Muir J L, Pfister H P
Physiol Behav. 1987;40(1):103-7. doi: 10.1016/0031-9384(87)90191-0.
Marked changes in corticosterone and prolactin levels are observed following repeated psychological stress. Furthermore, these responses appear to be affected by the pattern of exposure to the stressor. The present study examined the time course of the corticosterone and prolactin responses following predictable and unpredictable novelty stress. On the fifth day of stress treatment, predictable and unpredictable exposure to the novelty apparatus produced a peak corticosterone response after 15 min of stress treatment. Although corticosterone levels began to decline for both these treatment groups after 15 min, substantially higher levels were observed following unpredictable stress. The steroid levels of animals receiving unpredictable stress treatment continued to be significantly higher than those receiving predictable stress until 30 min post-stress. Predictable stress failed to significantly alter prolactin levels from controls at any of the time points examined. However, unpredictable exposure to the novel apparatus produced high baseline prolactin levels and a subsequent suppression of this response during exposure to the stressor. It was concluded that the differences obtained between animals receiving predictable and unpredictable exposure to novelty reflect a difference in the magnitude of these responses rather than a difference in their temporal pattern.
反复遭受心理应激后，可观察到皮质酮和催乳素水平发生显著变化。此外，这些反应似乎受应激源暴露模式的影响。本研究考察了可预测和不可预测的新奇应激后皮质酮和催乳素反应的时间进程。在应激治疗的第五天，可预测和不可预测地暴露于新奇装置后，应激治疗15分钟时皮质酮反应达到峰值。尽管这两个治疗组在15分钟后皮质酮水平开始下降，但不可预测应激后观察到的皮质酮水平显著更高。接受不可预测应激治疗的动物的类固醇水平在应激后30分钟内一直显著高于接受可预测应激的动物。在任何检测时间点，可预测应激均未显著改变催乳素水平。然而，不可预测地暴露于新奇装置会导致催乳素基线水平升高，随后在暴露于应激源期间该反应受到抑制。得出的结论是，接受可预测和不可预测新奇暴露的动物之间的差异反映了这些反应强度的差异，而非其时间模式的差异。
