Jiang Qian, Wang Jingmin, Wu Xiru, Jiang Yuwu
Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
Int J Dev Neurosci. 2007 May;25(3):165-70. doi: 10.1016/j.ijdevneu.2007.02.001. Epub 2007 Feb 21.
As an extreme form of abnormally synchronized activity, epilepsy may modify patterns of organization in the nervous system. It is clear that enhanced glutamatergic excitatory synaptic transmission with alterations in the expression of ionotropic glutamate receptors is a mechanism critical for seizure susceptibility and excitotoxicity. However, the exact quomodo and the roles of regulated N-methyl-D-aspartate receptor (NMDAR) composition and expression of a major postsynaptic density (PSD) scaffolding molecule, PSD-95, are as yet unclear. To study protein expression changes after epileptiform discharges in cultured immature rat cortical neurons, we divided cells into three groups which were transiently exposed to regular Neurobasal/B27 (control group), physiological solution (PS group) and magnesium-free physiological solution (MGF group) at cultured day 6. Neurons at three different culture ages (DIV7, DIV12 and DIV17) were collected for immunoblotting analysis. We found a decrease in expression of NR2B NMDAR subunit and PSD-95 (P<0.05) shortly after insult (within 24 h), which may show that brief magnesium-free media treatment of primary cultured rat cortical neurons, an in vitro model of seizure brain injury, has a major influence on the expression of NR2B subunit and PSD-95.
作为异常同步活动的一种极端形式，癫痫可能会改变神经系统的组织模式。很明显，离子型谷氨酸受体表达改变导致谷氨酸能兴奋性突触传递增强是癫痫易感性和兴奋性毒性的关键机制。然而，调节N-甲基-D-天冬氨酸受体（NMDAR）组成以及主要突触后致密物（PSD）支架分子PSD-95表达的确切方式和作用尚不清楚。为了研究培养的未成熟大鼠皮层神经元癫痫样放电后的蛋白质表达变化，我们在培养第6天将细胞分为三组，分别短暂暴露于常规Neurobasal/B27培养基（对照组）、生理溶液（PS组）和无镁生理溶液（MGF组）。收集三个不同培养年龄（DIV7、DIV12和DIV17）的神经元进行免疫印迹分析。我们发现，损伤后不久（24小时内），NR2B NMDAR亚基和PSD-95的表达下降（P<0.05），这可能表明，癫痫脑损伤的体外模型——对原代培养的大鼠皮层神经元进行短暂的无镁培养基处理，对NR2B亚基和PSD-95的表达有重大影响。
