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Get to Sleep or Your Brain Will Eat Your Past


In Stephen King’s story The Langoliers, a group of people in a plane fall asleep and travel back in time, only to discover that sharp-toothed little monsters clean up what’s left of the past by eating it. Well, it turns out the brain has a similar mechanism.

With headlines like “The brain starts to eat itself after chronic sleep deprivation,” this new finding sure sounds like a horror story, but the truth is a lot less scary. The brain does have a “housekeeping” system that purges debris and trims synapses—essentially eating the past by getting rid of memories that are no longer needed. When mice were deprived of sleep for up to five days in a row, this housekeeping system kicked into high gear, with more than double the number of synapses targeted by the cleanup mechanisms.

An astrocyte - one of the types of cell that helps clean up the brain.

An astrocyte—one of the types of cell that helps clean up the brain. It may look like a monster, but it serves many important functions. Image source

That still sounds kind of scary, but it can also be a good thing. As we’ve discussed before, similar brain housekeeping mechanisms occur during sleep too and help keep the brain running smoothly.

What’s more worrying is that failing to sleep seems to boost these systems into overdrive, beyond what is normal and necessary. That could provide the mechanism for previously discovered associations between sleep deprivation and neurodegenerative diseases like Alzheimer’s, which permanently rob the past from people by indiscriminately destroying memories.

There are still a lot of unknowns, as the researchers acknowledge. Next, they plan to investigate how long these effects last, and whether or not getting more sleep later can bring things back to normal.