Fig. 3.

Post-hoc analysis on VBM-defined hippocampal volumes for PDM vs. CON and PDM severity. (A) The volume of the VBM-defined localized left anterior hippocampus was significantly greater in the overall PDM group than in the overall CON group (indicated by the yellow sphere in the 3D visualization of the left hippocampal subfield segmentation). (B) Among Val/Val subjects, the volume of this region was greater among PDM subjects than among CON subjects (p = 0.003). (C) This region also manifested a significantly positive dosage-dependent relationship with the number of Val alleles in subjects with moderate PDM (r = 0.60, beta = 0.33, t = 2.53, p = 0.015). Note that among Val/Val subjects, the volume of this region was greater in cases of moderate PDM than in cases of severe PDM (p = 0.027). Note also that within-severity group post-hoc analysis revealed that the volume of this region was greater in the Val/Val group than in the Val/Met group (p = 0.006) and Met/Met group (p = 0.012). Among Met/Met subjects, the volume of the VBM-defined anterior hippocampus was greater in subjects with severe PDM than in subjects with moderate PDM (p = 0.007); however, we observed neither genotype main effects nor between-genotype differences in the severe PDM subgroup. All volumetric data were adjusted by age, concentration of estradiol, and total gray matter volume. Bar graphs show means and SEM. *p < 0.05; **p < 0.01, post-hoc Bonferroni test. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)