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=Volume 8 - 2014

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 delta and alpha 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 delta activity is in accord with observed data
for deepening propofol anesthesia; but is absolutely dependent on the inclusion of extra synaptic
(tonic) GABA action in the model.