Sleep helps to repair damaged DNA in neurons, scientists find

Chromosomes' movement when the brain is resting allows cells to mend DNA

Ernest Hemingway prized sleep for good reason. Not one to dwell on rest and recuperation, the novelist saw snoozing as a form of damage limitation. "I love sleep," he once said. "My life has the tendency to fall apart when I'm awake."

The author's observation may be truer than he imagined. Scientists have discovered that broken DNA builds up in brain cells in the daytime and repair work reverses the damage only during sleep.