Repeated ferret odor exposure induces different temporal patterns of same-stressor habituation and novel-stressor sensitization in both hypothalamic-pituitary-adrenal axis activity and forebrain c-fos expression in the rat.
Repeated ferret odor exposure induces different temporal patterns of same-stressor habituation and novel-stressor sensitization in both hypothalamic-pituitary-adrenal axis activity and forebrain c-fos expression in the rat.
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DOI：
10.1210/en.2008-0958
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发表时间：
2009-02
期刊：
影响因子：
4.8
通讯作者：
M. Weinberg;A. Bhatt;M. Girotti;C. V. Masini;H. Day;S. Campeau;R. Spencer
中科院分区：
文献类型：
--
作者：
M. Weinberg;A. Bhatt;M. Girotti;C. V. Masini;H. Day;S. Campeau;R. Spencer
重复暴露于中等强度的应激源通常会导致下丘脑-垂体-肾上腺（HPA）轴反应（习惯化）在重新呈现相同的应激源时减弱;然而，如果将新的应激源呈现给相同的动物，HPA轴反应可能会增强（致敏）。这种适应在神经活动模式中也很明显的程度是未知的。本研究测试是否重复雪貂气味（FO）曝光，一个中等强度的心理应激大鼠，导致相同的应激源习惯化和新的应激源敏感的HPA轴反应和神经元活动的决定立即早期基因诱导（c-fos mRNA）。将大鼠在其家中笼中给予FO，每天30分钟，持续长达2周，随后用FO或束缚进行激发。大鼠显示HPA轴活动习惯和广泛的习惯性c-fos mRNA表达（原位杂交）在整个大脑中，只有三个重复介绍FO。然而，反复FO暴露导致更渐进的发展致敏HPA轴和c-fos mRNA反应的限制，并不完全明显，直到14天前FO曝光。在许多表现出习惯性的大脑区域，包括初级感觉皮层和前额叶皮层，敏化反应是明显的。习惯化和敏感化神经反应模式的共享空间表达但不同的时间发展表明两个独立的过程在重叠的大脑系统中具有相反的影响。
Repeated exposure to a moderately intense stressor typically produces attenuation of the hypothalamic-pituitary-adrenal (HPA) axis response (habituation) on re-presentation of the same stressor; however, if a novel stressor is presented to the same animals, the HPA axis response may be augmented (sensitization). The extent to which this adaptation is also evident within neural activity patterns is unknown. This study tested whether repeated ferret odor (FO) exposure, a moderately intense psychological stressor for rats, leads to both same-stressor habituation and novel-stressor sensitization of the HPA axis response and neuronal activity as determined by immediate early gene induction (c-fos mRNA). Rats were presented with FO in their home cages for 30 min a day for up to 2 wk and subsequently challenged with FO or restraint. Rats displayed HPA axis activity habituation and widespread habituation of c-fos mRNA expression (in situ hybridization) throughout the brain in as few as three repeated presentations of FO. However, repeated FO exposure led to a more gradual development of sensitized HPA-axis and c-fos mRNA responses to restraint that were not fully evident until after 14 d of prior FO exposure. The sensitized response was evident in many of the same brain regions that displayed habituation, including primary sensory cortices and the prefrontal cortex. The shared spatial expression but distinct temporal development of habituation and sensitization neural response patterns suggests two independent processes with opposing influences across overlapping brain systems.