Mechanisms that regulate zebrafish Hypocretin neuron development and function

描述（由申请人提供）：超过10%的人类患有慢性睡眠障碍，但调节睡眠的遗传和神经机制知之甚少。下丘脑分泌素/食欲素（Hcrt）信号缺陷是嗜睡症的病因，这为睡眠研究提供了一个遗传切入点，但目前还没有找到有效的治疗方法。此外，只有一小部分睡眠障碍与发作性睡病有关，这表明控制睡眠和觉醒的其他基因和神经元仍有待确定。本提案的目的是利用斑马鱼作为一种简单且具有成本效益的脊椎动物模型系统来研究Hcrt信号和睡眠。斑马鱼是这些研究的一个有用的模型，因为它们有基本的大脑结构和基因，被认为可以调节哺乳动物的睡眠，但它们也是透明的，可以进行高通量的行为分析。拟议的研究有三个目的。首先，我们将在单个神经元水平上描述斑马鱼幼体Hcrt神经元的发育特征，并验证有关其发育的假设。其次，我们将使用遗传和药理学方法来确定哪些神经元被Hcrt信号激活，哪些神经递质系统需要Hcrt诱导的觉醒。第三，我们将确定其他睡眠调节因子，包括腺苷、褪黑激素和kv3型钾通道，是否通过Hcrt系统影响睡眠。这些实验将提高我们对Hcrt神经元发育和功能的理解，可能为慢性失眠等睡眠障碍的基础提供线索，并可能导致这些疾病的新疗法。

DESCRIPTION (provided by applicant): Over 10% of humans suffer chronic sleep disorders, but the genetic and neural mechanisms that regulate sleep are poorly understood. The identification of defective Hypocretin/Orexin (Hcrt) signaling as a cause of narcolepsy provided a genetic entry point into sleep research, but an effective treatment for this disorder has not yet been found. Moreover, only a small fraction of sleep disorders are associated with narcolepsy, indicating that additional genes and neurons that control sleep and wakefulness remain to be identified. The objective of this proposal is to use zebrafish as a simple and cost-effective vertebrate model system to study Hcrt signaling and sleep. Zebrafish are a useful model for these studies because they have the basic brain structures and genes that are thought to regulate mammalian sleep, but are also optically transparent and amenable to high-throughput behavior assays. The proposed research has three aims. First, we will characterize the development of larval zebrafish Hcrt neurons at the single neuron level and test hypotheses about their development. Second, we will use genetic and pharmacological approaches to determine which neurons are activated by Hcrt signaling and which neurotransmitter systems are required for Hcrt-induced wakefulness. Third, we will determine whether other sleep regulators, including adenosine, melatonin, and Kv3-type potassium channels, affect sleep via the Hcrt system. These experiments will improve our understanding of Hcrt neuron development and function, may provide clues to the basis of sleep disorders such as chronic insomnia, and may lead to novel therapies for these disorders. PUBLIC HEALTH RELEVANCE: Over 10% of humans suffer chronic sleep disorders, but the causes of most of these disorders are unknown. This proposal will use zebrafish to examine how sleep is regulated by studying a gene whose loss causes the human sleep disorder narcolepsy and may be involved in other sleep disorders. The proposed studies will improve understanding of the genetic and neuronal mechanisms that regulate sleep and may suggest new strategies to treat sleep disorders.