METHYLENEDIOXYMETHAMPHETAMINE INDUCES OPPOSITE CHANGES IN CENTRAL PRESYNAPTIC AND POSTSYNAPTIC 5-HT1A RECEPTORS IN RATS

The present study examined the short- and long-term effects of single and repeated administration of 3,4-methylenedioxymethamphetamine (MDMA , 'ecstasy') on somatodendritic and postsynaptic 5-HT1A receptors of t he rat brain. [H-3]8-Hydroxy-2-(di-n-propylamino)tetralin ([H-3]8-OH-D PAT) was used to label 5-HT1A receptors in the brain stem region conta ining the dorsal raphe nucleus and in the frontal cortex. As expected, both schedules of treatment reduced the serotonin :(5-hydroxytryptami ne, 5-HT) content and [H-3]paroxetine binding in the frontal cortex bu t not in the brain stem. Multiple but not single MDMA administration s ignificantly reduced 5-HT1A receptor density in the selected brain ste m region. In the frontal cortex, both MDMA treatments increased or ten ded to increase 5-HT1A receptor number, the effect being more marked a fter repeated drug administration.