Figure 6.

Subcutaneous injection of AG improves spatial memory and neuropathology in Tg2576 mice. (a and b) Tg2576 (Tg) mice and the wild-type (WT) littermates at 6-month old were subcutaneously injected with AG or NS for 3 months, then the spatial learning and memory were measured by Morris water maze. The mice were trained to remember the hidden platform in the maze for 6 days (learning process) and the latency (time to find platform) was recorded (a). The platform was removed at ninth day and the spatial memory was tested by measuring the time of platform quadrant crossing, the time stayed in the target quadrant and swimming paths (b and c). (d and e) The levels of presynaptic proteins (synapsin1, synaptophysin, and VAMP-2), postsynaptic proteins (NR2A, NR2B, PSD93, and PSD95) and the memory-related molecules (c-fos and arc) in hippocampus were measured by western blot and normalized against DM1A. (e and f) The phosphorylation levels of tau at Thr231, Ser396, Ser404, Thr205, and Tau-1 (Ser198/199/202) in hippocampus were measured by using phosphorylation site-specific antibodies as indicated in the blots normalized against total tau probed by Tau-5. (g) Slices of Tg mice treated with AG or NS were immunostained with antibody against phosphorylated tau at Thr231. b, c: n=8; d–g: n=3. *P<0.05, **P<0.01 versus WT+NS group; ^#P<0.05, ^##P<0.01 versus Tg+NS group. s: second in a and c. Scale bar in h, 50 μm