A recent experiment reveals that using lasers trigger the predatory instinct of normally timid mice, turning them into aggressive killer mice. Researchers explain that there are two sets of neurons activated by light. One triggers the instinctual pursuit of prey, while the other involuntarily makes the animal to clench its jaws and neck muscles, to bite and kill.
Scientists use the technique of using artificial light, called optogenetics, to activate certain parts of the brain. In this case the killer, predatorial part of the brain is activated in the mice. What is more interesting is that this technique allows scientists to turn on and off the behavior at will.
Ivan de Araujo, lead author of the study, explains that as they turn on the laser, the mice would jump on objects as if trying to kill it. The study puts the mice in a position where the automatically pursue anything in their way such as insects and inanimate objects such as bottle caps and small sticks. However, De Araujo says that the killer mice did not hurt their fellow mice during the experiment, killing only those that are smaller than them, The Guardian says.
In the study, which was published in the journal Cell, the scientists find that the two clusters of neurons do not necessarily follow each other. The first set of neurons render the mice scurrying after any small object that comes in their field of view. The second one makes them chomp on air, as if biting on something.
Both sets of neuron are independent of each other, reducing the ability of mice to bite when the "hunting" neurons are activated, and vice versa. According to the Science Mag, hunger plays a powerful influence on the "killer" behavior. Mice deprived of food tend to be more aggressive in chasing prey.
The same circuits are assumed to be present in the human brain although the primary reason for the predatory behavior would be to look for food rather than aggression or the desire to attack. Another unusual study was observed this week on a deer and monkey, prompting interesting research on animal behavior. The experiment on killer mice gives the opportunity for other scientists to study the link between light and aggression on humans.
