Innovation
26/01/2018

Researchers Find Mosquitos Can Recall Human Smells As Well As Swats




It may seem quite startling to know that mosquitoes have the ability to quickly learn and remembers the odor of their hosts which can also help them to remember an unsuccessful swat for a long time. 
 
This was published in a study in the journal Current Biology on January 25 which said that dopamine is the most important mediator of this process of remembering smell.
 
Mosquitoes are able to create their own preferences for a specific vertebrate host species, and additionally, certain individuals within that population, by the use of the gathered information and mixing with other stimuli.
 
The study has further stated that mosquitoes despite the condition that a mosquito preferring the smell of a particular individual, it also tends to associate any form of unpleasant physical sensation with the smell which can lead to the preferences getting shifted. Researchers said that this lead mosquitoes avoiding individuals who swat at them or does other defensive behaviors despite how alluring they find the smell to be.    
 
A trait that is known as aversive learning was exhibited by mosquitos through training of female Aedes aegypti mosquitoes so that they relate odors - including human body smell to the unpleasant sensations and shocks in the research by Clément Vinauger, an assistant professor of biochemistry in Virginia Tech's College of Agriculture and Life Sciences, and Chloé Lahondère, a research assistant professor in the Department of Biochemistry.
 
The researchers further tested the mosquitos in a Y-maze olfactometer where the insects were made to fly upwind and made to choose between the once-preferred human body odor and a control odor, twenty-four hours later. The successful training of the mosquitos was indicated after they chose to avoid the human body odor associated with an unpleasant sensation.
 
The scientists also made possible the identification of dopamine as a key mediator of aversive learning in mosquitoes through the adoption of a multidisciplinary approach and the use of cutting-edge techniques that included CRISPR gene editing and RNAi.
 
"Unfortunately, there is no way of knowing exactly what attracts a mosquito to a particular human—individuals are made up of unique molecular cocktails that include combinations of more than 400 chemicals," said Lahondère. "However, we now know that mosquitoes are able to learn odors emitted by their host and avoid those that were more defensive."
 
"Understanding these mechanisms of mosquito learning and preferences may provide new tools for mosquito control," said Vinauger. "For example, we could target mosquitoes' ability to learn and either impair it or exploit it to our advantage."
 
Zika fever, dengue fever, chikungunya, and yellow fever viruses are carried by and spread by the aedes aegypti mosquitoes which are typically found in tropical and subtropical regions all across the world. Vinauger and Lahondère are both affiliated with the university's Fralin Life Science Institute, which supports vector-borne disease research as a major thrust area.
 
(Source:www.phys.org)

Christopher J. Mitchell
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