What is Oxytocin?
Oxytocin, which is known to promote bonding between mother and child, is also an essential pillar for social bonding. Researchers have shown this function in mice. This discovery could lead to the development of treatments to help autistic people communicate with their environment.
Social bonds are established from birth and then develop throughout life. Human relationships are partly controlled by hormones, which are, as it were, the body’s little messengers. Oxytocin, for example, is involved in the affection that develops between individuals. This molecule is secreted by the pituitary gland, a small gland located deep in the brain.
Oxytocin plays a major role during pregnancy. It sets the tone of the uterus and induces the onset of contractions and childbirth. It then allows the milk to be expelled during lactation. According to specialists, it promotes the bond between a mother and her child. Oxytocin is also produced in response to touching and orgasms. It is often called the “love hormone” because it helps start the feeling of love between couples. It even promotes monogamy and tends to make men more faithful!
There is a lot of data being collected about the role of this hormone in social interactions. For example, research has shown that it promotes a relationship of trust between men and helps overcome shyness. In a new study, researchers from the University of Sandford in California have reinforced this idea. Their work, published in the journal Nature, showed that oxytocin contributes to the pleasure felt during social interactions.
The experiment started with mice. The scientists made rodents without oxytocin receptors in the nucleus accumbens, an area of the brain involved in feelings of attachment. They then studied a possible effect on their social interactions. “Mice can’t talk, so it’s hard to know if they’re happy with others,” says Robert Malenka, the director of research.
So we had to find another way. The researchers set up a standard exercise called “Conditioned Place Preference. The idea is very simple,” says Malenka. We like to go to places where we have had good times and avoid places that evoke bad memories. It’s the same for mice.
The perpetrators made a cage with two cameras, separated by a door. They first put a number of mice together in one of the rooms for 24 hours. Then they left a mouse alone in the other room for another 24 hours. Finally, they opened the door on the third day to let the mouse move freely between the two rooms. During this last phase, the time spent in each room was timed.
The results of this experiment showed that mice generally prefer to have company than to be alone. On the third day, they passed through the secret door to the other room and spend most of their time there. However, mutated mice with no oxytocin receptors stayed alone and didn’t seem to seek companionship. They moved around in the cage but didn’t seem to prefer one room over the other.
The scientists have gone one step further. Using complex neurological techniques they have succeeded in locating the oxytocin receptors in the nucleus accumbens. They have also shown that the binding of the hormone to these receptors induces the release of serotonin, a neurotransmitter involved in stress management. This phenomenon is accompanied by a feeling of happiness. Many antidepressants, such as Prozac, increase the amount of serotonin in the brain. In short, when we interact with others, our brains release oxytocin and then serotonin, which makes us happy.
A possible path to the treatment of Autism
These discoveries would make it possible to imagine treatments to cure certain pathologies, such as autism, in which social ties are difficult for the sufferers. “People with autism may not feel the same sense of satisfaction and pleasure as others,” says Malenka. By modulating the activity of oxytocin, we can help them overcome their social problems. However, many studies are still needed to treat this complex and still poorly understood condition.