ELECTRIC-MAGNETIC STIMULATION PREVENTS STRESS-INDUCED DETERIORATION OF SPATIAL MEMORY

In response to physical and psychological stressors, neurobiological processes are activated to maintain homeostasis. Stress alters the activity of the hypothalamic-pituitary-adrenal (HPA) axis. The mechanism for this effect is not yet clear. For the formation of moderate stress, the Chronic Immobilization Stress (CIS) model was chosen to perform the restriction of movement activity 2 hours every day for 20 days continuously. The impacts of CIS on cognitive function (elevated multi branch maze test) and Glucocorticoid receptor (GluR) levels in the hippocampus were studied in adult rats of both sexes. Electromagnetic stimulation (EMS) is an effective and non-invasive treatment method. After the end of CIS, the parameters of EMS (10000-15000 Hz, 1.5 m/Tesla, for 20 min, 10 days) on cognitive function and GluR changes were established in intact and gonadectomized rats. The study's goals were to determine the effect of CIS on spatial learning and GluR content in the hippocampus; b. the capacity of EMS to prevent or restore disorders developed in response to stress; and c. whether emerging stress responses are gender dependent. It has been revealed that immobilization stress increases the maze passing time and the number of errors in both male and female rats. The effect of stress was more significant in male rats than in female rats. Gonadectomy increased the maze passage time regardless of sex. EMS for ten days has a positive effect on spatial learning. In females subjected to stress, the time to complete the maze path was fully restored to the level of intact rats, although in males this time remained relatively high. The time spent to pass the trajectory was increased after ten days of stress without EMS. As a result of immobilization stress, in both intact and gonadectomized rats, the GluR content had decreased in the hippocampus but was restored after EMS. The CIS induced a reduction of GluRs in the hippocampus that is manifested as the deterioration of spatial memory. EMS restored GluR expression and had a facilitative effect on the performance of the intended task. The effects of EMS on GluRs were minimal in absence of sex hormones.