The Advanced Science Research Center, The City University of New York; The Graduate Center at the City University of New York, New York, United States.
VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium.
Elife. 2023 Oct 31;12:e91355. doi: 10.7554/eLife.91355.
Homeostatic control of sleep is typically addressed through mechanical stimulation-induced forced wakefulness and the measurement of subsequent increases in sleep. A major confound attends this approach: biological responses to deprivation may reflect a direct response to the mechanical insult rather than to the loss of sleep. Similar confounds accompany all forms of sleep deprivation and represent a major challenge to the field. Here, we describe a new paradigm for sleep deprivation in that fully accounts for sleep-independent effects. Our results reveal that deep sleep states are the primary target of homeostatic control and establish the presence of multi-cycle sleep rebound following deprivation. Furthermore, we establish that specific deprivation of deep sleep states results in state-specific homeostatic rebound. Finally, by accounting for the molecular effects of mechanical stimulation during deprivation experiments, we show that serotonin levels track sleep pressure in the fly's central brain. Our results illustrate the critical need to control for sleep-independent effects of deprivation when examining the molecular correlates of sleep pressure and call for a critical reassessment of work that has not accounted for such non-specific effects.
睡眠的内稳态控制通常通过机械刺激诱导的强制清醒和随后睡眠增加的测量来实现。这种方法存在一个主要的混淆因素：对剥夺的生物学反应可能反映了对机械损伤的直接反应，而不是对睡眠丧失的反应。所有形式的睡眠剥夺都伴随着类似的混淆因素，这是该领域的一个主要挑战。在这里，我们描述了一种新的 模型，该模型充分考虑了与睡眠无关的影响。我们的结果表明，深度睡眠状态是内稳态控制的主要目标，并确立了剥夺后多周期睡眠反弹的存在。此外，我们还证实，深度睡眠状态的特定剥夺会导致特定状态的内稳态反弹。最后，通过在剥夺实验中考虑机械刺激的分子效应，我们表明在果蝇中枢脑中，血清素水平与睡眠压力相关。我们的结果说明了在研究睡眠压力的分子相关性时，必须控制剥夺对睡眠无关的影响，这呼吁对未考虑此类非特异性影响的工作进行批判性重新评估。
