Fig. 5

IgMs from mouse plasma do not reach the granules of the hippocampus under physiological conditions. Representative images of the hippocampal region of brain sections from different mice stained with both the anti-MMP2 antibody (green) and Hoechst (blue). In the second incubation, an anti-mouse IgM antibody (red) is added. a and b: brain sections from representative ICR-CD1 mice aged 3 and 6 months, respectively. c and d: brain sections from representative SAMP8 mice aged 3 and 6 months, respectively. The granules are stained with the MMP2 antibody but the secondary anti-mouse IgM antibody did not stain the granules in any of the assayed mice, thus indicating that the anti-neo-epitope IgMs contained in their plasma do not reach the granules. Scale bar: 50 μm