Developmental Regulation of a Slowly-inactivating Potassium Conductance in Rat Neostriatal Neurons

In late embryonic and early post-natal rat neostriatal neurons, the voltage-dependent potassium currents activated by depolarization are largely attributable to a rapidly inactivating A-current and a delayed rectifier current. Over the first 4 weeks of post-natal life, a third potassium current emerges in most cells. This slowly inactivating conductance is distinct from the A-current and delayed rectifier in voltage-dependence, kinetics and pharmacology. The properties of this conductance suggest that it may be of central importance to the integrative behavior of neostriatal neurons by controlling such features as first spike latency and interspike interval.