Because the protein, TRPA1, is found in the majority about 75 percent -- of the body's pain-perceiving neurons, but not in major organs, drugs that could block TRPA1 would be novel pain killers with few or no side effects, although targeting the inner ear may have to be avoided, said Jaime Garcia-Aoveros, who led the research.
Garcia-Aoveros, assistant professor of anesthesiology, neurology and physiology at Feinberg and the Northwestern University Institute for Neuroscience and a fellow of the Hugh Knowles Center for Hearing Research, described the dual role of the protein, TRPA1, in the cover article of the April 20 issue of the Journal of Neuroscience. The other authors, all members of his research group at Northwestern University, were Keiichi Nagata, Anne Duggan and Gagan Kumar.
Garcia-Aoveros and his colleagues showed conclusive evidence that TRPA1, in addition to being expressed in nociceptors, or pain neurons, is present in the stereocilia of hair cells, the sensory part of the cells of the inner ear used for hearing as well as detecting gravity and maintaining balance.
Garcia-Aoveros and Duggan, currently a research assistant professor in anesthesiology at Feinberg and a researcher at the Northwestern University Institute for Neuroscience, initiated the study of TRPA1 in the late 90s, while searching for the channel that mediates hearing.
After they discovered that TRPA1 is expressed in the organ of Corti, the hearing organ of the inner ear, they were joined by colleagues at Harvard Medical School and Northwestern, and thus founded the groundbreaking group of scientists who in 2004 proposed that TRPA1 was a candidate for mechanosensory channel of hair cells.