托福听力课外资料练习：科学美国人60秒太空飞行改变宇航员脑区灰质相关内容分享

2017年07月28日14:57 来源：小站整理: 参与（0）阅读（3546）

摘要：托福听力的备考十分的重要，那么你应该如何练习呢?在备考过程中除了一些真题之外，一些常用的课外资料也是十分重要的。小编经常用到的就是科学美国人60秒，下面编在这里为为大家整理了科学美国人60秒：太空飞行改变宇航员脑区灰质相关的内容分享，希望对大家有帮助。

在托福听力考试的备考过程中，科学美国人60秒相信大家一定用得比较多，那么大家平时是如何利用这个课外资料的呢?这里小编整理了科学美国人60秒太空飞行改变宇航员脑区灰质的内容分享，大家一起来学习一下吧。

科学美国人60秒听力练习：太空飞行改变宇航员脑区灰质

科学美国人60秒英文文本

This is Scientific American — 60-Second Science. I'm Karen Hopkin.

Got a minute?

Time spent in zero G changes the body: Astronauts come home with bone loss and muscle weakness. But what happens in their heads? To find out, researchers examined MRI's of astronauts' brains taken before and after flight. They looked at 12 astronauts who spent two weeks on the shuttle crew and 14 who spent half a year on the International Space Station.

What they saw is that the spacefarers' gray matter appeared compressed...particularly around the front and sides of the brain and the area around the eyes. That's probably due to a redistribution of cerebrospinal fluid, which is no longer being pulled down by gravity, the researchers say.

The exception to this compression is in a small area of the brain that controls the feeling in, and movement of, the legs. This region expanded in the astronauts—particularly the ones who spent six months circling the earth. That change, the researchers say, could reflect the formation of new neural connections as the brain tries to adapt to the weightless conditions. The study is in the Nature partner journal Microgravity.

The findings could have applications back here on terra firma. For example, we could learn more about treating the brain changes that take place in people who are on extended bedrest, with their feet elevated and thus higher than their heads.

The brain change is yet another thing that future space travelers, like those that may someday head to Mars, should keep in mind. No matter what size that mind may be.

Thanks for listening for Scientific American — 60-Second Science Science. I'm Karen Hopkin.