Tamed foxes show brain changes in aggression-linked region

Brain Changes in Tamed Foxes

A new study found that foxes selectively bred for tameness exhibit changes in the ventromedial hypothalamus, a brain region known to influence aggression. This finding comes from comparing the brains of domesticated, aggressive, and wild foxes.

The ventromedial hypothalamus is located at the base of the brain and plays a role in aggression, energy use decisions, maternal instincts, and social behaviors in mice.

Background of the Fox Experiment

The research draws on a long-running experiment initiated in Siberia in the late 1950s. Russian geneticists began selectively breeding silver foxes based on their friendliness or aggression towards humans. After only six generations, the 'friendly' foxes developed tamed behaviors and physical traits associated with domestication, such as floppy ears and shorter snouts.

Neurological Underpinnings of Behavior

Researchers aimed to understand the neurological basis for these rapid behavioral changes. They focused on the ventromedial hypothalamus because previous studies identified cell types within it that control aggression in mice.

The study involved analyzing brain samples from tame, aggressive, and wild foxes. Using fluorescent RNA scope, they identified markers for different cell types in the ventromedial hypothalamus.

Implications for Brain Structure

This research suggests how environmental pressures can quickly alter brain structure. The findings contribute to understanding the biological mechanisms behind domestication and behavioral evolution.