NYT: As your body sleeps, your brain is quite actively playing the part of mental janitor.

While sleeping, we clean up our brain – literally cleaning up our cells, as well as our memories and thoughts.

NYT:  Goodnight. Sleep Clean.   By MARIA KONNIKOVA

In a sleeping brain, waste was being cleared two times faster.

MODERN society is increasingly ill equipped to provide our brains with the requisite cleaning time. The figures are stark. Some 80 percent of working adults suffer to some extent from sleep deprivation. According to the National Sleep Foundation, adults should sleep seven to nine hours. On average, we’re getting one to two hours less sleep a night than we did 50 to 100 years ago and 38 minutes less on weeknights than we did as little as 10 years ago. Between 50 and 70 million people in the United States suffer from some form of chronic sleep disorder. When our sleep is disturbed, whatever the cause, our cleaning system breaks down. At the University of Pennsylvania’s Center for Sleep and Circadian Neurobiology, Sigrid Veasey has been focusing on precisely how restless nights disturb the brain’s normal metabolism. What happens to our cognitive function when the trash piles up?

At the extreme end, the result could be the acceleration of neurodegenerative diseases like Alzheimer’s and Parkinson’s. While we don’t know whether sleep loss causes the disease, or the disease itself leads to sleep loss — what Dr. Veasey calls a “classic chicken-and-egg” problem — we do know that the two are closely connected. Along with the sleep disturbances that characterize neurodegenerative diseases, there is a buildup of the types of proteins that the glymphatic system normally clears out during regular sleep, like beta-amyloids and tau, both associated with Alzheimer’s and other types of dementia.