The electrodes in a cochlear implant can be used to direct gene therapy and regrow neurons.
Researchers have demonstrated a new way to restore lost hearing: with a cochlear implant that helps the auditory nerve regenerate by delivering gene therapy.
The researchers behind the work are investigating whether electrode-triggered gene therapy could improve other machine-body connections—for example, the deep-brain stimulation probes that are used to treat Parkinson’s disease, or retinal prosthetics.
More than 300,000 people worldwide have cochlear implants. The devices are implanted in patients who are profoundly deaf, having lost most or all of the ear’s hair cells, which detect sound waves through mechanical vibrations, and convert those vibrations into electrical signals that are picked up by neurons in the auditory nerve and passed along to the brain. Cochlear implants use up to 22 platinum electrodes to stimulate the auditory nerve; the devices make a tremendous difference for people but they restore only a fraction of normal hearing.
“Cochlear implants are very effective for picking up speech, but they struggle to reproduce pitch, spectral range, and dynamics,” says Gary Housley, a neuroscientist at the University of New South Wales in Sydney, Australia, who led development of the new implant.