Files F J, Samson H H, Denning C E
Department of Physiology and Pharmacology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157-1083, USA.
Alcohol. 1997 Jul-Aug;14(4):379-87. doi: 10.1016/s0741-8329(96)00187-5.
Initiation of alcohol drinking using the sucrose-substitution procedure was studied in inbred Lewis rats. One group of animals was initiated to self-administer alcohol prior to being placed in the continuous-access condition, whereas the second group of animals did not undergo initiation. During the continuous-access period, the animals were housed in operant chambers where they had continuous access to alcohol (10% v/v), food, and water during daily 23-h experimental sessions. After 5 weeks of baseline conditions, the response, requirement for food was increased over weeks. This was followed by weekly increases in the ethanol response requirement with the food response requirement returned to baseline conditions. In the continuous-access condition, both groups consumed similar amounts of alcohol by the end of the 4-week baseline period and showed similar numbers of dippers presented per alcohol bout and number of alcohol bouts per day. During the food response requirement manipulation, alcohol consumption increased for both groups but intake increased significantly more for the noninitiated group. The difference between groups was accounted for by a larger number of alcohol drinking bouts per day for the noninitiated group. Alcohol consumption decreased at each increase in ethanol reinforcement response requirement for both groups. Alcohol-reinforced responding per session increased for the noninitiated animals but remained unchanged for the initiated group during this condition. Responding increased substantially for both groups when the alcohol reinforcement response requirement was returned to baseline conditions. These results suggest that alcohol may serve more as a food source for noninitiated animals during the food reinforcement manipulation and that initiation may result in more resistance to change during the alcohol reinforcement manipulation. These data show that the type of initial exposure to alcohol can impact future drinking patterns.
采用蔗糖替代法对近交系Lewis大鼠的饮酒起始情况进行了研究。一组动物在进入持续获取条件之前开始自我给药酒精，而第二组动物未经历起始阶段。在持续获取期间，动物被安置在操作箱中，在每天23小时的实验时段内，它们可以持续获取酒精（10% v/v）、食物和水。在5周的基线条件后，反应方面，对食物的需求在数周内增加。随后每周增加乙醇反应需求，同时食物反应需求恢复到基线条件。在持续获取条件下，两组在4周基线期结束时消耗的酒精量相似，并且在每次饮酒回合中呈现的舀取次数以及每天的饮酒回合数也相似。在食物反应需求操控期间，两组的酒精消耗量均增加，但未起始组的摄入量增加得更为显著。两组之间的差异在于未起始组每天的饮酒回合数更多。两组在每次增加乙醇强化反应需求时，酒精消耗量均下降。在此条件下，未起始动物每次实验时段的酒精强化反应增加，而起始组则保持不变。当酒精强化反应需求恢复到基线条件时，两组的反应均大幅增加。这些结果表明，在食物强化操控期间，酒精对未起始动物而言可能更多地作为一种食物来源，并且起始可能导致在酒精强化操控期间对变化更具抵抗力。这些数据表明，最初接触酒精的类型会影响未来的饮酒模式。
