Peculiarities of Brain Cell Functioning in Hyperglycemia and Diabetes Mellitus

Hyperglycemia is a symptom and damaging factor of diabetes mellitus (DM) that leads to systemic complications in the body, including cerebral macro- and microangiopathies, impaired blood supply, appearance of neurodegeneration foci, and triggering neuroinflammation. Nervous tissue is characterized by a high level of energy consumption and is highly sensitive to fluctuations in the level of metabolic substrates. Therefore, it is extremely important to study the effect of high glucose levels on the functional state of the central nervous system. This review attempts to comprehensively assess the effects of hyperglycemia on brain cells. Analysis of experimental data on the morphofunctional state of neurons, microglia and astrocytes, obtained in in vivo and in vitro models of diabetes, showed that direct and indirect effects of high glucose concentrations depend on the cell type. Astrocytic and microglial receptors and intracellular signaling cascades, which mediate the effects of hyperglycemia and the development of neuroinflammation, can act as therapeutic targets for correcting diabetic consequences. Thus, the search for new ways to modulate the functional activity of glial cells may be an effective strategy in reducing the severity of CNS injuries and their aftereffects.