title: Spatiotemporal patterns of cortical fiber density in developing infants, and their relationship with cortical thickness.
abstract: The intrinsic relationship between the convoluted cortical folding and the underlying complex whiter matter fiber connections has received increasing attention in current neuroscience studies. Recently, the axonal pushing hypothesis of cortical folding has been proposed to explain the finding that the axonal fibers (derived from diffusion tensor images) connecting to gyri are significantly denser than those connecting to sulci in both adult human and non-human primate brains. However, it is still unclear about the spatiotemporal patterns of the fiber density on the cortical surface of the developing infant brains from birth to 2 years of age, which is the most dynamic phase of postnatal brain development. In this paper, for the first time, we systemically characterized the spatial distributions and longitudinal developmental trajectories of the cortical fiber density in the first 2 postnatal years, via joint analysis of longitudinal structural and diffusion tensor imaging from 33 healthy infants. We found that the cortical fiber density increases dramatically in the first year and then keeps relatively stable in the second year. Moreover, we revealed that the cortical fiber density on gyral regions was significantly higher at 0, 1, and 2 years of age than that on sulcal regions in the frontal, temporal, and parietal lobes. Meanwhile, the cortical fiber density was strongly positively correlated with cortical thickness at several three-hinge junction regions of gyri. These results significantly advanced our understanding of the intrinsic relationship between the cortical folding, cortical thickness and axonal wiring during early postnatal stages.
authors.affiliation: Department of Radiology and BRIC, University of North Carolina at Chapel Hill, North Carolina.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, Georgia.
authors.forename: Tianming
authors.initials: T
authors.lastname: Liu
authors.affiliation: Department of Biomedical Engineering, The Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Shenzhen University, Shenzhen, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Ni
authors.affiliation: Department of Radiology and BRIC, University of North Carolina at Chapel Hill, North Carolina.
authors.forename: Weili
authors.initials: W
authors.lastname: Lin
authors.affiliation: Department of Psychiatry, University of North Carolina at Chapel Hill, North Carolina.
authors.forename: John H
authors.initials: JH
authors.lastname: Gilmore
authors.affiliation: Department of Radiology and BRIC, University of North Carolina at Chapel Hill, North Carolina.|Department of Brain and Cognitive Engineering, Korea University, Seoul, Republic of Korea.
authors.forename: Dinggang
authors.initials: D
authors.lastname: Shen
mesh_terms: D000367:Age Factors; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000196:embryology / Q000254:growth & development; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005333:Fetus; D007839:Functional Laterality / Q000502:physiology; D005865:Gestational Age; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009434:Neural Pathways / Q000033:anatomy & histology / Q000196:embryology / Q000254:growth & development; D011247:Pregnancy
keywords: cortical folding; cortical surface; cortical thickness; fiber density; infant; longitudinal development