Differential expression of five N-methyl-D-aspartate receptor subunit mRNAs in vasopressin and oxytocin neuroendocrine cells
Differential expression of five N-methyl-D-aspartate receptor subunit mRNAs in vasopressin and oxytocin neuroendocrine cells
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DOI：
10.1016/s0169-328x(96)00205-7
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发表时间：
1997-03-01
期刊：
影响因子：
--
通讯作者：
Greenwood, RS
中科院分区：
文献类型：
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作者：
AlGhoul, WM;Meeker, RB;Greenwood, RS
视上核内的抗利尿激素和催产素神经内分泌细胞显示出独特的电生理特性和对选定的NMDA受体（NR）拮抗剂的不同反应。为了确定这些差异是否与NMDA受体组成有关，我们比较了免疫细胞化学鉴定的抗利尿激素和催产素神经内分泌细胞中NR1、NR2A、NR2B、NR2C和NR2D亚基mrna的表达。NR1亚基mRNA在加压素细胞和催产素细胞中均有表达，而NR2B和NR2C的表达模式截然不同。在催产素细胞中，NR2B亚基占NR2总表达的大部分（65%），NR2C和NR2D分别占6%和27%。抗利尿激素细胞表现出5倍的NR2C(32%)，大约一半的NR2B mRNA（39%）和相当的NR2D（31%）。体外表达研究表明，NR1-NR2C亚基组合比NR1-NR2B具有更弱的镁阻滞和更高的甘氨酸亲和力。因此，与催产素细胞相比，NR2C在加压素细胞中的高表达可能使这些细胞更容易受到谷氨酸激活的影响。这些在抗利尿激素和催产素细胞中的观察结果为研究不同的NMDA受体组成如何影响神经元的神经生理特性提供了工作模型的基础。
Vasopressin and oxytocin neuroendocrine cells within the supraoptic nucleus display distinctive electrophysiological properties and differential responses to selected NMDA receptor (NR) antagonists. To determine if these differences might be due to NMDA receptor composition, we compared the expression of NR1, NR2A, NR2B, NR2C and NR2D subunit mRNAs in immunocytochemically identified vasopressin and oxytocin neuroendocrine cells. In contrast to NR1 subunit mRNA which was equally expressed in both vasopressin and oxytocin cells, NR2B and NR2C displayed very different expression patterns. In oxytocin cells, the NR2B subunit comprised the majority (65%) of the total NR2 expression with NR2C and NR2D contributing 6% and 27%, respectively. Vasopressin cells exhibited 5-fold higher NR2C (32%), approximately half as much NR2B mRNA (39%) and equivalent NR2D (31%). In vitro expression studies have shown that the NR1-NR2C subunit combination exhibits weaker magnesium block and higher affinity for glycine than NR1-NR2B. Thus, the high expression of NR2C in vasopressin cells relative to oxytocin cells may make these cells more susceptible to glutamatergic activation. These observations in vasopressin and oxytocin cells provide the basis for a working model to investigate how differential NMDA receptor composition may shape the neurophysiological properties of neurons.