The effects of MDMA pretreatment on the behavioural effects of other drugs of abuse in the rat elevated plus-maze test

Pharmacol Biochem Behav. 2004 Apr;77(4):805-14. doi: 10.1016/j.pbb.2004.02.007.

Abstract

Few preclinical studies have found long-term behavioural consequences of the serotonergic neurotoxicity produced by 3,4-methylenedioxymethamphetamine (MDMA). This study investigated whether pretreatment with MDMA altered the behavioural effects of other drugs of abuse. Adult male Lister hooded rats (n=10/group) were pretreated with 10 mg/kg MDMA or 1 ml/kg saline vehicle intraperitoneally every 2 h for 6 h. Fourteen days later, the behavioural effects of d-amphetamine (2 mg/kg), cocaine (10 mg/kg), ethanol (2.0 g/kg), heroin (0.5 mg/kg), or MDMA (10 mg/kg) were assessed in the elevated plus-maze test. MDMA pretreatment produced approximately 20-25% decrease in hippocampal 5-HT and 5-HIAA concentrations, and [(3)H]paroxetine binding when analysed 2 weeks later. Despite inducing neurotoxicity, this regimen had no effect upon the plus-maze behaviour induced by ethanol, heroin, and MDMA. Acutely, and independent of neurotoxic pretreatment, MDMA produced a clear anxiogenic-like behavioural profile with a reduction of open arm entries and suppression of explorative behaviours. Despite being acutely anxiogenic, pretreatment with a neurotoxic regimen of MDMA has little effect on the anxiety-related effects of other drugs of abuse. It is possible that extended time points would produce significant changes, although the available evidence suggests that the plus-maze may not be a suitable model for detection of behavioural dysfunction after neurotoxic MDMA.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Anxiety / metabolism
  • Drug Interactions
  • Hippocampus / drug effects
  • Hippocampus / metabolism
  • Illicit Drugs / metabolism
  • Illicit Drugs / pharmacology*
  • Male
  • Maze Learning / drug effects*
  • Maze Learning / physiology
  • N-Methyl-3,4-methylenedioxyamphetamine / administration & dosage*
  • N-Methyl-3,4-methylenedioxyamphetamine / metabolism
  • Paroxetine / metabolism
  • Protein Binding / physiology
  • Rats

Substances

  • Illicit Drugs
  • Paroxetine
  • N-Methyl-3,4-methylenedioxyamphetamine