MOLECULAR CHARACTERIZATION OF GLUTAMATE RECEPTORS IN FRESHWATER SNAILS

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。谷氨酸是一种神经递质，在脊椎动物中，通常通过作用于几种特征明确的受体参与初级兴奋性神经传递、学习和记忆、癫痫和神经退行性疾病。在无脊椎动物中，谷氨酸通过受体介导行为，而这种受体的特征还不太明确。已知谷氨酸通过介导兴奋或抑制的受体来控制肺类软体动物的摄食行为，如池螺lynaea和Helisoma；这些受体仅被部分表征。从林蝇中克隆出两个与哺乳动物兴奋性亚基同源的受体亚基，但只有一个在生理上得到了表征。我们假设Helisoma中存在一个或多个类似的受体，因为谷氨酸刺激运动神经元控制进食的一个阶段。本研究的目的是克隆和测序来自三角帆状体（Helisoma trivolvis）和光斑生物（Biomphalaria glabrata）颊神经节的兴奋性谷氨酸受体，选择后者是因为基于其作为曼氏血吸虫（Schistosoma mansoni）中间宿主的医学重要性，基因组计划正在进行中。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Glutamate is a neurotransmitter that, in vertebrates, is usually involved in primary excitatory neurotransmission, learning and memory, epilepsy and neurodegenerative disorders through its actions on several well characterized receptors. In invertebrates, glutamate mediates behaviors through receptors that are less well characterized. Glutamate is known to control feeding behavior in pulmonate mollusks like the pond snails Lymnaea and Helisoma through receptors that mediate either excitation or inhibition; these receptors are only partially characterized. Two receptor subunits with homology to mammalian excitatory subunits have been cloned from Lymnaea, but only one has been characterized physiologically. We hypothesize the existence of one or more similar receptors in Helisoma since glutamate excites motor neurons controlling one phase of feeding. The goal of this research is to clone and sequence excitatory glutamate receptors from the buccal ganglia of both Helisoma trivolvis and Biomphalaria glabrata, the latter chosen because a genome project is underway based on its medical importance as the intermediate host of Schistosoma mansoni.