EFFECTS OF CELL CULTURE TRANSPLANTS ON CNS REGENERATION

尽管功能再生发生在外周 神经损伤，到目前为止，还不可能在临床上推广 成年哺乳动物中央脑内显著的轴突再生 神经系统(CNS)。因此，这项研究的主要重点是 建议是分析各种细胞和分子成分 对周围神经环境进行分析以确定影响因素 促进三叉神经节和中枢神经系统神经元的轴突生长。 由于未成熟的中枢神经系统能够表现出相当大的 损伤后的可塑性、细胞和分子组成 与未成熟的中枢神经胶质细胞(星形胶质细胞)相关的也将是 评估他们促进轴突生长的能力。两个基本要素 这些研究将使用实验程序。首先，在 体外隔膜外植体将在部分限定的或 在由胶质细胞组成的各种基质上的条件培养液 细胞层(星形胶质细胞和雪旺细胞)或细胞外基质 分子，以便确定促进 轴突生长。第二，那些在体外环境中促进 未成熟的隔膜外植体神经元的轴突生长将 适应于成年啮齿动物的中枢神经系统移植，以进一步 确定促进神经突起生长的制剂是否 培养也能促进成熟隔区胆碱能神经元的再生 活体中的神经元。这些实验将专门评估 是否：1)中枢神经轴突生长由膜介导 相关分子，2)细胞分泌的扩散因子增强 轴突生长；3)细胞外基质(ECM)成分 促进再生。一旦单个蜂窝组件具有 被确认为促进轴突生长，然后是最后一系列 实验将评估ECM的组合是否 相关成分、扩散因子和/或膜 分子是促进中枢神经系统最佳再生所必需的。 将使用免疫细胞化学程序来识别特定的 星形胶质细胞、雪旺细胞和胆碱能细胞等细胞表型 神经元和定位不同分子组成的神经元 培养和移植底物。各种神经解剖学 将采用追踪轴突投射的技术，并 确定中枢神经系统内再生轴突的来源。 建议的体外和体内外植体研究的结果 移植实验将有助于确定特定的 细胞成分和细胞外基质成分 可以刺激成人受伤后的再生 哺乳动物的大脑和脊髓。

Although functional regeneration occurs following peripheral nerve lesions, as yet, it has not been possible to promote clinically significant axonal regeneration in the adult mammalian central nervous system (CNS). Thus, the major emphasis of this research proposal is to analyze various cellular and molecular components of the peripheral nerve environment in order to identify factors that facilitate axonal growth for both PNS and CNS neurons. Since the immature CNS is capable of exhibiting considerable plasticity following injury, cellular and molecular components associated with immature CNS glia (astrocytes) also will be evaluated for their ability to foster axonal growth. Two basic experimental procedures will be used for these studies. First, in vitro septal explants will be grown in partially defined or conditioned media on a variety of substrates composed of glial cell layers (astrocytes and Schwann cells) or extracellular matrix molecules in order to identify culture conditions that facilitate neurite growth. Second, those in vitro environments that promote neurite growth from immature septal explant neurons will be adapted for transplantation in the CNS of adult rodents to further determine whether preparation that enhance neurite growth in culture also enhances regeneration from mature septal cholinergic neurons in vivo. These experiments will specifically evaluate whether: 1) CNS axonal growth is mediated by membrane associated molecules, 2) cell secreted diffusible factors enhance axon growth, and 3) components of the extracellular matrix (ECM) promote regeneration. Once individual cellular components have been identified as promoting axonal growth, then a final series of experiments will evaluate whether a combination of ECM components, diffusible factors and/or membrane associated molecules are necessary to promote optimal CNS regeneration. Immunocytochemical procedures will be used to identify specific cell phenotypes such as astrocytes, Schwann cells and cholinergic neurons and for localizing different molecular components in the culture and transplant substrates. A variety of neuroanatomical techniques will be employed for tracing axonal projections and for identifying the source of regenerating axons within the CNS. Results from the proposed in vitro explant studies and in vivo transplantation experiments will help characterize specific cellular components and extracellular matrix constituents that can stimulate regeneration following injury to the adult mammalian brain and spinal cord.