The F-Actin Cytoskeleton of the Frog Motor Nerve Terminal

为了神经系统的正常运作，每个神经细胞必须在其目标细胞的精确位置组装释放其信号所需的分子机器，即神经递质，在那里信号可以被接收并产生反应。神经末梢的释放机制与其目标的接收分子之间的这种精确对齐不仅对其构建和生长提出了挑战，而且对其维护也提出了挑战。神经细胞和靶标之间这种组织的精确性在青蛙神经肌肉连接处得到了很好的说明，在那里，神经末梢的释放位点的线性阵列被不同的非释放域分开。利用青蛙的运动神经末梢，康纳博士的实验室发现，包括f -肌动蛋白（一种参与细胞和细胞器的结构支持和运动的分子）在内的细胞骨架分子集中在非释放结构域。康纳博士项目的长期目标是确定细胞骨架和f -肌动蛋白在神经末梢的基本过程中的作用，这些过程可能发生在非释放域：神经递质释放机制的再循环和神经末梢在目标上的稳定。部分资金将提供给康纳博士的实验室，用于开展初步实验，使用最先进的电子显微镜断层扫描技术，构建神经末梢非释放区域细胞骨架的高分辨率三维地图。此外，这将为研究生提供培训当前技术的机会。

For proper functioning of the nervous system, each nerve cell must assemble the molecular machinery required for the release of its signal, the neurotransmitter, at the precise location on its target cell where the signal can be received and a response produced. This precise alignment between the release machinery of nerve terminals and the reception molecules of their targets presents a challenge not only for its construction and growth but also for its maintenance. The precision of this organization between nerve cells and targets is beautifully illustrated at the frog neuromuscular junction where a linear array of release sites in nerve terminals is separated by distinct nonrelease domains. Using the frog motor nerve terminal, Dr. Connor's laboratory discovered that cytoskeletal molecules including F-actin, a molecule involved in the structural support and movement of cells and organelles, is concentrated in nonrelease domains. The long range goal of Dr. Connor's project is to determine the role of the cytoskeleton and F-actin in fundamental processes of nerve terminals that may occur in nonrelease domains: the recycling of the neurotransmitter release machinery and the stabilization of nerve terminals at their targets. Partial funding is provided to Dr. Connor's laboratory to launch initial experiments using state-of-the-art, electron microscope tomography to construct a high resolution, three-dimension map of the cytoskeleton in nonrelease domains of nerve terminals. Further, this will provide training opportunities for graduate students in the current techniques.