Epifluorescence micrographs of transverse sections through the spinal cord at the site of an LPS injection 5 (A and B) or 7 days (C–H) earlier. Sections were double-labelled for PLP (left column; rhodamine-conjugated secondary antibody) and MAG (right column; fluorescein isothiocyanate-conjugated secondary antibody) and pairs of photographs taken using appropriate filters. At low magnification (A–D) the entire lower portion of the dorsal funiculus (outlined by arrowheads) can be seen. Five days after injection, the dorsal funiculus exhibits relatively uniform PLP labelling (A); however, nearly the entire lower half of the dorsal funiculus shows reduced MAG immunoreactivity (B). Seven days after injection, PLP immunoreactivity is again present in the entire dorsal funiculus (C); however, there is a substantial area deep in the dorsal funiculus that exhibits only very little MAG labelling (D). A portion of the non-lesioned, superficial dorsal columns from this section is shown at high magnification in E and F, and the myelin sheaths appear as labelled rings with both antibodies. In a similar image taken deep in the dorsal funiculus, PLP immunoreactivity remains evident (G); however, MAG immunoreactivity (H) is nearly absent. Scale bar (shown in H) = 200 µm in A–D and 20 µm in E–H.