Regional Gray Matter Growth, Sexual Dimorphism, and Cerebral Asymmetry in the Neonatal Brain

Abstract

Although there has been recent interest in the study of childhood and adolescent brain development, very little is known about normal brain development in the first few months of life. In older children, there are regional differences in cortical gray matter development, whereas cortical gray and white matter growth after birth has not been studied to a great extent. The adult human brain is also characterized by cerebral asymmetries and sexual dimorphisms, although very little is known about how these asymmetries and dimorphisms develop. We used magnetic resonance imaging and an automatic segmentation methodology to study brain structure in 74 neonates in the first few weeks after birth. We found robust cortical gray matter growth compared with white matter growth, with occipital regions growing much faster than prefrontal regions. Sexual dimorphism is present at birth, with males having larger total brain cortical gray and white matter volumes than females. In contrast to adults and older children, the left hemisphere is larger than the right hemisphere, and the normal pattern of fronto-occipital asymmetry described in older children and adults is not present. Regional differences in cortical gray matter growth are likely related to differential maturation of sensory and motor systems compared with prefrontal executive function after birth. These findings also indicate that whereas some adult patterns of sexual dimorphism and cerebral asymmetries are present at birth, others develop after birth.

Gender Differences in Language and Motor-Related Fibers in a Population of Healthy Preterm Neonates at Term-Equivalent Age: A Diffusion Tensor and Probabilistic Tractography Study

“…We found, like other studies in neonates 19 and in adults, 14,23 that at term-equivalent age healthy preterm male neonates had larger TBV than females. The original findings of our study were that female neonates had larger relative tract volumes bilaterally in the parieto-temporal SLF and in the left CST, with a trend toward lower MD and Ќ in the left parietotemporal SLF after Bonferroni correction.…”

“…[13][14][15] Interestingly, these differences are already present in children [16][17][18] and neonates. 19 In adults, the regional volumetric gray matter distribution patterns tend to show an enlargement in females when adjusting for brain size. 14,[20][21][22][23][24] In children, findings of sex differences in relative gray matter volume have shown enlargement in females, most prominently in the temporal and parietal cortices.…”

Synaptophysin and postsynaptic density protein 95 in the human prefrontal cortex from mid-gestation into early adulthood

“…Author manuscript; available in PMC 2008 November 9. Sowell et al 2002;Gilmore et al 2007). Specifically, the cortical gray matter volume, particularly the frontal and parietal regions, shows a volumetric decrease during this time period while white matter volume continues to increase (Giedd et al 1999;Sowell et al 2002).…”

The Urban Child Institute CANDLE Study: Methodological Overview and Baseline Sample Description

“…It is during these years that the brain undergoes its most dramatic growth, setting the stage for socialization and emotional development. We also know that a child's brain doubles in size in the first year and, by age 3, reaches 80 percent of its adult volume (Gilmore et al, 2007;Nowakowski, 2006).…”