慢性电刺激诱发大鼠癫痫模型中核磁共振检测信号异常的非对称性与特征性行为发作的关系  

Characteristic behavioral seizures and abnormal signal asymmetry of magnetic resonance imaging in an electrogenic rat model of chronic epilepsy

作　　者：韩丹[1] 张先荣[1] 唐岳枫[2] 刘买利[2] 尹世金[1] 

机构地区：[1]武汉大学医学院生理学教研室,武汉430071 [2]中国科学院武汉物理与数学研究所波谱与原子分子物理国家重点实验室,武汉430071

出　　处：《生理学报》2001年第3期224-230,共7页Acta Physiologica Sinica

基　　金：This work was supported by the National Natural Science Foundation of China (No.29925515) and the Natural Science Foundation of

摘　　要：本文旨在探讨内嗅皮质（ＥＣ）－海马环路在颞叶癫痫发生中的作用。慢性强直电刺激大鼠右背海马（ＤＨ－ＰＣ）或右中部颞叶新皮质（ＭＴＮＣ），每日一次（６０Ｈｚ，２ｓ，０．４～０．６ｍＡ），连续７～１０ｄ。刺激ＤＨＰＣ（５７．４％，８／１４只）或ＭＴＮＣ（７．４２％，１０／１４只）均能引起电极对侧出现非对称性脑区核磁共振（Ｔ２－ＷＩ）信号增强。组织学切片证实与扩大的侧脑室吻合，可能涉及脑实质结构的损伤。ＤＨＰＣ刺激组大鼠对侧脑损伤伴有高频原发性湿狗样抖（ＷＥＤＳ）；ＭＴＮＣ刺激组大鼠对侧脑损伤伴有低频原发性ＷＥＤＳ。后者在第２个刺激日开始出现，持续到第１０天以后。所有假电极组无脑区Ｔ２－ＷＩ信号和行为改变。我们推测，刺激ＨＰＣ或ＭＴＮＣ所致癫痫性早期脑损伤具有同一种机制，涉及ＥＣ－ＨＰＣ环路。刺激ＭＴＮＣ时，可能由于ＥＣ潜在的门控作用，削弱了进出ＥＣ－ＨＰＣ环路通往新皮质的信息流，致使脑损伤明显时行为发作频度低。另外，非对称性脑损伤提示了颞叶癫痫的致痫灶的对侧易感特征。Chronic tetani (60 Hz, 2 s, 0.4-0.6 mA) were administered to the dorsal hippocampua (DHPC) or the medial temporal lobe neocortex (MTNC) of rats, to study the role of the entorhinal cortex (EC)-hippocampal loop in temporal lobe epilepto-genesis. This was repeated once a day for 7 or 10 days. Magnification of hyper-intensity was induced by tetanization of the HPC or the MTNC, as detected by contralateral T2 weighted magnetic resonance imaging (T2-WI). The effects were associated with an en-larged volume of the lateral ventricle (LV), which was verified histologically. T2-WI hyper-intensities, contralateral to the tetanized hemispheres, were observed with high frequency primary wet dog shakes (WEDS) in the DHPC-stimulated rats and with low fre-quency WEDS in the MTNC-stimulated rats. It seems likely that the same neural mechanisms are shared by chronic tetanization of the tight HPC and the tight MTNC, involving the closed EC-HPC loop. Poor correelation between contralateral T2-WI hyper-intensi-ties and light primary behavioral seizures in the MTNC-stimulated rats might be attributed to a controlled information flow into or out of this loop because of potential EC gating In addition, asymmetric T2-WI hyper-intensities in the LV area reflected a hemispheric dependence, contralateral to the electrogenic focus in our model of rat epilepsy.

关 键 词：非对称性 T2加权核磁共振成像 原发性湿狗样抖 海马 中部颞叶新皮质 大鼠 电刺激 癫痫模型 

分 类 号：R742.1[医药卫生—神经病学与精神病学]