Why Mice Like Massages

Researchers pinpoint a gene marker for neurons sensitive to gentle touch such as grooming.

Edyta Zielinska
Feb 1, 2013

FLICKR, TODD HUFFMANThe gentle touch that calms pets can be traced to a genetically single, genetically tractable neuron, researchers from the California Institute of Technology reported this week (January 30) in Nature.

Researchers have known that a specific subset of neurons, sometimes called CT afferents, were responsible for conveying pleasant or anxiety-producing senses.  But no one had found the molecular marker for these nerves, nor been able to link them directly to behavior. By creating a window into a living mouse and genetically labeling the neurons they suspected were involved, researchers were able to see specific neurons light up when then mouse was stroked with a paintbrush.

In a second experiment, the researchers activated mice’s pleasant-touch nerves with a drug and placed them in a chamber with a specific smell and look. The investigators also injected the same mice with saline and placed them in an adjacent room...

The findings “imply that social touch is not simply nice, but that it has calming power in the context of something less-than-wonderful,” India Morrison, a neuroscientist at the University of Gothenburg in Sweden, told ScienceNOW.

(Read more about pleasant touch in our September 2012 feature “Pleasant to the Touch.”)