大鼠海马快速点燃模型的建立及机制研究

目的：建立大鼠海马快速点燃模型并对其机制进行初步探讨。方法：制备大鼠海马快速点燃模型;观察经典抗杏仁核点燃药物对该模型的影响;观察大鼠海马快速点燃模型和大鼠杏仁核点燃模型海马CA_3区和皮层区c-fos蛋白的表达情况及蛋白抑制剂对其表达的影响。结果：大鼠海马快速点燃模型点燃成功率与刺激参数有关;苯巴比妥20,50mg·kg~1 及地西泮2,5mg·kg~(-1)对大鼠海马快速点燃ADD和Racine＇s分级有抑制作用(P＜0．05);与正常组比较,海马快速点燃大鼠和杏仁核点燃大鼠海马CA_3区、大脑皮层c-fos免疫阳性细胞增多(P＜0．05),在蛋白抑制剂作用下,海马c-fos免疫阳性细胞减少,但仍比正常组高(P＜0．05)。结论：大鼠海马快速点燃成功率与刺激参数具有相关性;传统抗点燃药物具有抗海马快速点燃作用;大鼠海马快速点燃模型c-fos蛋白在不同脑区和核团的免疫阳性表达细胞增加。     

大鼠颞叶癫痫点燃后海马zif268mRNA及其蛋白的时空表达变化

目的 探讨海马zif268mRNA及其蛋白的时空表达变化与颞叶癫痫脑损伤的关系. 方法 将雄性Wistar大鼠随机分为3组:其中正常组6只,假手术对照组(Sham组)和海人酸(KA)颞叶癫痫点燃组(TLE组)各36只,后两组按点燃后6h、24h、3d、7d、14d、21d时间点各分为6小组,每小组6只.采用KA杏仁核点燃建立经典颞叶癫痫模型,应用原位杂交和免疫组织化学方法分别检测海马神经元zif268mRNA及其蛋白的表达.结果 TLE组zif268mRNA表达在总体上和点燃后远期21d海马CA1、CA3区和齿状同(DG)均高于Sham组(P＜0.05).TLE组Zif268蛋白表达在总体上和远期21d海马DG表达低于Sham组(P＜0.05).回归分析提示颞叶癫痫与海马zif268mRNA表达呈正相关(β=0.286,P＜0.001),与Zif268蛋白表达呈负相关(β=-0.153,P＜0.001).结论 颞叶癫痫大鼠海马zif268mRNA及其蛋白的时空表达变化可能参与颞叶癫痫发病及其脑损伤过程.     

耐药性杏仁核点燃癫痫模型海马组织中γ-氨基丁酸受体表达变化

目的 建立多药耐药性癫痫模型,观察海马组织γ-氨基丁酸(GABA)受体表达变化从而探讨其在耐药性杏仁核点燃癫痫形成中的作用.方法 选用Wistar大鼠100只制作慢性杏仁核点燃癫痫模型,模型制作成功(n=52)后用经典抗癫痫药苯妥英钠和苯巴比妥进行筛选,根据大鼠对苯妥英钠和苯巴比妥的反应区别出耐药癫痫大鼠(n=8)及药物敏感大鼠(n=8),然后处死动物留取脑组织标本,用免疫组织化学染色方法观察海马组织内GABAA受体表达变化,用蛋白质印迹法检测GABAA受体含量,观察耐药癫痫大鼠和药物敏感大鼠之间的不同.结果 耐药癫痫性颞叶大鼠海马细胞变性坏死,排列紊乱,结构特征消失;耐药性颞叶癫痫大鼠海马组织内GABAA受体阳性表达细胞的灰度值(141.15±14.72)比药物敏感大鼠增高(92.56 ±5.17;t =3.380,P=0.006);蛋白质印迹方法提示受体条带变淡变窄,蛋白含量明显减少(0.38 ±0.08),与药物敏感大鼠(0.88 ±0.18)比较,差异具有统计学意义(t=5.420,P=0.002);但两组间GABAA受体阳性细胞数百分率比较差异无统计学意义.结论 耐药性颞叶癫痫大鼠海马组织内GABA受体表达明显减少,这可能在耐药性颞叶癫痫的形成过程中发挥部分作用.     

癫痫幼鼠海马和颞叶皮质区缝隙连接蛋白43和突触体素表达的变化

目的观察神经元缝隙连接蛋白43（Cx43）和突触体素（synaptophysin P38）在戊四氮（PTZ）点燃癫痫幼鼠海马及颞叶皮质区中的表达，探讨两者与癫痫的关系及其在癫痫形成中的作用。方法将50只21日龄Wistar大鼠分为对照组和实验组。实验组采用PTZ点燃癫痫幼鼠，按点燃进程分为Ⅰ级、Ⅱ级、Ⅲ级、Ⅳ级及Ⅳ级发作组。采用免疫组化和图像分析技术，观察海马及颞叶皮质区Cx43和P38表达的变化。结果应用PTZ点燃后，实验各组幼鼠海马及颞叶皮质区Cx43和P38的表达明显高于对照组（P〈0．01），且随发作级别的增高，幼鼠海马及颞叶皮质各区Cx43和P38的表达均增加。但各组间海马区和颞叶皮质区Cx43和P38的表达情况的比较差异无统计学意义（P〉0．05）。结论Cx43和P38的表达水平与癫痫的发生发展有密切关系，为研究小儿癫痫的病因及发病机制提供依据。     

马桑内酯点燃癫痫大鼠海马及齿状回区CGRP变化的初步研究

目的了解马桑内酯（CL）点燃癫痫大鼠海马及齿状回降钙素基因相关肽（CGRP）表达变化，探讨其可能的作用及机理。方法健康雄性SD大鼠3（）只，随机分为2组：对照组（C组，n=6）和实验组（n=24）。实验组肌肉注射CL0．20ml／kg，次／60h，平均20次；24h内有3～5级（Racine scale）痼性发作，或连续2次注射期间发作10次或以上为点燃（K组），否则为未点燃（NK组）；C组注射等量生理盐水。取各组脑组织行CGRP免疫组化染色，应用Image-proplus4．5图像分析系统检测其变化。结果11只大鼠点燃成功，K组CGRP表达较NK组和C组显著增强（P〈O．05）。结论CL点燃癫痫诱发大鼠海马及齿状回CGRP表达明显增强，CGRP可能在CL点燃癫痫中发挥一定的作用。     

氟桂利嗪对杏仁核点燃鼠海马Bax mRNA表达的影响

目的:观察氟桂利嗪对杏仁核点燃鼠癎性发作及海马促凋亡基因Bax mRNA表达的影响。方法:建立杏仁核点燃模型,予不同剂量氟桂利嗪灌喂点燃鼠。原位杂交法检测鼠脑海马Bax mRNA表达,图像分析软件测量阳性细胞平均吸光度。结果:正常大鼠海马存在少量Bax mRNA表达阳性细胞,点燃鼠海马各区Bax mRNA表达阳性细胞数及平均吸光度增加,氟桂利嗪处理后平均吸光度下降与剂量有关。结论:氟桂利嗪具有抗癫癎效应和拮抗点燃鼠海马Bax mRNA表达的作用。     

海人酸致难治性癫痫大鼠脑组织及外周血P糖蛋白表达趋势相关性研究

目的 研究难治性癫痫大鼠脑组织及外周血中P糖蛋白表达的相关性,探讨难治性癫痫可能的耐药机制,并比较海人酸在不同核团致痫后P糖蛋白表达的差异.方法 用海人酸分别于大鼠杏仁核及海马进行化学点燃,制作难治性癫痫模型.采用免疫组化方法,分析比较难治性癫痫大鼠脑组织及外周血中P糖蛋白的表达.结果 杏仁核点燃组与海马点燃组大鼠脑组织及外周血P糖蛋白表达高于与其相对应的生理盐水卡马西平组及生理盐水对照组,有统计学意义(P＜0.05);杏仁核生理盐水卡马两平组及海马生理盐水卡马西平组大鼠脑组织及外周血P糖蛋白的表达高于杏仁核生理盐水对照组及海马生理盐水对照组,有统计学意义(P＜0.05);杏仁核点燃组和海马点燃组大鼠脑组织及外周血P糖蛋白的表达相近,无统计学意义(P＞0.05).结论 难治性癫痫大鼠外周血及脑组织中P糖蛋白的表达具有一定的相关性,难治性癫痫的耐药机制可能是癫痫本身、服用抗癫痫药物等多因素作用的结果.杏仁核点燃模型及海马点燃模型均可诱导相近似的P糖蛋白的表达.     

柴胡总皂甙对戊四氮慢性点燃大鼠海马谷氨酸细胞的影响

目的研究柴胡总皂甙对戊四氮(PTZ)慢性点燃癫痫模型大鼠海马区谷氨酸(Glu)阳性细胞表达的影响。方法48只健康SD大鼠被随机分为6组,即空白组(A组)、生理盐水组(B组)、丙戊酸钠(VPA)组(C组)和柴胡总皂甙高、中、低三种剂量组(D组、E组、F组),每组8只,除A组不做处理外,其他各组采用腹腔注射PTZ慢性点燃造模,造模同时给予VPA、柴胡总皂甙等不同处理因素,连续4周后取脑组织切片进行Glu免疫组化染色,从阳性细胞数、灰度值分析结果。结果在CAl区,B组海马阳性细胞数高于A、C、D、E、F组,有显著性差异(P＜0．05),B组海马各区阳性细胞灰度值低于其他各组,与A、C、D各组比较,有显著性差异(P＜0．05)；而在CA2区和DG区,B组阳性细胞数、灰度值与各组差异无统计学意义。结论柴胡总皂甙可以影响PTZ点燃大鼠海马CA1区的Glu表达水平,从而抑制PTZ慢性点燃大鼠的痫性发作。     

幼鼠癫痫模型海马神经元NMDA受体表达与MMP-3表达相关性

目的 探讨幼鼠癫痫模型海马神经元N-甲基-D-天冬氨酸受体（NMDAR）表达与基质金属蛋白酶-3（MMP-3）表达的相关性。方法 将60只2~4周龄SPF级C57/BL6小鼠随机分为正常组、癫痫组、MMP-3抑制剂组、NMDAR抑制剂组,每组15只。采用匹罗卡品建立幼鼠癫痫模型;采用RT-PCR检测海马神经元NMDAR2A、NMDAR2B、MMP-3 mRNA表达;采用尼氏染色观察海马区神经元形态;采用Western blot检测海马区P-糖蛋白（P-gp）、钙调蛋白激酶Ⅱ（CAMKⅡ）蛋白表达。结果 幼鼠癫痫模型海马区NMDAR2A/B、MMP-3 mRNA以及P-gp、CAMKⅡ蛋白较正常组显著增加（P<0.05）。注射NMDA受体抑制剂或MMP-3抑制剂可显著降低幼鼠癫痫模型NMDAR2A/B、MMP-3 mRNA及P-gp、CAMKⅡ蛋白表达,且明显改善海马区神经元结构。结论 幼鼠癫痫模型海马神经元MMP-3表达与MNDAR表达可能具有相关性。     

2004/大鼠杏仁核点燃癫痫不同脑区BDNF及其受体TrkB的变化

目的 检测大鼠杏仁核点燃癫痫后不同脑区脑源性神经营养因子（BDNF）及其受体TrkB的表达与定位。方法 建立大鼠杏仁核点燃癫痫模型，应用免疫组化方法观察点燃鼠不同脑区不同点燃时程BDNF及TrkB的表达及含量。结果 点燃后大鼠颞叶及海马BDNF随着点燃次数的增加而升高，并持续至点燃后 49d；TrkB的表达也是随着点燃次数的增加而升高，并持续至点燃后7d（改变同BDNF），点燃1周后表达逐渐减少，至点燃后7周时基本恢复正常。结论 BDNF及TrkB直接参与癫痫的发生与发展。早期具有保护作用，但随着表达的进一步增加，又促进癫痫的发生发展，并一定程度上促进了癫痫发作后的神经细胞凋亡及脑损伤过程。     

塞来昔布对慢性颞叶癫痫大鼠海马核因子-κBp65和P-糖蛋白表达的影响

目的探讨环氧合酶-2抑制药塞来昔布对慢性颞叶癫痫大鼠海马核因子-κBp65和P-糖蛋白表达的影响,以及核因子-κBp65和P-糖蛋白与颞叶癫痴发病机制的关系,以为环氧合酶-2抑制药用于抗癫痼药物辅助治疗提供实验依据。方法采用大鼠海马CA3区微量注射海人酸的方法制备颞叶癫痫动物模型,免疫组织化学染色和Westernblotting法观察塞来昔布治疗后大鼠海马核因子-κBp65和P-糖蛋白表达变化。结果与对照组相比较,颞叶癫痫大鼠海马核因子-κBp65、P-糖蛋白表达水平,以及核因子-κBp65核移位现象明显增加（均P〈0．05）;经塞来昔布治疗后,海马组织中核因子-κBp65、P-糖蛋白表达水平及核因子-κBp65核移位现象显著改善,与模型组比较差异有统计学意义（均P〈0．05）。结论核因子-κBp65和P-糖蛋白在颞叶癫痼慢性期表达上调、核因子-κBp65核移位现象增加,有可能是难治性癫痫发生与发展的分子生物学机制之一。环氧合酶-2抑制药塞来昔布通过降低慢性颞叶癫痫大鼠海马CA3区核因子。KBp65和P-糖蛋白表达水平,抑制核因子-κBp65核移位,最终降低炎性反应,逆转多药耐药而发挥抗癫癫作用。     

Effect of amygdaloid kindling on thyrotropin-releasing hormone, somatostatin, cholecystokinin and substance P contents of the amygdala/piriform cortex and hippocampus of rats

Recently, several systems of neuropeptides have been demonstrated to have anticonvulsant action in some forms of epilepsy to some extent. However, considerably less knowledge has been taken to their involvement in convulsive disorders either with regard to the development, expression or control of seizures. In this study, therefore, we examined the influence of amygdaloid kindling, an experimental model of temporal lobe epilepsy, on thyrotropin-releasing hormone (TRH), somatostatin (SS), cholecystokinin (CCK) and substance P (SP) content in the amygdala/piriform cortex and hippocampus. Male Sprague-Dawley rats were implanted bipolar electrodes into the left amygdala under pentobarbital anesthesia. Daily kindling stimulation was made to the left amygdala with 1 sec, 60 Hz, 400 microA, until 5 consecutive fully kindled generalized convulsive seizures were elicited. Subsequently, amygdaloid kindled rats were decapitated 30 min, 24 hrs, 48 hrs, 7 days and 21 days after the last amygdaloid stimulation, and the amygdala/piriform cortex and hippocampus were dissected. Control animals only received chronic electrodes, but no stimulation was delivered. The immunoreactivity of TRH, SS, CCK and SP was examined by methods of specific radioimmunoassay. The TRH content in these two brain regions significantly increased 24 hrs after the last kindled convulsion. This increase became maximal 48 hrs after the last convulsion: about 3-fold and 4-fold of the control in the amygdala/piriform cortex and hippocampus, respectively. Such increases in the TRH content tended to persist for 7 days, but returned to the control level 21 days after the last convulsion.(ABSTRACT TRUNCATED AT 250 WORDS)     

人参皂甙Rd对颞叶癫大鼠学习记忆能力及海马5-HT表达的影响

目的研究人参皂甙Rd对氯化锂-匹罗卡品点燃颞叶癫(temporal lobe epilepsy,TLE)大鼠学习记忆能力及海马5-HT表达的干预作用。方法建立氯化锂-匹罗卡品点燃颞叶癫大鼠模型,将30只造模成功的颞叶癫大鼠随机分为TLE组(生理盐水10ml/kg腹腔注射,15只)及GSRd干预组(人参皂甙Rd2mg/kg腹腔注射,15只),另选15只大鼠作为正常对照组;采用Morris水迷宫及免疫组化染色分别检测各组大鼠学习记忆能力及海马5-HT表达水平。结果与正常对照组比较,TLE组大鼠学习记忆能力下降,海马5-HT表达明显减少(P0.05);与TLE组比较,GSRd干预组可显著提高大鼠学习记忆能力及海马5-HT的表达水平(P0.05)。结论人参皂甙Rd可能通过增加海马5-HT的表达来提高颞叶癫大鼠学习记忆能力。     

大鼠杏仁核电刺激癫痫模型海马JNK的磷酸化改变

目的 研究大鼠杏仁核电点燃癫痫模型海马中JNK的磷酸化改变,探讨JNK磷酸化与癫痫发生发展的关系.方法 建立大鼠杏仁核电点燃癫痫模型.设立空白对照组、手术对照组、点燃组,癫痫点燃成功后取脑,分别采用Western blot和免疫荧光方法 检测海马中JNK的表达变化,采用TUNEL染色和GFAP免疫组化染色观察海马形态学改变.结果 36只大鼠在12-20 d成功点燃.Western blot显示点燃组磷酸化JNK水平较手术对照组和空白对照组高(P<0.05).形态学检测显示点燃组海马区神经元缺失及神经胶质细胞增生(P<0.05).结论 电刺激诱发大鼠癫痫发作后,海马组织JNK磷酸化水平升高,该信号通路的激活可能参与颞叶内侧癫痫海马硬化的发生过程.     

Amygdaloid kindling is anxiogenic but fails to alter object recognition or spatial working memory in rats

Kindling in rats produces enduring behavioral changes that parallel the psychobehavioral disturbances frequently accompanying temporal lobe epilepsy. Some evidence suggests that the site of kindling is an important determinant of the type of behavioral changes observed following kindling, although this variable has not been systematically investigated. In the present experiments, the effects of amygdaloid kindling were assessed on a battery of behavioral tests we used previously to assess the effects of kindling in dorsal hippocampus or perirhinal cortex. Three generalized seizures were kindled with stimulation in or near the basolateral amygdala. One week later, rats were tested successively on measures of anxiety, activity, object recognition memory, and spatial working memory over a period of 3 weeks. Amygdaloid kindling produced increased anxiety, but spared all other behaviors assessed. This pattern of results is partially distinct from the previously described effects of perirhinal cortical kindling, which increases anxiety but also impairs object recognition memory, and is completely distinct from dorsal hippocampal kindling, which selectively increases activity and impairs spatial working memory. The observations suggest that kindling of distinct highly interconnected temporal lobe sites produces distinct patterns of behavioral comorbidity. The underlying mechanisms are thus most likely localized to intrinsic circuits at the site of seizure origination.     

Neuronal injury and brain-derived neurotrophic factor expression in a rat model of amygdala kindling seizures Differences in brain regions and kindling courses

BACKGROUND:Studies have demonstrated that brain-derived neurotrophic factor (BDNF) has a dual effect on epilepsy. However, the relationship between epilepsy-induced brain injury and BDNF remains poorly understood.OBJECTIVE:According to ultrastructural and molecular parameters, to detect the degree of neuronal injury and BDNF expression changes at different brain regions and different kindling times to determine the effects of BDNF on epilepsy-induced brain injury.DESIGN, TIME AND SETTING:A randomized, controlled, animal experiment based on neuropathology and molecular biology was performed at the Department of Physiology and Department of Pathology, Basic Medical College of Jilin University in 2003.MATERIALS:UltraSensitiveTM SP kit for immunohistochemistry (Fuzhou Maxim Biotechnology, China), BDNF antibody (concentrated type, Wuhan Boster Biological Technology, China), JEM-1000SX transmission electron microscopy (JEOL, Japan), and BH-2 light microscope (Olympus, Japan) were used in the present study.METHODS:Wistar rats were randomly assigned to control (n = 6), sham-surgery (n = 6), and model (n = 60) groups. The control group rats were not treated; an electrode was embedded into the amygdala in rats from the sham-surgery and model groups; an amygdala kindling epilepsy model was established in the model group.MAIN OUTCOME MEASURES:Pathological changes in the temporal lobe and hippocampus were observed by light and electron microscopy at 1, 3, 7, 14, and 21 days following kindling, and BDNF expression in the various brain regions was determined by immunohistochemistry.RESULTS:In the model group, temporal lobe cortical and hippocampal neurons were swollen and the nuclei were laterally deviated. There were also some apoptotic neurons 3 days after kindling. The nucleoli disappeared and the nuclei appeared broken or lysed, as well as slight microglia hyperplasia, at 7 days. Electron microscopic observation displayed chromatin aggregation in the nuclei and slight mitochondrion swelling 3 days after kindling. Injury changes were aggravated at 7 days, characterized by broken cytoplasmic membrane and pyknosis. With the development of seizure, the number of BDNF-positive neurons in the hippocampus and temporal lobe increased and peaked at 7 days. Moreover, hippocampal and cortical temporal lobe injury continued. Following termination of electrical stimulation after 7 days of kindling, BDNF expression decreased, but continued to be expressed, up to 21 days of kindling. In addition, the number of temporal and hippocampal BDNF-positive neurons was greater than the control group.CONCLUSION:Brain injury and BDNF expression peaked at 7 days after kindling, and hippocampal changes were significant.     

伴海马硬化的颞叶癫痫患者的临床特点及手术治疗

目的探讨颞叶癫痫海马硬化的临床特点及手术治疗的效果。方法伴海马硬化的颞叶癫痫患者18例,其中男10例,女8例;年龄12~37岁,病程3~10年。癫痫复杂部分性发作10例,部分性发作继发全身性发作2例,全身强直-痉挛性发作6例。结合患者的临床表现、MRI检查和视频脑电图(V-EEG)监测结果,对这18例患者行前颞叶切除术(包括大部分海马和杏仁核)。结果所有患者术中皮层和深部电极脑电图均发现颞叶皮层海马、杏仁核有异常放电,术后病理检查均证实海马硬化的诊断。术后18例患者均出现发热,但经过抗炎、腰椎穿刺及支持治疗后渐好转。术后1年以上的随访发现16例癫痫发作完全消失,2例术后较术前显著改善,仅偶有癫痫发作,但均长期服用抗癫痫药物。结论对于颞叶癫痫伴有海马硬化的患者,如果同时脑电图又发现有同侧颞叶痫样放电,则可以考虑行该侧前颞叶切除术(包括大部分海马和杏仁核),若手术切除彻底,其术后疗效也较满意。     

硫丙咪胺对戊四氮致痈幼鼠海马GFAP、c—fos表达和学习认知的影响

目的：观察硫丙咪胺（Thi）对戊四氮（PTZ）致痫幼大鼠海马胶质原纤维酸性蛋白（GFAP）、c-fos表达及学习认知的影响。方法：发育期SD幼鼠40只随机分为对照组、PTZ致瘸组、TM 30mg·kg^-1干预组和Thi15mg·kg^-1干预组（均n=10）。观察各组大鼠瘸样行为，水迷宫实验观察学习认知能力、免疫组化检测海马GFAP和c-fos的变化。结果：对照组无痫样发作，阿z致痫组有重度发作，Thi30mg·kg^-1干预组有轻度发作（P〈0．05）；水迷宫实验中，PTZ致痫组寻找平台潜伏时间延长和通过平台次数减少，Thi30和15mg·kg^-1干预组寻找平台潜伏时间明显缩短，通过平台次数增加明显，差异有统计学意义（P〈0．05）；PTZ致痫组GFAP和c-fos表达明显强于Thi干预组，差异有统计学意义（P〈0．05），其中Tiff30与15mg·kg^-1干预组相比差异也有统计学意义（P〈o．05）；GFAP和c—fos免疫组化表达与大鼠空间学习记忆能力呈正相关。结论：Thi可能通过抑制PTZ致瘸幼大鼠海马GFAP、c—fos表达，减轻癫痫发作程度，提高其学习认知能力。     

尼莫地平对蛛网膜下腔出血大鼠额叶转化生长因子-β1表达的影响

目的：探讨尼莫地平对蛛网膜下腔出血（SAH）大鼠额叶转化生长因子-β1（TGF—β1）表达和血管痉挛的影响。方法：枕大池二次注血法制作SAH模型。54只成年健康雄性SD大鼠随机分为对照组（n=6）、SAH组（n=24）和尼莫地平处理组（n=24），其中SAH组和尼莫地平处理组随机均分为1、3、5和7d等4组（n=6）。尼莫地平处理组于二次注血后30min时经股静脉注入尼莫地平2mg／kg，此后每天经腹腔注射尼莫地平2mg／kg。HE染色光镜下观察基底动脉病理学变化，测定内径；免疫组化法检测各组大鼠额叶TGF—β1表达。结果：SAH组和尼莫地平处理组基底动脉内径显著小于对照组（P〈0．01），而SAH组与尼莫地平处理组无显著差异。SAH1d时，TGF—β1表达增加，3d时达高峰，5d和7d时显著低于1d和3d时（P〈0．01），但仍照著高于对照组（P〈0．01）。与SAH组相比，尼莫地平处理组1d和3d时TGF-β1表达无显著差异，5d和7d时显著增加。结论：SAH后额叶TGF—β1表达发生改变，与脑血管痉挛有关，提示TGF-β1参与了脑血管痉挛的病理学过程。尼莫地平可能通过增加SAH后啮组织中TGF-β1表达对缺血脑组织起着保护作用。     

Kindling-induced alterations in GABAA receptor-mediated inhibition and neurosteroid activity in the rat piriform cortex

The piriform cortex makes strong interconnections with limbic structures (amygdala, entorhinal cortex and hippocampus) that are involved in memory processing. These connections have also been implicated in the development of temporal lobe epilepsy. However, little is known about how neurones in this region may change during seizure genesis. Here we tested the hypothesis that in the kindling model of temporal lobe epilepsy GABAA receptor-mediated inhibition is altered in the piriform cortex. To do this we performed whole-cell patch-clamp recordings in piriform cortex brain slices obtained from non-kindled and amygdala-kindled adult rats. We found that kindling coincided with an increase in the amplitude and duration of miniature inhibitory post-synaptic currents (mIPSCs) recorded from non-pyramidal neurones, whereas the mIPSCs occurring on pyramidal (excitatory) cells did not change. Non-stationary noise analysis of mIPSCs occurring on the non-pyramidal neurones showed that inferred unitary conductance of synaptic channels were the same before and after kindling, implying that the channel number increased significantly. Immunocytochemical analysis of the inhibitory innervation showed that it was also unaltered by seizure induction. We also found that the effect of the positive modulator tetrahydrodeoxycorticosterone was reduced on the pyramidal neurones after kindling. In contrast, the potentiating effects of tetrahydrodeoxycorticosterone on non-pyramidal cells were about the same after kindling as in control (sham) rats. These data indicate that amygdala kindling causes a shift in the inhibition 'balance' between the pyramidal and non-pyramidal cells, perhaps leading to the disinhibition of pyramidal cells.