Chronobiology Laboratory, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore, Karnataka 560064, India
Department of Zoology, Central University of Punjab, Bathinda, Punjab 151001, India.
J Neurosci. 2021 Nov 10;41(45):9403-9418. doi: 10.1523/JNEUROSCI.0400-21.2021. Epub 2021 Oct 11.
The neuronal and genetic bases of sleep, a phenomenon considered crucial for well-being of organisms, has been under investigation using the model organism Although sleep is a state where sensory threshold for arousal is greater, it is known that certain kinds of repetitive sensory stimuli, such as rocking, can indeed promote sleep in humans. Here we report that orbital motion-aided mechanosensory stimulation promotes sleep of male and female , independent of the circadian clock, but controlled by the homeostatic system. Mechanosensory receptor ()-expressing neurons in the chordotonal organs mediate this sleep induction: flies in which these neurons are either silenced or ablated display significantly reduced sleep induction on mechanosensory stimulation. Transient activation of the -expressing neurons also enhances sleep levels, confirming the role of these neurons in sleep induction. We also reveal that certain regions of the antennal mechanosensory and motor center in the brain are involved in conveying information from the mechanosensory structures to the sleep centers. Thus, we show, for the first time, that a circadian clock-independent pathway originating from peripherally distributed mechanosensors can promote daytime sleep of flies Our tendency to fall asleep in moving vehicles or the practice of rocking infants to sleep suggests that slow rhythmic movement can induce sleep, although we do not understand the mechanistic basis of this phenomenon. We find that gentle orbital motion can induce behavioral quiescence even in flies, a highly genetically tractable system for sleep studies. We demonstrate that this is indeed true sleep based on its rapid reversibility by sensory stimulation, enhanced arousal threshold, and homeostatic control. Furthermore, we demonstrate that mechanosensory neurons expressing a TRPV channel , located in the antennae and chordotonal organs, mediate orbital motion-induced sleep by communicating with antennal mechanosensory motor centers, which in turn may project to sleep centers in the brain.
睡眠的神经和遗传基础是一个被认为对生物体的幸福至关重要的现象，一直以来都是使用模式生物进行研究的。虽然睡眠是一种感觉唤醒阈值较高的状态，但已知某些类型的重复感觉刺激，如摇晃，确实可以促进人类的睡眠。在这里，我们报告说轨道运动辅助机械感觉刺激促进雄性和雌性 的睡眠，这与生物钟无关，但受稳态系统控制。机械感觉受体 ()表达神经元在腱器官中介导这种睡眠诱导：这些神经元被沉默或消融的苍蝇在机械感觉刺激下显示出明显减少的睡眠诱导。 - 表达神经元的短暂激活也增强了睡眠水平，证实了这些神经元在睡眠诱导中的作用。我们还揭示了大脑中触角机械感觉和运动中心的某些区域参与了将信息从机械感觉结构传递到睡眠中心。因此，我们首次表明，起源于外周分布的机械感受器的生物钟独立途径可以促进苍蝇的白天睡眠。我们在移动车辆中入睡的倾向或摇晃婴儿入睡的做法表明，缓慢的有节奏的运动可以诱导睡眠，尽管我们不了解这种现象的机制基础。我们发现，即使在苍蝇中，轻微的轨道运动也可以诱导行为静止，苍蝇是一个高度可遗传的睡眠研究系统。我们证明，这确实是真正的睡眠，因为它可以通过感觉刺激快速逆转，增强唤醒阈值和稳态控制。此外，我们证明位于触角和腱器官中的表达 TRPV 通道的机械感觉神经元通过与触角机械感觉运动中心进行通信来介导轨道运动诱导的睡眠，而触角机械感觉运动中心反过来可能投射到大脑中的睡眠中心。
