Why Petting Feels Good

By Breanna Draxler | January 31, 2013 8:37 am

The research team was able to identify in mice a specific class of skin sensory neurons that responds to massage–like stroking of the skin. Data were obtained by in-vivo imaging of the specific neurons in the spinal cord while the mice were stroked with a paintbrush. Image courtesy of D. Anderson lab, Caltech



Petting feels good. You can see it in a cat’s slowly closing eyes or the contented panting of a dog getting his belly rubbed. In fact, all mammals enjoy being caressed, including humans. Researchers looked at this phenomenon in lab mice and found that stroking stimulates a very specific set of neurons that have to do with hair.

Some sensory neurons are relatively non-discriminatory. They respond to touch, temperature and pretty much anything that comes into contact with the skin. A few years back, researchers identified a rare type of neuron called MRGPRB4+, which is linked specifically to hair follicles. In lab tests on a patch of mouse skin, these neurons didn’t respond to a single stimulus. But with live mice the researchers got much more promising results, published in Nature on Wednesday.

Researchers genetically engineered mice so the MRGPRB4+ neurons would glow when active. Then they inserted a microscope into the mice’s spinal cords to see what happened as they stroked, poked and pinched the mice. Certain neurons responded to unpleasant stimuli like pokes, but the MRGPRB4+ neurons only responded to stroking.


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