Protein NT3 helps deaf to hear, says study

Scientists have recently restored hearing of mice that were partly deafened by noise using advanced tools to boost the production of a key protein NT3in their ears.

The technique showed the key role of protein in ear-to-brain communication, and as a target for future treatments.

By demonstrating the importance of the protein in maintaining communication between the ears and brain, these new findings have paved the way for research in humans that could improve treatment of hearing loss caused by noise exposure and normal aging.

NT3 has been crucial to the body's ability to form and maintain connections between hair cells and nerve cells, the researchers demonstrated. This special type of connection, called a ribbon synapse, allowed extra-rapid communication of signals that travelled back and forth across tiny gaps between the two types of cells.

Gabriel Corfas, Ph.D, who led the team and directs the U-M institute, said that it has become apparent that hearing loss due to damaged ribbon synapses was a very common problem, whether it's due to noise or normal aging. They had begun to work on these 15 years ago in order to answer very basic questions about the inner ear, and now have been able to restore hearing in partially deafened mice, a common problem for people too.

Using the special genetic technique, the researchers have made it possible for some mice to produce additional NT3 in cells of specific areas of the inner ear after they were exposed to noise loud enough to reduce hearing. Mice with extra NT3 regained their ability to hear much better than the control mice.

Corfas said that his team shall explore the role of NT3 in human ears, and seek drugs that might boost NT3 action or production. While the use of such drugs in humans could be several years away, the new discovery gave them a specific target to pursue.

The paper was published in the online journal eLife.