Increased activity levels of Mapk /Erk signaling pathway in BTBR mice. Western blot analysis of eight BTBR versus eight C57BL/6 mice. Brain lysates were evaluated at P0 and P30 time points with antibodies against Ras, t-Erk and p-Erk. Quantitative fold-changes of bands were assessed, after being normalized to actin levels (A- C). Despite t-Erk levels being unchanged, the mean expression levels of Ras and p-Erk were significantly increased in BTBR mice at both P0 and P30 using the non-parametric Mann-Whitney U test (*P <0.05, **P <0.005, Bars represent the mean values, whiskers shows standard deviations).