title: Reciprocal inhibitory effects of intravenous d-methamphetamine self-administration and wheel activity in rats.
abstract: BACKGROUND
  Some epidemiological and cessation studies suggest physical exercise attenuates or prevents recreational drug use in humans. Preclinical studies indicate that wheel activity reduces cocaine self-administration in rats; this may, however, require the establishment of compulsive wheel activity.
  
  
  METHODS
  Effects of concurrent wheel activity on intravenous d-methamphetamine (METH) self-administration were examined in male Wistar and Sprague Dawley rats with negligible prior wheel experience. Wistar rats self-administered METH (0.05 mg/kg/inf) under a fixed-ratio 1 (FR1) schedule with concurrent access to an activity wheel during sessions 1-14, 8-21 or 15-21. Control rats which did not self-administer METH had access to an activity wheel during sessions 1-14, 8-21 or 15-28. Sprague Dawley rats self-administered METH (0.1 mg/kg/inf) under FR1 for 14 sessions with either concurrent access to a locked or an unlocked activity wheel.
  
  
  RESULTS
  METH self-administration was lower when the wheel was available concurrently from the start of self-administration training in both strains, even though Sprague Dawley rats self-administered twice as many METH infusions and ran one-sixth as much on the wheel compared to Wistar rats. Wheel access initiated after 7 or 14 days had no effect on METH self-administration in Wistar rats. Wheel activity was significantly reduced in these groups compared with the group with concurrent wheel and METH access for the first 14 sessions.
  
  
  CONCLUSIONS
  These data show that METH self-administration is reduced by exercise if initiated from the start of self-administration and that prior METH self-administration experience interferes with the value of exercise as a reinforcer.
authors: Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors: M L
authors: ML
authors: Miller
authors: B D
authors: BD
authors: Vaillancourt
authors: M J
authors: MJ
authors: Wright
authors: S M
authors: SM
authors: Aarde
authors: S A
authors: SA
authors: Vandewater
authors: K M
authors: KM
authors: Creehan
authors: M A
authors: MA
authors: Taffe
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage*; D007262:Infusions, Intravenous; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage*; D009043:Motor Activity / Q000187:drug effects*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012054:Reinforcement, Psychology; D012646:Self Administration
chemical_list: D000697:Central Nervous System Stimulants; D008694:Methamphetamine