Mechanisms of Sleep Regulation in C. elegans

项目摘要 睡眠是一个基本的生物过程，对动物的生存至关重要。人类通常花费约30%的时间 我们一生中大部分时间都在睡觉，但睡眠障碍在现代社会中很普遍。睡眠异常不仅影响 日常表现还会导致对神经功能的不良影响，并有助于神经和其他 疾病。因此，了解我们睡眠的方式和原因是非常必要的。然而，在很大程度上仍不清楚是如何 睡眠是在分子、细胞和电路水平上控制的，部分原因是睡眠调节的复杂性。 关于睡眠的一个基本问题是，大脑如何控制与睡眠相关的不同行为变化，以 诱导一种强健的睡眠状态。我们的长期目标是建立对基础遗传学的全面理解 睡眠调节的通路和神经机制。睡眠是一个进化保守的过程， 不同生物体的共同特征包括行为静止，提高觉醒阈值， 以及快速恢复到清醒状态。与此相一致，最近对简单模式生物的研究，如蠕虫， 果蝇和斑马鱼为睡眠调节提供了有价值的见解。我们建议研究一种简单和 线虫强健的应激诱导睡眠状态：细胞应激激活表皮生长因子(EGF) 主要在单个神经元(ALA)内发出信号以诱导睡眠。单个神经元是如何控制 302-神经元大脑驱动线虫进入睡眠状态？为了解决这个问题，我们将利用 线虫的优势，如强大的遗传学，短的生命周期，光学透明，和紧凑 神经系统。我们的中心假设是激活ALA神经元中的EGF信号诱导睡眠 通过不同但可能重叠的分子通路和神经电路的作用来协调 各种睡眠行为表型。为了验证这一假设，我们提出了两个项目：1)执行一组 基因筛选和突变分析以确定新的睡眠调节基因和2)执行全脑功能 电路映射，以单神经元分辨率识别SIS的神经基础。我们将系统地操纵 并通过组合显示线虫整个神经系统中单个神经元的活动 光遗传学、化学遗传学、体内钙成像和基于GAL4的强大的两部分表达 我们开发的系统(CGAL)。这项拟议的研究具有重要意义，因为它将提供一个机械论的观点 睡眠是如何在分子、细胞和电路水平上运作的。这项研究也将潜在地改变 线虫功能电路分析的方法，因为本研究中产生的cGAL试剂将 成为整个研究社区的强大资源，并可随时用于分析潜在的 其他行为的神经回路。

Project Summary Sleep is a fundamental biological process that is essential for survival in animals. Humans normally spend ~ 30% of our lifetime sleeping, but sleep disorders are prevalent in modern societies. Sleep abnormalities not only affect daily performance but also lead to adverse effects on neuronal function and contribute to neurological and other diseases. Thus, it is imperative to understand how and why we sleep. However, it remains largely unclear how sleep is controlled at the molecular, cellular, and circuit levels, partially due to the complexity of sleep regulation. A fundamental question about sleep is how the brain controls different sleep-associated behavioral changes to induce a robust sleep state. Our long-term goal is to build a comprehensive understanding of basic genetic pathways and neural mechanisms underlying sleep regulation. Sleep is an evolutionarily conserved process, with shared features across different organisms that include behavioral quiescence, increased arousal threshold, and rapid reversibility to wakefulness. In line with this, recent studies in simple model organisms, such as worms, fruit flies, and zebrafish, have yielded valuable insights into sleep regulation. We propose to study a simple and robust stress-induced sleep (SIS) state in C. elegans: cellular stress activates epidermal growth factor (EGF) signaling primarily within a single neuron (ALA) to induce sleep. How does a single neuron control a 302-neuron brain to drive C. elegans into a sleep state? To address this question, we will exploit the advantages of C. elegans, such as powerful genetics, short life cycle, optical transparency, and a compact nervous system. Our central hypothesis is that activation of EGF signaling in the ALA neuron induces sleep through the actions of distinct yet potentially overlapping molecular pathways and neural circuits that coordinate various sleep behavioral phenotypes. To test this hypothesis, we propose two projects: 1) perform a set of genetic screens and mutant analyses to identify new sleep regulatory genes and 2) perform brain-wide functional circuit mapping to identify the neural basis for SIS at single-neuron resolution. We will systematically manipulate and visualize the activity of individual neurons in the entire nervous system of C. elegans through a combination of optogenetics, chemogenetics, in vivo calcium imaging, and a powerful GAL4-based bipartite expression system (cGAL) we developed. The proposed research is significant because it will provide a mechanistic view of how sleep operates at the molecular, cellular, and circuit levels. This study will also potentially transform approaches of functional circuit analyses in C. elegans because the cGAL reagents produced in this study will become a powerful resource for the entire research community and can be readily used to dissect underlying neural circuits for other behaviors.