REGENERATIVE PHENOMENA IN THE DEVELOPING ORGAN OF CORTI

拟议研究的长期目标是了解 感觉和神经细胞的再生过程， 机械损伤的耳蜗培养，并确定因素 导致了它们的形态恢复。鉴于缺乏公开的 证明哺乳动物的Corti器官能够形成新的 感觉细胞，并考虑到这些细胞很少， 一生只形成一次，研究意义在于 了解受体细胞的存活和恢复机制 伤后 具体而言，我们拟研究：1）创伤后细胞增殖 Corti器官：A）受损组织中有丝分裂细胞增殖 将使用3 H胸苷检查培养物，以研究同一性 有丝分裂反应的持续时间和年龄- 细胞分裂的相关发生; B）非有丝分裂细胞增殖， 通过支持细胞的广泛发芽来表达， 研究寻找可能的扩散性生长因子（NGF，EGF， FGF）由细胞响应于直接损伤或损伤而释放 的感觉细胞。2)受损感觉细胞的再生， 特别是表皮板和静纤毛的重建。 这项研究将包括再生的形态序列， 现象，与正常发展的比较，以及 年龄对感觉细胞再生能力的影响。3)变性和 螺旋神经元的再生，其末端的发芽（使用 GAP-43和NF蛋白的抗体），以及新条带的形成 突触 该研究将使用小鼠的短期和长期培养物进行 Corti器官伤害将由手完成，使用一个拉- 玻璃移液管或激光。光学和电子显微镜， 将采用放射自显影、生物化学和免疫细胞化学。 一些专门的免疫测定将与 博士比利时列日大学菲利普列费夫尔。

The long-term goal of the proposed research is to gain understanding of the process of regeneration of sensory and nerve cells following mechanical injury to the cochlea in culture, and to define the factors that lead to their morphological recovery. In light of the lack of overt evidence proving that the mammalian organ of Corti is able to form new sensory cells, and given the fact that these cells are few and may be formed only once in a life span the significance of the research lies in understanding the mechanism of survival and recovery of receptor cells after injury. Specifically, we propose to study: 1) Post-traumatic cell proliferation in the organ of Corti: A) Mitotic cell proliferation in the injured cultures will be examined using 3H thymidine to investigate the identity of dividing cells, the duration of the mitotic response and the age- related occurrence of cell division; B) Nonmitotic cell proliferation, expressed by extensive sprouting of supporting cells, will be investigated in search of possible diffusable growth factors (NGF, EGF, FGF) released by the cells in response to direct injury or to the injury of sensory cells. 2) Regeneration of the injured sensory cells, especially the reformation of their cuticular plates and stereocilia. The study will encompass the morphological sequence of the regenerative phenomena, its comparison with normal development, and the influence of age on the regenerative capacity of sensory cells. 3) Degeneration and regeneration of spiral neurons, sprouting of their endings (using antibodies to GAP-43 and NF proteins), and formation of new ribbon synapses. The study will be done using short- and long-term cultures of the mouse organ of Corti. The injury will be done by hand, using either a pulled- glass pipettes or a laser. Light and electron microscopy, autoradiography, biochemistry and immunocytochemistry will be employed. Some specialized immunological assays will be done in collaboration with Dr. Philippe Lefebvre, University de Liege, Belgium.