Analysis of the relationship between learning and synaptophysin in obese rats treated with DPP4 inhibitor

The aim of this study is; the hypothesis is that the change in cognitive functions due to obesity and the relationship of these changes with the synaptophysin molecule can be treated with DPP4 inhibitor, a drug used in the treatment of type 2 diabetes, and exercise. In our study, 42 Wistar albino rats were used. The animals were randomly divided into seven groups as obese, control, control+NaCl, obese+DPP4i, control+DPP4i, obese+exercise, control+exercise. To create experimental obesity, the animals that are targeted to be obese were separated and fed on a high fat diet for 8 weeks. After the obese model was created, sitagliptin was applied to the DPP4i groups and swimming exercise was applied to the exercise groups for obesity treatment. The last week of the study was performed reference memory learning test to the whole group with Morris water maze. Then, the hippocampus tissues were removed from the animals under anesthesia. mRNA and protein isolations were performed from the extracted tissues. Gene expression analysis of Synaptophysin was performed by Real-Time PCR method from mRNA samples. Synaptophysin protein levels were determined from protein lysates by Western Blot method. In the learning test, in the obese groups, there was a statistically significant difference between the average escape time of the DPP4i and exercise groups and the groups that did not (p<0.05). As a result, in groups where obesity is treated with DPP4i and exercise; It was concluded that cognitive performance was better than obese groups. There was a evident decrease in synaptophysin gene expression levels in obese groups compared to the control group. In the treatment groups, an increase was observed in synaptophysin gene expression levels in the DPP4 inhibitor and especially in the exercise groups compared to the control groups (p>0.05). Gene expression results were similar in analyzes performed at the protein level. According to these results, in terms of performance in cognitive function due to obesity and synaptophysin gene relationship; DPP4 inhibitor showed as effective a result as exercise. This provides a resource for advanced molecular and metabolic research.