Scientists Investigate What Makes Us Itch

Transcript

ARI SHAPIRO, HOST:

Scientists have just scratched the surface of another important problem - why some things make us itch. Today, there's progress to report. Researchers in California have found a molecule that may be crucial for our brains to sense itch. NPR's Joe Palca has more.

JOE PALCA, BYLINE: How do you go about discovering what makes us itch? Well, if you're Diana Bautista at the University of California, Berkeley, you ask what molecules are involved.

DIANA BAUTISTA: We say OK, what are the possible molecular players out there that might be contributing to itch or touch?

PALCA: Bautista says it turns out itch and touch, and even pain, all seem to be related - at least in the way our brains makes sense of these sensations. But how to tell which molecules are key players? Bautista says basically you try everything you can.

BAUTISTA: We test a lot of candidates. And if we're really lucky, one of our candidates - we can prove that it plays a really important role.

PALCA: And now she thinks she's found one. Working with colleagues at the Buck Institute for Research on Aging, she's found a molecule that's made by a gene called HTR7. When there's less of this molecule, animals with itchy skin conditions, like eczema, do less scratching. When there's more of it, itching gets worse. The way this molecule works is kind of interesting. It changes how sensitive brain cells are to a chemical called serotonin. Now, serotonin is a chemical that's related to depression. So Bautista's research might explain why certain antidepressant drugs that boost serotonin have a peculiar side effect. For some people, the drugs make them itch. Bautista says the new research is certainly not the end of the story when it comes to understanding itch.

BAUTISTA: As soon as you discover something new, it just poses more and more questions.

PALCA: In other words, it'll be a while before researchers scratch itch off their list of topics to study. Bautista's work appears in the journal Neuron. Joe Palca, NPR News. Transcript provided by NPR, Copyright NPR.