Ear protein discovery offers clues to hearing

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Ear protein discovery offers clues to hearing

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October 13 2004 at 09:03PM

 

London - A protein in the ear that converts sound into nerve impulses that

are sent to the brain could be the long-sought key to understanding hearing

and deafness, scientists said on Wednesday.

 

The discovery of the protein called TRPA1, by researchers in the United

States, could also lead to better treatments for patients with hearing

problems.

 

" People have been looking for this protein for a decade, " said Professor

David Corey, of the Howard Hughes Medical Institute in Boston.

 

TRPA1 is found on the tip of hair cells in the inner ear. It works by

forming a doughnut-like channel in the cell membrane of inner ear hair cells

which is thought to be at the centre of the body's hearing mechanism.

 

" In the absence of sound, the hole is closed, " said Jeffrey Holt, of the

University of Virginia Health System in Charlottesville, who contributed to

the research.

 

" But when sound strikes the protein, the hole pops open like a trap door,

allowing potassium and calcium ions to flood into the cells. Because these

elements carry a positive charge, an electrical signal is generated which is

relayed to the brain for interpretation, " he added.

 

The scientists suspect that some deaf patients may have a mutated form of

the TRPA1 gene. They believe a correct copy of the gene to replace the

mutated one could potentially restore hearing and balance to people with

hereditary inner ear disorders.

 

The findings are reported online by the science journal Nature.

 

" This could allow for the development of new gene therapies for deafness and

balance disorders in five to 10 years, " Holt added.

 

More than 28 million people in United States alone are deaf or hard of

hearing, according to the National Institute on Deafness and other

Communication Disorders.

 

Different TRP proteins are thought to be involved in seeing and hearing in

insects. They are also linked to taste and heat sensation in some mammals.