npr:
Scientists have pinpointed the ticklish bit of a rat’s brain.
The results, published in the journal Science, are another step toward understanding the origins of ticklishness, and its purpose in social animals.
Although virtually every human being on the planet has been tickled, scientists really don’t understand why people are ticklish. The idea that a certain kind of touching could easily lead to laughter is confusing to a neuroscientist, says Shimpei Ishiyama, a postdoctoral research fellow at the Bernstein Center for Computational Neuroscience in Berlin, Germany.
“Just a physical touch inducing such an emotional output — this is very mysterious,” Ishiyama says. “This is weird.”
To try and get a handle on how tickling works, Ishiyama studied rats, who seem to enjoy being tickled, according to previous research. He inserted electrodes into the rats’ brains, in a region called their somatosensory cortex.
Brain Scientists Trace Rat Ticklishness To Play Behavior
Photo: Shimpei Ishiyama and Michael Brecht/Science
“This is weird.” –Science, excitedly