Selective knockdown of NMDA receptors in primary afferent neurons decreases pain during phase 2 of the formalin test.
Selective knockdown of NMDA receptors in primary afferent neurons decreases pain during phase 2 of the formalin test.
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DOI：
10.1016/j.neuroscience.2010.10.045
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发表时间：
2011-01-13
期刊：
影响因子：
3.3
通讯作者：
Vissel, B.
中科院分区：
文献类型：
--
作者：
McRoberts, J. A.;Ennes, H. S.;Marvizon, J. C. G.;Fanselow, M. S.;Mayer, E. A.;Vissel, B.
初级传入神经元表达的NMDA受体（NMDARs）在伤害感受中的作用仍存在争议。本研究的目的是开发具有这些神经元中的NMDAR的组织选择性敲低的小鼠，并评估它们对不同类型的疼痛刺激的行为反应。将具有floxed NMDAR NR 1亚基基因（fNR 1）的小鼠与在外周蛋白启动子（Prph-Cre）控制下表达Cre重组酶的小鼠杂交。将雄性Prph-Cre+ floxed NR 1小鼠与Cre−同窝小鼠进行比较。定量RT/PCR和Western印迹均表明DRG提取物中NR 1表达降低约75%，而对脊髓、脑或肠神经系统中的NR 1表达无影响。NR 1抗体的免疫细胞化学显示，所有大小级别的DRG神经元染色减少。在Cre−小鼠培养的DRG神经元中，60%的[Ca 2 +]i出现可检测到的增加，但在Cre+小鼠培养的DRG神经元中，只有15%出现可检测到的增加。此外，峰值[Ca 2 +]i反应在Cre+小鼠的神经元中降低64%。Cre+和Cre−小鼠对热板或热伤害性感受的缩尾试验的反应潜伏期没有显著差异，对尾部或爪的机械刺激的缩尾阈值也没有差异。然而，与Cre−同窝小鼠相比，Cre+敲除小鼠对福尔马林注射的2期反应降低了50%（p<0.001）。对1期缓解无影响。这些结果表明，由初级传入神经表达的NMDA受体在致敏疼痛状态的发展中起着重要作用。
The role of NMDA receptors (NMDARs) expressed by primary afferent neurons in nociception remains controversial. The aim of this study was to develop mice with a tissue selective knockdown of NMDARs in these neurons and to evaluate their behavioral responses to different types of painful stimuli. Mice with floxed NMDAR NR1 subunit gene (fNR1) were crossed with mice expressing Cre recombinase under the control of the peripherin promotor (Prph-Cre). Male Prph-Cre+ floxed NR1 mice were compared to Cre− littermates. Both quantitative RT/PCR and Western blotting indicated a ~75 % reduction in NR1 expression in DRG extracts with no effect on NR1 expression in spinal cord, brain or the enteric nervous system. Immunocytochemistry with antibodies to NR1 revealed decreased staining in all size classes of DRG neurons. NMDA produced a detectable increase in [Ca2+]i in 60 % of DRG neurons cultured from Cre− mice, but only 15% of those from Cre+ mice. Furthermore, the peak [Ca2+]i responses were 64% lower in neurons from Cre+ mice. There was no significant difference between Cre+ and Cre− mice in response latencies to the hotplate or tail withdrawal tests of thermal nociception, nor was there a difference in withdrawal thresholds to mechanical stimuli of the tail or paw. However, compared to Cre− littermates, Cre+ knockdown mice had a 50% decrease in the phase 2 response to formalin injection (p<0.001). There was no effect on phase 1 responses. These results suggest that NMDA receptors expressed by primary afferent nerves play an important role in the development of sensitized pain states.
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影响因子：
2.5
作者：
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通讯作者：
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