HORMONAL CONTROL OF OLFACTORY LOBE DEVELOPMENT

神经元发育的激素控制在广泛的领域中发挥着重要作用 各种动物，包括脊椎动物。 其中最容易理解的 系统是变态昆虫，其中三种已识别的激素 在变态过程中协调神经系统的重塑。 这些激素，最著名的是蜕皮激素（及其代谢物，20- 羟基蜕皮酮），已被证明在节段体神经节中具有 对神经元增殖、程序性细胞死亡和生长的影响 以及神经元乔木的修剪。 本提案中描述的研究 专注于昆虫布莱恩神经发育的激素控制。 Manduca sexta 蛾大脑的嗅（触角）叶 被选择是为了探究由以下问题引起的具体问题 先前对短程细胞间相互作用的详细研究表明 指导该系统的开发。 其中很多问题还没有 在节段性神经节中被询问，并且所有这些在 嗅叶。 具体来说，蜕皮类固醇水平将被操纵 在变态的关键阶段进行实验来询问是否 蜕皮类固醇影响突触发生的时间和位置， 神经胶质细胞参与肾小球的形成、发育和神经炎乔木， 神经递质机制的发展和反应性的开始 嗅觉感觉神经元。 这五个发展事件被选中 因为它们跨越不同的细胞类型、不同的发育阶段，并且 细胞行为的不同方面。 前四个出现为 血液中的蜕皮类固醇升数正在上升；最后一个出现为滴度 细胞行为的各个方面。 前四个以蜕皮类固醇升的形式出现 血液中正在上升；当滴度回落至 基线。 所有这些都是嗅觉发育过程中的重要事件 叶，以及它们对传入轴突向内生长的时间和依赖性 详细研究了。 拟议的研究将涉及光和电子 显微镜检查、细胞内染料注射、免疫细胞化学和 放射自显影、生化测定和电生理学。 这项研究的结果将扩展对底层过程的了解 嗅叶的发育，并将阐明迄今为止 神经系统发育中尚未探索的方面可能受到影响 荷尔蒙控制。 这些研究将提供更好的理解 激素参与神经胶质细胞和神经元发育。

Hormonal control of neuronal development plays an important role in a wide variety of animals, including vertebrates. Among the best understood systems are the metamorphosing insects, where three identified hormones orchestrate the reshaping of the nervous system during metamorphosis. these hormones, most notably ecdysone (and its metabolite, 20- hydroxyecdysone), have been shown in the segmental body ganglia to have effects on neuronal proliferation, programmed cell death, and the growth and pruning of neuronal arbors. The study described in this proposal focusses on hormonal control of neural development within the insect brian. The olfactory (antennal) lobes of the brain of the moth Manduca sexta has been chosen in order to probe specific questions that have arisen from previous detailed studies of short-range intercellular interactions that guide development in that system. Many of these questions have not yet been asked in the segmental ganglia, and all are especially tractable in the olfactory lobes. Specifically, ecdysteroid levels will be manipulated experimentally during critical stages of metamorphosis to ask whether ecdysteroids affect timing and location of synaptogenesis, behavior of glial cells in the formation of glomeruli, development and neuritic arbors, development of neurotransmitter machinery, and onset of responsiveness of olfactory sensory neurons. These five developmental events were chosen because they span different cell types, different developmental stages, and different aspects of cellular behavior. The first four occur as ecdysteroid liters in the blood are rising; the last occurs as titers aspects of cellular behavior. The first four occur as ecdysteroid liters in the blood are rising; the last occurs as titers fall back toward baseline. All are significant events in the development of the olfactory lobe, and their timing and dependence upon afferent-axon ingrowth have been studied in detail. The proposed study will involve light and electron microscopy, intracellular dye-injection, immunocytochemistry and autoradiography, biochemical assays, and electrophysiology. Results of this study will extend knowledge of the processes underlying development of the olfactory lobe, and will shed light on hitherto unexplored aspects of development of the nervous system that may be under hormonal control. The studies will provide a better understanding of hormonal involvement in glial as well as neuronal development.