title: Between-network connectivity occurs in brain regions lacking layer IV input.
abstract: To better understand the cortical circuitry underlying connectivity between large-scale neural networks, we develop a novel, data-driven approach to identify potential integration subregions. Between-network connectivity (BNC) associated with any anatomical region is the amount of connectivity between that point and all large-scale networks, as measured using simple and multiple correlations. It is straightforward to calculate and applicable to functional networks identified using independent components analysis. We calculated BNC for all fMRI voxels within the brain and compared the results to known regional cytoarchitectural patterns. Based on previous observations of the relationship between macroscopic connectivity and microscopic cytoarchitecture, we predicted that areas with high BNC will be located in paralimbic subregions with an undifferentiated laminar structure. Results suggest that the anterior insula and dorsal posterior cingulate cortices play prominent roles in information integration. Cytoarchitecturely, these areas show agranular or dysgranular cytologies with absent or disrupted cortical layer IV. Since layer IV is the primary recipient of feed-forward thalamocortical connections, and due to the exclusive nature of driving connections to this layer, we suggest that the absence of cortical layer IV might allow for information to be exchanged across networks, and is an organizational characteristic of brain-subregions serving as inter-network communication hubs.
authors.affiliation: Department of Psychiatry, University of Colorado Anschutz Medical Campus, Bldg. 500, Mail Stop F546, 13001 East 17th Place, Aurora, CO, 80045, USA.
authors.forename: Korey P
authors.initials: KP
authors.lastname: Wylie
authors.affiliation: Department of Psychiatry, University of Colorado Anschutz Medical Campus, Bldg. 500, Mail Stop F546, 13001 East 17th Place, Aurora, CO, 80045, USA.
authors.forename: Eugene
authors.initials: E
authors.lastname: Kronberg
authors.affiliation: Department of Psychiatry, University of Colorado Anschutz Medical Campus, Bldg. 500, Mail Stop F546, 13001 East 17th Place, Aurora, CO, 80045, USA.
authors.forename: Keeran
authors.initials: K
authors.lastname: Maharajh
authors.affiliation: Department of Psychiatry, University of Colorado Anschutz Medical Campus, Bldg. 500, Mail Stop F546, 13001 East 17th Place, Aurora, CO, 80045, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Smucny
authors.affiliation: Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Mail Stop C263, 12348 E Montview Blvd., Aurora, CO, 80045, USA.
authors.forename: Marc-Andre
authors.initials: MA
authors.lastname: Cornier
authors.affiliation: Department of Psychiatry, University of Colorado Anschutz Medical Campus, Bldg. 500, Mail Stop F546, 13001 East 17th Place, Aurora, CO, 80045, USA; Research Service, Denver VA Medical Center, Research Service (151), Eastern Colorado Health System, 1055 Clermont St., Denver, CO, 80220, USA. Electronic address: Jason.Tregellas@UCDenver.edu.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Tregellas
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D002540:Cerebral Cortex / Q000166:cytology* / Q000502:physiology*; D005260:Female; D006801:Humans; D008032:Limbic System / Q000166:cytology / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009415:Nerve Net / Q000166:cytology* / Q000502:physiology*; D009434:Neural Pathways / Q000166:cytology / Q000502:physiology
keywords: Cytology; Independent components analysis; Paralimbic; Resting state; fMRI