DEVELOPMENT OF EFFERENT NERVE FIBERS IN THE COCHLEA

这项研究的长期目标是定义形态 与分化传出细胞免疫细胞化学特征的比较 系统在小鼠的光镜和电子显微镜水平。这个 在培养中分离的Corti器官将作为终极对照 辨别螺旋神经节细胞的局部神经支配 不同于中心起源的。特别重要的是研究 传出道样水泡末梢及其带状传入/传出 大鼠肾上腺皮质内毛细胞的相互突触 培养和在完好的动物中确定它们的本地来源和 免疫细胞化学特征。当前的目标是确定 传出神经内的多样性，并确定 不同亚基的发育顺序。具体来说，我们 建议：L)研究神经丝的详细发育模式 完整动物的免疫反应性(标记所有神经元成分) 并在培养中作为解释个体免疫细胞化学的指南 2)研究降钙素基因相关肽在大鼠耳蜗区的表达。 毛细胞的神经支配及其随后从外部消失 毛细胞区；3)电子免疫细胞化学研究 显微镜检测神经活性物质AChE、ChAT、GAD/GABA、CGRP和 脑啡肽来确定它们的分化顺序和 假定共定位；4)研究其超微结构同一性 内螺旋束中保留GAP-43的独特的新途径 (生长相关蛋白-43)在成年小鼠的活性。 拟议研究的最重要方面是首先，辨别 与内毛细胞相关的神经感觉传出特化 推测为耳蜗源性；第二，确定超微结构 和传出神经的发育顺序，最后到 区分短暂的发育模式和它们的 成熟动物中的同龄人。我们希望这些研究将 超越物种界限，帮助我们更好地理解我们自己的听觉 系统。

The long-term objectives of the research are to define the morphological versus immunocytochemical characteristics of the differentiating efferent system in the mouse at the light and electron microscope levels. The isolated organ of Corti in culture will be used as an ultimate control in discerning the innervation provided locally by the spiral ganglion cells from that of central origin. Of special importance will be the study of efferent-like vesiculated endings and their ribbon-afferent/efferent reciprocal synapses with the inner hair cells in the organ of Corti in culture and in the intact animal to determine their local source and immunocytochemical character. The immediate goal is to identify the diversity within the efferent innervation and to determine the developmental sequence of the different subunits. Specifically, we propose: l) to study the detailed developmental pattern of neurofilament immunoreactivity (which labels all neuronal elements) in the intact animal and in culture as a guide for interpreting individual immunocytochemical patterns of cochlear innervation; 2) to study CGRP expression in the innervation of the hair cells and its subsequent extinction from the outer hair cell region; 3) to study immunocytochemically at the electron microscope level the neuroactive substances AChE, ChAT, GAD/GABA, CGRP and enkephalins to determine the sequence of their differentiation and presumptive colocalization; 4) to study the ultrastructural identity of the distinct, new pathway in the inner spiral bundle which retains GAP-43 (growth-associated protein-43) activity in the adult mouse. The most important aspects of the proposed study are first, to discern the neurosensory efferent specializations associated with the inner hair cells presumed to be of cochlear origin; second, to define the ultrastructure and developmental sequence of efferent innervation, and lastly to distinguish between the transitory developmental patterns and their counterparts in the maturing animal. We hope that these studies will transcend species-lines and help us to better understand our own auditory system.