1. The Gulf War Illness Working Group, Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN 55417, USA
2. Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA
3. Department of Psychiatry, University of Minnesota Medical School, Minneapolis, MN 55455, USA
4. Department of Neurology, University of Minnesota Medical School, Minneapolis, MN 55455, USA