Expression of nerve construction protein in developing and regenerating auditory organ

神经细胞黏附分子(NCAM)在发育中的组织中是高度多唾液酸化的(NCAM-H)，最近的研究表明NCAM-H比低唾液酸化的NCAM(L)更重要。为了解NCAM-H、NGF和MAP-2在内耳发育、成体和再生中的确切作用，应用免疫组织化学方法检测了NCAM-H、NGF和MAP-2在内耳发育、成体和再生中的定位。NGF和NCAM-H的免疫反应最初在听神经节细胞上观察到，当传入纤维开始从神经节细胞中冒出时。当突触传入毛细胞时，在听上皮的神经纤维和毛细胞底部可见NGF和NCAM-H。在成体毛细胞，NCAM-H消失。在成熟毛细胞和再生毛细胞上观察到MAP-2的免疫反应，这与NCAM-H特异性调节内耳发育过程中传入神经纤维的生长和与毛细胞的突触发生的假设一致，MAP-2可能与听觉信息处理和神经可塑性有关。

Neural cell adhesion molecule (NCAM) is highly polysialylated (NCAM-H) in developing tissues, and recent findings suggest that NCAM-H is more essential development than poorly sialylated NCAM (NCAM-L). In order to understand the precise role of NCAM-H, NGF and MAP-2 in developing, adult and regenerating inner ear, the immunohistochemical localization of NCAM-H, NGF and MAP-2 was examined using a monoclonal antibody. Immunoreaction of NGF and NCAM-H were initially observed on acoustic ganglion cells, when afferent fibers begin to emerge from the ganglion cells. When afferent fibers from synapses with hair cells, NGF and NCAM-H were observed on nerve fibers and the base of hair cells in auditory epithelium. At the adult hair cells, NCAM-H was disappeared. Imunoreaction of MAP-2 were observed on matured hair cells and regenerated hair cells.These date are consisted with the hypothesis that NCAM-H specifically regulates the afferent nerve fiber growth and synaptogenesis with hair cells during inner ear development, and MAP-2 may be associated with processing auditory information and neural plasticity.