Maternal care influences brain chemistry into adulthood

In a study on mice, scientists have discovered that the effect of the peptide hormone of NPY depends on how much care and attention the young animals experienced in the first three weeks of life. Mice who had received little care from their mothers were more anxious adults than their counterparts who had received intensive attention in their early weeks of life. Credit: MPI for Medical Research

Neuropeptide Y (NPY) is the most abundant peptide hormone of the central nervous system. It is involved in various processes including stress management, the development of anxiety behaviour and body weight regulation. A collaborative research group including scientists from the Max Planck Institute for Medical Research in Heidelberg has demonstrated using mice that intensive maternal care during infancy promotes the effect of NPY in the brain. As a result of receiving such care, the animals were also less anxious in adulthood and weighed more than their counterparts who had received less affection. The research group was able to show that the effect is explained by the maternal care which stimulated the persistent formation of certain NPY receptors in the forebrain.

Neuropeptide Y (NPY) assumes several key roles in the brain's complex control circuits. The messenger substance not only influences body weight but also controls, among other things, the development of anxiety and stress responses. Hence NPY plays an important role in a series of such as post-traumatic stress disorders and . NPY takes effect in the brain by binding to different docking sites on the – the NPY . In this way, the hormone triggers signal cascades which control the different physical functions.

In a study on mice carried out in Rolf Sprengel from the Max Planck Institute for Medical Research and his colleagues in Italy have shown that the effect of NPY depends on how much care and attention the young animals experienced in the first three weeks of life. Mice who had received little care from their mothers were more anxious adults than their counterparts who had received intensive attention in their early weeks of life. They also remained slimmer throughout their lives. As the researchers discovered, the maternal behaviour influenced the formation of NPY1 receptors in the limbic system – the area of the brain responsible for the processing of emotions.

"We were able to show that the expression of the NPY1 receptor in the young animals' limbic system is increased by good ," explains Rolf Sprengel. "This ensures their healthy development in the long term." The positive effects of maternal care and attention were evidenced by the fact that the young animals gained weight faster and showed greater courage in behavioural experiments as adults than rodents which had experienced little warmth and security after birth.

For their study, the scientists had newborn mice, in which the NPY1 receptors had been switched off selectively, raised by mothers who differed in their behaviour towards the young animals. One group belonged to a mouse strain that was exemplary in caring for its young. These females spent a lot of time with their offspring, fed them frequently and, in addition to extensive grooming, also provided intensive physical contact. In young animals which grew up under such conditions, new NPY-1 receptors formed in the brain's limbic system. The second group of females were programmed to take far less care of the young. In this case, the number of NPY1 receptors in the young mice did not increase.

The neuroscientists' findings help us to reach a better understanding of how experience in the early life of an organism can affect it in later life. "The results of the study show how maternal care and attention have a sustained impact on the chemistry of the limbic system," says Rolf Sprengel. Maternal behaviour can influence the emotions and physical constitution into adulthood in this way.

More information: Ilaria Bertocchi, Alessandra Oberto, Angela Longo, Paolo Mele, Marianna Sabetta, Alessandro Bartolomucci, Paola Palanza, Rolf Sprengel, Carola Eva. Regulatory functions of limbic Y1 receptors in body weight and anxiety uncovered by conditional knockout and maternal care, PNAS, doi: 10.1073/pnas.1109468108

Related Stories

Importance of sex-specific testing shown in anxiety study

Oct 15, 2008

An Australian study has flagged an important truth for the medical research community. Like their human counterparts, male and female mice are not only different, their respective genetic responses can often be the reverse ...

Researchers investigate stress and breast cancer

Sep 20, 2011

It's a common belief that there's a link between chronic stress and an increased risk of cancer. In new research published online by the International Journal of Cancer, scientists at The University of Western Ontario have t ...

Maternal stress during pregnancy may affect child's obesity

Apr 12, 2011

There is increasing evidence from human and animal studies that offspring of parents who were physically or psychologically stressed are at higher risk of developing obesity, and that these offspring may in turn "transmit" ...

Control of fear in the brain decoded

Sep 06, 2011

When healthy people are faced with threatening situations, they react with a suitable behavioural response and do not descend into a state of either panic or indifference, as is the case, for example, with ...

Recommended for you

Diet affects men's and women's gut microbes differently

12 hours ago

The microbes living in the guts of males and females react differently to diet, even when the diets are identical, according to a study by scientists from The University of Texas at Austin and six other institutions published ...

Researchers explore what happens when heart cells fail

13 hours ago

Through a grant from the United States-Israel Binational Science Foundation, Biomedical Engineering Associate Professor Naomi Chesler will embark upon a new collaborative research project to better understand ...

Stem cells from nerves form teeth

15 hours ago

Researchers at Karolinska Institutet in Sweden have discovered that stem cells inside the soft tissues of the tooth come from an unexpected source, namely nerves. These findings are now being published in the journal Nature and co ...

User comments

Adjust slider to filter visible comments by rank

Display comments: newest first

JVK
not rated yet Dec 10, 2011
Isn't any effect of NPY dependent on olfactory/pheromonal input? I think the connection from olfaction to the mother-infant bond and associated physiological changes during behavioral development makes the NPY correlate more clear.