REINSTATEMENT OF DRUG-SEEKING BEHAVIOR PRODUCED BY HEROIN-PREDICTIVE ENVIRONMENTAL STIMULI

The current study examined whether stimuli predictive of heroin availa bility were capable of inducing a relapse of drug-seeking behavior in an operant runway task. Olfactory stimuli (orange and almond food extr act) served as discriminative cues about the availability (S+) or unav ailability (S-) of heroin reinforcement (a single 0.1 mg/kg IV infusio n) in the goal box of a straight arm runway. Following discrimination training, the running response was extinguished in the absence of the olfactory cues. On a single trial, the discriminative stimuli were the n tested for their ability to reinstate running behavior prior to pres entation of the heroin reinforcer. Subjects presented with the S+ on t est day took significantly less time to traverse the alley than they d id on the final day of extinction, while those subjects presented with the S- on test day continued to run slowly. These results, demonstrat e, in an animal model of drug self-administration, that environmental discriminative cues can produce a relapse in drug seeking behavior fol lowing a period of abstinence. The response-reinstating properties of the S+ odor were unaltered by pretreatment with any of three doses of haloperidol (0.0, 0.15 or 0.3 mg/kg IP), suggesting that the motivatin g properties of heroin-predictive stimuli or cues remain intact during dopamine receptor antagonism.