Experience with mice and humans: stroking soothes if you have experienced a mother’s love

Stroking calms human children and animals.

However, it may be that the calming effect is only produced by those who have received tenderness and care as children.

According to a Japanese study, the touch of a mother or other caregiver during infancy can affect how we perceive touch in later life.

Thing was investigated in a multipart study, and first the effects of stroking were studied in babies.

The little ones were placed on their mothers’ laps, and the mothers were tasked with stroking their children’s backs, napes and stomachs.

At the same time, the researchers measured the electrical activity of the babies’ hearts in order to get an idea of ​​the children’s restfulness.

According to the measurements, stroking the back in particular calmed the children.

Stomach stroking had no effect either way. Instead, stroking the back of the head made the children even slightly excited.

I will try the next step was done in mice.

Mother mice and other four-legged mammals nurture their young by licking their backs. The use and the feeling it creates are similar to stroking.

The mouse pups were divided into three groups. The chicks of the first group were isolated for half an hour in a closed space.

The same was done to the chicks of the second group, but in addition their backs were brushed with a soft brush during the isolation.

The third group was allowed to spend time normally with their siblings and mother.

Isolation without petting made the baby mice stressed. However, those who were comforted by stroking secreted fewer markers of stress.

This is how the researchers found out that stroking, similar to licking the back, calmed the baby mice.

But what if the mice have never received the mother’s care in their lives?

The researchers raised baby mice that were separated from their mothers immediately after birth.

The researchers fed the chicks but avoided touching them. The cubs grew up completely without the mother’s affection and physical touch.

Next, we investigated how these chicks, raised apart from their mother, reacted to petting.

In the isolation experiment, it was noticed that stroking did not calm these chicks, but actually increased the stress they experienced.

This was a surprise to the researchers. The relaxing effect of stroking was therefore not an innate quality, but developed only in chicks that received care.

Researchers wanted to find out if the phenomenon could have a physiological basis.

They looked at the hypothalamus in the mice’s brain, which regulates sleep and stress, among other things. The purpose was to find out which of the genes controlling the function of the hypothalamus were active and which were switched off.

The researchers noticed that the function of the so-called Cacna1b gene was clearly reduced in chicks raised apart from their mother.

The matter was tested with a new generation of chicks, whose brains the researchers silenced the function of the gene in question.

These chicks were allowed to grow up normally with their mother, but even so, stroking their backs did not relax them.

Same the mechanism may also apply to humans, the researchers estimate.

The calming effect is hardly related to just this one gene, said the professor Hiromasa Funato From Toho University Medicalxpresson the site.

Probably the action of the Cacna1b gene is just one of several mechanisms that make stroking relaxing.

According to Funato, however, the research produces new information on how early experiences affect the functioning of the developing brain concretely and at the molecular level

The study was published Communications Biology in the journal.