Boyle A.E.L., Smith B.R., Spivak K., Amit Z.
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, 1455 de Maisonneuve Blvd., W., H-1013, Montreal, Quebec, Canada H3G 1M8.
Behav Pharmacol. 1994 Aug;5(4 And 5):502-512.
The present investigation examined two methods of ethanol presentation to laboratory rats that have been used to examine the mechanisms mediating voluntary ethanol intake in animals. Experiment I examined whether a restricted access procedure had any significant and meaningful relationship in individual animals to drinking behavior in an unrestricted 24h paradigm. An unselected strain of rats was given free access (unrestricted 24h free choice) to ethanol and water, and later exposed to a restricted 10min access to ethanol. A significant positive relationship between the absolute amount of ethanol consumed in the 24h access paradigm and the amount ingested by the same animals in the restricted access procedure was demonstrated. Experiment 2 examined the extent to which a forced choice preference testing procedure, commonly used in screening ethanol-preferring P rats, was in and of itself sufficient to produce increased levels of ethanol consumption in unselected Long-Evans rats. Results indicated that subjects receiving only 4 days of forced exposure to 10% ethanol consumed, over the next eight ethanol presentations, levels of ethanol exceeding 5g/kg with a 0.60 preference ratio. A microstructural analysis of the pattern of free choice ethanol intake following forced ethanol exposure (Experiment 3) revealed that rats consumed ethanol within short discrete bouts with the largest of these daily bouts consisting of approximately 4ml (0.75g/kg) of 10% ethanol. The amount consumed during the restricted access bout of Experiment 1 was seen to be within the range of the bouts recorded in Experiment 3. These results suggest that consumption of ethanol during the restricted access may simulate an individual bout of ethanol intake during non-restricted access. The results support the notion that many of the different ethanol drinking models used may have a common basis and that the assessment of the amount and pattern of intake across methods and strains may represent different but equally valid approaches to the study of the same underlying mechanisms.
本研究考察了两种向实验大鼠呈现乙醇的方法，这两种方法已被用于探究介导动物自愿摄入乙醇的机制。实验I考察了在个体动物中，限制摄入程序与24小时无限制范式下的饮酒行为是否存在任何显著且有意义的关系。给一组未经挑选的大鼠自由获取（24小时无限制自由选择）乙醇和水的机会，随后让它们在10分钟内限制获取乙醇。结果表明，在24小时获取范式中消耗的乙醇绝对量与同一批动物在限制摄入程序中摄入的量之间存在显著的正相关。实验2考察了通常用于筛选偏好乙醇的P品系大鼠的强制选择偏好测试程序本身在多大程度上足以使未经挑选的Long-Evans大鼠的乙醇摄入量增加。结果表明，仅接受4天10%乙醇强制暴露的受试者，在接下来的八次乙醇呈现中，乙醇摄入量超过5g/kg，偏好比例为0.60。对强制乙醇暴露后自由选择乙醇摄入模式的微观结构分析（实验3）显示，大鼠在短时间内离散地饮用乙醇，其中最大的每日饮用量约为4ml（0.75g/kg）的10%乙醇。实验1中限制获取期间的饮用量处于实验3记录的饮用量范围内。这些结果表明，限制获取期间的乙醇消耗可能模拟了非限制获取期间的单次乙醇摄入。这些结果支持了这样一种观点，即许多不同的乙醇饮用模型可能有共同的基础，并且跨方法和品系对摄入量和摄入模式的评估可能代表了研究相同潜在机制的不同但同样有效的方法。
