Source | www.inc.com |
It doesn’t take a PhD to figure out that sleep is essential. Anyone who’s struggled to get through the next day after a late night out can tell you that.
But researchers are constantly adding interesting new additions to the long list of reasons we sleep, from cementing new learning, to scrubbing the emotional charge from painful memories, to preventing you from having crabby fights with your partner (yes, this has been scientifically proven).
And now a team out of Boston University has added yet another reason to the list, and it’s particularly bad news for those who don’t manage to get enough shut eye: Sleep physically washes toxins, including those that can lead to Alzheimer’s, from your brain.
A carwash for you brain
The new study published in the journal Science and highlighted in Wired (hat tip Kottke) builds on earlier studies with mice that suggested sleep physically cleans out toxins that build up around the brain due in its normal functions. Was something similar going on with humans? Biomedical engineer Laura Lewis asked a bunch of study subjects to take a snooze in an MRI machine to find out.
“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,” explains Wired’s Sara Harrison. “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.”
In short, completely non-scientific terms, sleep allows your brain to take a bath, washing off all the toxins that build up just as part of the day’s daily business.