Reversing the effects of noise induced hearing loss
Researchers have been able to recover hearing in mice that suffered noise induced hearing loss. This could lead to research developments into recovering hearing in humans, as the aim of their study was to be able to find new therapies that restore noise induced and age related hearing loss in humans.
In their study, researchers found cells in the inner ear which produced a small level of the protein called neurotrophin (NT-3) which is a key signal for communication between the ear and the brain. In the study they wanted to test what would happen if they increased this protein in the inner ear to see whether it would improve the signals from the inner ear to the brain. The process used is called conditional gene recombination, where researchers are able to reactivate cells by prompting them with a drug which allows them to read an additional copy of the gene which has been inserted into them. The drug which prompted the increased production of the protein NT3 was tamoxifen. When they increased the production of the protein using tamoxifen through the supporting cells, over a two week period it was found that the mice had regained their hearing compared with mice that had not had the boosted protein. They also tested the NT-3 drug against another cell growth drug called neurotrophin called BDNF but this did not have the same effect as the NT-3 drug.
One of the reasons that noise induced hearing loss and age related loss occur is that the ribbon synapse, the signal pathway from the brain to the inner ear through nerve conduction, is distorted causing a defective pathway. The ribbon synapse in this test was reformed upon the increased level of NT-3 which allowed for the mice’s hearing to improve.
Therefore, in humans, who are found to have a very similar brain to ear signal connection as mice, this has increased our understanding into the cause of noise induced hearing loss, as the ribbon synapse in the inner ear has been distorted by significant exposure to noise. The hair cells in the ear are damaged by this noise exposure and therefore are unable to communicate with the ribbon synapse and brain.
However, the researchers are unsure as to whether this would ultimately work for humans who are completely deaf as the mice involved in the study were only partially deaf. However, this is a step in the right direction to developing knowledge of noise induced hearing loss and age related loss and the ability to reverse noise induced hearing loss which had never been possible until this study.
We are Industrial Disease Solicitors who specialise in pursuing claims for employees who have suffered significant noise exposure through their work and have developed hearing loss or tinnitus as a result. When a person brings a claim, they only have three years from when they first became aware of their hearing problems and thought, at that time, that this may be related to their noise exposure through work, in which to issue court proceedings as otherwise the claim would be brought out of time and would be statute barred. If you have developed hearing loss symptoms within the last three years and have worked in a noisy working environment, please contact us as you may be entitled to a claim for compensation.