Developmental plasticity of NR1 and NR2B subunit expression in the supraoptic nucleus of the rat hypothalamus
Developmental plasticity of NR1 and NR2B subunit expression in the supraoptic nucleus of the rat hypothalamus
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DOI：
10.1016/s0165-3806(98)00060-1
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发表时间：
1998-07-01
期刊：
影响因子：
--
通讯作者：
Dao, J
中科院分区：
文献类型：
--
作者：
Currás, MC;Dao, J
成人下丘脑视上核（SON）内的加压素和催产素神经内分泌细胞显示NMDA受体亚基NR1和NR2B、NR2C和NR2D的mRNA表达。NR2B亚基具有缓慢的衰变动力学（相对于NR1/NR2A受体）和对NMDA受体反应的高镁敏感性，这些特性可能有助于这些细胞表现为NMDA受体介导的破裂。因此，我们检测了NR2B蛋白在SON中的表达及其发育特征，并将其与之前研究过的皮质和小脑区域的表达进行了比较。我们使用nr2b特异性抗体对胚胎、出生后（PN7、14、21）和成年大鼠的SON匀浆进行了Western blot分析。成人在SON和PVN中的NR2B水平相似，但相对于皮质的水平较低。SON NR2B蛋白水平在出生后第一周上升，在PN21期间保持高水平，随后在成年后显著下降至较低水平。在小脑中也观察到类似的情况，NR2B表达在PN14时出现一个尖峰，随后在成人中下降到最低或无法检测到的水平。相比之下，NR2B在成年期皮质中持续过表达。NR1表达的形成模式，包括出生后早期和成年期的上调，在SON和皮质中是相似的。在小脑中观察到不同的模式，在ED17后NR1水平逐渐增加，达到显着更高的成人水平。在研究的所有三个区域中，SON显示了NR1水平最早的发育上升。SON外植体培养被证明是一种有用的制备方法，因为它们含有合成NR1和NR2B亚基的神经元，其数量与ED17 SON相似。我们的研究结果表明，SON神经内分泌细胞上的NMDA受体是通过NR1和NR2B亚基组装的，并且它们在出生后早期的可塑性表达可能在发育过程中发挥作用。(C) 1998 Elsevier Science B.V.版权所有
Vasopressin and oxytocin neuroendocrine cells within the supraoptic nucleus of the adult hypothalamus (SON) display mRNA expression for the NMDA receptor subunits, NR1 and NR2B, NR2C and NR2D. The NR2B subunit confers slow decay kinetics (relative to NR1/NR2A receptors) and high magnesium sensitivity to NMDA receptor responses-properties which may contribute to the NMDA receptor-mediated bursting manifested by these cells. Therefore, we examined NR2B protein expression and its developmental profile in the SON and compared it to that in the cortex and cerebellum-areas which have been studied previously. We performed Western blot analysis on SON homogenates from embryonic, postnatal (PN7, 14, 21), and adult rats using an NR2B-specific antibody. Adult NR2B levels in the SON and PVN were similar but low relative to those of cortex. SON NR2B protein levels rose in the first postnatal week, remained high through PN21, and later declined to significantly lower levels in the adult. A similar profile was observed in cerebellum, where NR2B expression displayed a sharp peak at PN14 and later declined to minimal or undetectable levels in the adult. In contrast, NR2B continued to be overexpressed through adulthood in the cortex. The ontogenic pattern for NR1 expression, which included upregulation during early postnatal life and adulthood, was similar in the SON and cortex. A different pattern was observed for the cerebellum, where NR1 levels increased gradually after ED17 to reach significantly greater adult levels. Of all three areas studied, the SON displayed the earliest developmental rise in NR1 levels. SON explant cultures proved to be a useful preparation, since they contained neurons which synthesized NR1 and NR2B subunits in quantities similar to those of ED17 SON. Our findings suggest that NMDA receptors on SON neuroendocrine cells ate assembled using NR1 and NR2B subunits, and that their plastic expression in early postnatal life may play a role during development. (C) 1998 Elsevier Science B.V. All rights reserved.