The brain is magnificent. Sleep and its function is one more reason to marvel at it's efficiency. Watch this informative and entertaining Ted talk on how the brain "cleans up" during sleep.
From Ted.com website: The brain uses a quarter of the body's entire energy supply, yet only accounts for about two percent of the body's mass. So how does this unique organ receive and, perhaps more importantly, rid itself of vital nutrients? New research suggests it has to do with sleep.
View on Ted.com