Blockade of apomorphine-induced yawning in rats by the dopamine autoreceptor antagonist (+)-AJ 76.

Journal article

The effects of the putative, selective dopamine autoreceptor antagonist (+)-AJ 76 on yawning, penile grooming and mouth movements induced by small doses of apomorphine in male rats were examined. Yawning induced by 0.05mg/kg apomorphine was dose dependently blocked by (+)-AJ-76, significant decreases being observed at 0.86 and 3.5mg/kg of the drug. A dose of 0.86mg/kg (+)-AJ 76 caused a two fold shift to the right of the apomorphine dose response curve for yawning. In contrast, (+)-AJ 76 had no effect on penile grooming and vacuous mouth movements induced by small doses of apomorphine. This pattern of results is similar to that observed after bilateral 6-hydroxydopamine-induced lesions of the substantia nigra which also blocked apomorphine-induced yawning but spared penile grooming and mouth movements. Previous studies have suggested that (+)-AJ 76 is a selective dopamine autoreceptor antagonist that has little or no effect on behaviour mediated by post-synaptic dopamine receptors. Therefore, these data provide further support for the hypothesis that apomorphine-induced yawning is mediated by dopamine autoreceptors.

Authors: Dourish, C; Herbert, E; Iversen, S

• Publication status: Published
• Journal: Neuropharmacology
• Volume: 28
• Issue: 12
• Pages: 1423-1425
• Publication date: 1989-12-01
• DOI: 10.1016/0028-3908(89)90021-x
• EISSN: 1873-7064
• ISSN: 0028-3908
• Language: English
• Keywords: Receptors, Dopamine; Animals; Rats, Inbred Strains; Male; Naphthalenes; Tetrahydronaphthalenes; Rats; Apomorphine; Behavior, Animal; Yawning