 More dead white guys. These dead white guys? Dude, they won a Nobel Prize for discovering the action potential. And they discovered it in giant squid axons. And these like squid neurons, I don't know if the squid is the giant part or if the axon is the giant part. Regardless, whatever it was, something was giant. And that included the axon because they were like a millimetre in diameter. Which if you can imagine, I mean, I know that still is tiny, but that's like visible. Like you can actually pick it up and be like, oh, look, it's a twangable axon. So this allowed them to stick the voltmeter inside. So this allowed them to actually do this with a squid axon. So when they did it and they fired the neuron, they were able to figure out that this really weird thing happened when the axon fired. And guess what it is? The membrane potential changed. So they named it an action potential. The action potential is a rapid change in membrane potential from negative 70 up to like 30, positive 30, and back again. Oops, again. Seriously? True. How is that possible? But if you can, do you agree that if we could change this to make this positive 30, and it was like this big wave, and then it changed back to negative 70, do you agree that that's moving charged particles? And that's electricity? And that, my friends, is the action potential. That's it. Just kidding. Of course, we're going to do all the steps, the mechanism of the action potential. How? How does this actually happen? Now we're going to make our drawing of the neuron a little bit more complicated, a little bit more detailed, and we're going to have specific steps in the process so that you can see how the whole thing works. So exciting.