Development On Age-Related Hearing Loss

Jonas Bergsten via Wikimedia Commons  

Age-related hearing loss is usually blamed on the death of hair cells in the inner ear, but research from John Hopkins University suggests there may be more going on. 

The paper discovered that with age, more connections between sensory and nerve cells in the inner ear begin to form in mice. Similar connections to this are usually used to dampen hearing in response to loud sounds in younger years. 

“The nerve cells that connect to the sensory cells of the inner ear are known to inhibit hearing, and although it’s not yet clear whether that’s their function in older mice, it’s quite likely,” 

Mature hair cells (left) have less connections to outgoing neurons (blue) and more to incoming neurons (red) with age (right) Credit: Paul Fuchs, Johns Hopkins Medicine

Whilst loss of sensory hair cells themselves would negatively impact on hearing, connections with nerve cells (which transport the electrical signal to the brain) also change in response to their environment and it may be that with age, this process becomes maladapted or damaged. Previous work has found that with age, our inner hair cells attain more incoming connections from nerve cells, but lose some outgoing ones – suggesting that an inhibitory function may begin to dominate, decreasing the overall signal being relayed to the brain. With more research, this array of connections might be reverted back to a more youthful pattern. 

Read more at Medical Express