Deep inside the ear, specialized cells that are confusingly called “hair cells” – they have nothing to do those hairs protruding from your Uncle Fred’s ears – detect vibrations in the air and translate them into sound. Without them, you can’t hear. Unlike non-mammalian species, in humans, there are a limited number of these cells, and if enough of them get damaged or killed off, hearing loss occurs.
Hair cells are the key to understanding the process of hearing. By figuring out how these cells work at a molecular level, scientists believe they can eventually develop better treatments and possible cures for deafness. Key to this goal is figuring out how to regenerate these cells if they get damaged or die off.
A new Stanford study published in the journal Development takes one more step along this pathway by showing that these early hair cells can be grown back in newborn mice.
“The study builds on the hypothesis that younger cochlea – that portion of the inner ear where the hair cells are located – can regenerate,” said Alan Cheng, MD, one of the senior authors of the study, which was done in collaboration with St. Jude Children’s Research Hospital.
“No spontaneous auditory hair cell regeneration has been observed in postnatal mammals prior to this study,” Cheng, an assistant professor of otolaryngology and pediatrics, told me. “Extensive efforts from laboratories around the world have focused on understanding mechanisms that can drive mammalian hair cell regeneration.”
In their study, the scientists induced hair cell loss in their mouse models at birth and then observed there was “spontaneous regeneration of hair cells.” One week after birth, there was no much regeneration.
The research also showed, interestingly, that most of these regenerated hair cells in the young cochlea didn’t ultimately survive. “This lack of survival posits a new challenge to regenerating hearing,” Cheng said.
Previously: Battling hearing loss on and off the battlefield, Stanford researchers gain new insights into how auditory neurons develop in animal study, Stanford hearing study upends 30-year-old belief on how humans perceive sound and Stanford chair of otolaryngology discusses future regenerative therapies for hearing loss
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