Effects of prolonged exposure to context following contextual fear conditioning on synaptic properties in rat hippocampal slices
Effects of prolonged exposure to context following contextual fear conditioning on synaptic properties in rat hippocampal slices
复制标题
情境恐惧调节后长时间暴露于情境对大鼠海马切片突触特性的影响
DOI：
10.1016/j.neures.2008.04.006
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发表时间：
2008-08-01
影响因子：
2.9
通讯作者：
Xu, Lin
中科院分区：
文献类型：
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作者：
Gao, Ying;Han, Huili;Xu, Lin
急性应激事件会增加血浆皮质酮的释放，并深刻影响突触功能，这与应激相关的认知和精神障碍的发展有关。然而，如何暴露于应激环境后立即压力进一步调节生理反应还没有完全理解。在这里，我们发现，急性应激抑制配对脉冲易化的Wistar大鼠海马脑片进行上下文恐惧条件反射。但这种抑制被随后长时间暴露于足电击环境或返回笼舍1 h所逆转。有趣的是，由低频刺激（LFS，900脉冲，1 Hz）诱导的足电击应力促进LTD通过随后暴露于足电击环境得以维持，但通过返回到家庭笼环境而逆转。此外，血浆皮质酮水平仍然保持较高的大鼠暴露于足电击的背景下，而不是家庭笼。研究结果表明，在应激后立即保持在应激环境中维持急性应激促进LTD和更高水平的神经内分泌反应。我们的研究结果还有助于进一步了解及时干预在调解人类与压力相关的厌恶性变化方面的关键作用。(C)2008年爱思唯尔爱尔兰有限公司和日本神经科学学会。All rights reserved.
Acute stressful events enhance plasma corticosterone release and profoundly affect synaptic functions, which are involved in the development of stress-related cognitive and mental disorders. However, how exposure to stressful context immediately after stress further modulates the physiological responses is not fully understood. Here, we found that acute stress inhibited paired-pulse facilitation in hippocampal slices of Wistar rats which were subjected to contextual fear conditioning. But such inhibition was reversed by subsequent prolonged exposure to foot-shock context or returning to home cage for I h. Interestingly, foot-shock stress-facilitated LTD induced by low frequency stimulation (LFS, 900 pulses at 1 Hz) was maintained by subsequent exposure to foot-shock context but was reversed by returning to home cage environment. Moreover, plasma corticosterone level was still kept higher in rats exposed to foot-shock context but not to home cage. Findings suggest that remaining in stressful environment immediately after stress maintains acute stress-facilitated LTD and higher level of neuroendocrine response. Our results also contribute to further understanding the critical role of timely intervention in mediating stress-related aversive changes in human. (C) 2008 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.