[Kinetic analysis of a transient potassium current in rat cerebellar granule cells in vitro].
Thin slices were prepared from cerebella of 10-24 day old rats and examined with whole-cell patch-clamp methods. Depolarizing steps from holding potentials negative to -60 mV elicited an early transient outward current, identified as IA, and a late outward K+ current. Depolarizations from -50 mV failed to evoke any A current and gave only a slowly rising component similar to the delayed K+ current, which inactivated thereafter with a time constant of 2.5 s at -30 mV. The IA peaked in 1-2 ms, decayed following a double exponential with time constants of 8.1 and 53.2 ms at +20 mV and was half-inactivated at -82.5 mV. 4-AP 4 mM depressed both K+ currents showing little specificity between them, while TEA 20 mM selectively abolished only the delayed K+ current.
Bardoni
R
R
Istituto di Fisiologia Generale, Università di Ferrara.
Belluzzi
O
O
D000200:Action Potentials; D000818:Animals; D002478:Cells, Cultured; D002525:Cerebellar Cortex / Q000166:cytology*; D004558:Electric Stimulation; D015640:Ion Channel Gating; D007700:Kinetics; D011188:Potassium / Q000502:physiology*; D051381:Rats
D011188:Potassium
Analisi cinetica di una corrente potassio transiente nelle cellule dei granuli di cervelletto di ratto "in vitro".