The effect of intrahippocampal administration of dopamine or apomorphine on EEG of limbic structures in the rabbit brain.

The effect of intrahippocampal injections of dopamine or apomorphine on the energy level of EEG from limbic structures in the rabbit was investigated. The EEG was recorded from gyrus cinguli anterior, hippocampus dorsalis, nucleus amygdalae, hypothalamus medialis, and nucleus caudatus. Both apomorphine and dopamine in doses used produced stimulatory effects. The effect of apomorphine did not appear after pretreatment with haloperidol (2 or 24 hr, 1 mg/kg sc). This suggests the presence of dopamine receptors of stimulatory type in the dorsal part of rabbit hippocampus. The data confirm the prolonged action of haloperidol.