Antibiotics, chemotherapy, infections -- even normal aging -- can damage the hair cells of the human inner ear. Once these cells are gone, that's pretty much it: Only some of the cells will regenerate, and only minimally.
As a result, millions of people suffer from vestibular dysfunction, which causes dizziness, vertigo and balance problems. "This disabling condition is very common among the elderly, and one of the primary causes of falls," said Alan Cheng, MD, associate professor of otolaryngology-head and neck surgery.
There's no treatment for the dysfunction, only physical therapy to manage the symptoms. But research led by Cheng shows that perhaps there's a treatment on the horizon. An article about it was published July 9 in Cell Reports.
Cheng and his team found a way to regenerate the cells in mice -- the first time anyone has accomplished this in a mature mammal. (Birds and fish can completely regenerate their ear hair cells.)
The researchers impaired the mice inner ear hair cells and found that only about a third of the cells regenerated on their own. After damaging the cells in another set of mice, they manipulated ATOH1, a protein that regulates hair cell formation. In those mice, as much as 70% of the hair cells regenerated, and about 70% of them recovered their vestibular function.
"This is very exciting. It's an important first step to find treatment for vestibular disorders," Cheng said. "We couldn't get sufficient regeneration to recover function before."
Photo by Felix Hu