Cat noses and nasal structure function better than high-tech chemical analysis equipment

Scientists have cracked the secret behind the impressive abilities of cats’ noses. Cats have a unique airflow system in their nasal cavities that seems to be the key.

A complex labyrinth of bony airway structures inside their noses gives them an extraordinary ability to sniff out food, friends, and foes.

The first detailed examination of a cat’s nasal airway has revealed these fascinating insights. The research team built a 3D computer model of cats’ noses.

Using this model, they mimicked an inhalation of air laced with common cat food odors. Their findings were nothing short of impressive.

How cat noses operate internally

The team noticed that the air inhaled by the cat splits into two different streams. One stream gets cleaned and humidified.

The other stream carries the odor directly and swiftly to the olfactory region. This is the part of the cat’s brain responsible for smelling.

“In essence,” the researchers explain, “the cat nose functions as a highly efficient and dual-purposed gas chromatograph.”

Scientists compare cat noses to gas chromatographs

A gas chromatograph is a laboratory tool that detects and separates chemicals in vaporized form. Cats’ noses perform this function so effectively that they could inspire improvements to the gas chromatographs we use today.

Alligator noses also mimic gas chromatography. However, their long structure is much different from the compact head of a cat.

The researchers speculate that the cat’s smaller head led to evolutionary changes. This resulted in the formation of the intricate airway structure that fits snugly into their small heads. It allows cats to adapt to a variety of environments.

Kai Zhao, the study’s senior author and an associate professor of otolaryngology at Ohio State’s College of Medicine, offered his perspective.

“It’s a good design if you think about it,” he said. Zhao explained how important the sense of smell is for mammals. It aids them in tasks like finding food, identifying threats, and tracking environmental changes.

Dogs are a good example, Zhao noted. “A dog can take a sniff and know what has passed through – was it a friend or not?” He believes that there have likely been various ways for different species to evolve and enhance their olfactory systems.

The secret to cats’ amazing noses may lie in the airflow patterns

By closely observing and analyzing these airflow patterns, Zhao’s team deduced that the two different airflow zones might serve two distinct purposes. This fascinating research has been published in PLOS Computational Biology on June 29, 2023.

In the past, Zhao’s lab used models to study airflow patterns in the noses of rats and humans. But the high-resolution cat model and the corresponding simulation experiments are their most complex project to date.

They built these intricate models using micro-CT scans of a cat’s head. They identified different types of tissues in the nasal cavity at a microscopic level.

A great deal of time and effort went into developing this model and understanding the functional benefits of the cat’s nasal structure.

 Zhao said, “The cat nose probably has a similar complexity level as the dog’s, and it’s more complex than a rodent’s – and it begs the question – why was the nose evolved to be so complex?”

Airflow mystery solved using computer simulations

Computer simulations of breathing helped them find the answer. The researchers observed two distinct airflow zones during a simulated inhalation.

The lungs receive one stream of air that filters and slowly spreads above the roof of the mouth. The other stream carries odors quickly through a central passage to the olfactory region at the back of the nasal cavity.

The study also revealed an unexpected phenomenon. Once the air reaches the olfactory region, it circulates within parallel channels. “It’s like you take a sniff, the air is shooting back there and then is being processed for a much longer time,” Zhao shared.

Zhao and his team have become the first to quantify the efficiency differences in gas chromatography between mammals and other species. The cats’ noses, they estimate, are over 100 times more efficient at detecting odors than an amphibian-like straight nose found in a similarly sized skull.

They propose a parallel gas chromatography theory. In this model, parallel olfactory coils, fed by the high-speed odorant stream, increase the effective length of the flow path. This slows down local airflow speed. The slower speed could potentially allowing for improved odor processing.

Even though we understand vision and hearing significantly, we have limited knowledge about olfactory systems.

“We know so much about vision and hearing, but not so much about the nose,” Zhao admitted. However, his team’s work may serve as a steppingstone for understanding the evolutionary pathways behind different nasal structures and their specific functional purposes.

New technology mimicking the functionality of cat noses

The study’s results might go beyond shedding light on the evolution of mammalian noses. It also poses exciting prospects for technological applications.

The unique airflow mechanism found in cats’ noses could inspire more efficient designs for tools. Specifically, the enhancement of gas chromatographs used in various scientific fields.

In the end, it seems that cats, with their peculiar airway structures and compact noses, have much more to contribute to science than previously thought.

Their refined sniffing abilities might be the key to enhancing our understanding of the olfactory system. We have much to learn about its evolution and its potential application in technology.

Zhenxing Wu, a postdoctoral scholar in Zhao’s lab, is first author of the study. Additional co-authors include Jianbo Jiang and Fritz Lischka of Monell Chemical Senses Center in Philadelphia; Scott McGrane of Waltham Petcare Science Institute in the United Kingdom; and Yael Porat-Mesenco of the University of Pennsylvania.

This work was partly funded by the National Institutes of Health and Mars Petcare UK.

More about cats

Often kept as pets, cats are small carnivorous mammals, known scientifically as Felis catus.

They’re one of humanity’s oldest and most beloved pets.

Historically, cats were domesticated in the Near East about 9,500 years ago. Ancient Egyptians revered cats and even worshipped a cat goddess named Bastet.

Physical attributes

Physically, cats are nimble and agile creatures. Their bodies are extremely flexible. The cat family is notorious for its climbing and leaping capabilities.

A cat’s night vision is top-notch, better than most other animals. Due to their incredible smelling ability, people often compare cat noses to high-tech chromatographs.

They also have excellent hearing. They communicate using a variety of vocalizations (meowing, purring, hissing) as well as body language.

Behavior

Cats are solitary hunters that prefer to go after small prey like rodents or birds. Even well-fed domestic cats will often engage in this behavior. They are also territorial creatures that use scent marking to define their territory.

They groom themselves for a large part of their day and are known for their cleanliness. Cats also sleep a lot, with some older cats sleeping upwards of 20 hours a day.

Breeds

Cats come in a wide variety of breeds. Each breed has its own specific look and behavior traits.

For example, Siamese cats are known for their striking blue eyes and sleek, short coats, while Maine Coons are large, friendly cats with long fur.

Diet

Nutritionally, cats are necessary carnivores. This means their bodies require a diet of primarily meat. They have a unique metabolism that requires more protein than that of dogs.

Interestingly, cats also have a distinct disinterest in sweets due to a mutation in a key taste receptor. They can’t taste sweetness the way humans or some other animals can.

Reproduction

Reproductively, cats have a high birth rate. Females are “polyestrous.” This means they can have many cycles throughout the year if not spayed.

Overall, cats are independent yet affectionate pets, each with their unique personality. They’ve been companions to humans for thousands of years and continue to be beloved by people worldwide.