(A) Experimental time course for longitudinal assessment of cognitive development in WT and Fmr1 KO rats treated with lovastatin between 4 and 9 weeks of age. DI at different ages for WT and Fmr1 KO rats treated with control or lovastatin diet in (B) OPR and (C) OPCR tasks. (D) Effect of lovastatin treatment on OPR (left) and OPCR (right) memory tested at 7 to 9 weeks of age in WT and Fmr1 KO rats. (E) Effect of lovastatin treatment on OPCR memory in WT and Fmr1 KO rats tested at 14 and 23 weeks of age. (F) Effect of lovastatin treatment on hippocampal basal protein synthesis levels in WT and Fmr1 KO rats measured at 24 weeks of age, after behavioral testing was complete. Sample sizes: OPR 4 to 6 weeks: nWTcontrol = 13, nWTlova = 12, nKOcontrol = 12, nKOlova = 12; OPR 7 to 9 weeks: nWTcontrol = 13, nWTlova = 12, nKOcontrol = 12, nKOlova = 12; OPR 14 weeks: nWTcontrol = 10, nWTlova = 11, nKOcontrol = 11, nKOlova = 8; OPR 23 weeks: nWTcontrol = 11, nWTlova = 10, nKOcontrol = 11, nKOlova = 7; OPCR 4 to 6 weeks: nWTcontrol = 13, nWTlova = 12, nKOcontrol = 12, nKOlova = 12; OPCR 7 to 9 weeks: nWTcontrol = 13, nWTlova = 12, nKOcontrol = 12, nKOlova = 12; OPCR 14 weeks: nWTcontrol = 11, nWTlova = 11, nKOcontrol = 11, nKOlova = 8; OPCR 23 weeks: nWTcontrol = 10, nWTlova = 10, nKOcontrol = 11, nKOlova = 8; for protein synthesis, n = 6 for all groups. *P< 0.05 difference from chance (DI = 0), black for WT and red for KO; #P< 0.05 difference between groups. LMEs were fitted to the behavioral data (for details, see tables S7 and S9), and two-way analysis of variance (ANOVA) with post hoc two-sample t tests was used to analyze the effect of lovastatin on hippocampal protein synthesis levels (for details, see table S6F). P values from one-sample t tests and post hoc two-sample t tests have been controlled for the false discovery rate using the Benjamini-Hochberg procedure. For details on behavioral data t, df, and P values for one-sample t tests, see table S3, and for post hoc two-sample t tests, see table S4.