Giggling rats help reveal how brain creates joy

To trace nerve cell response, researcher spent three years tickling rodents

rat getting tickled

GOOCHY GOOCHY GOO  Rats seem to enjoy a good tickle, which activates nerve cells in a part of the brain that detects touch.

S. Ishiyama, Michael Brecht

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Tickle a rat and it will jump for joy, gleefully squeak and beg for more.