Scientists have successfully mapped the cortical surface of a young human brain at impressively high resolution. The mapping, performed using high-quality magnetic resonance imaging (MRI) data, shows development in key regions of the brain from two months before birth to two months later. . The researchers believe this achievement will likely aid future studies of brain development and possibly a new approach to studying brain developmental conditions such as autism and schizophrenia. The cerebral cortex is a sheet of brain cells that surrounds the brain and is the most advanced and evolved region of the brain. It is larger in humans than in any other mammal and is responsible for functions such as language abilities and abstract reasoning.
From the last trimester of pregnancy to the first two years of life, dynamic development of the cerebral cortex is witnessed. The cortex tends to thicken during this period and rapidly grows in surface area by forming complex cortical folds. Researchers have linked disruptions in this cortical thickening and expansion to schizophrenia and autism. However, due to the lack of high-resolution maps of this period, scientists were unable to gain a deeper understanding of this developmental stage in fetal age.
For the new study, researchers from the University of North Carolina Health Care collected a set of 1,037 high-quality MRIs of infants from the third trimester of pregnancy to the age of 2. The scan data is then analyzed by the team using a computer-based image processing method. In this way, they divided the cortical surface into a virtual mesh of small circular regions and measured the rate of surface expansion for each of these regions.
The team was able to identify 18 distinct regions and found that they correlated well with their existing knowledge of cortical functions. Gang Li, PhD, Associate Professor of Radiology at the UNC School of Medicine, said: “All of these regions show significant expansion in surface area during this development period, with each region having a separate religion. Li is the senior author of the study published on Proceedings of the National Academy of Sciences.
The map shows that each region of the cerebral cortex has the same developmental pathway as its region in the opposite hemisphere. In addition, the team was also able to detect sex differences during development. According to Li, the mapping has provided a new perspective on brain development.
Now, the team is aiming to expand the network and use the approach to study scan data sets of children with autism or other neurodevelopmental conditions.