title: Anxiolytic-like effect induced by the cannabinoid CB1 receptor agonist, arachydonilcyclopropylamide (ACPA), in the rat amygdala is mediated through the D1 and D2 dopaminergic systems.
abstract: In the present study the influence of the dopaminergic system(s) of the amygdala on the anxiolytic-like effect of the cannabinoid CB1 receptor agonist, arachydonilcyclopropylamide (ACPA), in male Wistar rats was investigated. An elevated plus-maze test of anxiety was used to assess anxiety-like behaviors. The results showed that bilateral intra-amygdala injections of ACPA (0.125, 1.25 and 5 ng/rat) and the mixed dopamine D1/D2 receptor agonist, apomorphine, at different doses (0.001, 0.01 and 0.1 µg/rat) increased percentage open arm time (%OAT) and percentage open arm entries (%OAE), indicating an anxiolytic-like effect for both of the drugs. In contrast, intra-amygdala administration of the dopamine D1 receptor antagonist SCH23390 (0.5 and 1 µg/rat) and the dopamine D2 receptor antagonist, sulpiride (2 and 3 µg/rat) decreased %OAT and %OAE, suggesting an anxiogenic-like effect for both of the drugs. Interestingly, pretreatment with a sub-effective dose of apomorphine (0.0005 µg/rat) increased, while SCH23390 (0.25 µg/rat) and sulpiride (1.5 µg/rat) decreased the anxiolytic-like effect of ACPA. It can be concluded that the dopaminergic system of the amygdala may be involved, at least partly, in the anxiolytic-like effects induced by ACPA in the rat amygdala.
authors.affiliation: Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. zarinmr@ams.ac.ir
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Zarrindast
authors.forename: Sara
authors.initials: S
authors.lastname: Mahboobi
authors.forename: Mitra-Sadat
authors.initials: MS
authors.lastname: Sadat-Shirazi
authors.forename: Shamseddin
authors.initials: S
authors.lastname: Ahmadi
mesh_terms: D000679:Amygdala / Q000187:drug effects*; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001007:Anxiety / Q000188:drug therapy; D001058:Apomorphine / Q000008:administration & dosage / Q000494:pharmacology; D001095:Arachidonic Acids / Q000494:pharmacology*; D001552:Benzazepines / Q000008:administration & dosage / Q000494:pharmacology; D065127:Dopamine D2 Receptor Antagonists; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000187:drug effects; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists*; D017447:Receptors, Dopamine D1 / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000819:agonists / Q000378:metabolism*; D013469:Sulpiride / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D014151:Anti-Anxiety Agents; D001095:Arachidonic Acids; D001552:Benzazepines; D065127:Dopamine D2 Receptor Antagonists; D043884:Receptor, Cannabinoid, CB1; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; C534628:SCH 23390; C119324:arachidonylcyclopropylamide; D013469:Sulpiride; D001058:Apomorphine