Well, there was the "washes the brain" mouse study[1] a couple of years ago, which is at least suggestive. 1: http://www.nih.gov/news-events/nih-research-matte

Well, there was the "washes the brain" mouse study[1] a couple of years ago, which is at least suggestive. 1: http://www.nih.gov/news-events/nih-research-matters/how-sleep-clears-brain http://www.nih.gov/news-events/nih-research-matters/how-slee...