熊子云

Why do we need sleep？ Is bedtime just a time for dreaming？ Do our brains turn off for the night？ What if I told you that scientists recently discovered that our brains may be just as busy at night as they are during the day？

为什么我们需要睡眠呢？睡觉的这段时间仅仅是为了做梦吗？我们的大脑在夜间是否处于休息状态呢？如果我告诉你，据最近的科学研究，我们的大脑在夜间也像白天一样忙碌，你对此有何看法？

While we sleep， our brains are doing much more than getting ready for the next day. Researchers at the University of Rochester found that the brain may be busy cleaning house— cleaning out harmful waste materials.

当我们处于睡眠状态时，大脑不仅仅只是为明天做准备。罗切斯特大学的研究人员发现，大脑在夜间也许正忙于清理房子——扫除有害的垃圾。

They studied mice that had colored dye injected1 into their brains. They observed the mice brains as they slept and when they were awake. The researchers say they saw that the brains of sleeping mice were hard at work.

研究人员将彩色染料注入老鼠的脑内并在它们睡眠和清醒时观察他们的大脑。结果发现，老鼠的大脑在它们睡眠时也在忙碌地工作。

Working Double Duty

双重任务

Dr. Maiken Nedergaard led the study. The brain expert says our brains perform two very different jobs. It seems they have daytime jobs. Later they “moonlight” at a nighttime job.

麦肯·尼达加特博士负责这项研究。脑专家认为我们的大脑执行着两项十分不同的工作，不仅有日间的工作，之后还要“兼职”做一些夜间的工作。

“When we are awake， the brain cells2 are working very hard at processing all the information about our surroundings3. Whereas when we are asleep， they work very， very hard at removing4 all the waste that builds up when we are awake.”

当我们醒着时，大脑细胞拼命工作，处理关于我们四周环境的信息。但是，当我们睡觉时，它们也仍然拼命扫除我们醒着时在脑中积累的垃圾。

The researchers say that the waste material includes poisons， or toxins， responsible for brain disorders5 such as Alzheimers disease.

研究人员认为这些垃圾包括各种毒素。这些毒素是一些大脑疾病——如老年痴呆症的诱因。

They also found that during sleep， the brains cells shrink， or become smaller. This shrinking permits waste to be removed more effectively.

研究人员也发现，大脑细胞在睡眠中会收缩或变小。这种收缩运动可以更有效的清理垃圾。

Dr. Nedergaard says these toxins end up in the liver. There， they are broken down and then removed from the body.

麦肯·尼达加特博士说这些毒素会转移到肝脏。在肝脏中，这些毒素被分解，然后被排出。

“So our study suggests we need to sleep because we have a macroscopic cleaning system that removes many of the toxic waste products from the brain.”

“所以我们的研究证明了睡眠对于人们的重要性。因为我们有一个微观的清理系统来清除大脑中的很多有害物质。”

The brains cleaning system could only be studied with new imaging technologies. The test animal must be alive in order to see for this brain process to be seen as it happens.

研究人员只能利用最新的成像技术来观察大脑的清理系统。试验中的动物必须是活的，以保证这一大脑运行过程能被观察到。

Dr. Nedergaard says the next step is to look for the process in human brains. She said the results demonstrate6 just how important sleep is to health and fighting disease. The research may also one day lead to treatments to prevent or help fight neurological disorders.

尼达加特博士表示下一步的工作将是观察人脑的运行过程。她指出目前的实验结果仅仅证明了睡眠对于健康和预防疾病的重要性。这一研究将来也许有助于预防和治疗神经性疾病。

7 Tips for Better Sleeping

7条保持良好睡眠的建议

Do you have trouble sleeping？ Not being able to sleep is called insomnia. According to the United States National Sleep Foundation， here are some tips for a good nights sleep：

你入睡困难吗？我们用“失眠”来定义人们无法入睡的情况。为了保证一夜的睡眠，美国国家睡眠基金会提出了以下建议：

1. Go to bed about the same time each night， even on weekends. This helps to“set” your bodys “sleep clock.”

每晚在同一时间上床睡觉，即使是周末也要如此。这一方法有助于“设定”身体的“睡眠生物钟。”

2. Exercise every day.

每天运动。

3. Have a calm， relaxing bedtime routine7—Take a warm bath or drink a hot cup of tea.

拥有一个平静、放松的睡前习惯——洗个热水澡或喝杯热茶。

4. Try not to take long naps during the day. Periods of sleep during the daytime can interfere8 with sleep at night.

白天小睡时间不宜过长。白天的睡眠时长会影响夜晚的睡眠。

5. Make sure you have a pleasant environment where you sleep. For most people， a cool， quiet and dark room is best for sleeping.

确保你有一个舒适的睡眠环境。对于大多数人来说，一个凉爽、安静和黑暗的房间最适合睡眠。

6. Avoid using television， computers and other electronic screens before bedtime.

睡前避免盯着电视，电脑和其它电子屏幕。

7. Also avoid alcohol， cigarettes and heavy meals before bedtime.

睡前避免喝酒、吸烟和饮食过量。

——英语原文摘自VOA Special

[1] inject vt. 注入；注射 [2] cell n. 细胞 [3] surrounding n. 环境，周围的事物

[4] remove vt. 移动，迁移；调动 [5] disorder n. 混乱 [6] demonstrate vt. 证明；展示；论证

[7] routine n. 例行公事 [8] interfere vi. 干涉；妨碍；打扰