Hearing loss caused by damage to the delicate hair cells of the inner ear (usually by loud noise) has been believed to be incurable. But now a team of scientists at Oregon Health and Science University (OHSU) are using gene therapy to grow functioning inner ear cells in mice embryos in the womb.

Gene therapy involves inserting a functional form of a gene called Atoh1 into the inner ear of unborn mice. The procedure showed that these animals ended up with more hair cells than normal. More importantly, the cells that had Atoh1 functioned in the same way as normal hair cells.

The work by OHSU and their exciting results has roots in similar scientific breakthroughs by other researchers at the University of Michigan who used gene therapy to generate hair cells in adult guinea pigs.

In other arenas, progress is being made in developing stem cell treatments for hearing loss. By injecting bone marrow stem cells into the inner ear of rats with damaged hearing, researchers found that they recovered more rapidly. You can read an article on stem cell research in mice in our Tinnitus Library.

Despite the encouraging news a functional procedure for humans is a long way off. There remain a range of obstacles to surmount before people with hearing problems see benefits from gene therapy treatment, such as how to deliver the hair cell genes into human ears. But as one researcher said, “it is no longer a pipe dream.”