DEVELOPMENT OF EFFERENT NERVE FIBERS IN THE COCHLEA

耳蜗传出神经纤维的发育

• 批准号: 6174806
• 负责人: HANNA M SOBKOWICZ
• 金额: $ 18.1万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 2002-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6174806
• 关键词: acetylcholine; cochlea; developmental neurobiology; ear hair cell; efferent nerve; electron microscopy; gamma aminobutyrate; histology; innervation; laboratory mouse; neural growth associated protein; organ of Corti; synapses

DESCRIPTION (Adapted from Applicant's Abstract) The long-term objectives of the project are the identification of morphological and biochemical diversity within the efferent innervation and the patterns of the associated synaptic connectivity in the developing, as compared to adult, mouse cochlea. The P.I. proposes to study the complex synaptic connectivity of the GABAergic and cholinergic efferent fibers of the inner spiral bundle. The research goals aim to answer two principle questions 1) Is the CNS type of synaptic connectivity the P.I. has described in the developing mouse a transitory developmental event, or is it also present, but not noticed before, in the adult cochlea? 2) Are the synaptic arrays of compound synapses formed only by GABAergic fibers, or are these patterns also used by other efferent subsystems? In order to answer these questions, the P.I. proposes the following projects: 1) Ultrastructural studies, using conventional electron microscopy, of the synaptic connectivity of efferent fibers in the adult mouse cochlea. The study will elucidate: a) The patterns of connectivity: The P.I. will identify different synaptic connections (14 of which were demonstrated in the developing mouse) formed between the efferents and afferents, and between the afferents themselves; b) The types of synapses: The P.I. will try to detect if the adult organ of Corti uses compound synapses as discovered in the developing (up to 1 PN) mouse, i.e., triadic, serial and converging synapses so far identified only in the organ of Corti in culture; c) The synaptic appendages used by the inner hair cells and by both the afferent and efferent terminals in reaching distant targets. 2 Immunocytochemical/ultrastructural studies to investigate GABAergic and cholinergic efferent fibers in the maturing and adult cochlea that may partake in compound synapses at the lower level of the inner hair cell receptor poles will also be conducted. Additionally, the P.I. plans to identify ultrastructurally the morphological and immunochemical character of vesiculated endings that express GAP-43 in the inner spiral bundle, the only neuronal pathway that contains this growth protein in the adult cochlea.

描述（根据申请人的摘要改编）长期目标 该项目的识别形态和生化 传出神经内的多样性和 与成人相比，发展中相关的突触连通性 小鼠耳蜗。 P.I.建议研究复合物突触 内部的GABA能和胆碱能传出纤维的连通性 螺旋束。研究目标旨在回答两个主要问题1） 是P.I.突触连通性的中枢神经系统类型在 开发鼠标暂时发育事件，或者也存在， 但是在成年耳蜗中没有注意到吗？ 2）是突触阵列 仅由GABA能纤维形成的复合突触 其他传出子系统也使用的模式？为了回答这些 问题，P.I。提出以下项目：1）超微结构 研究，使用突触的常规电子显微镜研究 成年小鼠耳蜗中传出纤维的连通性。研究将 阐明：a）连通性的模式：P.I。会识别 不同的突触连接（其中14个已在 开发鼠标）形成的象征和传统之间以及之间 传入本身； b）突触的类型：P.I。会尝试 检测Corti的成年器官是否使用中发现的化合物突触 发育的（最多1 pn）鼠标，即三合会，串行和收敛 到目前为止，突触仅在培养物中的Corti器官中被鉴定出来； c） 内毛细胞和传入的突触附属物 和传出的终端达到遥远的目标。 2 免疫细胞化学/超微结构研究，以研究GABA能和 在成熟和成人耳蜗中的胆碱能传出纤维可能 在内毛细胞的较低水平的化合物突触中。 也将进行受体杆。此外，P.I.计划 从形态学和免疫化学特征上识别超微结构 在内部螺旋束中表达GAP-43的囊泡末端 只有成年人中包含该生长蛋白的神经元途径 耳蜗。