Hippocampal mediation of shaking behavior induced by electrical stimulation of the perforant path in the rat.

Perforant path stimulation in awake, unrestrained rats caused frequency-dependent shaking behavior in the absence of detectable epileptiform activity. Granule cell discharge, monitored by evoked field potentials, was necessary for the induction of shaking behavior. Direct stimulation of the granule cell layer also caused shakes. Intracerebroventricular injections of kainic acid destroyed hippocampal CA3 pyramidal cells and blocked the shake response. These results indicate that hippocampal granule cell discharge mediates stimulation-induced shaking behavior, and, that epileptiform activity is not required for the induction of shaking behavior by electrical stimulation.