title: Age-dependent effects of stress on ethanol-induced motor activity in rats.
abstract: BACKGROUND
  It is important to study age-related differences that may put adolescents at risk for alcohol-related problems. Adolescents seem less sensitive to the aversive effects of ethanol than adults. Less is known of appetitive effects of ethanol and stress modulation of these effects.
  
  
  OBJECTIVE
  This study aims to describe the effects of acute social or restraint stress on ethanol-precipitated locomotor activity (LMA), in adolescent and adult rats. Effects of activation of the kappa system on ethanol-induced LMA were also evaluated.
  
  
  METHODS
  Adolescent or adult rats were restrained for 90 min, exposed to social deprivation stress for 90 or 180 min or administered with the kappa agonist U62,066E before being given ethanol, and assessed for LMA.
  
  
  RESULTS
  Adolescents were significantly more sensitive to the stimulating, and less sensitive to the sedative, effects of ethanol than adults. Basal locomotion was significantly increased by social deprivation stress in adult, but not in adolescent, rats. U62,066E significantly reduced basal and ethanol-induced locomotion in the adolescents. Corticosterone and progesterone levels were significantly higher in adolescents than in adults.
  
  
  CONCLUSIONS
  Adolescents exhibit greater sensitivity to ethanol-induced LMA and reduced sensitivity to ethanol-induced motor sedation than adult rats. Ethanol's effects on motor activity were not affected by acute stress. Unlike adults, adolescents were insensitive to acute restraint and social deprivation stress but exhibited motor depression after activation of the endogenous kappa opioid receptor system.
authors.affiliation: Instituto de Investigación Médica M. y M. Ferreyra (CONICET-UNC), Córdoba, 5016, Argentina.
authors.forename: María Belén
authors.initials: MB
authors.lastname: Acevedo
authors.forename: Ricardo Marcos
authors.initials: RM
authors.lastname: Pautassi
authors.forename: Norman E
authors.initials: NE
authors.lastname: Spear
authors.forename: Linda P
authors.initials: LP
authors.lastname: Spear
mesh_terms: D000367:Age Factors; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003345:Corticosterone / Q000378:metabolism; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D011374:Progesterone / Q000378:metabolism; D011759:Pyrrolidines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017473:Receptors, Opioid, kappa / Q000187:drug effects / Q000378:metabolism; D013315:Stress, Psychological / Q000378:metabolism*; D013997:Time Factors
chemical_list: D011759:Pyrrolidines; D017473:Receptors, Opioid, kappa; D000431:Ethanol; D011374:Progesterone; C051272:spiradoline; D003345:Corticosterone