[Spleen morpho-functional changes after the induction of cell-mediated immune reaction in behaviorally selected gray...

In rats selected for aggressive or domesticated (tame) behavior, spleen morpho-functional changes were examined under the conditions of cell-mediated immune response using experimental autoimmune encephalomyelitis (EAE) model. Tame rats were found to present more severe clinical manifestations, characteristic to EAE, than those with an aggressive behavior. Body mass changes in EAE were significantly different in tame and aggressive rats. The relative adrenal gland mass of control animals in both groups was not different, while in EAE it increased in aggressive rats and remained unchanged in tame rats. The relative spleen mass in control tame rats was greater than in aggressive ones. In EAE, it sharply increased in tame rats and slightly decreased in aggressive animals. Spleen lymphoid nodule diameter in control aggressive rats was smaller than in tame rats. In EAE, it decreased in aggressive rats and remained unchanged in tame rats. In aggressive rats with EAE, marginal zone width decreased more abruptly, while germinal center diameter increased more markedly than in tame animals. It is suggested that different responses to EAE of rats with dissimilar behavioral characteristics, are associated with differently directed effect of their hypothalamic-pituitary-adrenal systems on the balance of cell-mediated and humoral components of the immune response in animals with contrasting behavior.