Scientists have managed to use a flash of light to turn on the predatory instincts in mice, allowing them to suddenly pounce on prey and develop a range of hunting and killing activities.
How the brain works to control predatory acts has been a puzzle. Previous research states that the amygdala – the part of the brain that controls emotion and motivation – switches on when rats are hunting, Tech Times reports.
Researchers from Yale University decided to further test and validate this, by using a technique called optogenetics. Optogenetics fires up neurons when light hits them. The team infected the mice with a virus that made their brain neurons sensitive to blue light then shone a blue laser on the amygdala. This prompted a tense reaction from the animals, specifically in their jaws and necks.
They then turned the laser on and the mice turned into stalking predators, hunting everything in their paths, including inanimate objects like bottle caps and wood sticks. They also jumped on objects and bit them, like when hunting, even when there was nothing to hunt.
Predation is a complex behavior in both humans and animals. Ivan de Araujo, a professor of psychiatry and lead author on the study, says,
It is a major evolutionarily player in shaping the brain. There must be some primordial subcortical pathway that connects sensory input to the movement of the jaw and the biting.
Hunger was a factor in predation among the mice, with the hungrier ones more aggressively chasing prey. However, the laser-activate mice were still able to differentiate friend from food, the researchers note.
De Araujo explains, “When they were with another mouse, they might have become more curious, but we didn’t observe any attacks.”
Scientists previously believed that the central amygdala ended in fear when it came to emotions, but new studies now show that this region of the brain is actually part of a complex set of behaviors like grooming and predation.
The Yale team says these results help in understanding how the brain works on a larger scale, such as how neurons interact in specific tasks. There’s also no need to fear these mice as the predatory acts were specifically triggered, “as opposed to an uncontrolled killer instinct,” the researchers say.
The study was published in the journal Cell.
