Mechanisms of Nerve Sprouting in Muscle

神经系统中包含两种主要类型的细胞：神经元，它是产生、传导和传递信息给其他细胞的细胞；神经胶质细胞是包围和支持神经元的细胞。神经胶质细胞在损伤后神经组织修复中起重要作用；一类神经胶质细胞，雪旺细胞，通过延长长的突起，帮助受损的轴突（神经纤维）再生，然后作为新的轴突再生的基质。如果支配肌肉的许多运动轴突中的一些受损，其余的轴突就会开始发出新的“芽”，与去神经支配的肌纤维建立新的连接。在发芽过程中，周围的雪旺细胞似乎延长了诱导附近轴突生长的过程，并将这些生长的轴突引导到去神经纤维。本项目使用生理和免疫组织化学技术来确定肌肉活动和特定分子的基因表达在轴突引导中的作用，特别强调细胞粘附分子。这项工作的结果对于理解神经系统的其他细胞在发育和再生过程中如何影响发芽神经细胞的特异性靶向具有重要意义，并将对发育生物学和细胞生物学以及神经科学产生影响。

9513420 Thompson Two major types of cells are contained within the nervous system: neurons, which are the cells that generate, conduct and transmit information to other cells; and glia, which are the cells that surround and support the neurons. Glial cells are important in the repair of nerve tissue after injury; one class of glia, the Schwann cells, assist in regeneration of damaged axons (nerve fibers) by extending long processes that then serve as substrates along which the new axons re-grow. If some of the many motor axons that innervate a muscle are damaged, the remaining axons begin to send new "sprouts" to make new connections with the denervated muscle fibers. During sprouting, the surrounding Schwann cells appear to extend processes that induce the growth of nearby axons, and guide those growing axons to denervated fibers. This project uses physiological and immunohistochemical techniques to determine the roles that muscle activity and gene expression of particular molecules play in the guidance of axons, with particular emphasis on cell adhesion molecules. Results from this work will be important in understanding how the other cells of the nervous system influence the specific targeting of sprouting nerve cells during development and regeneration, and will have an impact on developmental biology and cell biology as well as neuroscience.