Stem Cells Could End Deafness

Stem cells help deaf gerbils hear again. Researchers have identified a way for coaxing early stem cells into specialized ear cells that helped the rodents hear sound once more.

The gerbils had been given a chemical to damage key nerve cells called spiral ganglion neurons (SGNs). These transmit to the brain the signals that are picked up by "hair" cells, which respond to noise.

Presbycusis (Age-related Hearing Loss)-Causes-Symptoms-Diagnosis-Treatment-FAQs
Presbycusis (age related hearing loss) is the gradual loss of hearing that occurs as people get older. Presbycusis involves progressive sensorineural hearing loss.

In a study published in the journal Nature, a team led by Marcelo Rivolta at Britain's University of Sheffield said they had found a way to turn human embryonic stem cells into precursors of these vital ear cells to reverse the deafness.

Stem cells are infant cells that develop into the specialised tissues of the body.

They have sparked great excitement as they offer hopes of rebuilding organs damaged by disease or accident.

About Stem Cells
Encyclopedia section of medindia gives general info about Stem Cells

Stem cells taken from an early embryonic stage are the most prized in research because they have the greatest versatility, but the big challenge is ensuring that they differentiate into the right tissue.

Rivolta nurtured the stem cells in a serum bath to gain "otic pregenitor" cells before gently implanting them in the gerbils.

Anatomy of Ear and Hearing
Ear converts sound waves into electrical impulses that are transmitted to the temporal lobe of the brain through the auditory nerve. It consists of outer, inner and middle sections.

After 10 weeks, the animals had, on average, recovered 46 percent of their hearing loss, according to electrodes that measured their brains' response to sound.

Their average level of detection was around 50 decibels, which is equivalent to a conversation in quiet surroundings.

Quiz on Stem Cells
Scientists believe (and are working hard) to use stem cells in the future to treat a wide range of diseases and injuries. But what exactly is a stem cell? How can it be used in curing disorders? See if you get your answers from this quiz.

"The range of recovery went from modest to almost complete, which is remarkable considering the technical challenges involved in the procedure," the paper said.

Many obstacles remain before this laboratory trial can be used on humans, a process that is closely regulated for safety.

But the researchers said that, if these hurdles are overcome, stemcell therapy could one day offer hope for deaf people when used with a cochlear implant, a device that circumvents loss of hair cells.

Source-AFP