Fig. 1.

EEG recording from the cortex and hippocampus of an animal subjected to continuous hippocampal stimulation. Ten second samples of the continuous record are displayed from a period just before stimulation (baseline), at the beginning of spontaneous seizures, and after 2 and 5 h of spontaneous seizures. Note that a persistent electrographic seizure (status epilepticus) lasted five hours after termination of stimulation. The pattern of electrographic seizure changed with time as demonstrated by a reduction in frequency of the discharges and changes in their morphology.