Eight weeks after transplantation, all animals were anesthetized with isoflurane, after perfused intracardially with 250 mL of saline followed by 250 mL of 4% paraformaldehyde in PBS. Six spinal cord tissue samples in each group were prepared as paraffin sagittal sections at 10 µm thickness, the rest were stored at −80°C. Paraffin sections were stained with hematoxylin–eosin (H&E) (Solarbio), as described previously.39 (link) Finally, the stained sections were observed under the microscope (Leica).