Damage to the auditory nerve connecting the inner ear and brain causes hearing loss in some individuals. Researchers Dr. Marcelo Rivolta from the University of Sheffield and colleagues have shown that human embryonic stem cells that were differentiated into auditory nerve cells can improve overall by ~45% hearing in gerbils that were treated with ouabain to damage the nerves. Ten weeks after transplantation, some of the differentiated cells were shown to grow projections that connected with the brain stem and the animals could perceive more faint sounds.
Of course the purpose of the studies was not to restore hearing in deaf gerbils, but rather to show that this type of treatment may be feasible and potentially used to treat hearing loss in humans. This was the first study to show that such differentiated stem cells could improve hearing in animals. Although treatments for humans are not expected to be available for some time since additional research is needed.
Chen W, Jongkamonwiwat N, Abbas L, Eshtan SJ, Johnson SL, Kuhn S, Milo M, Thurlow JK, Andrews PW, Marcotti W, Moore HD, Rivolta MN. Restoration of auditory evoked responses by human ES-cell-derived otic progenitors. Nature. 2012. doi:10.1038/nature11415