Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Animals learn to fine-tune their sniffs

31.10.2012
Animals use their noses to focus their sense of smell, much the same way that humans focus their eyes, new research at the University of Chicago shows.

A research team studying rats found that animals adjust their sense of smell through sniffing techniques that bring scents to receptors in different parts of the nose. The sniffing patterns changed according to what kind of substance the rats were attempting to detect.


Animals learn to fine tune their ability to smell in order to better detect predators and find food, research on rats at the University of Chicago Shows.

Credit: Reprinted with permission: Leslie Kay, et al. The Journal of Neuroscience 2012

The sense of smell is particularly important for many animals, as they need it to detect predators and to search out food. "Dogs, for instance, are quite dependent on their sense of smell," said study author Leslie Kay, associate professor of psychology and director of the Institute for Mind & Biology at the University of Chicago.

"But there are many chemicals in the smells they detect, so detecting the one that might be from a predator or an explosive, for instance, is a complex process."

Kay was joined in writing the paper by Daniel Rojas-Líbano, a postdoctoral scholar at the University of Chile in Santiago, who received his PhD from UChicago in 2011. Rojas-Líbano, who did the work as a doctoral scholar, was the first author on the publication. Their results are published in an article, "Interplay Between Sniffing and Odorant Properties in the Rat," in the current issue of the Journal of Neuroscience.

Scholars have hypothesized that animals may be able to focus sniffing, just as humans focus their sight to detect a target, like the face of a friend, in a crowd. Humans are also known to be able to adjust their ability to detect specific odors with practice when cooking or sampling wine, for instance.

Kay and Rojas-Libano drew from two ideas proposed by other scholars to test whether animals can focus their sniffs.

In one set of findings, researchers had shown that the nose can act like a gas chromatograph (a device that separates chemicals in complex blends like flower scents), absorbing substances for different times depending on how readily they interact with the water-based mucus on the sensory receptors in the nose. Odorants that have high "sorption values" are easily absorbed into the mucus, while odors that do not absorb easily into water have lower sorption values.

The other finding crucial to the current work was the discovery that changes in the airflow rates of scents entering the nose can change which odors the nose readily detects. Different parts of the nose have different airflows, and classes of receptors suited to detecting specific odors. Researchers had speculated that animals might be able to change airflow to target specific odors in a blend of chemicals, like focusing on smelling a particular scent in a perfume.

But until the publication of the paper by Kay and Rojas-Líbano, no one had been able to test the ideas that arose from those earlier findings.

"Daniel devised an excellent experiment to test these hypotheses," Kay explained.

Rojas-Líbano trained rats to detect a specific odor by rewarding them with a sugar pellet when they had detected a target odor and responded correctly. Electrodes attached to the rats' diaphragm muscles measured the rate at which they were taking in air. He then tested the animals with many mixtures of two chemicals to see if they could pick out those containing the target scent.

The rats were successful in making the distinctions, regardless of which type of odor they were seeking. But the rats learned to look for a highly absorbent odor much more quickly than the rats learning to detect a less absorbent odor.

The rats also inhaled differently, depending on which type of odor they were detecting. The animals inhaled for a longer time when they were learning to detect the low-absorbing odor, and then reduced flow rates once they had learned to detect the odor, researchers determined.

"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.

For highly absorbent odors, the animals inhaled more quickly because the parts of the nasal cavity that are sensitive to those smells are closer to the start of the nose's air pathway.

"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 said. "This shows that there is more to olfaction than just receptor types and combinations. If detection was solely based on chemical-receptor interactions (as people seem to assume quite often), performance levels should have been more similar between the groups of rats. The physical properties of the odors matter a lot, and so does the type of sniff that an individual uses to smell the odors."

The project was supported with a grant from the National Institute on Deafness and Other Communication Disorders.

William Harms | EurekAlert!
Further information:
http://www.uchicago.edu

Further reports about: animals sense of smell sniffing techniques

More articles from Life Sciences:

nachricht Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>