不同脑区注入D1受体拮抗剂SCH23390对颞叶癫痫的影响

Effects of infusion of D1 receptor antagonist SCH23390 to different encephalon regions on temporal epilepsy

目的:建立颞叶癫痫模型,探讨不同脑区给予多巴胺D1受体拮抗剂SCH23390对红藻氨酸所致的颞叶癫痫的影响。方法:实验于2004-08/12在解放军第一军医大学珠江医院全军神经医学研究所进行。①分组:取SD大鼠30只,随机分为生理盐水组3只,红藻氨酸组3只和实验组24只,实验组又分为海马、纹状体、黑质注射组各5只(共15只),以及同部位生理盐水注射作为对照,每组3只(共9只)。②造模:红藻氨酸组及实验组大鼠给红藻氨酸酸5μg(2.5g/L)右侧脑室注射制备颞叶癫痫模型,生理盐水组同部位给生理盐水2μL。③给药:实验组中的海马、纹状体、黑质注射组在相应部位缓慢注入1g/L的SCH233901μL,各部位以相同剂量生理盐水注入作为对照。④观察指标:观察各组间的大鼠行为变化及脑电图变化。3d后取脑作海马部TUNEL染色,观察海马部神经细胞凋亡情况。结果:30只大鼠全部进入结果分析。①行为变化:生理盐水组无癫痫发作。红藻氨酸组大鼠均出现癫痫发作,发作于脑室注射红藻氨酸后10min开始,1h达高峰。②脑电图变化:生理盐水组无尖波、棘波、棘慢综合波等痫性电活动表现,红藻氨酸组于注射后10min即有痫性波出现,其波幅为中幅及高幅波,但出现频率较低;1h左右癫痫发作达高峰时其波幅大部为高幅波,出现频率高;3～6h后波幅降低,12h后无痫性波出现。实验组中纹状体注射组波幅降低明显,与红藻氨酸组相比差异显著;黑质注射组亦有下降,而海马注射组无明显下降,与红藻氨酸组相比无差异。③细胞的凋亡:癫痫发作后伴随有海马细胞的凋亡,3d时明显。各脑区给予SCH23390后,海马部细胞凋亡减轻不一致,纹状体注射组阳性细胞数最少,与红藻氨酸组相比其差值有统计学意义(P﹤0.01)。结论:①一侧侧脑室注入红藻氨酸可成功建立癫痫模型。②红藻氨酸致痫后伴有海马神经凋亡改变,给予多巴胺D1受体拮抗剂SCH23390后,海马神经元凋亡减轻。③不同部位注射产生的凋亡细胞数不同,其中以纹状体注射所产生的凋亡细胞数最少,提示各部位在红藻氨酸所致的颞叶癫痫中的作用不同。

AIM：To establish animal model of temporal epilepsy in rat, and investigate the effects of infusing dopamine D1 antagonist SCH23390 into different encephalon regions on temporal epilepsy induced by kainic acid. METHODS：The experiment was performed in the Military Research Institute of Neurology, Zhujiang Hospital affiliated to Southern Medical Univemity from August to December 2004. （1）Grouping：Thirtty Spraque-Dawley （SD） rats were randomized into physiological saline group （n=3）, kainic acid group （n=3） and experimental group （n=24）. The experimental group was divided into 3 subgroups with 5 rats in each subgroup： hippocampus group, striatum group and substantia nigra group. SCH23390 were injected into hippocampus, striatum and suhstantia nigra respectively, with contrast physiological saline was injected to the corresponding positions（n=3 respectively）.（2）Model establishment：Rats in the kainic acid group and experimental group were made into models of temporal epilepsy by injecting kainic acid 5μg （2.5 g/L） into the right ventricle, and those in the physiological saline group were unilaterally injected with physiological saline （2 μL）.（3）Administration：SCH23390 1 g/L for each was injected on the right side successively and simultaneously,with contrast physiological saline was injected in the same position.（4）Observed indexes： The changes of behavior and electroencephalogram were observed in each group. Rats were killed at 3 days after injection. The section of brain was marked by TUNEL so as to observe apoptosis of hippocampus neurons cell. RESULTS：All the 30 rats entered the analysis of result. （1） Behavioral changes： The physiological saline group did not show the epileptic seizure. The epileptic seizure occurred at 10 minute after injecting kainic acid in lateral ventricle and reached the peak at 1 hour following the injection. （2） EEG record：In the physiological saline group,there was not epileptic activity manifestations,like sharp wave,spike wave, spike slow comprehensive wave, etc.ln the kainic acid group, epileptic wave presented immediately at 10 minutes after injection, the seizure developed to the peak at about 1 hour,the wave amplitude was decreased at 3 to 6 houm,presenting paroxysmal slow and spike slow waves and no epileptic wave appeared after 12 hours.The wave amplitude was decreased perfectly in striatum group as compared with the kainic acid group,which showed significant difference.The wave amplitude was also decreased in the substantia nigra group, but not in the hippocampus group as compared with the kainic acid group,which did not show significant difference. （3）Neuronal apoptosis： Hippocampus neurons cell apoptosis oecurred after epileptic seizure and reached the peak at 3 days.After injuring dopamine D1 antagonist SCH23390 in different encephalon regions,hippocampus neurons cell apoptosis reduced in different level.The quantities of apoptosis in the striatum group was the least as compared with kainic acid group,which showed significant differenee （P〈0.01）. CONCLUSION：Injecting kainic acid into lateral ventricle could induce animal model of temporal epilepsy.Hippoeampus neurons cell apoptosis occurred following epilepsy seizure which resulted from kainic acid.The quantities of apoptosis showed difference after injected SCH23390 in different encephalon regions and reached the least in striatum.it was implied that the role of different encephalon regions was distinction in temporal epilepsy occurred by kainic acid.