Stay awake long enough, and you’ll eventually start to feel drowsy. Your body is telling you it’s time to sleep. But why do we need shut-eye? Recently, a team of researchers discovered that the answer may have something to do with specialized structures within our cells: the mitochondria. These organelles generate energy to power our cells.
To uncover mitochondria’s role in sleep, scientists at the University of Oxford in England studied the brains of fruit flies. They found that when they kept flies awake longer than usual, mitochondria in certain brain cells became overworked. The organelles began to leak electrons, or negatively charged particles, which trigger reactions that could damage the brain.
Getting some shut-eye protected against this danger. The insect’s brain “puts the whole organism to sleep before widespread damage can occur,” explains Gero Miesenböck, a neuroscientist who led the study. This could be key “to solving the mystery of why animals need to sleep.”