Chilean scientist Daniel Rojas-Líbano, a postdoctoral scholar at the Universidad de Chile in Santiago, and Leslie Kay, associate professor of psychology and director of the Institute for Mind & Biology at the University of Chicago, have published findings about the nuances of lab rats’ senses of smell, leading to excitement in the scientific community about what this could mean for our own noses.
Their findings were released in the Journal of Neuroscience and entitled “Interplay Between Sniffing and Odorant Properties in the Rat.” The cross-cultural team ran a series of experiments that sought to prove or disprove pre-existing hypothesis about animals’ sense of smell.
Scientists have hypothesized for years that animals could focus their sniffing patterns similarly to the way human’s vision works. Humans can identify an individual target on which to focus their sights.
“Daniel devised an excellent experiment to test these hypotheses,” Kay said. These tests lead to two interesting and provocative conclusions.
First, they determined that the rats’ noses received and processed smells at different rates depending on how water-soluble the chemicals that comprised each smell were. Odors with high “sorption values” were quickly absorbed by the mucus membrane, while those with lower sorption values took longer to absorb.
Secondly, the team detected changes in the rats breathing patterns depending on the sorption values, thus supporting earlier hypothesis that rats might be able to focus their sense of smell.
When exposed to smells with high sorption values, the rats breathed in much quicker. Likewise, when odors with low sorption rates were perceived, rats breathed in for longer.
“What was happening was that the air was moving through the nose at a slower rate and targeting those parts of the nasal epithelium that are further along in the pathway—those more likely to pick up the low-absorbent odors,” Kay said.
Rojas-Líbano described the significance of the team’s recent findings.
“I think one of the most interesting aspects of these experiments is the finding of the difference in difficulty the rats displayed to detect different targets from the same set of mixtures,” Rojas-Líbano explained.