Neurodegenerative changes in the hippocampus within the early period of experimental diabetes mellitus

Abstract

We studied the dynamics of modifications of the structure and architectonics in different zones of the pyramidal layer of the rat hippocampus within the early periods (3, 7, and 14 days) after induction of diabetes mellitus by streptozotocin. Using confocal immunofluorescence microscopy, we found neurons containing a specific protein, NeuN; a fluorescence dye, Hoechst 33258, allowed us to visualize the cell nuclei. The density of localization of neurons in the CA2 area decreased significantly on the 3rd day of development of diabetes. In the CA1 and CA3 areas, a significant decrease in this index was observed beginning from the 7th day. Within this time interval, we observed neurons with clear condensation of chromatin in the nuclei of these cells. The obtained data indicate that formation of appreciable neurodegenerative changes in the hippocampus occurs within the initial stages of development of experimental diabetes mellitus; this phenomenon can be a factor in the development of diabetic encephalopathy.