Fig. 5.

Differential interference contrast (DIC) and confocal immunofluorescence micrographs showing the effect of caspase inhibitors on transected DRG axons in culture. P0 DRG explants were cultured for 7d, treated with zVAD-fmk or the calpain inhibitor ALLN for 1 hr, and then axotomized. After 24 hr, the transected axons were fixed and then studied by DICmicroscopy or stained with the N52 anti-neurofilament antibody and then studied with confocal immunofluorescence microscopy. Note that ALLN prevented the breakdown of some neurofilaments but not the axolemma, whereas zVAD-fmk had no effect on either. Different fields are shown for DIC images (scale bar, 33 μm) and immunofluorescence images (scale bar, 50 μm).