Cerebral Blood Flow Changes after Puberty, Study Finds
Puberty, which occurs during early adolescence, changes multiple parts of one's body. In a new study, a research team from the Perelman School of Medicine at the University of Pennsylvania examined the effects of puberty specifically on cerebral blood flow (CBF). They found that after puberty, CBF levels start to change differently for girls and boys.
For this study, the researchers recruited 922 children and young adults between the ages of eight and 22 who were a part of the Philadelphia Neurodevelopment Cohort, which is a National Institute of Mental Health-funded collaboration between the University of Pennsylvania Brain Behavior Laboratory and the Center for Applied Genomics at the Children's Hospital of Philadelphia. The team used arterial spin labeled (ASL) magnetic resonance imaging (MRI) in order to analyze the participants' brain.
They found differences in the CBF levels in males and females after puberty. Before puberty, both genders had similar levels of CBF. However, at the age of 16, CBF levels started to increase only in girls. By the end of adolescences, CBF levels were still higher in females than they were in males. The researchers noted that the differences were most obvious in parts of the brain that were tied to social behaviors and emotional regulation.
The team reasoned that varying CBF levels in both sexes could explain why females perform better on social cognition tasks. Furthermore, these elevated levels could also explain why women are more prone to depression and anxiety disorders where as men have a greater risk of flat affect and schizophrenia.
"These findings help us understand normal neurodevelopment and could be a step towards creating normal 'growth charts' for brain development in kids. These results also show what every parent knows: boys and girls grow differently. This applies to the brain as well," said Theodore D. Satterthwaite, MD, MA, assistant professor in the Department of Psychiatry in the Perelman School of Medicine at the University of Pennsylvania. "Hopefully, one day such growth charts might allow us to identify abnormal brain development much earlier before it leads to major mental illness."
The study was published in the Proceedings of the National Academy of Sciences (PNAS).