The latest stem cell news is a novel treatment using human embryonic that has successfully restored some hearing to gerbils that were previously deaf, according to a study published this week in the journal Nature.
The new strategy, designed by Marcelo Rivolta and his team at the University of Sheffield, uses techniques the group has recently developed to coax human embryonic stem cells to differentiate into what are called “otic progenitor cells” — cells that have the possibility to develop further into either hair cells or auditory nerve cells.
The progenitor cells are then transplanted into the ears of gerbils with damaged auditory nerves, and allowed to differentiate further.
Gerbils were used in the experiment because they hear a similar range of sounds as humans do.
In nearly all cases, the scientists could clearly see under the microscope that the new cells had targeted the right spots, reconnecting the hair cells to the brainstem.
But the ultimate test is hearing itself. To test this, the researchers used a standard approach called auditory-evoked responses, which are detected in the brainstem and provide a clear verdict of whether or not sound is being successfully transmitted to the brain.
The strength of the effect was akin to suddenly being able to hear someone talking while previously not being able to hear them yell.
The researchers hope that their method will spark a new interest in using stem cells to treat hearing loss in people, though much work needs to be done before that is a real possibility. Hurdles include developing a surgical technique to access the appropriate part of the ear in people, and ensuring that the treatment sticks over long periods of time.