Figure 4. NMDA receptor subunit mRNA expression in the rat retina following hypoxia and 24-h recovery in air. For each mRNA, transcript abundance, normalized to acidic ribosomal protein P0, was measured by qRT–PCR. Values were then further normalized to the control level of each transcript. Data represent mean (±SD) of 5 independent experiments. NMDAR1 mRNA levels were higher in hypoxic samples compared to control and in recovery samples compared to control. NMDAR2C mRNA levels were higher in hypoxia samples compared to the control samples. NMDAR2D mRNA levels were higher in hypoxia samples compared to the control samples. The asterisks indicate significance levels assessed via ANOVA followed by post-hoc tests: * - p<0.05; ** - p<0.01; *** - p<0.001.