Expression of NMDA receptor subunit proteins in various regions of the adult GluRε4 mutant mouse brain. The amount of each NMDA receptor subunit was determined by Western blot analysis using antibodies against GluRζ, GluRε1, or GluRε2. The synaptosomal protein samples were prepared from various regions of the adult GluRε4 mutant mouse brain. FC, Frontal cortex;HIP, hippocampus; STR, striatum;THA, thalamus. Each column represents the mean ± SEM (n = 4). *p < 0.05 versus wild-type (+/+).