Social isolation rearing of rats decreases the nervous system's resistance to the psychogenic stress stimuli.

Established that one of the factors promoting development of the psycho-nervous diseases, are various kinds of social deprivation. The purpose of this study was investigation of importance of social interactions at the early period of postnatal in development of resistance of the nervous system against the psychogenic stress in the adult rats. At weaning, male albino outbred rats from three litters were housed socially (control rats) (n=12) or in isolation (n=14) for 8 weeks. Modeling the psychogenic stress was performed with the modified active avoidance response method. Judging by the speed of acquisition of the active avoidance response, i.e. the learning speed, the isolated rats significantly lagged behind the control animals. Behavioral acts in the control animals manifested with different duration and ratio, depending on the complexity of the task and situation, which should point at differential activities of the self-regulatory mechanisms, at different stages of psychogenic stress. In all situations: in acquisition-stabilization of the active avoidance responses and in conditions of the 14-days stressing, behavior of the isolated animals did not change and the horizontal standings were dominating, while the vertical standings and grooming were poorly displayed. Thus, the isolated rats are characterized with insufficient development of the self-regulatory mechanisms of the brain. Therefore, social deprivation decreases the nervous system's resistance to the stressogenic stimuli.