Re-modeling the deafened cochlea for auditory sensation: Advances and obstacles

Hearing loss is one of the most common disabilities in the United States. The most common form of hearing loss is caused by the death of cochlear hair cells in the organ of Corti and once lost, hair cells in humans and other mammals do not regenerate. In contrast, non-mammalian vertebrates, such as birds, can functionally recover from deafening injury by mobilizing supporting cells in the cochlea to divide and differentiate, replacing lost hair cells. Since the discovery of hair cell regeneration in birds in the 1980s, research has focused on trying to understand the cellular and molecular mechanisms underlying regeneration and why these processes do not occur in mammals.