AUTHOR=Hashemi Meysam , Hutt Axel , Sleigh Jamie TITLE=Anesthetic action on extra-synaptic receptors: effects in neural population models of EEG activity JOURNAL=Frontiers in Systems Neuroscience VOLUME=8 YEAR=2014 URL=https://www.frontiersin.org/journals/systems-neuroscience/articles/10.3389/fnsys.2014.00232 DOI=10.3389/fnsys.2014.00232 ISSN=1662-5137 ABSTRACT=

The role of extra-synaptic receptors in the regulation of excitation and inhibition in the brain has attracted increasing attention. Because activity in the extra-synaptic receptors plays a role in regulating the level of excitation and inhibition in the brain, they may be important in determining the level of consciousness. This paper reviews briefly the literature on extra-synaptic GABA and NMDA receptors and their affinity to anesthetic drugs. We propose a neural population model that illustrates how the effect of the anesthetic drug propofol on GABAergic extra-synaptic receptors results in changes in neural population activity and the electroencephalogram (EEG). Our results show that increased tonic inhibition in inhibitory cortical neurons cause a dramatic increase in the power of both δ− and α− bands. Conversely, the effects of increased tonic inhibition in cortical excitatory neurons and thalamic relay neurons have the opposite effect and decrease the power in these bands. The increased δ-activity is in accord with observed data for deepening propofol anesthesia; but is absolutely dependent on the inclusion of extrasynaptic (tonic) GABA action in the model.