Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New study in moths shows insects not entirely ruled by instinct

13.07.2004


By examining the brain activity of moths, researchers have found that the behavior of these insects isn’t ruled entirely by instinct. Rather, they can learn which odors mean food.




The findings are more than academic: The researchers hope to develop methods for using trained moths to detect odors of interest for defense industry and law enforcement – such as odors given off by biological and chemical weapons.

Animal behaviorists have historically argued that most insects have a programmed response to a variety of situations, such as knowing which odors signal the presence of food and mates. But scientists are discovering that animals don’t always instinctively know what to do. In these cases, they have to learn, said Kevin Daly, the study’s lead author and a research scientist in entomology at Ohio State University.


He and his colleagues used tiny electrodes implanted in the heads of sphinx moths to continuously monitor the insect’s neuronal activity and feeding behavior before, during and after training the animal that one odor meant food – sugar water – was on the way and another odor did not.

"We saw a dramatic restructuring of the neural networks that convert scent into a code that the rest of the brain can understand," Daly said. "The changes in this coding suggest that the moths learned to differentiate between an odor that meant food and an odor that didn’t."

Understanding how moths detect and discriminate between scents could have wide-reaching applications. In related work, Daly and his colleagues are training moths and bees to detect odors from manufactured explosives.

"In principle, if we can understand how insects learn and distinguish between odors, we could ’train’ these animals to recognize any detectable odor of interest," he said.

The findings currently appear online in the Proceedings of the National Academy of Sciences.

The electrodes placed in the moths’ brains registered the activity of neurons. Electrodes were also placed on feeding muscles to monitor the activity of the proboscis – a long tube that a moth uses for feeding – when the insects were exposed to different odors and to sugar. The researchers wanted to see how a moth’s nervous system changed its response to an odor that was associated with food and how the moth responded behaviorally to that odor.

The moths were restrained in plastic tubes, leaving the antennae and proboscis accessible. Electrodes were inserted into each insect’s head; Daly said that brain recordings could be made for up to 48 hours in these conditions. These moths normally live for a few days as adults.

The investigators put the bound moths through different odor conditioning trials: one created a clear relationship between an odor and food. In this case, the researchers wanted to see what happened in the brain and proboscis before, during and after the moths were exposed to the food-associated odor. In the second trial, moths were exposed to two odors, but only one predicted food. Both trials exposed moths to a series of 20 millisecond-long puffs of odor.

When odor predicted food, the researchers saw a significant and progressive increase – by about 60 percent – in the number of neurons responding to the odor. This increase in the neural network response indicated that the moths learned to associate the odor with food.

The researchers also saw striking differences in neuronal activity between the odor that predicted food and the odor that had nothing to do with food.

"More neurons were recruited into action when a moth smelled the odor connected to food," Daly said. "After a few exposures to this odor, moths automatically started sucking for the food, even when they weren’t rewarded with food. They also learned to not respond to the odor that was unrelated to food. "After learning, the way their nervous system responded to odor changed," he said.

Now that he and his colleagues have documented these nervous system changes, their next step is to take a deeper look into the neural networks and figure out what causes them to respond to changes.

"This study is a first pass at trying to understand how sensory neural networks code information, and how that coding process changes as an animal gains experience," Daly said. "Ultimately, if we really want to understand how an animal changes its behavior, we have to go into the brain," he continued.

Daly conducted the research with Brian Smith, a professor of entomology at Ohio State, and in collaboration with Thomas Christensen, Hong Lei and John Hildebrand, all with the University of Arizona in Tucson.

The National Institutes of Health and the Defense Advanced Research Projects Agency funded this study.

Kevin Daly | EurekAlert!
Further information:
http://www.osu.edu

More articles from Life Sciences:

nachricht Water world
20.11.2017 | Washington University in St. Louis

nachricht Carefully crafted light pulses control neuron activity
20.11.2017 | University of Illinois at Urbana-Champaign

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Antarctic landscape insights keep ice loss forecasts on the radar

20.11.2017 | Earth Sciences

Filling the gap: High-latitude volcanic eruptions also have global impact

20.11.2017 | Earth Sciences

Water world

20.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>