Figure 3.

Syd and JNK are transported in both the anterograde and the retrograde pathways. (A) Sciatic nerves were ligated unilaterally at the midpoint and processed for immunofluorescence. APP accumulates primarily on the proximal side of the ligation, whereas phospho-TrkA primarily accumulates on the distal side (arrowheads point to nonspecific staining of the perineurium). Syd and JNK3 accumulate on both proximal and distal sides. White arrows point to ligation site. (B) Ligated and contralateral unligated sciatic nerves were dissected, and extracts were analyzed with the indicated antibodies. Tubulin is used as a loading control. Replicates are shown in the online supplemental material. (C) Sciatic nerve ligation was performed as in A. Nerves were dissected and processed for EM. Proximal and distal sections were stained for syd (15 nm of protein A gold; arrowheads). (D) Total gold particles on an area of 100 μm² on both proximal and distal axoplasm and an equivalent area on unligated nerve axoplasm were counted. The results are given as the number of gold particles per square micrometer ± SEM. Bars: (A) 100 μm; (C) 200 nm.