Neurodynamics of feeding behavior

我对理解动机状态的神经生理机制很感兴趣。在本研究中，我们将研究将大鼠的进食行为从寻找常规食物转向高美味食物（甜蔗糖溶液）的神经元动力学。寻找蔗糖的老鼠减少了它们的食物摄入量，同时显著增加了蔗糖的摄入量。人们普遍认为食欲是由下丘脑调节的。然而，进食的享乐方面取决于大脑奖励系统的活动。前额叶皮层（PFC）是奖赏系统的重要组成部分。PFC投射到外侧下丘脑（LH），这在蔗糖而不是食物寻求的大鼠中被激活。相反，下丘脑背内侧（DMH）接收来自LH的输入，在食物中被激活，而不是寻找蔗糖的动物。我们假设，下丘脑内的激活动态，发生在从常规食物导向行为到美味食物导向行为的转变过程中，取决于源自PFC的信号。提出的实验将研究(a)在寻找食物和蔗糖的大鼠中，PFC、LH和DMH的实时神经元活动动态；(b) PFC与下丘脑连接的神经形态和神经化学，以及(c) PFC在寻找食物和蔗糖的大鼠下丘脑激活中的作用。本研究旨在研究食物动机行为中涉及的神经元基质和神经元分布式网络的动态功能。为了实现这一目标，我们将使用分子生物学（原位杂交和免疫组织化学）、体内电生理技术和形态学方法（光学和电子显微镜）。拟议的研究将提供难得的培训机会。学生将使用众多最先进的研究技术来研究神经网络的基本组织和功能动态。他们的培训将在拥有多个本地和国际合作的研究中心（CRIUCPQ）的优秀环境中进行。

I am interested in understanding the neurophysiological mechanisms of motivational states. In the proposed study we will investigate the neuronal dynamics that re-direct rats' feeding behavior from seeking of regular chow to highly palatable food (sweet sucrose solution). Sucrose-seeking rats decrease their intake of chow while dramatically escalating intake of sucrose. It is commonly accepted that appetite is regulated by the hypothalamus. However, hedonic aspect of feeding depends on the activity of the brain reward system. The prefrontal cortex (PFC) is an important component of the reward system. The PFC projects to the lateral hypothalamus (LH), which is activated in the sucrose- but not chow-seeking rats. Conversely, the dorsomedial hypothalamus (DMH), which receives the input from the LH, is activated in the chow- but not sucrose-seeking animals. We hypothesize that dynamics in activation within the hypothalamus, which occur during transition from the regular- to palatable-food-oriented behaviour, depend on the signals originated in the PFC. The proposed experiments will investigate (a) the dynamics of real-time neuronal activity in the PFC, LH, and DMH in the chow- and sucrose-seeking rats; (b) the neuromorphology and neurochemistry of the connections between the PFC and the hypothalamus, and (c) the role of the PFC in the hypothalamic activation in the chow- and sucrose-seeking rats. The current proposal is designed to investigate the neuronal substrate and the dynamic functions of the neuronal distributed network involved in the food-motivated behavior. To achieve this objective, we will use the methods of molecular biology (in situ hybridization and immunohistochemistry), in vivo electrophysiological techniques, and morphological methods (light and electron microscopy). The proposed study will provide an exceptional opportunity for training. The students will investigate the basic organization and functional dynamics of the neuronal network using a multitude of state-of-the-art research techniques. Their training will occur in the outstanding environment of the research center (CRIUCPQ) with multiple local and international collaborations.