Scientists have revealed through a study published in journal Cell that they have managed to identify neurons, which when activated, cause a mouse to showcase aggressive behaviour including stalking and biting.
Researchers at Yale University have identified two subgroups of neurons within the central amygdala region of a mouse’s brain which they say are responsible for this aggressive behaviour. Scientists are optimistic that findings of their study could explain the neurological origin for hunting, an intrinsic behavior conserved across most vertebrate life.
Authors of the study note that it wasn’t clear how the brain processes information and instructs the body to exhibit hunting behaviour – a complex activity that involves a range of sub-activities including identification, tracking and killing of prey.
For the study, the team used both optogenetics, the use of light to control cells in living tissue, and chemogenetics, the processes by which macromolecules can be engineered to interact with previously unrecognized small molecules, to study the central amygdala region in mice.
The first step in their study was to engineer mice wherein the two neuronal subgroups of interest could be activated using a laser. When the laser source was on, mice would attack, seize and ingest both crickets and nonedible objects, but this activity stopped as soon as the laser was turned off.
The team then applied chemogenetics, another cutting-edge technique, to replicate their results without the disadvantages of optogenetics, which include brain implants and poor inhibitory control.
According to the study, the researchers concluded that the central amygdala regulated hunting behavior in mice. Since all jawed vertebrates have a homologous brain region, it is logical that these results might be generalizable for other species, scientists note. The team also notes that their study’s activation of the central amygdala has been misinterpreted as triggering a killer instinct in the mice. They point out that although mice whose central amygdala neurons were stimulated exhibited aggressive behavior, the behavior is a result of the need for food and not a kill switch.