Replacement of Inner Hair Cells. In our Future?

Stanford Discovery Could Lead To Cure For Deafness

Posted: 5:19 pm PDT May 13, 2010Updated: 6:50 pm PDT May 13, 2010
STANFORD, Calif. -- A new discovery from Stanford researchers may pave the
way for treatment -- and even a possible cure -- for deafness.

Stem cell scientists reported Thursday that they have for the first time
created in the laboratory the inner-ear cells responsible for hearing and
balance.

For the profoundly deaf, a risky and invasive cochlear implant is currently
the only way to restore hearing.

Doctors said in the vast majority of cases, the auditory nerve is intact.
But it's the inner ear that doesn't work.

"It's usually a loss of the sensory cells inside of the cochlea," said
Stanford Cochlear Implant Surgeon Dr. Nikolas Blevins. "And that is exactly
what a cochlear implant is designed to bypass."

Thursday's announcement suggests that there may be another way.

"It's a huge step forward for basic science," said Professor of
Otolaryngology Stefan Heller.

Professor Heller and his colleagues said the huge step is that they've
created the first functional cochlear sensory cells from stem cells.

Inside the spiral inner ear, there are only a few thousand sensory cells.
They do not regenerate once damaged by noise, virus or if genetically
absent. Deafness is permanent.

Scientists used mouse stem cells to create sensory cells that had a tiny but
critical hair bundle.

"This is a sensor which detects sound vibration and converts it to
electrical signal," explained Stanford researcher Dr. Kazuo Oshima.

"Fascinatingly, the cells were working which is a major step forward," said
Heller. "Eventually in the future possibly a cure for hearing loss."

Researchers cautioned that parents should not wait for this cure because it
could be a decade or more away. And while some people in the deaf community
applaud research, one summed it up to KTVU in a view not uncommon among deaf
people: "Why don't they quit trying to fix us.