Role of dopamine D-1 and D-2 antagonists in a model of focal epilepsy induced by electrical stimulation of hippocampus and amygdala in the rabbit.
1. The differential role played by blockade of D-1 or D-2 dopamine receptors 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 antagonist haloperidol (1 mg/Kg) increased significantly after-discharge duration after stimulation of either hippocampus or amygdala and lowered after-discharge threshold in few animals. 3. The D-1 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 model, having a clearer influence on D-2 receptors. SCH 23390 had no effect on amygdala whereas it exerted protection on the hippocampus. 5. The present data suggest that D-1 and D-2 receptors have different roles in generating and spreading the epileptic activity.
Neurological Institute C. Mondino Pavia, Italy.
P
P
Bo
D
D
Soragna
E
E
Marchioni
E
E
Candeloro
A
A
Albergati
F
F
Savoldi
D000679:Amygdala / Q000503:physiopathology*; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D004195:Disease Models, Animal; D018492:Dopamine Antagonists / Q000494:pharmacology*; D065127:Dopamine D2 Receptor Antagonists; D004558:Electric Stimulation; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000378:metabolism*; D006220:Haloperidol / Q000494:pharmacology; D006624:Hippocampus / Q000503:physiopathology*; D008297:Male; D011817:Rabbits; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors
D001552:Benzazepines; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D017447:Receptors, Dopamine D1; D006220:Haloperidol