Explosives detectionMice genetically modified to detect landmines

Genetically-modified mice effective at landmine detection // Source: bulfax.com

In another advancement in explosives detection, scientists have genetically modified mice to enable them to sniff out landmines. The GM mouse, known as MouSensor, may one day become a significant tool to help deal with the dangerous legacies of past wars.

Today, more than seventy countries are contaminated by landmines from previous conflicts.

“Long after wars have ended, communities are still impeded from going back to their normal, daily activities because of all these mines still affecting their land,” Charlotte D’Hulst of Hunter College, New York, told the Guardian.

One approach to clearing landmines from old battlefields is to use HeroRats — giant pouched rats which are trained by the Belgian company Apopo to sniff out landmines. These rats are indigenous to sub-Saharan Africa, where they are used, and thus well-suited to the climate. In addition, they are resistant to many of the diseases in the area and have a lifespan of six to eight years.

Two of the HeroRats, along with a handler, can clear an area of 300 square meters in less than two hours. It would take two people about two days to clear the same area. The only significant drawback is that the mice need nine months training before they can be used in the field.

D’Hulst wanted to improve on the concept of HeroRats by creating a genetically modified mouse which is sensitive to the specific odor of TNT.

The Guardian reports that scientists found a receptor in the mouse’s olfactory bulb (the collection of neurons in the nose that detect smells) which specifically recognized a chemical called DNT, a less explosive but similar-smelling version of TNT.

D’Hulst modified the genes of a mouse to give it a much larger proportion of DNT receptors in its nose compared to a normal mouse. The GM mouse thus has 500 times more the ability to detect the scent of DNT that a normal mouse can.

D’hulst will present the lasts results from her work at the annual meeting of the Society for Neuroscience in New Orleans.

The mice have yet to be tested in the field, and D’Hulst has yet to work out the best landmine-clearing protocol for her MouSensors. D’Hulst said that given the sensitivity the mice have to TNT, the mouse would probably have a seizure when it sniffed explosives, since so many neurons in the brain would be firing at once.

“We are thinking along the lines of implanting a chip under the skin of these animals that would wirelessly report back to a computer when the animal’s behavior is changing upon being triggered by a TNT landmine.” D’Hulst told the Guardian.

Once the location has been identify, a bomb disposal expert can neutralize it and the mouse itself would be safe from the landmine since it would be too small to trigger the explosion.

Ben Lark, head of the International Committee of the Red Cross Weapon Contamination Unit, said the mice would only be one way to detect landmines and would not replace any of the methods used today.

“They wouldn’t replace other means,” Lark told the Guardian. “There are three different types of approach: the manual approach, which is people with detectors; machines, such as a flail; and then you have biosensors – which are traditionally dogs. You never use one means on its own.

“The other thing is, the moment you have a minefield you have lots of mines together. If you have too many it saturates an area. I would assume if the mouse had such super-rodent powers it would be overwhelmed fairly quickly.”

The MouSensor is just the first step for D’Hulst; she wants GM mice to be able to detect a range of other odors as well. She gave an example of a mouse which is able to detect tuberculosis by sniffing compounds on the breath of sick individuals.

As far as the landmine-detecting mouse, D’Hulst knows she still has a ways to go, including carrying out more tests. “If we have to put a time on [testing in the field], we hope it will be within five years.” D’Hulst told the Guardian.