Sadly, as we age our ability to hear decreases due to damage from loud noises and medical treatments like cancer treatments.
We are born with tiny hair cells in our ears, which when we are young stick up and detect the vibrations from sound waves sending signals to our brain about the frequency and amplitude or pitch and volume of the sounds around us.
Hair cells develop in the embryo and our inner and outer hair cells work together to help us to hear. The outer hair cells expand and contract in response to the pressure of sound waves and then amplify the sound for the inner hair cells to transmit to the brain.
Sadly, as we age these cells are damaged and die – exposure to loud sounds is a really common way for them to be damaged, which causes them to lie down flat where they are unable to pick up the vibrations anymore.
This death of our outer hair cells is the most common cause of age-related hearing loss and deafness and to date, scientists have never figured out how to regrow them. New research published this week in the journal Nature (https://www.nature.com/articles/s41586-022-04668-3) has found that one single gene programmes cells to become either outer or inner cells.
This discovery opens the doors to understanding why outer hair cells are more prone to dying and causing deafness compared to inner hair cells.
The big discovery is that the production of the hairs is driven by a master gene called TBX2. When the gene is expressed, the cell becomes an inner hair cell. and when the gene is blocked, the cell becomes an outer hair cell.
Because scientists can already make a basic hair cell from a non-hair cell using a cocktail of genes, this new discovery could help researchers to eventually reprogram cells in the ear so they can reform as hair cells, and hopefully restore hearing.
With over 70% of people aged 70 and older suffering from age-related hearing loss, and with the correlation of this hearing loss to dementia, it's a huge step forwards to try and help repair the hearing damage that comes with living a modern, noisy life.
Dr Michelle Dickinson joined Francesca Rudkin.
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