Browsing by Subject "Drinking in the dark"

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    Sex and age differences in heavy binge drinking and its effects on alcohol responsivity following abstinence
    (Elsevier, 2013) Melón, Laverne C.; Wray, Kevin N.; Moore, Eileen M.; Boehm, Stephen L., II; Psychology, School of Science
    Binge drinking during adolescence may perturb the maturing neuroenvironment and increase susceptibility of developing an alcohol use disorder later in life. In the present series of experiments, we utilized a modified version of the drinking in the dark-multiple scheduled access (DID-MSA) procedure to study how heavy binge drinking during adolescence alters responsivity to ethanol later in adulthood. Adult and adolescent C57BL/6J (B6) and DBA/2J (D2) males and females were given access to a 20% ethanol solution for 3 hourly periods, each separated by 2h of free water access. B6 adults and adolescents consumed 2 to 3.5 g/kg ethanol an hour and displayed significant intoxication and binge-like blood ethanol concentrations. There was an interaction of sex and age, however, driven by high intakes in adult B6 females, who peaked at 11.01 g/kg. Adolescents of both sexes and adult males never consumed more than 9.3 g/kg. D2 mice consumed negligible amounts of alcohol and showed no evidence of intoxication. B6 mice were abstinent for one month and were retested on the balance beam 10 min following 1.75 g/kg ethanol challenge (20%v/v; i.p). They were also tested for changes in home cage locomotion immediately following the 1.75 g/kg dose (for 10 min prior to balance beam). Although there was no effect of age of exposure, all mice with a binge drinking history demonstrated a significantly dampened ataxic response to an ethanol challenge. Female mice that binge drank during adulthood showed a significantly augmented locomotor response to ethanol when compared to their water drinking controls. This alteration was not noted for males or for females that binge drank during adolescence. These results highlight the importance of biological sex, and its interaction with age, in the development of behavioral adaptation following binge drinking.
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    Site-specific microinjection of Gaboxadol into the infralimbic cortex modulates ethanol intake in male C57BL/6J mice
    (Elsevier, 2014-10-15) Fritz, Brandon M.; Boehm II, Stephen L.; Department of Psychology, School of Science
    Extrasynaptic GABAA receptors, often identified as those containing both α4 and δ subunits, demonstrate super-sensitivity to GABA and are involved in tonic inhibitory processes regulating activity within mesolimbocortical circuitry. Rodent studies testing the effects of the δ-subunit selective agonist Gaboxadol (THIP) on alcohol consumption have produced mixed results. The goal of this study was to determine the role of extrasynaptic GABAA receptors located in the infralimbic cortex (ILC) in the alcohol consumption of male C57BL/6J (B6) mice. The ILC is of interest due to its demonstrated involvement in stress reactivity. Furthermore, alcohol exposure has been shown to interfere with extinction learning; impairments of which may be related to inflexible behavior (i.e., problematic alcohol consumption). Adult male B6 mice were bilaterally implanted with guide cannulas aimed at the ILC and were subsequently offered daily limited access to 20% ethanol or 5% sucrose for 7 days. Immediately prior to ethanol or sucrose access on day 7, mice were bilaterally injected with 50 or 100ng THIP (25 or 50ng per side respectively) or saline vehicle into the ILC. The highest dose of intra-ILC THIP (100ng/mouse) increased alcohol intake relative to vehicle controls, although control animals consumed relatively little ethanol following infusion. Intra-ILC THIP had no effect on sucrose consumption (p>0.05), suggesting that the effect of THIP was selective for ethanol consumption. Together, these findings suggest that THIP may have effectively prevented the decrease in ethanol intake on day 7 induced by the microinjection process, perhaps supporting a suggested role for the ILC in adaptive learning processes and behavioral flexibility.