Temporal and spatial expressions of NR_2A mRNA and NR_2B mRNA in hippocampus in temporal lobe epileptic rats after kindling

Objective To investigate the relationship between the expression changes of NMDAR subunits in hippocampus and temporal lobe epilepsy.Methods Male Wistar rats were divided into three groups,five were in normal group;the other two groups,sham and epilepsy groups,were divided into 6 subgroups according to the time points of 6,24 and 72 h,7,14,and 21 d after kindling,respectively,each subgroup had 5 rats.Typical kindled model of temporal lobe epilepsy was established by kainic acid(KA) microinjected into right nucleus amygdalae in male Wistar rats.In situ hybridization was used to detect the expression changes of NR2A mRNA and NR2B mRNA in hippocampus after KA kindling.Results In general,NR2A mRNA significantly increased in regions of hippocampus in epilepsy group than that in sham group(P0.05),and gradually returned to normal level in epileptic rats after kindled for 21 d(P0.05).NR2B mRNA was significantly increased in DG and CA1 regions in epilepsy group than that in sham group(P0.05),while without difference in CA3 region between them.Stepwise regression analysis showed that the expressions of NR2A mRNA and NR2B mRNA in hippocampus were positively correlated with temporal lobe epilepsy(P= 0.0001).Conclusion NR2A mRNA and NR2B mRNA expressions in hippocampus present temporal and spatial changes in epileptic rats,which may be involved in the mechanisms of temporal epilepsy and the brain injury.