After too many drinks, we've been known to yell (or dance) our way through the bar — or even spend the rest of the night sobbing in a corner. No matter what type of booze you're drinking, there's one compound to blame for all the good (and bad) it's doing: ethanol. And, as this new BritLab video explains, there's plenty left to learn about our old friend ethanol. The compound acts on a bunch of our brain's neurotransmitter (including GABA) receptors. Normally, GABA acts as an inhibitor. When alcohol increases GABA's activity, your reactions are slowed and you start to feel drunk. Alcohol also inhibits the activity of the anti-diuretic hormone vasopressin, which normally controls our peeing schedule. So, if you feel more of an urge to go after drinking, you're not imagining it. One theory is that this dehydrating effect could be responsible for our hangovers; other research suggests it's actually an inflammatory immune response. Still others think it all boils down to glutathione, a compound that your liver needs to process alcohol — and one that runs out quickly. Check out the full video below to learn more. Of course, knowing why you have a hangover won't make it go away. But, it might make you think twice the next time you fill up on "liquid courage" at karaoke.