摘要
目的观察特异性α_5亚基γ-氨基丁酸A受体(GABAA-Rα_5)阻断剂L-655708对杏仁核电点燃大鼠成功点燃时间的影响,探讨其对癫痫形成的影响。方法雄性Sprague-Dawle大鼠30只,随机分为正常点燃组、对照点燃组和给药点燃组,每组10只。采用A-M SYSTEMS 2100刺激器持续电刺激各组大鼠左侧杏仁核基底外侧核,检测大鼠的后放阈,按后放阈1. 5倍的强度给予刺激。正常点燃组大鼠为单纯杏仁核电点燃;点燃对照组大鼠在正常点燃组的基础上给予侧脑室注射生理盐水,每次5μL,每日2次;给药点燃组大鼠在正常点燃组的基础上侧脑室注射8μmol·L-1的L-655708,每次5μL,每日2次;生理盐水及L-655708注射均于每次电刺激开始前进行,并于大鼠电点燃成功后停止注射。采用Alpha-Lab 4通道信号采集及处理系统记录大鼠脑电活动,比较各组大鼠杏仁核电刺激点燃成功时间。结果正常点燃组、点燃对照组和给药点燃组大鼠成功点燃时间分别为(11. 50±2. 93)、(11. 88±2. 83)、(17. 88±3. 85) d,正常点燃组与点燃对照组大鼠成功点燃时间比较差异无统计学意义(t=1. 052,P> 0. 05);给药点燃组大鼠的点燃成功时间显著长于正常点燃组和点燃对照组(t=2. 901、2. 867,P <0. 05)。结论 GABAA-Rα_5阻断剂L-655708可明显延长杏仁核电点燃大鼠点燃成功时间,从而延长癫痫形成时间;突触外GABAA-Rα_5在癫痫的形成过程中可能起到关键作用。
Objective To investigate the effect of specificα_5 subunit-γ-aminobutyrate A receptor( GABAA-Rα_5) blocker( L-655708) on the successful kindling time of amygdala kindling rats,and to explore the pathogenesis of GABAA-Rα_5 subunit in epilepsy. Methods Thirty male Sprague-Dawle rats were randomly divided into normal kindling group,control kindling group and drug kindling group,with 10 rats in each group. The lateral basal nucleus of the left amygdala in rats was continuously stimulated with 1. 5 times of the posterior release threshold by the A-M SYSTEMS 2100 stimulator. The rats in the normal kindling group were purely kindled in amygdala. On the basis of normal kindling group,the rats in the kindling control group were injected with normal saline into lateral ventricle,5 μL each time,twice a day; and the rats in the drug kindling group were injected with 8 μmol·L-1 L-655708 into lateral ventricle,5 μL each time,twice a day. The normal saline and L-655708 were injected before each electrical stimulation and stopped after the rats were successfully kindled. The electrical activity of brain of the rats was record by Alpha-Lab 4 channel signal acquisition and processing system. The successful kindling time of amygdale was compared in the three groups. Results The successful kindling time in the normal kindling group,the kindling control group and the drug kindling group was( 11. 50 ± 2. 93),( 11. 88 ± 2. 83) and( 17. 88 ± 3. 85) d,respectively. There was no significant difference in the successful kindling time of rats between the normal kindling group and kindling control group( t =1. 052,P > 0. 05). The successful kindling time of rats in the drug kindling group was significantly longer than that in the normal kindling group and kindling control group( t = 2. 901,2. 867; P < 0. 05). Conclusion GABAA-Rα_5 blocker L-655708 can significantly prolong the successful kindling time of amygdale in rats,thus prolong the time of epilepsy formation. The extrasynaptic GABAA-Rα_5 subunit may play a key role in the formation of epilepsy.
引文
[1] HALCXUK I,LIPA A,MITOSEK-SZEWCXYK K,et al. Evaluation of the effectiveness of add-on therapy with tiagabine and evaluation of cognitive functions after application of this therapy in patients with drug-resistant focal epilepsy-an observational study(GABIEPI)[J]. Wiad Lek,2015,68(42):680-689.
[2]王艳,张晓鑫,杨清成.丙戊酸钠和苯巴比妥钠联合治疗对难治性癫痫患者痫样放电及认知功能的影响[J].新乡医学院学报,2018,35(2):114-117.
[3] QI J S,YAO J,FANG C,et al. Downregulation of tonic GABA currents following epileptogenic stimulation of rat hippocampal cultures[J]. J Physiol,2006,577(Pt 2):579-590.
[4] HALPERN C,HURTIG H,JAGGI J,et al. Deep brain stimulation in neurologic disorders[J]. Parkinsonism Relat Disord,2007,13(1):1-16.
[5] JACOB T C,MOSS S J,JURD R. GABAAreceptor trafficking and its role in the dynamic modulation of neuronal inhibition[J]. Nat Rev Neurosci,2008,9:331-343.
[6] GLYKYS J,MANN E O,MODY I. Which GABAAreceptor subunits are necessary for tonic inhibition in the hippocampus[J]. J Neurosci,2008,28:1421-1426.
[7]申法政,惠磊,周祥,等.海马电刺激对海人酸致痫大鼠突触外GABAA受体α5亚基的影响[J].中华医学杂志,2014,94(23):1820-1824.
[8] VAN RIJCKEVORSEL K,ABU SERIEH B,DE TOURTCHANINOFF M,et al. Deep EEG recordings of the mammillary body in epilepsy patients[J]. Epilepsia,2005,46(5):781-785.
[9] WEISS S R,EIDSATH A,LI X L,et al. Quenching revisited:low level direct current inhibits amygdala-kindled seizures[J]. Exp Neurol,1998,154(1):185-192.
[10]刘谦,龚辉.大鼠断层解剖彩色图谱[M].武汉:华中科技大学出版社,2010:34-35.
[11] RACINE R J. Modification of seizure activity by electrical stimulation.Ⅱ. Motor seizure[J]. Electroencephalogr Clin Neurophysiol,1972,32(3):281-294.
[12] CHAMBERS M S,ATACK J R,BROUGHTON H B,et al. Identification of a novel,selective GABAAα5receptor inverse agonist which enhances cognition[J]. J Med Chem,2003,46(11):2227-2240.
[13]姚宝珍,黄婷婷,袁昊,等. microRNA-34a和Notch1信号通路在颞叶癫痫模型大鼠海马中的表达及作用机制[J].中华实用儿科临床杂志,2017,32(12):932-935.
[14]陈名涛,徐向勇,刘美.栝蒌桂枝汤联合西医疗法治疗癫痫疗效及对脑电图的影响[J].世界中医药,2018,13(8):1936-1939.
[15]苗林,王峰,解自行,等.活性调节细胞骨架蛋白siRNA慢病毒表达载体对杏仁核点燃大鼠学习记忆的影响[J].中华医学杂志,2013,93(11):860-863.
[16] GLYKYS J,MODY I. Hippocampal network hyperactivity after selective reduction of tonic inhibition in GABAAreceptor alpha5subunit-deficient mice[J]. J Neurophysiol,2006,95(5):2796-2807.
[17] SCIMEMI A,SEMYANOV A,SPERK G,et al. Multiple and plastic receptors mediate tonic GABAAreceptor currents in the hippocampus[J]. J Neurosci,2005,25(43):10016-10024.
[18] BIEDA M C,MACIVER M B. Major role for tonic GABAAconductances in anesthetic suppression of intrinsic neuronal excitability[J]. J Neurophysiol,2004,92(3):1658-1667.
[19]葛宇星. CIC-2对慢性颞叶癫痫大鼠海马CA1区α5亚基-GABAAR介导紧张性抑制的影响[D].上海:复旦大学,2012.