Relative expression of MyD88 expression in the brain of different mouse strains. (a) MyD88 mRNA expression is upregulated in 6 month-old APPswe/PS1 mice compared to WT littermates. ** P < 0.05 (vs WT) (b) APPswe/PS1-MyD88+/- mice expressed significantly lower level of MyD88 mRNAs compared to APPswe/PS1 mice at 3 months of age. ## P < 0.01, ### P < 0.001 (vs MyD88-/-); * P < 0.05 (vs APPswe/PS1). Data are expressed as mRNA arbitrary units normalized with housekeeping genes Hprt1 and 18S. Error bars: SEM; n = 3-4. (Statistical analysis was performed using Student's t-test in (a) and a one-way ANOVA followed by a Bonferroni post-hoc test in (b)).