Peculiarities of Formation and Reversibility of Neurogenic Stress-Related Emotional Disorders in Rats

Abstract

In experiments on rats, we modeled neurogenic stress-induced emotional disorders (stress was evoked by repetitive nociceptive stimulation) and studied their peculiarities within the stressory and post-stressory periods. In these animals, drastic changes in the brain electrical activity and emotional behavior gradually developed; such changes were manifested over a long time period after cessation of the stressory influences. Our experiments demonstrated that tight and stable interrelations among brain limbic structures and negative hypothalamic emotional centers are formed under conditions of prolonged action of emotional stress. This results in the development of a protracted state of negative emotional excitation. The hippocampus is considered one of the key limbic structures responsible for the development of stable pathological stress-related reactions of the brain. Within the post-stressory period, we observed dramatic worsening of the general functional state of the animals, which developed in a parallel manner with intensification of the activity of the negative emotiogenic brain system. It is probable that the existence of periods of unstable equilibrium between oppositely directed emotional reactions in the dynamics of stress and after cessation of stressory influences is a common rule. Such periods reflect peculiarities of rearrangements in the adaptive brain mechanisms under conditions of a stable change in the mode of brain functioning in one particular situation or another.