创新背景

人们普遍认为压力会导致睡眠质量下降，使人在晚上保持清醒，由此损坏人的身体机能和精神状况。但实际上，某些类型的压力并不会让人在夜间越来越清醒，反而会诱发睡眠。

创新过程

哺乳动物的睡眠大都相似，人和其他哺乳动物一样，经历过REM和非REM两种类型的睡眠。REM是指快速眼球运动睡眠，是常说的做梦的睡眠阶段；非REM是深度的、无梦的睡眠阶段，此期间大脑的活动下降到最低，使得人体能够得到完全的舒缓。基于两种睡眠类型，伦敦帝国理工学院和中国的研究人员合作，探索压力诱导睡眠的机制在小鼠大脑中如何发生。

研究将压力诱导的睡眠假设为抑制压力反应并帮助压力事件的心理处理，为小鼠施加心理社会压力的一种行为学模型——社会失败压力。小鼠被暴露在其他具有特别攻击性的小鼠面前，压力和血液中的激素急速上升。
研究在小鼠睡觉时跟踪它们的脑细胞活动，在小鼠中脑发现一组特定的神经元，是专门用于检测压力和诱导恢复性睡眠的特定电路。这些神经元可以检测并对压力荷尔蒙做出反应，一个子集的特化神经元接收应激输入，会通过下丘脑外侧诱导REM和非REM睡眠。

瞬时压力增强了这些神经元的活性数小时，神经元的活动以及两种睡眠水平在大约五个小时的睡眠中保持高位，并向其他神经元发送信号，调节压力荷尔蒙，阻止它们释放更多。该途径产生的压力诱导的睡眠减轻了压力水平，导致压力荷尔蒙降低。
研究人员表示，研究揭示了压力诱导睡眠的机制，增加了REM睡眠帮助我们应对压力的想法，为针对正确神经元的药物或其他干预措施铺平了道路，并增强了睡眠的减压能力。并且，研究人员还发现小鼠经历的睡眠似乎对第二天的焦虑水平有影响。

小鼠醒来以后研究人员通过测量它们在光明中度过的时间测试它们的焦虑反应，探索睡眠给它们的压力行为带来的影响。研究将从压力诱导睡眠中醒来的小鼠和受压的小鼠进行比较，没有得到压力诱导睡眠的小鼠在黑暗中花费了更多的时间，这表明它们更加焦虑，并且它们的压力荷尔蒙水平仍然很高。研究根据新的机制希望能找到选择性靶向负责神经元的方法，通过睡眠提高其积极作用。相关研究成果《中脑的特定回路可检测压力并诱导恢复性睡眠》刊登在2022年6月30日发表的《科学》杂志上。

创新关键点

反向思考压力和睡眠的关系，探索压力诱导睡眠的机制。

创新价值

哺乳动物的睡眠相似，人类大脑可能和小鼠存在一样的机制，如果认为干预这种机制提高其效果，或许有助于治疗创伤后应激障碍等持续性应激障碍。

Reverse thinking about the effects and effects of stress on sleep

Sleep in mammals is largely similar, and humans, like other mammals, experience both REM and non-REM sleep types. REM refers to rapid eye movement sleep, which is often referred to as the stage of dreaming sleep; non-REM is the stage of deep, dreamless sleep during which brain activity drops to a minimum, allowing the human body to be completely relieved. Based on two sleep types, researchers at Imperial College London and China collaborated to explore how the mechanisms of stress-induced sleep occur in the mouse brain.

The study hypothesized that stress-induced sleep suppresses stress responses and aids the psychological processing of stressful events, providing a behavioral model of psychosocial stress in mice—social failure stress. The mice were exposed to other particularly aggressive mice, and stress and blood hormones spiked.

The study tracked the activity of brain cells in mice as they slept, and found a specific set of neurons in the mouse midbrain, a specific circuit dedicated to detecting stress and inducing restorative sleep. These neurons detect and respond to stress hormones, and a subset of specialized neurons that receive stress input induces REM and non-REM sleep via the lateral hypothalamus. The transient stress boosted the activity of these neurons for hours, and the activity of the neurons, along with both sleep levels, remained high for about five hours of sleep and sent signals to other neurons that regulate stress hormones, preventing them from releasing more. The stress-induced sleep produced by this pathway reduces stress levels, resulting in lower stress hormones.

The researchers say the study sheds light on the mechanism by which stress induces sleep, increases the idea that REM sleep helps us cope with stress, paves the way for drugs or other interventions that target the right neurons, and enhances sleep's stress-reducing power. What's more, the researchers also found that the sleep the mice experienced appeared to have an effect on anxiety levels the next day.

After the mice woke up, the researchers tested their anxiety responses by measuring the time they spent in the light, exploring the effects of sleep on their stressful behaviors.The study will compare mice that wake up from stress-induced sleep and mice that are stressed. Mice that don't get stress-induced sleep spend more time in the dark, suggesting they are more anxious, and their stress hormones The level is still high. Based on the new mechanism, the research hopes to find ways to selectively target the responsible neurons, enhancing their positive effects through sleep. Related research results, "Specific circuits in the midbrain detect stress and induce restorative sleep," were published in the June 30, 2022 issue of the journal Science.