Acute and repeated stress differentially regulates behavioral, endocrine, neural parameters relevant to emotional and stress response in young and aged rats
Acute and repeated stress differentially regulates behavioral, endocrine, neural parameters relevant to emotional and stress response in young and aged rats
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DOI：
10.1016/j.bbr.2010.03.025
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发表时间：
2010-08-25
影响因子：
2.7
通讯作者：
Mizoguchi, Kazushige
中科院分区：
文献类型：
--
作者：
Shoji, Hirotaka;Mizoguchi, Kazushige
衰老与压力环境中情绪和内分泌反应的失调有关。为了了解应激易感性随年龄增长的发育机制，我们研究了重复应激对青年(3月龄)和老年(24月龄)F344/N雄性大鼠的行为、内分泌和神经参数的影响，这些参数与情绪和应激反应有关。青年大鼠和老年大鼠连续14天接受1h的束缚应激，或不受干扰。手术结束后，在开阔场地和高架正迷宫测试中检查行为，以评估衰老和重复应激引起的焦虑水平。在行为学测试后，检测血清皮质酮浓度和对急性束缚应激反应的脑内c-Fos免疫反应。在两项测试中，对照组和反复应激的老年大鼠比对照组和反复应激的年轻大鼠表现出更多的焦虑相关行为。特别是，反复应激老龄大鼠在高架+迷宫中表现出比对照老龄和反复应激青年大鼠更多的焦虑相关行为，尽管应激青年大鼠与对照青年大鼠没有区别。反复应激的老年大鼠在急性应激反应中表现出比所有其他条件下的受试者更高的血清皮质酮浓度。在c-Fos表达方面，与急性应激青年大鼠相比，急性应激大鼠的前额叶皮质、视前内侧区、终纹床核、伏隔核、杏仁内侧核和CA3区c-Fos阳性细胞减少，而中缝背核和室旁核的小细胞部c-Fos阳性细胞数增加。这些结果表明，反复应激增强了老年大鼠的情绪和应激反应，但对年轻大鼠没有影响，这表明衰老导致有机体对应激变得脆弱，这可能是通过调节情绪和应激反应的大脑系统功能障碍来调节的。(C)2010爱思唯尔B.V.保留所有权利。
Aging is associated with dysregulation of emotional and endocrine responses in a stressful environment. To understand the developmental mechanisms of stress vulnerability with aging, we investigated the effects of repeated stress on behavioral, endocrine, and neural parameters relating to emotional and stress responses in young (3 months old) and aged (24 months old) F344/N male rats. Young and aged rats were either subjected to 1-h restraint stress for 14 consecutive days or left undisturbed. After the procedures, behaviors were examined in open-field and elevated plus-maze tests to evaluate the level of anxiety induced by aging and repeated stress. Following the behavioral tests, serum corticosterone concentrations and c-Fos immunoreactivity throughout the brain in response to acute restraint stress were examined. Control and repeatedly stressed aged rats showed more anxiety-related behaviors than control and repeatedly stressed young rats in both tests. In particular, repeatedly stressed aged rats showed more anxiety-related behaviors in the elevated plus-maze than control aged and repeatedly stressed young rats, although stressed young rats were not different from control young rats. Repeatedly stressed aged rats showed higher serum corticosterone concentrations in response to acute stress than subjects in all other conditions. In c-Fos expression, control aged rats showed decreases in c-Fos-positive cells in response to acute stress in the prefrontal cortex, medial preoptic area, bed nucleus of the stria terminalis, nucleus accumbens, medial amygdaloid nucleus, and CA3 subfield of hippocampus, whereas they showed increases in the dorsal raphe nucleus and parvocellular part of the paraventricular nucleus of the hypothalamus compared to acutely stressed control young rats. These results indicate that repeated stress enhances emotional and stress responses in aged rats but not in young rats, suggesting that aging causes organisms to become vulnerable to stress, which might be mediated by dysfunction of the brain system regulating emotional and stress responses. (C) 2010 Elsevier B.V. All rights reserved.