Blunted cortisol rhythm is associated with learning impairment in aged hamsters
Blunted cortisol rhythm is associated with learning impairment in aged hamsters
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DOI：
10.1016/j.physbeh.2004.04.004
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发表时间：
2004-09-15
影响因子：
2.9
通讯作者：
Ralph, MR
中科院分区：
文献类型：
--
作者：
Cain, SW;Karatsoreos, I;Ralph, MR
在哺乳动物中，伴随着不成功的衰老而出现的认知衰退与昼夜节律障碍和循环中糖皮质激素水平的增加有关。这些因素之间可能的因果关系尚不清楚。为了测试生物钟功能紊乱与糖皮质激素水平升高对年龄相关学习障碍的主要影响，我们测量了老年仓鼠(15-18个月)的皮质醇和车轮跑步节奏以及上下文学习。在这个年龄段，学习者和非学习者的运动节奏被发现是难以区分的。然而，受损动物的血浆皮质醇水平较低，皮质醇节律的幅度降低。这些数据表明，与年龄相关的认知下降可能更多地与荷尔蒙节律性的丧失有关，而不是与行为节律性的丧失或荷尔蒙水平的增加有关。(C)2004 Elsevier Inc.保留所有权利。
In mammals, the cognitive decline that accompanies unsuccessful aging is associated with circadian rhythm dysfunction and increased levels of circulating glucocorticoids. The possible causal relations among these factors are not known. To test for primary effects of circadian clock dysfunction versus increased glucocorticoid levels as contributors to age-related learning impairment, we measured cortisol and wheel-running rhythms along with context learning in aged hamsters (15-18 months). At this age, locomotor rhythms of learners and nonlearners were found to be indistinguishable. However, plasma cortisol levels were lower, and the amplitude of the cortisol rhythm was reduced in the impaired animals. These data suggest that age-related cognitive decline may be related more to a loss of hormone rhythmicity than to a loss of behavioral rhythmicity or an increase in hormone level. (C) 2004 Elsevier Inc. All rights reserved.