Attenuation by pimozide of the suppressant effect ofd-amphetamine on operant behaviour

✍ Scribed by M. J. Morley; C. M. Bradshaw; E. Szabadi

• Publisher: Springer
• Year: 1987
• Tongue: English
• Weight: 592 KB
• Volume: 91
• Category: Article
• ISSN: 0033-3158
• DOI: 10.1007/bf00217071

✦ Synopsis

The interaction between pimozide (a selective D2-dopamine receptor antagonist) and d-amphetamine on the operant performance of rats maintained under variable-interval schedules of positive reinforcement was examined. In Experiment 1, eight rats responded under variable-interval 30-s and variable-interval 300-s. Pimozide (0.0625, 0.125, 0.25, 0.5 mg/kg) suppressed performance maintained under both schedules in a dose-dependent manner, the degrees of suppression being equivalent in the two schedules. In Experiment 2, 12 rats responded under the same schedules. d-Amphetamine (0.1-3.2 mg/kg) suppressed performance under both schedules, the degree of suppression being somewhat greater in the case of variable-interval 30-s. Pre-treatment with pimozide (0.0625, 0.125 mg/kg) significantly attenuated the suppressant effect of d-amphetamine under both schedules. It is suggested that D2-dopamine receptors may be involved in mediating the suppressant effect of d-amphetamine on operant behaviour.