Reinstatement of punishment-suppressed opioid self-administration in rats: an alternative model of relapse to drug abuse.
BACKGROUND
Animal models of relapse to drug abuse typically assess the ability of various manipulations to reinstate responding that has ceased due to non-reinforcement (extinction). However, there is a lack of information concerning the reinstatement of responding that has ceased for reasons other than extinction.


OBJECTIVE
This study examined the ability of response-independent reinforcer delivery (priming) to reinstate food- or drug-reinforced responding that had been suppressed by response-contingent footshock (punishment).


METHODS
Nose-poke responding by separate groups of rats was reinforced with food (45 mg/delivery) or intravenous remifentanil (4 micro g/kg per infusion), a short-acting micro -opioid agonist. After either 3 or 27 days of training (with 100 reinforcers/day), a punishment contingency was introduced that rapidly suppressed responding. Then, the punishment contingency was discontinued, and half the rats received priming.


RESULTS
Priming by non-contingent delivery of food or remifentanil significantly reduced the number of sessions required for responding to resume. There were no significant differences in this effect between short-term and long-term training or between food- and drug-trained groups.


CONCLUSIONS
Self-administration responding that has been suppressed by punishment can be reinstated by priming, and it can eventually resume even without priming. Under the conditions studied here, priming after punishment had effects qualitatively similar to those typically seen after extinction. This punishment/reinstatement procedure may be useful for comparing the effects of other manipulations known to affect behavior in the extinction/reinstatement model of relapse.
Panlilio
Leigh V
LV
Preclinical Pharmacology Section, Behavioral Neuroscience Branch, Intramural Research Program, National Institute on Drug Abuse, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA, USA. lpanlili@intra.nida.nih.gov.
Thorndike
Eric B
EB
Preclinical Pharmacology Section, Behavioral Neuroscience Branch, Intramural Research Program, National Institute on Drug Abuse, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA, USA.
Schindler
Charles W
CW
Preclinical Pharmacology Section, Behavioral Neuroscience Branch, Intramural Research Program, National Institute on Drug Abuse, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA, USA.
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D010880:Piperidines / Q000494:pharmacology; D011678:Punishment / Q000523:psychology; D051381:Rats; D020318:Rats, Long-Evans; D000077208:Remifentanil; D055502:Secondary Prevention; D012646:Self Administration; D019966:Substance-Related Disorders / Q000517:prevention & control* / Q000523:psychology
D000701:Analgesics, Opioid; D010880:Piperidines; D000077208:Remifentanil