Semax as a modulator of the psycho-emotional status of rats in an experimental model of depression based on stress

In modern physiology, the priority direction is the study of the influence of various types of stress, leading, as a rule, to the development of depressive states, on the physiological systems of the body. The main methods for assessing the neuroprotective effect, which is the main component of defense against stress, include the study of behavioral reactions that reflect motor, emotional, and cognitive changes. The study of drugs based on regulatory peptides is promising. Semax (ACTH4-7PGP) is a representative of a new synthetic peptide engineering, practically devoid of a hormonal effect and completely preserving the neurotropic activity of adrenocorticotropic hormone. The aim of the work was an experimental study of the effect of semax on the behavior of animals under the influence of experimental depression based on “social” stress. Material and methods. The study was carried out on 50 outbred male rats aged 6 months. Semax effects were studied under conditions of sensory contact - a model of experimental depression based on the formation of aggressive and submissive behavior in animals, using the multicomponent model the Suok test (“ropewalking”) and the Porsolt test to assess the depressive behavior of rats. Results and its discussion. Intermale confrontations led to a decrease in the time spent in the light half of the test, the number of “exploratory” downward glances, directional head movements; a decrease in the number of visited segments in the light section in victims and aggressors. As a whole, the study of behavioral reactions in animals in the Suok test and the Porsolt test in the model of experimental depression (sensory contact) showed the formation of an anxious-depressive state in animals, which was confirmed by a decrease in the motor and exploratory activity of rats. The results were obtained during the Porsolt test, indicating the formation of a depressive state in animals, which was confirmed by an increase in the total period of immobility in both aggressors and victims, an increase in the time of passive swimming, and a decrease in the time of active swimming. With a comprehensive assessment of animal behavior indicators in the Suok test, against the background of a decrease in the level of anxiety under the influence of semax, an improvement in the parameters of exploratory behavior was observed, in the Porsolt test – of motor activity indicators. Conclusions. Investigation of semax effect on the behavioral reactions of animals under conditions of sensory contact indicates that this drug exhibits an anxiolytic and antidepressant effect, eliminating pathological changes in the psycho-emotional status of animals.