Scientists able to use laser to wire mice brains to make them become more aggressive hunters.
Researchers have found a way to flip a switch in the brain of mice to turn them into a more aggressive killer, and in doing so, may have found a key to the way hunting behavior evolved millions of years ago.
An article on npr.org says the mice were subjected to a laser light,which activated two sets of neurons in the amygdala in the mice, after which the mice began to pursue live crickets at a more aggressive pace.
The mice even attacked other objects in their presence, including sticks, bottle caps and an insect-like toy, according to Ivan de Araujo, an associate professor of psychiatry at Yale University and an associate fellow at The John B. Pierce Laboratory in New Haven, Connecticut.
“The animals become very efficient in hunting,” said de Araujo, “”The animals intensively bite the toy and use their forepaws in an attempt to kill it.”
But, amazingly, the aggressive behavior was reserved for the prey, and did not cause the mice to attack each other, even after both sets of neurons were activated.
De Araujo says the findings hint at the way the brain evolved hundreds of millions of years ago when animals with jaws first began to appear. He adds that new ability must have led to the brain being wired in such a way as to take advantage of the new ability to use that mechanism. By that, he means the brain would have to develop circuits for hunting that would coordinate the movements of the jaw and neck and called the movement a “very complex and demanding task.”
The research team used a technique called optogenetics to create the switches in separate neurons, one for involved emotion and motivation, and another which took over when biting and killing its prey.
When the scientists flip the switches for both neurons, the mice “assume the body posture and actions usually associated with real hunting,” offered De Araujo.
Previous research has found similar evidence of hunting circuits in rats and even humans, who once hunted and killed prey to survive.
Findings from the study were published in the journal Cell.