Previously, we reported that forced exercise (treadmill running, 1.2 km/day × 6 weeks) administered to adult male Lewis rats prior to and during the development of EAN (an established CD4+ T-cell dependent rat model of human inflammatory demyelinating neuropathies) affords a novel measure of protection against the development of autoimmune-associated deficits in peripheral nerve function (Calik et al., 2012). This evidence concerns the gene CD4 and Guillain-Barre syndrome, familial.