title: Superficially located white matter structures commonly seen in the human and the macaque brain with diffusion tensor imaging.
abstract: The white matter of the brain consists of fiber tracts that connect different regions of the brain. Among these tracts, the intrahemispheric cortico-cortical connections are called association fibers. The U-fibers are short association fibers that connect adjacent gyri. These fibers were thought to work as part of the cortico-cortical networks to execute associative brain functions. However, their anatomy and functions have not been documented in detail for the human brain. In past studies, U-fibers have been characterized in the human brain with diffusion tensor imaging (DTI). However, the validity of such findings remains unclear. In this study, DTI of the macaque brain was performed, and the anatomy of U-fibers was compared with that of the human brain reported in a previous study. The macaque brain was chosen because it is the most commonly used animal model for exploring cognitive functions and the U-fibers of the macaque brain have been already identified by axonal tracing studies, which makes it an ideal system for confirming the DTI findings. Ten U-fibers found in the macaque brain were also identified in the human brain, with a similar organization and topology. The delineation of these species-conserved white matter structures may provide new options for understanding brain anatomy and function.
authors.affiliation: The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA. koishi@mri.hju.edu
authors.forename: Kenichi
authors.initials: K
authors.lastname: Oishi
authors.forename: Hao
authors.initials: H
authors.lastname: Huang
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshioka
authors.forename: Sarah H
authors.initials: SH
authors.lastname: Ying
authors.forename: David S
authors.initials: DS
authors.lastname: Zee
authors.forename: Karl
authors.initials: K
authors.lastname: Zilles
authors.forename: Katrin
authors.initials: K
authors.lastname: Amunts
authors.forename: Roger
authors.initials: R
authors.lastname: Woods
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Toga
authors.forename: G Bruce
authors.initials: GB
authors.lastname: Pike
authors.forename: Pedro
authors.initials: P
authors.lastname: Rosa-Neto
authors.forename: Alan C
authors.initials: AC
authors.lastname: Evans
authors.forename: Peter C M
authors.initials: PC
authors.lastname: van Zijl
authors.forename: John C
authors.initials: JC
authors.lastname: Mazziotta
authors.forename: Susumu
authors.initials: S
authors.lastname: Mori
mesh_terms: D000818:Animals; D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D006801:Humans; D008253:Macaca mulatta; D009413:Nerve Fibers, Myelinated / Q000502:physiology*; D013045:Species Specificity