When you think about the brain, it's difficult to understand, because if I were to ask you right now, how does the heart work, you would instantly tell me it's a pump. It pumps blood. If I were to ask about your lungs, you would say it exchanges oxygen for carbon dioxide. That's easy. If I were to ask you how the brain works, it's hard to understand because you can't just look at a brain and understand what it is. It's not a mechanical object, not a pump, not an airbag. It's just like, if you held it in your hand when it was dead, it's just a piece of fat. To understand how the brain works, you have to go inside a living brain. Because the brain's not mechanical, the brain is electrical and it's chemical. Your brain is made out of 100 billion cells, called neurons. And these neurons communicate with each other with electricity. And we're going to eavesdrop in on a conversation between two cells, and we're going to listen to something called a spike. But we're not going to record my brain or your brain or your teachers' brains, we're going to use our good friend the cockroach. Not just because I think they're cool, but because they have brains very similar to ours. So if you learn a little bit about how their brains work, we're going to learn a lot about how our brains work. I'm going to put them in some ice water here And then -- Audience: Ew! Greg Gabe: Yeah ... Right now they're becoming anesthetized. Because they're cold blooded, they become the temperature of the water and they can't control it so they just basically "chillax," right? They're not going to feel anything, which may tell you a little about what we're going to do, a scientific experiment to understand the brain. So ... This is the leg of a cockroach. And a cockroach has all these beautiful hairs and pricklies all over it. Underneath each one of those is a cell, and this cell's a neuron that is going to send information about wind or vibration. If you ever try to catch a cockroach, it's hard because they can feel you coming before you're even there, they start running. These cells are zipping up this information up to the brain using those little axons with electronic messages in there. We're going to record by sticking a pin right in there. We need to take off the leg of a cockroach -- don't worry, they'll grow back -- then we're going to put two pins in there. These are metal pins. One will pick up this electronic message, this electric message is going by. So, we're now going to do the surgery, let's see if you guys can see this. Yeah, it's gross ... All right. So there we go. You guys can see his leg right there. Now I'm going to take this leg, I'm going to put it in this invention that we came up with called the Spikerbox -- and this replaces lots of expensive equipment in a research lab, so you guys can do this in your own high schools, or in your own basements if it's me. (Audience: Laughter) So, there. Can you guys see that? Alright, so I'm going to go ahead and turn this on. I'm going to plug it in. (Tuning sound) To me, this is the most beautiful sound in the world. This is what your brain is doing right now. You have 100 billion cells making these raindrop-type noises. Let's take a look at what it looks like, let's pull it up on the iPad screen. I plugged my iPad into here as well. So remember we said the axon looks like a spike. So we're going to take a look at what one of them looks like in just a brief second. We're going to tap here, so we can sort of average this guy. So there we see it. That's an action potential. You've got 100 billion cells in your brain doing this right now, sending all this information back about what you're seeing, hearing. We also said this is a cell that's going to be taking up information about vibrations in the wind. So what if we do an experiment? We can actually blow on this and hear if we see a change. Are you guys going to be ready? If I blow on it you tell me if you hear anything. (Blowing) (Sound changes) Let me just touch this with a little pen here. (Noise) That was the neural firing rate. That actually took a while in neuroscience to understand this. This is called rate coding: the harder you press on something, the more spikes there are, and all that information is coming up to your brain. That's how you perceive things. So that's one way of doing an experiment with electricity. The other way is that your brain is not only taking in electrical impulses, you're also sending out. That's how you move your muscles around. Let's see what happens if I've plugged in something that's electric into the cockroach leg here. I'm going to take two pins, I'm going to plug them onto the cockroach. I'm going to take the other end, I'm going to plug in into my iPod. It's my iPhone actually. Do you guys know how your earbuds work in your ears? You have a battery in your phone, or iPod, right? It's sending electrical current into these magnets in your earbuds which shake back and forth and allow you to hear things. But that current's the same currency that our brain uses, so we can send that to our cockroach leg and hopefully if this works, we can actually see what happens when we play music into the cockroach. Let's take a look. (Music beat) Can we turn it up? There we go. (Audience reacts and gasps) GG: So what's happening? Audience: Wow! (Laughter) So you see what's moving. It's moving on the bass. All those audiophiles out there, if you have awesome, kicking car stereos, you know, the bass speakers are the biggest speakers. The biggest speakers have the longest waves, which have the most current, and the current is what's causing these things to move. So it's not just speakers that are causing electricity. Microphones also cause electricity. (Beat) So I'm going to go ahead and invite another person out on the stage here to help me out with this. So there we go. (Beatboxing) This is the first time this has ever happened in the history of mankind. Human beatbox to a cockroach leg. When you guys go back to your high school, think about neuroscience and how you guys can begin the neuro-revolution. Thank you very much. Bye bye. (Applause)
(音乐) 当你谈到大脑时, 你会觉得它很难理解。 如果我问你心脏是如何工作的, 你会说它像泵一样,抽运血液。 换作是肺, 你会说,它交换氧气和二氧化碳。这都很简单。 大脑的工作原理则很难理解, 因为你不能直观的观察大脑。 它不是机械装置,它不像泵或气囊。 将死亡的大脑放在手中,它就像是一堆脂肪。 想要了解大脑是如何工作的, 必须深入其内部。大脑不是机械的, 它是电能和化学能的结合。 它由一千亿个细胞组成, 这些细胞被称为神经元。他们靠电流传递信息。 我们来听听两个细胞间的谈话, 我们将听到所谓的“放电”。 我们用的并不是任何人的大脑, 而是蟑螂的大脑。 原因不是因为他们很酷,而是他们有 与我们相似的大脑。 从对他们的大脑的一点了解中, 我们将学到很多。 现在将他们放入冰水中, 然后…… (观众:呕!)……好的…… 他们已经失去知觉了, 因为他们的血液降到了冰水的温度, 身体不受控制,很“淡定”,是吧? 他们没有感觉。 我们接下来要做 一个科学实验来认识大脑。 嗯…… 这是一只蟑螂的腿, 它上面有很多 漂亮的毛刺。 在每一个毛刺下面有一个神经元, 它会将风和振动的信息传递出去。 你想抓住一只蟑螂是很难的, 因为它能在你行动前觉察,并迅速逃跑。 神经元通过轴突的电信号 将信息迅速上传给大脑。 在这里插一根针来记录。 我们需要取下蟑螂的一条腿 -- 别担心,会长回来的 -- 我们插入两根金属针。其中一根 将接收到电子信号,并将信号传递出去。 要做外科手术,你们也许看不下去。 啊,真恶心…… 好的……完成了…… 你们能看到它分离的腿。 现在将它放入我的发明装置 “放电盒” -- 它可以取代实验室中昂贵的仪器, 你们可以在学校自己动手做出来, 如果是我的话我会选在自家的地下室 -- 好了。(笑声) 你们看得见吗?我要打开它了。 插入接口。(神经元激发的声音) 对于我,这是世界上最美妙的声音。 这正是你的大脑正在做的。 一千亿个神经元发出雨滴似的声响, 看看呈现在iPad上的 波形图, 插上我的iPad。 还记得轴突吧,它看起来像放电。 我们马上就能看到它的样子。 我们轻拍下这里。 我们可以看到了,这是动作电位。 你脑中的一千亿个神经元亦是如此 处理感官信息的。 我们刚才提到神经元可以传递腿毛在风中振动的信息。 那么做个实验如何? 向它吹气并观察变化。 准备好了吗? 告诉我你在我吹气时听到什么。 (风吹产生的放电声音) 让我用一只笔触碰一下。 (声响) 这是神经元激发幅度。我们用了很久 才解释了它。它叫做频率编码, 你越用力按压,放电越明显, 信息传到大脑。我们就是这样感知事物的。 这是我们用电流做实验的方法。 你的大脑在接受电流脉冲时,也在发送信息。 这就是为什么你能够控制肌肉。 让我们看看将带电的针插入 蟑螂的腿,会发生什么。 我将两根针插在上面。 另一头接入我的iPod。 其实是iPhone。 知道耳机如何工作吗? 你手机里有块电池, 它向耳机中的磁体输送交替电流 这样你才能听到声音。 我们的大脑也运用同种电流, 所以我们将其直接输入蟑螂腿, 并观察播放音乐时的现象。 我们来看看。 (音乐节奏)我们来将他开启。 (观众惊讶)发生什么了? (音乐节奏) 你会看到它随着低音活动。 如果你是音箱发烧友,有最棒的车载立体声, 会知道低音扬声器是最大的扬声器。 它的波长最长且有最大的电流, 而正是电流使肢体活动。 所以并不只是扬声器制造电流, 麦克风也同样可以。(节拍) 接下来我要邀请另一个人到舞台 来协助我。来吧。(打Beatbox) 这是人类史上第一次。 人对着蟑螂腿打Beatbox。 等你们回到学校,要好好想想神经学,也许将来你们会带来革命。 谢谢大家。再见。(掌声)