The less you sleep one night, the more likely you are to stay awake the next night. You're also likely to be alert throughout the day despite the lack of sleep. And scientists have finally figured out why this is.
Our sleep-deprived brains produce more dopamine, a chemical that's found in amphetamine drugs, that keeps us wide awake. But although we remain stimulated, our cognitive performance goes down.
Researchers who studied 15 healthy volunteers, who were either allowed to sleep or were kept awake all night, found that the brain started producing dopamine after just one night without sleep.
(Source: Journal of Neuroscience, 2008; 28: 8462-9).