In a groundbreaking study, scientists have found striking evidence that brain function differences between the left and right hemispheres are linked to a person’s birth size as well as the weight of the placenta. The research, conducted at the University of Southampton and Southampton General Hospital, could lead to a better understanding of mental health problems.
The findings revealed that children who were small at birth, but with relatively large placentas, had more activity on the right side of their brains than the left. This type of brain activity has been linked to mood disorders such as depression.
There is a growing body of evidence showing that a negative fetal environment (indicated by smaller birth size and larger placental size) can create long-term changes in brain function.
“The way we grow before birth is influenced by many things including what our mothers eat during pregnancy and how much stress they are experiencing. This can have long-lasting implications for our mental and physical health in later life,” said study leader Dr. Alexander Jones, an epidemiologist.
“This is the first time we’ve been able to link growth before birth to brain activity many years later. We hope this research can begin to shed new light on why certain people are more prone to diseases such as depression.”
For the study, 140 children from Southampton, between the ages of eight and nine, were tested for changes in blood flow to the brain in response to increased brain activity, revealing variations in the activity of each side. Jones analyzed the subtle fluctuations in the temperature of the tympanic membrane in each ear, which are a marker of blood flow into different areas of the brain.
Disproportionate growth between the fetus and placenta is believed to occur during stressful pregnancies or from a lack of nutrition. Past research has found a link between this pattern of growth and other problems, including hypertension and a greater physical response to stress in later life.
The study is published in the online science journal, PLoS ONE.
Source: University of Southampton