Cats go crazy for catnip: they’ll chase after any catnip toy, rub and roll themselves all over it, and even substantially dilate their eyes. Another plant that affects cats in a similar way is called silver vine. A recent study led by Reiko Uenoyama from Iwate University in Japan identified the active compound in silver vine, and demonstrated that it possesses an insect-repellent activity. This property may be why cats are so attracted to silver vine, and could potentially explain their response to catnip too.
Silver vine is less known compared to catnip, but is considered to have an even more potent effect. The active ingredient in catnip is called nepetalacetone, and this study discovered a similar active ingredient in silver vine called nepetalactol. To observe the effect of this compound on cats, the researchers put out nepetalactol paper and observed the reactions of both domesticated and non-domesticated cats (such as leopards, jaguars, and lynxes). Just like with the plant, the cats rubbed their faces on and rolled over the nepetalactol paper. In addition, it was found that nepetalactol activates a reward and pleasure center in the cat brain. This part of the cat brain is similar to the opioid system that responds to morphine in humans, but the cats are not in danger of being addicted to or harmed by silver vine. Lastly, nepetalactol was found to be an insect repellent. If cats rub their heads against something covered with nepetalactol, mosquitoes are less likely to land on their heads and bite them. This insect-repellent activity could be evolutionarily advantageous for cats when hunting prey, which potentially explains why cats have maintained this attraction for catnip and silver vine today.
While the story may seem complete, there is still more that can be uncovered in this system. These include: 1) understanding the lack of addiction to the compounds in catnip and silver vine even though they activate a similar pathway as addictive substances in humans, 2) understanding why this behavior occurs only in felines, and 3) determining the genes and receptors specifically responsible for causing this behavior. Beyond just cats, there are many animal behaviors that involve specific interactions with plants. Given that a cat’s crazy behavior with catnip may have found us a new natural insect repellent, who knows what other studies of animal behaviors could uncover.
Reiko Uenoyama is a Master’s student in Masao Miyazaki’s lab at Iwate University. She does research in Biomolecular Science, Animal Behavior, Chemical Ecology, Biochemistry, and Chemical Biology.
Managing Correspondent: Jenny Zheng
Press Release: Sciencemag.org
Original Article: Science Advances
Image Credits: Pixabay