EFFECT OF 3,4-METHYLENEDIOXYMETHAMPHETAMINE (MDMA) ON HIPPOCAMPAL DOPAMINE AND SEROTONIN

The 3,4-methylenedioxymethamphetamine (MDMA)-induced increase in the e xtracellular concentration of dopamine and the long-term depletion of 5-HT were studied in the hippocampus of the rat brain. MDMA produced a dose-dependent increase in the extracellular concentration of dopamin e in the hippocampus, as well as in the striatum. The MDMA-induced inc rease in the extracellular concentration of dopamine in the hippocampu s, but not in the striatum, was suppressed in rats treated with the no repinephrine uptake inhibitor, desipramine, and in rats in which norad renergic neurons in the hippocampus were lesioned with DSP4 (N-(2-chlo roethyl)-N-ethyl-2-bromo benzylamine). However, the long-term depletio n of 5-HT in the hippocampus produced by MDMA was unaltered in desipra mine-treated rats. These results are supportive of the view that the M DMA-induced increase in the extracellular concentration of dopamine in the hippocampus is the result of an enhanced release of dopamine from noradrenergic neurons. In addition, the MDMA-induced depletion of 5-H T in the hippocampus appears not to involve dopamine-initiated process es, because suppression of MDMA-induced dopamine release did not atten uate the long-term depletion of 5-HT in the hippocampus. (C) 1998 Else vier Science Inc.