ULTRASTRUCTURAL BASIS FOR SYNAPTIC VESICLE RECYCLING IN CALYX OF HELD

持有花萼突触小泡回收的超微结构基础

• 批准号: 7957592
• 负责人: GEORGE A SPIROU
• 金额: $ 1.56万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-15 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7957592
• 关键词: Area; Auditory; Brain Stem; Cell Nucleus; Cells; Characteristics; Communication; Complex; Computer Retrieval of Information on Scientific Projects Database; Elements; Filament; Funding; Goals; Grant; Growth Cones; Image; Image Analysis; Institution; Laboratories; Link; Medial; Mitochondria; Mono-S; Mus; Nerve; Organelles; Postsynaptic Membrane; Recycling; Research; Research Personnel; Resolution; Resources; Shapes; Sound Localization; Source; Staging; Structure; Synapses; Synaptic Vesicles; Time; Transmission Electron Microscopy; United States National Institutes of Health; Work; base; digital; electron tomography; fluorescence imaging; metaplastic cell transformation; nerve supply; neuronal cell body; neurotransmission; postnatal; postsynaptic; presynaptic; reconstruction; research study; trapezoid body

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 calyx of Held and other large nerve terminals of the auditory brainstem are key elements of sound localization circuitry. Our goal is to reveal structural transformations and cellular communication that characterize contact of the calycigenic growth cone with its target and the early stages of synapse assembly and stabilization at large nerve terminals in the auditory brainstem. Our central hypothesis is that competition among calycigenic inputs precedes expansion of the terminal over the cell body to form a calyx. This hypothesis is based on work from our laboratory that reveals rapid formation of the calyx in mice between postnatal days (P)2 and P4. The calyx contains hundreds to greater than two thousand active zones, depending upon the species, many of which are located nearby specialized organelle complexes termed mitochondrion-associated adherens complexes (MACs). MAC structure had been described previously using standard transmission electron microscopy (sTEM), which revealed filaments tethering the mitochondrion to a punctum adherens that links the pre- and postsynaptic membranes. Confocal fluorescence imaging and electron tomography are being employed to study medial nucleus of the trapezoid body (MNTB) cell innervation during P0P4. This time period precedes and overlaps the formation of immature, cup-shaped calyces that envelop the MNTB cell body. These experiments will pinpoint time periods during which mono-innervation is established between pre- and postsynaptic partners and highlight structural and functional differences that may predict winning and losing inputs. In addition, we will describe structural features of mature calyces that support high-rate neurotransmission that is characteristic of this terminal. Because of the size of the calyx-MNTB contact and the desired high resolution of the reconstructions, serial volumetric imaging of domains of cells will be required. This project will require high-resolution, wide-field, large-area digital recording of images.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目及 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 耳萼和听觉脑干的其他大神经末梢是声音定位电路的关键元件。我们的目标是揭示结构转变和细胞通讯，这些结构转变和细胞通讯表征了致胆生长锥与其目标的接触，以及听觉脑干大神经末梢突触组装和稳定的早期阶段。我们的中心假设是，花萼输入之间的竞争先于细胞体末端扩张形成花萼。这一假设基于我们实验室的工作，该工作揭示了小鼠出生后 (P)2 和 P4 之间花萼的快速形成。根据物种的不同，花萼包含数百到两千多个活性区，其中许多位于称为线粒体相关粘附复合体（MAC）的特殊细胞器复合体附近。先前使用标准透射电子显微镜（sTEM）描述了 MAC 结构，它揭示了将线粒体束缚到连接突触前膜和突触后膜的泪点粘附物上的细丝。 共焦荧光成像和电子断层扫描正在用于研究 P0 P4 期间梯形体内侧核 (MNTB) 细胞的神经支配。这个时间段先于包围 MNTB 细胞体的未成熟杯状肾盏的形成，并与其重叠。这些实验将查明突触前和突触后伙伴之间建立单神经支配的时间段，并突出可能预测获胜和失败输入的结构和功能差异。此外，我们将描述成熟肾盏的结构特征，这些特征支持高速神经传递，这是该终端的特征。由于花萼-MNTB 接触的大小和重建所需的高分辨率，需要对细胞域进行连续体积成像。该项目需要高分辨率、宽视场、大面积的数字图像记录。