Coupled potassium channels induced by arachidonic acid in cultured neurons

Abstract

Exposure of the inside surface of patches of membrane excised from cultured rat hippocampal neurons to arachidonic acid (10-100 $\mu $M) caused the appearance of potassium currents of variable amplitude similar to those activated by GABA or baclofen in cell-attached patches. The amplitude of single-channel currents increased with time after exposure to 20 or 50 $\mu $M arachidonic acid and also increased when arachidonic acid concentration was increased from 20 to 50 or 100 $\mu $M. Current-amplitude probability histograms had peaks at integral multiples of an `elementary' current. It is proposed that arachidonic acid or its metabolites cause synchronous opening and closing of coupled conducting units (co-channels) in cell membranes.