Dynamic Patterns of Global Brain Communication Differentiate Conscious From Unconscious Patients After Severe Brain Injury

The neurophysiology of the subjective sensation of being conscious is elusive; therefore, it remains controversial how consciousness can be recognized in patients who are not responsive but seemingly awake. During general anesthesia, a model for the transition between consciousness and unconsciousness, specific covariance matrices between the activity of brain regions that we call patterns of global brain communication reliably disappear when people lose consciousness. This functional magnetic imaging study investigates how patterns of global brain communication relate to consciousness and unconsciousness in a heterogeneous sample during general anesthesia and after brain injury. First, we describe specific patterns of global brain communication during wakefulness that disappear during propofol (n = 11) and sevoflurane (n = 14) general anesthesia. Second, we search for these patterns in a cohort of unresponsive wakeful patients (n = 18) and unmatched healthy controls (n = 20) in order to evaluate their potential use in clinical practice. We found that patterns of global brain communication characterized by high covariance in sensory and motor areas or low overall covariance and their dynamic change were strictly associated with intact consciousness in this cohort. In addition, we show that the occurrence of these two patterns is significantly related to activity within the frontoparietal network of the brain, a network known to play a crucial role in conscious perception. We propose that this approach potentially recognizes consciousness in the clinical routine setting.

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Flexible Simultaneous Mesoscale Two-Photon Imaging of Neural Activity at High Speeds

10.1101/2021.04.19.440507 ◽

2021 ◽

Author(s):

Mitchell Clough ◽

Ichen Anderson Chen ◽

Seong-Wook Park ◽

Allison M Ahrens ◽

Jeffrey N Stirman ◽

...

Keyword(s):

Brain Function ◽

Brain Regions ◽

Two Photon ◽

High Speeds ◽

Trade Offs ◽

Acquisition Speed ◽

Photon Imaging ◽

Two Photon Imaging ◽

Global Brain ◽

The Brain

Understanding brain function requires monitoring local and global brain dynamics. Two-photon imaging of the brain across mesoscopic scales has presented trade-offs between imaging area and acquisition speed. We describe a flexible cellular resolution two-photon microscope capable of simultaneous video rate acquisition of four independently targetable brain regions spanning an approximate five-millimeter field of view. With this system, we demonstrate the ability to measure calcium activity across mouse sensorimotor cortex at behaviorally relevant timescales.

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Coding of Visual, Auditory, Rule, and Response Information in the Brain: 10 Years of Multivoxel Pattern Analysis

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00981 ◽

2016 ◽

Vol 28 (10) ◽

pp. 1433-1454 ◽

Cited By ~ 33

Author(s):

Alexandra Woolgar ◽

Jade Jackson ◽

John Duncan

Keyword(s):

Representational Content ◽

Brain Regions ◽

Brain Organization ◽

Frontoparietal Network ◽

Response Information ◽

Domain Generality ◽

Cognitive Operations ◽

Motor Information ◽

Types Of Information ◽

The Brain

How is the processing of task information organized in the brain? Many views of brain function emphasize modularity, with different regions specialized for processing different types of information. However, recent accounts also highlight flexibility, pointing especially to the highly consistent pattern of frontoparietal activation across many tasks. Although early insights from functional imaging were based on overall activation levels during different cognitive operations, in the last decade many researchers have used multivoxel pattern analyses to interrogate the representational content of activations, mapping out the brain regions that make particular stimulus, rule, or response distinctions. Here, we drew on 100 searchlight decoding analyses from 57 published papers to characterize the information coded in different brain networks. The outcome was highly structured. Visual, auditory, and motor networks predominantly (but not exclusively) coded visual, auditory, and motor information, respectively. By contrast, the frontoparietal multiple-demand network was characterized by domain generality, coding visual, auditory, motor, and rule information. The contribution of the default mode network and voxels elsewhere was minor. The data suggest a balanced picture of brain organization in which sensory and motor networks are relatively specialized for information in their own domain, whereas a specific frontoparietal network acts as a domain-general “core” with the capacity to code many different aspects of a task.

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Kv1.1 subunits localize to cardiorespiratory brain networks in mice where their absence induces astrogliosis and microgliosis

10.1101/2021.02.01.429209 ◽

2021 ◽

Author(s):

Hemangini A Dhaibar ◽

Kathryn A Hamilton ◽

Edward Glasscock

Keyword(s):

Brain Injury ◽

Gene Knockout ◽

Brain Regions ◽

Nucleus Ambiguus ◽

Motor Nucleus ◽

Breathing Patterns ◽

Unexpected Death ◽

Respiratory Dysfunction ◽

The Brain ◽

Related Mortality

ABSTRACTCardiorespiratory collapse following a seizure is a suspected cause of sudden unexpected death in epilepsy (SUDEP), the leading cause of epilepsy-related mortality. In the commonly used Kcna1 gene knockout (Kcna1−/−) mouse model of SUDEP, cardiorespiratory profiling reveals an array of aberrant breathing patterns that could contribute to risk of seizure-related mortality. However, the brain structures mediating these respiratory abnormalities remain unknown. We hypothesize that Kv1.1 deficiency in respiratory control centers of the brain contribute to respiratory dysfunction in Kcna1−/− mice leading to increased SUDEP risk. Thus, in this study, we first used immunohistochemistry to map expression of Kv1.1 protein in cardiorespiratory brain regions of wild-type Kcna1+/+ (WT) mice. Next, GFAP and Iba1 immunostaining was used to test for the presence of astrogliosis and microgliosis, respectively, in the cardiorespiratory centers of Kcna1−/− mice, which could be indicative of seizure-related brain injury that could impair breathing. In WT type mice, we detected Kv1.1 protein in all cardiorespiratory centers examined, including the basolateral amygdala, dorsal respiratory group, dorsal motor nucleus of vagus, nucleus ambiguus, ventral respiratory column, and pontine respiratory group, as well as chemosensory centers including the retrotrapezoid and median raphae nuclei. Extensive gliosis was observed in the same areas in Kcna1−/− mice suggesting that seizure-associated brain injury could contribute to respiratory abnormalities.

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Human Handedness: Genetics, Microtubules, Neuropsychiatric Diseases and Brain Language Areas

10.1101/454660 ◽

2018 ◽

Cited By ~ 1

Author(s):

A. Wiberg ◽

G. Douaud ◽

M. Ng ◽

Y. Al Omran ◽

F. Alfaro-Almagro ◽

...

Keyword(s):

Imaging Study ◽

Brain Regions ◽

Uk Biobank ◽

Left Handedness ◽

Genome Wide ◽

Neuropsychiatric Diseases ◽

Additional Locus ◽

Language Areas ◽

Related Proteins ◽

The Brain

AbstractBackgroundThe skew in distribution of handedness is a uniquely human trait, and has fascinated researchers for centuries. The heritability of handedness is estimated at 25%, but defining genetic variants contributing to this trait has so far proved elusive.MethodsWe performed GWAS of self-reported handedness in UK Biobank, a prospective cohort study of ∼500,000 individuals. Furthermore, we investigated correlations between our associated SNPs and brain imaging-derived phenotypes (IDPs) from >9,000 individuals in UK Biobank, as well as between self-reported handedness and IDPs.ResultsOur association study of 38,322 left-handers vs 356,567 right-handers (excluding ambidextrous participants) revealed three genome-wide significant loci (rs199512, 17q21.31, p=4.1x10−9; rs45608532, 22q11.22, p=1.4x10−8; rs13017199, 2q34, p=3.3x10−8). In the imaging study, we found strong associations between rs199512 and diffusion MRI measures mainly in white matter tracts connecting language-related brain regions (p<2.0x10−6). Direct investigation between handedness and IDPs revealed numerous associations with functional connectivity between the same language-related areas of the brain. A second GWAS of non-right handers (n=44,631) vs right-handers (n=356,567) revealed an additional locus: rs3094128, 6p21.33, p=2.9x10−8. Three of the four associated loci (2q34, 17q21.31, 6p21.33) contain genes that encode microtubule-related proteins that are highly expressed in the brain: MAP2, MAPT and TUBB. These genes are strongly implicated in the pathogenesis of diseases that are known to affect an excess of left-handed people, including schizophrenia.ConclusionsThis is the first GWAS to identify genome-wide significant loci for human handedness in the general population, and the genes at these loci have biological plausibility in contributing to neurodevelopmental lateralization of brain organisation, which appears to predispose both to left-handedness and to certain neurodegenerative and psychiatric diseases.

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Functional Neuroanatomy of Meaning Acquisition from Context

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2008.20150 ◽

2008 ◽

Vol 20 (12) ◽

pp. 2153-2166 ◽

Cited By ~ 68

Author(s):

Anna Mestres-Missé ◽

Estela Càmara ◽

Antoni Rodriguez-Fornells ◽

Michael Rotte ◽

Thomas F. Münte

Keyword(s):

Language Processing ◽

Inferior Frontal Gyrus ◽

Imaging Study ◽

Brain Regions ◽

Brain Network ◽

Parahippocampal Gyrus ◽

Middle Temporal Gyrus ◽

Functional Neuroanatomy ◽

Subcortical Structures ◽

The Brain

An important issue in language learning is how new words are integrated in the brain representations that sustain language processing. To identify the brain regions involved in meaning acquisition and word learning, we conducted a functional magnetic resonance imaging study. Young participants were required to deduce the meaning of a novel word presented within increasingly constrained sentence contexts that were read silently during the scanning session. Inconsistent contexts were also presented in which no meaning could be assigned to the novel word. Participants showed meaning acquisition in the consistent but not in the inconsistent condition. A distributed brain network was identified comprising the left anterior inferior frontal gyrus (BA 45), the middle temporal gyrus (BA 21), the parahippocampal gyrus, and several subcortical structures (the thalamus and the striatum). Drawing on previous neuroimaging evidence, we tentatively identify the roles of these brain areas in the retrieval, selection, and encoding of the meaning.

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Machine Learning Classification of Mild Traumatic Brain Injury Using Whole-Brain Functional Activity: A Radiomics Analysis

Disease Markers ◽

10.1155/2021/3015238 ◽

2021 ◽

Vol 2021 ◽

pp. 1-7

Author(s):

Xiaoping Luo ◽

Dezhao Lin ◽

Shengwei Xia ◽

Dongyu Wang ◽

Xinmang Weng ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Mild Traumatic Brain Injury ◽

Short Range ◽

Low Frequency ◽

Brain Regions ◽

Classification Performance ◽

Imaging Parameters ◽

The Brain ◽

Normal Controls

Objectives. To investigate the classification performance of support vector machine in mild traumatic brain injury (mTBI) from normal controls. Methods. Twenty-four mTBI patients (15 males and 9 females; mean age, 38.88 ± 13.33 years) and 24 age and sex-matched normal controls (13 males and 11 females; mean age, 40.46 ± 11.4 years) underwent resting-state functional MRI examination. Seven imaging parameters, including amplitude of low-frequency fluctuation (ALFF), fractional amplitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo), degree centrality (DC), voxel-mirrored homotopic connectivity (VMHC), long-range functional connectivity density (FCD), and short-range FCD, were entered into the classification model to distinguish the mTBI from normal controls. Results. The ability for any single imaging parameters to distinguish the two groups is lower than multiparameter combinations. The combination of ALFF, fALFF, DC, VMHC, and short-range FCD showed the best classification performance for distinguishing the two groups with optimal AUC value of 0.778, accuracy rate of 81.11%, sensitivity of 88%, and specificity of 75%. The brain regions with the highest contributions to this classification mainly include bilateral cerebellum, left orbitofrontal cortex, left cuneus, left temporal pole, right inferior occipital cortex, bilateral parietal lobe, and left supplementary motor area. Conclusions. Multiparameter combinations could improve the classification performance of mTBI from normal controls by using the brain regions associated with emotion and cognition.

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Immediate early gene activation throughout the brain is associated with dynamic changes in social context

10.1101/275495 ◽

2018 ◽

Cited By ~ 4

Author(s):

Cait M. Williamson ◽

Inbal S. Klein ◽

Won Lee ◽

James P. Curley

Keyword(s):

Social Context ◽

Dynamic Change ◽

Gene Activation ◽

Brain Regions ◽

Early Gene ◽

Alpha Male ◽

The Social ◽

Rapid Ascent ◽

Behavior Network ◽

The Brain

ABSTRACTSocial competence is dependent on successful processing of social context information. The social opportunity paradigm is a methodology in which dynamic shifts in social context are induced through removal of the alpha male in a dominance hierarchy, leading to rapid ascent in the hierarchy of the beta male and of other subordinate males in the social group. In the current study, we use the social opportunity paradigm to determine what brain regions respond to this dynamic change in social context, allowing an individual to recognize the absence of the alpha male and subsequently perform status-appropriate social behaviors. Replicating our previous work, we show that following removal of the alpha male, beta males rapidly ascend the social hierarchy and attain dominant status by increasing aggression towards more subordinate individuals. Analysis of patterns of Fos immunoreactivity throughout the brain indicates that in individuals undergoing social ascent, there is increased activity in regions of the social behavior network, as well as the infralimbic and prelimbic regions of the prefrontal cortex and areas of the hippocampus. Our findings demonstrate that male mice are able to respond to changes in social context and provide insight into the how the brain processes these complex behavioral changes.

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Neurobiological consequences of traumatic brain injury

Dialogues in Clinical Neuroscience ◽

10.31887/dcns.2011.13.2/tmcallister ◽

2011 ◽

Vol 13 (3) ◽

pp. 287-300 ◽

Cited By ~ 44

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Public Health Problem ◽

Brain Regions ◽

Common Clinical Presentation ◽

The Common ◽

The Brain ◽

Chronic Sequelae ◽

Ca Homeostasis ◽

Recent Attention

Traumatic brain injury (TBI) is a worldwide public health problem typically caused by contact and inertial forces acting on the brain. Recent attention has also focused on the mechanisms of injury associated with exposure to blast events or explosions. Advances in the understanding of the neuropathophysiology of TBI suggest that these forces initiate an elaborate and complex array of cellular and subcellular events related to alterations in Ca(++) homeostasis and signaling. Furthermore, there is a fairly predictable profile of brain regions that are impacted by neurotrauma and the related events. This profile of brain damage accurately predicts the acute and chronic sequelae that TBI survivors suffer from, although there is enough variation to suggest that individual differences such as genetic polymorphisms and factors governing resiliency play a role in modulating outcome. This paper reviews our current understanding of the neuropathophysiology of TBI and how this relates to the common clinical presentation of neurobehavioral difficulties seen after an injury.

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Overexpression of apoptosis inducing factor aggravates hypoxic-ischemic brain injury in neonatal mice

Cell Death and Disease ◽

10.1038/s41419-020-2280-z ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 4

Author(s):

Tao Li ◽

Kenan Li ◽

Shan Zhang ◽

Yafeng Wang ◽

Yiran Xu ◽

...

Keyword(s):

Brain Injury ◽

Molecular Mechanisms ◽

Brain Regions ◽

Ischemic Brain Injury ◽

Immature Brain ◽

Ischemic Brain ◽

Hypomorphic Mutation ◽

Splice Isoform ◽

Apoptosis Inducing Factor ◽

The Brain

AbstractApoptosis inducing factor (AIF) has been shown to be a major contributor to neuron loss in the immature brain after hypoxia-ischemia (HI). Indeed, mice bearing a hypomorphic mutation causing reduced AIF expression are protected against neonatal HI. To further investigate the possible molecular mechanisms of this neuroprotection, we generated an AIF knock-in mouse by introduction of a latent transgene coding for flagged AIF protein into the Rosa26 locus, followed by its conditional activation by a ubiquitously expressed Cre recombinase. Such AIF transgenic mice overexpress the pro-apoptotic splice variant of AIF (AIF1) at both the mRNA (5.9 times higher) and protein level (2.4 times higher), but not the brain-specific AIF splice-isoform (AIF2). Excessive AIF did not have any apparent effects on the phenotype or physiological functions of the mice. However, brain injury (both gray and white matter) after neonatal HI was exacerbated in mice overexpressing AIF, coupled to enhanced translocation of mitochondrial AIF to the nucleus as well as enhanced caspase-3 activation in some brain regions, as indicated by immunohistochemistry. Altogether, these findings corroborate earlier studies demonstrating that AIF plays a causal role in neonatal HI brain injury.

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Cerebral vasospasm and hypoperfusion after traumatic brain injury: Combined CT angiography and CT perfusion imaging study

Surgical Neurology International ◽

10.25259/sni_859_2020 ◽

2021 ◽

Vol 12 ◽

pp. 361

Author(s):

Tatsuya Maegawa ◽

Atsushi Sasahara ◽

Hidenori Ohbuchi ◽

Mikhail Chernov ◽

Hidetoshi Kasuya

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Ct Angiography ◽

Ct Perfusion ◽

Case Series ◽

Imaging Study ◽

Brain Regions ◽

Cerebral Hypoperfusion ◽

Ct Perfusion Imaging ◽

Post Traumatic

Background: Timely identification of the cerebral perfusion abnormalities after traumatic brain injury (TBI) is highly important. The objective of this study was the evaluation of the post traumatic vasospasm and cerebral hypoperfusion with the serial combined CT angiography (CTA) and CT perfusion (CTP) imaging examinations. Methods: The case series comprised 25 adult patients with closed TBI accompanied by various types of intracranial hematoma. Emergency surgery was done in 15 cases (60%). Combined CTA and CTP were performed on days 0 (D0) and 7 ± 1 (D7) after trauma. Results: CTA on D0 did not demonstrate vasospasm in any case but revealed it on D7 in 9 patients (36%). In the multivariate analysis, only the presence of subarachnoid hemorrhage (SAH) on D7 had confirmed a significant association with the development of vasospasm (P = 0.0201). Cerebral hypoperfusion at least in one evaluated brain region was noted on D0 and D7 in 76% and 60% of patients, respectively, and showed highly variable spatial distribution and temporal development. Treatment results were not associated with the presence of vasospasm (P = 0.7337) or the number of brain regions affected by hypoperfusion on D0 (P = 0.2285), but the number of brain regions affected by hypoperfusion on D7 was significantly greater in cases of unfavorable outcome (P = 0.0187). Conclusion: Vasospasm is merely related to SAH sustained at the subacute stage of TBI, but its spatial and temporary interrelationships with the post traumatic cerebral hypoperfusion are complex. Serial combined CTA and CTP examinations may facilitate monitoring of perfusion abnormalities and treatment guidance.

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