First, know that winter itch is definitely a thing. Weirdly, science hasn't totally nailed that down yet. However, there is evidence that scratching causes the release of serotonin in the brain the neurotransmitter responsible for feelings of happiness and satisfaction that some antidepressants try to keep more of in your brain in order to make you feel better , Dr.
Kim says. When your skin gets irritated, a specific set of nerve fibers sends signals to your brain and spinal cord that cue you to scratch an itch. As a result, nerve fibers send pain signals to your brain which temporarily suppress the itching sensation.
In order to dull the pain that comes from scratching, your brain releases that feel-good dose of serotonin. In fact, some people living with intensely itchy skin conditions like lichen planus commonly describe scratching an itch as straight-up orgasmic, he says. While the initial mood boost feels great, it also ironically leads to more itchiness, says Dr. That demonstrates that STT nerves react differently to the sensation of a scratch when it happens in response to an existing itch.
The researchers then injected a pain-producing chemical into the monkeys' legs, which also spurred the firing of STT neurons. Again scratching did nothing to calm them, suggesting that the nerve-dampening effect of scratching applies uniquely to itching, not pain. Scientists are still a long way from understanding the itch-scratch phenomenon, and while Giesler's study gives them a good place to start, neuroscientists caution that in humans, the mysteries of itching and scratching may go beyond the physiological: emotional and psychological factors are also often at play, especially in cases of unexplained, unremitting itching or itching of phantom limbs.
The hope is that doctors will one day be able to prescribe drugs or other treatments to alleviate persistent itch. See this year's strangest environmental ideas. See the top 10 scientific discoveries of Send to Kindle.
The new research also suggests that, if the results from the study also apply to humans, chronic itch disorder may be caused by a specific deficiency in these special spinal cells.
This may lead to targeted treatments to help people suffering with this disorder in the future. The researchers also revealed that while itching caused by light touch on the hairy skin was disrupted in the mice, there was no change in the way they responded to itches that caused an inflammatory response, for example one caused by a mosquito bite.
Why is this interesting? Because even though both kinds of itch feel subjectively the same to you, your body is sending specific information about the kind of itch is occurring to your brain, via completely distinct pathways.
The mice also showed completely normal responses to touch-induced pain. Interestingly, previous research has shown that there is a complicated relationship between chemical itch from things like insect bites and pain.
It turns out that a painful touch or heat sensation can actually suppress the feeling of a chemical itch not that this seems like a particularly good trade-off. It is for this reason that it feels so good to scratch at a rash — because it is the pain of scratching that actually relieves the itch.
Unfortunately, the effect is all too temporary. Surprisingly, there is some evidence to suggest it is not only occurrences on your skin that can cause itch and there may be a psychological element. Reports of contagious itching where watching others scratch can cause a person to feel an itch are widespread. Indeed, a recent study showed that visual and auditory scratch-related stimuli during a lecture caused a significant increase in scratching behaviour in the audience.
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