Fig. 3.

Tau deposits in the hippocampi of PS1 treated mice. A) Timeline of study. 8-week-old (8 w.) mice were stereotactically injected with EVs and then maintained for 4 additional weeks before undergoing Morris water maze (MWM testing). After testing, mice were sacrificed (Sac.) and biochemical analyses performed. B–G) PBS, NDC EV, and PS1 EV treated hippocampi were sliced sagittally (6 μm thick sections) and immunolabeled with anti-tau (K9JA) antibodies. NovaRed was used for chromonergic development and tau identified by the presence of red staining inclusions. Slices were counterstained with Gill’s hematoxylin (purple). Images are 5X (images B, D, and F. Scale bar = 20 μm. Black arrows indicate tau inclusions) or 40X (images C, E, and G. Scale bar = 10 μm) magnified view of the CA1 field. H) Image of a tau thread observed in PS1 treated hippocampus (80X magnification, scale bar = 5 μm). I) Image of tau deposits localized to the nucleus observed in PS1 treated hippocampus (80X magnification, scale bar = 10 μm) J) Data is mean # of K9JA positive cells/total cells in CA1 field, ± SEM. Data was analyzed with a 1-way ANOVA, Tukey’s post-hoc test. N = 3 mice/group. *p < 0.05.