GABA-mediated tonic inhibition differentially modulates gain in functional subtypes of cortical interneurons
Alexander Bryson, Robert J. Hatch, Bas‐Jan Zandt, Christian Rössert, Samuel F. Berkovic, Christopher A. Reid, David B. Grayden, Sean Hill, Steven Petrou
Abstract
receptors. Furthermore, tonic inhibition produced two biophysical changes in models of relevance to neuronal excitability: 1) enhanced action potential repolarization via increased current flow into the dendritic compartment, and 2) reduced activation of voltage-dependent potassium channels. Finally, we show theoretically that reduced potassium channel activation selectively increases gain in models possessing action potential dynamics typical for somatostatin interneurons. Potassium channels in parvalbumin-type models deactivate rapidly and are unavailable for further modulation. These findings show that GABA can differentially modulate interneuron excitability and suggest a mechanism through which this occurs in silico via differences of intrinsic electrophysiological properties.