The antibiotic minocycline prevents methamphetamine-induced rewarding effects in mice

Repeated use of methamphetamine (METH) causes dependence in humans, and to date, there are no effective medication treatments for METH addiction. We previously reported that the antibiotic minocycline attenuated behavioral abnormalities (hyperactivity and behavioral sensitization) and dopaminergic neurotoxicity in mice and monkeys, after the administration of METH. In this study, we examined the effect of minocycline on METH-induced rewarding effects in mice using the conditioned place preference (CPP) paradigm. Minocycline (40 mg/kg, IP) significantly attenuated METH (1.0 mg/kg, SC)-induced place preference in mice. In vivo microdialysis experiments using free-moving mice, showed that minocycline (40 mg/kg, IP) significantly attenuated the increased extracellular dopamine (DA) levels within the nucleus accumbens, typically seen after the administration of METH (1.0 mg/kg, SC). These findings suggest that minocycline may block METH-induced rewarding effects by down regulating extracellular DA levels in the nucleus accumbens of mice. This would make minocycline a potential therapeutic drug for the treatment of METH induced disorders.