Around 26 million Americans aged 20-69 have high-frequency hearing loss due to noise exposure, but scientists at the University of Michigan have discovered a potential way to reverse that damage, Medical News Today reported.
In mice, the protein Neurotrophin-3 (NT3) plays a key role in communication between the ears and the brain. Hearing loss can result when that connection— which researchers called the “ribbon synapse”— becomes damaged by aging or noise exposure.
For the study, published in eLife, researchers first identified supporting cells of NT3. They then activated the cells with tamoxifen, which caused the cells to read additional copies of a gene that had been inserted into them.
Using this technique on mice that had been partially deafened by a loud noise, they saw the animals’ NT3 production increase and the subjects regained their hearing over a two-week period.
"It has become apparent that hearing loss due to damaged ribbon synapses is a very common and challenging problem, whether it's due to noise or normal aging,” said lead researcher Gabriel Corfas, director of the Kresge Hearing Research Institute at the University of Michigan.
Corfas’ team noted that the gene therapy technique has the potential to work in humans, but the drug administration process would be “simpler” and given as frequently as needed to restore hearing.
The researchers noted out that the mice in the study were only partially deaf, so it is unclear whether increasing NT3 production would fix hearing in fully deaf subjects. Still, they said their findings hold promise.
“We began this work 15 years ago to answer very basic questions about the inner ear, and now we have been able to restore hearing after partial deafening with noise, a common problem for people,” Corfas said. “It's very exciting."