THE ACUTE EFFECTS OF AMPHETAMINE DERIVATIVES ON EXTRACELLULAR SEROTONIN AND DOPAMINE LEVELS IN RAT NUCLEUS-ACCUMBENS

The acute effects of amphetamine derivatives on extracellular concentr ation of serotonin (5-HT) and dopamine in the nucleus accumbens were s tudied with in vivo microdialysis using conscious, freely moving rats. 5-HT, dopamine, and their major metabolites were measured by HPLC wit h electrochemical detection. Amphetamine (1.0-9.0 mg/kg) elevated dopa mine levels considerably, but failed to affect the levels of 5-HT, exc ept at the highest dose administered. 3,4-Methylenedioxyamphetamine (M DA, 1.0-9.0 mg/kg) and 3,4-methylenedioxymethamphetamine (MDMA, 1.0-9. 0 mg/kg) elevated both 5-HT and dopamine levels dose dependently. The failure of 2,5-dimethoxy-4-methylamphetamine (DOM, 0.5-1.0 mg/kg) to a ffect the 5-HT levels suggests that extracellular levels of 5-HT play a minor role in hallucinogenic activity. The strong effects of MDA and MDMA on levels of 5-HT indicate that their actions on serotonergic me chanisms are different from those of the hallucinogens. In addition, m ethylenedioxyamphetamines may act via dopaminergic mechanisms similar to those of amphetamine. (C) 1998 Elsevier Science Inc.