科学美国人60秒 SSS 宇航员的大脑变化（在线收听）

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.

长时间处于零重力会使躯体发生变化：从太空归来的宇航员会出现骨质疏松以及肌无力。但是这些宇航员的脑部会发生何种变化?为了找到答案，研究人员分别对飞行前以及飞行后宇航员的大脑进行了核磁共振成像。研究人员对航天飞机组呆了两周的12位宇航员以及在国际空间站停留半年的14位宇航员进行了观察。

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.

研究人员观察到的结果是，宇航员的大脑灰质面积减少……尤其是大脑前侧以及周围的区域和眼睛周围的区域。研究人员表明，这可能是由于没有重力的推动，脑脊液的再分配出现了问题。

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.

与大脑灰质面积减少相反的是，控制感觉以及腿部活动的大脑区域发生的变化。在宇航员的头部，该部分区域扩大——其中环绕地球六个月的宇航员该区域特别明显。

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.

研究人员表明，这种变化能反应出，由于大脑要适应零重力的环境，所以形成了新的神经联接。该研究结果发表在《自然》杂志的合作伙伴《微重力》杂志上。

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 bed rest, with their feet elevated and thus higher than their heads.

该研究结果可以重新应用在地球上。例如，我们可以更多的了解如何治疗那些长时间卧床休息、其脚被抬高、高于头部的人群的大脑变化。

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.

大脑的变化也是未来某一天会去火星的宇航员需要牢记的事项。无论大脑(想法)的大小。