Abstract: Objective · To observe the changes of learning and memory functions and as well as the changes of the glucose metabolism in the corresponding functional brain regions in type 2 diabetic mice after abdominal surgery. Methods · Forty 5-week-old male mice of C57BL/6 wild-type, which were fed on 60% high-fat diet, and the type 2 diabetes models were established with nicotinamide and streptozocin 4 weeks later. These mice were then randomly divided into control group (n=15) and abdominal surgery group (surgery group, n=15). The open field experiment and the fear conditioning experiment were performed to assess the learning and memory functions in each group (n=10). Positron emission tomography/computed tomography (PET/CT) was used to measure the uptake of 18F-fluorodeoxyglucose (18F-FDG) in different brain regions of mice in each group (n=5). Results · In the open field experiment, there was no significant difference in the number of central grid crossings and total movement distance between the control group and the surgery group. In the fear conditioning experiment, the freezing time ratios of the surgery group in the contextual test and the tone-related test were lower than those in the control group (both P<0.05). The standard intake rates of 18F-FDG in hippocampus, cerebral cortex, striatum and amygdala in the surgery group were significantly higher than those of the control group (all P<0.05). Conclusion · Postoperative cognitive dysfunction after abdominal surgery in type 2 diabetic mice may be associated with the abnormal cerebral glucose metabolism in relevant cerebral areas.

Key words: postoperative cognitive dysfunction (PCOD), positron emission tomography/computed tomography (PET/CT), 18F-fluorodeoxyglucose (18F-FDG), cerebral glucose metabolism, diabetes