Massachusetts General Hospital (MGH) researchers have made important progress in their ongoing effort to regenerate the inner ear's hair cells, which convert sound vibrations to nerve impulses. In an upcoming issue of Proceeding of the National Academy of Sciences they report successfully creating a mouse model that allows them to build on earlier findings about the effect of deactivating a protein that controls the growth and division of hair cells.
Named for the hair-like projections on their surfaces, hair cells form a ribbon of vibration sensors along the length of the cochlea - the organ of the inner ear that senses sound - where they convert sonic vibrations to electrical signals that are carried to the brain. The cells are very sensitive to damage from excessive noise, infections and toxins. Once damaged, hair cells do not naturally regenerate in mammals, and their death accounts for most types of acquired hearing loss.
"We've shown that vestibular hair cell regeneration may be achieved and may be less of an obstacle than auditory cell regeneration," Chen says. "Now we need to find ways to create a similar system in the auditory cells, and this new model will help us better understand the mechanisms behind functional hair cell regeneration. Our next step will be developing a transient, reversible block of Rb function to assess its role in both types of hair cell." Chen is an assistant professor of Neurology of Harvard Medical School