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 Mass spectrometry sheds new light on thallium poisoning cold case
14.12.2018 | University of Maryland

nachricht Protein involved in nematode stress response identified
14.12.2018 | University of Illinois College of Agricultural, Consumer and Environmental Sciences

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>