RATIONALE: The role of heroin-related stimuli in motivating the resumption of heroin use is not fully understood. OBJECTIVES: The objective was to characterize the relative importance of drug-related contextual stimuli, discriminative stimuli (DS), or discrete conditioned stimuli (CSs) on drug seeking when rats were reintroduced into the operant context after withdrawal. METHODS: Nose-poke responding by male rats was reinforced with intravenous heroin (0.05 mg/kg per infusion, 4-h session daily) under a progressive ratio schedule of reinforcement for 14 days. Each session began with the illumination of a green light in the active hole that served as DS. Each earned heroin injection was paired with a 5-s compound cue light and the sound of the infusion pump that served as the discrete CSs. RESULTS: Response rates of heroin seeking induced by the contextual stimuli were comparable to the average rates of responding during self-administration training, but rates induced by either DS or CSs were greater than those induced by the contextual stimuli alone (P<0.05). The responding induced by contingent presentations of CSs was higher than that of DS after extinction of instrumental behavior. The drug seeking induced by CSs can be maintained after 3 days extinction with DS in the original context, although the responding elicited by DS cannot be recovered after 3 days of extinction with CSs. CONCLUSIONS: The relapse to drug seeking can be elicited separately by environmental cues, heroin-predictive DS, or discrete CSs in the same rat after withdrawal.
RATIONALE: The role of heroin-related stimuli in motivating the resumption of heroin use is not fully understood. OBJECTIVES: The objective was to characterize the relative importance of drug-related contextual stimuli, discriminative stimuli (DS), or discrete conditioned stimuli (CSs) on drug seeking when rats were reintroduced into the operant context after withdrawal. METHODS: Nose-poke responding by male rats was reinforced with intravenous heroin (0.05 mg/kg per infusion, 4-h session daily) under a progressive ratio schedule of reinforcement for 14 days. Each session began with the illumination of a green light in the active hole that served as DS. Each earned heroin injection was paired with a 5-s compound cue light and the sound of the infusion pump that served as the discrete CSs. RESULTS: Response rates of heroin seeking induced by the contextual stimuli were comparable to the average rates of responding during self-administration training, but rates induced by either DS or CSs were greater than those induced by the contextual stimuli alone (P<0.05). The responding induced by contingent presentations of CSs was higher than that of DS after extinction of instrumental behavior. The drug seeking induced by CSs can be maintained after 3 days extinction with DS in the original context, although the responding elicited by DS cannot be recovered after 3 days of extinction with CSs. CONCLUSIONS: The relapse to drug seeking can be elicited separately by environmental cues, heroin-predictive DS, or discrete CSs in the same rat after withdrawal.
Authors: Deanne M Buffalari; Nana Yaa A Marfo; Tracy T Smith; Melissa E Levin; Matthew T Weaver; Edda Thiels; Alan F Sved; Eric C Donny Journal: Pharmacol Biochem Behav Date: 2014-06-24 Impact factor: 3.533
Authors: Kara L Kuntz; Robert C Twining; Anne E Baldwin; Kent E Vrana; Patricia S Grigson Journal: Pharmacol Biochem Behav Date: 2008-04-03 Impact factor: 3.533
Authors: Peter W Marinelli; Douglas Funk; Stephen Harding; Zhaoxia Li; Walter Juzytsch; A D Lê Journal: Eur J Neurosci Date: 2009-08-03 Impact factor: 3.386