title: Early environmental factors differentially affect voluntary ethanol consumption in adolescent and adult male rats.
abstract: BACKGROUND
  Previous studies using the maternal separation (MS) model have shown that environmental factors early in life affect adult ethanol consumption. Prolonged MS is related to enhanced propensity for high adult ethanol intake when compared to short MS. Less is known about the environmental impact on adolescent ethanol intake. In this study, the aim was to compare establishment of voluntary ethanol consumption in adolescent and adult rats subjected to different rearing conditions.
  
  
  METHODS
  Wistar rat pups were separated from their mother 0 minutes (MS0), 15 minutes (MS15), or 360 minutes (MS360) daily during postnatal days (PNDs) 1 to 20. After weaning, the male rats were divided into two groups; rats were given free access to water, 5 and 20% ethanol at either PND 26 or 68. Ethanol was provided in 24-hour sessions three times per week for 5 weeks.
  
  
  RESULTS
  MS resulted in altered ethanol consumption patterns around the pubertal period but otherwise the rearing conditions had little impact on ethanol consumption in adolescents. In adults, the establishment of ethanol consumption was dependent on the rearing condition. The adult MS0 and MS15 rats had a stable ethanol intake, whereas the MS360 rats increased both their ethanol intake and preference over time.
  
  
  CONCLUSIONS
  With the use of intermittent access to ethanol, new data were provided, which confirm the notion that MS360 represents a risk environment related to higher ethanol intake compared to MS15. The adolescent rats had higher ethanol intake than adult rats but the consumption was independent of rearing condition. Experiences during the first three postnatal weeks thus affect the establishment of voluntary ethanol consumption differently in adolescent and adult rats. Further studies are now warranted to examine the consequences of a combination of early environmental influence and high adolescent ethanol intake.
authors.affiliation: Department of Pharmaceutical Biosciences, Division of Pharmacology, Uppsala University, Sweden. Loudin.Daoura@farmbio.uu.se
authors.forename: Loudin
authors.initials: L
authors.lastname: Daoura
authors.forename: Jan
authors.initials: J
authors.lastname: Haaker
authors.forename: Ingrid
authors.initials: I
authors.lastname: Nylander
mesh_terms: D000367:Age Factors; D000428:Alcohol Drinking / Q000523:psychology*; D000818:Animals; D000831:Animals, Newborn; D005260:Female; D008297:Male; D008426:Maternal Deprivation; D051381:Rats; D017208:Rats, Wistar; D012307:Risk Factors; D012931:Social Environment