Cortical Folding Patterns and Predicting Cytoarchitecture

Abstract

The human cerebral cortex is made up of a mosaic of structural areas, frequently referred to as Brodmann areas (BAs). Despite the widespread use of cortical folding patterns to perform ad hoc estimations of the locations of the BAs, little is understood regarding 1) how variable the position of a given BA is with respect to the folds, 2) whether the location of some BAs is more variable than others, and 3) whether the variability is related to the level of a BA in a putative cortical hierarchy. We use whole-brain histology of 10 postmortem human brains and surface-based analysis to test how well the folds predict the locations of the BAs. We show that higher order cortical areas exhibit more variability than primary and secondary areas and that the folds are much better predictors of the BAs than had been previously thought. These results further highlight the significance of cortical folding patterns and suggest a common mechanism for the development of the folds and the cytoarchitectonic fields.

Shape Analysis with Overcomplete Spherical Wavelets

“…The mechanism involved remains unclear. Cortical folds are known to correlate with function and cytoarchitecture [7]. The study of the folding formation process can therefore deepen our understanding of structure-function relationship and neurological diseases originating from abnormal structural and functional connectivity in neuro-development.…”

Studying neuroanatomy using MRI

“…Second, explicitly aligning cortical folding patterns significantly improves localization. The best illustration for this improvement is in the cross-subject correspondence of Broca's areas (cortical subdivisions based on neuron types and distributions invisible on MRI) after either volumetric or surface based registration, with the surface based algorithm considerably improving co-localization 103 . Even surface based registrations cannot completely account for differential folding patterns (where the true solution is not even known), and thus the third approach is explicitly map sulcal shapes.…”

Parcellations and Connectivity Patterns in Human and Macaque Cerebral Cortex

“…In contrast, the ninefold larger human cortical sheet is far more convoluted, with many primary, secondary and tertiary folds. It is also far more variable in the pattern of convolutions and in the relation of areal boundaries to cortical folds (Amunts et al 2007;Fischl et al 2008;Van Essen et al 2012c). Figure 1 illustrates the variability of human cortical folding in six exemplar right hemispheres, shown on the left as 3D 'midthickness' surfaces and on the right as FreeSurfer 'sulc' (depth) maps on inflated surfaces.…”