A single dose of vincristine does not cause axonal degeneration. a-d, Axons viewed transcutaneously in the pinna of the ear, before and 3 d after administration of vincristine (0.5 mg/kg). The areas boxed in a and b are shown at higher power in c and d. e, f, Confocal images of dorsal cutaneous axons from intact nerves (e, f) or proximal segments of crushed nerves (g, h) in untreated (e, g) or vincristine-treated (0.5 mg/kg) (f, h) mice. Scale bars: a, c, 1 mm; f, 10 μm.