Objective:To investigate the expression of nuclear factor-κB (NF-κB) subunits P50 and c-Rel protein in primary cortical neurons of Wistar rats at different time points of oxygen glucose deprivation/reoxygenation(OGD/R).Methods: The neurons dissociated from the cortex of the neonatal rats were primary cultured and were identified by immunocytochemistry.OGD/R model was established.The study was divided into 6 groups according to different processing methods,including normal group,OGD 4 h treated,OGD 4 h/R 2 h treated,OGD 4 h/R 6 h treated,OGD 4 h/R 12 h treated and OGD 4 h/R 24 h treated groups.The expression of NF-κB P50 and c-Rel protein in neurons was examined by immunocytochemistry method and Western blotting.Results: (1) Immunocytochemistry detection targeting neuron specific enolase (NSE) and beta-Ⅲ tubulin confirmed that the cultured cells were neurons.(2)The expression of NF-κB P50 protein was significantly higher in OGD 4 h group than in control group(P<0.05); the expression continued to increase in OGD 4 h/R 2 h andOGD 4 h/R 6 h groups,and reached its peak 6 h after reoxygenation (P<0.01),then began to decrease,but the expression in OGD 4 h/R 12 h group was significantly different from that of the control group (P<0.05); there was no significant difference between OGD 4 h/R 24 h group and control group.(3) The expression of NF-κB c-Rel protein was similar between OGD 4 h group and the control group; the expression increased in OGD 4 h/R 2 h and OGD 4 h/R 12 h groups and reached its peak 12 h after reoxygenation(P<0.01),and did not recover to the normal level in OGD 4 h/R 24 h group (P<0.05).Conclusion: Oxygen glucose deprivation/reoxygenation can activate NF-κB subunits P50 and c-Rel in the primary cortical neurons in rats in a time-associated manner.