 Let's look at serotonin. Now, serotonin is a neurotransmitter that is associated with all sorts of important stuff, like mood. Low amounts of serotonin can contribute to funky feeling moods. Your appetite is affected by serotonin. Your perceptions of reality are affected by serotonin. Also involved in memory and learning and sleep, it's kind of important. Low levels of serotonin, this is crazy. Low levels of serotonin are associated with increased risk-taking behavior. So you're more likely to do things that are dangerous if you have low serotonin levels. And I'm going to show you a drug, Prozac. This is an example, Prozac C. Prozac is an example of a selective serotonin reuptake inhibitor, which is an SSRI. So break that down. Selective serotonin reuptake inhibitor watch. This is amazing. So you have a neuron that's going to barf out serotonin. So here's my serotonin that gets barfed into the synapse. Totally scientific word. And then you have serotonin reuptake. I think they call them reuptake pumps. Prozac comes in and says, doggy, doggy, doggies. We do not need to reuptake this serotonin. We need to leave it in the synapse. Normally what's going to happen is that the little reuptake pump is going to bind to serotonin and stimulate endocytosis. And we're going to end up with serotonin back inside the axon terminal. And we're going to remove serotonin from the synapse. If you throw some Prozac into the mix, go ahead and do that. We're going to block those little reuptake pumps, which is going to leave the serotonin in the synapse, which increases the amount of serotonin you have, which decreases your risk-taking behaviors, betters your mood, gets you into a more stable place, which is one of the reasons why something like Prozac could be prescribed. Okay. I thought this was an interesting little fast fact as well. Serotonin inhibits pain in the spinal cord, so you won't feel as pained if you have a decent amount of serotonin. Do you think this is an important neurotransmitter? Yeah. And do you think a drug that acts like serotonin might be slightly addictive? Certainly. Let's talk about dopamine, another really important one.