Figure 3. Comparison of neuronal nitric oxide synthase (nNOS) mRNA in hippocampi of WT and FMR1 KO mice by RT-PCR at P7, P14, P21, and P28 (N = 4-7 mice per genotype, per age group). ΔCt = Ct (nNOS) - Ct (β-actin), where Ct = cycle threshold, β-actin is the endogenous reference. Relative nNOS mRNA expression: PΔCt = 2^−ΔCt, representing nNOS mRNA levels. The final data in the graph were magnified to 1000 × 2^−ΔCt. Data are reported as means ± SEM. ^*P < 0.05 vs WT on P21 (two-tailed Student t-test). mRNA = messenger ribonucleic acid; WT = wild-type mice; FMR1 KO = fragile X mental retardation 1 gene knockout mice; P7, P14, P21, P28 = postnatal days 7, 14, 21, and 28, respectively.