Selective antagonism of the rate-decreasing effect of d-amphetamine by chlorpromazine in a repeated-acquisition task.
Pigeons acquired a different four-response chain each session by responding sequentially on three keys in the presence of four colors. The response chain was maintained by food presentation under a fixed-ratio schedule. When d-amphetamine was administered alone, the overall response rate decreased and the percent errors increased with increasing doses. When a small dose of chlorpromazine, which was ineffective when given alone, was administered in combination with d-amphetamine, the rate-decreasing effect was antagonized. The antagonism was selective, however, in that the error-increasing effect of d-amphetamine was augmented by chlorpromazine. The nature of the joint effect of the two drugs thus depended on the behavioral measure: rate vs. accuracy.
D000818:Animals; D002746:Chlorpromazine / Q000494:pharmacology*; D010856:Columbidae; D003216:Conditioning, Operant / Q000187:drug effects*; D003913:Dextroamphetamine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008297:Male; D013997:Time Factors
D003913:Dextroamphetamine; D002746:Chlorpromazine