Ritz M C, George F R, Meisch R A
Behavior Genetics Laboratory, National Institute on Drug Abuse, Baltimore, MD 21224.
Alcohol. 1989 May-Jun;6(3):227-33. doi: 10.1016/0741-8329(89)90023-2.
The ALKO Alcohol Accepting (AA) rats and Alcohol Non-Accepting (ANA) rats were used to study the relationship between ethanol preference in a two-bottle choice paradigm and oral ethanol self-administration in an operant conditioning paradigm. Ethanol served as a positive reinforcer in the preferring AA line. Under a continuous reinforcement schedule (FR 1), ethanol deliveries were consistently greater than water (vehicle) deliveries and varied as an orderly inverted U-shaped function of ethanol concentration. Conversely, in nonpreferring ANA animals, ethanol did not serve as a reinforcer. Findings obtained with the AA rats were compared with those obtained with Sprague-Dawley rats. Sprague-Dawley rats maintained higher levels of responding and greater ethanol intake, relative to AA rats, at all concentrations of ethanol tested. The data are consistent with evidence that genotype is a critical factor in determining the extent to which ethanol serves as a reinforcer. The results also suggest that ethanol preference and the maintenance of ethanol reinforced behavior under operant conditions appear to have some common mechanisms. However, since the selection for ethanol preference in AA rats apparently did not maximize the maintenance of ethanol-reinforced behavior in an operant paradigm, ethanol drinking behavior in the preference paradigm may not be completely generalizable to that observed in the operant model.
采用酒精接受型（AA）大鼠和酒精非接受型（ANA）大鼠，研究两瓶装选择范式中乙醇偏好与操作性条件反射范式中口服乙醇自我给药之间的关系。在偏好性AA品系中，乙醇作为阳性强化物。在连续强化程序（固定比率1）下，乙醇给药量始终大于水（溶剂）给药量，并随乙醇浓度呈有序的倒U形函数变化。相反，在无偏好的ANA动物中，乙醇不作为强化物。将AA大鼠的研究结果与Sprague-Dawley大鼠的研究结果进行比较。在所有测试的乙醇浓度下，相对于AA大鼠，Sprague-Dawley大鼠保持较高的反应水平和更高的乙醇摄入量。这些数据与以下证据一致，即基因型是决定乙醇作为强化物程度的关键因素。结果还表明，乙醇偏好和操作性条件下乙醇强化行为的维持似乎有一些共同机制。然而，由于AA大鼠对乙醇偏好的选择显然并未使操作性范式中乙醇强化行为的维持最大化，偏好范式中的乙醇饮用行为可能无法完全推广到操作性模型中观察到的行为。
