Gao Ying, Han Huili, Xu Ruchang, Cao Jun, Luo Jianhong, Xu Lin
Department of Neurobiology, Institute for Neuroscience, Zhejiang University School of Medicine, Hangzhou 310058, PR China.
Neurosci Res. 2008 Aug;61(4):385-9. doi: 10.1016/j.neures.2008.04.006. Epub 2008 Apr 25.
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 1 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.
急性应激事件会增强血浆皮质酮的释放，并深刻影响突触功能，而这些功能与应激相关的认知和精神障碍的发展有关。然而，应激后立即暴露于应激环境如何进一步调节生理反应尚未完全清楚。在此，我们发现急性应激抑制了经历情境恐惧条件反射的Wistar大鼠海马切片中的双脉冲易化。但随后长时间暴露于足部电击情境或返回饲养笼1小时可逆转这种抑制。有趣的是，低频刺激（LFS，1 Hz下900个脉冲）诱导的足部电击应激促进的长时程抑制（LTD）在随后暴露于足部电击情境时得以维持，但返回饲养笼环境则可逆转。此外，暴露于足部电击情境而非饲养笼的大鼠血浆皮质酮水平仍保持较高。研究结果表明，应激后立即留在应激环境中会维持急性应激促进的LTD和较高水平的神经内分泌反应。我们的结果也有助于进一步理解及时干预在介导人类应激相关厌恶变化中的关键作用。
