EFFECTS OF CELL CULTURE TRANSPLANTS ON CNS REGENERATION

虽然功能再生发生在外周 神经病变，到目前为止，它还没有能够促进临床 在成年哺乳动物中枢神经系统中， 神经系统（CNS）。 因此，本研究的主要重点 一项建议是分析各种细胞和分子成分， 周围神经环境，以确定因素 促进PNS和CNS神经元轴突生长。 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，细胞和分子成分 与未成熟的CNS神经胶质细胞（星形胶质细胞）相关的神经胶质细胞也将被 评估它们促进轴突生长的能力。 两个基本 这些研究将采用实验方法。 一是在 体外隔膜外植体将在部分限定的或 条件培养基上的各种基质组成的胶质细胞 细胞层（星形胶质细胞和雪旺细胞）或细胞外基质 分子，以确定促进细胞增殖的培养条件。 神经突生长 第二，这些体外环境， 从未成熟的隔外植体神经元的神经突生长将是 适于移植到成年啮齿动物的CNS中， 确定增强神经突生长的制剂是否 培养也能促进成熟隔胆碱能神经再生， 体内神经元 这些实验将专门评估 是否：1）CNS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，和3）细胞外基质（ECM）的成分 促进再生。 一旦单个细胞成分 被确定为促进轴突生长，然后是最后一系列的 实验将评估ECM的组合是否 成分、扩散因子和/或膜相关 分子是促进最佳CNS再生所必需的。 免疫细胞化学程序将用于识别特定的 细胞表型如星形胶质细胞、雪旺细胞和胆碱能细胞 神经元和定位不同的分子成分， 培养和移植基质。 各种神经解剖学 技术将用于追踪轴突投射和用于 鉴定CNS内再生轴突的来源。 拟定体外外植体研究和体内研究的结果 移植实验将有助于描述特定的 细胞成分和细胞外基质成分， 可以刺激成年人受伤后的再生， 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.