sleep

Scientists in the US claim to have a new explanation for why we sleep: in the hours spent slumbering, a rubbish disposal service swings into action that cleans up waste in the brain.

Through a series of experiments on mice, the researchers showed that during sleep, cerebral spinal fluid is pumped around the brain, and flushes out waste products like a biological dishwasher.

Astronauts can suffer sleeping problems in space just as on Earth. Stress, heavy workloads, anxiety, background noise, light and air quality can all upset their body clocks. Minimizing sleep disturbances for astronauts is just one of the goals of the European Astronaut Centre's medical team.