FIG. 3.

Intra-axonal PCs. (A and B) Frequently, PCs are observed in distinct axonal swellings with no associated inflammation. There appears to be an abrupt swelling of the axonoplasm before the PC distends the axon. There is a distinct absence of axonal degeneration (Wallerian degeneration). H&E. Scale bar=50 μM. (C) Occasionally, spores can be seen trailing off at the base of the axonal swelling. Luna. Scale bar=50 μM. (D) Within a nerve root, a distinct line of spores can be seen trailing past the axonal swelling and up the axon. Giemsa. Scale bar=50 μM. (E and F). Occasionally, multiple PC are observed in a single axon, forming a “string of pearls” arrangement. H&E. Scale bar=50 μM. Bases of axonal swellings are indicated by arrows.