NEUROBIOLOGICAL STUDIES OF A NOVEL HYPOTHALAMIC PEPTIDE

新型下丘脑肽的神经生物学研究

基本信息

批准号：
6392813
负责人：
Thomas S Kilduff
金额：
$ 29.49万
依托单位：
SRI INTERNATIONAL
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-09-30 至 2004-05-31
项目状态：
已结题

项目摘要

Using subtractive hybridization, we have isolated a novel neuropeptide gene which is expressed exclusively in a subregion of the posterior hypothalamus. Hypocretin contains a eukaryotic secretory signal sequence and encodes two neuropeptides, 38 and 28 amino acids in length, which are conserved between mouse, rat, and human, indicating an evolutionarily conserved function for these novel neuropeptides. We have raised a high quality antiserum to the hypocretin neuropeptide precursor, localized cell bodies within the hypothalamus, and begun mapping of the terminal projections of hypocretin-containing neurons. We have also obtained evidence that these novel peptides affect neuronal excitability and intracellular calcium levels in vitro and body temperature in vivo. Other investigators have isolated these same molecules which they called the orexins and demonstrated that the affect food intake. Based on these results, we hypothesize that the hypocretin peptides play a role in regulating energy balance and metabolism. We propose to characterize further this novel neurotransmitter pathway by describing the phenotype of neurons which express hypocretin in the hypothalamus and identifying the neuroanatomical regions to which hypocretin-containing neurons project. In in vitro studies, we will characterize the response of neurons to hypocretin peptidergic stimulation and determine the cellular electrophysiological response of neurons to hypocretin application. We will also conduct in vivo studies in which we will obtain functional information about the effects of hypocretin neuropeptides on brain activity and test the hypothesis that hypocretin peptides play a CNS role in regulating energy balance and metabolism. This proposal presents an exciting, integrated research program to characterize a heretofore unstudied neurotransmitter system expressing this novel set of neuropeptides and to determine the effects of these peptides in vitro and in vivo.

通过消减杂交，我们分离出了一种新的神经肽基因，该基因仅在下丘脑后部的一个亚区域表达。下丘脑分泌素含有真核分泌信号序列，编码两种神经肽，长度分别为 38 和 28 个氨基酸，这两种神经肽在小鼠、大鼠和人类之间是保守的，表明这些新型神经肽在进化上具有保守的功能。我们已经制备出针对下丘脑分泌素神经肽前体的高质量抗血清，定位下丘脑内的细胞体，并开始绘制含有下丘脑分泌素的神经元的末端投影图。我们还获得证据表明这些新型肽影响神经元兴奋性和体外细胞内钙水平以及体内体温。其他研究人员分离出这些相同的分子，他们称之为食欲素，并证明它们会影响食物的摄入。基于这些结果，我们假设下丘脑分泌素肽在调节能量平衡和代谢中发挥作用。我们建议通过描述下丘脑中表达下丘脑分泌素的神经元的表型并识别含有下丘脑分泌素的神经元投射到的神经解剖区域来进一步表征这种新的神经递质途径。在体外研究中，我们将表征神经元对下丘脑分泌素肽能刺激的反应，并确定神经元对下丘脑分泌素应用的细胞电生理反应。我们还将进行体内研究，获得有关下丘脑分泌素神经肽对大脑活动影响的功能信息，并检验下丘脑分泌素肽在调节能量平衡和代谢中发挥中枢神经系统作用的假设。该提案提出了一项令人兴奋的综合研究计划，旨在表征迄今为止未经研究的表达这套新型神经肽的神经递质系统，并确定这些肽在体外和体内的作用。