Interaction of d-amphetamine with pentobarbital and chlordiazepoxide: effects on punished and unpunished behavior of pigeons.
Key pecking of two pigeons was maintained under a multiple schedule of food presentation. In the presence of one keylight stimulus responding produced food according to a fixed-interval 5-min schedule. Additionally, during this component, each 50th response produced electric shock. When a different keylight stimulus was present, key pecking resulted in food delivery under a variable-interval 3-min schedule. Responding was suppressed by shock presentation (punishment) but was still positively accelerated throughout each fixed-interval cycle; steady response rates occurred during the alternate component when only the variable-interval schedule was in effect. Overall rates of punished responding were largely unchanged with d-amphetamine (0.1-3.0 mg/kg); unpunished responding was generally either increased slightly or was decreased. Pentobarbital and chlordiazepoxide (1.0-17.0 mg/kg) administered alone increased both punished and unpunished responding at most doses. Combinations of d-amphetamine with either pentobarbital or chlordiazepoxide produced increases in punished responding that exceeded those obtained with either of these drugs alone. The combined effects of d-amphetamine and either pentobarbital or chlordiazepoxide on unpunished responding depended on the individual dose combinations. Combinations of d-amphetamine with pentobarbital or chlordiazepoxide produced effects on both punished and unpunished responding that differed substantially from those obtained when any of these drugs were administered separately.
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002707:Chlordiazepoxide / Q000494:pharmacology*; D010856:Columbidae; D003913:Dextroamphetamine / Q000494:pharmacology*; D010424:Pentobarbital / Q000494:pharmacology*; D011678:Punishment; D012055:Reinforcement Schedule; D013997:Time Factors
D002707:Chlordiazepoxide; D010424:Pentobarbital; D003913:Dextroamphetamine