Navigation Links
Swarming insect provides clues to how the brain processes smells
Date:11/25/2013

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."


'/>"/>

Contact: Neil Schoenherr
nschoenherr@wustl.edu
314-935-5235
Washington University in St. Louis
Source:Eurekalert  

Related biology news :

1. Crabs, insects and spiders vulnerable to oil spill, but also resilient
2. Entomology 2012 to present 105 insect symposia in November
3. A bit touchy: Plants insect defenses activated by touch
4. UCSB study shows forest insects and diseases arrive in US via imported plants
5. Unique adaptations to a symbiotic lifestyle reveal novel targets for aphid insecticides
6. Jurassic pain: Giant flea-like insects plagued dinosaurs 165 million years ago
7. Insect glands may illuminate human fertilization process
8. Protein signal is crucial for accurate control of insect size
9. Insect scientists to meet in Lincoln, Neb., in June
10. New rearing system may aid sterile insect technique against mosquitoes
11. NHM entomologist wins grant to investigate mega-diverse insect order
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Swarming insect provides clues to how the brain processes smells
(Date:4/15/2016)... April 15, 2016 Research ... Gait Biometrics Market 2016-2020,"  report to their offering.  ... ) , ,The global gait biometrics market is ... during the period 2016-2020. Gait analysis ... can be used to compute factors that are ...
(Date:4/13/2016)... April 13, 2016  IMPOWER physicians supporting Medicaid patients ... a new clinical standard in telehealth thanks to a ... the higi platform, IMPOWER patients can routinely track key ... body mass index, and, when they opt in, share ... visit to a local retail location at no cost. ...
(Date:3/31/2016)... , March 31, 2016  Genomics firm Nabsys has ... CEO, Barrett Bready , M.D., who returned to ... the original technical leadership team, including Chief Technology Officer, ... Product Development, Steve Nurnberg and Vice President of Software ... the company. Dr. Bready served as CEO ...
Breaking Biology News(10 mins):
(Date:5/19/2016)... 19, 2016 - I dati ... durante il 52 ° Congresso ... - Le conclusioni dello studio indicano un ... trattati, di cui il 90% presenta una d urata ... più. Il settantadue per cento dei pazienti ha riscontrato un ...
(Date:5/18/2016)... ... 18, 2016 , ... STACS DNA Inc., the sample tracking software company, today ... assault kit processing to help them save time and reduce errors. , Sexual Assault ... be processed and victims informed of results. Due to a previous lack of tools, ...
(Date:5/17/2016)... , May 18, 2016 Haselmeier ... prefilled pen following approval by EMA, the European Medicines ... science and technology company, the new pen version includes ... increased level of confidence to patients during use. ... prefilled pen easier to handle with a larger display ...
(Date:5/17/2016)... ... May 17, 2016 , ... The Children’s Tumor Foundation is enthusiastic to announce ... will show their support in the fight against neurofibromatosis (NF) by lighting up blue ... disorder that causes tumors to grow on nerves throughout the body. It affects 1 ...
Breaking Biology Technology: