Department of Psychology, Utah State University, 2810 Old Main Hill, Logan, UT 84322, USA.
Exp Clin Psychopharmacol. 2013 Apr;21(2):172-80. doi: 10.1037/a0031245. Epub 2013 Jan 28.
Naturally occurring impulsive choice has been found to positively predict alcohol consumption in rats. However, the extent to which experimental manipulation of impulsive choice may modify alcohol consumption remains unclear. In the present study, we sought to: (a) train low levels of impulsive choice in rats using early, prolonged exposure to reward delay, and (b) determine the effects of this manipulation on subsequent alcohol consumption. During a prolonged training regimen, three groups of male, adolescent Long-Evans rats (21-22 days old at intake) responded on a single lever for food rewards delivered after either a progressively increasing delay, a fixed delay, or no delay. Posttests of impulsive choice were conducted, as was an evaluation of alcohol consumption using a limited-access, two-bottle test. Following delay-exposure training, both groups of delay-exposed rats made significantly fewer impulsive choices than did rats in the no-delay group. In addition, fixed-delay rats consumed significantly more alcohol during daily, 30-min sessions than no-delay rats. Possible mechanisms of these effects are discussed, as is the significance of these findings to nonhuman models of addiction.
自然发生的冲动选择已被发现可正向预测大鼠的酒精消费。然而，实验性操纵冲动选择对酒精消费的影响程度尚不清楚。在本研究中，我们试图：（a）通过早期、长时间的奖励延迟暴露来训练大鼠的低水平冲动选择；（b）确定这种操作对随后的酒精消费的影响。在延长的训练过程中，三组雄性、青春期长耳大仓鼠（摄入时 21-22 天大）对单个杠杆进行反应，以获得在逐渐增加的延迟、固定延迟或无延迟后交付的食物奖励。进行冲动选择的后测，以及使用有限访问、双瓶测试评估酒精消费。在延迟暴露训练之后，两组暴露于延迟的大鼠比无延迟组的大鼠做出的冲动选择明显更少。此外，固定延迟大鼠在每天 30 分钟的时段内消耗的酒精明显多于无延迟大鼠。讨论了这些影响的可能机制，以及这些发现对成瘾的非人类模型的意义。
