The cerebral cortex of the developing human brain mapped using high-quality MRI scan data

Scientists have successfully mapped the surface of the cerebral cortex of a young human brain in impressively high resolution. The mapping, done using high-quality magnetic resonance imaging (MRI) data, shows development in key areas of the brain from two months before an individual’s birth to two months after. The researchers believe that this breakthrough will aid future research on brain development and serve as a new approach to studying brain developmental conditions such as autism and schizophrenia. The cerebral cortex is a sheet of brain cells that wraps around the brain and is the most evolved and advanced area of ​​the brain. It is larger in humans than in other mammals and is responsible for functions such as language ability and abstract reasoning.

From the third trimester of pregnancy to the first two years of life, dynamic cortical development is witnessed. During this period the cortex thickens and grows rapidly in terms of surface area forming complex cortical folds. Researchers have linked disruptions in this cortical thickening and expansion to schizophrenia and autism. But, due to a lack of high-resolution mapping of this period, scientists have been unable to gain a deeper understanding of this developmental stage in the fetus-to-toddler age.

In the new study, researchers at the University of North Carolina Health Care collected a set of 1,037 high-quality MRIs from the third trimester to two years of age. The scan data was then analyzed by the team using computer-based image processing methods. With this, they divided the cortical surface into a virtual mesh consisting of small spherical regions and calculated the amount of surface expansion for each of these regions.

The team was able to define 18 distinct regions and found that they correlated well with their existing knowledge of functional organs of the cortex. “All of these regions show a dramatic expansion in surface area within this developmental framework, with each region having a different trajectory,” said Gang Li, PhD, associate professor of radiology at the UNC School of Medicine. Lee is the senior author of the study published in Proceedings of the National Academy of Sciences,

The map showed that each part of the cortex followed the same developmental path as its counterpart in the opposite hemisphere. In addition, the team could also find gender differences in development. According to Lee, the mapping has provided a new insight into brain development.

Now, the team’s goal is to widen the net and use the approach to scan datasets of children with autism or other neurodevelopmental conditions.