SSS 2009-08-07

（单词翻译）

A friend’s four year old daughter recently complained to me about how badly her mosquito bite itched². She was about to burst into tears. The fact that an uncomfortable itchy sensation can drive many of us to distraction³ led many scientists to believe that the nervous system deals with itch¹ much as it does pain. Others spent years looking, unsuccessfully, for neurons that tell us to scratch rather than that we just hurt.

Now, according to a study in the August 7th issue of the journal Science, researchers say they’ve finally found specific itch neurons in mice. They located them in the mouse spinal⁴ cord by following up on previous research that showed that some mice respond to itchy stimuli⁵ more than others.

When scientists knocked out the itch neurons, the mice no longer had the urge to scratch in response to known itchy stimulus⁶. But they could still sense and avoid pain, showing that itch and pain are processed independently.The researchers hope that these findings could eventually lead to better treatments for chronic⁷ itch, by targeting the specific biochemical pathways involved. As for the four-year-old? She forgot about her itchy bug⁸ bite as soon as lunch arrived.