Scientists find lasers can be used to switch on 'killer instinct' in mice

Scientists have been hard at work testing futuristic beams of light on the brains of mice and then getting them to fight. What did you do today?

After researchers found – according to a feature published in scientific journal Cell this week, anyway, and our copy must’ve slipped out of the postie’s bag – that the amygdala, the two almond-shaped clusters of nuclei that are chilling in the middle of the brains of all complex vertebrates, not only controls fear – as previously known – but also other hunting behaviours. So, unnaturally, they fucked with it.

We’ll let Scientific American take it from here: 

To activate the central amygdala in mice, Ivan de Araujo, a neurobiologist at Yale University in New Haven, Connecticut, and his colleagues used a technique called optogenetics. First, they infected the mice with a virus that made the neurons in their brains sensitive to blue light. Then, the researchers used a tiny optic fibre to shine a blue laser on the amygdala. This prompted the animals to tense their jaw and neck muscles. The behaviour didn’t occur when the researchers stimulated other parts of the brain.

“This prompted the animals to tense their jaw and neck muscles” is very Daddy’s First Trip To 93 Feet East but let’s soldier on.

When the laser was on, the mice hunted just about everything placed in their paths, from edible treats such as crickets to non-food items like bottle caps. The researchers observed the same activity when they triggered the amygdala with chemogenetics, a similar technique that stimulates neurons with molecules rather than light. The hunting and feeding behaviours even happened when there was nothing to hunt. When mice in empty cages had their amygdalas activated, they stopped whatever they were doing, positioned their front legs as if they were holding food and moved their mouths as if they were chewing.

It’s all a bit Zoolander, innit. 

While the scientists in question were quick to assuage fears that they have been working on creating a breed of murderous mice capable of staging a rodent junta, we’re not so sure. The eggheads might try and blind you with numbers and stats and “things that actually happened in a controlled, peer-reviewed environment leaving little room for error, miscalculation or manipulation” but we know better. 

As SA add, they think “the amygdala might be acting as a ‘gate’, holding back a variety of programmes that are constantly running in the background of the brain” so who knows what’ll happen when, say, the world’s largest nation, with borders European and Asian countries as well as the Pacific and Arctic oceans, landscape ranges from tundra and forests to subtropical beaches, and a raging hard-on for dodgy shit, start testing it on humans. 

Amygdala – you’ve got one. And so have they. 

(Main Image: Basil The Mouse Detective* / Walt Disney Pictures)

*yes, Ratigan is a rat and not a mouse, but shut up. For god’s sake: shut up.