Catnip: You never imagined it, humans, but I am the "master" of your cat master

For many cats, the smell of catnip can easily make them "high", causing them to exhibit more exaggerated behaviors than usual, such as licking, rubbing, rolling, bumping, and drooling.

These behaviors are usually regarded as a kind of self-play of cats, but in fact, studies have shown that cats' various behaviors towards catnip can actually protect them from mosquito bites , and the story behind this is the "conspiracy" of catnip to domesticate cats for thousands of years...

Image source: ALAMY STOCK PHOTO

1. Cat, I am fascinated

The chemical reaction between catnip and cats is like when I suddenly hear Jay Chou's "Seven Miles of Fragrance" and start singing involuntarily. It is truly an operation engraved in our DNA.

Usually this reaction lasts about ten minutes, and cats will temporarily lose interest in catnip within half an hour, after which they will continue to frantically pursue the smell.

Image source: bing pictures

This smell comes from a terpene compound emitted by catnip, which is the familiar nepetalactone.

It enters the cat's nasal tissue and binds to the protein receptors of the sensory neurons above, forming a nerve signal. It propagates through synapses, causing the olfactory bulb neurons to respond, thereby triggering the "emotions" of the amygdala in the brain that is responsible for regulating emotions and triggering the brain's reward system.

So what kind of signal is it? It actually comes from an "imaginary" sexual response.

In other words, catnip and other plants that emit similar smells are equivalent to "aphrodisiacs" for cats, which can temporarily make them lose themselves in fantasies of primitive desires.

Image source: optimist daily

2. Enhanced insect repellent

For thousands of years, generation after generation of cats have rubbed, licked, and nibbled catnip.

At the same time, as a standard herb, catnip is also "taken care of" by many herbivorous insects.

But compared to cats, catnip actually hates these little things crawling on its body more.

If I could imagine the psychological process of catnip, it would probably be something like this: "After all, the cat is just playing with me, while those herbivorous 'evil bugs' really want to kill me. I can naturally distinguish the pros and cons of this."

So, catnip took advantage of the lost cat a little bit.

Just a slight smell will trigger the cat to come immediately, rubbing against the catnip's "arms" and humming.

Image source: GLDBURGER/ISTOCK/GETTY IMAGES PLUS

During this process, cats will inevitably lick and chew the leaves. Of course, this is also within the calculation of catnip. As the leaves are destroyed, a breath of "strength" immediately emanates from the thin body of catnip.

That's right, the iridoid compounds that cats go crazy for are actually insect repellents, and under normal circumstances, the odor of these compounds is not very strong.

However, as cats damage the leaves, more concentrated cyclopentane compounds are released. According to tests conducted by researchers, damaged catnip leaves release 10 times more cyclopentane than intact leaves, which is enough to deter malicious insects.

Silver vine and catnip emit more cyclopentane compounds after being licked or bitten by cats, and cats that are contaminated with the smell of catnip are not attacked by mosquitoes. Source: Research Attached Figure

This method is not uncommon. Plants produce specific compounds to resist herbivorous insects, and some herbivorous insects will ingest these compounds and store them in their own body tissues or on their bodies to disgust predators or inhibit the growth of parasites.

In addition, humans and other mammals use the "insect repellent fields" released by plants or apply plants to the surface of their bodies to obtain a layer of "chemical defense armor."

For example, mosquito repellents made from Dalmatian pyrethrum (Tanacetum cinerariifolium) have been used for centuries in human history, and chimpanzees also arrange their sleeping areas next to Cynometra plants to reduce mosquito bites.

Image source: Wikipedia

Catnip's ability to repel insects was first recorded in 1638 in Speculum botanicum by Johannes Franck, but it was not until modern times that researchers systematically explored the possibility of using catnip as an insect repellent and made breakthrough progress. In some experimental tests, catnip even performed better than the best insect repellents currently on the market. It can be said that there is a promising future for it.

The reason why catnip works is that cycloterpenoid compounds can cause aversion reactions in surface neurons that express TRPA1, an ion channel that is widely present in the nervous system of insects and can trigger negative sensations such as pain, cold, heat, and itching.

Image source: Research Attachment

In vitro, catnip extract and its active ingredients can directly activate insect TRPA1, making them perceive it as an unapproachable stimulus.

What’s more, some known cyclopentadiene terpenes have repellent effects not only on a variety of herbivorous insects, but also on non-herbivorous insects such as annoying flies and mosquitoes.

Scientists who study mosquito repellents have conducted experiments in which they placed flies into a space containing the active ingredient of catnip. The flies would not lay eggs in the space, and mosquitoes would not suck blood from the arms of people who had applied catnip. Of course, humans are not affected by the smell of catnip.

In the wild, catnip uses its scent barrier to block a large number of troublesome invertebrates. Perhaps in the future, it can also become a sword that humans wield against mosquitoes.

Image source: Research Attachment

References:

1.Domestic cat damage to plant leaves containing iridoids enhances chemical repellency to pests

https://doi.org/10.1016/j.isci.2022.104455

2.The irritant receptor TRPA1 mediates the mosquito repellent effect of catnip

https://doi.org/10.1016/j.cub.2021.02.010

Author: Fish

Winner of the Silver Award for Outstanding Science Popularization Works of China Science Writers Association

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Editor: Guru