Question: What dose Coffey do to your brain

Ciarán O'Brien answered on 19 Nov 2014:

The chemical in coffee that affects your brain is caffeine. It’s found in a lot of plant seeds, and can be very dangerous to insects (we think it evolved as a natural way of plants to avoid getting eaten).

Caffeine slows down how much brain uses adenosine as a signalling chemical by interfering with the proteins that like to bind to adenosine (we call them adenosine receptors). This has a lot of knock-on effects: Your brain starts to speed up your breathing and your heart beat, and it releases acetylcholine into your nervous system, which makes the signals passing through them jumpier and quicker to fire off, which is why coffee makes you feel like you’re full of energy and makes it harder to fall asleep. Scientists believe that adenosine is important for keeping brain activity low, and a lot of it is found in hibernating bears, so less adenosine would make your brain work faster!

A lot of people drink coffee with sugar, too, which gives you a quick boost of energy on top of the jumpy energetic feeling you get from coffee, so after a cup or two of coffee you feel more awake, you have more energy, and you feel far more like you should be doing something with the energy and awake-time!