Oinio Ville, Bäckström Pia, Uhari-Väänänen Johanna, Raasmaja Atso, Piepponen Petteri, Kiianmaa Kalervo
Department of Health, National Institute for Health and Welfare, Helsinki, Finland; Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland.
Department of Health, National Institute for Health and Welfare, Helsinki, Finland.
Behav Brain Res. 2017 May 30;326:87-95. doi: 10.1016/j.bbr.2017.03.007. Epub 2017 Mar 6.
R**esults from animal gambling models have highlighted the importance of dopaminergic neurotransmission in modulating decision making when large sucrose rewards are combined with uncertainty. The majority of these models use food restriction as a tool to motivate animals to accomplish operant behavioral tasks, in which sucrose is used as a reward. As enhanced motivation to obtain sucrose due to hunger may impact its reward-seeking effect, we wanted to examine the decision-making behavior of rats in a situation where rats were fed ad libitum. For this purpose, we chose alcohol-preferring AA (alko alcohol) rats, as these rats have been shown to have high preference for sweet agents. In the present study, AA rats were trained to self-administer sucrose pellet rewards in a two-lever choice task (one pellet vs. three pellets). Once rational choice behavior had been established, the probability of gaining three pellets was decreased over time (50%, 33%, 25% then 20%). The effect of d-amphetamine on decision making was studied at every probability level, as well as the effect of the dopamine D receptor agonist SKF-81297 and D agonist quinpirole at probability levels of 100% and 25%. d-Amphetamine increased unprofitable choices in a dose-dependent manner at the two lowest probability levels. Quinpirole increased the frequency of unprofitable decisions at the 25% probability level, and SKF-82197 did not affect choice behavior. These results mirror the findings of probabilistic discounting studies using food-restricted rats. Based on this, the use of AA rats provides a new approach for studies on reward-guided decision making.
动物赌博模型的结果突出了多巴胺能神经传递在调节决策中的重要性，此时大剂量蔗糖奖励与不确定性相结合。这些模型大多使用食物限制作为一种工具来激励动物完成操作性行为任务，其中蔗糖被用作奖励。由于饥饿导致的获取蔗糖的动机增强可能会影响其寻求奖励的效果，我们想研究在大鼠自由进食的情况下其决策行为。为此，我们选择了偏好酒精的AA（阿尔科酒精）大鼠，因为这些大鼠已被证明对甜味剂有很高的偏好。在本研究中，AA大鼠在双杠杆选择任务（一粒糖丸对三粒糖丸）中接受训练以自我给药蔗糖颗粒奖励。一旦建立了理性选择行为，获得三粒糖丸的概率会随着时间降低（50%、33%、25%，然后是20%）。在每个概率水平上研究了右旋苯丙胺对决策的影响，以及多巴胺D受体激动剂SKF - 81297和D2激动剂喹吡罗在100%和25%概率水平上的影响。在两个最低概率水平上，右旋苯丙胺以剂量依赖的方式增加了无利可图的选择。喹吡罗在25%概率水平上增加了无利可图决策的频率，而SKF - 82197不影响选择行为。这些结果反映了使用食物限制大鼠进行的概率折扣研究的结果。基于此，AA大鼠的使用为奖励引导决策的研究提供了一种新方法。
