Brain Gets Rid of Toxins During Sleep

Sleep is an integral part of being healthy. Lack of sleep causes harmful physiological effects ranging from simple skin problems to serious health complications like heart disease and stroke. Although sleep needs vary from person to person and across species, the complete absence of it is fatal. An experiment on rats found that depriving them entirely of sleep resulted in their death within 11-32 days.[2] Despite research such as this, there isn’t any scientific evidence that prove the physiological causes of death by sleep deprivation.

Related: People Who Sleep More Weigh Less

In fact, in the rat sleep deprivation experiment, it is not entirely clear whether sleep was what caused the deaths. It is possible the methods used to keep the rats awake, an electric shock, was what killed them. A recent 2013 study on mice, however, may have found the first scientific evidence proving the physiological importance of sleep.

Sleep is your brain’s trash collector

“We here report that sleep has a critical function in ensuring metabolic homeostasis…the restorative function of sleep may be a consequence of the enhanced removal of potentially neurotoxic waste products that accumulate in the awake central nervous system.” [1] The findings suggest sleep helps the brain get rid of toxins. With further examination, they have found that the mechanism behind this garbage collection lies in glial cells’ fluid control over cerebrospinal fluid. The brain’s glial cells expand when awake which block fluid flow and contract when asleep allowing the fluid to carry debris out of the brain into the liver for disposal. Surprisingly, pieces of protein that cause Alzheimer’s disease are among those flushed out of the mice’ brain. Many scientist were shocked by the results of this experiment and led some to redefine their views on the significance of sleep. Not only does it prove the importance of sleep, it also may revolutionize the future of Alzheimer’s disease treatment.


Despite the fact that this experiment was performed on laboratory mice, there is strong belief that the findings in this study may apply to other species as well, including humans. It gives some light to the observed harmful effects of sleep deprivation on humans. At the same time, it explains why a high quality good night’s sleep gives an us an extra spring to our steps – because we are literally several nano-grams lighter. To think that depriving yourself of sleep means that you are pretty much poisoning your brain with your own neurotoxins is interesting, yet alarming at the same time. It leaves a visceral reminder that sleep is like making sure you take out the trash everyday.

1. Xiel, Lulu, Hongyi Kangi, Qiwu Xul, Michael J. Chen, Yonghong Liao, Meenakshisundaram Thiyagarajan, John O’Donnell, Daniel Chistensen, Charles Nicholson, Jerffrey Illif, Takahiro Takano, Rashid Deane, and Maiken Nedergaard. “Sleep Drives Metabolite Clearance from the Adult Brain.” Sleep Drives Metabolite Clearance from the Adult Brain. Science Magazine, 18 Oct. 2013. Web. 17 Jan. 2014.
2. Everson, C.A., Bergmann, B.M., Rechtschaffen, A. (1989). Sleep deprivation in the rat: III. total sleep deprivation. Sleep, 12(1), 13-21.