Contrastive Representation Learning For Whole Brain Cytoarchitectonic Mapping In Histological Human Brain Sections

Studies investigating human brain response to emotional stimuli—particularly high-arousing versus neutral stimuli—have obtained inconsistent results. The present study was the first to combine magnetoencephalography (MEG) with the bootstrapping method to examine the whole brain and identify the cortical regions involved in this differential response. Seventeen healthy participants (11 females, aged 19 to 33 years; mean age, 26.9 years) were presented with high-arousing emotional (pleasant and unpleasant) and neutral pictures, and their brain responses were measured using MEG. When random resampling bootstrapping was performed for each participant, the greatest differences between high-arousing emotional and neutral stimuli during M300 (270–320 ms) were found to occur in the right temporo-parietal region. This finding was observed in response to both pleasant and unpleasant stimuli. The results, which may be more robust than previous studies because of bootstrapping and examination of the whole brain, reinforce the essential role of the right hemisphere in emotion processing.

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Capturing the non-stationarity of whole-brain dynamics underlying human brain states

NeuroImage ◽

10.1016/j.neuroimage.2021.118551 ◽

2021 ◽

pp. 118551

Author(s):

J.A. Galadí ◽

S. Silva Pereira ◽

Y. Sanz Perl ◽

M.L. Kringelbach ◽

I. Gayte ◽

...

Keyword(s):

Human Brain ◽

Brain Dynamics ◽

Whole Brain ◽

Brain States

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Scatterometry Measurements With Scattered Light Imaging Enable New Insights Into the Nerve Fiber Architecture of the Brain

Frontiers in Neuroanatomy ◽

10.3389/fnana.2021.767223 ◽

2021 ◽

Vol 15 ◽

Author(s):

Miriam Menzel ◽

Marouan Ritzkowski ◽

Jan A. Reuter ◽

David Gräßel ◽

Katrin Amunts ◽

...

Keyword(s):

Human Brain ◽

Nerve Fiber ◽

Brain Tissue ◽

Scattered Light ◽

Polar Angle ◽

Nerve Fibers ◽

Fiber Architecture ◽

Whole Brain ◽

Tissue Samples ◽

The Brain

The correct reconstruction of individual (crossing) nerve fibers is a prerequisite when constructing a detailed network model of the brain. The recently developed technique Scattered Light Imaging (SLI) allows the reconstruction of crossing nerve fiber pathways in whole brain tissue samples with micrometer resolution: the individual fiber orientations are determined by illuminating unstained histological brain sections from different directions, measuring the transmitted scattered light under normal incidence, and studying the light intensity profiles of each pixel in the resulting image series. So far, SLI measurements were performed with a fixed polar angle of illumination and a small number of illumination directions, providing only an estimate of the nerve fiber directions and limited information about the underlying tissue structure. Here, we use a display with individually controllable light-emitting diodes to measure the full distribution of scattered light behind the sample (scattering pattern) for each image pixel at once, enabling scatterometry measurements of whole brain tissue samples. We compare our results to coherent Fourier scatterometry (raster-scanning the sample with a non-focused laser beam) and previous SLI measurements with fixed polar angle of illumination, using sections from a vervet monkey brain and human optic tracts. Finally, we present SLI scatterometry measurements of a human brain section with 3 μm in-plane resolution, demonstrating that the technique is a powerful approach to gain new insights into the nerve fiber architecture of the human brain.

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Altered Weibull Degree Distribution in Resting-State Functional Brain Networks Is Associated With Cognitive Decline in Mild Cognitive Impairment

Frontiers in Aging Neuroscience ◽

10.3389/fnagi.2020.599112 ◽

2021 ◽

Vol 12 ◽

Author(s):

Yifei Zhang ◽

Xiaodan Chen ◽

Xinyuan Liang ◽

Zhijiang Wang ◽

Teng Xie ◽

...

Keyword(s):

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Human Brain ◽

Cognitive Performance ◽

Power Law ◽

Resting State ◽

Brain Networks ◽

Functional Networks ◽

Whole Brain ◽

Connectivity Degree

The topological organization of human brain networks can be mathematically characterized by the connectivity degree distribution of network nodes. However, there is no clear consensus on whether the topological structure of brain networks follows a power law or other probability distributions, and whether it is altered in Alzheimer's disease (AD). Here we employed resting-state functional MRI and graph theory approaches to investigate the fitting of degree distributions of the whole-brain functional networks and seven subnetworks in healthy subjects and individuals with amnestic mild cognitive impairment (aMCI), i.e., the prodromal stage of AD, and whether they are altered and correlated with cognitive performance in patients. Forty-one elderly cognitively healthy controls and 30 aMCI subjects were included. We constructed functional connectivity matrices among brain voxels and examined nodal degree distributions that were fitted by maximum likelihood estimation. In the whole-brain networks and all functional subnetworks, the connectivity degree distributions were fitted better by the Weibull distribution [f(x)~x(β−1)e(−λxβ)] than power law or power law with exponential cutoff. Compared with the healthy control group, the aMCI group showed lower Weibull β parameters (shape factor) in both the whole-brain networks and all seven subnetworks (false-discovery rate-corrected, p < 0.05). These decreases of the Weibull β parameters in the whole-brain networks and all subnetworks except for ventral attention were associated with reduced cognitive performance in individuals with aMCI. Thus, we provided a short-tailed model to capture intrinsic connectivity structure of the human brain functional networks in health and disease.

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Regional Metabolite Concentrations in Aging Human Brain: Comparison of Short-TE Whole Brain MR Spectroscopic Imaging and Single Voxel Spectroscopy at 3T

Clinical Neuroradiology ◽

10.1007/s00062-018-00757-x ◽

2019 ◽

Vol 30 (2) ◽

pp. 251-261 ◽

Cited By ~ 3

Author(s):

Helen Maghsudi ◽

Birte Schmitz ◽

Andrew A. Maudsley ◽

Sulaiman Sheriff ◽

Paul Bronzlik ◽

...

Keyword(s):

Human Brain ◽

Spectroscopic Imaging ◽

Whole Brain ◽

Single Voxel ◽

Metabolite Concentrations ◽

Mr Spectroscopic Imaging

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Dynamic coupling of whole-brain neuronal and neurotransmitter systems

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1921475117 ◽

2020 ◽

Vol 117 (17) ◽

pp. 9566-9576 ◽

Cited By ~ 23

Author(s):

Morten L. Kringelbach ◽

Josephine Cruzat ◽

Joana Cabral ◽

Gitte Moos Knudsen ◽

Robin Carhart-Harris ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Human Brain ◽

Brain Function ◽

Mutual Coupling ◽

Resonance Imaging ◽

Anatomical Connectivity ◽

Whole Brain ◽

Neurotransmitter Systems ◽

Healthy Humans

Remarkable progress has come from whole-brain models linking anatomy and function. Paradoxically, it is not clear how a neuronal dynamical system running in the fixed human anatomical connectome can give rise to the rich changes in the functional repertoire associated with human brain function, which is impossible to explain through long-term plasticity. Neuromodulation evolved to allow for such flexibility by dynamically updating the effectivity of the fixed anatomical connectivity. Here, we introduce a theoretical framework modeling the dynamical mutual coupling between the neuronal and neurotransmitter systems. We demonstrate that this framework is crucial to advance our understanding of whole-brain dynamics by bidirectional coupling of the two systems through combining multimodal neuroimaging data (diffusion magnetic resonance imaging [dMRI], functional magnetic resonance imaging [fMRI], and positron electron tomography [PET]) to explain the functional effects of specific serotoninergic receptor (5-HT2AR) stimulation with psilocybin in healthy humans. This advance provides an understanding of why psilocybin is showing considerable promise as a therapeutic intervention for neuropsychiatric disorders including depression, anxiety, and addiction. Overall, these insights demonstrate that the whole-brain mutual coupling between the neuronal and the neurotransmission systems is essential for understanding the remarkable flexibility of human brain function despite having to rely on fixed anatomical connectivity.

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Will We Hit a Wall? Forecasting Bottlenecks to Whole Brain Emulation Development

Journal of Artificial General Intelligence ◽

10.2478/jagi-2013-0009 ◽

2013 ◽

Vol 4 (3) ◽

pp. 153-163 ◽

Cited By ~ 1

Author(s):

Jeff Alstott

Keyword(s):

Human Brain ◽

Complex Network ◽

Human Behavior ◽

Brain Dynamics ◽

Human Society ◽

Whole Brain ◽

Complex Technology ◽

The Impact

Abstract Whole brain emulation (WBE) is the possible replication of human brain dynamics that reproduces human behavior. If created, WBE would have significant impact on human society, and forecasts frequently place WBE as arriving within a century. However, WBE would be a complex technology with a complex network of prerequisite technologies. Most forecasts only consider a fraction of this technology network. The unconsidered portions of the network may contain bottlenecks, which are slowly-developing technologies that would impede the development of WBE. Here I describe how bottlenecks in the network can be non-obvious, and the merits of identifying them early. I show that bottlenecks may be predicted even with noisy forecasts. Accurate forecasts of WBE development must incorporate potential bottlenecks, which can be found using detailed descriptions of the WBE technology network. Bottlenecks identification can also increase the impact of WBE researchers by directing effort to those technologies that will immediately affect the timeline of WBE development

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Significance of Lipid Composition in a Blood-Brain Barrier–Mimetic PAMPA Assay

CrossRef Listing of Deleted DOIs ◽

10.1177/1087057113497981 ◽

2013 ◽

Vol 19 (3) ◽

pp. 437-444 ◽

Cited By ~ 27

Author(s):

Scott D. Campbell ◽

Karen J. Regina ◽

Evan D. Kharasch

Keyword(s):

Endothelial Cell ◽

Human Brain ◽

Blood Brain Barrier ◽

Lipid Composition ◽

Brain Barrier ◽

Brain Lipid ◽

Passive Permeability ◽

Whole Brain ◽

Cell Lipid ◽

Drug Access

Endothelial cells forming the blood-brain barrier limit drug access into the brain, due to tight junctions, membrane drug transporters, and unique lipid composition. Passive permeability, thought to mediate drug access, is typically tested using porcine whole-brain lipid. However, human endothelial cell lipid composition differs. This investigation evaluated the influence of lipid composition on passive permeability across artificial membranes. Permeability of CNS-active drugs across an immobilized lipid membrane was determined using three lipid models: crude extract from whole pig brain, human brain microvessel lipid, and microvessel lipid plus cholesterol. Lipids were immobilized on polyvinylidene difluoride, forming donor and receiver chambers, in which drug concentrations were measured after 2 h. The log of effective permeability was then calculated using the measured concentrations. Permeability of small, neutral compounds was unaffected by lipid composition. Several structurally diverse drugs were highly permeable in porcine whole-brain lipid but one to two orders of magnitude less permeable across human brain endothelial cell lipid. Inclusion of cholesterol had the greatest influence on bulky amphipathic compounds such as glucuronide conjugates. Lipid composition markedly influences passive permeability. This was most apparent for charged or bulky compounds. These results demonstrate the importance of using species-specific lipid models in passive permeability assays.

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Vascular Genomics of the Human Brain

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-200203000-00001 ◽

2002 ◽

Vol 22 (3) ◽

pp. 245-252 ◽

Cited By ~ 36

Author(s):

Eric V. Shusta ◽

Ruben J. Boado ◽

Gary W. Mathern ◽

William M. Pardridge

Keyword(s):

Gene Expression ◽

Human Brain ◽

Differential Gene Expression ◽

Molecular Transport ◽

Brain Diseases ◽

Microvascular Endothelium ◽

Whole Brain ◽

Differential Gene ◽

Brain Microvasculature ◽

The Brain

The microvasculature of the human brain plays an important role in the development and maintenance of the central nervous system and in the pathogenesis of brain diseases, and is the site of differential gene expression within the brain. However, human brain microvascular-specific genes may not be detected in whole-brain gene microarray because the volume of the brain microvascular endothelium is relatively small (0.1%) compared with the whole brain. Therefore, the differential gene expression within the human brain microvasculature was evaluated using suppression subtractive hybridization with RNA isolated from human brain microvessels. Gene identification was restricted to the first 71 clones that were differentially expressed at the brain microvasculature. Twenty of these were genes encoding proteins with known function that were involved in angiogenesis, neurogenesis, molecular transport, and maintenance of endothelial tight junctions or the cytoskeleton. Eighteen genes coding for proteins of an unknown function were identified, including five genes containing satellite DNA sequences. The results provide the initial outline of the genomics of the human brain microvasculature, and have implications for the identification of both targets for brain-specific drug transport and changes in microvascular gene expression in brain diseases.

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Turbulent-like dynamics in the human brain

10.1101/865923 ◽

2019 ◽

Author(s):

Gustavo Deco ◽

Morten L. Kringelbach

Keyword(s):

Human Brain ◽

Brain Function ◽

Information Transfer ◽

Large Scale ◽

Brain Dynamics ◽

Whole Brain ◽

Large Scale Network ◽

Maximal Sensitivity ◽

Scale Network ◽

Best Fit

SummaryTurbulence facilitates fast energy/information transfer across scales in physical systems. These qualities are important for brain function, but it is currently unknown if the dynamic intrinsic backbone of brain also exhibits turbulence. Using large-scale neuroimaging empirical data from 1003 healthy participants, we demonstrate Kuramoto’s amplitude turbulence in human brain dynamics. Furthermore, we build a whole-brain model with coupled oscillators to demonstrate that the best fit to the data corresponds to a region of maximally developed amplitude turbulence, which also corresponds to maximal sensitivity to the processing of external stimulations (information capability). The model shows the economy of anatomy by following the Exponential Distance Rule of anatomical connections as a cost-of-wiring principle. This establishes a firm link between turbulence and optimal brain function. Overall, our results reveal a way of analysing and modelling whole-brain dynamics that suggests turbulence as the dynamic intrinsic backbone facilitating large scale network communication.

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