Hippocampal ECM protein levels are increased in 3 months old APP/PS1 mice. a Time course profiles of four ECM proteins, hyaluronan and proteoglycan link protein 1 (HAPLN1), neurocan (NCAN), brevican (BCAN) and tenascin-R (TNR), reveal significantly higher levels in APP/PS1 transgenic (TG) mice compared with wildtype (WT) littermates at 3 months of age; n = 5 mice per genotype (SAM analysis; mean ± SEM; *FDR < 10). b Higher ECM protein levels were confirmed by immunoblotting; n = 6 mice per genotype (Student’s t test; mean ± SEM; *p < 0.05). c, d PV/WFA double-labeling of coronal sections of the hippocampus confirms an increase in the number of WFA-positive PNNs around PV-positive cells in APP/PS1 transgenic (TG) mice compared with wildtype (WT) controls. CA, cornus ammonis; DG, dentate gyrus; sp, stratum pyramidale; sr, stratum radiatum; so, stratum oriens. Scale bars: 250 μm (c), 40 μm (d). e Quantification of PV-positive and PV/WFA-double-positive cells in the CA1 area reveals a significant increase in the number of PV-positive cells containing WFA-positive PNNs in APP/PS1 mice compared with wildtype controls, whereas the total number of PV-positive cells remained unaltered; n = 16 sections from 4 mice per genotype (Student’s t test; mean ± SEM; *p < 0.05).