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

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>