Topography of dopamine D-1 and D-2 receptor-mediated rotation after intrastriatal injections of dopamine-related drugs in normosensitive rats.
Naive rats were challenged systematically with apomorphine after receiving unilateral dorsal or ventral intracaudate injections of the dopamine D-1 receptor antagonist, SCH23390, or the D-2 receptor antagonist, sulpiride. Sulpiride injections into both the dorsal and ventral striatum induced a robust ipsilateral rotation, while SCH23390 elicited a weaker ipsilateral rotation only on injection into the ventral striatum. Both drugs were ineffective in saline-treated rats, although sulpiride injections into the ventral striatum after systemic saline elicited a small ipsilateral preference. The results from this rotational model mediated by normosensitive receptors indicate that only dopamine D-1 receptors in the ventral striatum mediate rotation while D-2 receptors in both striatal regions mediate rotation. A functional dichotomy between these two neostriatal regions is thus proposed.
Konitsiotis
S
S
Department of Pharmacology, Medical School, University of Ioannina, Greece.
Kafetzopoulos
E
E
D000704:Analysis of Variance; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects*; D001552:Benzazepines / Q000494:pharmacology*; D003342:Corpus Striatum / Q000187:drug effects*; D018492:Dopamine Antagonists; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D013469:Sulpiride / Q000494:pharmacology*
D001552:Benzazepines; D018492:Dopamine Antagonists; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D013469:Sulpiride; D001058:Apomorphine