Expression of Genes Regulating Synaptic Plasticity in the Hippocampus and Spatial Learning in Rats of Different Age with Streptozotocin-Induced Diabetes

This study presents the results of a comparative analysis of the expression of genes regulating synaptic plasticity, spatial learning ability, and the preservation of the acquired skill in 3-month-old and 18-month-old animals with streptozotocin-induced diabetes. The Morris maze was used to assess spatial learning. In the hippocampus, the relative level of transcripts of the c-fos, c-jun, Egr-1, and Cyt-c genes was investigated using real-time polymerase chain reaction. On the third day of testing in the Morris water maze, the time to reach the platform in 18-month-old rats exceeded the respective values of 3-month-old rats, as seen after modeling of streptozotocin-induced diabetes. The expression levels of the c-fos, c-jun, and Egr-1 genes in 3-month-old rats increased both in response to the development of spatial learning and modeling of diabetes; in 18-month-old rats, a decrease in the level of expression of this gene was observed in the model of streptozotocin-induced diabetes. In both groups, we observed an increase in the level of expression of the Cyt-c gene in diabetes relative to control and, in 18-month-old rats, the increase in this index was more pronounced.