Birds, fish and amphibians can do something that humans and other mammals generally cannot: re-grow damaged or lost inner ear hair cells.
Loss of these cells causes hearing deficiencies and disabling balance problems in an estimated 250 million people worldwide. Despite the compelling need for new treatments, research and development efforts have been hindered by the relative scarcity of inner ear hair cells. A new study by neuroscientists at the University of Virginia Health System promises to boost cell supplies and accelerate therapeutic advancements.
Humans and other mammals only produce hair cells before birth and lose them over time. “People lose hair cells in their inner ear for many reasons – trauma, infections, drug toxicity, genetic disorders and aging,” explains Jeffrey T. Corwin, PhD, professor of Neuroscience at the University of Virginia Health System and co-author of a study published this month in the Proceedings of the National Academy of Sciences (PNAS) .
Sensory cells in the inner ear have “hair bundles” that detect the presence of sound. These cells are not only essential for hearing but help to control reflexes that stabilize our visual world, posture and movements. While hair cell loss remains clinically irreversible in humans, related research indicates that the potential for regeneration lies in the supporting cells of our balance organs.