Four-choice drug discrimination in pigeons.
(+)Amphetamine was added as a training stimulus for pigeons previously trained to discriminate among pentobarbital, morphine and saline using a three-choice procedure. Pigeons quickly learned the four-choice drug discrimination. Generalization from the training drugs was similar to that established with simpler drug discriminations; pentobarbital generalized to chlordiazepoxide, morphine generalized to methadone, and (+)amphetamine generalized to cocaine and methamphetamine. Low doses of phencyclidine generalized to saline, while higher doses partially generalized to pentobarbital and (+)amphetamine. When dose-response curves were redetermined with a cumulative-dosing procedure, the same pattern of generalization occurred as under single-dose procedures. Dose-response curves were quantal under both the single-dose and the cumulative-dosing procedures. The four-choice procedure offers some important advantages for studying the discriminative stimulus effects of drugs that interact with multiple receptor subtypes and for studying drug mixtures.
Li
M
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Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock 72205, USA.
McMillan
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D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D010856:Columbidae; D003913:Dextroamphetamine / Q000494:pharmacology; D004193:Discrimination Learning; D004192:Discrimination, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D008297:Male; D009020:Morphine / Q000494:pharmacology; D010424:Pentobarbital / Q000494:pharmacology
D000701:Analgesics, Opioid; D000697:Central Nervous System Stimulants; D006993:Hypnotics and Sedatives; D009020:Morphine; D010424:Pentobarbital; D003913:Dextroamphetamine