Fig. 3

Early activation of TLR3 improved memory impairments in AD mice. A Representative track plots in the MWM during place navigation and the probe test. B The latency (time to find the hidden platform) increased in the AD + Saline mice and AD + Poly(I:C) mice compared with the WT + Saline mice. C As the test progressed, compared with AD + Saline mice, the WT + Saline mice converted the edge-type strategy to the straight-type searching strategy more frequently. D In the probe test, the distance covered in the target quadrant was longer in the WT + Saline mice than in AD + Saline mice. However, compared with the AD + Saline mice, the traveled distance in the target quadrant was longer in the AD + Poly(I:C) mice. E, F The frequencies of crossing the platform area were lower in the AD + Saline mice and AD + Poly(I:C) mice than in the WT + Saline mice. The number of times crossing over the platform area in AD + Saline mice and AD + Poly(I:C) mice was significantly less than that in the WT + Saline mice. No statistical significance was found in the frequencies of crossing the platform area or in the time spent in the target quadrant between AD + Saline mice and AD + Poly(I:C) mice (#: WT + Saline vs. AD + Saline, P < 0.05; &: WT + Saline vs. AD + Poly(I:C), P < 0.05; *: AD + Saline vs. AD + Poly(I:C), P < 0.05; n = 8–12/group)