Alzheimer's: What gets cleared—Amyloid-beta—a waste protein made in the brain. In Alzheimer patients, amyloid-beta builds up and gets backed up (acts like a pollutant). Clearance of this protein is rapid in sleep. Sleep problems often precede and may contribute to development of Alzheimer’s. Sleep keeps our brain clean and ready for important mental activity when we’re awake.
Link to Jeff Iliff’s TED Talk: http://www.ted.com/talks