Figure 4: Induced pluripotent stem cells-derived motor neurons (MNs) survive and extend axons in the host. (A) A diagram showing human induced pluripotent stem cells -derived MNs transplanted into 10 sites bilaterally between the C6–T2 vertebrae (red dots, transplant sites; T1 vertebra was removed by laminectomy). (B) MNs survived well in the spinal cord of adult immunodeficient rats 6 months after transplantation. Moreover, a large number of axons had projected to the caudal host spinal cord. (C) An enlarged view of the inset in B (red channel only) to show graft-derived axons in the caudal region. d: Dorsal; r: rostral; red: Stem121-labeled transplanted human cells; blue: 4′,6-diamidino-2-phenylindole (DAPI); scale bars: 250 μm in B, and 100 μm in C. Unpublished data.