Pentylenetetrazole-induced changes of the single potassium channel in primary cultured cerebral cortical neurons.

To elucidate the behavior of the single ionic channels of cerebral cortical neurons during bursting activity, the effects of pentylenetetrazole (PTZ) on a single potassium channel of primary cultured cerebral cortical neurons from mice were examined. All of the examined 10-day-old primary cultured neurons of the cerebral cortex showed clear bursting activity after extracellular application of PTZ using whole-cell patch-clamp recording. Less than half of the examined single potassium channels, both outward and inward, of the 2- and 3-day-old as well as 6-10-day-old primary cultured cerebral cortical neurons showed the bursting-type open-close state by application of PTZ. The PTZ-sensitive single potassium channels were found in the voltage-dependent as well as calcium-activated channels.