Summary: Researchers report the oxytocin receptor gene is activated more easily in infants of mothers who faced maternal stress and depression.
Source: University of Basel
Maternal stress and depression during pregnancy may activate certain protective mechanisms in babies. Psychologists from the University of Basel together with international colleagues report that certain epigenetic adaptations in newborns suggest this conclusion. Their results have been published in the journal Social Cognitive and Affective Neuroscience.
In their study, the researchers observed that increased concentrations of maternal stress hormones, depressive symptoms and general adversities during pregnancy were accompanied by epigenetic changes in the child. As a result of these changes the oxytocin receptor gene, which is important for social behavior and stress adaptations, is activated more easily. This mechanism could indicate that in these cases, the babies adapt to develop more resilience to cope with future challenges and adversities.
Switch reprogrammed
Whether a gene can be activated or not also depends on methyl groups that attach to the DNA and function as a switch. The researchers found that children from mothers with increased stress and depressive symptoms show a reduced methylation of the oxytocin receptor gene at birth. This results in the gene becoming more easily activated, which leads to a facilitated production of oxytocin receptors for oxytocin to react with and unfold its effects. Oxytocin not only has an important function in mother-child bonding and in induction of labor and lactation, it also influences social behavior.
For their study, the team of Prof. Gunther Meinlschmidt from the Faculty of Psychology at the University of Basel examined 100 mothers and their babies during and after pregnancy. They collected umbilical cord blood from 39 newborns and assessed the stress hormone cortisol in saliva samples of the mothers. In addition, the researchers evaluated stressful life events and mental health of the mothers via questionnaires. Since the data were only analyzed up to the newborn phase, no conclusions were drawn with regard to the long-term consequences that the epigenetic programming of oxytocin receptors might have for the children.
“Resilience research only at the beginning”
Researchers from the University of Basel, Ruhr University Bochum, Exeter University, McGill University Montreal, Ludwig Maximilian University of Munich, University of Trier, Zurich University of Applied Sciences and the Stress Center Trier were involved in this study funded by the Swiss National Science Foundation. Previous studies have shown, that adversities during pregnancy can increase the risk for mental disorders and physical diseases in the mother’s offspring. However, science has so far dedicated much less attention to potential protective mechanisms of the child.
“Resilience research in this area is only at the beginning,” explains Meinlschmidt. The observations made provide first evidence that an adverse environment during pregnancy could also activate protective mechanisms. “We need a comprehensive understanding of the psychological processes that allow humans to sustain long-term health even over generations despite adversities,” says Meinlschmidt. Based on this knowledge, resilience processes could be promoted in order to try preventing the development of mental disorders and physical illnesses.
Funding: Funding information is not available.
Source: Yannik Sprecher – University of Basel
Image Source: This NeuroscienceNews.com image is in the public domain.
Original Research: Abstract for “Maternal Adversities during Pregnancy and Cord Blood Oxytocin Receptor (OXTR) DNA Methylation” by Eva Unternaehrer, Margarete Bolten, Irina Nast, Simon Staehli, Andrea H. Meyer, Emma Dempster, Dirk H. Hellhammer, Roselind Lieb, and Gunther Meinlschmidt in Social Cognitive and Affective Neuroscience. Published online April 22 2016 doi:10.1093/scan/nsw051
[cbtabs][cbtab title=”MLA”]University of Basel. “Prenatal Stress Could Enhance Protective Mechanisms of Babies.” NeuroscienceNews. NeuroscienceNews, 13 May 2016.
https://neurosciencenews.com/oxytocin-maternal-stress-genetics-4235/ (accessed May 13, 2016).[/cbtab][/cbtabs]
Abstract
Maternal Adversities during Pregnancy and Cord Blood Oxytocin Receptor (OXTR) DNA Methylation
The aim of this study was to investigate whether maternal adversities and cortisol levels during pregnancy predict cord blood DNA methylation of the oxytocin receptor (OXTR). We collected cord blood of 39 babies born to mothers participating in a cross-sectional study (N=100) conducted in Basel, Switzerland (2007 – 2010). Mothers completed the Inventory of Life Events (ILE, second trimester: T2), the Edinburgh Postnatal Depression Scale (EPDS, third trimester: T3), the Trier Inventory of Chronic Stress (TICS-K, one to three weeks postpartum) and provided saliva samples (T2, T3) for maternal cortisol profiles, as computed by the area under the curve with respect to ground (AUCg) or increase (AUCi) for the cortisol awakening response (CAR) and for diurnal cortisol profiles (DAY). OXTR DNA methylation was quantified using Sequenom EpiTYPER®. The number of stressful life events (p=0.032), EPDS score (p=0.007) and cortisol AUCgs at T2 (CAR: p=0.020; DAY: p=0.024) were negatively associated with OXTR DNA methylation. Our findings suggest that distinct prenatal adversities predict decreased DNA methylation in a gene that is relevant for childbirth, maternal behavior and wellbeing of mother and offspring. If a reduced OXTR methylation increases OXTR expression, our findings could suggest an epigenetic adaptation to an adverse early environment.
“Maternal Adversities during Pregnancy and Cord Blood Oxytocin Receptor (OXTR) DNA Methylation” by Eva Unternaehrer, Margarete Bolten, Irina Nast, Simon Staehli, Andrea H. Meyer, Emma Dempster, Dirk H. Hellhammer, Roselind Lieb, and Gunther Meinlschmidt in Social Cognitive and Affective Neuroscience. Published online April 22 2016 doi:10.1093/scan/nsw051
