The survival and differentiation of MSCs in the injured spinal cord. A. BrdU-labeled nuclei (green) of MSCs in the injured spinal cord in the MSCs+EA group. Grafted BrdU-labeled MSCs were well integrated with host tissue and migrated into host tissue over the host/lesion interface in the spinal cord both rostrally and caudally. Two broken lines outline the lesion site. Inset in A showing the BrdU-labeled MSCs – at a higher magnification (Scale bars: 80 μm; Insets, 20 μm.). B. The number of survived MSCs in the lesion site (MSCs+EA vs. MSCs, * indicates P < 0.05). Data = means ± SD. C. ED1-immunostained activated macrophages (red) in the lesion site; numerous grafted MSCs (Hoechst labeled the nuclei of MSCs, blue) survived in the lesion site, some were phagocytosed by ED1 immunoreactive activated macrophages (arrowheads). D. NF150-positive neuron-like cells (green, arrows) co-localized with Hoechst-labeled nuclei of MSCs (Hoechst, blue), but not with ED1-positive activated macrophages (red). Scale bars: A = 80 μm, C and D = 20 μm.