Université de Bordeaux, 33077 Bordeaux, France.
CNRS, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, UMR 5287, 33077 Bordeaux, France.
eNeuro. 2017 Jun 1;4(3). doi: 10.1523/ENEURO.0120-17.2017. eCollection 2017 May-Jun.
Increasing evidence suggest that consumption of high-fat diet (HFD) can impact the maturation of brain circuits, such as during adolescence, which could account for behavioral alterations associated with obesity. In the present study, we used behavioral sensitization to amphetamine to investigate the effect of periadolescent HFD exposure (pHFD) in rats on the functionality of the dopamine (DA) system, a central actor in food reward processing. pHFD does not affect responding to an acute injection, however, a single exposure to amphetamine is sufficient to induce locomotor sensitization in pHFD rats. This is paralleled by rapid neurobiological adaptations within the DA system. In pHFD-exposed animals, a single amphetamine exposure induces an increase in bursting activity of DA cells in the ventral tegmental area (VTA) as well as higher DA release and greater expression of (tyrosine hydroxylase, TH) in the nucleus accumbens (NAc). Post-synaptically, pHFD animals display an increase in NAc D2 receptors and c-Fos expression after amphetamine injection. These findings highlight the vulnerability of DA system to the consumption of HFD during adolescence that may support deficits in reward-related processes observed in obesity.
越来越多的证据表明，高脂肪饮食（HFD）的摄入会影响大脑回路的成熟，例如在青春期期间，这可能是与肥胖相关的行为改变的原因。在本研究中，我们使用安非他命行为敏感化来研究青春期前 HFD 暴露（pHFD）对大鼠多巴胺（DA）系统功能的影响，DA 系统是食物奖励处理的核心因素。pHFD 并不影响对急性注射的反应，但是单次安非他命暴露足以诱导 pHFD 大鼠的运动敏化。这与 DA 系统内的快速神经生物学适应平行。在 pHFD 暴露的动物中，单次安非他命暴露会增加腹侧被盖区（VTA）中 DA 细胞的爆发活动，以及纹状体（NAc）中更高的 DA 释放和更大的（酪氨酸羟化酶，TH）表达。突触后，pHFD 动物在安非他命注射后显示 NAc D2 受体和 c-Fos 表达增加。这些发现强调了青春期 HFD 摄入对 DA 系统的脆弱性，这可能支持肥胖中观察到的与奖励相关过程的缺陷。
