The expression of Immediate Eearly Gene (IEG) during development.

为了验证IEG反应在突触可塑性中的假设作用，并进一步研究癫痫发生中异常可塑性的形成，我们研究了癫痫突变模型El小鼠的IEG表达，结果表明，在癫痫发作阈值相同的条件下，癫痫发作后30 min，大脑和小脑中的ZIF表达最高。癫痫发作史的研究结果表明，在边缘系统，频繁发作使最大表达部位从梨状皮质和内嗅皮质转移到齿状回，进而转移到海马CA 3和CA 1区，而发育的研究结果表明，在发育和反复发作过程中，c-fos表达位点从海马的初级输入系统逐渐转移;即，梨状皮质、内嗅皮质和齿状回至海马CA 1区。对于顶叶皮层，也表明表达位点最初是局部的，然后变得普遍。进一步证明，该表达位点最终在整个皮层变得普遍和微弱。

To examine the hypothesized role of the IEG response in synaptic plasticity and further the formation of abnormal plasticity in epileptogenesis, we studied the expression of IEGs in El mice, a well known mutant model of epilepsy.In the present study, it was obserbed that zif was expressed maximally 30 min after seizure in both cerebrum and cerebellum under the same condition of the seizure threshold. There were no regional differences.Results as examined with seizure history indicate that in the limbic system the maximum expression site shifts from the pyriform cortex and entorhinal cortex to the dentate gyrus and further to ther hippocampal CA3 and CA1 by frequent seizures.On the other hand, results with development indicate that through the development as well as repetitive seizures, the c-fos expression site shifts gradually from the primary input system of the hippocampus ; i.e., the pyriform cortex, entorhinal cortex and dentate gyrus, to the hippocampal CA1. It is also indicated as for the parietal cortex that the expression site is initially localized and then becomes universal. It is further demonstrated that the expression site finally becomes universal and weak in all over the cortex.