THE ACOUSTIC RANGE ELECTRIC-MAGNETIC FIELD EFFECT ON THE PASSIVE AVOIDANCE TASK IN DEPRESSED RATS

Depression linked to memory problems, such as forgetfulness or confusion. Stress and anxiety can also lead to poor memory. Memory processes are affected by repeated electric-magnetic stimulation (EMS). The current study aimed to explore the effects of EMS on locomotor activity and cognitive function in clomipramine-induced depressed rats. In the implementation of the project, the depressed rats and albino intact rats (250-450 g) were used (n=20). An animal model of depression was received by subcutaneous injection of Clomipramine from 8 to 21 days of neonatal development. The control group received a saline injection in the same period of life. The determination of depression and anxiety reaction of rats was performed 2 months later after clomipramine injection in open field and Forced Swim Tests. For studying EMS effects on the cognitive function of depressed rats, a passive avoidance test was used. During the initial phase, the animal learns that moving to the dark compartment has negative consequences (rat receives a mild foot shock-12 imp/min; 1.5mA). Animals were tested 1, 3, 5, 14 and 30 days after learning test in the chamber. Data reliability was assessed using parametric and non-parametric techniques, with the use of the one-way layout of factorial analysis. In pilot experiments, we have obtained the optimal parameters of repeated EMS (10000 -15000 Hz frequency, 1,5 m/Tesla, during 15 min, 10 days), which fully or partially Inhibit depressive-like ECoG and behavior activity in rats. On the background of EMS, in depressed rats, in the learning test, the latent period of entrance into the dark chamber decreased (p<0.01) compared to non-stimulated ones. The EMS before the learning test of depressed rats, did not affect the performance of the retention test 24 h, 3, 5 days later. The effects of EMS on the passive avoidance retention test were impaired only 14 days after the learning test. Non-stimulated depressed rats did not "make mistake", they had remembered the learning test 1 month later. Both stimulated or non-stimulated control, non-depressed rats attenuated the performance of passive avoidance on the14 day after the learning test. The behavior of rats also was different in the lit section. The number of attempts to enter into the dark section changed. The research activity was increased both in the depressed and non-depressed rats on the background of EMS compared to non-stimulated ones. We might think, that either the control rats have learned better the instrumental reflex (to perform a passive avoidance reaction) or due to the high degree of depression, the locomotor-exploratory activity of animals is decreased (p<0.01), which causes the test to be properly performed. The latter assertion is confirmed by data, received in the open field test. Therefore, the acoustic range EMS decreases fear and anxiety degree and consequently, increases the locomotor-exploratory activity and attenuates retention of passive avoidance task. Thus, the acoustic EMS reduces the level of fear and anxiety, and therefore, increases motor activity, which worsens the clomipramine. It offers clinicians a novel alternative for the treatment of this disorder.