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- 2017
Pilocarpine诱导的小鼠癫痫持续状态导致齿状回未成熟新生神经元形成异常整合
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Abstract:
摘要：目的 阐明癫痫持续状态(status epilepticus，SE)发生之前海马产生的未成熟神经元是否在SE之后发生异常整合，包括底树突形成、门区迁移和轴突芽发。方法?? Pilocarpine制作小鼠颞叶癫痫模型，在SE诱导前1周采用BrdU或携带绿荧光蛋白的逆转录病毒标记齿状回新生细胞。SE后8周，采用BrdU+Map2和BrdU+NeuN免疫荧光双标染色分别观察分析新生神经元底树突的形成和向齿状回门区的异常迁移。通过齿状回内分子层(inner molecular layer, IML)GFP荧光信号分析观察新生神经元的轴突芽发。采用t-检验分析对比SE组和对照诱导组异常整合细胞的数量。结果?? 对照诱导组动物标记的新生细胞基本未发生异常整合。在SE之后8周，(20.8±8.4)%的新生细胞形成底树突，(15.9±7.4)%的新生细胞发生门区异位迁移， 其数量较对照诱导组动物明显增多(P<0.05)。SE组动物齿状回IML出现明显的GFP阳性芽发信号，而在诱导对照组则未出现。 结论?? SE发生之前海马产生的未成熟神经元在SE之后仍可发生底树突形成、门区异位迁移和轴突芽发等异常整合。
ABSTRACT: Objective?? To determine whether the integration of immature neurons born before status epilepticus (SE) can be disrupted by an epileptogenic insult. Methods?? Pilocarpine was used to induce SE in mice. At week 1 before induction, BrdU or retroviral vector expressing green fluorescent protein (RV-GFP) was used to label the newly born cells in the dentate gyrus (DG). At week 8 after SE, BrdU+Map2 or BrdU+NeuN double-labeling staining was carried out to visualize hilar basal dendrite or hilar ectopic migration. Virus-transduced GFP signals were used to identify the mossy fiber sprouting from the newly generated neurons. The number of cells with aberrant integrations was compared using unpaired Student’s t-test. Results?? The percentage of newborn neurons with aberrant dendritic morphology was (20.8±8.4)% at week 8 after SE. The percentage of BrdU+NeuN double labeled cells ectopically migrated into the hilus was (15.9±7.4)%. At week 8 after SE, the chronically epileptic mice showed many GFP？？+ processes in the IML with the same axonal appearance and small mossy fiber bouton-like structures as those seen in the hilus. The number of newborn neurons with aberrant integrations in SE mice was significantly increased when compared with the control mice (P<0.05). Conclusion?? These data demonstrate the existence of aberrant integrations-hilar basal dendrites, hilar ectopic migration and mossy fiber sprouting in the DG-generated cells born 1 week before an SE insult
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