大脑皮层发育不良鼠脑皮层和海马中的突触生长相关蛋白表达

Expression of GAP-43 in cerebral cortex and hippocampus of cortical dysplasia in rats

目的：探寻皮层发育不良（diffuse cortical dysplasias，DCD）大鼠大脑半球、海马的突触生长相关蛋白（growth-associated protein 43, GAP-43）免疫组化病理学特点，探讨DCD所致难治性癫癎（Intractable epilepsy，IE）的皮层发生机制。方法：建立X-射线照射诱导的皮质下异位结节大鼠DCD模型，采用SP免疫组织化学方法检测GAP-43，在大鼠脑皮质下异位结节和海马中的表达，光镜观察并在Gundersen测试系统下计数，图文分析，SPSS18．0软件统计。结果：与正常对照组或母鼠组白质比较，皮质下异位结节内GAP-43免疫阳性产物数密度增加10倍（P〈0．05）。同龄DCD鼠脑皮质Ⅰ-Ⅲ层异位结节、皮质下异位结节和CAI异位结节中GAP-43数密度比较无变化。GAP-43数密度仅在CA3区多形层增加，提示苔藓纤维发芽（mossy fibers sprouting，MFS）。结论：DCD鼠脑GAP-43的分布变化也可佐证海马MFS，提示海马兴奋性神经网络的形成及导致癫癎发生的蛋白质表达异常。

Objective：To observe the expression of GAP-43 of animal models with diffuse cortical dysplasias（DCD） in cortex and hippocampus by the immunohistochemical method, and to discuss the mechamism of pathologic changes and epileprogenesis in this model. Methods：The animal models of DCD were made, including Postnatal P0, P1, P2, P3, P7, P14, P21, P28, P56, P84 and 31 weeks. The offsprings of irrated pregnant rats were killed for having been used for histomorphologic and histopathologic stud- ies. The expressions of GAP-43 in cortex and hippocampus were observed by immunohisochemistry. Sta- tistics analysis by mean standard deviation（x-±s）, student test analysis were used in SPSS 18. 0 were used. Results： The expressions of GAP 43 in cortex and hippocampi CA1 ,CA3 area were observed by im- munohisochemistry. Its density of immunepositive matter 10 times increased. Such expression of GAP 43 around CD in white matter of rats with DCD might be relatet to the mechanism of the intractable epilepsy （P〈0.05）. Hippocampal mossy fiber sprouting in adult rats with DCD induced by X--ray injury. The in- creased expression of GAP 43 in the DCD rats ＇ hippocampi CA3 area of DCDs might be related to the mechanism of intractable epilepsy （P〈0.05）. Conclusion： This study provides important mechanism of epileptogenicity because of increased Spy and GAP 43 in hippocampi CA3.