Contributed by Debbie Clason, staff writer, Healthy Hearing
Research about the causes of hearing loss, best methods for treating it and promising ways to prevent it is always underway. But sometimes, breakthroughs come from unexpected places: like deep in the sea. Remarkably, a new study with sea anemones is providing insights into how hearing works as well as giving scientists hope they may be able to restore lost hearing in the future.
Tiny but mighty hair cells
The tiny but mighty hair cells of the human inner ear are delicate sensory receptors responsible for converting noise collected by the outer ear into electrical impulses for the brain to interpret as recognizable sound. When they die or become damaged, it results in permanent hearing loss. So far, medical science has been unable to figure out how to repair them. Sensorineural hearing loss in humans is often a result of damage to hair cells in the inner ear.
While mammals are unable to regenerate hair cells when they are damaged, some invertebrates possess a repair protein capable of restoring lost function in structures similar to those found in a mammal’s inner ear. The tentacles of starlet sea anemones, for instance, are covered in tiny, hairlike cells. These receptors are responsible for detecting vibrations in the water made by nearby food or prey, much like the stereocilia of a mammal’s inner ear is responsible for detecting sound vibrations. When sea anemones reproduce, they tear themselves in half, then repair their tentacles and hair cells using a protein found in the mucus which coats their bodies.
New research shows promise in its early stages
Because this protein was successful in restoring similar hair-like cells in blind cave fish, Dr. Glen Watson, a biologist at the University of Louisiana at Lafayette, wondered if it would also work in mammals. To investigate, he and his colleagues purposely damaged hair cells in the cochleas of a group of mice to mimic traumatic hearing loss, then treated them with a solution concocted from sea anemone protein. The hair cells recovered significantly which indicated the sea anemone protein shows promise in having repair properties for the mammalian hearing system.
Upon further investigation, Dr. Watson discovered that mice produce proteins similar to the repair proteins in the sea anemone. This is good news as it suggests it may be possible someday to isolate a repair mechanism in mammals similar to that of sea anemone and use it to restore hearing loss.
Sea anemones aren’t the only invertebrates being studied for their ability to regenerate lost hair cells. Researchers at the Stowers Institute for Medical Research in Kansas City are currently studying zebrafish, a tropical, freshwater fish possessing support cells with the ability to divide and transform into a hair cell when they are needed. And, a 2014 study by the University of Virginia School of Medicine and the National Institute on Deafness and Communication Disorders (NIDCD) pinpointed two molecules present in chickens which allows them to regrow hair cells after suffering hearing loss.
Dr. Watson said sea anemone protein therapy is “years into the future.”
This research is certainly exciting, but don’t expect it to yield meaningful change in the way sensorineural hearing loss is treated in the near future. In an August 22, 2016 issue of Live Science, Dr. Watson said sea anemone protein therapy is “years into the future.” Hearing aids and cochlear implants are still the best solution available today for those with hearing loss. Numerous studies indicate these medical devices can significantly improve quality of life, preventing medical conditions exacerbated by untreated hearing loss such as anxiety, depression, social isolation as well as cognitive decline and dementia.
Good hearing health begins with a visit to a hearing healthcare professional for a hearing evaluation. Even if you don’t have hearing loss, the results can provide your healthcare team with baseline information to use in future checkups. You’re never too young to get started. To find a clinic in your community, search Healthy Hearing’s directory of clinics and hearing centers.