Maternal care determines rapid effects of stress mediators on synaptic plasticity in adult rat hippocampal dentate gyrus
Maternal care determines rapid effects of stress mediators on synaptic plasticity in adult rat hippocampal dentate gyrus
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DOI：
10.1016/j.nlm.2009.03.004
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发表时间：
2009-10-01
影响因子：
2.7
通讯作者：
Joels, Marian
中科院分区：
文献类型：
--
作者：
Bagot, Rosemary C.;van Hasselt, Felisa N.;Joels, Marian
大鼠的母亲护理影响海马发育、突触可塑性和认知。然而，以前的研究已经在最小压力条件下检查了动物。在这里，我们测试的假设，产妇护理影响海马功能不同，当这个结构暴露于皮质类固醇和去甲肾上腺素能激素，这是升高的早期阶段的应激反应。在Long-Evans母鼠的成年雄性后代中，特征为高或低的母性护理（1）用高尔基体染色法观察齿状回基底树突形态，（2）研究糖皮质激素和β-肾上腺素能刺激对齿状回长时程增强（LTP）的快速调节;（3）采用情境恐惧条件反射和线索恐惧条件反射研究应激条件下海马和杏仁核的学习功能。我们发现高和低LG母亲的成年后代海马齿状回形态的差异，低LG后代的树突复杂性较低。在基础条件下，LTP是较低的切片从低相比，高LG的后代。海马LTP迅速增加皮质酮（100纳米）或异丙肾上腺素（1.0 μ M）在低LG后代，这表明在压力下改善齿状回可塑性。这反映在海马体，但不是杏仁核依赖的学习，低LG后代表现出增强的上下文，但没有线索的恐惧条件反射。我们认为，在出生后的生活中，降低幼仔LG可能是适应高威胁的环境中，潜在的增强海马功能的条件下，逆境中的后代。(C)2009 Elsevier Inc. All rights reserved.
Maternal care in the rat influences hippocampal development, synaptic plasticity and cognition. Previous studies, however, have examined animals under minimally stressful conditions. Here we tested the hypothesis that maternal care influences hippocampal function differently when this structure is exposed to corticosteroid and noradrenergic hormones, which are elevated during the early phase of a stress response. In the adult male offspring of Long-Evans dams characterised as high or low in maternal care (high LG and low LG) we (1) examined basal dendritic morphology in the dentate gyrus by Golgi staining; (2) investigated rapid modulation of in vitro long term-potentiation (LTP) in the dentate gyrus by glucocorticoid and beta-adrenergic stimulation; (3) examined hippocampal and amygdala-dependent learning under stress using contextual and cued fear conditioning. We found differences in hippocampal dentate gyrus morphology in adult offspring of high and low LG mothers, with less dendritic complexity in low LG offspring. Under basal conditions LTP was lower in slices from low compared with high LG offspring. Hippocampal LTP was rapidly increased by either corticosterone (100 nM) or isoproterenol (1.0 mu M) in low LG offspring, suggesting improved dentate plasticity during stress. This was mirrored in hippocampal but not amygdala-dependent learning, as low LG offspring showed enhanced contextual but not cued fear conditioning. We suggest that decreased pup LG during postnatal life may be adaptive in high-threat environments, potentially enhancing hippocampal function in the offspring under conditions of adversity. (C) 2009 Elsevier Inc. All rights reserved.