Referenced in: none

Automatically associated channels: Kv4.1

Title: Activity-independent homeostasis in rhythmically active neurons.

Authors: Jason N MacLean, Ying Zhang, Bruce R Johnson, Ronald M Harris-Warrick

Journal, date & volume: Neuron, 2003 Jan 9 , 37, 109-20

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/12526777

Abstract
The shal gene encodes the transient potassium current (I(A)) in neurons of the lobster stomatogastric ganglion. Overexpression of Shal by RNA injection into neurons produces a large increase in I(A), but surprisingly little change in the neuron's firing properties. Accompanying the increase in I(A) is a dramatic and linearly correlated increase in the hyperpolarization-activated inward current (I(h)). The enhanced I(h) electrophysiologically compensates for the enhanced I(A), since pharmacological blockade of I(h) uncovers the physiological effects of the increased I(A). Expression of a nonfunctional mutant Shal also induces a large increase in I(h), demonstrating a novel activity-independent coupling between the Shal protein and I(h) enhancement. Since I(A) and I(h) influence neuronal activity in opposite directions, our results suggest a selective coregulation of these channels as a mechanism for constraining cell activity within appropriate physiological parameters.