We often think of our bodies and minds in simplistic ways, like seeing the way we wake up as a switch being flipped in our brains to 'turn us on' for the day. But new research from the University of Oxford has revealed we might not be far off the mark with this analogy.
Scientists have pinpointed a 'switch' in our brain that sends signals to our body to go to sleep or wake up. We know that sleep is controlled by two different body systems, the first is the circadian clock, which responds to environmental changes like daylight. The other system is the sleep homeostat, which is a little more mysterious. Professor Gero Miesenböck, who conducted the research, explained to WIRED:
"That explanation will likely come from understanding the second controller—called the sleep homeostat. The homeostat measures something - and we don't know what that something is - that happens in our brains while we are awake, and when that something hits a certain ceiling, we go to sleep. The system is reset during sleep, and the cycle begins anew when we wake up."
The study tested the sleep homeostat in brains of fruit flies which according to Miesenböck have similar sleep cells to mammals. The brain cells they measured show the output of the sleep homeostat. When active, the fly was asleep, and when silent, the fly was awake.
Researchers would control the fly's sleep switch by increasing dopamine levels, which stimulate and keep us awake like brain-brewed coffee. The increase in dopamine caused the sleep inducing brain cells to silence and the fly to wake up.
The study was a breakthrough in discovering an ion channel inside sleep neurons when they are active, which they have named 'Sandman.' In basic terms, this ion channel controls the sleep/awake impulses and communications between our brain cells flipping our brain from awake to asleep.
We know, it's a lot to take in. You can turn your switch off and relax for the rest of the day. You've earned it.