Fig. 4

Complement expression is associated with synapse loss following sciatic nerve transection in rat. Both C1q and C3 are up regulated in DA and PVG rats following SNT but with significantly higher levels in DA (a and b). Similar to VRA, Cr1 was not regulated after injury in either strain (c), whereas Cr2 was strongly up regulated in PVG (d). Increased complement expression following SNT is associated with loss of synaptic terminals in the ventral horn, as measured by a ratio of synaptophysin immunoreactivity in the dorsal spinal motor nucleus of the injured and control sides (e and f). Loss of synapses is more pronounced in the DA strain (g). C3 immunoreactivity is present as a diffuse labeling as well as a more distinct signal on the cell bodies of some motor neurons (h). C3 labeling is found in close proximity with synaptophysin on the contour of motor neurons visualized at higher magnification (i–j). White arrow heads show motor neurons distinguishable by their large nuclei (h–j). IL ipsilateral, CL contralateral. Scale bar equals 40 μm in e, f, and h and 10 μm in i and j. n = 5 + 5 RT-PCR and 6 + 6 IHC, all at 5 days post SNT, *p < 0.05, **p < 0.01, and ***p < 0.001. The results are represented as mean ± SEM