Sections from at least 3 separate experiments containing at least 3 mice per group were reviewed in a blinded manner. Numbers of GFAP + cells in spinal cord were determined in 15 non-overlapping 406 fields (0.2 mm 2 ) in white matter and gray matter. Stained spinal cord sections of all 6 levels on individual glass slides were scanned (406) and digitally imaged at high resolution with an Aperio ScanScope (Vista, CA). Aperio software was used to quantify areas of demyelination within the white matter tracks of each of the 6 sections per individual mouse. For analysis of CD4 + T cells spinal cords were embedded in Tissue-Tek O.C.T. (Andwin Scientific, Tryon, NC), flash frozen in liquid nitrogen and stored at 280uC. Blocks were warmed to 220uC prior to cutting 10 mm sections by cryostat. Following fixation with acetone for 2 min at 4uC, non-specific antibody binding was blocked with Cyto Q Background Buster (Innovex Biosciences, Richmond, CA) for 15 min. Sections were stained with anti-CD4 (L3T4) antibody (Vector Laboratories) diluted in Cyto Q Immuno Diluent (Innovex Biosciences) followed by biotinylated rabbit anti-rat, peroxidase ABC reagent and visualized with NovaRED substrate (all from Vector Laboratories). Sections were counter stained with hematoxylin to visualize the nuclei. Spinal cord sections were scanned (406) and digitally imaged at high resolution with an Aperio ScanScope.