Cats’ Nasal Structures Resemble Gas Chromatographs, Study Finds

A new study suggests that the nasal structures which enable the domestic cats to sense smell are similar to gas chromatograph, the equipment used for separating organic and volatile compounds in laboratories. The findings have been published recently in the open-access journal PLOS Computational Biology.

In basic gas chromatography, the substance being analyzed is vaporized and carried by a steady flow through a tube. Different chemical components interact with the tube in distinct ways along its length, enabling the identification of each. The technique is widely used in industries, including the manufacture of cars, chemicals and pharmaceuticals.

Cats are renowned for their sense of smell, and it is the primary way they identify people and objects. They have more than 200 million odor sensors in their noses in comparison to just five in humans. The new study has found complicated nasal structures involved in domestic cats resemble the tightly coiled gas chromatograph in which the efficiency of the process is enhanced by the use of multiple tubes branching off of one high-speed gas stream.

Lead author Dr. Zhenxing Wu of Ohio State University says, “The finding reveals novel mechanisms to support high olfactory performance, furthering our understanding of the successful adaptation of mammalian species, including cat, an important pet, to diverse environments.”

It can lead to an even more efficient analysis of the makeup of substances. According to Dr. Wu, parallels between gas chromatography and nose function have already been observed in amphibians. However, few studies have examined these parallels for mammalian noses, which have more convoluted channels through which air passes to enable odor detection.

The findings are based on an anatomically accurate three-dimensional computational model of our feline friend’s nose. High-resolution micro-CT images of cat’s nose and fluid dynamics simulations showed it mirrors gas chromatographs.

In experiments, simulation of air and odor flow through the virtual cat nose showed that, similar to a parallel coiled gas chromatograph, this flow was also branched off by the use of multiple tubes. In other words, if a cat’s nose only had one straight tube for odor detection, it would need to be longer than the physical size of the head.

Dr. Wu explains, “Having multiple complex channels appears to be 100 times more efficient than having a single straight tube – which most amphibians have.”

Vertebrates use their noses for both breathing and smelling. Receptors inside the nose detect odors in inhaled air. The findings deepen the understanding of how the evolution of more convoluted channels enables cats’ enhanced sense of smell.

The study indicates, “The evolutionary occurrence of the convoluted olfactory turbinate channels in mammalian noses remarkably resembles a different sensory organ, the snail-like coiled cochlea that is also unique to mammals.

“In birds and other non-mammalian vertebrates, the inner hearing organ, despite being called ‘cochlea,’ is instead a blind-ended tube.

“While we know that the evolution of mammalian cochlea enhances our hearing sensitivity and frequency range, we believe here that the mammalian ‘olfactory cochlea’ may similarly enhance the sense of smell by serving as a parallel coiled chromatograph.”

Cats’ eyes that light up in the glare of traffic were famously invented by British businessman Percy Shaw after being inspired by the furry feline’s peepers.

Produced in association with SWNS Talker

Edited by Bhujaya Ray Chowdhury and Virginia Van Zandt