This project will explore the hypothesis that individuals with a family history positive for alcohol dependence (FHP) (without any current DSM-IV Axis I disorder, except nicotine dependence), experience an alteration in the reward valence (balance of positive and negative effects) of the GABA-A receptor agonist barbiturate (thiopental) compared to family history negative (FHN) age-matched subjects. Further, the effect of variations in genes important in regulating brain GABA function may alter a component of the discriminative stimulus effects of ethanol. FHP individuals are defined as individuals with at least one first-degree relative and another first- or second-degree relatives. Preliminary results suggest that FHP individuals showed an attenuated response to thiopental as measured by the descending limb of the BAES during thiopental infusion relative to the FHN group. Further, preliminary results suggest that variation in genes involved in brain GABA function, glutamate decarboxylase-65 (GAD65), may influence the risk for alcoholism by altering a component of the discriminative stimulus effects of ethanol.~We plan to recruit 2 groups of healthy subjects between the ages of 21-30, one with a family history of alcoholism (family history positive=FHP) and a sex-matched control group without a family history of alcoholism (family history negative=FHN), to undergo two test days scheduled 3 days apart, in a randomized double-blind fashion. Test days will involve a 60-minute intravenous infusion of each of 2 conditions: saline or thiopental, in a randomized order under double-blind conditions. Behavioral ratings include the Biphasic Alcohol Effects Scale (BAES) and Visual Analog Scales (VAS). Exploratory measures include event-related potential recordings (ERP) and measures of eye-to-hand coordination. Blood will be collected for Deoxyribonucleic acid (DNA) extraction and genotyping.
This Project will explore the hypothesis that individuals with a family history positive for alcohol dependence (without any current Axis I disorder, except nicotine dependence), experience an alteration in the reward valence (balance of positive and negative effects) of the GABAA receptor agonist barbiturate (thiopental) compared to family history negative age-matched subjects. Further, variation in genes involved in brain GABA function may influence the risk for alcoholism by altering a component of the discriminative stimulus effects of ethanol.