Phylogenetically-Preserved Multiscale Neuronal Activity: Iterative Coarse-Graining Reconciles Scale-Dependent Theories of Brain Function

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: June 27, 2024

Abstract Brain recordings collected at different resolutions support statistically distinct signatures of information processing, leading to scale-dependent theories brain function. Here, we demonstrate that these disparate neural-coding emerge from the same multiscale functional organisation neuronal activity across calcium-imaging whole brains zebrafish and nematode, as well sensory regions fly, mouse, macaque brain. Network simulations show hierarchical-modular structural connectivity facilitates coordination, enhancing processing benefits such a maximal dynamic range. Finally, this cross-scale supports behavioural states species by reconfiguring affiliation temporal dynamics mesoscale. Our findings suggest self-similar scaling is universal principle reconciles function, facilitating both efficiency resiliency while enabling significant reconfiguration mesoscale cellular ensembles accommodate demands.

Language: Английский

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Propofol disrupts the functional core-matrix architecture of the thalamus in humans

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Sept. 9, 2024

Research into the role of thalamocortical circuits in anesthesia-induced unconsciousness is difficult due to anatomical and functional complexity. Prior neuroimaging studies have examined either thalamus as a whole or focused on specific subregions, overlooking distinct neuronal subtypes like core matrix cells. We conducted study heathy volunteers magnetic resonance imaging during conscious baseline, deep sedation, recovery. advanced gradient mapping technique delineate geometry circuits, within framework unimodal-transmodal axis cortex. Here we show significant shift this marked by transmodal-deficient geometry. This alteration closely linked spatial variations cell composition thalamus. research bridges cellular systems-level understanding, highlighting crucial thalamic core-matrix architecture understanding neural mechanisms states consciousness.

Language: Английский

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A mesoscale connectome-based model of conscious access in the macaque monkey

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown

Published: Feb. 22, 2022

Abstract A growing body of evidence suggests that conscious perception a sensory stimulus coincides with all-or-none activity across multiple cortical areas, phenomenon called ‘ignition’. In contrast, the same stimulus, when undetected, induces only transient activity. this work, we report large-scale model macaque cortex based on recently quantified structural mesoscopic connectome data. We use to simulate detection task, and demonstrate how dynamical bifurcation mechanism produces ignition-like events in network. The predicts feedforward excitatory transmission is primarily mediated by fast AMPA receptors ensure rapid signal propagation from associative areas. greater proportion inter-areal feedback projections local recurrent excitation depend slow NMDA receptors, ignition distributed frontoparietal Our predicts, counterintuitively, fast-responding areas contain higher ratio compared association show slow, sustained validate prediction using cortex-wide in-vitro receptor autoradiography Finally, can account for various behavioral physiological effects linked consciousness. Together, these findings clarify neurophysiological mechanisms access primate support concept gradients densities along hierarchy contribute cognitive functions.

Language: Английский

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A Burst-dependent Thalamocortical Substrate for Visual Rivalry

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: July 15, 2023

Abstract Models of perceptual awareness often lack tractable neurobiological constraints. Inspired by recent cellular recordings in a mouse model tactile threshold detection, we constructed biophysical that incorporated essential features thalamocortical anatomy and physiology. Our reproduced, mechanistically explains, the key vivo neural behavioural signatures model, as well response to set causal perturbations. We generalised same (with identical parameters) visual rivalry found thalamic-mediated mechanism determined dominance. This led generation novel, directly testable, electrophysiological predictions. Analyses based on dynamical systems theory showed simulations both detection arises from emergent systems-level dynamics loops.

Language: Английский

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Convergent effects of different anesthetics are due to changes in phase alignment of cortical oscillations

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: March 20, 2024

Abstract Many anesthetics cause loss of responsiveness despite having diverse underlying molecular and circuit actions. To explore the convergent effects these drugs, we examined how anesthetic doses ketamine dexmedetomidine affected oscillations in prefrontal cortex nonhuman primates. Both caused increases phase locking ventrolateral dorsolateral cortex, within across hemispheres. However, nature varied. Activity different subregions a hemisphere became more anti-phase with both drugs. Local analyses region suggested that this finding could be explained by broad cortical distance-based effects, such as large traveling waves. By contrast, homologous areas hemispheres in-phase. Our results suggest induce strong patterns alignment are markedly from those awake state, may common feature driving

Language: Английский

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Transthalamic Pathways for Cortical Function

Journal of Neuroscience, Journal Year: 2024, Volume and Issue: 44(35), P. e0909242024 - e0909242024

Published: Aug. 28, 2024

The cerebral cortex contains multiple, distinct areas that individually perform specific computations. A particular strength of the is communication signals between cortical allows outputs these compartmentalized computations to influence and build on each other, thereby dramatically increasing processing power its role in sensation, action, cognition. Determining how communicates individual is, therefore, critical for understanding function. Historically, corticocortical was thought occur exclusively by direct anatomical connections often sequentially linked a hierarchical fashion. More recently, anatomical, physiological, behavioral evidence accumulating indicating higher-order thalamus communication. Specifically, transthalamic pathway involves projections from one area neurons that, turn, project another cortex. Here, we consider implications having two routes with an emphasis unique available consequences disorders diseases affect

Language: Английский

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Thalamo-Cortical Interaction for Incremental Binding in Mental Contour-Tracing

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Dec. 21, 2023

Abstract Visual object-based attention marks a key process of mammalian perception. By which mechanisms this is implemented and how it can be interacted with by means attentional control not completely understood yet. Incremental binding mechanism required in more demanding scenarios likewise experimentally investigated quite well. Attention spreads across representation the visual object labels bound elements constant up-modulation neural activity. The speed incremental was found to dependent on spatial arrangement distracting scene scale invariant giving rise growth-cone hypothesis. In work, we propose dynamical model that provides mechanistic account for these findings. Through simulations, investigate properties demonstrate an spreading tags neurons participate process. They utilize Gestalt eventually show characteristics labeling perceptual items delayed activity enhancement neuronal firing rates. We discuss algorithmic underlying relate model’s computation. This theoretical investigation encompasses complexity considerations finds only explanatory value terms neurohpysiological evidence, but also efficient implementation striving establish normative account. relating connectivity motifs neuroanatomical suggest thalamo-cortical interactions likely candidate flexible realization suggested model. There, pyramidal cells are proposed serve as processors grouping information. Local bottom-up evidence about stimulus features integrated via basal dendritic sites. It combined apical signal consisting contextual information gated task-relevance selection mediated higher-order thalamic representations. Author Summary Understanding requires us tell apart objects from one another. Object-based mammals achieve this. Mental processing components determines whether they compatible overall and, thus, should grouped together perceived whole or not. For complicated objects, needs happen serially, determining compatibility step step. try answer question might brain. test case elongated lines compare available experimental evidence. additionally explains does so spending connections efficiently — property desirable brains machines. Together, findings brain areas involved realizing reason

Language: Английский

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An integrative, multiscale view on consciousness theories_Eary version of paper in press in NEURON

Published: Feb. 11, 2024

Summary. How is conscious experience related to material brain processes? A variety of theories aiming answer this age-old question have emerged from the recent surge in consciousness research, and some are now hotly debated. While most researchers so far focused on development validation their preferred theory relative isolation, article, written by a group scientists representing different theories, takes an alternative approach. Noting that various often try explain aspects or mechanistic levels consciousness, we argue do not necessarily contradict each other. Instead, several them may converge fundamental neuronal mechanisms be partly compatible complementary, multiple can simultaneously contribute our understanding. Here consider unifying, integration-oriented approaches been largely neglected, seeking combine valuable elements theories.

Language: Английский

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Transition to chaos separates learning regimes and relates to measure of consciousness in recurrent neural networks

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: May 15, 2024

Recurrent neural networks exhibit chaotic dynamics when the variance in their connection strengths exceed a critical value. Recent work indicates also modulates learning strategies; learn "rich" representations initialized with low coupling and "lazier" solutions larger variance. Using Watts-Strogatz of varying sparsity, structure, hidden weight variance, we find that strength dividing from ordered differentiates rich lazy strategies. Training moves both stable closer to edge chaos, richer before transition chaos. In contrast, biologically realistic connectivity structures foster stability over wide range variances. The chaos is reflected measure clinically discriminates levels consciousness, perturbational complexity index (PCIst). Networks high values PCIst learning, suggesting consciousness prior may promote learning. results suggest clear relationship between dynamics, regimes complexity-based measures consciousness.

Language: Английский

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Thalamic Roles in Conscious Perception Revealed by Low-Intensity Focused Ultrasound Neuromodulation

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 10, 2024

The neural basis of conscious perception remains incompletely understood. While cortical mechanisms content have been extensively investigated, the role subcortical structures, including thalamus, less explored. We aim to elucidate causal contributions different thalamic regions using transcranial low-intensity focused ultrasound (LIFU) neuromodulation. hypothesize that modulating would result in distinct perceptual outcomes. apply LIFU human volunteers investigate region-specific and sonication parameter-dependent effects. target anterior (transmodal-dominant) posterior (unimodal-dominant) regions, further divided into ventral dorsal while participants perform a near-threshold visual task. Task performance is evaluated Signal Detection Theory metrics. find high duty cycle stimulation thalamus enhanced object recognition sensitivity. also observe general (i.e., region-independent) effect on decision bias tendency toward particular response) categorization accuracy. Specifically, decreases accuracy, whereas low shifts towards more conservative stance. In conclusion, our results provide insight functional organization shaping experience highlight unique transmodal-dominant thalamus.

Language: Английский

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