Slow Depolarizing Potentials in “Epileptic” Neurons

Abstract

Slow depolarizing potentials following penicillin-induced epileptiform bursting were recorded intracellularly from cat cortical neurons in vivo and guinea pig hippocampal neurons in vitro. In in vitro experiments, blocking K conductance with tetraethylammonium resulted in epileptiform bursting and after potentials similar to those seen with penicillin application. It is hypothesized that an abnormality in K conductance, and a resulting increase in Ca influx, could be responsible for the long depolarizations characteristic of some neurons in epileptic foci.