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1.
Mol Brain ; 17(1): 64, 2024 Sep 02.
Article de Anglais | MEDLINE | ID: mdl-39223568

RÉSUMÉ

Aerobic exercise has many effects on brain function, particularly at the hippocampus. Exercise has been shown to increase the rate of adult neurogenesis within the dentate gyrus and decrease the density of perineuronal nets in area CA1. The relationship between the rate of neurogenesis and the density of perineuronal nets in CA1 is robust; however, these studies only ever examined these effects across longer time scales, with running manipulations of 4 weeks or longer. With such long periods of manipulation, the precise temporal nature of the relationship between running-induced neurogenesis and reduced perineuronal net density in CA1 is unknown. Here, we provided male and female mice with home cage access to running wheels for 0, 1, 2, or 4 weeks and quantified hippocampal neurogenesis and CA1 perineuronal net density. In doing so, we observed a 2-week delay period prior to the increase in neurogenesis, which coincided with the same delay prior to decreased CA1 perineuronal net density. These results highlight the closely linked temporal relationship between running-induced neurogenesis and decreased perineuronal net expression in CA1.


Sujet(s)
Région CA1 de l'hippocampe , Souris de lignée C57BL , Neurogenèse , Course à pied , Animaux , Mâle , Course à pied/physiologie , Femelle , Région CA1 de l'hippocampe/physiologie , Facteurs temps , Réseau nerveux/physiologie , Conditionnement physique d'animal , Souris
2.
Hum Brain Mapp ; 45(13): e70019, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-39230183

RÉSUMÉ

Understanding the brain's mechanisms in individuals with obesity is important for managing body weight. Prior neuroimaging studies extensively investigated alterations in brain structure and function related to body mass index (BMI). However, how the network communication among the large-scale brain networks differs across BMI is underinvestigated. This study used diffusion magnetic resonance imaging of 290 young adults to identify links between BMI and brain network mechanisms. Navigation efficiency, a measure of network routing, was calculated from the structural connectivity computed using diffusion tractography. The sensory and frontoparietal networks indicated positive associations between navigation efficiency and BMI. The neurotransmitter association analysis identified that serotonergic and dopaminergic receptors, as well as opioid and norepinephrine systems, were related to BMI-related alterations in navigation efficiency. The transcriptomic analysis found that genes associated with network routing across BMI overlapped with genes enriched in excitatory and inhibitory neurons, specifically, gene enrichments related to synaptic transmission and neuron projection. Our findings suggest a valuable insight into understanding BMI-related alterations in brain network routing mechanisms and the potential underlying cellular biology, which might be used as a foundation for BMI-based weight management.


Sujet(s)
Indice de masse corporelle , Encéphale , Humains , Mâle , Jeune adulte , Femelle , Adulte , Encéphale/imagerie diagnostique , Encéphale/physiologie , Imagerie par tenseur de diffusion , Réseau nerveux/imagerie diagnostique , Réseau nerveux/physiologie , Connectome , Voies nerveuses/imagerie diagnostique , Voies nerveuses/physiologie , Obésité/imagerie diagnostique , Obésité/physiopathologie , Obésité/anatomopathologie , Imagerie par résonance magnétique de diffusion
3.
Hum Brain Mapp ; 45(13): e70018, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-39230193

RÉSUMÉ

The characterisation of resting-state networks (RSNs) using neuroimaging techniques has significantly contributed to our understanding of the organisation of brain activity. Prior work has demonstrated the electrophysiological basis of RSNs and their dynamic nature, revealing transient activations of brain networks with millisecond timescales. While previous research has confirmed the comparability of RSNs identified by electroencephalography (EEG) to those identified by magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI), most studies have utilised static analysis techniques, ignoring the dynamic nature of brain activity. Often, these studies use high-density EEG systems, which limit their applicability in clinical settings. Addressing these gaps, our research studies RSNs using medium-density EEG systems (61 sensors), comparing both static and dynamic brain network features to those obtained from a high-density MEG system (306 sensors). We assess the qualitative and quantitative comparability of EEG-derived RSNs to those from MEG, including their ability to capture age-related effects, and explore the reproducibility of dynamic RSNs within and across the modalities. Our findings suggest that both MEG and EEG offer comparable static and dynamic network descriptions, albeit with MEG offering some increased sensitivity and reproducibility. Such RSNs and their comparability across the two modalities remained consistent qualitatively but not quantitatively when the data were reconstructed without subject-specific structural MRI images.


Sujet(s)
Électroencéphalographie , Magnétoencéphalographie , Réseau nerveux , Humains , Magnétoencéphalographie/méthodes , Électroencéphalographie/méthodes , Adulte , Réseau nerveux/physiologie , Réseau nerveux/imagerie diagnostique , Mâle , Femelle , Jeune adulte , Adulte d'âge moyen , Imagerie par résonance magnétique/méthodes , Sujet âgé , Connectome/méthodes , Adolescent , Encéphale/physiologie , Encéphale/imagerie diagnostique , Repos/physiologie
4.
Dev Psychobiol ; 66(7): e22546, 2024 Nov.
Article de Anglais | MEDLINE | ID: mdl-39236228

RÉSUMÉ

Attention-deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder with lifelong impairments. ADHD-related behaviors have been observed as early as toddlerhood for children who later develop ADHD. Children with ADHD have disrupted connectivity in neural circuitry involved in executive control of attention, including the prefrontal cortex (PFC) and dorsal attention network (DAN). It is not known if these alterations in connectivity can be identified before the onset of ADHD. Children (N = 51) 1.5-3 years old were assessed using functional near-infrared spectroscopy while engaging with a book. The relation between mother-reported ADHD-related behaviors and neural connectivity, computed using robust innovation-based correlation, was examined. Task engagement was high across the sample and unrelated to ADHD-related behaviors. Observed attention was associated with greater connectivity between the right lateral PFC and the right temporal parietal junction (TPJ). Children with greater ADHD-related behaviors had greater frontoparietal connectivity, particularly between the PFC bilaterally and the right TPJ. Toddlers at risk for developing ADHD may require increased frontoparietal connectivity to sustain attention. Future work is needed to examine early interventions that enhance developing attention and their effect on neural connectivity between the PFC and attention networks.


Sujet(s)
Trouble déficitaire de l'attention avec hyperactivité , Attention , Lobe pariétal , Cortex préfrontal , Spectroscopie proche infrarouge , Humains , Femelle , Mâle , Trouble déficitaire de l'attention avec hyperactivité/physiopathologie , Trouble déficitaire de l'attention avec hyperactivité/imagerie diagnostique , Lobe pariétal/physiopathologie , Lobe pariétal/imagerie diagnostique , Enfant d'âge préscolaire , Nourrisson , Attention/physiologie , Cortex préfrontal/physiopathologie , Cortex préfrontal/imagerie diagnostique , Fonction exécutive/physiologie , Réseau nerveux/physiopathologie , Réseau nerveux/imagerie diagnostique , Comportement de l'enfant/physiologie
5.
Nat Commun ; 15(1): 7714, 2024 Sep 04.
Article de Anglais | MEDLINE | ID: mdl-39231965

RÉSUMÉ

Differences in brain size between the sexes are consistently reported. However, the consequences of this anatomical difference on sex differences in intrinsic brain function remain unclear. In the current study, we investigate whether sex differences in intrinsic cortical functional organization may be associated with differences in cortical morphometry, namely different measures of brain size, microstructure, and the geodesic distance of connectivity profiles. For this, we compute a low dimensional representation of functional cortical organization, the sensory-association axis, and identify widespread sex differences. Contrary to our expectations, sex differences in functional organization do not appear to be systematically associated with differences in total surface area, microstructural organization, or geodesic distance, despite these morphometric properties being per se associated with functional organization and differing between sexes. Instead, functional sex differences in the sensory-association axis are associated with differences in functional connectivity profiles and network topology. Collectively, our findings suggest that sex differences in functional cortical organization extend beyond sex differences in cortical morphometry.


Sujet(s)
Cortex cérébral , Imagerie par résonance magnétique , Réseau nerveux , Caractères sexuels , Femelle , Mâle , Humains , Cortex cérébral/anatomie et histologie , Cortex cérébral/imagerie diagnostique , Cortex cérébral/physiologie , Réseau nerveux/anatomie et histologie , Réseau nerveux/physiologie , Réseau nerveux/imagerie diagnostique , Adulte , Cartographie cérébrale/méthodes , Jeune adulte , Encéphale/anatomie et histologie , Encéphale/physiologie , Encéphale/imagerie diagnostique , Taille d'organe
6.
Hum Brain Mapp ; 45(13): e70005, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-39225381

RÉSUMÉ

There has been extensive evidence that aging affects human brain function. However, there is no complete picture of what brain functional changes are mostly related to normal aging and how aging affects brain function similarly and differently between males and females. Based on resting-state brain functional connectivity (FC) of 25,582 healthy participants (13,373 females) aged 49-76 years from the UK Biobank project, we employ deep learning with explainable AI to discover primary FCs related to progressive aging and reveal similarity and difference between females and males in brain aging. Using a nested cross-validation scheme, we conduct 4200 deep learning models to classify all paired age groups on the main data for females and males separately and then extract gender-common and gender-specific aging-related FCs. Next, we validate those FCs using additional 21,000 classifiers on the independent data. Our results support that aging results in reduced brain functional interactions for both females and males, primarily relating to the positive connectivity within the same functional domain and the negative connectivity between different functional domains. Regions linked to cognitive control show the most significant age-related changes in both genders. Unique aging effects in males and females mainly involve the interaction between cognitive control and the default mode, vision, auditory, and frontoparietal domains. Results also indicate females exhibit faster brain functional changes than males. Overall, our study provides new evidence about common and unique patterns of brain aging in females and males.


Sujet(s)
Vieillissement , Encéphale , Apprentissage profond , Imagerie par résonance magnétique , Caractères sexuels , Humains , Femelle , Mâle , Adulte d'âge moyen , Sujet âgé , Vieillissement/physiologie , Encéphale/physiologie , Encéphale/imagerie diagnostique , Connectome/méthodes , Réseau nerveux/physiologie , Réseau nerveux/imagerie diagnostique
7.
Sci Rep ; 14(1): 20527, 2024 09 04.
Article de Anglais | MEDLINE | ID: mdl-39227732

RÉSUMÉ

Episodic memory is essential for forming and retaining personal experiences, representing a fundamental aspect of human cognition. Traditional studies of episodic memory have typically used static analysis methods, viewing the brain as an unchanging entity and overlooking its dynamic properties over time. In this study, we utilized dynamic functional connectivity analysis on fMRI data from healthy adults performing an episodic memory task. We quantified integration and recruitment metrics and examined their correlation with memory performance using Pearson correlation. During encoding, integration across the entire brain, especially within the frontoparietal subnetwork, was significantly correlated with memory performance. During retrieval, recruitment becomes significantly associated with memory performance in visual subnetwork, somatomotor subnetwork, and ventral attention subnetwork. At the nodal level, a significant negative correlation was observed between memory scores and integration of the anterior cingulate gyrus, precentral gyrus, and inferior frontal gyrus within the frontoparietal network during encoding task. During retrieval task, a significant negative correlation was found between memory scores and recruitment in the left progranular cortex and right transverse gyral ventral, whereas positive correlations were seen in the right posterior inferior temporal, left middle temporal, right frontal operculum, and left operculum nodes. Moreover, the dynamic reconfiguration of the functional network was predictive of predict memory performance, as demonstrated by a significant correlation between actual and predicted memory scores. These findings advance our understanding network mechanisms underlying memory processes and developing intervention approaches for memory-related disorders as they shed light on critical factors involved in cognitive processes and provide a deeper understanding of the underlying mechanisms driving cognitive function.


Sujet(s)
Cartographie cérébrale , Imagerie par résonance magnétique , Mémoire épisodique , Humains , Mâle , Femelle , Adulte , Jeune adulte , Encéphale/physiologie , Encéphale/imagerie diagnostique , Réseau nerveux/physiologie , Réseau nerveux/imagerie diagnostique
8.
PeerJ ; 12: e17774, 2024.
Article de Anglais | MEDLINE | ID: mdl-39099649

RÉSUMÉ

The adoption and growth of functional magnetic resonance imaging (fMRI) technology, especially through the use of Pearson's correlation (PC) for constructing brain functional networks (BFN), has significantly advanced brain disease diagnostics by uncovering the brain's operational mechanisms and offering biomarkers for early detection. However, the PC always tends to make for a dense BFN, which violates the biological prior. Therefore, in practice, researchers use hard-threshold to remove weak connection edges or introduce l 1-norm as a regularization term to obtain sparse BFNs. However, these approaches neglect the spatial neighborhood information between regions of interest (ROIs), and ROI with closer distances has higher connectivity prospects than ROI with farther distances due to the principle of simple wiring costs in resent studies. Thus, we propose a neighborhood structure-guided BFN estimation method in this article. In detail, we figure the ROIs' Euclidean distances and sort them. Then, we apply the K-nearest neighbor (KNN) to find out the top K neighbors closest to the current ROIs, where each ROI's K neighbors are independent of each other. We establish the connection relationship between the ROIs and these K neighbors and construct the global topology adjacency matrix according to the binary network. Connect ROI nodes with k nearest neighbors using edges to generate an adjacency graph, forming an adjacency matrix. Based on adjacency matrix, PC calculates the correlation coefficient between ROIs connected by edges, and generates the BFN. With the purpose of evaluating the performance of the introduced method, we utilize the estimated BFN for distinguishing individuals with mild cognitive impairment (MCI) from the healthy ones. Experimental outcomes imply this method attains better classification performance than the baselines. Additionally, we compared it with the most commonly used time series methods in deep learning. Results of the performance of K-nearest neighbor-Pearson's correlation (K-PC) has some advantage over deep learning.


Sujet(s)
Encéphale , Dysfonctionnement cognitif , Imagerie par résonance magnétique , Humains , Dysfonctionnement cognitif/diagnostic , Dysfonctionnement cognitif/imagerie diagnostique , Dysfonctionnement cognitif/physiopathologie , Imagerie par résonance magnétique/méthodes , Encéphale/imagerie diagnostique , Encéphale/physiopathologie , Réseau nerveux/imagerie diagnostique , Réseau nerveux/physiopathologie , Cartographie cérébrale/méthodes , Algorithmes
9.
Front Neural Circuits ; 18: 1449459, 2024.
Article de Anglais | MEDLINE | ID: mdl-39100199

RÉSUMÉ

To understand how neurons and neural circuits function during behaviors, it is essential to record neuronal activity in the brain in vivo. Among the various technologies developed for recording neuronal activity, molecular tools that induce gene expression in an activity-dependent manner have attracted particular attention for their ability to clarify the causal relationships between neuronal activity and behavior. In this review, we summarize recently developed activity-dependent gene expression tools and their potential contributions to the study of neural circuits.


Sujet(s)
Réseau nerveux , Neurones , Animaux , Neurones/physiologie , Réseau nerveux/physiologie , Humains , Encéphale/physiologie
10.
J Psychiatry Neurosci ; 49(4): E252-E262, 2024.
Article de Anglais | MEDLINE | ID: mdl-39122409

RÉSUMÉ

BACKGROUND: Psychosis involves a distortion of thought content, which is partly reflected in anomalous ways in which words are semantically connected into utterances in speech. We sought to explore how these linguistic anomalies are realized through putative circuit-level abnormalities in the brain's semantic network. METHODS: Using a computational large-language model, Bidirectional Encoder Representations from Transformers (BERT), we quantified the contextual expectedness of a given word sequence (perplexity) across 180 samples obtained from descriptions of 3 pictures by patients with first-episode schizophrenia (FES) and controls matched for age, parental social status, and sex, scanned with 7 T ultra-high field functional magnetic resonance imaging (fMRI). Subsequently, perplexity was used to parametrize a spectral dynamic causal model (DCM) of the effective connectivity within (intrinsic) and between (extrinsic) 4 key regions of the semantic network at rest, namely the anterior temporal lobe, the inferior frontal gyrus (IFG), the posterior middle temporal gyrus (MTG), and the angular gyrus. RESULTS: We included 60 participants, including 30 patients with FES and 30 controls. We observed higher perplexity in the FES group, indicating that speech was less predictable by the preceding context among patients. Results of Bayesian model comparisons showed that a DCM including the group by perplexity interaction best explained the underlying patterns of neural activity. We observed an increase of self-inhibitory effective connectivity within the IFG, as well as reduced self-inhibitory tone within the pMTG, in the FES group. An increase in self-inhibitory tone in the IFG correlated strongly and positively with inter-regional excitation between the IFG and posterior MTG, while self-inhibition of the posterior MTG was negatively correlated with this interregional excitation. LIMITATION: Our design did not address connectivity in the semantic network during tasks that selectively activated the semantic network, which could corroborate findings from this resting-state fMRI study. Furthermore, we do not present a replication study, which would ideally use speech in a different language. CONCLUSION: As an explanation for peculiar speech in psychosis, these results index a shift in the excitatory-inhibitory balance regulating information flow across the semantic network, confined to 2 regions that were previously linked specifically to the executive control of meaning. Based on our approach of combining a large language model with causal connectivity estimates, we propose loss in semantic control as a potential neurocognitive mechanism contributing to disorganization in psychosis.


Sujet(s)
Imagerie par résonance magnétique , Troubles psychotiques , Schizophrénie , Sémantique , Humains , Mâle , Femelle , Adulte , Schizophrénie/imagerie diagnostique , Schizophrénie/physiopathologie , Jeune adulte , Troubles psychotiques/imagerie diagnostique , Troubles psychotiques/physiopathologie , Lobe temporal/imagerie diagnostique , Lobe temporal/physiopathologie , Parole/physiologie , Théorème de Bayes , Encéphale/imagerie diagnostique , Encéphale/physiopathologie , Réseau nerveux/imagerie diagnostique , Réseau nerveux/physiopathologie
11.
Elife ; 122024 Aug 12.
Article de Anglais | MEDLINE | ID: mdl-39133541

RÉSUMÉ

In a developing nervous system, axonal arbors often undergo complex rearrangements before neural circuits attain their final innervation topology. In the lateral line sensory system of the zebrafish, developing sensory axons reorganize their terminal arborization patterns to establish precise neural microcircuits around the mechanosensory hair cells. However, a quantitative understanding of the changes in the sensory arbor morphology and the regulators behind the microcircuit assembly remain enigmatic. Here, we report that Semaphorin7A (Sema7A) acts as an important mediator of these processes. Utilizing a semi-automated three-dimensional neurite tracing methodology and computational techniques, we have identified and quantitatively analyzed distinct topological features that shape the network in wild-type and Sema7A loss-of-function mutants. In contrast to those of wild-type animals, the sensory axons in Sema7A mutants display aberrant arborizations with disorganized network topology and diminished contacts to hair cells. Moreover, ectopic expression of a secreted form of Sema7A by non-hair cells induces chemotropic guidance of sensory axons. Our findings propose that Sema7A likely functions both as a juxtracrine and as a secreted cue to pattern neural circuitry during sensory organ development.


Sujet(s)
Système de la ligne latérale , Sémaphorines , Danio zébré , Animaux , Sémaphorines/métabolisme , Sémaphorines/génétique , Système de la ligne latérale/embryologie , Protéines de poisson-zèbre/métabolisme , Protéines de poisson-zèbre/génétique , Axones/physiologie , Axones/métabolisme , Réseau nerveux/physiologie
12.
Sensors (Basel) ; 24(15)2024 Jul 29.
Article de Anglais | MEDLINE | ID: mdl-39123955

RÉSUMÉ

Abstracting causal knowledge from process measurements has become an appealing topic for decades, especially for fault root cause analysis (RCA) based on signals recorded by multiple sensors in a complex system. Although many causality detection methods have been developed and applied in different fields, some research communities may have an idiosyncratic implementation of their preferred methods, with limited accessibility to the wider community. Targeting interested experimental researchers and engineers, this paper provides a comprehensive comparison of data-based causality detection methods in root cause diagnosis across two distinct domains. We provide a possible taxonomy of those methods followed by descriptions of the main motivations of those concepts. Of the two cases we investigated, one is a root cause diagnosis of plant-wide oscillations in an industrial process, while the other is the localization of the epileptogenic focus in a human brain network where the connectivity pattern is transient and even more complex. Considering the differences in various causality detection methods, we designed several sets of experiments so that for each case, a total of 11 methods could be appropriately compared under a unified and reasonable evaluation framework. In each case, these methods were implemented separately and in a standard way to infer causal interactions among multiple variables to thus establish the causal network for RCA. From the cross-domain investigation, several findings are presented along with insights into them, including an interpretative pitfall that warrants caution.


Sujet(s)
Encéphale , Humains , Encéphale/imagerie diagnostique , Encéphale/physiopathologie , Analyse de cause racine/méthodes , Algorithmes , Réseau nerveux/physiopathologie , Électroencéphalographie/méthodes
13.
Sensors (Basel) ; 24(15)2024 Aug 01.
Article de Anglais | MEDLINE | ID: mdl-39124026

RÉSUMÉ

Brain networks are hypothesized to undergo significant changes over development, particularly during infancy. Thus, the aim of this study is to evaluate brain maturation in the first year of life in terms of electrophysiological (EEG) functional connectivity (FC). Whole-brain FC metrics (i.e., magnitude-squared coherence, phase lag index, and parameters derived from graph theory) were extracted, for multiple frequency bands, from baseline EEG data recorded from 146 typically developing infants at 6 (T6) and 12 (T12) months of age. Generalized linear mixed models were used to test for significant differences in the computed metrics considering time point and sex as fixed effects. Correlational analyses were performed to ascertain the potential relationship between FC and subjects' cognitive and language level, assessed with the Bayley-III scale at 24 (T24) months of age. The results obtained highlighted an increased FC, for all the analyzed frequency bands, at T12 with respect to T6. Correlational analyses yielded evidence of the relationship between FC metrics at T12 and cognition. Despite some limitations, our study represents one of the first attempts to evaluate brain network evolution during the first year of life while accounting for correspondence between functional maturation and cognitive improvement.


Sujet(s)
Encéphale , Électroencéphalographie , Humains , Électroencéphalographie/méthodes , Encéphale/physiologie , Encéphale/croissance et développement , Encéphale/imagerie diagnostique , Nourrisson , Mâle , Femelle , Cognition/physiologie , Réseau nerveux/physiologie , Réseau nerveux/croissance et développement
14.
Int J Mol Sci ; 25(15)2024 Jul 29.
Article de Anglais | MEDLINE | ID: mdl-39125856

RÉSUMÉ

The closed-loop control of pathological brain activity is a challenging task. In this study, we investigated the sensitivity of continuous epileptiform short discharge generation to electrical stimulation applied at different phases between the discharges using an in vitro 4-AP-based model of epilepsy in rat hippocampal slices. As a measure of stimulation effectiveness, we introduced a sensitivity function, which we then measured in experiments and analyzed with different biophysical and abstract mathematical models, namely, (i) the two-order subsystem of our previous Epileptor-2 model, describing short discharge generation governed by synaptic resource dynamics; (ii) a similar model governed by shunting conductance dynamics (Epileptor-2B); (iii) the stochastic leaky integrate-and-fire (LIF)-like model applied for the network; (iv) the LIF model with potassium M-channels (LIF+KM), belonging to Class II of excitability; and (v) the Epileptor-2B model with after-spike depolarization. A semi-analytic method was proposed for calculating the interspike interval (ISI) distribution and the sensitivity function in LIF and LIF+KM models, which provided parametric analysis. Sensitivity was found to increase with phase for all models except the last one. The Epileptor-2B model is favored over other models for subthreshold oscillations in the presence of large noise, based on the comparison of ISI statistics and sensitivity functions with experimental data. This study also emphasizes the stochastic nature of epileptiform discharge generation and the greater effectiveness of closed-loop stimulation in later phases of ISIs.


Sujet(s)
Stimulation électrique , Épilepsie , Animaux , Rats , Épilepsie/physiopathologie , Épilepsie/thérapie , Stimulation électrique/méthodes , Hippocampe/physiopathologie , Modèles neurologiques , Potentiels d'action/physiologie , Rat Wistar , Réseau nerveux/physiopathologie , Mâle
15.
Article de Anglais | MEDLINE | ID: mdl-39102321

RÉSUMÉ

Visual feedback gain is a crucial factor influencing the performance of precision grasping tasks, involving multiple brain regions of the visual motor system during task execution. However, the dynamic changes in brain network during this process remain unclear. The aim of this study is to investigate the impact of changes in visual feedback gain during precision grasping on brain network dynamics. Sixteen participants performed precision grip tasks at 15% of MVC under low (0.1°), medium (1°), and high (3°) visual feedback gain conditions, with simultaneous recording of EEG and right-hand precision grip data during the tasks. Utilizing electroencephalogram (EEG) microstate analysis, multiple parameters (Duration, Occurrence, Coverage, Transition probability(TP)) were extracted to assess changes in brain network dynamics. Precision grip accuracy and stability were evaluated using root mean square error(RMSE) and coefficient of variation(CV) of grip force. Compared to low visual feedback gain, under medium/high gain, the Duration, Occurrence, and Coverage of microstates B and D increase, while those of microstates A and C decrease. The Transition probability from microstates A, C, and D to B all increase. Additionally, RMSE and CV of grip force decrease. Occurrence and Coverage of microstates B and C are negatively correlated with RMSE and CV. These findings suggest that visual feedback gain affects the brain network dynamics during precision grasping; moderate increase in visual feedback gain can enhance the accuracy and stability of grip force, whereby the increased Occurrence and Coverage of microstates B and C contribute to improved performance in precision grasping. Our results play a crucial role in better understanding the impact of visual feedback gain on the motor control of precision grasping.


Sujet(s)
Électroencéphalographie , Rétroaction sensorielle , Force de la main , Performance psychomotrice , Humains , Rétroaction sensorielle/physiologie , Force de la main/physiologie , Mâle , Jeune adulte , Adulte , Femelle , Performance psychomotrice/physiologie , Réseau nerveux/physiologie , Volontaires sains , Algorithmes , Encéphale/physiologie
16.
Cell Syst ; 15(8): 770-786.e5, 2024 Aug 21.
Article de Anglais | MEDLINE | ID: mdl-39142285

RÉSUMÉ

Functional magnetic resonance imaging (fMRI) provides insights into cognitive processes with significant clinical potential. However, delays in brain region communication and dynamic variations are often overlooked in functional network studies. We demonstrate that networks extracted from fMRI cross-correlation matrices, considering time lags between signals, show remarkable reliability when focusing on statistical distributions of network properties. This reveals a robust brain functional connectivity pattern, featuring a sparse backbone of strong 0-lag correlations and weaker links capturing coordination at various time delays. This dynamic yet stable network architecture is consistent across rats, marmosets, and humans, as well as in electroencephalogram (EEG) data, indicating potential universality in brain dynamics. Second-order properties of the dynamic functional network reveal a remarkably stable hierarchy of functional correlations in both group-level comparisons and test-retest analyses. Validation using alcohol use disorder fMRI data uncovers broader shifts in network properties than previously reported, demonstrating the potential of this method for identifying disease biomarkers.


Sujet(s)
Encéphale , Électroencéphalographie , Imagerie par résonance magnétique , Encéphale/physiologie , Encéphale/imagerie diagnostique , Imagerie par résonance magnétique/méthodes , Animaux , Humains , Rats , Électroencéphalographie/méthodes , Mâle , Réseau nerveux/physiologie , Réseau nerveux/imagerie diagnostique , Cartographie cérébrale/méthodes , Callithrix/physiologie , Adulte
17.
Sci Rep ; 14(1): 19232, 2024 08 20.
Article de Anglais | MEDLINE | ID: mdl-39164353

RÉSUMÉ

Acceptance and reappraisal are considered adaptive emotion regulation strategies. While previous studies have explored the neural underpinnings of these strategies using task-based fMRI and sMRI, a gap exists in the literature concerning resting-state functional brain networks' contributions to these abilities, especially regarding acceptance. Another intriguing question is whether these strategies rely on similar or different neural mechanisms. Building on the well-known improved emotion regulation and increased cognitive flexibility of individuals who rely on acceptance, we expected to find decreased activity inside the affective network and increased activity inside the executive and sensorimotor networks to be predictive of acceptance. We also expect that these networks may be associated at least in part with reappraisal, indicating a common mechanism behind different strategies. To test these hypotheses, we conducted a functional connectivity analysis of resting-state data from 134 individuals (95 females; mean age: 30.09 ± 12.87 years, mean education: 12.62 ± 1.41 years). To assess acceptance and reappraisal abilities, we used the Cognitive Emotion Regulation Questionnaire (CERQ) and a group-ICA unsupervised machine learning approach to identify resting-state networks. Subsequently, we conducted backward regression to predict acceptance and reappraisal abilities. As expected, results indicated that acceptance was predicted by decreased affective, and executive, and increased sensorimotor networks, while reappraisal was predicted by an increase in the sensorimotor network only. Notably, these findings suggest both distinct and overlapping brain contributions to acceptance and reappraisal strategies, with the sensorimotor network potentially serving as a core common mechanism. These results not only align with previous findings but also expand upon them, illustrating the complex interplay of cognitive, affective, and sensory abilities in emotion regulation.


Sujet(s)
Encéphale , Imagerie par résonance magnétique , Humains , Femelle , Mâle , Adulte , Imagerie par résonance magnétique/méthodes , Encéphale/physiologie , Encéphale/imagerie diagnostique , Jeune adulte , Réseau nerveux/physiologie , Réseau nerveux/imagerie diagnostique , Régulation émotionnelle/physiologie , Émotions/physiologie , Repos/physiologie , Cartographie cérébrale/méthodes , Cognition/physiologie
19.
Nat Rev Neurosci ; 25(9): 625-642, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-39090214

RÉSUMÉ

Carrying out any everyday task, be it driving in traffic, conversing with friends or playing basketball, requires rapid selection, integration and segregation of stimuli from different sensory modalities. At present, even the most advanced artificial intelligence-based systems are unable to replicate the multisensory processes that the human brain routinely performs, but how neural circuits in the brain carry out these processes is still not well understood. In this Perspective, we discuss recent findings that shed fresh light on the oscillatory neural mechanisms that mediate multisensory integration (MI), including power modulations, phase resetting, phase-amplitude coupling and dynamic functional connectivity. We then consider studies that also suggest multi-timescale dynamics in intrinsic ongoing neural activity and during stimulus-driven bottom-up and cognitive top-down neural network processing in the context of MI. We propose a new concept of MI that emphasizes the critical role of neural dynamics at multiple timescales within and across brain networks, enabling the simultaneous integration, segregation, hierarchical structuring and selection of information in different time windows. To highlight predictions from our multi-timescale concept of MI, real-world scenarios in which multi-timescale processes may coordinate MI in a flexible and adaptive manner are considered.


Sujet(s)
Encéphale , Humains , Encéphale/physiologie , Animaux , Réseau nerveux/physiologie , Voies nerveuses/physiologie , Modèles neurologiques
20.
Elife ; 132024 Aug 05.
Article de Anglais | MEDLINE | ID: mdl-39102347

RÉSUMÉ

Resting-state brain networks (RSNs) have been widely applied in health and disease, but the interpretation of RSNs in terms of the underlying neural activity is unclear. To address this fundamental question, we conducted simultaneous recordings of whole-brain resting-state functional magnetic resonance imaging (rsfMRI) and electrophysiology signals in two separate brain regions of rats. Our data reveal that for both recording sites, spatial maps derived from band-specific local field potential (LFP) power can account for up to 90% of the spatial variability in RSNs derived from rsfMRI signals. Surprisingly, the time series of LFP band power can only explain to a maximum of 35% of the temporal variance of the local rsfMRI time course from the same site. In addition, regressing out time series of LFP power from rsfMRI signals has minimal impact on the spatial patterns of rsfMRI-based RSNs. This disparity in the spatial and temporal relationships between resting-state electrophysiology and rsfMRI signals suggests that electrophysiological activity alone does not fully explain the effects observed in the rsfMRI signal, implying the existence of an rsfMRI component contributed by 'electrophysiology-invisible' signals. These findings offer a novel perspective on our understanding of RSN interpretation.


The brain contains many cells known as neurons that send and receive messages in the form of electrical signals. The neurons in different regions of the brain must coordinate their activities to enable the brain to operate properly. Researchers often use a method called resting-state functional magnetic resonance imaging (rsfMRI) to study how different areas of the brain work together. This method indirectly measures brain activity by detecting the changes in blood flow to different areas of the brain. Regions that are working together will become active (that is, have higher blood flow and corresponding rsfMRI signal) and inactive (have lower blood flow and a lower rsfMRI signal) at the same time. These coordinated patterns of brain activity are known as "resting-state brain networks" (RSNs). Previous studies have identified RSNs in many different situations, but we still do not fully understand how these changes in blood flow are related to what is happening in the neurons themselves. To address this question, Tu et al. performed rsfMRI while also measuring the electrical activity (referred to as electrophysiology signals) in two distinct regions of the brains of rats. The team then used the data to generate maps of RSNs in those brain regions. This revealed that rsfMRI signals and electrophysiology signals produced almost identical maps in terms of the locations of the RSNs. However, the electrophysiology signals only contributed a small amount to the changes in the local rsfMRI signals over time at the same recording site. This suggests that RSNs may arise from cell activities that are not detectable by electrophysiology but do regulate blood flow to neurons. The findings of Tu et al. offer a new perspective for interpreting how rsfMRI signals relate to the activities of neurons. Further work is needed to explore all the features of the electrophysiology signals and test other methods to compare these features with rsfMRI signals in the same locations.


Sujet(s)
Encéphale , Imagerie par résonance magnétique , Imagerie par résonance magnétique/méthodes , Animaux , Rats , Encéphale/physiologie , Encéphale/imagerie diagnostique , Mâle , Repos/physiologie , Cartographie cérébrale/méthodes , Phénomènes électrophysiologiques , Réseau nerveux/physiologie , Réseau nerveux/imagerie diagnostique
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