The Experts below are selected from a list of 2706 Experts worldwide ranked by ideXlab platform
B. U. Forstmann - One of the best experts on this subject based on the ideXlab platform.
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Visualizing the Human Subcortex Using Ultra-high Field Magnetic Resonance Imaging
Brain Topography, 2018Co-Authors: M. C. Keuken, B. R. Isaacs, R. Trampel, W. Zwaag, B. U. ForstmannAbstract:With the recent increased availability of ultra-high field (UHF) magnetic resonance imaging (MRI), substantial progress has been made in visualizing the human brain, which can now be done in extraordinary detail. This review provides an extensive overview of the use of UHF MRI in visualizing the human Subcortex for both healthy and patient populations. The high inter-subject variability in size and location of subcortical structures limits the usability of atlases in the midbrain. Fortunately, the combined results of this review indicate that a large number of subcortical areas can be visualized in individual space using UHF MRI. Current limitations and potential solutions of UHF MRI for visualizing the Subcortex are also discussed.
Andrew Zalesky - One of the best experts on this subject based on the ideXlab platform.
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Topographic organization of the human Subcortex unveiled with functional connectivity gradients
Nature Neuroscience, 2020Co-Authors: Ye Tian, Daniel S. Margulies, Michael Breakspear, Andrew ZaleskyAbstract:This work by Tian and colleagues unveils the extraordinarily complex layout of the human Subcortex by identifying 27 new functional regions that organize hierarchically across four scales and adapt to changing cognitive demands. Brain atlases are fundamental to understanding the topographic organization of the human brain, yet many contemporary human atlases cover only the cerebral cortex, leaving the Subcortex a terra incognita. We use functional MRI (fMRI) to map the complex topographic organization of the human Subcortex, revealing large-scale connectivity gradients and new areal boundaries. We unveil four scales of subcortical organization that recapitulate well-known anatomical nuclei at the coarsest scale and delineate 27 new bilateral regions at the finest. Ultrahigh field strength fMRI corroborates and extends this organizational structure, enabling the delineation of finer subdivisions of the hippocampus and the amygdala, while task-evoked fMRI reveals a subtle subcortical reorganization in response to changing cognitive demands. A new subcortical atlas is delineated, personalized to represent individual differences and used to uncover reproducible brain–behavior relationships. Linking cortical networks to subcortical regions recapitulates a task-positive to task-negative axis. This new atlas enables holistic connectome mapping and characterization of cortico–subcortical connectivity.
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Topographic organization of the human Subcortex unveiled with functional connectivity gradients.
Nature neuroscience, 2020Co-Authors: Ye Tian, Daniel S. Margulies, Michael Breakspear, Andrew ZaleskyAbstract:Brain atlases are fundamental to understanding the topographic organization of the human brain, yet many contemporary human atlases cover only the cerebral cortex, leaving the Subcortex a terra incognita. We use functional MRI (fMRI) to map the complex topographic organization of the human Subcortex, revealing large-scale connectivity gradients and new areal boundaries. We unveil four scales of subcortical organization that recapitulate well-known anatomical nuclei at the coarsest scale and delineate 27 new bilateral regions at the finest. Ultrahigh field strength fMRI corroborates and extends this organizational structure, enabling the delineation of finer subdivisions of the hippocampus and the amygdala, while task-evoked fMRI reveals a subtle subcortical reorganization in response to changing cognitive demands. A new subcortical atlas is delineated, personalized to represent individual differences and used to uncover reproducible brain-behavior relationships. Linking cortical networks to subcortical regions recapitulates a task-positive to task-negative axis. This new atlas enables holistic connectome mapping and characterization of cortico-subcortical connectivity.
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Topographic organization of the human Subcortex unveiled with functional connectivity gradients
2020Co-Authors: Ye Tian, Daniel S. Margulies, Michael Breakspear, Andrew ZaleskyAbstract:Understanding the topographic organization of the human brain remains a major goal in neuroscience. Brain atlases are fundamental to this goal, yet many contemporary human atlases cover only the cerebral cortex, leaving the Subcortex a terra incognita. We revealed the complex topographic organization of the human Subcortex by disambiguating smooth connectivity gradients from discrete areal boundaries in resting-state fMRI data acquired from more than 1000 healthy adults. This unveiled four scales of subcortical organization, recapitulating well-known anatomical nuclei at the coarsest scale and delineating 27 new bilateral regions at the finest. Ultra-high field strength fMRI corroborated and extended this organizational structure, enabling delineation of finer subdivisions of hippocampus and amygdala, while task-evoked fMRI revealed a subtle reorganization of subcortical topography in response to changing cognitive demands. A new subcortical atlas was delineated, personalized to account for individual connectivity differences and utilized to uncover reproducible relationships between subcortical connectivity and individual variation in human behaviors. Linking cortical networks to subcortical regions recapitulated a task-positive to task-negative organizational axis. The new atlas enables holistic connectome mapping and characterization of cortico-subcortical connectivity.
James W Simpkins - One of the best experts on this subject based on the ideXlab platform.
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17beta-Estradiol extends ischemic thresholds and exerts neuroprotective effects in cerebral Subcortex against transient focal cerebral ischemia in rats.
Brain research, 2003Co-Authors: Tao Fan, Shao-hua Yang, Erik Johnson, Barbara Osteen, Ronald Hayes, Arthur L Day, James W SimpkinsAbstract:Neuroprotective effects of estrogens are demonstrated consistently in the cerebral cortex, but not in subcortical areas. In the present study, transient middle cerebral artery occlusions (MCAO) were induced for various duration, and protective effects of estrogen treatment on the cerebral cortex and Subcortex were evaluated. MCAO was induced for 30, 40 or 60 min in ovariectomized rats. Animals were treated with 17beta-estradiol (E2) or vehicle (OVX) 2 h before MCAO and sacrificed 24 h after the indicated duration of MCAO. Ischemic lesion was evaluated by 2,3,5-triphenyltetrazolium chloride staining, hematoxylin and eosin staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. E2 treatment reduced the magnitude and delayed the appearance of the total ischemic lesion area and largely prevented TUNEL staining in the cortex. In the Subcortex, E2 treatment prevented the ischemic lesion in the 30-min group, reduced lesion area in the 40-min group, but had no effect on ischemic lesion area in the 60-min group. E2 treatment significantly decreased apoptotic cell number in the subcortical area at 30 and 40 min, but not at 60 min of MCAO. This study demonstrated that estrogen treatment can protect the cerebral Subcortex in a severity-dependent manner, suggesting that the lack of protective effects of estrogen treatment in the Subcortex is not due to the lack of estrogen receptors. Further, this study indicates that estrogens could be used as a neuroprotectant to prolong the therapeutic window of thrombolysis and prolong the time of cerebral circulation intervention for neurosurgical procedure.
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17β-Estradiol extends ischemic thresholds and exerts neuroprotective effects in cerebral Subcortex against transient focal cerebral ischemia in rats
Brain Research, 2003Co-Authors: Tao Fan, Shao-hua Yang, Arthur L Day, Erik A. Johnson, Barbara E. O'steen, Ronald L. Hayes, James W SimpkinsAbstract:Abstract Neuroprotective effects of estrogens are demonstrated consistently in the cerebral cortex, but not in subcortical areas. In the present study, transient middle cerebral artery occlusions (MCAO) were induced for various duration, and protective effects of estrogen treatment on the cerebral cortex and Subcortex were evaluated. MCAO was induced for 30, 40 or 60 min in ovariectomized rats. Animals were treated with 17β-estradiol (E2) or vehicle (OVX) 2 h before MCAO and sacrificed 24 h after the indicated duration of MCAO. Ischemic lesion was evaluated by 2,3,5-triphenyltetrazolium chloride staining, hematoxylin and eosin staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. E2 treatment reduced the magnitude and delayed the appearance of the total ischemic lesion area and largely prevented TUNEL staining in the cortex. In the Subcortex, E2 treatment prevented the ischemic lesion in the 30-min group, reduced lesion area in the 40-min group, but had no effect on ischemic lesion area in the 60-min group. E2 treatment significantly decreased apoptotic cell number in the subcortical area at 30 and 40 min, but not at 60 min of MCAO. This study demonstrated that estrogen treatment can protect the cerebral Subcortex in a severity-dependent manner, suggesting that the lack of protective effects of estrogen treatment in the Subcortex is not due to the lack of estrogen receptors. Further, this study indicates that estrogens could be used as a neuroprotectant to prolong the therapeutic window of thrombolysis and prolong the time of cerebral circulation intervention for neurosurgical procedure.
Birte U. Forstmann - One of the best experts on this subject based on the ideXlab platform.
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Multi-contrast Anatomical Subcortical Structures Parcellation
2020Co-Authors: Pierre-louis Bazin, Anneke Alkemade, Martijn Mulder, Amanda G. Henry, Birte U. ForstmannAbstract:The human Subcortex is comprised of more than 450 individual nuclei which lie deep in the brain. Due to their small size and close proximity, up until now only 7% have been depicted in standard MRI atlases. Thus, the human Subcortex can largely be considered as terra incognita. Here we present a new open source parcellation algorithm to map terra incognita automatically. The new algorithm has been tested on 17 prominent subcortical structures based on a large quantitative MRI dataset at 7 Tesla. The algorithm is carefully validated against expert human raters, available in Open Source, and can easily be extended to other subcortical structures and applied to any quantitative MRI dataset. In sum, we hope this novel parcellation algorithm will facilitate functional and structural neuroimaging research into small subcortical nuclei and help to chart terra incognita.
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Large scale structure-function mappings of the human Subcortex
Scientific reports, 2018Co-Authors: Max C. Keuken, Leendert Van Maanen, Michiel Boswijk, Birte U. Forstmann, Mark SteyversAbstract:Currently little is known about structure-function mappings in the human Subcortex. Here we present a large-scale automated meta-analysis on the literature to understand the structure-function mapping in the human Subcortex. The results provide converging evidence into unique large scale structure-function mappings of the human Subcortex based on their functional and anatomical similarity.
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Towards a mechanistic understanding of the human Subcortex
Nature reviews. Neuroscience, 2016Co-Authors: Birte U. Forstmann, Leendert Van Maanen, Gilles De Hollander, Anneke Alkemade, Max C. KeukenAbstract:The human Subcortex is a densely populated part of the brain, of which only 7% of the individual structures are depicted in standard MRI atlases. In vivo MRI of the Subcortex is challenging owing to its anatomical complexity and its deep location in the brain. The technical advances that are needed to reliably uncover this 'terra incognita' call for an interdisciplinary human neuroanatomical approach. We discuss the emerging methods that could be used in such an approach and the incorporation of the data that are generated from these methods into model-based cognitive neuroscience frameworks.
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A probabilistic atlas of the basal ganglia using 7 T MRI
Data in brief, 2015Co-Authors: Max C. Keuken, Birte U. ForstmannAbstract:A common localization procedure in functional imaging studies includes the overlay of statistical parametric functional magnetic resonance imaging (fMRI) maps or coordinates with neuroanatomical atlases in standard space, e.g., MNI-space. This procedure allows the identification of specific brain regions. Most standard MRI software packages include a wide range of atlases but have a poor coverage of the Subcortex. We estimated that approximately 7% of the known subcortical structures are mapped in standard MRI-compatible atlases [1]. Here we provide a data description of a subcortical probabilistic atlas based on ultra-high resolution in-vivo anatomical imaging using 7 T (T) MRI. The atlas includes six subcortical nuclei: the striatum (STR), the globus pallidus internal and external segment (GPi/e), the subthalamic nucleus (STN), the substantia nigra (SN), and the red nucleus (RN). These probabilistic atlases are shared on freely available platforms such as NITRC and NeuroVault and are published in NeuroImage "Quantifying inter-individual anatomical variability in the Subcortex using 7 T structural MRI" [2].
M. C. Keuken - One of the best experts on this subject based on the ideXlab platform.
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Visualizing the Human Subcortex Using Ultra-high Field Magnetic Resonance Imaging
Brain Topography, 2018Co-Authors: M. C. Keuken, B. R. Isaacs, R. Trampel, W. Zwaag, B. U. ForstmannAbstract:With the recent increased availability of ultra-high field (UHF) magnetic resonance imaging (MRI), substantial progress has been made in visualizing the human brain, which can now be done in extraordinary detail. This review provides an extensive overview of the use of UHF MRI in visualizing the human Subcortex for both healthy and patient populations. The high inter-subject variability in size and location of subcortical structures limits the usability of atlases in the midbrain. Fortunately, the combined results of this review indicate that a large number of subcortical areas can be visualized in individual space using UHF MRI. Current limitations and potential solutions of UHF MRI for visualizing the Subcortex are also discussed.
