Figure 1.
AAV injection and strategy. A) AAV-mediated somatic gene transfer of IL-4. Non-Tg mice at 3 mo of age received bilateral hippocampal injection of AAV-GFP (2×109 viral particles (VP)/hippocampus, dotted line) or AAV-IL-4 (2×109 VP/hippocampus, solid line), were sacrificed 4, 12, and 24 wk postinjection. The amounts of IL-4 in mouse hippocampal protein extracts were quantified by enzyme-linked immunosorbent assay, showing sustained expression of IL-4. Error bars represent se (n=3). B) Experimental design. APP+PS1 mice received bilateral hippocampal injection of AAV-GFP or AAV-IL-4 at 3 mo of age and were tested by 2-d RAWM task at 7 mo of age. Non-Tg mice served as a positive control for the spatial learning task. Mice were intraperitoneally injected with BrdU 5 times for 2.5 d, 21 d before being sacrificed at 8 mo of age.