Figure 7.

Cognitive ability of hIAPP^−/− and hIAPP^+/– mice was impaired by a high-fat diet. (A,B) Social learning ability of hIAPP^−/− and hIAPP^+/– mice fed with a high/low-fat diet for 12 months was tested through the 3-chamber social test. (A) Time spent in different chambers was analyzed through the three-chamber social test (A). (B) Time spent in social areas occupied by familial mouse and novel mouse was analyzed (B). (C,D) Step-down test was used to evaluate the passive learning ability of hIAPP^−/− and hIAPP^+/– mice treated with a high/low-fat diet for 12 months. Times of error in step-down were analyzed (C). Time spent on the safe platform was analyzed (D). (E,F) Open-field test was performed to evaluate the movement function of hIAPP^−/− and hIAPP^+/– mice fed with a high/low-fat diet for 6 and 12 months. The movement distance (E) and movement time (F) were analyzed. 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 = 12, *p < 0.05, **p < 0.01, ***p < 0.001 compared with the L^−/− group.