ULTRASTRUCTURAL DEVELOPMENT OF ANTENNAL CENTER

神经元之间以及神经元和神经胶质细胞之间的相互作用 许多研究人员表明，这对儿童的正常发育至关重要 神经系统。本研究是一项发展性研究。 中枢神经形成过程中神经元与神经胶质细胞的相互作用 成虫系统，大部分发育发生在胚胎后。 目前对六纹夜蛾触角系统的研究表明 就像脊椎动物一样，感觉神经轴突指导着 它们的目标的发展，在这种情况下，天线叶 大脑。这项拟议的研究的目标是在细胞水平上理解 使触角感觉轴突所施加的影响的性质变得平坦。 以前的工作已经表明，触角轴突影响 神经纤维束的形态组织、分布和形态 神经胶质细胞和触角叶内突触的分布。 有几条证据表明，脑内神经胶质细胞 脑叶可能是感觉轴突和神经节之间的中介。 在其中一些相互作用中有二阶触角叶神经元。我们 建议主要使用两个实验模型来检验这一假设： 自始至终没有触角轴突的触角叶 发育，以及触角叶中胶质细胞的数量 在危急情况下暴露于伽马辐射后严重减少 神经胶质细胞增殖期。特色化的发展 叶的肾小球、突触的分布和数量 裂片和个体分枝模式的发育 将对触角叶神经元进行监测，并与正常进行比较。如果 在这些脑叶中，胶质细胞缺乏的叶类似于无神经支配的叶。 参数(正如初步实验表明的那样)，这将是 被解释为神经胶质细胞是血流的必要管道的证据 从感觉轴突到触角叶神经元的破坏性信息。 参数确实取决于感觉轴突的存在，但不取决于 胶质细胞的存在将被解释为最有可能是由于 神经元与神经元的直接相互作用。

Interactions between neurons and between neurons and glial cells have been shown by a number of researchers to be critical for normal development of the nervous system. The proposed research is a study of developmental interactions among neurons and glial cells in the forming central nervous system of a moth, where much of development occurs postembryonically. Current work on the antennal system of the moth Manduca sexta suggests that, just as in vertebrates, sensory axons guide many aspects of the development of their targets, in this case, the antennal lobes of the brain. The goal of the proposed research is to understand at a cellular level the nature of the influence exerted by the antennal sensory axons. Previous work has indicated that the antennal axons influence the morphological organization of the neuropil, the disposition and morphology of glial cells, and the distribution of synapses in the antennal lobe. Several lines of evidence lead to the hypothesis that the glial cells of the lobe may be acting as intermediaries between sensory axons and second-order antennal-lobe neurons in some of these interactions. We propose to test this hypothesis using primarily two experimental models: antennal lobes that have been deprived of antennal axons throughout development, and antennal lobes in which the number of glial cells has been severely reduced through exposure to gamma-irradiation during critical stages of glial proliferation. The development of the characteristic glomeruli of the lobe, the distribution and numbers of synapses in the lobe, and the development of the branching patterns of individual antennal-lobe neurons will be monitored and compared with normal. If glial-deficient lobes resemble uninnervated lobes in any of these parameters (as preliminary experiments indicate they may), this will be interpreted as evidence that glial cells were a necessary conduit for flow of insstructive information from sensory axons to antennal-lobe neurons. Parameters that do depend upon the presence of sensory axons but not upon the presence of glia will be interpreted as resulting most likely from direct neuron-neuron interactions.