Rostral spinal cord (G55). In the G55 fetus, CTB labelled cells were found in the ventral horn (VH) and dorsal horn (DH) of the spinal cord, rostral to the site of injection. Labelled cells were also observed in the gracile nucleus (Gr) and cuneate nucleus (Cu). cc = central canal. Both sides of the figure are ipsilateral labelling (see methods).