DYNAMICS OF THE NEURONAL CYTOSKELETON

描述：拟议的研究将检查的机制， 轴突微管阵列在轴突延伸过程中被精心制作。 的能力 神经元的轴突长距离延伸依赖于 高度有序的微管阵列的精细加工。 拟议 实验中，微管运输在轴突生长过程中的作用将是 在活细胞中处理。 具体目标有三：（1）第一， 目的是观察微管在神经元中心体的行为 来确定中心体微管是否真的 分离并进入轴突。 (2)第二个目标是荧光微管蛋白 将以稳定的微管片段的形式被引入神经元， 不能组装的微管蛋白亚基，或潜在的中间微管蛋白 聚集体，并将确定这些形式中的任何一种微管蛋白 沿着轴突积极运输。 (3)第三个目标是微管 侧支形成的轴突行为 将进行调查。 直接观察和药理学工具 将用于确定微管是否出现在新形成的 通过运输从母轴突分支。 总体而言，这些努力 将解决微管运输对关键特征的贡献 轴突的生长。

DESCRIPTION: The proposed research will examine the mechanisms by which the axonal microtubule array is elaborated during axon extension. The ability of neurons to extend axons over long distances is dependent upon the elaboration of highly organized arrays of microtubules. In the proposed experiments, the role of microtublule transport during axon growth will be addressed in living cells. There are 3 specific aims: (1) In the first aim, microtubule behaviors at the neuronal centrosome will be observed within living neurons to determine whether centrosomal microtubules actually detach and move into the axon. (2) In the second aim, fluorescent tubulin will be introduced into neurons in the form of stable microtubule fragments, assembly-incompetent tubulin subunits, or potential intermediate tubulin aggregates, and it will be determined whether tubulin in any of these forms is actively transported down the axon. (3) In the third aim, microtubule behaviors in the axon that underlie the formation of collateral branches will be investigated. Direct observation as well as pharmacologic tools will be used to determine whether microtubules arise within newly-forming branches via transport from the parent axon. Collectively, these efforts will resolve the contribution of microtubule transport to critical features of axon growth.