Ecstasy, (+/-)-3,4-methylenedioxy-metamphetamine (MDMA), is a popular recreational drug among young people. The present study aims to mimic MDMA intake among adolescents at dance clubs, taking repeated doses in the same evening on an intermittent basis. Male Sprague-Dawley rats received either 3 x 1 or 3 x 5 mg/kg/day (3 h apart) every seventh day during 4 weeks. We used real-time RT-PCR to determine the gene expression of serotonin 5HT(1A), 5HT(1B), 5HT(2A), 5HT(2C), 5HT(3), 5HT(6) receptors and dopamine D-1, D-2, D-3 receptors in seven brain nuclei. The highest dose of MDMA extensively increased the 5HT1(B)-receptor mRNA in the cortex, caudate putamen, nucleus accumbens, and hypothalamus. The 5HT(2A)-receptor mRNA was reduced at the highest MDMA dose in the cortex. The 5HT(2C) mRNA was significantly increased in a dose-dependent manner in the cortex and the hypothalamus, as well as the 5HT(3)-receptor mRNA was in the hypothalamus. The 5HT(6) mRNA level was increased in the forebrain cortex and the amygdala. Dopamine receptor mRNAs were only affected in the hypothalamus. In conclusion, this study provides evidence for a unique implication of serotonin rather than dopamine receptor mRNA levels, in response to repeated intermittent MDMA administration. We therefore suggest that serotonin regulated functions also primarily underlie repeated MDMA intake at rave parties.