Developmental regulation of the A-type potassium-channel current in hippocampal neurons: Role of the Kv beta 1.1 subunit

The rapidly inactivating A-type K+ current (IA) is prominent in hippocampal neurons; and the speed of its inactivation may regulate electrical excitability. The auxiliary K+ channel subunit Kvbeta 1.1 confers fast inactivation to Shaker-related channels and is postulated to affect IA. Whole-cell patch clamp recordings of rat hippocampal pyramidal neurons in primary culture showed a developmental decrease in the time constant of inactivation (tau(in)) of voltage-gated K+ currents: 17.9+/-1.5 ms in young neurons (5-7 days in vitro; n=53, mean+/-S.E.M.); 9.9+/-1.0 ms in mature neurons (12-15 days in vitro; n=72, mean+/-S.E.M., P