Sensorineural hearing loss is present in all forms of Usher syndrome and is caused by damage to the inner ear, in particular the hair cells. The hair cells convert sound into electrical impulses, which are processed by the brain. Once hair cells are damaged, they are unable to regenerate or repair themselves, leading to permanent hearing loss.
Massachusetts Eye and Ear researchers were able to reprogram adult mouse cochlear cells to become immature cells. Through this research, they identified several genes and signals that are important in the development of hair cells. They then delivered a combination of these chemical signals and a gene called Atoh1 to the inner ear of adult mice. Following this treatment, the adult mice were found to have formed new hair cells in the inner ear.
What this means for Usher syndrome: This research expands our understanding of how the inner ear is formed. Further studies may be able to build on this groundwork and lead to possible treatments for hearing loss.