ULTRASTRUCTURE OF AFFERENT INNERVATION AT INNER HAIR CELLS IN MOUSE

小鼠内毛细胞传入神经支配的超微结构

• 批准号: 7601038
• 负责人: Howard W Francis
• 金额: $ 1.3万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7601038
• 关键词: Accounting; Acoustic Nerve; Animal Model; Animals; Binding; Chromosome Pairing; Cochlea; Computer Retrieval of Information on Scientific Projects Database; Depth; Felis catus; Funding; Grant; Hearing; Inner Hair Cells; Institution; Membrane; Mitochondria; Morphology; Mus; Nerve; Nerve Fibers; Organelles; Physiology; Presynaptic Terminals; Research; Research Personnel; Resources; Role; Site; Source; Structure; Synapses; Synaptic Membranes; Synaptic Transmission; Transducers; United States National Institutes of Health; Vesicle; electron tomography; insight; nerve supply; novel; sound; spatial relationship; three dimensional structure

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The structure and underlying physiology of afferent innervation in the mammalian cochlea is only partially understood in cat and is essentially unknown in mouse. The increasing importance of mouse as an animal model in hearing research necessitates a more detailed analysis of the critical synaptic interface between the inner hair cell (IHC), the transducer of sound, and auditory nerve fibers. Preliminary studies of afferent terminal and synaptic ultrastructure at this interface in the C57BL/6J mouse have revealed two morphologically distinct groups of afferent endings. One of these endings is a conventional bouton, whereas the other has novel morphological features including the presence of a deep sulcus apparently created by the invagination of the outer membrane. This ending has been called the folded ending and accounts for about a half of the terminals that form afferent synapses with IHCs at 8, 16 and 32 kHz sites. This morphology has been observed in 3 out of 4 C57BL/6J mice studied so far. We propose a study in which electron tomography is used to elucidate the 3-dimensional structure of the sulcus in folded terminals and particularly its relationship to the outer membrane of the nerve terminal. The sulcus partially compartmentalizes the terminal and appears to sequester mitochondria and other organelles. Electron tomography would be helpful in providing insight into the functional role of this unusual structure. We propose to examine the spatial relationships between components of the afferent synapse including the pre-synaptic body, and vesicles bound to both the pre-synaptic membrane and ribbon. This study will provide valuable information about the synaptic machinery and would find immediate use in on-going studies of afferent synaptic transmission in this animal.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此，可以在其他清晰的条目中表示。列出的机构是 对于中心，这不一定是调查员的机构。 哺乳动物耳蜗中传入神经的结构和潜在生理学仅在CAT中得到部分理解，并且在小鼠中基本上未知。小鼠作为动物模型在听力研究中的重要性越来越重要，需要对内毛细胞（IHC），声音传感器和听觉神经纤维之间的关键突触界面进行更详细的分析。在C57BL/6J小鼠中，该界面处的传入末端和突触超微结构的初步研究表明，两个形态上不同的传入结尾。这些结局之一是一种常规的布顿，而另一个具有新颖的形态学特征，包括显然是由于外膜的内陷而产生的深沟。该结尾称为折叠结尾，约占在8、16和32 kHz位点与IHC形成传入突触的终端的一半。到目前为止，在4个C57BL/6J小鼠中，已经观察到了这种形态。我们提出了一项研究，其中使用电子断层扫描来阐明折叠末端中沟的3维结构，尤其是其与神经末端外膜的关系。沟部分分裂为末端，并似乎隔离线粒体和其他细胞器。电子断层扫描将有助于提供对这种异常结构的功能作用的见解。 我们建议检查传入突触的组成部分之间的空间关系，包括突触前体，以及与突触前膜和色带结合的囊泡。这项研究将提供有关突触机械的有价值的信息，并将在正在进行的该动物传入突触传播的研究中立即使用。