Cocaine seeking by rats is a goal-directed action.
In two experiments rats were trained to self-administer intravenous cocaine on chained schedules using different responses in the initial (drug-seeking) and terminal (drug-taking) links. In both between- (Experiment 1) and within-subject designs (Experiment 2), the drug-taking response was then either extinguished or reinforced in the absence of the opportunity to perform the seeking response. In a subsequent extinction test with the seeking manipulanda alone, the rate of drug seeking was reduced after the prior extinction of the associated taking response. An additional group trained with a sucrose reinforcer showed a comparable devaluation effect. These findings demonstrate that seeking responses for cocaine and food rewards are mediated by a representation of the contingency between seeking responses and the opportunity to take the reward.
Olmstead
M C
MC
Department of Psychology, Queen's University, Kingston, Ontario, Canada. olmstead@psyc.queensu.ca
Lafond
M V
MV
Everitt
B J
BJ
Dickinson
A
A
D000818:Animals; D003042:Cocaine / Q000494:pharmacology; D019970:Cocaine-Related Disorders / Q000523:psychology*; D004305:Dose-Response Relationship, Drug; D005108:Extinction, Psychological / Q000187:drug effects; D008297:Male; D009042:Motivation; D051381:Rats; D012055:Reinforcement Schedule; D012646:Self Administration / Q000523:psychology; D015819:Substance Abuse, Intravenous / Q000523:psychology; D013395:Sucrose
D013395:Sucrose; D003042:Cocaine