General anaesthetics and consciousness

Why and how do we sleep and what is consciousness? Are all animals that sleep by definition conscious when they are awake? Associate Professor Bruno van Swinderen studies fruit flies and has recently published research which shows that flies have distinct sleep stages. General anaesthetics extinguish consciousness in humans, but how do they really work? His research shows that common mechanisms might be involved in all animals. What do sleep and general anaesthesia together tell us about how the brain works?