Summary: Researchers found sex differences and developmental changes in the brain’s white matter in infants and five-year-old children.
New research published in Human Brain Mapping reveals sex differences and developmental changes in the brain’s white matter—which provides communication between different parts of the brain—in healthy, typically developing infants and 5-year-olds.
The results, which highlighted sexual dimorphism in brain structure during development with significant detectable differences in multiple regions at the age of 5 years, agree with prior studies showing earlier brain development in females.
Also, changes in white matter asymmetry patterns occurred during early childhood, and in 5-year-olds the pattern already resembled adult-like patterns.
“We observed sex differences in white matter microstructure of 5-year-olds that may, in light of previous literature, be a transient feature during brain development,” said corresponding author Venla Kumpulainen, MSc, MD, of the University of Turku, in Finland.
“More investigations are required to examine whether these findings associate with developmental cognitive and emotional differences between girls and boys.”
About this neurodevelopment research news
Author: Sara Henning-Stout
Contact: Sara Henning-Stout – Wiley
Image: The image is in the public domain
Original Research: Open access.
“Sex differences, asymmetry and age-related white matter development in infants and 5-year-olds as assessed with Tract-Based Spatial Statistics” by Venla Kumpulainenet al. Human Brain Mapping
Sex differences, asymmetry and age-related white matter development in infants and 5-year-olds as assessed with Tract-Based Spatial Statistics
The rapid white matter (WM) maturation of first years of life is followed by slower yet long-lasting development, accompanied by learning of more elaborate skills. By the age of 5 years, behavioural and cognitive differences between females and males, and functions associated with brain lateralization such as language skills are appearing.
Diffusion tensor imaging (DTI) can be used to quantify fractional anisotropy (FA) within the WM and increasing values correspond to advancing brain development. To investigate the normal features of WM development during early childhood, we gathered a DTI data set of 166 healthy infants (mean 3.8 wk, range 2–5 wk; 89 males; born on gestational week 36 or later) and 144 healthy children (mean 5.4 years, range 5.1–5.8 years; 76 males).
The sex differences, lateralization patterns and age-dependent changes were examined using tract-based spatial statistics (TBSS).
In 5-year-olds, females showed higher FA in wide-spread regions in the posterior and the temporal WM and more so in the right hemisphere, while sex differences were not detected in infants. Gestational age showed stronger association with FA values compared to age after birth in infants.
Additionally, child age at scan associated positively with FA around the age of 5 years in the body of corpus callosum, the connections of which are important especially for sensory and motor functions.
Lastly, asymmetry of WM microstructure was detected already in infants, yet significant changes in lateralization pattern seem to occur during early childhood, and in 5-year-olds the pattern already resembles adult-like WM asymmetry.