A Greek scientist had made an exciting new discovery surrounding the biological mechanism that underpins aggressive behaviour in humans.

Titled ‘A neural network for intermale aggression to establish social hierarchy’ and published in scientific journal Nature Neuroscience, the study conducted on male mice was led by Christian Broberger together with lead author Stefanos Stagkourakis and a group of researchers from medical university Karolinska Institutet in Sweden.

Through their observations they have shed light on the up until now mysterious group of brain cells that are linked to aggression and subsequent reactions, and even managed to manipulate the aggression response by inhibiting and activating the neurons.

The group of neurons located in the ventral premammillary nucleus (PMv) of the hypothalamus, which controls many of our fundamental drives, play a key role in initiating aggressive behaviour.

During the study researchers noted the mice become aggressive when a new male mouse was placed in their cage, resulting in an increase in active PMv neurons.

The team then manually activated the PMv neurons through optogenetics – a form of light used to control cells in living tissue – and as a result manipulated the initiation of aggressive behaviour in situations where the mice would not normally instinctively attack, while on the other hand, they were also able to inhibit the PMv to stop an attack.

Meanwhile the team also noted that PMv neurons had the ability to activate other parts of the brain, including reward centres, which Stagkourakis said could explain why mice naturally make their way to a place where they have experienced an aggressive situation.

“We also found that the brief activation of the PMv cells could trigger a protracted outburst, which may explain something we all recognise – how after a quarrel has ended, the feeling of antagonism can persist for a long time,” he said.

The team hopes their findings will add to the knowledge surrounding aggressive behaviour and the origins of violence to assist with or, better yet, avoid lasting mental trauma and the costly structural and economic consequences on society.

Stagkourakis graduated from The University General Hospital of Heraklion’s Department of Neurology. He went on to pursue studies at the Karolinska Institutet’s Department of Neuroscience, and now conducts research on the neural control of innate and learnt animal behaviour.