Effect of induced diabetes on morphometric indexes of the cerebellar cortex and gene expression in C57BL mice

OBJECTIVE(S): Diabetes is a metabolic disorder that affects the development of the central nervous system and plays an important role in learning and memory. Diabetes increases the reactive oxygen species (ROS) level in cells and changes the expression of several genes, including SYP, BDNF, PAX7, and SYNCAM1, through the FOXO transcription factor. This study was done to assess the effect of diabetes on morphometric indexes of the cerebellar cortex and gene expression in mice. MATERIALS AND METHODS: Diabetes was induced in twelve adult, male C57BL mice using an injection of streptozotocin. After two months, the mice were dissected, and the cerebellum was stored for further analysis. For the morphometric analysis, tissue sections were stained with cresyl violet and examined with a light microscope. For gene expression analysis, the RNA was extracted, and cDNA was synthesized. The mRNA levels of SYP, BDNF, PAX7, and SYNCAM1 genes were measured by the real-time PCR method. RESULTS: The thickness of the molecular layer and Purkinje layer, and the number of Purkinje and granular cells in the diabetic group were significantly reduced compared to controls P<0.0 1). The area, perimeter, and diameter of Purkinje cells in the diabetic group were significantly reduced compared to controls P<0.0 1). The expression of PAX7, SYP, and BDNF genes of the diabetic group was significantly reduced. However, SYNCAM1 expression in the cerebellum of the diabetic group was significantly increased compared to controls (P<0.05). CONCLUSION: Induced diabetes in mice can decrease the expression of memory-related genes in the cerebellum. Also, these genes affect the morphology and thickness of the cerebellum.