Neuron Path Discovery May Change Our Conception of Itching

Hugh Pickens writes "Historically, many scientists have regarded itching as just a less intense version of pain, though decades spent searching for itch-specific nerve cells have been unfruitful. Now, Nature reports that neuroscientist Zhou-Feng Chen and his colleagues at Washington University in St. Louis, Missouri have found the first behavioral evidence that there are separate circuits of nerve cells to convey itchiness and pain, and their studies suggest that itch and pain signals are transmitted along different pathways in the spinal cord. 'Most people accept that there are specific, highly specialized neurons for sensations like taste,' says Chen. 'But for pain and itch this is much more controversial.'" (Continues below.) "Two years ago, Chen's group discovered that a cell-surface protein called the gastrin-releasing peptide receptor (GRPR) is important for sensing itchiness but not pain in mice. When Chen and his colleagues destroyed GRPR-bearing neurons by means of a cell toxin, the mice reacted to painful stimuli just like normal mice, licking themselves and flinching or jumping in response to heat, highly irritant chemicals and mechanical pressure. But when the researchers injected the animals with chemicals that normally cause scratching, such as histamine, they barely responded, and the greater the number of GRPR-expressing neurons destroyed, the more subdued was the scratching response."

Comments

Re:Uh

[im_thatoneguy]

I always thought it was obvious: remove epidermal defects.

Dead skin, parasites etc.

This is old news

[The_mad_linguist]

Saw it in Science News last year. November 22, 2008.

http://www.sciencenews.org/view/feature/id/38338/title/Itch

Eczema

[TheLink]

Would this help?

http://www.webmd.com/skin-problems-and-treatments/eczema/news/20090427/bleach-baths-may-help-kids-with-ezcema

Remember - use a _dilute_ solution. And consult a doc about this - maybe your eczema is different.

Re:Interesting from an evolution POV

[WindBourne]

Actually, I used to be an EMT back in the 80's. I can tell you that it was easier to deal with ppl that lost fingers or limbs because they RARELY felt it. Likewise, the guy who had been in a gasoline explosion (but his pain was to come; horrible injury to have). The reason is that their body regularly shut down in terms of pain. OTH, a compound fracture of the femur was wicked painful. The gal was screaming, but did not notice the bit that we drilled into her knee. The reason is that all the various muscles around the femur had contracted and the muscles were cramping. Severe pain, but not enough for her body to shut it down. Likewise, a nail had been pulled off and in another case, a piece of wood had gone under a nail (accident), etc. In each case, the pain was enormous, but not enough to shut them down.