Inner Ear: Sensory Organogenesis and Gene Expression

听力和平衡的内耳障碍影响超过3000万美国人，其中许多人是 孩子本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。拟议的研究将使用非洲爪蟾和热带爪蟾的声前庭系统，以获得有关三种内耳终器的结构，生理学和遗传特征的比较数据：球囊（声前庭器官），椭圆囊（前庭器官）和两栖动物乳头（声器官）。实验将集中于机械感觉毛细胞和感觉神经节细胞，目的是确定外周神经系统的这些细胞如何在发育过程中获得其独特的表型。实验还旨在辨别机械感觉毛细胞如何在损伤或创伤后恢复或再生到其正常表型。具体目标是：（1）获得关于椭圆囊、两栖类乳头和球囊的比较发育的结构和生理数据，（2）使用体外培养系统启动机械感觉毛细胞发育和再生的研究，以及（3）确定从内耳cDNA文库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和分子数据将通过在线数据库在公共领域传播。研究方法包括细胞培养、免疫组化、膜片钳、多光子和共聚焦等 显微镜、RT-PCR指导的cDNA文库构建和酵母双杂交分析。本研究的技术目标是开发用于内耳细胞和器官的活体成像的方法。 实验结果将为毛细胞的分化和增殖提供基础数据 在感觉器官形成过程中，并将增加对听觉前庭系统遗传学的了解。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。这些研究旨在产生适用于开发遗传性和环境引起的听觉和平衡障碍的治疗方法的结果。

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.