Opioid system in the medial prefrontal cortex mediates binge-like eating.
Opioid system in the medial prefrontal cortex mediates binge-like eating.
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DOI：
10.1111/adb.12033
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发表时间：
2014-07
影响因子：
3.4
通讯作者：
Cottone P
中科院分区：
文献类型：
--
作者：
Blasio A;Steardo L;Sabino V;Cottone P
暴饮暴食障碍是一种类似成瘾的障碍，其特征是在不同的时间段内过度进食。这项研究的目的是了解mPFC内的阿片系统在暴饮暴食的消耗性和激励性方面的作用。为此，我们训练雄性大鼠每天吃一小时含糖的、非常可口的食物(可口的大鼠)或饮食(Chow大鼠)。然后，我们评估了阿片受体拮抗剂纳曲酮对固定比率1(FR1)和进行性食物强化比率的影响，系统地或局部特异性地给予NAcc或mPFC。最后，我们评估了前OpioMelanoCortin(POMC)、前强啡肽原(PDyn)和前脑啡肽原(Penk)基因在两组NAcc和mPFC中编码阿片肽的表达。可口的大鼠迅速增加了4倍的摄入量。当系统地将纳曲酮注入NAcc时，在Chow大鼠和可口大鼠中都以递增的比例降低了FR1对食物的反应和进食动机；相反，当NAcc中注入mPFC时，这种效果对暴饮暴食的大鼠具有高度的选择性。此外，我们还发现，与对照组相比，美味大鼠的mPFC中POMC增加了两倍，PDyn基因表达减少了约50%；而NAcc则没有观察到变化。我们的数据表明，mPFC中阿片系统的神经适应发生在间歇性接触高度美味的食物后，这可能是暴饮式进食的原因。
Binge eating disorder is an addiction-like disorder characterized by excessive food consumption within discrete periods of time. This study was aimed at understanding the role of the opioid system within the mPFC in the consummatory and motivational aspects of binge-like eating. For this purpose, we trained male rats to obtain either a sugary, highly palatable diet (Palatable rats) or a chow diet (Chow rats) for 1h a day. We then evaluated the effects of the opioid receptor antagonist, naltrexone, given either systemically or site-specifically into the NAcc or the mPFC on a fixed ratio 1 (FR1) and a progressive ratio schedule of reinforcement for food. Finally, we assessed the expression of the genes preOpioMelanoCortin (POMC), Pro-Dynorphin (PDyn), and Pro-Enkephalin (PEnk), coding for the opioids peptides in the NAcc and the mPFC in both groups. Palatable rats rapidly escalated their intake by 4 times. Naltrexone, when administered systemically and into the NAcc, reduced FR1 responding for food and motivation to eat under a progressive ratio in both Chow and Palatable rats; conversely, when administered into the mPFC, the effects were highly selective for binge eating rats. Furthermore, we found a two-fold increase in POMC and a ~50% reduction in PDyn gene expression in the mPFC of Palatable rats, when compared to control rats; however, no changes were observed in the NAcc. Our data suggest that neuroadaptations of the opioid system in the mPFC occur following intermittent access to highly palatable food, which may be responsible for the development of binge-like eating.