Sleep essential to make space for new memories

Parliamentarians who sleep on the job might have a new reason to justify their behaviour. For decades, competing theories about why we need to sleep have perplexed scientists - until now.New evidence suggests that when we are asleep synapses in the brain are pruned to make space for new memories.Researcher Giulio Tonono of the University of Wisconsin-Madison in the US and his team measured the size of the junctions [synapses] in slices taken from the brains of mice before they slept.