時(shí)差N小時(shí):我們?yōu)槭裁葱枰X?
親愛的《科學(xué)一科》欄目組：
Why do we sleep?
我們?yōu)槭裁葱枰X?
I know this question has been debated by scientistsand philosophers forcenturies, but are there any hardand fast answers?
我知道科學(xué)家們和哲學(xué)家們就這個(gè)問題爭(zhēng)論了好幾個(gè)世紀(jì)，但現(xiàn)在有沒有確實(shí)的，現(xiàn)成的答案?
Good question!
問得好!
First, it's true that scientists have long pondered the mystery of sleep why we do itand why it'snecessary.
首先，科學(xué)家們長(zhǎng)期以來(lái)確實(shí)在思考睡眠這一謎題，我們?yōu)槭裁葱枰撸瑸槭裁此呤直匾?
We know that going without sleep for too long can seriously damage health, so there's goodreason to believe that getting enough sleep is important for our well-being.
我們知道長(zhǎng)期失眠會(huì)嚴(yán)重的危害健康，因此，有必要相信保證睡眠充足對(duì)健康很重要。
But exactly how and why that's the case is still an open question.
但失眠為什么會(huì)影響健康，又是如何影響的，這個(gè)問題仍沒有答案。
Some research, though, may shed a little light on the problem.
一些研究也許可以稍稍解答這個(gè)問題。
For instance, scientists at the University of Rochester Medical Center in New York did a studywith mice, and found that during sleep their brains flush out toxins that accumulate duringthe day.
比如，紐約羅切斯特大學(xué)醫(yī)學(xué)中心的科學(xué)家們用老鼠做了一個(gè)研究，發(fā)現(xiàn)老鼠在睡覺時(shí)，他們的大腦會(huì)排除白天積累的毒素。
More specifically, the study found that sleep sort of changes the brain's cellular structure.
更確切的說(shuō)，該研究發(fā)現(xiàn)睡眠在某種程度上改變了大腦的細(xì)胞結(jié)構(gòu)。
When the mice were asleep or anesthetized, the researchers found that there was more spacebetween their brain cells, allowing a sort of brain plumbing apparatus called the glymphaticsystem to open wide and allow fluid to flow quickly through the brain.
當(dāng)老鼠處于睡眠狀態(tài)或被麻醉是，研究人員發(fā)現(xiàn)，他們大腦細(xì)胞之間的空間增大了，使被稱為腦部類淋巴系統(tǒng)的類似排污管道的器官大大的打開，這樣腦脊液就能在大腦中快速的流動(dòng)。
Other studies have shown that toxic molecules build up in the space between brain cells.
其他的研究表明，有毒分子在腦細(xì)胞的間隙中生成。
Researchers at the University of Rochester found that those molecules vanished faster fromthe brain when the mice were asleep.
羅切斯特大學(xué)的研究人員發(fā)現(xiàn)，這些分子在老鼠睡覺時(shí)從大腦中消失得更快。
So what does this mean?
所以，這意味著什么呢?
Well, it could give scientists new ways to study and potentially treatbrain disorders likeAlzheimer's by targeting the glymphatic system and helping it better flush awaybrain toxins.
這意味著通過針對(duì)腦部類淋巴系統(tǒng)可以幫助大腦更好的排除腦部毒素，使科學(xué)家們有新的方法研究并很有可能治好像老年癡呆癥這樣的大腦疾病。
