Diversity of single potassium channels in isolated snail neurons.
Comparison of K+ channels in mollusk and mammalian neurons has been made to elucidate their fundamental properties. Using patch clamp cell-attached configuration, K+ channels in isolated snail neurons were separated into three subtypes: with big (BKC), medium (MKC) and small (SKC) unitary conductances. BKC and MKC were activated at -30 mV and SKC at more negative potentials. BKC and MKC proved sensitive to TEA, whereas SKC were sensitive to 4-AP. Cd2+ in the pipet decreased unitary conductance of BKC by 55% and of MKC by about 31%. Bath application of 5-HT selectively suppressed MKC. It is suggested that BKC can be referred to large conductance Ca(2+)-dependent K+ currents (KCa), MKC to intermediate conductance KCa and SKC channels comply with the characteristics of A current of mammals. These data show that KCa and A currents may be the most general types of currents generated by K+ channels.
Sotkis
A V
AV
Department of General Physiology of Nervous System, Bogomoletz Institute of Physiology, Kiev, Ukraine.
Kostyuk
P G
PG
Lukyanetz
E A
EA
D000818:Animals; D006372:Helix, Snails; D066298:In Vitro Techniques; D008322:Mammals; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology; D019789:Tetraethylammonium / Q000494:pharmacology
D015221:Potassium Channels; D012701:Serotonin; D019789:Tetraethylammonium