How the cortico-thalamic feedback affects the EEG power spectrum over frontal and occipital regions during propofol-induced anaesthetic sedation - Inria - Institut national de recherche en sciences et technologies du numérique Accéder directement au contenu
Pré-Publication, Document De Travail Année : 2014

How the cortico-thalamic feedback affects the EEG power spectrum over frontal and occipital regions during propofol-induced anaesthetic sedation

Résumé

Increasing concentrations of the anaesthetic agent propofol initially induces sedation before achieving full general anaesthesia. The characteristic changes in electroencephalographic (EEG) rhythms include increased activity in the δ− (1-4 Hz) and α− (8-12 Hz) frequency bands over the frontal region, but increased δ− and decreased α−activity over the occipital region. It is known that the cortex, the thalamus, and the thalamo-cortical feedback loop contribute to some degree to the propofol-induced changes in the EEG power spectrum. However the precise role of each structure to the dynamics of the EEG is unknown. In this paper we apply a neuronal population model of a single thalamo-cortical module to repro-duce the power spectrum changes in EEG during propofol-induced anaesthesia sedation. Based on recent experimental data, the effect of propofol is modelled as an increase in inhibitory synaptic response amplitude and decay time constant in thalamo-cortical relay cells while cortical inhibition is neglected. The model reproduces the power spectrum features observed experimentally both in frontal and occipital electrodes. Moreover a detailed analysis of the model indicates the importance of multiple resting states in brain activity. The work suggests that the α−activity originates from the cortico-thalamic relay interaction, whereas the emergence of δ−activity results from the full cortico-reticular-relay-cortical feedback loop with a prominent enforced thalamic reticular-relay interac-tion. This model suggests an essential role of synaptic GABAergic receptors at relay neurons and, more generally, for the thalamus in the generation of both the α− and the δ−EEG patterns that are seen during propofol anaesthesia sedation.

Domaines

Neurosciences
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Dates et versions

hal-01091503 , version 1 (05-12-2014)

Identifiants

  • HAL Id : hal-01091503 , version 1

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Meysam Hashemi, Axel Hutt, Jamie Sleigh. How the cortico-thalamic feedback affects the EEG power spectrum over frontal and occipital regions during propofol-induced anaesthetic sedation. 2014. ⟨hal-01091503⟩
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