Hearing Nerves Adjust to Implants
WASHINGTON (AP) _ A study using deaf kittens showed that devices called cochlear implants can stimulate growth and change in the nerves of the hearing system among the very young.
Researchers at the Physiologisches Institut of Frankfurt, Germany, tested the effects of the cochlear implants by putting them into the brains of kittens that were deaf at birth.
The scientists report Friday in the journal Science that as the cats got older, they began to respond to sounds in the same way as cats that were born with normal hearing.
The researchers, led by Rainer Klinke, found in congenitally deaf cats that the unstimulated auditory nervous system did not develop in the same way as for normal cats. They found that when the deaf cats were outfitted with the cochlear implants at three to four months after birth, parts of their brains changed so that sounds were processed and the animals responded to commands and signals.
Such changes did not occur in congenitally deaf cats without the devices, the researchers found.
Dr. Josef P. Rauschecker of the Georgetown University Medical Center said in Science the study shows that the young brain is adaptable to stimulation from the implant and offers some explanation for the medical experience with the device in humans.
Though the use of cochlear implants is controversial among the deaf, Rauschecker implants early in life of children born deaf ``have proven quite successful.″ However, among adults who have been deaf since childhood, the history of cochlear implants ``abounds with examples of failure.″