火星任务可能会导致学习障碍和焦虑

火星任务可能会导致学习障碍和焦虑

Can the human brain handle space?

人类大脑能处理空间吗?

On a long-term spaceflight mission to Mars, astronauts will be continuously exposed to low-dose radiation in deep space. A new study found that this exposure can cause impairments in the brains of mice, resulting in learning and memory issues as well as anxiety.

在长期的火星飞行任务中，宇航员将持续暴露在深太空的低剂量辐射中。一项新的研究发现，这种接触会导致老鼠大脑受损，导致学习和记忆问题以及焦虑。

The study was published Monday in the journal eNeuro.

这项研究周一发表在《eNeuro》杂志上。

Previous studies looking at the effect of radiation on the brain have used shorter rates of exposure but higher doses of radiation, which the researchers of the new study say inaccurately reflects deep space conditions.

之前的研究着眼于辐射对大脑的影响，使用的是更短的暴露率，但更高的辐射剂量，新研究的研究人员称，这并不准确地反映了深空条件。

This study now shows that radiation delivered at space relevant dose rates (i.e. 1 mGy/day) over extended ties ( 6 months) elicits adverse neurocognitive effects - similar to our past studies using dose rates ~ 400 times higher.

这项研究现在表明，在与空间相关的剂量率(即1 mGy/天)下，在延长的时间(6个月)内进行的辐射会引起不良的神经认知效应——与我们过去使用剂量率约400倍高的研究相似。

In the new study, male mice were exposed to chronic low-dose radiation for six months. After six months had passed, the researchers found that signaling in the prefrontal cortex and hippocampus was impaired by the radiation.

在这项新的研究中，雄性老鼠被暴露在慢性低剂量辐射下6个月。六个月后，研究人员发现，辐射会破坏前额皮质和海马区的信号。

This created impairments in both memory and learning for the mice.

这给老鼠的记忆力和学习能力造成了损害。

The researchers also observed behaviors indicating anxiety in the mice, which led them to believe that the radiation also affected the amygdala.

研究人员还观察到老鼠表现出焦虑的行为，这让他们相信辐射也会影响杏仁核。

"This study now shows that radiation delivered at space relevant dose rates over extended times elicits adverse neurocognitive effects similar to our past studied using dose rates that were about 400 times higher," said Charlies Limoli, study author and professor of radiation oncology at the University of California, Irvine.

该研究的作者、加州大学欧文分校(University of California, Irvine)放射肿瘤学教授查理斯•利莫里(Charlies Limoli)表示:“这项研究现在显示，以空间相关剂量率在较长时间内进行的辐射，会引发与我们过去使用剂量率高出约400倍的剂量进行的研究类似的负面神经认知效应。”

Based on their findings, the researchers believe that one out of five astronauts on a deep space mission would likely experienced anxiety. One in three would be more likely to deal with memory issues. And all of them may struggle when it comes to making decisions, which would be crucial on a mission to Mars where communications with the Earth are delayed by up to 20 minutes.

根据他们的发现，研究人员认为，在执行深空任务的宇航员中，五分之一的人可能会感到焦虑。三分之一的人更有可能处理记忆问题。所有人在做决定时都可能会遇到困难，这对火星任务至关重要，因为火星与地球的通讯会延迟20分钟。

The research highlights the need for safety measures to protect astronauts undergoing long-term spaceflight. Currently, astronauts on the International Space Station aren't exposed to much radiation because the station is in the protective habitat of low-Earth orbit. Outside of that orbit, the exposure to radiation will only increase.

这项研究强调了采取安全措施保护长期太空飞行的宇航员的必要性。目前，国际空间站的宇航员没有受到太多的辐射，因为该空间站位于近地轨道的保护栖息地。在这个轨道之外，辐射只会增加。

"NASA is working one more advanced shielding approaches for protecting astronauts and we along with other groups are working on pharmacologic countermeasures for protecting the brain and body from the harmful effects of space radiation exposure," Limoli said.

利莫里说:“美国宇航局正在研究一种更先进的屏蔽方法来保护宇航员，我们和其他小组正在研究保护大脑和身体免受太空辐射伤害的药理学对策。”

But Limoli and his team aren't concerned about the potential for these impairments and behaviors during future missions.

但利莫里和他的团队并不担心在未来的任务中可能出现这些损伤和行为。