Abstract
Gray matter connectivity can be described in terms of its topographical organization, but the differential role of white matter connections underlying that organization is often unknown. In this study, we propose a method for unveiling principles of organization of both gray and white matter based on white matter connectivity as assessed using diffusion magnetic ressonance imaging (MRI) tractography with spectral embedding gradient mapping. A key feature of the proposed approach is its capacity to project the individual connectivity gradients it reveals back onto its input data in the form of projection images, allowing one to assess the contributions of specific white matter tracts to the observed gradients. We demonstrate the ability of our proposed pipeline to identify connectivity gradients in prefrontal and occipital gray matter. Finally, leveraging the use of tractography, we demonstrate that it is possible to observe gradients within the white matter bundles themselves. Together, the proposed framework presents a generalized way to assess both the topographical organization of structural brain connectivity and the anatomical features driving it.
Highlights
The function of a given brain region is defined by its internal aspects— cytoarchitectonical and cytochemical features and by the afferent and efferent projections it has from and to other parts of the brain, respectively (Mars, Passingham, & Jbabdi, 2018; Passingham, Stephan, & Kötter, 2002; Saygin et al, 2016)
We investigated the potential of the connectopic mapping approach to unravel overlapping modes of brain organization using diffusion magnetic ressonance imaging (MRI) tractography data
We demonstrated that biologically relevant, overlapping, robust, and individual connectopies can be mapped using Laplacian Eigenmaps (LE) of Diffusion MRI tractography data
Summary
The function of a given brain region is defined by its internal aspects— cytoarchitectonical and cytochemical features and by the afferent and efferent projections it has from and to other parts of the brain, respectively (Mars, Passingham, & Jbabdi, 2018; Passingham, Stephan, & Kötter, 2002; Saygin et al, 2016). These connectivity patterns give rise to networks and the dynamic balance between these networks characterizes function and, behavior (Jbabdi, Sotiropoulos, & Behrens, 2013; Peer, Nitzan, Bick, Levin, & Arzy, 2017). Global gradients exist across species and reflect a hierarchies in the cognitive landscape, with multimodal
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
