FACTORS AFFECTING REGENERATION THRU THE GLIAL SCAR

描述：（改编自申请人的摘要。）中的实验 该建议试图比较和对比细胞和分子 星形胶质细胞可能抑制两种细胞中轴突生长的机制 脊髓区域：1）顶板，这是一个短暂的 在发育过程中与背柱轴突的边界和2） 背根进入区，形成传入神经进入 中枢神经系统在发育过程中，但成为边界的背根传入 出生后的再生 申请人及其同事计划 将背柱的发育与后来的形成联系起来， 背连合与中线胶质细胞的形态发生和与 角蛋白最初存在和随后消失 硫酸/硫酸软骨素糖胺聚糖，推定的边界分子 它们在这个地区的分布。 屋顶的酶消化 在体外切片制备中平板GAG将测试背侧是否 柱状轴突异常地穿过中线。 对于DREZ的研究，他们计划首先描述正常的 CNS/PNS界面的细胞和基底层元件， 在轴突向内生长进入神经元的过程中表达的分子， 脊髓 然后，他们将这些成分与 DREZ在动物的挤压伤的根，以确定是否机械 或化学因素可能导致该区域的再生失败。 初步研究表明在正常的神经胶质屏障中发现了糖胺聚糖 如屋顶板出现在反应性胶质细胞以下的根病变。 的 顶板和受损DREZ的假定星形胶质细胞边界分子 将在体外试验系统中进行研究， 将受到假定途径和边界细胞组合的挑战 或各种几何图案的分子。

DESCRIPTION: (Adapted from the Applicant's Abstract.) The experiments in this proposal seek to compare and contrast the cellular and molecular mechanisms by which astroglia may inhibit the growth of axons in two regions of the spinal cord: 1) the roof plate, which is a transient boundary to dorsal column axons during development and 2) the glial dome of the dorsal root entry zone, which forms a doorway for afferents into the CNS during development but becomes a boundary to dorsal root afferent regeneration after birth. The applicant and his colleagues plan to correlate the development of the dorsal columns and the later forming dorsal commissure with morphogenesis of the midline glia and with the initial presence and subsequent disappearance of keratin sulfate/chondroitin sulfate glycosaminoglycans, putative boundary molecules that they have localized in this region. Enzyme digestion of the roof plate GAG's in an in vitro slice preparation will test whether dorsal column axons aberrantly cross the midline. For the studies on the DREZ, they plan first to describe the normal cellular and basal lamina elements at the CNS/PNS interface and the molecules that are expressed during the period of axonal ingrowth into the spinal cord. They will then compare these constituents with those of the DREZ in animals with crush injuries of the roots to determine if mechanical or chemical factors may contribute to regenerative failure in this region. Preliminary studies have shown that GAG's found in normal glial barriers such as the roof plate appear in reactive glia following root lesions. The putative astroglial boundary molecules of the roof plate and lesioned DREZ will be investigated in an in vitro assay system where the growing axons will be challenged with combination of putative pathway and boundary cells or molecules in various geometric patterns.