title: Asymmetry of White Matter Pathways in Developing Human Brains.
abstract: Little is known about the emergence of structural asymmetry of white matter tracts during early brain development. We examined whether and when asymmetry in diffusion parameters of limbic and association white matter pathways emerged in humans in 23 brains ranging from 15 gestational weeks (GW) up to 3 years of age (11 ex vivo and 12 in vivo cases) using high-angular resolution diffusion imaging tractography. Age-related development of laterality was not observed in a limbic connectional pathway (cingulum bundle or fornix). Among the studied cortico-cortical association pathways (inferior longitudinal fasciculus [ILF], inferior fronto-occipital fasciculus, and arcuate fasciculus), only the ILF showed development of age-related laterality emerging as early as the second trimester. Comparisons of ages older and younger than 40 GW revealed a leftward asymmetry in the cingulum bundle volume and a rightward asymmetry in apparent diffusion coefficient and leftward asymmetry in fractional anisotropy in the ILF in ages older than 40 GW. These results suggest that morphometric asymmetry in cortical areas precedes the emergence of white matter pathway asymmetry. Future correlative studies will investigate whether such asymmetry is anatomically/genetically driven or associated with functional stimulation.
authors.affiliation: Department of Medicine, Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Current address: Department of Radiology, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: Jae W
authors.initials: JW
authors.lastname: Song
authors.affiliation: Clinical Research Center, Boston Children's Hospital, Boston, MA 02115, USA.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Mitchell
authors.affiliation: Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA Current address: Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.
authors.forename: James
authors.initials: J
authors.lastname: Kolasinski
authors.affiliation: Department of Medicine, Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
authors.forename: P
authors.initials: P
authors.lastname: Ellen Grant
authors.affiliation: Department of Neurology, Division of Cognitive Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Albert M
authors.initials: AM
authors.lastname: Galaburda
authors.affiliation: Department of Medicine, Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
authors.forename: Emi
authors.initials: E
authors.lastname: Takahashi
mesh_terms: D000367:Age Factors; D001921:Brain / Q000033:anatomy & histology / Q000196:embryology / Q000254:growth & development; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005333:Fetus / Q000033:anatomy & histology; D007839:Functional Laterality / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D066127:White Matter / Q000033:anatomy & histology / Q000196:embryology / Q000254:growth & development
keywords: asymmetry; brain; development; diffusion imaging; human; tractography; white matter