Cellular and molecular mechanisms of peripheral sensory neuron regeneration

描述（由申请人提供）：由于疾病或创伤导致的周围神经变性可导致永久性虚弱、麻木或慢性疼痛的严重残疾。更好地了解外周轴突再生和神经再支配的细胞和分子机制可能会导致改善治疗策略。本研究以斑马鱼三叉神经元为模型，描述了一种切断单个轴突并直接观察外周靶神经再支配的细胞动力学的方法。该技术用于定量表征在几个发育阶段的野生型再生。拟议的研究的总体目标是确定参与外周靶点神经再支配的细胞和分子机制。野生型动物中神经再支配的表征将作为比较各种斑马鱼突变体和药物治疗的效果的基线。这项工作可能会发现新的分子靶点，可用于治疗目的，在人类周围神经病变。该项目的具体目标概述如下。目的1）通过明确Rho通路在何时、何地以及如何介导神经再支配抑制来研究单个损伤轴突中的细胞内信号传导。目的2）利用斑马鱼突变体和药物操作来鉴定调节神经再支配能力的外在因素。这一目标特别关注吞噬细胞，外周神经胶质细胞，细胞外基质成分和炎症反应的作用。

DESCRIPTION (provided by applicant): Peripheral nerve degeneration due to disease or trauma can result in serious disability from permanent weakness, numbness or chronic pain. A better understanding of the cellular and molecular mechanisms of peripheral axon regeneration and reinnervation may lead to improved treatment strategies. This proposal describes a method to transect individual axons and directly observe the cellular dynamics of peripheral target reinnervation in vivo, using zebrafish trigeminal neurons as a model. This technique was used to quantitatively characterize wildtype regeneration at several developmental stages. The overall objective of the proposed research is to define the cellular and molecular mechanisms involved in reinnervation of peripheral targets. The characterization of reinnervation in wildtype animals will serve as a baseline to compare the effects of various zebrafish mutants and pharmacological treatments. This work may identify novel molecular targets that can be exploited for therapeutic purposes in peripheral neuropathy in humans. The specific goals of the project are outlined below. Aim 1) To investigate intracellular signaling in individual injured axons by specifically determining when, where, and how the Rho pathway acts to mediate inhibition of reinnervation. Aim 2) To identify extrinsic factors that modulate the capacity for reinnervation using zebrafish mutants and pharmacological manipulations. This aim specifically focuses on the role of phagocytic cells, peripheral glia, the extra cellular matrix components, and the inflammatory response.