Rats were divided into sham-operated control (Con), sham-operated plus 100 mg/kg magnesium control (Mg), STZ ICV (STZ) or STZ ICV plus 100 mg/kg magnesium (STZ+Mg) groups and treated as shown in Figure 1A. The total GSK-3β, GSK-3β (Ser9), GSK-3β (Tyr216), total PP2A and PP2A (pY307) levels in whole hippocampus extracts were measured using Western blotting (A, C) and quantitative analysis (B, D). The level of p-GSK-3β (Ser9) was significantly decreased in ICV-STZ-treated rats, and magnesium supplementation restored the levels. No alterations in total GSK-3β, p-GSK-3β (Y216), total PP2A and PP2A (pY307) levels were detected in these groups. Data were presented as means ± SD. *P<0.05 versus the control group, #P<0.05 versus the STZ group.