Catnip, also known as catmint, is a plant in the mint family that elicits a euphoric reaction in many domestic cats when they smell or consume it. The plant has been known for centuries to evoke a stimulant effect in felines. Historical references date back to at least the 17th century when botanist John Gerard noted that cats were strongly attracted to nepeta cataria, the scientific name for catnip. The observation that cats “make it their play” and “tumble and turn” when exposed to catnip can be found in literature and folklore throughout the ensuing centuries.
Catnip’s intoxicating qualities on cats are produced by an essential oil called nepetalactone found in the leaves and stems of the plant. When cats detect this volatile oil, they often respond by rolling, flipping, rubbing, and rapidly shaking their heads. The oil binds to receptors in a cat’s nose and mouth tissue, which in turn triggers a response along neural pathways that induce a transient state of euphoria. While not all cats have sensitivity to nepetalactone, an estimated 50-70% of cats show a response when exposed to catnip.
## Chemical Composition
The active chemical in catnip that causes a response in cats is called nepetalactone. This is an organic compound that is produced in the leaves, stems, and flowers of catnip plants. Nepetalactone is a type of terpenoid, which are chemicals produced as part of the plant’s normal metabolic processes.
The concentration of nepetalactone varies in different parts of the catnip plant, with the highest levels found in the leaves and flowers. On average, catnip leaves contain around 0.3-0.7% nepetalactone by weight, though potency can vary. The essential oil extracted from catnip may contain up to 90% nepetalactone.
Nepetalactone is continually produced by the plant and accumulates in the leaves, stems, and flowers as the plant grows. Young leaves tend to have lower concentrations than mature leaves at flowering. The highest levels of nepetalactone are produced during the hottest months of summer.
When cats detect nepetalactone, either through directly smelling catnip plants or catnip-based products, it triggers a response. Not all cats are affected by nepetalactone due to genetic differences, but in sensitive cats it can induce a temporary euphoric state. The effects are short-lived and harmless.
## Olfactory Response
While we smell catnip primarily through our main olfactory system, cats have a more complex olfactory system that allows them to detect the nepetalactone in catnip. Cats possess a vomeronasal organ in the roof of their mouth that detects pheromones and binds nepetalactone. The vomeronasal organ connects to the accessory olfactory bulb in the brain.
Cats also have an olfactory epithelium lining their nasal cavity containing olfactory receptors that bind to nepetalactone molecules. These olfactory receptors send signals to the main olfactory bulb in the brain, which combines with signals from the vomeronasal organ to elicit the cat’s response to catnip.
The main olfactory system and the vomeronasal system allow cats to detect extremely small quantities of nepetalactone in catnip. This makes catnip powerfully enticing to cats at a neurological level. The chemical structure and concentration of nepetalactone triggers neural pathways that induce the characteristic catnip response.
## Neural Pathways
The effects of catnip on cats are mediated through the chemical nepetalactone activating particular neural pathways. When cats inhale nepetalactone, it binds to olfactory receptors in the nose that trigger neurons signaling the olfactory bulb. From there, signals are transmitted to higher brain regions like the amygdala and hypothalamus that regulate emotions and instinctual behaviors.
Specifically, catnip appears to stimulate neural pathways involved in pleasure and reward. This produces positive feelings and emotions similar to what humans experience with certain addictive drugs. Catnip also seems to trigger neural circuits regulating predatory behaviors. The areas activated are linked to hunting, attack, and play instincts. So cats may perceive catnip as an artificial proxy for natural prey Drive and aggressive response pathways also light up. Overall, catnip hijacks key neural systems regulating pleasure, fear, and predatory behaviors in cats. This potent neurological activation underlies the distinctive reactions and temporary “high” that cats exhibit when exposed to catnip.
## Behaviors Elicited
Catnip elicits a range of behaviors when smelled or ingested by cats. The most common behaviors displayed include:
– Sniffing – Cats will sniff catnip intensely, taking rapid, deep breaths through their nose and mouth. They often sniff it for an extended period of time.
– Licking and Chewing – Cats will lick catnip and often chew on it as well, sometimes even appearing to eat it. The licking and chewing response aids in releasing more of the active chemical compounds.
– Head Shaking – Cats will shake their head rapidly from side to side when exposed to catnip. Head shaking further releases catnip’s active ingredients.
– Chin and Cheek Rubbing – Cats will rub their chin and cheeks on catnip frequently, marking it with their scent glands located there.
– Rolling – Cats often lose muscle control and coordination when exposed to catnip, causing them to roll head over heels repeatedly. They may roll on their back, flip over, and generally be uncoordinated.
– Kneading – Cats often exhibit kneading behaviors on catnip or soft objects near it, mimicking the kneading done on their mother’s belly as kittens.
– Playfulness – Many cats will become very playful when given catnip, chasing imaginary prey, pouncing, leaping, and performing acrobatics.
These amusing antics are all typical cat behaviors when given fresh or dried catnip. The behaviors tend to be exaggerated versions of their normal feline activities. Not all cats react identically, but most exhibit a range of these behaviors when exposed to catnip’s active compounds.
## Individual Variability
Not all cats respond to catnip in the same way. Genetics play a large role in determining how sensitive a cat is to nepetalactone. Studies estimate that about [70-80% of cats](www.catfact url) exhibit a response to catnip, meaning 20-30% experience no observable reaction. Catnip responsiveness is an inherited trait thought to be passed on through a dominant gene.
A cat’s gender influences its response as well. Males are typically more sensitive to catnip compared to females. Neutered males have the most intense reaction, while spayed females have the lowest response. The reason is unclear, but sex hormones like testosterone could play a modulating role.
Age is another determining factor. Kittens younger than 6 months generally do not respond to catnip. Responsiveness typically emerges around puberty. As cats mature and reach senior age, they often become less sensitive or interested in catnip.
In summary, genetics largely determines whether a cat will respond to catnip at all. But among responding cats, factors like sex, neuter status, and age can further modify sensitivity, leading to significant individual variability.
## Effects of Active vs Passive Use
Cats respond very differently to catnip depending on whether they actively sniff or ingest it versus passive exposure. When a cat actively sniffs catnip, the volatile oils are detected by the vomeronasal organ and olfactory bulb, which elicits the classic catnip response of euphoria including rolling, flipping, and cheek rubbing. However, with passive exposure like a cat toy infused with catnip, the response is often more mellow – the cat may play with the toy and appear mildly euphoric but not exhibit the intense crazy response.
This is likely because the volatile catnip oils have to vaporize into the air first before the cat inhales them into the nose/vomeronasal organ. With passive exposure the concentration is much lower and it takes longer to reach the olfactory system. Direct active sniffing provides a concentrated dose straight to the receptors that elicit the neural and behavioral response. Passive exposure results in a milder, subtler effect. But in both cases, engaging the olfactory system is key – catnip infused toys or treats are only attractive when cats can smell them.
## Temporary Tolerance
After cats experience the effects of catnip, they temporarily develop a tolerance and do not respond to further exposure for a period of time. Research has shown that the active chemical compounds in catnip, called nepetalactones, bind to olfactory receptors in a cat’s nose. This binding triggers a neurological response leading to the characteristic catnip behaviors.
However, after a cat has been exposed to catnip, their olfactory receptors essentially become “fatigued” and additional nepetalactone molecules have no effect. This results in a temporary tolerance period where cats show no behavioral response to catnip, typically lasting between 30 minutes and 2 hours.
The exact duration of the tolerance period appears to depend on the individual cat, as well as the method and dosage of catnip exposure. Sniffing or eating catnip seems to lead to a shorter tolerance period compared to rolling in or rubbing on catnip. The tolerance period also seems shorter in kittens and young cats compared to mature adult cats.
Understanding this temporary tolerance phenomenon helps explain why catnip is able to consistently induce behavioral effects in cats. The tolerance window allows the olfactory receptors to reset their sensitivity after an initial exposure. Once the tolerance dissipates, the cat’s response to catnip is restored and they can once again experience the euphoric effects.
## Comparisons to Human Reactions
The euphoric response cats have to catnip is often compared to the psychoactive effects some compounds have on humans. There are some notable similarities in the behavioral and physiological responses.
The active chemical that causes the response to catnip, nepetalactone, is structurally similar to compounds like THC found in cannabis. Both can induce relaxation, euphoria, and sensory enhancements in those affected. The neurological pathways involved also show parallels.
Nepetalactone interacts with olfactory receptors and activates reward pathways in a cat’s brain by stimulating dopamine releases. THC and other cannabinoids do something very similar in humans by binding to CB1 receptors concentrated in certain parts of the brain. This mimics the function of neurotransmitters and causes dopamine flooding leading to the classic marijuana “high.”
So while the specific receptors and neurotransmitter systems differ between species, there seem to be analogous effects produced by analogous chemical structures working through similar neural pathways involved in regulating mood and cognition. The subjective experience of humans imbibing cannabis and cats indulging in catnip may have more in common than meets the eye!
## Conclusion
While we now understand many of the key mechanisms behind catnip’s effects on cats, there are still some open questions that warrant further research.
We know catnip contains nepetalactone, which binds to olfactory receptors and stimulates a response mediated by the amygdala and ventral tegmental area of the brain. This leads to euphoric behaviors like rolling, paw kneading, head shaking, and playfulness. However, not all cats respond to catnip, and the reason for this variability remains unclear.
More research is needed to understand if there are differences in olfactory receptors, neural pathways, or metabolism of nepetalactone that underlie the variability in response to catnip among cats. Additionally, while temporary tolerance develops with active catnip use, we don’t fully understand the mechanisms behind this temporary desensitization.
Comparative studies looking at parallels with human responses to herbal stimulants like catnip could shed light on the evolution of these pathways across species. Overall, while we have uncovered much about why catnip elicits such a strong response in many cats, the individual variability and mechanisms behind tolerance highlight remaining areas for future investigations by feline behaviorists and neuroscientists.
