Reversing Hearing Loss By Regrowing Cochlear Hair Cells

Scientists have found a way to reverse hearing loss and make it possible for the ears to hear again.

A study published in Frontiers in Cellular Neuroscience fueled hope in the research community’s efforts to address hearing loss caused by the death of cochlear hair cells.

The research team acknowledged that lost auditory hair cells in adult mammals could not be regenerated, so hearing loss is permanent. Interestingly, they discovered that hair cells in birds are restored through regeneration from supporting cells.

Hearing restoration in birds occurs regardless of age. Scientists at the Del Monte Institute for Neuroscience made this a reference in their quest to find a mechanism that could promote the same type of regeneration in mammals.

A team of researchers at the University of Rochester Medical Center already managed to regrow cochlear hair cells in mice five years ago. The new study sheds light on the underlying mechanism that allowed the ear hair cells to regrow in mice, according to ZME Science.

“We know from our previous work that expression of an active growth gene, called ERBB2, was able to activate the growth of new hair cells (in mammals), but we didn’t fully understand why,” Patricia White, Ph.D., a professor of Neuroscience and Otolaryngology at the University of Rochester Medical Center, said in a press release.

“This new study tells us how that activation is happening — a significant advance toward the ultimate goal of generating new cochlear hair cells in mammals,” she added.

The hair cells in the ears are responsible for hearing. They sense sound vibrations and convert them into understandable brain signals. Humans have around 16,000 hair cells in each ear. But over time, they get damaged due to several reasons, including loud noises, ear infections and aging, as per ZME Science.

Through the years, scientists found that reptiles, birds and fish can regrow cochlear hair cells, reversing hearing loss in them. Through recent research efforts, scientists were able to uncover the mechanism behind this, which involves some genes making ear cells behave like stem cells and produce a protein responsible for hair cell regeneration.

In humans, many patients feel hopeless when they get diagnosed with permanent hearing loss since there is no cure for their condition. The new study could pave the way for a cure that would reverse hearing loss in humans. But there is still a long way to go.

“This discovery has made it clear that regeneration is not only restricted to the early stages of development. We believe we can use these findings to drive regeneration in adults,” first author Dorota Piekna-Przybylska, Ph.D., said in the press release.

“We plan to further [investigate] this phenomenon from a mechanistic perspective to determine whether it can improve auditory function after damage in mammals. That is the ultimate goal,” White added.