Olfactory Development: Cell Proliferation and Maturation

描述(由申请者提供)：本项目的总体目标是了解是什么调节了嗅觉外周的胚胎后再生。这项提案的重点是该项目的一个主要方面--成年动物体内新的嗅觉感受器神经元和相关细胞的增殖。嗅觉感受器神经元的持续增殖和更新是人类的一个特征，在本研究中使用的动物模型中也表达了这一点。这三个具体目标是：1)哪些基因与新的嗅觉细胞的增殖有关？2)局部和激素因素如何改变嗅觉细胞的增殖？以及3)哪些功能变化与嗅觉细胞的增殖、成熟和分化有关？为了研究这些问题，这项建议将使用龙虾嗅觉系统的关键优势特征，其中包括关于该系统功能组织的丰富知识，成年嗅觉组织的连续周转可以受到损伤和激素的调节(如在哺乳动物中)，以及到其嗅觉器官的发育轴，其中增殖区、成熟区和衰老区在物理上是分开的(哺乳动物并非如此)。因此，这些实验在龙虾身上是可能的，但在其他著名的无脊椎动物模型中是不可能的，例如果蝇和线虫，它们缺乏胚胎后嗅觉神经元的更新。实验设计将包括分子技术，包括寻找新基因(通过代表性差异分析)和同源基因(通过RT-PCR)，分析基因及其产物的表达模式(通过原位杂交和免疫细胞化学)，以及功能分析(通过膜片钳和细胞电生理学)。这些关于胚胎后成年动物的干细胞样活性和神经发生的研究是重要的，因为这些再生过程不仅对于理解感觉器官功能的调节具有基本的重要性，而且对于帮助我们理解如何通过控制系统的调节来补偿活动和功能的丧失具有实际意义。

DESCRIPTION (provided by applicant): The overall goal of this project is to understand what regulates the post-embryonic regeneration of the olfactory periphery. This proposal focuses on one major aspect of the project - the proliferation of new olfactory receptor neurons and associated cells in adult animals. Continuous proliferation and turnover of olfactory receptor neurons, even in adults, is a feature of humans that is also expressed in the animal model used in this study. The three specific aims are 1) What genes are associated with proliferation of new olfactory cells? 2) How do local and hormonal factors alter proliferation of olfactory cells? and 3) What functional changes are correlated with proliferation, maturation, and differentiation of olfactory cells? To investigate these issues, this proposal will use critical advantageous features of the lobster olfactory system, which include a wealth of knowledge about the functional organization of this system, continuous turnover of adult olfactory tissue that can be modulated by damage and hormones (as in mammals), and a developmental axis to its olfactory organ in which the zones of proliferation, maturation, and senescence, are physically separated (not so in mammals). Consequently, these experiments are possible in the lobster, but not in other prominent invertebrate models such as Drosophila and C. elegans which lack post-embryonic turnover of olfactory neurons. The experimental design will include molecular techniques including searches for novel genes (by representational difference analysis) and homologous genes (by RT-PCR), analysis of expression patterns of genes and their products (by in-situ hybridization and immunocytochemistry), and analysis of function (by patch-clamp and sing]e cell electrophysiology). These studies of stem cell-like activity and neurogenesis in post-embryonic adult animals are important since these regenerative processes are not only of basic importance to understanding regulation of function of a sensory organ, but also have the practical importance of helping us understand how to compensate for loss of activity and function through regulation by control systems.