The rewarding properties of MDMA are preserved in mice lacking µ‐opioid receptors
European Journal of Neuroscience July 15, 2004 Patricia Robledo, Victoria Mendizábal, Jordi Ortuño et al. 40 citations
The rewarding effects of MDMA do not require µ-opioid receptors, unlike those of opioids, ethanol, nicotine, and THC. In mice lacking µ-opioid receptors, MDMA still produced a conditioned place preference and increased dopamine release in the nucleus accumbens, while decreasing dopamine metabolites DOPAC and HVA. Basal dopamine and metabolite levels were similar between knockout and wild-type mice. The findings indicate that MDMA's effects on dopamine neurons are independent of µ-opioid receptor activation.