Scientists find protein that may be key to hearing

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 donut-like channel in the cell membrane of inner ear hair cells, which are thought to be at the center 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.

Provided by ArmMed Media
Revision date: July 7, 2011
Last revised: by Janet A. Staessen, MD, PhD