Stem cells for hearing loss

Researchers at the University of Sheffield, together with colleagues in Thailand, have made a big step forward in developing stem cell therapy for hearing loss, publishing their work in Nature. The team converted human embryonic stem cells grown in the lab into cells known as "otic progenitors" - the precursors of nerve cells known as spiral ganglion neurons in the inner ear, which send sound signals to the brain.

When they transplanted these progenitors into deaf gerbils whose spiral ganglion neurons had been damaged, the animals had a roughly 46% improvement in hearing over 10 weeks, compared with deaf  gerbils who didn't get the stem cells transplant. If scaled up to humans, the researchers suggest this might be the difference between only being able to hear loud noises like passing trucks, or being able to hold a conversation. In case you're wondering how you measure how deaf a gerbil is, the scientists measured the animals' brainwaves in response to noise rather than trying to put a tiny pair of headphones on them.

Although this story was widely reported as a "stem cell deafness cure", this research is just a proof of concept for restoring hearing after one specific type of damage, and it's still very early days.