EXCITATORY AMINO ACID RECEPTOR GENES AND PROTEINS IN AD

兴奋性氨基酸(EAA)是大多数的神经递质。 哺乳动物大脑皮质和海马区兴奋通路的研究 可能是大脑皮层和海马锥体的神经递质 神经元。大脑皮质和海马区联合锥体神经元 在AD早期形成神经原纤维缠结。生化和解剖学 对Ad脑的研究表明，谷氨酸水平和EAA受体水平都有所下降。 EAA被假设在AD中发挥作用，因为EAA激动剂 兴奋性毒性，因为AD中受影响最大的区域有高 EAA和EAA受体浓度。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-丙酸受体和海人藻酸 受体)，NMDA受体的下降幅度大于 其他。存在两种类型的代谢型EAA受体，一种与 阿尔茨海默病和阿尔茨海默病患者脑组织中磷脂酰肌醇代谢的变化 一个与腺苷环化酶有关，后者在AD中显着降低。不 这些标记物密度高的所有皮质区域都会受到影响 然而，EAA在AD发病机制中的任何作用都必须是 其次是它们神经元易损性的额外特征。这个 细胞对神经原纤维易感性的区域分级 退化在衰老和阿尔茨海默病中已被定义。此外，这些基因 对于不同的EAA受体亚型已经被克隆和特异性地 已经产生了对大多数病毒的抗体。因此，有可能 明确特定的EAA受体亚型基因与 蛋白质与其他潜在的阿尔茨海默病神经变性标志物。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关于 EAA在衰老和阿尔茨海默病中的作用第一个假设是高密度 在NMDA受体中，mGluR5受体高密度和低密度 的mGluR1受体在优先丢失的神经元中表达 在衰老和阿尔茨海默病。第二个假设是高密度的NMDA 受体在高密度的MAPK和MAPK表达 APP和APLP以及低密度的NMDA受体在NO中表达 含有一氧化氮合酶的神经元。这些研究将在#年进行。 与项目2、3和4密切合作，这些项目将独立 检查潜在代谢和兴奋性毒性的相关方面 与衰老和AD的细胞脆弱性有关的级联反应。这个 该项目还将使用试剂核心进行组织采集和 EAA受体蛋白和基因的Western和Northern印迹分析 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.