New Tool to Study Neurochemical Modulation of Feeding

描述(由申请人提供)：饮食失调的流行程度越来越高，人们对其健康成本的认识也越来越高。为了影响人类健康，需要更多地了解调节摄食行为的机制。长期以来，外侧下丘脑一直与摄食行为有关，神经递质谷氨酸似乎在该区域发挥着独特的启动作用。在这项建议中，低流量推拉灌注法将被用于：1.确定与进餐开始一致的内源性谷氨酸能峰的准确位置；2.从药理上操纵下丘脑外侧亚区，以验证摄食行为和谷氨酸信号之间的联系。由于我们新的活体采样方法采用了体内采样技术中最低的灌流流率，因此大约200-#m的空间分辨率明显好于现有方法，并且在光学显微镜下没有看到组织损伤。此外，使用低流量推拉采样，分析物的回收率很高，这将有助于回收大的、扩散较慢的分子。我们将确定最佳的低流量推拉条件以最大限度地回收蛋白质，并将确定最丰富的脑脊液蛋白质的蛋白质含量。灌流液中的蛋白酶活性将通过使用毛细管壁涂层进行测量并降至最低。本R21提案中的发展研究突出了使用低流量推拉灌注法将提供的特殊优势，并将导致适合于未来研究与摄食行为有关的神经肽的采样条件。低流量推拉灌流的独特功能是对其他采样方法的补充，广泛适用于活体采样研究。

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.