Scientists Now Know How Sleep Cleans Toxins From the Brain | WIRED

When I read Why We Sleep it introduced me to the different types of non-REM sleep. This new research shows a bit more about what those other four stages of sleep do.

What she discovered was that during non-REM sleep, large, slow waves of cerebrospinal fluid were washing over the brain. The EEG readings helped show why. During non-REM sleep, neurons start to synchronize, turning on and off at the same time. “First you would see this electrical wave where all the neurons would go quiet,” says Lewis. Because the neurons had all momentarily stopped firing, they didn’t need as much oxygen. That meant less blood would flow to the brain. But Lewis’s team also observed that cerebrospinal fluid would then rush in, filling in the space left behind.

There is a lot of important and poorly understood things that happen when we sleep. Of course I’m typing this comment late at night, when I should be drifting off to sleep instead. 😬😴