Inner Ear: Sensory Organogenesis and Gene Expression

内耳听力和平衡障碍影响着3000多万美国人，其中许多人 孩子们。这项研究的目的是阐明内耳发育过程中感觉器官发生的细胞和分子过程。这项拟议的研究将利用非洲爪哇和热带非洲爪哇的声音前庭系统来获得关于三个内耳内脏的结构、生理和遗传图谱的比较数据：球囊(前庭听觉器官)、椭圆形(前庭器官)和两栖乳头(声音器官)。实验将集中在机械感觉毛细胞和感觉神经节细胞上，目的是确定这些周围神经系统细胞在发育过程中如何获得其独特的表型。实验还旨在弄清机械感觉毛细胞如何在受损或创伤后恢复或再生为正常表型。其具体目的是：(1)获得关于椭圆囊、两栖乳头和球囊比较发育的结构和生理数据；(2)利用体外培养系统启动机械感觉毛细胞发育和再生的研究；(3)确定从内耳cDNA文库中筛选的基因的功能和发育表达模式。作为这项研究的一部分收集的解剖学和分子数据将准备通过在线数据库在公共领域传播。研究中使用的方法包括细胞培养、免疫组织化学、膜片钳、多光子和共聚焦 显微镜观察、RT-PCR指导的cDNA文库构建、酵母双杂交分析。这项研究的一个技术目标是开发内耳细胞和器官的生命成像方法。 实验结果将为毛细胞分化和增殖提供基础数据 在感官器官形成过程中，并将增加对声学前庭系统的遗传学知识。这项研究的一个长期目标是确定内耳中表达的基因在发育、再生和衰老过程中是如何调节的。这些研究的目的是为开发遗传性和环境诱导性健康和平衡障碍的治疗方法提供具有适用性的结果。

Inner ear disorders of hearing and balance affect over 30 million Americans, many of whom are children. The goal of this research is to elucidate the cellular and molecular processes that underlie sensory organogenesis during inner ear development. The proposed research will use the acoustico-vestibular systems of Xenopus laevis and Xenopus (Silurana) tropicalis to obtain comparative data about the structure, physiology, and genetic profile of three inner ear endorgans: the sacculus (an acoustico-vestibular organ), the utricle (a vestibular organ) and the amphibian papilla (an acoustic organ). Experiments will focus on mechanosensory hair cells and sensory ganglion cells with the aim of determining how these ceils of the peripheral nervous system acquire their unique phenotype during development. Experiments also aim to discern how mechanosensory hair cells can be restored or regenerated to their normal phenotype after damage or trauma. The specific aims are: (1) to obtain structural and physiological data about the comparative development of the utricle, amphibian papilla, and sacculus, (2) to initiate studies of mechanosensory hair cell development and regeneration using an in vitro culture system, and (3) to determine the function and developmental expression patterns of genes screened from inner ear cDNA libraries. Anatomical and molecular data gathered as part of this research will be prepared for dissemination in the public domain via online databases. Methods used in this research include cell culture, immunohistochemistry, patch clamp, multiphoton and confocal microscopy, RT-PCR directed cDNA library construction, and yeast two hybrid analysis. A technical objective of this research is to develop methods for vital imaging of ceils and organs of the inner ear. Experimental results will provide fundamental data about hair cell differentiation and proliferation during sensory organogenesis, and will increase knowledge of the genetics of the acoustico-vestibular systems. A long term goal of this research is to determine how genes expressed in the inner ear are regulated during development, regeneration, and aging. These investigations aim to produce results with applicability for the development of treatments for hereditary and environmentally-induced disorders of heanng and balance.