00:00:14
When you think about the brain,
00:00:16
it's sort of a difficult thing to understand,
00:00:18
because if I were to ask you right now, how does the heart work,
00:00:21
you would instantly tell me it's a pump. It pumps blood.
00:00:24
And if I were to ask you how your lungs work,
00:00:25
you would say it exchanges oxygen for carbon dioxide. That's easy.
00:00:29
Now if I were to ask you how the brain works, it's a hard thing to understand
00:00:32
because you can't just look at a brain and understand what it is.
00:00:35
It's not a mechanical object, it's not a pump, it's not an airbag.
00:00:38
It's just like, if you held it in your hand when it was dead, it's just a piece of fat.
00:00:42
And so to understand how the brain works,
00:00:45
you have to go inside a living brain. Because the brain's not mechanical,
00:00:48
the brain is electrical and it's chemical.
00:00:51
Your brain is made out of 100 billion cells,
00:00:53
and these cells are called neurons. And these neurons communicate with each other with electricity.
00:00:57
And we're going to eavesdrop in on a conversation between two cells,
00:01:01
and we're going to listen to something called a spike.
00:01:04
But we're not going to record my brain or your brain or your teacher's brains,
00:01:07
we're going to use our good friend the cockroach.
00:01:09
Not just because I think they're cool,
00:01:12
but because they have brains very similar to ours.
00:01:14
And so if you learn a little bit about how their brains work,
00:01:17
we're going to learn a lot about how our brains work.
00:01:19
So I'm going to put them in some ice water here
00:01:24
(Audience: Ew!) ... yeah ...
00:01:27
So what's happening right now is that they're becoming anesthetized,
00:01:29
because they're cold blooded, they become the temperature of the water
00:01:32
and they can't control it so they just basically "chillax," right?
00:01:35
They're not going to be able to feel anything,
00:01:37
and that may just tell you a little bit about what we're going to be doing.
00:01:39
We're going to be doing a scientific experiment to understand the brain.
00:01:44
This is the leg of a cockroach
00:01:46
and a cockroach has all these beautiful hairs
00:01:48
and pricklies all over it.
00:01:50
Underneath each one of those is a cell,
00:01:53
and this cell's a neuron, and this neuron's going to send information
00:01:56
about wind or vibrations. If you ever try to catch a cockroach, it's hard
00:01:59
because they can feel you coming before you're even there, they start running.
00:02:03
So these cells are zipping up this information up to the brain
00:02:05
using those little axons with electronic messages in there.
00:02:08
So we're going to record by sticking a pin right in there.
00:02:10
So we need to take off the leg of a cockroach --
00:02:14
don't worry, they'll grow back --
00:02:16
then we're going to put two pins in there. One of the pins, these are metal pins,
00:02:19
will pick up this electronic message, this electric message is going by.
00:02:23
So, we're now going to do the surgery, let's see if you guys can see this.
00:02:26
Yeah, it's gross ...
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