My stretch is about movement. So in order to understand movement we are going to take about quite a bit of movement disorders. And here's a question to you. Since all students here are biology department students, I believe we don't have students from the medical school, right? Am I right? Okay. Why do we biologists, why should we care about those diseases? You made your choice when you're in your senior year in high school. You didn't go to medical school, so why should we care? I think, in general, not only movement, and the movement disorders, neuro signs, and neurological diseases. But in general, biology and that diseases is literally, as you said, it's the function of the living system, and it's the disturbance, damage to the system that eventually precipitates into a disease that we know. So it is for that reason. There are two issues at hand that we can consider. First of all, all these diseases including neurological diseases are specially neurological diseases in movement is all in category, all of them are public health issues. Very, very serious public health issues. And to address those public health issues, we need to tackle that from all kinds of angles. Some people are M.D.s. They treat patients. Some people are nurses. They help the patients to recover, taking care of them. The other ones are actually our basic scientists. We study the biology of cellular molecular mechanisms, so on and so forth, and try to understand the disease. So that one day we can have a better approach to develop treatments for patients. So that's for the first one, it is a medical need. The second one is, remember, when you are trying to understand a highly complex system, that you have no idea of. You have nowhere to start. Studying the mutations is one of the most effective ways to understand a question. The idea of studying mutants or mutations has been extremely important for the whole development of modern biology. That's a great example. In people made random mutations, first with an EMS, mutagenesis and then with a element jumping right? So from all that, people are looking at those mutations, mutants, as long as you have a good essay, you know what you're looking at. It could be embryogenesis, it could be the development of some certain organs, it could be a photo reception. It could be smell, right? So from that, she says, well Sonic Hedgehog, and all these important signaling pathways, wind, and all that. Which the beginning of that is really from understanding mutations. And that's how the name was obtained like the wind, the seven less, and all that. Very good, very good. So, in our biology, and the examples goes beyond that. We start with, for example, bacteria, all right every time we want to do something, there is a direct path and there is always a detour that through disturbing something and see how they respond then we start to understand a process. Of that idea we can collectively call it mutational study. And in that sense, human diseases are the best mutations that nature has experimented. If you remember, in evolution things just change. They don't have a purpose on their own. They just change. They mutate, they adapt, and all that. And it's the selection pressure from nature, that selects some of them are harmful, so they will have a disadvantage. Other ones are an advantage of doing something. And even more, in the middle, are neutral to a certain extent. But then, when the environment changed, these neutral changes suddenly they manifest, either disadvantaged or advantaged, right? That's the beauty of evolution. Not all changes are being selected right away. Some are dormant. [FOREIGN] But later on they will be selected one way or the other. Okay, so in human, [FOREIGN] one case without the other. My favorite one is the discovery of cholesterol pathway. Does anybody know the story of that from truly studying human diseases that leads to a great discovery and ends with a Nobel Prize to two collaborating fellows? Does anybody know the story of that? No? All right, I'll give you another hint. Those two scientists are mentors to [INAUDIBLE]. Still no? Yes? Does everybody know [INAUDIBLE]? I can't take that for granted. Okay, all right. So, the story goes like this, [FOREIGN] he did his PHD with Brown in the goat state to distinguish the scientists at University of Texas southwestern. Okay. And both of them, interestingly, they were doctors. And they were doing their residence. They observed a very, very interesting but small family of patients who has major problems in cholesterol metabolism. They didn't know why, but they saw it's a pretty small family, and they saw a clear genetic inheritance. So, starting from their residency years they followed that up through many years of hard work and a little bit of luck. They discovered the whole pathway of cholesterol metabolism which is not only a big clinical question, but one of the most fundamental biological questions. Right, so that's how, starting from a disease, they dig in, they dig in. It's really, it's almost like nature made these mutants, unfortunately, and presented it to a scientist who have the great eye of spotting them and then follow that up. So I want to drill that idea into your brain very, very strongly. These mutational studies, it's true for medical reasons we want to study diseases. But also, for basic science point of view. We Basic Scientist, should always think about, and then care about it's relevance in terms of function, dysfunction, neuroscience, neurological diseases. Movement? Movement disorders, always think about that in pairs.
