Age-related Volumetric Changes of Prefrontal Gray and White Matter from Healthy Infancy to Adulthood

Despite increasing evidence of the role of the prefrontal cortex in providing the neural substrate of higher cognitive function and neurodevelopment, little is known about neuroanatomic changes in prefrontal subregions during human development. In this prospective study, we evaluated prefrontal gray and white matter volume in healthy infants, children, adolescents, and adults. Magnetic resonance imaging was performed on 107 healthy people aged one month to 25 years. Gray and white matter volumes of the dorsolateral, dorsomedial, orbitolateral, and orbitomedial prefrontal cortex were quantified. The results indicated that both children and early adolescents had larger dorsolateral gray matter volume than infants and adults. Dorsolateral white matter volumes in children, early adolescents, and late adolescents were larger than those of infants. Dorsomedial white matter volumes of early adolescents, late adolescents, and adults were also larger than those of infants. There was no significant difference among age groups in both orbital prefrontal regions. These findings suggest that there are two important stages of structural change of the prefrontal cortex from infancy to young adulthood. First, growth spurts of both gray matter and white matter during the first 2 years of life have been shown to occur specifically in the dorsal prefrontal cortex. Second, gray matter changes have been shown to be regionally specific, with changes in the dorsal, but not orbital, prefrontal cortex peaking during late childhood or early adolescence. Thus, developmental differences within sectors of the prefrontal lobe and evidence of neural pruning and myelination may be useful in understanding the mechanisms of neurodevelopmental disorders.