If you pinch a tiger by the scruff of its neck, will it become as obedient as a cat?

Can you control the tiger?

Written by Su Chengyu

Cat owners should know that if a cat is disobedient, pinch its neck and it will behave. If such a mythical animal can be controlled with one hand, what about a big cat (tiger)?

This behavior is common, of course, first of all in tiger cubs, as well as some other animals in their infancy. It is not limited to cats. Mothers of rodents, such as mice and squirrels, also use biting the back of the neck to control their cubs.

Adult animals rarely have this reflex behavior, so if you want to subdue them, never use sliding tackle or pinching the back of the neck. Secondly, it is no longer feasible from a biomechanical point of view. Because its weight and size are far beyond the range that the thickness and toughness of its skin can withstand.

Let’s first talk about why pinching the back of a cub’s neck has a calming effect?

Dennis Normile published an article in Science in 2013 titled How Rocking a Baby Is Like Mouth-Carrying a Mouse Pup. As the title of the article suggests, caring for an animal baby by holding it by the scruff of the neck is similar to rocking a human baby when it cries - the physiological effects of both methods are the same and both are based on the maternal protective instinct.

The article introduces that Japanese neurologist Kumi Kuroda noticed that when he picked up a crying child and walked around, the child would often calm down quickly. After returning to the laboratory, he observed and recorded the crying and noisy behaviors of 12 babies (1 to 6 months old) in three situations: staying in the crib; the mother holding the baby sitting; and the mother holding the baby walking around. The results showed that the probability of crying and noisy when the mother was holding the baby walking around was the lowest. And surprisingly, when the mother was holding the baby and walking around, the baby's pulse decreased and the crying and noisy behavior lasted for two or three seconds, not several minutes.

Back to the topic: Why would cats (and other creatures) be "immobilized" when force is applied to the back of their necks?

The animals grasp the skin of the back of the neck of the pup with their mouths, and when they are carried, they behave passively and adopt a compact posture with their hind legs bent inward. Kuroda's team designed an experiment in which the mother mouse had to take the pup from the cup (which meant holding it by the back of the neck), and then tracked and recorded the heart rate and behavior. The results were obvious. The pup's heart rate decreased when it was held by the back of the neck, and it behaved passively and tensed.

In subsequent experiments, they anesthetized the nerves that sense movement in the back of the pups' necks, and the results showed that the "calming effect" caused by "being picked up" was weakened. At the same time, surgically removing part of the brain to interfere with incoming signals to the cerebellar cortex also caused mother mice to spend more time calming their pups.

If the pups cannot sense that their necks are being held, they will not curl up; if the cerebellum cannot receive the signal, the pups will not calm down and obey. In other words, the weakening of the heartbeat and the change in body posture (the so-called immobilization) are directly achieved by the parasympathetic nerves and the efferent nerves of the cerebellum. This series of physiological reactions causes the pups to have a lower heart rate, calm down, and curl up, making it easier for the mother mice to take them to a safe place.

in conclusion

When the cub’s neck is grabbed (pinched), the sensory nerves sense a signal that “Oops, my neck is being grabbed” and this signal is transmitted to the brain. After processing, the brain knows “I need to be quiet” and the body part “freezes” according to the command.

The Japanese experimental team also conducted further experiments to determine which part of the brain "issued the command" to produce such physiological effects. According to a 2018 study, the researchers isolated the pups from their mothers after birth and found that the sedative effect of holding the rat by the scruff of the neck was also weakened. After isolation, multiple brain regions including the periventricular nucleus of the hypothalamus were activated. This shows that maternal absence can cause stress responses and lead to a series of changes in the brain.

After further research, the experimental team found that this series of reactions was mediated by corticotropin-releasing factor receptor 1 (CRHR1), which is released by the anterior cingulate cortex.

So, to control the little tiger, you should first become a "tiger mom".

References

[1] How Rocking a Baby Is Like Mouth-Carrying a Mouse Pup

[2] Esposito, Gianluca, et al. "Infant calming responses during maternal carrying in humans and mice." Current Biology 23.9 (2013): 739-745. DOI: https://doi.org/10.1016/j.cub.2013.03.041

[3] https://www.frontiersin.org/articles/10.3389/fncel.2018.00204/full

This article was originally published on the author’s Zhihu account and revised by the author and published in Fanpu.