title: Mephedrone (4-methylmethcathinone) and d-methamphetamine improve visuospatial associative memory, but not spatial working memory, in rhesus macaques.
abstract: OBJECTIVE
  The novel cathinone derivative 4-methylmethcathinone (4-MMC; mephedrone) is increasingly popular with recreational users. Little scientific information is available but users report both entactogen-like and classic stimulant-like subjective properties. A recent study in humans reported psychomotor speed improvement after intranasal 4-MMC suggesting classic stimulant properties. Limitations of the user group (which was impaired on some tasks) prompt controlled laboratory investigation.
  
  
  METHODS
  Adult male rhesus monkeys were trained to perform tasks from the non-human primate Cambridge Neuropsychological Test Automated Battery, which assess spatial working memory, visuospatial associative memory, learning and motivation for food reward. Test of bimanual motor coordination and manual tracking were also included. The subjects were challenged with 0.178-0.56 mg·kg(-1) 4-MMC and 0.056-0.56 mg·kg(-1) d-methamphetamine (MA), i.m., in randomized order for behavioural evaluation.
  
  
  RESULTS
  A pronounced improvement in visuospatial memory and learning was observed after the 0.32 mg·kg(-1) dose of each compound, this effect was confirmed with subsequent repetition of these conditions. Spatial working memory was not improved by either drug, and the progressive ratio, bimanual motor and rotating turntable tasks were all disrupted in a dose-dependent manner.
  
  
  CONCLUSIONS
  These studies show that 4-MMC produces behavioural effects, including improvements in complex spatial memory and learning that are in large part similar to those of MA in non-human primates. Thus, the data suggest that the effects of 4-MMC in monkeys can be classified with classical psychomotor stimulants.
authors: Committee on the Neurobiology of Addictive Disorders Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors: M J
authors: MJ
authors: Wright
authors: S A
authors: SA
authors: Vandewater
authors: D
authors: D
authors: Angrish
authors: T J
authors: TJ
authors: Dickerson
authors: M A
authors: MA
authors: Taffe
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D013287:Illicit Drugs / Q000494:pharmacology*; D007858:Learning / Q000187:drug effects; D008253:Macaca mulatta; D008297:Male; D008568:Memory / Q000187:drug effects*; D008694:Methamphetamine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000187:drug effects
chemical_list: D000697:Central Nervous System Stimulants; D013287:Illicit Drugs; D008694:Methamphetamine; C548233:mephedrone