Synaptic Microcircuits Controlling Sleep

 描述(申请人提供)：大脑中的神经网络控制睡眠和昼夜节律，这是调节许多生理和行为输出的关键交互过程。睡眠和昼夜节律调节受损引起或加剧的人类疾病--如发作性睡病、遗传性睡眠相紊乱、时差、倒班工作、睡眠不足、抑郁等--是发病率、死亡率和经济困难的主要来源。通过了解睡眠和昼夜节律控制电路如何在体内发挥作用，重要的包括细胞间突触信号和内稳态可塑性，它们的改善将得到促进。睡眠-觉醒调节的关键特征之一是能够快速从一种状态转换到另一种状态，例如在接收到发出危险信号的感觉刺激时醒来。目前哺乳动物快速睡眠状态转换的模型包括促进睡眠和促进觉醒的神经元群体之间相互抑制的反馈环，以实现双稳态的“触发器”。睡眠触发和昼夜节律调节电路依赖于经典的、快速的突触信号，以及小分子和多肽神经调节剂。我们的长期目标是对完整动物的突触通讯、神经调节及其在睡眠和昼夜节律控制电路中的相互作用进行机械解剖。为了实现这一目标，我们将果蝇模型系统的细胞特异性神经遗传学可操纵性与全细胞膜片钳和功能成像相结合。我们将结合经典突触释放、光遗传神经元刺激、全细胞膜片钳以及细胞内钙离子和膜电位的荧光成像的神经遗传学操作来分析蘑菇体促进睡眠和促进觉醒的神经元内部和之间的功能关系，以确定蘑菇体是如何双向控制睡眠的，以及它是否表现为双稳态触发器。我们将结合经典突触释放的神经遗传学操作、光遗传神经元刺激和完整苍蝇脑中的全细胞膜片钳来确定功能网络下的突触连接。我们还将测试这样的假设，即一个或多个促进睡眠和/或唤醒的蘑菇体神经元类别编码了使网络偏向一种或另一种状态的稳态睡眠驱动。

 DESCRIPTION (provided by applicant): Neural networks in the brain control sleep and circadian rhythms, key interacting processes that regulate numerous physiological and behavioral outputs. Human disorders caused or exacerbated by impaired regulation of sleep and circadian rhythms - such as narcolepsy, genetic sleep phase disturbances, jet lag, shift work, sleep deprivation, depression, etc. - are a major source of morbidity, mortality, and economic hardship. Their amelioration will be facilitated by understanding how sleep and circadian rhythm control circuits function in vivo, importantly including intercellular synaptic signaling and homeostatic plasticity. One of the key features of sleep-wake regulation is the ability to rapidly transition from one state to the other, such as to wake up upon receipt of sensory stimuli signaling danger. Current models of rapid sleep state switching in mammals involve mutually inhibitory feedback loops between sleep-promoting and wake-promoting populations of neurons to implement a bistable "flip-flop". Sleep flip-flop and circadian regulator circuits rely on classical, rapid synaptic signaling, as well as small molecule and peptide neuromodulators. Our long-term goal is mechanistic dissection of synaptic communication, neuromodulation, and their interaction in sleep and circadian control circuits of the intact animal In pursuit of this goal we combine the cell-specific neurogenetic manipulability of the Drosophila model system with whole-cell patch-clamp and functional imaging. We will combine neurogenetic manipulation of classical synaptic release, optogenetic neuronal stimulation, whole-cell patch-clamp, and fluorescent imaging of intracellular Ca2+ and membrane potential to analyze the functional relationships within and between the sleep-promoting and wake-promoting neurons of the mushroom body to determine how the mushroom body controls sleep bidirectionally and whether it behaves as a bistable flip-flop. We will combine neurogenetic manipulation of classical synaptic release, optogenetic neuronal stimulation, and whole-cell patch-clamp in intact fly brain to determine the synaptic connections that underlie the functional network. We will also test the hypothesis that one or more of the sleep- and/or wake-promoting mushroom body neuron classes encodes homeostatic sleep drive that biases the network to one or the other state.