Basic research on the effect that coping behavior against emotional stress has on immunity.

点击翻译按钮获取中文摘要

The aim of this study is to examine whether or not an acquired coping behavior to a stressor can prevent the emergence of physical diseases caused by stress. For that purpose, we used emotional stress caused by direct electrical stimulation to the center of emotion in the brain in order to elucidate the effects of switch-off behavior on the changes in immunity under emotional stress.Our study suggested :1. When electrical stimulation to the hypothalamus, which elicits an emotional behavior called restlessness, and is known to be one kind of emotional stress, the number of peripheral blood granulocytes increased while, in contrast, the number of T lymphocytes decreased. These changes in the number of leukocytes in the peripheral blood might indicate that the immune system is in a "battle state". However, if such a "battle state" continues for too long a period, then the immune system may become exhausted.2. When the cat learned switch-off behavior in which the cat was able to turn off the hypothalamic stimulation, then the increase in the number of granulocytes caused by restlessness was suppressed. As a result, appropriate coping behavior to an aversive emotional stress may suppress the induction of unnecessary immunity activation, thereby preventing immune exhaustion.3. A behavioral analysis and the measurement of the plasma concentration levels of cortisol and catecholamines revealed that the effect of the switch-off behavior in immunity was not merely due to the physical exercise of the cat.In general, the suppression of the immune function caused by stress has been reported to possibly enhance the development of such diseases as infections or tumors. Our study suggested that learning an appropriate coping behavior to aversive emotional stress may suppress some of the needless changes in immunity caused by stress, and thereby prevent the onset of stress-related physical diseases.