We are in the inner ear of a chick embryo – an unusual place to be – looking at the surface of its hair cells. The tiny blue skyscrapers are stereocilia. Hair cells are tuned to different pitches depending on the length of these microscopic bundles. High pitch sounds are detected by short stereocilia, found close to where the sound enters the ear; lower pitch sounds are detected by taller ones, found deeper within. But why are researchers interested in the hair cells of a chicken? Because, unlike humans, chickens can regrow these sound-detecting cells after suffering hearing loss. If we are exposed to a sound for so long it destroys our ability to hear a certain pitch, we can never hear that sound again. But the chicken’s phoenix-like hair cells would be functioning normally within a few weeks. Replicating this process in humans may one day help reverse hearing loss.
Written by Nick Kennedy