How an itch hitches a ride to the brain
Area in the brain stem acts as a relay station between spinal cord and yet-unknown destination for prickly sensations
DON’T SCRATCH Scientists reveal how the spinal cord communicates the discomfort of itchy bug bites to the brain.
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Scientists have traced the sensation of itch to a place you can’t scratch.
The discomfort of a mosquito bite or an allergic reaction activates itch-sensitive nerve cells in the spinal cord. Those neurons talk to a structure near the base of the brain called the parabrachial nucleus, researchers report in the Aug. 18 Science. It’s a region that’s known to receive information about other sensations, such as pain and taste.
The discovery gets researchers one step closer to finding out where itch signals ultimately end up. “The parabrachial nucleus is just the first relay center for [itch signals] going into the brain,” says study coauthor Yan-Gang Sun, a neuroscientist at the Chinese Academy of Sciences in Shanghai.
Understanding the way these signals are processed by the brain could someday provide relief for people with chronic itch, Sun says. While the
