Catnip - a really good kitty drug

I've said it before, and I'll say it again - science is everywhere, all around us, in so many different things that we see all the time. I am reminded of that quite frequently when I spend a few minutes looking at our cats. There are many things that our two kitties do that spark questions in my mind, and today is no exception. What I want to explore today is the following question - how does catnip work?

For those of you with cats, you are probably familiar with what catnip does to a cat. But for those of you who don't, let me describe a scene for you. We have a toy for our cats that is a catnip-stuffed mouse. Fairly standard, as far as housecat toys go, but this one is a cut above most catnip-stuffed mice in that it has a pouch inside of it that you can refill with new catnip. So as the cats play with the mouse, though the catnip (a) slowly loses potency and (b) slowly leaks out of the pouch, it doesn't matter, because we can put new, fresh catnip in. Now, right after we fill the mouse with new catnip, it's quite amusing to watch our cats play with it. They rub their faces all over it, they lick it over and over again (until it's drenched in cat spit), they bat it around and around and around, and then they run like maniacs chasing it. And, just so you know, this is the only toy that causes them to act like this. (This is not really normal behavior for them). It's the fresh catnip - they love it. Love, love, love, love, love it! And from what I understand, our cats are not alone in their catnip obsession. Many cats love catnip. About 70-80% of domestic cats have some sort of reaction to it. They love to smell it, roll in it, lick it, rub their faces in it, and it tends to make them go a little bit nutso. Honestly, it's like a kitty drug!

So I was watching this unfold the other day, and I wondered - why does catnip affect cats so strongly?

Catnip is an herb related to mint. It's native to Europe, Asia and Africa, but has long since been established in the Americas, too. It's not entirely clear why it has such a potent affect on most cats, but here's what I've been able to find out. Catnip leaves contain a volatile oil (volatile means that it vaporizes easily) called nepetalactone. The nasal passages of cats is sensitive to this oil; when cats smell the oil, it stimulates sensory neurons that transmit messges to several parts of the cat's brain. In particular, it stimulates the amygdala (which controls emotional response to stimuli) and the hypothalamus (which regulates lots of different activities including emotions). The stimulation of these two areas of the brain cause the intense emotional reaction to the herb.

There are a few things that should be noted about catnip. First, cats will become desensitized to it after a few minutes. This seems to be analogous to how our noses become desensitized to a particular odor if we'rearound it long enough. A cat will only respond to catnip for a short while, then it ceases to have an effect. However, if they walk away from it for a while, then come back, their noses will be sensitive to it again. Second, it is not addictive. Cats do not become dependent on it, no matter how much of it they have. Third, it apparently has no effect in humans. This is presumably because our noses do not have the receptor for the nepetalactone oil. And finally, even large cats like tigers and lions appear to be susceptible to it.

I think it would be fairly amusing to watch a big, ferocious tiger rolling around, rubbing his face in a catnip bush! It would strike me as fairly undignified, for what is otherwise a thoroughly dignified animal.