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Amazing way sleep cleans the brain uncovered

Kathleen Blanchard's picture
Sleeping is a brain cleanser

We all know sleep is important for a number of reasons related to optimal health. Now scientists have discovered seeping is a way the body cleans the brain to protect from toxic buildup that might lead to dementia and Alzheimer's disease.

In mouse studies scientists from the Center for Translational Neuromedicine at the University of Rochester Medical Center in New York found when we sleep we gain brain space that in turn aids the removal of brain toxins.

Sleep changes the cellular structure of the brain

Studies have recently shown sleep is important for storing memories. Poor quality sleep is linked to a variety of health conditions that are just beginning to be completely understood.

The new study finds when we sleep the cellular structure of the brain undergoes changes that flushes toxic molecules from the cells.

Maiken Nedergaard, M.D., D.M.Sc., co-director of the Center for Translational Neuromedicine at the University of Rochester Medical Center in New York, and a leader of the study in a press release the brain changes that occur during sleep seem to come from a completely different state.

During sleep the brain undergoes a process akin to plumbing. The study authors say the glymphatic system that is a pathway that clears waste products in the central nervous system may open.

University of Rochester researcher Jeffrey Iliff discusses the brain’s glymphatic system in the video below that was discovered just last year.

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The new study builds on the glymphatic system discovery. When the researchers tested mice by injecting a dye to observe the flow of cerebrospinal fluid they noticed the flow was much better during sleep compared to when the mice were awake.

Dr. Nedergaard in a press release the finding “…suggested that the space between brain cells changed greatly between conscious and unconscious states”.

Brain cells known as glia were shown to shrink and swell during conscious and unconscious states. The researcher attached electrodes to the mouse brains to directly measure the space between the cells during their experiment.

When the scientists blocked an arousing hormone known as Noradrenaline that also controls cell volume in mice that were awake they noted increased brain fluid flow between the glia cells.

When they injected the mice with beta-amyloid cells that accumulate in the brains of people with Alzheimer’s disease the toxic molecules disappeared faster when the mice were asleep, showing that the glymphatic system clean the brain during sleep.

“These results may have broad implications for multiple neurological disorders,” said Jim Koenig, Ph.D., a program directorat NINDS. Koenig adds cells that regular the glymphatic system could be new targets for treating a number of neurological diseases.

Watch this amazing video showing how the brain clears brain toxins during sleep.

The finding, published in the journal Science, highlights how important sleep is for maintaining brain health. Based on the new study finding, sleeping is important for cleansing the brain of toxins that could lead to dementia and Alzheimer’s disease. Tell that to your boss the next time you feel the sudden urge for a daytime nap!

Science 18 October 2013:
Vol. 342 no. 6156 pp. 373-377
DOI: 10.1126/science.1241224


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