[Psychoendocrinological study on the pituitary-adrenocortical system in rats. Part 2: The relationship of the nature of emotional stress and individual emotionality to plasma corticosterone (author's transl)].
In the previous paper the author described the effect of one kind of emotional stress (novel stimulus) on adrenocortical activity. In this study, two experiments were performed; the first experiment was to determine the relationship between the emotional state and adrenocortical response. The second experiment was to compare the effects of different kinds of emotional stress on corticosterone response. 1. An abnormal emotional state, i.e. a hyperemotional state, was induced by raising animals in a solitary condition for 3 weeks. Both group- and single-housed rats were subjected to repeated 3-min open field tests every day. At the first exposure to the stimulus, both rats responded with an almost identical rise of plasma corticosterone. In contrast with the group-housed animals, in which plasma corticosterone response to the stimulus diminished progressively during the repeated trials, plasma corticosterone in the single-housed rats continued to respond with almost the same magnitude as in the first trial. This indicates a defect in adaptation to a novel stimulus in rats raised alone. 2. Another type of emotional stress (communicated anxiety) was produced by an apparatus, called a communication box, in which test animals can sense the reaction of foot-shocked animals in the neighboring compartments. In contrast with the novel stimulus in the open field, the effect of communicated anxiety on plasma corticosterone did not diminish by repetition of the stimulus. This suggests that adaptation to a communicated anxiety stimulus is difficult to acquire as compared to that of a novel stimulus.
D000223:Adaptation, Psychological; D000819:Animal Communication; D000818:Animals; D001007:Anxiety; D003345:Corticosterone / Q000097:blood*; D004644:Emotions; D006801:Humans; D010913:Pituitary-Adrenal System / Q000502:physiology*; D051381:Rats; D012934:Social Isolation; D013315:Stress, Psychological / Q000502:physiology*
D003345:Corticosterone