Effect of the repeated administration of (+/-)-3,4-methylenedioxymethamphetamine on the behavioral response of rats to the 5-HT1A receptor agonist (+/-)-8-hydroxy-(di-n-propylamino)tetralin.

In this study, we examined the effect of the subcutaneous administration (twice daily for 4 consecutive days) of 3,4-methylenedioxymethamphetamine (MDMA, 20 mg/kg) or saline (1 ml/kg) on the response of rats to the behavioral effects of the 5-HT1A agonist (+/-)-8-hydroxy-(di-n-propylamino)tetralin (8-OH-DPAT) 30 days after the last saline or MDMA treatment. The reciprocal forepaw treading elicited by the 0.25-mg/kg dose of 8-OH-DPAT was significantly lower in animals pretreated with MDMA compared to vehicle-treated animals. However, there were no significant differences between the MDMA- and vehicle-treated animals in flat body posture, locomotor activity and rectal temperature measured after the systemic administration of 8-OH-DPAT. Overall, our results suggest that the depletion of 5-HT levels by the repeated administration of MDMA does not produce a supersensitivity of central 5-HT1A receptors in the rat as determined via our approach.