A new study from the University of Copenhagen shows that the stress hormone norepinephrine causes us to wake up many times during the night, and this is part of a full night’s sleep.
Most people believe that a good night’s sleep should be uninterrupted. However, our body seems to think otherwise. While norepinephrine technically causes the brain to wake up over a hundred times each night, we don’t think of it as waking up. Neurologically, a person actually wakes up over a hundred times in a single night, and brain wave activity indicates that we are awake. But it’s so short that it’s impossible to notice.
Even though the researchers studied mice, their findings can in all likelihood be transferred to humans because they focused on basic biological mechanisms, that is, mechanisms that are common to all mammals.
The new discovery is an important piece of the puzzle to understand what happens in the brain when we sleep. The stress transmitter norepinephrine affects sleep waves, which have proven to be important for memory: they literally reboot the brain. This is the basis of that part of sleep that helps people feel rested in the morning, and allows you to improve memory and remember what we learned the day before.