So today, it will be the second course, second class of the stretch that we discuss movement and movement disorders. The way we will pursue this one is by looking at the two sides of the same coin. [FOREIGN], okay. And I want to raise your attention to some of the ways of studying for these processes. Some of the knowledge points were covered by other lecturers. But I will repeat some of them for a different purpose. Since this class is called Advanced to Neurobiology and is intended to upper level undergraduate students or graduate students. So the way we study these topics, is slightly different from what we used to do, namely, the basic courses. What we try to convey to you, is the way to think about these questions. So the same knowledge points can be looked at from different angles. Now, I put today's title as, The two sides of the same coin. Function and dysfunction. And the range is from molecules to to animals. In last lecture, we looked at things from a ladder. Okay, Shao Ko, what are the ones that we put? Sit down please. You don't need to stand up. Can you give me some examples of quote unquote the most basic, the lowest level of our complexity of life. What are these things? >> [INAUDIBLE] >> The molecules, all right. So let's start with small molecules. What are they, can you give us some examples? >> [INAUDIBLE] >> Ions, good, calcium, chloride, sodium, potassium, and what? >> [INAUDIBLE] small- >> Yeah, small molecules. >> [INAUDIBLE] water. >> Water, good, very good. They are important for biology, okay, and? Slightly more complex than this. >> [INAUDIBLE] Amino Acid. >> Amino Acids. >> [INAUDIBLE] >> Some energy molecule, for example. >> Sugar, okay, and ATP, right? >> [INAUDIBLE] >> So and so forth. So those are the molecules. And of course, we have bio macromolecules that are DNA, protein, lipids, and indeed the other ones. So that's the molecules, all right. What's the next step, if we go up? >> Sub cellular [INAUDIBLE]. >> Exactly, sub cellular. Can you give us one or two examples? >> Mitochondria >> Mitochondria. >> Nuclears. >> Nuclears, okay, very nice. And how about one more level up? >> Cellular. >> Cellular, now, what are the basic concepts at this level? The question is, give us some examples of the organizing components of this ladder of complexity. when you say cellular level, what are the basic things we have at this level? >> Membranes. >> Membranes, that's still sub, yeah. >> Protons >> Proton, you mean? [FOREIGN] If that's more comfortable to you, that's okay. >> [FOREIGN] >> [FOREIGN] okay, all right. >> [INAUDIBLE] >> Cell types, right. We have all kinds of cell types. We have neurons, ,and so on and so forth, all right. So then of course that's the tissue. Maybe that's the circuitry, especially in nervous system, and that's the organ, that's the individual. We have all these levels of complexity, all right? Now, if we are going to understand movement, what do we need to do is really to understand all of these. We need to understand the molecules that are involved in this process. And a subcellular organelles that are involved and the cellular, tissue, circulatory, organ especially. In the end, it's the individual good. They have their behavior. Now, seems like this is a daunting task. You will say, hey, CJ, what we are talking about is literally the whole biology of it? Because if you think about it, this, this, here, it's pretty much all biology is about. We have molecular biology. We have cellular biology. We have physiology and so on and so forth. And the answer to you is, yes, that is right. To understand a physiological process, we actually do go from molecules all the way up to individuals. And that's how we are going to study movement and movement disorders. Now, when I say two sides of the same coin, we have function and will have dysfunction.