Xu Pan, Wang Kezhu, Lu Cong, Dong Liming, Chen Yixi, Wang Qiong, Shi Zhe, Yang Yanyan, Chen Shanguang, Liu Xinmin
Research Center for Pharmacology & Toxicology, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Southwest Medical University, Luzhou, 646000, China.
Behav Brain Res. 2017 Mar 15;321:185-192. doi: 10.1016/j.bbr.2016.12.045. Epub 2017 Jan 5.
Chronic mild or unpredictability stress produces a persistent depressive-like state. The main symptoms of depression include weight loss, despair, anhedonia, diminished motivation and mild cognition impairment, which could influence the ability of reward-related learning. In the present study, we aimed to evaluate the effects of chronic restraint stress on the performance of reward-related learning of rats. We used the exposure of repeated restraint stress (6h/day, for 28days) to induce depression-like behavior in rats. Then designed tasks including Pavlovian conditioning (magazine head entries), acquisition and maintenance of instrumental conditioning (lever pressing) and goal directed learning (higher fixed ratio schedule of reinforcement) to study the effects of chronic restraint stress. The results indicated that chronic restraint stress influenced rats in those aspects including the acquisition of a Pavlovian stimulus-outcome (S-O) association, the formation and maintenance of action-outcome (A-O) causal relation and the ability of learning in higher fixed ratio schedule. In conclusion, depression could influence the performances in reward-related learning obviously and the series of instrumental learning tasks may have potential as a method to evaluate cognitive changes in depression.
慢性轻度或不可预测性应激会产生持续的抑郁样状态。抑郁症的主要症状包括体重减轻、绝望、快感缺失、动机减退和轻度认知障碍，这些可能会影响与奖赏相关的学习能力。在本研究中，我们旨在评估慢性束缚应激对大鼠奖赏相关学习表现的影响。我们通过重复束缚应激（每天6小时，持续28天）来诱导大鼠出现抑郁样行为。然后设计了包括巴甫洛夫条件反射（杂志探头进入）、工具性条件反射的获得和维持（杠杆按压）以及目标导向学习（更高固定比率强化程序）等任务，以研究慢性束缚应激的影响。结果表明，慢性束缚应激在这些方面影响大鼠，包括巴甫洛夫刺激-结果（S-O）关联的获得、动作-结果（A-O）因果关系的形成和维持以及在更高固定比率程序中的学习能力。总之，抑郁症会明显影响奖赏相关学习的表现，并且这一系列工具性学习任务可能有潜力作为评估抑郁症认知变化的一种方法。
