Neuron Path Discovery May Change Our Conception of Itching 161
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."
Pondering the luck of others (Score:5, Funny)
[...] 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.
.
Re:Pondering the luck of others (Score:5, Insightful)
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Phantom Scrotum Syndrome?
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Phantom Scrotum Syndrome?
Well, just ask any nice lady whether she got it...
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If they're only missing one limb then scratching the other side usually makes it stop. Now if you've lost BOTH limbs to that terrible accident then... errrr... well there's always transcendental meditation.
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The (oversimplified) idea was that once your brain sees yourself with the missing limb apparently there and alright...it stops thinking that there is something wrong. I can't remember where I saw this.
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Re:Pondering the luck of others (Score:4, Interesting)
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You know. I just realized that there is actually a condition under which I might consider castration... phantom blowjob syndrom. Where my phantom member always feels like I'm getting head.
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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!"
You wait til people are gone before you scratch?
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Well... quadriplegics don't get that! Lucky bastards.
Are you sure, quads get phantom limb pain, so I assume phantom limb itching is also likely; imagine an itch that can't be scratched. I burned my hand a few years ago, at the burn clinic they, in a teaching hospital, aways ask about pain, never about itching. Finally one Dr. from another hospital casually mentioned that benedryl would stop the itching. Imagine the gritty itch from a bad sunburn lasting for 3 months, God bless that Dr.
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As my old friend Willy the Pimp used to say, "I hate the itch, but I love that scratch."
Ouch. Torturous. (Score:3, Insightful)
"Mice that had lost the GRPR-producing neurons reacted to painful stimuli just like normal mice, licking themselves and flinching or jumping in response to heat, highly irritant chemicals and mechanical pressure."
Poor mice :(
Re:Ouch. Torturous. (Score:5, Insightful)
--Nick Dipaolo
Re:Ouch. Torturous. (Score:5, Insightful)
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Well to be fair, they aren't dressing like that for nothing.
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You shouldn't be joking about other peoples' misery.
"If a bus hits you, it's comedy. If I get a splinter, it's tragedy" -- Mel Brooks
Having said that, the gp was not "joking". He was using a hyperbole to demonstrate a point. While some jokes are hyperbole, not all hyperbole are jokes -- some simply demonstrate a point.
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Millions of people die of AIDS in Africa without doing anything in particular to go looking for it. Thousands got AIDS in France simply by receiving tainted blood transfusions. Millions of babies get it from their mom while still in the womb. Now, please explain, how is that "lifestyle"?
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Come to think of it I could say the same thing about how the food industry, particularly fast food, deliberately taints their product to make you fat, hungry, and addicted to the food.
Besides Kevin Trudeau, you should also take a look at Super Size Me, as well as Fast Food Nation, two other authors who have nothing at ALL to do with KT.
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Now, please explain, how is that "lifestyle"?
I don't believe I have the burden of proof of that statement. You attacked the style of the statement (hyperbole) by mis-characterizing it as a joke. I explained your mis-characterization. That doesn't mean that I agreed with the content of the statement. Nor does this very comment mean that I disagree with the content of that statement. So far I made no judgment on the content of that statement. And I don't have a burden of proof of a statement on which I made no judgment.
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Aaaaaaah!!! Stop it! You obviously disagreed with
You probably think that because you think that this comment:
So if you get raped and get AIDS, it's because of your lifestyle? Damn these girls in their miniskirts. They were asking for it!
was mine. It wasn't.
hell... the entire thread started off with "poor mice", let's get back to that.
Please!!!
I am 100% for testing on animals if it means we can make advances in medical science.
hear, hear
Now, the science of itchiness... I'm quite positive that there is some better project on which these researchers can work.
That's a common misconception about academic research. It does basic science. So it doesn't try to be "useful". Its aim is (a) to be interesting to the researchers (b) to provide description of natural phenomena without concern for its use. The fact that some of the basic research ends up being useful is purely coincidental.
In this particular case, it's actually not a bad idea to do a a completely exhaus
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It's even better when you realize that AIDS is a lifestyle disease, like obesity.
It boggles the mind that there are still people ignorant enough to believe this. Even here - or perhaps especially here.
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Re:Ouch. Torturous. (Score:5, Insightful)
"If hooking a car battery up to a monkey's brain will help find the cure for AIDS and save somebody's life, I have two things to say... the red is positive and the black is negative.
--Nick Dipaolo"
What if it's a hundred monkeys? A million monkeys? A billion? What if there's a 5% chance it might help? What if it's a researcher who thinks it might help, but hasn't been right to date?
Re:Ouch. Torturous. (Score:5, Funny)
They're just monkeys.
Lazy bastards haven't finished my copy of Hamlet.
Work harder, you ingrates!
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They might not have finished your copy of Hamlet, but have produced an enormous amount of Perl code.
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Just remember, the internet is proof that a large amount of monkeys behind a large amount of keyboards does not produce Hamlet. Just porn.
lol r u srs?! Ill tell my bff!
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yes, i had it covered on the infinite amount of monkeys and infinite amount of typewriters, but i must have neglected to get the infinite amount of ink. at least they're not using computers with windows, because then they'd have an infinite number of BSOD
That's overkill - you only need one Windows ME CD for that.
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What if you had AIDS and it might cure you?
Re:Ouch. Torturous. (Score:5, Funny)
The problems are the resulting side effects and reduced longevity.
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What if it's a hundred monkeys? A million monkeys? A billion? What if there's a 5% chance it might help? What if it's a researcher who thinks it might help, but hasn't been right to date?
As long as it's not an infinite number of monkeys brains being bashed in with an infinite number of typewriters because then we'd not only destroy the complete works of Shakespeare, but also the cure for every problem there is.
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What if it's a hundred monkeys? A million monkeys? A billion?
This is a ridiculous rhetorical situation for several reasons. Mostly because frying monkey brains isn't going to cure aids, but also because you're not going to get a billion damn monkeys.
What if there's a 5% chance it might help?
Another ridiculous point: describe to me how a research experiment might have a "5% chance" instead of "Well, it seems like it might work, but we won't know until we test" you know, like every research project out there. You think you have a cure and it's only afterward that you find out that you do or don't, there's no
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What if it's a hundred monkeys? A million monkeys? A billion?
Then you'd probably have enough dead monkeys to open up your own chain restaurant. Thankfully, fried monkey brain and fried monkey toes are still a delicacy in some parts of the world.
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Dammit! I CANNOT find the red terminal on this monkey!
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Peoples' well-being comes before animals'.
I take it then that you are against other people smoking, drinking, eating fatty foods, red meat, white meat, fish, or even simply living (just to name a few things), even if it does not affect you in any way?
If someone wants to volunteer themselves to be a guinea pig, I say let them.
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I wonder if you would still have that opinion if you were reincarnated as a lab monkey.
I don't wonder that. I am also going to continue not wondering that. I'll take my chances. But I do appreciate the concern. Really... I really do.
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STD detection neuron pathway (Score:3, Funny)
I propose the name "STD detection neuron pathway". Now hand me that cream and leave me alone.
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Who are you and how did you get on Slashdot!?
Itch (Score:5, Insightful)
Re:Itch (Score:4, Funny)
i was gona mod you Informative, but i decided that telling people to not read his comment is more important, otherwise it will drive you insane.
OMG THE ICHING
Re:Itch (Score:4, Insightful)
I was already itching - stupid eczema.
Now hopefully these people will hurry up and find a way to turn this off. I can't wait.
Eczema (Score:4, Informative)
Would this help?
http://www.webmd.com/skin-problems-and-treatments/eczema/news/20090427/bleach-baths-may-help-kids-with-ezcema [webmd.com]
Remember - use a _dilute_ solution. And consult a doc about this - maybe your eczema is different.
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Interesting from an evolution POV (Score:4, Interesting)
I wonder what was the stimuli for that?
Re:Interesting from an evolution POV (Score:4, Insightful)
Removal of parasites, probably.
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the two sensations could have evolved at differing times. pain would be most useful to prevent damage and the abiltiy to sense an itch is useful for correcting problems such as dry skin, certain chemical exposure etc. pain is associated with injury perhaps cells that sense an itch don't work the same way [no one has lopped off an arm and felt an itch for it after all...]
Re:Interesting from an evolution POV (Score:5, Interesting)
[no one has lopped off an arm and felt an itch for it after all...]
Clearly you've never lost a limb. Phantom limb sensations cover pressure, pain, temperature, and irritation. You definitely can feel an itch on an arm or leg that has been lopped off.
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if someone hacks off an arm they are not going to experience anything other than pain first.
Re:Interesting from an evolution POV (Score:5, Informative)
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When the thought "Wow I'm not screaming like a school girl" runs through your mind, you know your really fucked up.
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It doesn't even have to be lopped off. A friend of mine lost all use of one of his arms in a motorcycle wreck, and even though the limb is still there but the nerves were severed, he still feels pain. The doctors can't do anything about it.
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Re:Interesting from an evolution POV (Score:4, Insightful)
The reason for pain is to make you escape something.
Such as burning yourself on a stove, getting stabbed, bitten, stung, etc. You don't want these things to happen. Pain is strongly connected with negative in most minds. At least, most pain..
The reason for itching is to call your attention to something.
It's kind of the difference between a critical error and an error. One's a dire warning, and the other one is just an exclamation. It would be very fucking useful to distinguish between the two. One, so that you don't freak out every time you walk through some grasses that tickle your legs. Two, so you don't beat your bed-mate to death when they rub up against you. Three, so you don't let bugs chew on you or flip out every time one does.
I'll bet the 'itching' pathways have other uses as well. Perhaps the tickling response is there?
Re:Interesting from an evolution POV (Score:4, Interesting)
>>I'll bet the 'itching' pathways have other uses as well. Perhaps the tickling response is there?
Tickling, I believe, is linked with touch. Your brain suppresses/mutes touches done to yourself, which is why most people can't tickle themselves. How does the brain tell? If your motion and the sensation come within a threshold of each other, it mutes the sensation. I think there's something like a 45ms threshold involved - when people moved a machine that then moved a tickling finger, if they added a delay of more than 45ms to it, suddenly people could tickle themselves.
There's a lot of interesting hacks inside the human brain.
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Tickling, I believe, is linked with touch. Your brain suppresses/mutes touches done to yourself, which is why most people can't tickle themselves.
You can't tickle yourself with numb fingers either.
And yet masturbation works.
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You don't touch yourself much do you?? Sexual stimuli is very close to itching. Try it, you might like it.
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I think you are anthropomorphizing a very broad theory/process waaay too much...
Evolution is basically a series of random changes that results in a higher overall rate of survival. There is really nothing logical or simplifying about it - for example, the vast majority of a human brain, or even the human DNA sequence, is unused. Could be "obsolete" structures, or just random changes/development that never served a purpose but also never had any negative consequences.
If someone were able to design a human
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for example, the vast majority of a human brain, or even the human DNA sequence, is unused.
[citation needed]
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It has often occurred to me that, from an evolutionary standpoint, a great many things that aren't distinctly *negative* (that is, they don't particularly *negatively* impact survival/reproduction) could, once introduced into the genepool through random mutation, could continue to survive for a *very long time* before they *eventually* get removed from the genepool.
Why does *everything* necessarily have to be particularly useful? Mutations are random, so the chances are good that there are random things whi
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You're completely right.
Evolution doesn't really incentivize anything. It provides disincentives for exactly one thing: structures and behaviors that result in a higher likelihood of death before reproduction.
Evolution doesn't give a shit what your quality of life is like- unless it prevents you from reproducing. It doesn't give a shit what you do- after you've produce offspring. This is why male and female end-of-fertility times are correlated, and why that's also highly correlated with degradation of heal
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Evolution doesn't really incentivize anything. It provides disincentives for exactly one thing: structures and behaviors that result in a higher likelihood of death before reproduction.
Don't forget number of offspring. A mutation that limited each parent to producing only one child in their lifetime would wipe itself out pretty quickly.
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Not if that child had N times more survival chance than a relative who could have N children.
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Not if that child had N times more survival chance than a relative who could have N children.
No, even then the mutation will die out quickly. It takes two to reproduce. If each individual can only have one child, then even if every child lives to reproduce, the population will still shrink by half with each generation.
Perhaps what you meant to say is that a mutation allowing individuals to have many children will also wipe itself out quickly if each child's chance of survival is too low.
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"Did you know men can breastfeed? Seriously. I read that somewhere. OK, I made it up. No, I read it somewhere, no, really. I wrote it down and then I read it. I believe everything I read. No, it's true. Men can breastfeed. Apparently you have to strap a couple cans of evaporated milk to your chest, and then you give the kid a can opener."
-- Bob Sagat
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Evolution prefers simplicity for EXACTLY that reason. In general, a simpler system will have a better chance of survival and reproduction. Otherwise, more energy going into survival means that it takes the creature longer periods of time before reproduction, which increases the odds of death. OTH, some amount of systems will move towards complexities.
BTW, if you think that complex sy
Important and relevant research (Score:4, Insightful)
Remember, every successful FOSS project started with a developer who had an itch to scratch. Clearly we need more itching.
Obviously... (Score:2)
Obviously so did porn. Not sure if "scratch" is the right word there, though ;)
No, no, no... (Score:2)
When I say a niche, I don't mean an itch like you have when you have an itch. I mean a niche like you have when you have a notch.
This is old news (Score:5, Informative)
Saw it in Science News last year. November 22, 2008.
http://www.sciencenews.org/view/feature/id/38338/title/Itch [sciencenews.org]
Torture (Score:4, Interesting)
I hope they don't use this to build the Agony Booth found in Star Trek.
I could have told them that after my dentist visit (Score:5, Interesting)
Stroking vs touch (Score:2)
Two Channel Interpretations (Score:3, Interesting)
A nice article and summary. Not entirely new nor inclusive of present theory unfortunately.
Pain is handled by two channels: nocioception, the sensation itself, and the perceptual distress component. This can easily be seen in the actions of the agents affecting each. Sensation is blocked by anesthesia. Interpretation of the pain signal is altered by analgseia -- you may still feel a sensation but you don't care, or at lest you're not so bothered by it. There are different neural pathways and processes to handle these.
It is likely that itching relates to pain in this fashion. The sensation of pressure or stretching of the skin in certain places would be common to all as their are receptors in the skin for these. A parallel pathway governing perceptual interpretation of that sensation, possibly the same one as for pain, would also exist. The resulting interpretation based on personal experience and/or genetically determined wiring would cause different interpretations of the same experience on different individuals, the same individual under different conditions, or (as is common) different locations on the same individual.
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When I got my wisdom teeth out, I was given an analgesic instead of anesthesia. I knew it hurt like a bitch, but I thought it was the coolest thing ever, since it didn't bother me in the least.
My dentist said he kind of regretted giving me the choice, because the assistant had to keep me from poking at the sockets and getting in the way.
Man, was I wishing for some more analgesic when I only had painkillers the next day. I'd rather be in pain and not give a shit then have the choice between kinda hurts vs
a curse you should never wish on your worst enemy: (Score:4, Interesting)
the phantom itch
http://www.newyorker.com/reporting/2008/06/30/080630fa_fact_gawande?currentPage=all [newyorker.com]
same neurological basis as a phantom limb, but far more rare (blessedly so)
it is probably one of the greatest definitions of hell on earth. the itch that never, ever goes away:
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that article actually changed my world (Score:3, Interesting)
i have tinnitus
which, really, is "phantom hearing"
i hear a steady tone all day, and its not in my ear, its in my brain. i've grown used to it, accepting the fact i'll have this my whole life, and so it doesn't really bother me that much anymore, i go whole weeks now barely paying it any attention, and your mind just edits it out of daily life
but in the article they talk about the guy with the phantom limb pain... and they do a little trick with him standing perpendicular to mirror, and the brain sees two ar
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Assuming your tinnitus is a near-constant frequency sine wave, what happens if you try to cancel the imaginary sound out using an external sound?
I have no idea whether it's even possible to try to sync soundwaves that exactly by hand/mind, but maybe you can hear/perceive some interference, at least?
I'm not saying that this could be a cure for tinnitus, but me, at least, would be fascinated if imaginary sounds can interfere and maybe even cancel out physical sounds...
thats a good thought (Score:2)
noise cancellation by matching the frequencies and volumes is actually not that wacky, because the tone i hear is very high frequency, very low volume, perfectly constant and a perfect tone. meaning it is simple, not complex. so it wouldn't be difficult to match and cancel out
however, the problem is, like a phantom limb, phantom hearing is deafness... its just that with tinnitus the matching circuitry in the brain is left in the on position rather than the off position
the tiny hairs in my ear at that freque
yeah i thought about that (Score:2)
the problem is that it is equivalent in both ears. but i agree with you that twiddling around that frequency, some sort of volume/ frequency oscillations, might just jigger the neurological circuit into noticing. thanks! ;-)
Re:Uh (Score:5, Informative)
I always thought it was obvious: remove epidermal defects.
Dead skin, parasites etc.
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To convince you to lick them? Or maybe it doesn't have a purpose and it's merely something that isn't harmful. Interesting question.
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So we know how we could (possibly) get rid of itches, but is there any research showing what purpose itching has?
Making you scratch?
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Me.
Also during the article. Right buttock.