Vestibular Hair Cell Regeneration

项目描述（由申请人提供）：本项目旨在研究成体龙猫（前庭研究的著名模型）内耳手术注射庆大霉素（GM）后水平前庭嵴毛细胞恢复的形态学、生理学和分子机制。实验方案设计的假设是，转基因的影响是剂量和区域依赖的，有效耳毒性剂量有三倍的差异，I型毛细胞比II型毛细胞更敏感。在I型毛细胞中，也存在与它们在不同嵴区的位置有关的差异。当每种类型的毛细胞在特定的致耳毒性范围内接受剂量治疗时，就会发生不同毛细胞的自发再生。具体目的包括以下研究：1)研究四种药效学选择剂量转基因后感觉细胞和神经元的损伤和再生的时间过程；2)平行测量前庭眼反射（VOR）功能和单个前庭神经纤维生理反应的变化，与解剖变化进行比较；3) BDNF、FGF-2及其联合在VOR和毛细胞中潜在的保护性神经营养因子作用的研究。解剖和生理变化将在基于解剖和生理原理和初步研究结果的病理-生理嵴模型的背景下进行评估。应用的技术包括组织学、免疫组织化学、荧光和共聚焦显微镜、计算机测量和一种新的无创动物前庭眼成像技术用于VOR功能测试和电生理单纤维记录方法。经过十多年的研究，哺乳动物前庭毛细胞的解剖和功能再生能力的控制仍未得到解决。然而，我们的初步结果提供了毛细胞自发再生能力的证据和研究战略，这些研究战略将使我们更接近毛细胞医学治疗的时代，以减轻目前无法治疗的疾病造成的不平衡和耳聋的祸害。推进对这些过程的理解将产生关于前庭器官正常功能的新概念，并导致预防与转基因药物相关的并发症的方法/治疗方法，这些药物被广泛用于挽救生命的细菌感染和其他耳科治疗目标，如梅尼埃的。

DESCRIPTION (provided by applicant): The objective of this project is to investigate the morphological, physiological and molecular mechanisms of recovery of the horizontal crista vestibularis hair cells following surgical intraotic administration of gentamicin (GM) in the inner ear of adult chinchillas, a well known model for vestibular research. The experimental protocol is designed with the hypothesis that the effect of GM is dose and zone dependent with a threefold difference in the effective ototoxic dose, with type I hair cells being more sensitive than type II hair cells. Among type I hair cells there are also differences related to their location in different crista zones. Spontaneous regeneration of different hair cells takes place when each type is treated with doses that fall within the specific iaotrogenic ototoxic range. The specific aims include the following studies: 1) Investigation of the temporal course of damage and regeneration of the sensory cells and neurons following four pharmaco-kinetically selected doses of GM; 2) Parallel measurements of the changes in the Vestibulo Ocular Reflex (VOR) function and of single vestibular nerve fibers physiological responses to be compared with the anatomical changes; 3) Investigation of the potential protective neurotrophins effect of BDNF, FGF-2, and a combination of both in the VOR and hair cells. The anatomical and physiological changes will be evaluated in the context of a patho-physiological crista model based on anatomical and physiological principles and on the results of the preliminary studies findings. The applied techniques include histology, immunohistochemistry, fluorescence and confocal microscopy, computerized measurements with a new non-invasive animal technique of vestibule oculography for VOR function testing and electrophysiological single fiber recording methods. After more than a decade of research, the control of the anatomical and functional regeneration capacity of vestibular hair cells in mammals remains unresolved. However, our preliminary results have provided evidence of the capacity of spontaneous hair cell regeneration and the research strategies that will place us closer to the era of hair cell medical treatments for the relief of the scourge of presently untreatable diseases that cause disequilibrium and deafness. Advancing the understanding of these processes will precipitate new concepts regarding the normal function of the vestibular organs and lead to methods/treatment preventing complications associated with drugs like GM that are widely used in life saving bacterial infections on other therapeutic otological objectives as in Meniere's.