Mechanisms of Sleep Regulation in C. elegans

项目摘要 睡眠是动物生存所必需的基本生物过程。人类通常花费约30% 我们一生的睡眠时间，但睡眠障碍在现代社会中很普遍。睡眠异常不仅影响 但是也导致对神经元功能的不利影响，并有助于神经系统和其他 疾病因此，我们必须了解我们如何以及为什么睡觉。然而，在很大程度上仍然不清楚如何 睡眠在分子、细胞和电路水平上受到控制，这部分是由于睡眠调节的复杂性。 关于睡眠的一个基本问题是大脑如何控制不同的睡眠相关行为变化， 从而诱导稳健睡眠状态。我们的长期目标是建立一个全面的了解基本遗传 睡眠调节的神经通路和神经机制。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，唤醒阈值增加， 和快速恢复清醒的能力与此相一致的是，最近对简单模式生物（如蠕虫）的研究， 果蝇和斑马鱼已经对睡眠调节产生了有价值的见解。我们建议研究一个简单的， C.具有强大的应激诱导睡眠（SIS）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。一个神经元是如何控制 302-神经元脑驱动C.进入睡眠状态为了解决这个问题，我们将利用 C的优点。线虫，如强大的遗传，短生命周期，光学透明，和一个紧凑 神经系统我们的中心假设是ALA神经元中EGF信号的激活诱导睡眠 通过不同但可能重叠的分子通路和神经回路的作用， 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）进行全脑功能 电路映射，以确定在单神经元分辨率SIS的神经基础。我们将系统地操纵 并将C.通过一个组合 光遗传学、化学遗传学、体内钙成像和基于GAL4的强大双向表达 系统（cGAL）。这项研究是有意义的，因为它将提供一个机械的观点， 睡眠是如何在分子、细胞和电路层面上运作的。这项研究也将有可能改变 功能电路分析的方法。因为本研究中生产的cGAL试剂将 成为整个研究界的强大资源，可以很容易地用来剖析潜在的 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.