Fig. 3

Overexpression of hTau in excitatory and PV neurons impairs social memory. a Timeline of the experimental procedures. b Representative images showing the expression of AAV-CaMKII-Cre-mCherry and AAV-DIO-hTau-eGFP in the vCA1 of C57BL/6 mice. The arrows indicate colabelled cells. Scale bar = 100 μm. Quantitative analysis revealed that 91% of the hTau⁺ neurons were colocalized with CaMKII and 75% of the CaMKII⁺ neurons were colocalized with hTau. c vCA1-hTau^CaMKII and control mice spent more time investigating conspecifics than empty cups. d vCA1-hTau^CaMKII mice failed to familiarize themselves with the same social partner in trials 1 to 3 (T1–T3). e In the social memory test, vCA1-hTau^CaMKII mice spent similar amounts of time investigating familiar and novel conspecifics. The social discrimination score was lower in the vCA1-hTau^CaMKII group. f Representative images showing AAV-DIO-hTau-mCherry virus infection (red) and anti-PV immunofluorescence staining (green) in the vCA1 of PV-Cre mice. The arrows indicate colabelled cells. Scale bar = 100 μm. Quantitative analysis revealed that 94% of the neurons with hTau were PV⁺ and 84% of the PV⁺ neurons were colocalized with hTau. g Both vCA1-hTau^PV group and control group exhibited a preference for conspecifics over empty cups. h vCA1-hTau^PV mice succeeded in familiarizing themselves with the same social partner in trials 1 to 3 (T1–T3). i In the social memory test, vCA1-hTau^PV mice spent similar amounts of time investigating familiar and novel conspecifics. The social discrimination score was lower in the vCA1-hTau^PV group than in the control group. n = 8 per group. ^**P < 0.01, as determined by two-way ANOVA, two-way repeated ANOVA or two-tailed unpaired t test. The data are presented as the mean ± SEM. IHC immunohistochemistry, CaMKII calcium/calmodulin-dependent protein kinase II, PV parvalbumin, vCA1 ventral hippocampal CA1, hTau human tau