Environmental enrichment as a potential intervention for heroin seeking

Abstract

Background: Heroin-related cues can trigger craving and relapse in addicts or heroin seeking in rats. In the present study we investigated whether environmental enrichment (EE) implemented after heroin exposure can reduce cue-induced reinstatement of heroin seeking and expression of heroin conditioned place preference.

Methods: In Experiment 1, male Long Evans rats that already acquired a heroin self-administration habit, were housed in enriched or non-enriched environments, underwent extinction training and later were tested for cue-induced reinstatement of heroin seeking. In Experiment 2, rats were conditioned with heroin in one compartment of a CPP apparatus and saline in the other, exposed to 30days of enrichment or no enrichment and were later tested for heroin CPP.

Results: The results showed that exposure to EE significantly reduced responding during the reinstatement test (Experiment 1) and prevented the expression of heroin CPP (Experiment 2).

Conclusion: Our findings suggest that EE can be an effective behavioral approach to diminish the effects of conditioned cues on heroin seeking.

Keywords: Conditioned place preference; Cue-induced reinstatement; Environmental enrichment; Heroin; Heroin seeking.