New Tool to Study Neurochemical Modulation of Feeding

描述（由申请人提供）：饮食失调的发病率越来越高，人们对其健康成本的认识也越来越高。为了影响人类健康，需要对调节摄取行为的机制有更深入的了解。外侧下丘脑长期以来与摄食行为有关，神经递质谷氨酸似乎在该区域起着独特的启动作用。在本研究中，低流量推拉灌注法将用于：1.确定与用餐开始同时发生的内源性谷氨酸能激增的精确位置；药理学操作外侧下丘脑亚区，以验证摄取行为和谷氨酸信号传导之间的联系。由于我们的新体内采样方法采用的灌注流率是所有体内采样技术中最低的，因此大约200-#m的空间分辨率明显优于现有方法，并且在光学显微镜下没有看到组织损伤。此外，低流量推拉取样分析物回收率高，将有助于恢复大，缓慢扩散的分子。我们将确定最佳的低流量推拉条件，以最大限度地恢复蛋白质，并确定最丰富的脑脊液蛋白质的蛋白质含量。灌注液中的蛋白酶活性将通过使用毛细管壁涂层来测量和最小化。本R21提案中的发育研究强调了使用低流量推拉灌注法所提供的特殊优势，并将为未来研究与摄食行为有关的神经肽提供合适的采样条件。低流量推拉灌注的独特能力补充了其他采样方法，并广泛适用于体内采样研究。

DESCRIPTION (provided by applicant): There is an increased prevalence of eating disorders and a growing appreciation of their health costs. In order to effect human health, a greater understanding of the mechanisms modulating ingestive behaviors is needed. The lateral hypothalamus has long been associated with feeding behavior and the neurotransmitter glutamate appears to play a unique, initiatory role at this region. In this proposal the low-flow push-pull perfusion method will be used to: 1.determine the precise location of an endogenous glutamatergic surge that is coincident with the initiation of a meal, 2.pharmacologically manipulate lateral hypothalamic sub areas to verify the link between ingestive behaviors and glutamate signaling. Because our new in vivo sampling method employs perfusion flow rates among the lowest of any in vivo sampling technique, the approximate 200-#m spatial resolution is significantly better than existing methods and no tissue damage is seen by light microscopy. Also, with low-flow push-pull sampling analyte recoveries are high and will be useful for recovery of large, slower diffusing molecules. We will determine optimal low-flow push-pull conditions for maximal protein recovery and the protein content will be determined for the most abundant cerebrospinal fluid proteins. Protease activity in perfusates will be measured and minimized by the use of capillary wall coatings. The developmental studies in this R21 proposal highlight the particular advantages that will be afforded by the use of the low-flow push-pull perfusion method and will lead to sampling conditions appropriate for future studies of neuropeptides implicated in feeding behavior. The unique capabilities of low-flow push-pull perfusion complement other sampling methodologies and are widely applicable to in vivo sampling studies.