Adaptation and bursting in neocortical neurones may be controlled by a single fast potassium conductance.

We have used computer simulation of a model neurone and in vitro intracellular recording to demonstrate that the adaptation of repetitive discharge in neocortical neurones can be explained by a fast potassium current whose inactivation is retarded by intracellular calcium. The maximum amplitude of this current determines whether the neurone will discharge in regular or burst mode.