【摘要】 目的:探讨红藻氨酸处理的C57BL/6J小鼠癫痫发作后癫痫发作敏感性能否形成及其机制。方法:实验于2004--03/06在大连医科大学生理学教研室进行。选用C57BL6J小鼠36只,实验分为盐水对照组(n=8)和红藻氨酸处理组(n=24),红藻氨酸处理组根据不同时间点又分为红藻氨酸处理后0.5h,2h,24h组,每组8只。盐水对照组为C57BL/6J小鼠颈部皮下注射0.2mL盐水,红藻氨酸处理组为C57BL/6J小鼠颈部皮下注射0.2mL惊厥剂量红藻氨酸(25mg/kg)诱导癫痫发作,分别在红藻氨酸处理后0.5,2,24h,用免疫组化技术检测海马内c-Jun免疫阳性神经元,作为神经元兴奋的形态功能指标来观察癫痫发作相关脑区的兴奋传递通路,同时检测海马门区γ-氨基丁酸免疫反应活性阳性神经元数目。红藻氨酸处理后7d,存活的C57BL/6J小鼠被给予皮下注射12.5mg/kg阈下剂量的红藻氨酸,以检测癫痫发作敏感性。结果:实验纳入36只C57BL/6J小鼠,中途有4只脱落,最终有32只进入结果分析。①惊厥剂量红藻氨酸诱发C57BL/6J小鼠(n=24)在30min内出现癫痫持续状态,并伴有全身强直阵挛性惊厥,其中4只在30min内死亡。②7d后阈下剂量未引起癫痫发作,即癫痫发作敏感性未形成。③脑内免疫组化显示,海马各部位γ-氨基丁酸免疫反应阳性神经元在检测各时间点内均未见任何脱失现象;与盐水对照组比较,红藻氨酸组诱发急性癫痫发作,红藻氨酸处理后,在海马齿状回颗粒细胞c-Jun免疫反应最早增强(P<0.05),CA3部位不增强,以CA1部位c-Jun免疫反应在24h显著性升高(P<0.001)。④与盐水对照组相比,惊厥剂量的红藻氨酸处理后0.5h,2h,24h,海马门区γ-氨基丁酸免疫阳性神经元的数目及染色程度未见明显改变(P>0.05)。结论:C57BL/6J小鼠具有对红藻氨酸引起癫痫急性发作的敏感,可能与CA1接受内嗅皮层海马穿通通路的直接投射有关,同时C57BL/6J小鼠海马对红藻氨酸引起的γ--氨基丁酸能神经元损伤不敏感,海马门区γ-氨基丁酸免疫反应阳性神经元的结构功能完整性可能在防止癫痫敏感性形成方面起着关键的作用。更多还原

【Abstract】 AIM: To explore whether there is seizure sensitivity in C57BL/6J mice after seizure induced by kainic acid treatment and its mechanisms. METHODS:The experiment was carried out in the Department of Physiology, Dalian Medical University from March to June 2004. Thirty-six C57BL/6J mice were divided into saline control group (n=8), kainic acid treatment group (n=24), and the latter was subdivided in to kainic acid treatment 0.5, 2 and 24 hours group with 8 mice in each. C57BL/6J mice in the saline control group were subcutaneously injected with 2 mL saline, and those in the kainic acid treatment group were injected with a convulsive dose of 2 mL kainic acid (25 mg/kg) to induce seizure, and at the following 0.5, 2 and 24 hours, immunohistochemistry was used to measure the c-Jun immunoreactivity (IR) positive neurons in mice hippocampus to map the activated pathways of seizure, and gamma-aminobutyric acid (GABA)- IR positive neurons were observed at the same time. Severn days later, the seizure susceptibility was detected by subcutaneously injection of sub-threshold dose of kainic acid (12.5 mg/kg). RESULTS: Totally 36 C57BL/6J mice were used in the experiment, 4 withdrew midway, finally 32 mice were involved in the analysis. ① C57BL/6J mice (n=24) presented seizure and accompanied by rigid clonic convulsion of whole body after the injection of a single convulsive dose of kainic acid within 30 minutes, and 4 of them even died. ② Seizure did not occur in the rest mice when sub-threshold dose of kainic acid was administrated at seven days after convulsive dose kainic acid treatment. ③ The immunohistochemistry results showed that GABA- IR positive neurons had no difference in the hippocampal region and time course; As compared with saline control group, acute seizure was evoked in the kainic acid treatment group, and the, and the induction of c-Jun was firstly found in dentate gyrus cells (P < 0.05), the most significantly increased in CA1 at 24 hours after kainic acid treatment (P < 0.001), but not in CA3. ④ As compared with the saline control group, the number of GABA-IR positive neurons and stained degree in hilus of hippocampus had no obvious changes at 0.5, 2 and 24 hours after kainic acid treatment of convulsive dose (P > 0.05). CONCLUSION: C57BL/6J mice are sensitive to kainic acid to present seizure, which might be related to the temporammonic pass path directly projecting form to CA1, and its GABA-nergic neurons are not likely injured by kainic acid, the integrity of intermediated neurons in hippocampus hilus attributes to the prevent again the formation of seizure susceptibility.更多还原