Increased ectopic action potential generation accompanies epileptogenesis in vitro.

We studied changes in the characteristics of action potentials of CA3 pyramidal cells accompanying electrographic seizure (EGS) induction, using an in vitro model similar to kindling. We found an increased propensity to fire action potentials which lack EPSPs or other triggering depolarizing potentials. Such 'baseline spikes' appear to be initiated at a site electrically distant from the soma.