Performance effects with repeated-response measures during pimozide-produced dopamine receptor blockade.
Rats were trained to lever-press for either food reward or brain-stimulation reward on a continuous reinforcement schedule. Following training each animal was extinguished (i.e. tested with the reward omitted) under the influence of pimozide (0.25 mg/Kg or 0.5 mg/Kg). Pimozide produced a dose-dependent reduction in the mean number of responses to extinction made by rats in ecach group. In a second experiment, pimozide produced a similar dose-dependent decrease in the performance of a naturally occurring behavior (nose-poking) that had never been associated with reward. These data suggest that dopamine receptor blockade can produce a perofrmance deficit in situations which require repetitive responses, and that this deficit is unrelated to the presence or absence of reward.
D000818:Animals; D001921:Brain / Q000502:physiology; D003216:Conditioning, Operant / Q000187:drug effects* / Q000502:physiology; D004558:Electric Stimulation; D005108:Extinction, Psychological / Q000502:physiology; D005502:Food; D008297:Male; D010868:Pimozide / Q000494:pharmacology*; D051381:Rats; D011954:Receptors, Dopamine / Q000187:drug effects*
D011954:Receptors, Dopamine; D010868:Pimozide