Significant reduction of brain-derived neurotrophic factor (BDNF) mRNA in the BTBR hippocampus. (A) There was prominent expression of BDNF mRNA in the hippocampus in B6 forebrain. (B) BDNF mRNA expression in the BTBR forebrain was markedly reduced compared with the B6 forebrain (compare (A) and (B)). (C) Quantitative densitrometry of the CA1, CA2, CA3 and dentate gyrus (DG) subregions of the hippocampus revealed that mRNA expression was significantly decreased in BTBR compared with B6 mice in the CA3 and dentate gyrus. The results are expressed as the mean ± SEM (n = 6/group). ***P ≤ 0.001 for both CA3 and DG, two-way ANOVA with Bonferroni post hoc analysis).