Fig. 3

Paclitaxel causes distal to proximal axonal degeneration in mice. Mice were treated with i.v. 30 mg/kg paclitaxel 3 times a week for 2 weeks. a–c are cross-sectioned semithin (1 µm) plastic sections stained for toluidine blue. a Vehicle-treated (cremophor) mice at the mid-thigh level of sciatic nerve. No degenerated axons are observed. b Paclitaxel-treated mice at the mid-thigh level of sciatic nerve. Degenerated myelin profiles were present across the nerve crossed section. Arrows point to large (black arrow) and small (white arrow) degenerated myelinated axons. c Paclitaxel-treated mice at 7–8 mm distal to the sciatic nerve segment in a. Greater numbers of degenerated myelin profiles are present across the distal segment of the nerve, indicating distal to proximal degeneration pattern. d Quantification of degenerating myelinated fibers in the whole cross-sectional area of nerve segments. N = 3 per nerve segment. Values are mean ± SEM. e Electron micrograph of distal nerve intoxicated with paclitaxel showing occasional swollen unmyelinated axon (arrow) and degeneration of myelinated axon (*). f Quantification of Remak bundles. N = 3 mice per treatment. There was no statistical difference between vehicle- and paclitaxel-treated nerves. Scale bar in c = 20 μm and applies to a–c. Scale bar in e = 500 nm