Behavioral Reactions, Corticosterone Concentrations, and the Expression of Cytokine Genes in Experimental Postviral Fatigue in Animals

The aim of the present work was to study the processes of the interaction between the nervous, endocrine, and immune systems in experimental postviral fatigue, by studying behavioral reactions, changes in blood corticosterone levels, and changes in the level of expression of the IL-1β and IL-10 genes in the hypothalamus and interferon-α in the hypothalamus and spleen in rats. Decreases in the physical activity displayed by the animals were seen on days 7 and 10 after modeling of experimental postviral fatigue by i.p. administration of poly I:C, along with increases in the blood corticosterone concentration and increases in the expression of genes for pro- and anti-inflammatory cytokines and interferon. Repeat administration of poly I:C was followed by increases in physical activity and repeated delayed changes in the functions of the endocrine and immune systems. The changes seen in the ratio of changes in the study parameters provides evidence of the need for complex studies of changes in the functions of the nervous, endocrine, and immune systems in this disease.