Prenatal high sucrose intake affected learning and memory of aged rat offspring with abnormal oxidative stress and NMDARs/Wnt signaling in the hippocampus

Maternal over-nutrition may predispose offspring to obesity, type 2 diabetes and other adult diseases. The present study investigated long-term impact of prenatal high sucrose (HS) diets on cognitive capabilities in aged rat offspring. The fasting plasma glucose concentration did not differ between the control and HS groups. However, the fasting plasma insulin and insulin resistance index values were significantly increased in HS offspring that showed abnormal glucose tolerance test. HS offspring exhibited increased escape latency and swimming path length to the platform, and reduced time in the target quadrant and the number of crossing the platform, as compared with the control group. The expression of Grin2b/NR2B, Wnt2, Wnt3a and active form of β-catenin protein were decreased, and Dickkopf-related protein 1 was increased in the HS group. In addition, the levels of lipid peroxidation biomarker thiobarbituricacid reactive substance, nicotinamide adenine dinucleotide phosphate oxidases 2 and superoxide dismutase 1 were significantly increased, and the activity of catalase was decreased in the hippocampus in the HS group. The results demonstrate that prenatal HS-induced metabolic changes cause cognitive deficits in aged rat offspring, probably due to altered N-methyl-D-aspartate receptors/Wnt signaling and oxidative stress in the hippocampus.