HAIR CELL REGENERATION IN THE INNER-EAR

Hearing and balance disorders caused by the loss of inner ear hair cel ls is a common problem encountered in otolaryngology-head and neck sur gery. The postembryonic production of hair cells in cold-blooded verte brates has been known for several decades, and recent studies in the a vian inner ear after ototoxic drug and noise damage have demonstrated a remarkable capacity for both anatomic and functional recovery. The r egeneration of sensory hair cells has been shown to be integral to thi s repair process. Current work is focusing on the cellular progenitor source of new hair cells and the trigger mechanism responsible for ind ucing hair cell regeneration. Preliminary studies suggest that reparat ive proliferation may also occur in the mammalian inner ear. Work in t his field is moving at a rapid pace. The results thus far have yielded optimism that direct stimulation of hair cell production or transplan tation Of living hair cells may eventually become treatment modalities for the damaged human inner ear. These proposals would have been cons idered unrealistic less than 10 years ago, but they now have caught th e full attention of both clinician and researcher.