5-HT1A receptor agonist affects fear conditioning through stimulations of the postsynaptic 5-HT1A receptors in the hippocampus and amygdala
5-HT1A receptor agonist affects fear conditioning through stimulations of the postsynaptic 5-HT1A receptors in the hippocampus and amygdala
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DOI：
10.1016/j.ejphar.2005.12.008
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发表时间：
2006-02-17
影响因子：
5
通讯作者：
Koyama, T
中科院分区：
文献类型：
--
作者：
Li, XB;Inoue, T;Koyama, T
临床前和临床研究的证据表明，5-HT1A受体激动剂具有抗焦虑作用。5-HT1A受体激动剂的抗焦虑作用已经通过我们先前使用恐惧条件反射的研究进行了测试。然而，在这种情况下，对5-HT1A受体激动剂抗焦虑作用的大脑区域知之甚少。在本研究中，我们研究了双侧向海马、杏仁核和内侧前额皮质微注射肉肉素（一种选择性5-HT1A受体激动剂）对大鼠条件恐惧应激诱导的情境性条件冻结表达和排便的影响。这些结果表明，海马和杏仁核内注射肉肉素均能降低条件冻结的表达，而内侧前额叶皮层注射肉肉素则没有。此外，杏仁核内注射filesinoxan可减轻条件恐惧引起的排便增加，但海马和内侧前额叶皮质注射无效。这些结果表明，filesinoxan通过刺激海马和杏仁核的突触后5-HT1A受体在恐惧条件反射中发挥其抗焦虑作用。(c) 2005 Elsevier B.V.版权所有
Evidence from preclinical and clinical studies has shown that 5-HT1A receptor agonists have anxiolytic actions. The anxiolytic actions of 5-HT1A receptor agonists have been tested by our previous studies using fear conditioning. However, little is known about the brain regions of anxiolytic actions of 5-HT1A receptor agonists in this paradigm. In the present study, we investigated the effects of bilateral microinjections of flesinoxan, a selective 5-HT1A receptor agonist, into the hippocampus, amygdala and medial prefrontal cortex on the expression of contextual conditioned freezing and the defecation induced by conditioned fear stress in rats. These results reveal that both intrahippocampal and intraamygdala injections of flesinoxan decreased the expression of conditioned freezing, while injections into the medial prefrontal cortex did not. In addition, intraamygdala injection of filesinoxan attenuated the increased defecation induced by conditioned fear, but injections into the hippocampus and medial prefrontal cortex failed. These results suggest that filesinoxan exerts its anxiolytic actions in the fear conditioning through stimulations of the postsynaptic 5-HT1A receptors in the hippocampus and amygdala. (c) 2005 Elsevier B.V. All rights reserved.