Transganglionic labelling with CT-HRP of dorsal column axons after spinal cord injury. Horizontal sections through the dorsal columns of the spinal cord of wild-type (Figs. 2a, c, e) and knockout (Figs. 2b, d, f) mice 28 days after unilateral transection of the dorsal column and ipsilateral sciatic nerve crush, and 3 days after injection of CT-HRP proximal to the sciatic nerve crush site. All sections were reacted for HRP. In Figs. 2a and b, at the lesion site (lesion marked with an asterisk and adjacent area enlarged in Figs. 2c and d) there is no indication of more extensive labelling or increased sprouting into or around the lesion site in the knockout relative to the wild-type control, and in both many axons displayed enlarged end bulbs (e.g. at arrows). Figs. 2e and f are taken approximately 2mm rostral to the lesion site. There are no regenerating or spared axons in the injured dorsal column in either. The dotted lines mark the midline; the injured dorsal column is below (to the left of) the midline in both figures. The orientation markers in Figs. 2a and b show medial (m) and caudal (c) for the left (injured) dorsal column. Scale bars = 100 μm; the bar in Fig. 2a applies to 2b also; the bar in Fig. 2c applies to 2d–f also.