Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2014377 | Pharmacology Biochemistry and Behavior | 2006 | 9 Pages |
Abstract
The dopaminergic system requires combined dopamine D1/D2 receptor stimulation to express its activity; a phenomenon called synergism D1/D2. Dopamine receptors develop supersensitivity following dopamine de-afferentation and/or reserpine treatment. Acute supersensitivity occurs with reserpine treatment. The breakdown of D1/D2 synergism has been proposed implicating the genesis of this kind of supersensitivity. We sought to determine the best conditions for inducing acute dopaminergic supersensitivity evaluated by apomorphine-induced stereotyped behaviour, to examine whether D1/D2 synergism breakdown occurs in this reserpine-induced acute supersensitivity model, and whether it can be prevented by the monoamino-oxidase (MAO) inhibitor selegiline. Reserpine (2.0Â mg/kg) was injected 3Â h before apomorphine (0.6Â mg/kg) induced stereotypy. D1/D2 synergism was investigated using specific antagonists (D1-SKF 83566 2.5Â mg/kg, D2-haloperidol 2.0Â mg/kg) and selegiline (10Â mg/kg) was used to analyze the influence of dopamine “de-novo” synthesis. All antagonist treatments suppressed stereotypy and selegiline prevented supersensitivity. These data suggest that reserpine-induced acute dopaminergic supersensitivity is not due to the breakdown of D1/D2 synergism and such supersensitivity can be prevented by recently synthesised dopamine.
Related Topics
Life Sciences
Biochemistry, Genetics and Molecular Biology
Biochemistry
Authors
Ana Kleinman, Carla A. Tieppo, Gabriela M. Florez, Luciano F. Felicio, Antonia G. Nasello,