Department of Psychology, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA.
Appetite. 2012 Oct;59(2):437-47. doi: 10.1016/j.appet.2012.06.007. Epub 2012 Jun 18.
Cues that predict food can stimulate appetite and feeding independent of physiological hunger. How long such effects might last is currently unknown. Here we began to characterize long-term effects in a rodent model of cue-potentiated feeding. Rats were conditioned to associate a tone with food pellets distinct from their regular laboratory chow, and then were tested along with controls for food consumption following tone presentations. In Experiment 1, rats were tested under sated or food-deprived conditions to determine whether fasting would augment cue-driven feeding. Rats in the control group regulated intake based on physiological state, while conditioned rats consumed similar large amounts of food regardless. Experiment 2 tested the durability of cue-potentiated feeding to repeated testing in sated rats. We observed robust cue-potentiated feeding during the first two tests, while in the third and fourth tests both groups ate similar large amounts of pellets. In both experiments the conditioned tone-cue induced binge-like consumption of the cued food and persistent feeding for the duration of 4-h tests. Rats then failed to adjust daily chow consumption to account for their increased intake post-cue. In summary, brief cue priming stimulated substantial intake in sated states that was behaviorally uncompensated for by homeostatic mechanisms.
线索可以预测食物，从而刺激食欲和摄食，而与生理饥饿无关。目前还不清楚这些效应会持续多久。在这里，我们开始在一种与强化摄食相关的啮齿动物模型中描述长期效应。大鼠被训练将一种音调与不同于其常规实验室食物的食物丸联系起来，然后与对照组一起测试在呈现音调后的食物消耗。在实验 1 中，大鼠在饱腹或禁食状态下进行测试，以确定禁食是否会增强线索驱动的摄食。对照组大鼠根据生理状态调节摄入量，而条件反射大鼠则不管怎样都摄入了相似的大量食物。实验 2 在饱腹大鼠中测试了线索强化摄食的耐久性，以重复测试。我们观察到在头两次测试中存在强烈的线索强化摄食，而在第三次和第四次测试中，两组大鼠都摄入了相似数量的食物丸。在这两个实验中，条件化的音调线索引起了类似暴食的被提示食物的消费，并且在 4 小时的测试期间持续进食。然后，大鼠未能调整日常食物摄入量以适应摄食后增加的摄入量。总之，短暂的线索刺激在饱腹状态下引起了大量的摄食，而这种摄食并没有被体内平衡机制所补偿。
