Territoriality is a pretty common trait among male members of many species. This is as true for animals as it is for humans. Animals have several ways of marking their territory. Some of them put rocks to create a makeshift border; others leave their smell either by scratching themselves against a surface or by urinating on said surface, and then there are those that resort to violence when an intruder enters their domain. We have all seen men who pick fights with each other in bars, and we can also see countless examples of male territoriality in history, from early humans, to Roman and Greek empires, and all up to the wars of today.
In 2017 scientists from Stanford University decided to take a closer look at the roots of this aggression by experimenting on lab mice. They were even able to find the specific brain cell that causes the rise in hostility connected to territoriality.
The ventromedial hypothalamus is located deep in the center of the brain, and it has an active role in many hormone-related activities. This is the part of the brain where fear comes from, for example. Scientists have known for a long time that this part of the brain is involved in aggression, but they have only now been able to pinpoint which cells exactly are to blame. Funnily enough, the 4,000 cells in question are also closely related to sexual activity.
As soon as the scientists were able to activate those cells in the brain, the mice started to act up. The aggression levels became so high that the mice attacked even the female members of their species. This is not common for male mice. They even struck inanimate objects like mirrors. The mice also became territorial on foreign turf, where they themselves were the intruders.
Another big factor was how the mice lived before having their brains tampered with. The ones that lived alone in cages were much more aggressive than the ones living with other mice. These mice only got aggressive when their territory was intruded, and they were well-mannered guests when placed in other cages, even with the aggression neurons triggered.
Scientists believe that this comes down to the fact that the mice were able to detect the owner’s pheromones. If the mice had their ability to detect pheromones blocked, they instantly became aggressive even when visiting other cages. It did not matter whether they lived solitary or if they were a part of a community.
There is a constant discussion about the origin of anger. These experiments show that it comes from a dichotomy, a dichotomy of nature and nurture; even when the neurons were activated in the mouse brain if it had a healthy social upbringing the mouse knew how to behave.
This goes against many previous studies about aggression and how it is triggered, but it still offers an intriguing new possibility. The study also looked at variables that have been often overlooked in the past. The fact that the study revealed that housing and social conditions affected aggression is something that scientists did not take into consideration and is quite intriguing.
The next steps after the study are to determine how and why housing and social interactions affect the ability to detect pheromones in mice. Scientists also need to determine how precisely the neurons affect aggression and if territorial aggression has a specific electrical signature.
The most intriguing fact about the study is that it might help us better understand aggression in other species as well as our own. The study might even be helpful in explaining conditions like intermittent explosive disorder where people exhibit bursts of disproportionate rage.
Lee has one of the most genuine smiles you have ever seen. His warm smile, and friendly personally give evidence of just how much joy he finds in his research. He has worked on numerous projects, which seek to learn more about terrible illnesses, with the hope of learning how to eradicate them altogether. Lee is also a huge basketball fan and is often found shooting hoops whenever he is not buried in a pile of books in his lab. He also makes time to coach at-risk youths and finds ingenious ways to remind them of the beauty of science even while they play around.