Drug discrimination using a Pavlovian conditional discrimination paradigm in pigeons.
Three pigeons were studied using a discriminated autoshaping procedure in which the presence or absence of methadone served as a conditional stimulus signalling which of two key light CSs would be followed by grain access. Drug sessions alternated randomly with no-drug sessions. Methadone (2.0 mg/kg) was administered prior to drug sessions in which a black vertical line on a white background served as CS+ and a diffuse white keylight served as CS- (reversed for bird 681). Saline or no injection was administered prior to no-drug sessions and the CS+/CS- contingencies were reversed. Discriminated performances emerged in which over 80% of the responding occurred to the appropriate stimulus. Stimulus control by methadone was assessed by presenting a range of methadone doses during 10-trial extinction sessions. A graded dose-effect curve was produced with low doses of methadone controlling saline-appropriate responding and higher doses controlling drug-appropriate responding. A range of doses of morphine, cocaine, and pentobarbital were also tested. Morphine produced methadone-appropriate responding while cocaine and pentobarbital did not.
Parker
B K
BK
Department of Psychology, West Virginia University, Morgantown 26506-6040.
Schaal
D W
DW
Miller
M
M
D000818:Animals; D003042:Cocaine / Q000494:pharmacology; D010856:Columbidae; D003214:Conditioning, Classical / Q000187:drug effects*; D004193:Discrimination Learning / Q000187:drug effects; D004192:Discrimination, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005108:Extinction, Psychological / Q000187:drug effects; D005795:Generalization, Stimulus / Q000187:drug effects; D008691:Methadone / Q000494:pharmacology; D010424:Pentobarbital / Q000494:pharmacology
D010424:Pentobarbital; D003042:Cocaine; D008691:Methadone