Heartbreak? You can learn this from the field mouse

The field mouse is more like us humans than you might initially think: it lives in monogamous relationships and takes care of its young together with its partner. And she feels a kind of separation pain, similar to how we humans do. Our species may learn a lesson from how it overcomes this, as new research now suggests.

A research team from the US recently investigated how mice from the steppes of North America get over their ex-partners. For this purpose, the dopamine level in the brains of the test animals was measured. Dopamine is also called the happiness hormone because it controls our desires.

In one experiment, a mouse had to press a lever to open a door to get to the mouse or climb over a fence. When the mouse’s partner waited behind it, dopamine levels increased. However, when a strange mouse was on the other side of the obstacle, dopamine levels in the brain did not change.

Applied to humans, this means that the reward system is activated more strongly when we spend time with someone important to us, whether that is a partner or a close friend.

To investigate the effects of separation on the brains of mice, the pairs were separated for four weeks. That’s a long time for animals that only live about a year in the wild. When the two met again, the measured biochemical reaction was different: life partners had become ex-partners. Although the animals remembered each other, the dopamine rush did not occur. “We see this as a kind of reset in the brain that allows the animal to form a new bond,” explains neuroscientist Zoe Donaldson, who was involved in the study.

The extent to which this mechanism can be transferred to humans is still uncertain. However, if dopamine release also plays such a central role in relationships between people, it would help to understand what healthy connections look like in the brain. This finding could help in the treatment of people with mental health problems, Donaldson says. If this mechanism also applies to humans, it would mean that our brain protects us against unrequited love. And that every heartbreak must be over sooner or later. (anb)