SYNAPTIC ORGANIZATION OF THE OPTIC TECTUM

视顶盖的突触组织

• 批准号: 3255680
• 负责人: JOHN A FREEMAN
• 金额: $ 26.39万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-03-01 至 1992-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3255680
• 关键词: Anura; axon; biophysics; calcium; chemical fingerprinting; electron microscopy; electrophoresis; electrophysiology; fresh water environment; goldfish; growth cones; histochemistry /cytochemistry; interneurons; laboratory rat; membrane channels; membrane permeability; membrane proteins; nervous system regeneration; neural information processing; neuroanatomy; neurochemistry; neurogenesis; neuronal guidance; neuronal transport; neurophysiology; optic nerve; phosphorylation; radioassay; retinal ganglion; synapses; tissue /cell culture

The principal objective of the proposed research is to identify and characterize some critical cellular mechamisms controlling the growth of optic nerve fibers and the formation of retinotectal synapses. There are four major goals. The first is to investigate the role of calcium in growth of retinal ganglion cells. We have recently discovered that retinal neurite growth cones generate steady Ca2+ currents across their tips, and grow in the direction of an applied field. We plan to measure calcium dynamics in the growth cones of retinal ganglion cells of goldfish, frogs, and rates in culture using a calcium sensitive dye and a new fast digital imaging camera. Using vibrating probe and patch clamp recordings to examine macroscopic and microscopic ion currents, we will determin whether variations in intraterminal calcium levels affect the conductrances of other ion channels; and, using video-enhanced microscopy, we will determine whether this variation is associated with morphological changes in the growth cone and with changes in the rate of growth. The second goal is to examine the effect of electric fields on the growth of optic nerve fibers. We plan to determine the effects of fields on the rate of growth of retinal ganglion cell axons, and to correlate this with changes in the rate of axoplasmic transport and with changes in the calcium dynamics of growth cones. The third goal is to examine synaptic interactions between retinal ganglion cell terminals and tectal interneurons. We will employ voltage sensitive dyes to determine detailed synaptic interactions between developing and regenerating retinal ganglion cells and interneurons in the tectum, including the isthmo-tectal input, which appears to modulate retinotectal synaptogenesis. We will use a new method to examine changes in the expression of specific proteins that occur during retinoctectal synaptogenesis in single isolated tectal neurons. These studies should provide detailed insights into molecular mechamisms that determine how and where retinal neurites grow, and how specific connections form between different cells in the visual system. This information is of paramount importance in understanding the normal development and function of the visual system, as well as its response to injury.

拟议研究的主要目标是确定和 描述了一些关键的细胞机制， 视神经纤维的生长和视网膜顶盖的形成 突触 有四个主要目标。 一是调查 钙离子在视网膜神经节细胞生长中的作用 我们有 最近发现视网膜神经突生长锥产生 稳定的Ca 2+电流穿过它们的尖端，并朝着 一个应用领域。 我们计划测量 金鱼、青蛙和大鼠视网膜神经节细胞的生长锥 在培养中使用钙敏感染料和新的快速数字 成像相机 使用振动探针和膜片钳 记录以检查宏观和微观离子电流， we will determine确定whether是否variations变化in intraterminal内calcium钙 水平影响其他离子通道的电导率;并且，使用 视频增强显微镜，我们将确定这是否 变异与生长过程中的形态变化有关 锥和增长率的变化。 第二个目标是 研究电场对光学晶体生长的影响， 神经纤维 我们计划确定磁场对 视网膜神经节细胞轴突的生长速率，并将其与 轴浆运输速率的变化， 在生长锥的钙动力学中。 第三个目标是 检查视网膜神经节细胞之间的突触相互作用 终末和顶盖中间神经元。 我们将使用电压 敏感的染料来确定详细的突触相互作用 视网膜神经节细胞的发育和再生之间的关系， 顶盖中的中间神经元，包括峡-顶盖输入， 它似乎调节视网膜顶盖突触发生。 我们将 使用一种新的方法来检查 在视网膜顶盖突触发生过程中发生的特异性蛋白质， 单个分离的顶盖神经元。 这些研究将提供 对分子机制的详细了解， 视网膜神经突在哪里生长， 在视觉系统的不同细胞之间形成。 这 信息对于理解 视觉系统的正常发育和功能，以及 对伤害的反应。