A transient voltage-dependent outward potassium current in mammalian cerebellar Purkinje cells

• Published in: Brain research Vol. 567; no. 1; p. 153
• Main Authors: Wang, Y, Strahlendorf, J C, Strahlendorf, H K
• Format: Journal Article
• Language: English
• Published: Netherlands 13-12-1991
• Subjects: 4-Aminopyridine - pharmacology; Animals; Cerebellum - physiology; Cesium - pharmacology; Evoked Potentials - drug effects; In Vitro Techniques; Kinetics; Neurons - physiology; Potassium Channels - drug effects; Potassium Channels - physiology; Purkinje Cells - drug effects; Purkinje Cells - physiology; Rats; Tetraethylammonium; Tetraethylammonium Compounds - pharmacology; Tetrodotoxin - pharmacology
• ISSN: 0006-8993
• DOI: 10.1016/0006-8993(91)91449-B

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.