Sample preparation and imaging was performed by the Microscopy and Imaging Laboratory (MIL) at the University of Michigan.
For each of the investigated SNP, voxel-by-voxel group comparisons were made using SPM99 (Welcome Functional Imaging Laboratory, London, United Kingdom) using proportional scaling, setting the height threshold at P≤0.001 and cluster size threshold at >100 voxels, and including group (C-LHPA vs. LPA) as a covariate.
Processing of fMRI images was performed using SPM5 (Functional Imaging Laboratory, London, UK).
Functional MRI analysis used SPM8 (Functional Imaging Laboratory, London, United Kingdom; www.fil.ion.ucl.ac.uk/spm).ac.uk/spm
T1-images were then segmented into WM, GM, cerebrospinal fluid (CSF), and lesions, using SPM8 (Functional Imaging Laboratory, Wellcome Department of Imaging Neuroscience, London).
Following polymerization, tissue sections were counterstained and imaged using the Hitachi H7000 transmission electron microscope (Microscopy Imaging Laboratory, University of Toronto).
The functional and structural MRI data were analysed using SPM5 (Functional Imaging Laboratory, Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, UK) running under MATLAB 7.6 (Mathworks Inc., USA).
Analyses of the DTI data were done using a software package (version 2.3; Nordic ICE Diffusion/DTI Module, Nordic Imaging Laboratory, Bergen, Norway) on a voxel-by-voxel basis.
MRIs were co-registered to the individual add-images using Statistical Parametric Mapping 5 (SPM5; Functional Imaging Laboratory, University College London, UK) and then normalized into Montreal Neurological Institute (MNI) space (International Consortium for Brain Mapping) using bias-corrected segmentation in SPM5.
