Western blot analysis shows the decreased p-ERK1/2 following ID and hypothyroidism (n = 3 for each group). The levels of p-ERK1/2 in ID and hypothyroidism groups were significantly lower than controls in CA1 and CA3 regions on PN21 (A), PN28 (B) and PN42 (C). (a) Representative blots of p-ERK1/2 in hipocampal CA1, CA3 and DG regions of control, 5 ppm PTU-treatment, 15 ppm PTU-treatment and iodine-deficient groups. (b and c) p-ERK1 and p-ERK2 levels. Each bar represents the mean ± SEM. *P < 0.05, as compared to control. #P < 0.05, as compared to 5 ppm PTU-treatment group. ΔP < 0.05, as compared to 15 ppm PTU-treatment group.