[1] Univ N Carolina, Dept Hlth & Wellness, Asheville, NC 28804 USA
[2] Washington Univ, Sch Med, Dept Anat, St Louis, MO USA
[3] Washington Univ, Sch Med, Dept Neurobiol, St Louis, MO USA
[4] Washington Univ, Sch Med, Dept Neurol, St Louis, MO 63110 USA
[5] NIH, Dept Rehabil Med, Bethesda, MD 20892 USA