Ageing brains show a weakening in brain waves associated with deep sleep (right) compared with younger adults (left), with consequent memory impairments.Deterioration of a specific brain region impairs sleep quality as people age, leading to poorer memory retention, according to research published today in Nature Neuroscience1. Ageing is associated with the gradual loss of brain cells, sleep disturbances and declining memory function, but how these factors are related to each other has been unclear.Neuroscientist Bryce Mander at the University of California, Berkeley, and his colleagues recruited 33 healthy adults — 18 around the age of 20, and