Hearing loss in babies
Research & Innovation
Most cases of deafness are caused by the dysfunction or death of cells in the cochlea, the snail-shell-shaped structure in the inner ear. Douglas Cotanche, PhD, a researcher in Otolaryngology, now reports that his lab has grown all the assorted cell types in the cochlea from just one source: neural stem cells. The study was published online June 20 by the journal Hearing Research.
Neural stem cells were first isolated from mice in 1998 by Evan Snyder, MD, PhD, formerly of Children's Department of Neurology. Cotanche's team implanted the cells deep inside the sound-damaged cochleas of guinea pigs and mice. Six weeks later, the cells had migrated throughout the cochlea and formed satellite cells, spiral ganglion cells and Schwann cells, which make up the cochlea's nervous tissue, as well as the hair cells and supporting cells of the organ of Corti (the actual hearing organ). "Getting these cells to integrate into the damaged ear and make the variety of cochlear cell types is a big step," says Cotanche.
The researchers couldn't show complete rebuilding of the cochlea, but they believe that with more time and more stem cells, most of the cochlea could be repopulated. Cotanche's next goal is to implant human neural stem cells in animals and test whether the new cochlear cells connect with the auditory nerve and the brain, and whether they respond to sound stimulation—in other words, whether they restore hearing.