title: Subcomponents and connectivity of the superior longitudinal fasciculus in the human brain.
abstract: The subcomponents of the human superior longitudinal fasciculus (SLF) are disputed. The objective of this study was to investigate the segments, connectivity and asymmetry of the SLF. We performed high angular diffusion spectrum imaging (DSI) analysis on ten healthy adults. We also conducted fiber tracking on a 30-subject DSI template (CMU-30) and 488-subject template from the Human Connectome Project (HCP-488). In addition, five normal brains obtained at autopsy were microdissected. Based on tractography and microdissection results, we show that the human SLF differs significantly from that of monkey. The fibers corresponding to SLF-I found in 6 out of 20 hemispheres proved to be part of the cingulum fiber system in all cases and confirmed on both DSI and HCP-488 template. The most common patterns of connectivity bilaterally were as follows: from angular gyrus to caudal middle frontal gyrus and dorsal precentral gyrus representing SLF-II (or dorsal SLF), and from supramarginal gyrus to ventral precentral gyrus and pars opercularis to form SLF-III (or ventral SLF). Some connectivity features were, however, clearly asymmetric. Thus, we identified a strong asymmetry of the dorsal SLF (SLF-II), where the connectivity between the supramarginal gyrus with the dorsal precentral gyrus and the caudal middle frontal gyrus was only present in the left hemisphere. Contrarily, the ventral SLF (SLF-III) showed fairly constant connectivity with pars triangularis only in the right hemisphere. The results provide a novel neuroanatomy of the SLF that may help to better understand its functional role in the human brain.
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh School of Medicine, 200 Lothrop Street, PUH B400, Pittsburgh, PA, 15213, USA.|Department of Neurological Surgery, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China.
authors.forename: Xuhui
authors.initials: X
authors.lastname: Wang
authors.affiliation: Learning Research and Development Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA.
authors.forename: Sudhir
authors.initials: S
authors.lastname: Pathak
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh School of Medicine, 200 Lothrop Street, PUH B400, Pittsburgh, PA, 15213, USA.
authors.forename: Lucia
authors.initials: L
authors.lastname: Stefaneanu
authors.affiliation: Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.
authors.forename: Fang-Cheng
authors.initials: FC
authors.lastname: Yeh
authors.affiliation: Department of Neurological Surgery, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China.
authors.forename: Shiting
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh School of Medicine, 200 Lothrop Street, PUH B400, Pittsburgh, PA, 15213, USA. fernandezmirandajc@upmc.edu.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Fernandez-Miranda
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology*; D063132:Connectome; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009434:Neural Pathways / Q000033:anatomy & histology; D066127:White Matter / Q000033:anatomy & histology*; D055815:Young Adult
keywords: Arcuate fasciculus; Fiber tractography; Fiber tracts; Microdissection; Superior longitudinal fasciculus; White matter