Impaired Memory and Cognitive Performance in Zucker Rats with Insulin Resistance and Obesity

Studies on the underlying pathophysiological alterations in type 2 diabetes have made considerable use of the genetically obese Zucker rat. Both obese and lean Zucker rats had their brainpower measured using a variable-interval delayed alternation test. Obese rats were no worse than control rats at learning the alternation rule and at shorter intervals, but their performance at longer intervals, which requires the hippocampus, was impaired. The insulin-sensitive glucose transporter and its receptor are both expressed at similar levels in the brains of obese rats, but there is a decrease in the plasma membrane form of the GLUT4 in the hippocampus. These results are in line with those from studies involving humans, and they indicate that the hippocampus and related tissues are more susceptible to the negative effects of diabetes mellitus. In this study have been tested the Cognitive Performance and Impaired Memory in Zucker rats.