Department of Psychology, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA.
Appetite. 2013 Oct;69:186-95. doi: 10.1016/j.appet.2013.06.004. Epub 2013 Jun 14.
Previously we have shown that food-deprived male and female rats inhibit food consumption when presented with a discrete conditioned stimulus that signals danger. Here, in a series of three experiments, we examined whether contextual conditioned stimuli can exert the same effect. Experiment 1 paired a distinct context with footshocks, to examine food intake in food-deprived rats upon re-exposure to the context. Experiment 2 used a discrimination protocol with two alternating contexts; rats were given food in one, and received footshocks in the other. This protocol allowed us to monitor food consumption during training in a context never associated with footshocks, and to evaluate consumption at test in a context that had been previously paired with footshocks. Experiments 1 and 2 compared experimental groups to controls that never received footshocks. Experiment 3 used a within-subjects design to assess the specificity of the inhibition by the contextual cues, separate from any generalized effects due solely to the prior experience of footshocks. Our results demonstrate that similar to discrete cues, contextual cues previously associated with aversive events can inhibit feeding in food-deprived animals. These findings are important for our understanding of environmental contributions to the control of food intake.
先前我们已经表明，在给予指示危险的离散条件刺激时，饥饿的雄性和雌性大鼠会抑制食物摄取。在这里，我们通过三个实验系列检验了语境条件刺激是否可以产生相同的效果。实验 1 将一个独特的环境与电击配对，以检验在重新暴露于该环境时，饥饿的大鼠的食物摄入量。实验 2 使用了具有两个交替环境的辨别协议；在一个环境中给予大鼠食物，而在另一个环境中给予电击。该协议允许我们在从未与电击相关联的环境中进行训练期间监测食物消耗，并在以前与电击相关联的环境中评估测试时的消耗。实验 1 和 2 将实验组与从未接受过电击的对照组进行了比较。实验 3 使用了一个被试内设计，以评估语境线索的抑制作用的特异性，而不仅仅是由于先前的电击经历所导致的任何一般性影响。我们的结果表明，类似于离散线索，与不愉快事件相关联的语境线索也可以抑制饥饿动物的进食。这些发现对于我们理解环境对食物摄入控制的贡献非常重要。
