The Daily Mail has welcome news. It reports on the development of a drug that has been shown to regenerate the sensory hair cells in the inner ear. From the article:
The drug, codenamed LY411575, triggers the regeneration of sensory hair cells.
Until now it has not been possible to restore the cells once they have been lost due to factors such as loud noise exposure, infection and toxic drugs.
Scientists succeeded in partially restoring hearing to mice that had been deafened by loud noise.
Although the research is at an early stage, they believe it could lead to effective treatments for acute noise-induced deafness in humans.
The tiny sensory hairs in the cochlea are vital to hearing. Sound vibrations transferred from the eardrum shake the hairs, causing nerve messages to be fired to the brain.
Without the hairs, the hearing pathway is blocked and no signals are received by the brain’s auditory centre.
While birds and fish are capable of regenerating sound-sensing hair cells, mammals are not.
The new approach involves reprogramming inner ear cells by inhibiting a protein called Notch.
Previous laboratory research had shown that Notch signals help prevent stem cells in the cochlea transforming themselves into new sensory hair cells.
The drug LY411575 suppresses Notch. Mice with noise-induced hearing loss generated functioning sensory hair cells after the drug was injected into their damaged cochleas.