Barnum C J, Blandino P, Deak T
Behavioural Neuroscience Program, Department of Psychology, State University of New York, Binghamton, NY 13902-6000, USA.
J Neuroendocrinol. 2007 Aug;19(8):632-42. doi: 10.1111/j.1365-2826.2007.01571.x.
Previous studies have shown that repeated daily exposure to the same (homotypic) stressor results in habituation of the corticosterone (CORT) response. Others have found that the stress response to a more ethologically relevant stressor, social defeat, does not habituate and, in some cases, sensitisation has been observed. Similar observations have been noted when core temperature is examined. Although habituation and/or sensitisation have been reported during stressor exposure, little is known about the development of an anticipatory fever in response to daily stressor exposure. The aim of the present study was to compare systematically commonly used laboratory stressors (i.e. restraint, cage confinement and social defeat) using a common set of procedures and analyses. Specifically, we examined: (i) the development of an anticipatory fever to repeated (5 days) homotypic stressor exposure; (ii) the adaptation of the fever response during stressor exposure; and (iii) the resolution of the fever response to stressors presented at the same time each day. For comparison, adaptation of the CORT response was also examined to assess the degree to which habituation to repeated stressor exposure may represent a more general response observed across diverse physiological measures. Habituation was observed after restraint and cage confinement, but not observed in either the CORT or hyperthermic responses to repeated social defeat. Furthermore, no anticipatory fever response was observed with repeated exposure to restraint, cage confinement, or social defeat. These data suggest that habituation to repeated stressor exposure may not occur with all homotypic stressor paradigms. In addition, rats do not appear to entrain an anticipatory fever response to a stressor presented at the same time each day, at least not within 5-6 days of repeated exposure.
先前的研究表明，每天重复暴露于相同（同型）应激源会导致皮质酮（CORT）反应产生习惯化。其他人发现，对更符合行为学的应激源——社会挫败的应激反应不会产生习惯化，并且在某些情况下，还观察到了敏感化现象。在检查核心体温时也有类似的观察结果。尽管在应激源暴露期间已经报道了习惯化和/或敏感化现象，但对于每日应激源暴露所引发的预期性发热的发展情况却知之甚少。本研究的目的是使用一套通用的程序和分析方法，系统地比较常用的实验室应激源（即束缚、笼养限制和社会挫败）。具体而言，我们研究了：（i）重复（5天）同型应激源暴露后预期性发热情况的发展；（ii）应激源暴露期间发热反应的适应性；以及（iii）每天同一时间出现的应激源所引发的发热反应的消退情况。为了进行比较，还检查了CORT反应的适应性，以评估重复应激源暴露后的习惯化在多大程度上可能代表了在各种生理指标中观察到的更普遍的反应。在束缚和笼养限制后观察到了习惯化现象，但在对重复社会挫败的CORT或体温过高反应中均未观察到习惯化现象。此外，重复暴露于束缚、笼养限制或社会挫败后，均未观察到预期性发热反应。这些数据表明，并非所有同型应激源模式都会出现重复应激源暴露后的习惯化现象。此外，大鼠似乎不会对每天同一时间出现的应激源产生预期性发热反应，至少在重复暴露的5 - 6天内不会出现。
