火星任務可能會導致學習障礙和焦慮

火星任務可能會導致學習障礙和焦慮

Can the human brain handle space?

人類大腦能處理空間嗎?

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.

在長期的火星飛行任務中，宇航員將持續(xù)暴露在深太空的低劑量輻射中。一項新的研究發(fā)現，這種接觸會導致老鼠大腦受損，導致學習和記憶問題以及焦慮。

The study was published Monday in the journal eNeuro.

這項研究周一發(fā)表在《eNeuro》雜志上。

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.

之前的研究著眼于輻射對大腦的影響，使用的是更短的暴露率，但更高的輻射劑量，新研究的研究人員稱，這并不準確地反映了深空條件。

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.

這項研究現在表明，在與空間相關的劑量率(即1 mGy/天)下，在延長的時間(6個月)內進行的輻射會引起不良的神經認知效應——與我們過去使用劑量率約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.

在這項新的研究中，雄性老鼠被暴露在慢性低劑量輻射下6個月。六個月后，研究人員發(fā)現，輻射會破壞前額皮質和海馬區(qū)的信號。

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

這給老鼠的記憶力和學習能力造成了損害。

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

研究人員還觀察到老鼠表現出焦慮的行為，這讓他們相信輻射也會影響杏仁核。

"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.

該研究的作者、加州大學歐文分校(University of California, Irvine)放射腫瘤學教授查理斯•利莫里(Charlies Limoli)表示:“這項研究現在顯示，以空間相關劑量率在較長時間內進行的輻射，會引發(fā)與我們過去使用劑量率高出約400倍的劑量進行的研究類似的負面神經認知效應。”

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.

根據他們的發(fā)現，研究人員認為，在執(zhí)行深空任務的宇航員中，五分之一的人可能會感到焦慮。三分之一的人更有可能處理記憶問題。所有人在做決定時都可能會遇到困難，這對火星任務至關重要，因為火星與地球的通訊會延遲20分鐘。

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.

這項研究強調了采取安全措施保護長期太空飛行的宇航員的必要性。目前，國際空間站的宇航員沒有受到太多的輻射，因為該空間站位于近地軌道的保護棲息地。在這個軌道之外，輻射只會增加。

"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.

利莫里說:“美國宇航局正在研究一種更先進的屏蔽方法來保護宇航員，我們和其他小組正在研究保護大腦和身體免受太空輻射傷害的藥理學對策。”

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

但利莫里和他的團隊并不擔心在未來的任務中可能出現這些損傷和行為。