EXCITATORY AMINO ACID RECEPTOR GENES AND PROTEINS IN AD

兴奋性氨基酸（EAA）是大多数神经递质， 哺乳动物大脑皮层和海马兴奋性通路， 可能是皮层和海马锥体神经递质 神经元 联合皮层和海马锥体神经元 在AD早期出现神经元缠结。 生物化学和解剖学 Ad脑的研究显示谷氨酸水平和EAA受体降低。 已经假设EAA在AD中起作用，因为EAA激动剂是 兴奋毒性，因为在AD中受影响最大的区域具有高 EAA和EAA受体的浓度。 在三种EAA受体中 连接到离子通道（N-甲基-D-天冬氨酸（NMDA），α-氨基-3- 羟基-5-甲基-4-异恶唑-4-丙酸受体（AMPA）和红藻氨酸 受体），NMDA受体降低的程度大于 他人 存在两种类型的代谢型EAA受体，一种与 磷酸肌醇代谢在AD脑中显著降低， 一种与腺苷酸环化酶有关，而腺苷酸环化酶在AD中显著降低。 不 所有具有高密度这些标记的皮质区域都受到影响， 然而，EAA在AD的发病机制中的任何作用都必须被研究。 继发于其神经元脆弱性的额外特征。 的 细胞对神经元的易损性的区域等级 退化已被定义为衰老和AD。 此外，基因 已经克隆了各种EAA受体亚型， 其中大多数的抗体已经产生。 因此可以 确定特定EAA受体亚型基因的关系， 蛋白质与AD中神经变性的其他潜在标志物。 在这 项目、受体放射自显影、原位杂交和 免疫细胞化学将被用来解决两个假设， EAA在衰老和AD中的作用。 第一个假设是高密度 NMDA受体的密度、MGluR 5受体的高密度和低密度 的mGluR 1受体表达在那些优先丢失的神经元中 在老化和AD中。 第二个假设是高密度的NMDA 受体在具有高密度MPA激酶的细胞中表达， APP和APLP以及低密度的NMDA受体在一氧化氮合酶中表达。 含氧化物合酶的神经元。 这些研究将在 与项目2、3和4密切合作， 检查潜在的代谢和兴奋毒性的相关方面， 参与衰老和AD的细胞脆弱性的级联。 的 项目还将使用试剂核心进行组织采集， 通过Western和北方印迹分析EAA受体蛋白和基因 分析.

Excitatory amino acids (EAA) are the neurotransmitters of the majority of cortical and hippocampal excitatory pathways in mammalian brain and are the likely neurotransmitters of cortical and hippocampal pyramidal neurons. The pyramidal neurons of association cortex and hippocampus develop neurofibrillary tangles early in AD. Biochemical and anatomical studies of Ad brain show decreases in glutamate levels and EAA receptors. EAA have been hypothesized to play a role in AD because EAA agonists are excitotoxic and because the area most affected in AD have high concentrations of EAA and EAA receptors. Among the three EAA receptors linked to ion channels (the N-methyl-D-aspartate (NMDA), alpha-amino-3- hydroxy-5-methyl-4-isoxazole-4-propionic acid receptor (AMPA) and kainate receptors), the NMDA receptors are decreased to a greater extent than others. Two types of metabotropic EAA receptor exist, one linked to phosphoinositol metabolism which is variably decreased in AD brain and one linked to adenylate cyclase which is markedly decreased in AD. Not all cortical areas with high densities of these markers are affected in AD, however, and thus any role of EAA in the pathogenesis of AD must be secondary to their additional features of neuronal vulnerability. The regional hierarchy of cellular vulnerability to neurofibrillary degeneration has been defined in aging and AD. Furthermore, the genes for the various EAA receptor subtypes have been cloned and specific antibodies to most of them have been produced. It is thus possible to define the relationship of particular EAA receptor subtype genes and proteins to other potential markers of neurodegeneration in AD. In this project, receptor autoradiography, in situ hybridization and immunocytochemistry will be used to address two hypotheses concerning the role of EAA in aging and AD. The first hypothesis is that high densities of NMDA receptors, high densities of MGluR5 receptors and low densities of mGluR1 receptors are expressed in those neurons preferentially lost in aging and AD. The second hypothesis is that high densities of NMDA receptors are expressed in cells with high densities of MPA kinases and APP and APLP and low densities of NMDA receptors are expressed in nitric oxide synthase containing neurons. These studies will be carried out in close collaboration with projects 2,3, and 4 which will independently be examining related aspects of the potential metabolic and excitotoxic cascades involved in the cellular vulnerability of aging and AD. The project will also use the reagent core for tissue acquisition and analysis of EAA receptor proteins and genes by Western and Northern blot analysis.