ROLE OF DOPAMINE D-1 AND D-2 ANTAGONISTS IN A MODEL OF FOCAL EPILEPSYINDUCED BY ELECTRICAL-STIMULATION OF HIPPOCAMPUS AND AMYGDALA IN THE RABBIT

1. The differential role played by blockade of D-1 or D-2 dopamine rec eptors in mechanisms underlying seizures was studied in a model of EEG after-discharge induced by electrical stimulation of selective brain regions (dorsal hippocampus and amygdala) in the rabbit. 2. The D-2 an tagonist haloperidol (1 mg/Kg) increased significantly afterdischarge duration after stimulation of either hippocampus or amygdala and lower ed after-discharge threshold in few animals. 3. The D-l antagonist SCH 23390 (0.3 mg/Kg) caused no changes following stimulation of amygdala and reduced after-discharge duration when hippocampus was stimulated. 4. Haloperidol exerted a proconvulsant action in this experimental mo del, having a clearer influence on D-2 receptors. SCH 23390 had no eff ect on amygdala whereas it exerted protection on the hippocampus. 5. T he present data suggest that D-l and D-2 receptors have different role s in generating and spreading the epileptic activity.