Inhibition by peripheral electric stimulation of the reinstatement of morphine-induced place preference in rats and drug-craving in heroin addicts.

OBJECTIVE: To test the hypothesis that peripheral electric stimulation (PES) may suppress the reinstatement of morphine-induced conditioned place preference (CPP) in rats as well as the drug craving of detoxified heroin addicts in a frequency-dependent manner. METHODS: CPP model of the rat was constructed with two compartment automatic CPP apparatus, and the craving of the heroin addicts was assessed with a visual analogue scale (VAS). RESULTS: (1) PES of low frequency could prevent the drug priming- or foot shock-induced reinstatement of morphine CPP; (2) this effect was naloxone-reversible, suggesting a possible involvement of endogenous opioid mechanisms; and (3) PES of low frequency could also accelerate the rate of natural decay of drug craving in heroin addicts after successful abstinence. CONCLUSION: PES might serve as a therapeutic measure for the treatment of heroin addiction.