POSSIBLE EFFECTS OF ELECTRIC-MAGNETIC STIMULATION ON HYPOTHALMIC-HYPOPHISIAL-ADRENAL AXIS: BEHAVIOURAL STUDY

The goal of this investigation was to study the effect of the electric-magnetic stimulation (EMS) on the activity of the HPA axis, which can change behavior activity. The experiments were conducted on mongrel, albino male rats, weighing 150- 200 g (n=14). Proceeding from the goals set, the experimental group (dexamethasone-treated-1mg/ per animal for 10 days) and the control group of rats were involved in the experiments. Each group was divided into subgroups. Some rats from the subgroup were given EMS. The Control group of rats received the same amount of saline. Electro-Magnetic stimulation parameters: 10000 -15000 Hz frequency, 1,5 m/Tesla, for 15 min, during 10 consecutive days. The Forced Swimming, the Open Field, and the Active Wheel Tests were choosing for monitoring of behavior indicators. The obtained results were processed using an adequate statistical program. 1. In FST on the background of dexamethasone injection, the time of immobilization (p<0.01) was increased, the active swimming time (p<0.05), the time of the struggling (p<0.05) and the time spent under the water (p<0.05) were decreased. This fact indicates the development of depressive-like behavior. The EMS reduced immobility time in the FST (p<0.01) and increased struggling behavior (p<0.05), swimming in the FST (p<0.05), and the time spent under the water in the dexamethasone-treated rat. The Injection of Dexamethasone caused changes in motivational-emotional behavior in Open Field Test: all parameters of research-motor activity were reduced compared to normal (untreated) rats. The EMS after dexamethasone injection enhanced behavior activity of rats: research-motivated activity. We can assume that EMS strengthens self-regulatory mechanisms, which increases the resistance of the organism to stress factors, in this case, under the conditions of artificial administration of dexamethasone. 3. After 10 days of administration of dexamethasone, the locomotor activity of rats was significantly reduced during the 24-hour active wheel test. On the background EMS the motor activity dramatically increased in dexamethasone-treated rats It is possible to assume that EMS exerts antidepressant effects against the background of dexamethasone injection and inhibits the activity of the hypothalamic-pituitary-adrenal system. Against the background of high doses of dexamethasone, EMS causes the body to become more active, change the depressive-like behavior, reduces the alarm response, and increases research activity. We suppose that EMS suppresses the GRs expression (negative feedback) which reduces the activity of the HPA axis, and recover behavioral disorders induced by depression.