REGULATION OF NEURITE OUTGROWTH AND CONNECTIVITY

神经突生长和连接的调节

基本信息

批准号：
2332951
负责人：
CHRISTOPHER S COHAN
金额：
$ 17.08万
依托单位：
STATE UNIVERSITY OF NEW YORK AT BUFFALO
依托单位国家：
美国
项目类别：
财政年份：
1988
资助国家：
美国
起止时间：
1988-02-01 至 1999-01-31
项目状态：
已结题

项目摘要

The overall objective of this proposal is to define the intracellular mechanisms that regulate neuronal growth and connectivity.The experiments focus on movements of growth cones at the elongating tips of nerve fibers to reveal mechanisms that govern their function. These structures contain the motile machinery and decision making apparatus involved in neurite elongation, path finding, and synaptogenesis. The hypothesis that will be tested is that alterations in growth cone movements are mediated by changes in internal Ca. The experiments exploit the large identified neurons of the snail Helisoma in culture. These neurons develop large growth cones whose structure and movements can be studied quantitatively. Moreover, identified neurons provide an opportunity to reveal common, as well as unique, regenerative properties based upon study of individual neurons. The first Specific Aim addresses how Ca regulates growth cone movement. Progress over the last four years has established multiple stimuli that have a broad range of effects on growth cones. The effects of graded alterations in growth cone movements caused by these stimuli on internal Ca levels will be tested by imaging growth cones loaded with fura-2. The second Specific Aim focuses on the role of Ca in axonal regeneration using a newly developed preparation that makes it possible to study dynamic events associated with extension of neurites from an axon stump. This preparation duplicates in culture the regeneration that normally occurs in vivo after an axon is damaged. The importance of Ca in allowing conditioning factors to induce outgrowth from the axon stump will be examined. Specific Aim 3 will investigate how changes in the growth cone cytoskeleton are related to changes in growth cone movement.The structure and motility of growth cones depends on the organization of cytoskeletal components.Computer enhanced DIC and fluorescence microscopy will be used to reveal how dynamic changes in the cytoskeleton regulate growth cone structure and function. The hypothesis that changes in internal Ca influence the cytoskeleton and thereby alter growth cone structure and movement will be tested using multiple stimuli that have been identified as growth regulators.

该提议的总体目的是定义细胞内调节神经元生长和连通性的机制。实验专注于神经纤维伸长尖端的生长锥运动揭示控制其功能的机制。这些结构包含涉及神经突的动力机械和决策机构伸长，路径发现和突触发生。将是测试的是，生长锥运动的改变是由内部CA的变化。实验利用了大型确定的蜗牛热瘤的神经元培养。这些神经元发展很大可以定量研究其结构和运动的生长锥。此外，确定的神经元为揭示共同的机会，因为以及基于个人研究的独特，再生特性神经元。第一个特定目的解决了CA如何调节生长锥移动。过去四年的进步已经建立了多个对生长锥有广泛影响的刺激。效果由这些刺激引起的生长锥运动的分级变化内部CA水平将通过成像加载的成像生长锥进行测试 Fura-2。第二个特定目的侧重于CA在轴突中的作用使用新开发的制剂再生，使得研究动态事件与轴突的神经突扩展有关树桩。这种准备在文化中重复了通常在轴突受损后体内发生。 CA的重要性允许调节因素诱导轴突树桩的生长被检查。特定目标3将调查增长的变化锥细胞骨架与生长锥运动的变化有关。生长锥的结构和运动性取决于组织细胞骨架组件。将用于揭示细胞骨架中的动态变化如何调节生长锥结构和功能。假设改变了内部CA影响细胞骨架，从而改变生长锥结构和运动将使用具有多种具有的刺激被确定为增长调节剂。