Wilhelm C J, Mitchell S H
Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA.
Genes Brain Behav. 2008 Oct;7(7):705-13. doi: 10.1111/j.1601-183X.2008.00406.x. Epub 2008 Jun 2.
Alcoholics and heavy drinkers score higher on measures of impulsivity than nonalcoholics and light drinkers. This may be because of factors that predate drug exposure (e.g. genetics). This study examined the role of genetics by comparing impulsivity measures in ethanol-naive rats selectively bred based on their high [high alcohol drinking (HAD)] or low [low alcohol drinking (LAD)] consumption of ethanol. Replicates 1 and 2 of the HAD and LAD rats, developed by the University of Indiana Alcohol Research Center, completed two different discounting tasks. Delay discounting examines sensitivity to rewards that are delayed in time and is commonly used to assess 'choice' impulsivity. Probability discounting examines sensitivity to the uncertain delivery of rewards and has been used to assess risk taking and risk assessment. High alcohol drinking rats discounted delayed and probabilistic rewards more steeply than LAD rats. Discount rates associated with probabilistic and delayed rewards were weakly correlated, while bias was strongly correlated with discount rate in both delay and probability discounting. The results suggest that selective breeding for high alcohol consumption selects for animals that are more sensitive to delayed and probabilistic outcomes. Sensitivity to delayed or probabilistic outcomes may be predictive of future drinking in genetically predisposed individuals.
酗酒者和大量饮酒者在冲动性测量上的得分高于非酗酒者和轻度饮酒者。这可能是由于药物接触之前的一些因素（例如基因）。本研究通过比较基于乙醇高摄入量[高酒精饮用量（HAD）]或低摄入量[低酒精饮用量（LAD）]而选择性培育的未接触过乙醇的大鼠的冲动性测量结果，来研究基因的作用。由印第安纳大学酒精研究中心培育的HAD和LAD大鼠的第1代和第2代完成了两项不同的折扣任务。延迟折扣考察对延迟奖励的敏感性，常用于评估“选择”冲动性。概率折扣考察对奖励不确定交付的敏感性，已被用于评估冒险行为和风险评估。高酒精饮用量大鼠比LAD大鼠更急剧地折扣延迟和概率性奖励。与概率性和延迟性奖励相关的折扣率呈弱相关，而在延迟折扣和概率折扣中，偏差与折扣率均呈强相关。结果表明，对高酒精饮用量进行选择性育种会选择出对延迟和概率性结果更敏感的动物。对延迟或概率性结果的敏感性可能预示着基因易感性个体未来的饮酒情况。
