Retrograde labeling of cell bodies in the red nucleus. Three months after spinal contusion at the level of T9 followed immediately by immunization with anti-MBP T cells or injection of PBS, three rats from each group were reanesthetized, and the dye rhodamine dextran amine (Fluoro-ruby) was applied below the site of contusion. Sections taken through the red nucleus were inspected and analyzed qualitatively and quantitatively by fluorescence and confocal microscopy. Significantly more labeled red nuclei were seen in the rats treated with anti-MBP T cells than in the PBS-treated rats (p = 0.046; Student's ttest, with correction for thickness and size of neurons). The bar graph shows the average of the total numbers of labeled red nuclei per brain. The behavioral scores of the three rats were 10.5, 12, and 12.75 in the experimental group and 6, 8, and 8.5 in the control group. The bar graph shows the mean ± SD values.