Normal probability plots of the distribution of NMDA receptor subunit mRNA expression data expressed on a 2−ΔCT scale (upper panel) or a ΔCT scale (lower panel). All the 2−ΔCT distributions differed significantly from normal by Shapiro–Wilks tests, P < 0.01 in each instance. Open circles, NR1 mRNA in SFC; open squares, NR1 in PMC; open triangles, NR2A in SFC; open diamonds, NR2A in PMC; solid circles, NR2B in SFC; solid squares, NR2B in PMC.