DEVELOPMENT OF SEXUALLY DIMORPHIC OLFACTORY GLOMERULI

性二态性嗅球的发育

基本信息

批准号：
7090676
负责人：
LESLIE P TOLBERT
金额：
$ 17.85万
依托单位：
UNIVERSITY OF ARIZONA
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-07-01 至 2007-06-30
项目状态：
已结题

项目摘要

Primary olfactory neuropils in both vertebrates and invertebrates are characterized by arrays of synaptic glomeruli, each of which processes information about particular attributes of odorous stimuli; but little is known about how these striking spatial arrays develop. In the moth Manduca sexta, the olfactory neuropil comprises 64 glomeruli that appear to be similar in males and females, and two to three specialized and easily recognizable glomeruli that are unique to each sex and that process information about odors important for reproduction. Previous experiments have demonstrated that male-specific group of specialized glomeruli, including recruitment of female target neurons into that circuitry. Furthermore, even if entering the brain from an abnormal position, those male-specific axons find the correct target site. Thus, the sexually dimorphic olfactory system of Manduca offers a special opportunity to investigate a central question in olfactory development: what cellular interactions underlie the development of the array of glomeruli. The proposed project addresses the question, with two specific aims: (1) to explore aspects of the "address" that male-specific olfactory receptor axons recognize in the target olfactory neuropil and to determine whether synaptic interactions between those axons and particular target neurons underlie the dendritic morphology that the axons induce in those neurons; and (2) to determine the role of nitric oxide, a gaseous intercellular signaling molecule which appears to be released by developing olfactory axons, in the development of both sexually isomorphic and sexually dimorphic glomeruli in the antennal lobe. The project, taking advantage of the relative cellular simplicity of the moth olfactory system, and using state-of-the-art microscopical methods in addition to electrophysiological, biochemical, and molecular biological approaches is expected to provide insights into the development of less accessible mammalian olfactory systems.

脊椎动物和无脊椎动物的初级嗅觉神经元都具有突触肾小球阵列的特征，每个突触肾小球都处理有关气味刺激的特定属性的信息。但人们对这些引人注目的空间阵列是如何形成的知之甚少。在天蛾（Manduca sexta）中，嗅觉神经纤维由 64 个在雄性和雌性中似乎相似的肾小球组成，以及两到三个专门且易于识别的肾小球，这些肾小球对于每种性别都是独特的，并且处理对繁殖重要的气味信息。先前的实验已经证明，男性特异性肾小球组，包括将女性目标神经元招募到该电路中。此外，即使从异常位置进入大脑，那些男性特有的轴突也会找到正确的目标位置。因此，曼杜卡的两性异形嗅觉系统提供了一个特殊的机会来研究嗅觉发育中的一个核心问题：哪些细胞相互作用是肾小球阵列发育的基础。拟议的项目解决了这个问题，有两个具体目标：（1）探索男性特异性嗅觉受体轴突在目标嗅觉神经元中识别的“地址”的各个方面，并确定这些轴突和特定目标神经元之间的突触相互作用是否是其基础轴突在这些神经元中诱导的树突形态； (2) 确定一氧化氮（一种气态细胞间信号分子，似乎是通过嗅觉轴突发育而释放的）在触角叶中性同形和性二形性肾小球发育中的作用。该项目利用飞蛾嗅觉系统的相对细胞简单性，并使用最先进的显微方法以及电生理学、生物化学和分子生物学方法，预计将为难以接近的哺乳动物的发展提供见解。嗅觉系统。