New research restores noise induced hearing loss in mice

New research restores noise induced hearing loss in mice

Hearing loss is a common issue and something that has become expected with old age. With working environments in the past contributing heavily to noise exposure, many more people are affected with hearing loss. Hearing loss damage can be seen in the way in which the connection, the ribbon synapse, between the ear and the brain becomes damaged. The symptoms of hearing loss vary in severity however it is common for people to struggle with conversations, TV volume and tinnitus. However hearing loss could soon be an issue of the pasts recent findings show.

A new study, researched at the University of Michigan and the Harvard Medical School in Boston are close to finding treatment to restore the damage to a person’s hearing. In the study researchers used mice to see if they could increase the production of a protein called Neurotrphin-3 (NT-3). NT3 plays a key role in the supporting cells in the inner ear that allow the connection between the ears and the brain to send sound signals. The researchers then investigated how increasing the protein NT3 within these supporting cells could potentially lead to a reconstruction of the synapse.

The study team used a method called conditional gene recombination. This method allows specific genes, within cells, to copy additional genes that have been inserted into them. The study team then used this method to allow the cells to copy additional NT3 genes which in turn meant researchers were able to repair hearing loss. The researchers used the drug, tamoxifen, which starts the production of NT3. To then analyse whether the drug had been effective on the mice, the study team tested the hearing of the mice using the auditory brainstem response (ABR).

The results proved successful and a stark contrast was found within the mice who had demonstrated increased NT3 production and the mice that hadn’t. The mice that displayed a higher production of NT3 regained hearing over a two week period when compared with the mice that didn’t have any extra NT3 production.

The study team now aims to investigate this method in humans, specifically the role of NT3 and drugs that can produce the extra protein needed. It is important to note that the researchers did state that the study was done on mice who only displayed minor hearing issues. It is not being celebrated as means of curing complete deafness.

Lead study author Gabriel Corfas commented with the following

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. 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. It’s very exciting

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