Drug enables deafened mice to hear again

January 10, 2013

“Sqeeeek! What? I said SQEEEEK! Oh.” Mice with inner ear damage due to noise (left) recover hearing with drug treatment (right) that can prompt the regrowth of sound-sensing hair cells (green) (credit: Mizutari et al./Neuron)

All you graying, half-deaf Def Leppard fans, listen up. A drug applied to the ears of mice deafened by noise can restore some hearing in the animals, Science Now reports.

By blocking a key protein, the drug allows sound-sensing “hair cells” damaged by loud noises to regrow. The treatment isn’t anywhere near ready for use in humans, but the advance at least raises the prospect of restoring hearing to some deafened people.

Albert Edge, a stem cell biologist at the Massachusetts Eye and Ear Infirmary in Boston and colleagues have tested several gamma-secretase inhibitors to find the one with the strongest regenerative effect on inner ear stem cells. They then tested that drug on adult mice that had been deafened after 2 hours in an extremely loud sound chamber. The drug prompted supporting cells in the inner ear to become hair cells, and the treated mice regained some hearing, the group reports online today in Neuron.

One caveat, notes Yehoash Raphael, an auditory neuroscientist at the University of Michigan, is that the drug was applied just a day after the noise exposure. It’s not clear how well the treatment would work if it were applied after a longer delay. If not, Matthew Kelley, who studies the development of the inner ear at the National Institute on Deafness and Other Communication Disorders in Bethesda, Maryland, suggests that the most obvious application would be for soldiers who have become deafened suddenly by a bomb blast or other explosion.