The womb environment may play a significant role in a teenager’s brain structure, according to a new study published in the journal Human Brain Mapping.
For the study, researchers followed pairs of genetically identical twins from birth into their teenage years. They discovered that the in utero environment is linked to the development of the cortex, a part of the brain that has many functions including emotional regulation and cognition.
Since twins share a prenatal environment, the fetuses have many environmental characteristics in common, such as gestational age and the mother’s lifestyle. However, when they’re born, they can still differ in birth weight.
Previous research has found that birth weight is a predictor of how the brain will develop. In the new study, the research team found that variations in birth weight were related to differences in the structure of the cortex, an association that cannot be explained by the genetic code in this case.
“Since the twins in our study are genetically identical, this difference in birth weight must be due to specific factors acting in utero,” said Dr. Linda Booij, associate professor of psychology in Concordia University’s Faculty of Arts and Science and a researcher at Sainte-Justine Hospital Research Center in Montreal, Canada. “For instance, one fetus might have a better placement in the womb or better access to nutrition.”
In a subgroup of 52 pairs of twins, the researchers conducted brain imaging to study the structure of the cortex. They also collected DNA to study epigenetics, changes in the activity of how a gene is expressed through environmental experiences rather than alteration of the genetic code itself.
“By the time our participants had reached teenagehood, differences in brain volume were present in the cortex, which is where much of our regulation of emotions and cognitive processes takes place,” said Booij, who is now also affiliated with Concordia’s PERFORM Centre.
“Interestingly, twins with large differences in birth weight and cortical structure also had epigenetic differences. This means that what happens in utero may affect a person’s brain development by the time they reach their teen years, and that epigenetic processes may play a role in this relationship.”
Booij and her colleagues hope that this study will shed more light on the specific role of early environmental influences on brain development, gene expression and emotional regulation.
“Our results will hopefully contribute to a better understanding of possible ways to foster optimal early brain development and prevent emotional and cognitive problems in youth.”
Source: Concordia University