Stem cells helped restore hearing in a study of gerbils, suggesting the approach may help some deaf people who currently have no treatment options, according to a study published in the journal Nature today.
Human embryonic stem cells helped improve hearing in 18 gerbils, as measured by auditory-evoked response thresholds, by 46 percent, according to a study by researchers at the University of Sheffield in England. Further investigation is necessary before the approach can be tested in humans, which may be “a few years” away, according to researchers.
The approach targets the 10 percent to 15 percent of the deaf population with damage to sensory neurons, which can’t be addressed by cochlear implants. Those devices, which may be combined with the stem cell therapy, help restore hearing in people with lost sensory hair cells.
“Our priority is on the neurons since for hair cells, you already have the cochlear implants,” Marcelo Rivolta, one of the study authors, told reporters in London today. “A lot more work needs to be done in vitro and in animals” before the approach can be studied in humans.
In the study, about 50,000 cells were implanted per injection at the base of the cochlea portion of the rodents’ chemically damaged ears. Compared with other stem cell applications, the relatively small number of cells needed to treat hearing loss makes the approach feasible, Rivolta said.
Gerbils were used in the study as they have a hearing range closer to humans than mice, which have a higher pitch range, Rivolta said.
The study was funded by the U.K. research charity Action on Hearing Loss, Deafness Research U.K., the Wellcome Trust and the Medical Research Council.