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17 April 2014 12:48 pm ,
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Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
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Scratch That Gene
25 July 2007 (All day)
Scratchers of the world take heart. Researchers have identified the first gene in the central nervous system that is responsible for itching. Although other itch genes are known, this is the first one directly linked to the brain and could pave the way for novel drugs to sooth serious itching.
The irritating culprit made by the gene is gastrin-releasing peptide receptor (GRPR). Researchers have been studying the gene for its role in pain, but no one ever tied it to itching. A team led by geneticist Zhou-Feng Chen of Washington University School of Medicine in St. Louis, Missouri, started looking at GRPR because it was interested in pain genes. GRPR is found only in a few spinal nerve cells that send pain and itch signals to the brain. The team soon discovered that the receptor wasn't essential to perceiving pain; mice whose GRPR genes had been knocked out responded normally to various types of pain from heat, inflammation, and mechanical pressure.
The researchers then tested whether GRPR is required for feeling itchy by injecting several itch-inducing compounds into the knockout mice, including histamines--the substances responsible for the itchiness of allergies. The mutant mice didn't scratch anywhere near as much as the normal mice did in response to the injections. Conversely, when the scientists injected normal mice with a substance mimicking the gastrin-releasing peptide, they scratched even more, the team reports online today in Nature.
The authors believe this signaling pathway offers a promising new target for chronic itching. This problem, often intractable, stems from a host of maladies, from skin disorders to tumors.
"It's an excellent study and provides a new molecular target ... that may be exploited to relieve itch," says Earl Carstens, a neuroscientist at the University of California, Davis.
Jeffrey Mogil, who heads the pain genetics lab at McGill University in Montreal, Canada, seconds that conclusion, calling GRPR "an eminently druggable target."