Researchers restore hearing in animals using stem cells

Regardless of the controversy surrounding the field, stem-cell research is widely considered to be the future of medicine, heralding in a new age in treatment and cures. Researchers have said that stem cells, which are taken from embryos, have the potential to cure just about any ailment that afflicts the human body, and new research regarding deafness certainly points in that direction.

Researchers from the University of Sheffield have found that by using stem cells they were, for the first time, able to restore hearing in deaf animals. Using stem cells, the researchers, who published their work in the journal Nature, were able to regrow nerves in the ear that passed aural stimulation to the brain, letting the animals in question—gerbils—hear once again.

Deafness occurs when nerve cells responsible for hearing, known as spiral ganglion neurons, are damaged, disallowing the passing of any aural stimulus to the brain. The aim of the researchers was to rebuild these damaged neurons and using stem cells, combined with a “chemical soup,” injected into the ears of 18 deaf gerbils.

Over a period of 10 weeks it was noted that, on average, the hearing of the test gerbils improved with a 45 percent restoration of hearing by the end of the study. The researchers were able to detect an improvement in hearing by measuring the gerbil’s brain waves. Around a third of the test gerbils were noted to recover their hearing, while in the most encouraging of results, some gerbils had 90 percent of their hearing restored.

Speaking about the research, Dr. Marcelo Rivolta said, "It would mean going from being so deaf that you wouldn't be able to hear a lorry or truck in the street to the point where you would be able to hear a conversation. It is not a complete cure, they will not be able to hear a whisper, but they would certainly be able to maintain a conversation in a room."

While the researchers were successful, human testing is still very far off. Of course, the added issue of stem-cell use would be further prohibiting, but the director of the Medical Research Council's Institute of Hearing Research in Nottingham, UK, Prof. Dave Moore, said, "It is a big moment, it really is a major development,” adding that, "the biggest issue is actually getting into the part of the inner ear where they'll do some good. It's extremely tiny and very difficult to get to and that will be a really formidable undertaking."