Mice are typically viewed as relatively meek animals that are more likely to scurry away from danger. This is normally true because mice tend to survive longer when they flee instead of fighting, but it turns out that mice may also have the capability to behave in a very predatory manner. Researchers have found that it is possible to activate a more aggressive response in mice simply by exposing them to light from a laser.
Researchers Make Mice Predatory With Laser Light
Mice are frequently used in research because these tiny and easy to care for animals share many physical similarities with humans. This makes them ideal for experiments that attempt to discover how the brain works, so a team of researchers from Yale University used mice to study the amygdala which is a part of the brain that regulates emotions. The research team lead by Ivan de Araujo recently published their findings in the Cell Journal.
In the article, the researchers explained that they used a virus to transplant a sensitivity for blue light to the mice. When an optic fibre was used to expose the mice to a blue laser, the amygdala was activated. The main physical difference was just that the mice tensed up their neck and mouth muscles, but their behavior was vastly different. The formerly friendly and peaceful mice dashed around their habitats attacking everything, including live prey and inanimate objects.
Even if nothing was in the cage, the mice would chomp their jaws as if they were biting on objects. When the blue laser was turned off, the mice would become peaceful again. To test whether or not the laser was activating hunger instead of aggression, the researchers also monitored animal intake.
The mice exposed to blue light did not eat an excessive amount, but they spent more time attempting to catch prey. This means that they were not just hunting because they were hungry. The stimulated amygdala seems to directly cause more predatory instincts.
Mouse Study Provides Important Information
This research was originally begun because Araujo and his researchers wanted to determine if the amygdala was responsible for controlling predatory behavior in mice. They knew that the amygdala was more active when rats were hunting, but they did not know if activating it could cause rodents to display predatory behavior. The research team cautions that it cannot be used as method for provoking murderous behavior in mice or humans.
Still, this new study does provide valuable insight into the way mice and other mammals respond to the amygdala. Previous research has linked the amygdala to many other instinctual behaviors, such as mating or remembering to fear natural predators. This research shows that the amygdala can also control the instinct to hunt and attack smaller objects.
Araujo and his team of researchers theorize that the predation response of a stimulated amygdala is similar among all vertebrates with jaws that hunt. The amygdala is a little understood part of the brain, but amygdala dysfunction has been linked to a variety of mental health issues like alcoholism and bipolar disorder. Any research that furthers the scientific understanding of the amygdala’s functions could one day be used to treat these issues.
The Next Steps for Researchers
This study by the team of Yale University researchers is important because it shows just how much the amygdala influences predatory action. Currently, the results only show that the amygdala causes predation and aggression in rodents, so it would be necessary for researchers to find a way of replicating the results in human test subjects if they want to expand the study’s impact. Further research could help us to better understand the mysteries of the human brain.
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