Figure 4.

Nerve cell aging in the hippocampi of hIAPP^−/− and hIAPP^−/+ mice was accelerated by a high-fat diet. (A) Representative images of β-gal-positive staining in the hippocampal CA1 regions of hIAPP^−/− and hIAPP^+/– mice fed with a high/low-fat diet for 6 or 12 months. Black arrows indicate β-gal-positive cells. (B) Six sections per mouse were stained, and semiquantitative analysis was performed using ImageJ software. (C) Representative images of β-gal-positive staining in the hippocampal CA3 regions of hIAPP^−/− and hIAPP^+/– mice treated with a high/low-fat diet for 6 or 12 months. Black arrows indicate β-gal-positive cells. (D) Six sections per mouse were stained, and semiquantitative analysis was performed using ImageJ software. L^−/− denotes hIAPP^−/− mice on a low-fat diet; L^+/– denotes hIAPP^+/– mice on a low-fat diet; H^−/− denotes hIAPP^−/− mice on a high-fat diet; H^+/– denotes hIAPP^+/– mice on a high-fat diet. n = 6, *p < 0.05, **p < 0.01 compared with the L^−/− group.