Researchers regrow crucial hair in inner ear

WASHINGTON (Reuters) - Researchers working on mice have regrown the tiny hairs in the inner ear that are crucial to hearing, and said on Wednesday their findings might lead to ways to restore hearing loss in humans.

The loss of these minute hairs in the cochlea, or the nerves that control them, is the most common cause of deafness, and mammals are unable to regenerate them.

John Brigande and colleagues at Oregon Health & Science University used gene therapy to restore the cochlear hair cells in mice.

Reporting in the journal Nature, they said their genetic engineering of mice fetuses while still in the mother's womb caused non-sensory cells to become hair cells.

"One approach to restore auditory function is to replace defective cells with healthy new cells," Brigande said in a statement.

"Our work shows that it is possible to produce functional auditory hair cells in the mammalian cochlea."

Dr. Anthony Ricci of the Stanford University School of Medicine in California showed that the hair cells appear to function normally.

"It remains to be determined whether gene transfer into a deaf mouse will lead to the production of healthy cells that enable hearing. However, we have made an important step toward defining an approach that may lead to therapeutic intervention for hearing loss," Brigande said.

These tiny hairs malfunction or die naturally as people age, and can be quickly damaged by prolonged loud noises. While gene therapy is still highly experimental in people, the researchers said understanding how they activate the gene might lead to other ways to treat deafness.

(Reporting by Maggie Fox; Editing by Eric Beech)