Relating diffusion tensor imaging measurements to microstructural quantities in the cerebral cortex in multiple sclerosis.

To investigate whether the observed anisotropic diffusion in cerebral cortex may reflect its columnar cytoarchitecture and myeloarchitecture, as a potential biomarker for disease-related changes, we compared postmortem diffusion magnetic resonance imaging scans of nine multiple sclerosis brains with histology measures from the same regions. Histology measurements assessed the cortical minicolumnar structure based on cell bodies and associated axon bundles in dorsolateral prefrontal cortex (Area 9), Heschl's gyrus (Area 41), and primary visual cortex (V1). Diffusivity measures included mean diffusivity, fractional anisotropy of the cortex, and three specific measures that may relate to the radial minicolumn structure: the angle of the principal diffusion direction in the cortex, the component that was perpendicular to the radial direction, and the component that was parallel to the radial direction.

Wider minicolumns in autism: a neural basis for altered processing?

Previous studies have found alterations in the columnar organization of the cortex in autism spectrum disorders. Such changes have been suggested to be limited to higher order association areas and to spare primary sensory areas. In addition, evidence from gene-expression studies have suggested that there may be an attenuation of cortical differentiation in autism spectrum disorders.