中國科學家揭示曬太陽爲何讓人更聰明大綱

Science has already proved that sunny days can lead to sunny dispositions, helping improve a person's mood, intelligence and memory -- and researchers in China have now shed light on why.

科學已經證明，曬太陽能讓人的個性也變得陽光，有助於改善心情、激發才智，提高記憶力--我國研究人員如今揭示了其中的原理。

A team at the University of Science and Technology of China in Hefei, Anhui province, discovered that ultraviolet light -- an element of sunshine -- activates a change in the brain that can make us smarter.

位於安徽合肥的中國科技大學的研究團隊發現，陽光中的紫外線能激活大腦中的變化，從而使人們變得更加聰明。

Tests on mice showed that moderate exposure to UV light enhances perception and learning, according to Xiong Wei, a professor at the university's School of Life Sciences who co-led the study.

據牽頭這項研究的中國科學技術大學生命科學學院的熊偉教授表示，對小鼠的試驗表明，適度暴露在紫外線下可以增強感知和學習能力。

Mice were exposed to 50 milijoules per square centimeter of UV, he said, which is equal to 20 to 30 minutes of ambient midday sun in Florida in summer.

他表示，這些小鼠被暴露在每平方釐米50毫焦的紫外線中，這相當於在佛羅里達夏季的正午曬20到30分鐘的太陽。

Using single-cell mass spectrometry, an extremely sensitive and specific analytical technique, scientists found that a metabolic pathway in the brain was involved.

通過利用單細胞質譜分析技術--一種極其靈敏和具體的分析技術，科學家們發現大腦中有一種代謝途徑與此有關。

Exposure to UV increases blood urocanic acid, which reacts with brain cells to boost levels of glutamate, a neurotransmitter involved in cognitive functions such as learning and memory.

紫外線照射能夠增加血液中的尿刊酸，尿刊酸與大腦細胞發生反應，從而提升穀氨酸水平，而穀氨酸是一種與學習和記憶等認知功能相關的神經遞質。

Xiong said previous research had found that urocanic acid was converted to glutamate in the liver, but this is the first time it has been demonstrated that the synthesis process can happen in the brain--a finding that surprised the team.

熊偉教授稱，先前的研究曾發現尿刊酸在肝臟中被轉化爲穀氨酸，但現在是第一次證明該合成過程還可以發生在大腦中，這是一個讓該研究團隊驚喜的發現。