Corticosterone slowly enhances miniature excitatory postsynaptic current amplitude in mice CA1 hippocampal cells
Corticosterone slowly enhances miniature excitatory postsynaptic current amplitude in mice CA1 hippocampal cells
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DOI：
10.1152/jn.00143.2005
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发表时间：
2005-11-01
影响因子：
2.5
通讯作者：
Joëls, M
中科院分区：
文献类型：
--
作者：
Karst, H;Joëls, M
皮质类固醇激素在应激后大量释放，并与大脑中的细胞内受体结合，这些受体以活化形式起转录因子的作用。我们在这里测试了高剂量的皮质酮对CA 1海马区AMPA受体介导的传递的影响，该区域富含皮质类固醇受体。为了关注激素的缓慢基因介导的作用，在肾上腺完整的成年小鼠切片上短暂应用100 nM皮质酮后至少1小时测量兴奋性突触后电流。结果发现，微突触后兴奋性电流的幅度而非频率显著增强。这些作用被100 nM RU 28362模拟，RU 28362是细胞内糖皮质激素受体的选择性激动剂。诱发AMPA反应在单细胞显着增强时，测量2-4小时后，应用100 nM皮质酮，但不是在更早的时刻，也没有更长的延迟。总之，本研究结果表明，海马糖皮质激素受体的激活诱导AMPA受体介导的反应，在单细胞水平的缓慢增强。
Corticosteroid hormones are released in high amounts after stress and bind to intracellular receptors in the brain, which in activated form function as transcription factors. We here tested the effect of a high dose of corticosterone on AMPA-receptor-mediated transmission in the CA1 hippocampal area, which is enriched in corticosteroid receptors. To focus on slow gene-mediated effects of the hormone, excitatory postsynaptic currents were measured at least 1 h after a brief application of 100 nM corticosterone to slices from adrenally intact adult mice. The amplitude but not frequency of miniature postsynaptic excitatory currents was found to be significantly enhanced. These effects were mimicked by 100 nM RU 28362, a selective agonist for intracellular glucocorticoid receptors. Evoked AMPA responses at the single cell were significantly enhanced when measured 2-4 h after application of 100 nM corticosterone, but not at earlier moments nor with a longer delay. In summary, the present results show that activation of hippocampal glucocorticoid receptors induces a slow enhancement of AMPA-receptor-mediated responses, at the single-cell level.