Structural development of frontal regions in late childhood and adolescence: a longitudinal MRI study

Abstract

Adolescence is an important developmental period between childhood and adulthood. During adolescence, significant structural changes take place in the brain and in particularly in the frontal cortex. The frontal cortex plays a crucial role in higher brain functions such as working memory, inhibition and selective attention. Therefore, accurate information about development of the frontal cortex helps to better understanding these functions. In this study, magnetic resonance imaging (MRI) was used to study structural changes in frontal gray and white matter volume during the transition from late childhood to adolescence (age 9 to 17), while taking sex differences and pubertal timing in account. Participants were 76 healthy twin pairs (46 % females). The results showed significant increases in frontal white matter volume and a volume reduction of frontal gray matter throughout late childhood and adolescence. Development of frontal regions appears to occur more rapidly from early adolescence to middle adolescence (ages 12 to 17) than from childhood to early adolescence (ages 9 to 12). Sex differences were found for structural development of frontal gray and white matter. Boys showed more increase of white matter volume throughout late childhood and adolescence, while girls showed more reduction of gray matter volume during this time. There was limited evidence that stage of puberty predicts brain maturation better than age. The study is unique in comparing volumetric changes of the frontal regions between twee periods and future studies need to replicate these findings.