RETROGRADE SIGNALING IN NERVE TERMINAL FORMATION

神经末梢形成中的逆行信号传导

• 批准号: 6188162
• 负责人: Hsiao-Ming B Peng
• 金额: $ 19.8万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-12 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6188162
• 关键词: Xenopus oocyte; biological signal transduction; calcium flux; cell differentiation; cytoskeleton; electron microscopy; exocytosis; fluorescent dye /probe; hippocampus; immunocytochemistry; laboratory mouse; neuromuscular junction; neurotransmitter transport; neurotrophic factors; synaptic vesicles; synaptogenesis; tissue /cell culture; voltage /patch clamp

DESCRIPTION (adapted from the applicant's abstract):The formation of synaptic connections is the grand finale in the development of the nervous system. When the growth cone of an axon comes into contact with its synaptic target, a series of changes takes place that transforms it from a sensor for pathway seeking to a highly efficient nerve terminal capable of activity-regulated secretion of neurotransmitters. The nerve terminal, characterized by the highly organized clusters of synaptic vesicles at the site of transmitter release and the elaborate molecular complex for the activity- dependent exocytosis of these vesicles at the presynaptic membrane, is a remarkable example of cellular differentiation. Recent studies have suggested that the extracellular matrix surrounding the target cell harbors molecular cues that instruct the growth cone to undergo presynaptic differentiation. This study is aimed at understanding the molecular interactions between the pre- and postsynaptic cells that lead to the formation of the nerve terminal. The development of the nerve terminal at the neuromuscular junction will be used as the main model for presynaptic differentiation of this study. The aims of this study are: (1) to study the role of peptide growth factors that are bound to the extracellular matrix of the skeletal muscle in signaling presynaptic development; (2) to understand the role of the cytoskeleton in the assembly of synaptic vesicle clusters; (3) to characterize the movement and clustering of synaptic vesicles within the neuronal process during presynaptic development. Tissue cultures of spinal cord neurons from the amphibian Xenopus embryos and hippocampal neurons from normal mice and mice with deficiency in the synaptic-vesicle protein synapsin will be used in this study. The presynaptic differentiation will be induced by coculturing neurons with muscle cells or with other neurons, or by applying growth factor-coated microbeads to neurons to mimic the target contact. A range of techniques, including light and electron microscopy, immunochemistry, protein biochemistry, molecular biology and electrophysiology, will be used to observe the development of the nerve terminal in response to synaptogenic signals. The overall goal is to understand the signal transduction mechanism involved in presynaptic differentiation at the neuromuscular junction as well as within the central nervous system. Many neurological and neuromuscular disorders are results of malfunction of synaptic connections in the nervous system. The principles garnered from this study should lead to a better understanding of the causes of these maladies.

描述（改编自申请人的摘要）：编队 突触连接的是发展的大结局 神经系统。当轴突的生长锥进入 与其突触目标接触，发生了一系列更改 这将其从寻求高度寻求的路径的传感器转变 有效的神经终末能够活性调节的分泌 神经递质。神经末端，以高度为特征 发射机部位的突触囊泡的有组织的簇 释放和精致的分子复合物用于活性 这些囊泡在突触前膜上的依赖性胞吐作用， 是细胞分化的非凡例子。最近的研究 已经提出了目标周围的细胞外基质 细胞包含指示生长锥到的分子提示 进行突触前分化。这项研究针对 了解前和 导致神经形成的突触后细胞 终端。神经终末的发展 神经肌肉连接将用作主要模型 这项研究的突触前分化。这项研究的目的 是：（1）研究结合的肽生长因子的作用 信号传导中骨骼肌的细胞外基质 突触前发展； （2）了解 突触囊泡簇组装中的细胞骨架； （3）到 表征突触囊泡的运动和聚类 在突触前发育过程中的神经元过程中。组织 来自两栖动物Xenopus胚胎的脊髓神经元培养 来自正常小鼠和缺乏症小鼠的海马神经元 在突触中，将使用突触 - 蛋白突触素 学习。突触前的分化将由 与肌肉细胞或其他神经元或通过 将生长因子涂覆的微型脱落到神经元中以模仿 目标联系。一系列技术，包括光和电子 显微镜，免疫化学，蛋白质生化，分子 生物学和电生理学将用于观察 响应突触源的神经末端的发展 信号。总体目标是了解信号转导 与突触前分化有关的机制 神经肌肉连接以及中枢神经内 系统。许多神经系统和神经肌肉疾病是结果 神经系统突触连接故障。这 从这项研究中获得的原则应导致更好 了解这些疾病的原因。