DYNAMICS OF THE NEURONAL CYTOSKELETON

描述：这项拟议的研究将考察 在轴突延伸过程中，阐述了轴突微管阵列。一种能力 神经元将轴突延伸到很远的距离取决于 高度组织的微管阵列的精加工。在建议的 实验中，微管运输在轴突生长中的作用将是 在活细胞中寻址。具体目标有三个：(1)第一个 目的：观察神经元中心体的微管行为。 以确定中心体微管是否确实 分离并移入轴突。(2)第二个目标是荧光微管蛋白 将以稳定的微管碎片的形式被引入神经元， 装配不合格的微管蛋白亚基，或潜在的中间微管蛋白 聚集，并将确定这些形式中的任何一种微管蛋白 正在积极地沿着轴突向下运输。(3)第三个目标是微管 侧支形成的轴突中的行为 将会被调查。直接观察和药理工具 将被用来确定在新形成的细胞中是否出现微管 从父代轴突运输而来的分支。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.