Scientists from the University of Michigan Medical School’s Kresge Hearing Research Institute and Harvard University have restored the hearing of mice partly deafened by noise, using advanced tools to boost the production of a key protein called NT3. These new findings pave the way for research in humans that could improve treatment of hearing loss caused by noise exposure and normal aging.

NT3 is crucial to the body’s ability to form and maintain connections between hair cells and nerve cells, the researchers demonstrate. This special type of connection, called a ribbon synapse, allows extra-rapid communication of signals that travel back and forth across tiny gaps between the two types of cells.

Anyone who has experienced problems making out the voice of the person next to them in a crowded room has felt the effects of reduced ribbon synapses. So has anyone who has experienced temporary reduction in hearing after going to a loud concert. The damage caused by noise reduces the ability of hair cells to talk to the brain via ribbon synapse connections with nerve cells.

Using a special genetic technique, the researchers 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.

Now the University of Michigan team will 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 gives them a specific target to pursue.

Content provided by Hearing Review