Navigation Links
Human Stem Cells Restore Hearing to Deaf Gerbils in Study

By Jenifer Goodwin
HealthDay Reporter

WEDNESDAY, Sept. 12 (HealthDay News) -- Using nerve cells grown from human embryonic stem cells, researchers report that they restored hearing in deaf gerbils.

About 80 percent to 90 percent of deafness is due to problems with the cells in the inner ear, explained senior study author Marcelo Rivolta, a reader in sensory stem cell biology at the University of Sheffield, in England. In the inner ear, two types of cells are key to hearing. One type are tiny projections called hair cells, which convert sound vibrations into electrical signals, which then travel along the auditory nerve to the brain.

When hair cells are damaged, cochlear implants can help overcome that by converting sound vibrations into electrical signals, bypassing the hair cells and directing stimulating the auditory nerve, experts explained. But when the cause of deafness is damage to the neurons that make up the auditory nerve, much less can be done about it, Rivolta said.

"We have concentrated on trying to fix the problem at the neuronal level. The cochlear implant is a device that functionally replaces the hair cell -- it takes sound and transforms it into an electrical signal," Rivolta said. "But for the cochlear implant to work, you have to have a good connection to the brain."

In the study, which is published online in the Sept. 12 issue of Nature, researchers coaxed human embryonic stem cells -- which have the potential to grow into any type of cell in the body -- into differentiating into otic (ear) progenitor cells. They did this by placing the stem cells into a test tube that contained certain molecules known to be present during fetal development when the ear forms.

Progenitors are immature cells that haven't fully differentiated into their specific role, but have certain characteristics that have started them down that path. Researchers then further coaxed the progenitors into becoming hair cells or auditory neurons.

"We have a system in vitro [in a test tube] that we can use to produce these important cell types, a little factory of hair cells and neurons whenever we need them," Rivolta said.

Researchers then transplanted the progenitor cells into about a dozen gerbils that had auditory nerve damage. Ten weeks after transplantation, brain wave measurements showed the gerbils could hear again.

"What we have seen is the progenitors engraft, survive and connect to the other cells that are there, and more important, they produce a functional recovery," Rivolta said.

Though exciting, much needs to be learned before the technique could be used in humans, Rivolta said.

"From here to humans, there is still quite a way to go. This is a very important step forward, but one of the first steps," Rivolta said. "What we need to do now is to understand if this recovery is permanent. We have only followed the gerbils for 10 weeks or so. And we want to also know if the treatment is safe, so we will monitor the behavior of the animals long-term."

Dr. John Goddard, a neurotologist at the House Clinic in Los Angeles, said the idea of using stem cells to regenerate stem cells in the inner ear is of great interest to researchers, and others are working on similar studies. This study is exciting in that researchers showed that not only did the nerve cells regrow, but that the gerbils recovered some hearing, he said.

"It is clearly of interest for a lot of people because the potential is dramatic," Goddard said. "The specific article sheds additional light that there is some potential there for regrowth, or regeneration, of sensory cells. But this is going to take many years" to perfect, he added.

Experts also note that while studies involving animals can be useful, they frequently fail to produce similar results in humans.

More information

The U.S. National Institute on Deafness and other Communication Disorders has more on deafness.

SOURCES: Marcelo Rivolta, reader, sensory stem cell biology, University of Sheffield, England; John Goddard, M.D., neurotologist, House Clinic, Los Angeles; Sept. 12, 2012, Nature online

Copyright©2012 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. New drug prevents spread of human prostate cancer cells
2. Scientists solving the mystery of human consciousness
3. First targeted nanomedicine to enter human clinical studies
4. Edith Mitchell, M.D., FACP, named 2012 recipient of ASCO Humanitarian Award
5. Novel compound demonstrates anti-leukemic effect in zebrafish, shows promise for human treatment
6. 2 genetic deletions in human genome linked to the development of aggressive prostate cancer
7. IBN discovers human neural stem cells with tumor targeting ability
8. RANK protein promotes the initiation, progression and metastasis of human breast cancer
9. CNIO researchers describe new functions of cohesin relevant for human disease
10. New Clues to the Evolution of the Human Brain
11. Humanist funerals
Post Your Comments:
Related Image:
Human Stem Cells Restore Hearing to Deaf Gerbils in Study 
(Date:6/24/2016)... ... ... was in a crisis. Her son James, eight, was out of control. Prone to extreme ... “When something upset him, he couldn’t control his emotions,” remembers Marcy. “If there was ... other children and say he was going to kill them. If we were driving ...
(Date:6/24/2016)... Francisco, CA (PRWEB) , ... June 24, 2016 ... ... CitiDent, is now offering micro-osteoperforation for accelerated orthodontic treatment. Dr. Cheng has extensive ... self-ligating Damon brackets , AcceleDent, and accelerated osteogenic orthodontics. , Micro-osteoperforation ...
(Date:6/24/2016)... Plano, TX (PRWEB) , ... June 24, 2016 , ... ... taking part in Genome magazine’s Code Talker Award, an essay contest in which patients ... for an award to be presented at the 2016 National Society of Genetic Counselors ...
(Date:6/24/2016)... Vegas, Nevada (PRWEB) , ... June 24, 2016 ... ... Las Vegas client, The Grove Investment Group (TGIG), has initiated cultivation and processing ... Grove, in Las Vegas and Pahrump, Nevada. , Puradigm is the manufacturer of ...
(Date:6/24/2016)... ... 2016 , ... Venture Construction Group (VCG) sponsors Luke’s Wings ... at the Woodmont Country Club at 1201 Rockville Pike, Rockville, Maryland, 20852. The ... members that have been wounded in battle and their families. Venture Construction Group is ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... 23, 2016  MedSource announced today that it ... software solution of choice.  This latest decision demonstrates ... to their clients by offering a state-of-the-art electronic ... establishes nowEDC as the EDC platform of choice ... clients.  "nowEDC has long been a preferred EDC ...
(Date:6/23/2016)... Any dentist who has made an implant supported ... Many of them do not even offer this as a ... laboratory costs involved. And those who ARE able to offer ... high cost that the majority of today,s patients would not ... Zadeh , founder of Dental Evolutions Inc. and inventor of ...
(Date:6/23/2016)... , June 23, 2016  In a startling report released today, ... their residents by lacking a comprehensive, proven plan to eliminate prescription ... definitive ranking of how states are tackling the worst drug crisis ... four states – Kentucky , New ... Vermont . Of the 28 failing states, three – ...
Breaking Medicine Technology: