Protecting auditory nerve cells using genetic therapy

The purpose of this work is to preserve or regenerate the highly structured neural organisation of the cochlea using gene therapy techniques.

Loss of hair cells leads to progressive degeneration of the auditory neurons potentially reducing the efficacy of the cochlear implant. We previously discovered that flooding the cochlea with neurotrophins protected auditory neurons after deafness, but we noticed that the nerve fibres grew abnormally which could result in a confusing sound perception with a cochlear implant.

Using clues from the normal development of the inner ear, we proposed that a more localised source of neurotrophins will provide the neurons with survival signals directional cues to guide their growth to the right location.

Gene therapy techniques allow the cochlea’s own cells to produce neurotrophins just as hair cells would normally do. This study provides the first steps towards controlling nerve growth in the cochlea after hearing loss.

If we can achieve long-term nerve survival and controlled regrowth of nerve fibres after hearing loss, then we can potentially improve bionic ear performance.