Oland L A, Tolbert L P
Department of Anatomy and Cell Biology, Georgetown University, Washington, D.C. 20007.
J Comp Neurol. 1988 Dec 15;278(3):377-87. doi: 10.1002/cne.902780307.
Previous observations (Oland and Tolbert: J. Comp. Neurol. 255:196-207, '87, Soc. Neurosci. Abstr. 13:1144, '87; Oland et al.: J. Neurosci. 8:353-367, '88) have provided evidence that the afferent-axon-induced development of synaptic glomeruli in the antennal lobe of the moth Manduca sexta depends upon an interaction between ingrowing sensory axons and the glial cells of the antennal lobe. In order to differentiate between the roles of glial cells and of afferent axons on the partitioning of the lobe into glomeruli, we have used the antimitotic agent hydroxyurea to produce lobes deficient in glial cells but retaining sensory input. The resulting lobes were analyzed in the light and electron microscopes, and the integrity of their antennal input was evaluated by examining the gross and microscopic structure of the antennae, the number of antennal afferent axons, and electroantennogram responses to odors. Our results with hydroxyurea show that in treated animals with adequate antennal input the degree to which the antennal-lobe neuropil becomes glomerular varies with the number of glial cells remaining in the lobe; when less than approximately one-quarter of the normal glial complement is present, glomeruli do not develop at all. These experiments complement and extend previous experiments in which the number of glial cells was reduced with radiation (Oland et al.: J. Neurosci. 8:353-367, '88). The fact that the present results mimic the previous results with radiation strongly suggest that glial cells do mediate the afferent-axon-induced formation of olfactory glomeruli in the moth.
先前的观察结果（奥兰德和托尔伯特：《比较神经学杂志》255:196 - 207，1987年，神经科学学会摘要13:1144，1987年；奥兰德等人：《神经科学杂志》8:353 - 367，1988年）表明，传入轴突诱导烟草天蛾触角叶中突触小球的发育取决于生长中的感觉轴突与触角叶神经胶质细胞之间的相互作用。为了区分神经胶质细胞和传入轴突在将触角叶划分为小球过程中的作用，我们使用抗有丝分裂剂羟基脲来产生缺乏神经胶质细胞但保留感觉输入的触角叶。对所得的触角叶进行了光学显微镜和电子显微镜分析，并通过检查触角的大体和微观结构、触角传入轴突的数量以及对气味的触角电图反应来评估其触角输入的完整性。我们使用羟基脲的结果表明，在具有足够触角输入的经处理动物中，触角叶神经纤维网形成小球的程度随叶中剩余神经胶质细胞的数量而变化；当存在的神经胶质细胞少于正常数量的约四分之一时，根本不会形成小球。这些实验补充并扩展了先前用辐射减少神经胶质细胞数量的实验（奥兰德等人：《神经科学杂志》8:353 - 367，1988年）。目前的结果与先前辐射实验结果相似这一事实强烈表明，神经胶质细胞确实介导了烟草天蛾中传入轴突诱导的嗅觉小球的形成。
