A team of neurobiologists at Yale University in New Haven, Connecticut (USA) has discovered a switch that appears to activate predatory instincts in mice, because when certain parts of the rodent brain were stimulated with light, the mice They displayed a complex range of hunting activities, what we might call their hunting instincts.
The brain circuits involved in predatory behaviors such as grabbing and biting are a mystery. The researchers wanted to know if it is the amygdala (where basic emotions such as anger or fear prevail) that controls hunting behaviors, and this study published in the journal Cell suggests that it is.
To activate the central amygdala in the mice, the experts used a technique called optogenetics that makes it possible to glimpse and activate certain neurons; Thus, they used a tiny fiber optic to shine a blue laser on the brain’s amygdala. This led the rodents to tighten their jaw and neck muscles, a behavior that was not repeated when the researchers stimulated other parts of the brain.
When the laser was on, the mice hunted almost everything that was put in their trails , from edible treats like crickets to non-food items like bottle caps. They observed the same activity when they activated the central amygdala with chemogenetics, a similar technique that stimulates neurons with molecules instead of light. The hunting behavior was repeated even when there was nothing to hunt : the mice placed their front legs as if they were holding food and moved their mouths as if they were chewing. The experiment was repeated to check that the mice were not very hungry. The result was the same. So the experiments were triggering predation, not starvation or other motive. At no time did the mice attack each other, which summarizes that this instinct is limited to the need to feed.
“This is significant because predation is a very complex behavior. It is not just physiological, it is about hunting, biting and eating. Those are motor sequences that require a lot of information, so it is remarkable that you can get this behavior with that kind of brutal manipulation, “says Kay Tye, a neuroscientist at the Massachusetts Institute of Technology in Cambridge and a co-author of the study.
The work has shown that this area of the brain is involved in the complex task of predation but “future research needs to discover the precise neural circuits involved in hunting. The central amygdala has been linked to flight and flight; but this is Completely different, as an animal that hunts is looking for something for a reward, while a creature in flight or escape mode is actively avoiding something, “Tye clarifies.
