Microstructural and functional gradients are increasingly dissociated in transmodal cortices

• Published in: PLoS biology Vol. 17; no. 5; p. e3000284
• Main Authors: Paquola, Casey, Vos De Wael, Reinder, Wagstyl, Konrad, Bethlehem, Richard A. I., Hong, Seok-Jun, Seidlitz, Jakob, Bullmore, Edward T., Evans, Alan C., Misic, Bratislav, Margulies, Daniel S., Smallwood, Jonathan, Bernhardt, Boris C.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 20.05.2019; Public Library of Science (PLoS)
• Subjects: Adult; Aged; Biology and Life Sciences; Brain; Brain architecture; Cerebral Cortex - anatomy & histology; Cerebral Cortex - physiology; Cognition; Cognitive ability; Cognitive science; Columns (structural); Cortex; Decoding; Decoupling; Differentiation; Female; Functionally gradient materials; Humans; Image reconstruction; Magnetic Resonance Imaging; Male; Medical imaging; Medicine and Health Sciences; Microstructure; Myelin; Neural circuitry; Neuroimaging; Neuroscience; Neurosciences; NMR; Nuclear magnetic resonance; Physical Sciences; Physiological aspects; Psychiatry; Research and Analysis Methods; Social interactions; Software; Structure-function relationships; United Kingdom > UK; Canada; Montreal Quebec Canada
• ISSN: 1545-7885; 1544-9173; 1545-7885
• DOI: 10.1371/journal.pbio.3000284

While the role of cortical microstructure in organising neural function is well established, it remains unclear how structural constraints can give rise to more flexible elements of cognition. While nonhuman primate research has demonstrated a close structure-function correspondence, the relationship between microstructure and function remains poorly understood in humans, in part because of the reliance on post mortem analyses, which cannot be directly related to functional data. To overcome this barrier, we developed a novel approach to model the similarity of microstructural profiles sampled in the direction of cortical columns. Our approach was initially formulated based on an ultra-high-resolution 3D histological reconstruction of an entire human brain and then translated to myelin-sensitive magnetic resonance imaging (MRI) data in a large cohort of healthy adults. This novel method identified a system-level gradient of microstructural differentiation traversing from primary sensory to limbic regions that followed shifts in laminar differentiation and cytoarchitectural complexity. Importantly, while microstructural and functional gradients described a similar hierarchy, they became increasingly dissociated in transmodal default mode and fronto-parietal networks. Meta-analytic decoding of these topographic dissociations highlighted involvement in higher-level aspects of cognition, such as cognitive control and social cognition. Our findings demonstrate a relative decoupling of macroscale functional from microstructural gradients in transmodal regions, which likely contributes to the flexible role these regions play in human cognition.