EMBRYONIC DEVELOPMENT OF THE EFFERENT SYSTEM

投射到耳朵的传出运动神经元系统在小鼠身上发育 和鸡肉从脸颊运动原基出来。像其他人一样 运动系统，传出细胞很可能依赖于它们的生存 就未知而言，神经营养因子(S)可用于其靶点。在……里面 此外，到达时间和大小等各种条件 所支配的靶区中的一部分被建议在 运动神经元的生存。这个项目试图通过以下方式来测试这一概念 量化随着时间的推移投射到耳朵的传出信号的数量。 我们将使用传出系统独有的某些功能来探索 到达时间和目标大小的问题在 传出的各种亚群，无法调查 在任何其他马达系统中。我们还将探索具有变量的突变 传入和传出神经减少到一定程度 感觉上皮或耳朵缩小，包括手术切除， 进一步分析发展与经济增长之间的数量关系 耳朵和发育中的传出器。我们的实验还将提供 对营养支持可能有限的洞察力 通过测试重新路由到耳囊的传出细胞的存活率 鸡的非耳鸣靶标。这些信息加在一起将提供 可帮助找到干预措施线索的基线数据 患者毛细胞丢失，防止传出细胞丢失。

The efferent motoneuron system that projects to the ear develops in mice and chicken out of the facial branchial motor primordium. Like other motor systems, the efferent cells will likely depend for their survival on unknown, neurotrophic factor(s) available at their target. In addition, various conditions such as the time of arrival and the size of the target area innervated have been suggested to play a role in the survival of motoneurons. This project seeks to test this notion by quantifying the numbers of efferents projecting to the ear over time. We will use certain features unique to the efferent system to explore issues of timing of arrival and target size which is different in the various subpopulations of efferents, and which cannot be investigated in any other motor system. We will also explore mutants with variable reductions of both the afferent and efferent innervation to certain sensory epithelia or reduction of the ear, including surgical removal, to analyze further the quantitative relationship between the developing ear and the developing efferents. Our experiments will also provide insights into the possibly limited availability of trophic support only at the otocyst by testing the survival of efferent cells rerouted to a non-otic target in chickens. Together this information will provide baseline data that can help to find clues for interventive measures in patients with loss of hair cells to prevent loss of efferents.