In a new study, a team from the Kresge Hearing Research Institute at the University of Michigan along with Harvard University was able to successfully restore hearing in mice that were partially deafened by noise. Using advanced tools, the production of a key protein in the ears was boosted. These findings were published in the online journal eLife.
The protein, called NT3, works by maintaining communication between the ears and brain. Researchers were able to demonstrate just how vital NT3s are, thereby opening the door for research in humans. Many experts believe the findings of this study will improve treatment for humans with hearing loss caused by normal aging and noise exposure.
The work of this dedicated team illustrated that rather than serve in a supporting role, these cells are vital for ear-to-brain communication. Interestingly, NT3s are still referred to as “supporting cells”, which form the physical foundation for the hearing system’s “stars”, which are hair cells within the ear that interact directly with nerves responsible for carrying sound signals to the brain.
Researchers identified that NT3s are far more than supporters but also learned about the molecules they produce. As stated by Gabriel Corfas, team leader and director of the U-M Institute, hearing loss due to damaged ribbon synapses may be common but it is also very challenging, regardless if it comes from aging or noise.
Ribbon synapse is special type of connection that allows very fast communication of signals traveling back and forth across small gaps between the two types of cells.
To answer very basic questions about the inner ear, researchers began conducting studies more than 15 years ago. Now for the first time, they have been able to restore hearing after partial deafening associated with noise, a common problem for humans.
With a special genetic technique, researchers were able to produce additional NT3 in cells of specific areas of the inner ear after being exposed to noise so loud it caused decreased hearing. In the mice with extra NT3, the ability to hear better was accomplished.
Corfas says that now his team must conduct further exploration pertaining to the role of NT3 in humans. They also want to look for drugs that have the ability to bolster the action of NT3 production. However, using these drugs in humans is probably years in the future but based on the discovery of this new study, experts now have a special target to reach for.