title: Structural connectivity asymmetry in the neonatal brain.
abstract: Asymmetry of the neonatal brain is not yet understood at the level of structural connectivity. We utilized DTI deterministic tractography and structural network analysis based on graph theory to determine the pattern of structural connectivity asymmetry in 124 normal neonates. We tracted white matter axonal pathways characterizing interregional connections among brain regions and inferred asymmetry in left and right anatomical network properties. Our findings revealed that in neonates, small-world characteristics were exhibited, but did not differ between the two hemispheres, suggesting that neighboring brain regions connect tightly with each other, and that one region is only a few paths away from any other region within each hemisphere. Moreover, the neonatal brain showed greater structural efficiency in the left hemisphere than that in the right. In neonates, brain regions involved in motor, language, and memory functions play crucial roles in efficient communication in the left hemisphere, while brain regions involved in emotional processes play crucial roles in efficient communication in the right hemisphere. These findings suggest that even at birth, the topology of each cerebral hemisphere is organized in an efficient and compact manner that maps onto asymmetric functional specializations seen in adults, implying lateralized brain functions in infancy.
authors.affiliation: Department of Bioengineering, National University of Singapore, Singapore, Singapore.
authors.forename: Nagulan
authors.initials: N
authors.lastname: Ratnarajah
authors.affiliation: Singapore Institute for Clinical Sciences, the Agency for Science, Technology and Research, Singapore, Singapore.
authors.forename: Anne
authors.initials: A
authors.lastname: Rifkin-Graboi
authors.affiliation: Department of Diagnostic and Interventional Imaging, KK Women's and Children's Hospital (KKH), Singapore, Singapore.
authors.forename: Marielle V
authors.initials: MV
authors.lastname: Fortier
authors.affiliation: Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore, Singapore.
authors.forename: Yap Seng
authors.initials: YS
authors.lastname: Chong
authors.affiliation: Department of Maternal Fetal Medicine, KK Women's and Children's Hospital, Singapore, Singapore.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Kwek
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.
authors.forename: Seang-Mei
authors.initials: SM
authors.lastname: Saw
authors.affiliation: Medical Research Council Lifecourse Epidemiology Unit (University of Southampton), Southampton, UK; Southampton NIHR Nutrition Biomedical Research Centre, Southampton, UK.
authors.forename: Keith M
authors.initials: KM
authors.lastname: Godfrey
authors.affiliation: Liggins Institute, University of Auckland, Auckland, New Zealand.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Gluckman
authors.affiliation: Singapore Institute for Clinical Sciences, the Agency for Science, Technology and Research, Singapore, Singapore; Douglas Mental Health University Institute, McGill University, Montréal, Canada.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Meaney
authors.affiliation: Department of Bioengineering, National University of Singapore, Singapore, Singapore; Clinical Imaging Research Centre, National University of Singapore, Singapore, Singapore; Singapore Institute for Clinical Sciences, the Agency for Science, Technology and Research, Singapore, Singapore. Electronic address: bieqa@nus.edu.sg.
authors.forename: Anqi
authors.initials: A
authors.lastname: Qiu
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology*; D001931:Brain Mapping; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007231:Infant, Newborn; D008297:Male; D009434:Neural Pathways / Q000033:anatomy & histology*