Investigation of the rat hippocamus with experimental diabetes using light, electron microscopic and stereological techniques

Objective: In our study, it was aimed to investigate the possible pathological effects of peripheral nerve damage and diabetes on the hippocampus tissue and to determine whether the phytochemicals of Garcinia kola and curcumin have curative effects. Materials and Methods: In our study; 35 male Wistar albino rats, 10-14 weeks old, weighing 250-300 grams, were divided into 5 groups, each containing 7 animals. A single dose of Streptozotocin was injected intraperitoneally to create a diabetes model in groups other than the control and sham groups. While no procedure was applied to the control group, sciatic nerve transection was applied to all groups except the control group. One of our antioxidant groups was given Garcinia cola and the other was given curcumin. At the end of the ninety-day experiment period, cardiac perfusion was applied to all animals in five groups, with 6 animals remaining in each group. Sections taken from the hippocampus region of the obtained brain tissues; were used in stereological, histopathological and immunohistochemical evaluations. In stereological analyses, the ratios of the volumes of the hippocampus layers to the whole hippocampus volume were compared between the groups. Sections taken for histopathological evaluations were examined by light microscopic and electron microscopic methods. S100, Caspase 3 and SOX 2 antibodies were used in immunohistochemical studies. Results: In stereological analysis, no statistically significant difference was observed in the volume ratio of the four layers of the hippocampus. Only stratum lucidum layer volume ratio increased. It was observed that sciatic nerve damage and diabetes cause pathological changes in different degrees and forms. It was determined that curcumin, one of the antioxidants given, had a healing effect on histopathological changes, and Garcinia kola had a less protective effect. Discussion and Conclusion: While sciatic nerve damage and diabetes did not change the volume ratio of the layers, except for the stratum lucidum, only the volume ratio of this layer increased. Histopathological and immunohistochemical findings in the sham and diabetes groups showed partial improvement and changes in the Garcinia kola and curcumin groups.