The F-Actin Cytoskeleton of the Frog Motor Nerve Terminal

为了使神经系统正常运作，每个神经细胞必须在其靶细胞上的精确位置组装释放其信号（神经递质）所需的分子机器，在该位置可以接收信号并产生反应。 神经末梢的释放机制与其靶点的受体分子之间的这种精确对齐不仅对神经末梢的构建和生长，而且对神经末梢的维持提出了挑战。 神经细胞和目标之间的这种组织的精确性在青蛙的神经肌肉接头中得到了很好的说明，在那里，神经末梢中的线性释放位点被不同的非释放域分开。 利用青蛙运动神经末梢，康纳博士的实验室发现，包括F-肌动蛋白在内的细胞骨架分子集中在非释放区，F-肌动蛋白是一种参与细胞和细胞器的结构支撑和运动的分子。 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其靶点的稳定。 部分资金提供给康纳博士的实验室启动初始实验使用国家的最先进的，电子显微镜断层扫描，以构建一个高分辨率，三维地图的细胞骨架在nonrelease域的神经末梢。 此外，这将为研究生提供培训机会。

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.