Median raphe- and contralateral hippocampus-elicited EEG spikes which correspond to hyperpolarizations of pyramidal cells in the kindled hippocampus of the rabbit.

Rabbit hippocampus was chronically stimulated with implanted electrodes until interictal EEG spikes were kindled in it. The kindled hippocampus was then studied in acute experiments. Stimulation of the median raphe nucleus and that of the opposite hippocampus produced EEG spikes, whose intracellular correlates were hyperpolarizations of pyramidal cells (referred to as inhibitory EEG spikes).