Institute of Biology, Department of Animal Physiology, University of Stuttgart, D-70550 Stuttgart, Germany.
Learn Mem. 2013 Nov 19;20(12):700-9. doi: 10.1101/lm.032987.113.
Here we examined effects of acute stressors that involve either systemic coadministration of corticosterone/yohimbine (3 mg/kg each) to increase glucocorticoid/noradrenaline activity (denoted as "pharmacological" stressor) or one or several distinct restraint stressors (denoted as "single" vs. "multiple" stressor) on performance of goal-directed actions. Rats were trained over 11 d to perform two instrumental actions, one for food pellets the other for sucrose solution, followed by two consecutive tests days. On each test day, rats were first sated in a counterbalanced manner on one of the two outcomes by prefeeding (selective outcome devaluation), then subjected to an acute stressor, and tested afterward in a two-lever choice task in extinction to assess whether instrumental performance is goal-directed, i.e., sensitive to changes in outcome value. Like in control rats, in rats subjected to the pharmacological or single restraint stressor prior to the choice test, performance of instrumental action was goal-directed, i.e., sensitive to outcome devaluation. By contrast, in rats exposed to the multiple stressor prior to the choice test, performance of instrumental action was habitual, i.e., insensitive to outcome devaluation. Pretreatment with diazepam (1 and 2 mg/kg) did not alleviate (or only marginally) this multiple stressor-induced effect. Thus, an intense acute stressor can render performance of previously acquired instrumental action habitual, possibly due to a compromised retrieval of encoded relationships between actions and their outcome value. Our observation in rats that an acute stressor can shift instrumental responding from goal-directed to habitual control is consistent with similar findings in humans.
在这里，我们研究了急性应激源对目标导向行为表现的影响，这些应激源包括全身性给予皮质酮/育亨宾（各 3mg/kg）以增加糖皮质激素/去甲肾上腺素的活性（称为“药理学”应激源），或单一或多种不同的束缚应激源（称为“单一”与“多种”应激源）。大鼠经过 11 天的训练，执行两种工具性动作，一种是获取食物丸，另一种是获取蔗糖溶液，然后进行连续两天的测试。在每个测试日，大鼠首先通过预先喂食（选择性结果贬值）以平衡的方式在两种结果中的一种上获得满足，然后接受急性应激源，之后在消退的双杠选择任务中进行测试，以评估工具性表现是否具有目标导向性，即对结果价值的变化是否敏感。与对照大鼠一样，在选择测试前接受药理学或单一束缚应激源的大鼠，其工具性动作表现具有目标导向性，即对结果贬值敏感。相比之下，在选择测试前暴露于多种应激源的大鼠，其工具性动作表现是习惯性的，即对结果贬值不敏感。预先给予地西泮（1 毫克/千克和 2 毫克/千克）并不能减轻（或仅轻微减轻）这种多种应激源引起的效应。因此，强烈的急性应激源可能使先前习得的工具性动作表现变得习惯化，这可能是由于动作与其结果价值之间编码关系的检索受到损害。我们在大鼠中观察到，急性应激源可以将工具性反应从目标导向控制转变为习惯性控制，这与人类的类似发现一致。
