title: Adolescent C57BL/6J mice show elevated alcohol intake, but reduced taste aversion, as compared to adult mice: a potential behavioral mechanism for binge drinking.
abstract: BACKGROUND
  Binge alcohol drinking during adolescence is a serious health problem that may increase future risk of an alcohol use disorder. Although there are several different procedures by which to preclinically model binge-like alcohol intake, limited-access procedures offer the advantage of achieving high voluntary alcohol intake and pharmacologically relevant blood alcohol concentrations (BACs). Therefore, in the current study, developmental differences in binge-like alcohol drinking using a limited-access cycling procedure were examined. In addition, as alcohol drinking has been negatively correlated with sensitivity to the aversive properties of alcohol, we examined developmental differences in sensitivity to an alcohol-induced conditioned taste aversion (CTA).
  
  
  METHODS
  Binge-like alcohol consumption was investigated in adolescent (4 weeks) and adult (10 weeks) male C57BL/6J mice for 2 to 4 h/d for 16 days. Developmental differences in sensitivity to an alcohol-induced CTA were examined in adolescent and adult mice, with saline or alcohol (3 or 4 g/kg) repeatedly paired with the intake of a novel tastant (NaCl).
  
  
  RESULTS
  Adolescent mice showed a significant increase in alcohol intake as compared to adults, with adolescents achieving higher BACs and increasing alcohol consumption over successive cycles of the binge procedure. Conversely, adolescent mice exhibited a dose-dependent reduction in sensitivity to the aversive properties of alcohol, as compared to adult mice, with adolescent mice failing to develop a CTA to 3 g/kg alcohol. Finally, extinction of an alcohol CTA was observed following conditioning with a higher dose of alcohol in adolescent, versus adult, mice.
  
  
  CONCLUSIONS
  These results indicate that adolescent mice consume more alcohol, per kilogram body weight, than adults in a binge-like model of alcohol drinking and demonstrate a blunted sensitivity to the conditioned aversive effects of alcohol. Overall, this supports a behavioral framework by which heightened binge alcohol intake during adolescence occurs, in part, via a reduced sensitivity to the aversive properties of alcohol.
authors.affiliation: Bowles Center for Alcohol Studies, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7178, USA.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Holstein
authors.forename: Marina
authors.initials: M
authors.lastname: Spanos
authors.forename: Clyde W
authors.initials: CW
authors.lastname: Hodge
mesh_terms: D000367:Age Factors; D000428:Alcohol Drinking / Q000097:blood / Q000473:pathology* / Q000523:psychology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D002492:Central Nervous System Depressants / Q000097:blood / Q000494:pharmacology / Q000506:poisoning*; D003213:Conditioning, Psychological / Q000187:drug effects*; D004195:Disease Models, Animal; D004408:Dysgeusia; D000431:Ethanol / Q000097:blood / Q000494:pharmacology / Q000506:poisoning*; D005108:Extinction, Psychological; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D002492:Central Nervous System Depressants; D000431:Ethanol