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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Syst. Neurosci. | doi: 10.3389/fnsys.2019.00059

COALIA: a computational model of human EEG for consciousness research.

 Siouar Bensaid1, 2,  Julien Modolo1, 2, Isabelle Merlet1, 2,  Fabrice Wendling1, 2* and Pascal Benquet1, 2
  • 1University of Rennes 1, France
  • 2INSERM U1099 Laboratoire Traitement du Signal et de l'Image, France

Understanding the origin of the main physiological processes involved in consciousness is a major challenge of contemporary neuroscience, with crucial implications for the study of Disorders of Consciousness (DOC). The difficulties in achieving this task include the considerable quantity of experimental data in this field, along with the non-intuitive, nonlinear nature of neuronal dynamics. One possibility of integrating the main results from the experimental literature into a cohesive framework, while accounting for nonlinear brain dynamics, is the use of physiologically-inspired computational models. In this study, we present a physiologically-grounded computational model, attempting to account for the main micro-circuits identified in the human cortex, while including the specificities of each neuronal type. More specifically, the model accounts for thalamo-cortical (vertical) regulation of cortico-cortical (horizontal) connectivity, which is a central mechanism for brain information integration and processing. The distinct neuronal assemblies communicate through feedforward and feedback excitatory and inhibitory synaptic connections implemented in a template brain accounting for long-range connectome. The EEG generated by this physiologically-based simulated brain is validated through comparison with brain rhythms recorded in humans in two states of consciousness (wakefulness, sleep). Using the model, it is possible to reproduce the local disynaptic disinhibition of basket cells (fast GABAergic inhibition) and glutamatergic pyramidal neurons through long-range activation of VIP interneurons that induced inhibition of SST interneurons. The model (COALIA) predicts that the strength and dynamics of the thalamic output on the cortex control the local and long-range cortical processing of information. Furthermore, the model reproduces and explains clinical results regarding the complexity of transcranial magnetic stimulation TMS-evoked EEG responses in DOC patients and healthy volunteers, through a modulation of thalamo-cortical connectivity that governs the level of cortico-cortical communication. This new model provides a quantitative framework to accelerate the study of the physiological mechanisms involved in the emergence, maintenance and disruption (sleep, anesthesia, DOC) of consciousness.

Keywords: computational modeling, feedforward inhibition, GABA, disinhibition, TMS-EEG, disorders of consciousness (DOC), brain connectivity

Received: 08 Mar 2019; Accepted: 07 Oct 2019.

Copyright: © 2019 Bensaid, Modolo, Merlet, Wendling and Benquet. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Prof. Fabrice Wendling, University of Rennes 1, Rennes, 35065, France, fabrice.wendling@univ-rennes1.fr