小剂量伽玛刀照射对致癎大鼠脑神经元nNOS表达的影响

目的 通过观察低剂量伽玛刀照射对致痫大鼠大脑皮质及海马神经元nNOS表达的影响，初步探讨伽玛刀治疗癫痫的作用机制。方法 将44只青霉素致痫大鼠模型等分为实验组和实验对照组，对实验组进行伽玛刀照射（周边剂量12Gy），应用免疫组化方法检测两组大脑皮质及海马神经元nNOS表达的变化。结果 nNOS在两组动物的皮质和海马表达均有显著性差别．实验组显著性低于实验对照组；实验对照组表达呈双高峰现象。结论 nNOS在伽玛刀治疗癫痫的机制中具有重要作用。     

低剂量伽玛刀照射对致大鼠皮质及海马神经元c-fos和nNOS表达的影响

目的 通过观察低剂量伽玛刀照射对致痫大鼠大脑皮质及海马神经元c—fos和脑型一氧化氮合酶（nNOS）表达的影响，探讨伽玛刀治疗癫痫的作用机制。方法将44只青霉素致痫大鼠模型等分为实验组和实验对照组大鼠各22只，另取4只正常大鼠作为正常对照组。实验组行伽玛刀照射（周边剂量12Gy）后，应用免疫组化方法，观察大脑皮质及海马神经元c-fos和nNOS表达的变化。结果无论是皮质还是海马，c—fos和nNOS在实验组与实验对照组动物之间，表达均有明显的差别，实验组表达明显少于实验对照组，而后者呈现双高峰现象。结论c—fos和nNOS在伽玛刀治疗癫痫的机制中发挥了重要作用。     

低剂量伽玛刀照射对致(癎)大鼠皮质及海马神经元c-fos和nNOS表达的影响

目的 通过观察低剂量伽玛刀照射对致(癎)大鼠大脑皮质及海马神经元c-fos和脑型一氧化氮合酶(nNOS)表达的影响,探讨伽玛刀治疗癫(癎)的作用机制.方法 将44只青霉素致(癎)大鼠模型等分为实验组和实验对照组大鼠各22只,另取4只正常大鼠作为正常对照组.实验组行伽玛刀照射(周边剂量12 Gy)后,应用免疫组化方法,观察大脑皮质及海马神经元c-fos和nNOS表达的变化.结果 无论是皮质还是海马,c-fos和nNOS在实验组与实验对照组动物之间,表达均有明显的差别,实验组表达明显少于实验对照组,而后者呈现双高峰现象.结论 c-fos和nNOS在伽玛刀治疗癫(癎)的机制中发挥了重要作用.     

低剂量伽玛刀照射对癫痫大鼠皮层及海马NMDA受体亚基表达的影响

目的观察低剂量伽玛刀照射对癫痫大鼠皮层和海马N-甲基-D-天氡氨酸(N-methyl-Daspartate,NMDA)受体亚基表达的影响。方法根据动物是否致痫及接受伽玛刀照射,将大鼠分为4组:对照组、伽玛刀组、药物致痫组、伽玛刀+药物组。腹腔连续注射戊四氮(pentylenetetrazole,PTZ)制备癫痫大鼠模型,以双侧额叶为照射靶区对大鼠进行低剂量伽玛刀照射,边缘剂量为15Gy。观察并记录各组大鼠伽玛刀照射前、后癫痫发作情况,并于伽玛刀照射后12周后留取脑组织,分别利用免疫组化及免疫蛋白印迹法对大鼠皮层及海马NMDA受体亚基NR1、NR2A和NR2B进行检测。结果对照组及伽玛刀组大鼠无痫性发作表现,与药物致痫组大鼠相比,伽玛刀+药物组大鼠经低剂量伽玛刀照射后12周,痫性发作明显减轻(P0.05)。与对照组相比,药物致痫组大鼠额叶皮层及海马CA1、CA3区NR1、NR2A和NR2B表达均明显增强(P0.05),阳性神经元数目及平均吸光度值均明显增加(P0.05);与药物致痫组比较,伽玛刀+药物组额叶皮层及海马CA1、CA3区NR1、NR2A和NR2B表达均明显降低(P0.05),阳性神经元数目及平均吸光度值明显减少(P0.05);伽玛刀组与对照组无明显差别(P0.05)。结论癫痫大鼠额叶皮层及海马NR1、NR2A及NR2B亚单位蛋白表达增强,低剂量伽玛刀照射可能引起癫痫大鼠皮层及海马NMDA受体亚基表达减少,这可能是低剂量伽玛刀抑制癫痫发作的分子机制之一。     

伽玛刀对癫痫大鼠模型的治疗作用及机制研究

目的 研究伽玛刀照射对癫痫大鼠的放射生物学作用,探讨伽玛刀治疗癫痫的作用机制.方法 制备海人酸大鼠癫痫模型,利用自行设计的伽玛刀动物定向头架,分别应用100Gy和20Gy的伽玛射线对癫痫大鼠海马组织进行照射,观察大鼠行为学、脑电图、MRI及超微结构、脑组织氨基酸含量及GABA能神经元表达变化.结果 伽玛刀照射后大鼠癫痫发作次数明显减少.100Gy组照射后2个月MRI表现为靶区高信号,20Gy组5个月MRI未见改变.伽玛刀照射后兴奋性氨基酸含量显著低于癫痫组,GABA能神经元表达低于正常,但高于癫痫组.结论 伽玛刀照射对癫痫大鼠具有治疗作用,高剂量伽玛射线(100Gy)对致痫灶有毁损作用.低剂量伽玛射线(20Gy)通过抑制兴奋性神经元释放兴奋性氨基酸使癫痫发作减少.     

海马神经元激活物致疒间大鼠大脑皮质和海马γ-氨基丁酸受体的表达

目的 观察大鼠海马神经元在激活物作用下γ-氨基丁酸（GABA。）受体的表达,进一步探讨癫痫发病机制。方法 将大鼠海马神经尢被戊四氮（PTZ）作用后的激活物（实验组）及无血清培养基（对照组）注入大鼠侧脑室后观察其行为、脑电图（EEG）及脑组织GABA,受体表达的变化。结果 实验组大鼠注射后15～30min出现Ⅱ～Ⅲ级惊厥反应,EEG呈短程中高幅尖波、尖慢复合波;对照组的行为及EEG未见异常;各时点实验组大鼠脑组织GABA、免疫反应阳性细胞表达明显低于对照组（均P〈0．05）,对照组GABA,免疫反应阳性细胞广泛分布于大脑皮质、海马回、齿状回。结论 海马神经元激活物具有明显致痫作用,其致痫效应与GABAA受体含量下降有关。     

低剂量伽玛刀照射癫癎大鼠脑神经元的超微结构研究

目的探索伽玛刀治疗原发性癫的细胞学机理。方法建立大鼠皮质青霉素局灶性癫癎模型,将SD大鼠随机分为实验组、实验对照组和对照组。照射周边剂量12 Gy, 等剂量曲线为50%。分别于0.5 h~2个月后取靶区皮质及海马标本制备光镜、常规透射电镜样品。结果癫癎模型鼠可见较多凋亡神经元,而癫癎模型鼠经低剂量伽玛刀照射后同时程的神经元改变较轻微,凋亡细胞少见。结论凋亡参与了青霉素致癫癎发作后海马神经元的死亡过程,低剂量伽玛刀照射对抑制神经元的死亡过程有重要作用。     

低剂量伽玛刀照射对癫痫模型大鼠癫痫发作及认知功能的影响

目的观察低剂量伽玛刀照射对癫痫大鼠的抗癫痫作用及对认知功能的影响。方法根据动物是否致痫及接受伽玛刀照射,将60只大鼠分为4组:①正常对照组;②伽玛刀对照组;③戊四氮(pentylenetetrazole,PTZ)组;④PTZ+伽玛刀组。腹腔连续注射PTZ制备癫痫大鼠模型,以双侧额叶为照射靶区对大鼠进行低剂量伽玛刀照射,边缘剂量为15Gy。观察并记录各组大鼠伽玛刀照射前、后的癫痫发作情况及脑电图变化,并于伽玛刀照射后12周,应用Morris水迷宫评测各组大鼠学习和记忆功能。结果与PTZ组大鼠比较,PTZ+伽玛刀组大鼠经低剂量伽玛刀照射后,于8～12周时,发作程度明显减轻,癫痫波发放的潜伏期延长,频率显著减少(P0.05)。在Morris水迷宫试验中,与正常对照组比较,PTZ组大鼠搜索策略变差,寻找平台逃避潜伏期时间显著延长,游泳距离增加,穿越平台的次数及在原平台象限的游泳时间的百分率减少(P0.05);而与PTZ组相比,PTZ+伽玛刀组搜索策略明显改善,寻找平台逃避潜伏期时间缩短,游泳距离减少,穿越平台的次数及在原平台象限的游泳时间的百分率明显增加(P0.05)。结论 PTZ致痫大鼠认知功能明显受损,低剂量伽玛刀照射在控制大鼠癫痫发作的同时,可改善认知功能。     

伽玛刀低剂量照射对致疒间大鼠海马中氨基酸递质的影响

目的观察伽玛刀低剂量照射对致疒间大鼠海马中谷氨酸(Glu)、γ-氨基丁酸(GABA)的影响,探讨伽玛刀治疗癫疒间的作用机制。方法将50只锂-匹罗卡品致疒间大鼠随机分为照射组和非照射组,各25只,另取正常大鼠25只(腹腔注射生理盐水)作为对照组。照射组大鼠进行伽玛刀低剂量照射(周边剂量20Gy),对照组和非照射组大鼠不进行伽玛刀照射。用高效液相色谱-质谱-质谱(HPLC-MS-MS)分析法检测各组大鼠海马Glu、GABA的含量。结果伽玛刀照射2周后,照射组和非照射组大鼠海马中Glu含量均高于对照组,照射组GLu含量低于非照射组,差异具有统计学意义(P0.05);照射组和非照射组GABA含量均低于对照组,照射组GABA含量高于非照射组,差异具有统计学意义(P0.05)。结论伽玛刀低剂量照射通过调节海马中Glu与GABA的平衡,以达到抗癫疒间的作用。     

伽玛刀照射对癫痫大鼠海马氨基酸递质及超微结构的影响

目的研究伽玛刀照射对癫痫大鼠的放射生物学作用,探讨伽玛刀治疗癫痫的作用机制。方法利用海人酸制备癫痫大鼠模型50只(癫痫组25只,伽玛刀照射组25只),对照组为正常大鼠25只(注射生理盐水),观察各组行为学改变;采集伽玛刀照射后1d、1w、2w、4w、8w后各组大鼠海马细胞外液,并测定Glu和GABA含量及观察海马超微结构变化。结果 1w后,照射组和癫痫组GABA含量均低于对照组;2w后,照射组和癫痫组Glu含量均高于对照组;4w后,照射组Glu含量低于癫痫组,GABA含量高于癫痫组;差异均具有统计学意义(P<0.05)。海马组织超微结构显示照射组早中期与癫痫组基本一致,其晚期部分结构恢复,线粒体修复较为明显。结论伽玛刀照射可调节海马中Glu与GABA以达到新的平衡,并在癫痫发作引起的病理性损伤修复中起到重要作用。     

柴胡疏肝汤对戊四氮致痫大鼠海马及额叶皮质c-fos表达的影响

目的 观察柴胡疏肝汤对戊四氮致痫大鼠海马及额叶皮质c-fos表达的影响.方法 选取经戊四氮诱导制作的癫痫模型大鼠48只,按随机数字表法分成6组:癫痫模型组、德巴金组、定痫丸组、柴胡疏肝汤低剂量组、柴胡疏肝汤中剂量组和柴胡疏肝汤高剂量组,每组各8只;另设正常对照组8只.正常对照组和癫痫模型组常规饲养,其他各组给予药物德巴金,定痫丸,低、中、高剂量柴胡疏肝汤处理,均连续灌胃治疗5周.免疫组化染色检测各组大鼠海马及额叶皮质c-fos的表达情况.结果 戊四氮致痫后大鼠海马及额叶皮质c-fos表达明显增强,而应用中、高剂量的柴胡疏肝汤,德巴金和定痫丸治疗后,大鼠海马及额叶皮质c-fos表达均明显减弱,与癫痫模型组比较差异均有统计学意义(P<0.05),而柴胡疏肝汤低剂量组大鼠海马及额叶皮质c-fos表达无明显减弱.结论 柴胡疏肝汤的抗癫痫作用机制可能与其含有柴胡皂甙及其他多种有效的抗癫痫成份多靶点干预海马及额叶皮质c-fos表达水平有关.

Abstract：

Objective To observe the effect of chaihushugantang on the expression of c-fos in the hippocampus and frontal lobe cortex of pentylenetetrazole (PTZ)-induced epileptic rats. Methods Forty-eight PTZ-induced epileptic rats were randomly divided into 6 groups: epileptic model group,Valproate treatment group, Dingxianwan treatment group, and lower-dose, medium-dose and high-dose chaihushugantang treatment groups (n=8). Normal control group was also employed (n=8). The epileptic rats in the normal control group and epileptic model group were fed normally. Rats of the treatment groups were performed intragastric administration of medicines (Valproate, Dingxianwan and chaihushugantang) for 5 weeks in succession respectively. The expression of c-fos in the hippocampus and frontal lobe cortex of all the rats was observed. Results The expression of c-fos in the hippocampus and frontal lobe cortex of rats in the epileptic model group was significantly increased, while the c-fos expression in the hippocampus and the frontal lobe cortex of rats in the medium-dose and high-dose chaihushugantang treatment groups and Valproate treatment group and Dingxianwan treatment group was significantly decreased as compared with that in epileptic model group (P<0.05). But the c-fos expression in the hippocampus and the frontal lobe cortex of rats in the low-dose chaihushugantang treatment group showed no obvious decrease. Conclusion Chaihushugantang has good antiepileptic effect, might through affecting the c-fos expression in the epileptic rats. The antiepileptic mechanism of chaihushugantang can be related to saikosaponins and other antiepileptic constituents in it.     

伽玛刀照射癫痫大鼠海马神经元超微结构及线粒体计量分析

目的观察低剂量伽玛刀照射对癫大鼠海马神经元超微结构的影响。方法建立大鼠青霉素局灶性癫动物模型,将58只SD大鼠分为对照组、癫模型组和伽玛刀照射组。对大鼠行伽玛刀照射,照射中心剂量24 Gy、周边剂量12 Gy、等剂量曲线50%,术后3 h～60 d取靶区海马,透射电镜观察并采用图像分析系统对线粒体形态进行计量分析。结果对照组细胞结构基本正常;癫模型组可见神经元细胞器明显空化,线粒体体密度、数密度、比表面和嵴膜密度较对照组明显减少(均P<0.05),线粒体平均体积和平均截面积较对照组明显增大(均P<0.05)。伽玛刀照射组早期线粒体的平均体积、平均截面积、数密度、比表面与对照组相比差异显著(均P<0.05),中期和晚期线粒体各项参数与对照组相比差异不显著。结论大鼠癫发作早期线粒体形态结构变化明显,低剂量伽玛刀照射对神经元修复起重要作用。     

Pinealectomy stimulates and exogenous melatonin inhibits harmful effects of epileptiform activity during pregnancy in the hippocampus of newborn rats: an immunohistochemical study

Objectives Epilepsy during the pregnancy is an important problem in clinical practice for newborn individuals. Recently, it has been demonstrated that mothers’ epileptic seizures have some harmful effects on newborns, but present data concerning the effects of epileptic phenomena in pregnant mothers on newborn pups are still limited. The current study was undertaken to investigate the morphological changes in the hippocampus of newborn pups of pinealectomized rats subjected to experimental epilepsy during pregnancy.Methods In this study, rats were randomly divided into four groups (ten animals each): intact control group, epilepsy control group, surgical pinealectomy + epilepsy group, and group with melatonin treatment following pinealectomy procedure. The animals in surgical pinealectomy + epilepsy and melatonin treatment groups underwent a surgical intervention consisting of pineal gland removal. At 1 month after surgical pinealectomy, an acute grand mal epileptic seizure was induced by 400 IU penicillin G administration into their hippocampal CA3 region on the 13th day of their pregnancy in all animals except the intact control animals. On the first neonatal day, the hippocampi were removed and processed for microscopic examination. Nestin expression was analysed in the developing hippocampal tissue.Results Normal migration and hippocampal maturation were determined in the postnatal rat hippocampus in intact control group, but the morphological structure of the hippocampus in the epilepsy control group corresponded to the early embryonal period. It was found that experimental epilepsy and pinealectomy enhanced nestin immunoreactivity, whereas exogenous melatonin treatment (30 μg/100 g body weight, intraperitoneal) inhibited pinealectomy-stimulated nestin expression in CA1 region of the hippocampus.Conclusion These findings suggest that epileptic seizures during pregnancy may cause an impaired hippocampal neurogenesis and neuronal maturation in the newborn, and the negative effects in the postnatal rat hippocampus are more dramatic after pinealectomy of the mother; conversely, melatonin administration suppresses these negative changes. This is the first report investigating the effects of maternal epilepsy during pregnancy in pinealectomized rats on nestin immunoexpression in the newborn rat hippocampus.Presented in part at the 4th Asian-Pacific International Congress of Anatomists (APICA), Kuşadası, Turkey, 7-10 September 2005.     

Upregulation of dysbindin in temporal lobe epileptic foci of human and experimental animals

The gene encoding dystrobrevin-binding-protein-1 (dysbindin) is expressed in many areas of the central nervous system and plays a role in intracellular vesicle trafficking, synaptic vesicle trafficking, and neurotransmitter release. At a cellular level, dysbindin is thought to mediate presynaptic glutamatergic transmission. Using Western blotting and immunofluorescence, we investigated dysbindin expression in brain tissues of the patients with temporal lobe epilepsy (TLE) and rats with TLE (lithium chloride pilocarpine model) to explore its possible role in epileptogenesis. Twenty-five samples of temporal neocortex from patients undergoing surgery for drug-refractory TLE epilepsy and 10 histologically normal temporal lobes tissues from control subjects were used in our study. We also examined dysbindin expression in the hippocampus and adjacent cortex from experimental Sprague-Dawley rats. Dysbindin was expressed in the cytoplasm of neurons from epileptic specimens, and levels of dysbindin proteins were significantly increased in patients with TLE. Dysbindin was also expressed in the neurons of the hippocampus and adjacent cortex from experimental and control rats. Western blotting of rat brain tissue showed that dysbindin was upregulated gradually from 6 h after kindling. Maximal expression was seen around 2 months in chronic epileptic phase. These results demonstrated that the increased expression of dysbindin might play a role in the pathogenesis of drug-refractory TLE.     

雌激素调控瞬时外向钾通道对大鼠慢性颞叶癫发作的影响

目的探讨雌激素对大鼠慢性颞叶癫发作的影响及其与瞬时外向钾通道(kv4.2)之间的关系。方法 SD雌性大鼠随机分为正常对照组、去势对照组、正常致组、去势致组。应用毛果芸香碱诱导大鼠癫持续状态(SE),观察大鼠行为学变化。经4周后成为慢性颞叶癫大鼠。Western bolt方法检测大鼠海马瞬时外向钾通道Kv4.2蛋白表达水平。结果与正常致组比较,去势致组达到SE的潜伏期延长、死亡率降低,但差异无统计学意义(P0.05);去势致组的癫发作强度较正常致组轻,差异有统计学意义(P0.05)。去势致组和正常致组在SE 4周后海马Kv4.2均较正常对照组显著升高,均差异有统计学意义(P0.05和P0.01)。去势对照组和去势致组比较,均未见对Kv4.2蛋白表达产生影响,说明Kv4.2蛋白表达升高为癫发作所致。结论大鼠癫发作后Kv4.2表达增加、瞬时外向钾电流增强、神经冲动的发放频率减慢,可能是产生代偿性自我保护反应的结果;虽然去势雌性大鼠未对Kv4.2表达产生影响,但出现潜伏期延长和死亡率降低、发作强度降低的行为学趋势,提示低剂量雌激素可能存在对癫发作的保护作用。     

伽玛刀照射正常大鼠海马组织的放射生物学研究

目的研究伽玛刀照射对正常大鼠海马组织的放射生物学作用,探讨伽玛刀作用于正常脑组织的机制,为立体定向放射外科的开展提供理论依据。方法利用自行设计的伽玛刀动物定向头架,应用不同剂量的伽玛射线对大鼠海马组织进行照射,原位杂交观察c-fosmRNA和HSP70mRNA表达,免疫组化观察FOS、HSP70、GFAP和bcl-2蛋白表达。结果c-fosmRNA在照射后3h、7d出现2个高峰,HSP70mRNA在照射后1~3h即有表达。FOS、HSP70、GFAP和bcl-2蛋白表达随照射时间和部位的不同而各有自己的特点。结论自行设计的伽玛刀动物定向头架定位准确、可靠。c-fos和HSP70表达说明伽玛刀照射虽局限于海马,但引起的反应却是强烈的。bcl-2具有抑制电离辐射所致细胞凋亡作用,GFAP阳性细胞反应可作为脑组织损伤的一种标志。