EXPRESSION OF C-FOS MESSENGER-RNA AFTER A MILD FOCAL CEREBRAL-ISCHEMIA IN SOD-1 TRANSGENIC MICE

To clarify the role of oxygen free radicals in expression of the c-fos protooncogene, the distribution of c-fos mRNA was investigated in CuZ n-superoxide dismutase (SOD-1) transgenic (Tg) mice compared to contro l nontransgenic (nTg) littermates after a mild (i.e. 10 min) focal cer ebral ischemia. c-fos mRNA expression occurred at 1 to 6 h after reper fusion in the ipsilateral hippocampus and thalamus in Tg mice, whereas it did only at 1 h in the same regions in nTg mice. In the ipsilatera l cortex, there were no significant differences in the pattern of the expression between nTg and Tg mice. These results suggest that oxygen radicals may suppress the expression of c-fos in the hippocampus and t halamus, the areas known to be without blood supply from the middle ce rebral artery, following a mild focal cerebral ischemia and reperfusio n.