Rhythmic Circadian Network Analysis

摘要 时差、倒班工作和睡眠活动周期的干扰都会导致智力和 身体健康。开始解决这种现象的时间生物学基础 病理生理学，这个建议试图描述神经基础，以产生和提炼 组织和触发日常节律生理的计时信号。 在这里，我概述了三个相关但独立的昼夜节律神经生理学研究的建议。 成像和数据分析的最新进展可以记录越来越多的网络现象 空间和时间精度。昼夜节律起搏器系统产生生理性的 自发和有节奏的活动，促进了深入的分析。我们有 采用平面照明方法进行24小时活体全脑扫描 果蝇昼夜节律神经回路。这项工作勾勒出了一个新的框架，说明昼夜节律如何 网络编码时间：内部时钟强同步的起搏器网络， 其仍然显示由不同识别的起搏器组顺序激活 在这一天里。此外，起搏器细胞的相互作用主要以数小时的形式 神经肽介导的延迟似乎是优势机制，通过它 组织起搏器的顺序活动。因此，这一点的科学前提是 该项目的基础是需要更好地了解神经基础，以进行这种定时的操作 电路及其调制。在这里，我建议进一步进行大脑的实时活体研究 该网络由果蝇~150个核心昼夜节律起搏神经元组成。 为了更好地了解起搏网络的神经元特性，并 扩大我们初步研究的范围，我们将追求三个目标。起搏器细胞相互作用 是理解支配序列和节奏的动态关系的关键 网络输出，到目前为止，我们的知识仅限于少数几个这样的信号。因此目标1 将系统地测试整个网络中起搏器细胞与化学发生的相互作用 控制剂，以钙离子为报告离子。目标2旨在将我们的工作范围扩大到 通过使用环核苷酸的遗传实时报告程序发出钙信号，环核苷酸是 在昼夜节律回路中建立了第二信使，但其体内动力学很差 已定义。最后，目标3将研究昼夜节律回路中的多巴胺信号-我们将定义 体内多巴胺细胞活动的自发24小时模式和检验两个假说 关于多巴胺信号在起搏器网络中的假定功能。同舟共济 这些努力将提供关于动态状态的多层次信息 起搏器系统在体内全天全网起搏。

Abstract Jet-lag, shift-work and disturbances in sleep-activity cycles all contribute to degrade mental and physical well-being. To begin addressing the chronobiological bases for such pathophysiologies, this proposal seeks to describe the neural basis to generate and refine the timing signals that organize and trigger daily rhythmic physiology. Here I outline proposals for three related yet independent studies of circadian neurophysiology. Recent advances in imaging and data analysis can record network phenomena with increasing spatial and temporal precision. The circadian pacemaker system produces physiological activity both spontaneously and rhythmically, which promotes an in-depth analysis. We have introduced planar illumination methods to perform 24 hr in vivo brain-wide scans of the Drosophila circadian neural circuit. That work outlines a new framework for how the circadian network encodes time: a pacemaker network whose internal clocks are strongly synchronized, which nevertheless displays sequential activation by different identified pacemaker groups across the day. Furthermore pacemaker cell interactions, principally in the form of multi-hour neuropeptide-mediated delays, appear to be the preponderant mechanism by which the sequential activities of pacemakers are organized. Therefore, the scientific premise for this project rests on the need to better understand the neural basis for the operations of this timing circuit and its modulation. Here I propose work to further real-time in vivo studies of the brain network that is composed of the core ~150 Drosophila circadian pacemaker neurons. To provide a better understanding of neuronal properties of the pacemaking network, and to extend the scope of our initial studies, we will pursue three Aims. Pacemaker cell interactions are the keys to understanding the dynamic relationships that govern the sequence and tempo of network outputs, and to-date our knowledge is limited to only a few such signals. Thus Aim 1 will systematically test pacemaker cell interactions across the network with chemogenetic control agents, using Ca2+ as a reporter. Aim 2 seeks to extend the scope of our work beyond Ca2+ signals by employing a genetic realtime reporter for cyclic nucleotides, which are established 2nd messengers in the circadian circuit but whose in vivo dynamics are poorly defined. Finally, Aim 3 will study dopamine signaling within the circadian circuit – we will define spontaneous 24 hr patterns of dopamine cell activity in vivo and test two hypotheses concerning the putative functions of dopamine signals in the pacemaker network. Together these efforts will provide multi-layered information regarding the dynamic state of the pacemaker system network-wide in vivo for the course of the entire day.