AXON TARGET INTERACTIONS IN SENSORY MAP FORMATION

这项提议涉及到有关形成 哺乳动物大脑中的感觉图谱。建议进行实验，以整理 生长轴突所固有的因素的作用与这些因素的作用 从他们所处的环境中衍生出一个体外模型系统。 啮齿动物的三叉神经系统是一种高度专业化的感觉系统；它是 以轴突和神经元的特殊排列为特征的 它们与感觉受体(周围)的分布是同形的 胡须)在鼻子上。感官受体的图案化分布， 或感觉图，由初级感觉神经元传递到大脑 它们位于三叉神经节。在这项提案中，处于萌芽状态 三叉神经节将与多种外周靶点共培养 组织和中枢神经系统外植体。这是最近开发的 将使用技术方法来实验测试目标的作用- 衍生的影响，如细胞和底物黏附分子，神经胶质 目标组织内的组织，可能嵌入的位置线索 目标，以及在目标中制造的增长因素 揭示轴突-靶相互作用的许多未知方面，从而导致 大脑中感觉图的形成。 了解细胞和分子机制的基础 神经通路的形成及其束和束内的空间秩序 终末区是发育神经生物学的一项主要工作。是这样的 知识对我们修复损伤的能力有很大的影响 大脑的特定感觉通路。

This proposal addresses fundamental issues regarding the formation of sensory maps in the mammalian brain. Experiments are proposed to sort out the role of factors that are Intrinsic to growing axons vs. of those derived from their environment in a model in vitro system. The rodent trigeminal system is a highly specialized sensory system; it is characterized by a specific arrangement of axonal and neuronal elements which are homeomorphic to the distribution of sensory receptors (around whiskers) on the snout. The patterned distribution of sensory receptors, or the sensory map, is conveyed to the brain by primary sensory neurons which reside in the trigeminal ganglion. In this proposal, embryonic trigeminal ganglia will be co-cultured with a variety of peripheral target tissue and central nervous system explants. This recently developed technical approach will be used to experimentally test the role of target- derived influences, such as cell and substrate adhesion molecules, glial organization within target tissues, possible positional cues embedded in the target, and of growth factors that are manufactured in the targets to reveal many unknown facets of axon-target interactions which lead to the formation of sensory maps in the brain. Understanding cellular and molecular mechanisms which underlie the formation of neural pathways and the spatial order within their tracts and terminal zones is a major endeavor in developmental neurobiology. Such knowledge has powerful implications for our ability to repair damage in specific sensory pathways of the brain.