Caffeine and Adenosine Receptors
Caffeine can prevent neurodegenerative disease: There have been studies that found a correlation between drinking a few cups of coffee a day and slower onset of neurodegenerative diseases, but it is still unclear how caffeine does this. If you recall from the video, when adenosine stimulates A2A receptors on wake-promoting neurons, those neurons increase in activity. A2A receptors are also found on other neurons and also increase their activity. The idea is that in neurodegenerative diseases, these neurons actually begin to become overworked and die off. When caffeine binds to A2A receptors, it actually allows them to rest, making caffeine a neuroprotective agent. Keep in mind that this is just one theory and may be shown to be completely wrong in a few years time when new research shows an entirely different mechanism, but it is the best guess that scientists have now.