几年之后，哈佛大学的艾米•魏杰斯成功重现了这一实验结果，而其他人的实验表明，在胰、肝和心脏也可以观察到类似的年轻化效果。
This was reproduced by Amy Wagers at Harvard a few years later, and others then showed that similar rejuvenating effects could be observed in the pancreas, the liver and the heart.
但最让我，还有其它几个实验室感到兴奋的地方在于，这一效果甚至可能应用于大脑。
But what I'm most excited about, and several other labs as well, is that this may even apply to the brain.
因此，我们发现，将老年老鼠置于年轻环境之中，这一模型被称为连体共生，它的大脑变得年轻了——功能也变得更好。
So, what we found is that an old mouse exposed to a young environment in this model called parabiosis, shows a younger brain — and a brain that functions better.
我再重复一遍：一只老年老鼠，通过共通的血液循环得到年轻血液，其大脑显得更加年轻，功能也更年轻化。
And I repeat: an old mouse that gets young blood through shared circulation looks younger and functions younger in its brain.
当我们逐渐变老时——我们可以看看人类认知能力的不同方面，从这张幻灯片上，大家可以看到推理、语言能力等等。
So when we get older — we can look at different aspects of human cognition, and you can see on this slide here, we can look at reasoning, verbal ability and so forth.
一直到大约50或60岁，这些功能都没有受损，我看了下坐在这里的年轻观众，大家都没有问题。
And up to around age 50 or 60, these functions are all intact, and as I look at the young audience here in the room, we're all still fine.
但是看到这些曲线开始下降还是挺吓人的。
But it's scary to see how all these curves go south.
当我们变老时，会开始出现像阿尔茨海默症（老年痴呆）这样的疾病。
And as we get older, diseases such as Alzheimer's and others may develop.
我们知道，随着年龄增加，神经元之间的联系——神经元之间进行对话的突触——开始退化；神经元开始衰亡，大脑逐渐萎缩，人们也就越来越容易患上这些神经退化疾病。
We know that with age, the connections between neurons — the way neurons talk to each other, the synapses — they start to deteriorate; neurons die, the brain starts to shrink, and there's an increased susceptibility for these neurodegenerative diseases.
我们面临的一大问题是——想要在分子和功能机制层面上搞清楚这个过程是如何发生的——但我们还无法研究活体人类大脑活动的细节问题。
One big problem we have — to try to understand how this really works at a very molecular mechanistic level — is that we can't study the brains in detail, in living people.
我们可以进行认知测试，可以做成像——各种复杂测试。
We can do cognitive tests, we can do imaging — all kinds of sophisticated testing.
但通常我们得等到人死亡之后，才能看到大脑，才能了解因为年龄或疾病，它到底发生了什么变化。
But we usually have to wait until the person dies to get the brain and look at how it really changed through age or in a disease.
这就是神经病理学家的工作。
This is what neuropathologists do, for example.
那么，我们不妨把大脑当做有机体的一部分。
So, how about we think of the brain as being part of the larger organism.
我们是否可能有更深入的了解，从分子层面了解，大脑内部是怎样运转的，如果我们把大脑看作整个身体的一部分？
Could we potentially understand more about what happens in the brain at the molecular level if we see the brain as part of the entire body?
那么如果身体变老或生病了，会影响到大脑吗？
So if the body ages or gets sick, does that affect the brain?
而且反过来：如果大脑变老了，会影响到身体其它部分吗？
And vice versa: as the brain gets older, does that influence the rest of the body?
而将身体各个不同组织联系到一起的就是：血液。
And what connects all the different tissues in the body is blood.
血液是一种组织，它不只含有携带氧气的细胞，比如说，红细胞，或对抗感染性疾病的细胞，它还含有信使分子，这些类激素的因子，能够在细胞之间传递信息，还能在身体组织之间传递信息，其中也包括大脑。
Blood is the tissue that not only carries cells that transport oxygen, for example, the red blood cells, or fights infectious diseases, but it also carries messenger molecules, hormone-like factors that transport information from one cell to another, from one tissue to another, including the brain.
那么如果我们看到了血液因为疾病或年龄而发生了怎样的变化，我们是否也可以以此来获得大脑的信息呢？
So if we look at how the blood changes in disease or age, can we learn something about the brain?
我们知道，随着我们逐渐变老，血液也在同样变化，所以这类激素因子也随着变老而变化。
We know that as we get older, the blood changes as well, so these hormone-like factors change as we get older.
从总体上来说，这些因子，我们已知是组织发育所需的，维持其功能的因子——随着我们变老，它们开始变少，而与修复、伤害和炎症有关的那些因子——它们随着身体的衰老却在增加。
And by and large, factors that we know are required for the development of tissues, for the maintenance of tissues — they start to decrease as we get older, while factors involved in repair, in injury and in inflammation — they increase as we get older.
然后我们选取了给大家展示过的这些主要因子，来计算他们的相对年龄，生理年龄。
And then we take these top factors that I showed you, and we calculate their relative age, their biological age.
大家可以看到，其中有明显的相关性，所以我们可以相当准确地预测一个人的相对年龄。
And what you see is that there is a pretty good correlation, so we can pretty well predict the relative age of a person.