Electrical experiments with plants that count and communicate | Greg Gage

翻译人员: JIE LEI 校对人员: Cissy Yun

I'm a neuroscientist,

我是位神经学家，

and I'm the co-founder of Backyard Brains,

Backyard Brains的联合创始人，

and our mission is to train the next generation of neuroscientists

我们的使命是 培养下一代的神经学家，

by taking graduate-level neuroscience research equipment

通过将研究生运用的研究设备

and making it available for kids in middle schools and high schools.

融入到初高中课程中。

And so when we go into the classroom,

开始上课的时候，

one way to get them thinking about the brain, which is very complex,

我们让他们开始思考关于大脑， 这个十分复杂的物体的一个方法，

is to ask them a very simple question about neuroscience,

就是向他们提出一个非常简单的 关于神经科学的问题，

and that is, "What has a brain?"

“什么东西具有大脑“？

When we ask that,

当我们提问的时候，

students will instantly tell you that their cat or dog has a brain,

学生们会马上告诉你 他们的猫或狗有大脑，

and most will say that a mouse or even a small insect has a brain,

大多数学生会说一只老鼠 甚至一只小昆虫有大脑，

但几乎没人会说一棵植物或者树，

but almost nobody says that a plant or a tree

or a shrub has a brain.

或者一株灌木有大脑。

And so when you push --

所以当你进一步启发他们——

because this could actually help describe a little bit

因为这实际上可以帮助描述

how the brain actually functions --

大脑是如何运作的——

so you push and say,

所以当你继续问

"Well, what is it that makes living things have brains versus not?"

“是什么让有些生物拥有大脑， 而有些则没有？”

And often they'll come back with the classification

他们往往会分类作答，

that things that move tend to have brains.

那就是移动的物体拥有大脑。

And that's absolutely correct.

这绝对是正确的。

Our nervous system evolved because it is electrical.

我们的神经系统因电流而进化。

It's fast, so we can quickly respond to stimuli in the world

它们速度很快， 在我们需要的情况下

and move if we need to.

使我们能快速对 外界刺激做出反应。

But you can go back and push back on a student,

但是你可以引导学生逆向思维，

and say, "Well, you know, you say that plants don't have brains,

“很好，你说植物没有大脑，”

but plants do move."

“但它们可以移动啊。”

Anyone who has grown a plant

任何养过植物的人

has noticed that the plant will move

都会注意到植物可以移动，

and face the sun.

并且趋光。

But they'll say, "But that's a slow movement.

但他们会说， “这是一个缓慢的过程。”

You know, that doesn't count. That could be a chemical process."

“这不算，那可能是一种化学过程。”

But what about fast-moving plants?

但如果是快速运动的植物呢？

Now, in 1760, Arthur Dobbs, the Royal Governor of North Carolina,

在1760年，北卡罗莱纳州的 皇家总督亚瑟▪多布斯

made a pretty fascinating discovery.

发现一个很有趣的现象。

In the swamps behind his house,

在他房子后面的沼泽地，

he found a plant that would spring shut

生长着一种植物，每当有虫子落在

every time a bug would fall in between it.

它们的叶片之间，叶片就会闭合。

He called this plant the flytrap,

他称之为捕蝇草。

and within a decade, it made its way over to Europe,

十年内，捕蝇草已经到了欧洲，

where eventually the great Charles Darwin got to study this plant,

伟大的查尔斯▪达尔文 开始研究这种植物，

and this plant absolutely blew him away.

捕蝇草让他十分着迷。

He called it the most wonderful plant in the world.

达尔文称之为世界上最奇妙的植物。

This is a plant that was an evolutionary wonder.

这是一种进化奇迹。

This is a plant that moves quickly,

植物可以快速运动，

which is rare,

非常罕见。

and it's carnivorous, which is also rare.

而且捕蝇草是 肉食性植物，同样罕见。

And this is in the same plant.

两种特征合二为一。

But I'm here today to tell you

但是，今天在这里我要告诉你

that's not even the coolest thing about this plant.

这并不是捕蝇草最奇特的地方。

The coolest thing is that the plant can count.

最奇特的是这种植物有计算能力。

So in order to show that,

为了证明这一点，

we have to get some vocabulary out of the way.

我们需要认识一些词汇。

So I'm going to do what we do in the classroom with students.

今天我要在这里做一项 和学生们在教室里一起做的实验。

We're going to do an experiment on electrophysiology,

我们今天要做一个 关于电生理现象的实验，

which is the recording of the body's electrical signal,

就是记录身体中

either coming from neurons or from muscles.

来自神经元或肌肉的电信号。

And I'm putting some electrodes here on my wrists.

我在手腕上贴上电极。

As I hook them up,

当我连接上之后，

we're going to be able to see a signal

我们可以看到有信号

on the screen here.

显示在记录仪屏幕上。

And this signal may be familiar to you.

这种图案你可能很熟悉。

It's called the EKG, or the electrocardiogram.

就是所谓的心电图。

And this is coming from neurons in my heart

来自我心脏的神经元，

that are firing what's called action potentials,

正在发射所谓的动作电位，

potential meaning voltage and action meaning it moves quickly up and down,

电位即电压，动作即意味着 它能快速上下运动，

which causes my heart to fire,

使我的心脏跳动，

which then causes the signal that you see here.

然后你就能在这儿看到电信号。

And so I want you to remember the shape of what we'll be looking at right here,

现在，你要记住你所看到的 仪器上显示的信号形状，

这是非常重要的一步。

because this is going to be important.

这是大脑以动作电位

This is a way that the brain encodes information

in the form of an action potential.

编码信息的一种方式。

So now let's turn to some plants.

现在，我们来关注一些植物。

So I'm going to first introduce you to the mimosa,

第一步，我将向你介绍含羞草，

not the drink, but the Mimosa pudica,

不是那种饮料，是含羞草植物，

and this is a plant that's found in Central America and South America,

这种植物发现于 美州中部和南部地区，

and it has behaviors.

这种植物具有行为。

And the first behavior I'm going to show you

我将向你展示 含羞草的第一种行为，

is if I touch the leaves here,

碰到它这里的叶片，

you get to see that the leaves tend to curl up.

你会看到叶子蜷起来了。

And then the second behavior is,

第二种行为是，

if I tap the leaf,

如果我轻点叶子，

the entire branch seems to fall down.

整个枝条似乎都垂下了。

So why does it do that?

问题来了，含羞草 为什么要这样呢？

It's not really known to science.

这在科学上仍然未知。

One of the reasons why could be that it scares away insects

其中原因之一 可能是为了吓跑昆虫，

or it looks less appealing to herbivores.

或者看起来不太吸引食草动物。

But how does it do that? Now, that's interesting.

但它是怎么做到的呢？ 这就非常有趣了。

We can do an experiment to find out.

我们可以做个实验了解一下。

So what we're going to do now,

我们要做的是，

just like I recorded the electrical potential from my body,

就像我记录我身体的电流一样，

we're going to record the electrical potential from this plant, this mimosa.

我们将记录含羞草的电流数据。

And so what we're going to do is I've got a wire wrapped around the stem,

我们要用一根电线 缠绕在含羞草的茎上，

and I've got the ground electrode where?

我把接地线放哪了？

In the ground. It's an electrical engineering joke. Alright.

在地上呢，这是个电气工程玩笑。

(Laughter)

（笑声）

Alright. So I'm going to go ahead and tap the leaf here,

好了，接下来 我要继续轻点叶子了，

你将会看到在植物内部

and I want you to look at the electrical recording

记录下的电子数据。

that we're going to see inside the plant.

Whoa. It is so big, I've got to scale it down.

哇，波动很强烈，让我把 整个信号调整到屏幕以内。

Alright. So what is that?

好了，那是什么呢？

That is an action potential that is happening inside the plant.

那是植物内部发生的一种动作电位。

Why was it happening?

为什么会发生这样的情况呢？

因为它（含羞草）想要移动，对吗？

Because it wanted to move. Right?

And so when I hit the touch receptors,

所以当我碰到传感器（枝叶）的时候，

it sent a voltage all the way down to the end of the stem,

它将电流传送到枝叶末端，

这就导致它垂落枝条。

which caused it to move.

And now, in our arms, we would move our muscles,

我们可以让手臂上的 肌肉动起来，

but the plant doesn't have muscles.

但植物并没有肌肉。

What it has is water inside the cells

植物的细胞内充满液体，

and when the voltage hits it, it opens up, releases the water,

当电流传导时，细胞打开，释放液体，

changes the shape of the cells, and the leaf falls.

并改变细胞的形态，然后枝叶垂落。

OK. So here we see an action potential encoding information to move. Alright?

好的，我们看到了动作电位 通过编码信息来运动。

But can it do more?

但是，植物可以做更多的事情吗？

So let's go to find out.

我们再来深入了解一下。

We're going to go to our good friend, the Venus flytrap here,

现在请出我们的好朋友， 维纳斯捕蝇草，

and we're going to take a look at what happens inside the leaf

当苍蝇落在叶子中间，

when a fly lands on here.

我们来观察会发生什么。

So I'm going to pretend to be a fly right now.

现在我要假装是一只苍蝇。

And now here's my Venus flytrap,

这是维纳斯捕蝇草，

and inside the leaf, you're going to notice

在叶片内侧，你会注意到

that there are three little hairs here, and those are trigger hairs.

有三根毛发，这是它的触发毛。

And so when a fly lands --

所以当苍蝇降落的时候——

I'm going to touch one of the hairs right now.

我要触碰触发毛了。

Ready? One, two, three.

准备好了吗？1,2,3。

What do we get? We get a beautiful action potential.

看，我们得到了一条优美的 动作电位图。

However, the flytrap doesn't close.

然而，捕蝇草叶片并没有闭合。

And to understand why that is,

为了了解为什么会这样，

我们需要了解一些捕蝇草的行为。

we need to know a little bit more about the behavior of the flytrap.

第一条，它需要很长时间 来打开陷阱（叶片）——

Number one is that it takes a long time to open the traps back up --

you know, about 24 to 48 hours if there's no fly inside of it.

如果没有苍蝇在里面， 大概需要24到48小时。

And so it takes a lot of energy.

所以需要大量的能量。

And two, it doesn't need to eat that many flies throughout the year.

第二条，它全年 不需要吃太多苍蝇。

Only a handful. It gets most of its energy from the sun.

几只就够了，它通过 阳光来摄取大部分的能量。

It's just trying to replace some nutrients in the ground with flies.

它只是想用苍蝇替代一些 从地下获得的养分。

And the third thing is,

第三条，

直到叶片枯萎，

it only opens then closes the traps a handful of times

until that trap dies.

陷阱只能开合几次。

So therefore, it wants to make really darn sure

因此，它要确保捕虫叶闭合前，

that there's a meal inside of it before the flytrap snaps shut.

里面一定有顿美餐。

So how does it do that?

所以，它怎么做到的呢？

It counts the number of seconds

捕蝇草是通过

between successive touching of those hairs.

计算连续触碰触发毛的秒数。

And so the idea is that there's a high probability,

所以，我们的想法是 有一个高的概率，

if there's a fly inside of there, they're going to be quick together,

如果里面有只苍蝇，可以视为触碰，

当捕蝇草接收第一次的信号时，

and so when it gets the first action potential,

开始计数，1，2，

it starts counting, one, two,

如果计数到20又没有中断，

and if it gets to 20 and it doesn't fire again,

它不会闭合捕虫叶，

then it's not going to close,

但如果苍蝇依然在里面， 陷阱就闭合了。

but if it does it within there, then the flytrap will close.

我们继续实验。

So we're going to go back now.

I'm going to touch the Venus flytrap again.

我将再次触碰维纳斯捕蝇草。

我已经说了超过20秒话了。

I've been talking for more than 20 seconds.

So we can see what happens when I touch the hair a second time.

让我们来看看再次 碰到触发毛会发生什么。

So what do we get? We get a second action potential,

我们得到了什么？ 第二次动作电位，

but again, the leaf doesn't close.

但是，捕虫叶仍然没有闭合。

So now if I go back in there

现在，我再回到那里，

and if I'm a fly moving around,

假装我是一只苍蝇到处移动，

我将触碰叶片几次。

I'm going to be touching the leaf a few times.

刷几下。

I'm going to go and brush it a few times.

And immediately,

捕蝇草

the flytrap closes.

立刻闭合了。

So here we are seeing the flytrap actually doing a computation.

我们看到捕蝇草实际上是在计算。

这取决于苍蝇是否在陷阱里，

It's determining if there's a fly inside the trap,

and then it closes.

然后就闭合了。

So let's go back to our original question.

那么，让我们回到最初的问题上。

Do plants have brains?

植物有大脑吗？

Well, the answer is no.

答案是否定的。

There's no brains in here.

植物并没有大脑。

There's no axons, no neurons.

没有轴突，没有神经元。

It doesn't get depressed.

它不会郁郁寡欢。

It doesn't want to know what the Tigers' score is.

不会考虑底特律 老虎队的得分是多少。

没有自我实现的问题。

It doesn't have self-actualization problems.

But what it does have is something that's very similar to us,

但它们的行为与我们如此相似，

which is the ability to communicate using electricity.

是使用生物电交流的能力。

It just uses slightly different ions than we do,

它仅是使用了 与我们稍微不用的离子，

但实际上做的是同样的事情。

but it's actually doing the same thing.

So just to show you

这个实验是为了展示，

the ubiquitous nature of these action potentials,

动作电位的自然普遍性，

we saw it in the Venus flytrap,

我们能在维纳斯捕蝇草上看到，

we've seen an action potential in the mimosa.

在含羞草上看到，

在人类身上也能看到。

We've even seen an action potential in a human.

Now, this is the euro of the brain.

这就是大脑的神经。

It's the way that all information is passed.

所有信息的传递方式。

And so what we can do is we can use those action potentials

所以我们能做的就是 利用这些动作电位

to pass information

在不同种类的植物间

between species of plants.

传递信息。

And so this is our interspecies plant-to-plant communicator,

所以，这就是植物与植物间的交流，

and what we've done is we've created a brand new experiment

我们所做的是创造出了 一种全新的实验，

where we're going to record the action potential from a Venus flytrap,

从维纳斯捕蝇草中记录动作电位，

and we're going to send it into the sensitive mimosa.

然后传送到敏感的含羞草中。

So I want you to recall what happens

所以，我想要你回想一下，

when we touch the leaves of the mimosa.

当我们触碰含羞草叶片的 时候发生了什么。

It has touch receptors that are sending that information

它拥有以动作电位的形式

back down in the form of an action potential.

传递信息的传感器。

And so what would happen

所以，如果我们

if we took the action potential from the Venus flytrap

从维纳斯捕蝇草中捕捉到 电动电位，并将之发送到

and sent it into all the stems of the mimosa?

含羞草的所有茎叶中，会发生什么？

We should be able to create the behavior of the mimosas

我们应该可以引发 含羞草的收缩行为，

without actually touching it ourselves.

而不需要亲自触碰。

And so if you'll allow me,

所以，让我来展示，

I'm going to go ahead and trigger this mimosa right now

我将继续通过触碰 捕蝇草的触发毛来

by touching on the hairs of the Venus flytrap.

触发含羞草的收缩行为。

So we're going to send information about touch from one plant to another.

我们要将触碰信息 从一株植物传递到另一株植物上。

So there you see it.

看到（含羞草枝叶收缩）了吧。

So --

那么——

(Applause)

（掌声）

So I hope you learned a little bit, something about plants today,

希望你今天能学到 一些关于植物的知识，

and not only that.

而且不仅仅如此。

You learned that plants could be used to help teach neuroscience

你了解到植物可以 用来帮助神经教学，

并带来神经学革命。

and bring along the neurorevolution.

Thank you.

谢谢。

（掌声）

(Applause)