre-operative evaluation presented the challenge of accurately and robustly mapping the cerebral cortex for an individual with a high probability of significant cortical re-organization. Additionally, a blind individual has unique priorities in one’s ability to read Braille by touch and sense the environment primarily by sound than the non-vision impaired person. For these reasons we employed additional measures to map sensory, motor, speech, language, and auditory perception by employing a number of cortical electrophysiologic mapping and functional magnetic resonance imaging methods. Our data show promising results in the application of these adjunctive methods in the pre-operative mapping of otherwise difficult to localize, and highly variable, functional cortical areas.

  5. The relationship between brain cortical activity and brain oxygenation in the prefrontal cortex during hypergravity exposure.

    Science.gov (United States)

    Smith, Craig; Goswami, Nandu; Robinson, Ryan; von der Wiesche, Melanie; Schneider, Stefan

    2013-04-01

    Artificial gravity has been proposed as a method to counteract the physiological deconditioning of long-duration spaceflight; however, the effects of hypergravity on the central nervous system has had little study. The study aims to investigate whether there is a relationship between prefrontal cortex brain activity and prefrontal cortex oxygenation during exposure to hypergravity. Twelve healthy participants were selected to undergo hypergravity exposure aboard a short-arm human centrifuge. Participants were exposed to hypergravity in the +Gz axis, starting from 0.6 +Gz for women, and 0.8 +Gz for men, and gradually increasing by 0.1 +Gz until the participant showed signs of syncope. Brain cortical activity was measured using electroencephalography (EEG) and localized to the prefrontal cortex using standard low-resolution brain electromagnetic tomography (LORETA). Prefrontal cortex oxygenation was measured using near-infrared spectroscopy (NIRS). A significant increase in prefrontal cortex activity (P Prefrontal cortex oxygenation was significantly decreased during hypergravity exposure, with a decrease in oxyhemoglobin levels (P prefrontal cortex activity and oxy-/deoxyhemoglobin. It is concluded that the increase in prefrontal cortex activity observed during hypergravity was most likely not the result of increased +Gz values resulting in a decreased oxygenation produced through hypergravity exposure. No significant relationship between prefrontal cortex activity and oxygenation measured by NIRS concludes that brain activity during exposure to hypergravity may be difficult to measure using NIRS. Instead, the increase in prefrontal cortex activity might be attributable to psychological stress, which could pose a problem for the use of a short-arm human centrifuge as a countermeasure.

  6. Sensory cortical re-mapping following upper-limb amputation and subsequent targeted reinnervation: A case report

    Directory of Open Access Journals (Sweden)

    Jun Yao

    2015-01-01

    Full Text Available This case study demonstrates the change of sensory cortical representations of the residual parts of the arm in an individual who underwent a trans-humeral amputation and subsequent targeted reinnervation (TR. As a relatively new surgical technique, TR restores a direct neural connection from amputated sensorimotor nerves to specific target muscles. This method has been successfully applied to upper-limb and lower-limb amputees, and has shown effectiveness in regaining control signals via the newly re-innervated muscles. Correspondingly, recent study results have shown that motor representations for the missing limb move closer to their original locations following TR. Besides regaining motor control signals, TR also restores the sensation in the re-innervated skin areas. We therefore hypothesize that TR causes analogous cortical sensory remapping that may return closer to their original locations. In order to test this hypothesis, cortical activity in response to sensory-level electrical stimulation in different parts of the arm was studied longitudinally in one amputated individual before and up to 2 years after TR. Our results showed that 1 before TR, the cortical response to sensory electrical stimulation in the residual limb showed a diffuse bilateral pattern without a clear focus in either the time or spatial domain; and 2 2 years after TR, the sensory map of the reinnervated median nerve reorganized, showing predominant activity over the contralateral S1 hand area as well as moderate activity over the ipsilateral S1. Therefore, this work provides new evidence for long-term sensory cortical plasticity in the human brain after TR.

  7. Sensory cortical re-mapping following upper-limb amputation and subsequent targeted reinnervation: A case report.

    Science.gov (United States)

    Yao, Jun; Chen, Albert; Kuiken, Todd; Carmona, Carolina; Dewald, Julius

    2015-01-01

    This case study demonstrates the change of sensory cortical representations of the residual parts of the arm in an individual who underwent a trans-humeral amputation and subsequent targeted reinnervation (TR). As a relatively new surgical technique, TR restores a direct neural connection from amputated sensorimotor nerves to specific target muscles. This method has been successfully applied to upper-limb and lower-limb amputees, and has shown effectiveness in regaining control signals via the newly re-innervated muscles. Correspondingly, recent study results have shown that motor representations for the missing limb move closer to their original locations following TR. Besides regaining motor control signals, TR also restores the sensation in the re-innervated skin areas. We therefore hypothesize that TR causes analogous cortical sensory remapping that may return closer to their original locations. In order to test this hypothesis, cortical activity in response to sensory-level electrical stimulation in different parts of the arm was studied longitudinally in one amputated individual before and up to 2 years after TR. Our results showed that 1) before TR, the cortical response to sensory electrical stimulation in the residual limb showed a diffuse bilateral pattern without a clear focus in either the time or spatial domain; and 2) 2 years after TR, the sensory map of the reinnervated median nerve reorganized, showing predominant activity over the contralateral S1 hand area as well as moderate activity over the ipsilateral S1. Therefore, this work provides new evidence for long-term sensory cortical plasticity in the human brain after TR.

  8. Brain volumetrics, regional cortical thickness and radiographic findings in children with cyanotic congenital heart disease using quantitative magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Alsiagy A. Salama, M.D.

    2016-12-01

    Conclusions: Children with CCHD show MRI evidence of micro- and macro vascular injury, reduced brain volume and cortical thickness. Brain volume loss correlated with hsCRP, oxygen saturation and packed cell volume.

  9. Mapping how local perturbations influence systems-level brain dynamics

    OpenAIRE

    Gollo, Leonardo L.; James A. Roberts; Cocchi, Luca

    2016-01-01

    The human brain exhibits a relatively stable spatiotemporal organization that supports brain function and can be manipulated via local brain stimulation. Such perturbations to local cortical dynamics are globally integrated by distinct neural systems. However, it remains unclear how and why local changes in neural activity affect large-scale system dynamics. Here, we briefly review empirical and computational studies addressing how localized perturbations affect brain activity. We then system...

  10. A new cortical thickness mapping method with application to an in vivo finite element model.

    Science.gov (United States)

    Kim, Young Ho; Kim, Jong-Eun; Eberhardt, Alan W

    2014-01-01

    Finite element modelling of musculoskeletal systems, with geometrical structures constructed from computed tomography (CT) scans, is a useful and powerful tool for biomechanical studies. The use of CT scans from living human subjects, however, is still limited. Accurate reconstruction of thin cortical bone structures from CT scans of living human subjects is especially problematic, due to low CT resolution that results from mandatory low radiation doses and/or involuntary movements of the subject. In this study, a new method for mapping cortical thickness is described. Using the method, cortical thickness measurements of a coxal (pelvis) bone obtained from CT scans of a cadaver were mapped to the coxal geometry as obtained through CT scans of a live human subject, resulting in accurate cortical thickness while maintaining geometric fidelity of the live subject. The mapping procedure includes shape-preserving parameterisation, mesh movement and interpolation of thickness using a search algorithm. The methodology is applicable to modelling of other bones where accurate cortical thickness is needed and for which such data exist.

  11. Learning strategy refinement reverses early sensory cortical map expansion but not behavior: Support for a theory of directed cortical substrates of learning and memory.

    Science.gov (United States)

    Elias, Gabriel A; Bieszczad, Kasia M; Weinberger, Norman M

    2015-12-01

    Primary sensory cortical fields develop highly specific associative representational plasticity, notably enlarged area of representation of reinforced signal stimuli within their topographic maps. However, overtraining subjects after they have solved an instrumental task can reduce or eliminate the expansion while the successful behavior remains. As the development of this plasticity depends on the learning strategy used to solve a task, we asked whether the loss of expansion is due to the strategy used during overtraining. Adult male rats were trained in a three-tone auditory discrimination task to bar-press to the CS+ for water reward and refrain from doing so during the CS- tones and silent intertrial intervals; errors were punished by a flashing light and time-out penalty. Groups acquired this task to a criterion within seven training sessions by relying on a strategy that was "bar-press from tone-onset-to-error signal" ("TOTE"). Three groups then received different levels of overtraining: Group ST, none; Group RT, one week; Group OT, three weeks. Post-training mapping of their primary auditory fields (A1) showed that Groups ST and RT had developed significantly expanded representational areas, specifically restricted to the frequency band of the CS+ tone. In contrast, the A1 of Group OT was no different from naïve controls. Analysis of learning strategy revealed this group had shifted strategy to a refinement of TOTE in which they self-terminated bar-presses before making an error ("iTOTE"). Across all animals, the greater the use of iTOTE, the smaller was the representation of the CS+ in A1. Thus, the loss of cortical expansion is attributable to a shift or refinement in strategy. This reversal of expansion was considered in light of a novel theoretical framework (CONCERTO) highlighting four basic principles of brain function that resolve anomalous findings and explaining why even a minor change in strategy would involve concomitant shifts of involved brain

  12. Mapping functional brain development: Building a social brain through interactive specialization.

    Science.gov (United States)

    Johnson, Mark H; Grossmann, Tobias; Cohen Kadosh, Kathrin

    2009-01-01

    The authors review a viewpoint on human functional brain development, interactive specialization (IS), and its application to the emerging network of cortical regions referred to as the social brain. They advance the IS view in 2 new ways. First, they extend IS into a domain to which it has not previously been applied--the emergence of social cognition and mentalizing computations in the brain. Second, they extend the implications of the IS view from the emergence of specialized functions within a cortical region to a focus on how different cortical regions with complementary functions become orchestrated into networks during human postnatal development.

  13. A case of hypoglycemic brain injuries with cortical laminar necrosis.

    Science.gov (United States)

    Lee, Byung-Wan; Jin, Eun Sun; Hwang, Hyung-Sik; Yoo, Hyung-Joon; Jeong, Je Hoon

    2010-06-01

    We report a case of 68-yr-old male who died from brain injuries following an episode of prolonged hypoglycemia. While exploring controversies surrounding magnetic resonance imaging (MRI) findings indicating the bad prognosis in patients with hypoglycemia-induced brain injuries, we here discuss interesting diffusion-MRI of hypoglycemic brain injuries and their prognostic importance focusing on laminar necrosis of the cerebral cortex.

  14. Mind the blind brain to understand the sighted one! Is there a supramodal cortical functional architecture?

    Science.gov (United States)

    Ricciardi, Emiliano; Bonino, Daniela; Pellegrini, Silvia; Pietrini, Pietro

    2014-04-01

    While most of the research in blind individuals classically has focused on the compensatory plastic rearrangements that follow loss of sight, novel behavioral, anatomical and functional brain studies in individuals born deprived of sight represent a powerful tool to understand to what extent the brain functional architecture is programmed to develop independently from any visual experience. Here we review work from our lab and others, conducted in sighted and congenitally blind individuals, whose results indicate that vision is not a mandatory prerequisite for the brain cortical organization to develop and function. Similar cortical networks subtend visual and/or non-visual perception of form, space and movement, as well as action recognition, both in sighted and in congenitally blind individuals. These findings support the hypothesis of a modality independent, supramodal cortical organization. Visual experience, however, does play a role in shaping specific cortical sub-regions, as loss of sight is accompanied also by cross-modal plastic phenomena. Altogether, studying the blind brain is opening our eyes on how the brain develops and works.

  15. 4D segmentation of brain MR images with constrained cortical thickness variation.

    Directory of Open Access Journals (Sweden)

    Li Wang

    Full Text Available Segmentation of brain MR images plays an important role in longitudinal investigation of developmental, aging, disease progression changes in the cerebral cortex. However, most existing brain segmentation methods consider multiple time-point images individually and thus cannot achieve longitudinal consistency. For example, cortical thickness measured from the segmented image will contain unnecessary temporal variations, which will affect the time related change pattern and eventually reduce the statistical power of analysis. In this paper, we propose a 4D segmentation framework for the adult brain MR images with the constraint of cortical thickness variations. Specifically, we utilize local intensity information to address the intensity inhomogeneity, spatial cortical thickness constraint to maintain the cortical thickness being within a reasonable range, and temporal cortical thickness variation constraint in neighboring time-points to suppress the artificial variations. The proposed method has been tested on BLSA dataset and ADNI dataset with promising results. Both qualitative and quantitative experimental results demonstrate the advantage of the proposed method, in comparison to other state-of-the-art 4D segmentation methods.

  16. A Brain-Machine-Brain Interface for Rewiring of Cortical Circuitry after Traumatic Brain Injury

    Science.gov (United States)

    2011-09-01

    lesion vi- cinity, from approximately 3.7 mm anterior to the bregma to 3.2 mm posterior to the bregma, were then collected using a cryostat ( Paxinos and...mice. J. Neurotrauma 25, 153–171. Paxinos , G., and Watson, C. (2007). The Rat Brain in Stereotaxic Coordinates, 6th ed. Academic Press: New York

  17. Regional brain differences in cortical thickness, surface area and subcortical volume in individuals with Williams syndrome.

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    Shashwath A Meda

    Full Text Available Williams syndrome (WS is a rare genetic neurodevelopmental disorder characterized by increased non-social anxiety, sensitivity to sounds and hypersociability. Previous studies have reported contradictory findings with regard to regional brain variation in WS, relying on only one type of morphological measure (usually volume in each study. The present study aims to contribute to this body of literature and perhaps elucidate some of these discrepancies by examining concurrent measures of cortical thickness, surface area and subcortical volume between WS subjects and typically-developing (TD controls. High resolution MRI scans were obtained on 31 WS subjects and 50 typically developing control subjects. We derived quantitative regional estimates of cortical thickness, cortical surface area, and subcortical volume using FreeSurfer software. We evaluated between-group ROI differences while controlling for total intracranial volume. In post-hoc exploratory analyses within the WS group, we tested for correlations between regional brain variation and Beck Anxiety Inventory scores. Consistent with our hypothesis, we detected complex patterns of between-group cortical variation, which included lower surface area in combination with greater thickness in the following cortical regions: post central gyrus, cuneus, lateral orbitofrontal cortex and lingual gyrus. Additional cortical regions showed between-group differences in one (but not both morphological measures. Subcortical volume was lower in the basal ganglia and the hippocampus in WS versus TD controls. Exploratory correlations revealed that anxiety scores were negatively correlated with gray matter surface area in insula, OFC, rostral middle frontal, superior temporal and lingual gyrus. Our results were consistent with previous reports showing structural alterations in regions supporting the socio-affective and visuospatial impairments in WS. However, we also were able to effectively capture novel and

  18. Regional brain differences in cortical thickness, surface area and subcortical volume in individuals with Williams syndrome.

    Science.gov (United States)

    Meda, Shashwath A; Pryweller, Jennifer R; Thornton-Wells, Tricia A

    2012-01-01

    Williams syndrome (WS) is a rare genetic neurodevelopmental disorder characterized by increased non-social anxiety, sensitivity to sounds and hypersociability. Previous studies have reported contradictory findings with regard to regional brain variation in WS, relying on only one type of morphological measure (usually volume) in each study. The present study aims to contribute to this body of literature and perhaps elucidate some of these discrepancies by examining concurrent measures of cortical thickness, surface area and subcortical volume between WS subjects and typically-developing (TD) controls. High resolution MRI scans were obtained on 31 WS subjects and 50 typically developing control subjects. We derived quantitative regional estimates of cortical thickness, cortical surface area, and subcortical volume using FreeSurfer software. We evaluated between-group ROI differences while controlling for total intracranial volume. In post-hoc exploratory analyses within the WS group, we tested for correlations between regional brain variation and Beck Anxiety Inventory scores. Consistent with our hypothesis, we detected complex patterns of between-group cortical variation, which included lower surface area in combination with greater thickness in the following cortical regions: post central gyrus, cuneus, lateral orbitofrontal cortex and lingual gyrus. Additional cortical regions showed between-group differences in one (but not both) morphological measures. Subcortical volume was lower in the basal ganglia and the hippocampus in WS versus TD controls. Exploratory correlations revealed that anxiety scores were negatively correlated with gray matter surface area in insula, OFC, rostral middle frontal, superior temporal and lingual gyrus. Our results were consistent with previous reports showing structural alterations in regions supporting the socio-affective and visuospatial impairments in WS. However, we also were able to effectively capture novel and complex

  19. Targeted enhancement of cortical-hippocampal brain networks and associative memory.

    Science.gov (United States)

    Wang, Jane X; Rogers, Lynn M; Gross, Evan Z; Ryals, Anthony J; Dokucu, Mehmet E; Brandstatt, Kelly L; Hermiller, Molly S; Voss, Joel L

    2014-08-29

    The influential notion that the hippocampus supports associative memory by interacting with functionally distinct and distributed brain regions has not been directly tested in humans. We therefore used targeted noninvasive electromagnetic stimulation to modulate human cortical-hippocampal networks and tested effects of this manipulation on memory. Multiple-session stimulation increased functional connectivity among distributed cortical-hippocampal network regions and concomitantly improved associative memory performance. These alterations involved localized long-term plasticity because increases were highly selective to the targeted brain regions, and enhancements of connectivity and associative memory persisted for ~24 hours after stimulation. Targeted cortical-hippocampal networks can thus be enhanced noninvasively, demonstrating their role in associative memory.

  20. Childhood cognitive ability accounts for associations between cognitive ability and brain cortical thickness in old age.

    Science.gov (United States)

    Karama, S; Bastin, M E; Murray, C; Royle, N A; Penke, L; Muñoz Maniega, S; Gow, A J; Corley, J; Valdés Hernández, M del C; Lewis, J D; Rousseau, M-É; Lepage, C; Fonov, V; Collins, D L; Booth, T; Rioux, P; Sherif, T; Adalat, R; Starr, J M; Evans, A C; Wardlaw, J M; Deary, I J

    2014-05-01

    Associations between brain cortical tissue volume and cognitive function in old age are frequently interpreted as suggesting that preservation of cortical tissue is the foundation of successful cognitive aging. However, this association could also, in part, reflect a lifelong association between cognitive ability and cortical tissue. We analyzed data on 588 subjects from the Lothian Birth Cohort 1936 who had intelligence quotient (IQ) scores from the same cognitive test available at both 11 and 70 years of age as well as high-resolution brain magnetic resonance imaging data obtained at approximately 73 years of age. Cortical thickness was estimated at 81 924 sampling points across the cortex for each subject using an automated pipeline. Multiple regression was used to assess associations between cortical thickness and the IQ measures at 11 and 70 years. Childhood IQ accounted for more than two-third of the association between IQ at 70 years and cortical thickness measured at age 73 years. This warns against ascribing a causal interpretation to the association between cognitive ability and cortical tissue in old age based on assumptions about, and exclusive reference to, the aging process and any associated disease. Without early-life measures of cognitive ability, it would have been tempting to conclude that preservation of cortical thickness in old age is a foundation for successful cognitive aging when, instead, it is a lifelong association. This being said, results should not be construed as meaning that all studies on aging require direct measures of childhood IQ, but as suggesting that proxy measures of prior cognitive function can be useful to take into consideration.

  1. Higher cortical modulation of pain perception in the human brain: Psychological determinant.

    Science.gov (United States)

    Chen, Andrew Cn

    2009-10-01

    Pain perception and its genesis in the human brain have been reviewed recently. In the current article, the reports on pain modulation in the human brain were reviewed from higher cortical regulation, i.e. top-down effect, particularly studied in psychological determinants. Pain modulation can be examined by gene therapy, physical modulation, pharmacological modulation, psychological modulation, and pathophysiological modulation. In psychological modulation, this article examined (a) willed determination, (b) distraction, (c) placebo, (d) hypnosis, (e) meditation, (f) qi-gong, (g) belief, and (h) emotions, respectively, in the brain function for pain modulation. In each, the operational definition, cortical processing, neuroimaging, and pain modulation were systematically deliberated. However, not all studies had featured the brain modulation processing but rather demonstrated potential effects on human pain. In our own studies on the emotional modulation on human pain, we observed that emotions could be induced from music melodies or pictures perception for reduction of tonic human pain, mainly in potentiation of the posterior alpha EEG fields, likely resulted from underneath activities of precuneous in regulation of consciousness, including pain perception. To sum, higher brain functions become the leading edge research in all sciences. How to solve the information bit of thinking and feeling in the brain can be the greatest challenge of human intelligence. Application of higher cortical modulation of human pain and suffering can lead to the progress of social humanity and civilization.

  2. Mean cortical curvature reflects cytoarchitecture restructuring in mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Jace B. King

    2016-01-01

    Full Text Available In the United States alone, the number of persons living with the enduring consequences of traumatic brain injuries is estimated to be between 3.2 and 5 million. This number does not include individuals serving in the United States military or seeking care at Veterans Affairs hospitals. The importance of understanding the neurobiological consequences of mild traumatic brain injury (mTBI has increased with the return of veterans from conflicts overseas, many of who have suffered this type of brain injury. However, identifying the neuroanatomical regions most affected by mTBI continues to prove challenging. The aim of this study was to assess the use of mean cortical curvature as a potential indicator of progressive tissue loss in a cross-sectional sample of 54 veterans with mTBI compared to 31 controls evaluated with MRI. It was hypothesized that mean cortical curvature would be increased in veterans with mTBI, relative to controls, due in part to cortical restructuring related to tissue volume loss. Mean cortical curvature was assessed in 60 bilateral regions (31 sulcal, 29 gyral. Of the 120 regions investigated, nearly 50% demonstrated significantly increased mean cortical curvature in mTBI relative to controls with 25% remaining significant following multiple comparison correction (all, pFDR < .05. These differences were most prominent in deep gray matter regions of the cortex. Additionally, significant relationships were found between mean cortical curvature and gray and white matter volumes (all, p < .05. These findings suggest potentially unique patterns of atrophy by region and indicate that changes in brain microstructure due to mTBI are sensitive to measures of mean curvature.

  3. A Brain-Machine-Brain Interface for Rewiring of Cortical Circuitry after Traumatic Brain Injury

    Science.gov (United States)

    2014-09-01

    Task 1 (Electronics Testing/Microsystem Packaging) 1.1 Conduct in vivo experiments in brain-injured monkeys using a fully assembled microsystem...rodent studies in constructing the microsystem for non- human primate (squirrel monkey ) studies. This is because the capabilities of the rat ASIC (e.g...Aplysia californica (see Appendix II). In Year 4, the SAR algorithm was integrated on an ASIC that combined spike recording, electrical microstimulation

  4. Direct cortical stimulation but not transcranial electrical stimulation motor evoked potentials detect brain ischemia during brain tumor resection.

    Science.gov (United States)

    Li, Fenghua; Deshaies, Eric M; Allott, Geoffrey; Canute, Gregory; Gorji, Reza

    2011-09-01

    Motor evoked potentials (MEPs) elicited by both direct cortical stimulation (DCS) and transcranial electrical stimulation are used during brain tumor resection. Parallel use of direct cortical stimulation motor evoked potentials (DCS-MEPs) and transcranial electrical stimulation motor evoked potentials (TCeMEPs) has been practiced during brain tumor resection. We report that DCS-MEPs elicited by direct subdural grid stimulation, but not TCeMEPs, detected brain ischemia during brain tumor resection. Following resection of a brainstem high-grade glioma in a 21-year-old, the threshold of cortical motor-evoked-potentials (cMEPs) increased from 13 mA to 20 mA while amplitudes decreased. No changes were noted in transcranial motor evoked potentials (TCMEPs), somatosensory evoked potentials (SSEPs), auditory evoked potentials (AEPs), anesthetics, or hemodynamic parameters. Our case showed the loss of cMEPs and SSEPs, but not TCeMEPs. Permanent loss of DCS-MEPs and SSEPs was correlated with permanent left hemiplegia in our patient even when appropriate action was taken. Parallel use of DCS- and TCeMEPs with SSEPs improves sensitivity of intraoperative detection of motor impairment. DCS may be superior to TCeMEPs during brain tumor resection.

  5. Conformal mapping via metric optimization with application for cortical label fusion.

    Science.gov (United States)

    Shi, Yonggang; Lai, Rongjie; Toga, Arthur W

    2013-01-01

    In this paper we develop a novel approach for computing conformal maps between anatomical surfaces with the ability of aligning anatomical features and achieving greatly reduced metric distortion. In contrast to conventional approaches that focused on conformal maps to the sphere or plane, our method computes the conformal map between surfaces in the embedding space formed the intrinsically defined Laplace-Beltrami (LB) eigenfunctions. Utilizing the power of LB eigenfunctions as informative descriptors of global geometry, the conformal maps computed by our method can effectively align anatomical features on cortical surfaces. By computing such feature-aware conformal maps to a group-wisely optimal atlas surface, which is also computed with metric optimization in the LB embedding space, we develop a fully automated system for cortical labeling with the fusion of labels on a large number of atlas surfaces. In our experiments, we build our system with 40 labeled surfaces and demonstrate its excellent performance with leave-one-out cross validation. We also applied the automated labeling system to cortical surfaces reconstructed from MR scans of 50 patients with Alzheimer's disease (AD) and 50 normal controls (NC) to illustrate its robustness and effectiveness in clinical data analysis.

  6. Disruption of Transient Serotonin Accumulation by Non-Serotonin-Producing Neurons Impairs Cortical Map Development

    Directory of Open Access Journals (Sweden)

    Xiaoning Chen

    2015-01-01

    Full Text Available Polymorphisms that alter serotonin transporter SERT expression and functionality increase the risks for autism and psychiatric traits. Here, we investigate how SERT controls serotonin signaling in developing CNS in mice. SERT is transiently expressed in specific sets of glutamatergic neurons and uptakes extrasynaptic serotonin during perinatal CNS development. We show that SERT expression in glutamatergic thalamocortical axons (TCAs dictates sensory map architecture. Knockout of SERT in TCAs causes lasting alterations in TCA patterning, spatial organizations of cortical neurons, and dendritic arborization in sensory cortex. Pharmacological reduction of serotonin synthesis during the first postnatal week rescues sensory maps in SERTGluΔ mice. Furthermore, knockdown of SERT expression in serotonin-producing neurons does not impair barrel maps. We propose that spatiotemporal SERT expression in non-serotonin-producing neurons represents a determinant in early life genetic programming of cortical circuits. Perturbing this SERT function could be involved in the origin of sensory and cognitive deficits associated with neurodevelopmental disorders.

  7. Cortical activity in the left and right hemispheres during language-related brain functions

    DEFF Research Database (Denmark)

    Lassen, N A; Larsen, B

    1980-01-01

    The blood flow to a given brain region increases as the level of neural activity is augmented. Hence mapping of variations in regional cerebral blood flow affords a means of imaging the activity of various brain regions during various types of brain work. The paper summarizes the patterns...

  8. Neuroblast Distribution After Cortical Impact is Influenced by White Matter Injury in the Immature Gyrencephalic Brain.

    Directory of Open Access Journals (Sweden)

    Sabrina Taylor

    2016-08-01

    Full Text Available Cortical contusions are a common type of traumatic brain injury (TBI in children. Current knowledge of neuroblast response to cortical injury arises primarily from studies utilizing aspiration or cryoinjury in rodents. In infants and children, cortical impact affects both gray and white matter and any neurogenic response may be complicated by the large expanse of white matter between the subventricular zone (SVZ and the cortex, and the large number of neuroblasts in transit along the major white matter tracts to populate brain regions. Previously, we described an age-dependent increase of neuroblasts in the SVZ in response to cortical impact in the immature gyrencephalic brain. Here, we investigate if neuroblasts target the injury, if white matter injury influences repair efforts, and if postnatal population of brain regions are disrupted. Piglets received a cortical impact to the rostral gyrus cortex or sham surgery at postnatal day (PND 7, BrdU 2 days prior to (PND 5 and 6 or after injury (PND 7 and 8, and brains were collected at PND 14. Injury did not alter the number of neuroblasts in the white matter between the SVZ and the rostral gyrus. In the gray matter of the injury site, neuroblast density was increased in cavitated lesions, and the number of BrdU+ neuroblasts was increased, but comprised less than 1% of all neuroblasts. In the white matter of the injury site, neuroblasts with differentiating morphology were densely arranged along the cavity edge. In a ventral migratory stream, neuroblast density was greater in subjects with a cavitated lesion, indicating that TBI may alter postnatal development of regions supplied by that stream. Cortical impact in the immature gyrencephalic brain produced complicated and variable lesions, increased neuroblast density in cavitated gray matter, resulted in potentially differentiating neuroblasts in the white matter, and may alter the postnatal population of brain regions utilizing a population of

  9. The slowed brain: cortical oscillatory activity in hepatic encephalopathy.

    Science.gov (United States)

    Butz, Markus; May, Elisabeth S; Häussinger, Dieter; Schnitzler, Alfons

    2013-08-15

    Oscillatory activity of the human brain has received growing interest as a key mechanism of large-scale integration across different brain regions. Besides a crucial role of oscillatory activity in the emergence of other neurological and psychiatric diseases, recent evidence indicates a key role in the pathophysiology of hepatic encephalopathy (HE). This review summarizes the current knowledge on pathological alterations of oscillatory brain activity in association with liver dysfunction and HE in the context of spontaneous brain activity, motor symptoms, sensory processing, and attention. The existing literature demonstrates a prominent slowing of the frequency of oscillatory activity as shown for spontaneous brain activity at rest, with respect to deficits of motor behavior and motor symptoms, and in the context of visual attention processes. The observed slowing extends across different subsystems of the brain and has been confirmed across different frequency bands, providing evidence for ubiquitous changes of oscillatory activity in HE. For example, the frequency of cortico-muscular coherence in HE patients appears at the frequency of the mini-asterixis (⩽12Hz), while cirrhotics without overt signs of HE show coherence similar to healthy subjects, i.e. at 13-30Hz. Interestingly, the so-called critical flicker frequency (CFF) as a measure of the processing of an oscillating visual stimulus has emerged as a useful tool to quantify HE disease severity, correlating with behavioral and neurophysiological alterations. Moreover, the CFF reliably distinguishes patients with manifest HE from cirrhotics without any signs of HE and healthy controls using a cut-off frequency of 39Hz. In conclusion, oscillatory activity is globally slowed in HE in close association with HE symptoms and disease severity. Although the underlying causal mechanisms are not yet understood, these results indicate that pathological changes of oscillatory activity play an important role in the

  10. Cortical spreading depression in traumatic brain injuries: is there a role for astrocytes?

    Science.gov (United States)

    Torrente, Daniel; Cabezas, Ricardo; Avila, Marco Fidel; García-Segura, Luis Miguel; Barreto, George E; Guedes, Rubem Carlos Araújo

    2014-04-17

    Cortical spreading depression (CSD) is a presumably pathophysiological phenomenon that interrupts local cortical function for periods of minutes to hours. This phenomenon is important due to its association with different neurological disorders such as migraine, malignant stroke and traumatic brain injury (TBI). Glial cells, especially astrocytes, play an important role in the regulation of CSD and in the protection of neurons under brain trauma. The correlation of TBI with CSD and the astrocytic function under these conditions remain unclear. This review discusses the possible link of TBI and CSD and its implication for neuronal survival. Additionally, we highlight the importance of astrocytic function for brain protection, and suggest possible therapeutic strategies targeting astrocytes to improve the outcome following TBI-associated CSD.

  11. Age of language learning shapes brain structure: a cortical thickness study of bilingual and monolingual individuals.

    Science.gov (United States)

    Klein, Denise; Mok, Kelvin; Chen, Jen-Kai; Watkins, Kate E

    2014-04-01

    We examined the effects of learning a second language (L2) on brain structure. Cortical thickness was measured in the MRI datasets of 22 monolinguals and 66 bilinguals. Some bilingual subjects had learned both languages simultaneously (0-3 years) while some had learned their L2 after achieving proficiency in their first language during either early (4-7 years) or late childhood (8-13 years). Later acquisition of L2 was associated with significantly thicker cortex in the left inferior frontal gyrus (IFG) and thinner cortex in the right IFG. These effects were seen in the group comparisons of monolinguals, simultaneous bilinguals and early and late bilinguals. Within the bilingual group, significant correlations between age of acquisition of L2 and cortical thickness were seen in the same regions: cortical thickness correlated with age of acquisition positively in the left IFG and negatively in the right IFG. Interestingly, the monolinguals and simultaneous bilinguals did not differ in cortical thickness in any region. Our results show that learning a second language after gaining proficiency in the first language modifies brain structure in an age-dependent manner whereas simultaneous acquisition of two languages has no additional effect on brain development.

  12. The Impact of CXCR4 Blockade on the Survival of Rat Brain Cortical Neurons

    Science.gov (United States)

    Merino, José Joaquín; Garcimartín, Alba; López-Oliva, María Elvira; Benedí, Juana; González, María Pilar

    2016-01-01

    Background: Chemokine receptor type 4 (CXCR4) plays a role in neuronal survival/cell repair and also contributes to the progression of cancer and neurodegenerative diseases. Chemokine ligand 12 (CXCL12) binds to CXCR4. In this study, we have investigated whether CXCR4 blockade by AMD3100 (a CXCR4 antagonist, member of bicyclam family) may affect neuronal survival in the absence of insult. Thus, we have measured the mitochondrial membrane potential (MMP), Bax and Bcl-2 protein translocation, and cytochrome c release in AMD3100-treated brain cortical neurons at 7 DIV (days in vitro). Methods: For this aim, AMD3100 (200 nM) was added to cortical neurons for 24 h, and several biomarkers like cell viability, reactive oxygen species (ROS) generation, lactate dehydrogenase (LDH) release, caspase-3/9 activity, proteins Bax and Bcl-2 translocation, and cytochrome c release were analyzed by immunoblot. Results: CXCR4 blockade by AMD3100 (200 nM, 24 h) induces mitochondrial hyperpolarization and increases caspase-3/9 hyperpolarization without affecting LDH release as compared to untreated controls. AMD3100 also increases cytochrome c release and promotes Bax translocation to the mitochondria, whereas it raises cytosolic Bcl-2 levels in brain cortical neurons. Conclusion: CXCR4 blockade induces cellular death via intrinsic apoptosis in rat brain cortical neurons in absence of insult. PMID:27916896

  13. Measuring Brain Stimulation Induced Changes in Cortical Properties Using TMS-EEG.

    Science.gov (United States)

    Chung, Sung Wook; Rogasch, Nigel C; Hoy, Kate E; Fitzgerald, Paul B

    2015-01-01

    Neuromodulatory brain stimulation can induce plastic reorganization of cortical circuits that persist beyond the period of stimulation. Most of our current knowledge about the physiological properties has been derived from the motor cortex. The integration of transcranial magnetic stimulation (TMS) and electroencephalography (EEG) is a valuable method for directly probing excitability, connectivity and oscillatory dynamics of regions throughout the brain. Offering in depth measurement of cortical reactivity, TMS-EEG allows the evaluation of TMS-evoked components that may act as a marker for cortical excitation and inhibition. A growing body of research is using concurrent TMS and EEG (TMS-EEG) to explore the effects of different neuromodulatory techniques such as repetitive TMS and transcranial direct current stimulation on cortical function, particularly in non-motor regions. In this review, we outline studies examining TMS-evoked potentials and oscillations before and after, or during a single session of brain stimulation. Investigating these studies will aid in our understanding of mechanisms involved in the modulation of excitability and inhibition by neuroplasticity following different stimulation paradigms.

  14. Mapping fetal brain development in utero using magnetic resonance imaging: the Big Bang of brain mapping.

    Science.gov (United States)

    Studholme, Colin

    2011-08-15

    The development of tools to construct and investigate probabilistic maps of the adult human brain from magnetic resonance imaging (MRI) has led to advances in both basic neuroscience and clinical diagnosis. These tools are increasingly being applied to brain development in adolescence and childhood, and even to neonatal and premature neonatal imaging. Even earlier in development, parallel advances in clinical fetal MRI have led to its growing use as a tool in challenging medical conditions. This has motivated new engineering developments encompassing optimal fast MRI scans and techniques derived from computer vision, the combination of which allows full 3D imaging of the moving fetal brain in utero without sedation. These promise to provide a new and unprecedented window into early human brain growth. This article reviews the developments that have led us to this point, examines the current state of the art in the fields of fast fetal imaging and motion correction, and describes the tools to analyze dynamically changing fetal brain structure. New methods to deal with developmental tissue segmentation and the construction of spatiotemporal atlases are examined, together with techniques to map fetal brain growth patterns.

  15. Mapping and Reducing the Brain on the Cloud

    OpenAIRE

    Sahai, Esha; Sahai, Tuhin

    2012-01-01

    The emergence of cloud computing has enabled an incredible growth in available hardware resources at very low costs. These resources are being increasingly utilized by corporations for scalable analysis of "big data" problems. In this work, we explore the possibility of using commodity hardware such as Amazon EC2 for performing large scale scientific computation. In particular, we simulate interconnected cortical neurons using MapReduce. We build and model a network of 1000 spiking cortical n...

  16. Decoding brain responses to pixelized images in the primary visual cortex: implications for visual cortical prostheses.

    Science.gov (United States)

    Guo, Bing-Bing; Zheng, Xiao-Lin; Lu, Zhen-Gang; Wang, Xing; Yin, Zheng-Qin; Hou, Wen-Sheng; Meng, Ming

    2015-10-01

    Visual cortical prostheses have the potential to restore partial vision. Still limited by the low-resolution visual percepts provided by visual cortical prostheses, implant wearers can currently only "see" pixelized images, and how to obtain the specific brain responses to different pixelized images in the primary visual cortex (the implant area) is still unknown. We conducted a functional magnetic resonance imaging experiment on normal human participants to investigate the brain activation patterns in response to 18 different pixelized images. There were 100 voxels in the brain activation pattern that were selected from the primary visual cortex, and voxel size was 4 mm × 4 mm × 4 mm. Multi-voxel pattern analysis was used to test if these 18 different brain activation patterns were specific. We chose a Linear Support Vector Machine (LSVM) as the classifier in this study. The results showed that the classification accuracies of different brain activation patterns were significantly above chance level, which suggests that the classifier can successfully distinguish the brain activation patterns. Our results suggest that the specific brain activation patterns to different pixelized images can be obtained in the primary visual cortex using a 4 mm × 4 mm × 4 mm voxel size and a 100-voxel pattern.

  17. Information content in cortical spike trains during brain state transitions.

    Science.gov (United States)

    Arnold, Maria M; Szczepanski, Janusz; Montejo, Noelia; Amigó, José M; Wajnryb, Eligiusz; Sanchez-Vives, Maria V

    2013-02-01

    Even in the absence of external stimuli there is ongoing activity in the cerebral cortex as a result of recurrent connectivity. This paper attempts to characterize one aspect of this ongoing activity by examining how the information content carried by specific neurons varies as a function of brain state. We recorded from rats chronically implanted with tetrodes in the primary visual cortex during awake and sleep periods. Electro-encephalogram and spike trains were recorded during 30-min periods, and 2-4 neuronal spikes were isolated per tetrode off-line. All the activity included in the analysis was spontaneous, being recorded from the visual cortex in the absence of visual stimuli. The brain state was determined through a combination of behavior evaluation, electroencephalogram and electromyogram analysis. Information in the spike trains was determined by using Lempel-Ziv Complexity. Complexity was used to estimate the entropy of neural discharges and thus the information content (Amigóet al. Neural Comput., 2004, 16: 717-736). The information content in spike trains (range 4-70 bits s(-1) ) was evaluated during different brain states and particularly during the transition periods. Transitions toward states of deeper sleep coincided with a decrease of information, while transitions to the awake state resulted in an increase in information. Changes in both directions were of the same magnitude, about 30%. Information in spike trains showed a high temporal correlation between neurons, reinforcing the idea of the impact of the brain state in the information content of spike trains.

  18. Your Brain on Art: Emergent Cortical Dynamics During Aesthetic Experiences.

    Science.gov (United States)

    Kontson, Kimberly L; Megjhani, Murad; Brantley, Justin A; Cruz-Garza, Jesus G; Nakagome, Sho; Robleto, Dario; White, Michelle; Civillico, Eugene; Contreras-Vidal, Jose L

    2015-01-01

    The brain response to conceptual art was studied with mobile electroencephalography (EEG) to examine the neural basis of aesthetic experiences. In contrast to most studies of perceptual phenomena, participants were moving and thinking freely as they viewed the exhibit The Boundary of Life is Quietly Crossed by Dario Robleto at the Menil Collection-Houston. The brain activity of over 400 subjects was recorded using dry-electrode and one reference gel-based EEG systems over a period of 3 months. Here, we report initial findings based on the reference system. EEG segments corresponding to each art piece were grouped into one of three classes (complex, moderate, and baseline) based on analysis of a digital image of each piece. Time, frequency, and wavelet features extracted from EEG were used to classify patterns associated with viewing art, and ranked based on their relevance for classification. The maximum classification accuracy was 55% (chance = 33%) with delta and gamma features the most relevant for classification. Functional analysis revealed a significant increase in connection strength in localized brain networks while subjects viewed the most aesthetically pleasing art compared to viewing a blank wall. The direction of signal flow showed early recruitment of broad posterior areas followed by focal anterior activation. Significant differences in the strength of connections were also observed across age and gender. This work provides evidence that EEG, deployed on freely behaving subjects, can detect selective signal flow in neural networks, identify significant differences between subject groups, and report with greater-than-chance accuracy the complexity of a subject's visual percept of aesthetically pleasing art. Our approach, which allows acquisition of neural activity "in action and context," could lead to understanding of how the brain integrates sensory input and its ongoing internal state to produce the phenomenon which we term aesthetic experience.

  19. Applications of fMRI for Brain Mapping

    Directory of Open Access Journals (Sweden)

    Nivedita Daimiwal

    2012-11-01

    Full Text Available Brain-mapping techniques have proven to be vital in understanding the molecular, cellular, and functional mechanisms of the brain. Normal anatomical imaging can provide structural information on certain abnormalities in the brain. However there are many neurological disorders for which only structure studies are not sufficient. In such cases it is required to investigate the functional organization of the brain. Further it is necessary to study the brain functions under normal as well as diseased conditions. Brain mapping techniques can help in deriving useful and important information on these issues. Brain functions and brain area responsible for the particular activities like motor, sensory speech and memory process could be investigated. The authors provide an overview of various Brain Mapping techniques and fMRI signal processing methods.

  20. Adaptive training of cortical feature maps for a robot sensorimotor controller.

    Science.gov (United States)

    Adams, Samantha V; Wennekers, Thomas; Denham, Sue; Culverhouse, Phil F

    2013-08-01

    This work investigates self-organising cortical feature maps (SOFMs) based upon the Kohonen Self-Organising Map (SOM) but implemented with spiking neural networks. In future work, the feature maps are intended as the basis for a sensorimotor controller for an autonomous humanoid robot. Traditional SOM methods require some modifications to be useful for autonomous robotic applications. Ideally the map training process should be self-regulating and not require predefined training files or the usual SOM parameter reduction schedules. It would also be desirable if the organised map had some flexibility to accommodate new information whilst preserving previous learnt patterns. Here methods are described which have been used to develop a cortical motor map training system which goes some way towards addressing these issues. The work is presented under the general term 'Adaptive Plasticity' and the main contribution is the development of a 'plasticity resource' (PR) which is modelled as a global parameter which expresses the rate of map development and is related directly to learning on the afferent (input) connections. The PR is used to control map training in place of a traditional learning rate parameter. In conjunction with the PR, random generation of inputs from a set of exemplar patterns is used rather than predefined datasets and enables maps to be trained without deciding in advance how much data is required. An added benefit of the PR is that, unlike a traditional learning rate, it can increase as well as decrease in response to the demands of the input and so allows the map to accommodate new information when the inputs are changed during training.

  1. Correlations between brain cortical thickness and cutaneous pain thresholds are atypical in adults with migraine.

    Directory of Open Access Journals (Sweden)

    Todd J Schwedt

    Full Text Available BACKGROUND/OBJECTIVE: Migraineurs have atypical pain processing, increased expectations for pain, and hypervigilance for pain. Recent studies identified correlations between brain structure and pain sensation in healthy adults. The objective of this study was to compare cortical thickness-to-pain threshold correlations in migraineurs to healthy controls. We hypothesized that migraineurs would have aberrant relationships between the anatomical neurocorrelates of pain processing and pain thresholds. METHODS: Pain thresholds to cutaneously applied heat were determined for 31 adult migraineurs and 32 healthy controls. Cortical thickness was determined from magnetic resonance imaging T1-weighted sequences. Regional cortical thickness-to-pain threshold correlations were determined for migraineurs and controls separately using a general linear model whole brain vertex-wise analysis. A pain threshold-by-group interaction analysis was then conducted to estimate regions where migraineurs show alterations in the pain threshold-to-cortical thickness correlations relative to healthy controls. RESULTS: Controls had negative correlations (p<0.01 uncorrected between pain thresholds and cortical thickness in left posterior cingulate/precuneus, right superior temporal, right inferior parietal, and left inferior temporal regions, and a negative correlation (p<0.01 Monte Carlo corrected with a left superior temporal/inferior parietal region. Migraineurs had positive correlations (p<0.01 uncorrected between pain thresholds and cortical thickness in left superior temporal/inferior parietal, right precuneus, right superior temporal/inferior parietal, and left inferior parietal regions. Cortical thickness-to-pain threshold correlations differed between migraine and control groups (p<0.01 uncorrected for right superior temporal/inferior parietal, right precentral, left posterior cingulate/precuneus, and right inferior parietal regions and (p<0.01 Monte Carlo corrected

  2. Superresolution improves MRI cortical segmentation with FACE

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Manjón, José V.; Coupé, Pierrick

    Brain cortical surface extraction from MRI has applications for measurement of gray matter (GM) atrophy, functional mapping, source localization and preoperative neurosurgical planning. Accurate cortex segmentation requires high resolution morphological images and several methods for extracting...

  3. Mapping Functional Brain Development: Building a Social Brain through Interactive Specialization

    Science.gov (United States)

    Johnson, Mark H.; Grossmann, Tobias; Kadosh, Kathrin Cohen

    2009-01-01

    The authors review a viewpoint on human functional brain development, interactive specialization (IS), and its application to the emerging network of cortical regions referred to as the "social brain." They advance the IS view in 2 new ways. First, they extend IS into a domain to which it has not previously been applied--the emergence of social…

  4. Cortical hypoexcitation defines neuronal responses in the immediate aftermath of traumatic brain injury.

    Directory of Open Access Journals (Sweden)

    Victoria Philippa Anne Johnstone

    Full Text Available Traumatic brain injury (TBI from a blow to the head is often associated with complex patterns of brain abnormalities that accompany deficits in cognitive and motor function. Previously we reported that a long-term consequence of TBI, induced with a closed-head injury method modelling human car and sporting accidents, is neuronal hyper-excitation in the rat sensory barrel cortex that receives tactile input from the face whiskers. Hyper-excitation occurred only in supra-granular layers and was stronger to complex than simple stimuli. We now examine changes in the immediate aftermath of TBI induced with same injury method. At 24 hours post-trauma significant sensorimotor deficits were observed and characterisation of the cortical population neuronal responses at that time revealed a depth-dependent suppression of neuronal responses, with reduced responses from supragranular layers through to input layer IV, but not in infragranular layers. In addition, increased spontaneous firing rate was recorded in cortical layers IV and V. We postulate that this early post-injury suppression of cortical processing of sensory input accounts for immediate post-trauma sensory morbidity and sets into train events that resolve into long-term cortical hyper-excitability in upper sensory cortex layers that may account for long-term sensory hyper-sensitivity in humans with TBI.

  5. Reproducibility of brain-cognition relationships using three cortical surface-based protocols: An exhaustive analysis based on cortical thickness.

    Science.gov (United States)

    Martínez, Kenia; Madsen, Sarah K; Joshi, Anand A; Joshi, Shantanu H; Román, Francisco J; Villalon-Reina, Julio; Burgaleta, Miguel; Karama, Sherif; Janssen, Joost; Marinetto, Eugenio; Desco, Manuel; Thompson, Paul M; Colom, Roberto

    2015-08-01

    People differ in their cognitive functioning. This variability has been exhaustively examined at the behavioral, neural and genetic level to uncover the mechanisms by which some individuals are more cognitively efficient than others. Studies investigating the neural underpinnings of interindividual differences in cognition aim to establish a reliable nexus between functional/structural properties of a given brain network and higher order cognitive performance. However, these studies have produced inconsistent results, which might be partly attributed to methodological variations. In the current study, 82 healthy young participants underwent MRI scanning and completed a comprehensive cognitive battery including measurements of fluid, crystallized, and spatial intelligence, along with working memory capacity/executive updating, controlled attention, and processing speed. The cognitive scores were obtained by confirmatory factor analyses. T1 -weighted images were processed using three different surface-based morphometry (SBM) pipelines, varying in their degree of user intervention, for obtaining measures of cortical thickness (CT) across the brain surface. Distribution and variability of CT and CT-cognition relationships were systematically compared across pipelines and between two cognitively/demographically matched samples to overcome potential sources of variability affecting the reproducibility of findings. We demonstrated that estimation of CT was not consistent across methods. In addition, among SBM methods, there was considerable variation in the spatial pattern of CT-cognition relationships. Finally, within each SBM method, results did not replicate in matched subsamples.

  6. Cortical modulations increase in early sessions with brain-machine interface.

    Directory of Open Access Journals (Sweden)

    Miriam Zacksenhouse

    Full Text Available BACKGROUND: During planning and execution of reaching movements, the activity of cortical motor neurons is modulated by a diversity of motor, sensory, and cognitive signals. Brain-machine interfaces (BMIs extract part of these modulations to directly control artificial actuators. However, cortical modulations that emerge in the novel context of operating the BMI are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: Here we analyzed the changes in neuronal modulations that occurred in different cortical motor areas as monkeys learned to use a BMI to control reaching movements. Using spike-train analysis methods we demonstrate that the modulations of the firing-rates of cortical neurons increased abruptly after the monkeys started operating the BMI. Regression analysis revealed that these enhanced modulations were not correlated with the kinematics of the movement. The initial enhancement in firing rate modulations declined gradually with subsequent training in parallel with the improvement in behavioral performance. CONCLUSIONS/SIGNIFICANCE: We conclude that the enhanced modulations are related to computational tasks that are significant especially in novel motor contexts. Although the function and neuronal mechanism of the enhanced cortical modulations are open for further inquiries, we discuss their potential role in processing execution errors and representing corrective or explorative activity. These representations are expected to contribute to the formation of internal models of the external actuator and their decoding may facilitate BMI improvement.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.).

  8. Cortical Abnormalities in ADHD

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2003-12-01

    Full Text Available Grey-matter abnormalities at the cortical surface and regional brain size were mapped by high-resolution MRI and surface-based, computational image analytical techniques in a group of 27 children and adolescents with attention deficit hyperactivity disorder (ADHD and 46 controls, matched by age and sex, at the University of California at Los Angeles.

  9. Computational Analysis of LDDMM for Brain Mapping

    Directory of Open Access Journals (Sweden)

    Can eCeritoglu

    2013-08-01

    Full Text Available One goal of computational anatomy is to develop tools to accurately segment brain structures in healthy and diseased subjects. In this paper, we examine the performance and complexity of such segmentation in the framework of the large deformation diffeomorphic metric mapping (LDDMM registration method with reference to atlases and parameters. First we report the application of a multi-atlas segmentation approach to define basal ganglia structures in healthy and diseased kids’ brains. The segmentation accuracy of the multi-atlas approach is compared with the single atlas LDDMM implementation and two state-of-the-art segmentation algorithms – Freesurfer and FSL – by computing the overlap errors between automatic and manual segmentations of the six basal ganglia nuclei in healthy subjects as well as subjects with diseases including ADHD and Autism. The high accuracy of multi-atlas segmentation is obtained at the cost of increasing the computational complexity because of the calculations necessary between the atlases and a subject. Second, we examine the effect of parameters on total LDDMM computation time and segmentation accuracy for basal ganglia structures. Single atlas LDDMM method is used to automatically segment the structures in a population of 16 subjects using different sets of parameters. The results show that a cascade approach and using fewer time steps can reduce computational complexity as much as five times while maintaining reliable segmentations.

  10. Mapping brain response to pain in fibromyalgia patients using temporal analysis of FMRI.

    Directory of Open Access Journals (Sweden)

    Jesus Pujol

    Full Text Available BACKGROUND: Nociceptive stimuli may evoke brain responses longer than the stimulus duration often partially detected by conventional neuroimaging. Fibromyalgia patients typically complain of severe pain from gentle stimuli. We aimed to characterize brain response to painful pressure in fibromyalgia patients by generating activation maps adjusted for the duration of brain responses. METHODOLOGY/PRINCIPAL FINDINGS: Twenty-seven women (mean age: 47.8 years were assessed with fMRI. The sample included nine fibromyalgia patients and nine healthy subjects who received 4 kg/cm(2 of pressure on the thumb. Nine additional control subjects received 6.8 kg/cm(2 to match the patients for the severity of perceived pain. Independent Component Analysis characterized the temporal dynamics of the actual brain response to pressure. Statistical parametric maps were estimated using the obtained time courses. Brain response to pressure (18 seconds consistently exceeded the stimulus application (9 seconds in somatosensory regions in all groups. fMRI maps following such temporal dynamics showed a complete pain network response (sensory-motor cortices, operculo-insula, cingulate cortex, and basal ganglia to 4 kg/cm(2 of pressure in fibromyalgia patients. In healthy subjects, response to this low intensity pressure involved mainly somatosensory cortices. When matched for perceived pain (6.8 kg/cm(2, control subjects showed also comprehensive activation of pain-related regions, but fibromyalgia patients showed significantly larger activation in the anterior insula-basal ganglia complex and the cingulate cortex. CONCLUSIONS/SIGNIFICANCE: The results suggest that data-driven fMRI assessments may complement conventional neuroimaging for characterizing pain responses and that enhancement of brain activation in fibromyalgia patients may be particularly relevant in emotion-related regions.

  11. The brain decade in debate: VI. Sensory and motor maps: dynamics and plasticity

    Directory of Open Access Journals (Sweden)

    A. Das

    2001-12-01

    Full Text Available This article is an edited transcription of a virtual symposium promoted by the Brazilian Society of Neuroscience and Behavior (SBNeC. Although the dynamics of sensory and motor representations have been one of the most studied features of the central nervous system, the actual mechanisms of brain plasticity that underlie the dynamic nature of sensory and motor maps are not entirely unraveled. Our discussion began with the notion that the processing of sensory information depends on many different cortical areas. Some of them are arranged topographically and others have non-topographic (analytical properties. Besides a sensory component, every cortical area has an efferent output that can be mapped and can influence motor behavior. Although new behaviors might be related to modifications of the sensory or motor representations in a given cortical area, they can also be the result of the acquired ability to make new associations between specific sensory cues and certain movements, a type of learning known as conditioning motor learning. Many types of learning are directly related to the emotional or cognitive context in which a new behavior is acquired. This has been demonstrated by paradigms in which the receptive field properties of cortical neurons are modified when an animal is engaged in a given discrimination task or when a triggering feature is paired with an aversive stimulus. The role of the cholinergic input from the nucleus basalis to the neocortex was also highlighted as one important component of the circuits responsible for the context-dependent changes that can be induced in cortical maps.

  12. The brain's router: a cortical network model of serial processing in the primate brain.

    Science.gov (United States)

    Zylberberg, Ariel; Fernández Slezak, Diego; Roelfsema, Pieter R; Dehaene, Stanislas; Sigman, Mariano

    2010-04-29

    The human brain efficiently solves certain operations such as object recognition and categorization through a massively parallel network of dedicated processors. However, human cognition also relies on the ability to perform an arbitrarily large set of tasks by flexibly recombining different processors into a novel chain. This flexibility comes at the cost of a severe slowing down and a seriality of operations (100-500 ms per step). A limit on parallel processing is demonstrated in experimental setups such as the psychological refractory period (PRP) and the attentional blink (AB) in which the processing of an element either significantly delays (PRP) or impedes conscious access (AB) of a second, rapidly presented element. Here we present a spiking-neuron implementation of a cognitive architecture where a large number of local parallel processors assemble together to produce goal-driven behavior. The precise mapping of incoming sensory stimuli onto motor representations relies on a "router" network capable of flexibly interconnecting processors and rapidly changing its configuration from one task to another. Simulations show that, when presented with dual-task stimuli, the network exhibits parallel processing at peripheral sensory levels, a memory buffer capable of keeping the result of sensory processing on hold, and a slow serial performance at the router stage, resulting in a performance bottleneck. The network captures the detailed dynamics of human behavior during dual-task-performance, including both mean RTs and RT distributions, and establishes concrete predictions on neuronal dynamics during dual-task experiments in humans and non-human primates.

  13. Mapping cortical haemodynamics during neonatal seizures using diffuse optical tomography: A case study

    Directory of Open Access Journals (Sweden)

    Harsimrat Singh

    2014-01-01

    Full Text Available Seizures in the newborn brain represent a major challenge to neonatal medicine. Neonatal seizures are poorly classified, under-diagnosed, difficult to treat and are associated with poor neurodevelopmental outcome. Video-EEG is the current gold-standard approach for seizure detection and monitoring. Interpreting neonatal EEG requires expertise and the impact of seizures on the developing brain remains poorly understood. In this case study we present the first ever images of the haemodynamic impact of seizures on the human infant brain, obtained using simultaneous diffuse optical tomography (DOT and video-EEG with whole-scalp coverage. Seven discrete periods of ictal electrographic activity were observed during a 60 minute recording of an infant with hypoxic–ischaemic encephalopathy. The resulting DOT images show a remarkably consistent, high-amplitude, biphasic pattern of changes in cortical blood volume and oxygenation in response to each electrographic event. While there is spatial variation across the cortex, the dominant haemodynamic response to seizure activity consists of an initial increase in cortical blood volume prior to a large and extended decrease typically lasting several minutes. This case study demonstrates the wealth of physiologically and clinically relevant information that DOT–EEG techniques can yield. The consistency and scale of the haemodynamic responses observed here also suggest that DOT–EEG has the potential to provide improved detection of neonatal seizures.

  14. A DTI-Based Template-Free Cortical Connectome Study of Brain Maturation

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    Tymofiyeva, Olga; Hess, Christopher P.; Ziv, Etay; Lee, Patricia N.; Glass, Hannah C.; Ferriero, Donna M.; Barkovich, A. James; Xu, Duan

    2013-01-01

    Improved understanding of how the human brain is “wired” on a macroscale may now be possible due to the emerging field of MRI connectomics. However, mapping the rapidly developing infant brain networks poses challenges. In this study, we applied an automated template-free “baby connectome” framework using diffusion MRI to non-invasively map the structural brain networks in subjects of different ages, including premature neonates, term-born neonates, six-month-old infants, and adults. We observed increasing brain network integration and decreasing segregation with age in term-born subjects. We also explored how the equal area nodes can be grouped into modules without any prior anatomical information – an important step toward a fully network-driven registration and analysis of brain connectivity. PMID:23675475

  15. Mapping the cortical representation of speech sounds in a syllable repetition task.

    Science.gov (United States)

    Markiewicz, Christopher J; Bohland, Jason W

    2016-11-01

    Speech repetition relies on a series of distributed cortical representations and functional pathways. A speaker must map auditory representations of incoming sounds onto learned speech items, maintain an accurate representation of those items in short-term memory, interface that representation with the motor output system, and fluently articulate the target sequence. A "dorsal stream" consisting of posterior temporal, inferior parietal and premotor regions is thought to mediate auditory-motor representations and transformations, but the nature and activation of these representations for different portions of speech repetition tasks remains unclear. Here we mapped the correlates of phonetic and/or phonological information related to the specific phonemes and syllables that were heard, remembered, and produced using a series of cortical searchlight multi-voxel pattern analyses trained on estimates of BOLD responses from individual trials. Based on responses linked to input events (auditory syllable presentation), predictive vowel-level information was found in the left inferior frontal sulcus, while syllable prediction revealed significant clusters in the left ventral premotor cortex and central sulcus and the left mid superior temporal sulcus. Responses linked to output events (the GO signal cueing overt production) revealed strong clusters of vowel-related information bilaterally in the mid to posterior superior temporal sulcus. For the prediction of onset and coda consonants, input-linked responses yielded distributed clusters in the superior temporal cortices, which were further informative for classifiers trained on output-linked responses. Output-linked responses in the Rolandic cortex made strong predictions for the syllables and consonants produced, but their predictive power was reduced for vowels. The results of this study provide a systematic survey of how cortical response patterns covary with the identity of speech sounds, which will help to constrain

  16. Coupling brain-machine interfaces with cortical stimulation for brain-state dependent stimulation: enhancing motor cortex excitability for neurorehabilitation

    Directory of Open Access Journals (Sweden)

    Alireza eGharabaghi

    2014-03-01

    Full Text Available Motor recovery after stroke is an unsolved challenge despite intensive rehabilitation training programs. Brain stimulation techniques have been explored in addition to traditional rehabilitation training to increase the excitability of the stimulated motor cortex. This modulation of cortical excitability augments the response to afferent input during motor exercises, thereby enhancing skilled motor learning by long-term potentiation-like plasticity. Recent approaches examined brain stimulation applied concurrently with voluntary movements to induce more specific use-dependent neural plasticity during motor training for neurorehabilitation. Unfortunately, such approaches are not applicable for the many severely affected stroke patients lacking residual hand function. These patients require novel activity-dependent stimulation paradigms based on intrinsic brain activity. Here, we report on such brain state-dependent stimulation (BSDS combined with haptic feedback provided by a robotic hand orthosis. Transcranial magnetic stimulation of the motor cortex and haptic feedback to the hand were controlled by sensorimotor desynchronization during motor-imagery and applied within a brain-machine interface environment in one healthy subject and one patient with severe hand paresis in the chronic phase after stroke. BSDS significantly increased the excitability of the stimulated motor cortex in both healthy and post-stroke conditions, an effect not observed in non-BSDS protocols. This feasibility study suggests that closing the loop between intrinsic brain state, cortical stimulation and haptic feedback provides a novel neurorehabilitation strategy for stroke patients lacking residual hand function, a proposal that warrants further investigation in a larger cohort of stroke patients.

  17. 101 labeled brain images and a consistent human cortical labeling protocol

    Directory of Open Access Journals (Sweden)

    Arno eKlein

    2012-12-01

    Full Text Available We introduce the Mindboggle-101 dataset, the largest and most complete set of free, publicly accessible, manually labeled human brain images. To manually label the macroscopic anatomy in magnetic resonance images of 101 healthy participants, we created a new cortical labeling protocol that relies on robust anatomical landmarks and minimal manual edits after initialization with automated labels. The Desikan-Killiany-Tourville (DKT protocol is intended to improve the ease, consistency, and accuracy of labeling human cortical areas. Given how difficult it is to label brains, the Mindboggle-101 dataset is intended to serve as brain atlases for use in labeling other brains, as a normative dataset to establish morphometric variation in a healthy population for comparison against clinical populations, and contribute to the development, training, testing, and evaluation of automated registration and labeling algorithms. To this end, we also introduce benchmarks for the evaluation of such algorithms by comparing our manual labels with labels automatically generated by probabilistic and multi-atlas registration-based approaches. All data and related software and updated information are available on the http://www.mindboggle.info/data/ website.

  18. Progressive brain damage, synaptic reorganization and NMDA activation in a model of epileptogenic cortical dysplasia.

    Directory of Open Access Journals (Sweden)

    Francesca Colciaghi

    Full Text Available Whether severe epilepsy could be a progressive disorder remains as yet unresolved. We previously demonstrated in a rat model of acquired focal cortical dysplasia, the methylazoxymethanol/pilocarpine - MAM/pilocarpine - rats, that the occurrence of status epilepticus (SE and subsequent seizures fostered a pathologic process capable of modifying the morphology of cortical pyramidal neurons and NMDA receptor expression/localization. We have here extended our analysis by evaluating neocortical and hippocampal changes in MAM/pilocarpine rats at different epilepsy stages, from few days after onset up to six months of chronic epilepsy. Our findings indicate that the process triggered by SE and subsequent seizures in the malformed brain i is steadily progressive, deeply altering neocortical and hippocampal morphology, with atrophy of neocortex and CA regions and progressive increase of granule cell layer dispersion; ii changes dramatically the fine morphology of neurons in neocortex and hippocampus, by increasing cell size and decreasing both dendrite arborization and spine density; iii induces reorganization of glutamatergic and GABAergic networks in both neocortex and hippocampus, favoring excitatory vs inhibitory input; iv activates NMDA regulatory subunits. Taken together, our data indicate that, at least in experimental models of brain malformations, severe seizure activity, i.e., SE plus recurrent seizures, may lead to a widespread, steadily progressive architectural, neuronal and synaptic reorganization in the brain. They also suggest the mechanistic relevance of glutamate/NMDA hyper-activation in the seizure-related brain pathologic plasticity.

  19. Three Types of Cortical Layer 5 Neurons That Differ in Brain-wide Connectivity and Function.

    Science.gov (United States)

    Kim, Euiseok J; Juavinett, Ashley L; Kyubwa, Espoir M; Jacobs, Matthew W; Callaway, Edward M

    2015-12-16

    Cortical layer 5 (L5) pyramidal neurons integrate inputs from many sources and distribute outputs to cortical and subcortical structures. Previous studies demonstrate two L5 pyramid types: cortico-cortical (CC) and cortico-subcortical (CS). We characterize connectivity and function of these cell types in mouse primary visual cortex and reveal a new subtype. Unlike previously described L5 CC and CS neurons, this new subtype does not project to striatum [cortico-cortical, non-striatal (CC-NS)] and has distinct morphology, physiology, and visual responses. Monosynaptic rabies tracing reveals that CC neurons preferentially receive input from higher visual areas, while CS neurons receive more input from structures implicated in top-down modulation of brain states. CS neurons are also more direction-selective and prefer faster stimuli than CC neurons. These differences suggest distinct roles as specialized output channels, with CS neurons integrating information and generating responses more relevant to movement control and CC neurons being more important in visual perception.

  20. Effects of ketamine, midazolam, thiopental, and propofol on brain ischemia injury in rat cerebral cortical slices

    Institute of Scientific and Technical Information of China (English)

    Qing-shengXUE; Bu-weiYU; Ze-jianWANG; Hong-zhuanCHEN

    2004-01-01

    AIM: To compare the effects of ketamine, midazolam, thiopental, and propofol on brain ischemia by the model of oxygen-glucose deprivation (OGD) in rat cerebral cortical slices. METHODS: Cerebral cortical slices were incu-bated in 2 % 2,3,5-triphenyltetrazolium chloride (TTC) solution after OGD, the damages and effects of ketamine,midazolam, thiopental, and propofol were quantitativlye evaluated by ELISA reader of absorbance (A) at 490 nm,which indicated the red formazan extracted from slices, lactic dehydrogenase (LDH) releases in the incubated supernate were also measured. RESULTS: Progressive prolongation of OGD resulted in decreases of TTC staining.The percentage of tissue injury had a positive correlation with LDH releases, r=0.9609, P<0.01. Two hours of reincubation aggravated the decrease of TTC staining compared with those slices stained immediately after OGD(P<0.01). These four anesthetics had no effects on the TTC staining of slices. Ketamine completely inhibited thedecrease of A value induced by 10 min of OGD injury. High concentrations of midazolam (10 μmol/L) and thiopental (400μmol/L) partly attenuated this decrease. Propofol at high concentration (100 μmol/L) enhanced the decrease of A value induced by 10 min of OGD injury (P<0.01). CONCLUSION; Ketamine, high concentration of midazolam and thiopental have neuroprotective effects against OGD injury in rat cerebral cortical slices, while high concentration of propofol augments OGD injury in rat cerebral cortical slices.

  1. Functional localization of the cortical motor area in the brain Electrocorticogram analysis

    Institute of Scientific and Technical Information of China (English)

    Tao Jiang; Xiaoming Wu; Binggang Ye; Sijuan Huang

    2010-01-01

    The method for rapidly,precisely and non-invasively localizing functional regions of the brain is a problem in neuromedicine research.Cortical electrostimulation is the optimal localization method during brain surgery,with a degree of accuracy of approximately 5 mm.However,electrostimulation can damage the cerebral cortex,trigger epilepsy,and extend the operation time.Studies are required to determine whether cortical motor regions can be localized by wavelet analysis from electrocorticograms.In this study,based on wavelet analysis of electrocorticograms,a selection of algorithms for classification of the mu rhythm in the motor regions utilizing experimental data was verified.Results demonstrated that a characteristic quantity of energy ratio in the reconstructed signal was filtered in the d6(7.81-15.62 Hz)band prior to and following motion events.A characteristic threshold was considered to be 40%.The accuracy of localization detection was 93%.The degree of accuracy was less than 5 mm.The present study avoided the problems of cerebral cortex injury and epilepsy onset,with an operation time of 60 seconds.Therefore,wavelet analysis on electrocorticogram is feasible for localizing cortical motor regions.Furthermore,this localization technique is accurate,safe and rapid.

  2. Assessment of quantitative cortical biomarkers in the developing brain of preterm infants

    Science.gov (United States)

    Moeskops, Pim; Benders, Manon J. N. L.; Pearlman, Paul C.; Kersbergen, Karina J.; Leemans, Alexander; Viergever, Max A.; Išgum, Ivana

    2013-02-01

    The cerebral cortex rapidly develops its folding during the second and third trimester of pregnancy. In preterm birth, this growth might be disrupted and influence neurodevelopment. The aim of this work is to extract quantitative biomarkers describing the cortex and evaluate them on a set of preterm infants without brain pathology. For this study, a set of 19 preterm - but otherwise healthy - infants scanned coronally with 3T MRI at the postmenstrual age of 30 weeks were selected. In ten patients (test set), the gray and white matter were manually annotated by an expert on the T2-weighted scans. Manual segmentations were used to extract cortical volume, surface area, thickness, and curvature using voxel-based methods. To compute these biomarkers per region in every patient, a template brain image has been generated by iterative registration and averaging of the scans of the remaining nine patients. This template has been manually divided in eight regions, and is transformed to every test image using elastic registration. In the results, gray and white matter volumes and cortical surface area appear symmetric between hemispheres, but small regional differences are visible. Cortical thickness seems slightly higher in the right parietal lobe than in other regions. The parietal lobes exhibit a higher global curvature, indicating more complex folding compared to other regions. The proposed approach can potentially - together with an automatic segmentation algorithm - be applied as a tool to assist in early diagnosis of abnormalities and prediction of the development of the cognitive abilities of these children.

  3. Modulation of spike timing by sensory deprivation during induction of cortical map plasticity.

    Science.gov (United States)

    Celikel, Tansu; Szostak, Vanessa A; Feldman, Daniel E

    2004-05-01

    Deprivation-induced plasticity of sensory cortical maps involves long-term potentiation (LTP) and depression (LTD) of cortical synapses, but how sensory deprivation triggers LTP and LTD in vivo is unknown. Here we tested whether spike timing-dependent forms of LTP and LTD are involved in this process. We measured spike trains from neurons in layer 4 (L4) and layers 2 and 3 (L2/3) of rat somatosensory cortex before and after acute whisker deprivation, a manipulation that induces whisker map plasticity involving LTD at L4-to-L2/3 (L4-L2/3) synapses. Whisker deprivation caused an immediate reversal of firing order for most L4 and L2/3 neurons and a substantial decorrelation of spike trains, changes known to drive timing-dependent LTD at L4-L2/3 synapses in vitro. In contrast, spike rate changed only modestly. Thus, whisker deprivation is likely to drive map plasticity by spike timing-dependent mechanisms.

  4. Brain dynamics during natural viewing conditions--a new guide for mapping connectivity in vivo.

    Science.gov (United States)

    Bartels, Andreas; Zeki, Semir

    2005-01-15

    We describe here a new way of obtaining maps of connectivity in the human brain based on interregional correlations of blood oxygen level-dependent (BOLD) signal during natural viewing conditions. We propose that anatomical connections are reflected in BOLD signal correlations during natural brain dynamics. This may provide a powerful approach to chart connectivity, more so than that based on the 'resting state' of the human brain, and it may complement diffusion tensor imaging. Our approach relies on natural brain dynamics and is therefore experimentally unbiased and independent of hypothesis-driven, specialized stimuli. It has the advantage that natural viewing leads to considerably stronger cortical activity than rest, thus facilitating detection of weaker connections. To validate our technique, we used functional magnetic resonance imaging (fMRI) to record BOLD signal while volunteers freely viewed a movie that was interrupted by resting periods. We used independent component analysis (ICA) to segregate cortical areas before characterizing the dynamics of their BOLD signal during free viewing and rest. Natural viewing and rest each revealed highly specific correlation maps, which reflected known anatomical connections. Examples are homologous regions in visual and auditory cortices in the two hemispheres and the language network consisting of Wernicke's area, Broca's area, and a premotor region. Correlations between regions known to be directly connected were always substantially higher than between nonconnected regions. Furthermore, compared to rest, natural viewing specifically increased correlations between anatomically connected regions while it decreased correlations between nonconnected regions. Our findings therefore demonstrate that natural viewing conditions lead to particularly specific interregional correlations and thus provide a powerful environment to reveal anatomical connectivity in vivo.

  5. Calbindin distribution in cortical and subcortical brain structures of normal and rabies-infected mice.

    Science.gov (United States)

    Torres-Fernández, Orlando; Yepes, Gloria E; Gómez, Javier E; Pimienta, Hernán J

    2005-10-01

    Rabies has been an enigmatic disease of the nervous system because microscopic findings in the brain tissue are not paralleled by the severity of the clinical illness. The calcium binding protein calbindin (CB) is a neuronal marker of great interest in neuroanatomy and neuropathology. CB-ir neurons in the striatum and cerebral cortex are gabaergic cells. In the present work CB-immunoreactivity was evaluated in brains of normal and rabies-infected mice. Rabies infection caused loss of CB-immunostaining in the cortical supragranular layers as well as in the striatum. Loss of CB in the brains of mice infected with rabies virus can produce impairment in Ca++ homeostasis and in the gabaergic neurotransmission.

  6. Cortical thickness mapping to identify focal osteoporosis in patients with hip fracture.

    Directory of Open Access Journals (Sweden)

    Kenneth E S Poole

    Full Text Available BACKGROUND: Individuals with osteoporosis are predisposed to hip fracture during trips, stumbles or falls, but half of all hip fractures occur in those without generalised osteoporosis. By analysing ordinary clinical CT scans using a novel cortical thickness mapping technique, we discovered patches of markedly thinner bone at fracture-prone regions in the femurs of women with acute hip fracture compared with controls. METHODS: We analysed CT scans from 75 female volunteers with acute fracture and 75 age- and sex-matched controls. We classified the fracture location as femoral neck or trochanteric before creating bone thickness maps of the outer 'cortical' shell of the intact contra-lateral hip. After registration of each bone to an average femur shape and statistical parametric mapping, we were able to visualise and quantify statistically significant foci of thinner cortical bone associated with each fracture type, assuming good symmetry of bone structure between the intact and fractured hip. The technique allowed us to pinpoint systematic differences and display the results on a 3D average femur shape model. FINDINGS: The cortex was generally thinner in femoral neck fracture cases than controls. More striking were several discrete patches of statistically significant thinner bone of up to 30%, which coincided with common sites of fracture initiation (femoral neck or trochanteric. INTERPRETATION: Femoral neck fracture patients had a thumbnail-sized patch of focal osteoporosis at the upper head-neck junction. This region coincided with a weak part of the femur, prone to both spontaneous 'tensile' fractures of the femoral neck, and as a site of crack initiation when falling sideways. Current hip fracture prevention strategies are based on case finding: they involve clinical risk factor estimation to determine the need for single-plane bone density measurement within a standard region of interest (ROI of the femoral neck. The precise sites of focal

  7. Clinical significance of ventricular enlargement and cortical atrophy in computed tomography of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Busse, O.; Agnoli, A.L.; Lippmann, R.; Schuetz, H.J.

    1981-02-01

    The diagnosis of atrophy of the brain based on the visual interpretation of CT findings appears questionable. In 56 patients there was no correlation between the CT findings of enlarged ventricles and sulci and clinical findings of psychoorganic syndromes. Only the group of 60 to 80 year old patients showed a statistically significant correlation between psychoorganic findings and the area of the lateral ventricles - measured planimetrically - and the diameter of the cella medica, but not the group of the 40 to 60 year old. There was no relationship between the number of cortical sulci and psychopathology. The morphological findings of ventricular enlargement and cortical atrophy in CT - even with exact measurements - do not allow any conclusions in regard to psychoorganic findings.

  8. Involvement of the right inferior longitudinal fascicle in visual hemiagnosia: a brain stimulation mapping study.

    Science.gov (United States)

    Fernández Coello, Alejandro; Duvaux, Sophie; De Benedictis, Alessandro; Matsuda, Ryosuke; Duffau, Hugues

    2013-01-01

    Neural foundations underlying visual agnosia are poorly understood. The authors present the case of a patient who underwent awake surgery for a right basal temporooccipital low-grade glioma in which direct electrostimulation was used both at the cortical and subcortical level. Brain mapping over the inferior longitudinal fascicle generated contralateral visual hemiagnosia. These original findings are in agreement with recent tractography data that have confirmed the existence of an occipitotemporal pathway connecting occipital visual input to higher-level processing in temporal lobe structures. This is the first report of a true transient visual hemiagnosia elicited through electrostimulation, supporting the crucial role of inferior longitudinal fascicle in visual recognition.

  9. K-shell decomposition reveals hierarchical cortical organization of the human brain

    Science.gov (United States)

    Lahav, Nir; Ksherim, Baruch; Ben-Simon, Eti; Maron-Katz, Adi; Cohen, Reuven; Havlin, Shlomo

    2016-08-01

    In recent years numerous attempts to understand the human brain were undertaken from a network point of view. A network framework takes into account the relationships between the different parts of the system and enables to examine how global and complex functions might emerge from network topology. Previous work revealed that the human brain features ‘small world’ characteristics and that cortical hubs tend to interconnect among themselves. However, in order to fully understand the topological structure of hubs, and how their profile reflect the brain’s global functional organization, one needs to go beyond the properties of a specific hub and examine the various structural layers that make up the network. To address this topic further, we applied an analysis known in statistical physics and network theory as k-shell decomposition analysis. The analysis was applied on a human cortical network, derived from MRI\\DSI data of six participants. Such analysis enables us to portray a detailed account of cortical connectivity focusing on different neighborhoods of inter-connected layers across the cortex. Our findings reveal that the human cortex is highly connected and efficient, and unlike the internet network contains no isolated nodes. The cortical network is comprised of a nucleus alongside shells of increasing connectivity that formed one connected giant component, revealing the human brain’s global functional organization. All these components were further categorized into three hierarchies in accordance with their connectivity profile, with each hierarchy reflecting different functional roles. Such a model may explain an efficient flow of information from the lowest hierarchy to the highest one, with each step enabling increased data integration. At the top, the highest hierarchy (the nucleus) serves as a global interconnected collective and demonstrates high correlation with consciousness related regions, suggesting that the nucleus might serve as a

  10. Clinical relevance of cortical spreading depression in neurological disorders: migraine, malignant stroke, subarachnoid and intracranial hemorrhage, and traumatic brain injury

    DEFF Research Database (Denmark)

    Lauritzen, Martin; Dreier, Jens Peter; Fabricius, Martin

    2011-01-01

    Cortical spreading depression (CSD) and depolarization waves are associated with dramatic failure of brain ion homeostasis, efflux of excitatory amino acids from nerve cells, increased energy metabolism and changes in cerebral blood flow (CBF). There is strong clinical and experimental evidence...... treatment strategies, which may be used to prevent or attenuate secondary neuronal damage in acutely injured human brain cortex caused by depolarization waves....

  11. Coronary artery disease affects cortical circuitry associated with brain-heart integration during volitional exercise.

    Science.gov (United States)

    Norton, Katelyn N; Badrov, Mark B; Barron, Carly C; Suskin, Neville; Heinecke, Armin; Shoemaker, J Kevin

    2015-08-01

    This study tested the hypothesis that coronary artery disease (CAD) alters the cortical circuitry associated with exercise. Observations of changes in heart rate (HR) and in cortical blood oxygenation level-dependent (BOLD) images were made in 23 control subjects [control; 8 women; 63 ± 11 yr; mean arterial pressure (MAP): 90 ± 9 mmHg] (mean ± SD) and 17 similarly aged CAD patients (4 women; 59 ± 9 yr; MAP: 87 ± 10 mmHg). Four repeated bouts each of 30%, 40%, and 50% of maximal voluntary contraction (MVC) force (LAB session), and seven repeated bouts of isometric handgrip (IHG) at 40% MVC force (fMRI session), were performed, with each contraction lasting 20 s and separated by 40 s of rest. There was a main effect of group (P = 0.03) on HR responses across all IHG intensities. Compared with control, CAD demonstrated less task-dependent deactivation in the posterior cingulate cortex and medial prefrontal cortex, and reduced activation in the right anterior insula, bilateral precentral cortex, and occipital lobe (P < 0.05). When correlated with HR, CAD demonstrated reduced activation in the bilateral insula and posterior cingulate cortex, and reduced deactivation in the dorsal anterior cingulate cortex, and bilateral precentral cortex (P < 0.05). The increased variability in expected autonomic regions and decrease in total cortical activation in response to the IHG task are associated with a diminished HR response to volitional effort in CAD. Therefore, relative to similarly aged and healthy individuals, CAD impairs the heart rate response and modifies the cortical patterns associated with cardiovascular control during IHG.

  12. Interhemispheric transfalcine approach and awake cortical mapping for resection of peri-atrial gliomas associated with the central lobule.

    Science.gov (United States)

    Malekpour, Mahdi; Cohen-Gadol, Aaron A

    2015-02-01

    Medial posterior frontal and parietal gliomas extending to the peri-atrial region are difficult to reach surgically because of the working angle required to expose the lateral aspect of the tumor and the proximity of the tumor to the sensorimotor lobule; retraction of the sensorimotor cortex may lead to morbidity. The interhemispheric transfalcine approach is favorable and safe for resection of medial hemispheric tumors adjacent to the falx cerebri, but the literature on this approach is scarce. Awake cortical mapping using this operative route for tumors associated with the sensorimotor cortex has not been previously reported to our knowledge. We present the first case of a right medial posterior frontoparietal oligoastrocytoma that was resected through the interhemispheric transfalcine approach using awake cortical and subcortical mapping. Through a contralateral frontoparietal craniotomy, we excised a section of the falx and exposed the contralateral medial hemisphere. Cortical stimulation allowed localization of the supplementary motor cortex, and suprathreshold stimulation mapping excluded the primary motor cortex corresponding to the leg area. Gross total tumor resection was accomplished without any intraoperative or postoperative deficits. Awake cortical mapping using the contralateral transfalcine approach allows a "cross-court" operative route to map functional cortices and resect peri-atrial low-grade gliomas. This technique can minimize the otherwise necessary retraction on the ipsilateral hemisphere through an ipsilateral craniotomy.

  13. Echo-acoustic flow dynamically modifies the cortical map of target range in bats

    Science.gov (United States)

    Bartenstein, Sophia K.; Gerstenberg, Nadine; Vanderelst, Dieter; Peremans, Herbert; Firzlaff, Uwe

    2014-08-01

    Echolocating bats use the delay between their sonar emissions and the reflected echoes to measure target range, a crucial parameter for avoiding collisions or capturing prey. In many bat species, target range is represented as an orderly organized map of echo delay in the auditory cortex. Here we show that the map of target range in bats is dynamically modified by the continuously changing flow of acoustic information perceived during flight (‘echo-acoustic flow’). Combining dynamic acoustic stimulation in virtual space with extracellular recordings, we found that neurons in the auditory cortex of the bat Phyllostomus discolor encode echo-acoustic flow information on the geometric relation between targets and the bat’s flight trajectory, rather than echo delay per se. Specifically, the cortical representation of close-range targets is enlarged when the lateral passing distance of the target decreases. This flow-dependent enlargement of target representation may trigger adaptive behaviours such as vocal control or flight manoeuvres.

  14. Neural network models for spatial data mining, map production, and cortical direction selectivity

    Science.gov (United States)

    Parsons, Olga

    A family of ARTMAP neural networks for incremental supervised learning has been developed over the last decade. The Sensor Exploitation Group of MIT Lincoln Laboratory (LL) has incorporated an early version of this network as the recognition engine of a hierarchical system for fusion and data mining of multiple registered geospatial images. The LL system has been successfully fielded, but it is limited to target vs. non-target identifications and does not produce whole maps. This dissertation expands the capabilities of the LL system so that it learns to identify arbitrarily many target classes at once and can thus produce a whole map. This new spatial data mining system is designed particularly to cope with the highly skewed class distributions of typical mapping problems. Specification of a consistent procedure and a benchmark testbed has permitted the evaluation of candidate recognition networks as well as pre- and post-processing and feature extraction options. The resulting default ARTMAP network and mapping methodology set a standard for a variety of related mapping problems and application domains. The second part of the dissertation investigates the development of cortical direction selectivity. The possible role of visual experience and oculomotor behavior in the maturation of cells in the primary visual cortex is studied. The responses of neurons in the thalamus and cortex of the cat are modeled when natural scenes are scanned by several types of eye movements. Inspired by the Hebbian-like synaptic plasticity, which is based upon correlations between cell activations, the second-order statistical structure of thalamo-cortical activity is examined. In the simulations, patterns of neural activity that lead to a correct refinement of cell responses are observed during visual fixation, when small ocular movements occur, but are not observed in the presence of large saccades. Simulations also replicate experiments in which kittens are reared under stroboscopic

  15. Mutated Genes in Schizophrenia Map to Brain Networks

    Science.gov (United States)

    ... Matters NIH Research Matters August 12, 2013 Mutated Genes in Schizophrenia Map to Brain Networks Schizophrenia networks in the ... in People with Serious Mental Illness Clues for Schizophrenia in Rare Gene Glitch Recognizing Schizophrenia: Seeking Clues to a Difficult ...

  16. Beyond Scale-Free Small-World Networks: Cortical Columns for Quick Brains

    Science.gov (United States)

    Stoop, Ralph; Saase, Victor; Wagner, Clemens; Stoop, Britta; Stoop, Ruedi

    2013-03-01

    We study to what extent cortical columns with their particular wiring boost neural computation. Upon a vast survey of columnar networks performing various real-world cognitive tasks, we detect no signs of enhancement. It is on a mesoscopic—intercolumnar—scale that the existence of columns, largely irrespective of their inner organization, enhances the speed of information transfer and minimizes the total wiring length required to bind distributed columnar computations towards spatiotemporally coherent results. We suggest that brain efficiency may be related to a doubly fractal connectivity law, resulting in networks with efficiency properties beyond those by scale-free networks.

  17. Registering cortical surfaces based on whole-brain structural connectivity and continuous connectivity analysis.

    Science.gov (United States)

    Gutman, Boris; Leonardo, Cassandra; Jahanshad, Neda; Hibar, Derrek; Eschenburg, Kristian; Nir, Talia; Villalon, Julio; Thompson, Paul

    2014-01-01

    We present a framework for registering cortical surfaces based on tractography-informed structural connectivity. We define connectivity as a continuous kernel on the product space of the cortex, and develop a method for estimating this kernel from tractography fiber models. Next, we formulate the kernel registration problem, and present a means to non-linearly register two brains' continuous connectivity profiles. We apply theoretical results from operator theory to develop an algorithm for decomposing the connectome into its shared and individual components. Lastly, we extend two discrete connectivity measures to the continuous case, and apply our framework to 98 Alzheimer's patients and controls. Our measures show significant differences between the two groups.

  18. Mapping distributed brain function and networks with diffuse optical tomography

    Science.gov (United States)

    Eggebrecht, Adam T.; Ferradal, Silvina L.; Robichaux-Viehoever, Amy; Hassanpour, Mahlega S.; Dehghani, Hamid; Snyder, Abraham Z.; Hershey, Tamara; Culver, Joseph P.

    2014-06-01

    Mapping of human brain function has revolutionized systems neuroscience. However, traditional functional neuroimaging by positron emission tomography or functional magnetic resonance imaging cannot be used when applications require portability, or are contraindicated because of ionizing radiation (positron emission tomography) or implanted metal (functional magnetic resonance imaging). Optical neuroimaging offers a non-invasive alternative that is radiation free and compatible with implanted metal and electronic devices (for example, pacemakers). However, optical imaging technology has heretofore lacked the combination of spatial resolution and wide field of view sufficient to map distributed brain functions. Here, we present a high-density diffuse optical tomography imaging array that can map higher-order, distributed brain function. The system was tested by imaging four hierarchical language tasks and multiple resting-state networks including the dorsal attention and default mode networks. Finally, we imaged brain function in patients with Parkinson's disease and implanted deep brain stimulators that preclude functional magnetic resonance imaging.

  19. Cortical and white matter mapping in the visual system- more than meets theeye: on the importance of functional imaging to understand visual systempathologies

    Directory of Open Access Journals (Sweden)

    Noa eRaz

    2014-08-01

    Full Text Available Information transmission within the visual system is highly organized with the ultimate goal of accomplishing higher-order, complex visuo-spatial and object identity processing. Perception is dependent on the intactness of the entire system and damage at each stage – in the eye itself, the visual pathways, or within cortical processing - might result in perception disturbance.Herein we will review several examples of lesions along the visual system, from the retina, via the optic nerve and chiasm and through the occipital cortex. We will address their clinical manifestation and their cortical substrate. The latter will be studied via functional magnetic resonance imaging (fMRI and Diffusion Tensor Imaging (DTI, enabling cortical and white matter mapping of the human brain. In contrast to traditional signal recording, these procedures enable simultaneous evaluation of the entire brain network engaged when subjects undertake a particular task or evaluate the entirety of associated white matter pathways.These examples provided will highlight the importance of using advanced imaging methods to better understand visual pathologies. We will argue that clinical manifestation cannot always be explained solely by structural damage and a functional view is required to understand the clinical symptom. In such cases we recommend using advanced imaging methods to better understand the neurological basis of visual phenomena.

  20. Cortical and white matter mapping in the visual system-more than meets the eye: on the importance of functional imaging to understand visual system pathologies.

    Science.gov (United States)

    Raz, Noa; Levin, Netta

    2014-01-01

    Information transmission within the visual system is highly organized with the ultimate goal of accomplishing higher-order, complex visuo-spatial and object identity processing. Perception is dependent on the intactness of the entire system and damage at each stage-in the eye itself, the visual pathways, or within cortical processing-might result in perception disturbance. Herein we will review several examples of lesions along the visual system, from the retina, via the optic nerve and chiasm and through the occipital cortex. We will address their clinical manifestation and their cortical substrate. The latter will be studied via functional magnetic resonance imaging (fMRI) and Diffusion Tensor Imaging (DTI), enabling cortical, and white matter mapping of the human brain. In contrast to traditional signal recording, these procedures enable simultaneous evaluation of the entire brain network engaged when subjects undertake a particular task or evaluate the entirety of associated white matter pathways. These examples provided will highlight the importance of using advanced imaging methods to better understand visual pathologies. We will argue that clinical manifestation cannot always be explained solely by structural damage and a functional view is required to understand the clinical symptom. In such cases we recommend using advanced imaging methods to better understand the neurological basis of visual phenomena.

  1. Patterns of accentuated grey-white differentiation on diffusion-weighted imaging or the apparent diffusion coefficient maps in comatose survivors after global brain injury

    Energy Technology Data Exchange (ETDEWEB)

    Kim, E., E-mail: xmida@hanmail.ne [Department of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Sohn, C.-H.; Chang, K.-H. [Department of Radiology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Chang, H.-W. [Departement of Radiology, Keimyung University Dongsan Medical Center, Daegu (Korea, Republic of); Lee, D.H. [Department of Radiology, Seoul Medical Center, Seoul (Korea, Republic of)

    2011-05-15

    Aim: To determine what disease entities show accentuated grey-white differentiation of the cerebral hemisphere on diffusion-weighted images (DWI) or apparent diffusion coefficient (ADC) maps, and whether there is a correlation between the different patterns and the cause of the brain injury. Methods and materials: The DWI and ADC maps of 19 patients with global brain injury were reviewed and evaluated to investigate whether there was a correlation between the different patterns seen on the DWI and ADC maps and the cause of global brain injury. The ADC values were measured for quantitative analysis. Results: There were three different patterns of ADC decrease: a predominant ADC decrease in only the cerebral cortex (n = 8; pattern I); an ADC decrease in both the cerebral cortex and white matter (WM) and a predominant decrease in the WM (n = 9; pattern II); and a predominant ADC decrease in only the WM (n = 3; pattern III). Conclusion: Pattern I is cerebral cortical injury, suggesting cortical laminar necrosis in hypoxic brain injury. Pattern II is cerebral cortical and WM injury, frequently seen in brain death, while pattern 3 is mainly WM injury, especially found in hypoglycaemic brain injury. It is likely that pattern I is decorticate injury and pattern II is decerebrate injury in hypoxic ischaemic encephalopathy.Patterns I and II are found in severe hypoxic brain injury, and pattern II is frequently shown in brain death, whereas pattern III was found in severe hypoglycaemic injury.

  2. Estimation of neural dynamics from MEG/EEG cortical current density maps: application to the reconstruction of large-scale cortical synchrony.

    Science.gov (United States)

    David, Olivier; Garnero, Line; Cosmelli, Diego; Varela, Francisco J

    2002-09-01

    There is a growing interest in elucidating the role of specific patterns of neural dynamics--such as transient synchronization between distant cell assemblies--in brain functions. Magnetoencephalography (MEG)/electroencephalography (EEG) recordings consist in the spatial integration of the activity from large and multiple remotely located populations of neurons. Massive diffusive effects and poor signal-to-noise ratio (SNR) preclude the proper estimation of indices related to cortical dynamics from nonaveraged MEG/EEG surface recordings. Source localization from MEG/EEG surface recordings with its excellent time resolution could contribute to a better understanding of the working brain. We propose a robust and original approach to the MEG/EEG distributed inverse problem to better estimate neural dynamics of cortical sources. For this, the surrogate data method is introduced in the MEG/EEG inverse problem framework. We apply this approach on nonaveraged data with poor SNR using the minimum norm estimator and find source localization results weakly sensitive to noise. Surrogates allow the reduction of the source space in order to reconstruct MEG/EEG data with reduced biases in both source localization and time-series dynamics. Monte Carlo simulations and results obtained from real MEG data indicate it is possible to estimate non invasively an important part of cortical source locations and dynamic and, therefore, to reveal brain functional networks.

  3. Speech perception in the child brain: cortical timing and its relevance to literacy acquisition.

    Science.gov (United States)

    Parviainen, Tiina; Helenius, Päivi; Poskiparta, Elisa; Niemi, Pekka; Salmelin, Riitta

    2011-12-01

    Speech processing skills go through intensive development during mid-childhood, providing basis also for literacy acquisition. The sequence of auditory cortical processing of speech has been characterized in adults, but very little is known about the neural representation of speech sound perception in the developing brain. We used whole-head magnetoencephalography (MEG) to record neural responses to speech and nonspeech sounds in first-graders (7-8-year-old) and compared the activation sequence to that in adults. In children, the general location of neural activity in the superior temporal cortex was similar to that in adults, but in the time domain the sequence of activation was strikingly different. Cortical differentiation between sound types emerged in a prolonged response pattern at about 250 ms after sound onset, in both hemispheres, clearly later than the corresponding effect at about 100 ms in adults that was detected specifically in the left hemisphere. Better reading skills were linked with shorter-lasting neural activation, speaking for interdependence of the maturing neural processes of auditory perception and developing linguistic skills. This study uniquely utilized the potential of MEG in comparing both spatial and temporal characteristics of neural activation between adults and children. Besides depicting the group-typical features in cortical auditory processing, the results revealed marked interindividual variability in children.

  4. Control-display mapping in brain-computer interfaces

    NARCIS (Netherlands)

    Thurlings, M.E.; Erp, J.B.F. van; Brouwer, A.-M.; Blankertz, B.; Werkhoven, P.J.

    2012-01-01

    Event-related potential (ERP) based brain-computer interfaces (BCIs) employ differences in brain responses to attended and ignored stimuli. When using a tactile ERP-BCI for navigation, mapping is required between navigation directions on a visual display and unambiguously corresponding tactile stimu

  5. Mapping Human Brain Function with MRI at 7 Tesla

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ In the past decade, the most significant development in MRI is the introduction of fMRI, which permits the mapping of human brain function with exquisite details noninvasively. Functional mapping can be achieved by measuring changes in the blood oxygenation level (I.e. The BOLD contrast) or cerebral blood flow.

  6. Morphine enhances the release of /sup 3/H-purines from rat brain cerebral cortical prisms

    Energy Technology Data Exchange (ETDEWEB)

    Wu, P.H.; Phillis, J.W.; Yuen, H.

    1982-10-01

    In vitro experiments have shown that /sup 3/H-purines can be released from /sup 3/H-adenosine preloaded rat brain cortical prisms by a KCl-evoked depolarization. The KCl-evoked release of /sup 3/H-purines is dependent on the concentration of KCl present in the superfusate. At concentrations of 10(-7) approximately 10(-5)M morphine did not influence the basal release of /sup 3/H-purines from the prisms, although it enhanced the KCl-evoked release of /sup 3/H-purines. The enhancement of KCl-evoked /sup 3/H-purine release by morphine was concentration-dependent and was antagonized by naloxone, suggesting the involvement of opiate receptors. Uptake studies with rat brain cerebral cortical synaptosomes show that morphine is a very weak inhibitor of adenosine uptake. Comparisons with dipyridamole, a potent inhibitor of adenosine uptake, suggest that this low level of inhibition of the uptake did not contribute significantly to the release of /sup 3/H-purine by morphine seen in our experiments. It is therefore suggested that morphine enhances KCl-evoked /sup 3/H-purine release by an interaction with opiate receptors and that the resultant increase in extracellular purine (adenosine) levels may account for some of the actions of morphine.

  7. Brain-derived neurotrophic factor stimulates energy metabolism in developing cortical neurons.

    Science.gov (United States)

    Burkhalter, Julia; Fiumelli, Hubert; Allaman, Igor; Chatton, Jean-Yves; Martin, Jean-Luc

    2003-09-10

    Brain-derived neurotrophic factor (BDNF) promotes the biochemical and morphological differentiation of selective populations of neurons during development. In this study we examined the energy requirements associated with the effects of BDNF on neuronal differentiation. Because glucose is the preferred energy substrate in the brain, the effect of BDNF on glucose utilization was investigated in developing cortical neurons via biochemical and imaging studies. Results revealed that BDNF increases glucose utilization and the expression of the neuronal glucose transporter GLUT3. Stimulation of glucose utilization by BDNF was shown to result from the activation of Na+/K+-ATPase via an increase in Na+ influx that is mediated, at least in part, by the stimulation of Na+-dependent amino acid transport. The increased Na+-dependent amino acid uptake by BDNF is followed by an enhancement of overall protein synthesis associated with the differentiation of cortical neurons. Together, these data demonstrate the ability of BDNF to stimulate glucose utilization in response to an enhanced energy demand resulting from increases in amino acid uptake and protein synthesis associated with the promotion of neuronal differentiation by BDNF.

  8. Human brain mapping: Experimental and computational approaches

    Energy Technology Data Exchange (ETDEWEB)

    Wood, C.C.; George, J.S.; Schmidt, D.M.; Aine, C.J. [Los Alamos National Lab., NM (US); Sanders, J. [Albuquerque VA Medical Center, NM (US); Belliveau, J. [Massachusetts General Hospital, Boston, MA (US)

    1998-11-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This program developed project combined Los Alamos' and collaborators' strengths in noninvasive brain imaging and high performance computing to develop potential contributions to the multi-agency Human Brain Project led by the National Institute of Mental Health. The experimental component of the project emphasized the optimization of spatial and temporal resolution of functional brain imaging by combining: (a) structural MRI measurements of brain anatomy; (b) functional MRI measurements of blood flow and oxygenation; and (c) MEG measurements of time-resolved neuronal population currents. The computational component of the project emphasized development of a high-resolution 3-D volumetric model of the brain based on anatomical MRI, in which structural and functional information from multiple imaging modalities can be integrated into a single computational framework for modeling, visualization, and database representation.

  9. Towards a parts-based approach to sub-cortical brain structure parsing

    Science.gov (United States)

    Gagneja, Digvijay; Xiong, Caiming; Corso, Jason J.

    2011-03-01

    The automatic localization and segmentation, or parsing, of neuroanatomical brain structures is a key step in many neuroscience tasks. However, the inherent variability in these brain structures and their appearance continues to challenge medical image processing methods. The state of the art primarily relies upon local voxelbased morphometry, Markov random field, and probabilistic atlas based approaches, which limits the ability to explicitly capture the parts-based structure inherent in the brain. We propose a method that defines a principled parts-based representation of the sub-cortical brain structures. Our method is based on the pictorial structures model and jointly models the appearance of each part as well as the layout of the parts as a whole. Inference is cast as a maximum a posteriori problem and solved in a steepest-descent manner. Experimental results on a 28-case data set demonstrate high accuracy of our method and substantiate our claim that there is significant promise in a parts-based approach to modeling medical imaging structures.

  10. Imaging separation of neuronal from vascular effects of cocaine on rat cortical brain in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Z.; Du, C.; Yuan, Z.; Luo, Z.; Volkow, N.D.; Pan, Y.; Du, C.

    2010-09-08

    MRI techniques to study brain function assume coupling between neuronal activity, metabolism and flow. However, recent evidence of physiological uncoupling between neuronal and cerebrovascular events highlights the need for methods to simultaneously measure these three properties. We report a multimodality optical approach that integrates dual-wavelength laser speckle imaging (measures changes in blood flow, blood volume and hemoglobin oxygenation), digital-frequency-ramping optical coherence tomography (images quantitative 3D vascular network) and Rhod2 fluorescence (images intracellular calcium for measure of neuronal activity) at high spatiotemporal resolutions (30 {micro}m, 10 Hz) and over a large field of view (3 x 5 mm{sup 2}). We apply it to assess cocaine's effects in rat cortical brain and show an immediate decrease 3.5 {+-} 0.9 min, phase (1) in the oxygen content of hemoglobin and the cerebral blood flow followed by an overshoot 7.1 {+-} 0.2 min, phase (2) lasting over 20 min whereas Ca{sup 2+} increased immediately (peaked at t = 4.1 {+-} 0.4 min) and remained elevated. This enabled us to identify a delay (2.9 {+-} 0.5 min) between peak neuronal and vascular responses in phase 2. The ability of this multimodality optical approach for simultaneous imaging at high spatiotemporal resolutions permits us to distinguish the vascular versus cellular changes of the brain, thus complimenting other neuroimaging modalities for brain functional studies (e. g., PET, fMRI).

  11. Increased cortical expression of two synaptogenic thrombospondins in human brain evolution.

    Science.gov (United States)

    Cáceres, Mario; Suwyn, Carolyn; Maddox, Marcelia; Thomas, James W; Preuss, Todd M

    2007-10-01

    Thrombospondins are extracellular-matrix glycoproteins implicated in the control of synaptogenesis and neurite growth. Previous microarray studies suggested that one gene of this family, thrombospondin 4 (THBS4), was upregulated during human brain evolution. Using independent techniques to examine thrombospondin expression patterns in adult brain samples, we report approximately 6-fold and approximately 2-fold greater expression of THBS4 and THBS2 messenger RNA (mRNA), respectively, in human cerebral cortex compared with chimpanzees and macaques, with corresponding differences in protein levels. In humans and chimpanzees, thrombospondin expression differences were observed in the forebrain (cortex and caudate), whereas the cerebellum and most nonbrain tissues exhibited similar levels of the 2 mRNAs. Histological examination revealed THBS4 mRNA and protein expression in numerous pyramidal and glial cells in the 3 species but humans also exhibited very prominent immunostaining of the synapse-rich cortical neuropil. In humans, additionally, THBS4 antibodies labeled beta-amyloid containing plaques in Alzheimer's cases and some control cases. This is the first detailed characterization of gene-expression changes in human evolution that involve specific brain regions, including portions of cerebral cortex. Increased expression of thrombospondins in human brain evolution could result in changes in synaptic organization and plasticity, and contribute to the distinctive cognitive abilities of humans, as well as to our unique vulnerability to neurodegenerative disease.

  12. Minimum conditions for the induction of cortical spreading depression in brain slices

    Science.gov (United States)

    Tang, Yujie T.; Mendez, Jorge M.; Theriot, Jeremy J.; Sawant, Punam M.; López-Valdés, Héctor E.; Ju, Y. Sungtaek

    2014-01-01

    Cortical spreading depression (CSD) occurs during various forms of brain injury such as stroke, subarachnoid hemorrhage, and brain trauma, but it is also thought to be the mechanism of the migraine aura. It is therefore expected to occur over a range of conditions including the awake behaving state. Yet it is unclear how such a massive depolarization could occur under relatively benign conditions. Using a microfluidic device with focal stimulation capability in a mouse brain slice model, we varied extracellular potassium concentration as well as the area exposed to increased extracellular potassium to determine the minimum conditions necessary to elicit CSD. Importantly, we focused on potassium levels that are physiologically plausible (≤145 mM; the intracellular potassium concentration). We found a strong correlation between the threshold concentration and the slice area exposed to increased extracellular potassium: minimum area of exposure was needed with the highest potassium concentration, while larger areas were needed at lower concentrations. We also found that moderate elevations of extracellular potassium were able to elicit CSD in relatively small estimated tissue volumes that might be activated under noninjury conditions. Our results thus show that CSD may be inducible under the conditions that expected in migraine aura as well as those related to brain trauma. PMID:25122714

  13. Glasgow Coma Scale, brain electric activity mapping and Glasgow Outcome Scale after hyperbaric oxygen treatment of severe brain injury

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To study the effect of hyperbaric oxygen (HBO) treatment of severe brain injury.Methods: Fifty-five patients were divided into a treatment group (n = 35 receiving HBO therapy ) and a control group (n = 20 receiving dehydrating, cortical steroid and antibiotic therapy) to observe the alteration of clinic GCS (Glasgow Coma Scale), brain electric activity mapping (BEAM), prognosis and GOS (Glasgow Outcome Scale) before and after hyperbaric oxygen treatment.Results: In the treatment group GCS, BEAM and GOS were improved obviously after 3 courses of treatment,GCS increased from 5.1 to 14.6 ( P < 0.01-0.001 ), the BEAM abnormal rate reduced from 94.3% to 38% (P <0.01-0.001 ), the GOS good-mild disability rate was 83.7%, and the middle-severe disability rate was 26.3%compared with the control group. There was a statistic significant difference between the two groups (P < 0.01-0.001).Conclusions: Hyperbaric oxygen treatment could improve obviously GCS, BEAM and GOS of severe brain injury patients, and effectively reduce the mortality and morbidity. It is an effective method to treat severe brain injury. two g

  14. ERK is involved in the reorganization of somatosensory cortical maps in adult rats submitted to hindlimb unloading.

    Directory of Open Access Journals (Sweden)

    Erwan Dupont

    Full Text Available Sensorimotor restriction by a 14-day period of hindlimb unloading (HU in the adult rat induces a reorganization of topographic maps and receptive fields. However, the underlying mechanisms are still unclear. Interest was turned towards a possible implication of intracellular MAPK signaling pathway since Extracellular-signal-Regulated Kinase 1/2 (ERK1/2 is known to play a significant role in the control of synaptic plasticity. In order to better understand the mechanisms underlying cortical plasticity in adult rats submitted to a sensorimotor restriction, we analyzed the time-course of ERK1/2 activation by immunoblot and of cortical reorganization by electrophysiological recordings, on rats submitted to hindlimb unloading over four weeks. Immunohistochemistry analysis provided evidence that ERK1/2 phosphorylation was increased in layer III neurons of the somatosensory cortex. This increase was transient, and parallel to the changes in hindpaw cortical map area (layer IV. By contrast, receptive fields were progressively enlarged from 7 to 28 days of hindlimb unloading. To determine whether ERK1/2 was involved in cortical remapping, we administered a specific ERK1/2 inhibitor (PD-98059 through osmotic mini-pump in rats hindlimb unloaded for 14 days. Results demonstrate that focal inhibition of ERK1/2 pathway prevents cortical reorganization, but had no effect on receptive fields. These results suggest that ERK1/2 plays a role in the induction of cortical plasticity during hindlimb unloading.

  15. Dwelling Quietly in the Rich Club: Brain Network Determinants of Slow Cortical Fluctuations

    CERN Document Server

    Gollo, Leonardo L; Hutchison, R Matthew; Heuvel, Martijn van den; Breakspear, Michael

    2016-01-01

    For more than a century, cerebral cartography has been driven by investigations of structural and morphological properties of the brain across spatial scales and the temporal/functional phenomena that emerge from these underlying features. The next era of brain mapping will be driven by studies that consider both of these components of brain organization simultaneously -- elucidating their interactions and dependencies. Using this guiding principle, we explored the origin of slowly fluctuating patterns of synchronization within the topological core of brain regions known as the rich club, implicated in the regulation of mood and introspection. We find that a constellation of densely interconnected regions that constitute the rich club (including the anterior insula, amygdala, and precuneus) play a central role in promoting a stable, dynamical core of spontaneous activity in the primate cortex. The slow time scales are well matched to the regulation of internal visceral states, corresponding to the somatic cor...

  16. Whole brain myelin mapping using T1- and T2-weighted MR imaging data

    Directory of Open Access Journals (Sweden)

    Marco eGanzetti

    2014-09-01

    Full Text Available Despite recent advancements in MR imaging, non-invasive mapping of myelin in the brain still remains an open issue. Here we attempted to provide a potential solution. Specifically, we developed a processing workflow based on T1-w and T2-w MR data to generate an optimized myelin enhanced contrast image. The workflow allows whole brain mapping using the T1-w/T2-w technique, which was originally introduced as a non-invasive method for assessing cortical myelin content. The hallmark of our approach is a retrospective calibration algorithm, applied to bias-corrected T1-w and T2-w images, that relies on image intensities outside the brain. This permits standardizing the intensity histogram of the ratio image, thereby allowing for across-subject statistical analyses. Quantitative comparisons of image histograms within and across different datasets confirmed the effectiveness of our normalization procedure. Not only did the calibrated T1-w/T2-w images exhibit a comparable intensity range, but also the shape of the intensity histograms was largely corresponding. We also assessed the reliability and specificity of the ratio image compared to other MR-based techniques, such as magnetization transfer ratio, fractional anisotropy and fluid-attenuated inversion recovery. With respect to these other techniques, T1-w/T2-w had consistently high values, as well as low inter-subject variability, in brain structures where myelin is most abundant. Overall, our results suggested that the T1-w/T2-w technique may be a valid tool supporting the non-invasive mapping of myelin in the brain. Therefore, it might find important applications in the study of brain development, aging and disease.

  17. IMAGING THE BRAIN AS SCHIZOPHRENIA DEVELOPS: DYNAMIC & GENETIC BRAIN MAPS.

    Science.gov (United States)

    Thompson, Paul; Rapoport, Judith L; Cannon, Tyrone D; Toga, Arthur W

    2002-01-01

    Schizophrenia is a chronic, debilitating psychiatric disorder that affects 0.2-2% of the population worldwide. Often striking without warning in the late teens or early twenties, its symptoms include auditory and visual hallucinations, psychotic outbreaks, bizarre or disordered thinking, depression and social withdrawal. To combat the disease, new antipsychotic drugs are emerging; these atypical neuroleptics target dopamine and serotonin pathways in the brain, offering increased therapeutic efficacy with fewer side effects. Despite their moderate success in controlling some patients' symptoms, little is known about the causes of schizophrenia, and what triggers the disease. Its peculiar age of onset raises key questions: What physical changes occur in the brain as a patient develops schizophrenia? Do these deficits spread in the brain, and can they be opposed? How do they relate to psychotic symptoms? As risk for the disease is genetically transmitted, do a patient's relatives exhibit similar brain changes? Recent advances in brain imaging and genetics provide exciting insight on these questions. Neuroimaging can now chart the emergence and progression of deficits in the brain, providing an exceptionally sharp scalpel to dissect the effects of genetic risk, environmental triggers, and susceptibility genes. Visualizing the dynamics of the disease, these techniques also offer new strategies to evaluate drugs that combat the unrelenting symptoms of schizophrenia.

  18. Mapping human whole-brain structural networks with diffusion MRI.

    Directory of Open Access Journals (Sweden)

    Patric Hagmann

    Full Text Available Understanding the large-scale structural network formed by neurons is a major challenge in system neuroscience. A detailed connectivity map covering the entire brain would therefore be of great value. Based on diffusion MRI, we propose an efficient methodology to generate large, comprehensive and individual white matter connectional datasets of the living or dead, human or animal brain. This non-invasive tool enables us to study the basic and potentially complex network properties of the entire brain. For two human subjects we find that their individual brain networks have an exponential node degree distribution and that their global organization is in the form of a small world.

  19. The dynamic brain: from spiking neurons to neural masses and cortical fields.

    Directory of Open Access Journals (Sweden)

    Gustavo Deco

    Full Text Available The cortex is a complex system, characterized by its dynamics and architecture, which underlie many functions such as action, perception, learning, language, and cognition. Its structural architecture has been studied for more than a hundred years; however, its dynamics have been addressed much less thoroughly. In this paper, we review and integrate, in a unifying framework, a variety of computational approaches that have been used to characterize the dynamics of the cortex, as evidenced at different levels of measurement. Computational models at different space-time scales help us understand the fundamental mechanisms that underpin neural processes and relate these processes to neuroscience data. Modeling at the single neuron level is necessary because this is the level at which information is exchanged between the computing elements of the brain; the neurons. Mesoscopic models tell us how neural elements interact to yield emergent behavior at the level of microcolumns and cortical columns. Macroscopic models can inform us about whole brain dynamics and interactions between large-scale neural systems such as cortical regions, the thalamus, and brain stem. Each level of description relates uniquely to neuroscience data, from single-unit recordings, through local field potentials to functional magnetic resonance imaging (fMRI, electroencephalogram (EEG, and magnetoencephalogram (MEG. Models of the cortex can establish which types of large-scale neuronal networks can perform computations and characterize their emergent properties. Mean-field and related formulations of dynamics also play an essential and complementary role as forward models that can be inverted given empirical data. This makes dynamic models critical in integrating theory and experiments. We argue that elaborating principled and informed models is a prerequisite for grounding empirical neuroscience in a cogent theoretical framework, commensurate with the achievements in the

  20. More 'mapping' in brain mapping: statistical comparison of effects

    DEFF Research Database (Denmark)

    Jernigan, Terry Lynne; Gamst, Anthony C.; Fennema-Notestine, Christine

    2003-01-01

    , or for that matter of brain structure, are generally constructed using analyses that yield no basis for inferences regarding the spatial nonuniformity of the effects. In the normal analysis path for functional images, for example, there is nowhere a statistical comparison of the observed effect in any voxel relative...

  1. Mild traumatic brain injury is associated with reduced cortical thickness in those at risk for Alzheimer's disease.

    Science.gov (United States)

    Hayes, Jasmeet P; Logue, Mark W; Sadeh, Naomi; Spielberg, Jeffrey M; Verfaellie, Mieke; Hayes, Scott M; Reagan, Andrew; Salat, David H; Wolf, Erika J; McGlinchey, Regina E; Milberg, William P; Stone, Annjanette; Schichman, Steven A; Miller, Mark W

    2017-01-11

    Moderate-to-severe traumatic brain injury is one of the strongest environmental risk factors for the development of neurodegenerative diseases such as late-onset Alzheimer's disease, although it is unclear whether mild traumatic brain injury, or concussion, also confers risk. This study examined mild traumatic brain injury and genetic risk as predictors of reduced cortical thickness in brain regions previously associated with early Alzheimer's disease, and their relationship with episodic memory. Participants were 160 Iraq and Afghanistan War veterans between the ages of 19 and 58, many of whom carried mild traumatic brain injury and post-traumatic stress disorder diagnoses. Whole-genome polygenic risk scores for the development of Alzheimer's disease were calculated using summary statistics from the largest Alzheimer's disease genome-wide association study to date. Results showed that mild traumatic brain injury moderated the relationship between genetic risk for Alzheimer's disease and cortical thickness, such that individuals with mild traumatic brain injury and high genetic risk showed reduced cortical thickness in Alzheimer's disease-vulnerable regions. Among males with mild traumatic brain injury, high genetic risk for Alzheimer's disease was associated with cortical thinning as a function of time since injury. A moderated mediation analysis showed that mild traumatic brain injury and high genetic risk indirectly influenced episodic memory performance through cortical thickness, suggesting that cortical thinning in Alzheimer's disease-vulnerable brain regions is a mechanism for reduced memory performance. Finally, analyses that examined the apolipoprotein E4 allele, post-traumatic stress disorder, and genetic risk for schizophrenia and depression confirmed the specificity of the Alzheimer's disease polygenic risk finding. These results provide evidence that mild traumatic brain injury is associated with greater neurodegeneration and reduced memory performance

  2. Mapping small-world properties through development in the human brain: disruption in schizophrenia.

    Directory of Open Access Journals (Sweden)

    Dardo Tomasi

    Full Text Available Evidence from imaging studies suggests that the human brain has a small-world network topology that might be disrupted in certain brain disorders. However, current methodology is based on global graph theory measures, such as clustering, C, characteristic path length, L, and small-worldness, S, that lack spatial specificity and are insufficient to identify regional brain abnormalities. Here we propose novel ultra-fast methodology for mapping local properties of brain network topology such as local C, L and S (lC, lL and lS in the human brain at 3-mm isotropic resolution from 'resting-state' magnetic resonance imaging data. Test-retest datasets from 40 healthy children/adolescents were used to demonstrate the overall good reliability of the measures across sessions and computational parameters (intraclass correlation > 0.5 for lC and lL and their low variability across subjects (< 29%. Whereas regions with high local functional connectivity density (lFCD; local degree in posterior parietal and occipital cortices demonstrated high lC and short lL, subcortical regions (globus pallidus, thalamus, hippocampus and amygdala, cerebellum (lobes and vermis, cingulum and temporal cortex also had high, lS, demonstrating stronger small-world topology than other hubs. Children/adolescents had stronger lFCD, higher lC and longer lL in most cortical regions and thalamus than 74 healthy adults, consistent with pruning of functional connectivity during maturation. In contrast, lFCD, lC and lL were weaker in thalamus and midbrain, and lL was shorter in frontal cortical regions and cerebellum for 69 schizophrenia patients than for 74 healthy controls, suggesting exaggerated pruning of connectivity in schizophrenia. Follow up correlation analyses for seeds in thalamus and midbrain uncovered lower positive connectivity of these regions in thalamus, putamen, cerebellum and frontal cortex (cingulum, orbitofrontal, inferior frontal and lower negative connectivity in

  3. The contribution of brain sub-cortical loops in the expression and acquisition of action understanding abilities☆

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    Caligiore, Daniele; Pezzulo, Giovanni; Miall, R. Chris; Baldassarre, Gianluca

    2013-01-01

    Research on action understanding in cognitive neuroscience has led to the identification of a wide “action understanding network” mainly encompassing parietal and premotor cortical areas. Within this cortical network mirror neurons are critically involved implementing a neural mechanism according to which, during action understanding, observed actions are reflected in the motor patterns for the same actions of the observer. We suggest that focusing only on cortical areas and processes could be too restrictive to explain important facets of action understanding regarding, for example, the influence of the observer's motor experience, the multiple levels at which an observed action can be understood, and the acquisition of action understanding ability. In this respect, we propose that aside from the cortical action understanding network, sub-cortical processes pivoting on cerebellar and basal ganglia cortical loops could crucially support both the expression and the acquisition of action understanding abilities. Within the paper we will discuss how this extended view can overcome some limitations of the “pure” cortical perspective, supporting new theoretical predictions on the brain mechanisms underlying action understanding that could be tested by future empirical investigations. PMID:23911926

  4. An evolutionary theory of schizophrenia: cortical connectivity, metarepresentation, and the social brain.

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    Burns, Jonathan Kenneth

    2004-12-01

    Schizophrenia is a worldwide, prevalent disorder with a multifactorial but highly genetic aetiology. A constant prevalence rate in the face of reduced fecundity has caused some to argue that an evolutionary advantage exists in unaffected relatives. Here, I critique this adaptationist approach, and review--and find wanting--Crow's "speciation" hypothesis. In keeping with available biological and psychological evidence, I propose an alternative theory of the origins of this disorder. Schizophrenia is a disorder of the social brain, and it exists as a costly trade-off in the evolution of complex social cognition. Paleoanthropological and comparative primate research suggests that hominids evolved complex cortical interconnectivity (in particular, frontotemporal and frontoparietal circuits) to regulate social cognition and the intellectual demands of group living. I suggest that the ontogenetic mechanism underlying this cerebral adaptation was sequential hypermorphosis and that it rendered the hominid brain vulnerable to genetic and environmental insults. I argue that changes in genes regulating the timing of neurodevelopment occurred prior to the migration of Homo sapiens out of Africa 100,000-150,000 years ago, giving rise to the schizotypal spectrum. While some individuals within this spectrum may have exhibited unusual creativity and iconoclasm, this phenotype was not necessarily adaptive in reproductive terms. However, because the disorder shared a common genetic basis with the evolving circuitry of the social brain, it persisted. Thus schizophrenia emerged as a costly trade-off in the evolution of complex social cognition.

  5. Mapping entrained brain oscillations during transcranial alternating current stimulation (tACS).

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    Witkowski, Matthias; Garcia-Cossio, Eliana; Chander, Bankim S; Braun, Christoph; Birbaumer, Niels; Robinson, Stephen E; Soekadar, Surjo R

    2016-10-15

    Transcranial alternating current stimulation (tACS), a non-invasive and well-tolerated form of electric brain stimulation, can influence perception, memory, as well as motor and cognitive function. While the exact underlying neurophysiological mechanisms are unknown, the effects of tACS are mainly attributed to frequency-specific entrainment of endogenous brain oscillations in brain areas close to the stimulation electrodes, and modulation of spike timing dependent plasticity reflected in gamma band oscillatory responses. tACS-related electromagnetic stimulator artifacts, however, impede investigation of these neurophysiological mechanisms. Here we introduce a novel approach combining amplitude-modulated tACS during whole-head magnetoencephalography (MEG) allowing for artifact-free source reconstruction and precise mapping of entrained brain oscillations underneath the stimulator electrodes. Using this approach, we show that reliable reconstruction of neuromagnetic low- and high-frequency oscillations including high gamma band activity in stimulated cortical areas is feasible opening a new window to unveil the mechanisms underlying the effects of stimulation protocols that entrain brain oscillatory activity.

  6. An implantable VLSI architecture for real time spike sorting in cortically controlled Brain Machine Interfaces.

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    Aghagolzadeh, Mehdi; Zhang, Fei; Oweiss, Karim

    2010-01-01

    Brain Machine Interface (BMI) systems demand real-time spike sorting to instantaneously decode the spike trains of simultaneously recorded cortical neurons. Real-time spike sorting, however, requires extensive computational power that is not feasible to implement in implantable BMI architectures, thereby requiring transmission of high-bandwidth raw neural data to an external computer. In this work, we describe a miniaturized, low power, programmable hardware module capable of performing this task within the resource constraints of an implantable chip. The module computes a sparse representation of the spike waveforms followed by "smart" thresholding. This cascade restricts the sparse representation to a subset of projections that preserve the discriminative features of neuron-specific spike waveforms. In addition, it further reduces telemetry bandwidth making it feasible to wirelessly transmit only the important biological information to the outside world, thereby improving the efficiency, practicality and viability of BMI systems in clinical applications.

  7. Treatment of Traumatic Brain Injury by Localized Application of Sub-atmospheric Pressure to the Site of Cortical Impact

    Science.gov (United States)

    2013-07-01

    Resuscitation (MTR – the controlled application of vacuum) to the cerebral cortex following a controlled cortical impact (CCI) injury reduces brain... edema and the extent of injury, modulates metabolites in injured neuronal tissues, preserves neuronal tissue, and improves functional recovery. The...hyperintense region ipsilateral to the injured site. There was a large area of T2 hyperintensity ( edema ) sometimes associated with hypointensity

  8. Automated in situ brain imaging for mapping the Drosophila connectome.

    Science.gov (United States)

    Lin, Chi-Wen; Lin, Hsuan-Wen; Chiu, Mei-Tzu; Shih, Yung-Hsin; Wang, Ting-Yuan; Chang, Hsiu-Ming; Chiang, Ann-Shyn

    2015-01-01

    Mapping the connectome, a wiring diagram of the entire brain, requires large-scale imaging of numerous single neurons with diverse morphology. It is a formidable challenge to reassemble these neurons into a virtual brain and correlate their structural networks with neuronal activities, which are measured in different experiments to analyze the informational flow in the brain. Here, we report an in situ brain imaging technique called Fly Head Array Slice Tomography (FHAST), which permits the reconstruction of structural and functional data to generate an integrative connectome in Drosophila. Using FHAST, the head capsules of an array of flies can be opened with a single vibratome sectioning to expose the brains, replacing the painstaking and inconsistent brain dissection process. FHAST can reveal in situ brain neuroanatomy with minimal distortion to neuronal morphology and maintain intact neuronal connections to peripheral sensory organs. Most importantly, it enables the automated 3D imaging of 100 intact fly brains in each experiment. The established head model with in situ brain neuroanatomy allows functional data to be accurately registered and associated with 3D images of single neurons. These integrative data can then be shared, searched, visualized, and analyzed for understanding how brain-wide activities in different neurons within the same circuit function together to control complex behaviors.

  9. Spatial mapping of structural and connectional imaging data for the developing human brain with diffusion tensor imaging.

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    Ouyang, Austin; Jeon, Tina; Sunkin, Susan M; Pletikos, Mihovil; Sedmak, Goran; Sestan, Nenad; Lein, Ed S; Huang, Hao

    2015-02-01

    During human brain development from fetal stage to adulthood, the white matter (WM) tracts undergo dramatic changes. Diffusion tensor imaging (DTI), a widely used magnetic resonance imaging (MRI) modality, offers insight into the dynamic changes of WM fibers as these fibers can be noninvasively traced and three-dimensionally (3D) reconstructed with DTI tractography. The DTI and conventional T1 weighted MRI images also provide sufficient cortical anatomical details for mapping the cortical regions of interests (ROIs). In this paper, we described basic concepts and methods of DTI techniques that can be used to trace major WM tracts noninvasively from fetal brain of 14 postconceptional weeks (pcw) to adult brain. We applied these techniques to acquire DTI data and trace, reconstruct and visualize major WM tracts during development. After categorizing major WM fiber bundles into five unique functional tract groups, namely limbic, brain stem, projection, commissural and association tracts, we revealed formation and maturation of these 3D reconstructed WM tracts of the developing human brain. The structural and connectional imaging data offered by DTI provides the anatomical backbone of transcriptional atlas of the developing human brain.

  10. A quantitative transcriptome reference map of the normal human brain.

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    Caracausi, Maria; Vitale, Lorenza; Pelleri, Maria Chiara; Piovesan, Allison; Bruno, Samantha; Strippoli, Pierluigi

    2014-10-01

    We performed an innovative systematic meta-analysis of 60 gene expression profiles of whole normal human brain, to provide a quantitative transcriptome reference map of it, i.e. a reference typical value of expression for each of the 39,250 known, mapped and 26,026 uncharacterized (unmapped) transcripts. To this aim, we used the software named Transcriptome Mapper (TRAM), which is able to generate transcriptome maps based on gene expression data from multiple sources. We also analyzed differential expression by comparing the brain transcriptome with those derived from human foetal brain gene expression, from a pool of human tissues (except the brain) and from the two normal human brain regions cerebellum and cerebral cortex, which are two of the main regions severely affected when cognitive impairment occurs, as happens in the case of trisomy 21. Data were downloaded from microarray databases, processed and analyzed using TRAM software and validated in vitro by assaying gene expression through several magnitude orders by 'real-time' reverse transcription polymerase chain reaction (RT-PCR). The excellent agreement between in silico and experimental data suggested that our transcriptome maps may be a useful quantitative reference benchmark for gene expression studies related to the human brain. Furthermore, our analysis yielded biological insights about those genes which have an intrinsic over-/under-expression in the brain, in addition offering a basis for the regional analysis of gene expression. This could be useful for the study of chromosomal alterations associated to cognitive impairment, such as trisomy 21, the most common genetic cause of intellectual disability.

  11. Alternative Stimulation Intensities for Mapping Cortical Motor Area with Navigated TMS.

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    Kallioniemi, Elisa; Julkunen, Petro

    2016-05-01

    Navigated transcranial magnetic stimulation (nTMS) is becoming a popular tool in pre-operative mapping of functional motor areas. The stimulation intensities used in the mapping are commonly suprathreshold intensities with respect to the patient's resting motor threshold (rMT). There is no consensus on which suprathreshold intensity should be used nor on the optimal criteria for selecting the appropriate stimulation intensity (SI). In this study, the left motor cortices of 12 right-handed volunteers (8 males, age 24-61 years) were mapped using motor evoked potentials with an SI of 110 and 120 % of rMT and with an upper threshold (UT) estimated by the Mills-Nithi algorithm. The UT was significantly lower than 120 % of rMT (p rMT (p = 0.112). The representation sizes followed a similar trend, i.e. areas computed based on UT (5.9 cm(2)) and 110 % of rMT (5.0 cm(2)) being smaller than that of 120 % of rMT (8.8 cm(2)) (p ≤ 0.001). There was no difference in representation sizes between 110 % of rMT and UT. The variance in representation size was found to be significantly lower with UT compared to 120 % of rMT (p = 0.048, uncorrected), while there was no difference between 110 % of rMT and UT or 120 % of rMT. Indications of lowest inter-individual variation in representation size were observed with UT; this is possibly due to the fact that it takes into account the individual input-output characteristics of the motor cortex. Therefore, the UT seems to be a good option for SI in motor mapping applications to outline functional motor areas with nTMS and it could potentially reduce the inter-individual variation caused by the selection of SI in motor mapping in pre-surgical applications and radiosurgery planning.

  12. Methylphenidate and the juvenile brain: enhancement of attention at the expense of cortical plasticity?

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    Urban, Kimberly R; Gao, Wen-Jun

    2013-12-01

    Methylphenidate (Ritalin) is the most commonly prescribed psychoactive drug for juveniles and adolescents. Used to treat attention-deficit/hyperactivity disorder (ADHD) and for cognitive enhancement in healthy individuals, it has been regarded as a relatively safe medication for the past several decades. However, a thorough review of the literature reveals that the age-dependent activities of the drug, as well as potential developmental effects, are largely ignored. In addition, the diagnosis of ADHD is subjective, leaving open the possibility of misdiagnosis and excessive prescription of the drug. Recent studies have suggested that early life exposure of healthy rodent models to methylphenidate resulted in altered sleep/wake cycle, heightened stress reactivity, and, in fact, a dosage previously thought of as therapeutic depressed neuronal function in juvenile rats. Furthermore, juvenile rats exposed to low-dose methylphenidate displayed alterations in neural markers of plasticity, indicating that the drug might alter the basic properties of prefrontal cortical circuits. In this review of the current literature, we propose that juvenile exposure to methylphenidate may cause abnormal prefrontal function and impaired plasticity in the healthy brain, strengthening the case for developing a more thorough understanding of methylphenidate's actions on the developing, juvenile brain, as well as better diagnostic measures for ADHD.

  13. Shaping the aging brain: Role of auditory input patterns in the emergence of auditory cortical impairments

    Directory of Open Access Journals (Sweden)

    Brishna Soraya Kamal

    2013-09-01

    Full Text Available Age-related impairments in the primary auditory cortex (A1 include poor tuning selectivity, neural desynchronization and degraded responses to low-probability sounds. These changes have been largely attributed to reduced inhibition in the aged brain, and are thought to contribute to substantial hearing impairment in both humans and animals. Since many of these changes can be partially reversed with auditory training, it has been speculated that they might not be purely degenerative, but might rather represent negative plastic adjustments to noisy or distorted auditory signals reaching the brain. To test this hypothesis, we examined the impact of exposing young adult rats to 8 weeks of low-grade broadband noise on several aspects of A1 function and structure. We then characterized the same A1 elements in aging rats for comparison. We found that the impact of noise exposure on A1 tuning selectivity, temporal processing of auditory signal and responses to oddball tones was almost indistinguishable from the effect of natural aging. Moreover, noise exposure resulted in a reduction in the population of parvalbumin inhibitory interneurons and cortical myelin as previously documented in the aged group. Most of these changes reversed after returning the rats to a quiet environment. These results support the hypothesis that age-related changes in A1 have a strong activity-dependent component and indicate that the presence or absence of clear auditory input patterns might be a key factor in sustaining adult A1 function.

  14. Brain cortical thickness and surface area correlates of neurocognitive performance in patients with schizophrenia, bipolar disorder, and healthy adults.

    Science.gov (United States)

    Hartberg, C B; Sundet, K; Rimol, L M; Haukvik, U K; Lange, E H; Nesvåg, R; Dale, A M; Melle, I; Andreassen, O A; Agartz, I

    2011-11-01

    Relationships between cortical brain structure and neurocognitive functioning have been reported in schizophrenia, but findings are inconclusive, and only a few studies in bipolar disorder have addressed this issue. This is the first study to directly compare relationships between cortical thickness and surface area with neurocognitive functioning in patients with schizophrenia (n = 117) and bipolar disorder (n = 121) and healthy controls (n = 192). MRI scans were obtained, and regional cortical thickness and surface area measurements were analyzed for relationships with test scores from 6 neurocognitive domains. In the combined sample, cortical thickness in the right rostral anterior cingulate was inversely related to working memory, and cortical surface area in four frontal and temporal regions were positively related to neurocognitive functioning. A positive relationship between left transverse temporal thickness and processing speed was specific to schizophrenia. A negative relationship between right temporal pole thickness and working memory was specific to bipolar disorder. In conclusion, significant cortical structure/function relationships were found in a large sample of healthy controls and patients with schizophrenia or bipolar disorder. The differences that were found between schizophrenia and bipolar may indicate differential relationship patterns in the two disorders, which may be of relevance for understanding the underlying pathophysiology.

  15. Multicenter R2* mapping in the healthy brain

    DEFF Research Database (Denmark)

    Ropele, Stefan; Wattjes, Mike P; Langkammer, Christian;

    2014-01-01

    PURPOSE: The R2* relaxation rate constant has been suggested as a sensitive measure for iron accumulation. The aim of this multi-center study was to assess the inter-scanner and inter-subject variability of R2* mapping and to investigate the relationship between brain volume and R2* in specific...

  16. Mapping the calcitonin receptor in human brain stem

    DEFF Research Database (Denmark)

    Bower, Rebekah L; Eftekhari, Sajedeh; Waldvogel, Henry J

    2016-01-01

    understanding of these hormone systems by mapping CTR expression in the human brain stem, specifically the medulla oblongata. Widespread CTR-like immunoreactivity was observed throughout the medulla. Dense CTR staining was noted in several discrete nuclei, including the nucleus of the solitary tract...

  17. How concepts are encoded in the human brain: A modality independent, category-based cortical organization of semantic knowledge.

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    Handjaras, Giacomo; Ricciardi, Emiliano; Leo, Andrea; Lenci, Alessandro; Cecchetti, Luca; Cosottini, Mirco; Marotta, Giovanna; Pietrini, Pietro

    2016-07-15

    How conceptual knowledge is represented in the human brain remains to be determined. To address the differential role of low-level sensory-based and high-level abstract features in semantic processing, we combined behavioral studies of linguistic production and brain activity measures by functional magnetic resonance imaging in sighted and congenitally blind individuals while they performed a property-generation task with concrete nouns from eight categories, presented through visual and/or auditory modalities. Patterns of neural activity within a large semantic cortical network that comprised parahippocampal, lateral occipital, temporo-parieto-occipital and inferior parietal cortices correlated with linguistic production and were independent both from the modality of stimulus presentation (either visual or auditory) and the (lack of) visual experience. In contrast, selected modality-dependent differences were observed only when the analysis was limited to the individual regions within the semantic cortical network. We conclude that conceptual knowledge in the human brain relies on a distributed, modality-independent cortical representation that integrates the partial category and modality specific information retained at a regional level.

  18. Laser-scanning astrocyte mapping reveals increased glutamate-responsive domain size and disrupted maturation of glutamate uptake following neonatal cortical freeze-lesion

    Directory of Open Access Journals (Sweden)

    Mortiz eArmbruster

    2014-09-01

    Full Text Available Astrocytic uptake of glutamate shapes extracellular neurotransmitter dynamics, receptor activation, and synaptogenesis. During development, glutamate transport becomes more robust. How neonatal brain insult affects the functional maturation of glutamate transport remains unanswered. Neonatal brain insult can lead to developmental delays, cognitive losses, and epilepsy; the disruption of glutamate transport is known to cause changes in synaptogenesis, receptor activation, and seizure. Using the neonatal freeze-lesion (FL model, we have investigated how insult affects the maturation of astrocytic glutamate transport. As lesioning occurs on the day of birth, a time when astrocytes are still functionally immature, this model is ideal for identifying changes in astrocyte maturation following insult. Reactive astrocytosis, astrocyte proliferation, and in vitro hyperexcitability are known to occur in this model. To probe astrocyte glutamate transport with better spatial precision we have developed a novel technique, Laser Scanning Astrocyte Mapping (LSAM, which combines glutamate transport current (TC recording from astrocytes with laser scanning glutamate photolysis. LSAM allows us to identify the area from which a single astrocyte can transport glutamate and to quantify spatial heterogeneity in the rate of glutamate clearance kinetics within that domain. Using LSAM, we report that cortical astrocytes have an increased glutamate-responsive area following FL and that TCs have faster decay times in distal, as compared to proximal processes. Furthermore, the developmental shift from GLAST- to GLT-1-dominated clearance is disrupted following FL. These findings introduce a novel method to probe astrocyte glutamate uptake and show that neonatal cortical FL disrupts the functional maturation of cortical astrocytes.

  19. Whole brain susceptibility mapping using compressed sensing.

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    Wu, Bing; Li, Wei; Guidon, Arnaud; Liu, Chunlei

    2012-01-01

    The derivation of susceptibility from image phase is hampered by the ill-conditioned filter inversion in certain k-space regions. In this article, compressed sensing is used to compensate for the k-space regions where direct filter inversion is unstable. A significantly lower level of streaking artifacts is produced in the resulting susceptibility maps for both simulated and in vivo data sets compared to outcomes obtained using the direct threshold method. It is also demonstrated that the compressed sensing based method outperforms regularization based methods. The key difference between the regularized inversions and compressed sensing compensated inversions is that, in the former case, the entire k-space spectrum estimation is affected by the ill-conditioned filter inversion in certain k-space regions, whereas in the compressed sensing based method only the ill-conditioned k-space regions are estimated. In the susceptibility map calculated from the phase measurement obtained using a 3T scanner, not only are the iron-rich regions well depicted, but good contrast between white and gray matter interfaces that feature a low level of susceptibility variations are also obtained. The correlation between the iron content and the susceptibility levels in iron-rich deep nucleus regions is studied, and strong linear relationships are observed which agree with previous findings.

  20. Mapping the Stability of Human Brain Asymmetry across Five Sex-Chromosome Aneuploidies

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    Lin, Amy; Clasen, Liv; Lee, Nancy Raitano; Wallace, Gregory L.; Lalonde, Francois; Blumenthal, Jonathan; Giedd, Jay N.

    2015-01-01

    The human brain displays stereotyped and early emerging patterns of cortical asymmetry in health. It is unclear if these asymmetries are highly sensitive to genetic and environmental variation or fundamental features of the brain that can survive severe developmental perturbations. To address this question, we mapped cortical thickness (CT) asymmetry in a group of genetically defined disorders known to impact CT development. Participants included 137 youth with one of five sex-chromosome aneuploidies [SCAs; XXX (n = 28), XXY (n = 58), XYY (n = 26), XXYY (n = 20), and XXXXY (n = 5)], and 169 age-matched typically developing controls (80 female). In controls, we replicated previously reported rightward inferior frontal and leftward lateral parietal CT asymmetry. These opposing frontoparietal CT asymmetries were broadly preserved in all five SCA groups. However, we also detected foci of shifting CT asymmetry with aneuploidy, which fell almost exclusively within regions of significant CT asymmetry in controls. Specifically, X-chromosome aneuploidy accentuated normative rightward inferior frontal asymmetries, while Y-chromosome aneuploidy reversed normative rightward medial prefrontal and lateral temporal asymmetries. These findings indicate that (1) the stereotyped normative pattern of opposing frontoparietal CT asymmetry arises from developmental mechanisms that can withstand gross chromosomal aneuploidy and (2) X and Y chromosomes can exert focal, nonoverlapping and directionally opposed influences on CT asymmetry within cortical regions of significant asymmetry in health. Our study attests to the resilience of developmental mechanisms that support the global patterning of CT asymmetry in humans, and motivates future research into the molecular bases and functional consequences of sex chromosome dosage effects on CT asymmetry. PMID:25568109

  1. Mapping the stability of human brain asymmetry across five sex-chromosome aneuploidies.

    Science.gov (United States)

    Lin, Amy; Clasen, Liv; Lee, Nancy Raitano; Wallace, Gregory L; Lalonde, Francois; Blumenthal, Jonathan; Giedd, Jay N; Raznahan, Armin

    2015-01-07

    The human brain displays stereotyped and early emerging patterns of cortical asymmetry in health. It is unclear if these asymmetries are highly sensitive to genetic and environmental variation or fundamental features of the brain that can survive severe developmental perturbations. To address this question, we mapped cortical thickness (CT) asymmetry in a group of genetically defined disorders known to impact CT development. Participants included 137 youth with one of five sex-chromosome aneuploidies [SCAs; XXX (n = 28), XXY (n = 58), XYY (n = 26), XXYY (n = 20), and XXXXY (n = 5)], and 169 age-matched typically developing controls (80 female). In controls, we replicated previously reported rightward inferior frontal and leftward lateral parietal CT asymmetry. These opposing frontoparietal CT asymmetries were broadly preserved in all five SCA groups. However, we also detected foci of shifting CT asymmetry with aneuploidy, which fell almost exclusively within regions of significant CT asymmetry in controls. Specifically, X-chromosome aneuploidy accentuated normative rightward inferior frontal asymmetries, while Y-chromosome aneuploidy reversed normative rightward medial prefrontal and lateral temporal asymmetries. These findings indicate that (1) the stereotyped normative pattern of opposing frontoparietal CT asymmetry arises from developmental mechanisms that can withstand gross chromosomal aneuploidy and (2) X and Y chromosomes can exert focal, nonoverlapping and directionally opposed influences on CT asymmetry within cortical regions of significant asymmetry in health. Our study attests to the resilience of developmental mechanisms that support the global patterning of CT asymmetry in humans, and motivates future research into the molecular bases and functional consequences of sex chromosome dosage effects on CT asymmetry.

  2. Modulation of sensitivity to alcohol by cortical and thalamic brain regions.

    Science.gov (United States)

    Jaramillo, Anel A; Randall, Patrick A; Frisbee, Suzanne; Besheer, Joyce

    2016-10-01

    The nucleus accumbens core (AcbC) is a key brain region known to regulate the discriminative stimulus/interoceptive effects of alcohol. As such, the goal of the present work was to identify AcbC projection regions that may also modulate sensitivity to alcohol. Accordingly, AcbC afferent projections were identified in behaviorally naïve rats using a retrograde tracer which led to the focus on the medial prefrontal cortex (mPFC), insular cortex (IC) and rhomboid thalamic nucleus (Rh). Next, to examine the possible role of these brain regions in modulating sensitivity to alcohol, neuronal response to alcohol in rats trained to discriminate alcohol (1 g/kg, intragastric [IG]) vs. water was examined using a two-lever drug discrimination task. As such, rats were administered water or alcohol (1 g/kg, IG) and brain tissue was processed for c-Fos immunoreactivity (IR), a marker of neuronal activity. Alcohol decreased c-Fos IR in the mPFC, IC, Rh and AcbC. Lastly, site-specific pharmacological inactivation with muscimol + baclofen (GABAA agonist + GABAB agonist) was used to determine the functional role of the mPFC, IC and Rh in modulating the interoceptive effects of alcohol in rats trained to discriminate alcohol (1 g/kg, IG) vs. water. mPFC inactivation resulted in full substitution for the alcohol training dose, and IC and Rh inactivation produced partial alcohol-like effects, demonstrating the importance of these regions, with known projections to the AcbC, in modulating sensitivity to alcohol. Together, these data demonstrate a site of action of alcohol and the recruitment of cortical/thalamic regions in modulating sensitivity to the interoceptive effects of alcohol.

  3. Increased brain cortical activity during parabolic flights has no influence on a motor tracking task.

    Science.gov (United States)

    Schneider, Stefan; Brümmer, Vera; Mierau, Andreas; Carnahan, Heather; Dubrowski, Adam; Strüder, Heiko K

    2008-03-01

    Previous studies showed that changing forces of gravity as they typically occur during parabolic flights might be responsible for adaptional processes of the CNS. However, until now it has not been differentiated between primary influences of weightlessness and secondary influences due to psycho-physiological factors (e.g., physical or mental strain). With the aim of detecting parabolic flight related changes in central cortical activity, a resting EEG was deduced in 16 subjects before, during and after parabolic flights. After subdividing EEG into alpha-, beta-,delta- and theta-wave bands, an increase in beta-power was noticeable inflight, whereas alpha(1)-power was increased postflight. No changes could be observed for the control group. To control possible effects of cortical activation, a manual tracking task with mirror inversion was performed during either the phase of weightlessness or during the normal gravity phase of a parabolic flight. No differences in performance nor in adaptation could be observed between both groups. A third group, performing under normal and stress-free conditions in a lab showed similar tracking values. We assume that the specific increase in brain activity is a sign of an increase in arousal inflight. This does support previous assumptions of non-specific stressors during parabolic flights and has to be considered as a relevant factor for experiments on central nerve adaptation. Although no influences of stress and/or weightlessness on motor performance and adaptation could be observed, we suggest that an "inflight" control group seems to be more adequate than a laboratory control group to investigate gravity-dependent changes in motor control.

  4. High frequency deep brain stimulation attenuates subthalamic and cortical rhythms in Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Diane eWhitmer

    2012-06-01

    Full Text Available Parkinson’s disease (PD is marked by excessive synchronous activity in the beta (8-35 Hz band throughout the cortico-basal ganglia network. The optimal location of high frequency deep brain stimulation (HF DBS within the subthalamic nucleus (STN region and the location of maximal beta hypersynchrony are currently matters of debate. Additionally, the effect of STN HF DBS on neural synchrony in functionally connected regions of motor cortex is unknown and of great interest. Scalp EEG studies demonstrated that stimulation of the STN can activate motor cortex antidromically, but the spatial specificity of this effect has not been examined. The present study examined the effect of STN HF DBS on neural synchrony within the cortico-basal ganglia network in patients with PD. We measured local field potentials dorsal to and within the STN of PD patients, and additionally in the motor cortex in a subset of these patients. We used diffusion tensor imaging (DTI to guide the placement of subdural cortical surface electrodes over the DTI-identified origin of the hyperdirect pathway between motor cortex and the STN. The results demonstrated that local beta power was attenuated during HF DBS both dorsal to and within the STN. The degree of attenuation was monotonic with increased DBS voltages in both locations, but this voltage-dependent effect was greater in the central STN than dorsal to the STN (p < 0.05. Cortical signals over the estimated origin of the hyperdirect pathway also demonstrated attenuation of beta hypersynchrony during DBS dorsal to or within STN, whereas signals from non-specific regions of motor cortex were not attenuated. The spatially specific suppression of beta synchrony in the motor cortex support the hypothesis that DBS may treat Parkinsonism by reducing excessive synchrony in the functionally connected sensorimotor network.

  5. BDNF stimulation of protein synthesis in cortical neurons requires the MAP kinase-interacting kinase MNK1.

    Science.gov (United States)

    Genheden, Maja; Kenney, Justin W; Johnston, Harvey E; Manousopoulou, Antigoni; Garbis, Spiros D; Proud, Christopher G

    2015-01-21

    Although the MAP kinase-interacting kinases (MNKs) have been known for >15 years, their roles in the regulation of protein synthesis have remained obscure. Here, we explore the involvement of the MNKs in brain-derived neurotrophic factor (BDNF)-stimulated protein synthesis in cortical neurons from mice. Using a combination of pharmacological and genetic approaches, we show that BDNF-induced upregulation of protein synthesis requires MEK/ERK signaling and the downstream kinase, MNK1, which phosphorylates eukaryotic initiation factor (eIF) 4E. Translation initiation is mediated by the interaction of eIF4E with the m(7)GTP cap of mRNA and with eIF4G. The latter interaction is inhibited by the interactions of eIF4E with partner proteins, such as CYFIP1, which acts as a translational repressor. We find that BDNF induces the release of CYFIP1 from eIF4E, and that this depends on MNK1. Finally, using a novel combination of BONCAT and SILAC, we identify a subset of proteins whose synthesis is upregulated by BDNF signaling via MNK1 in neurons. Interestingly, this subset of MNK1-sensitive proteins is enriched for functions involved in neurotransmission and synaptic plasticity. Additionally, we find significant overlap between our subset of proteins whose synthesis is regulated by MNK1 and those encoded by known FMRP-binding mRNAs. Together, our data implicate MNK1 as a key component of BDNF-mediated translational regulation in neurons.

  6. Dynamic Quantitative T1 Mapping in Orthotopic Brain Tumor Xenografts

    Directory of Open Access Journals (Sweden)

    Kelsey Herrmann

    2016-04-01

    Full Text Available Human brain tumors such as glioblastomas are typically detected using conventional, nonquantitative magnetic resonance imaging (MRI techniques, such as T2-weighted and contrast enhanced T1-weighted MRI. In this manuscript, we tested whether dynamic quantitative T1 mapping by MRI can localize orthotopic glioma tumors in an objective manner. Quantitative T1 mapping was performed by MRI over multiple time points using the conventional contrast agent Optimark. We compared signal differences to determine the gadolinium concentration in tissues over time. The T1 parametric maps made it easy to identify the regions of contrast enhancement and thus tumor location. Doubling the typical human dose of contrast agent resulted in a clearer demarcation of these tumors. Therefore, T1 mapping of brain tumors is gadolinium dose dependent and improves detection of tumors by MRI. The use of T1 maps provides a quantitative means to evaluate tumor detection by gadolinium-based contrast agents over time. This dynamic quantitative T1 mapping technique will also enable future quantitative evaluation of various targeted MRI contrast agents.

  7. Brain maps of Iowa gambling task

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    Chiu Yao-Chu

    2008-07-01

    Full Text Available Abstract Background Somatic Marker Hypothesis (SMH, based on clinical observations, delineates neuronal networks for interpreting consciousness generation and decision-making. The Iowa gambling task (IGT was designed to verify the SMH. However, more and more behavioral and brain imaging studies had reported incongruent results that pinpointed a need to re-evaluate the central representations of SMH. The current study used event-related fMRI (functional Magnetic Resonance Imaging to examine neural correlates of anticipation vs. outcome, wins vs. losses, and differential decks' contingencies of IGT. Results Behavioral results showed a prominent effect of frequency in driving choices. The insula and basal ganglia were activated during the anticipation phase while the inferior parietal lobule was activated during the outcome phase. The activation of medial prefrontal cortex was especially targeted during the high punishment contingencies. The data suggest that under uncertainty the normal decision makers can become myopic. Conclusion The insula and basal ganglia might play a vital role in long-term guidance of decision-making. Inferior parietal lobule might participate in evaluating the consequence and medial prefrontal cortex may service the function of error monitoring.

  8. BrainMaps.org - Interactive High-Resolution Digital Brain Atlases and Virtual Microscopy.

    Science.gov (United States)

    Mikula, Shawn; Stone, James M; Jones, Edward G

    2008-01-01

    BrainMaps.org is an interactive high-resolution digital brain atlas and virtual microscope that is based on over 20 million megapixels of scanned images of serial sections of both primate and non-primate brains and that is integrated with a high-speed database for querying and retrieving data about brain structure and function over the internet. Complete brain datasets for various species, including Homo sapiens, Macaca mulatta, Chlorocebus aethiops, Felis catus, Mus musculus, Rattus norvegicus, and Tyto alba, are accessible online. The methods and tools we describe are useful for both research and teaching, and can be replicated by labs seeking to increase accessibility and sharing of neuroanatomical data. These tools offer the possibility of visualizing and exploring completely digitized sections of brains at a sub-neuronal level, and can facilitate large-scale connectional tracing, histochemical and stereological analyses.

  9. Three-dimensional brain mapping using fMRI

    Energy Technology Data Exchange (ETDEWEB)

    Fukunaga, Masaki; Tanaka, Chuzo; Umeda, Masahiro; Ebisu, Toshihiko; Aoki, Ichio [Meiji Univ. of Oriental Medicine, Hiyoshi, Kyoto (Japan); Higuchi, Toshihiro; Naruse, Shoji

    1997-10-01

    Functional mapping of the activated brain, the location and extent of the activated area were determined, during motor tasks and sensory stimulation using fMRI superimposed on 3D anatomical MRI. Twelve volunteers were studied. The fMR images were acquired using a 2D gradient echo echo planar imaging sequence. The 3D anatomical MR images of the whole brain were acquired using a conventional 3D gradient echo sequence. Motor tasks were sequential opposition of fingers, clenching a hand and elbow flexion. Somatosensory stimulation were administered by scrubbing the palm and sole with a washing sponge. Visual stimulation consisted of full visual field stimulation. Data were analyzed by the cross-correlation method. Transversal fMR images and anatomical images were reconstructed using both volume-, surface-rendering methods, and reconstructed for coronal and sagittal sections. Activated areas were expressed using the three primary colors. Motor tasks activated the contralateral primary motor area (M1), the primary somatosensory area (S1) and the supplementary motor area (SMA). Somatosensory tasks activated the contralateral S1, M1 and secondary sensory area (S2). Activated areas during full visual field stimulation was observed in the bilateral occipital lobe, including both the primary cortex. Three-dimensional brain mapping allowed visualization of the anatomical location and extent of the activated brain during both motor task and sensory stimulation. Using this method we could obtain a functional map similar to the Penfield`s schema. (author)

  10. The INIA19 template and NeuroMaps atlas for primate brain image parcellation and spatial normalization

    Directory of Open Access Journals (Sweden)

    Torsten eRohlfing

    2012-12-01

    Full Text Available The INIA19 is a new, high-quality template for imaging-based studies of non-human primate brains created from high-resolution T1-weighted magnetic resonance (MR images of 19 rhesus macaque (Macaca mulatta animals. Combined with the comprehensive cortical and subcortical label map of the NeuroMaps atlas, the INIA19 is equally suitable for studies requiring both spatial normalization and atlas label propagation. Population-averaged template images are provided for both the brain and the whole head, to allow alignment of the atlas with both skull-stripped and unstripped data, and thus to facilitate its use for skull stripping of new images. This article describes the construction of the template using freely-available software tools, as well as the template itself, which is being made available to the scientific community (http://nitrc.org/projects/inia19/.

  11. Spatial co-adaptation of cortical control columns in a micro-ECoG brain-computer interface

    Science.gov (United States)

    Rouse, A. G.; Williams, J. J.; Wheeler, J. J.; Moran, D. W.

    2016-10-01

    Objective. Electrocorticography (ECoG) has been used for a range of applications including electrophysiological mapping, epilepsy monitoring, and more recently as a recording modality for brain-computer interfaces (BCIs). Studies that examine ECoG electrodes designed and implanted chronically solely for BCI applications remain limited. The present study explored how two key factors influence chronic, closed-loop ECoG BCI: (i) the effect of inter-electrode distance on BCI performance and (ii) the differences in neural adaptation and performance when fixed versus adaptive BCI decoding weights are used. Approach. The amplitudes of epidural micro-ECoG signals between 75 and 105 Hz with 300 μm diameter electrodes were used for one-dimensional and two-dimensional BCI tasks. The effect of inter-electrode distance on BCI control was tested between 3 and 15 mm. Additionally, the performance and cortical modulation differences between constant, fixed decoding using a small subset of channels versus adaptive decoding weights using the entire array were explored. Main results. Successful BCI control was possible with two electrodes separated by 9 and 15 mm. Performance decreased and the signals became more correlated when the electrodes were only 3 mm apart. BCI performance in a 2D BCI task improved significantly when using adaptive decoding weights (80%-90%) compared to using constant, fixed weights (50%-60%). Additionally, modulation increased for channels previously unavailable for BCI control under the fixed decoding scheme upon switching to the adaptive, all-channel scheme. Significance. Our results clearly show that neural activity under a BCI recording electrode (which we define as a ‘cortical control column’) readily adapts to generate an appropriate control signal. These results show that the practical minimal spatial resolution of these control columns with micro-ECoG BCI is likely on the order of 3 mm. Additionally, they show that the combination and

  12. Flow velocity change in the cortical vein during motor activation and its effect on functional brain MRI

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Kazuhiro [Kyoto Prefectural Univ. of Medicine (Japan)

    1998-06-01

    On the brain functional magnetic resonance imaging (fMRI) using the gradient-recalled echo technique with clinical MR scanner, the activated areas nearly correspond with the cortical veins. This suggests that the fMRI signal mainly originates from the cortical veins. In this study, we analyzed the flow velocity in the cortical vein quantitatively during brain activation and resting status using 2 dimensional time-of-flight cine MR venography (2D-TOF-cine-MRV) and 2 dimensional phase contrast MRV (2D-PC-MRV) techniques, and demonstrated that the flow velocity increased in the cortical vein corresponding to the activated area during activation status. The increase of flow velocity was calculated to be about 20%. The reason for the increased flow velocity is probably due to the increased regional cerebral blood flow and volume in the activated area. We should be careful to analyze the data of the fMRI because the flow velocity affects the fMRI signal such as the inflow effect and the oblique flow effect. When using the gradient echo method, the effect of the flow velocity is one of the important factors of the fMRI signal. (author)

  13. Mapping the connectivity underlying multimodal (verbal and non-verbal) semantic processing: a brain electrostimulation study.

    Science.gov (United States)

    Moritz-Gasser, Sylvie; Herbet, Guillaume; Duffau, Hugues

    2013-08-01

    Accessing the meaning of words, objects, people and facts is a human ability, made possible thanks to semantic processing. Although studies concerning its cortical organization are proficient, the subcortical connectivity underlying this semantic network received less attention. We used intraoperative direct electrostimulation, which mimics a transient virtual lesion during brain surgery for glioma in eight awaken patients, to map the anatomical white matter substrate subserving the semantic system. Patients performed a picture naming task and a non-verbal semantic association test during the electrical mapping. Direct electrostimulation of the inferior fronto-occipital fascicle, a poorly known ventral association pathway which runs throughout the brain, induced in all cases semantic disturbances. These transient disorders were highly reproducible, and concerned verbal as well as non-verbal output. Our results highlight for the first time the essential role of the left inferior fronto-occipital fascicle in multimodal (and not only in verbal) semantic processing. On the basis of these original findings, and in the lights of phylogenetic considerations regarding this fascicle, we suggest its possible implication in the monitoring of the human level of consciousness related to semantic memory, namely noetic consciousness.

  14. An Improved Unscented Kalman Filter Based Decoder for Cortical Brain-Machine Interfaces.

    Science.gov (United States)

    Li, Simin; Li, Jie; Li, Zheng

    2016-01-01

    Brain-machine interfaces (BMIs) seek to connect brains with machines or computers directly, for application in areas such as prosthesis control. For this application, the accuracy of the decoding of movement intentions is crucial. We aim to improve accuracy by designing a better encoding model of primary motor cortical activity during hand movements and combining this with decoder engineering refinements, resulting in a new unscented Kalman filter based decoder, UKF2, which improves upon our previous unscented Kalman filter decoder, UKF1. The new encoding model includes novel acceleration magnitude, position-velocity interaction, and target-cursor-distance features (the decoder does not require target position as input, it is decoded). We add a novel probabilistic velocity threshold to better determine the user's intent to move. We combine these improvements with several other refinements suggested by others in the field. Data from two Rhesus monkeys indicate that the UKF2 generates offline reconstructions of hand movements (mean CC 0.851) significantly more accurately than the UKF1 (0.833) and the popular position-velocity Kalman filter (0.812). The encoding model of the UKF2 could predict the instantaneous firing rate of neurons (mean CC 0.210), given kinematic variables and past spiking, better than the encoding models of these two decoders (UKF1: 0.138, p-v Kalman: 0.098). In closed-loop experiments where each monkey controlled a computer cursor with each decoder in turn, the UKF2 facilitated faster task completion (mean 1.56 s vs. 2.05 s) and higher Fitts's Law bit rate (mean 0.738 bit/s vs. 0.584 bit/s) than the UKF1. These results suggest that the modeling and decoder engineering refinements of the UKF2 improve decoding performance. We believe they can be used to enhance other decoders as well.

  15. An Improved Unscented Kalman Filter Based Decoder for Cortical Brain-Machine Interfaces

    Science.gov (United States)

    Li, Simin; Li, Jie; Li, Zheng

    2016-01-01

    Brain-machine interfaces (BMIs) seek to connect brains with machines or computers directly, for application in areas such as prosthesis control. For this application, the accuracy of the decoding of movement intentions is crucial. We aim to improve accuracy by designing a better encoding model of primary motor cortical activity during hand movements and combining this with decoder engineering refinements, resulting in a new unscented Kalman filter based decoder, UKF2, which improves upon our previous unscented Kalman filter decoder, UKF1. The new encoding model includes novel acceleration magnitude, position-velocity interaction, and target-cursor-distance features (the decoder does not require target position as input, it is decoded). We add a novel probabilistic velocity threshold to better determine the user's intent to move. We combine these improvements with several other refinements suggested by others in the field. Data from two Rhesus monkeys indicate that the UKF2 generates offline reconstructions of hand movements (mean CC 0.851) significantly more accurately than the UKF1 (0.833) and the popular position-velocity Kalman filter (0.812). The encoding model of the UKF2 could predict the instantaneous firing rate of neurons (mean CC 0.210), given kinematic variables and past spiking, better than the encoding models of these two decoders (UKF1: 0.138, p-v Kalman: 0.098). In closed-loop experiments where each monkey controlled a computer cursor with each decoder in turn, the UKF2 facilitated faster task completion (mean 1.56 s vs. 2.05 s) and higher Fitts's Law bit rate (mean 0.738 bit/s vs. 0.584 bit/s) than the UKF1. These results suggest that the modeling and decoder engineering refinements of the UKF2 improve decoding performance. We believe they can be used to enhance other decoders as well. PMID:28066170

  16. Repetitive mild traumatic brain injury induces ventriculomegaly and cortical thinning in juvenile rats.

    Science.gov (United States)

    Goddeyne, Corey; Nichols, Joshua; Wu, Chen; Anderson, Trent

    2015-05-01

    Traumatic brain injury (TBI) most frequently occurs in pediatric patients and remains a leading cause of childhood death and disability. Mild TBI (mTBI) accounts for nearly 75% of all TBI cases, yet its neuropathophysiology is still poorly understood. While even a single mTBI injury can lead to persistent deficits, repeat injuries increase the severity and duration of both acute symptoms and long-term deficits. In this study, to model pediatric repetitive mTBI (rmTBI) we subjected unrestrained juvenile animals (postnatal day 20) to repeat weight-drop impacts. Animals were anesthetized and subjected to sham injury or rmTBI once per day for 5 days. Magnetic resonance imaging (MRI) performed 14 days after injury revealed marked cortical atrophy and ventriculomegaly in rmTBI animals. Specifically, beneath the impact zone the thickness of the cortex was reduced by up to 46% and the area of the ventricles increased by up to 970%. Immunostaining with the neuron-specific marker NeuN revealed an overall loss of neurons within the motor cortex but no change in neuronal density. Examination of intrinsic and synaptic properties of layer II/III pyramidal neurons revealed no significant difference between sham-injured and rmTBI animals at rest or under convulsant challenge with the potassium channel blocker 4-aminopyridine. Overall, our findings indicate that the neuropathological changes reported after pediatric rmTBI can be effectively modeled by repeat weight drop in juvenile animals. Developing a better understanding of how rmTBI alters the pediatric brain may help improve patient care and direct "return to game" decision making in adolescents.

  17. Epileptiform synchronization and high-frequency oscillations in brain slices comprising piriform and entorhinal cortices.

    Science.gov (United States)

    Hamidi, S; Lévesque, M; Avoli, M

    2014-12-05

    We employed field potential recordings in extended in vitro brain slices form Sprague-Dawley rats containing the piriform and entorhinal cortices (PC and EC, respectively) to identify the characteristics of epileptiform discharges and concomitant high-frequency oscillations (HFOs, ripples: 80-200Hz, fast ripples: 250-500Hz) during bath application of 4-aminopyridine (4AP, 50μM). Ictal-like discharges occurred in PC and EC either synchronously or independently of each other; synchronous ictal discharges always emerged from a synchronous "fast" interictal background whereas asynchronous ictal discharges were preceded by a "slow" interictal event. In addition, asynchronous ictal discharges had longer duration and interval of occurrence than synchronous ictal discharges, and contained a higher proportion of ripples and fast ripples. Cutting the connections between PC and EC made synchronicity disappear and increased ictal discharges duration in the EC but failed in changing HFO occurrence in both areas. Finally, antagonizing ionotropic glutamatergic receptors abolished ictal activity in all experiments, increased the duration and rate of occurrence of interictal discharges occurring in PC-EC interconnected slices while it did not influence the slow asynchronous interictal discharges in both areas. Our results identify some novel in vitro interactions between olfactory (PC) and limbic (EC) structures that presumably contribute to in vivo ictogenesis as well.

  18. Cortical Brain Connectivity and B-Type Natriuretic Peptide in Patients With Congestive Heart Failure.

    Science.gov (United States)

    Vecchio, Fabrizio; Miraglia, Francesca; Valeriani, Lavinia; Scarpellini, Maria Gabriella; Bramanti, Placido; Mecarelli, Oriano; Rossini, Paolo M

    2015-07-01

    The brain has a high level of complexity and needs continuous oxygen supply. So it is clear that any pathological condition, or physiological (aging) change, in the cardiovascular system affects functioning of the central nervous system. We evaluated linear aspects of the relationship between the slowness of cortical rhythms, as revealed by the modulation of a graph connectivity parameter, and congestive heart failure (CHF), as a reflection of neurodegenerative processes. Eyes-closed resting electroencephalographic (EEG) data of 10 patients with CHF were recorded by 19 electrodes positioned according the international 10-20 system. Graph theory function (normalized characteristic path length λ) was applied to the undirected and weighted networks obtained by lagged linear coherence evaluated by eLORETA software, therefore getting rid of volumetric propagation influences. The EEG frequency bands of interest were: delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), beta 2 (20-30 Hz), and gamma (30-40 Hz). The analysis between B-type natriuretic peptide (BNP) values and λ showed positive correlation in delta, associated with a negative correlation in alpha 2 band. Namely, the higher the severity of the disease (as revealed by the BNP vales), the higher the λ in delta, and lower in alpha 2 band. Results suggest that delta and alpha λ indices are good markers of the severity of CHF.

  19. Visual imagery influences brain responses to visual stimulation in bilateral cortical blindness.

    Science.gov (United States)

    de Gelder, Beatrice; Tamietto, Marco; Pegna, Alan J; Van den Stock, Jan

    2015-11-01

    Mental imagery is a powerful mechanism that may facilitate visual perception as well as compensate for it. The role of V1 in mental imagery is still a matter of debate. Our goal here was to investigate whether visual imagery was still possible in case of bilateral V1 destruction behaviorally evidenced by total clinical blindness and if so, whether it might boost residual visual perception. In a factorial fMRI design, faces, scenes or scrambled images were presented while a rare patient with cortical blindness over the whole visual field due to bilateral V1-lesions (TN) was instructed to imagine either an angry person or a neutral object (tree). The results show that visual imagery of a person activates frontal, parietal and occipital brain regions similar to control subjects and hence suggest that V1 is not necessary for visual imagery. In addition, the combination of visual stimulation and visual imagery of socio-emotional stimuli triggers activation in superior parietal lobule (SPL) and ventromedial (vmPFC) and dorsolateral prefrontal cortex (DLPFC). Finally, activation during residual vision, visual imagery and their interaction overlapped in the SPL, arguing for a central role of feeling in V1-independent vision and imagery.

  20. Global and regional cortical connectivity maturation index (CCMI) of developmental human brain with quantification of short-range association tracts

    Science.gov (United States)

    Ouyang, Minhui; Jeon, Tina; Mishra, Virendra; Du, Haixiao; Wang, Yu; Peng, Yun; Huang, Hao

    2016-03-01

    From early childhood to adulthood, synaptogenesis and synaptic pruning continuously reshape the structural architecture and neural connection in developmental human brains. Disturbance of the precisely balanced strengthening of certain axons and pruning of others may cause mental disorders such as autism and schizophrenia. To characterize this balance, we proposed a novel measurement based on cortical parcellation and diffusion MRI (dMRI) tractography, a cortical connectivity maturation index (CCMI). To evaluate the spatiotemporal sensitivity of CCMI as a potential biomarker, dMRI and T1 weighted datasets of 21 healthy subjects 2-25 years were acquired. Brain cortex was parcellated into 68 gyral labels using T1 weighted images, then transformed into dMRI space to serve as the seed region of interest for dMRI-based tractography. Cortico-cortical association fibers initiated from each gyrus were categorized into long- and short-range ones, based on the other end of fiber terminating in non-adjacent or adjacent gyri of the seed gyrus, respectively. The regional CCMI was defined as the ratio between number of short-range association tracts and that of all association tracts traced from one of 68 parcellated gyri. The developmental trajectory of the whole brain CCMI follows a quadratic model with initial decreases from 2 to 16 years followed by later increases after 16 years. Regional CCMI is heterogeneous among different cortical gyri with CCMI dropping to the lowest value earlier in primary somatosensory cortex and visual cortex while later in the prefrontal cortex. The proposed CCMI may serve as sensitive biomarker for brain development under normal or pathological conditions.

  1. Neural correlates of apathy revealed by lesion mapping in participants with traumatic brain injuries.

    Science.gov (United States)

    Knutson, Kristine M; Monte, Olga Dal; Raymont, Vanessa; Wassermann, Eric M; Krueger, Frank; Grafman, Jordan

    2014-03-01

    Apathy, common in neurological disorders, is defined as disinterest and loss of motivation, with a reduction in self-initiated activity. Research in diseased populations has shown that apathy is associated with variations in the volume of brain regions such as the anterior cingulate and the frontal lobes. The goal of this study was to determine the neural signatures of apathy in people with penetrating traumatic brain injuries (pTBIs), as to our knowledge, these have not been studied in this sample. We studied 176 male Vietnam War veterans with pTBIs using voxel-based lesion-symptom mapping (VLSM) and apathy scores from the UCLA Neuropsychiatric Inventory (NPI), a structured inventory of symptoms completed by a caregiver. Our results revealed that increased apathy symptoms were associated with brain damage in limbic and cortical areas of the left hemisphere including the anterior cingulate, inferior, middle, and superior frontal regions, insula, and supplementary motor area. Our results are consistent with the literature, and extend them to people with focal pTBI. Apathy is a significant symptom since it can reduce participation of the patient in family and other social interactions, and diminish affective decision-making.

  2. Cortical Connectivity Maps Reveal Anatomically Distinct Areas in the Parietal Cortex of the Rat

    Directory of Open Access Journals (Sweden)

    Aaron eWilber

    2015-01-01

    Full Text Available A central feature of theories of spatial navigation involves the representation of spatial relationships between objects in complex environments. The parietal cortex has long been linked to the processing of spatial visual information and recent evidence from single unit recording in rodents suggests a role for this region in encoding egocentric and world-centered frames. The rat parietal cortex can be subdivided into up to four distinct rostral-caudal and medial-lateral regions, which includes a zone previously characterized as secondary visual cortex. At present, very little is known regarding the relative connectivity of these parietal subdivisions. Thus, we set out to map the connectivity of the entire anterior-posterior and medial-lateral span of this region. To do this we used anterograde and retrograde tracers in conjunction with open source neuronal segmentation and tracer detection tools to generate whole brain connectivity maps of parietal inputs and outputs. Our present results show that inputs to the parietal cortex varied significantly along the medial-lateral, but not the rostral-caudal axis. Specifically, retrosplenial connectivity is greater medially, but connectivity with visual cortex, though generally sparse, is more significant laterally. Finally, based on connection density, the connectivity between parietal cortex and hippocampus is indirect and likely achieved largely via dysgranular retrosplenial cortex. Thus, similar to primates, the parietal cortex of rats exhibits a difference in connectivity along the medial-lateral axis, which may represent functionally distinct areas.

  3. A comparison of brain volume and cortical thickness in excoriation (skin picking) disorder and trichotillomania (hair pulling disorder) in women.

    Science.gov (United States)

    Roos, Annerine; Grant, Jon E; Fouche, Jean-Paul; Stein, Dan J; Lochner, Christine

    2015-02-15

    Skin picking disorder (SPD) and trichotillomania (hair pulling disorder, or HPD) significantly overlap in terms of clinical features. However, few studies have directly compared structural brain data in these disorders. The aim of this study was to compare volumes of brain structures and cortical thickness in patients with SPD and HPD, and determine involvement of fronto-striatal pathways. Seventeen female SPD, 17 HPD and 15 healthy age-matched controls underwent clinical assessment and structural MRI imaging. Group differences were determined in brain volume and cortical thickness, controlling for illness severity. Participants with SPD had greater volume of the ventral striatum bilaterally; and reduced cortical thickness in right hemisphere frontal areas, and greater thickness of the cuneus bilaterally compared to HPD and control participants. HPD participants demonstrated reduced thickness of the right parahippocampal gyrus compared to SPD and control participants. The findings here are partially consistent with previous structural work in SPD, and suggest some differences in the neurobiology of SPD and HPD. The more extensive involvement of the ventral striatum in SPD may suggest greater involvement of the reward system, while the more extensive involvement of the parahippocampal gyrus in HPD may be consistent with the dissociative symptoms often seen in these patients.

  4. Light microscopy mapping of connections in the intact brain.

    Science.gov (United States)

    Kim, Sung-Yon; Chung, Kwanghun; Deisseroth, Karl

    2013-12-01

    Mapping of neural connectivity across the mammalian brain is a daunting and exciting prospect. Current approaches can be divided into three classes: macroscale, focusing on coarse inter-regional connectivity; mesoscale, involving a finer focus on neurons and projections; and microscale, reconstructing full details of all synaptic contacts. It remains to be determined how to bridge the datasets or insights from the different levels of study. Here we review recent light-microscopy-based approaches that may help in integration across scales.

  5. Visual cortical mechanisms of perceptual grouping: interacting layers, networks, columns, and maps.

    Science.gov (United States)

    Ross, W D; Grossberg, S; Mingolla, E

    2000-07-01

    The visual cortex has a laminar organization whose circuits form functional columns in cortical maps. How this laminar architecture supports visual percepts is not well understood. A neural model proposes how the laminar circuits of V1 and V2 generate perceptual groupings that maintain sensitivity to the contrasts and spatial organization of scenic cues. The model can decisively choose which groupings cohere and survive, even while balanced excitatory and inhibitory interactions preserve contrast-sensitive measures of local boundary likelihood or strength. In the model, excitatory inputs from lateral geniculate nucleus (LGN) activate layers 4 and 6 of V1. Layer 6 activates an on-center off-surround network of inputs to layer 4. Together these layer 4 inputs preserve analog sensitivity to LGN input contrasts. Layer 4 cells excite pyramidal cells in layer 2/3, which activate monosynaptic long-range horizontal excitatory connections between layer 2/3 pyramidal cells, and short-range disynaptic inhibitory connections mediated by smooth stellate cells. These interactions support inward perceptual grouping between two or more boundary inducers, but not outward grouping from a single inducer. These boundary signals feed back to layer 4 via the layer 6-to-4 on-center off-surround network. This folded feedback joins cells in different layers into functional columns while selecting winning groupings. Layer 6 in V1 also sends top-down signals to LGN using an on-center off-surround network, which suppresses LGN cells that do not receive feedback, while selecting, enhancing, and synchronizing activity of those that do. The model is used to simulate psychophysical and neurophysiological data about perceptual grouping, including various Gestalt grouping laws.

  6. Visualization and modelling of STLmax topographic brain activity maps.

    Science.gov (United States)

    Mammone, Nadia; Principe, José C; Morabito, Francesco C; Shiau, Deng S; Sackellares, J Chris

    2010-06-15

    This paper evaluates the descriptive power of brain topography based on a dynamical parameter, the Short-Term Maximum Lyapunov Exponent (STLmax), estimated from EEG, for finding out a relationship of STLmax spatial distribution with the onset zone and with the mechanisms leading to epileptic seizures. Our preliminary work showed that visual assessment of STLmax topography exhibited a link with the location of seizure onset zone. The objective of the present work is to model the spatial distribution of STLmax in order to automatically extract these features from the maps. One-hour preictal segments from four long-term continuous EEG recordings (two scalp and two intracranial) were processed and the corresponding STLmax profiles were estimated. The spatial STLmax maps were modelled by a combination of two Gaussians functions. The parameters of the fitted model allow automatic extraction of quantitative information about the spatial distribution of STLmax: the EEG signal recorded from the brain region where seizures originate exhibited low-STLmax levels, long before the seizure onset, in 3 out of 4 patients (1 out of 2 of scalp patients and 2 out of 2 in intracranial patients). Topographic maps extracted directly from the EEG power did not provide useful information about the location, therefore we conclude that the analysis so far carried out suggests the possibility of using a model of STLmax topography as a tool for monitoring the evolution of epileptic brain dynamics. In the future, a more elaborate approach will be investigated in order to improve the specificity of the method.

  7. The Estimation of Cortical Activity for Brain-Computer Interface: Applications in a Domotic Context

    OpenAIRE

    Babiloni, F.; Cincotti, F; M. Marciani; Salinari, S.; Astolfi, L.; A. Tocci; Aloise, F.; De Mattia, D.; De Vico Fallani, F.; Bufalari, S.

    2007-01-01

    In order to analyze whether the use of the cortical activity, estimated from noninvasive EEG recordings, could be useful to detect mental states related to the imagination of limb movements, we estimate cortical activity from high-resolution EEG recordings in a group of healthy subjects by using realistic head models. Such cortical activity was estimated in region of interest associated with the subject's Brodmann areas by using a depth-weighted minimum norm...

  8. Motor area localization using fMRI-constrained cortical current density reconstruction of movement-related cortical potentials, a comparison with fMRI and TMS mapping.

    Science.gov (United States)

    Inuggi, Alberto; Filippi, Massimo; Chieffo, Raffaella; Agosta, Federica; Rocca, Maria A; González-Rosa, Javier J; Cursi, Marco; Comi, Giancarlo; Leocani, Letizia

    2010-01-13

    The localization of human hand primary motor area (M1) has been the object of several studies during the last decades. EEG source analysis, functional magnetic resonance imaging (fMRI) and focal transcranial magnetic stimulation (TMS) are non-invasive methods for localizing M1 with good accuracy compared to direct electrocorticography (ECoG) results. EEG sources were reconstructed with Cortical Current Density (CCD) method, allowing to evaluate simultaneous and distributed patterns of activation and to increase accuracy by constraining on information derived from fMRI (fMRI-CCD). The aim of this study was to compare the M1 contribution of movement-related cortical potentials (MRCP) with TMS and fMRI results and to test the effect of constraints strength, algorithm norm and localization methods over CCD reconstruction. Seven right-handed healthy subjects underwent 64-channel EEG recording of MRCP to right thumb movement, focal TMS mapping of the right abductor pollicis brevis muscle and fMRI during right hand movement. We found fMRI activations, EEG sources and TMS mapping corresponding to the anatomical landmark of the hand area in all subjects with fMRI and TMS center-of-gravity and in almost all subjects using fMRI-CCD with moderate constraint. A significant improvement was found using fMRI-CCD compared to CCD alone. This study confirms the usefulness of multimodal integration of fMRI, EEG and TMS in localizing M1 and the possibility to increase EEG spatial resolution using fMRI information.

  9. Recording human electrocorticographic (ECoG) signals for neuroscientific research and real-time functional cortical mapping.

    Science.gov (United States)

    Hill, N Jeremy; Gupta, Disha; Brunner, Peter; Gunduz, Aysegul; Adamo, Matthew A; Ritaccio, Anthony; Schalk, Gerwin

    2012-06-26

    Neuroimaging studies of human cognitive, sensory, and motor processes are usually based on noninvasive techniques such as electroencephalography (EEG), magnetoencephalography or functional magnetic-resonance imaging. These techniques have either inherently low temporal or low spatial resolution, and suffer from low signal-to-noise ratio and/or poor high-frequency sensitivity. Thus, they are suboptimal for exploring the short-lived spatio-temporal dynamics of many of the underlying brain processes. In contrast, the invasive technique of electrocorticography (ECoG) provides brain signals that have an exceptionally high signal-to-noise ratio, less susceptibility to artifacts than EEG, and a high spatial and temporal resolution (i.e., intentions to enhance or improve communication and control. Nevertheless, human ECoG data are often hard to obtain because of the risks and limitations of the invasive procedures involved, and the need to record within the constraints of clinical settings. Still, clinical monitoring to localize epileptic foci offers a unique and valuable opportunity to collect human ECoG data. We describe our methods for collecting recording ECoG, and demonstrate how to use these signals for important real-time applications such as clinical mapping and brain-computer interfacing. Our example uses the BCI2000 software platform and the SIGFRIED method, an application for real-time mapping of brain functions. This procedure yields information that clinicians can subsequently use to guide the complex and laborious process of functional mapping by electrical stimulation. PREREQUISITES AND PLANNING: Patients with drug-resistant partial epilepsy may be candidates for resective surgery of an epileptic focus to minimize the frequency of seizures. Prior to resection, the patients undergo monitoring using subdural electrodes for two purposes: first, to localize the epileptic focus, and second, to identify nearby critical brain areas (i.e., eloquent cortex) where

  10. 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.

  11. Exercise training reinstates cortico-cortical sensorimotor functional connectivity following striatal lesioning: Development and application of a subregional-level analytic toolbox for perfusion autoradiographs of the rat brain

    Science.gov (United States)

    Peng, Yu-Hao; Heintz, Ryan; Wang, Zhuo; Guo, Yumei; Myers, Kalisa; Scremin, Oscar; Maarek, Jean-Michel; Holschneider, Daniel

    2014-12-01

    Current rodent connectome projects are revealing brain structural connectivity with unprecedented resolution and completeness. How subregional structural connectivity relates to subregional functional interactions is an emerging research topic. We describe a method for standardized, mesoscopic-level data sampling from autoradiographic coronal sections of the rat brain, and for correlation-based analysis and intuitive display of cortico-cortical functional connectivity (FC) on a flattened cortical map. A graphic user interface “Cx-2D” allows for the display of significant correlations of individual regions-of-interest, as well as graph theoretical metrics across the cortex. Cx-2D was tested on an autoradiographic data set of cerebral blood flow (CBF) of rats that had undergone bilateral striatal lesions, followed by 4 weeks of aerobic exercise training or no exercise. Effects of lesioning and exercise on cortico-cortical FC were examined during a locomotor challenge in this rat model of Parkinsonism. Subregional FC analysis revealed a rich functional reorganization of the brain in response to lesioning and exercise that was not apparent in a standard analysis focused on CBF of isolated brain regions. Lesioned rats showed diminished degree centrality of lateral primary motor cortex, as well as neighboring somatosensory cortex--changes that were substantially reversed in lesioned rats following exercise training. Seed analysis revealed that exercise increased positive correlations in motor and somatosensory cortex, with little effect in non-sensorimotor regions such as visual, auditory, and piriform cortex. The current analysis revealed that exercise partially reinstated sensorimotor FC lost following dopaminergic deafferentation. Cx-2D allows for standardized data sampling from images of brain slices, as well as analysis and display of cortico-cortical FC in the rat cerebral cortex with potential applications in a variety of autoradiographic and histologic

  12. Exercise training reinstates cortico-cortical sensorimotor functional connectivity following striatal lesioning: Development and application of a subregional-level analytic toolbox for perfusion autoradiographs of the rat brain

    Directory of Open Access Journals (Sweden)

    Yu-Hao ePeng

    2014-12-01

    Full Text Available Current rodent connectome projects are revealing brain structural connectivity with unprecedented resolution and completeness. How subregional structural connectivity relates to subregional functional interactions is an emerging research topic. We describe a method for standardized, mesoscopic-level data sampling from autoradiographic coronal sections of the rat brain, and for correlation-based analysis and intuitive display of cortico-cortical functional connectivity (FC on a flattened cortical map. A graphic user interface Cx-2D allows for the display of significant correlations of individual regions-of-interest, as well as graph theoretical metrics across the cortex. Cx-2D was tested on an autoradiographic data set of cerebral blood flow (CBF of rats that had undergone bilateral striatal lesions, followed by 4 weeks of aerobic exercise training or no exercise. Effects of lesioning and exercise on cortico-cortical FC were examined during a locomotor challenge in this rat model of Parkinsonism. Subregional FC analysis revealed a rich functional reorganization of the brain in response to lesioning and exercise that was not apparent in a standard analysis focused on CBF of isolated brain regions. Lesioned rats showed diminished degree centrality of lateral primary motor cortex, as well as neighboring somatosensory cortex–-changes that were substantially reversed in lesioned rats following exercise training. Seed analysis revealed that exercise increased positive correlations in motor and somatosensory cortex, with little effect in non-sensorimotor regions such as visual, auditory, and piriform cortex. The current analysis revealed that exercise partially reinstated sensorimotor FC lost following dopaminergic deafferentation. Cx-2D allows for standardized data sampling from images of brain slices, as well as analysis and display of cortico-cortical FC in the rat cerebral cortex with potential applications in a variety of autoradiographic and

  13. Improved delineation of short cortical association fibers and gray/white matter boundary using whole-brain three-dimensional diffusion tensor imaging at submillimeter spatial resolution.

    Science.gov (United States)

    Song, Allen W; Chang, Hing-Chiu; Petty, Christopher; Guidon, Arnaud; Chen, Nan-Kuei

    2014-11-01

    Recent emergence of human connectome imaging has led to a high demand on angular and spatial resolutions for diffusion magnetic resonance imaging (MRI). While there have been significant growths in high angular resolution diffusion imaging, the improvement in spatial resolution is still limited due to a number of technical challenges, such as the low signal-to-noise ratio and high motion artifacts. As a result, the benefit of a high spatial resolution in the whole-brain connectome imaging has not been fully evaluated in vivo. In this brief report, the impact of spatial resolution was assessed in a newly acquired whole-brain three-dimensional diffusion tensor imaging data set with an isotropic spatial resolution of 0.85 mm. It was found that the delineation of short cortical association fibers is drastically improved as well as the definition of fiber pathway endings into the gray/white matter boundary-both of which will help construct a more accurate structural map of the human brain connectome.

  14. Cortical network dynamics with time delays reveals functional connectivity in the resting brain.

    NARCIS (Netherlands)

    Ghosh, A.; Rho, Y.; McIntosh, A.R.; Kotter, R.; Jirsa, V.K.

    2008-01-01

    In absence of all goal-directed behavior, a characteristic network of cortical regions involving prefrontal and cingulate cortices consistently shows temporally coherent fluctuations. The origin of these fluctuations is unknown, but has been hypothesized to be of stochastic nature. In the present pa

  15. Clinical, electrophysiological and brain imaging features during recurrent ictal cortical blindness associated with chronic liver failure.

    Science.gov (United States)

    van Pesch, V; Hernalsteen, D; van Rijckevorsel, K; Duprez, Th; Boschi, A; Ivanoiu, A; Sindic, C J M

    2006-12-01

    Transient neuroimaging features indicating primary cortical and secondary subcortical white matter cytotoxic oedema have been described in association with prolonged or intense seizures. We describe the unusual condition of recurrent ictal cortical blindness due to focal occipital status epilepticus, in the context of chronic hepatic failure. There was a close association between the onset and disappearance of clinical, electrophysiological and magnetic resonance imaging abnormalities.

  16. Toward noninvasive optical human brain mapping: improvements of the spectral, temporal, and spatial resolution of near-infrared spectroscopy

    Science.gov (United States)

    Heekeren, Hauke R.; Wenzel, Rudiger; Obrig, Hellmuth; Ruben, Jan; Ndayisaba, J.-P.; Luo, Qingming; Dale, A.; Nioka, Shoko; Kohl-Bareis, Matthias; Dirnagl, Ulrich; Villringer, Arno; Chance, Britton

    1997-08-01

    Near-infrared spectroscopy (NIRS) can detect changes in cerebral hemoglobin oxygenation in response to motor, visual or cognitive stimulation. This study explored potential improvements for functional human brain mapping with NIRS: (1) So far, only primary cortical areas, like motor cortex or primary visual areas were studied. We tested the feasibility of identifying an extrastriate visual motion area (MT) with single site NIRS. (2) The temporal resolution of commercial systems is on the order of seconds and their spectral resolution is poor. We tested the feasibility of the detection of cerebral hemoglobin oxygenation changes during visual stimulation at high temporal (100 ms) and spectral resolution (5 nm) using a whole spectrum approach (CCD-NIRS). (3) The spatial resolution of commercial systems is poor. In this study we used a 16 channel functional NIRS-imaging device to test the feasibility of mapping changes in cortical blood volume during visual stimulation (over primary and secondary areas). We show that (1) even conventional single site NIRS allows to identify secondary visual areas, (2) a CCD-NIRS system affords a high temporal (100 ms) and spectral (5 nm) resolution for the detection of changes in cerebral hemoglobin oxygenation during visual stimulation, (3) functional NIRS- imaging can localize focal blood volume changes over both primary and secondary cortical areas.

  17. Cortical brain morphology in young, estrogen-naive, and adolescent, estrogen-treated girls with Turner syndrome.

    Science.gov (United States)

    Lepage, Jean-Francois; Mazaika, Paul K; Hong, David S; Raman, Mira; Reiss, Allan L

    2013-09-01

    Turner syndrome (TS) is a genetic condition that permits direct investigation of the complex interaction among genes, hormones, behavior, and brain development. Here, we used automated segmentation and surface-based morphometry to characterize the differences in brain morphology in children (n = 30) and adolescents (n = 16) with TS relative to age- and sex-matched control groups (n = 21 and 24, respectively). Our results show that individuals with TS, young and adolescent, present widespread reduction of gray matter volume, white matter volume and surface area (SA) over both parietal and occipital cortices bilaterally, as well as enlarged amygdala. In contrast to the young cohort, adolescents with TS showed significantly larger mean cortical thickness and significantly smaller total SA compared with healthy controls. Exploratory developmental analyses suggested aberrant regional brain maturation in the parahippocampal gyrus and orbitofrontal regions from childhood to adolescence in TS. These findings show the existence of abnormal brain morphology early in development in TS, but also suggest the presence of altered neurodevelopmental trajectories in some regions, which could potentially be the consequences of estrogen deficiency, both pre- and postnatally.

  18. Mapping blood flow directionality in the human brain.

    Science.gov (United States)

    Park, Sung-Hong; Do, Won-Joon; Choi, Seung Hong; Zhao, Tiejun; Bae, Kyongtae Ty

    2016-07-01

    Diffusion properties of tissue are often expressed on the basis of directional variance, i.e., diffusion tensor imaging. In comparison, common perfusion-weighted imaging such as arterial spin labeling yields perfusion in a scalar quantity. The purpose of this study was to test the feasibility of mapping cerebral blood flow directionality using alternate ascending/descending directional navigation (ALADDIN), a recently-developed arterial spin labeling technique with sensitivity to blood flow directions. ALADDIN was applied along 3 orthogonal directions to assess directional blood flow in a vector form and also along 6 equally-spaced directions to extract blood flow tensor matrix (P) based on a blood flow ellipsoid model. Tensor elements (eigenvalues, eigenvectors, etc) were calculated to investigate characteristics of the blood flow tensor, in comparison with time-of-flight MR angiogram. While the directions of the main eigenvectors were heterogeneous throughout the brain, regional clusters of blood flow directionality were reproducible across subjects. The technique could show heterogeneous blood flow directionality within and around brain tumor, which was different from that of the contralateral normal side. The proposed method is deemed to provide information of blood flow directionality, which has not been demonstrated before. The results warrant further studies to assess changes in the directionality map as a function of scan parameters, to understand the signal sources, to investigate the possibility of mapping local blood perfusion directionality, and to evaluate its usefulness for clinical diagnosis.

  19. Characterization of normal brain and brain tumor pathology by chisquares parameter maps of diffusion-weighted image data

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Stephan E. E-mail: stephan@bwh.harvard.edu; Mamata, Hatsuho; Mulkern, Robert V

    2003-03-01

    Objective: To characterize normal and pathologic brain tissue by quantifying the deviation of diffusion-related signal from a simple monoexponential decay, when measured over a wider than usual range of b-factors. Methods and materials: Line scan diffusion imaging (LSDI), with diffusion weighting at multiple b-factors between 100 and 5000 s/mm{sup 2}, was performed on 1.5 T clinical scanners. Diffusion data of single slice sections were acquired in five healthy subjects and 19 brain tumor patients. In-patients, conventional T2-weighted and contrast-enhanced T1-weighted images were obtained for reference purposes. The chisquare ({chi}{sup 2}) error parameter associated with the monoexponential fits of the measured tissue water signals was then used to quantify the departure from a simple monoexponential signal decay on a pixel-by-pixel basis. Results: Diffusion-weighted images over a wider b-factor range than typically used were successfully obtained in all healthy subjects and patients. Normal and pathologic tissues demonstrated signal decays, which clearly deviate from a simple monoexponential behavior. The {chi}{sup 2} of cortical and deep grey matter was considerably lower than in white matter. In peritumoral edema, however, {chi}{sup 2} was 68% higher than in normal white matter. In highly malignant brain tumors, such as glioblastoma multiforme (GBM) or anaplastic astrocytoma, {chi}{sup 2} values were on average almost 400% higher than in normal white matter, while for one low grade astrocytoma and two cases of metastasis, {chi}{sup 2} was not profoundly different from the {chi}{sup 2} value of white matter. Maps of the {chi}{sup 2} values provide good visualization of spatial details. However, the tumor tissue contrast generated appeared in many cases to be different from the enhancement produced by paramagnetic contrast agents. For example, in cases where the contrast agent only highlighted the rim of the tumor, {chi}{sup 2} enhancement was present within the

  20. Mapping Multiplex Hubs in Human Functional Brain Networks

    Science.gov (United States)

    De Domenico, Manlio; Sasai, Shuntaro; Arenas, Alex

    2016-01-01

    Typical brain networks consist of many peripheral regions and a few highly central ones, i.e., hubs, playing key functional roles in cerebral inter-regional interactions. Studies have shown that networks, obtained from the analysis of specific frequency components of brain activity, present peculiar architectures with unique profiles of region centrality. However, the identification of hubs in networks built from different frequency bands simultaneously is still a challenging problem, remaining largely unexplored. Here we identify each frequency component with one layer of a multiplex network and face this challenge by exploiting the recent advances in the analysis of multiplex topologies. First, we show that each frequency band carries unique topological information, fundamental to accurately model brain functional networks. We then demonstrate that hubs in the multiplex network, in general different from those ones obtained after discarding or aggregating the measured signals as usual, provide a more accurate map of brain's most important functional regions, allowing to distinguish between healthy and schizophrenic populations better than conventional network approaches. PMID:27471443

  1. Mapping brain activity with flexible graphene micro-transistors

    CERN Document Server

    Blaschke, Benno M; Guimerà-Brunet, Anton; Weinert, Julia; Rousseau, Lionel; Heimann, Axel; Drieschner, Simon; Kempski, Oliver; Villa, Rosa; Sanchez-Vives, Maria V; Garrido, Jose A

    2016-01-01

    Establishing a reliable communication interface between the brain and electronic devices is of paramount importance for exploiting the full potential of neural prostheses. Current microelectrode technologies for recording electrical activity, however, evidence important shortcomings, e.g. challenging high density integration. Solution-gated field-effect transistors (SGFETs), on the other hand, could overcome these shortcomings if a suitable transistor material were available. Graphene is particularly attractive due to its biocompatibility, chemical stability, flexibility, low intrinsic electronic noise and high charge carrier mobilities. Here, we report on the use of an array of flexible graphene SGFETs for recording spontaneous slow waves, as well as visually evoked and also pre-epileptic activity in vivo in rats. The flexible array of graphene SGFETs allows mapping brain electrical activity with excellent signal-to-noise ratio (SNR), suggesting that this technology could lay the foundation for a future gene...

  2. Pharmacological Characterization of the Native Store-Operated Calcium Channels of Cortical Neurons from Embryonic Mouse Brain

    Science.gov (United States)

    Chauvet, Sylvain; Jarvis, Louis; Chevallet, Mireille; Shrestha, Niroj; Groschner, Klaus; Bouron, Alexandre

    2016-01-01

    In the murine brain, the first post-mitotic cortical neurons formed during embryogenesis express store-operated channels (SOCs) sensitive to Pyr3, initially proposed as a blocker of the transient receptor potential channel of C type 3 (TRPC3 channel). However, Pyr3 does not discriminate between Orai and TRPC3 channels, questioning the contribution of TRPC3 in SOCs. This study was undertaken to clarify the molecular identity and the pharmacological profile of native SOCs from E13 cortical neurons. The mRNA expression of STIM1-2 and Orai1-3 was assessed by quantitative reverse transcription polymerase chain reaction. E13 cortical neurons expressed STIM1-2 mRNAs, with STIM2 being the predominant isoform. Only transcripts of Orai2 were found but no Orai1 and Orai3 mRNAs. Blockers of Orai and TRPC channels (Pyr6, Pyr10, EVP4593, SAR7334, and GSK-7975A) were used to further characterize the endogenous SOCs. Their activity was recorded using the fluorescent Ca2+ probe Fluo-4. Cortical SOCs were sensitive to the Orai blockers Pyr6 and GSK-7975A, as well as to EVP4593, zinc, copper, and gadolinium ions, the latter one being the most potent SOCs blocker tested (IC50 ∼10 nM). SOCs were insensitive to the TRPC channel blockers Pyr10 and SAR7334. In addition, preventing mitochondrial Ca2+ uptake inhibited SOCs which were unaffected by inhibitors of the Ca2+-independent phospholipase A2. Altogether, Orai2 channels are present at the beginning of the embryonic murine cortico-genesis and form the core component of native SOCs in the immature cortex. This Ca2+ route is likely to play a role in the formation of the brain cortex. PMID:28018223

  3. A hybrid CPU-GPU accelerated framework for fast mapping of high-resolution human brain connectome.

    Directory of Open Access Journals (Sweden)

    Yu Wang

    Full Text Available Recently, a combination of non-invasive neuroimaging techniques and graph theoretical approaches has provided a unique opportunity for understanding the patterns of the structural and functional connectivity of the human brain (referred to as the human brain connectome. Currently, there is a very large amount of brain imaging data that have been collected, and there are very high requirements for the computational capabilities that are used in high-resolution connectome research. In this paper, we propose a hybrid CPU-GPU framework to accelerate the computation of the human brain connectome. We applied this framework to a publicly available resting-state functional MRI dataset from 197 participants. For each subject, we first computed Pearson's Correlation coefficient between any pairs of the time series of gray-matter voxels, and then we constructed unweighted undirected brain networks with 58 k nodes and a sparsity range from 0.02% to 0.17%. Next, graphic properties of the functional brain networks were quantified, analyzed and compared with those of 15 corresponding random networks. With our proposed accelerating framework, the above process for each network cost 80∼150 minutes, depending on the network sparsity. Further analyses revealed that high-resolution functional brain networks have efficient small-world properties, significant modular structure, a power law degree distribution and highly connected nodes in the medial frontal and parietal cortical regions. These results are largely compatible with previous human brain network studies. Taken together, our proposed framework can substantially enhance the applicability and efficacy of high-resolution (voxel-based brain network analysis, and have the potential to accelerate the mapping of the human brain connectome in normal and disease states.

  4. Reestablishing speech understanding through musical ear training after cochlear implantation: a study of the potential cortical plasticity in the brain

    DEFF Research Database (Denmark)

    Petersen, Bjørn; Mortensen, Malene V; Gjedde, Albert

    2009-01-01

    Cochlear implants (CIs) provide impressive speech perception for persons with severe hearing loss, but many CI recipients fail in perceiving speech prosody and music. Successful rehabilitation depends on cortical plasticity in the brain and postoperative measures. The present study evaluates...... the behavioral and neurologic effects of musical ear training on CI users' speech and music perception. The goal is to find and work out musical methods to improve CI users' auditory capabilities and, in a longer perspective, provide an efficient strategy for improving speech understanding for both adults...

  5. Two-dimensional map of direction selectivity in cortical visual area MT of Cebus monkey

    Directory of Open Access Journals (Sweden)

    ANTONIA CINIRA M. DIOGO

    2002-09-01

    Full Text Available We studied the spatial organization of direction of motion in visual area MT of the Cebus apella monkey. We used arrays of 6 (700 µm apart parallel electrodes in penetrations tangential to the cortical layers to record multi-unit responses to moving bars, at 200 µm steps. We determined the direction selectivity at each recording site. The data from single penetrations showed cyclic and gradual changes in the direction selectivity of clusters of cells, intermixed with abrupt 180º discontinuities along the electrode track. In order to obtain maps of direction of motion selectivity, we examined the spatial distribution of direction of motion in MT and we applied a method to determine the location of the centers of radial arrangements of direction selectivity. This tangential organization is characterized by slow continuous changes in direction of motion, interrupted by discontinuities. The changes in direction selectivity are organized radially in a pinwheel fashion and in slabs of linear variation. The pinwheel arrangements have 800-1400 µm in diameter. The size of the radial arrangement is comparable to the point image size in area MT at each eccentricity.Estudamos a organização espacial da seletividade ao sentido do movimento na área visual MT do macaco Cebus apella. Utilizamos um arranjo de 6 eletródios paralelos (separados por 700µm em penetrações tangenciais às camadas corticais para registrar, a cada 200µm, a atividade multi-unitária em resposta a barras em movimento. Determinamos a seletividade ao sentido de movimento em cada sítio de registro. Os dados captados por um único eletródio mostraram uma mudança cíclica e gradual na seletividade ao sentido de movimento dos grupos de neurônios registrados ao longo da trajetória do eletródio, interrompida por mudanças abruptas de 180º ocasionando descontinuidades na seletividade ao sentido do movimento. Para obter mapas de seletividade ao sentido do movimento, examinamos a

  6. Mapping brain development during childhood, adolescence and young adulthood

    Science.gov (United States)

    Guo, Xiaojuan; Jin, Zhen; Chen, Kewei; Peng, Danling; Li, Yao

    2009-02-01

    Using optimized voxel-based morphometry (VBM), this study systematically investigated the differences and similarities of brain structural changes during the early three developmental periods of human lives: childhood, adolescence and young adulthood. These brain changes were discussed in relationship to the corresponding cognitive function development during these three periods. Magnetic Resonance Imaging (MRI) data from 158 Chinese healthy children, adolescents and young adults, aged 7.26 to 22.80 years old, were included in this study. Using the customized brain template together with the gray matter/white matter/cerebrospinal fluid prior probability maps, we found that there were more age-related positive changes in the frontal lobe, less in hippocampus and amygdala during childhood, but more in bilateral hippocampus and amygdala and left fusiform gyrus during adolescence and young adulthood. There were more age-related negative changes near to central sulcus during childhood, but these changes extended to the frontal and parietal lobes, mainly in the parietal lobe, during adolescence and young adulthood, and more in the prefrontal lobe during young adulthood. So gray matter volume in the parietal lobe significantly decreased from childhood and continued to decrease till young adulthood. These findings may aid in understanding the age-related differences in cognitive function.

  7. Mapping brain activity at scale with cluster computing.

    Science.gov (United States)

    Freeman, Jeremy; Vladimirov, Nikita; Kawashima, Takashi; Mu, Yu; Sofroniew, Nicholas J; Bennett, Davis V; Rosen, Joshua; Yang, Chao-Tsung; Looger, Loren L; Ahrens, Misha B

    2014-09-01

    Understanding brain function requires monitoring and interpreting the activity of large networks of neurons during behavior. Advances in recording technology are greatly increasing the size and complexity of neural data. Analyzing such data will pose a fundamental bottleneck for neuroscience. We present a library of analytical tools called Thunder built on the open-source Apache Spark platform for large-scale distributed computing. The library implements a variety of univariate and multivariate analyses with a modular, extendable structure well-suited to interactive exploration and analysis development. We demonstrate how these analyses find structure in large-scale neural data, including whole-brain light-sheet imaging data from fictively behaving larval zebrafish, and two-photon imaging data from behaving mouse. The analyses relate neuronal responses to sensory input and behavior, run in minutes or less and can be used on a private cluster or in the cloud. Our open-source framework thus holds promise for turning brain activity mapping efforts into biological insights.

  8. Wide spectrum of developmental brain disorders from megalencephaly to focal cortical dysplasia and pigmentary mosaicism caused by mutations of MTOR

    Science.gov (United States)

    Solovieff, Nadia; Goold, Carleton; Jansen, Laura A.; Menon, Suchithra; Timms, Andrew E.; Conti, Valerio; Biag, Jonathan D.; Adams, Carissa; Boyle, Evan August; Collins, Sarah; Ishak, Gisele; Poliachik, Sandra; Girisha, Katta M.; Yeung, Kit San; Chung, Brian Hon Yin; Rahikkala, Elisa; Gunter, Sonya A.; McDaniel, Sharon S.; Macmurdo, Colleen Forsyth; Bernstein, Jonathan A.; Martin, Beth; Leary, Rebecca; Mahan, Scott; Liu, Shanming; Weaver, Molly; Doerschner, Michael; Jhangiani, Shalini; Muzny, Donna M.; Boerwinkle, Eric; Gibbs, Richard A.; Lupski, James R.; Shendure, Jay; Saneto, Russell P.; Novotny, Edward J.; Wilson, Christopher J.; Sellers, William R.; Morrissey, Michael; Hevner, Robert F.; Ojemann, Jeffrey G.; Guerrini, Renzo; Murphy, Leon O.; Winckler, Wendy; Dobyns, William B.

    2016-01-01

    Importance Focal cortical dysplasia (FCD), hemimegalencephaly (HMEG) and megalencephaly constitute a spectrum of malformations of cortical development with shared neuropathologic features. Collectively, these disorders are associated with significant childhood morbidity and mortality. FCD, in particular, represents the most frequent cause of intractable focal epilepsy in children. Objective To identify the underlying molecular etiology of FCD, HMEG, and diffuse megalencephaly. Design, Setting and Participants We performed whole exome sequencing (WES) on eight children with FCD or HMEG using standard depth (~50-60X) sequencing in peripheral samples (blood, saliva or skin) from the affected child and their parents, and deep (~150-180X) sequencing in affected brain tissue. We used both targeted sequencing and WES to screen a cohort of 93 children with molecularly unexplained diffuse or focal brain overgrowth (42 with FCD-HMEG, and 51 with diffuse megalencephaly). Histopathological and functional assays of PI3K-AKT-MTOR pathway activity in resected brain tissue and cultured neurons were performed to validate mutations. Main Outcomes and Measures Whole exome sequencing and targeted sequencing identified variants associated with this spectrum of developmental brain disorders. Results We identified low-level mosaic mutations of MTOR in brain tissue in four children with FCD type 2a with alternative allele fractions ranging from 0.012–0.086. We also identified intermediate level mosaic mutation of MTOR (p.Thr1977Ile) in three unrelated children with diffuse megalencephaly and pigmentary mosaicism in skin that resembles hypomelanosis of Ito. Finally, we identified a constitutional de novo mutation of MTOR (p.Glu1799Lys) in three unrelated children with diffuse megalencephaly and intellectual disability. Molecular and functional analysis in two children with FCD type 2a from whom multiple affected brain tissue samples were available revealed a gradient of alternate allele

  9. Mapping primary gyrogenesis during fetal development in primate brains: high-resolution in utero structural MRI study of fetal brain development in pregnant baboons

    Directory of Open Access Journals (Sweden)

    Peter Kochunov

    2010-05-01

    Full Text Available The global and regional changes in the fetal cerebral cortex in primates were mapped during primary gyrification (PG; weeks 17-25 of 26 weeks total gestation. Studying pregnant baboons using high-resolution MRI in utero, measurements included cerebral volume, cortical surface area, gyrification index and length and depth of ten primary cortical sulci. Seven normally developing fetuses were imaged in two animals longitudinally and sequentially. We compared these results to those on PG that from the ferret studies and analyzed them in the context of our recent studies of phylogenetics of cerebral gyrification. We observed that in both primates and non-primates, the cerebrum undergoes a very rapid transformation into the gyrencephalic state, subsequently accompanied by an accelerated growth in brain volume and cortical surface area. However, PG trends in baboons exhibited some critical differences from those observed in ferrets. For example, in baboons, the growth along the long (length axis of cortical sulci was unrelated to the growth along the short (depth axis and far outpaced it. Additionally, the correlation between the rate of growth along the short sulcal axis and heritability of sulcal depth was negative and approached significance (r=-0.60;p<.10, while the same trend for long axis was positive and not significant (p=0.3;p=0.40. These findings, in an animal that shares a highly orchestrated pattern of PG with humans, suggest that ontogenic processes that influence changes in sulcal length and depth are diverse and possibly driven by different factors in primates than in non-primates.

  10. Do Studies on Cortical Plasticity Provide a Rationale for Using Non-Invasive Brain Stimulation as a Treatment for Parkinson’s Disease Patients?

    OpenAIRE

    Koch, Giacomo

    2013-01-01

    Animal models of Parkinson’s disease (PD) have shown that key mechanisms of cortical plasticity such as long-term potentiation (LTP) and long-term depression (LTD) can be impaired by the PD pathology. In humans protocols of non-invasive brain stimulation, such as paired associative stimulation (PAS) and theta-burst stimulation (TBS), can be used to investigate cortical plasticity of the primary motor cortex. Through the amplitude of the motor evoked potential these transcranial magnetic stimu...

  11. Two-dimensional map of direction selectivity in cortical visual area MT of Cebus monkey

    OpenAIRE

    ANTONIA CINIRA M. DIOGO; Soares, Juliana G. M.; Albright, Thomas D.; RICARDO GATTASS

    2002-01-01

    We studied the spatial organization of direction of motion in visual area MT of the Cebus apella monkey. We used arrays of 6 (700 µm apart) parallel electrodes in penetrations tangential to the cortical layers to record multi-unit responses to moving bars, at 200 µm steps. We determined the direction selectivity at each recording site. The data from single penetrations showed cyclic and gradual changes in the direction selectivity of clusters of cells, intermixed with abrupt 180º discontinuit...

  12. Three-dimensional mapping of cortical bone thickness in subjects with different vertical facial dimensions

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    Mais Medhat Sadek

    2016-10-01

    Full Text Available Abstract Background The purpose of this study was to determine differences in cortical bone thickness among subjects with different vertical facial dimensions using cone beam computed tomography (CBCT. Methods From 114 pre-treatment CBCT scans, 48 scans were selected to be included in the study. CBCT-synthesized lateral cephalograms were used to categorize subjects into three groups based on their vertical skeletal pattern. Cortical bone thickness (CBT at two vertical levels (4 and 7 mm from the alveolar crest were measured in the entire tooth-bearing region in the maxilla and mandible. Results Significant group differences were detected with high-angle subjects having significantly narrower inter-radicular CBT at some sites as compared to average- and low-angle subjects. Conclusions Inter-radicular cortical bone is thinner in high-angle than in average- or low-angle subjects in few selected sites at the vertical height in which mini-implants are commonly inserted for orthodontic anchorage.

  13. Directed cortical information flow during human object recognition: analyzing induced EEG gamma-band responses in brain's source space.

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    Gernot G Supp

    Full Text Available The increase of induced gamma-band responses (iGBRs; oscillations >30 Hz elicited by familiar (meaningful objects is well established in electroencephalogram (EEG research. This frequency-specific change at distinct locations is thought to indicate the dynamic formation of local neuronal assemblies during the activation of cortical object representations. As analytically power increase is just a property of a single location, phase-synchrony was introduced to investigate the formation of large-scale networks between spatially distant brain sites. However, classical phase-synchrony reveals symmetric, pair-wise correlations and is not suited to uncover the directionality of interactions. Here, we investigated the neural mechanism of visual object processing by means of directional coupling analysis going beyond recording sites, but rather assessing the directionality of oscillatory interactions between brain areas directly. This study is the first to identify the directionality of oscillatory brain interactions in source space during human object recognition and suggests that familiar, but not unfamiliar, objects engage widespread reciprocal information flow. Directionality of cortical information-flow was calculated based upon an established Granger-Causality coupling-measure (partial-directed coherence; PDC using autoregressive modeling. To enable comparison with previous coupling studies lacking directional information, phase-locking analysis was applied, using wavelet-based signal decompositions. Both, autoregressive modeling and wavelet analysis, revealed an augmentation of iGBRs during the presentation of familiar objects relative to unfamiliar controls, which was localized to inferior-temporal, superior-parietal and frontal brain areas by means of distributed source reconstruction. The multivariate analysis of PDC evaluated each possible direction of brain interaction and revealed widespread reciprocal information-transfer during familiar

  14. The Estimation of Cortical Activity for Brain-Computer Interface: Applications in a Domotic Context

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    F. Babiloni

    2007-01-01

    Full Text Available In order to analyze whether the use of the cortical activity, estimated from noninvasive EEG recordings, could be useful to detect mental states related to the imagination of limb movements, we estimate cortical activity from high-resolution EEG recordings in a group of healthy subjects by using realistic head models. Such cortical activity was estimated in region of interest associated with the subject's Brodmann areas by using a depth-weighted minimum norm technique. Results showed that the use of the cortical-estimated activity instead of the unprocessed EEG improves the recognition of the mental states associated to the limb movement imagination in the group of normal subjects. The BCI methodology presented here has been used in a group of disabled patients in order to give them a suitable control of several electronic devices disposed in a three-room environment devoted to the neurorehabilitation. Four of six patients were able to control several electronic devices in this domotic context with the BCI system.

  15. The estimation of cortical activity for brain-computer interface: applications in a domotic context.

    Science.gov (United States)

    Babiloni, F; Cincotti, F; Marciani, M; Salinari, S; Astolfi, L; Tocci, A; Aloise, F; De Vico Fallani, F; Bufalari, S; Mattia, D

    2007-01-01

    In order to analyze whether the use of the cortical activity, estimated from noninvasive EEG recordings, could be useful to detect mental states related to the imagination of limb movements, we estimate cortical activity from high-resolution EEG recordings in a group of healthy subjects by using realistic head models. Such cortical activity was estimated in region of interest associated with the subject's Brodmann areas by using a depth-weighted minimum norm technique. Results showed that the use of the cortical-estimated activity instead of the unprocessed EEG improves the recognition of the mental states associated to the limb movement imagination in the group of normal subjects. The BCI methodology presented here has been used in a group of disabled patients in order to give them a suitable control of several electronic devices disposed in a three-room environment devoted to the neurorehabilitation. Four of six patients were able to control several electronic devices in this domotic context with the BCI system.

  16. Phonetically Irregular Word Pronunciation and Cortical Thickness in the Adult Brain

    Science.gov (United States)

    Blackmon, Karen; Barr, William B.; Kuzniecky, Ruben; DuBois, Jonathan; Carlson, Chad; Quinn, Brian T.; Blumberg, Mark; Halgren, Eric; Hagler, Donald J.; Mikhly, Mark; Devinsky, Orrin; McDonald, Carrie R.; Dale, Anders M.; Thesen, Thomas

    2010-01-01

    Accurate pronunciation of phonetically irregular words (exception words) requires prior exposure to unique relationships between orthographic and phonemic features. Whether such word knowledge is accompanied by structural variation in areas associated with orthographic-to-phonemic transformations has not been investigated. We used high resolution MRI to determine whether performance on a visual word-reading test composed of phonetically irregular words, the Wechsler Test of Adult Reading (WTAR), is associated with regional variations in cortical structure. A sample of 60 right-handed, neurologically intact individuals were administered the WTAR and underwent 3T volumetric MRI. Using quantitative, surface-based image analysis, cortical thickness was estimated at each vertex on the cortical mantle and correlated with WTAR scores while controlling for age. Higher scores on the WTAR were associated with thicker cortex in bilateral anterior superior temporal gyrus, bilateral angular gyrus/posterior superior temporal gyrus, and left hemisphere intraparietal sulcus. Higher scores were also associated with thinner cortex in left hemisphere posterior fusiform gyrus and central sulcus, bilateral inferior frontal gyrus, and right hemisphere lingual gyrus and supramarginal gyrus. These results suggest that the ability to correctly pronounce phonetically irregular words is associated with structural variations in cortical areas that are commonly activated in functional neuroimaging studies of word reading, including areas associated with grapheme-to–phonemic conversion. PMID:20302944

  17. Caffeine/nutrition interaction in the rat brain: Influence on latent inhibition and cortical spreading depression.

    Science.gov (United States)

    de Aguiar, Márlison José Lima; de Aguiar, Cilene Rejane Ramos Alves; Guedes, Rubem Carlos Araújo

    2011-01-10

    Caffeine, like malnutrition, can produce behavioral and electrophysiological alterations. However, the interaction of both factors remains unclear. Here this interaction has been studied in male Wistar rats previously malnourished during the lactation period by feeding their dams the "regional basic diet" of Northeast Brazil, containing about 8% protein, predominantly from vegetable sources (RBD(8)). At 70-75days of life, a subset of the pups was treated intraperitoneally with 30mg/kg caffeine for 4days while being tested according to the behavioral model of latent inhibition. Another group was subjected to an electrophysiological recording of the phenomenon known as cortical spreading depression, and the effects of caffeine injected during the recording session were evaluated. Caffeine did not affect cortical spreading depression, but antagonized latent inhibition in both the RBD(8)-malnourished rats and in the well-nourished control group fed a chow diet with 22% protein. This effect of caffeine was not seen in malnourished rats fed a protein-supplemented RBD (protein increased to 22% by increasing the proportion of foodstuffs from vegetable origin; RBD(22) group), suggesting that the amino acid imbalance of this diet may modulate the caffeine effects on latent inhibition. The results indicate a differential effect of caffeine in the latent inhibition behavioral model, as compared to the cortical spreading depression phenomenon, and this effect is influenced by the early nutritional status of the animal. We suggest that caffeine may modulate dopaminergic subcortical receptors participating in attention processes, but does not interact at the cortical level, in a way that would affect cortical spreading depression.

  18. Mapping multiplex hubs in human functional brain networks

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    Alex Arenas

    2016-07-01

    Full Text Available Typical brain networks consist of many peripheral regions and a few highly centralones, i.e. hubs, playing key functional roles in cerebral inter-regional interactions. Studieshave shown that networks, obtained from the analysis of specific frequency components ofbrain activity, present peculiar architectures with unique profiles of region centrality. However,the identification of hubs in networks built from different frequency bands simultaneouslyis still a challenging problem, remaining largely unexplored. Here we identify eachfrequency component with one layer of a multiplex network and face this challenge by exploitingthe recent advances in the analysis of multiplex topologies. First, we show that eachfrequency band carries unique topological information, fundamental to accurately modelbrain functional networks. We then demonstrate that hubs in the multiplex network, in generaldifferent from those ones obtained after discarding or aggregating the measured signalsas usual, provide a more accurate map of brain’s most important functional regions, allowingto distinguish between healthy and schizophrenic populations better than conventionalnetwork approaches.

  19. Mapping the spatio-temporal structure of motor cortical LFP and spiking activities during reach-to-grasp movements

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    Alexa eRiehle

    2013-03-01

    Full Text Available Grasping an object involves shaping the hand and fingers in relation to the object's physical properties. Following object contact, it also requires a fine adjustment of grasp forces for secure manipulation. Earlier studies suggest that the control of hand shaping and grasp force involve partially segregated motor cortical networks. However, it is still unclear how information originating from these networks is processed and integrated. We addressed this issue by analyzing massively parallel signals from population measures (local field potentials, LFPs and single neuron spiking activities recorded simultaneously during a delayed reach-to-grasp task, by using a 100 electrode array chronically implanted in monkey motor cortex. Motor cortical LFPs exhibit a large multi-component movement-related potential (MRP around movement onset. Here, we show that the peak amplitude of each MRP component and its latency with respect to movement onset vary along the cortical surface covered by the array. Using a comparative mapping approach, we suggest that the spatio-temporal structure of the MRP reflects the complex physical properties of the reach-to-grasp movement. In addition, we explored how the spatio-temporal structure of the MRP relates to two other measures of neuronal activity: the temporal profile of single neuron spiking activity at each electrode site and the somatosensory receptive field properties of single neuron activities. We observe that the spatial representations of LFP and spiking activities overlap extensively and relate to the spatial distribution of proximal and distal representations of the upper limb. Altogether, these data show that, in motor cortex, a precise spatio-temporal pattern of activation is involved for the control of reach-to-grasp movements and provide some new insight about the functional organization of motor cortex during reaching and object manipulation.

  20. Mapping the spatio-temporal structure of motor cortical LFP and spiking activities during reach-to-grasp movements.

    Science.gov (United States)

    Riehle, Alexa; Wirtssohn, Sarah; Grün, Sonja; Brochier, Thomas

    2013-01-01

    Grasping an object involves shaping the hand and fingers in relation to the object's physical properties. Following object contact, it also requires a fine adjustment of grasp forces for secure manipulation. Earlier studies suggest that the control of hand shaping and grasp force involve partially segregated motor cortical networks. However, it is still unclear how information originating from these networks is processed and integrated. We addressed this issue by analyzing massively parallel signals from population measures (local field potentials, LFPs) and single neuron spiking activities recorded simultaneously during a delayed reach-to-grasp task, by using a 100-electrode array chronically implanted in monkey motor cortex. Motor cortical LFPs exhibit a large multi-component movement-related potential (MRP) around movement onset. Here, we show that the peak amplitude of each MRP component and its latency with respect to movement onset vary along the cortical surface covered by the array. Using a comparative mapping approach, we suggest that the spatio-temporal structure of the MRP reflects the complex physical properties of the reach-to-grasp movement. In addition, we explored how the spatio-temporal structure of the MRP relates to two other measures of neuronal activity: the temporal profile of single neuron spiking activity at each electrode site and the somatosensory receptive field properties of single neuron activities. We observe that the spatial representations of LFP and spiking activities overlap extensively and relate to the spatial distribution of proximal and distal representations of the upper limb. Altogether, these data show that, in motor cortex, a precise spatio-temporal pattern of activation is involved for the control of reach-to-grasp movements and provide some new insight about the functional organization of motor cortex during reaching and object manipulation.

  1. Age Effects on Cortical Thickness in Cognitively Normal Elderly Individuals

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    Sona Hurtz

    2014-07-01

    Full Text Available Background/Aims: Atrophy in both grey and white matter is found in normal aging. The prefrontal cortex and the frontal lobe white matter are thought to be the most affected regions. Our aim was to examine the effects of normal aging on cortical grey matter using a 3D quantitative cortical mapping method. Methods: We analyzed 1.5-tesla brain magnetic resonance imaging data from 44 cognitively normal elderly subjects using cortical pattern matching and cortical thickness analyses. Linear regression analysis was used to study the effect of age on cortical thickness. 3D map-wide correction for multiple comparisons was conducted with permutation analyses using a threshold of p Results: We found a significant negative association between age and cortical thickness in the right hemisphere (pcorrected = 0.009 and a trend level association in the left hemisphere (pcorrected = 0.081. Age-related changes were greatest in the sensorimotor, bilateral dorsal anterior cingulate and supplementary motor cortices, and the right posterior middle and inferior frontal gyri. Age effects greater in the medial than lateral visual association cortices were also seen bilaterally. Conclusion: Our novel method further validates that normal aging results in diffuse cortical thinning that is most pronounced in the frontal and visual association cortices.

  2. Rapid Changes in Cortical and Subcortical Brain Regions after Early Bilateral Enucleation in the Mouse.

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    Olga O Kozanian

    Full Text Available Functional sensory and motor areas in the developing mammalian neocortex are formed through a complex interaction of cortically intrinsic mechanisms, such as gene expression, and cortically extrinsic mechanisms such as those mediated by thalamic input from the senses. Both intrinsic and extrinsic mechanisms are believed to be involved in cortical patterning and the establishment of areal boundaries in early development; however, the nature of the interaction between intrinsic and extrinsic processes is not well understood. In a previous study, we used a perinatal bilateral enucleation mouse model to test some aspects of this interaction by reweighting sensory input to the developing cortex. Visual deprivation at birth resulted in a shift of intraneocortical connections (INCs that aligned with ectopic ephrin A5 expression in the same location ten days later at postnatal day (P 10. A prevailing question remained: Does visual deprivation first induce a change in gene expression, followed by a shift in INCs, or vice versa? In the present study, we address this question by investigating the neuroanatomy and patterns of gene expression in post-natal day (P 1 and 4 mice following bilateral enucleation at birth. Our results demonstrate a rapid reduction in dorsal lateral geniculate nucleus (dLGN size and ephrin A5 gene expression 24-hours post-enucleation, with more profound effects apparent at P4. The reduced nuclear size and diminished gene expression mirrors subtle changes in ephrin A5 expression evident in P1 and P4 enucleated neocortex, 11 and 8 days prior to natural eye opening, respectively. Somatosensory and visual INCs were indistinguishable between P1 and P4 mice bilaterally enucleated at birth, indicating that perinatal bilateral enucleation initiates a rapid change in gene expression (within one day followed by an alteration of sensory INCs later on (second postnatal week. With these results, we gain a deeper understanding of how gene

  3. Re-examine tumor-induced alterations in hemodynamic responses of BOLD fMRI. Implications in presurgical brain mapping

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Liya [Dept. of Radiology and Imaging Sciences, Emory Univ., School of Medicine, Atlanta (United States); Dept. of Radiology, Baoan Hospital, Shenzhen (China); Ali, Shazia; Fa, Tianning; Mao, Hui [Dept. of Radiology and Imaging Sciences, Emory Univ., School of Medicine, Atlanta (United States)], e-mail: hmao@emory.edu; Dandan, Chen [Dept. of Physics, Emory Univ., Atlanta, (United States); School of Radiation Medicine and Protection, Soochow Univ., Suzhou (China); Olson, Jeffrey [Dept. of Neurosurgery, Emory Univ., School of Medicine, Atlanta (United States)

    2012-09-15

    Background: Blood oxygenation level dependent (BOLD) fMRI is used for presurgical functional mapping of brain tumor patients. Abnormal tumor blood supply may affect hemodynamic responses and BOLD fMRI signals. Purpose: To perform a multivariate and quantitative investigation of the effect of brain tumors on the hemodynamic responses and its impact on BOLD MRI signal time course, data analysis in order to better understand tumor-induced alterations in hemodynamic responses, and accurately mapping cortical regions in brain tumor patients. Material and Methods: BOLD fMRI data from 42 glioma patients who underwent presurgical mapping of the primary motor cortex (PMC) with a block designed finger tapping paradigm were analyzed, retrospectively. Cases were divided into high grade (n = 24) and low grade (n = 18) groups based on pathology. The tumor volume and distance to the activated PMCs were measured. BOLD signal time courses from selected regions of interest (ROIs) in the PMCs of tumor affected and contralateral unaffected hemispheres were obtained from each patient. Tumor-induced changes of BOLD signal intensity and time to peak (TTP) of BOLD signal time courses were analyzed statistically. Results: The BOLD signal intensity and TTP in the tumor-affected PMCs are altered when compared to that of the unaffected hemisphere. The average BOLD signal level is statistically significant lower in the affected PMCs. The average TTP in the affected PMCs is shorter in the high grade group, but longer in the low grade tumor group compared to the contralateral unaffected hemisphere. Degrees of alterations in BOLD signal time courses are related to both the distance to activated foci and tumor volume with the stronger effect in tumor distance to activated PMC. Conclusion: Alterations in BOLD signal time courses are strongly related to the tumor grade, the tumor volume, and the distance to the activated foci. Such alterations may impair accurate mapping of tumor-affected functional

  4. Predicting Hip Fracture Type With Cortical Bone Mapping (CBM) in the Osteoporotic Fractures in Men (MrOS) Study.

    Science.gov (United States)

    Treece, Graham M; Gee, Andrew H; Tonkin, Carol; Ewing, Susan K; Cawthon, Peggy M; Black, Dennis M; Poole, Kenneth E S

    2015-11-01

    Hip fracture risk is known to be related to material properties of the proximal femur, but fracture prediction studies adding richer quantitative computed tomography (QCT) measures to dual-energy X-ray (DXA)-based methods have shown limited improvement. Fracture types have distinct relationships to predictors, but few studies have subdivided fracture into types, because this necessitates regional measurements and more fracture cases. This work makes use of cortical bone mapping (CBM) to accurately assess, with no prior anatomical presumptions, the distribution of properties related to fracture type. CBM uses QCT data to measure the cortical and trabecular properties, accurate even for thin cortices below the imaging resolution. The Osteoporotic Fractures in Men (MrOS) study is a predictive case-cohort study of men over 65 years old: we analyze 99 fracture cases (44 trochanteric and 55 femoral neck) compared to a cohort of 308, randomly selected from 5994. To our knowledge, this is the largest QCT-based predictive hip fracture study to date, and the first to incorporate CBM analysis into fracture prediction. We show that both cortical mass surface density and endocortical trabecular BMD are significantly different in fracture cases versus cohort, in regions appropriate to fracture type. We incorporate these regions into predictive models using Cox proportional hazards regression to estimate hazard ratios, and logistic regression to estimate area under the receiver operating characteristic curve (AUC). Adding CBM to DXA-based BMD leads to a small but significant (p < 0.005) improvement in model prediction for any fracture, with AUC increasing from 0.78 to 0.79, assessed using leave-one-out cross-validation. For specific fracture types, the improvement is more significant (p < 0.0001), with AUC increasing from 0.71 to 0.77 for trochanteric fractures and 0.76 to 0.82 for femoral neck fractures. In contrast, adding DXA-based BMD to a CBM-based predictive model

  5. Abnormal brain processing of pain in migraine without aura: a high-density EEG brain mapping study

    DEFF Research Database (Denmark)

    Egsgaard, L L; Jensen, R; Buchgreitz, L

    2010-01-01

    In the present study we used high-density EEG brain mapping to investigate spatio-temporal aspects of brain activity in response to experimentally induced muscle pain in 17 patients with migraine without aura and 15 healthy controls. Painful electrical stimuli were applied to the trapezius muscle...... to the tonic muscle pain condition (z = 29 mm vs. z =¿-13 mm, P aura....

  6. Different Brain Wave Patterns and Cortical Control Abilities in Relation to Different Creative Potentials

    Science.gov (United States)

    Li, Ying-Han; Tseng, Chao-Yuan; Tsai, Arthur Chih-Hsin; Huang, Andrew Chih-Wei; Lin, Wei-Lun

    2016-01-01

    Contemporary understanding of brain functions provides a way to probe into the mystery of creativity. However, the prior evidence regarding the relationship between creativity and brain wave patterns reveals inconsistent conclusions. One possible reason might be that the means of selecting creative individuals in the past has varied in each study.…

  7. Mapping auditory core, lateral belt, and parabelt cortices in the human superior temporal gyrus

    DEFF Research Database (Denmark)

    Sweet, Robert A; Dorph-Petersen, Karl-Anton; Lewis, David A

    2005-01-01

    the location of the lateral belt and parabelt with respect to gross anatomical landmarks. Architectonic criteria for the core, lateral belt, and parabelt were readily adapted from monkey to human. Additionally, we found evidence for an architectonic subdivision within the parabelt, present in both species......The goal of the present study was to determine whether the architectonic criteria used to identify the core, lateral belt, and parabelt auditory cortices in macaque monkeys (Macaca fascicularis) could be used to identify homologous regions in humans (Homo sapiens). Current evidence indicates...... that auditory cortex in humans, as in monkeys, is located on the superior temporal gyrus (STG), and is functionally and structurally altered in illnesses such as schizophrenia and Alzheimer's disease. In this study, we used serial sets of adjacent sections processed for Nissl substance, acetylcholinesterase...

  8. Mapping the dynamics of cortical neuroplasticity of skilled motor learning using micro X-ray fluorescence and histofluorescence imaging of zinc in the rat.

    Science.gov (United States)

    Alaverdashvili, Mariam; Paterson, Phyllis G

    2017-02-01

    Synchrotron-based X-ray fluorescence imaging (XFI) of zinc (Zn) has been recently implemented to understand the efficiency of various therapeutic interventions targeting post-stroke neuroprotection and neuroplasticity. However, it is uncertain if micro XFI can resolve neuroplasticity-induced changes. Thus, we explored if learning-associated behavioral changes would be accompanied by changes in cortical Zn concentration measured by XFI in healthy adult rats. Proficiency in a skilled reach-to-eat task during early and late stages of motor learning served as a functional measure of neuroplasticity. c-Fos protein and vesicular Zn expression were employed as indirect neuronal measures of brain plasticity. A total Zn map (20×20×30μm(3) resolution) generated by micro XFI failed to reflect increases in either c-Fos or vesicular Zn in the motor cortex contralateral to the trained forelimb or improved proficiency in the skilled reaching task. Remarkably, vesicular Zn increased in the late stage of motor learning along with a concurrent decrease in the number of c-fos-ip neurons relative to the early stage of motor learning. This inverse dynamics of c-fos and vesicular Zn level as the motor skill advances suggest that a qualitatively different neural population, comprised of fewer active but more efficiently connected neurons, supports a skilled action in the late versus early stage of motor learning. The lack of sensitivity of the XFI-generated Zn map to visualize the plasticity-associated changes in vesicular Zn suggests that the Zn level measured by micro XFI should not be used as a surrogate marker of neuroplasticity in response to the acquisition of skilled motor actions. Nanoscopic XFI could be explored in future as a means of imaging these subtle physiological changes.

  9. Cortical Auditory Disorders: A Case of Non-Verbal Disturbances Assessed with Event-Related Brain Potentials

    Directory of Open Access Journals (Sweden)

    Sönke Johannes

    1998-01-01

    Full Text Available In the auditory modality, there has been a considerable debate about some aspects of cortical disorders, especially about auditory forms of agnosia. Agnosia refers to an impaired comprehension of sensory information in the absence of deficits in primary sensory processes. In the non-verbal domain, sound agnosia and amusia have been reported but are frequently accompanied by language deficits whereas pure deficits are rare. Absolute pitch and musicians’ musical abilities have been associated with left hemispheric functions. We report the case of a right handed sound engineer with the absolute pitch who developed sound agnosia and amusia in the absence of verbal deficits after a right perisylvian stroke. His disabilities were assessed with the Seashore Test of Musical Functions, the tests of Wertheim and Botez (Wertheim and Botez, Brain 84, 1961, 19–30 and by event-related potentials (ERP recorded in a modified 'oddball paradigm’. Auditory ERP revealed a dissociation between the amplitudes of the P3a and P3b subcomponents with the P3b being reduced in amplitude while the P3a was undisturbed. This is interpreted as reflecting disturbances in target detection processes as indexed by the P3b. The findings that contradict some aspects of current knowledge about left/right hemispheric specialization in musical processing are discussed and related to the literature concerning cortical auditory disorders.

  10. Formation mechanism of propagated sensation along the meridians, as verified by cortical somatosensory-evoked potential topographic maps

    Institute of Scientific and Technical Information of China (English)

    Jinsen Xu; Xiaohua Pan; Shuxia Zheng; Xianglong Hu; Zheyan Sa

    2011-01-01

    The peripheral driver stimulating theory states that as a driver passes along a certain meridian during acupuncture; the driver provokes nerve sense devices along the meridian, resulting in the nerve impulse entering the central nervous system. Accordingly, volunteers have reported propagated sensations along the meridians (PSM). The present study was designed to utilize a cortical somatosensory-evoked potential (CSEP) topographic map for determining whether stimulation expansion occurs in somatosensory area I when sensation was provoked in individuals with obvious PSM. The sensation was blocked by mechanical compression, and the sensation was imitated in individuals without PSM. Results revealed a red, high-potential signal in the representative area of the lower limbs in individuals with obvious PSM symptoms when the Gall Bladder Meridian (GBM) sensation passed to the head and face. This representative area was near the middle line of the CSEP topographic map, and a red, high-potential signal, which jumps over the representative area of the upper limbs, also appeared in the representative face area, which was at the external region of the CSEP topographic map. However, in individuals exhibiting no PSM, only a red high-potential signal appeared in the representative lower limb area. When Hegu (LI 4) was stimulated in individuals without PSM, an obvious evoked response appeared only in the representative upper limb area. However, when Hegu was stimulated in individuals exhibiting PSM, the response area was larger in the representative upper limb area and extended to the representative face area. When Guangming (GB 37) was stimulated in PSM individuals, the face representation response disappeared and was confined to a foot representation of the somatosensory area I when PSM was blocked by mechanical pressure. Results suggested that mechanical compression blocked PSM, and corresponding changes were exhibited in the CSEP topographic map. These results provide

  11. Neuroprotection afforded by diazepam against oxygen/glucose deprivation-induced injury in rat cortical brain slices.

    Science.gov (United States)

    Ricci, Lorenzo; Valoti, Massimo; Sgaragli, Giampietro; Frosini, Maria

    2007-04-30

    The aim of the present investigation was to assess neuroprotection exerted by diazepam (0.1-25 microM) in rat cortical brain slices subjected to oxygen-glucose deprivation and reoxygenation. Neuronal injury and neuroprotection were assessed by measuring the release of glutamate and lactate dehydrogenase and tissue water content. Results demonstrate that diazepam exerted neuroprotective effects according to a "U-shaped", hormetic-like, concentration-response curve, with an efficacy window of 0.5-5 microM concentration. Flumazenil (20 microM) fully antagonised neuroprotection afforded by 5 microM diazepam. In conclusion, the hormetic response of diazepam should be taken into consideration when designing experiments aimed at assessing diazepam neuroprotection against ischemia/reoxygenation injury.

  12. The evolution of the brain, the human nature of cortical circuits and intellectual creativity

    Directory of Open Access Journals (Sweden)

    Javier eDeFelipe

    2011-05-01

    Full Text Available The tremendous expansion and the differentiation of the neocortex constitute two major events in the evolution of the mammalian brain. The increase in size and complexity of our brains opened the way to a spectacular development of cognitive and mental skills. This expansion during evolution facilitated the addition of archetypical microcircuits, which increased the complexity of the human brain and contributed to its uniqueness. However, fundamental differences even exist between distinct mammalian species. Here, we shall discuss the issue of our humanity from a neurobiological and historical perspective.

  13. The Evolution of the Brain, the Human Nature of Cortical Circuits, and Intellectual Creativity

    Science.gov (United States)

    DeFelipe, Javier

    2011-01-01

    The tremendous expansion and the differentiation of the neocortex constitute two major events in the evolution of the mammalian brain. The increase in size and complexity of our brains opened the way to a spectacular development of cognitive and mental skills. This expansion during evolution facilitated the addition of microcircuits with a similar basic structure, which increased the complexity of the human brain and contributed to its uniqueness. However, fundamental differences even exist between distinct mammalian species. Here, we shall discuss the issue of our humanity from a neurobiological and historical perspective. PMID:21647212

  14. Patterns of brain activity distinguishing free and forced actions: contribution from sensory cortices

    Science.gov (United States)

    Kostelecki, Wojciech; Mei, Ye; Garcia Dominguez, Luis; Pérez Velázquez, José L.

    2012-01-01

    The neural basis of decision-making is extremely complex due to the large number of factors that contribute to the outcome of even the most basic actions as well as the range of appropriate responses within many behavioral contexts. To better understand the neural processes underlying basic forms of decision-making, this study utilized an experiment that required a choice about whether to press a button with the right or left hand. These instances of decision-making were compared to identical button presses that were experimentally specified rather than selected by the subject. Magnetoencephalography (MEG) was used to record neural activity during these—what are being termed—free and forced actions and differences in the MEG signal between these two conditions were attributed to the distinct forms of neural activity required to carry out the two types of actions. To produce instances of free and forced behavior, cued button-pressing experiments were performed that use visual, aural, and memorized cues to instruct experimental subjects of the expected outcome of individual trials. Classification analysis of the trials revealed that cortical regions that allowed for the most accurate classification of free and forced actions primarily handle sensory input for the modality used to cue the trials: occipital cortex for visually cued trials, temporal cortex for aurally cued trials, and minor non-localized differences in MEG activity for trials initiated from memory. The differential roles of visual and auditory sensory cortices during free and forced actions provided insight into the neural processing steps that were engaged to initiate cued actions. Specifically, it suggested that detectable differences exist in the activity of sensory cortices and their target sites when subjects performed free and forced actions in response to sensory cues. PMID:23060760

  15. Cortical surface-based analysis reduces bias and variance in kinetic modeling of brain PET data

    DEFF Research Database (Denmark)

    Greve, Douglas N; Svarer, Claus; Fisher, Patrick M;

    2014-01-01

    -based smoothing resulted in dramatically less bias and the least variance of the methods tested for smoothing levels 5mm and higher. When used in combination with PVC, surface-based smoothing minimized the bias without significantly increasing the variance. Surface-based smoothing resulted in 2-4 times less...... intersubject variance than when volume smoothing was used. This translates into more than 4 times fewer subjects needed in a group analysis to achieve similarly powered statistical tests. Surface-based smoothing has less bias and variance because it respects cortical geometry by smoothing the PET data only...

  16. Unexpected effects of peripherally administered kynurenic acid on cortical spreading depression and related blood–brain barrier permeability

    Directory of Open Access Journals (Sweden)

    Oláh G

    2013-09-01

    Full Text Available Gáspár Oláh,1 Judit Herédi,1 Ákos Menyhárt,1 Zsolt Czinege,2 Dávid Nagy,1 János Fuzik,1 Kitti Kocsis,1 Levente Knapp,1 Erika Krucsó,1 Levente Gellért,1 Zsolt Kis,1 Tamás Farkas,1 Ferenc Fülöp,3 Árpád Párdutz,4 János Tajti,4 László Vécsei,4 József Toldi1 1Department of Physiology, Anatomy and Neuroscience, 2Department of Software Engineering, 3Institute of Pharmaceutical Chemistry and MTA-SZTE Research Group for Stereochemistry, 4Department of Neurology and MTA-SZTE Neuroscience Research Group, University of Szeged, Szeged, Hungary Abstract: Cortical spreading depression (CSD involves a slowly-propagating depolarization wave in the cortex, which can appear in numerous pathophysiological conditions, such as migraine with aura, stroke, and traumatic brain injury. Neurons and glial cells are also depolarized transiently during the phenomena. CSD is followed by a massive increase in glutamate release and by changes in the brain microcirculation. The aim of this study was to investigate the effects of two N-methyl-D-aspartate receptor antagonists, endogenous kynurenic acid (KYNA and dizocilpine, on CSD and the related blood–brain barrier (BBB permeability in rats. In intact animals, KYNA hardly crosses the BBB but has some positive features as compared with its precursor L-Kynurenine, which is frequently used in animal studies (KYNA cannot be metabolized to excitotoxic agents such as 3-hydroxy-L-kynurenine and quinolinic acid. We therefore investigated the possible effects of peripherally administered KYNA. Repetitive CSD waves were elicited by the application of 1 M KCl solution to the cortex. Direct current-electrocorticograms were measured for 1 hour. Four parameters of the waves were compared. Evans blue dye and fluorescent microscopy were used to study the possible changes in the permeability of the BBB. The results demonstrated that N-methyl-D-aspartate receptor antagonists can reduce the number of CSD waves and decrease

  17. Quantitative analysis of axonal fiber activation evoked by deep brain stimulation via activation density heat maps

    Directory of Open Access Journals (Sweden)

    Christian J. Hartmann

    2015-02-01

    Full Text Available Background: Cortical modulation is likely to be involved in the various therapeutic effects of deep brain stimulation (DBS. However, it is currently difficult to predict the changes of cortical modulation during clinical adjustment of DBS. Therefore, we present a novel quantitative approach to estimate anatomical regions of DBS-evoked cortical modulation. Methods: Four different models of the subthalamic nucleus (STN DBS were created to represent variable electrode placements (model I: dorsal border of the posterolateral STN; model II: central posterolateral STN; model III: central anteromedial STN; model IV: dorsal border of the anteromedial STN. Axonal fibers of passage near each electrode location were reconstructed using probabilistic tractography and modeled using multi-compartment cable models. Stimulation-evoked activation of local axon fibers and corresponding cortical projections were modeled and quantified. Results: Stimulation at the border of the STN (models I and IV led to a higher degree of fiber activation and associated cortical modulation than stimulation deeply inside the STN (models II and III. A posterolateral target (models I and II was highly connected to cortical areas representing motor function. Additionally, model I was also associated with strong activation of fibers projecting to the cerebellum. Finally, models III and IV showed a dorsoventral difference of preferentially targeted prefrontal areas (models III: middle frontal gyrus; model IV: inferior frontal gyrus.Discussion: The method described herein allows characterization of cortical modulation across different electrode placements and stimulation parameters. Furthermore, knowledge of anatomical distribution of stimulation-evoked activation targeting cortical regions may help predict efficacy and potential side effects, and therefore can be used to improve the therapeutic effectiveness of individual adjustments in DBS patients.

  18. Mapping abnormal subcortical brain morphometry in an elderly HIV+ cohort

    Directory of Open Access Journals (Sweden)

    Benjamin S.C. Wade

    2015-01-01

    Full Text Available Over 50% of HIV+ individuals exhibit neurocognitive impairment and subcortical atrophy, but the profile of brain abnormalities associated with HIV is still poorly understood. Using surface-based shape analyses, we mapped the 3D profile of subcortical morphometry in 63 elderly HIV+ participants and 31 uninfected controls. The thalamus, caudate, putamen, pallidum, hippocampus, amygdala, brainstem, accumbens, callosum and ventricles were segmented from high-resolution MRIs. To investigate shape-based morphometry, we analyzed the Jacobian determinant (JD and radial distances (RD defined on each region's surfaces. We also investigated effects of nadir CD4+ T-cell counts, viral load, time since diagnosis (TSD and cognition on subcortical morphology. Lastly, we explored whether HIV+ participants were distinguishable from unaffected controls in a machine learning context. All shape and volume features were included in a random forest (RF model. The model was validated with 2-fold cross-validation. Volumes of HIV+ participants' bilateral thalamus, left pallidum, left putamen and callosum were significantly reduced while ventricular spaces were enlarged. Significant shape variation was associated with HIV status, TSD and the Wechsler adult intelligence scale. HIV+ people had diffuse atrophy, particularly in the caudate, putamen, hippocampus and thalamus. Unexpectedly, extended TSD was associated with increased thickness of the anterior right pallidum. In the classification of HIV+ participants vs. controls, our RF model attained an area under the curve of 72%.

  19. Task-Driven Activity Reduces the Cortical Activity Space of the Brain: Experiment and Whole-Brain Modeling.

    Science.gov (United States)

    Ponce-Alvarez, Adrián; He, Biyu J; Hagmann, Patric; Deco, Gustavo

    2015-08-01

    How a stimulus or a task alters the spontaneous dynamics of the brain remains a fundamental open question in neuroscience. One of the most robust hallmarks of task/stimulus-driven brain dynamics is the decrease of variability with respect to the spontaneous level, an effect seen across multiple experimental conditions and in brain signals observed at different spatiotemporal scales. Recently, it was observed that the trial-to-trial variability and temporal variance of functional magnetic resonance imaging (fMRI) signals decrease in the task-driven activity. Here we examined the dynamics of a large-scale model of the human cortex to provide a mechanistic understanding of these observations. The model allows computing the statistics of synaptic activity in the spontaneous condition and in putative tasks determined by external inputs to a given subset of brain regions. We demonstrated that external inputs decrease the variance, increase the covariances, and decrease the autocovariance of synaptic activity as a consequence of single node and large-scale network dynamics. Altogether, these changes in network statistics imply a reduction of entropy, meaning that the spontaneous synaptic activity outlines a larger multidimensional activity space than does the task-driven activity. We tested this model's prediction on fMRI signals from healthy humans acquired during rest and task conditions and found a significant decrease of entropy in the stimulus-driven activity. Altogether, our study proposes a mechanism for increasing the information capacity of brain networks by enlarging the volume of possible activity configurations at rest and reliably settling into a confined stimulus-driven state to allow better transmission of stimulus-related information.

  20. Task-Driven Activity Reduces the Cortical Activity Space of the Brain: Experiment and Whole-Brain Modeling.

    Directory of Open Access Journals (Sweden)

    Adrián Ponce-Alvarez

    2015-08-01

    Full Text Available How a stimulus or a task alters the spontaneous dynamics of the brain remains a fundamental open question in neuroscience. One of the most robust hallmarks of task/stimulus-driven brain dynamics is the decrease of variability with respect to the spontaneous level, an effect seen across multiple experimental conditions and in brain signals observed at different spatiotemporal scales. Recently, it was observed that the trial-to-trial variability and temporal variance of functional magnetic resonance imaging (fMRI signals decrease in the task-driven activity. Here we examined the dynamics of a large-scale model of the human cortex to provide a mechanistic understanding of these observations. The model allows computing the statistics of synaptic activity in the spontaneous condition and in putative tasks determined by external inputs to a given subset of brain regions. We demonstrated that external inputs decrease the variance, increase the covariances, and decrease the autocovariance of synaptic activity as a consequence of single node and large-scale network dynamics. Altogether, these changes in network statistics imply a reduction of entropy, meaning that the spontaneous synaptic activity outlines a larger multidimensional activity space than does the task-driven activity. We tested this model's prediction on fMRI signals from healthy humans acquired during rest and task conditions and found a significant decrease of entropy in the stimulus-driven activity. Altogether, our study proposes a mechanism for increasing the information capacity of brain networks by enlarging the volume of possible activity configurations at rest and reliably settling into a confined stimulus-driven state to allow better transmission of stimulus-related information.

  1. Temporal Genetic Modifications after Controlled Cortical Impact—Understanding Traumatic Brain Injury through a Systematic Network Approach

    Directory of Open Access Journals (Sweden)

    Yung-Hao Wong

    2016-02-01

    Full Text Available Traumatic brain injury (TBI is a primary injury caused by external physical force and also a secondary injury caused by biological processes such as metabolic, cellular, and other molecular events that eventually lead to brain cell death, tissue and nerve damage, and atrophy. It is a common disease process (as opposed to an event that causes disabilities and high death rates. In order to treat all the repercussions of this injury, treatment becomes increasingly complex and difficult throughout the evolution of a TBI. Using high-throughput microarray data, we developed a systems biology approach to explore potential molecular mechanisms at four time points post-TBI (4, 8, 24, and 72 h, using a controlled cortical impact (CCI model. We identified 27, 50, 48, and 59 significant proteins as network biomarkers at these four time points, respectively. We present their network structures to illustrate the protein–protein interactions (PPIs. We also identified UBC (Ubiquitin C, SUMO1, CDKN1A (cyclindependent kinase inhibitor 1A, and MYC as the core network biomarkers at the four time points, respectively. Using the functional analytical tool MetaCore™, we explored regulatory mechanisms and biological processes and conducted a statistical analysis of the four networks. The analytical results support some recent findings regarding TBI and provide additional guidance and directions for future research.

  2. Contralateral cortical organisation of information in visual short-term memory: evidence from lateralized brain activity during retrieval.

    Science.gov (United States)

    Fortier-Gauthier, Ulysse; Moffat, Nicolas; Dell'Acqua, Roberto; McDonald, John J; Jolicœur, Pierre

    2012-07-01

    We studied brain activity during retention and retrieval phases of two visual short-term memory (VSTM) experiments. Experiment 1 used a balanced memory array, with one color stimulus in each hemifield, followed by a retention interval and a central probe, at the fixation point that designated the target stimulus in memory about which to make a determination of orientation. Retrieval of information from VSTM was associated with an event-related lateralization (ERL) with a contralateral negativity relative to the visual field from which the probed stimulus was originally encoded, suggesting a lateralized organization of VSTM. The scalp distribution of the retrieval ERL was more anterior than what is usually associated with simple maintenance activity, which is consistent with the involvement of different brain structures for these distinct visual memory mechanisms. Experiment 2 was like Experiment 1, but used an unbalanced memory array consisting of one lateral color stimulus in a hemifield and one color stimulus on the vertical mid-line. This design enabled us to separate lateralized activity related to target retrieval from distractor processing. Target retrieval was found to generate a negative-going ERL at electrode sites found in Experiment 1, and suggested representations were retrieved from anterior cortical structures. Distractor processing elicited a positive-going ERL at posterior electrodes sites, which could be indicative of a return to baseline of retention activity for the discarded memory of the now-irrelevant stimulus, or an active inhibition mechanism mediating distractor suppression.

  3. Prenatal Exposure to Autism-Specific Maternal Autoantibodies Alters Proliferation of Cortical Neural Precursor Cells, Enlarges Brain, and Increases Neuronal Size in Adult Animals.

    Science.gov (United States)

    Martínez-Cerdeño, Verónica; Camacho, Jasmin; Fox, Elizabeth; Miller, Elaine; Ariza, Jeanelle; Kienzle, Devon; Plank, Kaela; Noctor, Stephen C; Van de Water, Judy

    2016-01-01

    Autism spectrum disorders (ASDs) affect up to 1 in 68 children. Autism-specific autoantibodies directed against fetal brain proteins have been found exclusively in a subpopulation of mothers whose children were diagnosed with ASD or maternal autoantibody-related autism. We tested the impact of autoantibodies on brain development in mice by transferring human antigen-specific IgG directly into the cerebral ventricles of embryonic mice during cortical neurogenesis. We show that autoantibodies recognize radial glial cells during development. We also show that prenatal exposure to autism-specific maternal autoantibodies increased stem cell proliferation in the subventricular zone (SVZ) of the embryonic neocortex, increased adult brain size and weight, and increased the size of adult cortical neurons. We propose that prenatal exposure to autism-specific maternal autoantibodies directly affects radial glial cell development and presents a viable pathologic mechanism for the maternal autoantibody-related prenatal ASD risk factor.

  4. Brain Mapping Center Opens at Institute of Biophysics

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Agroup of world-class scie, ntists in brain imaging came to China's capital to .witness the inauguration of the Beijing MRI Center for Brain Research, which was officially opened on May 25 at the CAS Institute of Biophysics.

  5. Abnormal Changes of Brain Cortical Anatomy and the Association with Plasma MicroRNA107 Level in Amnestic Mild Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Tao eWang

    2016-05-01

    Full Text Available MicroRNA107 (Mir107 has been thought to relate to the brain structure phenotype of Alzheimer’s disease. In this study, we evaluated the cortical anatomy in amnestic mild cognitive impairment (aMCI and the relation between cortical anatomy and plasma levels of Mir107 and beta-site amyloid precursor protein cleaving enzyme 1 (BACE1. 20 aMCI and 24 cognitively normal control (NC subjects were recruited, and T1-weighted MR images were acquired. Cortical anatomical measurements, including cortical thickness (CT, surface area (SA, and local gyrification index (LGI, were assessed. Quantitative RT-PCR was used to examine plasma expression of Mir107, BACE1 mRNA. Thinner cortex was found in aMCI in areas associated with episodic memory and language, but with thicker cortex in other areas. SA decreased in aMCI in the areas associated with working memory and emotion. LGI showed a significant reduction in aMCI in the areas involved in language function. Changes in Mir107 and BACE1 messenger RNA plasma expression were correlated with changes in CT and SA. We found alterations in key left brain regions associated with memory, language, and emotion in aMCI that were significantly correlated with plasma expression of mir107 and BACE1 mRNA. This combination study of brain anatomical alterations and gene information may shed lights on our understanding of the pathology of AD.

  6. Implantable Microsystems for Anatomical Rewiring of Cortical Circuitry: A New Approach for Brain Repair

    Science.gov (United States)

    2009-03-01

    reaching, retrieval of small food items, and locomotion demonstrate that deficits persist during the 5-week recovery period following injury. This will...Implantable microsystem; Neuroplasticity ; Rehabilitation; Traumatic brain injury 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER...we have successfully induced TBI in the CFA, sparing the RFA. Behavioral assessments of reaching, retrieval of small food items, and locomotion

  7. Ultrastructural localization of cholinergic muscarinic receptors in rat brain cortical capillaries

    NARCIS (Netherlands)

    Luiten, PGM; deJong, GI; VanderZee, EA; vanDijken, H; Dijken, H. van

    1996-01-01

    Cholinergic innervation of the cerebrovasculature is known to regulate vascular tone, perfusion rate and permeability of the microvascular wall. Notably the cholinergic innervation of cerebral capillaries is of interest since these capillaries form the blood-brain barrier. Although there is a genera

  8. Cortical and brain stem changes in neural activity during static handgrip and postexercise ischemia in humans

    DEFF Research Database (Denmark)

    Sander, Mikael; Macefield, Vaughan G; Henderson, Luke A

    2010-01-01

    , and to differentiate between central command and reflex inputs, we used blood oxygen level-dependent (BOLD) functional MRI (fMRI) of the whole brain (3 T). Subjects performed submaximal static handgrip exercise for 2 min followed by 6 min of PEI; MSNA was recorded on a separate day. During the contraction phase...

  9. Cortical evoked potential and extracellular K+ and H+ at critical levels of brain ischemia

    DEFF Research Database (Denmark)

    Astrup, J; Symon, L; Branston, N M;

    1977-01-01

    As shown previously, the electrical function of the brain is critically dependent on cerebral blood flow in the sense that reduction beyond an ischemic threshold of approximately 15 ml/100 gm per minute (approximately 35% of control) in the baboon leads to complete failure of the somatosensory...

  10. Mapping plasticity: sex/gender and the changing brain

    NARCIS (Netherlands)

    Kleinherenbrink, A.

    2014-01-01

    There is a consensus in the neuroscientific literature that brains are either male or female, and that ‘brain sex’ is a fixed, immutable trait. Feminist critics have challenged this idea, raising questions, for example, about brain plasticity (the role of sociocultural factors in the emergence and e

  11. A single dose of PPARγ agonist pioglitazone reduces cortical oxidative damage and microglial reaction following lateral fluid percussion brain injury in rats.

    Science.gov (United States)

    Pilipović, Kristina; Župan, Željko; Dolenec, Petra; Mršić-Pelčić, Jasenka; Župan, Gordana

    2015-06-03

    Neuroprotective actions of the peroxisome proliferator-activated receptor-γ (PPARγ) agonists have been observed in various animal models of the brain injuries. In this study we examined the effects of a single dose of pioglitazone on oxidative and inflammatory parameters as well as on neurodegeneration and the edema formation in the rat parietal cortex following traumatic brain injury (TBI) induced by the lateral fluid percussion injury (LFPI) method. Pioglitazone was administered in a dose of 1mg/kg at 10min after the brain trauma. The animals of the control group were sham-operated and injected by vehicle. The rats were decapitated 24h after LFPI and their parietal cortices were analyzed by biochemical and histological methods. Cortical edema was evaluated in rats sacrificed 48h following TBI. Brain trauma caused statistically significant oxidative damage of lipids and proteins, an increase of glutathione peroxidase (GSH-Px) activity, the cyclooxygenase-2 (COX-2) overexpression, reactive astrocytosis, the microglia activation, neurodegeneration, and edema, but it did not influence the superoxide dismutase activity and the expressions of interleukin-1 beta, interleukin-6 and tumor necrosis factor-alpha in the rat parietal cortex. Pioglitazone significantly decreased the cortical lipid and protein oxidative damage, increased the GSH-Px activity and reduced microglial reaction. Although a certain degree of the TBI-induced COX-2 overexpression, neurodegeneration and edema decrease was detected in pioglitazone treated rats, it was not significant. In the injured animals, cortical reactive astrocytosis was unchanged by the tested PPARγ agonist. These findings demonstrate that pioglitazone, administered only in a single dose, early following LFPI, reduced cortical oxidative damage, increased antioxidant defense and had limited anti-inflammatory effect, suggesting the need for further studies of this drug in the treatment of TBI.

  12. ‘Your Brain on Art’: Emergent cortical dynamics during aesthetic experiences

    Directory of Open Access Journals (Sweden)

    Kimberly eKontson

    2015-11-01

    Full Text Available The brain response to conceptual art was studied with mobile electroencephalography (EEG to examine the neural basis of aesthetic experiences. In contrast to most studies of perceptual phenomena, participants were moving and thinking freely as they viewed the exhibit The Boundary of Life is Quietly Crossed by Dario Robleto at the Menil Collection-Houston. The brain activity of over 400 subjects was recorded using dry-electrode and one reference gel-based EEG systems over a period of 3 months. Here, we report initial findings based on the reference system. EEG segments corresponding to each art piece were grouped into one of three classes (complex, moderate, and baseline based on analysis of a digital image of each piece. Time, frequency, and wavelet features extracted from EEG were used to classify patterns associated with viewing art, and ranked based on their relevance for classification. The maximum classification accuracy was 55% (chance = 33% with delta and gamma features the most relevant for classification. Functional analysis revealed a significant increase in connection strength in localized brain networks while subjects viewed the most aesthetically pleasing art compared to viewing a blank wall. The direction of signal flow showed early recruitment of broad posterior areas followed by focal anterior activation. Significant differences in the strength of connections were also observed across age and gender. This work provides evidence that EEG, deployed on freely behaving subjects, can detect selective signal flow in neural networks, identify significant differences between subject groups, and report with greater-than-chance accuracy the complexity of a subject’s visual percept of aesthetically pleasing art. Our approach, which allows acquisition of neural activity ‘in action and context’, could lead to understanding of how the brain integrates sensory input and its ongoing internal state to produce the phenomenon which we term

  13. Orbitofrontal cortical thinning and aggression in mild traumatic brain injury patients

    OpenAIRE

    Epstein, Daniel J.; Legarreta, Margaret; Bueler, Elliot; King, Jace; McGlade, Erin; Yurgelun‐Todd, Deborah

    2016-01-01

    Abstract Introduction Although mild traumatic brain injury (mTBI) comprises 80% of all TBI, the morphological examination of the orbitofrontal cortex (OFC) in relation to clinical symptoms such as aggression, anxiety and depression in a strictly mTBI sample has never before been performed. Objectives The primary objective of the study was to determine if mTBI patients would show morphological differences in the OFC and if the morphology of this region would relate to clinical symptoms. Method...

  14. Using data-driven model-brain mappings to constrain formal models of cognition.

    Directory of Open Access Journals (Sweden)

    Jelmer P Borst

    Full Text Available In this paper we propose a method to create data-driven mappings from components of cognitive models to brain regions. Cognitive models are notoriously hard to evaluate, especially based on behavioral measures alone. Neuroimaging data can provide additional constraints, but this requires a mapping from model components to brain regions. Although such mappings can be based on the experience of the modeler or on a reading of the literature, a formal method is preferred to prevent researcher-based biases. In this paper we used model-based fMRI analysis to create a data-driven model-brain mapping for five modules of the ACT-R cognitive architecture. We then validated this mapping by applying it to two new datasets with associated models. The new mapping was at least as powerful as an existing mapping that was based on the literature, and indicated where the models were supported by the data and where they have to be improved. We conclude that data-driven model-brain mappings can provide strong constraints on cognitive models, and that model-based fMRI is a suitable way to create such mappings.

  15. Estradiol decreases cortical reactive astrogliosis after brain injury by a mechanism involving cannabinoid receptors.

    Science.gov (United States)

    López Rodríguez, Ana Belén; Mateos Vicente, Beatriz; Romero-Zerbo, Silvana Y; Rodriguez-Rodriguez, Noé; Bellini, María José; Rodriguez de Fonseca, Fernando; Bermudez-Silva, Francisco Javier; Azcoitia, Iñigo; Garcia-Segura, Luis M; Viveros, María-Paz

    2011-09-01

    The neuroactive steroid estradiol reduces reactive astroglia after brain injury by mechanisms similar to those involved in the regulation of reactive gliosis by endocannabinoids. In this study, we have explored whether cannabinoid receptors are involved in the effects of estradiol on reactive astroglia. To test this hypothesis, the effects of estradiol, the cannabinoid CB1 antagonist/inverse agonist AM251, and the cannabinoid CB2 antagonist/inverse agonist AM630 were assessed in the cerebral cortex of male rats after a stab wound brain injury. Estradiol reduced the number of vimentin immunoreactive astrocytes and the number of glial fibrillary acidic protein immunoreactive astrocytes in the proximity of the wound. The effect of estradiol was significantly inhibited by the administration of either CB1 or CB2 receptor antagonists. The effect of estradiol may be in part mediated by alterations in endocannabinoid signaling because the hormone increased in the injured cerebral cortex the messenger RNA levels of CB2 receptors and of some of the enzymes involved in the synthesis and metabolism of endocannabinoids. These findings suggest that estradiol may decrease reactive astroglia in the injured brain by regulating the activity of the endocannabinoid system.

  16. [QEEG and brain mapping. Historial develoment, clinical practices and epistemological issues].

    Science.gov (United States)

    Matusevich, Daniel; Ruiz, Martín; Vairo, María Carolina

    2002-01-01

    Although it has been more than two decades since brain mapping was introduced in medicine, its scientific value and clinical practice have not been proved. This paper makes an overview about the historical development of brain mapping, its usefulness in psychiatry and lays epistemological issues concerning the role of technology in medical settings. Both historical and technological development of qEEG gives us the opportunity to think about complexity between ethics, science, technology and medicine.

  17. In vivo imaging reveals that pregabalin inhibits cortical spreading depression and propagation to subcortical brain structures

    Science.gov (United States)

    Cain, Stuart M.; Bohnet, Barry; LeDue, Jeffrey; Yung, Andrew C.; Garcia, Esperanza; Tyson, John R.; Alles, Sascha R. A.; Han, Huili; van den Maagdenberg, Arn M. J. M.; Kozlowski, Piotr; MacVicar, Brian A.; Snutch, Terrance P.

    2017-01-01

    Migraine is characterized by severe headaches that can be preceded by an aura likely caused by cortical spreading depression (SD). The antiepileptic pregabalin (Lyrica) shows clinical promise for migraine therapy, although its efficacy and mechanism of action are unclear. As detected by diffusion-weighted MRI (DW-MRI) in wild-type (WT) mice, the acute systemic administration of pregabalin increased the threshold for SD initiation in vivo. In familial hemiplegic migraine type 1 mutant mice expressing human mutations (R192Q and S218L) in the CaV2.1 (P/Q-type) calcium channel subunit, pregabalin slowed the speed of SD propagation in vivo. Acute systemic administration of pregabalin in vivo also selectively prevented the migration of SD into subcortical striatal and hippocampal regions in the R192Q strain that exhibits a milder phenotype and gain of CaV2.1 channel function. At the cellular level, pregabalin inhibited glutamatergic synaptic transmission differentially in WT, R192Q, and S218L mice. The study describes a DW-MRI analysis method for tracking the progression of SD and provides support and a mechanism of action for pregabalin as a possible effective therapy in the treatment of migraine. PMID:28223480

  18. Zebrafish brain mapping--standardized spaces, length scales, and the power of N and n.

    Science.gov (United States)

    Hunter, Paul R; Hendry, Aenea C; Lowe, Andrew S

    2015-06-01

    Mapping anatomical and functional parameters of the zebrafish brain is moving apace. Research communities undertaking such studies are becoming ever larger and more diverse. The unique features, tools, and technologies associated with zebrafish are propelling them as the 21st century model organism for brain mapping. Uniquely positioned as a vertebrate model system, the zebrafish enables imaging of anatomy and function at different length scales from intraneuronal compartments to sparsely distributed whole brain patterns. With a variety of diverse and established statistical modeling and analytic methods available from the wider brain mapping communities, the richness of zebrafish neuroimaging data is being realized. The statistical power of population observations (N) within and across many samples (n) projected onto a standardized space will provide vast databases for data-driven biological approaches. This article reviews key brain mapping initiatives at different levels of scale that highlight the potential of zebrafish brain mapping. By way of introduction to the next wave of brain mappers, an accessible introduction to the key concepts and caveats associated with neuroimaging are outlined and discussed.

  19. Size-weight illusion and anticipatory grip force scaling following unilateral cortical brain lesion.

    Science.gov (United States)

    Li, Yong; Randerath, Jennifer; Goldenberg, Georg; Hermsdörfer, Joachim

    2011-04-01

    The prediction of object weight from its size is an important prerequisite of skillful object manipulation. Grip and load forces anticipate object size during early phases of lifting an object. A mismatch between predicted and actual weight when two different sized objects have the same weight results in the size-weight illusion (SWI), the small object feeling heavier. This study explores whether lateralized brain lesions in patients with or without apraxia alter the size-weight illusion and impair anticipatory finger force scaling. Twenty patients with left brain damage (LBD, 10 with apraxia, 10 without apraxia), ten patients with right brain damage (RBD), and matched control subjects lifted two different-sized boxes in alternation. All subjects experienced a similar size-weight illusion. The anticipatory force scaling of all groups was in correspondence with the size cue: higher forces and force rates were applied to the big box and lower forces and force rates to the small box during the first lifts. Within few lifts, forces were scaled to actual object weight. Despite the lack of significant differences at group level, 5 out of 20 LBD patients showed abnormal predictive scaling of grip forces. They differed from the LBD patients with normal predictive scaling by a greater incidence of posterior occipito-parietal lesions but not by a greater incidence of apraxia. The findings do not support a more general role for the motor-dominant left hemisphere, or an influence of apraxia per se, in the scaling of finger force according to object properties. However, damage in the vicinity of the parietal-occipital junction may be critical for deriving predictions of weight from size.

  20. Analysis of Neural Stem Cells from Human Cortical Brain Structures In Vitro.

    Science.gov (United States)

    Aleksandrova, M A; Poltavtseva, R A; Marei, M V; Sukhikh, G T

    2016-05-01

    Comparative immunohistochemical analysis of the neocortex from human fetuses showed that neural stem and progenitor cells are present in the brain throughout the gestation period, at least from week 8 through 26. At the same time, neural stem cells from the first and second trimester fetuses differed by the distribution, morphology, growth, and quantity. Immunocytochemical analysis of neural stem cells derived from fetuses at different gestation terms and cultured under different conditions showed their differentiation capacity. Detailed analysis of neural stem cell populations derived from fetuses on gestation weeks 8-9, 18-20, and 26 expressing Lex/SSEA1 was performed.

  1. Cortical abnormalities in adults and adolescents with major depression based on brain scans from 20 cohorts worldwide in the ENIGMA Major Depressive Disorder Working Group.

    Science.gov (United States)

    Schmaal, L; Hibar, D P; Sämann, P G; Hall, G B; Baune, B T; Jahanshad, N; Cheung, J W; van Erp, T G M; Bos, D; Ikram, M A; Vernooij, M W; Niessen, W J; Tiemeier, H; Hofman, A; Wittfeld, K; Grabe, H J; Janowitz, D; Bülow, R; Selonke, M; Völzke, H; Grotegerd, D; Dannlowski, U; Arolt, V; Opel, N; Heindel, W; Kugel, H; Hoehn, D; Czisch, M; Couvy-Duchesne, B; Rentería, M E; Strike, L T; Wright, M J; Mills, N T; de Zubicaray, G I; McMahon, K L; Medland, S E; Martin, N G; Gillespie, N A; Goya-Maldonado, R; Gruber, O; Krämer, B; Hatton, S N; Lagopoulos, J; Hickie, I B; Frodl, T; Carballedo, A; Frey, E M; van Velzen, L S; Penninx, B W J H; van Tol, M-J; van der Wee, N J; Davey, C G; Harrison, B J; Mwangi, B; Cao, B; Soares, J C; Veer, I M; Walter, H; Schoepf, D; Zurowski, B; Konrad, C; Schramm, E; Normann, C; Schnell, K; Sacchet, M D; Gotlib, I H; MacQueen, G M; Godlewska, B R; Nickson, T; McIntosh, A M; Papmeyer, M; Whalley, H C; Hall, J; Sussmann, J E; Li, M; Walter, M; Aftanas, L; Brack, I; Bokhan, N A; Thompson, P M; Veltman, D J

    2016-05-03

    The neuro-anatomical substrates of major depressive disorder (MDD) are still not well understood, despite many neuroimaging studies over the past few decades. Here we present the largest ever worldwide study by the ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) Major Depressive Disorder Working Group on cortical structural alterations in MDD. Structural T1-weighted brain magnetic resonance imaging (MRI) scans from 2148 MDD patients and 7957 healthy controls were analysed with harmonized protocols at 20 sites around the world. To detect consistent effects of MDD and its modulators on cortical thickness and surface area estimates derived from MRI, statistical effects from sites were meta-analysed separately for adults and adolescents. Adults with MDD had thinner cortical gray matter than controls in the orbitofrontal cortex (OFC), anterior and posterior cingulate, insula and temporal lobes (Cohen's d effect sizes: -0.10 to -0.14). These effects were most pronounced in first episode and adult-onset patients (>21 years). Compared to matched controls, adolescents with MDD had lower total surface area (but no differences in cortical thickness) and regional reductions in frontal regions (medial OFC and superior frontal gyrus) and primary and higher-order visual, somatosensory and motor areas (d: -0.26 to -0.57). The strongest effects were found in recurrent adolescent patients. This highly powered global effort to identify consistent brain abnormalities showed widespread cortical alterations in MDD patients as compared to controls and suggests that MDD may impact brain structure in a highly dynamic way, with different patterns of alterations at different stages of life.Molecular Psychiatry advance online publication, 3 May 2016; doi:10.1038/mp.2016.60.

  2. Cortical mapping of mismatch negativity with deviance detection property in rat.

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    Tomoyo Isoguchi Shiramatsu

    Full Text Available Mismatch Negativity (MMN is an N-methyl-d-aspartic acid (NMDA-mediated, negative deflection in human auditory evoked potentials in response to a cognitively discriminable change. MMN-like responses have been extensively investigated in animal models, but the existence of MMN equivalent is still controversial. In this study, we aimed to investigate how closely the putative MMN (MMNp in rats exhibited the comparable properties of human MMN. We used a surface microelectrode array with a grid of 10 × 7 recording sites within an area of 4.5 × 3.0 mm to densely map evoked potentials in the auditory cortex of anesthetized rats under the oddball paradigm. Firstly, like human MMN, deviant stimuli elicited negative deflections in auditory evoked potentials following the positive middle-latency response, termed P1. Secondly, MMNp exhibited deviance-detecting property, which could not be explained by simple stimulus specific adaptation (SSA. Thirdly, this MMNp occurred focally in the auditory cortex, including both the core and belt regions, while P1 activation focus was obtained in the core region, indicating that both P1 and MMNp are generated in the auditory cortex, yet the sources of these signals do not completely overlap. Fourthly, MMNp significantly decreased after the application of AP5 (D-(--2-amino-5-phosphonopentanoic acid, an antagonist at NMDA receptors. In stark contrast, AP5 affected neither P1 amplitude nor SSA of P1. These results provide compelling evidence that the MMNp we have examined in rats is functionally comparable to human MMN. The present work will stimulate translational research into MMN, which may help bridge the gap between electroencephalography (EEG/magnetoencephalography (MEG studies in humans and electrophysiological studies in animals.

  3. Using data-driven model-brain mappings to constrain formal models of cognition

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    Borst, Jelmer P; Nijboer, Menno; Taatgen, Niels A; van Rijn, Hedderik; Anderson, John R

    2015-01-01

    In this paper we propose a method to create data-driven mappings from components of cognitive models to brain regions. Cognitive models are notoriously hard to evaluate, especially based on behavioral measures alone. Neuroimaging data can provide additional constraints, but this requires a mapping f

  4. Cortical neurogenesis in adult rats after ischemic brain injury:most new neurons fail to mature

    Institute of Scientific and Technical Information of China (English)

    Qing-quan Li; Guan-qun Qiao; Jun Ma; Hong-wei Fan; Ying-bin Li

    2015-01-01

    The present study examines the hypothesis that endogenous neural progenitor cells isolated from the neocortex of ischemic brain can differentiate into neurons or glial cells and contribute to neural regeneration. We performed middle cerebral artery occlusion to establish a model of cerebral ischemia/reperfusion injury in adult rats. Immunohistochemical staining of the cortex 1, 3, 7, 14 or 28 days after injury revealed that neural progenitor cells double-positive for nestin and sox-2 appeared in the injured cortex 1 and 3 days post-injury, and were also positive for glial ifbrillary acidic protein. New neurons were labeled using bromodeoxyuridine and different stages of maturity were identiifed using doublecortin, microtubule-associated protein 2 and neuronal nuclei antigen immunohistochemistry. Immature new neurons coexpressing doublecortin and bromodeoxyuridine were observed in the cortex at 3 and 7 days post-injury, and semi-mature and mature new neurons double-positive for microtubule-associated protein 2 and bromode-oxyuridine were found at 14 days post-injury. A few mature new neurons coexpressing neuronal nuclei antigen and bromodeoxyuridine were observed in the injured cortex 28 days post-injury. Glial ifbrillary acidic protein/bromodeoxyuridine double-positive astrocytes were also found in the injured cortex. Our ifndings suggest that neural progenitor cells are present in the damaged cortex of adult rats with cerebral ischemic brain injury, and that they differentiate into astrocytes and immature neurons, but most neurons fail to reach the mature stage.

  5. Do studies on cortical plasticity provide a rationale for using non-invasive brain stimulation as a treatment for Parkinson's disease patients?

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    Koch, Giacomo

    2013-11-06

    Animal models of Parkinson's disease (PD) have shown that key mechanisms of cortical plasticity such as long-term potentiation (LTP) and long-term depression (LTD) can be impaired by the PD pathology. In humans protocols of non-invasive brain stimulation, such as paired associative stimulation (PAS) and theta-burst stimulation (TBS), can be used to investigate cortical plasticity of the primary motor cortex. Through the amplitude of the motor evoked potential these transcranial magnetic stimulation methods allow to measure both LTP-like and LTD-like mechanisms of cortical plasticity. So far these protocols have reported some controversial findings when tested in PD patients. While various studies described evidence for reduced LTP- and LTD-like plasticity, others showed different results, demonstrating increased LTP-like and normal LTD-like plasticity. Recent evidence provided support to the hypothesis that these different patterns of cortical plasticity likely depend on the stage of the disease and on the concomitant administration of l-DOPA. However, it is still unclear how and if these altered mechanisms of cortical plasticity can be taken as a reliable model to build appropriate protocols aimed at treating PD symptoms by applying repetitive sessions of repetitive TMS (rTMS) or transcranial direct current stimulation (tDCS). The current article will provide an up-to-date overview of these issues together with some reflections on future studies in the field.

  6. Do studies on cortical plasticity provide a rationale for using non invasive brain stimulation as a treatment for Parkinson’s disease patients?

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    Giacomo eKoch

    2013-11-01

    Full Text Available Animal models of Parkinson’s disease (PD have shown that key mechanisms of cortical plasticity such as long-term potentiation (LTP and long-term depression (LTD can be impaired by the PD pathology. In humans protocols of non-invasive brain stimulation, such as paired associative stimulation (PAS and theta burst stimulation (TBS, can be used to investigate cortical plasticity of the primary motor cortex. Through the amplitude of the motor evoked potential (MEP these transcranial magnetic stimulation methods allow to measure both LTP-like and LTD-like mechanisms of cortical plasticity. So far these protocols have reported some controversial findings when tested in PD patients. While various studies described evidence for reduced LTP- and LTD-like plasticity, others showed different results, demonstrating increased LTP-like and normal LTD-like plasticity. Recent evidence provided support to the hypothesis that these different patterns of cortical plasticity likely depend on the stage of the disease and on the concomitant administration of levo-dopa. However, it still unclear how and if these altered mechanisms of cortical plasticity can be taken as a reliable model to build appropriate protocols aimed at treating PD symptoms b

  7. Effect of. cap alpha. -,. beta. -adrenergic receptor agonists and antagonists of the efflux of /sup 22/Na and uptake of /sup 42/K by rat brain cortical slices

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    Phillis, J.W.; Wu, P.H.; Thierry, D.L.

    1982-03-18

    The effects of norepinephrine on ion fluxes in rat brain cortical slices have now been ascertained. /sup 22/Na efflux and /sup 42/K influx are enhanced by norepinephrine. The increase in ion fluxes can be blocked by ouabain, phentolamine and propranolol, suggesting that the catecholamine activates a membrane sodium pump by a receptor-mediated step. The facilitation of /sup 22/Na efflux is stereospecific as demonstrated by the very weak action of D-norepinephrine at 10/sup -5/ M concentration. Various ..cap alpha..-adrenergic and ..beta..-adrenergic receptor agonists, including oxymetazoline, naphazoline, clonidine, tramazoline, methoxamine, phenylephrine, L-isoproterenol and methoxyphenamine are potent stimulants of the sodium pump as demonstrated by their enhancement of ion fluxes in rat brain cortical slices. The results are consistent with the hypothesis that norepinephrine hyperpolarizes central neurons by activating an ouabain-sensitive, receptor-mediated sodium pump.

  8. Magnitude Processing in the Brain: An fMRI Study of Time, Space, and Numerosity as a Shared Cortical System

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    Skagerlund, Kenny; Karlsson, Thomas; Träff, Ulf

    2016-01-01

    Continuous dimensions, such as time, space, and numerosity, have been suggested to be subserved by common neurocognitive mechanisms. Neuroimaging studies that have investigated either one or two dimensions simultaneously have consistently identified neural correlates in the parietal cortex of the brain. However, studies investigating the degree of neural overlap across several dimensions are inconclusive, and it remains an open question whether a potential overlap can be conceptualized as a neurocognitive magnitude processing system. The current functional magnetic resonance imaging study investigated the potential neurocognitive overlap across three dimensions. A sample of adults (N = 24) performed three different magnitude processing tasks: a temporal discrimination task, a number discrimination task, and a line length discrimination task. A conjunction analysis revealed several overlapping neural substrates across multiple magnitude dimensions, and we argue that these cortical nodes comprise a distributed magnitude processing system. Key components of this predominantly right-lateralized system include the intraparietal sulcus, insula, premotor cortex/SMA, and inferior frontal gyrus. Together with previous research highlighting intraparietal sulcus, our results suggest that the insula also is a core component of the magnitude processing system. We discuss the functional role of each of these components in the magnitude processing system and suggest that further research of this system may provide insight into the etiology of neurodevelopmental disorders where cognitive deficits in magnitude processing are manifest. PMID:27761110

  9. Mapping metals in Parkinson's and normal brain using rapid-scanning x-ray fluorescence

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    Popescu, Bogdan F. Gh; George, Martin J.; Bergmann, Uwe; Garachtchenko, Alex V.; Kelly, Michael E.; McCrea, Richard P. E.; Lüning, Katharina; Devon, Richard M.; George, Graham N.; Hanson, Akela D.; Harder, Sheri M.; Chapman, L. Dean; Pickering, Ingrid J.; Nichol, Helen

    2009-02-01

    Rapid-scanning x-ray fluorescence (RS-XRF) is a synchrotron technology that maps multiple metals in tissues by employing unique hardware and software to increase scanning speed. RS-XRF was validated by mapping and quantifying iron, zinc and copper in brain slices from Parkinson's disease (PD) and unaffected subjects. Regions and structures in the brain were readily identified by their metal complement and each metal had a unique distribution. Many zinc-rich brain regions were low in iron and vice versa. The location and amount of iron in brain regions known to be affected in PD agreed with analyses using other methods. Sample preparation is simple and standard formalin-fixed autopsy slices are suitable. RS-XRF can simultaneously and non-destructively map and quantify multiple metals and holds great promise to reveal metal pathologies associated with PD and other neurodegenerative diseases as well as diseases of metal metabolism.

  10. Differential recruitment of brain networks following route and cartographic map learning of spatial environments.

    Science.gov (United States)

    Zhang, Hui; Copara, Milagros; Ekstrom, Arne D

    2012-01-01

    An extensive neuroimaging literature has helped characterize the brain regions involved in navigating a spatial environment. Far less is known, however, about the brain networks involved when learning a spatial layout from a cartographic map. To compare the two means of acquiring a spatial representation, participants learned spatial environments either by directly navigating them or learning them from an aerial-view map. While undergoing functional magnetic resonance imaging (fMRI), participants then performed two different tasks to assess knowledge of the spatial environment: a scene and orientation dependent perceptual (SOP) pointing task and a judgment of relative direction (JRD) of landmarks pointing task. We found three brain regions showing significant effects of route vs. map learning during the two tasks. Parahippocampal and retrosplenial cortex showed greater activation following route compared to map learning during the JRD but not SOP task while inferior frontal gyrus showed greater activation following map compared to route learning during the SOP but not JRD task. We interpret our results to suggest that parahippocampal and retrosplenial cortex were involved in translating scene and orientation dependent coordinate information acquired during route learning to a landmark-referenced representation while inferior frontal gyrus played a role in converting primarily landmark-referenced coordinates acquired during map learning to a scene and orientation dependent coordinate system. Together, our results provide novel insight into the different brain networks underlying spatial representations formed during navigation vs. cartographic map learning and provide additional constraints on theoretical models of the neural basis of human spatial representation.

  11. Model-Based Analysis and Optimization of the Mapping of Cortical Sources in the Spontaneous Scalp EEG

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    Andrei V. Sazonov

    2007-01-01

    Full Text Available The mapping of brain sources into the scalp electroencephalogram (EEG depends on volume conduction properties of the head and on an electrode montage involving a reference. Mathematically, this source mapping (SM is fully determined by an observation function (OF matrix. This paper analyses the OF-matrix for a generation model for the desynchronized spontaneous EEG. The model involves a four-shell spherical volume conductor containing dipolar sources that are mutually uncorrelated so as to reflect the desynchronized EEG. The reference is optimized in order to minimize the impact in the SM of the sources located distant from the electrodes. The resulting reference is called the localized reference (LR. The OF-matrix is analyzed in terms of the relative power contribution of the sources and the cross-channel correlation coefficient for five existing references as well as for the LR. It is found that the Hjorth Laplacian reference is a fair approximation of the LR, and thus is close to optimum for practical intents and purposes. The other references have a significantly poorer performance. Furthermore, the OF-matrix is analyzed for limits to the spatial resolution for the EEG. These are estimated to be around 2 cm.

  12. Overweight is not associated with cortical thickness alterations in children

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    Rachel Jane Sharkey

    2015-02-01

    Full Text Available IntroductionSeveral studies report an association between body mass index (BMI and cortical thickness in adults. Some studies demonstrate diffuse cortical thinning in obesity, while others report effects in areas that are associated with self-regulation, such as lateral prefrontal cortex. MethodsThis study used multilevel modelling of data from the NIH Pediatric MRI Data Repository, a mixed longitudinal and cross-sectional database, to examine the relationship between cortical thickness and body weight in children. Cortical thickness was computed at 81,942 vertices of 716 MRI scans from 378 children aged between 4 and 18 years. Body mass index Z score for age was computed for each participant. We preformed vertex-wise statistical analysis of the relationship between cortical thickness and BMI, accounting for age and gender. In addition, cortical thickness was extracted from regions of interest in prefrontal cortex and insula.ResultsNo significant association between cortical thickness and BMI was found, either by statistical parametric mapping or by region of interest analysis. Results remained negative when the analysis was restricted to children aged 12-18.ConclusionsThe correlation between BMI and cortical thickness was not found in this large pediatric sample. The association between BMI and cortical thinning develops after adolescence. This has implications for the nature of the relationship between brain anatomy and weight gain.

  13. Altered Spontaneous Brain Activity in Cortical and Subcortical Regions in Parkinson’s Disease

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    Jie Xiang

    2016-01-01

    Full Text Available Purpose. The present study aimed to explore the changes of amplitude of low-frequency fluctuations (ALFF at rest in patients with Parkinson’s disease (PD. Methods. Twenty-four PD patients and 22 healthy age-matched controls participated in the study. ALFF was measured on the whole brain of all participants. A two-sample t-test was then performed to detect the group differences with age, gender, education level, head motion, and gray matter volume as covariates. Results. It was showed that PD patients had significantly decreased ALFF in the left thalamus/caudate and right insula/inferior prefrontal gyrus, whereas they had increased ALFF in the right medial prefrontal cortex (BA 8/6 and dorsolateral prefrontal cortex (BA 9/10. Conclusions. Our results indicated that significant alterations of ALFF in the subcortical regions and prefrontal cortex have been detected in PD patients, independent of age, gender, education, head motion, and structural atrophy. The current findings further provide insights into the biological mechanism of the disease.

  14. Macro-to-micro cortical vascular imaging underlies regional differences in ischemic brain.

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    Dziennis, Suzan; Qin, Jia; Shi, Lei; Wang, Ruikang K

    2015-05-05

    The ability to non-invasively monitor and quantify hemodynamic responses down to the capillary level is important for improved diagnosis, treatment and management of neurovascular disorders, including stroke. We developed an integrated multi-functional imaging system, in which synchronized dual wavelength laser speckle contrast imaging (DWLS) was used as a guiding tool for optical microangiography (OMAG) to test whether detailed vascular responses to experimental stroke in male mice can be evaluated with wide range sensitivity from arteries and veins down to the capillary level. DWLS enabled rapid identification of cerebral blood flow (CBF), prediction of infarct area and hemoglobin oxygenation over the whole mouse brain and was used to guide the OMAG system to hone in on depth information regarding blood volume, blood flow velocity and direction, vascular architecture, vessel diameter and capillary density pertaining to defined regions of CBF in response to ischemia. OMAG-DWLS is a novel imaging platform technology to simultaneously evaluate multiple vascular responses to ischemic injury, which can be useful in improving our understanding of vascular responses under pathologic and physiological conditions, and ultimately facilitating clinical diagnosis, monitoring and therapeutic interventions of neurovascular diseases.

  15. Macro-to-micro cortical vascular imaging underlies regional differences in ischemic brain

    Science.gov (United States)

    Dziennis, Suzan; Qin, Jia; Shi, Lei; Wang, Ruikang K.

    2015-05-01

    The ability to non-invasively monitor and quantify hemodynamic responses down to the capillary level is important for improved diagnosis, treatment and management of neurovascular disorders, including stroke. We developed an integrated multi-functional imaging system, in which synchronized dual wavelength laser speckle contrast imaging (DWLS) was used as a guiding tool for optical microangiography (OMAG) to test whether detailed vascular responses to experimental stroke in male mice can be evaluated with wide range sensitivity from arteries and veins down to the capillary level. DWLS enabled rapid identification of cerebral blood flow (CBF), prediction of infarct area and hemoglobin oxygenation over the whole mouse brain and was used to guide the OMAG system to hone in on depth information regarding blood volume, blood flow velocity and direction, vascular architecture, vessel diameter and capillary density pertaining to defined regions of CBF in response to ischemia. OMAG-DWLS is a novel imaging platform technology to simultaneously evaluate multiple vascular responses to ischemic injury, which can be useful in improving our understanding of vascular responses under pathologic and physiological conditions, and ultimately facilitating clinical diagnosis, monitoring and therapeutic interventions of neurovascular diseases.

  16. Coupling BCI and cortical stimulation for brain-state-dependent stimulation: Methods for spectral estimation in the presence of stimulation after-effects

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    Armin eWalter

    2012-11-01

    Full Text Available Brain-state-dependent stimulation combines brain-computer interfaces (BCI and cortical stimulation into one paradigm that allows the online decoding for example of movement intention from brain signals while simultaneously applying stimulation. If the BCI decoding is performed by spectral features, stimulation after-effects such as artefacts and evoked activity present a challenge for a successful implementation of brain-state-dependent stimulation because they can impair the detection of targeted brain states. Therefore, efficient and robust methods are needed to minimize the influence of the stimulation-induced effects on spectral estimation without violating the real-time constraints of the BCI.In this work, we compared 4 methods for spectral estimation with autoregressive (AR models in the presence of pulsed cortical stimulation. Using combined EEG-TMS as well as combined ECoG and epidural electrical stimulation, 3 patients performed a motor task using a sensorimotor-rhythm BCI. Three stimulation paradigms were varied between sessions: (1 no stimulation, (2 single stimulation pulses applied independently (open-loop or (3 coupled to the BCI output (closed-loop such that stimulation was given only while an intention to move was detected using neural data.We found that removing the stimulation after-effects by linear interpolation can introduce a bias in the estimation of the spectral power of the sensorimotor rhythm, leading to an overestimation of decoding performance in the closed-loop setting. We propose the use of the Burg algorithm for segmented data to deal with stimulation after-effects. This work shows that the combination of BCIs controlled with spectral features and cortical stimulation in a closed-loop fashion is possible when the influence of stimulation after-effects on spectral estimation is minimized.

  17. Molecular mapping of brain areas involved in parrot vocal communication.

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    Jarvis, E D; Mello, C V

    2000-03-27

    Auditory and vocal regulation of gene expression occurs in separate discrete regions of the songbird brain. Here we demonstrate that regulated gene expression also occurs during vocal communication in a parrot, belonging to an order whose ability to learn vocalizations is thought to have evolved independently of songbirds. Adult male budgerigars (Melopsittacus undulatus) were stimulated to vocalize with playbacks of conspecific vocalizations (warbles), and their brains were analyzed for expression of the transcriptional regulator ZENK. The results showed that there was distinct separation of brain areas that had hearing- or vocalizing-induced ZENK expression. Hearing warbles resulted in ZENK induction in large parts of the caudal medial forebrain and in 1 midbrain region, with a pattern highly reminiscent of that observed in songbirds. Vocalizing resulted in ZENK induction in nine brain structures, seven restricted to the lateral and anterior telencephalon, one in the thalamus, and one in the midbrain, with a pattern partially reminiscent of that observed in songbirds. Five of the telencephalic structures had been previously described as part of the budgerigar vocal control pathway. However, functional boundaries defined by the gene expression patterns for some of these structures were much larger and different in shape than previously reported anatomical boundaries. Our results provide the first functional demonstration of brain areas involved in vocalizing and auditory processing of conspecific sounds in budgerigars. They also indicate that, whether or not vocal learning evolved independently, some of the gene regulatory mechanisms that accompany learned vocal communication are similar in songbirds and parrots.

  18. Elemental mapping inventory of the fish Liza aurata brain: a biomarker of metal pollution vulnerability.

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    Godinho, Rita M; Pereira, Patricia; Raimundo, Joana; Pacheco, Mário; Pinheiro, Teresa

    2015-02-01

    The elemental distributions in optic tectum of brains of wild Liza aurata a teleost fish captured in polluted and reference coastal areas were assessed quantitatively by nuclear microscopy providing insights into brain vulnerability to metal pollution. Elemental maps enabled us to visualize optic tectum layers and identify cellular arrangements. Whereas Cl, K and Ca contents identify meninges, the Ca, Fe and Zn concentrations distinguish the underneath grey matter, white matter and inner cellular layers. Exposed animals showed significantly decreased P concentrations and increased contents of Cu, Zn and Ni in all brain structures. These changes highlight homeostasis modification, altered permeability of the blood-brain barrier and suggest risk for neurological toxicity. Our study initiated for the first time an inventory of physiological measures containing images and elemental compositions of brain regions of fish exposed to different environmental conditions. This will help defining total and local brain vulnerability to metals and pollution levels.

  19. Anomia produced by direct cortical stimulation of the pre-supplementary motor area in a patient undergoing preoperative language mapping.

    Science.gov (United States)

    Rozanski, Verena Eveline; Peraud, Aurelia; Noachtar, Soheyl

    2015-06-01

    There is sparse data on the analysis of supplementary motor area in language function using direct cortical stimulation of the supplementary motor area. Here, we report a patient who experienced isolated anomia during stimulation of the anterior supplementary motor area and discuss the role of the supplementary motor area in speech production. The role of the pre-supplementary motor· area in word selection, observed in fMRI studies, can be confirmed by direct cortical stimulation.

  20. Opiate sensitization induces FosB/ΔFosB expression in prefrontal cortical, striatal and amygdala brain regions.

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    Gary B Kaplan

    Full Text Available Sensitization to the effects of drugs of abuse and associated stimuli contributes to drug craving, compulsive drug use, and relapse in addiction. Repeated opiate exposure produces behavioral sensitization that is hypothesized to result from neural plasticity in specific limbic, striatal and cortical systems. ΔFosB and FosB are members of the Fos family of transcription factors that are implicated in neural plasticity in addiction. This study examined the effects of intermittent morphine treatment, associated with motor sensitization, on FosB/ΔFosB levels using quantitative immunohistochemistry. Motor sensitization was tested in C57BL/6 mice that received six intermittent pre-treatments (on days 1, 3, 5, 8, 10, 12 with either subcutaneous morphine (10 mg/kg or saline followed by a challenge injection of morphine or saline on day 16. Mice receiving repeated morphine injections demonstrated significant increases in locomotor activity on days 8, 10, and 12 of treatment (vs. day 1, consistent with development of locomotor sensitization. A morphine challenge on day 16 significantly increased locomotor activity of saline pre-treated mice and produced even larger increases in motor activity in the morphine pre-treated mice, consistent with the expression of opiate sensitization. Intermittent morphine pre-treatment on these six pre-treatment days produced a significant induction of FosB/ΔFosB, measured on day 16, in multiple brain regions including prelimbic (PL and infralimbic (IL cortex, nucleus accumbens (NAc core, dorsomedial caudate-putamen (CPU, basolateral amygdala (BLA and central nucleus of the amygdala (CNA but not in a motor cortex control region. Opiate induced sensitization may develop via Fos/ΔFosB plasticity in motivational pathways (NAc, motor outputs (CPU, and associative learning (PL, IL, BLA and stress pathways (CNA.

  1. Regulation of brain-derived neurotrophic factor exon IV transcription through calcium responsive elements in cortical neurons.

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    Fei Zheng

    Full Text Available Activity-dependent transcription of brain-derived neurotrophic factor (BDNF has been studied as an important model to elucidate the mechanisms underlying numerous aspects of neuroplasticity. It has been extensively emphasized that Ca(2+ influx through different routes may have significantly different effects on BDNF transcription. Here, we examined the regulatory property of the major calcium responsive elements (CaRE in BDNF promoter IV in cultured rat cortical neurons. BDNF promoter IV, as well as CaRE1 and CaRE3, was significantly activated by Ca(2+ influx through L-type voltage-gated calcium channel (L-VGCC or NMDA receptor (NMDAR. However, the L-VGCC- and NMDAR-mediated activation of CaRE was differentially regulated by different Ca(2+-stimulated protein kinases. Specifically, PKA, CaMKI, and CaMKIV activity were required for L-VGCC-, but not NMDAR-mediated CaRE1 activation. CaMKI activity was required for NMDAR- but not L-VGCC-mediated CaRE3 activation. Surprisingly, the activation of CaRF, a previously identified transcription factor for CaRE1, was stimulated via L-VGCC but not NMDAR, and required MEK, PI3K and CaMKII activity. These results suggest a new working model that activity-dependent BDNF IV up-regulation may be coordinately mediated by CaRE1 and CaRE3 activity, which show different responses to Ca(2+-stimulated kinases. Our data also explain how the individual cis-element in BDNF promoter is distinctively coupled to different Ca(2+ routes.

  2. Cortical grey matter and subcortical white matter brain microstructural changes in schizophrenia are localised and age independent: a case-control diffusion tensor imaging study.

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    Chiara Chiapponi

    Full Text Available It is still unknown whether the structural brain impairments that characterize schizophrenia (SZ worsen during the lifetime. Here, we aimed to describe age-related microstructural brain changes in cortical grey matter and subcortical white matter of patients affected by SZ. In this diffusion tensor imaging study, we included 69 patients diagnosed with SZ and 69 healthy control (HC subjects, age and gender matched. We carried out analyses of covariance, with diagnosis as fixed factor and brain diffusion-related parameters as dependent variables, and controlled for the effect of education. White matter fractional anisotropy decreased in the entire age range spanned (18-65 years in both SZ and HC and was significantly lower in younger patients with SZ, with no interaction (age by diagnosis effect in fiber tracts including corpus callosum, corona radiata, thalamic radiations and external capsule. Also, grey matter mean diffusivity increased in the entire age range in both SZ and HC and was significantly higher in younger patients, with no age by diagnosis interaction in the left frontal operculum cortex, left insula and left planum polare and in the right temporal pole and right intracalcarine cortex. In individuals with SZ we found that localized brain cortical and white matter subcortical microstructural impairments appear early in life but do not worsen in the 18-65 year age range.

  3. Cortical grey matter and subcortical white matter brain microstructural changes in schizophrenia are localised and age independent: a case-control diffusion tensor imaging study.

    Science.gov (United States)

    Chiapponi, Chiara; Piras, Fabrizio; Piras, Federica; Fagioli, Sabrina; Caltagirone, Carlo; Spalletta, Gianfranco

    2013-01-01

    It is still unknown whether the structural brain impairments that characterize schizophrenia (SZ) worsen during the lifetime. Here, we aimed to describe age-related microstructural brain changes in cortical grey matter and subcortical white matter of patients affected by SZ. In this diffusion tensor imaging study, we included 69 patients diagnosed with SZ and 69 healthy control (HC) subjects, age and gender matched. We carried out analyses of covariance, with diagnosis as fixed factor and brain diffusion-related parameters as dependent variables, and controlled for the effect of education. White matter fractional anisotropy decreased in the entire age range spanned (18-65 years) in both SZ and HC and was significantly lower in younger patients with SZ, with no interaction (age by diagnosis) effect in fiber tracts including corpus callosum, corona radiata, thalamic radiations and external capsule. Also, grey matter mean diffusivity increased in the entire age range in both SZ and HC and was significantly higher in younger patients, with no age by diagnosis interaction in the left frontal operculum cortex, left insula and left planum polare and in the right temporal pole and right intracalcarine cortex. In individuals with SZ we found that localized brain cortical and white matter subcortical microstructural impairments appear early in life but do not worsen in the 18-65 year age range.

  4. Spatiotemporal 16p11.2 protein network implicates cortical late mid-fetal brain development and KCTD13-Cul3-RhoA pathway in psychiatric diseases.

    Science.gov (United States)

    Lin, Guan Ning; Corominas, Roser; Lemmens, Irma; Yang, Xinping; Tavernier, Jan; Hill, David E; Vidal, Marc; Sebat, Jonathan; Iakoucheva, Lilia M

    2015-02-18

    The psychiatric disorders autism and schizophrenia have a strong genetic component, and copy number variants (CNVs) are firmly implicated. Recurrent deletions and duplications of chromosome 16p11.2 confer a high risk for both diseases, but the pathways disrupted by this CNV are poorly defined. Here we investigate the dynamics of the 16p11.2 network by integrating physical interactions of 16p11.2 proteins with spatiotemporal gene expression from the developing human brain. We observe profound changes in protein interaction networks throughout different stages of brain development and/or in different brain regions. We identify the late mid-fetal period of cortical development as most critical for establishing the connectivity of 16p11.2 proteins with their co-expressed partners. Furthermore, our results suggest that the regulation of the KCTD13-Cul3-RhoA pathway in layer 4 of the inner cortical plate is crucial for controlling brain size and connectivity and that its dysregulation by de novo mutations may be a potential determinant of 16p11.2 CNV deletion and duplication phenotypes.

  5. BrainCycles: Experimental Setup for the Combined Measurement of Cortical and Subcortical Activity in Parkinson's Disease Patients during Cycling

    Science.gov (United States)

    Gratkowski, Maciej; Storzer, Lena; Butz, Markus; Schnitzler, Alfons; Saupe, Dietmar; Dalal, Sarang S.

    2017-01-01

    Recently, it has been demonstrated that bicycling ability remains surprisingly preserved in Parkinson's disease (PD) patients who suffer from freezing of gait. Cycling has been also proposed as a therapeutic means of treating PD symptoms, with some preliminary success. The neural mechanisms behind these phenomena are however not yet understood. One of the reasons is that the investigations of neuronal activity during pedaling have been up to now limited to PET and fMRI studies, which restrict the temporal resolution of analysis, and to scalp EEG focused on cortical activation. However, deeper brain structures like the basal ganglia are also associated with control of voluntary motor movements like cycling and are affected by PD. Deep brain stimulation (DBS) electrodes implanted for therapy in PD patients provide rare and unique access to directly record basal ganglia activity with a very high temporal resolution. In this paper we present an experimental setup allowing combined investigation of basal ganglia local field potentials (LFPs) and scalp EEG underlying bicycling in PD patients. The main part of the setup is a bike simulator consisting of a classic Dutch-style bicycle frame mounted on a commercially available ergometer. The pedal resistance is controllable in real-time by custom software and the pedal position is continuously tracked by custom Arduino-based electronics using optical and magnetic sensors. A portable bioamplifier records the pedal position signal, the angle of the knee, and the foot pressure together with EEG, EMG, and basal ganglia LFPs. A handlebar-mounted display provides additional information for patients riding the bike simulator, including the current and target pedaling rate. In order to demonstrate the utility of the setup, example data from pilot recordings are shown. The presented experimental setup provides means to directly record basal ganglia activity not only during cycling but also during other movement tasks in patients who

  6. Different Mode of Afferents Determines the Frequency Range of High Frequency Activities in the Human Brain: Direct Electrocorticographic Comparison between Peripheral Nerve and Direct Cortical Stimulation.

    Directory of Open Access Journals (Sweden)

    Katsuya Kobayashi

    Full Text Available Physiological high frequency activities (HFA are related to various brain functions. Factors, however, regulating its frequency have not been well elucidated in humans. To validate the hypothesis that different propagation modes (thalamo-cortical vs. cortico-coritcal projections, or different terminal layers (layer IV vs. layer II/III affect its frequency, we, in the primary somatosensory cortex (SI, compared HFAs induced by median nerve stimulation with those induced by electrical stimulation of the cortex connecting to SI. We employed 6 patients who underwent chronic subdural electrode implantation for presurgical evaluation. We evaluated the HFA power values in reference to the baseline overriding N20 (earliest cortical response and N80 (late response of somatosensory evoked potentials (HFA(SEP(N20 and HFA(SEP(N80 and compared those overriding N1 and N2 (first and second responses of cortico-cortical evoked potentials (HFA(CCEP(N1 and HFA(CCEP(N2. HFA(SEP(N20 showed the power peak in the frequency above 200 Hz, while HFA(CCEP(N1 had its power peak in the frequency below 200 Hz. Different propagation modes and/or different terminal layers seemed to determine HFA frequency. Since HFA(CCEP(N1 and HFA induced during various brain functions share a similar broadband profile of the power spectrum, cortico-coritcal horizontal propagation seems to represent common mode of neural transmission for processing these functions.

  7. Non-invasive optical mapping of the piglet brain in real time

    Science.gov (United States)

    Fantini, Sergio; Franceschini, Maria Angela; Gratton, Enrico; Hueber, Dennis; Rosenfeld, Warren; Maulik, Dev; Stubblefield, Phillip; Stankovic, Mikjan

    1999-04-01

    We have performed non-invasive, real-time optical mapping of the piglet brain during a subcortical injection of autologous blood. The time resolution of the optical maps is 192 ms, thus allowing us to generate a real-time video of the growing subcortical hematoma. The increased absorption at the site of blood injection is accompanied by a decreased absorption at the contralateral brain side. This contralateral decrease in the optical absorption and the corresponding time traces of the cerebral hemoglobin parameters are consistent with a reduced cerebral blood flow caused by the increased intracranial pressure.

  8. Brain mapping in stereotactic surgery: a brief overview from the probabilistic targeting to the patient-based anatomic mapping.

    Science.gov (United States)

    Lemaire, Jean-Jacques; Coste, Jérôme; Ouchchane, Lemlih; Caire, François; Nuti, Christophe; Derost, Philippe; Cristini, Vittorio; Gabrillargues, Jean; Hemm, Simone; Durif, Franck; Chazal, Jean

    2007-01-01

    In this article, we briefly review the concept of brain mapping in stereotactic surgery taking into account recent advances in stereotactic imaging. The gold standard continues to rely on probabilistic and indirect targeting, relative to a stereotactic reference, i.e., mostly the anterior (AC) and the posterior (PC) commissures. The theoretical position of a target defined on an atlas is transposed into the stereotactic space of a patient's brain; final positioning depends on electrophysiological analysis. The method is also used to analyze final electrode or lesion position for a patient or group of patients, by projection on an atlas. Limitations are precision of definition of the AC-PC line, probabilistic location and reliability of the electrophysiological guidance. Advances in MR imaging, as from 1.5-T machines, make stereotactic references no longer mandatory and allow an anatomic mapping based on an individual patient's brain. Direct targeting is enabled by high-quality images, an advanced anatomic knowledge and dedicated surgical software. Labeling associated with manual segmentation can help for the position analysis along non-conventional, interpolated planes. Analysis of final electrode or lesion position, for a patient or group of patients, could benefit from the concept of membership, the attribution of a weighted membership degree to a contact or a structure according to its level of involvement. In the future, more powerful MRI machines, diffusion tensor imaging, tractography and computational modeling will further the understanding of anatomy and deep brain stimulation effects.

  9. Acute functional reactivation of the language network during awake intraoperative brain mapping.

    Science.gov (United States)

    Spena, Giannantonio; Costi, Emanuele; Panciani, Pier Paolo; Roca, Elena; Migliorati, Karol; Fontanella, Marco Maria

    2015-01-01

    Acute brain plasticity during resection of central lesions has been recently described. In the cases reported, perilesional latent networks, useful to preserve the neurological functions, were detected in asymptomatic patients. In this paper, we presented a case of acute functional reactivation (AFR) of the language network in a symptomatic patient. Tumor resection allowed to acutely restore the neurological deficit. Intraoperative direct cortical stimulation (DCS) and functional neuroimaging showed new epicentres of activation of the language network after tumor excision. DCS in awake surgery is mandatory to reveal AFR needful to improve the extent of resection preserving the quality of life.

  10. Three-Dimensional Computer Graphics Brain-Mapping Project

    Science.gov (United States)

    1988-03-24

    commisuralis - commisstri.ob 129 Commisural Nucleus of Stria Terminalis N. septi medialis pars ventralis -medseptal.ob 130 Medial Septal Nucleus N. taenia ...tecta -taentecta.ob 131 Taenia Tecta N. olfactorius anteriorus -olftrigone.ob 132 Olfactory Trigone Cortex insularis -insularcor.ob 135 Insular Cortex...septalvein.ob 143 great emmissary vein gremmisvn.ob 144 124 Brain 118 3 Yakolev Study stria terminals striaterm.ob 145 taenia tecta taentecta.ob 146 131

  11. A setup for administering TMS to medial and lateral cortical areas during whole-brain FMRI recording

    NARCIS (Netherlands)

    Weijer, A.D. de; Sommer, I.E.C.; Bakker, E.J.; Bloemendaal, M.; Bakker, C.J.; Klomp, D.W.J.; Bestmann, S.; Neggers, S.F.W.

    2014-01-01

    SUMMARY: Stimulating brain areas with transcranial magnetic stimulation (TMS) while concurrently and noninvasively recording brain activity changes through functional MRI enables a new range of investigations about causal interregional interactions in the human brain. However, standard head-coil arr

  12. Increased brain iron deposition is a risk factor for brain atrophy in patients with haemodialysis: a combined study of quantitative susceptibility mapping and whole brain volume analysis.

    Science.gov (United States)

    Chai, Chao; Zhang, Mengjie; Long, Miaomiao; Chu, Zhiqiang; Wang, Tong; Wang, Lijun; Guo, Yu; Yan, Shuo; Haacke, E Mark; Shen, Wen; Xia, Shuang

    2015-08-01

    To explore the correlation between increased brain iron deposition and brain atrophy in patients with haemodialysis and their correlation with clinical biomarkers and neuropsychological test. Forty two patients with haemodialysis and forty one age- and gender-matched healthy controls were recruited in this prospective study. 3D whole brain high resolution T1WI and susceptibility weighted imaging were scanned on a 3 T MRI system. The brain volume was analyzed using voxel-based morphometry (VBM) in patients and to compare with that of healthy controls. Quantitative susceptibility mapping was used to measure and compare the susceptibility of different structures between patients and healthy controls. Correlation analysis was used to investigate the relationship between the brain volume, iron deposition and neuropsychological scores. Stepwise multiple regression analysis was used to explore the effect of clinical biomarkers on the brain volumes in patients. Compared with healthy controls, patients with haemodialysis showed decreased volume of bilateral putamen and left insular lobe (All P putamen, substantia nigra, red nucleus and dentate nucleus were significantly higher (All P putamen (P putamen (P < 0.05). Our study indicated increased brain iron deposition and dialysis duration was risk factors for brain atrophy in patients with haemodialysis. The decreased gray matter volume of the left insular lobe was correlated with neurocognitive impairment.

  13. R2* mapping for brain iron: associations with cognition in normal aging.

    Science.gov (United States)

    Ghadery, Christine; Pirpamer, Lukas; Hofer, Edith; Langkammer, Christian; Petrovic, Katja; Loitfelder, Marisa; Schwingenschuh, Petra; Seiler, Stephan; Duering, Marco; Jouvent, Eric; Schmidt, Helena; Fazekas, Franz; Mangin, Jean-Francois; Chabriat, Hugues; Dichgans, Martin; Ropele, Stefan; Schmidt, Reinhold

    2015-02-01

    Brain iron accumulates during aging and has been associated with neurodegenerative disorders including Alzheimer's disease. Magnetic resonance (MR)-based R2* mapping enables the in vivo detection of iron content in brain tissue. We investigated if during normal brain aging iron load relates to cognitive impairment in region-specific patterns in a community-dwelling cohort of 336 healthy, middle aged, and older adults from the Austrian Stroke Prevention Family Study. MR imaging and R2* mapping in the basal ganglia and neocortex were done at 3T. Comprehensive neuropsychological testing assessed memory, executive function, and psychomotor speed. We found the highest iron concentration in the globus pallidus, and pallidal and putaminal iron was significantly and inversely associated with cognitive performance in all cognitive domains, except memory. These associations were iron load dependent. Vascular brain lesions and brain volume did not mediate the relationship between iron and cognitive performance. We conclude that higher R2*-determined iron in the basal ganglia correlates with cognitive impairment during brain aging independent of concomitant brain abnormalities. The prognostic significance of this finding needs to be determined.

  14. Unified segmentation based correction of R1 brain maps for RF transmit field inhomogeneities (UNICORT).

    Science.gov (United States)

    Weiskopf, Nikolaus; Lutti, Antoine; Helms, Gunther; Novak, Marianne; Ashburner, John; Hutton, Chloe

    2011-02-01

    Quantitative mapping of the longitudinal relaxation rate (R1=1/T1) in the human brain enables the investigation of tissue microstructure and macroscopic morphology which are becoming increasingly important for clinical and neuroimaging applications. R1 maps are now commonly estimated from two fast high-resolution 3D FLASH acquisitions with variable excitation flip angles, because this approach is fast and does not rely on special acquisition techniques. However, these R1 maps need to be corrected for bias due to RF transmit field (B1(+)) inhomogeneities, requiring additional B1(+) mapping which is usually time consuming and difficult to implement. We propose a technique that simultaneously estimates the B1(+) inhomogeneities and R1 values from the uncorrected R1 maps in the human brain without need for B1(+) mapping. It employs a probabilistic framework for unified segmentation based correction of R1 maps for B1(+) inhomogeneities (UNICORT). The framework incorporates a physically informed generative model of smooth B1(+) inhomogeneities and their multiplicative effect on R1 estimates. Extensive cross-validation with the established standard using measured B1(+) maps shows that UNICORT yields accurate B1(+) and R1 maps with a mean deviation from the standard of less than 4.3% and 5%, respectively. The results of different groups of subjects with a wide age range and different levels of atypical brain anatomy further suggest that the method is robust and generalizes well to wider populations. UNICORT is easy to apply, as it is computationally efficient and its basic framework is implemented as part of the tissue segmentation in SPM8.

  15. Using a concept map as a tool for strategic planning: The Healthy Brain Initiative.

    Science.gov (United States)

    Anderson, Lynda A; Day, Kristine L; Vandenberg, Anna E

    2011-09-01

    Concept mapping is a tool to assist in strategic planning that allows planners to work through a sequence of phases to produce a conceptual framework. Although several studies describe how concept mapping is applied to various public health problems, the flexibility of the methods used in each phase of the process is often overlooked. If practitioners were more aware of the flexibility, more public health endeavors could benefit from using concept mapping as a tool for strategic planning. The objective of this article is to describe how the 6 concept-mapping phases originally outlined by William Trochim guided our strategic planning process and how we adjusted the specific methods in the first 2 phases to meet the specialized needs and requirements to create The Healthy Brain Initiative: A National Public Health Road Map to Maintaining Cognitive Health. In the first stage (phases 1 and 2 of concept mapping), we formed a steering committee, convened 4 work groups over a period of 3 months, and generated an initial set of 42 action items grounded in science. In the second stage (phases 3 and 4), we engaged stakeholders in sorting and rating the action items and constructed a series of concept maps. In the third and final stage (phases 5 and 6), we examined and refined the action items and generated a final concept map consisting of 44 action items. We then selected the top 10 action items, and in 2007, we published The Healthy Brain Initiative: A National Public Health Road Map to Maintaining Cognitive Health, which represents the strategic plan for The Healthy Brain Initiative.

  16. Towards the "baby connectome": mapping the structural connectivity of the newborn brain.

    Directory of Open Access Journals (Sweden)

    Olga Tymofiyeva

    Full Text Available Defining the structural and functional connectivity of the human brain (the human "connectome" is a basic challenge in neuroscience. Recently, techniques for noninvasively characterizing structural connectivity networks in the adult brain have been developed using diffusion and high-resolution anatomic MRI. The purpose of this study was to establish a framework for assessing structural connectivity in the newborn brain at any stage of development and to show how network properties can be derived in a clinical cohort of six-month old infants sustaining perinatal hypoxic ischemic encephalopathy (HIE. Two different anatomically unconstrained parcellation schemes were proposed and the resulting network metrics were correlated with neurological outcome at 6 months. Elimination and correction of unreliable data, automated parcellation of the cortical surface, and assembling the large-scale baby connectome allowed an unbiased study of the network properties of the newborn brain using graph theoretic analysis. In the application to infants with HIE, a trend to declining brain network integration and segregation was observed with increasing neuromotor deficit scores.

  17. Monitoring stroke progression: in vivo imaging of cortical perfusion, blood-brain barrier permeability and cellular damage in the rat photothrombosis model.

    Science.gov (United States)

    Schoknecht, Karl; Prager, Ofer; Vazana, Udi; Kamintsky, Lyn; Harhausen, Denise; Zille, Marietta; Figge, Lena; Chassidim, Yoash; Schellenberger, Eyk; Kovács, Richard; Heinemann, Uwe; Friedman, Alon

    2014-11-01

    Focal cerebral ischemia is among the main causes of death and disability worldwide. The ischemic core often progresses, invading the peri-ischemic brain; however, assessing the propensity of the peri-ischemic brain to undergo secondary damage, understanding the underlying mechanisms, and adjusting treatment accordingly remain clinically unmet challenges. A significant hallmark of the peri-ischemic brain is dysfunction of the blood-brain barrier (BBB), yet the role of disturbed vascular permeability in stroke progression is unclear. Here we describe a longitudinal in vivo fluorescence imaging approach for the evaluation of cortical perfusion, BBB dysfunction, free radical formation and cellular injury using the photothrombosis vascular occlusion model in male Sprague Dawley rats. Blood-brain barrier dysfunction propagated within the peri-ischemic brain in the first hours after photothrombosis and was associated with free radical formation and cellular injury. Inhibiting free radical signaling significantly reduced progressive cellular damage after photothrombosis, with no significant effect on blood flow and BBB permeability. Our approach allows a dynamic follow-up of cellular events and their response to therapeutics in the acutely injured cerebral cortex.

  18. Mapping social behavior-induced brain activation at cellular resolution in the mouse.

    Science.gov (United States)

    Kim, Yongsoo; Venkataraju, Kannan Umadevi; Pradhan, Kith; Mende, Carolin; Taranda, Julian; Turaga, Srinivas C; Arganda-Carreras, Ignacio; Ng, Lydia; Hawrylycz, Michael J; Rockland, Kathleen S; Seung, H Sebastian; Osten, Pavel

    2015-01-13

    Understanding how brain activation mediates behaviors is a central goal of systems neuroscience. Here, we apply an automated method for mapping brain activation in the mouse in order to probe how sex-specific social behaviors are represented in the male brain. Our method uses the immediate-early-gene c-fos, a marker of neuronal activation, visualized by serial two-photon tomography: the c-fos-GFP+ neurons are computationally detected, their distribution is registered to a reference brain and a brain atlas, and their numbers are analyzed by statistical tests. Our results reveal distinct and shared female and male interaction-evoked patterns of male brain activation representing sex discrimination and social recognition. We also identify brain regions whose degree of activity correlates to specific features of social behaviors and estimate the total numbers and the densities of activated neurons per brain areas. Our study opens the door to automated screening of behavior-evoked brain activation in the mouse.

  19. Mapping Social Behavior-Induced Brain Activation at Cellular Resolution in the Mouse

    Directory of Open Access Journals (Sweden)

    Yongsoo Kim

    2015-01-01

    Full Text Available Understanding how brain activation mediates behaviors is a central goal of systems neuroscience. Here, we apply an automated method for mapping brain activation in the mouse in order to probe how sex-specific social behaviors are represented in the male brain. Our method uses the immediate-early-gene c-fos, a marker of neuronal activation, visualized by serial two-photon tomography: the c-fos-GFP+ neurons are computationally detected, their distribution is registered to a reference brain and a brain atlas, and their numbers are analyzed by statistical tests. Our results reveal distinct and shared female and male interaction-evoked patterns of male brain activation representing sex discrimination and social recognition. We also identify brain regions whose degree of activity correlates to specific features of social behaviors and estimate the total numbers and the densities of activated neurons per brain areas. Our study opens the door to automated screening of behavior-evoked brain activation in the mouse.

  20. Cortical motor hand area. Validation of functional magnetic resonance imaging by intraoperative cortical stimulation mapping; Das motorische Handareal. Nichtinvasiver Nachweis mittels fMRT und operative Validierung mit kortikaler Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Yousry, T. [Inst. fuer Radiologische Diagnostik, Klinikum Grosshadern, Univ. Muenchen (Germany); Schmid, U.D. [Neurochirurgische Klinik, Klinikum Grosshadern, Univ. Muenchen (Germany); Schmidt, D. [Inst. fuer Radiologische Diagnostik, Klinikum Grosshadern, Univ. Muenchen (Germany); Heiss, D. [Inst. fuer Radiologische Diagnostik, Klinikum Innenstadt, Univ. Muenchen (Germany); Jassoy, A. [Inst. fuer Radiologische Diagnostik, Klinikum Innenstadt, Univ. Muenchen (Germany); Eisner, W. [Neurochirurgische Klinik, Klinikum Grosshadern, Univ. Muenchen (Germany); Reulen, H.J. [Neurochirurgische Klinik, Klinikum Grosshadern, Univ. Muenchen (Germany); Reiser, M. [Inst. fuer Radiologische Diagnostik, Klinikum Grosshadern, Univ. Muenchen (Germany)

    1995-04-01

    In this study, activation of cortical sites by specific motor tasks (opening and closing of the hand) was examined by fMRI utilizing the blood-oxygen-level-dependent (BOLD) technique. fMRI was employed in five volunteers and in six patients with tumors in the vicinity of the central region. In the patients, the fMRI data and intraoperative cortical mapping were compared. Our results indicate good correlation of these two methods and that there are no significant differences in the localization of the motor hand area. (orig.) [Deutsch] Die funktionelle Magnetresonanztomographie (fMRT) ermoeglicht die nichtinvasive Lokalisation bestimmter Hirnfunktionen mit hoher raeumlicher Aufloesung. Um zu ueberpruefen, ob die mittels fMRT dargestellten Signalintensitaetsaenderungen wirklich dem Repraesentationsareal einer definierten Funktion entspricht, verglichen wir bei einem Patientenkollektiv die Resultate der fMRT mit den Ergebnissen der intraoperativen motorischen Kortexstimulation. Es zeigte sich, dass Lokalisation und Ausdehnung des von uns untersuchten motorischen Handareals bei beiden Methoden uebereinstimmte. Unsere Ergebnisse zeigen, dass die kortikale Repraesentation des motorischen Handareals durch fMRT mit hoher raeumlicher Aufloesung und nichtinvasiv lokalisiert werden kann. (orig.)

  1. Structural and connectomic neuroimaging for the personalized study of longitudinal alterations in cortical shape, thickness and connectivity after traumatic brain injury.

    Science.gov (United States)

    Irimia, A; Goh, S Y; Torgerson, C M; Vespa, P; Van Horn, J D

    2014-09-01

    The integration of longitudinal brain structure analysis with neurointensive care strategies continues to be a substantial difficulty facing the traumatic brain injury (TBI) research community. For patient-tailored case analysis, it remains challenging to establish how lesion profile modulates longitudinal changes in cortical structure and connectivity, as well as how these changes lead to behavioral, cognitive and neural dysfunction. Additionally, despite the clinical potential of morphometric and connectomic studies, few analytic tools are available for their study in TBI. Here we review the state of the art in structural and connectomic neuroimaging for the study of TBI and illustrate a set of recently-developed, patient-tailored approaches for the study of TBI-related brain atrophy and alterations in morphometry as well as inter-regional connectivity. The ability of such techniques to quantify how injury modulates longitudinal changes in cortical shape, structure and circuitry is highlighted. Quantitative approaches such as these can be used to assess and monitor the clinical condition and evolution of TBI victims, and can have substantial translational impact, especially when used in conjunction with measures of neuropsychological function.

  2. Proteomic analysis of cortical brain tissue from the BTBR mouse model of autism: Evidence for changes in STOP and myelin-related proteins.

    Science.gov (United States)

    Wei, H; Ma, Y; Liu, J; Ding, C; Hu, F; Yu, L

    2016-01-15

    Autism is a neurodevelopmental disorder characterized by abnormal reciprocal social interactions, communication deficits, and repetitive behaviors with restricted interests. However, the widely accepted biomarkers for autism are still lacking. In this study, we carried out a quantitative proteomic profiling study of cortical brain tissue from BTBR T(+)Itpr3(tf) (BTBR) mice, a mouse model that displays an autism-like phenotype. Using isobaric tag for relative and absolute quantification (iTRAQ) coupled with LC-MS/MS, a total of 3611 proteins were quantitated in mouse cortices. As compared to C57BL/6J (B6) mice, 126 differentially expressed proteins were found in the brain from BTBR mice. The functional annotation and categories of differentially expressed proteins were analyzed. Especially, the stable tubule only polypeptide (STOP) protein and myelin-related proteins down-regulated significantly in BTBR mice were confirmed by Western blotting. Furthermore, the BTBR mice displayed reduced levels of staining with ferric alum in comparison to B6 controls, indicative of myelin disruption. Finally, we propose that reduced STOP expression in the brain could be involved in the mediation of autism-like behaviors through impairments of myelination in oligodendrocytes and synaptic function in neurons. Manipulation of STOP protein could be a promising avenue for therapeutic interventions to autism.

  3. Temporal dynamics of cerebral blood flow, cortical damage, apoptosis, astrocyte-vasculature interaction and astrogliosis in the pericontusional region after traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Sonia eVillapol

    2014-06-01

    Full Text Available Traumatic brain injury (TBI results in a loss of brain tissue at the moment of impact in the cerebral cortex. Subsequent secondary injury involves the release of molecular signals with dramatic consequences for the integrity of damaged tissue, leading to the evolution of a pericontusional-damaged area minutes to days after in the initial injury. The mechanisms behind the progression of tissue loss remain under investigation. In this study, we analyzed the spatial-temporal profile of blood flow, apoptotic and astrocytic-vascular events in the cortical regions around the impact site at time points ranging from 5 hours to 2 months after TBI. We performed a mild-moderate controlled cortical impact injury in young adult mice and analyzed the glial and vascular response to injury. We observed a dramatic decrease in perilesional cerebral blood flow (CBF immediately following the cortical impact that lasted until days later. CBF finally returned to baseline levels by 30 days post-injury (dpi. The initial impact also resulted in an immediate loss of tissue and cavity formation that gradually increased in size until 3 dpi. An increase in dying cells localized in the pericontusional region and a robust astrogliosis were also observed at 3 dpi. A strong vasculature interaction with astrocytes was established at 7 dpi. Glial scar formation began at 7 dpi and seemed to be compact by 60 dpi. Altogether, these results suggest that TBI results in a progression from acute neurodegeneration that precedes astrocytic activation, reformation of the neurovascular unit to glial scar formation. Understanding the multiple processes occurring after TBI is critical to the ability to develop neuroprotective therapeutics to ameliorate the short and long-term consequences of brain injury.

  4. Spatiotemporal brain mapping during preparation, perception, and action.

    Science.gov (United States)

    Di Russo, Francesco; Lucci, Giuliana; Sulpizio, Valentina; Berchicci, Marika; Spinelli, Donatella; Pitzalis, Sabrina; Galati, Gaspare

    2016-02-01

    Deciding whether to act or not to act is a fundamental cognitive function. To avoid incorrect responses, both reactive and proactive modes of control have been postulated. Little is known, however, regarding the brain implementation of proactive mechanisms, which are deployed prior to an actual need to inhibit a response. Via a combination of electrophysiological and neuroimaging measures (recorded in 21 and 16 participants, respectively), we describe the brain localization and timing of neural activity that underlies the anticipatory proactive mechanism. From these results, we conclude that proactive control originates in the inferior Frontal gyrus, is established well before stimulus perception, and is released concomitantly with stimulus appearance. Stimulus perception triggers early activity in the anterior insula and intraparietal cortex contralateral to the responding hand; these areas likely mediate the transition from perception to action. The neural activities leading to the decision to act or not to act are described in the framework of a three-stage model that includes perception, action, and anticipatory functions taking place well before stimulus onset.

  5. Bilateral cortical atrophy after severe brain trauma and extradural homatoma Atrofia cortical bilateral após traumatismo cranioencefálico grave e hematoma extradural

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Louzada

    2007-12-01

    Full Text Available We report the case of a severe head injured 43-year old male patient with a large extradural hematoma, Glasgow Coma Scale 3 and dilated fixed pupils. Patient was promptly submitted to surgical evacuation of the lesion, but remained in persistent vegetative state in the post-operative time. Head computed tomography scans performed before surgery, and at early and late post-operative periods comparatively revealed extreme bilateral cortical atrophy. Late consequences of severe head trauma drastically affect the prognosis of patients, being its prevention, and neuroprotection against secondary injury still a therapeutical challenge for neurosurgeons.Relatamos o caso de um paciente de 43 anos, com traumatismo cranioencefálico grave, com grande hematoma extradural, Escala de Coma de Glasgow 3 e pupilas fixas e dilatadas. O paciente foi prontamente submetido à evacuação cirúrgica da lesão mas permaneceu em estado vegetativo persistente no período pós-operatório. As TC de crânio realizadas antes da cirurgia e nos períodos pós-operatórios precoce e tardio revelaram comparativamente extrema atrofia cerebral bilateral. As conseqüências tardias do traumatismo craniano grave afetam drasticamente o prognóstico dos pacientes, sendo sua prevenção, e a neuroproteção contra a injúria secundária ainda um desafio terapêutico para os neurocirurgiões.

  6. [Brain potential mapping by a new method of polynomial interpolation].

    Science.gov (United States)

    Pérez-Cobo, J C; Asencor, F J; Sánchez-Suero, S; Pérez-Arroyo, M

    1993-06-01

    The mapping of evoked cerebral activity is largely determined by the choice of the interpolation system used. When the number of electrodes is very large, practically any interpolation system is valid, but the geometrical and anatomical limitations imposed by the animals normally chosen for these experiments impede the use of a large number of electrodes; hence the overriding importance of a workable interpolation system. The polynomic interpolation method on the monomial structure is presented as valid, and compared with the pseudolineal interpolation method, which is more commonly used.

  7. High-throughput mapping of brain-wide activity in awake and drug-responsive vertebrates.

    Science.gov (United States)

    Lin, Xudong; Wang, Shiqi; Yu, Xudong; Liu, Zhuguo; Wang, Fei; Li, Wai Tsun; Cheng, Shuk Han; Dai, Qiuyun; Shi, Peng

    2015-02-01

    The reconstruction of neural activity across complete neural circuits, or brain activity mapping, has great potential in both fundamental and translational neuroscience research. Larval zebrafish, a vertebrate model, has recently been demonstrated to be amenable to whole brain activity mapping in behaving animals. Here we demonstrate a microfluidic array system ("Fish-Trap") that enables high-throughput mapping of brain-wide activity in awake larval zebrafish. Unlike the commonly practiced larva-processing methods using a rigid gel or a capillary tube, which are laborious and time-consuming, the hydrodynamic design of our microfluidic chip allows automatic, gel-free, and anesthetic-free processing of tens of larvae for microscopic imaging with single-cell resolution. Notably, this system provides the capability to directly couple pharmaceutical stimuli with real-time recording of neural activity in a large number of animals, and the local and global effects of pharmacoactive drugs on the nervous system can be directly visualized and evaluated by analyzing drug-induced functional perturbation within or across different brain regions. Using this technology, we tested a set of neurotoxin peptides and obtained new insights into how to exploit neurotoxin derivatives as therapeutic agents. The novel and versatile "Fish-Trap" technology can be readily unitized to study other stimulus (optical, acoustic, or physical) associated functional brain circuits using similar experimental strategies.

  8. Stable long-term chronic brain mapping at the single-neuron level.

    Science.gov (United States)

    Fu, Tian-Ming; Hong, Guosong; Zhou, Tao; Schuhmann, Thomas G; Viveros, Robert D; Lieber, Charles M

    2016-10-01

    Stable in vivo mapping and modulation of the same neurons and brain circuits over extended periods is critical to both neuroscience and medicine. Current electrical implants offer single-neuron spatiotemporal resolution but are limited by such factors as relative shear motion and chronic immune responses during long-term recording. To overcome these limitations, we developed a chronic in vivo recording and stimulation platform based on flexible mesh electronics, and we demonstrated stable multiplexed local field potentials and single-unit recordings in mouse brains for at least 8 months without probe repositioning. Properties of acquired signals suggest robust tracking of the same neurons over this period. This recording and stimulation platform allowed us to evoke stable single-neuron responses to chronic electrical stimulation and to carry out longitudinal studies of brain aging in freely behaving mice. Such advantages could open up future studies in mapping and modulating changes associated with learning, aging and neurodegenerative diseases.

  9. On Initial Brain Activity Mapping of Associative Memory Code in the Hippocampus

    Science.gov (United States)

    Tsien, Joe Z.; Li, Meng; Osan, Remus; Chen, Guifen; Lin, Longian; Lei Wang, Phillip; Frey, Sabine; Frey, Julietta; Zhu, Dajiang; Liu, Tianming; Zhao, Fang; Kuang, Hui

    2013-01-01

    It has been widely recognized that the understanding of the brain code would require large-scale recording and decoding of brain activity patterns. In 2007 with support from Georgia Research Alliance, we have launched the Brain Decoding Project Initiative with the basic idea which is now similarly advocated by BRAIN project or Brain Activity Map proposal. As the planning of the BRAIN project is currently underway, we share our insights and lessons from our efforts in mapping real-time episodic memory traces in the hippocampus of freely behaving mice. We show that appropriate large-scale statistical methods are essential to decipher and measure real-time memory traces and neural dynamics. We also provide an example of how the carefully designed, sometime thinking-outside-the-box, behavioral paradigms can be highly instrumental to the unraveling of memory-coding cell assembly organizing principle in the hippocampus. Our observations to date have led us to conclude that the specific-to-general categorical and combinatorial feature-coding cell assembly mechanism represents an emergent property for enabling the neural networks to generate and organize not only episodic memory, but also semantic knowledge and imagination. PMID:23838072

  10. On initial Brain Activity Mapping of episodic and semantic memory code in the hippocampus.

    Science.gov (United States)

    Tsien, Joe Z; Li, Meng; Osan, Remus; Chen, Guifen; Lin, Longian; Wang, Phillip Lei; Frey, Sabine; Frey, Julietta; Zhu, Dajiang; Liu, Tianming; Zhao, Fang; Kuang, Hui

    2013-10-01

    It has been widely recognized that the understanding of the brain code would require large-scale recording and decoding of brain activity patterns. In 2007 with support from Georgia Research Alliance, we have launched the Brain Decoding Project Initiative with the basic idea which is now similarly advocated by BRAIN project or Brain Activity Map proposal. As the planning of the BRAIN project is currently underway, we share our insights and lessons from our efforts in mapping real-time episodic memory traces in the hippocampus of freely behaving mice. We show that appropriate large-scale statistical methods are essential to decipher and measure real-time memory traces and neural dynamics. We also provide an example of how the carefully designed, sometime thinking-outside-the-box, behavioral paradigms can be highly instrumental to the unraveling of memory-coding cell assembly organizing principle in the hippocampus. Our observations to date have led us to conclude that the specific-to-general categorical and combinatorial feature-coding cell assembly mechanism represents an emergent property for enabling the neural networks to generate and organize not only episodic memory, but also semantic knowledge and imagination.

  11. Volumetric T1 and T2 magnetic resonance brain toolkit for relaxometry mapping simulation

    Directory of Open Access Journals (Sweden)

    Antonio Carlos da Silva Senra Filho

    Full Text Available Abstract Introduction Relaxometry images are an important magnetic resonance imaging (MRI technique in the clinical routine. Many diagnoses are based on the relaxometry maps to infer abnormal state in the tissue characteristic relaxation constant. In order to study the performance of these image processing approaches, a controlled simulated environment is necessary. However, a simulated relaxometry image tool is still lacking. This study proposes a computational anatomical brain phantom for MRI relaxometry images, which aims to offer an easy and flexible toolkit to test different image processing techniques, applied to MRI relaxometry maps in a controlled simulated environment. Methods A pipeline of image processing techniques such as brain extraction, image segmentation, normalization to a common space and signal relaxation decay simulation, were applied to a brain structural ICBM brain template, on both T1 and T2 weighted images, in order to simulate a volumetric brain relaxometry phantom. The FMRIB Software Library (FSL toolkits were used here as the base image processing needed to all the relaxometry reconstruction. Results All the image processing procedures are performed using automatic algorithms. In addition, different artefact levels can be set from different sources such as Rician noise and radio-frequency inhomogeneity noises. Conclusion The main goal of this project is to help researchers in their future image processing analysis involving MRI relaxometry images, offering reliable and robust brain relaxometry simulation modelling. Furthermore, the entire pipeline is open-source, which provides a wide collaboration between researchers who may want to improve the software and its functionality.

  12. Molecular cloning, chromosomal mapping, and functional expression of human brain glutamate receptors

    Energy Technology Data Exchange (ETDEWEB)

    Sun, W.; Ferrer-Montiel, A.V.; Schinder, A.F.; Montal, M. (Univ. of California, San Diego, La Jolla (United States)); McPherson, J.P. (Univ. of California, Irvine (United States)); Evans, G.A. (Salk Inst. for Biological Studies, La Jolla, CA (United States))

    1992-02-15

    A full-length cDNA clone encoding a glutamate receptor was isolated from a human brain cDNA library, and the gene product was characterized after expression in Xenopus oocytes. Degenerate PCR primers to conserved regions of published rat brain glutamate receptor sequences amplified a 1-kilobase fragment from a human brain cDNA library. This fragment was used as a probe for subsequent hybridization screening. Two clones were isolated that, based on sequence information, code for different receptors: a 3-kilobase clone, HBGR1, contains a full-length glutamate receptor cDNA highly homologous to the rat brain clone GluR1, and a second clone, HBGR2, contains approximately two-thirds of the coding region of a receptor homologous to rat brain clone GluR2. Southern and PCr analysis of a somatic cell-hybrid panel mapped HBGR1 to human chromosome 5q31.3-33.3 and mapped HBGR2 to chromosome 4q25-34.3. Xenopus oocytes injected with in vitro-synthesized HBGR1 cRNA expressed currents activated by glutamate receptor agonists. These results indicate that clone HBGR1 codes for a glutamate receptor of the kainate subtype cognate to members of the glutamate receptor family from rodent brain.

  13. Cerebrospinal fluid volumetric MRI mapping as a simple measurement for evaluating brain atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Vis, J.B. de; Zwanenburg, J.J.; Kleij, L.A. van der; Spijkerman, J.M.; Hendrikse, J. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Biessels, G.J. [University Medical Center Utrecht, Department of Neurology, Brain Center Rudolf Magnus, Utrecht (Netherlands); Petersen, E.T. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Hvidovre Hospital, Danish Research Centre for Magnetic Resonance, Hvidovre (Denmark)

    2016-05-15

    To assess whether volumetric cerebrospinal fluid (CSF) MRI can be used as a surrogate for brain atrophy assessment and to evaluate how the T{sub 2} of the CSF relates to brain atrophy. Twenty-eight subjects [mean age 64 (sd 2) years] were included; T{sub 1}-weighted and CSF MRI were performed. The first echo data of the CSF MRI sequence was used to obtain intracranial volume, CSF partial volume was measured voxel-wise to obtain CSF volume (V{sub CSF}) and the T{sub 2} of CSF (T{sub 2,CSF}) was calculated. The correlation between V{sub CSF} / T{sub 2,CSF} and brain atrophy scores [global cortical atrophy (GCA) and medial temporal lobe atrophy (MTA)] was evaluated. Relative total, peripheral subarachnoidal, and ventricular V{sub CSF} increased significantly with increased scores on the GCA and MTA (R = 0.83, 0.78 and 0.78 and R = 0.72, 0.62 and 0.86). Total, peripheral subarachnoidal, and ventricular T{sub 2} of the CSF increased significantly with higher scores on the GCA and MTA (R = 0.72, 0.70 and 0.49 and R = 0.60, 0.57 and 0.41). A fast, fully automated CSF MRI volumetric sequence is an alternative for qualitative atrophy scales. The T{sub 2} of the CSF is related to brain atrophy and could thus be a marker of neurodegenerative disease. (orig.)

  14. Brain regions involved in voluntary movements as revealed by radioisotopic mapping of CBF or CMR-glucose changes

    DEFF Research Database (Denmark)

    Lassen, N A; Ingvar, D H

    1990-01-01

    Mapping of cortical and subcortical grey matter active during voluntary movements by means of measurements of local increases of CBF or CMR-Glucose is reviewed. Most of the studies concern observations in man during hand movements using the intracarotid Xenon-133 injection technique, an approach...

  15. Localisation of motor areas in brain tumour patients: a comparison of preoperative [{sup 18}F]FDG-PET and intraoperative cortical electrostimulation

    Energy Technology Data Exchange (ETDEWEB)

    Schreckenberger, M.; Sabri, O.; Meyer, P.T.; Zeggel, T.; Zimny, M.; Buell, U. [Technische Univ. Aachen (Germany). Dept. of Nuclear Medicine; Spetzger, U.; Gilsbach, J. [Dept. of Neurosurgery, Aachen Univ. of Technology (Germany)

    2001-09-01

    Assessment of the exact spatial relation between tumour and adjacent functionally relevant brain areas is a primary tool in the presurgical planning in brain tumour patients. The purpose of this study was to compare a preoperative fluorine-18 fluorodeoxyglucose positron emission tomography ([{sup 18}F]FDG PET) activation protocol in patients with tumours near the central area with the results of intraoperative direct cortical electrostimulation, and to determine whether non-invasive preoperative PET imaging can provide results equivalent to those achieved with the invasive neurosurgical ''gold standard''. In this prospective study, we examined 20 patients with various tumours of the central area, performing two PET scans (each 30 min after i.v. injection of 134-341 MBq [{sup 18}F]FDG) in each patient: (1) a resting baseline scan and (2) an activation scan using a standardised motor task (finger tapping, foot stretching). Following PET/MRI realignment and normalisation to the whole brain counts, parametric images of the activation versus the rest study were calculated and pixels above categorical threshold values were projected to the individual MRI for bimodal assessment of morphology and function (PET/MRI overlay). Intraoperative direct cortical electrostimulation was performed using a Viking IV probe (5 pulses, each of 100 {mu}s) and documented using a dedicated neuro navigation system. Results were compared with the preoperative PET findings. PET revealed significant activation of the contralateral primary motor cortex in 95% (19/20) of the brain tumour patients (hand activation 13/13, foot activation 6/7), showing a mean increase in normalised [{sup 18}F]FDG uptake of 20.5%{+-}5.2% (hand activation task) and 17.2%{+-}2.5% (foot activation task). Additionally detected activation of the ipsilateral primary motor cortex was interpreted as a metabolic indication for interhemispheric compensational processes. Evaluation of the PET findings by

  16. Changes in Motor-related Cortical Activity Following Deep Brain Stimulation for Parkinson's Disease Detected by Functional Near Infrared Spectroscopy: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Takashi Morishita

    2016-12-01

    Full Text Available It remains unclear how deep brain stimulation (DBS modulates the global neuronal network involving cortical activity. We aimed to evaluate changes in cortical activity in six (two men; four women patients with Parkinson's disease (PD who underwent unilateral globus pallidus interna DBS surgery using a multi-channel near infrared spectroscopy (NIRS system. As five of the patients were right-handed, DBS was performed on the left in these five cases. The mean age was 66.8 ± 4.0 years. The unified Parkinson's disease rating scale (UPDRS motor scores were evaluated at baseline and 1- and 6-month follow-up. Task-related NIRS experiments applying the block design were performed at baseline and one-month follow-up. The mean of the total UPDRS motor score was 48.5 ± 11.1 in the off-medication state preoperatively. Postoperatively, total UPDRS motor scores improved to 26.8 ± 16.6 (p < 0.05 and 22.2 ± 8.6 (p < 0.05 at 1- and 6-month follow-up, respectively. A task-related NIRS experiment showed a postoperative increase in the cortical activity of the prefrontal cortex comparable to the preoperative state. To our knowledge, this is the first study to use a multi-channel NIRS system for PD patients treated with DBS. In this pilot study, we showed changes in motor-associated cortical activities following DBS surgery. Therapeutic DBS was concluded to have promoted the underlying neuronal network remodeling.

  17. Graph theory analysis of complex brain networks: new concepts in brain mapping applied to neurosurgery.

    Science.gov (United States)

    Hart, Michael G; Ypma, Rolf J F; Romero-Garcia, Rafael; Price, Stephen J; Suckling, John

    2016-06-01

    Neuroanatomy has entered a new era, culminating in the search for the connectome, otherwise known as the brain's wiring diagram. While this approach has led to landmark discoveries in neuroscience, potential neurosurgical applications and collaborations have been lagging. In this article, the authors describe the ideas and concepts behind the connectome and its analysis with graph theory. Following this they then describe how to form a connectome using resting state functional MRI data as an example. Next they highlight selected insights into healthy brain function that have been derived from connectome analysis and illustrate how studies into normal development, cognitive function, and the effects of synthetic lesioning can be relevant to neurosurgery. Finally, they provide a précis of early applications of the connectome and related techniques to traumatic brain injury, functional neurosurgery, and neurooncology.

  18. Evaluation of three-dimensional anisotropic head model for mapping realistic electromagnetic fields of brain tissues

    Directory of Open Access Journals (Sweden)

    Woo Chul Jeong

    2015-08-01

    Full Text Available Electromagnetic fields provide fundamental data for the imaging of electrical tissue properties, such as conductivity and permittivity, in recent magnetic resonance (MR-based tissue property mapping. The induced voltage, current density, and magnetic flux density caused by externally injected current are critical factors for determining the image quality of electrical tissue conductivity. As a useful tool to identify bio-electromagnetic phenomena, precise approaches are required to understand the exact responses inside the human body subject to an injected currents. In this study, we provide the numerical simulation results of electromagnetic field mapping of brain tissues using a MR-based conductivity imaging method. First, we implemented a realistic three-dimensional human anisotropic head model using high-resolution anatomical and diffusion tensor MR images. The voltage, current density, and magnetic flux density of brain tissues were imaged by injecting 1 mA of current through pairs of electrodes on the surface of our head model. The current density map of anisotropic brain tissues was calculated from the measured magnetic flux density based on the linear relationship between the water diffusion tensor and the electrical conductivity tensor. Comparing the current density to the previous isotropic model, the anisotropic model clearly showed the differences between the brain tissues. This originates from the enhanced signals by the inherent conductivity contrast as well as the actual tissue condition resulting from the injected currents.

  19. Evaluation of three-dimensional anisotropic head model for mapping realistic electromagnetic fields of brain tissues

    Science.gov (United States)

    Jeong, Woo Chul; Wi, Hun; Sajib, Saurav Z. K.; Oh, Tong In; Kim, Hyung Joong; Kwon, Oh In; Woo, Eung Je

    2015-08-01

    Electromagnetic fields provide fundamental data for the imaging of electrical tissue properties, such as conductivity and permittivity, in recent magnetic resonance (MR)-based tissue property mapping. The induced voltage, current density, and magnetic flux density caused by externally injected current are critical factors for determining the image quality of electrical tissue conductivity. As a useful tool to identify bio-electromagnetic phenomena, precise approaches are required to understand the exact responses inside the human body subject to an injected currents. In this study, we provide the numerical simulation results of electromagnetic field mapping of brain tissues using a MR-based conductivity imaging method. First, we implemented a realistic three-dimensional human anisotropic head model using high-resolution anatomical and diffusion tensor MR images. The voltage, current density, and magnetic flux density of brain tissues were imaged by injecting 1 mA of current through pairs of electrodes on the surface of our head model. The current density map of anisotropic brain tissues was calculated from the measured magnetic flux density based on the linear relationship between the water diffusion tensor and the electrical conductivity tensor. Comparing the current density to the previous isotropic model, the anisotropic model clearly showed the differences between the brain tissues. This originates from the enhanced signals by the inherent conductivity contrast as well as the actual tissue condition resulting from the injected currents.

  20. Interpretability of Multivariate Brain Maps in Linear Brain Decoding: Definition, and Heuristic Quantification in Multivariate Analysis of MEG Time-Locked Effects

    Science.gov (United States)

    Kia, Seyed Mostafa; Vega Pons, Sandro; Weisz, Nathan; Passerini, Andrea

    2017-01-01

    Brain decoding is a popular multivariate approach for hypothesis testing in neuroimaging. Linear classifiers are widely employed in the brain decoding paradigm to discriminate among experimental conditions. Then, the derived linear weights are visualized in the form of multivariate brain maps to further study spatio-temporal patterns of underlying neural activities. It is well known that the brain maps derived from weights of linear classifiers are hard to interpret because of high correlations between predictors, low signal to noise ratios, and the high dimensionality of neuroimaging data. Therefore, improving the interpretability of brain decoding approaches is of primary interest in many neuroimaging studies. Despite extensive studies of this type, at present, there is no formal definition for interpretability of multivariate brain maps. As a consequence, there is no quantitative measure for evaluating the interpretability of different brain decoding methods. In this paper, first, we present a theoretical definition of interpretability in brain decoding; we show that the interpretability of multivariate brain maps can be decomposed into their reproducibility and representativeness. Second, as an application of the proposed definition, we exemplify a heuristic for approximating the interpretability in multivariate analysis of evoked magnetoencephalography (MEG) responses. Third, we propose to combine the approximated interpretability and the generalization performance of the brain decoding into a new multi-objective criterion for model selection. Our results, for the simulated and real MEG data, show that optimizing the hyper-parameters of the regularized linear classifier based on the proposed criterion results in more informative multivariate brain maps. More importantly, the presented definition provides the theoretical background for quantitative evaluation of interpretability, and hence, facilitates the development of more effective brain decoding algorithms

  1. Sensory cortical re-mapping following upper-limb amputation and subsequent targeted reinnervation: A case report

    OpenAIRE

    Jun Yao; Albert Chen; Todd Kuiken; Carolina Carmona; Julius Dewald

    2015-01-01

    This case study demonstrates the change of sensory cortical representations of the residual parts of the arm in an individual who underwent a trans-humeral amputation and subsequent targeted reinnervation (TR). As a relatively new surgical technique, TR restores a direct neural connection from amputated sensorimotor nerves to specific target muscles. This method has been successfully applied to upper-limb and lower-limb amputees, and has shown effectiveness in regaining control signals via th...

  2. Mapping cortico-striatal connectivity onto the cortical surface: a new tractography-based approach to study Huntington disease.

    Directory of Open Access Journals (Sweden)

    Linda Marrakchi-Kacem

    Full Text Available Huntington disease (HD is associated with early and severe damage to the basal ganglia and particularly the striatum. We investigated cortico-striatal connectivity modifications occurring in HD patients using a novel approach which focuses on the projection of the connectivity profile of the basal ganglia onto the cortex. This approach consists in computing, for each subcortical structure, surface connectivity measures representing its strength of connections to the cortex and comparing these measures across groups. In this study, we focused on Huntington disease as an application of this new approach. First, surface cortico-striatal connectivity measures of a group of healthy subjects were averaged in order to infer the "normal" connectivity profile of the striatum to the cortex. Second, a statistical analysis was performed from the surface connectivity measures of healthy subjects and HD patients in order to detect the cortical gyri presenting altered cortico-striatal connectivity in HD. Lastly, percentage differences of connectivity between healthy subjects and patients were inferred, for each nucleus of the striatum, from the connectivity measures of the cortical gyri presenting a significant connectivity difference between the two groups. These percentage differences characterize the axonal disruptions between the striatum and the cortex occurring in HD. We found selective region-specific degeneration of cortical connections predominating for associative and primary sensorimotor connections and with relative preservation of limbic connections. Our method can be used to infer novel connectivity-based markers of HD pathological process.

  3. Neuronal deletion of caspase 8 protects against brain injury in mouse models of controlled cortical impact and kainic acid-induced excitotoxicity.

    Directory of Open Access Journals (Sweden)

    Maryla Krajewska

    Full Text Available Acute brain injury is an important health problem. Given the critical position of caspase 8 at the crossroads of cell death pathways, we generated a new viable mouse line (Ncasp8(-/-, in which the gene encoding caspase 8 was selectively deleted in neurons by cre-lox system.Caspase 8 deletion reduced rates of neuronal cell death in primary neuronal cultures and in whole brain organotypic coronal slice cultures prepared from 4 and 8 month old mice and cultivated up to 14 days in vitro. Treatments of cultures with recombinant murine TNFα (100 ng/ml or TRAIL (250 ng/mL plus cyclohexamide significantly protected neurons against cell death induced by these apoptosis-inducing ligands. A protective role of caspase 8 deletion in vivo was also demonstrated using a controlled cortical impact (CCI model of traumatic brain injury (TBI and seizure-induced brain injury caused by kainic acid (KA. Morphometric analyses were performed using digital imaging in conjunction with image analysis algorithms. By employing virtual images of hundreds of brain sections, we were able to perform quantitative morphometry of histological and immunohistochemical staining data in an unbiased manner. In the TBI model, homozygous deletion of caspase 8 resulted in reduced lesion volumes, improved post-injury motor performance, superior learning and memory retention, decreased apoptosis, diminished proteolytic processing of caspases and caspase substrates, and less neuronal degeneration, compared to wild type, homozygous cre, and caspase 8-floxed control mice. In the KA model, Ncasp8(-/- mice demonstrated superior survival, reduced seizure severity, less apoptosis, and reduced caspase 3 processing. Uninjured aged knockout mice showed improved learning and memory, implicating a possible role for caspase 8 in cognitive decline with aging.Neuron-specific deletion of caspase 8 reduces brain damage and improves post-traumatic functional outcomes, suggesting an important role for this

  4. Whole-brain mapping of neuronal activity in the learned helplessness model of depression

    Directory of Open Access Journals (Sweden)

    Yongsoo eKim

    2016-02-01

    Full Text Available Some individuals are resilient, whereas others succumb to despair in repeated stressful situations. The neurobiological mechanisms underlying such divergent behavioral responses remain unclear. Here, we employed an automated method for mapping neuronal activity in search of signatures of stress responses in the entire mouse brain. We used serial two-photon tomography to detect expression of c-FosGFP – a marker of neuronal activation – in c-fosGFP transgenic mice subjected to the learned helplessness (LH procedure, a widely used model of stress-induced depression-like phenotype in laboratory animals. We found that mice showing helpless behavior had an overall brain-wide reduction in the level of neuronal activation compared with mice showing resilient behavior, with the exception of a few brain areas, including the locus coeruleus, that were more activated in the helpless mice. In addition, the helpless mice showed a strong trend of having higher similarity in whole brain activity profile among individuals, suggesting that helplessness is represented by a more stereotypic brain-wide activation pattern. This latter effect was confirmed in rats subjected to the LH procedure, using 2-deoxy-2[18F]fluoro-D-glucose positron emission tomography to assess neural activity. Our findings reveal distinct brain activity markings that correlate with adaptive and maladaptive behavioral responses to stress, and provide a framework for further studies investigating the contribution of specific brain regions to maladaptive stress responses.

  5. Nonrigid Registration of Brain Tumor Resection MR Images Based on Joint Saliency Map and Keypoint Clustering

    Directory of Open Access Journals (Sweden)

    Binjie Qin

    2009-12-01

    Full Text Available This paper proposes a novel global-to-local nonrigid brain MR image registration to compensate for the brain shift and the unmatchable outliers caused by the tumor resection. The mutual information between the corresponding salient structures, which are enhanced by the joint saliency map (JSM, is maximized to achieve a global rigid registration of the two images. Being detected and clustered at the paired contiguous matching areas in the globally registered images, the paired pools of DoG keypoints in combination with the JSM provide a useful cluster-to-cluster correspondence to guide the local control-point correspondence detection and the outlier keypoint rejection. Lastly, a quasi-inverse consistent deformation is smoothly approximated to locally register brain images through the mapping the clustered control points by compact support radial basis functions. The 2D implementation of the method can model the brain shift in brain tumor resection MR images, though the theory holds for the 3D case.

  6. Statistical parametric maps of {sup 18}F-FDG PET and 3-D autoradiography in the rat brain: a cross-validation study

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, Elena; Marti-Climent, Josep M. [Clinica Universidad de Navarra, Nuclear Medicine Department, Pamplona (Spain); Collantes, Maria; Molinet, Francisco [Center for Applied Medical Research (CIMA) and Clinica Universidad de Navarra, Small Animal Imaging Research Unit, Pamplona (Spain); Delgado, Mercedes; Garcia-Garcia, Luis; Pozo, Miguel A. [Universidad Complutense de Madrid, Brain Mapping Unit, Madrid (Spain); Juri, Carlos [Center for Applied Medical Research (CIMA), Movement Disorders Group, Neurosciences Division, Pamplona (Spain); Clinica Universidad de Navarra, Department of Neurology and Neurosurgery, Pamplona (Spain); Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Pamplona (Spain); Pontificia Universidad Catolica de Chile, Department of Neurology, Santiago (Chile); Fernandez-Valle, Maria E. [Universidad Complutense de Madrid, MRI Research Center, Madrid (Spain); Gago, Belen [Center for Applied Medical Research (CIMA), Movement Disorders Group, Neurosciences Division, Pamplona (Spain); Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Pamplona (Spain); Obeso, Jose A. [Center for Applied Medical Research (CIMA), Movement Disorders Group, Neurosciences Division, Pamplona (Spain); Clinica Universidad de Navarra, Department of Neurology and Neurosurgery, Pamplona (Spain); Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Pamplona (Spain); Penuelas, Ivan [Clinica Universidad de Navarra, Nuclear Medicine Department, Pamplona (Spain); Center for Applied Medical Research (CIMA) and Clinica Universidad de Navarra, Small Animal Imaging Research Unit, Pamplona (Spain)

    2011-12-15

    Although specific positron emission tomography (PET) scanners have been developed for small animals, spatial resolution remains one of the most critical technical limitations, particularly in the evaluation of the rodent brain. The purpose of the present study was to examine the reliability of voxel-based statistical analysis (Statistical Parametric Mapping, SPM) applied to {sup 18}F-fluorodeoxyglucose (FDG) PET images of the rat brain, acquired on a small animal PET not specifically designed for rodents. The gold standard for the validation of the PET results was the autoradiography of the same animals acquired under the same physiological conditions, reconstructed as a 3-D volume and analysed using SPM. Eleven rats were studied under two different conditions: conscious or under inhalatory anaesthesia during {sup 18}F-FDG uptake. All animals were studied in vivo under both conditions in a dedicated small animal Philips MOSAIC PET scanner and magnetic resonance images were obtained for subsequent spatial processing. Then, rats were randomly assigned to a conscious or anaesthetized group for postmortem autoradiography, and slices from each animal were aligned and stacked to create a 3-D autoradiographic volume. Finally, differences in {sup 18}F-FDG uptake between conscious and anaesthetized states were assessed from PET and autoradiography data by SPM analysis and results were compared. SPM results of PET and 3-D autoradiography are in good agreement and led to the detection of consistent cortical differences between the conscious and anaesthetized groups, particularly in the bilateral somatosensory cortices. However, SPM analysis of 3-D autoradiography also highlighted differences in the thalamus that were not detected with PET. This study demonstrates that any difference detected with SPM analysis of MOSAIC PET images of rat brain is detected also by the gold standard autoradiographic technique, confirming that this methodology provides reliable results, although

  7. Voxel-based statistical analysis of cerebral glucose metabolism in the rat cortical deafness model by 3D reconstruction of brain from autoradiographic images

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Sung; Park, Kwang Suk [Seoul National University College of Medicine, Department of Nuclear Medicine, 28 Yungun-Dong, Chongno-Ku, Seoul (Korea); Seoul National University College of Medicine, Department of Biomedical Engineering, Seoul (Korea); Ahn, Soon-Hyun; Oh, Seung Ha; Kim, Chong Sun; Chung, June-Key; Lee, Myung Chul [Seoul National University College of Medicine, Department of Otolaryngology, Head and Neck Surgery, Seoul (Korea); Lee, Dong Soo; Jeong, Jae Min [Seoul National University College of Medicine, Department of Nuclear Medicine, 28 Yungun-Dong, Chongno-Ku, Seoul (Korea)

    2005-06-01

    Animal models of cortical deafness are essential for investigation of the cerebral glucose metabolism in congenital or prelingual deafness. Autoradiographic imaging is mainly used to assess the cerebral glucose metabolism in rodents. In this study, procedures for the 3D voxel-based statistical analysis of autoradiographic data were established to enable investigations of the within-modal and cross-modal plasticity through entire areas of the brain of sensory-deprived animals without lumping together heterogeneous subregions within each brain structure into a large region of interest. Thirteen 2-[1-{sup 14}C]-deoxy-D-glucose autoradiographic images were acquired from six deaf and seven age-matched normal rats (age 6-10 weeks). The deafness was induced by surgical ablation. For the 3D voxel-based statistical analysis, brain slices were extracted semiautomatically from the autoradiographic images, which contained the coronal sections of the brain, and were stacked into 3D volume data. Using principal axes matching and mutual information maximization algorithms, the adjacent coronal sections were co-registered using a rigid body transformation, and all sections were realigned to the first section. A study-specific template was composed and the realigned images were spatially normalized onto the template. Following count normalization, voxel-wise t tests were performed to reveal the areas with significant differences in cerebral glucose metabolism between the deaf and the control rats. Continuous and clear edges were detected in each image after registration between the coronal sections, and the internal and external landmarks extracted from the spatially normalized images were well matched, demonstrating the reliability of the spatial processing procedures. Voxel-wise t tests showed that the glucose metabolism in the bilateral auditory cortices of the deaf rats was significantly (P<0.001) lower than that in the controls. There was no significantly reduced metabolism in

  8. Virtual brain mapping: Meta-analysis and visualization in functional neuroimaging

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup

    Results from functional neuroimaging such as positron emission tomography and functional magnetic resonance are often reported as sets of 3-dimensional coordinates in Talairach stereotactic space. By utilizing data collected in the BrainMap database and from our own small XML database we can...... data matrix. By conditioning on elements in the databases other than the coordinate data, e.g., anatomical labels associated with many coordinates we can make conditional novelty detection identifying outliers in the database that might be errorneous entries or seldom occuring patterns. In the Brain......Map database we found errors, e.g., stemming from confusion of centimeters and millimeters during entering and errors in the original article. Conditional probability density modeling also enables generation of probabilistic atlases and automatic probabilistic anatomical labeling of new coordinates...

  9. Local signal time-series during rest used for areal boundary mapping in individual human brains.

    Directory of Open Access Journals (Sweden)

    Satoshi Hirose

    Full Text Available It is widely thought that resting state functional connectivity likely reflects functional interaction among brain areas and that different functional areas interact with different sets of brain areas. A method for mapping areal boundaries has been formulated based on the large-scale spatial characteristics of regional interaction revealed by resting state functional connectivity. In the present study, we present a novel analysis for areal boundary mapping that requires only the signal timecourses within a region of interest, without reference to the information from outside the region. The areal boundaries were generated by the novel analysis and were compared with those generated by the previously-established standard analysis. The boundaries were robust and reproducible across the two analyses, in two regions of interest tested. These results suggest that the information for areal boundaries is readily available inside the region of interest.

  10. Mapping of brain function with positron emission tomography for pathophysiological analysis of neurological disorders

    Energy Technology Data Exchange (ETDEWEB)

    Nariai, Tadashi [Tokyo Medical and Dental Univ. (Japan). Graduate School

    2001-02-01

    The role of PET is discussed mainly through author's clinical experience in patients with brain lesions from the view of mapping of brain function. Procedure for PET concept in clinical practice is summarized. PET using tracers like [{sup 15}O]water and [{sup 18}F]fluorodeoxyglucose for mapping of the function has been used in combination with MRI, MEG (magnetoencephalography), SPECT and other imaging means for morphological identification. Actual those images before and after surgery are presented in cases of epilepsy, moyamoya disease, stegnosis of cervical artery, arteriovenous malformation and oligodendroglioma. Images of [{sup 11}C]flumazenil in epilepsies are also presented to show the neurological dysfunctions. PET evaluation of neurological functions is concluded to become more important in parallel with the advancement of therapeutics. (K.H.)

  11. Characterization of interictal epileptiform discharges with time-resolved cortical current maps using the helmholtz-hodge decomposition.

    Science.gov (United States)

    Slater, Jeremy D; Khan, Sheraz; Li, Zhimin; Castillo, Eduardo

    2012-01-01

    Source estimates performed using a single equivalent current dipole (ECD) model for interictal epileptiform discharges (IEDs) which appear unifocal have proven highly accurate in neocortical epilepsies, falling within millimeters of that demonstrated by electrocorticography. Despite this success, the single ECD solution is limited, best describing sources which are temporally stable. Adapted from the field of optics, optical flow analysis of distributed source models of MEG or EEG data has been proposed as a means to estimate the current motion field of cortical activity, or "cortical flow." The motion field so defined can be used to identify dynamic features of interest such as patterns of directional flow, current sources, and sinks. The Helmholtz-Hodge Decomposition (HHD) is a technique frequently applied in fluid dynamics to separate a flow pattern into three components: (1) a non-rotational scalar potential U describing sinks and sources, (2) a non-diverging scalar potential A accounting for vortices, and (3) an harmonic vector field H. As IEDs seem likely to represent periods of highly correlated directional flow of cortical currents, the U component of the HHD suggests itself as a way to characterize spikes in terms of current sources and sinks. In a series of patients with refractory epilepsy who were studied with magnetoencephalography as part of their evaluation for possible resective surgery, spike localization with ECD was compared to HHD applied to an optical flow analysis of the same spike. Reasonable anatomic correlation between the two techniques was seen in the majority of patients, suggesting that this method may offer an additional means of characterization of epileptic discharges.

  12. Repeated mild lateral fluid percussion brain injury in the rat causes cumulative long-term behavioral impairments, neuroinflammation, and cortical loss in an animal model of repeated concussion.

    Science.gov (United States)

    Shultz, Sandy R; Bao, Feng; Omana, Vanessa; Chiu, Charlotte; Brown, Arthur; Cain, Donald Peter

    2012-01-20

    There is growing evidence that repeated brain concussion can result in cumulative and long-term behavioral symptoms, neuropathological changes, and neurodegeneration. Little is known about the factors and mechanisms that contribute to these effects. The current study addresses the need to investigate and better understand the effects of repeated concussion through the development of an animal model. Male Long-Evans rats received 1, 3, or 5 mild lateral fluid percussion injuries or sham injuries spaced 5 days apart. After the final injury, rats received either a short (24 h) or long (8 weeks) post-injury recovery period, followed by a detailed behavioral analysis consisting of tests for rodent anxiety-like behavior, cognition, social behavior, sensorimotor function, and depression-like behavior. Brains were examined immunohistochemically to assess neuroinflammation and cortical damage. Rats given 1, 3, or 5 mild percussion injuries displayed significant short-term cognitive impairments. Rats given repeated mild percussion injuries displayed significantly worse short- and long-term cognitive impairments. Rats given 5 mild percussion injuries also displayed increased anxiety- and depression-like behaviors. Neuropathological analysis revealed short-term neuroinflammation in 3-injury rats, and both short- and long-term neuroinflammation in 5-injury rats. There was also evidence that repeated injuries induced short- and long-term cortical damage. These cumulative and long-term changes are consistent with findings in human patients suffering repeated brain concussion, provide support for the use of repeated mild lateral fluid percussion injuries to study repeated concussion in the rat, and suggest that neuroinflammation may be important for understanding the cumulative and chronic effects of repeated concussion.

  13. A re-examination of neural basis of language processing: proposal of a dynamic hodotopical model from data provided by brain stimulation mapping during picture naming.

    Science.gov (United States)

    Duffau, Hugues; Moritz-Gasser, Sylvie; Mandonnet, Emmanuel

    2014-04-01

    From recent findings provided by brain stimulation mapping during picture naming, we re-examine the neural basis of language. We studied structural-functional relationships by correlating the types of language disturbances generated by stimulation in awake patients, mimicking a transient virtual lesion both at cortical and subcortical levels (white matter and deep grey nuclei), with the anatomical location of the stimulation probe. We propose a hodotopical (delocalized) and dynamic model of language processing, which challenges the traditional modular and serial view. According to this model, following the visual input, the language network is organized in parallel, segregated (even if interconnected) large-scale cortico-subcortical sub-networks underlying semantic, phonological and syntactic processing. Our model offers several advantages (i) it explains double dissociations during stimulation (comprehension versus naming disorders, semantic versus phonemic paraphasias, syntactic versus naming disturbances, plurimodal judgment versus naming disorders); (ii) it takes into account the cortical and subcortical anatomic constraints; (iii) it explains the possible recovery of aphasia following a lesion within the "classical" language areas; (iv) it establishes links with a model executive functions.

  14. Brain mapping with transcranial magnetic stimulation using a refined correlation ratio and Kendall's tau.

    Science.gov (United States)

    Matthäus, L; Trillenberg, P; Fadini, T; Finke, M; Schweikard, A

    2008-11-10

    Transcranial magnetic stimulation provides a mean to stimulate the brain non-invasively and painlessly. The effect of the stimulation hereby depends on the stimulation coil used and on its placement. This paper presents a mapping algorithm based on the assumption of a monotonous functional relationship between the applied electric field strength at the representation point of a muscle and the evoked motor potential. We combine data from coil characteristics, coil placement, and stimulation outcome to calculate a likelihood map for the representation of stimulated muscles in the brain. Hereby, correlation ratio (CR) and Kendall's rank coefficient tau are used to find areas in the brain where there is most likely a functional or monotonous relationship between electric field strength applied to this area and the muscle response. First results show a good accordance of our method with mapping from functional magnetic resonance imaging. In our case, classical evaluation of CR with binning is impossible, because sample data sets are too small and data are continuous. We therefore introduce a refined CR formula based on a Parzen windowing of the X-data to solve the problem. In contrast to usual windowing approaches, which require numeric integration, it can be evaluated directly in O(n2) time. Hence, its advantage lies in fast evaluation while maintaining robust applicability to small sample sets. We suggest that the presented formula can generally be used in CR-related problems where sample size is small and data range is continuous.

  15. Denoising and Frequency Analysis of Noninvasive Magnetoencephalography Sensor Signals for Functional Brain Mapping

    CERN Document Server

    Ukil, A

    2015-01-01

    Magnetoencephalography (MEG) is an important noninvasive, nonhazardous technology for functional brain mapping, measuring the magnetic fields due to the intracellular neuronal current flow in the brain. However, most often, the inherent level of noise in the MEG sensor data collection process is large enough to obscure the signal(s) of interest. In this paper, a denoising technique based on the wavelet transform and the multiresolution signal decomposition technique along with thresholding is presented, substantiated by application results. Thereafter, different frequency analysis are performed on the denoised MEG signals to identify the major frequencies of the brain oscillations present in the denoised signals. Time-frequency plots (spectrograms) of the denoised signals are also provided.

  16. 3D Data Mapping and Real-Time Experiment Control and Visualization in Brain Slices.

    Science.gov (United States)

    Navarro, Marco A; Hibbard, Jaime V K; Miller, Michael E; Nivin, Tyler W; Milescu, Lorin S

    2015-10-20

    Here, we propose two basic concepts that can streamline electrophysiology and imaging experiments in brain slices and enhance data collection and analysis. The first idea is to interface the experiment with a software environment that provides a 3D scene viewer in which the experimental rig, the brain slice, and the recorded data are represented to scale. Within the 3D scene viewer, the user can visualize a live image of the sample and 3D renderings of the recording electrodes with real-time position feedback. Furthermore, the user can control the instruments and visualize their status in real time. The second idea is to integrate multiple types of experimental data into a spatial and temporal map of the brain slice. These data may include low-magnification maps of the entire brain slice, for spatial context, or any other type of high-resolution structural and functional image, together with time-resolved electrical and optical signals. The entire data collection can be visualized within the 3D scene viewer. These concepts can be applied to any other type of experiment in which high-resolution data are recorded within a larger sample at different spatial and temporal coordinates.

  17. Neural Imaginaries and Clinical Epistemology: Rhetorically Mapping the Adolescent Brain in the Clinical Encounter

    Science.gov (United States)

    Buchbinder, Mara

    2014-01-01

    The social work of brain images has taken center stage in recent theorizing of the intersections between neuroscience and society. However, neuroimaging is only one of the discursive modes through which public representations of neurobiology travel. This article adopts an expanded view toward the social implications of neuroscientific thinking to examine how neural imaginaries are constructed in the absence of visual evidence. Drawing on ethnographic fieldwork conducted over 18 months (2008–2009) in a United States multidisciplinary pediatric pain clinic, I examine the pragmatic clinical work undertaken to represent ambiguous symptoms in neurobiological form. Focusing on one physician, I illustrate how, by rhetorically mapping the brain as a therapeutic tool, she engaged in a distinctive form of representation that I call neural imagining. In shifting my focus away from the purely material dimensions of brain images, I juxtapose the cultural work of brain scanning technologies with clinical neural imaginaries in which the teenage brain becomes a space of possibility, not to map things as they are, but rather, things as we hope they might be. These neural imaginaries rely upon a distinctive clinical epistemology that privileges the creative work of the imagination over visualization technologies in revealing the truths of the body. By creating a therapeutic space for adolescents to exercise their imaginative faculties and a discursive template for doing so, neural imagining relocates adolescents’ agency with respect to epistemologies of bodily knowledge and the role of visualization practices therein. In doing so, it provides a more hopeful alternative to the dominant popular and scientific representations of the teenage brain that view it primarily through the lens of pathology. PMID:24780561

  18. Neural imaginaries and clinical epistemology: Rhetorically mapping the adolescent brain in the clinical encounter.

    Science.gov (United States)

    Buchbinder, Mara

    2015-10-01

    The social work of brain images has taken center stage in recent theorizing of the intersections between neuroscience and society. However, neuroimaging is only one of the discursive modes through which public representations of neurobiology travel. This article adopts an expanded view toward the social implications of neuroscientific thinking to examine how neural imaginaries are constructed in the absence of visual evidence. Drawing on ethnographic fieldwork conducted over 18 months (2008-2009) in a United States multidisciplinary pediatric pain clinic, I examine the pragmatic clinical work undertaken to represent ambiguous symptoms in neurobiological form. Focusing on one physician, I illustrate how, by rhetorically mapping the brain as a therapeutic tool, she engaged in a distinctive form of representation that I call neural imagining. In shifting my focus away from the purely material dimensions of brain images, I juxtapose the cultural work of brain scanning technologies with clinical neural imaginaries in which the teenage brain becomes a space of possibility, not to map things as they are, but rather, things as we hope they might be. These neural imaginaries rely upon a distinctive clinical epistemology that privileges the creative work of the imagination over visualization technologies in revealing the truths of the body. By creating a therapeutic space for adolescents to exercise their imaginative faculties and a discursive template for doing so, neural imagining relocates adolescents' agency with respect to epistemologies of bodily knowledge and the role of visualization practices therein. In doing so, it provides a more hopeful alternative to the dominant popular and scientific representations of the teenage brain that view it primarily through the lens of pathology.

  19. Amelioration of cold injury-induced cortical brain edema formation by selective endothelin ETB receptor antagonists in mice.

    Directory of Open Access Journals (Sweden)

    Shotaro Michinaga

    Full Text Available Brain edema is a potentially fatal pathological condition that often occurs in stroke and head trauma. Following brain insults, endothelins (ETs are increased and promote several pathophysiological responses. This study examined the effects of ETB antagonists on brain edema formation and disruption of the blood-brain barrier in a mouse cold injury model (Five- to six-week-old male ddY mice. Cold injury increased the water content of the injured cerebrum, and promoted extravasation of both Evans blue and endogenous albumin. In the injury area, expression of prepro-ET-1 mRNA and ET-1 peptide increased. Intracerebroventricular (ICV administration of BQ788 (ETB antagonist, IRL-2500 (ETB antagonist, or FR139317 (ETA antagonist prior to cold injury significantly attenuated the increase in brain water content. Bolus administration of BQ788, IRL-2500, or FR139317 also inhibited the cold injury-induced extravasation of Evans blue and albumin. Repeated administration of BQ788 and IRL-2500 beginning at 24 h after cold injury attenuated both the increase in brain water content and extravasation of markers. In contrast, FR139317 had no effect on edema formation when administrated after cold injury. Cold injury stimulated induction of glial fibrillary acidic protein-positive reactive astrocytes in the injured cerebrum. Induction of reactive astrocytes after cold injury was attenuated by ICV administration of BQ788 or IRL-2500. These results suggest that ETB receptor antagonists may be an effective approach to ameliorate brain edema formation following brain insults.

  20. Mapping inter-regional connectivity of the entire cortex to characterize major depressive disorder: a whole-brain diffusion tensor imaging tractography study.

    Science.gov (United States)

    Korgaonkar, Mayuresh S; Cooper, Nicholas J; Williams, Leanne M; Grieve, Stuart M

    2012-06-20

    Diffusion tensor imaging (DTI) can be used to study the organization of brain white matter noninvasively. The aim of this study was to present a proof of concept for integrating DTI with high-resolution anatomical (T1) images to map and assess inter-regional connectivity across the entire cortex in a cohort of healthy participants and compared with patients with major depressive disorder. We used MRI data of 23 patients and 23 matched controls, assessed as part of baseline testing in the International Study to Predict Optimized Treatment in Depression (iSPOT-D). Freesurfer was used to analyze the T1 images to automatically label 35 gyral-based areas for each hemisphere. DTI tractography was performed to parcellate intercortical tracts using each of these areas in seed-target combinations. We quantified fractional anisotropy, number-of-fiber connections, and fiber path length for each DTI connection, with the goal of identifying the best measure or combination of measures to characterize major depression. The best classification accuracy for the individual measures was achieved using the number-of-fibers data, whereas the combination model provided a slight improvement. The most discriminant features between the two groups were for white matter associated with the limbic, frontal, and thalamic projection fibers and as part of cortical connections between the left inferior temporal and the postcentral cortex; the left parstriangularis and the left superior frontal; the left cuneus and the corpus callosum; the left lingual and the right lateral occipital, the right superior parietal and the right superior temporal cortices; and the right inferior parietal and the right insula and postcentral cortices.

  1. Predictive timing functions of cortical beta oscillations are impaired in Parkinson's disease and influenced by L-DOPA and deep brain stimulation of the subthalamic nucleus

    Directory of Open Access Journals (Sweden)

    A. Gulberti

    2015-01-01

    Full Text Available Cortex-basal ganglia circuits participate in motor timing and temporal perception, and are important for the dynamic configuration of sensorimotor networks in response to exogenous demands. In Parkinson's disease (PD patients, rhythmic auditory stimulation (RAS induces motor performance benefits. Hitherto, little is known concerning contributions of the basal ganglia to sensory facilitation and cortical responses to RAS in PD. Therefore, we conducted an EEG study in 12 PD patients before and after surgery for subthalamic nucleus deep brain stimulation (STN-DBS and in 12 age-matched controls. Here we investigated the effects of levodopa and STN-DBS on resting-state EEG and on the cortical-response profile to slow and fast RAS in a passive-listening paradigm focusing on beta-band oscillations, which are important for auditory–motor coupling. The beta-modulation profile to RAS in healthy participants was characterized by local peaks preceding and following auditory stimuli. In PD patients RAS failed to induce pre-stimulus beta increases. The absence of pre-stimulus beta-band modulation may contribute to impaired rhythm perception in PD. Moreover, post-stimulus beta-band responses were highly abnormal during fast RAS in PD patients. Treatment with levodopa and STN-DBS reinstated a post-stimulus beta-modulation profile similar to controls, while STN-DBS reduced beta-band power in the resting-state. The treatment-sensitivity of beta oscillations suggests that STN-DBS may specifically improve timekeeping functions of cortical beta oscillations during fast auditory pacing.

  2. Comparison of cortical and white matter traumatic brain injury models reveals differential effects in the subventricular zone and divergent Sonic hedgehog signaling pathways in neuroblasts and oligodendrocyte progenitors.

    Science.gov (United States)

    Mierzwa, Amanda J; Sullivan, Genevieve M; Beer, Laurel A; Ahn, Sohyun; Armstrong, Regina C

    2014-01-01

    The regenerative capacity of the central nervous system must be optimized to promote repair following traumatic brain injury (TBI) and may differ with the site and form of damage. Sonic hedgehog (Shh) maintains neural stem cells and promotes oligodendrogenesis. We examined whether Shh signaling contributes to neuroblast (doublecortin) or oligodendrocyte progenitor (neural/glial antigen 2 [NG2]) responses in two distinct TBI models. Shh-responsive cells were heritably labeled in vivo using Gli1-CreER(T2);R26-YFP bitransgenic mice with tamoxifen administration on Days 2 and 3 post-TBI. Injury to the cerebral cortex was produced with mild controlled cortical impact. Yellow fluorescent protein (YFP) cells decreased in cortical lesions. Total YFP cells increased in the subventricular zone (SVZ), indicating Shh pathway activation in SVZ cells, including doublecortin-labeled neuroblasts. The alternate TBI model produced traumatic axonal injury in the corpus callosum. YFP cells decreased within the SVZ and were rarely double labeled as NG2 progenitors. NG2 progenitors increased in the cortex, with a similar pattern in the corpus callosum. To further test the potential of NG2 progenitors to respond through Shh signaling, Smoothened agonist was microinjected into the corpus callosum to activate Shh signaling. YFP cells and NG2 progenitors increased in the SVZ but were not double labeled. This result indicates that either direct Smoothened activation in NG2 progenitors does not signal through Gli1 or that Smoothened agonist acts indirectly to increase NG2 progenitors. Therefore, in all conditions, neuroblasts exhibited differential Shh pathway utilization compared with oligodendrocyte progenitors. Notably, cortical versus white matter damage from TBI produced opposite responses of Shh-activated cells within the SVZ.

  3. Comparison of Cortical and White Matter Traumatic Brain Injury Models Reveals Differential Effects in the Subventricular Zone and Divergent Sonic Hedgehog Signaling Pathways in Neuroblasts and Oligodendrocyte Progenitors

    Directory of Open Access Journals (Sweden)

    Amanda J. Mierzwa

    2014-09-01

    Full Text Available The regenerative capacity of the central nervous system must be optimized to promote repair following traumatic brain injury (TBI and may differ with the site and form of damage. Sonic hedgehog (Shh maintains neural stem cells and promotes oligodendrogenesis. We examined whether Shh signaling contributes to neuroblast (doublecortin or oligodendrocyte progenitor (neural/glial antigen 2 [NG2] responses in two distinct TBI models. Shh-responsive cells were heritably labeled in vivo using Gli1-CreERT2;R26-YFP bitransgenic mice with tamoxifen administration on Days 2 and 3 post-TBI. Injury to the cerebral cortex was produced with mild controlled cortical impact. Yellow fluorescent protein (YFP cells decreased in cortical lesions. Total YFP cells increased in the subventricular zone (SVZ, indicating Shh pathway activation in SVZ cells, including doublecortin-labeled neuroblasts. The alternate TBI model produced traumatic axonal injury in the corpus callosum. YFP cells decreased within the SVZ and were rarely double labeled as NG2 progenitors. NG2 progenitors increased in the cortex, with a similar pattern in the corpus callosum. To further test the potential of NG2 progenitors to respond through Shh signaling, Smoothened agonist was microinjected into the corpus callosum to activate Shh signaling. YFP cells and NG2 progenitors increased in the SVZ but were not double labeled. This result indicates that either direct Smoothened activation in NG2 progenitors does not signal through Gli1 or that Smoothened agonist acts indirectly to increase NG2 progenitors. Therefore, in all conditions, neuroblasts exhibited differential Shh pathway utilization compared with oligodendrocyte progenitors. Notably, cortical versus white matter damage from TBI produced opposite responses of Shh-activated cells within the SVZ.

  4. Using a hybrid brain computer interface and virtual reality system to monitor and promote cortical reorganization through motor activity and motor imagery training.

    Science.gov (United States)

    Bermúdez i Badia, S; García Morgade, A; Samaha, H; Verschure, P F M J

    2013-03-01

    Stroke is one of the leading causes of adult disability with high economical and societal costs. In recent years, novel rehabilitation paradigms have been proposed to address the life-long plasticity of the brain to regain motor function. We propose a hybrid brain-computer interface (BCI)-virtual reality (VR) system that combines a personalized motor training in a VR environment, exploiting brain mechanisms for action execution and observation, and a neuro-feedback paradigm using mental imagery as a way to engage secondary or indirect pathways to access undamaged cortico-spinal tracts. Furthermore, we present the development and validation experiments of the proposed system. More specifically, EEG data on nine naïve healthy subjects show that a simultaneous motor activity and motor imagery paradigm is more effective at engaging cortical motor areas and related networks to a larger extent. Additionally, we propose a motor imagery driven BCI-VR version of our system that was evaluated with nine different healthy subjects. Data show that users are capable of controlling a virtual avatar in a motor imagery training task that dynamically adjusts its difficulty to the capabilities of the user. User self-report questionnaires indicate enjoyment and acceptance of the proposed system.

  5. Rapid geodesic mapping of brain functional connectivity: implementation of a dedicated co-processor in a field-programmable gate array (FPGA) and application to resting state functional MRI.

    Science.gov (United States)

    Minati, Ludovico; Cercignani, Mara; Chan, Dennis

    2013-10-01

    Graph theory-based analyses of brain network topology can be used to model the spatiotemporal correlations in neural activity detected through fMRI, and such approaches have wide-ranging potential, from detection of alterations in preclinical Alzheimer's disease through to command identification in brain-machine interfaces. However, due to prohibitive computational costs, graph-based analyses to date have principally focused on measuring connection density rather than mapping the topological architecture in full by exhaustive shortest-path determination. This paper outlines a solution to this problem through parallel implementation of Dijkstra's algorithm in programmable logic. The processor design is optimized for large, sparse graphs and provided in full as synthesizable VHDL code. An acceleration factor between 15 and 18 is obtained on a representative resting-state fMRI dataset, and maps of Euclidean path length reveal the anticipated heterogeneous cortical involvement in long-range integrative processing. These results enable high-resolution geodesic connectivity mapping for resting-state fMRI in patient populations and real-time geodesic mapping to support identification of imagined actions for fMRI-based brain-machine interfaces.

  6. Brain-derived neurotrophic factor enhances the basal rate of protein synthesis by increasing active eukaryotic elongation factor 2 levels and promoting translation elongation in cortical neurons.

    Science.gov (United States)

    Takei, Nobuyuki; Kawamura, Mihoko; Ishizuka, Yuta; Kakiya, Naomasa; Inamura, Naoko; Namba, Hisaaki; Nawa, Hiroyuki

    2009-09-25

    The constitutive and activity-dependent components of protein synthesis are both critical for neural function. Although the mechanisms controlling extracellularly induced protein synthesis are becoming clear, less is understood about the molecular networks that regulate the basal translation rate. Here we describe the effects of chronic treatment with various neurotrophic factors and cytokines on the basal rate of protein synthesis in primary cortical neurons. Among the examined factors, brain-derived neurotrophic factor (BDNF) showed the strongest effect. The rate of protein synthesis increased in the cortical tissues of BDNF transgenic mice, whereas it decreased in BDNF knock-out mice. BDNF specifically increased the level of the active, unphosphorylated form of eukaryotic elongation factor 2 (eEF2). The levels of active eEF2 increased and decreased in BDNF transgenic and BDNF knock-out mice, respectively. BDNF decreased kinase activity and increased phosphatase activity against eEF2 in vitro. Additionally, BDNF shortened the ribosomal transit time, an index of translation elongation. In agreement with these results, overexpression of eEF2 enhanced protein synthesis. Taken together, our results demonstrate that the increased level of active eEF2 induced by chronic BDNF stimulation enhances translational elongation processes and increases the total rate of protein synthesis in neurons.

  7. Influence of wiring cost on the large-scale architecture of human cortical connectivity.

    Science.gov (United States)

    Samu, David; Seth, Anil K; Nowotny, Thomas

    2014-04-01

    In the past two decades some fundamental properties of cortical connectivity have been discovered: small-world structure, pronounced hierarchical and modular organisation, and strong core and rich-club structures. A common assumption when interpreting results of this kind is that the observed structural properties are present to enable the brain's function. However, the brain is also embedded into the limited space of the skull and its wiring has associated developmental and metabolic costs. These basic physical and economic aspects place separate, often conflicting, constraints on the brain's connectivity, which must be characterized in order to understand the true relationship between brain structure and function. To address this challenge, here we ask which, and to what extent, aspects of the structural organisation of the brain are conserved if we preserve specific spatial and topological properties of the brain but otherwise randomise its connectivity. We perform a comparative analysis of a connectivity map of the cortical connectome both on high- and low-resolutions utilising three different types of surrogate networks: spatially unconstrained ('random'), connection length preserving ('spatial'), and connection length optimised ('reduced') surrogates. We find that unconstrained randomisation markedly diminishes all investigated architectural properties of cortical connectivity. By contrast, spatial and reduced surrogates largely preserve most properties and, interestingly, often more so in the reduced surrogates. Specifically, our results suggest that the cortical network is less tightly integrated than its spatial constraints would allow, but more strongly segregated than its spatial constraints would necessitate. We additionally find that hierarchical organisation and rich-club structure of the cortical connectivity are largely preserved in spatial and reduced surrogates and hence may be partially attributable to cortical wiring constraints. In contrast

  8. Influence of wiring cost on the large-scale architecture of human cortical connectivity.

    Directory of Open Access Journals (Sweden)

    David Samu

    2014-04-01

    Full Text Available In the past two decades some fundamental properties of cortical connectivity have been discovered: small-world structure, pronounced hierarchical and modular organisation, and strong core and rich-club structures. A common assumption when interpreting results of this kind is that the observed structural properties are present to enable the brain's function. However, the brain is also embedded into the limited space of the skull and its wiring has associated developmental and metabolic costs. These basic physical and economic aspects place separate, often conflicting, constraints on the brain's connectivity, which must be characterized in order to understand the true relationship between brain structure and function. To address this challenge, here we ask which, and to what extent, aspects of the structural organisation of the brain are conserved if we preserve specific spatial and topological properties of the brain but otherwise randomise its connectivity. We perform a comparative analysis of a connectivity map of the cortical connectome both on high- and low-resolutions utilising three different types of surrogate networks: spatially unconstrained ('random', connection length preserving ('spatial', and connection length optimised ('reduced' surrogates. We find that unconstrained randomisation markedly diminishes all investigated architectural properties of cortical connectivity. By contrast, spatial and reduced surrogates largely preserve most properties and, interestingly, often more so in the reduced surrogates. Specifically, our results suggest that the cortical network is less tightly integrated than its spatial constraints would allow, but more strongly segregated than its spatial constraints would necessitate. We additionally find that hierarchical organisation and rich-club structure of the cortical connectivity are largely preserved in spatial and reduced surrogates and hence may be partially attributable to cortical wiring constraints

  9. Brain-wide map of efferent projections from rat barrel cortex

    Directory of Open Access Journals (Sweden)

    Izabela M. Zakiewicz

    2014-02-01

    Full Text Available The somatotopically organized whisker barrel field of the rat primary somatosensory (S1 cortex is a commonly used model system for anatomical and physiological investigations of sensory processing. The neural connections of the barrel cortex have been extensively mapped. But most investigations have focused on connections to limited regions of the brain, and overviews in the literature of the connections across the brain thus build on a range of material from different laboratories, presented in numerous publications. Furthermore, given the limitations of the conventional journal article format, analyses and interpretations are hampered by lack of access to the underlying experimental data. New opportunities for analyses have emerged with the recent release of an online resource of experimental data consisting of collections of high-resolution images from 6 experiments in which anterograde tracers were injected in S1 whisker or forelimb representations. Building on this material, we have conducted a detailed analysis of the brain wide distribution of the efferent projections of the rat barrel cortex. We compare our findings with the available literature and reports accumulated in the Brain Architecture Management System (BAMS2 database. We report well-known and less known intracortical and subcortical projections of the barrel cortex, as well as distinct differences between S1 whisker and forelimb related projections. Our results correspond well with recently published overviews, but provide additional information about relative differences among S1 projection targets. Our approach demonstrates how collections of shared experimental image data are suitable for brain-wide analysis and interpretation of connectivity mapping data.

  10. Automated, highly reproducible, wide-field, light-based cortical mapping method using a commercial stereo microscope and its applications

    Science.gov (United States)

    Jiang, Su; Liu, Ya-Feng; Wang, Xiao-Min; Liu, Ke-Fei; Zhang, Ding-Hong; Li, Yi-Ding; Yu, Ai-Ping; Zhang, Xiao-Hui; Zhang, Jia-Yi; Xu, Jian-Guang; Gu, Yu-Dong; Xu, Wen-Dong; Zeng, Shao-Qun

    2016-01-01

    We introduce a more flexible optogenetics-based mapping system attached on a stereo microscope, which offers automatic light stimulation to individual regions of interest in the cortex that expresses light-activated channelrhodopsin-2 in vivo. Combining simultaneous recording of electromyography from specific forelimb muscles, we demonstrate that this system offers much better efficiency and precision in mapping distinct domains for controlling limb muscles in the mouse motor cortex. Furthermore, the compact and modular design of the system also yields a simple and flexible implementation to different commercial stereo microscopes, and thus could be widely used among laboratories. PMID:27699114

  11. Anatomo-functional study of the temporo-parieto-occipital region: dissection, tractographic and brain mapping evidence from a neurosurgical perspective.

    Science.gov (United States)

    De Benedictis, Alessandro; Duffau, Hugues; Paradiso, Beatrice; Grandi, Enrico; Balbi, Sergio; Granieri, Enrico; Colarusso, Enzo; Chioffi, Franco; Marras, Carlo Efisio; Sarubbo, Silvio

    2014-08-01

    The temporo-parieto-occipital (TPO) junction is a complex brain territory heavily involved in several high-level neurological functions, such as language, visuo-spatial recognition, writing, reading, symbol processing, calculation, self-processing, working memory, musical memory, and face and object recognition. Recent studies indicate that this area is covered by a thick network of white matter (WM) connections, which provide efficient and multimodal integration of information between both local and distant cortical nodes. It is important for neurosurgeons to have good knowledge of the three-dimensional subcortical organisation of this highly connected region to minimise post-operative permanent deficits. The aim of this dissection study was to highlight the subcortical functional anatomy from a topographical surgical perspective. Eight human hemispheres (four left, four right) obtained from four human cadavers were dissected according to Klingler's technique. Proceeding latero-medially, the authors describe the anatomical courses of and the relationships between the main pathways crossing the TPO. The results obtained from dissection were first integrated with diffusion tensor imaging reconstructions and subsequently with functional data obtained from three surgical cases, all resection of infiltrating glial tumours using direct electrical mapping in awake patients. The subcortical limits for performing safe lesionectomies within the TPO region are as follows: within the parietal region, the anterior horizontal part of the superior longitudinal fasciculus and, more deeply, the arcuate fasciculus; dorsally, the vertical projective thalamo-cortical fibres. For lesions located within the temporal and occipital lobes, the resection should be tailored according to the orientation of the horizontal associative pathways (the inferior fronto-occipital fascicle, inferior longitudinal fascicle and optic radiation). The relationships between the WM tracts and the ventricle

  12. Whole-brain quantitative mapping of metabolites using short echo 3D-proton- MRSI

    Science.gov (United States)

    Lecocq, Angèle; Le Fur, Yann; Maudsley, Andrew A; Le Troter, Arnaud; Sheriff, Sulaiman; Sabati, Mohamad; Donnadieu, Maxime; Confort-Gouny, Sylviane; Cozzone, Patrick J.; Guye, Maxime; Ranjeva, Jean-Philippe

    2014-01-01

    Purpose To improve the extent over which whole brain quantitative 3D-MRSI maps can be obtained and be used to explore brain metabolism in a population of healthy volunteers. Materials and Methods Two short TE (20 ms) acquisitions of 3D Echo Planar Spectroscopic Imaging at two orientations, one in the anterior commissure – posterior commissure (AC-PC) plane and the second tilted in the AC-PC +15° plane were obtained at 3T in a group of ten healthy volunteers. B1+, B1−, and B0 correction procedures and normalization of metabolite signals with quantitative water proton density measurements were performed. A combination of the two spatially normalized 3D-MRSI, using a weighted mean based on the pixel wise standard deviation metabolic maps of each orientation obtained from the whole group, provided metabolite maps for each subject allowing regional metabolic profiles of all parcels of the automated anatomical labeling (AAL) atlas to be obtained. Results The combined metabolite maps derived from the two acquisitions reduced the regional inter-subject variance. The numbers of AAL regions showing NAA SD/Mean ratios lower than 30% increased from 17 in the AC-PC orientation and 41 in the AC-PC+15° orientation, to a value of 76 regions out of 116 for the combined NAA maps. Quantitatively, regional differences in absolute metabolite concentrations (mM) over the whole brain were depicted such as in the GM of frontal lobes (cNAA=10.03+1.71, cCho=1.78±0.55, cCr=7.29±1.69; cmIns=5.30±2.67) and in cerebellum (cNAA=5.28±1.77, cCho=1.60±0.41, cCr=6.95±2.15; cmIns=3.60±0.74). Conclusion A double-angulation acquisition enables improved metabolic characterization over a wide volume of the brain. PMID:25431032

  13. Functional brain network organisation of children between 2 and 5 years derived from reconstructed activity of cortical sources of high-density EEG recordings.

    Science.gov (United States)

    Bathelt, Joe; O'Reilly, Helen; Clayden, Jonathan D; Cross, J Helen; de Haan, Michelle

    2013-11-15

    There is increasing interest in applying connectivity analysis to brain measures (Rubinov and Sporns, 2010), but most studies have relied on fMRI, which substantially limits the participant groups and numbers that can be studied. High-density EEG recordings offer a comparatively inexpensive easy-to-use alternative, but require channel-level connectivity analysis which currently lacks a common analytic framework and is very limited in spatial resolution. To address this problem, we have developed a new technique for studies of network development that overcomes the spatial constraint and obtains functional networks of cortical areas by using EEG source reconstruction with age-matched average MRI templates (He et al., 1999). In contrast to previously reported channel-level analysis, this approach provides information about the cortical areas most likely to be involved in the network as well as their functional relationship (Babiloni et al., 2005; De Vico Fallani et al., 2007). In this study, we applied source reconstruction with age-matched templates to task-free high-density EEG recordings in typically-developing children between 2 and 6 years of age (O'Reilly, 2012). Graph theory was then applied to the association strengths of 68 cortical regions of interest based on the Desikan-Killiany atlas. We found linear increases of mean node degree, mean clustering coefficient and maximum betweenness centrality between 2 years and 6 years of age. Characteristic path length was negatively correlated with age. The correlation of the network measures with age indicates network development towards more closely integrated networks similar to reports from other imaging modalities (Fair et al., 2008; Power et al., 2010). We also applied eigenvalue decomposition to obtain functional modules (Clayden et al., 2013). Connection strength within these modules did not change with age, and the modules resembled hub networks previously described for MRI (Hagmann et al., 2010; Power et al

  14. Anisotropy mapping in rat brains using Intermolecular Multiple Quantum Coherence Effects

    CERN Document Server

    Han, Yi

    2014-01-01

    This document reports an unconventional and rapidly developing approach to magnetic resonance imaging (MRI) using intermolecular multiple-quantum coherences (iMQCs). Rat brain images are acquired using iMQCs. We detect iMQCs between spins that are 10 {\\mu}m to 500 {\\mu}m apart. The interaction between spins is dependent on different directions. We can choose the directions on physical Z, Y and X axis by choosing correlation gradients along those directions. As an important application, iMQCs can be used for anisotropy mapping. In the rat brains, we investigate tissue microstructure. We simulated images expected from rat brains without microstructure. We compare those with experimental results to prove that the dipolar field from the overall shape only has small contributions to the experimental iMQC signal. Because of the underlying low signal to noise ratio (SNR) in iMQCs, this anisotropy mapping method still has comparatively large potentials to grow. The ultimate goal of my project is to develop creative a...

  15. Maladaptive Plasticity in Aphasia: Brain Activation Maps Underlying Verb Retrieval Errors

    Directory of Open Access Journals (Sweden)

    Kerstin Spielmann

    2016-01-01

    Full Text Available Anomia, or impaired word retrieval, is the most widespread symptom of aphasia, an acquired language impairment secondary to brain damage. In the last decades, functional neuroimaging techniques have enabled studying the neural basis underlying anomia and its recovery. The present study aimed to explore maladaptive plasticity in persistent verb anomia, in three male participants with chronic nonfluent aphasia. Brain activation maps associated with semantic verb paraphasia occurring within an oral picture-naming task were identified with an event-related fMRI paradigm. These maps were compared with those obtained in our previous study examining adaptive plasticity (i.e., successful verb naming in the same participants. The results show that activation patterns related to semantic verb paraphasia and successful verb naming comprise a number of common areas, contributing to both maladaptive and adaptive neuroplasticity mechanisms. This finding suggests that the segregation of brain areas provides only a partial view of the neural basis of verb anomia and successful verb naming. Therefore, it indicates the importance of network approaches which may better capture the complexity of maladaptive and adaptive neuroplasticity mechanisms in anomia recovery.

  16. Maladaptive Plasticity in Aphasia: Brain Activation Maps Underlying Verb Retrieval Errors

    Science.gov (United States)

    Durand, Edith; Marcotte, Karine; Ansaldo, Ana Inés

    2016-01-01

    Anomia, or impaired word retrieval, is the most widespread symptom of aphasia, an acquired language impairment secondary to brain damage. In the last decades, functional neuroimaging techniques have enabled studying the neural basis underlying anomia and its recovery. The present study aimed to explore maladaptive plasticity in persistent verb anomia, in three male participants with chronic nonfluent aphasia. Brain activation maps associated with semantic verb paraphasia occurring within an oral picture-naming task were identified with an event-related fMRI paradigm. These maps were compared with those obtained in our previous study examining adaptive plasticity (i.e., successful verb naming) in the same participants. The results show that activation patterns related to semantic verb paraphasia and successful verb naming comprise a number of common areas, contributing to both maladaptive and adaptive neuroplasticity mechanisms. This finding suggests that the segregation of brain areas provides only a partial view of the neural basis of verb anomia and successful verb naming. Therefore, it indicates the importance of network approaches which may better capture the complexity of maladaptive and adaptive neuroplasticity mechanisms in anomia recovery. PMID:27429808

  17. Brain abnormalities in bipolar disorder detected by quantitative T1ρ mapping.

    Science.gov (United States)

    Johnson, C P; Follmer, R L; Oguz, I; Warren, L A; Christensen, G E; Fiedorowicz, J G; Magnotta, V A; Wemmie, J A

    2015-02-01

    Abnormal metabolism has been reported in bipolar disorder, however, these studies have been limited to specific regions of the brain. To investigate whole-brain changes potentially associated with these processes, we applied a magnetic resonance imaging technique novel to psychiatric research, quantitative mapping of T1 relaxation in the rotating frame (T1ρ). This method is sensitive to proton chemical exchange, which is affected by pH, metabolite concentrations and cellular density with high spatial resolution relative to alternative techniques such as magnetic resonance spectroscopy and positron emission tomography. Study participants included 15 patients with bipolar I disorder in the euthymic state and 25 normal controls balanced for age and gender. T1ρ maps were generated and compared between the bipolar and control groups using voxel-wise and regional analyses. T1ρ values were found to be elevated in the cerebral white matter and cerebellum in the bipolar group. However, volumes of these areas were normal as measured by high-resolution T1- and T2-weighted magnetic resonance imaging. Interestingly, the cerebellar T1ρ abnormalities were normalized in participants receiving lithium treatment. These findings are consistent with metabolic or microstructural abnormalities in bipolar disorder and draw attention to roles of the cerebral white matter and cerebellum. This study highlights the potential utility of high-resolution T1ρ mapping in psychiatric research.

  18. Statistical parametric mapping in brain single photon computed emission tomography after carbon monoxide intoxication.

    Science.gov (United States)

    Watanabe, N; Nohara, S; Matsuda, H; Sumiya, H; Noguchi, K; Shimizu, M; Tsuji, S; Kinuya, S; Shuke, N; Yokoyama, K; Seto, H

    2002-04-01

    The purpose of this retrospective study was to assess regional cerebral blood flow in patients after carbon monoxide intoxication by using brain single photon emission computed tomography and statistical parametric mapping. Eight patients with delayed neuropsychiatric sequelae and ten patients with no neuropsychiatric symptoms after carbon monoxide intoxication were studied with brain single photon emission tomography imaging with 99mTc-hexamethyl-propyleneamine oxime. Forty-four control subjects were also studied. We used the adjusted regional cerebral blood flow images in relative flow distribution (normalization of global cerebral blood flow for each subject to 50 ml x 100 g(-1) x min(-1) with proportional scaling) to compare these groups with statistical parametric mapping. Using this technique, significantly decreased regional cerebral blood flow was noted extensively in the bilateral frontal lobes as well as the bilateral insula and a part of the right temporal lobe in the patients with delayed neuropsychiatric sequelae as compared with normal volunteers (Pparametric mapping is a useful technique for highlighting differences in regional cerebral blood flow in patients following carbon monoxide intoxication as compared with normal volunteers. The selectively reduced blood flow noted in this investigation supports the contention that the decrease following carbon monoxide intoxication may be prolonged and further worsen in the frontal lobe. In addition, the present study may help to clarify the characteristics of the pathophysiological alteration underlying delayed neuropsychiatric sequelae.

  19. Broadcasting of cortical activity to the olfactory bulb.

    Science.gov (United States)

    Boyd, Alison M; Kato, Hiroyuki K; Komiyama, Takaki; Isaacson, Jeffry S

    2015-02-24

    Odor representations are initially formed in the olfactory bulb, which contains a topographic glomerular map of odor molecular features. The bulb transmits sensory information directly to piriform cortex, where it is encoded by distributed ensembles of pyramidal cells without spatial order. Intriguingly, piriform cortex pyramidal cells project back to the bulb, but the information contained in this feedback projection is unknown. Here, we use imaging in awake mice to directly monitor activity in the presynaptic boutons of cortical feedback fibers. We show that the cortex provides the bulb with a rich array of information for any individual odor and that cortical feedback is dependent on brain state. In contrast to the stereotyped, spatial arrangement of olfactory bulb glomeruli, cortical inputs tuned to different odors commingle and indiscriminately target individual glomerular channels. Thus, the cortex modulates early odor representations by broadcasting sensory information diffusely onto spatially ordered bulbar circuits.

  20. Different uptake of 99mTc-ECD adn 99mTc-HMPAO in the same brains: analysis by statistical parametric mapping.

    Science.gov (United States)

    Hyun, Y; Lee, J S; Rha, J H; Lee, I K; Ha, C K; Lee, D S

    2001-02-01

    The purpose of this study was to investigate the differences between technetium-99m ethyl cysteinate dimer (99mTc-ECD) and technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) uptake in the same brains by means of statistical parametric mapping (SPM) analysis. We examined 20 patients (9 male, 11 female, mean age 62+/-12 years) using 99mTc-ECD and 99mTc-HMPAO single-photon emission tomography (SPET) and magnetic resonance imaging (MRI) of the brain less than 7 days after onset of stroke. MRI showed no cortical infarctions. Infarctions in the pons (6 patients) and medulla (1), ischaemic periventricular white matter lesions (13) and lacunar infarction (7) were found on MRI. Split-dose and sequential SPET techniques were used for 99mTc-ECD and 99mTc-HMPAO brain SPET, without repositioning of the patient. All of the SPET images were spatially transformed to standard space, smoothed and globally normalized. The differences between the 99mTc-ECD and 99mTc-HMPAO SPET images were statistically analysed using statistical parametric mapping (SPM) 96 software. The difference between two groups was considered significant at a threshold of uncorrected P values less than 0.01. Visual analysis showed no hypoperfused areas on either 99mTc-ECD or 99mTc-HMPAO SPET images. SPM analysis revealed significantly different uptake of 99mTc-ECD and 99mTc-HMPAO in the same brains. On the 99mTc-ECD SPET images, relatively higher uptake was observed in the frontal, parietal and occipital lobes, in the left superior temporal lobe and in the superior region of the cerebellum. On the 99mTc-HMPAO SPET images, relatively higher uptake was observed in the medial temporal lobes, thalami, periventricular white matter and brain stem. These differences in uptake of the two tracers in the same brains on SPM analysis suggest that interpretation of cerebral perfusion is possible using SPET with 99mTc-ECD and 99mTc-HMPAO.

  1. Different uptake of {sup 99m}Tc-ECD and {sup 99m}Tc-HMPAO in the same brains: analysis by statistical parametric mapping

    Energy Technology Data Exchange (ETDEWEB)

    Hyun, I.Y. [Dept. of Nuclear Medicine, Inha University College of Medicine, Incheon (Korea); Lee, J.S.; Lee, D.S. [Dept. of Nuclear Medicine, Seoul National University College of Medicine, Seoul (Korea); Rha, J.H.; Lee, I.K.; Ha, C.K. [Dept. of Neurology, Inha University College of Medicine, Incheon (Korea)

    2001-02-01

    The purpose of this study was to investigate the differences between technetium-99m ethyl cysteinate dimer ({sup 99m}Tc-ECD) and technetium-99m hexamethylpropylene amine oxime ({sup 99m}Tc-HMPAO) uptake in the same brains by means of statistical parametric mapping (SPM) analysis. We examined 20 patients (9 male, 11 female, mean age 62{+-}12 years) using {sup 99m}Tc-ECD and {sup 99m}Tc-HMPAO single-photon emission tomography (SPET) and magnetic resonance imaging (MRI) of the brain less than 7 days after onset of stroke. MRI showed no cortical infarctions. Infarctions in the pons (6 patients) and medulla (1), ischaemic periventricular white matter lesions (13) and lacunar infarction (7) were found on MRI. Split-dose and sequential SPET techniques were used for {sup 99m}Tc-ECD and {sup 99m}Tc-HMPAO brain SPET, without repositioning of the patient. All of the SPET images were spatially transformed to standard space, smoothed and globally normalized. The differences between the {sup 99m}Tc-ECD and {sup 99m}Tc-HMPAO SPET images were statistically analysed using statistical parametric mapping (SPM) 96 software. The difference between two groups was considered significant at a threshold of uncorrected P values less than 0.01. Visual analysis showed no hypoperfused areas on either {sup 99m}Tc-ECD or {sup 99m}Tc-HMPAO SPET images. SPM analysis revealed significantly different uptake of {sup 99m}Tc-ECD and {sup 99m}Tc-HMPAO in the same brains. On the {sup 99m}Tc-ECD SPET images, relatively higher uptake was observed in the frontal, parietal and occipital lobes, in the left superior temporal lobe and in the superior region of the cerebellum. On the {sup 99m}Tc-HMPAO SPET images, relatively higher uptake was observed in the medial temporal lobes, thalami, periventricular white matter and brain stem. These differences in uptake of the two tracers in the same brains on SPM analysis suggest that interpretation of cerebral perfusion is possible using SPET with {sup 99m}Tc-ECD and

  2. Mapping brain morphological and functional conversion patterns in predementia late-onset bvFTD

    Energy Technology Data Exchange (ETDEWEB)

    Morbelli, Silvia; Fiz, Francesco; Bossert, Irene; Buschiazzo, Ambra; Picori, Lorena; Sambuceti, Gianmario [University of Genoa and IRCCS AOU San Martino-IST, Nuclear Medicine Unit, Department of Health Science (DISSAL), Genoa (Italy); Ferrara, Michela; Dessi, Barbara; Arnaldi, Dario; Picco, Agnese; Accardo, Jennifer; Nobili, Flavio [University of Genoa and IRCCS AOU San Martino-IST, Clinical Neurology, Department of Neuroscience (DINOGMI), Genoa (Italy); Girtler, Nicola [University of Genoa and IRCCS AOU San Martino-IST, Clinical Neurology, Department of Neuroscience (DINOGMI), Genoa (Italy); University of Genoa and IRCCS AOU San Martino-IST, Clinical Psychology, Department of Neuroscience (DINOGMI), Genoa (Italy); Mandich, Paola [University of Genoa and IRCCS AOU San Martino-IST, Medical Genetics, Department of Neuroscience (DINOGMI), Genoa (Italy); Pagani, Marco [Institute of Cognitive Sciences and Technologies, CNR, Rome (Italy); Karolinska Hospital, Department of Nuclear Medicine, Stockholm (Sweden)

    2016-07-15

    The diagnosis of behavioural variant frontotemporal dementia (bvFTD) is challenging during the predementia stage when symptoms are subtle and confounding. Morphological and functional neuroimaging can be particularly helpful during this stage but few data are available. We retrospectively selected 25 patients with late-onset probable bvFTD. Brain structural MRI and FDG PET were performed during the predementia stage (mean MMSE score 27.1 ± 2.5) on average 2 years before. The findings with the two imaging modalities were compared (SPM8) with those in a group of 20 healthy subjects. The bvFTD patients were divided into two subgroups: those with predominant disinhibition (bvFTD+) and those with apathy (bvFTD-). Hypometabolism exceeded grey matter (GM) density reduction in terms of both extension and statistical significance in all comparisons. In the whole bvFTD group, hypometabolism involved the bilateral medial, inferior and superior lateral frontal cortex, anterior cingulate, left temporal and right parietal cortices and the caudate nuclei. GM density reduction was limited to the right frontal cortex and the left medial temporal lobe. In bvFTD+ patients hypometabolism was found in the bilateral medial and basal frontal cortex, while GM reduction involved the left anterior cingulate and left inferior frontal cortices, and the right insula. In bvFTD- patients, atrophy and mainly hypometabolism involved the lateral frontal cortex and the inferior parietal lobule. These findings suggest that hypometabolism is more extensive than, and thus probably precedes, atrophy in predementia late-onset bvFTD, underscoring different topographic involvement in disinhibited and apathetic presentations. If confirmed in a larger series, these results should prompt biomarker operationalization in bvFTD, especially for patient selection in therapeutic clinical trials. (orig.)

  3. GRIN2B Gene and Associated Brain Cortical White Matter Changes in Bipolar Disorder: A Preliminary Combined Platform Investigation

    Directory of Open Access Journals (Sweden)

    Carissa Nadia Kuswanto

    2013-01-01

    Full Text Available Abnormalities in glutamate signaling and glutamate toxicity are thought to be important in the pathophysiology of bipolar disorder (BD. Whilst previous studies have found brain white matter changes in BD, there is paucity of data about how glutamatergic genes affect brain white matter integrity in BD. Based on extant neuroimaging data, we hypothesized that GRIN2B risk allele is associated with reductions of brain white matter integrity in the frontal, parietal, temporal, and occipital regions and cingulate gyrus in BD. Fourteen patients with BD and 22 healthy controls matched in terms of age, gender and handedness were genotyped using blood samples and underwent diffusion tensor imaging. Compared to G allele, brain FA values were significantly lower in BD patients with risk T allele in left frontal region (P=0.001, right frontal region (P=0.002, left parietal region (P=0.001, left occipital region (P=0.001, right occipital region (P<0.001, and left cingulate gyrus (P=0.001. Further elucidation of the interactions between different glutamate genes and their relationships with such structural, functional brain substrates will enhance our understanding of the link between dysregulated glutamatergic neurotransmission and neuroimaging endophenotypes in BD.

  4. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy.

    Science.gov (United States)

    Shakespeare, Timothy J; Kaski, Diego; Yong, Keir X X; Paterson, Ross W; Slattery, Catherine F; Ryan, Natalie S; Schott, Jonathan M; Crutch, Sebastian J

    2015-07-01

    The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal 'visual dementia' and most common atypical Alzheimer's disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation and basic visual phenomena (e.g. visual crowding). Given the extensive attention paid to patients' (higher order) perceptual function, it is surprising that there have been no systematic analyses of basic oculomotor function in this population. Here 20 patients with posterior cortical atrophy, 17 patients with typical Alzheimer's disease and 22 healthy controls completed tests of fixation, saccade (including fixation/target gap and overlap conditions) and smooth pursuit eye movements using an infrared pupil-tracking system. Participants underwent detailed neuropsychological and neurological examinations, with a proportion also undertaking brain imaging and analysis of molecular pathology. In contrast to informal clinical evaluations of oculomotor dysfunction frequency (previous studies: 38%, current clinical examination: 33%), detailed eyetracking investigations revealed eye movement abnormalities in 80% of patients with posterior cortical atrophy (compared to 17% typical Alzheimer's disease, 5% controls). The greatest differences between posterior cortical atrophy and typical Alzheimer's disease were seen in saccadic performance. Patients with posterior cortical atrophy made significantly shorter saccades especially for distant targets. They also exhibited a significant exacerbation of the normal gap/overlap effect, consistent with 'sticky fixation'. Time to reach saccadic targets was significantly associated with parietal and occipital cortical thickness measures. On fixation stability tasks, patients with typical Alzheimer's disease showed more square wave jerks whose frequency was associated with lower cerebellar grey matter volume, while patients with posterior cortical atrophy showed large saccadic intrusions

  5. From Brain Maps to Cognitive Ontologies: Informatics and the Search for Mental Structure.

    Science.gov (United States)

    Poldrack, Russell A; Yarkoni, Tal

    2016-01-01

    A major goal of cognitive neuroscience is to delineate how brain systems give rise to mental function. Here we review the increasingly large role informatics-driven approaches are playing in such efforts. We begin by reviewing a number of challenges conventional neuroimaging approaches face in trying to delineate brain-cognition mappings--for example, the difficulty in establishing the specificity of postulated associations. Next, we demonstrate how these limitations can potentially be overcome using complementary approaches that emphasize large-scale analysis--including meta-analytic methods that synthesize hundreds or thousands of studies at a time; latent-variable approaches that seek to extract structure from data in a bottom-up manner; and predictive modeling approaches capable of quantitatively inferring mental states from patterns of brain activity. We highlight the underappreciated but critical role for formal cognitive ontologies in helping to clarify, refine, and test theories of brain and cognitive function. Finally, we conclude with a speculative discussion of what future informatics developments may hold for cognitive neuroscience.

  6. Mapping causal functional contributions derived from the clinical assessment of brain damage after stroke.

    Science.gov (United States)

    Zavaglia, Melissa; Forkert, Nils D; Cheng, Bastian; Gerloff, Christian; Thomalla, Götz; Hilgetag, Claus C

    2015-01-01

    Lesion analysis reveals causal contributions of brain regions to mental functions, aiding the understanding of normal brain function as well as rehabilitation of brain-damaged patients. We applied a novel lesion inference technique based on game theory, Multi-perturbation Shapley value Analysis (MSA), to a large clinical lesion dataset. We used MSA to analyze the lesion patterns of 148 acute stroke patients together with their neurological deficits, as assessed by the National Institutes of Health Stroke Scale (NIHSS). The results revealed regional functional contributions to essential behavioral and cognitive functions as reflected in the NIHSS, particularly by subcortical structures. There were also side specific differences of functional contributions between the right and left hemispheric brain regions which may reflect the dominance of the left hemispheric syndrome aphasia in the NIHSS. Comparison of MSA to established lesion inference methods demonstrated the feasibility of the approach for analyzing clinical data and indicated its capability for objectively inferring functional contributions from multiple injured, potentially interacting sites, at the cost of having to predict the outcome of unknown lesion configurations. The analysis of regional functional contributions to neurological symptoms measured by the NIHSS contributes to the interpretation of this widely used standardized stroke scale in clinical practice as well as clinical trials and provides a first approximation of a 'map of stroke'.

  7. Building a 5-HT3A Receptor Expression Map in the Mouse Brain

    Science.gov (United States)

    Koyama, Yoshihisa; Kondo, Makoto; Shimada, Shoichi

    2017-01-01

    Of the many serotonin receptors, the type 3 receptors (5-HT3R) are the only ionotropic ones, playing a key role in fast synaptic transmission and cognitive and emotional brain function through controlled neuronal excitation. To better understand the various functions of 5-HT3Rs, it is very important to know their expression pattern in the central nervous system (CNS). To date, many distributional studies have shown localized 5-HT3R expression in the brain and spinal cord. However, an accurate pattern of 5-HT3R expression in the CNS remains to be elucidated. To investigate the distribution of 5-HT3R in the mouse brain in detail, we performed immunofluorescent staining using 5-HT3AR-GFP transgenic mice. We found strong 5-HT3AR expression in the olfactory bulb, cerebral cortex, hippocampus, and amygdala; and partial expression in the pons, medulla, and spinal cord. Meanwhile, the thalamus, hypothalamus, and midbrain exhibited a few 5-HT3AR-expressing cells, and no expression was detected in the cerebellum. Further, double-immunostaining using neural markers confirmed that 5-HT3AR is expressed in GABAergic interneurons containing somatostatin or calretinin. In the present study, we built a 5-HT3AR expression map in the mouse brain. Our findings make significant contributions in elucidating the novel functions of 5-HT3R in the CNS. PMID:28276429

  8. INHERITED NEURODEVELOPMENTAL BRAIN DISEASES: APPLICATIONS OF HOMOZYGOSITY MAPPING TO IDENTIFY NEW GENETIC CAUSES OF DISEASE

    Directory of Open Access Journals (Sweden)

    Joseph G. Gleeson

    2008-06-01

    Full Text Available ObjectiveThe last two decades have seen major advancements in our understanding of some of the most common neurodevelopmental disorders in the field of child neurology. However, in the majority of individual patients, it is still not possible to arrive at a molecular diagnosis, due in part to lack of knowledge ofmolecular causes of these tremendously complex conditions. Common genetic disorders of brain development include septo-optic dysplasia, schizencephaly, holoprosencephaly, lissencephaly and hindbrain malformations. For each of these disorders, a critical step in brain development is disrupted. Specific genetic diagnosis is now possible in some patients with most of these conditions. For the remaining patients, it is possible to apply gene-mapping strategies using newly developed high-density genomic arrays to clone novel genes. This is especially important in countries like Iran where large family size and marriage between relatives makes these strategies tremendously powerful.

  9. Neurotransmitter Specific, Cellular-Resolution Functional Brain Mapping Using Receptor Coated Nanoparticles: Assessment of the Possibility

    Science.gov (United States)

    Forati, Ebrahim; Sabouni, Abas; Ray, Supriyo; Head, Brian; Schoen, Christian; Sievenpiper, Dan

    2015-01-01

    Receptor coated resonant nanoparticles and quantum dots are proposed to provide a cellular-level resolution image of neural activities inside the brain. The functionalized nanoparticles and quantum dots in this approach will selectively bind to different neurotransmitters in the extra-synaptic regions of neurons. This allows us to detect neural activities in real time by monitoring the nanoparticles and quantum dots optically. Gold nanoparticles (GNPs) with two different geometries (sphere and rod) and quantum dots (QDs) with different sizes were studied along with three different neurotransmitters: dopamine, gamma-Aminobutyric acid (GABA), and glycine. The absorption/emission spectra of GNPs and QDs before and after binding of neurotransmitters and their corresponding receptors are reported. The results using QDs and nanorods with diameter 25nm and aspect rations larger than three were promising for the development of the proposed functional brain mapping approach. PMID:26717196

  10. [Cortical blindness].

    Science.gov (United States)

    Chokron, S

    2014-02-01

    Cortical blindness refers to a visual loss induced by a bilateral occipital lesion. The very strong cooperation between psychophysics, cognitive psychology, neurophysiology and neuropsychology these latter twenty years as well as recent progress in cerebral imagery have led to a better understanding of neurovisual deficits, such as cortical blindness. It thus becomes possible now to propose an earlier diagnosis of cortical blindness as well as new perspectives for rehabilitation in children as well as in adults. On the other hand, studying complex neurovisual deficits, such as cortical blindness is a way to infer normal functioning of the visual system.

  11. How the human brain goes virtual: distinct cortical regions of the person-processing network are involved in self-identification with virtual agents.

    Science.gov (United States)

    Ganesh, Shanti; van Schie, Hein T; de Lange, Floris P; Thompson, Evan; Wigboldus, Daniël H J

    2012-07-01

    Millions of people worldwide engage in online role-playing with their avatar, a virtual agent that represents the self. Previous behavioral studies have indicated that many gamers identify more strongly with their avatar than with their biological self. Through their avatar, gamers develop social networks and learn new social-cognitive skills. The cognitive neurosciences have yet to identify the neural processes that underlie self-identification with these virtual agents. We applied functional neuroimaging to 22 long-term online gamers and 21 nongaming controls, while they rated personality traits of self, avatar, and familiar others. Strikingly, neuroimaging data revealed greater avatar-referential cortical activity in the left inferior parietal lobe, a region associated with self-identification from a third-person perspective. The magnitude of this brain activity correlated positively with the propensity to incorporate external body enhancements into one's bodily identity. Avatar-referencing furthermore recruited greater activity in the rostral anterior cingulate gyrus, suggesting relatively greater emotional self-involvement with one's avatar. Post-scanning behavioral data revealed superior recognition memory for avatar relative to others. Interestingly, memory for avatar positively covaried with play duration. These findings significantly advance our knowledge about the brain's plasticity to self-identify with virtual agents and the human cognitive-affective potential to live and learn in virtual worlds.

  12. Quantitative Susceptibility Mapping Indicates a Disturbed Brain Iron Homeostasis in Neuromyelitis Optica – A Pilot Study

    Science.gov (United States)

    Granado, Vanessa; Rueda, Fernanda; Deistung, Andreas; Reichenbach, Juergen R.; Tukamoto, Gustavo; Gasparetto, Emerson Leandro; Schweser, Ferdinand

    2016-01-01

    Dysregulation of brain iron homeostasis is a hallmark of many neurodegenerative diseases and can be associated with oxidative stress. The objective of this study was to investigate brain iron in patients with Neuromyelitis Optica (NMO) using quantitative susceptibility mapping (QSM), a quantitative iron-sensitive MRI technique. 12 clinically confirmed NMO patients (6 female and 6 male; age 35.4y±14.2y) and 12 age- and sex-matched healthy controls (7 female and 5 male; age 33.9±11.3y) underwent MRI of the brain at 3 Tesla. Quantitative maps of the effective transverse relaxation rate (R2*) and magnetic susceptibility were calculated and a blinded ROI-based group comparison analysis was performed. Normality of the data and differences between patients and controls were tested by Kolmogorov-Smirnov and t-test, respectively. Correlation with age was studied using Spearman’s rank correlation and an ANCOVA-like analysis. Magnetic susceptibility values were decreased in the red nucleus (p0.95; between -15 and -22 ppb depending on reference region) with a trend toward increasing differences with age. R2* revealed significantly decreased relaxation in the optic radiations of five of the 12 patients (p<0.0001; -3.136±0.567 s-1). Decreased relaxation in the optic radiation is indicative for demyelination, which is in line with previous findings. Decreased magnetic susceptibility in the red nucleus is indicative for a lower brain iron concentration, a chemical redistribution of iron into less magnetic forms, or both. Further investigations are necessary to elucidate the pathological cause or consequence of this finding. PMID:27171423

  13. Whole-brain mapping of inputs to projection neurons and cholinergic interneurons in the dorsal striatum.

    Science.gov (United States)

    Guo, Qingchun; Wang, Daqing; He, Xiaobin; Feng, Qiru; Lin, Rui; Xu, Fuqiang; Fu, Ling; Luo, Minmin

    2015-01-01

    The dorsal striatum integrates inputs from multiple brain areas to coordinate voluntary movements, associative plasticity, and reinforcement learning. Its projection neurons consist of the GABAergic medium spiny neurons (MSNs) that express dopamine receptor type 1 (D1) or dopamine receptor type 2 (D2). Cholinergic interneurons account for a small portion of striatal neuron populations, but they play important roles in striatal functions by synapsing onto the MSNs and other local interneurons. By combining the modified rabies virus with specific Cre- mouse lines, a recent study mapped the monosynaptic input patterns to MSNs. Because only a small number of extrastriatal neurons were labeled in the prior study, it is important to reexamine the input patterns of MSNs with higher labeling efficiency. Additionally, the whole-brain innervation pattern of cholinergic interneurons remains unknown. Using the rabies virus-based transsynaptic tracing method in this study, we comprehensively charted the brain areas that provide direct inputs to D1-MSNs, D2-MSNs, and cholinergic interneurons in the dorsal striatum. We found that both types of projection neurons and the cholinergic interneurons receive extensive inputs from discrete brain areas in the cortex, thalamus, amygdala, and other subcortical areas, several of which were not reported in the previous study. The MSNs and cholinergic interneurons share largely common inputs from areas outside the striatum. However, innervations within the dorsal striatum represent a significantly larger proportion of total inputs for cholinergic interneurons than for the MSNs. The comprehensive maps of direct inputs to striatal MSNs and cholinergic interneurons shall assist future functional dissection of the striatal circuits.

  14. Breaches of the pial basement membrane and disappearance of the glia limitans during development underlie the cortical lamination defect in the mouse model of muscle-eye-brain disease.

    Science.gov (United States)

    Hu, Huaiyu; Yang, Yuan; Eade, Amber; Xiong, Yufang; Qi, Yue

    2007-05-10

    Neuronal overmigration is the underlying cellular mechanism of cerebral cortical malformations in syndromes of congenital muscular dystrophies caused by defects in O-mannosyl glycosylation. Overmigration involves multiple developmental abnormalities in the brain surface basement membrane, Cajal-Retzius cells, and radial glia. We tested the hypothesis that breaches in basement membrane and the underlying glia limitans are the key initial events of the cellular pathomechanisms by carrying out a detailed developmental study with a mouse model of muscle-eye-brain disease, mice deficient in O-mannose beta1,2-N-acetylglucosaminyltransferase 1 (POMGnT1). The pial basement membrane was normal in the knockout mouse at E11.5. It was breached during rapid cerebral cortical expansion at E13.5. Radial glial endfeet, which comprise glia limitans, grew out of the neural boundary. Neurons moved out of the neural boundary through these breaches. The overgrown radial glia and emigrated neurons disrupted the overlying pia mater. The overmigrated neurons did not participate in cortical plate (CP) development; rather they formed a diffuse cell zone (DCZ) outside the original cortical boundary. Together, the DCZ and the CP formed the knockout cerebral cortex, with disappearance of the basement membrane and the glia limitans. These results suggest that disappearance of the basement membrane and the glia limitans at the cerebral cortical surface during development underlies cortical lamination defects in congenital muscular dystrophies and a cellular mechanism of cortical malformation distinct from that of the reeler mouse, double cortex syndrome, and periventricular heterotopia.

  15. Brain-Map Based Carangiform Swimming Behaviour Modeling and Control in a Robotic Fish Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Abhra Roy Chowdhury

    2015-05-01

    Full Text Available Fish swimming demonstrates impressive speeds and exceptional characteristics in the fluid environment. The objective of this paper is to mimic undulatory swimming behaviour and its control of a body caudal fin (BCF carangiform fish in a robotic counterpart. Based on fish biology kinematics study, a 2-level behavior based distributed control scheme is proposed. The high-level control is modeled by robotic fish swimming behavior. It uses a Lighthill (LH body wave to generate desired joint trajectory patterns. Generated LH body wave is influenced by intrinsic kinematic parameters Tail-beat frequency (TBF and Caudal amplitude (CA which can be modulated to change the trajectory pattern. Parameter information is retrieved from a fish memory (cerebellum inspired brain map. This map stores operating region information on TBF and CA parameters obtained from yellow fin tuna kinematics study. Based on an environment based error feedback signal, robotic fish map selects the right parameter/s value showing adaptive behaviour. A finite state machine methodology has been used to model this brain-kinematic-map control. The low-level control is implemented using inverse dynamics based computed torque method (CTM with dynamic PD compensation. It tracks high-level generated and encoded patterns (trajectory for fish-tail undulation. Three types of parameter adaptation for the two chosen parameters have been shown to successfully emulate robotic fish swimming behavior. Based on the proposed control strategy joint-position and velocity tracking results are discussed. They are found to be satisfactory with error magnitudes within permissible bounds.

  16. Contralateral Cortical Organisation of Information in Visual Short-Term Memory: Evidence from Lateralized Brain Activity during Retrieval

    Science.gov (United States)

    Fortier-Gauthier, Ulysse; Moffat, Nicolas; Dell'Acqua, Robert; McDonald, John J.; Jolicoeur, Pierre

    2012-01-01

    We studied brain activity during retention and retrieval phases of two visual short-term memory (VSTM) experiments. Experiment 1 used a balanced memory array, with one color stimulus in each hemifield, followed by a retention interval and a central probe, at the fixation point that designated the target stimulus in memory about which to make a…

  17. Variation in the topography of the speech production cortex verified by cortical stimulation and high gamma activity.

    Science.gov (United States)

    Babajani-Feremi, Abbas; Rezaie, Roozbeh; Narayana, Shalini; Choudhri, Asim F; Fulton, Stephen P; Boop, Frederick A; Wheless, James W; Papanicolaou, Andrew C

    2014-12-17

    In this study, we have addressed the question of functional brain reorganization for language in the presence and absence of anatomical lesions in two patients with epilepsy using cortical stimulation mapping and high gamma (HG) activity in subdural grid recordings. In both, the expressive language cortex was defined as the cortical patch below the electrode(s) that when stimulated resulted in speech arrest, and during speech expression tasks generated HG activity. This patch fell within the borders of Broca's area, as defined anatomically, in the case of the patient with a lesion, but outside that area in the other, lesion-free patient. Such results highlight the necessity for presurgical language mapping in all cases of surgery involving the language-dominant hemisphere and suggest that HG activity during expressive language tasks can be informative and helpful in conjunction with cortical stimulation mapping for expressive language mapping.

  18. Divergent temporal expression of hyaluronan metabolizing enzymes and receptors with craniotomy vs. controlled cortical impact injury in rat brain: A pilot study

    Directory of Open Access Journals (Sweden)

    Guoqiang eXing

    2014-09-01

    Full Text Available Traumatic brain injury triggers many secondary changes in tissue biology which ultimately determine the extent of injury and clinical outcome. Hyaluronan (hyaluronic acid, HA is a protective cementing gel present in the intercellular spaces whose degradation has been reported as a causative factor in tissue damage. Yet little is known about the expression and activities of genes involved in HA catabolism after TBI. Young adult male Sprague-Dawley rats were assigned to three groups: naïve control, craniotomy and, controlled-cortical impact-induced TBI (CCI-TBI. Four animals per group were sacrificed at 4h, 1d, 3d and 7d post CCI. The mRNA expression of hyaluronan synthases (HAS1-3, hyaluronidases (enzymes for HA degradation, HYAL 1-4 & PH20 and CD44 and RHAMM (membrane receptors for HA signaling and removal were determined using real-time PCR. Compared to the naïve controls, expression of HAS1 and HAS2 mRNA, but not HAS3 mRNA increased significantly following craniotomy alone and following CCI with differential kinetics. Expression of HAS2 mRNA increased significantly in the ipsilateral brain at 1d and 3d post CCI. HYAL1 mRNA expression also increased significantly in the craniotomy group and in the contralateral CCI at 1d and 3d post CCI. CD44 mRNA expression increased significantly in the ipsilateral CCI at 4h, 1d, 3d and 7d post CCI (up to 25 fold increase. These data suggest a dynamic regulation and role for HA metabolism in secondary responses to traumatic brain injury.

  19. Mapping between Language-object and Brain%语言-事物与大脑之间的映射

    Institute of Scientific and Technical Information of China (English)

    闫以聪

    2016-01-01

    Applying the ideas of topology,assuming that language space L set the mapping between ob-ject space A and the brain space B:L:A→B and its inverse mapping L:B→A.Then separately research map-ping L and inverse mapping L to conduce space constructed by brain nerve information unit.%应用拓扑学思想,假设由事物或事件单位构成的空间A与大脑神经信息单位构成的空间B之间,通过语言空间L建立了映射L:A→B和它的逆映射L-1:B→A。将映射空间L和它的逆L-1单独取出进行研究,借以推导大脑神经信息单位构成的空间。

  20. Associations between cortical thickness and general intelligence in children, adolescents and young adults.

    Science.gov (United States)

    Menary, Kyle; Collins, Paul F; Porter, James N; Muetzel, Ryan; Olson, Elizabeth A; Kumar, Vipin; Steinbach, Michael; Lim, Kelvin O; Luciana, Monica

    2013-09-01

    Neuroimaging research indicates that human intellectual ability is related to brain structure including the thickness of the cerebral cortex. Most studies indicate that general intelligence is positively associated with cortical thickness in areas of association cortex distributed throughout both brain hemispheres. In this study, we performed a cortical thickness mapping analysis on data from 182 healthy typically developing males and females ages 9 to 24 years to identify correlates of general intelligence (g) scores. To determine if these correlates also mediate associations of specific cognitive abilities with cortical thickness, we regressed specific cognitive test scores on g scores and analyzed the residuals with respect to cortical thickness. The effect of age on the association between cortical thickness and intelligence was examined. We found a widely distributed pattern of positive associations between cortical thickness and g scores, as derived from the first unrotated principal factor of a factor analysis of Wechsler Abbreviated Scale of Intelligence (WASI) subtest scores. After WASI specific cognitive subtest scores were regressed on g factor scores, the residual score variances did not correlate significantly with cortical thickness in the full sample with age covaried. When participants were grouped at the age median, significant positive associations of cortical thickness were obtained in the older group for g-residualized scores on Block Design (a measure of visual-motor integrative processing) while significant negative associations of cortical thickness were observed in the younger group for g-residualized Vocabulary scores. These results regarding correlates of general intelligence are concordant with the existing literature, while the findings from younger versus older subgroups have implications for future research on brain structural correlates of specific cognitive abilities, as well as the cognitive domain specificity of behavioral

  1. Development of post-traumatic epilepsy after controlled cortical impact and lateral fluid-percussion-induced brain injury in the mouse.

    Science.gov (United States)

    Bolkvadze, Tamuna; Pitkänen, Asla

    2012-03-20

    The present study investigated the development of hyperexcitability and epilepsy in mice with traumatic brain injury (TBI) induced by controlled cortical impact (CCI) or lateral fluid-percussion injury (FPI), which are the two most commonly used experimental models of human TBI in rodents. TBI was induced with CCI to 50 (14 controls) and with lateral FPI to 45 (15 controls) C57BL/6S adult male mice. The animals were followed-up for 9 months, including three 2-week periods of continuous video-electroencephalographic (EEG) monitoring, and a seizure susceptibility test with pentylenetetrazol (PTZ). In the end, the animals were perfusion-fixed for histology. The experiment included two independent cohorts of animals. Late post-traumatic spontaneous electrographic seizures were detected in 9% of mice after CCI and 3% after lateral FPI. Eighty-two percent of mice after CCI and 71% after lateral FPI had spontaneous epileptiform spiking on EEG. In addition, 58% of mice with lateral FPI showed spontaneous epileptiform discharges. A PTZ test demonstrated increased seizure susceptibility in the majority of mice in both models, compared to control mice. There was no further progression in the occurrence of epilepsy or epileptiform spiking when follow-up was extended from 6 to 9 months. The severity of cortical or hippocampal damage did not differentiate mice with or without epileptiform activity in either model. Finally, two independent series of experiments in both injury models provided comparable data demonstrating reproducibility of the modeling. These data show that different types of impact can trigger epileptogenesis in mice. Even though the frequency of spontaneous seizures in C57BL/6S mice is low, a large majority of animals develop hyperexcitability.

  2. Cortical hypoxic-ischemic brain damage in shaken-baby (shaken impact) syndrome: value of diffusion-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Parizel, Paul M.; Oezsarlak, Oezkan; Goethem, Johan W. van [Department of Radiology, University of Antwerp, Wilrijkstraat 10, 2650, Edegem (Belgium); Ceulemans, Berten; Laridon, Annick [Department of Pediatric Neurology, University of Antwerp, Wilrijkstraat 10, 2650, Edegem (Belgium); Jorens, Philippe G. [Department of Pediatric Intensive Care Medicine, University of Antwerp, Wilrijkstraat 10, 2650, Edegem (Belgium)

    2003-12-01

    Shaken-baby syndrome (SBS) is a type of child abuse caused by violent shaking of an infant, with or without impact, and characterized by subdural hematomas, retinal hemorrhages, and occult bone fractures. Parenchymal brain lesions in SBS may be missed or underestimated on CT scans, but can be detected at an earlier stage with diffusion-weighted MRI (DW-MRI) as areas of restricted diffusion. We demonstrate the value of DW-MRI in a 2-month-old baby boy with suspected SBS. The pattern of diffusion abnormalities indicates that the neuropathology of parenchymal lesions in SBS is due to hypoxic-ischemic brain injuries, and not to diffuse axonal injury. (orig.)

  3. Brain SPECT analysis using statistical parametric mapping in patients with posttraumatic stress disorder

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Euy Neyng; Sohn, Hyung Sun; Kim, Sung Hoon; Chung, Soo Kyo; Yang, Dong Won [College of Medicine, The Catholic Univ. of Korea, Seoul (Korea, Republic of)

    2001-07-01

    This study investigated alterations in regional cerebral blood flow (rCBF) in patients with posttraumatic stress disorder (PTSD) using statistical parametric mapping (SPM99). Noninvasive rCBF measurements using {sup 99m}Tc-ethyl cysteinate dimer (ECD) SPECT were performed on 23 patients with PTSD and 21 age matched normal controls without re-exposure to accident-related stimuli. The relative rCBF maps in patients with PTSD and controls were compared. In patients with PTSD, significant increased rCBF was found along the limbic system in the brain. There were a few foci of decreased rCBF in the superior frontal gyrus, parietal and temporal region. PTSD is associated with increased rCBF in limbic areas compared with age-matched normal controls. These findings implicate regions of the limbic brain, which may mediate the response to aversive stimuli in healthy individuals, play on important role in patients suffering from PTSD and suggest that ongoing hyperfunction of 'overlearned survival response' or flashbacks response in these regions after painful, life threatening, or horrifying events without re-exposure to same traumatic stimulus.

  4. Cortico-cortical communication dynamics

    Directory of Open Access Journals (Sweden)

    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.

  5. Left Hemispheric Imbalance and Reward Mechanisms Affect Gambling Behavior: The Contribution of the Metacognition and Cortical Brain Oscillations.

    Science.gov (United States)

    Balconi, Michela; Finocchiaro, Roberta; Canavesio, Ylenia

    2015-07-01

    The present research used the Iowa Gambling Task to test the effect of the reward-sensitivity Behavioral Activation System-Reward (BAS-Reward) construct on the ability to distinguish between high- and low-risk decisions. To elucidate the individual differences that influence the decisional processes, making the strategies more or less advantageous, we considered the impact of the BAS motivational system and the frontal left and right cortical activity on subjects' decisions. More specifically, the lateralization effect, which is related to the increased activation of the left (BAS-Reward-related) hemisphere, was explored by using frequency band analysis. Specifically, behavioral responses (gain/loss options), metacognition, and delta, theta, alpha, and beta band modulation (asymmetry index) were considered. Thirty subjects were divided into high-BAS and low-BAS groups. In comparison with low-BAS, the high-BAS group showed an increased tendency to opt in favor of the immediate reward (losing strategy) instead of the long-term option (winning strategy), and members of this group were more impaired in metacognitive monitoring of their strategies and showed an increased left hemisphere activation when they responded to losing choices. A "reward bias" effect was hypothesized to act for high BAS, based on a left-hemisphere hyperactivation.

  6. Reliability and statistical power analysis of cortical and subcortical FreeSurfer metrics in a large sample of healthy elderly.

    Science.gov (United States)

    Liem, Franziskus; Mérillat, Susan; Bezzola, Ladina; Hirsiger, Sarah; Philipp, Michel; Madhyastha, Tara; Jäncke, Lutz

    2015-03-01

    FreeSurfer is a tool to quantify cortical and subcortical brain anatomy automatically and noninvasively. Previous studies have reported reliability and statistical power analyses in relatively small samples or only selected one aspect of brain anatomy. Here, we investigated reliability and statistical power of cortical thickness, surface area, volume, and the volume of subcortical structures in a large sample (N=189) of healthy elderly subjects (64+ years). Reliability (intraclass correlation coefficient) of cortical and subcortical parameters is generally high (cortical: ICCs>0.87, subcortical: ICCs>0.95). Surface-based smoothing increases reliability of cortical thickness maps, while it decreases reliability of cortical surface area and volume. Nevertheless, statistical power of all measures benefits from smoothing. When aiming to detect a 10% difference between groups, the number of subjects required to test effects with sufficient power over the entire cortex varies between cortical measures (cortical thickness: N=39, surface area: N=21, volume: N=81; 10mm smoothing, power=0.8, α=0.05). For subcortical regions this number is between 16 and 76 subjects, depending on the region. We also demonstrate the advantage of within-subject designs over between-subject designs. Furthermore, we publicly provide a tool that allows researchers to perform a priori power analysis and sensitivity analysis to help evaluate previously published studies and to design future studies with sufficient statistical power.

  7. Brain metabolic maps in Mild Cognitive Impairment predict heterogeneity of progression to dementia

    Directory of Open Access Journals (Sweden)

    Chiara Cerami

    2015-01-01

    Full Text Available [18F]FDG-PET imaging has been recognized as a crucial diagnostic marker in Mild Cognitive Impairment (MCI, supporting the presence or the exclusion of Alzheimer's Disease (AD pathology. A clinical heterogeneity, however, underlies MCI definition. In this study, we aimed to evaluate the predictive role of single-subject voxel-based maps of [18F]FDG distribution generated through statistical parametric mapping (SPM in the progression to different dementia subtypes in a sample of 45 MCI. Their scans were compared to a large normal reference dataset developed and validated for comparison at single-subject level. Additionally, Aβ42 and Tau CSF values were available in 34 MCI subjects. Clinical follow-up (mean 28.5 ± 7.8 months assessed subsequent progression to AD or non-AD dementias. The SPM analysis showed: 1 normal brain metabolism in 14 MCI cases, none of them progressing to dementia; 2 the typical temporo-parietal pattern suggestive for prodromal AD in 15 cases, 11 of them progressing to AD; 3 brain hypometabolism suggestive of frontotemporal lobar degeneration (FTLD subtypes in 7 and dementia with Lewy bodies (DLB in 2 subjects (all fulfilled FTLD or DLB clinical criteria at follow-up; and 4 7 MCI cases showed a selective unilateral or bilateral temporo-medial hypometabolism without the typical AD pattern, and they all remained stable. In our sample, objective voxel-based analysis of [18F]FDG-PET scans showed high predictive prognostic value, by identifying either normal brain metabolism or hypometabolic patterns suggestive of different underlying pathologies, as confirmed by progression at follow-up. These data support the potential usefulness of this SPM [18F]FDG PET analysis in the early dementia diagnosis and for improving subject selection in clinical trials based on MCI definition.

  8. Susceptibility-weighted imaging and quantitative susceptibility mapping in the brain.

    Science.gov (United States)

    Liu, Chunlei; Li, Wei; Tong, Karen A; Yeom, Kristen W; Kuzminski, Samuel

    2015-07-01

    Susceptibility-weighted imaging (SWI) is a magnetic resonance imaging (MRI) technique that enhances image contrast by using the susceptibility differences between tissues. It is created by combining both magnitude and phase in the gradient echo data. SWI is sensitive to both paramagnetic and diamagnetic substances which generate different phase shift in MRI data. SWI images can be displayed as a minimum intensity projection that provides high resolution delineation of the cerebral venous architecture, a feature that is not available in other MRI techniques. As such, SWI has been widely applied to diagnose various venous abnormalities. SWI is especially sensitive to deoxygenated blood and intracranial mineral deposition and, for that reason, has been applied to image various pathologies including intracranial hemorrhage, traumatic brain injury, stroke, neoplasm, and multiple sclerosis. SWI, however, does not provide quantitative measures of magnetic susceptibility. This limitation is currently being addressed with the development of quantitative susceptibility mapping (QSM) and susceptibility tensor imaging (STI). While QSM treats susceptibility as isotropic, STI treats susceptibility as generally anisotropic characterized by a tensor quantity. This article reviews the basic principles of SWI, its clinical and research applications, the mechanisms governing brain susceptibility properties, and its practical implementation, with a focus on brain imaging.

  9. Mapping cocaine binding sites in human and baboon brain in vivo.

    Science.gov (United States)

    Fowler, J S; Volkow, N D; Wolf, A P; Dewey, S L; Schlyer, D J; Macgregor, R R; Hitzemann, R; Logan, J; Bendriem, B; Gatley, S J

    1989-01-01

    The first direct measurements of cocaine binding in the brain of normal human volunteers and baboons have been made by using positron emission tomography (PET) and tracer doses of [N-11C-methyl]-(-)-cocaine ([11C]cocaine). Cocaine's binding and release from brain are rapid with the highest regional uptake of carbon-11 occurring in the corpus striatum at 4-10 minutes after intravenous injection of labeled cocaine. This was followed by a clearance to half the peak value at about 25 minutes with the overall time course paralleling the previously documented time course of the euphoria experienced after intravenous cocaine administration. Blockade of the dopamine reuptake sites with nomifensine reduced the striatal but not the cerebellar uptake of [11C]cocaine in baboons indicating that cocaine binding is associated with the dopamine reuptake site in the corpus striatum. A comparison of labeled metabolites of cocaine in human and baboon plasma showed that while cocaine is rapidly metabolized in both species, the profile of labeled metabolites is different, with baboon plasma containing significant amounts of labeled carbon dioxide, and human plasma containing no significant labeled carbon dioxide. These studies demonstrate the feasibility of using [11C]cocaine and PET to map binding sites for cocaine in human brain, to monitor its kinetics, and to characterize its binding mechanism by using appropriate pharmacological challenges.

  10. Spatial mapping of drug delivery to brain tissue using hyperspectral spatial frequency-domain imaging

    Science.gov (United States)

    Singh-Moon, Rajinder P.; Roblyer, Darren M.; Bigio, Irving J.; Joshi, Shailendra

    2014-09-01

    We present an application of spatial frequency-domain imaging (SFDI) to the wide-field imaging of drug delivery to brain tissue. Measurements were compared with values obtained by a previously validated variation of diffuse reflectance spectroscopy, the method of optical pharmacokinetics (OP). We demonstrate a cross-correlation between the two methods for absorption extraction and drug concentration determination in both experimental tissue phantoms and freshly extracted rodent brain tissue. These methods were first used to assess intra-arterial (IA) delivery of cationic liposomes to brain tissue in Sprague Dawley rats under transient cerebral hypoperfusion. Results were found to be in agreement with previously published experimental data and pharmacokinetic models of IA drug delivery. We then applied the same scheme to evaluate IA mitoxantrone delivery to glioma-bearing rats. Good correlation was seen between OP and SFDI determined concentrations taken from normal and tumor averaged sites. This study shows the feasibility of mapping drug/tracer distributions and encourages the use of SFDI for spatial imaging of tissues for drug/tracer-tagged carrier deposition and pharmacokinetic studies.

  11. Mapping the brain in type II diabetes: Voxel-based morphometry using DARTEL

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhiye [Department of Radiology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China); Li, Lin [Department of Geriatric Endocrinology, PLA General Hospital, Beijing 100853 (China); Sun, Jie [Department of Endocrinology, PLA General Hospital, Beijing 100853 (China); Ma, Lin, E-mail: cjr.malin@vip.163.com [Department of Radiology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China)

    2012-08-15

    Purpose: To investigate the pattern of brain volume changes of the brain in patients with type II diabetes mellitus using voxel-based morphometry. Material and methods: Institutional ethics approval and informed consent were obtained. VBM based on the high resolution three-dimensional T1-weighted fast spoiled gradient recalled echo MRI images was obtained from 16 type II diabetes patients (mean age 61.2 years) and 16 normal controls (mean age 59.6 years). All images were spatially preprocessed using Diffeomorphic Anatomical Registration using Exponentiated Lie algebra (DARTEL) algorithm, and the DARTEL templates were made from 100 normal subjects. Statistical parametric mapping was generated using analysis of covariance (ANCOVA). Results: An atrophy pattern of gray matter was seen in type II diabetes patients compared with controls that involved the right superior, middle, and inferior temporal gyri, right precentral gyrus, and left rolandic operculum region. The loss of white matter volume in type II diabetes mellitus was observed in right temporal lobe and left inferior frontal triangle region. ROI analysis revealed that the gray and white matter volume of right temporal lobe were significant lower in type II diabetes mellitus than that in controls (P < 0.05). Conclusion: This work demonstrated that type II diabetes mellitus patients mainly exhibited gray and white matter atrophy in right temporal lobe, and this finding supported that type II diabetes mellitus could lead to subtle diabetic brain structural changes in patients without dementia or macrovascular complications.

  12. Comparison of normal adult and children brain SPECT imaging using statistical parametric mapping(SPM)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myoung Hoon; Yoon, Seok Nam; Joh, Chul Woo; Lee, Dong Soo [Ajou University School of Medicine, Suwon (Korea, Republic of); Lee, Jae Sung [Seoul national University College of Medicine, Seoul (Korea, Republic of)

    2002-07-01

    This study compared rCBF pattern in normal adult and normal children using statistical parametric mapping (SPM). The purpose of this study was to determine distribution pattern not seen visual analysis in both groups. Tc-99m ECD brain SPECT was performed in 12 normal adults (M:F=11:1, average age 35 year old) and 6 normal control children (M:F=4:2, 10.5{+-}3.1y) who visited psychiatry clinic to evaluate ADHD. Their brain SPECT revealed normal rCBF pattern in visual analysis and they were diagnosed clinically normal. Using SPM method, we compared normal adult group's SPECT images with those of 6 normal children subjects and measured the extent of the area with significant hypoperfusion and hyperperfusion (p<0.001, extent threshold=16). The areas of both angnlar gyrus, both postcentral gyrus, both superior frontal gyrus, and both superior parietal lobe showed significant hyperperfusion in normal adult group compared with normal children group. The areas of left amygdala gyrus, brain stem, both cerebellum, left globus pallidus, both hippocampal formations, both parahippocampal gyrus, both thalamus, both uncus, both lateral and medial occipitotemporal gyrus revealed significantly hyperperfusion in the children. These results demonstrated that SPM can say more precise anatomical area difference not seen visual analysis.

  13. Structural asymmetry of the human cerebral cortex: Regional and between-subject variability of surface area, cortical thickness, and local gyrification.

    Science.gov (United States)

    Chiarello, Christine; Vazquez, David; Felton, Adam; McDowell, Alessandra

    2016-12-01

    Structural asymmetry varies across individuals, brain regions, and metrics of cortical organization. The current study investigated regional differences in asymmetry of cortical surface area, thickness, and local gyrification, and the extent of between-subject variability in these metrics, in a sample of healthy young adults (N=200). Between-subject variability in cortical structure may provide a means to assess the extent of biological flexibility or constraint of brain regions, and we explored the potential influence of this variability on the phenotypic expression of structural asymmetry. The findings demonstrate that structural asymmetries are nearly ubiquitous across the cortex, with differing regional organization for the three cortical metrics. This implies that there are multiple, only partially overlapping, maps of structural asymmetry. The results further indicate that the degree of asymmetry of a brain region can be predicted by the extent of the region's between-subject variability. These findings provide evidence that reduced biological constraint promotes the expression of strong structural asymmetry.

  14. Ketogenic diet restores aberrant cortical motor maps and excitation-to-inhibition imbalance in the BTBR mouse model of autism spectrum disorder.

    Science.gov (United States)

    Smith, Jacklyn; Rho, Jong M; Teskey, G Campbell

    2016-05-01

    Autism spectrum disorder (ASD) is an increasingly prevalent neurodevelopmental disorder characterized by deficits in sociability and communication, and restricted and/or repetitive motor behaviors. Amongst the diverse hypotheses regarding the pathophysiology of ASD, one possibility is that there is increased neuronal excitation, leading to alterations in sensory processing, functional integration and behavior. Meanwhile, the high-fat, low-carbohydrate ketogenic diet (KD), traditionally used in the treatment of medically intractable epilepsy, has already been shown to reduce autistic behaviors in both humans and in rodent models of ASD. While the mechanisms underlying these effects remain unclear, we hypothesized that this dietary approach might shift the balance of excitation and inhibition towards more normal levels of inhibition. Using high-resolution intracortical microstimulation, we investigated basal sensorimotor excitation/inhibition in the BTBR T+Itpr(tf)/J (BTBR) mouse model of ASD and tested whether the KD restores the balance of excitation/inhibition. We found that BTBR mice had lower movement thresholds and larger motor maps indicative of higher excitation/inhibition compared to C57BL/6J (B6) controls, and that the KD reversed both these abnormalities. Collectively, our results afford a greater understanding of cortical excitation/inhibition balance in ASD and may help expedite the development of therapeutic approaches aimed at improving functional outcomes in this disorder.

  15. Protein kinase D stabilizes aldosterone-induced ERK1/2 MAP kinase activation in M1 renal cortical collecting duct cells to promote cell proliferation.

    LENUS (Irish Health Repository)

    McEneaney, Victoria

    2010-01-01

    Aldosterone elicits transcriptional responses in target tissues and also rapidly stimulates the activation of protein kinase signalling cascades independently of de novo protein synthesis. Here we investigated aldosterone-induced cell proliferation and extra-cellular regulated kinase 1 and 2 (ERK1\\/2) mitogen activated protein (MAP) kinase signalling in the M1 cortical collecting duct cell line (M1-CCD). Aldosterone promoted the proliferative growth of M1-CCD cells, an effect that was protein kinase D1 (PKD1), PKCdelta and ERK1\\/2-dependent. Aldosterone induced the rapid activation of ERK1\\/2 with peaks of activation at 2 and 10 to 30 min after hormone treatment followed by sustained activation lasting beyond 120 min. M1-CCD cells suppressed in PKD1 expression exhibited only the early, transient peaks in ERK1\\/2 activation without the sustained phase. Aldosterone stimulated the physical association of PKD1 with ERK1\\/2 within 2 min of treatment. The mineralocorticoid receptor (MR) antagonist RU28318 inhibited the early and late phases of aldosterone-induced ERK1\\/2 activation, and also aldosterone-induced proliferative cell growth. Aldosterone induced the sub-cellular redistribution of ERK1\\/2 to the nuclei at 2 min and to cytoplasmic sites, proximal to the nuclei after 30 min. This sub-cellular distribution of ERK1\\/2 was inhibited in cells suppressed in the expression of PKD1.

  16. Correlation mapping method of OCT for visualization blood vessels in brain

    Science.gov (United States)

    Izotova, O. A.; Kalyanov, A. L.; Lychagov, V. V.; Semyachkina-Glushkovskaya, O. V.

    2013-11-01

    The burning issue in modern medicine is the diagnosis and treatment of various life-threatening diseases, in particular the diseases of brain. One of them is intracranial hemorrhage (ICH). It occurs especially among newborn babies and is hard-diagnosed. In order to understand the nature of the ICH, the microcirculation of blood, which serves key functions within the body, is analyzed. On this basis a series of experiments was done, in the results of which it was showed, that latent stage of ICH is characterized by decrease of venous blood outflow and the loss of sensitivity of sagittal vein to vasoconstrictor effect of adrenaline. So, stress-related changes of the cerebral venous blood flow (CVBF) can be the source of this disease. In this paper registration CVBF was made with the help of commercially available Thorlabs Swept Source OCT System, using the correlation mapping method. In this method values of correlation coefficient of several images are analyzed. In the result of the algorithm the correlation map was obtained. By the resulting map the diameter of vessels was calculated, which is necessary for examination of effects of adrenalin to the vessels and identification symptoms of ICH.

  17. Metaphoric identity mapping: facilitating goal setting and engagement in rehabilitation after traumatic brain injury.

    Science.gov (United States)

    Ylvisaker, Mark; McPherson, Kathryn; Kayes, Nicola; Pellett, Ellen

    2008-01-01

    Difficulty re-establishing an organised and compelling sense of personal identity has increasingly been identified as a critical theme in outcome studies of individuals with severe traumatic brain injury (TBI) and a serious obstacle to active engagement in rehabilitation. There exists little empirical support for approaches to identity reconstruction that address common impairments associated with TBI. Similarly, there is as yet little empirical support for theoretically sound approaches to promoting engagement in goal setting for this population. This article has two purposes. First, theory and procedures associated with metaphoric identity mapping are discussed in relation to goal setting in TBI rehabilitation. Second, the results of a qualitative pilot study are presented. The study explored metaphoric identity mapping as a facilitator of personally meaningful goal setting with five individuals with significant disability many years after their injury. Drawing on principles of grounded theory, the investigators extracted data from semi-structured interviews with clients and clinicians, from focus groups with the clinicians, and from observation of client-clinician interaction. Analysis of the data yielded five general themes concerning the use of this approach: All clients and clinicians found identity mapping to be an acceptable process and also useful for deriving meaningful rehabilitation goals. Both clients and clinicians saw client-centred goals as important. Cognitive impairments posed obstacles to this goal-setting intervention and mandated creative compensations. And finally, identity-related goal setting appeared to require a "mind shift" for some clinicians and demanded clinical skills not uniformly distributed among rehabilitation professionals.

  18. Robust biological parametric mapping: an improved technique for multimodal brain image analysis

    Science.gov (United States)

    Yang, Xue; Beason-Held, Lori; Resnick, Susan M.; Landman, Bennett A.

    2011-03-01

    Mapping the quantitative relationship between structure and function in the human brain is an important and challenging problem. Numerous volumetric, surface, region of interest and voxelwise image processing techniques have been developed to statistically assess potential correlations between imaging and non-imaging metrics. Recently, biological parametric mapping has extended the widely popular statistical parametric approach to enable application of the general linear model to multiple image modalities (both for regressors and regressands) along with scalar valued observations. This approach offers great promise for direct, voxelwise assessment of structural and functional relationships with multiple imaging modalities. However, as presented, the biological parametric mapping approach is not robust to outliers and may lead to invalid inferences (e.g., artifactual low p-values) due to slight mis-registration or variation in anatomy between subjects. To enable widespread application of this approach, we introduce robust regression and robust inference in the neuroimaging context of application of the general linear model. Through simulation and empirical studies, we demonstrate that our robust approach reduces sensitivity to outliers without substantial degradation in power. The robust approach and associated software package provides a reliable way to quantitatively assess voxelwise correlations between structural and functional neuroimaging modalities.

  19. MAP training: combining meditation and aerobic exercise reduces depression and rumination while enhancing synchronized brain activity.

    Science.gov (United States)

    Alderman, B L; Olson, R L; Brush, C J; Shors, T J

    2016-02-02

    Mental and physical (MAP) training is a novel clinical intervention that combines mental training through meditation and physical training through aerobic exercise. The intervention was translated from neuroscientific studies indicating that MAP training increases neurogenesis in the adult brain. Each session consisted of 30 min of focused-attention (FA) meditation and 30 min of moderate-intensity aerobic exercise. Fifty-two participants completed the 8-week intervention, which consisted of two sessions per week. Following the intervention, individuals with major depressive disorder (MDD; n=22) reported significantly less depressive symptoms and ruminative thoughts. Typical healthy individuals (n=30) also reported less depressive symptoms at follow-up. Behavioral and event-related potential indices of cognitive control were collected at baseline and follow-up during a modified flanker task. Following MAP training, N2 and P3 component amplitudes increased relative to baseline, especially among individuals with MDD. These data indicate enhanced neural responses during the detection and resolution of conflicting stimuli. Although previous research has supported the individual beneficial effects of aerobic exercise and meditation for depression, these findings indicate that a combination of the two may be particularly effective in increasing cognitive control processes and decreasing ruminative thought patterns.

  20. Palmitoylethanolamide Reduces Neuropsychiatric Behaviors by Restoring Cortical Electrophysiological Activity in a Mouse Model of Mild Traumatic Brain Injury

    Science.gov (United States)

    Guida, Francesca; Boccella, Serena; Iannotta, Monica; De Gregorio, Danilo; Giordano, Catia; Belardo, Carmela; Romano, Rosaria; Palazzo, Enza; Scafuro, Maria A.; Serra, Nicola; de Novellis, Vito; Rossi, Francesco; Maione, Sabatino; Luongo, Livio

    2017-01-01

    Traumatic brain injury (TBI) represents a major public health problem, which is associated with neurological dysfunction. In severe or moderate cases of TBI, in addition to its high mortality rate, subjects may encounter diverse behavioral dysfunctions. Previous reports suggest that an association between TBI and chronic pain syndromes tends to be more common in patients with mild forms of brain injury. Despite causing minimal brain damage, mild TBI (mTBI) often leads to persistent psychologically debilitating symptoms, which can include anxiety, various forms of memory and learning deficits, and depression. At present, no effective treatment options are available for these symptoms, and little is known about the complex cellular activity affecting neuronal activity that occurs in response to TBI during its late phase. Here, we used a mouse model to investigate the effect of Palmitoylethanolamide (PEA) on both the sensorial and neuropsychiatric dysfunctions associated with mTBI through behavioral, electrophysiological, and biomolecular approaches. Fourteen-day mTBI mice developed anxious, aggressive, and reckless behavior, whilst depressive-like behavior and impaired social interactions were observed from the 60th day onward. Altered behavior was associated with changes in interleukin 1 beta (IL-1β) expression levels and neuronal firing activity in the medial prefrontal cortex. Compared with vehicle, PEA restored the behavioral phenotype and partially normalized the biochemical and functional changes occurring at the supraspinal level. In conclusion, our findings reveal some of the supraspinal modifications responsible for the behavioral alterations associated with mTBI and suggest PEA as a pharmacological tool to ameliorate neurological dysfunction induced by the trauma. PMID:28321191

  1. Evolution of technetium-99m-HMPAO SPECT and brain mapping in a patient presenting with echolalia and palilalia.

    Science.gov (United States)

    Dierckx, R A; Saerens, J; De Deyn, P P; Verslegers, W; Marien, P; Vandevivere, J

    1991-08-01

    A 78-yr-old woman presented with transient echolalia and palilalia. She had suffered from Parkinson's disease for 2 yr. Routine laboratory examination showed hypotonic hyponatremia, but was otherwise unremarkable. Brain mapping revealed a bifrontal delta focus, more pronounced on the right. Single photon emission computed tomography (SPECT) of the brain with technetium-99m labeled d,l hexamethylpropylene-amine oxime (99mTc-HMPAO), performed during the acute episode showed relative frontoparietal hypoactivity. Brain mapping performed after disappearance of the echolalia and palilalia, which persisted only for 1 day, was normal. By contrast, SPECT findings persisted for more than 3 wk. Features of particular interest in the presented patient are the extensive defects seen on brain SPECT despite the absence of morphologic lesions, the congruent electrophysiologic changes and their temporal relationship with the clinical evolution.

  2. Cyclin-Dependent Kinase 5 Regulates Dendritic Spine Formation and Maintenance of Cortical Neuron in the Mouse Brain.

    Science.gov (United States)

    Mita, Naoki; He, Xiaojuan; Sasamoto, Kodai; Mishiba, Tomohide; Ohshima, Toshio

    2016-03-01

    Cyclin-dependent kinase 5 (Cdk5) activity is dependent on its association with 1 of 2 neuron-specific activators, p35 or p39. Cdk5 and its activators play an important role in brain development as well as higher functions like synaptic plasticity, learning, and memory. Reduction in p35 was reported in postmortem schizophrenia brain, in which reduced dendritic spine density was observed. Previous in vitro experiments have shown that Cdk5 is involved in dendritic spine formation, although in vivo evidence is limited. We examined dendritic spine formation in inducible-p35 conditional knockout (p35 cKO); p39 KO mice. When we deleted the p35 gene either during early postnatal days or at adult stage, we observed reduced spine densities of layer V neurons in the cerebral cortex and CA1 pyramidal neurons in the hippocampus. We further generated CA1-specific p35 conditional knockout (CA1-p35 cKO) mice and also CA1-p35 cKO; p39 KO mice in which have specific deletion of p35 in the CA1 region of hippocampus. We found a greater reduction in spine densities in CA1 pyramidal neurons in CA1-p35 cKO; p39 KO mice than in CA1-p35 cKO mice. These results indicate that dendritic spine formation and neuronal maintenance are dependent on Cdk5 activity.

  3. Fat-Free Body Mass but not Fat Mass is Associated with Reduced Gray Matter Volume of Cortical Brain Regions Implicated in Autonomic and Homeostatic Regulation

    Science.gov (United States)

    Weise, Christopher M; Thiyyagura, Pradeep; Reiman, Eric M; Chen, Kewei; Krakoff, Jonathan

    2014-01-01

    Obesity has been associated with alterations of both functional and structural aspects of the human central nervous system. In obese individuals both fat mass (FM; primarily consisting of adipose tissue) and fat-free mass (FFM; all non-adipose tissues) are increased and it remains unknown whether these compartments have separate effects on human brain morphology. We used voxel-based morphometry to investigate the relationships between measures of body composition and regional gray matter volume (GMV) in 76 healthy adults with a wide range of adiposity (24F/52M; age 32.1±8.8y; percentage of body fat [PFAT%] 25.5±10.9%; BMI 29.8±8.9). Faf-free mass index (FFMI kg*m-2) showed negative associations in bilateral temporal regions, the bilateral medial and caudolateral OFC, and the left insula. Fat mass index (FMI kg*m-2) showed similar, but less extensive negative associations within temporal cortical regions and the left caudolateral orbitofrontal cortex (OFC). In addition, negative associations were seen for FMI with GMV of the cerebellum. Associations of FFMI with temporal and medial orbitofrontal GMV appeared to be independent of adiposity. No associations were seen between measures of adiposity (i.e. FM and PFAT) and GMV when adjusted for FFM. The majority of regions that we find associated with FFM have been implicated in the regulation of eating behavior and show extensive projections to central autonomic and homeostatic core structures. These data indicate that not adipose tissue or relative adiposity itself, but obesity related increases in absolute tissue mass and particularly FFM may have a more predominant effect on the human brain. This might be explained by the high metabolic demand of FFM and related increases in total energy needs. PMID:22974975

  4. SIRT3 Expression Decreases with Reactive Oxygen Species Generation in Rat Cortical Neurons during Early Brain Injury Induced by Experimental Subarachnoid Hemorrhage

    Science.gov (United States)

    Huang, Wei; Huang, Yong; Huang, Ren-qiang; Gu, Jin-mao; Dong, Yan

    2016-01-01

    Sirtuin3 (SIRT3) is an important protein deacetylase which predominantly presents in mitochondria and exhibits broad bioactivities including regulating energy metabolism and counteracting inflammatory effect. Since inflammatory cascade was proved to be critical for pathological damage following subarachnoid hemorrhage (SAH), we investigated the overall expression and cell-specific distribution of SIRT3 in the cerebral cortex of Sprague-Dawley rats with experimental SAH induced by internal carotid perforation. Results suggested that SIRT3 was expressed abundantly in neurons and endothelia but rarely in gliocytes in normal cerebral cortex. After experimental SAH, mRNA and protein expressions of SIRT3 decreased significantly as early as 8 hours and dropped to the minimum value at 24 h after SAH. By contrast, SOD2 expression increased slowly as early as 12 hours after experimental SAH, rose up sharply at the following 12 hours, and then was maintained at a higher level. In conclusion, attenuated SIRT3 expression in cortical neurons was associated closely with enhanced reactive oxygen species generation and cellular apoptosis, implying that SIRT3 might play an important neuroprotective role during early brain injury following SAH. PMID:28053989

  5. β-Secretase inhibitor increases amyloid-β precursor protein level in rat brain cortical primary neurons induced by okadaic acid

    Institute of Scientific and Technical Information of China (English)

    YU Chun-Jiang; WANG Wei-zhi; LIU Wei

    2008-01-01

    Background Senile plaques and neurofibrillary tangles (NFTs) represent two of the major histopathological hallmarks of Alzheimer's disease (AD). The plaques are primarily composed of aggregated amyloid β (Aβ) peptides. The processing of amyloid-β precursor protein (AβPP) in okadaic acid (OA)-induced tau phosphorylation primary neurons was studied.Methods Primary cultures of rat brain cortical neurons were treated with OA and β-secretase inhibitor. Neurons' viability was measured. AβPP processing was examined by immunocytochemistry and Western blotting with specific antibodies against the AβPP-N-terminus (NT) and AβPP-C-terminus (CT).Results Ten nrnol/L OA had a time-dependent suppression effect on primary neurons' viability. The suppression effect was alleviated markedly by pretreatment with β-secretase inhibitor. After OA treatment, both AβPP and β-C-terminal fragment (βCTF) were significantly increased in neurons. AβPP level was increased further in neurons pretreated with β-secretase inhibitor.Conclusions In OA-induced tau phosphorylation cell model, inhibition of β-secretase may protect neurons from death induced by OA. Because of increased accumulation of AβPP in neurons after OA treatment, more AβPP turns to be cleaved by β-secretase, producing neurotoxic βCTF. As a potential effective therapeutic target, β-secretase is worth investigating further.

  6. Effect of brain-derived neurotrophic factor on activity-regulated cytoskeleton-associated protein gene expression in primary frontal cortical neurons. Comparison with NMDA and AMPA

    DEFF Research Database (Denmark)

    El-Sayed, Mona; Hofman-Bang, Jacob; Mikkelsen, Jens D

    2011-01-01

    The effect of brain-derived neurotrophic factor (BDNF) on activity-regulated cytoskeleton-associated protein (Arc) mRNA levels in primary neuronal cultures of rat frontal cortex was characterized pharmacologically and compared to the effect on expression of c-fos, bdnf, neuritin, cox-2 as examples...... of other immediate early genes. BDNF induced a very strong increase (around 100 fold) in Arc mRNA and the maximal effect seen at 25 ng/ml. The effect was dose-dependent with EC50 around 1.6 ng/ml. The time profile revealed a significant effect after 25 min. BDNF also increased levels of c-Fos, neuritin...... and BDNF mRNA, but not COX-2 mRNA. The pharmacological profile of NMDA and AMPA-induced arc gene expression in frontal cortical neurons was compared to BDNF. NMDA and AMPA increased Arc mRNA but their maximal effect did not exceed 20-fold. The effect of AMPA was completely blocked by the NMDA receptor...

  7. Brain-derived neurotrophic factor-mediated retrograde signaling required for the induction of long-term potentiation at inhibitory synapses of visual cortical pyramidal neurons.

    Science.gov (United States)

    Inagaki, Tsuyoshi; Begum, Tahamina; Reza, Faruque; Horibe, Shoko; Inaba, Mie; Yoshimura, Yumiko; Komatsu, Yukio

    2008-06-01

    High-frequency stimulation (HFS) induces long-term potentiation (LTP) at inhibitory synapses of layer 5 pyramidal neurons in developing rat visual cortex. This LTP requires postsynaptic Ca2+ rise for induction, while the maintenance mechanism is present at the presynaptic site, suggesting presynaptic LTP expression and the necessity of retrograde signaling. We investigated whether the supposed signal is mediated by brain-derived neurotrophic factor (BDNF), which is expressed in pyramidal neurons but not inhibitory interneurons. LTP did not occur when HFS was applied in the presence of the Trk receptor tyrosine kinase inhibitor K252a in the perfusion medium. HFS produced LTP when bath application of K252a was started after HFS or when K252a was loaded into postsynaptic cells. LTP did not occur in the presence of TrkB-IgG scavenging BDNF or function-blocking anti-BDNF antibody in the medium. In cells loaded with the Ca2+ chelator BAPTA, the addition of BDNF to the medium enabled HFS to induce LTP without affecting baseline synaptic transmission. These results suggest that BDNF released from postsynaptic cells activates presynaptic TrkB, leading to LTP. Because BDNF, expressed activity dependently, regulates the maturation of cortical inhibition, inhibitory LTP may contribute to this developmental process, and hence experience-dependent functional maturation of visual cortex.

  8. High-resolution three-dimensional quantitative map of the macromolecular proton fraction distribution in the normal rat brain

    Directory of Open Access Journals (Sweden)

    Anna V. Naumova

    2017-02-01

    Full Text Available The presented dataset provides a normative high-resolution three-dimensional (3D macromolecular proton fraction (MPF map of the healthy rat brain in vivo and source images used for its reconstruction. The images were acquired using the protocol described elsewhere (Naumova, et al. High-resolution three-dimensional macromolecular proton fraction mapping for quantitative neuroanatomical imaging of the rodent brain in ultra-high magnetic fields. Neuroimage (2016 doi: 10.1016/j.neuroimage.2016.09.036. The map was reconstructed from three source images with different contrast weightings (proton density, T1, and magnetization transfer using the single-point algorithm with a synthetic reference image. Source images were acquired from a living animal on an 11.7 T small animal MRI scanner with isotropic spatial resolution of 170 µm3 and total acquisition time about 1.5 h. The 3D dataset can be used for multiple purposes including interactive viewing of rat brain anatomy, measurements of reference MPF values in various brain structures, and development of image processing techniques for the rodent brain segmentation. It also can serve as a gold standard image for implementation and optimization of rodent brain MRI protocols.

  9. NEREC, an effective brain mapping protocol for combined language and long-term memory functions.

    Science.gov (United States)

    Perrone-Bertolotti, Marcela; Girard, Cléa; Cousin, Emilie; Vidal, Juan Ricardo; Pichat, Cédric; Kahane, Philippe; Baciu, Monica

    2015-12-01

    and long-term memory encoding/recall) instead of applying isolated tasks to map temporoparietal regions, (b) analyzing NE data based on performances recorded during REC, (c) double-mapping networks involved in naming and in long-term memory encoding and retrieval, (d) focusing on remembering with hippocampal activation and familiarity judgment with lateral temporal cortices activation, and (e) short duration of examination and feasibility. These aspects are of particular interest in patients with TLE, who frequently show impairment of these cognitive functions. Here, we show that the novel protocol is suited for this clinical evaluation.

  10. Motor cortical prediction of EMG: evidence that a kinetic brain-machine interface may be robust across altered movement dynamics.

    Science.gov (United States)

    Cherian, A; Krucoff, M O; Miller, L E

    2011-08-01

    During typical movements, signals related to both the kinematics and kinetics of movement are mutually correlated, and each is correlated to some extent with the discharge of neurons in the primary motor cortex (M1). However, it is well known, if not always appreciated, that causality cannot be inferred from correlations. Although these mutual correlations persist, their nature changes with changing postural or dynamical conditions. Under changing conditions, only signals directly controlled by M1 can be expected to maintain a stable relationship with its discharge. If one were to rely on noncausal correlations for a brain-machine interface, its generalization across conditions would likely suffer. We examined this effect, using multielectrode recordings in M1 as input to linear decoders of both end point kinematics (position and velocity) and proximal limb myoelectric signals (EMG) during reaching. We tested these decoders across tasks that altered either the posture of the limb or the end point forces encountered during movement. Within any given task, the accuracy of the kinematic predictions tended to be somewhat better than the EMG predictions. However, when we used the decoders developed under one task condition to predict the signals recorded under different postural or dynamical conditions, only the EMG decoders consistently generalized well. Our results support the view that M1 discharge is more closely related to kinetic variables like EMG than it is to limb kinematics. These results suggest that brain-machine interface applications using M1 to control kinetic variables may prove to be more successful than the more standard kinematic approach.

  11. Quantitative EEG Brain Mapping In Psychotropic Drug Development, Drug Treatment Selection, and Monitoring.

    Science.gov (United States)

    Itil, Turan M.; Itil, Kurt Z.

    1995-05-01

    Quantification of standard electroencephalogram (EEG) by digital computers [computer-analyzed EEG (CEEG)] has transformed the subjective analog EEG into an objective scientific method. Until a few years ago, CEEG was only used to assist in the development of psychotropic drugs by means of the quantitative pharmaco EEG. Thanks to the computer revolution and the accompanying reductions in cost of quantification, CEEG can now also be applied in psychiatric practice. CEEG can assist the physician in confirming clinical diagnoses, selecting psychotropic drugs for treatment, and drug treatment monitoring. Advancements in communications technology allow physicians and researchers to reduce the costs of acquiring a high-technology CEEG brain mapping system by utilizing the more economical telephonic services.

  12. Developmental changes of TrkB signaling in response to exogenous brain-derived neurotrophic factor in primary cortical neurons.

    Science.gov (United States)

    Zhou, Xianju; Xiao, Hua; Wang, Hongbing

    2011-12-01

    Neocortical circuits are most sensitive to sensory experience during a critical period of early development. Previous studies implicate that brain-derived neurotrophic factor (BDNF) and GABAergic inhibition may control the timing of the critical period. By using an in vitro maturation model, we found that neurons at DIV (day in vitro) 7, around a period when functional synapses start to form and GABAergic inhibition emerges, displayed the most dynamic activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and CREB by exogenous BDNF. The BDNF-stimulated transcriptional up-regulation of CREB target genes was also the highest in DIV 7 neurons. The basal level of ERK1/2 and CREB activity, as well as the expression of CREB target genes, increased along with maturation, and neurons at DIV 13 and 22 displayed less dynamic responses to BDNF. Furthermore, we found that the developmentally regulated GABAergic inhibition correlated with the decline of BDNF-mediated signaling during maturation. BDNF stimulation along with suppression of GABAergic inhibition enhanced the activation of ERK1/2-CREB signaling and gene transcription in mature neurons. Conversely, BDNF stimulation along with enhancement of GABAergic inhibition reduced the overall induction of intracellular signaling in younger neurons. We propose that the less dynamic molecular changes may play a certain role in the loss of plasticity during maturation.

  13. Wide-field optical mapping of neural activity and brain haemodynamics: considerations and novel approaches

    Science.gov (United States)

    Ma, Ying; Shaik, Mohammed A.; Kozberg, Mariel G.; Thibodeaux, David N.; Zhao, Hanzhi T.; Yu, Hang

    2016-01-01

    Although modern techniques such as two-photon microscopy can now provide cellular-level three-dimensional imaging of the intact living brain, the speed and fields of view of these techniques remain limited. Conversely, two-dimensional wide-field optical mapping (WFOM), a simpler technique that uses a camera to observe large areas of the exposed cortex under visible light, can detect changes in both neural activity and haemodynamics at very high speeds. Although WFOM may not provide single-neuron or capillary-level resolution, it is an attractive and accessible approach to imaging large areas of the brain in awake, behaving mammals at speeds fast enough to observe widespread neural firing events, as well as their dynamic coupling to haemodynamics. Although such wide-field optical imaging techniques have a long history, the advent of genetically encoded fluorophores that can report neural activity with high sensitivity, as well as modern technologies such as light emitting diodes and sensitive and high-speed digital cameras have driven renewed interest in WFOM. To facilitate the wider adoption and standardization of WFOM approaches for neuroscience and neurovascular coupling research, we provide here an overview of the basic principles of WFOM, considerations for implementation of wide-field fluorescence imaging of neural activity, spectroscopic analysis and interpretation of results. This article is part of the themed issue ‘Interpreting BOLD: a dialogue between cognitive and cellular neuroscience’. PMID:27574312

  14. Using geographical information systems mapping to identify areas presenting high risk for traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Colantonio Angela

    2011-11-01

    Full Text Available Abstract Background The aim of this study is to show how geographical information systems (GIS can be used to track and compare hospitalization rates for traumatic brain injury (TBI over time and across a large geographical area using population based data. Results & Discussion Data on TBI hospitalizations, and geographic and demographic variables, came from the Ontario Trauma Registry Minimum Data Set for the fiscal years 1993-1994 and 2001-2002. Various visualization techniques, exploratory data analysis and spatial analysis were employed to map and analyze these data. Both the raw and standardized rates by age/gender of the geographical unit were studied. Data analyses revealed persistent high rates of hospitalization for TBI resulting from any injury mechanism between two time periods in specific geographic locations. Conclusions This study shows how geographic information systems can be successfully used to investigate hospitalizaton rates for traumatic brain injury using a range of tools and techniques; findings can be used for local planning of both injury prevention and post discharge services, including rehabilitation.

  15. Distribution of Alox15 in the Rat Brain and Its Role in Prefrontal Cortical Resolvin D1 Formation and Spatial Working Memory.

    Science.gov (United States)

    Shalini, Suku-Maran; Ho, Christabel Fung-Yih; Ng, Yee-Kong; Tong, Jie-Xin; Ong, Eng-Shi; Herr, Deron R; Dawe, Gavin S; Ong, Wei-Yi

    2017-02-08

    Docosahexaenoic acid (DHA) is enriched in membrane phospholipids of the central nervous system (CNS) and has a role in aging and neuropsychiatric disorders. DHA is metabolized by the enzyme Alox15 to 17S-hydroxy-DHA, which is then converted to 7S-hydroperoxy,17S-hydroxy-DHA by a 5-lipoxygenase, and thence via epoxy intermediates to the anti-inflammatory molecule, resolvin D1 (RvD1 or 7S,8R,17S-trihydroxy-docosa-Z,9E,11E,13Z,15E,19Z-hexaenoic acid). In this study, we investigated the distribution and function of Alox15 in the CNS. RT-PCR of the CNS showed that the prefrontal cortex exhibits the highest Alox15 mRNA expression level, followed by the parietal association cortex and secondary auditory cortex, olfactory bulb, motor and somatosensory cortices, and the hippocampus. Western blot analysis was consistent with RT-PCR data, in that the prefrontal cortex, cerebral cortex, hippocampus, and olfactory bulb had high Alox15 protein expression. Immunohistochemistry showed moderate staining in the olfactory bulb, cerebral cortex, septum, striatum, cerebellar cortex, cochlear nuclei, spinal trigeminal nucleus, and dorsal horn of the spinal cord. Immuno-electron microscopy showed localization of Alox15 in dendrites, in the prefrontal cortex. Liquid chromatography mass spectrometry analysis showed significant decrease in resolvin D1 levels in the prefrontal cortex after inhibition or antisense knockdown of Alox15. Alox15 inhibition or antisense knockdown in the prefrontal cortex also blocked long-term potentiation of the hippocampo-prefrontal cortex pathway and increased errors in alternation, in the T-maze test. They indicate that Alox15 processing of DHA contributes to production of resolvin D1 and LTP at hippocampo-prefrontal cortical synapses and associated spatial working memory performance. Together, results provide evidence for a key role of anti-inflammatory molecules generated by Alox15 and DHA, such as resolvin D1, in memory. They suggest that neuroinflammatory

  16. Inter- and intrahemispheric dissociations in ideomotor apraxia: a large-scale lesion-symptom mapping study in subacute brain-damaged patients.

    Science.gov (United States)

    Manuel, Aurelie L; Radman, Narges; Mesot, Delphine; Chouiter, Leila; Clarke, Stephanie; Annoni, Jean-Marie; Spierer, Lucas

    2013-12-01

    Pantomimes of object use require accurate representations of movements and a selection of the most task-relevant gestures. Prominent models of praxis, corroborated by functional neuroimaging studies, predict a critical role for left parietal cortices in pantomime and advance that these areas store representations of tool use. In contrast, lesion data points to the involvement of left inferior frontal areas, suggesting that defective selection of movement features is the cause of pantomime errors. We conducted a large-scale voxel-based lesion-symptom mapping analyses with configural/spatial (CS) and body-part-as-object (BPO) pantomime errors of 150 left and right brain-damaged patients. Our results confirm the left hemisphere dominance in pantomime. Both types of error were associated with damage to left inferior frontal regions in tumor and stroke patients. While CS pantomime errors were associated with left temporoparietal lesions in both stroke and tumor patients, these errors appeared less associated with parietal areas in stroke than in tumor patients and less associated with temporal in tumor than stroke patients. BPO errors were associated with left inferior frontal lesions in both tumor and stroke patients. Collectively, our results reveal a left intrahemispheric dissociation for various aspects of pantomime, but with an unspecific role for inferior frontal regions.

  17. Large field-of-view and depth-specific cortical microvascular imaging underlies regional differences in ischemic brain

    Science.gov (United States)

    Qin, Jia; Shi, Lei; Dziennis, Suzan; Wang, Ruikang K.

    2014-02-01

    Ability to non-invasively monitor and quantify of blood flow, blood vessel morphology, oxygenation and tissue morphology is important for improved diagnosis, treatment and management of various neurovascular disorders, e.g., stroke. Currently, no imaging technique is available that can satisfactorily extract these parameters from in vivo microcirculatory tissue beds, with large field of view and sufficient resolution at defined depth without any harm to the tissue. In order for more effective therapeutics, we need to determine the area of brain that is damaged but not yet dead after focal ischemia. Here we develop an integrated multi-functional imaging system, in which SDW-LSCI (synchronized dual wavelength laser speckle imaging) is used as a guiding tool for OMAG (optical microangiography) to investigate the fine detail of tissue hemodynamics, such as vessel flow, profile, and flow direction. We determine the utility of the integrated system for serial monitoring afore mentioned parameters in experimental stroke, middle cerebral artery occlusion (MCAO) in mice. For 90 min MCAO, onsite and 24 hours following reperfusion, we use SDW-LSCI to determine distinct flow and oxygenation variations for differentiation of the infarction, peri-infarct, reduced flow and contralateral regions. The blood volumes are quantifiable and distinct in afore mentioned regions. We also demonstrate the behaviors of flow and flow direction in the arterials connected to MCA play important role in the time course of MCAO. These achievements may improve our understanding of vascular involvement under pathologic and physiological conditions, and ultimately facilitate clinical diagnosis, monitoring and therapeutic interventions of neurovascular diseases, such as ischemic stroke.

  18. Investigating relationships between cortical thickness and cognitive performance in patients with schizophrenia and healthy adults.

    Science.gov (United States)

    Hartberg, Cecilie Bhandari; Lawyer, Glenn; Nyman, Håkan; Jönsson, Erik G; Haukvik, Unn K; Saetre, Peter; Bjerkan, Petr S; Andreassen, Ole A; Hall, Håkan; Agartz, Ingrid

    2010-05-30

    Relationships between prefrontal and temporal lobe grey matter volumes as assessed by magnetic resonance imaging and neurocognitive test results have been reported in schizophrenia. This investigation aimed to localize brain regions where cortical thickness and neurocognitive performance were related, and investigate if such relationships might differ in schizophrenia patients and healthy controls. Sixty-seven patients with schizophrenia and 69 healthy controls were characterized by neurocognitive testing and by brain cortical thickness maps. Putative cortical thickness/cognitive score relationships were investigated with contrast analyses of general linear models for the combined sample. Regions in which relationships were present were further investigated for diagnostic interaction. In the combined sample, significant positive relationships were found between frontal, temporal and occipital regions and tests for verbal IQ, verbal learning and executive functions. Diagnostic interaction was found for the relationships between verbal IQ and the right temporo-occipital junction and the left middle occipital gyrus. In conclusion, the significant relationships between cortical thickness and neurocognitive performances were localized in brain areas known to be involved in cognition. The relationships were similar in patients and controls, except for the right temporo-occipital and left occipital cortical areas, indicating a disrupted structure-function relationship in patients with schizophrenia compared to healthy control subjects.

  19. Functional mapping of language networks in the normal brain using a word-association task

    Directory of Open Access Journals (Sweden)

    Ghosh Shantanu

    2010-01-01

    Full Text Available Background: Language functions are known to be affected in diverse neurological conditions, including ischemic stroke, traumatic brain injury, and brain tumors. Because language networks are extensive, interpretation of functional data depends on the task completed during evaluation. Aim: The aim was to map the hemodynamic consequences of word association using functional magnetic resonance imaging (fMRI in normal human subjects. Materials and Methods: Ten healthy subjects underwent fMRI scanning with a postlexical access semantic association task vs lexical processing task. The fMRI protocol involved a T2FNx01-weighted gradient-echo echo-planar imaging (GE-EPI sequence (TR 4523 ms, TE 64 ms, flip angle 90º with alternate baseline and activation blocks. A total of 78 scans were taken (interscan interval = 3 s with a total imaging time of 587 s. Functional data were processed in Statistical Parametric Mapping software (SPM2 with 8-mm Gaussian kernel by convolving the blood oxygenation level-dependent (BOLD signal with an hemodynamic response function estimated by general linear method to generate SPM{t} and SPM{F} maps. Results: Single subject analysis of the functional data (FWE-corrected, P≤0.001 revealed extensive activation in the frontal lobes, with overlaps among middle frontal gyrus (MFG, superior, and inferior frontal gyri. BOLD activity was also found in the medial frontal gyrus, middle occipital gyrus (MOG, anterior fusiform gyrus, superior and inferior parietal lobules, and to a smaller extent, the thalamus and right anterior cerebellum. Group analysis (FWE-corrected, P≤0.001 revealed neural recruitment of bilateral lingual gyri, left MFG, bilateral MOG, left superior occipital gyrus, left fusiform gyrus, bilateral thalami, and right cerebellar areas. Conclusions: Group data analysis revealed a cerebellar-occipital-fusiform-thalamic network centered around bilateral lingual gyri for word association, thereby indicating how these

  20. 颈动脉狭窄伴局限性皮质脑萎缩22例临床观察%Carotid Stenosis with Limitations of Cortical Brain Atrophy of 22 Cases of Clinical Observation

    Institute of Scientific and Technical Information of China (English)

    常晓侠

    2015-01-01

    目的:通过回顾22例局限性皮质脑萎缩患者临床病例,探讨颈动脉狭窄和局限性皮质脑萎缩的关联性。方法研究选取发生轻度脑梗死患者22例,对其颈动脉血管狭窄情况进行检查评价。结果患者颈动脉正常侧狭窄率正常的比例为22.7%,发生局限性皮质脑萎缩侧均不同程度存在动脉粥样硬化斑块,血管狭窄程度均在中度以上,显著高于正常侧。结论研究显示颈动脉狭窄和脑部局限性皮质脑萎缩之间存在关联性,临床上应重视对局限性皮质脑萎缩患者的颈动脉血管情况检查,及时掌握病情。%Objective Through the review of 22 patients with localized cortical brain atrophy clinical cases, to explore the correlation of carotid stenosis and limitations of cortical brain atrophy.Methods To study the selection of 22 patients with mild cerebral infarction, to evaluate check its carotid artery stenosis. Results The patients with carotid artery stenosis rate is 22.7% of normal, normal side in limitations of cortical brain atrophy side are different degree of atherosclerosis plaques, vascular stenosis degree above moderate, is significantly higher than the normal side.Conclusion The study shows that carotid stenosis and limitations of cortical brain atrophy, and correlation between clinical should pay attention to the limitations of the carotid artery in patients with cortical brain atrophy inspection, timely grasp the condition.

  1. Impairments in brain-derived neurotrophic factor-induced glutamate release in cultured cortical neurons derived from rats with intrauterine growth retardation: possible involvement of suppression of TrkB/phospholipase C-γ activation.

    Science.gov (United States)

    Numakawa, Tadahiro; Matsumoto, Tomoya; Ooshima, Yoshiko; Chiba, Shuichi; Furuta, Miyako; Izumi, Aiko; Ninomiya-Baba, Midori; Odaka, Haruki; Hashido, Kazuo; Adachi, Naoki; Kunugi, Hiroshi

    2014-04-01

    Low birth weight due to intrauterine growth retardation (IUGR) is suggested to be a risk factor for various psychiatric disorders such as schizophrenia. It has been reported that developmental cortical dysfunction and neurocognitive deficits are observed in individuals with IUGR, however, the underlying molecular mechanisms have yet to be elucidated. Brain-derived neurotrophic factor (BDNF) and its receptor TrkB are associated with schizophrenia and play a role in cortical development. We previously demonstrated that BDNF induced glutamate release through activation of the TrkB/phospholipase C-γ (PLC-γ) pathway in developing cultured cortical neurons, and that, using a rat model for IUGR caused by maternal administration of thromboxane A2, cortical levels of TrkB were significantly reduced in IUGR rats at birth. These studies prompted us to hypothesize that TrkB reduction in IUGR cortex led to impairment of BDNF-dependent glutamatergic neurotransmission. In the present study, we found that BDNF-induced glutamate release was strongly impaired in cultured IUGR cortical neurons where TrkB reduction was maintained. Impairment of BDNF-induced glutamate release in IUGR neurons was ameliorated by transfection of human TrkB (hTrkB). Although BDNF-stimulated phosphorylation of TrkB and of PLC-γ was decreased in IUGR neurons, the hTrkB transfection recovered the deficits in their phosphorylation. These results suggest that TrkB reduction causes impairment of BDNF-stimulated glutamatergic function via suppression of TrkB/PLC-γ activation in IUGR cortical neurons. Our findings provide molecular insights into how IUGR links to downregulation of BDNF function in the cortex, which might be involved in the development of IUGR-related diseases such as schizophrenia.

  2. MR-based automatic delineation of volumes of interest in human brain PET images using probability maps

    DEFF Research Database (Denmark)

    Svarer, Claus; Madsen, Karina; Hasselbalch, Steen G.;

    2005-01-01

    delineation of the VOI set. The approach was also shown to work equally well in individuals with pronounced cerebral atrophy. Probability-map-based automatic delineation of VOIs is a fast, objective, reproducible, and safe way to assess regional brain values from PET or SPECT scans. In addition, the method......The purpose of this study was to develop and validate an observer-independent approach for automatic generation of volume-of-interest (VOI) brain templates to be used in emission tomography studies of the brain. The method utilizes a VOI probability map created on the basis of a database of several...... subjects' MR-images, where VOI sets have been defined manually. High-resolution structural MR-images and 5-HT(2A) receptor binding PET-images (in terms of (18)F-altanserin binding) from 10 healthy volunteers and 10 patients with mild cognitive impairment were included for the analysis. A template including...

  3. Brain metabolism in patients with vegetative state after post-resuscitated hypoxic-ischemic brain injury: statistical parametric mapping analysis of F-18 fluorodeoxyglucose positron emission tomography

    Institute of Scientific and Technical Information of China (English)

    Yong Wook Kim; Hyoung Seop Kim; Young-Sil An

    2013-01-01

    Background Hypoxic-ischemic brain injury (HIBI) after cardiopulmonary resuscitation is one of the most devastating neurological conditions that causing the impaired consciousness.However,there were few studies investigated the changes of brain metabolism in patients with vegetative state (VS) after post-resuscitated HIBI.This study aimed to analyze the change of overall brain metabolism and elucidated the brain area correlated with the level of consciousness (LOC) in patients with VS after post-resuscitated HIBI.Methods We consecutively enrolled 17 patients with VS after HIBI,who experienced cardiopulmonary resuscitation.Overall brain metabolism was measured by F-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET) and we compared regional brain metabolic patterns from t7 patients with those from 15 normal controls using voxel-by-voxel based statistical parametric mapping analysis.Additionally,we correlated the LOC measured by the JFK-coma recovery scale-revised of each patient with brain metabolism by covariance analysis.Results Compared with normal controls,the patients with VS after post-resuscitated HIBI revealed significantly decreased brain metabolism in bilateral precuneus,bilateral posterior cingulate gyrus,bilateral middle frontal gyri,bilateral superior parietal gyri,bilateral middle occipital gyri,bilateral precentral gyri (PFEw correctecd <0.0001),and increased brain metabolism in bilateral insula,bilateral cerebella,and the brainstem (PFEw correctecd <0.0001).In covariance analysis,the LOC was significantly correlated with brain metabolism in bilateral fusiform and superior temporal gyri (P uncorrected <0.005).Conclusions Our study demonstrated that the precuneus,the posterior cingulate area and the frontoparietal cortex,which is a component of neural correlate for consciousness,may be relevant structure for impaired consciousness in patient with VS after post-resuscitated HIBI.In post-resuscitated HIBI,measurement of brain

  4. Right hemisphere dominance directly predicts both baseline V1 cortical excitability and the degree of top-down modulation exerted over low-level brain structures.

    Science.gov (United States)

    Arshad, Q; Siddiqui, S; Ramachandran, S; Goga, U; Bonsu, A; Patel, M; Roberts, R E; Nigmatullina, Y; Malhotra, P; Bronstein, A M

    2015-12-17

    Right hemisphere dominance for visuo-spatial attention is characteristically observed in most right-handed individuals. This dominance has been attributed to both an anatomically larger right fronto-parietal network and the existence of asymmetric parietal interhemispheric connections. Previously it has been demonstrated that interhemispheric conflict, which induces left hemisphere inhibition, results in the modulation of both (i) the excitability of the early visual cortex (V1) and (ii) the brainstem-mediated vestibular-ocular reflex (VOR) via top-down control mechanisms. However to date, it remains unknown whether the degree of an individual's right hemisphere dominance for visuospatial function can influence, (i) the baseline excitability of the visual cortex and (ii) the extent to which the right hemisphere can exert top-down modulation. We directly tested this by correlating line bisection error (or pseudoneglect), taken as a measure of right hemisphere dominance, with both (i) visual cortical excitability measured using phosphene perception elicited via single-pulse occipital trans-cranial magnetic stimulation (TMS) and (ii) the degree of trans-cranial direct current stimulation (tDCS)-mediated VOR suppression, following left hemisphere inhibition. We found that those individuals with greater right hemisphere dominance had a less excitable early visual cortex at baseline and demonstrated a greater degree of vestibular nystagmus suppression following left hemisphere cathodal tDCS. To conclude, our results provide the first demonstration that individual differences in right hemisphere dominance can directly predict both the baseline excitability of low-level brain structures and the degree of top-down modulation exerted over them.

  5. Spatio-temporal 16p11.2 protein network implicates cortical late mid-fetal brain development and KCTD13-Cul3-RhoA pathway in psychiatric diseases

    Science.gov (United States)

    Lin, Guan Ning; Corominas, Roser; Lemmens, Irma; Yang, Xinping; Tavernier, Jan; Hill, David E.; Vidal, Marc; Sebat, Jonathan; Iakoucheva, Lilia M.

    2015-01-01

    Summary Psychiatric disorders autism and schizophrenia have a strong genetic component, and copy number variants (CNVs) are firmly implicated. Recurrent deletions and duplications of chromosome 16p11.2 confer high risk for both diseases, but the pathways disrupted by this CNV are poorly defined. Here we investigate the dynamics of 16p11.2 network by integrating physical interactions of 16p11.2 proteins with spatio-temporal gene expression from developing human brain. We observe profound changes in protein interaction networks throughout different stages of brain development and/or in different brain regions. We identify late mid-fetal period of cortical development as most critical for establishing connectivity of 16p11.2 proteins with their co-expressed partners. Furthermore, our results suggest that the regulation of KCTD13-Cul3-RhoA pathway in layer four of inner cortical plate is crucial for controlling brain size and connectivity, and its dysregulation by the de novo mutations may be a potential determinant of 16p11.2 CNV deletion and duplication phenotypes. PMID:25695269

  6. Cerebral blood flow in posterior cortical nodes of the default mode network decreases with task engagement but remains higher than in most brain regions.

    Science.gov (United States)

    Pfefferbaum, Adolf; Chanraud, Sandra; Pitel, Anne-Lise; Müller-Oehring, Eva; Shankaranarayanan, Ajit; Alsop, David C; Rohlfing, Torsten; Sullivan, Edith V

    2011-01-01

    Functional neuroimaging studies provide converging evidence for existence of intrinsic brain networks activated during resting states and deactivated with selective cognitive demands. Whether task-related deactivation of the default mode network signifies depressed activity relative to the remaining brain or simply lower activity relative to its resting state remains controversial. We employed 3D arterial spin labeling imaging to examine regional cerebral blood flow (CBF) during rest, a spatial working memory task, and a second rest. Change in regional CBF from rest to task showed significant normalized and absolute CBF reductions in posterior cingulate, posterior-inferior precuneus, and medial frontal lobes . A Statistical Parametric Mapping connectivity analysis, with an a priori seed in the posterior cingulate cortex, produced deactivation connectivity patterns consistent with the classic "default mode network" and activation connectivity anatomically consistent with engagement in visuospatial tasks. The large task-related CBF decrease in posterior-inferior precuneus relative to its anterior and middle portions adds evidence for the precuneus' heterogeneity. The posterior cingulate and posterior-inferior precuneus were also regions of the highest CBF at rest and during task performance. The difference in regional CBF between intrinsic (resting) and evoked (task) activity levels may represent functional readiness or reserve vulnerable to diminution by conditions affecting perfusion.

  7. An approach for parcellating human cortical areas using resting-state correlations.

    Science.gov (United States)

    Wig, Gagan S; Laumann, Timothy O; Petersen, Steven E

    2014-06-01

    Resting State Functional Connectivity (RSFC) reveals properties related to the brain's underlying organization and function. Features related to RSFC signals, such as the locations where the patterns of RSFC exhibit abrupt transitions, can be used to identify putative boundaries between cortical areas (RSFC-Boundary Mapping). The locations of RSFC-based area boundaries are consistent across independent groups of subjects. RSFC-based parcellation converges with parcellation information from other modalities in many locations, including task-evoked activity and probabilistic estimates of cellular architecture, providing evidence for the ability of RSFC to parcellate brain structures into functionally meaningful units. We not only highlight a collection of these observations, but also point out several limitations and observations that mandate careful consideration in using and interpreting RSFC for the purposes of parcellating the brain's cortical and subcortical structures.

  8. Acute hepatic encephalopathy with diffuse cortical lesions

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, S.M.; Spreer, J.; Schumacher, M. [Section of Neuroradiology, Univ. of Freiburg (Germany); Els, T. [Dept. of Neurology, University of Freiburg (Germany)

    2001-07-01

    Acute hepatic encephalopathy is a poorly defined syndrome of heterogeneous aetiology. We report a 49-year-old woman with alcoholic cirrhosis and hereditary haemorrhagic telangiectasia who developed acute hepatic coma induced by severe gastrointestinal bleeding. Laboratory analysis revealed excessively elevated blood ammonia. MRI showed lesions compatible with chronic hepatic encephalopathy and widespread cortical signal change sparing the perirolandic and occipital cortex. The cortical lesions resembled those of hypoxic brain damage and were interpreted as acute toxic cortical laminar necrosis. (orig.)

  9. Flexible Neural Electrode Array Based-on Porous Graphene for Cortical Microstimulation and Sensing

    Science.gov (United States)

    Lu, Yichen; Lyu, Hongming; Richardson, Andrew G.; Lucas, Timothy H.; Kuzum, Duygu

    2016-09-01

    Neural sensing and stimulation have been the backbone of neuroscience research, brain-machine interfaces and clinical neuromodulation therapies for decades. To-date, most of the neural stimulation systems have relied on sharp metal microelectrodes with poor electrochemical properties that induce extensive damage to the tissue and significantly degrade the long-term stability of implantable systems. Here, we demonstrate a flexible cortical microelectrode array based on porous graphene, which is capable of efficient electrophysiological sensing and stimulation from the brain surface, without penetrating into the tissue. Porous graphene electrodes show superior impedance and charge injection characteristics making them ideal for high efficiency cortical sensing and stimulation. They exhibit no physical delamination or degradation even after 1 million biphasic stimulation cycles, confirming high endurance. In in vivo experiments with rodents, same array is used to sense brain activity patterns with high spatio-temporal resolution and to control leg muscles with high-precision electrical stimulation from the cortical surface. Flexible porous graphene array offers a minimally invasive but high efficiency neuromodulation scheme with potential applications in cortical mapping, brain-computer interfaces, treatment of neurological disorders, where high resolution and simultaneous recording and stimulation of neural activity are crucial.

  10. Mapping homeostatic synaptic plasticity using cable properties of dendrites.

    Science.gov (United States)

    Queenan, B N; Lee, K J; Tan, H; Huganir, R L; Vicini, S; Pak, D T S

    2016-02-19

    When chronically silenced, cortical and hippocampal neurons homeostatically upregulate excitatory synaptic function. However, the subcellular position of such changes on the dendritic tree is not clear. We exploited the cable-filtering properties of dendrites to derive a parameter, the dendritic filtering index (DFI), to map the spatial distribution of synaptic currents. Our analysis indicates that young rat cortical neurons globally scale AMPA receptor-mediated currents, while mature hippocampal neurons do not, revealing distinct homeostatic strategies between brain regions and developmental stages. The DFI presents a useful tool for mapping the dendritic origin of synaptic currents and the location of synaptic plasticity changes.

  11. Computational neuroanatomy: mapping cell-type densities in the mouse brain, simulations from the Allen Brain Atlas

    Science.gov (United States)

    Grange, Pascal

    2015-09-01

    The Allen Brain Atlas of the adult mouse (ABA) consists of digitized expression profiles of thousands of genes in the mouse brain, co-registered to a common three-dimensional template (the Allen Reference Atlas).This brain-wide, genome-wide data set has triggered a renaissance in neuroanatomy. Its voxelized version (with cubic voxels of side 200 microns) is available for desktop computation in MATLAB. On the other hand, brain cells exhibit a great phenotypic diversity (in terms of size, shape and electrophysiological activity), which has inspired the names of some well-studied cell types, such as granule cells and medium spiny neurons. However, no exhaustive taxonomy of brain cell is available. A genetic classification of brain cells is being undertaken, and some cell types have been chraracterized by their transcriptome profiles. However, given a cell type characterized by its transcriptome, it is not clear where else in the brain similar cells can be found. The ABA can been used to solve this region-specificity problem in a data-driven way: rewriting the brain-wide expression profiles of all genes in the atlas as a sum of cell-type-specific transcriptome profiles is equivalent to solving a quadratic optimization problem at each voxel in the brain. However, the estimated brain-wide densities of 64 cell types published recently were based on one series of co-registered coronal in situ hybridization (ISH) images per gene, whereas the online ABA contains several image series per gene, including sagittal ones. In the presented work, we simulate the variability of cell-type densities in a Monte Carlo way by repeatedly drawing a random image series for each gene and solving the optimization problem. This yields error bars on the region-specificity of cell types.

  12. Neuropsin Expression Correlates with Dendritic Marker MAP2c Level in Different Brain Regions of Aging Mice.

    Science.gov (United States)

    Konar, Arpita; Thakur, M K

    2015-01-01

    Neuropsin (NP) is a serine protease, implicated in synaptic plasticity and memory acquisition through cleavage of synaptic adhesion molecule, L1CAM. However, NP has not been explored during brain aging that entails drastic deterioration of plasticity and memory with selective regional vulnerability. Therefore, we have analysed the expression of NP and correlated with its function via analysis of endogenous cleavage of L1CAM and level of dendritic marker MAP2c in different regions of the aging mouse brain. While NP expression gradually decreased in the cerebral cortex during aging, it showed a sharp rise in both olfactory bulb and hippocampus in adult and thereafter declined in old age. NP expression was moderate in young medulla, but undetectable in midbrain and cerebellum. It was positively correlated with L1CAM cleavage and MAP2c level in different brain regions during aging. Taken together, our study shows age-dependent regional variation in NP expression and its positive correlation with MAP2c level, suggesting the involvement of NP in MAP2c mediated alterations in dendritic morphology during aging.

  13. Gamma event-related synchronization analysis: a new method for cortical function mapping%通过Gamma频段能量分析进行大脑皮层功能区定位

    Institute of Scientific and Technical Information of China (English)

    潘鑫; 钱天翼; 韩宏彦; 周文静; 孙朝晖; 王东明; 左焕琮

    2012-01-01

    目的 通过分析颅内脑电中Gamma频段能量变化来实现大脑皮层感觉运动区定位.方法 利用Gamma频段能量分析法、诱发电位(SEP)和皮层电刺激(CES)等电生理检查对8例因难治性癫痫而行颅内电极植入术的患者进行大脑皮层感觉运动区定位,以减少术后功能缺失等并发症.将Gamma频段能量分析方法的定位结果与SEP与CES进行比较.结果 通过统计对比,Gamma频段能量分析所得上肢感觉运动区电极编号与CES和SEP所得感觉运动区电极编号完全重合的占80.7%,完全重合或者紧邻的达92.3%.结论 Gamma频段能量分析方法是一种敏感性高、结果准确的大脑皮层功能区定位的新方法.%Objective To localize the sensory motor cortex of human brain by analyzing the power change in Gamma band ( > 60 Hz ) of electrocorticography (ECoG) data.Methods Eight patients with intractable epilepsy underwent temporary placement of subdural electrodes. After surgery,scnsory cvokcd potential (SEP),electrocortical stimulation (CES) and event-related synchronization analysis of Gamma band ( Gamma ERS analysis) were performed to reduce the risk of complications.The results of Gamma ERS analysis were compared with those of SEP and CES.Results The results of Gamma ERS analysis had 80.7% electrodes fitting perfectly those of CES and SEP.And the percentage reached 92.3% if electrodes were superimposed or added adjacently.Conclusion The Gamma ERS analysis is a new sensitive and precise method for cortical function mapping.

  14. Current trends in intraoperative optical imaging for functional brain mapping and delineation of lesions of language cortex.

    Science.gov (United States)

    Prakash, Neal; Uhlemann, Falk; Sheth, Sameer A; Bookheimer, Susan; Martin, Neil; Toga, Arthur W

    2009-08-01

    Resection of a cerebral arteriovenous malformation (AVM), epileptic focus, or glioma, ideally has a prerequisite of microscopic delineation of the lesion borders in relation to the normal gray and white matter that mediate critical functions. Currently, Wada testing and functional magnetic resonance imaging (fMRI) are used for preoperative mapping of critical function, whereas electrical stimulation mapping (ESM) is used for intraoperative mapping. For lesion delineation, MRI and positron emission tomography (PET) are used preoperatively, whereas microscopy and histological sectioning are used intraoperatively. However, for lesions near eloquent cortex, these imaging techniques may lack sufficient resolution to define the relationship between the lesion and language function, and thus not accurately determine which patients will benefit from neurosurgical resection of the lesion without iatrogenic aphasia. Optical techniques such as intraoperative optical imaging of intrinsic signals (iOIS) show great promise for the precise functional mapping of cortices, as well as delineation of the borders of AVMs, epileptic foci, and gliomas. Here we first review the physiology of neuroimaging, and then progress towards the validation and justification of using intraoperative optical techniques, especially in relation to neurosurgical planning of resection AVMs, epileptic foci, and gliomas near or in eloquent cortex. We conclude with a short description of potential novel intraoperative optical techniques.

  15. CLINICAL STUDY OF ISCHEMIC PENUMBRA REGION IN BRAIN ELECTRICAL ACTIVITY MAPPING

    Institute of Scientific and Technical Information of China (English)

    Liu Qingrui; Liu Mingshun; Gu Lanjie; Mei Fengjun

    2000-01-01

    Department of Neurology, Fourth Affiliated Hospital. Hebei Medical University, Shijiazhuang ABSTRACT OBJETIVE To study features and clinical usage of ischemic penumbra region(IPR) in brain electrical activity mapping(BEAM).BACKGROUND To explore the functional improvement index of IPR untraumaticly. METH0DS 69 patients with acute cerebral infarction were divided into two groups according to different therapeutic time window--early treatment group( 32 cases, treatment in 12 hours)and contral group (37 cases, treatment in 12-72 hours).They were analysed in BEAM pre-and post-treatment Results: BEAM showed that the power of infarcted core was decreased and IPR became smaller in slow waves significantly after treatment in early treatment group and this change was in good agreement with improvement of clinical functions and SPECT DISCUSSION The key to treat acute cerebral infarction was to improve functions of IPR as 8oos as possible, BEAM could show the location and size of IPR. CONCLUSION BEAM was one of important index in evaluating the function of IPR.

  16. Mapping the mouse brain with rs-fMRI: An optimized pipeline for functional network identification.

    Science.gov (United States)

    Zerbi, Valerio; Grandjean, Joanes; Rudin, Markus; Wenderoth, Nicole

    2015-12-01

    The use of resting state fMRI (rs-fMRI) in translational research is a powerful tool to assess brain connectivity and investigate neuropathology in mouse models. However, despite encouraging initial results, the characterization of consistent and robust resting state networks in mice remains a methodological challenge. One key reason is that the quality of the measured MR signal is degraded by the presence of structural noise from non-neural sources. Notably, in the current pipeline of the Human Connectome Project, a novel approach has been introduced to clean rs-fMRI data, which involves automatic artifact component classification and data cleaning (FIX). FIX does not require any external recordings of physiology or the segmentation of CSF and white matter. In this study, we evaluated the performance of FIX for analyzing mouse rs-fMRI data. Our results showed that FIX can be easily applied to mouse datasets and detects true signals with 100% accuracy and true noise components with very high accuracy (>98%), thus reducing both within- and between-subject variability of rs-fMRI connectivity measurements. Using this improved pre-process