Molecular Organization of CNS Synapses

描述(申请人提供)：兴奋性突触传递 哺乳动物的大脑主要通过神经递质谷氨酸的作用来调节 突触后谷氨酸受体的两种类型：NMDA受体和AMPA 受体(NMDARs和AMPAR)。我们的长期目标是了解 谷氨酸受体靶向细胞的分子机制 突触后膜以及如何调节这些机制来控制 突触传递的强度。因此，这项提议涉及一个 与大脑相关的突触可塑性的基本问题 发展以及学习和记忆。 最近的研究表明，突触后AMPAR的受控运输是一种 长效增强和抑制的主要机制 突触传递。然而，细胞生物学事件只是 表面上(主要是定性的)描述，以及潜在的 分子机制仍然知之甚少。要解决这些重要问题 问题，我们将使用定量免疫细胞化学和生化 全面研究AMPAR内化(内吞)的技术 以及在培养的海马神经元中插入(胞吐)。分子 突触调节AMPAR内化/插入的机制 活性和生长因子将用GluR1和GluR2亚基进行研究。这个 新的AMPAR插入神经元表面的位置将在高海拔可视化 决议。此外，我们还将搜索小说并对其进行功能描述 Ampar结合蛋白，可能在AMPAR运输中发挥作用，因此 突触可塑性。最后，分子的功能意义。 这些发现将通过海马区的电生理实验进行验证。 切片。在每个目标中，我们都有强有力的初步数据表明 证实了该计划的重要性和可行性 拟议的实验。 因为谷氨酸受体功能与脑突触密切相关 功能和兴奋性毒性，这项研究可能与人类急性和 慢性神经退行性疾病和精神障碍。

DESCRIPTION (provided by applicant): Excitatory synaptic transmission in the mammalian brain is primarily mediated by the neurotransmitter glutamate acting on two classes of postsynaptic glutamate receptors: NMDA receptors and AMPA receptors (NMDARs and AMPARs). Our long-term objective is to understand the molecular mechanisms by which glutamate receptors are targeted to the postsynaptic membrane and how these mechanisms can be regulated to control the strength of synaptic transmission. This proposal therefore addresses a fundamental issue in synaptic plasticity, which is of relevance to brain development and to learning and memory. Recent studies suggest that regulated trafficking of postsynaptic AMPARs is a major mechanism underlying the long-lasting potentiation and depression of synaptic transmission. However, the cell biological events have only been superficially (and largely qualitatively) described, and the underlying molecular mechanisms remain poorly understood. To address these important questions, we will use quantitative immunocytochemical and biochemical techniques to comprehensively investigate AMPAR internalization (endocytosis) and insertion (exocytosis) in cultured hippocampal neurons. The molecular mechanisms by which AMPAR internalization/insertion is regulated by synaptic activity and growth factors will be studied with subunits GluR1 and GluR2. The site of new AMPAR insertion in the neuronal surface will be visualized at high resolution. In addition, we will search for and functionally characterize novel AMPAR-binding proteins that may play a role in AMPAR trafficking, and hence synaptic plasticity. Finally, the functional significance of the molecular findings will be tested by electrophysiological experiments in hippocampal slices. In each of these aims, we have strong Preliminary Data that substantiate the significance and that demonstrate the feasibility of the proposed experiments. Because glutamate receptor function is intimately involved in brain synaptic function and excitotoxicity, this research may be relevant to human acute and chronic neurodegenerative disease and to psychiatric disorders.