Sleep 'cleans' the brain of toxins

The brain uses sleep to wash away the waste toxins built up during a hard day's thinking, researchers have shown. The US team believe the "waste removal system" is one of the fundamental reasons for sleep. via Pocket http://www.bbc.co.uk/news/health-24567412#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa