Here’s Lulu, our new puppy. At only 3 months old, she displays everything we love about dogs: affection, curiosity, a certain sense of humour, and – specifically for her breed – a good dose of stubbornness. I often wonder what goes on in Lulu’s head when she stares at me. Is it a mere plea for a treat or is it something else that she wants? Although we will never know, there are probably many answers to this question. All of them likely have one thing in common: staring into our eyes allows these domesticated descendants of wolves to establish a bond.
As someone who has been interested in cyclic peptides for a while, I chuckled when I found out that, on a molecular level, the tie that binds us involves a familiar chemical. In a paper recently published in Science, Japanese researchers presented evidence suggesting that there is measurable feedback that links human oxytocin levels with those in their pet dogs. The authors measured changes in both the dogs’ and the owners’ urinary oxytocin levels before and after their interaction, discovering large and correlated (!) increases in oxytocin concentration in both species. A control group of human subjects under investigation was also made to stare into wolves’ eyes. Nothing happened: there were no recorded oxytocin changes in either wolves or humans as there does not appear to be any cyclic peptide-driven communication between us and those predators.