Morphofunctional changes in cerebral motor cortex in experimental type I diabetes mellitus

Abstract

The aim was to study morphofunctional changes in neurons in the motor cortex of rats with experimental type 1 diabetes mellitus (DM) and its pharmacological correction with mefargine, aminolone and succicard. Material and methods. Modeling of diabetes mellitus was performed on white mongrel female laboratory rats at the age of 12 months. The animals were divided into 5 groups: I – group of intact animals; II-1 – group of pharmacological correction with succicard, II-2 – correction with aminalon, II-3 – correction with mefargine and III – group of DM without treatment. DM was modeled by a single intraperitoneal administration of streptozotocin dissolved in citrate buffer (0.1 M, pH 4.5) (Sigma, USA) at a dose of 60 mg/kg after 48 hours of food deprivation. Treatment was started 6 months after the DM simulation. Statistical processing of the obtained results was carried out using descriptive and analytical statistics using Prism 6 software (GraphPad Software Inc., USA). Results. Histological examination of the motor cortex of intact rats (group I) revealed hyperchromic neurons in all the cortical layers. In group III, pronounced hyperchromatosis was observed in layers 2, 3, 5, in comparison with group I, a decrease in the area of pericaryons was revealed by 17.2% (p<0.001), the area of nuclei was less by 26% (p<0.001), there was a decrease in nuclear-cytoplasmic ratio (NCR) by 18% (p<0.001). The animals treated with succicard (II-1) showed the least pronounced neurodegenerative changes in comparison with groups I, II-2 (aminalon) and II-3 (mefargine). In group II-1, there was an increase in the area of pericaryons by 26% (p<0.001), the area of nuclei by 39.7% (p<0.001), and the NCR by 23% (p<0.001) compared with the group without treatment (I-1). Conclusion. Morphometric examination of the inner pyramidal layer of the motor cortex of the studied groups revealed the most pronounced pathomorphological changes in diabetic rats without treatment, which were expressed in a tendency to increase the content of damaged neurons, in a statistically significant decrease in the area of pericaryons and nuclei. The most pronounced neuroprotective effect was observed with the use of succicard.