Development and afferent regulation of auditory neurons

描述（由申请人提供）：神经元树突的形态和内在特性是其功能的专门化。树突缺陷与许多神经发育障碍密切相关。在这个计划中，我奋进确定脆性X智力低下蛋白（FMRP）在听觉神经元树突调控中的作用。缺乏FMRP会导致脆性X综合征（FXS），这是自闭症最常见的遗传性单基因原因，表现出一系列症状，包括智力缺陷和感觉功能障碍。我建议研究FMRP调节过程中的发展非常好的特点双耳电路在脑干和它的作用，在调节树突状细胞形态和生物化学传入活动和完整性的变化。我将进行详细的分析，在鸡核magnocellularis（NM）和核laminaris（NL），一个很好的特点的动物模型，研究听觉时间处理和基因操作的一个易处理的系统，并将一些分析扩展到人类大脑。我将使用Western印迹和免疫细胞化学来表征鸡NM和NL中FMRP的发育概况，并确定FMRP与树突发育和专门生理特性的良好记录特征的时间相关性。我将确定如何敲低FMRP表达影响鸡NM和NL神经元的树突形态和关键蛋白的表达的发展。将使用具有时间和空间控制的基因操作、单个细胞填充、免疫细胞化学和高分辨率共聚焦显微镜。我将确定FMRP如何调节鸡NL的传入依赖性树突状细胞重组。我将首先研究传入如何调节FMRP，然后评估FMRP敲低对树突结构和生物化学传入影响的影响。将使用组合的遗传和传入操作，以及固定和活组织的共聚焦和多光子成像。与Kulesza博士合作，我们将开始探索FMRP在人类听觉脑干神经元中的潜在功能，通过使用免疫细胞化学检查固定的人类脑干切片中FMRP和FMRP结合蛋白的时空分布。总之，这些研究将提供深入了解FMRP调节树突状树枝化和专门的属性，听觉处理神经元，并深入了解脊椎动物神经元发育和疾病病理机制。

DESCRIPTION (provided by applicant): Neuronal dendritic morphology and intrinsic properties are specialized for their function. Dendritic defects are strongly associated with numerous neurodevelopmental disorders. In this proposal, I endeavor to identify roles of fragile X mental retardation protein (FMRP) in dendritic regulation of auditory neurons. Absence of FMRP results in fragile X syndrome (FXS), the most frequent inherited monogenetic cause of autism, presenting with a constellation of symptoms that include intelligence deficits and sensory dysfunction. I propose to study FMRP regulation during development of very well characterized binaural circuitry in the brainstem and its role in regulation of dendritic morpholog and biochemistry following changes in afferent activity and integrity. I will conduct detailed analyses in the chicken nucleus magnocellularis (NM) and nucleus laminaris (NL), a well-characterized animal model for studying auditory temporal processing and a tractable system for gene manipulation, and will extend some analyses to human brains. I will characterize the developmental profile of FMRP in chicken NM and NL using Western blot and immunocytochemistry, and identify the temporal correlations of FMRP with well-documented characteristics of dendritic development and specialized physiological properties. I will determine how knockdown of FMRP expression affects the development of dendritic morphology and expression of key proteins of chicken NM and NL neurons. Gene manipulations with temporal and spatial control, individual cell filling, immunocytochemistry, and high-resolution confocal microscopy will be used. I will determine how FMRP regulates afferent-dependent dendritic reorganization in chicken NL. I will first examine how afferent regulates FMRP and then assess the effects of FMRP knockdown on afferent influence of dendritic structure and biochemistry. Combined genetic and afferent manipulations, as well as confocal and multi-photon imaging of fixed and live tissues, will be used. In collaboration with Dr. Kulesza, we will start to explore potential function of FMRP in human auditory brainstem neurons by examining the temporal and spatial distribution of FMRP and FMRP-binding proteins in fixed human brainstem sections using immunocytochemistry. Overall, these studies will provide insight into FMRP regulation of dendritic arborization and specialized properties for auditory processing neurons, and insight into mechanisms of vertebrate neuronal development and disease pathology.