PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Fruit flies -- fermented-fruit connoisseurs -- are relentless party crashers

2014-02-05
(Press-News.org) Contact information: Sandra Hines
shines@uw.edu
206-543-2580
University of Washington
Fruit flies -- fermented-fruit connoisseurs -- are relentless party crashers

That fruit fly joining you just moments after you poured that first glass of cabernet, has just used its poppy-seed-sized brain to conduct a finely-choreographed search, one that's been described for the first time by researchers at the University of Washington. The search mission is another example of fruit flies executing complex behaviors with very little "computational" power, their brains having 100,000 neurons compared to house flies with 300,000 neurons and humans with 100 billion.

Such computational efficiency is the envy of robot makers everywhere and of interest to neuroscientists wanting to know more about the brains of insects, animals and humans, according to Floris van Breugel, a UW post-doctoral researcher and lead author of a paper in the Feb. 3 issue of Current Biology. Michael Dickinson, UW professor of biology, is the paper's co-author.

It's the smell of fermentation that draws fruit flies, genus Drosophila, to your wine or the fruit ripening on the kitchen counter, the same smell that leads them to food in orchards and compost heaps outdoors.

If not already in your house when you pour your wine, fruit flies come calling from outside, following attractive odors through open doors and windows, being small enough to slip around the edges of screens if not simply passing through the openings in the mesh.

Fruit flies use their antennae to detect odors and it's long been known they have a keen sense of smell. But odors travel in whiffs of scent, not steady streams, particularly outdoors in the wind. Nothing this detailed has ever been published about how free-flying fruit flies conduct successful searches, van Breugel said.

Using wind tunnel results, van Breugel and Dickinson described the reflexive surging upwind when an odor is detected and then the casting about when the whiff of scent is lost.

One surprise – and another example of how efficiently fruit flies use their neurons – was that in the presence of attractive odors, flies began using their eyes to look for roundish objects that might be fruit, van Breugel said. Without an attractive odor, flies ignore such objects.

"Because an odor plume can be so chaotic, just tracking the plume may or may not get them to the source of the smell," he said. "So that's when visual exploration starts to take over. They start to explore objects with visual contrast that could be the source of the odor. They land and if it's not something to eat, they continue the search." A glass of wine would be a contrasting shape, like fruit, that would merit their attention.

Flies, a dozen at a time, were observed trying to locate an attractive odor at one end of a 3-foot-long wind tunnel specially designed by Dickinson and his lab group. The tunnel generates a steady flow of air about the velocity of a light wind. Ten cameras collected more than 70 hours of flight data including 50,000 individual trajectories.

During the work, van Breugel wasn't expecting to find evidence that flies would search for food visually. Then he noticed them exploring the floor of the wind tunnel, which had a checkerboard pattern, when odors were present but not in their absence. He devised an experiment without the checkerboard, but with a round shape on the floor and each of two walls. When an attractive odor was present, fruit flies explored around and landed on those shapes.

"Their senses interact in very sophisticated ways so what they smell literally influences what they see," Dickinson said. "These interactions between vision and olfaction is part of the secret of how flies do so much with such tiny brains, they have clever ways to combine information from different senses."

Modeling how insect brains function could be useful in developing efficient robots, indeed one of the funders of the research is the U.S. Air Force Office of Scientific Research.

"The study of behavior has often been very subjective, but we're at the point where we can collect data with enough richness and information that we can come up with quantitative interpretations of what's happening," van Breugel said. For example, van Breugel and Dickinson modeled the behavior of flies as a simple algorithm of three reflexes: surging, casting and attraction to small visual features. An algorithm is a set of rules that precisely defines a sequence of operations whether in a brain or in a computer.

Using a computer simulation, the authors showed that this simple three-step algorithm could reliably guide a fruit fly to food without the need for a long range plan or mental map.

"As we quantify more of their behaviors in such detail, we could discover more efficient and robust algorithms for controlling robotic systems of all kinds," van Breugel said.

"Although finding fruit flies in your wine or beer can be a bit annoying, I hope people will pause to admire the tenacity of these clever little creatures," Dickinson said. "They are really just hungry animals looking for something to eat, and have no intention of ruining your happy hour."



INFORMATION:

While working on this project in the Dickinson lab, van Breugel earned his doctorate from California Institute of Technology.

Other funding for the work came from the National Science Foundation, the Paul G. Allen Family Foundation and the Hertz Foundation.

For more information:

Van Breugel: floris@uw.edu

Dickinson: 206-221-1928, flyman@uw.edu



ELSE PRESS RELEASES FROM THIS DATE:

Taking statins to lower cholesterol? New guidelines

2014-02-05
ROCHESTER, Minn. — Feb. 4, 2014 — Clinicians and patients should use shared decision-making to select individualized treatments based on the new guidelines to prevent cardiovascular disease, according to a commentary ...

3D mapping biopsy finds 3x prostate cancer of ultrasound-guided biopsy

2014-02-05
Ultrasound-guided biopsies miss prostate cancers that are detected by the slightly more expensive and slightly more invasive 3D mapping biopsies. For example, in a 2006 study of 180 men diagnosed ...

AGU journal highlights -- Feb. 4, 2014

2014-02-05
The following highlights summarize research papers that have been recently published in Geophysical Research Letters (GRL), Journal of Geophysical Research-Solid Earth (JGR-B), and Paleoceanography. In this release: 1. Canada's ...

New study finds feeling 'in control' can help you live longer

2014-02-05
Do you believe in your own ability to succeed, or do you believe life events are largely beyond your control? Think carefully ...

Good hair day: New technique grows tiny 'hairy' materials at the microscale

2014-02-05
Scientists at the U.S. Department of Energy's Argonne National Laboratory attacked a tangled problem by developing a new technique to grow tiny "hairy" materials that assemble themselves ...

Story tips from the Department of Energy's Oak Ridge National Laboratory, February 2014

2014-02-05
ENERGY – LEDs to light UT arena . . . With the installation this month of LED fixtures, the University of Tennessee's Thompson-Boling Arena will become the first major sports ...

Brain scans show we take risks because we can't stop ourselves

2014-02-05
A new study correlating brain activity with how people make decisions ...

For viewers, Sochi will be first 'fully mobile' Olympics

2014-02-05
Akron, Ohio, Feb. 4, 2014 — The Sochi Winter Olympics, Feb. 7-23, are expected to generate a dramatic rise in Web and mobile viewing, but that does not mean viewers will ...

Nerve block eases troublesome hot flashes

2014-02-05
CLEVELAND, Ohio (February 5, 2014)—Injecting a little anesthetic near a nerve bundle ...

Wider-faced dates more attractive as short-term mates

2014-02-05
Women may perceive men with wider faces as more dominant and more attractive for short-term relationships, according to a new study in Psychological Science, a journal of the Association ...

LAST 30 PRESS RELEASES:

Pink skies

Monkeys are world’s best yodellers - new research

Key differences between visual- and memory-led Alzheimer’s discovered

% weight loss targets in obesity management – is this the wrong objective?

An app can change how you see yourself at work

NYC speed cameras take six months to change driver behavior, effects vary by neighborhood, new study reveals

New research shows that propaganda is on the rise in China

Even the richest Americans face shorter lifespans than their European counterparts, study finds

Novel genes linked to rare childhood diarrhea

New computer model reveals how Bronze Age Scandinavians could have crossed the sea

Novel point-of-care technology delivers accurate HIV results in minutes

Researchers reveal key brain differences to explain why Ritalin helps improve focus in some more than others

Study finds nearly five-fold increase in hospitalizations for common cause of stroke

Study reveals how alcohol abuse damages cognition

Medicinal cannabis is linked to long-term benefits in health-related quality of life

Microplastics detected in cat placentas and fetuses during early pregnancy

Ancient amphibians as big as alligators died in mass mortality event in Triassic Wyoming

Scientists uncover the first clear evidence of air sacs in the fossilized bones of alvarezsaurian dinosaurs: the "hollow bones" which help modern day birds to fly

Alcohol makes male flies sexy

TB patients globally often incur "catastrophic costs" of up to $11,329 USD, despite many countries offering free treatment, with predominant drivers of cost being hospitalization and loss of income

Study links teen girls’ screen time to sleep disruptions and depression

Scientists unveil starfish-inspired wearable tech for heart monitoring

Footprints reveal prehistoric Scottish lagoons were stomping grounds for giant Jurassic dinosaurs

AI effectively predicts dementia risk in American Indian/Alaska Native elders

First guideline on newborn screening for cystic fibrosis calls for changes in practice to improve outcomes

Existing international law can help secure peace and security in outer space, study shows

Pinning down the process of West Nile virus transmission

UTA-backed research tackles health challenges across ages

In pancreatic cancer, a race against time

Targeting FGFR2 may prevent or delay some KRAS-mutated pancreatic cancers

[Press-News.org] Fruit flies -- fermented-fruit connoisseurs -- are relentless party crashers