title: Reinforcing properties and neurochemical response of ethanol within the posterior ventral tegmental area are enhanced in adulthood by periadolescent ethanol consumption.
abstract: Alcohol drinking during adolescence is associated with increased alcohol drinking and alcohol dependence in adulthood. Research examining the biologic consequences of adolescent ethanol (EtOH) consumption on the response to EtOH in the neurocircuitry shown to regulate drug reinforcement is limited. The experiments were designed to determine the effects of periadolescent alcohol drinking on the reinforcing properties of EtOH within the posterior ventral tegmental area (pVTA) and the ability of EtOH microinjected into the pVTA to stimulate dopamine (DA) release in the nucleus accumbens shell (AcbSh). EtOH access (24-hour free-choice) by alcohol-preferring rats occurred during postnatal days (PND) 30-60. Animals were tested for their response to EtOH after PND 85. Intracranial self-administration techniques were performed to assess EtOH self-infusion into the pVTA. In the second experiment, rats received microinjections of EtOH into the pVTA, and dialysis samples were collected from the AcbSh. The results indicate that in rats that consumed EtOH during adolescence, the pVTA was more sensitive to the reinforcing effects of EtOH (a lower concentration of EtOH supported self-administration) and the ability of EtOH microinjected into the pVTA to stimulate DA release in the AcbSh was enhanced (sensitivity and magnitude). The data indicate that EtOH consumption during adolescence altered the mesolimbic DA system to be more sensitive and responsive to EtOH. This increase in the response to EtOH within the mesolimbic DA during adulthood could be part of biologic sequelae that are the basis for the deleterious effects of adolescent alcohol consumption on the rate of alcoholism during adulthood.
authors.affiliation: Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana jtoalsto@iupui.edu.
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Toalston
authors.affiliation: Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Deehan
authors.affiliation: Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Sheketha R
authors.initials: SR
authors.lastname: Hauser
authors.affiliation: Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Engleman
authors.affiliation: Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Bell
authors.affiliation: Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: James M
authors.initials: JM
authors.lastname: Murphy
authors.affiliation: Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: William A
authors.initials: WA
authors.lastname: Truitt
authors.affiliation: Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: William J
authors.initials: WJ
authors.lastname: McBride
authors.affiliation: Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Zachary A
authors.initials: ZA
authors.lastname: Rodd
mesh_terms: D000428:Alcohol Drinking / Q000009:adverse effects*; D000818:Animals; D004298:Dopamine / Q000378:metabolism; D000431:Ethanol / Q000009:adverse effects* / Q000494:pharmacology*; D008297:Male; D008845:Microinjections / Q000379:methods; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D012054:Reinforcement, Psychology; D012646:Self Administration / Q000379:methods; D017557:Ventral Tegmental Area / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000431:Ethanol; D004298:Dopamine