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 培养过程中对耳蜗组织的机械性损伤及其影响因素 这导致了它们的形态恢复。鉴于缺乏公开的 有证据证明哺乳动物的科尔蒂器官能够形成新的 感觉细胞，考虑到这些细胞很少，而且可能是 一生只形成一次，研究的意义在于 了解受体细胞存活和恢复的机制 受伤后。 具体地说，我们建议研究：1)创伤后细胞增殖 在Corti器官中：a)损伤后的有丝分裂细胞增殖 培养物将用~3H胸腺嘧啶核苷进行检查，以确定其身份 分裂细胞，有丝分裂反应的持续时间和年龄- 与细胞分裂有关的发生；B)非有丝分裂细胞增殖， 通过支持细胞的广泛萌发来表达，将是 研究可能的可扩散生长因子(NGF、EGF、 成纤维细胞生长因子)由细胞对直接损伤或损伤作出反应 感觉细胞。2)损伤感觉细胞的再生； 尤其是角质板和立体纤毛的改建。 这项研究将围绕再生细胞的形态序列展开 现象，它与正常发展的比较，以及 年龄对感觉细胞再生能力的影响。3)退化和退化 螺旋神经元的再生，其末端的萌发(使用 抗GAP-43和NF蛋白的抗体)，并形成新的条带 突触。 这项研究将使用小鼠的短期和长期培养进行 科尔蒂风琴。损伤将用手完成，使用拉动的- 玻璃吸管或激光。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。 一些专门的免疫学检测将与 菲利普·勒菲布雷博士，比利时列日大学。

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.