Deep sleep important for brain to clear out toxic proteins: Study

ROCHESTER, NEW YORK — The depth of one's sleep can affect the brain's ability to adequately remove waste and toxic proteins, according to a new study published in the journal Science Advances.

An increase of toxic proteins such as beta amyloid and tau in the brain are often linked with Alzheimer's disease, according to a University of Rochester Medical Center news release.

The researchers injected six mice with six different anesthetic regimens to replicate different stages of sleep.

This was to identify if a certain phase of sleep could be associated with the glymphatic system, which the brain uses to clear waste.

The scientists determined the best glymphatic system activity takes place in the stage that was most similar to a human's deep, non REM, short-wave sleep, efficiently stimulating the cleaning process of the brain.

Mice that were given anesthetics which did not lead to slower brain activity had a decline in glymphatic activity, according to the study.

The study reinforces the link between poor sleep and Alzheimer's disease, and the importance of deep sleep for the brain's cleaning system to work effectively.