Synaptic Organization in a Simple Olfactory System

昆虫重要的感觉附属物是触角的鞭毛，它包含数千个被称为感受器的感受器，这些感受器被分为不同的类型，包括一些专门用于化学感觉功能的感受器。来自鞭毛的神经包含许多神经纤维或轴突，当它们进入大脑时形成特定的组，并在称为肾小球的特殊结构中终止。每一个肾小球都是一个球体状的复合体，神经细胞在其中进行被称为突触的功能性接触，在那里输入和输出的信息发生相互作用，由局部神经细胞调节。昆虫的肾小球结构与脊椎动物嗅球中的肾小球有许多相似之处，人们认为这种结构形成了突触相互作用的信息处理模块。这项工作将关注嗅觉信息如何在肾小球中被映射，看看昆虫嗅觉受体是否根据它们的功能调节，它们的触角位置，或两者兼而有之，在不同的肾小球中表示。光学显微镜和电子显微镜将用于阐明提供输入和输出的神经元之间的连接结构，以及处理嗅觉信息的收敛和局部电路。昆虫系统提供了一个有利的模型，因为它有可能在大脑中找到唯一可识别的单个神经元。这项工作的结果将对理解一般的信息处理，对脊椎动物和无脊椎动物的化学感觉神经科学，以及在高度特异性神经连接的神经发育过程中将昆虫作为模型系统的研究有价值。以及与农业有关的昆虫摄食或繁殖的研究，这些研究都有化学感觉成分。

An important sensory appendage for insects is the flagellum of the antenna, containing thousands of receptors called sensilla that have been classified into types, including some specialized for chemosensory functions. The nerve from the flagellum contains many nerve fibers, or axons, which form particular groupings when they enter the brain and terminate in distinctive structures called glomeruli. Each glomerulus is a sphere-like complex in which nerve cells make functional contacts called synapses, where interactions occur between incoming and outgoing information, modulated by local nerve cells. The glomerular structure in insects has several similarities to the glomerulus also found in the vertebrate olfactory bulb, and it is believed that this structure forms an information processing module for synaptic interactions. This work will focus on how olfactory information is mapped in the glomeruli, to see whether in insects olfactory receptors are represented in different glomeruli according to their functional tuning, their antennal location, or both. Light microscopy and electron microscopy will be used to clarify the architecture underlying the connections between neurons that provide input and output, and the convergence and local circuits that process olfactory information. The insect system offers an advantageous model because it is possible find uniquely identifiable single neurons in the brain. Results from this work will be valuable to understanding information processing in general, to chemosensory neuroscience in the vertebrates as well as invertebrates, to studies on insects as model systems during neural development of highly specific neural connections, and to agriculturally related studies of insect feeding or reproduction which have chemosensory components.