难治性癫痫相关局灶性皮质发育不良中NMDA受体及微小清蛋白阳性神经元的分布与表达

目的探讨局灶性皮质发育不良（FCD）中N-甲基-D-天冬氨酸（NMDA）受体亚单位组成的变化,并探讨其NMDA受体及微小清蛋白（PV）阳性神经元分布与表达的特点。方法对20例包括FCD全部4种亚型的癫痫手术切除标本及4例对照进行NMDA受体亚单位NR1、NR2A／B及PV免疫组织化学EnVision二步法染色。结果发现NR1亚单位在FCD巨大神经元及形态异常神经元胞质中的表达有增强;NR2A／B亚单位在FCD中的未成熟神经元、巨大神经元及形态异常神经元中有显著表达,并以未成熟神经元的胞质及突起内为著。与对照相比,FCD皮层的PV阳性神经元和纤维呈分散排列,PV阳性神经元的数量及背景染色都有显著下降,上述改变以FCDⅡ型的病灶处为著。结论FCD的异常神经元中有NMDA受体亚单位NR1和NR2A／B表达增加,同时在上述皮层中PV阳性神经元及纤维表达下调且分散。

Research on distribution and expression of NMDA receptors and parvalbumin-positive neurons in intractable epilepsy-related focal cortical dysplasia

OBJECTIVE: To evaluate the alteration of subunits composition in NMDA receptor and the alterations of the expression and distribution of NMDA receptors and parvalbumin (PV)-positive neurons in focal cortical dysplasia (FCD) cortices. METHODS: Twenty cases of FCD samples (including all four subtypes of FCD) obtained during epilepsy surgery and 4 controls were analysed by immunohistochemical staining for NR1, NR2A/B and PV. RESULTS: Increased expression of NR1 was detected in the giant neurons and dysmorphic neurons in FCD; while pronounced expression of NR2A/B was detected in immature neurons, giant neurons and dysmorphic neurons of FCD, especially in somata and processes of the immature neurons. Compared with the controls, FCD cortices showed prominent scattered arrangement of PV positive neurons and fibers, dramatically decreased number of PV positive interneurons and PV background staining, especially in foci of FCD II subtype. CONCLUSION: There are increased expressions of NR1 and NR2A/B subunits in FCD abnormal neurons, as well as scattered and reduced expressions of PV positive neurons and fibers in FCD cortices.