Emi Takahashi1, Rebecca D. Folkerth2, Rudolph Pienaar1, Albert M. Galaburda3, P. Ellen Grant1,4
1Department of Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA, United States; 2Department of Pathology, Childrens Hospital Boston, MA, United States; 3Department of Neurology, Beth Israel Deaconess Hospital, Harvard Medical School, Boston, MA, United States; 4Department of Radiology, Massachusetts General Hospital, Boston, MA, United States
Examination of the three-dimensional axonal pathways in the developing brain is key to understanding the formation of cerebral connectivity. Using high-angular resolution imaging (HARDI) tractography, we imaged developing cerebral fiber pathways in human fetal specimens ranged from 18 to 33 post-gestational weeks (W). We observed dominant radial pathways at 18-20W, and at later stages, emergence of short- and long-range cortico-cortical association pathways, subcortical U-fibers in specific brain regions. Although radial pathways still remained, they were less dominant at 33W. These results demonstrate that HARDI tractography can detect radial migration and emerging regional specification of connectivity during fetal development.