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.
A researcher from Imperial College London and his colleagues have developed for the first time a map of a typical bird brain, showing how different regions are connected together to process information. By comparing it to brain diagrams for different mammals such as humans, the team discovered that areas important for high-level cognition such as long-term memory and problem solving are wired up to other regions of the brain in a similar way. This is despite the fact that both mammal and bird brains have been evolving down separate paths over hundreds of millions of years.