In this undated photo provided by the University of Rochester Medical Center, Dr. Maiken Nedergaard, left, points to images of brain scans of mice joined
In this undated photo provided by the University of Rochester Medical Center, Dr. Maiken Nedergaard, left, points to images of brain scans of mice joined by her colleague Lulu Xie, of the University of Rochester Medical Center. The team, who observed the brains of mice during the sleep and awake states, has published a study in the journal Science that found the brain does a better job of clearing out cellular waste during sleep, a finding that may lead to new ways to treat Alzheimer s and other brain disorders. (AP Photo / University of Rochester Medical Center)