(A) Representative pictures of WGA-labeled neuronal cell bodies located in the ventral horn at 14 weeks after SCI. Spinal cord sections were stained with anti-WGA (red) and -MAP2ab (magenta) antibodies and Hoechst (blue). Scale bar: 20 μm. Intense WGA immunoreactivity was observed as intracellular granule-like structures. Left panels show the rostral area (Th4–Th7), and right panels show the caudal area (Th11 to lumbar vertebra [L] 1). In uninjured mice, WGA injected into the bilateral motor cortices was transsynaptically transported to neurons in areas rostral and caudal to the injured site (top panels). In the SCI model mice that did not receive treatment, very little WGA was observed in caudal areas (middle panels). However, in spinal cords of animals that underwent dual treatment with NSC and VPA, WGA was clearly observed in neurons in the caudal areas (bottom panels). Representative results of GFP-NSC–transplanted SCI model mice are shown. (B–D) The percentages of WGA-positive cells in the neurons localized in the ventral horn were quantified. **P < 0.05 (Student’s t test). All data shown are from at least 30 images, containing more than 600 cells, from 3 individuals (5 images per area) in parallel experiments, with error bars representing SD. (E) Representative confocal images of WGA-labeled transplant-derived MAP2-positive neurons. Sections were stained with anti-WGA (red), anti-MAP2ab (magenta) and anti-GFP (green) antibodies, and Hoechst (blue). Granule-like WGA structures (yellow arrowheads) could be seen in the GFP and MAP2ab–double-positive transplant-derived neurons. Scale bar: 10 μm.