Figure 4.

IPC attenuates axonal degradation after OGD. Axons were fixed and stained for SM-31 (green), an antibody that binds phosphorylated neurofilaments, as well as the nuclear marker DAPI (blue). The 40× objective images in A were obtained with an immunofluorescent microscope as described in Materials and Methods. Higher-magnification images in B are digital zoom. Axonal morphology was quantified systematically as described in Materials and Methods (maximum possible score is 12). IPC pulse alone did not significantly alter axonal morphology, but after OGD, there was a significant increase in the amount of axonal injury. Arrows indicate head/bulb formation in the injured fields after OGD (right panels in A). Axonal integrity after OGD was significantly greater in the Ipsi-OGD (7.5 ± 0.5) versus Contra-OGD (4.8 ± 0.4) MONs; **p < 0.01 (C). Scale bars: A, ∼30 μm; B, ∼8 μm. n = 3 MONs per group.