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

Pondering the luck of others

[grub]

[...] 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.

This got me thinking...

You know how it is when you're stuck in a conversation at work with Bob the Office Drone and you get a terrible itch building up in waves across your scrotum? The kind that makes you force a smile on your face while you're thinking "Man oh man, I wish Bob would fuck off so I could scratch myself!"

Well... quadriplegics don't get that! Lucky bastards.

Guess I'm a "the glass is 3% full" kind-of-guy.

.

Itch

[Tofof]

Great. After reading that, now I'm keenly aware of itching sensations all over my body - not unlike watching someone yawn.

Re:Ouch. Torturous.

[The_mad_linguist]

They're just monkeys.

Lazy bastards haven't finished my copy of Hamlet.

Work harder, you ingrates!

I could have told them that after my dentist visit

[mrjb]

After a dentist visit with local anesthesia, I got bitten by a mosquito which caused a terrible itch on my cheek- but I couldn't feel my scratching to relief it. NOT FUN.