title: Mephedrone, compared with MDMA (ecstasy) and amphetamine, rapidly increases both dopamine and 5-HT levels in nucleus accumbens of awake rats.
abstract: OBJECTIVE
  The designer drug 1-(4-methylphenyl)-2-methylaminopropan-1-one (4-methylmethcathinone, mephedrone) is reported to possess psychostimulant, entactogenic and hallucinogenic effects. The purpose of this study was to examine the effects of acute administration of mephedrone on extracellular levels of dopamine (DA) and 5-HT in the nucleus accumbens of awake rats and compare these effects with those induced by 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) and amphetamine.
  
  
  METHODS
  Microdialysis sampling was performed while simultaneously recording locomotor activity in rats and the monoamines were determined by HPLC with electrochemical detection.
  
  
  RESULTS
  Mephedrone (3 mg·kg(-1) s.c.) and (+)-amphetamine (1 mg·kg(-1) s.c.) caused rapid increases in extracellular DA levels of 496% and 412%, respectively, whereas MDMA (3 mg·kg(-1) s.c.) showed only a moderate effect (235%). The corresponding 5-HT levels increased to 941% (mephedrone) and 911% (MDMA), but only to 165% following amphetamine. The calculated t(1/2) values for elimination rate of mephedrone, MDMA and amphetamine-induced increases in extracellular DA levels were 25, 303 and 51 min, the corresponding t(1/2) values for 5-HT were 26, 48 and 84 min, respectively. Locomotor activity was increased most by amphetamine, whereas both mephedrone and MDMA showed about three times lower and shorter-lasting effects.
  
  
  CONCLUSIONS
  The neurochemical and functional properties of mephedrone resemble those of MDMA, but it also shows an amphetamine-like effect in that it evokes a rapid release and elimination of DA in the brain reward system, a feature that may contribute to its potent reinforcing properties.
authors: Department of Physiology and Pharmacology, Karolinska Institutet Science Park, Fogdevreten 2a, Stockholm, Sweden. jk@pronexus.se
authors: J
authors: J
authors: Kehr
authors: F
authors: F
authors: Ichinose
authors: S
authors: S
authors: Yoshitake
authors: M
authors: M
authors: Goiny
authors: T
authors: T
authors: Sievertsson
authors: F
authors: F
authors: Nyberg
authors: T
authors: T
authors: Yoshitake
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