The researchers discovered that the back regions of the brain, which control vision and sensory integration, grew significantly faster than the prefrontal region, which controls abstract reasoning. In addition, the type of brain tissue called gray matter, which contains most of the neurons or nerve cells, grew much more robustly than another type of tissue called white matter, which contains the connecting fibers between neurons in different brain regions. Gray matter size grew by roughly 40 percent in the first months after birth, while white matter grew very little.
"This pattern of brain growth in newborns has not been described before," said Dr. John Gilmore, a professor of psychiatry in the UNC School of Medicine and lead author of the study. "An enormous amount of brain development takes place between birth and late childhood that we know very little about. This study gives us the first glimpse into understanding that," he said.
The study is the first to systematically obtain very high resolution magnetic resonance imaging (MRI) scans on a large group of newborns. The results appear in the Feb. 7 issue of the Journal of Neuroscience. Funding was provided by the National Institute of Mental Health and the UNC School of Medicine.
Another key finding by the UNC team is that boys, on average, are born with brains about 10 percent larger than the brains of girls. This is consistent with the pattern seen in adults, Gilmore said -- men typically have a brain about 10 percent larger than that seen in women.
"What's interesting about this is it shows that the gender difference in brain size arises during prenatal brain developm
Source:University of North Carolina School of Medicine