The cortical wiring scheme of hierarchical information processing

The vast net of fibres within and underneath the cortical mantle is optimised to support the convergence of different levels of brain organisation, specifically through linking cellular and architectural features of different cortical areas to give rise to more integrated neural function. Leveraging multimodal neuroimaging and machine learning techniques, we identified a novel manifold space that is governed by geometric, microstructural, and connectional aspects of cortico-cortical wiring. Principal dimensions of this manifold recapitulated established sensory-limbic and anterior-posterior gradients of brain organisation, and were found to reflect neural and glial gradients of cytoarchitectural organisation and gene expression. Manifold features were accurate in predicting cortico-cortical functional interactions derived from resting-state functional neuroimaging. Furthermore, application of this approach to a group of neurological patients, who underwent intracerebral encephalographic recordings, established that manifold features also explained the direction of information flow between different cortical areas. These results advance our understanding of how cell-specific neurobiological gradients produce a hierarchical cortical wiring scheme that is concordant with increasing functional sophistication of human brain organisation.