Arachidonic acid augments potassium currents in rat neocortical neurones.

We analysed the effects induced by arachidonic acid on voltage-dependent outward currents generated by rat neocortical neurones in culture in the presence of Na+ and Ca2+ channel blockers. These currents, recorded with whole-cell voltage-clamping techniques, were presumably carried by K+ and were characterized by an early transient and a late persistent component. Extracellular application of arachidonic acid (50 microM) enhanced both components of the voltage-dependent K+ response by 15-29% (n > 20 cells). These effects were reversible and not observed when a low dose (50 microM) of indomethacin was present in the bath (n = 7 cells). We conclude that one or more of the arachidonic acid metabolites of the cyclooxygenase pathway might be involved in the modulation of outward currents in neocortical cells in culture.