MOLECULAR DELINEATION OF THE COCHLEAR HAIR CELLS

描述：（改编自研究者摘要）我们的长期目标是 为了了解耳蜗毛细胞如何作为一个有效的频率 周边听觉系统的分析仪。本提案的目标是 鉴定在细胞中表达的电压门控离子通道超家族成员， 耳蜗毛细胞，并确定其空间和时间模式， 在发育和成年阶段表达。这些研究将力求 相关的解剖成熟和神经元的神经支配的器官， Corti与耳蜗毛细胞受体功能成熟 电位和突触传递。我们的研究将集中在表征 在分子水平上塑造受体电位的离子通道。 这些通道包括电压门控K+（Kv）和Na+（Scn）离子通道， 内向整流器（Kir）。电压依赖性钙离子通道（CACN）和 钙激活钾通道（Kca），参与耳蜗毛细胞 突触传递，也将被表征。初始基因表达 这些离子通道的分析将使用退化基因家族， 基因特异性寡核苷酸引物扩增耳蜗，内 毛细胞和外毛细胞cDNA文库以及单细胞RT-PCR。 第一个目标将是表征正常毛细胞的离子通道， 成年大鼠和小鼠在分子水平上使用整体和切片 Corti器官的制备和应用针对候选者的探针 蛋白质（免疫细胞化学）和mRNA（原位杂交）。一旦成年人 空间表达模式的建立，我们将研究的时空 在产前和新生儿时间过程中小鼠的表达模式， 确定这些离子通道的采集时间，并将这些变化 神经支配和解剖学成熟。最后，我们将确定 空突变小鼠（Ngn-1，Ntrk 2）中离子通道表达空间模式 （trkB）、Ntf 3（Nt-3）、Ntrk 2 +/Ntf 3 +/-和Ntf 3 +-PDGF启动子-Ntf 3+）， 阐明神经支配与电生理的关系 成熟识别参与受体的分子元件 耳蜗毛细胞的潜在和突触传递应该导致一个 更好地了解内耳功能，有助于我们理解 听觉病理学

DESCRIPTION: (Adapted from the Investigator's Abstract) Our long term goal is to understand how cochlear hair cells function as an effective frequency analyzer of the peripheral auditory system. The goals of this proposal are to identify members of the voltage-gated ion channel superfamily expressed in cochlear hair cells and to determine their spatial and temporal patterns of expression in developmental and adult stages. These studies will seek to correlate the anatomical maturation and neuronal innervation of the organ of Corti with the functional maturation of the cochlear hair cells' receptor potential and synaptic transmission. Our studies will focus on characterization of the ion channels that shape the receptor potential at the molecular level. These channels include the voltage-gated K+ (Kv) and Na+ (Scn) ion channels and the inward rectifiers (Kir). The voltage-dependent Ca2+ (CACN) channels and calcium-activated K+ channels (Kca), which are involved in cochlear hair cell synaptic transmissions, will also be characterized. Initial gene expression analysis of these ion channels will use degenerative gene-family and gene-specific oligonucleotide primers to amplify cDNAs from cochlear, inner hair cell, and outer hair cell cDNA libraries as well as single cell RT-PCR. The first aim will be to characterize the hair cells' ion channels in normal adult rats and mice at the molecular level using wholemount and section preparations of the organ of Corti and applying probes directed at candidate proteins (immunocytochemistry) and mRNA (in situ hybridization). Once the adult spatial expression patterns are established, we will study the spatio-temporal expression patterns in mice during a prenatal and neonatal time course to determine acquisition time of these ion channels and to correlate these changes with innervation and anatomical maturation. Lastly we will determine the spatial pattern of ion channel expression in null mutant mice (Ngn-1, Ntrk2 (trkB), Ntf3 (Nt-3), Ntrk2+/Ntf3+/-, and Ntf3+-PDGF promoter-Ntf3+) to elucidate the relationship between innervation and electrophysiological maturation. Identification of molecular elements involved in the receptor potential and synaptic transmission of cochlear hair cells should lead to a greater understanding of inner ear function and contribute to our comprehension of auditory pathologies.