Cerebral Blood Flow Changes in Boys and Girls After Puberty: Study

The brain blood flow varies in boys and girls after puberty, according to a study.

It is known that adolescents undergo physical developments and changes upon attaining sexual maturity. Besides having major physiological transformations, males and females develop different intellectual and emotional tendencies that influences their behavior and thinking.

 A new research by the Perelman School of Medicine at the University of Pennsylvania found notable differences in cerebral blood flow levels in young boys and girls before and after puberty that helps explain the psychological and behavioral distinctions in both genders.  The study examined the brain structure and activity of 922 individuals aged between eight and 22 using arterial spin labeled (ASL) MRI scans.

The scans revealed decrease in the levels of cerebral blood flow (CBF) in prepubescent children that drastically changes during puberty. After reaching puberty the levels increased for girls but reduced in boys. It was observed that the changes in CBF levels occur at age 16 in both boys and girls but that keeps declining with gradual aging process in males.

The researchers discovered the CBF level variations impacted the orbitofrontal cortex, a brain region that controls social behavior and emotions. These differences justify why women have better social intelligence than men and higher risk for depression and anxiety disorders. Furthermore, the study noted decreased CBF levels in males contribute to increased susceptibility for 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, study author and assistant professor in the Department of Psychiatry in the Perelman School of in a news release.

"Hopefully, one day such growth charts might allow us to identify abnormal brain development much earlier before it leads to major mental illness."

Past researches on brain postulate that puberty is important for drawing sex differences. They also suggest CBF levels change at the onset of puberty and this alerts the brain structure and is termed as cerebral perfusion.

"We know that adult women have higher blood flow than men, but it was not clear when that difference began, so we hypothesized that the gap between women and men would begin in adolescence and coincide with puberty," Satterthwaite said.

More information is available online in the journal the Proceeding of the National Academy of Sciences.