Brain atrophy in db/db mice.

<p><b>A</b>) Brain weight was significantly reduced is db/db mice as disease progressed. At 4 weeks of age brains were significantly smaller in Control and db/db mice, when compared with adult brains. As T2D worsened a significant reduction in brain weight was observed in 14 and 26 weeks of age db/db mice, whereas no effect of prediabetes was observed in HFD treated mice [F_(7,31) = 23.70, **p<0.01 vs. Control 14 and 26 weeks, C57 RD and C57 HFD]. <b>B</b>) Cortical thickness affected as disease progressed and specific cortical areas were significantly reduced. Frontal cortex was thinner in db/db mice by 14 weeks of age and this effect was worsened by 26 weeks of age [F_(7,337) = 11.683, **p<0.01 vs. Control 14 weeks, Control 26 weeks, Control and db/db 4 weeks, RD and HFD treated mice]. A similar profile was observed in the parietal cortex and a progressive thinning effect was observed in db/db mice [F_(7,161) = .34, **p<0.01 vs. Control 14 weeks, Control 26 weeks, Control and db/db 4 weeks, RD and HFD treated mice]. Temporal cortex was only affected in 26 weeks db/db mice when compared with the rest of the groups [F_(7,250) = 114.232, **p<0.01 vs. Control and db/db 4 weeks, RD and HFD treated mice]. <b>C</b>) A similar profile was observed in the hippocampus, although thinning effect was detected at later stages. A significant reduction in dental gyrus thickness was only detectable in db/db mice at 26 weeks of age [F(7,118) = 1.11, *p = 0.47 vs. Control 26 weeks]. Hippocampal CA2 thickness was also significantly reduced in db/db 26 weeks [F(7,116) = 2.313, *p = 0.30 vs. Control 26 weeks]. Although a reduction in CA3 thicknes was observed in db/db mice at 14 weeks of age, differences only reached statistical significance in db/db 26 weeks mice [F(7,115) = 2.970, **p = 0.007 vs. RD and HFD treated mice]. <b>D</b>) Illustrative example of cortical thinning in db/db and control mice at 4, 14 and 26 weeks of age. Scale bar: 500 µm.</p

Body weight, glucose and insulin levels in 4, 14 and 26 weeks db/db and Control mice as well as in 26 weeks C57Bl6 mice after 18 weeks fed with HFD.

<p>Metabolic parameters including body weight, glucose and insulin levels were determined at the end of the experiments. Differences were detected by one-way ANOVA followed by Tuckey b or Tamhane tests as required. When we compared all groups under study we observed a significant increase in body weight as age progressed, and even higher body weights were observed in overweight mice (db/db 14 weeks old mice, db/db 26 weeks old mice and HFD treated mice), when compared to the rest of the groups [F_(7,35) = 63.03, **p<0.01 vs. Control 14 weeks, Control 26 weeks, RD and 4 weeks old mice (db/db and Control), ††<0.01 vs. Control and db/db 4 weeks]. Glucose levels were significantly higher in db/db mice both at 14 and 26 weeks of age when compared with the rest of the groups [F_(7,35) = 74.36, **p<0.01 vs. Control 14 weeks, Control 26 weeks, RD, HFD and 4 weeks old mice (db/db and Control)]. Increased insulin levels were observed in db/db 4 weeks mice, although these differences did not reach statistical significance. Significant hyperinsulinemia was observed in db/db 14 weeks and db/db 26 weeks whereas statistically higher levels were observed in HFD treated mice [F_(7,35) = 11.498, **p<0.01 vs. Control 14 weeks, Control 26 weeks, RD and 4 weeks old mice (db/db and Control), ††p<0.01 vs. rest of the groups].</p