scholarly journals BigBrain 3D atlas of cortical layers: cortical and laminar thickness gradients diverge in sensory and motor cortices

2019 ◽  
Author(s):  
Konrad Wagstyl ◽  
Stéphanie Larocque ◽  
Guillem Cucurull ◽  
Claude Lepage ◽  
Joseph Paul Cohen ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Human Brain ◽  
Cortical Thickness ◽  
Functional Organization ◽  
Functional Neuroanatomy ◽  
Cortical Layers ◽  
Opposite Pattern ◽  
Isotropic Resolution ◽  
Brain Microstructure ◽  
Laminar Thickness

AbstractHistological atlases of the cerebral cortex, such as those made famous by Brodmann and von Economo, are invaluable for understanding human brain microstructure and its relationship with functional organization in the brain. However, these existing atlases are limited to small numbers of manually annotated samples from a single cerebral hemisphere, measured from 2D histological sections. We present the first whole-brain quantitative 3D laminar atlas of the human cerebral cortex. This atlas was derived from a 3D histological model of the human brain at 20 micron isotropic resolution (BigBrain), using a convolutional neural network to segment, automatically, the cortical layers in both hemispheres. Our approach overcomes many of the historical challenges with measurement of histological thickness in 2D and the resultant laminar atlas provides an unprecedented level of precision and detail.We utilized this BigBrain cortical atlas to test whether previously reported thickness gradients, as measured by MRI in sensory and motor processing cortices, were present in a histological atlas of cortical thickness, and which cortical layers were contributing to these gradients. Cortical thickness increased across sensory processing hierarchies, primarily driven by layers III, V and VI. In contrast, fronto-motor cortices showed the opposite pattern, with decreases in total and pyramidal layer thickness. These findings illustrate how this laminar atlas will provide a link between single-neuron morphology, mesoscale cortical layering, macroscopic cortical thickness and, ultimately, functional neuroanatomy.

scholarly journals Functional Territories of Human Dentate Nucleus

2019 ◽  
Vol 30 (4) ◽  
pp. 2401-2417 ◽  
Author(s):  
Xavier Guell ◽  
Anila M D’Mello ◽  
Nicholas A Hubbard ◽  
Rachel R Romeo ◽  
John D E Gabrieli ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Cerebellar Cortex ◽  
Broad Spectrum ◽  
Neural Control ◽  
Functional Organization ◽  
Neural Processing ◽  
Functional Neuroanatomy ◽  
Default Mode ◽  
Healthy Humans ◽  
Spatio Temporal

Abstract Anatomical connections link the cerebellar cortex with multiple sensory, motor, association, and paralimbic cerebral areas. The majority of fibers that exit cerebellar cortex synapse in dentate nuclei (DN) before reaching extracerebellar structures such as cerebral cortex, but the functional neuroanatomy of human DN remains largely unmapped. Neuroimaging research has redefined broad categories of functional division in the human brain showing that primary processing, attentional (task positive) processing, and default-mode (task negative) processing are three central poles of neural macroscale functional organization. This broad spectrum of human neural processing categories is represented not only in the cerebral cortex, but also in the thalamus, striatum, and cerebellar cortex. Whether functional organization in DN obeys a similar set of macroscale divisions, and whether DN are yet another compartment of representation of a broad spectrum of human neural processing categories, remains unknown. Here, we show for the first time that human DN are optimally divided into three functional territories as indexed by high spatio-temporal resolution resting-state MRI in 77 healthy humans, and that these three distinct territories contribute uniquely to default-mode, salience-motor, and visual cerebral cortical networks. Our findings provide a systems neuroscience substrate for cerebellar output to influence multiple broad categories of neural control.

scholarly journals Functional Territories of Human Dentate Nucleus

2019 ◽  
Author(s):  
Xavier Guell ◽  
Anila M D’Mello ◽  
Nicholas A Hubbard ◽  
Rachel R Romeo ◽  
John DE Gabrieli ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Cerebellar Cortex ◽  
Broad Spectrum ◽  
Brain Function ◽  
Functional Organization ◽  
Data Driven ◽  
Neural Processing ◽  
Functional Neuroanatomy ◽  
Default Mode ◽  
Macro Scale

ABSTRACTAnatomical connections link the cerebellar cortex with multiple distinct sensory, motor, association, and paralimbic areas of the cerebrum. These projections allow a topographically precise cerebellar modulation of multiple domains of neurological function, and underscore the relevance of the cerebellum for the pathophysiology of numerous disorders in neurology and psychiatry. The majority of fibers that exit the cerebellar cortex synapse in the dentate nuclei (DN) before reaching extracerebellar structures such as cerebral cortex. Although the DN have a central position in the anatomy of the cerebello-cerebral circuits, the functional neuroanatomy of human DN remains largely unmapped. Neuroimaging research has redefined broad categories of functional division in the human brain showing that primary processing, attentional (task positive) processing, and default-mode (task negative) processing are three central poles of neural macro-scale functional organization. This new macro-scale understanding of the range and poles of brain function has revealed that a broad spectrum of human neural processing categories (primary, task positive, task negative) is represented not only in the cerebral cortex, but also in the thalamus, striatum, and cerebellar cortex. Whether functional organization in DN obeys a similar set of macroscale divisions, and whether DN are yet another compartment of representation of a broad spectrum of human neural processing categories, remains unknown. Here we show for the first time that human DN is optimally divided into three functional territories as indexed by high spatio-temporal resolution resting-state MRI in 60 healthy adolescents, and that these three distinct territories contribute uniquely to default-mode, salience-motor, and visual brain networks. These conclusions are supported by novel analytical strategies in human studies of DN organization, including 64-channel MRI imaging, data-driven methods, and replication in an independent sample. Our findings provide a systems neuroscience substrate for cerebellar output to influence multiple broad categories of neural control - namely default- mode, attentional, and multiple unimodal streams of information processing including motor and visual. They also provide a validated data-driven mapping of functions in human DN, crucial for the design of methodology and interpretation of results in future neuroimaging studies of brain function and dysfunction.

Magnetoencephalography Reveals Functions of the Human Brain

Physiology ◽  
1993 ◽  
Vol 8 (5) ◽  
pp. 213-215
Author(s):  
R Hari
Keyword(s):  
Cerebral Cortex ◽  
Human Brain ◽  
Cognitive Functions ◽  
Functional Organization ◽  
Human Head ◽  
Accurate Information ◽  
Neural Basis ◽  
Human Cerebral Cortex

Magnetoencephalographic signals, detected noninvasively outside the human head, arise from intracellular currents in the fissural cortex. Localization of these currents gives spatially and temporally accurate information about functional organization of the healthy and diseased human cerebral cortex and about neural basis of cognitive functions.

scholarly journals Brainwide functional networks associated with anatomically- and functionally-defined hippocampal subfields using ultrahigh-resolution fMRI

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wei-Tang Chang ◽  
Stephanie K. Langella ◽  
Yichuan Tang ◽  
Sahar Ahmad ◽  
Han Zhang ◽  
...  
Keyword(s):  
Resting State ◽  
Functional Organization ◽  
A Priori ◽  
Longitudinal Axis ◽  
Functional Networks ◽  
Resting State Functional Connectivity ◽  
Underlying Assumption ◽  
Isotropic Resolution ◽  
Hippocampal Subfields ◽  
Fine Grained

AbstractThe hippocampus is critical for learning and memory and may be separated into anatomically-defined hippocampal subfields (aHPSFs). Hippocampal functional networks, particularly during resting state, are generally analyzed using aHPSFs as seed regions, with the underlying assumption that the function within a subfield is homogeneous, yet heterogeneous between subfields. However, several prior studies have observed similar resting-state functional connectivity (FC) profiles between aHPSFs. Alternatively, data-driven approaches investigate hippocampal functional organization without a priori assumptions. However, insufficient spatial resolution may result in a number of caveats concerning the reliability of the results. Hence, we developed a functional Magnetic Resonance Imaging (fMRI) sequence on a 7 T MR scanner achieving 0.94 mm isotropic resolution with a TR of 2 s and brain-wide coverage to (1) investigate the functional organization within hippocampus at rest, and (2) compare the brain-wide FC associated with fine-grained aHPSFs and functionally-defined hippocampal subfields (fHPSFs). This study showed that fHPSFs were arranged along the longitudinal axis that were not comparable to the lamellar structures of aHPSFs. For brain-wide FC, the fHPSFs rather than aHPSFs revealed that a number of fHPSFs connected specifically with some of the functional networks. Different functional networks also showed preferential connections with different portions of hippocampal subfields.

scholarly journals Myelin densities in retinotopically defined dorsal visual areas of the macaque

2021 ◽  
Author(s):  
Xiaolian Li ◽  
Qi Zhu ◽  
Wim Vanduffel
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Cortical Thickness ◽  
New World Monkeys ◽  
Isotropic Resolution ◽  
Density Mapping ◽  
Area V2 ◽  
Visual Areas ◽  
Density Results

AbstractThe visuotopic organization of dorsal visual cortex rostral to area V2 in primates has been a longstanding source of controversy. Using sub-millimeter phase-encoded retinotopic fMRI mapping, we recently provided evidence for a surprisingly similar visuotopic organization in dorsal visual cortex of macaques compared to previously published maps in New world monkeys (Zhu and Vanduffel, Proc Natl Acad Sci USA 116:2306–2311, 2019). Although individual quadrant representations could be robustly delineated in that study, their grouping into hemifield representations remains a major challenge. Here, we combined in-vivo high-resolution myelin density mapping based on MR imaging (400 µm isotropic resolution) with fine-grained retinotopic fMRI to quantitatively compare myelin densities across retinotopically defined visual areas in macaques. Complementing previously documented differences in populational receptive-field (pRF) size and visual field signs, myelin densities of both quadrants of the dorsolateral posterior area (DLP) and area V3A are significantly different compared to dorsal and ventral area V3. Moreover, no differences in myelin density were observed between the two matching quadrants belonging to areas DLP, V3A, V1, V2 and V4, respectively. This was not the case, however, for the dorsal and ventral quadrants of area V3, which showed significant differences in MR-defined myelin densities, corroborating evidence of previous myelin staining studies. Interestingly, the pRF sizes and visual field signs of both quadrant representations in V3 are not different. Although myelin density correlates with curvature and anticorrelates with cortical thickness when measured across the entire cortex, exactly as in humans, the myelin density results in the visual areas cannot be explained by variability in cortical thickness and curvature between these areas. The present myelin density results largely support our previous model to group the two quadrants of DLP and V3A, rather than grouping DLP- with V3v into a single area VLP, or V3d with V3A+ into DM.

scholarly journals Impact of Zika Virus on adult human brain structure and functional organization

2018 ◽  
Vol 5 (6) ◽  
pp. 752-762 ◽  
Author(s):  
Richard Bido-Medina ◽  
Jonathan Wirsich ◽  
Minelly Rodríguez ◽  
Jairo Oviedo ◽  
Isidro Miches ◽  
...  
Keyword(s):  
Human Brain ◽  
Zika Virus ◽  
Brain Structure ◽  
Functional Organization ◽  
Adult Human Brain ◽  
Adult Human

Brain asymmetry, immunity, handedness

Open Medicine ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Zlatislav Stoyanov ◽  
Lyoubka Decheva ◽  
Irina Pashalieva ◽  
Piareta Nikolova
Keyword(s):  
Immune Response ◽  
Human Brain ◽  
Right Hemisphere ◽  
Functional Organization ◽  
Brain Asymmetry ◽  
Internal Environment ◽  
Living Nature ◽  
Left Right Asymmetry ◽  
The Right

AbstractThe principle of symmetry-asymmetry is widely presented in the structural and functional organization of the nonliving and living nature. One of the most complex manifestations of this principle is the left-right asymmetry of the human brain. The present review summarizes previous and contemporary literary data regarding the role of brain asymmetry in neuroimmunomodulation. Some handedness-related peculiarities are outlined additionally. Brain asymmetry is considered to be imprinted in the formation and regulation of the individual’s responses and relationships at an immunological level with the external and internal environment. The assumptions that the hemispheres modulate immune response in an asymmetric manner have been confirmed in experiments on animals. Some authors assume that the right hemisphere plays an indirect role in neuroimmunomodulation, controlling and suppressing the left hemispheric inductive signals.

scholarly journals The contribution of cortical thickness and surface area to gray matter asymmetries in the healthy human brain

2014 ◽  
Vol 35 (12) ◽  
pp. 6011-6022 ◽  
Author(s):  
Katja Koelkebeck ◽  
Jun Miyata ◽  
Manabu Kubota ◽  
Waldemar Kohl ◽  
Shuraku Son ◽  
...  
Keyword(s):  
Human Brain ◽  
Surface Area ◽  
Cortical Thickness ◽  
Gray Matter ◽  
Healthy Human

scholarly journals Shaping brain structure: Genetic and phylogenetic axes of macroscale organization of cortical thickness

2020 ◽  
Vol 6 (39) ◽  
pp. eabb3417 ◽  
Author(s):  
Sofie L. Valk ◽  
Ting Xu ◽  
Daniel S. Margulies ◽  
Shahrzad Kharabian Masouleh ◽  
Casey Paquola ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Cortical Thickness ◽  
Structural Organization ◽  
Perception And Action ◽  
Human Cognition ◽  
Evolutionary Patterns ◽  
Structural Covariance ◽  
Cortical Organization ◽  
Functional Topography ◽  
Dual Origin

The topology of the cerebral cortex has been proposed to provide an important source of constraint for the organization of cognition. In a sample of twins (n = 1113), we determined structural covariance of thickness to be organized along both a posterior-to-anterior and an inferior-to-superior axis. Both organizational axes were present when investigating the genetic correlation of cortical thickness, suggesting a strong genetic component in humans, and had a comparable organization in macaques, demonstrating they are phylogenetically conserved in primates. In both species, the inferior-superior dimension of cortical organization aligned with the predictions of dual-origin theory, and in humans, we found that the posterior-to-anterior axis related to a functional topography describing a continuum of functions from basic processes involved in perception and action to more abstract features of human cognition. Together, our study provides important insights into how functional and evolutionary patterns converge at the level of macroscale cortical structural organization.

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