title: Profound reduction in sensitivity to the aversive effects of methamphetamine in mice bred for high methamphetamine intake.
abstract: Reduced sensitivity to aversive effects of methamphetamine (MA) may increase risk for MA abuse. Studies in two replicate sets of mouse lines that were selectively bred for high and low levels of MA intake support this view. Current studies examined the extent of insensitivity to aversive MA effects of mice bred for high levels of MA drinking. Conditioning procedures in which drugs are delivered shortly after cue exposure have been used to detect aversive drug effects and, in some cases, are more sensitive to such effects. Aversive effects induced by MA injected immediately after exposure to cues from two different sensory modalities were examined. In addition, effects of higher MA doses than those used previously were examined. MA-associated place conditioning utilized tactile cues, whereas MA-induced taste conditioning utilized a novel tastant. Second replicate, MA high drinking (MAHDR-2) and low drinking (MALDR-2) mice were treated with doses of MA up to 4 mg/kg. MAHDR-2 mice were insensitive to aversive effects of MA, except after place conditioning with the 4 mg/kg dose; MALDR-2 mice exhibited sensitivity to aversive effects of MA at doses as low as 1 mg/kg. These studies show that the expression of aversion is dependent upon procedure and MA dose, and that MAHDR-2 mice have markedly reduced sensitivity to the aversive effects of MA. The current and previous results support a strong genetic relationship between level of MA intake and level of sensitivity to aversive effects of MA, a factor that could impact risk for MA use in humans. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
authors: Department of Behavioral Neuroscience and Methamphetamine Abuse Research Center, Oregon Health & Science University, 3181 SW Sam Jackson Park Road L470, Portland, OR 97239-3098, USA. shabanis@scripps.edu
authors: Shkelzen
authors: S
authors: Shabani
authors: Carrie S
authors: CS
authors: McKinnon
authors: Christopher L
authors: CL
authors: Cunningham
authors: Tamara J
authors: TJ
authors: Phillips
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage*; D003213:Conditioning, Psychological / Q000187:drug effects*; D003463:Cues; D004305:Dose-Response Relationship, Drug; D008694:Methamphetamine / Q000008:administration & dosage*; D051379:Mice; D009042:Motivation; D012201:Reward; D013649:Taste / Q000187:drug effects
chemical_list: D000697:Central Nervous System Stimulants; D008694:Methamphetamine