Links among synaptic activity, translation and structure

描述(由申请人提供)： 谷氨酸能突触功能特征的变化被认为 为大脑发育和学习的基本过程奠定基础。总目标 是为了定义谷氨酸和谷氨酸之间的相互关系 受体激活、蛋白质合成和树突棘形状可能是 参与了这种突触变化的稳定。建议进行的研究 有三个具体目标：1)确定空间对应程度 突触之间以与功能相关的水平进行活动 通过涉及帽依赖机制的蛋白质合成的变化和位置 和内部核糖体进入序列(IRES)的翻译机制；2)到 定义依赖上限和内部启动的相对贡献 树突转化为活性诱导蛋白质合成的机制； 以及，3)确定平移和脊椎之间的一般相互依赖关系 结构，并测试蛋白质合成在形成中的特定作用 脆性X综合征模型中看到的异常长脊椎 对代谢性谷氨酸受体的刺激。新型荧光试剂 已开发用于进行这些研究，包括基于以下内容的标记 荧光共振能量转移(FRET)，用于标记正在进行的突触 塑料变化，以及帽依赖和IRES的几种荧光记者 介导的树突状翻译。这些研究将在分离的情况下进行 和海马体器官型切片培养，并将使用假共聚焦 由一个软件包控制的荧光显微镜系统，该软件包包括 图像分析工具用于定量荧光报告表达。这个 拟议的实验应该为我们的理解提供有价值的信息 树突状蛋白合成如何与突触活性、结构和 为大脑整体过程奠定基础的功效改变形式 发展、学习和记忆。

DESCRIPTION (provided by applicant): Changes in the functional characteristics of glutamatergic synapses are thought to underlie basic processes of brain development and learning. The overall goal of the proposed project is to define interrelationships between glutamate receptor activation, protein synthesis, and dendritic spine shape that may be involved in the stabilization of such synaptic changes. The proposed studies have three specific aims: 1) to determine the degree of spatial correspondence between synapses undergoing activity at a level associated with functional change and sites of protein synthesis via mechanisms that involve cap-dependent and internal ribosomal entry sequence (IRES) mechanisms of translation; 2) to define the relative contributions of cap-dependent and internal initiation mechanisms of translation to activity-induced protein synthesis in dendrites; and, 3) to determine the general interdependence between translation and spine structure, and to test the specific role of protein synthesis in the formation of abnormally long spines seen in a fragile X syndrome model and with stimulation of metabotropic glutamate receptors. Novel fluorescent reagents have been developed to conduct these studies, including a marker, based on fluorescence resonance energy transfer (FRET), for marking synapses undergoing plastic change, and several fluorescent reporters of cap-dependent and IRES mediated dendritic translation. The studies will be conducted in dissociated and organotypic slice cultures of hippocampus, and will use a pseudoconfocal fluorescence microscope system controlled by a software package that includes image analysis tools for quantification of fluorescent reporter expression. The proposed experiments should provide valuable information for our understanding of how dendritic protein synthesis relates to synaptic activity, structure, and forms of efficacy change thought to underlie global processes of brain development, learning, and memory.