Velázquez-Sánchez Clara, Santos Jeffrey W, Smith Karen L, Ferragud Antonio, Sabino Valentina, Cottone Pietro
Laboratory of Addictive Disorders, Departments of Pharmacology and Psychiatry, Boston University School of Medicine.
Behav Neurosci. 2015 Apr;129(2):219-24. doi: 10.1037/bne0000042.
Binge eating disorder is characterized by excessive consumption of highly palatable food within short periods of time accompanied by loss of control over eating. Extensive evidence provides support for the consideration of binge eating disorder as an addiction-like disorder. In this study, we wanted to determine whether rats undergoing an operant binge-like eating procedure could develop maladaptive forms of conditioned feeding behaviors. For this purpose, we trained male rats to self-administer either a sugary, highly palatable diet ("Palatable" rats) or a chow diet ("Chow" rats) for 1 hour a day. After escalation and stabilization of palatable food intake, we tested Chow and Palatable rats in (a) a conditioned place preference test, (b) a second-order schedule of reinforcement, (c) a cue-induced suppression of feeding test. In the conditioned place preference task, Palatable rats spent significantly more time in the compartment that was previously paired with the palatable food, compared to Chow controls. Furthermore, in the second-order schedule of reinforcement task, Palatable rats exhibited active lever responding 4- to 6-fold higher than Chow control rats. Finally, in the cue-induced suppression of feeding test, although Chow control subjects reduced responding by 32% in the presence of the conditioned punishment, Palatable rats persevered in responding despite the aversive cue. These results further characterize this animal model of binge-like eating and provide additional evidence for the addictive properties of highly palatable food.
暴饮暴食症的特征是在短时间内过度食用美味食物，并伴有进食失控。大量证据支持将暴饮暴食症视为一种成瘾性疾病。在本研究中，我们想确定经历操作性暴饮暴食程序的大鼠是否会发展出适应不良的条件性进食行为形式。为此，我们训练雄性大鼠每天自我给药含糖的美味饮食（“美味组”大鼠）或普通饮食（“普通组”大鼠）1小时。在美味食物摄入量增加并稳定后，我们在（a）条件性位置偏爱测试、（b）二级强化程序、（c）线索诱导的进食抑制测试中对普通组和美味组大鼠进行了测试。在条件性位置偏爱任务中，与普通组对照相比，美味组大鼠在先前与美味食物配对的隔间中花费的时间明显更多。此外，在二级强化程序任务中，美味组大鼠表现出的主动杠杆反应比普通组对照大鼠高4至6倍。最后，在线索诱导的进食抑制测试中，尽管普通组对照大鼠在有条件惩罚的情况下反应减少了32%，但美味组大鼠在有厌恶线索的情况下仍坚持反应。这些结果进一步描述了这种暴饮暴食样进食动物模型的特征，并为美味食物的成瘾特性提供了额外证据。
