科学家发现年轻血液具有返老还童的神奇力量

At Stanford, researchers were investigating whether the blood of young mice altered the brains of old mice. In 2011, Saul Villeda, then a graduate student, and his colleagues reported that it did. When old mice received young blood, they had a burst of new neurons in the hippocampus, a region of the brain that is crucial for forming memories.
斯坦福大学(Stanford)的研究人员曾对幼龄鼠的血液是否能改变老龄鼠的脑功能进行过研究。2011年，当时还是研究生的索尔·比列达(Saul Villeda)和同事表示，答案是肯定的。接受幼龄鼠的血液之后，老龄鼠的海马体就会大量产生新的神经元。海马体是大脑中的一个区域，对记忆的形成具有关键作用。

In a study published Sunday in the journal Nature Medicine, Dr. Villeda, now a faculty fellow at the University of California, San Francisco, and his colleagues unveiled more details of what young blood does to the brains of old mice.
在周日发表于《自然医学》(Nature Medicine)杂志的一篇文章中，现已成为加州大学旧金山分校(University of California, San Francisco)研究员的比列达和同事披露了更多细节，阐述了幼龄鼠的血液对老龄鼠大脑造成的影响。

After parabiosis, Dr. Villeda and his colleagues found that the neurons in the hippocampus of the old mice sprouted new connections. They then moved beyond parabiosis by removing the cells and platelets from the blood of young mice and injecting the plasma that remained into old mice. That injection caused the old mice to perform far better on memory tests.
比列达和同事发现，异种共生过程之后，老龄鼠海马体中的神经元长出了新的联结。然后，除了异种共生之外，他们还移除了幼龄鼠血液中的细胞和血小板，再把剩下的血浆注入老龄鼠体内。这种注射大幅改善了老龄鼠在记忆测试中的表现。

Dr. Wagers's team has been investigating a specific region of the brain involved in perceiving smells.
韦杰斯的团队一直在对大脑中与嗅觉相关的一个特殊区域进行研究。

In a second study in Science, the team reports that parabiosis spurred the growth of blood vessels in the brain. The new blood supply led to the growth of neurons and gave older mice a sharper sense of smell.
他们的团队在《科学》刊载的另一篇文章中指出，异种共生能刺激脑血管的生长。新的血液能促进神经元的生长，让老龄鼠具有更灵敏的嗅觉。

After linking the GDF11 protein to the rejuvenation of skeletal muscle and the heart, Dr. Wagers and her colleagues studied whether the protein was also responsible for the changes in the brain. They injected GDF11 alone into the mice and found that it spurred the growth of blood vessels and neurons in the brain, although the change was not as large as that from parabiosis.
将GDF11蛋白质与骨骼肌肉和心脏的复苏联系起来以后，韦杰斯和同事还对这种蛋白质是否与脑部变化有关进行了研究。他们对老鼠注射了单一的GDF11，然后发现它促进了脑部血管和神经元的生长，虽然相关变化并不像异种共生那么明显。

"There's no conflict between the two groups, which is heartening," said Dr. Richard M. Ransohoff, director of the Neuroinflammation Research Center at the Cleveland Clinic.
克利夫兰医学中心神经炎症研究中心(Neuroinflammation Research Center at the Cleveland Clinic)负责人理查德·M·兰索霍夫博士(Dr. Richard M. Ransohoff)称，“两个团队的发现没有冲突，这很令人振奋。”

Dr. Ransohoff and others hope the experiments on mice will lead to studies on people to see if the human version of GDF11, or other molecules in the blood of young people, has a similar effect on older adults.
兰索霍夫和其他一些人都希望，以小鼠为对象的实验能够衍生以人为对象的研究，以探明人类版的GDF11或年轻人血液中的其他分子能否对老年人产生类似影响。

"We can turn back the clock instead of slowing the clock down," said Dr. Toren Finkel, director of the Center for Molecular Medicine at the National Heart, Lung and Blood Institute. "That's a nice thought if it pans out."
“我们可以让时间倒流，不只是让它放慢脚步，”美国国家心脏、肺和血液研究所(National Heart, Lung and Blood Institute)分子医学研究中心负责人托伦·芬克尔博士(Dr. Toren Finkel)说。“如果能成功，这将是个不错的想法。”