Cigar-shaped ellipsoidal representation of the principal eigenvectors estimated from the DTI measurements. The eigenvector estimates from the Mn-labeled regions were only plotted on backgrounds that are the same as those rostral, epicenter and caudal images in Fig. 4. Therefore, the density of the vectors is associated with the size of the Mn-enhancement. Vector directions are all aligned along the cord in all the three images. The direction of the alignment is consistent with the anatomical orientation of the descending neuronal fibers in the CST. The DTI data acquisition included first the baseline image, followed by the diffusion-weighted images obtained with applying diffusion sensitizing gradients along the directions (110,101,011,-110,-101,0-11). Diffusion weighting was achieved using gradient strength = 80 mT/m, width (δ) = 6.5 ms and separation (Δ) = 11 ms to produce b-value of b = 342 s/mm2. Other parameters were TR/TE = 2500/26 ms, FOV = 10 × 10 mm2, acquisition matrix = 128 × 128, slice thickness = 2 mm and NEX = 2.