A transient voltage-dependent outward potassium current in mammalian cerebellar Purkinje cells.
Utilizing the single electrode voltage clamp technique applied to rat Purkinje cells (PCs), we have recorded a transient outward voltage-dependent potassium current, Ito. Half maximal values for inactivation and activation were -65 mV and -39 mV, respectively. Ito decays as a single exponential with a time constant of 95 ms and is reduced by 4-aminopyridine. Based on criteria of voltage dependency of activation and inactivation, kinetics of inactivation, ionic selectivity and pharmacologic sensitivity, we have verified a strong resemblance between the typical A current in other neurons, and Ito in PCs. As in other cells, Ito may be important in shaping PC output by modulating intrinsic and extrinsic factors that govern PC firing.
Wang
Y
Y
Department of Physiology, Texas Tech. University Health Sciences Center, Lubbock 79430.
Strahlendorf
J C
JC
Strahlendorf
H K
HK
D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D002531:Cerebellum / Q000502:physiology; D002586:Cesium / Q000494:pharmacology; D005071:Evoked Potentials / Q000187:drug effects; D066298:In Vitro Techniques; D007700:Kinetics; D009474:Neurons / Q000502:physiology; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D011689:Purkinje Cells / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology
D015221:Potassium Channels; D013757:Tetraethylammonium Compounds; D002586:Cesium; D013779:Tetrodotoxin; D019789:Tetraethylammonium; D015761:4-Aminopyridine