scholarly journals A Fast Transform for Brain Connectivity Difference Evaluation

2021 ◽  
Author(s):  
Massimiliano Zanin ◽  
Ilinka Ivanoska ◽  
Bahar Güntekin ◽  
Görsev Yener ◽  
Tatjana Loncar-Turukalo ◽  
...  
Keyword(s):  
Brain Function ◽  
Functional Significance ◽  
Brain Connectivity ◽  
Network Reconstruction ◽  
Auxiliary Space ◽  
Fast Transform

AbstractAnatomical and dynamical connectivity are essential to healthy brain function. However, quantifying variations in connectivity across conditions or between patient populations and appraising their functional significance are highly non-trivial tasks. Here we show that link ranking differences induce specific geometries in a convenient auxiliary space that are often easily recognisable at mere eye inspection. Link ranking can also provide fast and reliable criteria for network reconstruction parameters for which no theoretical guideline has been proposed.

scholarly journals Integrating TMS, EEG, and MRI as an Approach for Studying Brain Connectivity

2020 ◽  
Vol 26 (5-6) ◽  
pp. 471-486
Author(s):  
Romina Esposito ◽  
Marta Bortoletto ◽  
Carlo Miniussi
Keyword(s):  
Brain Function ◽  
Closed Loop ◽  
Current Knowledge ◽  
Brain Connectivity ◽  
Brain Activity ◽  
Brain Regions ◽  
Integrative Approach ◽  
Resonance Imaging ◽  
Neural Communication ◽  
Neural Interactions

The human brain is a complex network in which hundreds of brain regions are interconnected via thousands of axonal pathways. The capability of such a complex system emerges from specific interactions among smaller entities, a set of events that can be described by the activation of interconnections between brain areas. Studies that focus on brain connectivity have the aim of understanding and modeling brain function, taking into account the spatiotemporal dynamics of neural communication between brain regions. Much of the current knowledge regarding brain connectivity has been obtained from stand-alone neuroimaging methods. Nevertheless, the use of a multimodal approach seems to be a powerful way to investigate effective brain connectivity, overcoming the limitations of unimodal approaches. In this review, we will present the advantages of an integrative approach in which transcranial magnetic stimulation–electroencephalography coregistration is combined with magnetic resonance imaging methods to explore effective neural interactions. Moreover, we will describe possible implementations of the integrative approach in open- and closed-loop frameworks where real-time brain activity becomes a contributor to the study of cognitive brain networks.

scholarly journals Analysis of brain networks and fecal metabolites reveals brain–gut alterations in premenopausal females with irritable bowel syndrome

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Vadim Osadchiy ◽  
Emeran A. Mayer ◽  
Kan Gao ◽  
Jennifer S. Labus ◽  
Bruce Naliboff ◽  
...  
Keyword(s):  
Irritable Bowel Syndrome ◽  
Amino Acid ◽  
Brain Function ◽  
Brain Connectivity ◽  
Resting State Fmri ◽  
Group Differences ◽  
Neuroimaging Data ◽  
Acid Metabolites ◽  
Brain Changes ◽  
Irritable Bowel

Abstract Alterations in brain–gut–microbiome (BGM) interactions have been implicated in the pathogenesis of irritable bowel syndrome (IBS). Here, we apply a systems biology approach, leveraging neuroimaging and fecal metabolite data, to characterize BGM interactions that are driving IBS pathophysiology. Fecal samples and resting state fMRI images were obtained from 138 female subjects (99 IBS, 39 healthy controls (HCs)). Partial least-squares discriminant analysis (PLS-DA) was conducted to explore group differences, and partial correlation analysis explored significantly changed metabolites and neuroimaging data. All correlational tests were performed controlling for age, body mass index, and diet; results are reported after FDR correction, with q < 0.05 as significant. Compared to HCs, IBS showed increased connectivity of the putamen with regions of the default mode and somatosensory networks. Metabolite pathways involved in nucleic acid and amino acid metabolism differentiated the two groups. Only a subset of metabolites, primarily amino acids, were associated with IBS-specific brain changes, including tryptophan, glutamate, and histidine. Histidine was the only metabolite positively associated with both IBS-specific alterations in brain connectivity. Our findings suggest a role for several amino acid metabolites in modulating brain function in IBS. These metabolites may alter brain connectivity directly, by crossing the blood–brain-barrier, or indirectly through peripheral mechanisms. This is the first study to integrate both neuroimaging and fecal metabolite data supporting the BGM model of IBS, building the foundation for future mechanistic studies on the influence of gut microbial metabolites on brain function in IBS.

scholarly journals Recognition of Biomarkers of Brain Connectivity and Pain Using Multi-Modal Imaging in Patients with Sickle Cell Disease

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 971-971
Author(s):  
Michelle Case ◽  
Clara Zhang ◽  
John Mundahl ◽  
Yvonne Datta ◽  
Stephen C Nelson ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Sickle Cell Disease ◽  
Resting State ◽  
Brain Function ◽  
Brain Connectivity ◽  
Fmri Data ◽  
Healthy Controls ◽  
Cell Disease ◽  
Non Invasive ◽  
Microstate Analysis

Abstract Sickle cell disease (SCD) is associated with impaired cognitive function, pain, cerebral stroke and other neural dysfunctions suggestive of altered brain function. The most common reason for hospitalization of SCD patients is pain. Sickle pain is unique compared to other clinical pain conditions because it includes chronic pain as well as acute pain due to vasoocclusive crisis. The neuropathic and nociceptive aspects of pain in SCD make pain treatment challenging. Opioids, the most common analgesics, are associated with liabilities, such as addiction and tolerance. As a result, patients are often under-treated because of a lack of an objective pain measurement system. We therefore sought to develop an unbiased pain quantification method using non-invasive imaging techniques to recognize the biomarkers of pain and altered brain function. We examined the brain network connectivity in SCD patients (N=14) and healthy controls (N=13) to identify altered activity between the two groups that can be used as biomarkers for chronic pain. All experimental procedures were approved by the IRB of the University of Minnesota, and all subjects gave written informed consent before participating in the study. Functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) were simultaneously recorded while the subjects were in a wakeful resting state. A 3T Siemens Trio whole-body scanner and a 16 channel head coil with an echo-planar imaging (EPI) sequence were used to acquire fMRI data. EEG data was recorded using a 64-channel EEG cap and MR-compatible amplifiers. Seed-based region of interest (ROI) analysis was performed on the fMRI data using Brain Voyager QX software. EEG informed fMRI (EEG-fMRI) was performed for power and microstate analysis using Matlab and SPM8 software. Statistical activation maps (p<0.001, uncorrected) were generated from general linear models (GLM) based on the time courses found from power and microstate analysis. Seeds were placed in the insula regions, and the functional connectivity between the left and right insula appeared to be stronger in SCD patients than in healthy controls. This result was verified in EEG-fMRI analysis. Activation of the insula and striatum regions positively correlated with the beta band in SCD patients, where healthy controls showed less activation in the insula in the same frequency band. Microstates corresponding to insula activation were observed in both healthy controls and SCD patients; however, activation seems stronger in SCD patients. Activation in the striatum regions was also observed in microstates for SCD patients, but not for healthy controls. These results show that the insula and striatum regions have greater activation in SCD patients compared to controls, and that patients have altered brain connectivity during resting state. Insula activation could be related to the salience network, a resting state network that is responsible for processing external input, or to pain processing. The insula and striatum are some of the common brain regions that have been shown to be active during painful stimuli. This altered activation could be caused by sickle pain and could be a potential biomarker of pain intensity. Due to the non-invasive nature of these quantitative data, this method can have applications in the unbiased objective quantification of pain and treatment outcomes. Altered connectivity observed in SCD patients can also be used to help better understand the neural pathophysiology of sickle pain and can lead to better management strategies for these patients. This work was supported in part by NIH grant U01-HL117664 and NSF IGERT grant DGE-1069104. Disclosures No relevant conflicts of interest to declare.

Abstract W P387: Neurological Correlates Of Brain Function After Acute Stroke--A Dense Array EEG Study

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Jennifer Wu ◽  
Ramesh Srinivasan ◽  
Ana Solodkin ◽  
Steven L Small ◽  
Steven C Cramer
Keyword(s):  
Motor Cortex ◽  
Acute Stroke ◽  
Brain Function ◽  
Brain Connectivity ◽  
Brain Activity ◽  
Dense Array ◽  
Whole Brain ◽  
Regional Brain ◽  
Eeg Connectivity ◽  
Regional Brain Activity

INTRODUCTION: Measures of brain function can complement assessment of injury to inform clinical decision-making after stroke, but the most useful metrics remain uncertain. An acute stroke alters brain function in widespread areas. We therefore reasoned that a whole brain measure of brain function would be better related to behavioral deficits than a regional measure of brain function. METHODS: In 24 patients hospitalized for acute stroke, resting EEG (256 leads) was recorded for 3 min at the bedside and analyzed offline. Two EEG measures of brain function were extracted: [1] whole brain connectivity, which found the EEG frequency (from 1-30 Hz) and seed point (from among the 256 leads) that best fit whole brain coherence with total NIHSS scores, using a partial least squares regression model; and [2] regional brain activity, which found the EEG frequency and lead where spectral power was most strongly correlated with total NIHSS scores. Analyses were repeated focused on NIHSS motor subscores (Q4-6). All models were validated using a leave-one-out approach. RESULTS: The 24 patients were age 60.9±13.1yr, 3.5 ± 2.9 d post-onset (range 3hr-12d), and were studied in settings that included ER, ICU, and stroke ward. Whole brain EEG connectivity explained a large fraction of the variance in total NIHSS scores (r^2=0.72); this was achieved in the 2-4 Hz range, with seed over ipsilesional motor cortex, and with model predicting higher NIHSS score when this seed had greater coherence with contralesional frontal/motor regions. Regional brain activity, by comparison, explained a smaller fraction of variance (r^2=0.51), with maximal correlation between total NIHSS and regional EEG power found using a lead over contralesional motor cortex, at 2 Hz. Similar results for whole brain EEG connectivity were obtained when modeling NIHSS motor subscores in the 14 subjects with motor deficits (validated r^2=0.71). CONCLUSIONS: Dense array EEG recordings could be obtained early after stroke, rapidly and reliably, and at the bedside in widespread hospital settings. Whole brain connectivity measures corresponded to behavioral state better than measures of regional brain activity do. Results support the utility of EEG as a bedside method for evaluating brain functional status after stroke.

scholarly journals Neurobiology of Consciousness: Current Research and Perspectives

Studia Humana ◽  
2015 ◽  
Vol 4 (4) ◽  
pp. 23-38 ◽  
Author(s):  
Beata Płonka
Keyword(s):  
Experimental Data ◽  
Brain Function ◽  
Brain Connectivity ◽  
Brain Activity ◽  
Neural Correlates ◽  
Philosophical Tradition ◽  
Scientific Objective ◽  
Philosophical Approach ◽  
Philosophical Perspective ◽  
Neurobiological Research

Abstract Scientific, objective approach to consciousness has allowed to obtain some experimental data concerning brain activity, ignoring, however, the longstanding philosophical tradition. Spectacular development of neuroscience which has been observed recently made this dissonance particularly noticeable. The paper addresses the main problems of discrepancy between neurobiological research and philosophical perspective. Current opinions concerning neural correlates and models of consciousness are discussed, as well as the problems of working memory, attention, self, and disorders of consciousness. A new neurobiological approach to describe brain function in terms of brain connectivity (so-called connectome) is also presented. Finally, the need to introduce at least some aspects of philosophical approach directly into neurobiological research of consciousness is postulated.

scholarly journals Role of Astrocytic Mitochondria in Limiting Ischemic Brain Injury?

Physiology ◽  
2018 ◽  
Vol 33 (2) ◽  
pp. 99-112 ◽  
Author(s):  
Evelyn K. Shih ◽  
Michael B. Robinson
Keyword(s):  
Brain Injury ◽  
Neuronal Activity ◽  
Brain Function ◽  
Functional Significance ◽  
Normal Brain ◽  
Ischemic Brain Injury ◽  
Ischemic Brain ◽  
Normal Brain Function

Until recently, astrocyte processes were thought to be too small to contain mitochondria. However, it is now clear that mitochondria are found throughout fine astrocyte processes and are mobile with neuronal activity resulting in positioning near synapses. In this review, we discuss evidence that astrocytic mitochondria confer selective resiliency to astrocytes during ischemic insults and the functional significance of these mitochondria for normal brain function.

Studies of synaptic elimination identify an intersection of neurocomputational and neurodevelopmental perspectives

2000 ◽  
Vol 23 (4) ◽  
pp. 543-544
Author(s):  
Ralph E. Hoffman
Keyword(s):  
Neural Network ◽  
Temporal Processing ◽  
Brain Function ◽  
Functional Significance ◽  
Network Pruning ◽  
Cortical Connections ◽  
Computational Capacity ◽  
Selective Elimination ◽  
Potential Synergy ◽  
Shed Light

In order to reach a better understanding of brain function, conceptual synergies linking empirical neurobiological studies and neurocomputational studies should be pursued. I describe an example of a potential synergy based on studies of neural network pruning. Simulations demonstrate that selective elimination of connections enhances the computational capacity of networks capable of temporal processing. These findings may shed light on the functional significance of postnatal neuro-developmental pruning of cortical connections that occurs in mammals.

scholarly journals Brain Asymmetry: Towards an Asymmetrical Neurovisceral Integration

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2409
Author(s):  
Manuel Ramírez-Sánchez ◽  
Isabel Prieto ◽  
Ana Belén Segarra ◽  
Inmaculada Banegas ◽  
Magdalena Martínez-Cañamero ◽  
...  
Keyword(s):  
Language Processing ◽  
Brain Function ◽  
Functional Significance ◽  
Brain Asymmetry ◽  
Asymmetric Distribution ◽  
Bidirectional Communication ◽  
Evolutionary Advantage ◽  
Communication Pathway ◽  
Overall Functioning ◽  
Static Concept

Despite the ancestral evidence of an asymmetry in motor predominance, going through the inspiring discoveries of Broca and Wernicke on the localization of language processing, continuing with the subsequent noise coinciding with the study of brain function in commissurotomized patients—and the subsequent avalanche of data on the asymmetric distribution of multiple types of neurotransmitters in physiological and pathological conditions—even today, the functional significance of brain asymmetry is still unknown. Currently, multiple evidence suggests that functional asymmetries must have a neurochemical substrate and that brain asymmetry is not a static concept but rather a dynamic one, with intra- and inter-hemispheric interactions between its various processes, and that it is modifiable depending on changing endogenous and environmental conditions. Furthermore, based on the concept of neurovisceral integration in the overall functioning of an organism, some evidence has emerged suggesting that this integration could be organized asymmetrically, using the autonomic nervous system as a bidirectional communication pathway, whose performance would also be asymmetric. However, the functional significance of this distribution, as well as the evolutionary advantage of an asymmetric nervous organization, is still unknown.

PHASE SYNCHRONIZATION IN BRAIN NETWORKS DERIVED FROM CORRELATION BETWEEN PROBABILITIES OF RECURRENCES IN FUNCTIONAL MRI DATA

2013 ◽  
Vol 23 (02) ◽  
pp. 1350003 ◽  
Author(s):  
D. RANGAPRAKASH ◽  
XIAOPING HU ◽  
GOPIKRISHNA DESHPANDE
Keyword(s):  
Linear Correlation ◽  
Resting State ◽  
Brain Function ◽  
Phase Synchronization ◽  
Human Subjects ◽  
Brain Connectivity ◽  
Brain Networks ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Fmri Data

It is increasingly being recognized that resting state brain connectivity derived from functional magnetic resonance imaging (fMRI) data is an important marker of brain function both in healthy and clinical populations. Though linear correlation has been extensively used to characterize brain connectivity, it is limited to detecting first order dependencies. In this study, we propose a framework where in phase synchronization (PS) between brain regions is characterized using a new metric "correlation between probabilities of recurrence" (CPR) and subsequent graph-theoretic analysis of the ensuing networks. We applied this method to resting state fMRI data obtained from human subjects with and without administration of propofol anesthetic. Our results showed decreased PS during anesthesia and a biologically more plausible community structure using CPR rather than linear correlation. We conclude that CPR provides an attractive nonparametric method for modeling interactions in brain networks as compared to standard correlation for obtaining physiologically meaningful insights about brain function.

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