Representative images of np-NFH, Hsp27 and Hsp70 in the ON and OT after ON crush.

In the uninjured pathway (contralateral ON and corresponding ipsilateral OT), a pattern of uniform labelling of RGC axons by np-NFH is largely evident (A, C). In the injured pathway (ipsilateral ON and corresponding contralateral OT), numerous swollen, beaded np-NFH-labelled axons are apparent, indicative of Wallerian degeneration (B, D). In the uninjured ON and OT, Hsp27 is associated with a population of glial cells. One week after induction of ON crush, Hsp27 expression is markedly upregulated throughout the injured pathway. No expression of Hsp70 is readily apparent in the uninjured or injured ON or OT (I–L). ON, optic nerve; OT, optic tract; Np-NFH, non-phosphorylated neurofilament heavy chain. Scale bar  = 50 µm.