A new mechanism of inner-ear repair has been discovered by researchers at the University of Kentucky.

hearing loss

there are over 360 million people in the world living with disabling hearing loss.

PLOS Biology







  • protocadherin-15 (PCDH15) – Located closest to the shorter stereocilium
  • cadherin-23 (CDH23) – Links to the longer stereocilium
When these proteins mutate it can result in deafness.

physiologyPCDH15 triggers the re-formation of the chain and as soon as CDH23 is back in place there is full restoration of normal mechanotransduction.





Changes in the molecular composition of the restored tip links were linked to the final normalization.

The Role of Hair Cells in Hearing





calcium



inner ear cells
The inner ear interprets sound via tip links that open up ion channels.

Image credit: Gregory I. Frolenkov.
This two-step process also occurred when mouse’s hair cells initially developed.



“This study resolves a dispute over the composition of tip links, in which one camp argued for a PCDH15-only structure, and the other for a combination of the two proteins. Apparently, both are right, depending on when one looks. More importantly, it reveals the details of a process that is likely to be vital for the development, maintenance, and restoration of normal hearing.”

short-term hearing loss following sustained exposure to loud noise doesn’t reflect damage to our hearing: rather, it is the body’s way of coping.