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

Swarming insect provides clues to how the brain processes smells

2013-11-26
(Press-News.org) Contact information: Neil Schoenherr
nschoenherr@wustl.edu
314-935-5235
Washington University in St. Louis
Swarming insect provides clues to how the brain processes smells

Our sense of smell is often the first response to environmental stimuli. Odors trigger neurons in the brain that alert us to take action. However, there is often more than one odor in the environment, such as in coffee shops or grocery stores. How does our brain process multiple odors received simultaneously?

Barani Raman, PhD, of the School of Engineering & Applied Science at Washington University in St. Louis, set out to find an answer. Using locusts, which have a relatively simple sensory system ideal for studying brain activity, he found the odors prompted neural activity in the brain that allowed the locust to correctly identify the stimulus, even with other odors present.

The results were published in Nature Neuroscience as the cover story of the December 2013 print issue.

The team uses a computer-controlled pneumatic pump to administer an odor puff to the locust, which has olfactory receptor neurons in its antennae, similar to sensory neurons in our nose. A few seconds after the odor puff is given, the locust gets a piece of grass as a reward, as a form of Pavlovian conditioning. As with Pavlov's dog, which salivated when it heard a bell ring, trained locusts anticipate the reward when the odor used for training is delivered.

Instead of salivating, they open their palps, or finger-like projections close to the mouthparts, when they predict the reward. Their response was less than half of a second. The locusts could recognize the trained odors even when another odor meant to distract them was introduced prior to the target cue.

"We were expecting this result, but the speed with which it was done was surprising," says Raman, assistant professor of biomedical engineering. "It took only a few hundred milliseconds for the locust's brain to begin tracking a novel odor introduced in its surrounding. The locusts are processing chemical cues in an extremely rapid fashion."

"There were some interesting cues in the odors we chose," Raman says. "Geraniol, which smells like rose to us, was an attractant to the locusts, but citral, which smells like lemon to us, is a repellant to them. This helped us identify principles that are common to the odor processing.

Raman has spent a decade learning how the human brain and olfactory system operate to process scent and odor signals. His research seeks to take inspiration from the biological olfactory system to develop a device for noninvasive chemical sensing. Such a device could be used in homeland security applications to detect volatile chemicals and in medical diagnostics, such as a device to test blood-alcohol level.

This study is the first in a series seeking to understand the principles of olfactory computation, Raman says.

"There is a precursory cue that could tell the brain there is a predator in the environment, and it has to predict what will happen next," Raman says. "We want to determine what kinds of computations have to be done to make those predictions."

In addition, the team is looking to answer other questions.

"Neural activity in the early processing centers does not terminate until you stop the odor pulse," he says. "If you have a lengthy pulse – 5 or 10 seconds long – what is the role of neural activity that persists throughout the stimulus duration and often even after you terminate the stimulus? What are the roles of the neural activity generated at different points in time, and how do they help the system adapt to the environment? Those questions are still not clear."



INFORMATION:

The School of Engineering & Applied Science at Washington University in St. Louis focuses intellectual efforts through a new convergence paradigm and builds on strengths, particularly as applied to medicine and health, energy and environment, entrepreneurship and security. With 82 tenured/tenure-track and 40 additional full-time faculty, 1,300 undergraduate students, 700 graduate students and more than 23,000 alumni, we are working to leverage our partnerships with academic and industry partners — across disciplines and across the world — to contribute to solving the greatest global challenges of the 21st century.

Saha D, Leong K, Li C, Peterson S, Siegel G, Raman B. A spatiotemporal coding mechanism for background-invariant odor recognition. Nature Neuroscience. Advance online publication Nov. 3, 2013; December 2013 print edition (Volume 16 No. 12 pp1709-1908).

Funding for this research was provided by the McDonnell Center for System Neuroscience and the Department of Biomedical Engineering at Washington University and the Office of Naval Research of the U.S. Department of Defense.



ELSE PRESS RELEASES FROM THIS DATE:

Ancient minerals: Which gave rise to life?

2013-11-26
Ancient minerals: Which gave rise to life? Washington, D.C.— Life originated as a result of natural processes that exploited early Earth's raw materials. Scientific models of life's origins almost always look to minerals for such essential tasks as the synthesis ...

Mach 1000 shock wave lights supernova remnant

2013-11-26
Mach 1000 shock wave lights supernova remnant When a star explodes as a supernova, it shines brightly for a few weeks or months before fading away. Yet the material blasted outward from the explosion still glows hundreds or thousands ...

UCSB biomedical scientist discovers a new method to increase survival in sepsis

2013-11-26
UCSB biomedical scientist discovers a new method to increase survival in sepsis The findings have the potential to translate into millions of saved lives (Santa Barbara, Calif.) — Sepsis, the body's response to severe infections, kills more people ...

Nanotubes can solder themselves, markedly improving device performance

2013-11-26
Nanotubes can solder themselves, markedly improving device performance CHAMPAIGN, Ill. — University of Illinois researchers have developed a way to heal gaps in wires too small for even the world's tiniest soldering iron. Led by electrical ...

Increasing cropping frequency offers opportunity to boost food supply

2013-11-26
Increasing cropping frequency offers opportunity to boost food supply More frequent harvest could substantially boost global food production on existing agricultural lands MINNEAPOLIS / ST. PAUL (11/25/2013) —Harvesting existing cropland more frequently could substantially ...

Bad proteins branch out

2013-11-26
Bad proteins branch out Rice U. researchers find misfolded proteins are capable of forming tree-like aggregates HOUSTON – (Nov. 25, 2013) – A method by Rice University researchers to model the way proteins fold – and sometimes misfold – has revealed branching behavior that ...

CSI-type study identifies snakehead

2013-11-26
CSI-type study identifies snakehead Several Canadian biologists, including two at Simon Fraser University, are breathing a collective sigh of relief after learning that a monstrous fish found in a Burnaby, B.C. pond is not a northern snakehead. But they say ...

Sounding rocket to peek at atmosphere of Venus

2013-11-26
Sounding rocket to peek at atmosphere of Venus A week after launching a new orbiter to investigate the upper atmosphere of Mars, NASA is sending a sounding rocket to probe the atmosphere of Venus. The Mars Atmosphere and Volatile Evolution, ...

Study: Arctic seafloor methane releases double previous estimates

2013-11-26
Study: Arctic seafloor methane releases double previous estimates Storm activity hastens release of greenhouse gas into the atmosphere The seafloor off the coast of Northern Siberia is releasing more than twice the amount of methane as previously ...

Risk of HIV treatment failure present even in those with low viral load

2013-11-26
Risk of HIV treatment failure present even in those with low viral load Study proposes new benchmarks for clinical treatment of HIV People with human immunodeficiency virus (HIV) run a higher risk of virologic failure than previously thought, even ...

LAST 30 PRESS RELEASES:

CPA journal wins prestigious award at high-quality development conference

Disruptive investments can build a cleaner aviation industry

Wearable optical device distinguishes blood flow signals from the brain and scalp

USC-Caltech study moves novel tool to measure brain blood flow closer to the clinic

Changes in colorectal cancer screening modalities among insured individuals

Seaweed makes for eco-friendly tissue scaffolds and reduces animal testing

New study: AI chatbots systematically violate mental health ethics standards

Smoking both cannabis and tobacco may alter brain’s ‘bliss molecule,’ study finds

The rise of longevity clinics: Promise, risk, and the future of aging

Decoding the T-cell burst: Signature genes that predict T-cell expansion in cancer immunotherapy

Biomarker can help predict preeclampsia risk in women with sickle cell disease

AI models can now be customized with far less data and computing power

Twenty-five centers join Bronchiectasis and NTM Care Center Network

Botox-like substance brings relief to Ukrainian war amputees

People with dark personality traits use touch to manipulate their partners

It’s not just diet: where a child lives also raises type 2 diabetes risk

Predicting physical activity change after a cardiovascular diagnosis

Algorithmic outreach leads to information inequality

Szeged researchers accelerate personalized medicine with AI-powered 3D cell analysis

Offline interactions predict voting patterns better than online networks

Hanyang University researchers develop novel facet guided metal plating strategy, improving stability anode-free metal batteries

When cells run a red light: Double trouble for old models in cell division

Epigenetic reprogramming safely modifies multiple genes in T Cells simultaneously for CAR-T therapies

How hard is it to dim the Sun?

Researchers launch survey to unlock the secrets of vivid memory

Exotic roto-crystals

Dr Harriet Kildahl joins PeroCycle as Technical Director

Exercise counteracts junk food's depression-like effects through gut-brain metabolic signaling

Genetic link discovered between childhood intelligence and parental longevity

Psychedelics reshape time perception offering new therapeutic pathways

[Press-News.org] Swarming insect provides clues to how the brain processes smells