Repeated administration of 3,4-methylenedioxymethamphetamine augments cocaine's action on dopamine in the nucleus accumbens: a microdialysis study

Eur J Pharmacol. 1997 Jul 16;331(1):R1-3. doi: 10.1016/s0014-2999(97)01035-2.


In this study, we examined the ability of a single injection of cocaine (20 mg/kg, i.p.) to augment extracellular dopamine levels in the nucleus accumbens two weeks after pretreating rats with either saline (1 ml/kg, i.p.) or the serotonin neurotoxin 3,4-methylenedioxymethamphetamine (20 mg/kg, s.c., twice daily for 4 days). The level of dopamine in the nucleus accumbens was measured using in vivo microdialysis. Cocaine produced a 400% increase in extracellular nucleus accumbens dopamine levels in control rats, whereas in 3,4-methylenedioxymethamphetamine treated rats the increase produced by cocaine was 800%, which was significantly different from controls. This suggests that 3,4-methylenedioxymethamphetamine, a relatively common drug of abuse, may alter subsequent vulnerability to cocaine dependence and abuse.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cocaine / pharmacology*
  • Dopamine / metabolism*
  • Dopamine Uptake Inhibitors / pharmacology*
  • Drug Synergism
  • Male
  • Microdialysis
  • N-Methyl-3,4-methylenedioxyamphetamine / administration & dosage*
  • Nucleus Accumbens / drug effects*
  • Nucleus Accumbens / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Serotonin Agents / administration & dosage*
  • Substance-Related Disorders / etiology


  • Dopamine Uptake Inhibitors
  • Serotonin Agents
  • Cocaine
  • N-Methyl-3,4-methylenedioxyamphetamine
  • Dopamine