title: The geometric structure of the brain fiber pathways.
abstract: The structure of the brain as a product of morphogenesis is difficult to reconcile with the observed complexity of cerebral connectivity. We therefore analyzed relationships of adjacency and crossing between cerebral fiber pathways in four nonhuman primate species and in humans by using diffusion magnetic resonance imaging. The cerebral fiber pathways formed a rectilinear three-dimensional grid continuous with the three principal axes of development. Cortico-cortical pathways formed parallel sheets of interwoven paths in the longitudinal and medio-lateral axes, in which major pathways were local condensations. Cross-species homology was strong and showed emergence of complex gyral connectivity by continuous elaboration of this grid structure. This architecture naturally supports functional spatio-temporal coherence, developmental path-finding, and incremental rewiring with correlated adaptation of structure and function in cerebral plasticity and evolution.
authors.affiliation: Department of Radiology, Massachusetts General Hospital (MGH), Harvard Medical School and the MGH/Massachussetts Institute of Technology, Charlestown, MA 02129, USA. van@nmr.mgh.harvard.edu
authors.forename: Van J
authors.initials: VJ
authors.lastname: Wedeen
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Rosene
authors.forename: Ruopeng
authors.initials: R
authors.lastname: Wang
authors.forename: Guangping
authors.initials: G
authors.lastname: Dai
authors.forename: Farzad
authors.initials: F
authors.lastname: Mortazavi
authors.forename: Patric
authors.initials: P
authors.lastname: Hagmann
authors.forename: Jon H
authors.initials: JH
authors.lastname: Kaas
authors.forename: Wen-Yih I
authors.initials: WY
authors.lastname: Tseng
mesh_terms: D000818:Animals; D016645:Aotidae; D001369:Axons / Q000648:ultrastructure; D005075:Biological Evolution; D001931:Brain Mapping; D002144:Callithrix; D002540:Cerebral Cortex / Q000033:anatomy & histology* / Q000196:embryology / Q000648:ultrastructure; D038524:Diffusion Magnetic Resonance Imaging; D005701:Galago; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008253:Macaca mulatta; D009412:Nerve Fibers; D009434:Neural Pathways / Q000033:anatomy & histology* / Q000196:embryology / Q000648:ultrastructure; D016548:Prosencephalon / Q000033:anatomy & histology / Q000648:ultrastructure; D013045:Species Specificity