Hearing Loss: How The Ear Works
The brain interprets sounds is a relatively simple process.
- a sound enters the ear via sound waves. It then moves down the ear until it hits the eardrum.
- the eardrum vibrates and sends these vibrations to bones in the middle ear, which then boosts them
- Then, hair-like cells in the inner ear or cochlea pick up these vibrations and transform them into electrical signals that the brain can process.
Age or excessive exposure to loud noise will damage the cochlea, resulting in permanent hearing loss. According to the World Health Organization (WHO), hearing loss affects more than 400 million people world-wide.
Some people experience more severe loss than others, and the prescribed treatment is hearing aids. Its effectiveness depends on the individual and also on the quality of the hearing aid.
Hearing Loss: The Inner Ear
In birds, for example, a group of receptors is responsible for regenerating damaged or dead hair cells in the cochlea. These receptors are called the epidermal growth factor. EGF turns on and promotes growth of sensory hair cells in birds.
In a new study just published in the European Journal of Neuroscience, researchers from the University of Rochester and the Massachusetts Ear and Eye Infirmary, succeeded in re-generating sensory hair cells in mice.
The scientists were able to regrow the all-important sensory hair cells in mammals for the first time. They tested two drugs in one group of mice and induced a virus in the other groups. These treatments were designed to activate the EEBB2 receptor in the cochlea.
These treatments activated the EERB2 which led to the production of cochlear support cells, followed by sensory hair cells. Next, the hair cells integrated with nerve cells, which is necessary for hearing.
This research shows that a signaling pathway that can be activated by different methods. It could represent a new approach to cochlear regeneration and, ultimately, restoration of hearing.
Additional research is necessary, but this new approach to reverse hearing loss, looks promising.