We are born with about 16,000 auditory hair cells. These cells are in the cochlea of the inner ear. They are needed to translate sound waves — from the softest rustling leaves to the loudest thunder clap — into nerve impulses that are interpreted in the brain.
Hearing is lost for good if too many hair cells are damaged due to aging; loud noise; illness; or certain drugs, including chemotherapy used to treat certain childhood cancers. That is because unlike fish or birds, humans cannot regrow these cells.
St. Jude Children’s Research Hospital scientists have used clues from studying fish and chickens to advance efforts to regrow hair cells in humans.
By switching some genes on and off in specific inner-ear cells, scientists caused those cells to look and act like immature auditory hair cells. The report apparently marks the first time genetic manipulation was used to regrow auditory hair cells in an adult mammal.
“We looked to Mother Nature for answers, and we were rewarded,” said Jian Zuo, PhD, of the Department of Developmental Neurobiology. “The results suggest that regenerating auditory hair cells will likely require multiple factors to stimulate the process.”
The research appeared in Cell Reports.