We write about sleep a lot here at DailyXY (see here, and here, and here, and here, and here), but that’s mainly because sleep has attracted a lot of scientific attention recently. Scientifically speaking, it’s weird that mammals sleep. It makes us vulnerable, we don’t need it to regular our temperature or metabolism, and it reduces the amount of time we can spend playing GTA V. However, a new study published in Science may shed light on one of the fundamental reasons why we sleep.
According to the study, mammalian brains use sleep to clear neurotoxic waste products from the brain. Waste products build up naturally in an awake nervous system, but this new study suggests that the brain can only exist in one of two states at a time: awake and alert, or asleep and performing maintenance. Imaging the brains of mice, the authors of the study found that the gymphatic system, a network of tubes in the brain that carry away waste, became ten times more active during sleep.
Of course, the next step here is to reproduce the results of this study on humans—not only would this confirm why we need sleep, but it might explain the causes of brain diseases like Alzheimer’s and dementia. In the mean time, sleep tight—it’s a matter of health.