Fig. 3.

Increased hippocampal DG/CA3 activation is observed in the context of impaired memory performance in three aMCI cohorts. Task related activation and behavioral performance during the placebo condition in participants with aMCI in the (A) 62.5 mg BID treatment group, (B) 125 mg BID treatment group and (C) 250 mg BID treatment group. (A–C) Top left in A–C: sagittal view of the left medial temporal lobe. Green vertical lines identify slices through the hippocampus shown to the right. Top middle in A–C: segmentation of the structures of interest including the CA1, dentate gyrus/CA3 (DG/CA3), and subiculum (SUB) subregions of the hippocampus. Top right in A–C: coronal slices show statistical maps of the extent of task related activity in the left DG/CA3 from anterior to posterior. Bottom left in A–C: mean activity during lure trials correctly called similar. Participants with aMCI on placebo in each of the treatment groups show increased activity in the left DG/CA3 compared to healthy control subjects during lure trials based on independent samples t-tests. Bottom right in A–C: participants with aMCI on placebo in each of the treatment groups show impaired memory performance by more often incorrectly judging lure items as “old” instead of similar when compared to healthy control subjects. Statistics show p-values resulting from a planned post-hoc contrast for the interaction of group as a function of response type (old versus similar). Values are means ± SEM. *p < 0.05.