Mutant analysis shows that the Ca2+-induced K+ current shuts off one type of excitation in Paramecium.
Two mutants of Paramecium tetraurelia, called "pantophobiacs," were found to lack most of the slow Ca2+-induced K+ outward current. Passive properties, the transient Ca2+ inward current, and the fast depolarization-induced K+ outward current remain normal. The mutant defect reduces the ability to shut off a normal, excited state of the membrane and results in repeated, long backward swimming instead of the wild-type jerks in response to a variety of ions, to heat, and to touch.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002462:Cell Membrane / Q000502:physiology; D004533:Egtazic Acid / Q000494:pharmacology; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D008959:Models, Neurological; D009154:Mutation; D010247:Paramecium / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D011188:Potassium / Q000378:metabolism*
D004533:Egtazic Acid; D011188:Potassium; D002118:Calcium