Anyone with insomnia knows the frustration that accompanies sleeplessness, longing for a button that could instantly dampen mental activity.

失眠患者都深谙难以入眠的焦灼，都渴望有个按钮可以一键平息活跃的思绪。

The idea of a mental dimmer switch is not quite as far-fetched as it might seem.

这种“大脑调光开关”的设想并非那么不切实际。

Our wakefulness is coordinated by a network of brain regions, at the heart of which lies a tiny bundle of neurons known as the "locus coeruleus", Latin for "blue dot". They are dyed blue from the production of norepinephrine, which controls our physiological and psychological arousal.

我们的清醒状态由一组大脑区域网络协同调控，位于网络核心位置的是一小簇被称为“蓝斑核”（locus coeruleus，拉丁语，意为“蓝点”）的神经元。这些神经元呈现蓝色是因为合成了去甲肾上腺素，这一神经递质控制着我们生理和心理的唤醒水平。

The neuroscience researcher Mithu Storoni describes the locus coeruleus, and its control over norepinephrine signalling, as the brain's gearbox with different modes.

神经科学研究员米图·斯托罗尼将蓝斑核及其对去甲肾上腺素传递的控制，比喻成大脑配备的多档位变速箱。

A burgeoning understanding of this neural pathway is leading some scientists to investigate whether different kinds of brain stimulation can calm the blue dot to improve sleep.

对这种神经通路日益深入的理解，正推动着科学家们开始探索不同类型的大脑刺激能否“安抚”蓝斑核以改善睡眠。

For now, we can try to avoid over-stimulation before we go to sleep. Letting our minds relax before bedtime — without TV, phones, or tablets — has long been considered good "sleep hygiene".

目前，我们可以尝试在入睡前避免过度刺激。睡前让大脑放松——远离电视、手机或平板——这长期以来都被视为良好的“睡眠卫生”。

We may also take advantage of the two-way traffic between the locus coeruleus and the body. The blue dot is part of the autonomic nervous system, which is divided into two arms: the sympathetic nervous system for stress responses, and the parasympathetic nervous system for relaxation. We can activate each arm with different physical activities.

我们还可以利用蓝斑核与身体间的双向通路。蓝斑核属于自主神经系统的一部分，该系统有两个分支：负责应激反应的交感神经系统，和主导放松的副交感神经系统。我们可以通过不同的身体活动来分别激活这两个系统。

Moderate to intense exercise is likely to kick the sympathetic arm into action, accelerating the blue dot's activity and increasing our mental arousal. Gentle stretching and controlled breathing exercises, on the other hand, promote a relaxation response in the parasympathetic nervous system.

中度至剧烈的运动可能会激活交感神经系统，加速蓝斑核的活动，提升精神的亢奋度。而轻柔的拉伸运动和有控制的呼吸练习则可促进副交感神经系统的放松反应。

We do not have a physical switch to turn down our mental activity at will. By managing our daily routine, however, we will have a better chance of getting the deep rest.

虽然我们无法随心所欲地一键调低大脑活跃度，但管理好日常习惯，或许就能更易获得深度休息。