title: Altered locomotor and stereotyped responses to acute methamphetamine in adolescent, maternally separated rats.
abstract: BACKGROUND
  Neonatal maternal separation (MS) has been used to model the effects of early life stress in rodents. MS alters behavioral responses to a variety of abused drugs, but few studies have examined its effects on methamphetamine sensitivity.
  
  
  OBJECTIVE
  We sought to determine the effects of MS on locomotor and stereotyped responses to low-to-moderate doses of methamphetamine in male and female adolescent rats.
  
  
  METHODS
  Male and female rat pups were subjected to 3 h per day of MS on postnatal days (PN) 2-14 or a brief handling control procedure during the same period. During adolescence (approximately PN 40), all rats were tested for locomotor activity and stereotyped behavior in response to acute methamphetamine administration (0, 1.0, or 3.0 mg/kg, s.c.).
  
  
  RESULTS
  MS rats of both sexes exhibited increased locomotor activity in a novel environment, relative to handled controls. MS increased the locomotor response to methamphetamine (METH), and this effect occurred at different doses for male (3.0 mg/kg) and female (1.0 mg/kg) rats. MS also increased stereotyped behavior in response to METH (1.0 mg/kg) in both sexes.
  
  
  CONCLUSIONS
  MS enhances the locomotor response to METH in a dose- and sex-dependent manner. These results suggest that individuals with a history of early life stress may be particularly vulnerable to the psychostimulant effects of METH, even at relatively low doses.
authors.affiliation: Department of Psychology, University of Nevada Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154-5030, USA. laurel.pritchard@unlv.edu
authors.forename: Laurel M
authors.initials: LM
authors.lastname: Pritchard
authors.forename: Emily
authors.initials: E
authors.lastname: Hensleigh
authors.forename: Sarah
authors.initials: S
authors.lastname: Lynch
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D008426:Maternal Deprivation; D008694:Methamphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D020318:Rats, Long-Evans; D012737:Sex Factors; D013239:Stereotyped Behavior / Q000187:drug effects; D013315:Stress, Psychological / Q000503:physiopathology
chemical_list: D000697:Central Nervous System Stimulants; D008694:Methamphetamine