Analysis of K inactivation and TEA action in the supramedullary cells of puffer.
Under the voltage clamp condition, the K inactivation was analyzed in cells bathed in the isosmotic KCl Lophius-Ringer solution. After conditioning hyperpolarization, the cells respond to depolarizations with increased K permeability, which in turn is decreased during maintained depolarizations. The steady-state levels of the K inactivation as a function of the membrane potential are related by an S-shaped curve similar to that which describes the steady-state Na inactivation in the squid giant axon. TEA reduced the K conductance by a factor which is independent of the potential, and without a shift of the inactivation curve along the voltage axis. The rapid phase of the K activation is less susceptible to TEA than the slow phase of the K activation. Hyperpolarizing steps remove the K inactivation, the rate of the removal being faster the larger the hyperpolarization from the standard potential of about -60 mv.
D000818:Animals; D002463:Cell Membrane Permeability; D004594:Electrophysiology; D005399:Fishes; D066298:In Vitro Techniques; D007700:Kinetics; D009474:Neurons / Q000187:drug effects*; D011189:Potassium Chloride / Q000494:pharmacology*; D013757:Tetraethylammonium Compounds / Q000494:pharmacology*
D013757:Tetraethylammonium Compounds; D011189:Potassium Chloride