Regulation of sleep-like behavior in C. elegans

描述(申请人提供)：这项研究的长期目标是了解睡眠和类似睡眠状态的基因调节。睡眠-唤醒调节由时钟定时以及睡眠开始和偏移信号组成。睡眠状态的执行需要感觉门控，这指的是睡眠期间响应性降低的现象。感觉门控是睡眠的一个鲜为人知的基本属性，它有别于安静的清醒状态。这项建议旨在利用模式生物秀丽线虫来推进我们对感官门控的机械理解。研究方法是研究嗜睡症，这是一种发生在线虫生命周期中的类似睡眠的时期。在这个授权期，需要检验的全球假说是，EGL-4/PKG和cAMP信号在感觉神经元中相互拮抗地作用，以调节嗜睡期间的感觉输入，而感觉输入的减少反过来促进了类似睡眠的行为。这一全球假说将通过四个具体目标进行检验。《特定目标1》将检验这样一种假设，即在昏睡期间调节感觉反应的分子机制与调节化学感觉适应的分子机制是相同的。这一假设将通过评估感觉适应缺陷和昏睡期间感觉门控缺陷之间的关联来检验。此外，我们将测试动物在昏睡期间是否比在昏睡之外更容易适应。特定目标2将测试cAMP信号作用于感觉神经元以对抗嗜睡期间感觉门控的假设。这一假说将通过在感觉神经元中表达pde-4基因来验证，pde-4通常会降解cAMP。此外，我们将评估EGL-4和PDE-4之间的基因顺序关系是调节感觉门控的。《特定目标3》将检验感官输入调节类睡眠行为的假设。第三个目标将通过检测在嗜睡期间抑制感觉输入对睡眠行为的影响，以及突变体和降低感觉功能的手术的影响来测试。最终的特定目标将进行遗传筛选，以确定在功能突变的EGL-4获得中增强睡眠样行为所需的基因。鉴于睡眠和类似睡眠状态的系统发育保守，以及cGMP和cAMP依赖的信号通路的保守，这些实验很可能会揭示其他物种的睡眠调节。提高对睡眠调节的理解将提高对睡眠障碍患者的诊断和治疗。公共卫生相关性：睡眠障碍和睡眠剥夺是尚未得到满足的主要公共卫生问题。这项建议旨在增加我们对睡眠调节的理解，以提高对睡眠障碍患者的诊断和治疗。

DESCRIPTION (provided by applicant): The long-term goal of this research is to understand the genetic regulation of sleep and sleep-like states. Sleep-wake regulation consists of clock timing and of sleep onset and offset signals. Execution of the sleep state requires sensory gating, which refers to the phenomenon of reduced responsiveness during sleep. Sensory gating is a poorly-understood yet fundamental property of sleep that distinguishes it from quiet wakefulness. This proposal aims to advance our mechanistic understanding of sensory gating using the model organism Caenorhabditis elegans. The approach is to study lethargus, a sleep-like period that occurs during the life cycle of C. elegans. In this grant period, the global hypothesis to be tested is that EGL-4/PKG and cAMP signaling act antagonistically in sensory neurons to regulate sensory input during lethargus, and that reduced sensory input in turn facilitates sleep-like behavior. This global hypothesis will be tested through four specific aims. Specific aim 1 will test the hypothesis that the molecular mechanism that regulates sensory responsiveness during lethargus is the same molecular mechanism that regulates chemosensory adaptation. This hypothesis will be tested by assessing for an association between defects in sensory adaptation and defects in sensory gating during lethargus. Additionally, we will test whether animals adapt more readily during lethargus than outside of lethargus. Specific aim 2 will test the hypothesis that cAMP signaling acts in sensory neurons to antagonize sensory gating during lethargus. This hypothesis will be tested by expressing the gene pde-4, which normally degrades cAMP, in sensory neurons. In addition, we will assess the gene order relationship between egl-4 and pde-4 is regulating sensory gating. Specific aim 3 will test the hypothesis that sensory input regulates sleep-like behavior. This third aim will be tested by examining the effects on sleep-like behavior of dampening sensory input during lethargus and of mutants and operations that reduce sensory function. The final specific aim will perform a genetic screen to identify genes required for the enhanced sleep- like behavior in egl-4 gain of function mutants. Given the phylogenetic conservation of sleep and sleep-like states and the conservation of cGMP-and cAMP-dependent signaling pathways, it is likely that these experiments will shed light on sleep regulation in other species. Improved understanding of sleep regulation will enhance the diagnosis and treatment of people with sleep-disorders. PUBLIC HEALTH RELEVANCE: Sleep disorders and sleep deprivation are major unmet public health problems. This proposal aims to add to our understanding of sleep regulation, in order to enhance the diagnosis and treatment of patients with sleep disorders.