Figure 4. ApoE4 impairs synaptic integrity and cognitive function. Brain tissues (temporal lobe) were collected from 12-month old ApoE3 and ApoE4 mice. Synaptic proteins were measured and normalized with an internal control (β-actin) in Western blot. (A) Representative Western blot and plotted data of PSD95; (B) Representative Western blot and plotted data of Synaptophysin (n= 6-9 per group, **p< 0.01). The ability of learning and memory of ApoE4 mice and ApoE3 mice were also evaluated in MWM, the data of performance were analyzed for (C) the escape latency during 4-day learning period; (D) the time spent at the target quadrant on day 5 (n=11-12, * p< 0.05, **p< 0.01).