5-HT3A receptor subunit is expressed in a subpopulation of GABAergic and enkephalinergic neurons in the mouse dorsal spinal cord
5-HT3A receptor subunit is expressed in a subpopulation of GABAergic and enkephalinergic neurons in the mouse dorsal spinal cord
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5-HT3A 受体亚基在小鼠背脊髓 GABA 能和脑啡肽能神经元亚群中表达
DOI：
10.1016/j.neulet.2008.04.105
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发表时间：
2008-08-15
影响因子：
2.5
通讯作者：
Wu, Sheng-Xi
中科院分区：
文献类型：
--
作者：
Huang, Jing;Wang, Ya-Yun;Wu, Sheng-Xi
5-羟色胺（5-HT）（3）受体已被认为在脊髓水平调节伤害性感受和疼痛反应。为了深入了解5-HT 3受体的细胞机制，我们用单细胞逆转录-聚合酶链反应（RT-PCR）检测了它们在脊髓背角（SDH）GABA能和脑啡肽能（ENKergic）神经元中的表达。使用谷氨酸羧化酶（GAD）（67）-绿色荧光蛋白（GFP）基因敲入小鼠，其中所有的GABA能神经元都是荧光的。常规组织RT-PCR结果显示，小鼠SDH中存在5-HT 3A受体亚基mRNA，而5-HT 3B受体亚基mRNA缺失。单细胞RT-PCR结果显示，GAD和前脑啡肽原（PPE，ENK的前体）阳性神经元分别占5-HT 3A阳性神经元总数的76.2%（16/21）和33.3%（7/21）。5-HT 3A受体亚单位在GABA能神经元和ENK能神经元中的阳性率分别为28.1%（16/57）和22.6%（7/31）。40.4%（23/57）的GABA能神经元表达PPE mRNA。在GAD（67）mRNA和PPE mRNA共表达的神经元中，约22%表达5-HT 3A mRNA。这些结果表明5-HT 3A受体与GABA和ENK共定位于SDH，提示5-HT可能通过5-HT 3A受体亚单位激活GABA能和ENK能神经元，从而影响GABA和ENK的释放。5-HT_（3A）受体亚单位的不同细胞定位提示该受体复杂地参与SDH神经元的抑制性神经回路。(C)2008爱思唯尔爱尔兰有限公司保留所有权利。
5-Hydroxytryptamine (5-HT)(3) receptors have been proposed to modulate nociception and pain responses at the spinal level. To gain insight into the cellular mechanism of 5-HT3 receptors, we examined their expression in GABAergic and enkephalinergic (ENKergic) neurons in the spinal dorsal horn (SDH) using single-cell reverse transcription-polymerase chain reaction (RT-PCR). The glutamic acid clecarboxylase (GAD)(67)-green fluorescent protein (GFP) knock-in mouse was used in which all GABAergic neurons were fluorescent. The general tissue RT-PCR results showed that 5-HT3A receptor subunit mRNA was present in the mouse SDH, while 5-HT3B receptor subunit was absent. Single-cell RT-PCR results showed that 76.2% (16/21) and 33.3% (7/21) of the total 5-HT3A-expressing neurons were positive for GAD(67) and preproenkephalin (PPE, a precursor of ENK), respectively. 5-HT3A receptor subunit was detected in 28.1% (16/57) of GABAergic neurons and 22.6% (7/31) of ENKergic neurons. About 40.4% (23/57) of GABAergic neurons expressed PPE mRNA. Of the neurons that co-express GAD(67) mRNA and PPE mRNA, about 22% expressed 5-HT3A mRNA. These observations indicate that 5-HT3A receptor co-localizes with GABA and ENK in the SDH, suggesting that serotonin may activate GABAergic and ENKergic neurons via 5-HT3A receptor subunit and therefore affect the release of GABA and ENK. The different cellular localization of 5-HT3A receptor subunit suggest the complex participation of this receptor in the inhibitory neuronal circuits of the SDH neurons. (C) 2008 Elsevier Ireland Ltd. All rights reserved.