You can grow new brain cells. Here's how | Sandrine Thuret | TED

翻译人员: Zhiting Chen 校对人员: Geoff Chen

Can we, as adults, grow new nerve cells?

我们，作为成人，还能生长 新的神经细胞吗？

There's still some confusion about that question,

这个问题还未完全清晰，

as this is a fairly new field of research.

因为这还是新的研究领域。

For example, I was talking to one of my colleagues, Robert,

比方说，我跟我的同事罗伯特说，

who is an oncologist,

罗伯特是一名肿瘤学家，

and he was telling me,

他告诉我，

"Sandrine, this is puzzling.

“桑德琳，这很令人疑惑。

Some of my patients that have been told they are cured of their cancer

我的一些病人，即使被告知 他们的癌症已治愈，

still develop symptoms of depression."

仍有抑郁的症状。”

And I responded to him,

我回答道，

"Well, from my point of view that makes sense.

“嗯，在我看来这是可以解释的。

The drug you give to your patients that stops the cancer cells multiplying

你给病人开的， 用以阻止癌细胞增生的药

also stops the newborn neurons being generated in their brain."

同时也阻止了他们大脑中 生长出新的神经元。”

And then Robert looked at me like I was crazy and said,

罗伯特看着我，仿佛我疯了似的，

"But Sandrine, these are adult patients --

“但是桑德琳，他们是成年的病人--

adults do not grow new nerve cells."

成人不会生长新的神经细胞。”

And much to his surprise, I said, "Well actually, we do."

非常惊讶，我说， “事实上，我们可以。”

And this is a phenomenon that we call neurogenesis.

这个现象我们称之为 神经生成。

[Neurogenesis]

[神经生成]

Now Robert is not a neuroscientist,

罗伯特不是一名脑神经科学家，

and when he went to medical school he was not taught what we know now --

当他在医学院上学的时候 并没有学到我们现在所知道的

that the adult brain can generate new nerve cells.

成人大脑能够生成新的神经细胞。

So Robert, you know, being the good doctor that he is,

因此罗伯特， 作为一名好医生，

wanted to come to my lab

想要到我的实验室来

to understand the topic a little bit better.

更深层的了解一下这个研究。

And I took him for a tour

我向他展示了

of one of the most exciting parts of the brain

大脑最令人兴奋的部分

when it comes to neurogenesis --

有关神经生成的活动--

and this is the hippocampus.

这是海马体。

So this is this gray structure in the center of the brain.

就是大脑中心这个灰色的结构。

And what we've known already for very long,

我们早已得知，

is that this is important for learning, memory, mood and emotion.

这对学习，记忆，情绪和情感 很重要。

However, what we have learned more recently

然而，我们进来新研究出的是

is that this is one of the unique structures of the adult brain

这是一个对成人大脑来说 很特别的结构，

where new neurons can be generated.

这里能够生成新的神经元。

And if we slice through the hippocampus

当我们切开海马体

and zoom in,

并放大，

what you actually see here in blue

你所看到的这些蓝色物质

is a newborn neuron in an adult mouse brain.

就是成年老鼠大脑中 新生张出来的神经元。

So when it comes to the human brain --

在人类大脑中--

my colleague Jonas Frisén from the Karolinska Institutet,

我来自卡罗林斯卡学院的同事 Jonas Frisén说，

has estimated that we produce 700 new neurons per day

人类每天生长约700个新的神经元

in the hippocampus.

在海马体内。

You might think this is not much,

你可能认为这并不是很多，

compared to the billions of neurons we have.

因为人体有数十亿神经元。

But by the time we turn 50,

但是当我们快到50岁的时候，

we will have all exchanged the neurons we were born with in that structure

我们出生时所有的神经元 都会变成那个结构中

with adult-born neurons.

成人时期生长出的神经元。

So why are these new neurons important and what are their functions?

为什么新的神经元是重要的 它们有怎样的作用呢？

First, we know that they're important for learning and memory.

首先，我们指导它们对于 学习和记忆功能来说很重要。

And in the lab we have shown

在实验室中，我们发现

that if we block the ability of the adult brain

如果我们阻止了成人大脑中

to produce new neurons in the hippocampus,

海马体生长新的神经元的功能，

then we block certain memory abilities.

那意味着我们也阻止了 某些记忆能力。

And this is especially new and true for spatial recognition --

这对空间识别感 非常重要--

so like, how you navigate your way in the city.

就像，你如何在城市中活动。

We are still learning a lot,

我们仍在学习，

and neurons are not only important for memory capacity,

神经元对于记忆能力，

but also for the quality of the memory.

以及记忆的质量来说 非常重要。

And they will have been helpful to add time to our memory

他们能够帮助我们的记忆 加入时间概念

and they will help differentiate very similar memories, like:

他们也会帮助我们区分 非常相近的记忆，比如：

how do you find your bike

如何寻找你的自行车

that you park at the station every day in the same area,

你每天都将它停在 车站附近的同一块地方，

but in a slightly different position?

但是在这片地不同的位置？

And more interesting to my colleague Robert

对我的同事罗伯特来说 更有意思的是

is the research we have been doing on neurogenesis and depression.

我们正在做有关神经生成 和抑郁的研究。

So in an animal model of depression,

在这个关于抑郁的动物模型，

we have seen that we have a lower level of neurogenesis.

我们可以看到 它的神经生成在较低的水平，

And if we give antidepressants,

如果给牠们服用抗抑郁剂，

then we increase the production of these newborn neurons,

我们增加了新生的神经元，

and we decrease the symptoms of depression,

于是抑郁的症状就减轻了，

establishing a clear link between neurogenesis and depression.

在细胞生成和抑郁症状间 建立了清晰地联系。

But moreover, if you just block neurogenesis,

此外，如果你阻止了细胞生成，

then you block the efficacy of the antidepressant.

那你也就阻止了抗抑郁剂的功效。

So by then, Robert had understood

那时，罗伯特理解到

that very likely his patients were suffering from depression

他的病人们很有可能会 遭受抑郁的症状

even after being cured of their cancer,

即使在癌症治愈以后，

because the cancer drug had stopped newborn neurons from being generated.

因为抗癌药物阻止了 身体新的神经元的生成。

And it will take time to generate new neurons

那需要一些时间 生成新的神经元

that reach normal functions.

让它达到正常的运作。

So, collectively, now we think we have enough evidence

总的来说， 我想我们有足够的证据

to say that neurogenesis is a target of choice

来表明细胞生成是一个目标方法，

if we want to improve memory formation or mood,

如果我们想要提高记忆力 或是提高情绪，

or even prevent the decline associated with aging,

或是防止衰老，

or associated with stress.

或是抗击压力。

So the next question is:

下一个问题就是：

can we control neurogenesis?

我们能够控制神经生成吗？

The answer is yes.

答案是，是。

And we are now going to do a little quiz.

我们现在进行一个小问答。

I'm going to give you a set of behaviors and activities,

我会给你们一组行为或是活动，

and you tell me if you think they will increase neurogenesis

你们来判断 这些能否促进细胞新生

or if they will decrease neurogenesis.

或是这些会降低细胞生成。

Are we ready?

准备好了吗？

OK, let's go.

现在开始。

So what about learning?

学习？

Increasing?

增长？

Yes.

是的。

Learning will increase the production of these new neurons.

学习能够提高神经细胞的生成。

How about stress?

压力？

Yes, stress will decrease the production of new neurons in the hippocampus.

是的，压力会降低海马体内 神经细胞的生成。

How about sleep deprivation?

那么睡眠匮乏呢？

Indeed, it will decrease neurogenesis.

确实，它会降低神经生成。

How about sex?

性爱呢？

Oh, wow!

哇！

(Laughter)

（笑声）

Yes, you are right, it will increase the production of new neurons.

是，你们是对的，它能促进 神经新生。

However, it's all about balance here.

然而，这一切都有关平衡。

We don't want to fall in a situation --

我们不希望出现这样的情况--

(Laughter)

（笑声）

about too much sex leading to sleep deprivation.

太多的性爱导致睡眠匮乏。

(Laughter)

（笑声）

How about getting older?

年龄增长？

So the neurogenesis rate will decrease as we get older,

细胞生成率会随着我们变老而降低，

but it is still occurring.

但它仍会生成。

And then finally, how about running?

最后，跑步？

I will let you judge that one by yourself.

这要看你们各自的情况自己决定。

So this is one of the first studies

这是第一个研究

that was carried out by one of my mentors, Rusty Gage from the Salk Institute,

是我在索尔克研究所的导师 Rusty Gage做的，

showing that the environment can have an impact

显示出环境对于

on the production of new neurons.

生长新的神经有影响。

And here you see a section of the hippocampus of a mouse

这幅图片是老鼠的海马体，

that had no running wheel in its cage.

它的笼子里没有滚动跑轮。

And the little black dots you see are actually newborn neurons-to-be.

黑色的小点点 是将要新生的神经元。

And now, you see a section of the hippocampus of a mouse

现在，这幅是老鼠的海马体

that had a running wheel in its cage.

它的笼子里有滚动跑轮。

So you see the massive increase

你可以看到数量巨大的

of the black dots representing the new neurons-to-be.

黑色小点点显示出 它的神经元生成状况。

So activity impacts neurogenesis, but that's not all.

所以，活动会影响神经生成， 但并不只是如此。

What you eat will have an effect

你吃的东西会影响到

on the production of new neurons in the hippocampus.

海马体生长新的神经元。

So here we have a sample of diet --

这里我们有一个健康饮食的样本--

of nutrients that have been shown to have efficacy.

这些有功效的营养物质。

And I'm just going to point a few out to you:

我要指出一些来：

Calorie restriction of 20 to 30 percent will increase neurogenesis.

卡路里保持在20%-30% 会增强细胞生长。

Intermittent fasting -- spacing the time between your meals --

间歇地断食-- 在餐与餐之间空下时间--

will increase neurogenesis.

会提高神经细胞新生。

Intake of flavonoids,

摄入黄酮类物质，

which are contained in dark chocolate or blueberries,

在黑巧克力或蓝莓中，

will increase neurogenesis.

会提高神经细胞新生。

Omega-3 fatty acids,

欧米伽-3 脂肪酸，

present in fatty fish, like salmon,

在脂质鱼中，比如三文鱼，

will increase the production of these new neurons.

会提高神经细胞新生率。

Conversely, a diet rich in high saturated fat

相对的，那些高饱和脂肪

will have a negative impact on neurogenesis.

会对神经生成有不好的影响。

Ethanol -- intake of alcohol -- will decrease neurogenesis.

乙醇--酒精中摄取-- 会降低神经新生。

However, not everything is lost;

然而，并不是所有都不好，

resveratrol, which is contained in red wine,

白藜芦醇，红酒中的物质，

has been shown to promote the survival of these new neurons.

就能够促进新生神经的存活率。

So next time you are at a dinner party,

下次你再去晚宴派对的时候，

you might want to reach for this possibly "neurogenesis-neutral" drink.

你也许想要喝这种 可能“神经新生——中立”饮品。

(Laughter)

（笑声）

And then finally, let me point out the last one --

最后， 让我在说最后一点——

a quirky one.

古怪的一点

So Japanese groups are fascinated with food textures,

日本人着迷于食物的质感，

and they have shown that actually soft diet impairs neurogenesis,

软质饮食减少神经生成，

as opposed to food that requires mastication -- chewing -- or crunchy food.

相对于那些需要咀嚼，或是脆的食物。

So all of this data,

这些数据，

where we need to look at the cellular level,

我们用于观察细胞水平的，

has been generated using animal models.

都是通过动物模型完成。

But this diet has also been given to human participants,

但这样的饮食同样也给与了人类参与者，

and what we could see is that the diet modulates memory and mood

我们能看到的是 饮食调节记忆和情绪

in the same direction as it modulates neurogenesis,

和它调节神经生成同样的方向，

such as: calorie restriction will improve memory capacity,

比如：卡路里限制会 提高记忆能力，

whereas a high-fat diet will exacerbate symptoms of depression --

反之，一个高脂肪的饮食会 加剧抑郁的症状。

as opposed to omega-3 fatty acids, which increase neurogenesis,

相反的，欧米伽-3脂肪酸， 会提高神经生成，

and also help to decrease the symptoms of depression.

同时也会帮助减缓 抑郁的症状。

So we think that the effect of diet

因此我们认为饮食的效用

on mental health, on memory and mood,

在神经健康、记忆和情绪，

is actually mediated by the production of the new neurons in the hippocampus.

是通过在海马体内 制造新的神经元间接完成的。

And it's not only what you eat,

不只是你吃什么，

but it's also the texture of the food, when you eat it

还有食物的质地， 什么时候吃

and how much of it you eat.

吃了多少来决定。

On our side -- neuroscientists interested in neurogenesis --

在我们神经科学家这边-- 有兴趣的神经生成--

we need to understand better the function of these new neurons,

我们需要更好的了解 这些新生神经的功能，

and how we can control their survival and their production.

以及我们如何控制 它们的存活率和制造情况。

We also need to find a way to protect the neurogenesis of Robert's patients.

我们同样也要寻找一个方法 来保护罗伯特病人的神经生成。

And on your side --

在你们这边--

I leave you in charge of your neurogenesis.

请你们自己决定自己的细胞生成。

Thank you.

谢谢

(Applause)

（鼓掌）

Margaret Heffernan: Fantastic research, Sandrine.

玛格丽特·赫夫南： 太精彩的研究，桑德琳。

Now, I told you you changed my life --

现在，我告诉你你改变了我的生活--

I now eat a lot of blueberries.

我现在开始吃大量的蓝莓。

Sandrine Thuret: Very good.

桑德琳·苏瑞：这太好了。

MH: I'm really interested in the running thing.

玛格丽特：我很好奇 关于跑步的那个讨论。

Do I have to run?

我需要跑步吗？

Or is it really just about aerobic exercise,

还是指我们要做有氧运动，

getting oxygen to the brain?

让大脑吸氧？

Could it be any kind of vigorous exercise?

可以是任何激烈运动吗？

ST: So for the moment,

桑德琳：此时此刻，

we can't really say if it's just the running itself,

我们无法准确说明 是否只能跑步，

but we think that anything that indeed will increase the production --

但我想任何事 能够提高生成--

or moving the blood flow to the brain,

或是血液移动到大脑的，

should be beneficial.

应该都是有益的。

MH: So I don't have to get a running wheel in my office?

玛格丽特： 那我不需要在我的办公室放一个转轮了？

ST: No, you don't!

桑德琳：不，你不需要！

MH: Oh, what a relief! That's wonderful.

玛格丽特：真是松了口气！太精彩了。

Sandrine Thuret, thank you so much.

桑德琳·苏瑞，非常感谢你。

ST: Thank you, Margaret.

桑德琳：谢谢你，玛格丽特。

(Applause)

（鼓掌）