Diabetes mellitus has a major impact on the brain and its cognitive function. The pathogenesis of these disorders is still not well understood. Therefore, it is necessary to find ways of solving these manifestations in hyperglycemia in order to prevent the risk of complications that will lead to a worsening of living conditions.
In the experiment, the state of conditioned-reflex and orientation-research activity of rats of different ages (middle-aged rats and old rats) in conditions of experimental hyperglycemia was found. The animals were kept under standard vivarium conditions. Experimental hyperglycemia was modeled by intraperitoneal solution injection of alloxan monohydrate (120 mg/kg body weight, Sigma). For 10 days, blood glucose was determined using a portable glucometer «Bionime». On day 10, those animals were selected that had a blood glucose value above 28 mmol/L. The analysis of orientation-research and emotional activity was carried out using the «Open Field» technique. The number of squares crossed, the number of lifts on the hind legs, the number of peeking into the burrows, grooming, and the number of bowel movements were recorded. The conditioned passive avoidance technique was used to study the stable and labile phases of memory. In both age groups, the indicators of orientation-research activity differed significantly (p < 0.05). The decrease in the number of squares crossed, the number of racks up and the study of minks was more pronounced in middle-aged animals with diabetes mellitus. The increase in the number of amnesiac animals was also more pronounced in the middle-aged rats of the research group. A decrease in the latency period was noted in both age groups. Thus, it was found that experimental hyperglycemia had pronounced consequences for the cognitive function of animals, respectively, diabetes mellitus has a negative effect on the brain.
Diet-induced insulin resistance impairs hippocampal synaptic plasticity and cognition in middle-aged rats