[Effect of extracellular potassium ions on the potassium outward current which depends on extracellular calcium ions].

Changes in the delayed potassium outward current induced by introduction of K+ ions into extracellular solution have been studied in experiments on isolated intracellularly perfused Helix neurons. It is shown that extracellular administration of 5-10 mmol/l K+ ions into the solution produces a reversible increase of the potassium outward current which depends on the extracellular Ca2+ ions (IK(Ca out)). Extracellular potassium increases this component of the potassium current as a result of weakening of its inactivation.