Axonal Pathfinding in the Developing Retina

9511298 Halfter在早期胚胎发育过程中，轴突突连接神经系统的不同部分。其中一种轴突连接是视觉通路，它通过视轴突在功能上连接眼睛和大脑。产生视神经轴突的细胞是视网膜的神经节细胞。视轴突到达大脑的先决条件是导航到视盘，视盘是视网膜的一个小中心部分，允许轴突离开眼睛。轴突导航到其目标（如视盘）的机制在很大程度上是未知的。这项拨款提案旨在研究在发育过程中参与轴突导航的分子和其他因素。移植实验将进行，以了解更多的一般机制轴突引导在眼睛。生物化学研究的目的是识别可能在轴突通路形成中起重要作用的分子。其中一种分子是硫酸软骨素蛋白多糖。这种蛋白多糖在一定时间内存在，其分布与视神经轴突的外观和分布完全吻合，这表明该成分在轴突束的发育中起作用。在本项目中，将研究蛋白聚糖的分子特性及其在发育中的视觉系统中的功能。这项研究的结果将促进对发育过程中指导神经连接的机制的更深层次的理解。

9511298 Halfter During early embryonic development axonal processes connect the different parts of the nervous system. One such axonal connection is the visual pathway that functionally connects the eye with the brain by optic axons. The cells that generate the optic axons are the ganglion cells of the retina. A prerequisite for optic axons to reach the brain is to navigate to the optic disc, a small central segment of the retina that allows the axons to exit the eye. The mechanisms underlying the navigation of axons to their target, such as the optic disc, are largely unknown. This grant proposal is aimed at studying molecules and other factors involved in the navigation of axons during development. Transplantation experiments will be performed to learn more about the general mechanisms of axonal guidance in the eye. Biochemical studies are aimed at identifying molecules that might be important in the formation of axonal pathways. One such molecule is a chondroitin sulfate proteoglycan. This proteoglycan is present at a time and with a distribution that matches exactly the appearance and distribution of optic axons suggesting that the component has a function in the development of this axonal tract. In the present project, the molecular identity of the proteoglycan and its function in the developing visual system will be studied. The results of this research will promote a deeper understanding of the mechanisms that guide neural connections during development.