Scientists Scratch the Surface of the Science of Itchiness
Let's scratch the surface of the science of itchiness.
Researchers have previously not quite understood the science of itchiness. What is its evolutionary purpose? Is it a form of pain? Why is itching contagious? In fact, are you feeling itchy right now, just reading about itching?
It may seem that this is not the most important subject that researchers should be studying, but in fact, for some people, itching is more than just an inconvenience. According to the Independent, itching can drastically reduce a person's quality of life. Conditions like psoriasis and eczema cause long-term itching, and severe itching has been documented to physically cause people to damage people's bodies. Patients have been documented in medical literature at literally scratching to the bone, at times even tearing off the scalp.
Researchers suspected that the culprit was a chemical produced by nerve cells called a neurotransmitter. The Smithsonian reports that researchers pinpointed natriuretic polypeptide b for their study, or Nppb. The reason that researchers targeted this neurotransmitter was that it was secreted in excess when mice were exposed to itchy substances, like histamines, which become a particular problem due to allergies, and chloroquine, a drug for malaria that causes itching as a side effect.
The researchers genetically engineered some mice so that they would not have Nppb. First, the mice were tested to make sure that removing the neurotransmitter would not affect their feeling of other sensations, like heat or cold. However, studies indicated that the genetically engineered mice were able to feel other sensations just fine.
Then the researchers exposed the mice to itchy substances. While the mice used as control subjects scratched away, the mice that had been genetically engineered were impervious to the substances.
Unfortunately, Nppb is also important for other roles in the body, like for blood pressure and circulation. However, perhaps closely examining the switch of Nppb can enable researchers to find a way to safely turn it off, without affecting its other purposes.
The study was published in the journal Science.