Referenced in: none

Automatically associated channels: SK2

Title: Gating of Ca2+-activated K+ channels controls fast inhibitory synaptic transmission at auditory outer hair cells.

Authors: D Oliver, N Klöcker, J Schuck, T Baukrowitz, J P Ruppersberg, B Fakler

Journal, date & volume: Neuron, 2000 Jun , 26, 595-601

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/10896156

Abstract
Fast inhibitory synaptic transmission in the central nervous system is mediated by ionotropic GABA or glycine receptors. Auditory outer hair cells present a unique inhibitory synapse that uses a Ca2+-permeable excitatory acetylcholine receptor to activate a hyperpolarizing potassium current mediated by small conductance calcium-activated potassium (SK) channels. It is shown here that unitary inhibitory postsynaptic currents at this synapse are mediated by SK2 channels and occur rapidly, with rise and decay time constants of approximately 6 ms and approximately 30 ms, respectively. This time course is determined by the Ca2+ gating of SK channels rather than by the changes in intracellular Ca2+. The results demonstrate fast coupling between an excitatory ionotropic neurotransmitter receptor and an inhibitory ion channel and imply rapid, localized changes in subsynaptic calcium levels.