[MUSIC] I want to take a moment to express sort of full confessions here. The cerebellum is probably one of the top five best studied areas in the brain. We've known about it's basic anatomy since Ramon y Cajal. We know a lot about how it's hooked up, we know a lot about its anatomy, a lot about its physiology. Unfortunately that hasn't transferred into a widely-held consensus as to how this agreed upon structure and function, or structure and physiology produces a function. So we still are missing some piece of understanding, or at least a consensus about what the proper understanding is, about how we get from the basics to the actual function of the, of the cerebellum. But. I'm not going to go into a lot of detail about how the cerebellum is, how it looks and how it's hooked up. It's a beautiful subject, and, but I do want to just give you a teaser about how beautiful it is. And that is this lovely goldgy stained picture from a mouse cerebellum. This right here, this, this cell that's outlined in black is a Purkinge cell. And the Purkinge cell is a, is a wonderful cell. First of all, it's gorgeous. Look at that. Amazing. This is in the mouse, so we're talking about a cell body that's maybe 20 microns in, in diameter. In the human it's more like 50 to 75 microns in diameter. This enormous dendritic arborization is, is just striking and it reminds everyone of a sea fan. Another aspect of this of this cell's anatomy that's really amazing is that it's completely oriented. If we made a slice in this plane, if we sliced this way what we would see is that this cell is very, very thin. So in one plane, the cell has a huge arborization, and in the other plane, it's completely flat. Another amazing feature about the Perkinge cell is that it has all these, I don't know if you can see that, but if you look in on here, this is a dendrite, but it's littered with spines. So these are little spines, and you can see that they're just spines that dot every single dendrite. Finally I want to point out that this is the axon. So, the Purkinge Cell is an amazing cell. It, it forms a, its own layer within the cerebellar cortex, we'll look at that a little bit. But just to say, if, if this picture moves you, you, you may actually have a, a, a future in, Neurobiology and Neurobiology research, because, I can tell you that I, I am very moved by the aesthetics of neurons that look so gorgeous like this. And that is a motivating aesthetic for you. That I encourage you to, pursue that. Okay so now what we're going to do is turn from this, the, turn and look at the cerebellar functions. [MUSIC]