CAS Key Laboratory of Mental Health, Institute of Psychology, 16 Lincui Road, Chaoyang District, 100101, Beijing, China.
Department of Psychology, University of Chinese Academy of Sciences, 19A Yuquan Rd, Shijingshan District, Beijing, 100049, China.
Psychopharmacology (Berl). 2019 Nov;236(11):3197-3208. doi: 10.1007/s00213-019-05272-6. Epub 2019 Jul 12.
Negative affective states, e.g., anhedonia, may be linked to the long-lasting motivational processes associated with relapse. Here, this study investigated whether, and how, anhedonic states are influenced by stressful events that contribute to craving and relapse.
All male rats were pretreated with a binge-like morphine paradigm for five days. After 12 to 16 days of withdrawal, rats were subjected to a one-hour free consumption test or three operant tasks with increasing cost/benefit ratio, i.e., fixed ratio 1 (FR1), progressive ratio (PR), and PR-punishment procedure of reinforcement, with sucrose solutions of three concentrations (4%, 15%, and 60%) as rewards. The consumption and operant responses under FR1 and PR procedures were measured following exposure to acute foot-shock stress (intermittent foot shock, 0.5 mA × 0.5 s × 10 min; mean intershock interval, 40 s), and the operant responses for 60% sucrose solution under PR-punishment procedure was measured following a forced-swim stress (5 minutes).
Foot-shock stress increased water consumption in a subpopulation of rats and decreased consumption of sucrose solutions, while it did not influence the operant responses for sucrose solutions under either FR1 or PR procedure. The forced-swim stress reduced operant responses for 60% sucrose solution under PR-punishment procedure, but did not influence responding for 60% sucrose solution under PR procedure. In addition, the forced-swim stress also elevated anxiety level of rats in an open area test.
Acute stress induced hedonic but not motivational deficit for sucrose reward in protracted drug-abstinent animals. Additional negative emotional states besides anhedonia were evoked by acute stress.
消极的情绪状态，如快感缺失，可能与导致成瘾和复吸的持久动机过程有关。在这里，这项研究调查了快感缺失状态是否以及如何受到导致成瘾和复吸的应激事件的影响。
所有雄性大鼠均接受为期五天的类似狂欢的吗啡预处理。在戒断 12-16 天后，大鼠进行了一小时的自由消耗测试或三种操作任务，即固定比率 1（FR1）、递增比率（PR）和 PR-惩罚性强化程序，以三种浓度（4%、15%和 60%）的蔗糖溶液作为奖励。在经历急性足底电击应激（间歇性足底电击，0.5 mA×0.5 s×10 min；平均间隔时间 40 s）后，测量 FR1 和 PR 程序下的消耗和操作反应，以及 PR-惩罚性强化程序下的 60%蔗糖溶液的操作反应，在强迫游泳应激（5 分钟）后测量。
足底电击应激增加了一部分大鼠的水摄入量，并减少了蔗糖溶液的消耗，而对 FR1 或 PR 程序下的蔗糖溶液的操作反应没有影响。强迫游泳应激降低了 PR-惩罚性强化程序下 60%蔗糖溶液的操作反应，但对 PR 程序下 60%蔗糖溶液的反应没有影响。此外，强迫游泳应激还增加了大鼠在开放式区域测试中的焦虑水平。
急性应激导致慢性药物戒断动物的快感缺失，但不影响蔗糖奖励的动机缺陷。急性应激还会引起除快感缺失以外的其他负性情绪状态。
