Figure 3

Total Cu/Zn SOD expression in control, and saline or NMDA injected postnatal cortex. Western blot (A) and semi-quantification of total levels of Cu/Zn SOD protein from intact, saline-injected, or NMDA-injected brain cortical extracts are represented as percentage of Cu/Zn SOD level in P9 (B). A single band of the expected molecular weight of 16 KDa of the Cu/Zn SOD monomer was observed in all samples (A). The intracortical injection of saline solution induced a trend towards the transient upregulation of Cu/Zn SOD which showed a peak at 10 hours post-injection (B: solid circles). In contrast, after NMDA injection, total cortical Cu/Zn SOD expression showed a trend towards rapidly diminishing (A, B: triangles). This trend of Cu/Zn SOD reduction at 4 hours after NMDA injection in total cortical extracts is comparable to the % of lesioned cortex which was around 20% (not shown). However, at later time points, Cu/Zn SOD was significantly upregulated peaking at 7 days (168 hours) post-lesion. In intact control brain (B: opened circles), total enzyme level significantly increased from postnatal day 9 to postnatal day 16. (# p < 0.05 in relation to P9 control animals and * p < 0.05 in relation to NMDA 4 hours).