1. Department of Neurology, Mayo Clinic, Rochester, Minnesota
2. Department of Neurology, Mayo Clinic, Rochester, Minnesota2Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
3. Department of Neurology, Mayo Clinic, Rochester, Minnesota3Department Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
4. Multiple Sclerosis Center, Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois
5. Center for Brain Research, Medical University of Vienna, Vienna, Austria