ACTIVITY-DEPENDENT DEVELOPMENT OF CALCIUM HOMEOSTASIS

钙稳态的活动依赖性发展

• 批准号: 6342375
• 负责人: Lance Zirpel
• 金额: $ 5.17万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2002-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6342375
• 关键词: acoustic nerve; afferent nerve; auditory nuclei; bioimaging /biomedical imaging; biological signal transduction; brain stem; calcium flux; calcium ion; chick embryo; confocal scanning microscopy; developmental neurobiology; electrophysiology; fluorescence microscopy; homeostasis; immunocytochemistry; western blottings

The proposed research project is aimed at understanding how interactions between afferent activity and central auditory neurons affects development of those neurons and their abilities to cope with changing activity levels. The first set of experiments will address how neurons in the cochlear nucleus respond to the onset and increasing levels of afferent input from the cochlear nerve during development with the implementation of mechanisms to regulate intracellular ion homeostasis. Previous studies have indicated that these mechanisms become prominent at about the same time as onset of afferent activity. The hypothesis that activity determines that implementation of these mechanisms will be experimentally evaluated in chick embryos by surgically or pharmacologically eliminating afferent activity to the nucleus during development. The homeostatic mechanisms will then be evaluated in cochlear nucleus neurons and compared to neurons from normal embryos. Protein quantification and dynamic optical imaging will be used for these evaluations. The ability of a neuron to regulate intracellular calcium is critical for its survival. Many proteins are involved in this regulation and combined to restrict not only the amplitude of a calcium signal, but also the time course and area of that signal. During development of the auditory system, the input that generates these calcium signals changes dramatically. The second set of proposed experiments aims to understand how this input affects the ability of cochlear nucleus neurons to regulate these changing calcium signals. Similar to the first set of experiments, surgical and pharmacological techniques will be used to eliminate afferent activity during development of the brain stem auditory nuclei, and protein quantification and dynamic optical imaging will be used to evaluate specific components and functions of the cellular calcium regulatory machinery. In addition, a specialized imaging technique will be used that allows great precision in measuring the temporal and spatial aspects of the calcium signals within neurons. These studies will contribute to understanding the interactions between afferent activity and the development of specialized central auditory neurons. This understanding will allow for more accurate evaluations of the impact of early sensory deprivation on central neurons. In addition, they will contribute to an animal model of congenital hearing deficits that is widely used for studies on the development and regeneration of auditory function.

拟议的研究项目旨在了解传入活动与中央听觉神经元之间的相互作用如何影响这些神经元的发展及其能力，以应对不断变化的活动水平。第一组实验将解决人工耳蜗中的神经元如何响应发育过程中人工耳神经的传入输入水平，并通过实施机制来调节细胞内离子稳态。先前的研究表明，这些机制在大约在传入活动的同时变得突出。活动确定这些机制的实施将通过手术或药理上消除发育过程中对细胞核的传入活性来实验评估的假设。然后，将在耳蜗神经元中评估体内稳态机制，并将其与正常胚胎的神经元进行比较。蛋白质定量和动态光学成像将用于这些评估。神经元调节细胞内钙的能力对于其存活至关重要。许多蛋白质参与了该调节，并合并以限制钙信号的幅度，还限制了该信号的时间过程和面积。在听觉系统的开发过程中，生成这些钙信号的输入发生了巨大变化。第二组提出的实验旨在了解该输入如何影响耳蜗神经元调节这些不断变化的钙信号的能力。与第一组实验相似，将使用手术和药理学技术来消除脑干听觉核过程中传入活性，蛋白质定量和动态光学成像将用于评估细胞钙调节机械的特定组件和功能。此外，将使用一种专门的成像技术，可以很好地测量神经元内钙信号的时间和空间方面。这些研究将有助于理解传入活动与专门中央听觉神经元的发展之间的相互作用。这种理解将允许对早期感觉剥夺对中心神经元的影响进行更准确的评估。此外，它们还将为先天性听力缺陷的动物模型做出贡献，该模型广泛用于研究听觉功能的发展和再生。