title: An in vivo microdialysis assessment of concurrent MDMA and cocaine administration in Sprague-Dawley rats.
abstract: OBJECTIVE
  Despite the popularity of polysubstance abuse among recreational methylendioxymethamphetamine (MDMA) users, relatively few controlled experimental studies have documented the neurobehavioral effects of MDMA in combination with other abused substances.
  
  
  OBJECTIVE
  In this study, the combined acute effects of MDMA and cocaine were examined by conducting in vivo microdialysis in the rat nucleus accumbens while simultaneously monitoring locomotor activity.
  
  
  METHODS
  Male Sprague-Dawley rats were administered cocaine (10 or 20 mg/kg, i.p.), MDMA (1.5 or 3.0 mg/kg, i.p.), or one of four combinations of cocaine and MDMA during microdialysis experiments. Locomotor activity was monitored, and dialysis samples were collected every 30 min for 3 h prior to injections, for one 30-min period following saline injections, and for an additional 3-h period following drug injections. Samples were analyzed for dopamine content by high-performance liquid chromatography with electrochemical detection.
  
  
  RESULTS
  Significant differences in locomotor activity and dopamine efflux were found among treatment groups, with some MDMA/cocaine combinations producing significantly greater increases compared to single doses of cocaine or MDMA within the first 30 min after injection.
  
  
  CONCLUSIONS
  Considering the popularity of polysubstance use among recreational MDMA users, the clinical implications of the current findings warrant further investigation.
authors.affiliation: Department of Psychology, Western Michigan University, Kalamazoo, MI 49008, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Panos
authors.forename: Lisa E
authors.initials: LE
authors.lastname: Baker
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D003042:Cocaine / Q000008:administration & dosage / Q000633:toxicity*; D004298:Dopamine / Q000378:metabolism; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006213:Hallucinogens / Q000008:administration & dosage / Q000633:toxicity; D008297:Male; D017551:Microdialysis; D009043:Motor Activity / Q000187:drug effects*; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000008:administration & dosage / Q000633:toxicity*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018765:Dopamine Uptake Inhibitors; D006213:Hallucinogens; D003042:Cocaine; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D004298:Dopamine