ALTERATIONS OF NMDA RECEPTOR SUBUNIT 1 mRNA EXPRESSION IN HIPPOCAMPUS OF RAT FOLLOWING TRANSIENT FOREBRAIN ISCHEMIA

Objective To observe the expression of NMDA receptor subunit 1 mRNA in hippocampus of rat following transient forebrain ischemia. Methods Fifteen minutes forebrain ischemia and 05h-7d reperfusions (IR) model of rats were created by four-vessel occlusion.The expression of NR1 mRNA was examined by in situ hybridization histochemistry and image analysis system. Results After IR, the expression of NR1 mRNA raised up obviously in the CA1 region and reached to the highest at IR 24h. Then its expression came back and dropped to the lowest on the IR 7d. The pattern of NR1 mRNA expression in the CA3 region was similar to that in the CA1 region, but the range of its change was less abrupt than that in the CA1. The expression of NR1 mRNA in the dentate gyrus had no significant change until IR/72h,and dropped to the lowest on the IR7d.Conclusion The expression of NR1 mRNA in hippocampus of rat showed different time and region dependent patterns after transient forebrain ischemia.These patterns suggest that the alterations of NR1 mRNA expression may contribute to selective vulnerability and delayed cell death of hippocampus.