EFFECTS OF CELL CULTURE TRANSPLANTS ON CNS REGENERATION

最近的研究引起了人们的极大兴趣， 利用移植来促进受伤的轴突再生， 成年哺乳动物中枢神经系统（CNS）。 然而，目前 已知的细胞来源的积极轴突生长促进 似乎存在于外周神经或胚胎CNS中的因子 组织. 因此，拟议研究的长期目标是 鉴定和表征促进轴突再生因子， 成年哺乳动物中枢神经系统中受损的神经元。 实验范例， 用于拟议的研究是移植各种 细胞和非细胞基质进入双侧脑内腔， 所有的轴突连接都被切断， 海马体。 将使用四种实验性移植制剂：1） 在组织培养物中制备的特异性非神经元PNS或CNS细胞，2） 对照无细胞基质，3）完整的CNS或PNS神经，和4） 细胞外基质分子 这些实验的具体目的是 重点是确定移植环境对以下方面的影响：1） 轴突再生率，2）产生轴突的神经元类型，3） 促进轴突再生的特定细胞和/或分子，以及4） 再生轴突与细胞间的形态学关系 移植的地形。 将使用几种光学显微镜神经解剖学程序， 识别和追踪移植物和宿主之间的轴突连接 CNS。 这些将包括逆行追踪程序（荧光染料 和辣根过氧化物酶），顺行追踪技术 （放射自显影，辣根过氧化物酶，神经原纤维和髓鞘 染色），用于鉴定特定轴突类型的组织化学方案 （儿茶酚胺组织荧光和乙酰胆碱酯酶组织化学）， 免疫组织化学染色技术用于鉴定所选细胞 主要成分（层粘连蛋白、纤连蛋白、胶质细胞酸性蛋白、髓鞘 碱性蛋白质、血清素和C-4）。 此外，这些实验， 分析移植物和移植宿主中的细胞事件 接口将利用透射电子显微镜。 拟议研究的结果将为以下方面提供重要见解： 促进轴突再生的细胞因子和细胞外因子 在成年哺乳动物的中枢神经系统中。 这些轴突生长的特征 促进因素应该证明有利于开发治疗方法， 治疗人的创伤性脑和脊髓损伤。

Considerable interest has been generated by recent studies which have utilized transplants to facilitate the regeneration of axons in the injured adult mammalian central nervous system (CNS). However, little is currently known about the cellular sources of the positive axonal growth promoting factors that appear to be present in peripheral nerve or embryonic CNS tissue. Thus, the long-term objectives of the proposed research are to identify and characterize factors which promote axonal regeneration from injured neurons in the adult mammalian CNS. The experimental paradigm to be used for the proposed studies is the transplantation of a variety of cellular and acellular substrates into bilateral intracephalic cavities in which all axonal connections are severed between the septum and hippocampus. Four experimental transplant preparations will be used: 1) specific non-neuronal PNS or CNS cells prepared in tissue culture, 2) control acellular substrates, 3) intact CNS or PNS nerves, and 4) extracellular matrix molecules. The specific aims of these experiments are focused to determine the effects of the transplant environments on: 1) the rate of axonal regrowth, 2) the types of neurons generating axons, 3) specific cells and/or molecules which promote axonal regeneration, and 4) the morphological relationship between regenerating axons and the cellular terrain of the transplant. Several light microscopic neuroanatomical procedures will be utilized for identifying and tracing axonal connections between the transplant and host CNS. These will include retrograde tracing procedures (fluorescent dyes and horseradish peroxidase), anterograde tracing techniques (autoradiography, horseradish peroxidase, neurofibrillar and myelin stains), histochemical protocols for identifying specific axon types (catecholamine histofluorescence and acetylcholinesterase histochemistry), and immunohistochemical staining techniques for identifying selected cell components (laminin, fibronectin, glial fibrillary acidic protein, myelin basic protein, serotonin and C-4). In addition, those experiments which analyze cellular events in the transplant and at the transplant-host interface will utilize transmission electron microscopy. The results from the proposed research will provide important insight into the cellular and extracellular factors that can promote axonal regeneration in the adult mammalian CNS. The characterization of these axonal growth promoting factors should prove beneficial for developing therapies for treating traumatic brain and spinal cord injuries in man.