Catnip is a popular plant among cat owners because it makes their cat more playful. Some cat owners use catnip to avoid cat boredom, give it as a treat to train their cat, or to make their cat happy and active.
Within seconds of sniffing dried catnip, your cat’s eyes dilate, and he suddenly can’t control his urge to bury his nose and lovingly rub his face in the dried flakes spread on the carpet. He licks and then rolls over; in the process, he ends up scattering the flakes all over himself. He occupies himself with those flakes for a while before proudly walking away from the mess.
Catnip belongs to the plants from the mint family that includes some common fragrant herbs in your kitchen. Even so, your cat won’t be as frisky when offered basil, oregano, or mint. So, what is it about catnip that sends your cat to his magical place?
Cat’s Responses to Catnip
Catnip stimulates the playful responses in cats. While uncommon, your cat may clutch, kick, or chase his imaginary mouse.
Cats can either become more active or more passive after sniffing catnip. If you want to see some examples of their active responses, you can check out this video below.
During the active response, cats sensitive to catnip show most of four reactions below (Hill et al., 1976; Todd, 1962):
- Licking and chewing with head shaking
- Rubbing chin and cheek
- Rolling over
But, some cats may also show any of these passive responses (Espín-Iturbe et al., 2017):
- Less grooming
- Reduced vocalizations
- Less movements
Although most cats respond to catnip, few cats have a tendency to ignore it, probably due to their insensitivity to the plant.
Why Some Cats are Actively Attracted to Catnip and Others Aren’t
The genetics of your cat plays a role on why catnip is appealing for him or her. Catnip-sensitive cats inherit this autosomal-dominant trait from their parents (Todd, 1962).
In addition to genetics, the environment, stress level, and age of the cats may also affect their reactions (Espín-Iturbe et al., 2017; Grognet, 1990). In particular, 6 month- or older cats are more playful than younger kittens in response to catnip.
How Does Catnip Affect Cat Behavior?
A cat comes in direct contact with catnip in two ways, by eating it or by smelling it.These two different contact points receive two completely different types of cues that stimulate behavioral responses.
When it comes to contact via ingestion, some researchers suggested catnip stimulates regions of the brain controlling the responses through vomeronasal system. Cats use this organ located above the roof of the mouth to pick up odorless or nonvolatile chemicals (or compounds that are not easy to evaporate) to enhance their sense of smell.
Contact through scent triggers a different response pathway. According to other researchers, a cat’s reaction after catnip exposure through smell occurs through the main olfactory (smell) system (Hart & Leedy,1985; Todd, 1963). Volatile cues, such as cats’ pheromones and catnip odor, stimulate connections of neurons between odor receptors in the nose and the olfactory bulb (near the front part of the brain) (Hatch, 1971; Riss et al., 1969). Then, this stimulus travels to areas of the brain responsible for emotion and motivation, including pleasure.
Cats have highly developed olfactory systems, so they can detect odor cues around them (Bol et al., 2017). Due to reaction similarities across many cats (rubbing their heads on it, rolling around, and salivating), some researchers think catnip produces a scent which mimics cat’s pheromones.
Therefore, the reason behind their attraction to catnip must involve: A special compound acting as a trigger for cat’s pleasure.
What is the Chemical in Catnip that Attracts Cats?
Along roadsides and wastelands of parts of North America, catnip grows wild. This feline enticing herb is a perennial plant belonging to the mint family. The ancestors of mint family plants produce chemicals, iridoids, which repel insects. Instead of typical iridoids, a volatile compound isolated from catnip is nepetalactone.
What is nepetalactone?
What makes catnip different from other plants from the mint family is its ability to make a unique form of iridoids, nepetalactone. It’s this chemical that gives catnip that special magic for cats—although cats are the unintended target of nepetalactone. Other plants closely related to catnip in the mint family (including basil, mint, and oregano) have lost the ability to make neptalactone.
Repeated Evolution with A Twist
The production of nepetalactone in catnip has a fascinating evolutionary history. It is an example where a genetic trait was gained, lost, and then re-emerged within the same family lineage.
To understand the timeline that led to nepetalactone biosynthesis in catnip, researchers investigated the evolution of catnip by using a genome study (Lichman et al., 2020).The researchers sequenced and analyzed the genome of closely related plants, catnip and catmint (that produce nepetalactone) and non-iridoid-producing hyssop plant. They also analyzed and compared the biosynthetic enzymes of those three plants with the enzymes from iridoid-producing plants (the distant relatives of catnip, catmint, and hyssop plants).
This study found hyssop had a missing copy of a gene encoding the key enzyme for the iridoid synthesis and the expression level of additional genes encoding some enzymes in this pathway was low. In the lineage containing catnip and hyssop, these shortcomings might cause ancestor plants to lose the ability to produce iridoids.
The descendants of this lineage, catnip and catmint, might gain these features back to make nepetalactone. Interestingly, these plants make a new version of the key enzyme and add an extra enzyme. Both plants use two unique enzymes to make some stereoisomers (or a compound with spatial orientations of their atoms) of nepetalactone. Among those stereoisomers, cis-trans-nepetalactone is the main isomer that drives cats crazy.
This evolutionary history of nepetalactone biosynthesis is interesting, because it is—as mentioned by the researchers—“repeated evolution with a twist”. It also provides new information about how catnip plant has evolved in the mint family.
Catnip Safety Concerns
Catnip produces nepetalactone, a magical compound that takes cats to their happy place. Since it is non -addictive, catnip is relatively safe to introduce to your cat. Your cat may enjoy getting a good amount of catnip once a while to keep them active. But, keep in mind that too much catnip can cause nausea or vomiting. Before regularly introducing catnip to your cat’s playtime, you may want to ask the veterinarian.
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