Hippocampal seizure and secondary epileptogenesis in the "kindled" cat preparations.

The behavioral, electrographic and transference characteristics were investigated in hippocampal kindled cats. All animals developed generalized convulsions following daily hippocampal stimulation (mean 51.8 days). A distinct sequence of behavioral events was observed prior to the seizure and classified into six stages. Motor seizure manifestations appeared along with the emergence of an entirely independent after-discharge and interictal discharge in the bilateral globus pallidus (GP) and amygdala (AM). Secondary site convulsions were triggered with initial stimulation in the GP, contralateral dorsal hippocampus and in most AM sites. This finding suggests that after the primary site was kindled, these previously unstimulated secondary structures attained a response potency equal to that of the primary site. Furthermore, the "all-or nothing" response was confirmed both in the primary and secondary site convulsions.