title: Patterns of ethanol intake in preadolescent, adolescent, and adult Wistar rats under acquisition, maintenance, and relapse-like conditions.
abstract: BACKGROUND
  Animal behavioral models of voluntary ethanol consumption represent a valuable tool to investigate the relationship between age and propensity to consume alcohol using an experimental methodology. Although adolescence has been considered as a critical age, few are the studies that consider the preadolescence age. This study examines the ethanol consumption/preference and the propensity to show an alcohol deprivation effect (ADE) after a short voluntary ethanol exposure from a developmental perspective.
  
  
  METHODS
  Three groups of heterogeneous Wistar rats of both sexes with ad libitum food and water were exposed for 10 days to 3 ethanol solutions at 3 different ontogenetic periods: preadolescence (PN19), adolescence (PN28), and adulthood (PN90). Ethanol intake (including circadian rhythm), ethanol preference, water and food consumption, and ADE were measured.
  
  
  RESULTS
  During the exposure, the 3 groups differed in their ethanol intake; the greatest amount of alcohol (g/kg) was consumed by the preadolescent rats while the adolescents showed a progressive decrease in alcohol consumption as they approached the lowest adult levels by the end of the assessed period. The pattern of ethanol consumption was not fully explained in terms of hyperphagia and/or hyperdipsia at early ages, and showed a wholly circadian rhythm in adolescent rats. After an abstinence period of 7 days, adult rats showed an ADE measured both as an increment in ethanol consumption and preference, whereas adolescent rats only showed an increment in ethanol preference. Preadolescent rats decreased their consumption and their preference remained unchanged.
  
  
  CONCLUSIONS
  In summary, using a short period of ethanol exposure and a brief deprivation period the results revealed a direct relationship between chronological age and propensity to consume alcohol, being the adolescence a transition period from the infant to the adult pattern of alcohol consumption. Preadolescent animals showed the highest ethanol consumption level. The ADE was only found in adult animals for both alcohol consumption and preference, whereas adolescents showed an ADE only for preference. No effect of sex was detected in any phase of the experiment.
authors.affiliation: Department of Experimental Psychology and Physiology of Behaviour, University of Granada, Granada, Spain. davidgb@ugr.es
authors.forename: David
authors.initials: D
authors.lastname: García-Burgos
authors.forename: Felisa
authors.initials: F
authors.lastname: González
authors.forename: Tatiana
authors.initials: T
authors.lastname: Manrique
authors.forename: Milagros
authors.initials: M
authors.lastname: Gallo
mesh_terms: D000375:Aging / Q000502:physiology*; D000428:Alcohol Drinking / Q000503:physiopathology*; D000437:Alcoholism / Q000503:physiopathology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology; D004195:Disease Models, Animal; D004326:Drinking / Q000502:physiology; D004435:Eating / Q000502:physiology; D005260:Female; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012008:Recurrence