氯喹对癫痫大鼠海马区神经元自噬的影响

目的:研究戊四氮诱导大鼠癫痫发病过程中出现的神经元自噬现象,探讨氯喹对神经元自噬现象的影响,探讨氯喹缓解癫痫的作用机制。方法:Wistar大鼠24只随机分为对照组、戊四氮致痫组及氯喹干预组。观察各组大鼠行为表现和脑电图变化,用HE、Nissl染色检测各组大鼠海马区神经元的损伤程度,应用免疫组化检测各组海马自噬标记物微管相关蛋白l轻链3(LC3)的表达。结果:对照组无痫样发作,脑电图波形正常,神经元处于正常状态,自噬处于低水平;戊四氮致痫组有重型的痫样发作,脑电图记录呈高频高幅的癫痫波形,并且出现神经元的大量死亡(P0.05),LC3较对照组表达增高(P0.05);氯喹干预组有轻型痫样发作,与戊四氮致痫组对比,脑电图记录癫痫波形减少,神经元的损伤明显减轻(P0.05),LC3的表达显著升高(P0.05),自噬过程被抑制。结论:氯喹可以有效的抑制癫痫发作过程中出现的神经元自噬现象,减少神经元的死亡,从而达到缓解癫痫发作的作用。     

丙戊酸钠处理对于癫痫大鼠模型海马内细胞自噬的影响

目的:研究丙戊酸钠(VPA)对癫痫模型大鼠海马内细胞自噬、动物脑电图和行为学的影响。方法:制作癫痫大鼠模型并随机分为癫痫组、3甲基腺嘌呤(3MA)组、VPA组及VPA联合3MA组四组,设正常大鼠为对照组。观察各组行为学及脑电图变化,HE及Nissl染色显示神经元的损伤情况,免疫组织化学染色、Western Blot、Real-time PCR检测自噬标记物微管相关蛋白1轻链3(LC3)表达。结果:行为学观察及脑电图检测显示,丙戊酸钠组及丙戊酸钠联合3MA组均可降低癫痫发作等级,3MA组无抗癫痫效果。HE及Nissl染色显示,对照组未见明显异常,癫痫组神经元损伤严重,丙戊酸钠组与癫痫组相比,神经元损伤明显减轻;3MA组与癫痫组相比,神经元损伤明显减轻;丙戊酸钠联合3MA组与丙戊酸钠组相比,神经元损伤明显减轻。免疫组织化学染色、Western Blot、Real-time PCR检测显示,对照组LC3呈低表达,癫痫组LC3表达明显高于对照组;丙戊酸钠组LC3表达明显高于癫痫组;3MA组LC3表达明显低于癫痫组;丙戊酸钠联合3MA组LC3表达明显低于丙戊酸钠组。结论:VPA处理能够诱导癫痫大鼠海马内细胞自噬增加和导致神经元损伤。     

自噬标志性分子LC3B在大鼠全脑缺血复灌损伤中海马CA1区的表达及意义

目的　探讨自噬标志分子LC3B在大鼠全脑缺血复灌不同时间的表达以及对海马神经元损伤的影响。 方法　采用四血管法(4-vessel-occlusion,4-VO)法制作大鼠全脑缺血模型,随机将33只　SD大鼠分成假手术组和缺血再灌注组。在大鼠全脑缺血20 min后,分别恢复血流灌注30 min、1、2、4、6、8、12、24、48、72 h,用免疫组织化学法检测海马CA1区神经元LC3B的表达。 结果　LC3B在大鼠全脑缺血20 min复灌2 h开始表达,在复灌12 h表达到达高峰,之后逐渐减弱。 结论　自噬的激活介导了大鼠全脑缺血再灌注海马CA1区神经元的损伤死亡,长时间脑缺血再灌注损伤中自噬激活的时间更早及介导神经元的损伤更严重。     

远程缺血后处理抑制心肺复苏后大鼠海马神经细胞自噬

目的:观察远程缺血后处理(RIPostC)对心肺复苏后(CPR)大鼠海马神经细胞自噬水平的影响。方法:45只雄性SD大鼠随机分为假手术组(sham组)、心脏停搏(CA)/CPR组和RIPostC组,每组15只。通过夹闭气管导管建立窒息性CA/CPR模型。在自主循环恢复(ROSC)后不同时点进行神经功能缺损评分(NDS),ROSC后24 h处死大鼠并取出海马组织,Western blot法检测海马神经细胞LC3-Ⅱ/LC3-Ⅰ和beclin-1蛋白的表达,TUNEL法检测细胞凋亡,免疫荧光观察LC3颗粒形成,透射电镜观察细胞自噬小体和线粒体的超微结构形态学变化。结果:与sham组相比,CA/CPR组NDS评分降低,LC3-Ⅱ/LC3-Ⅰ和beclin-1蛋白表达均升高(P0.05),神经细胞凋亡增多(P0.05);与CA/CPR组相比,RIPostC组的NDS评分升高,LC3-Ⅱ/LC3-Ⅰ和beclin-1表达下降(P0.05),神经细胞凋亡减少(P0.05),LC3颗粒形成减少,细胞内自噬小体减少,线粒体结构损伤减轻。结论:远程缺血后处理可改善心肺复苏后大鼠神经功能,这可能与抑制海马神经细胞过度自噬有关。     

两种给药途径致痫大鼠海马神经元超微结构损伤及caspase-3的表达特征

为了观察两种给药途径致痫大鼠海马神经元超微结构的损伤及caspase-3的表达特征,本研究分别采用海人酸腹膜腔注射(A组)和尾静脉注射(B组)诱发大鼠癫痫持续状态(SE)。分别于SE终止后3、6、24、48和72h取海马,电镜观察神经元超微结构的变化,免疫组化方法检测caspase-3的表达。结果显示:两组大鼠均在SE后3h出现线粒体损伤,细胞核的改变出现于SE后24h。A组致痫的潜伏期为97min±11min,神经元以凋亡为主;B组为48min±13min,神经元以坏死为主。SE后6～24h,两组大鼠海马内caspase-3的表达由胞浆向胞核逐渐移位,且均在SE后6h明显增高,24h达顶峰;A组高表达持续至72h,B组在48h显著降低。上述结果提示,线粒体的损伤出现于SE的早期,且可能是神经元损伤的关键环节;致痫方法不同,神经元的死亡形式也不同;而caspase-3的激活是神经元凋亡和坏死的共同通路。     

血管性痴呆大鼠海马神经元LC3和Beclin-1的表达

目的:在血管性痴呆(vascular dementia,VD)模型大鼠,观察自噬相关蛋白LC3和Beclin-1在海马CA1区神经元中的表达变化情况。方法:采用重复夹闭双侧颈总动脉(CCA)同时腹腔注射硝普钠溶液方法制备VD大鼠模型,在1、3、5和7 d四个时间点,分别采用Morris水迷宫检测大鼠空间学习记忆能力;HE染色观察CA1区神经元形态变化情况;免疫组化和Western Blot观察海马CA1区神经元上LC3和Beclin-1的表达情况。结果:模型组大鼠各时间点的逃逸潜伏期(escape latency,EL)比假手术组均明显延长(P0.01)。HE染色结果发现,与假手术组相比,模型组大鼠海马神经元出现严重损伤,且随时间延长逐渐加重。免疫组化和Western Blot积分光密度值测定结果显示,模型组大鼠各时间点LC3和Beclin-1的表达均比假手术组明显升高(P0.01),5 d时间点达到高峰。结论:VD模型大鼠缺血再灌注短时间内海马CA1区神经元出现严重损伤,伴有自噬相关的LC3和Beclin-1一过性表达升高。     

创伤后应激障碍大鼠海马神经元自噬增强

目的:观察创伤后应激障碍(PTSD)模型大鼠海马神经元自噬的改变,探讨PTSD致海马体积异常的可能机制。方法:成年健康雄性SD大鼠20只,随机被分为对照组和模型组。采用改良的单一连续应激后给予不可逃避足底电击方法制备PTSD大鼠模型;采用透射电镜技术观察海马神经元超微结构,Western blot方法检测海马微管相关蛋白轻链3(microtube-associated protein 1 light chain 3,LC-3)和Beclin-1的表达水平。结果:模型组海马神经元自噬体增多;海马组织LC3-Ⅱ/LC3-Ⅰ比值和Beclin-1表达水平高于对照组(P<0.05)。结论:PTSD模型大鼠海马神经元存在明显的细胞自噬,可能与海马体积异常变化有关。     

细胞自噬缓解氧-糖剥夺诱导原代培养小鼠脑皮质神经元缺血损伤

目的 在离体细胞水平,探讨氧-糖剥夺(OGD)致原代培养小鼠脑皮质神经元缺血损伤过程中,细胞自噬的变化情况和可能作用.方法 出生24h内C57BL/6J乳鼠脑皮质神经元原代培养7d后,分为常氧(Nor.)、15、30、60、90和120 min OGD后24h复糖复氧等6组,每组n=6;免疫印迹(Western blot)法检测细胞自噬相关蛋白Beclin-1表达和LC3Ⅱ/Ⅰ比值;借助MTT比色法和乳酸脱氢酶(LDH)漏出率,检测神经元的损伤;用细胞自噬下游抑制剂巴弗洛霉素A1(BafA1 100 nmol/L)抑制自噬后,观察神经元的损伤.结果 与对照组相比,随OGD时间的延长,自噬相关蛋白Beclin-1表达水平和LC3Ⅱ/Ⅰ比值显著升高,30 min达到峰值,之后略有回降(P＜0.05);在OGD处理30和60 min致使神经元显著损伤的基础上,细胞自噬抑制剂BafA1可明显加重60 min OGD处理神经元的损伤和提高LC3Ⅱ/Ⅰ的比值(P＜0.05).结论 OGD可诱发原代培养小鼠脑皮质神经元自噬发生,且细胞自噬可缓解OGD处理皮质神经元的缺血损伤.     

急性癫痫大鼠海马Ca3区的Bcl-2、Caspase-3蛋白表达变化

目的探讨Bcl-2、Caspase-3在马桑内酯所致癫痫大鼠海马Ca3区的表达变化。方法40只SD大鼠随机分为癫痫组30只（又分为3h、6h、24h三个亚组）和对照组10只，应用免疫组织化学方法检测海马神经元中Bcl-2、Caspase-3的表达。结果①Bcl-2于致痫后6h表达增加，并于24h减少，与对照组比较有显著性差异（p〈0．05）。②Caspase-3于致痫后6h表达增加，并持续增加到24h，与对照组比较有显著性差异（p〈0．05）。③致痫组Bcl-2与Caspase-3的表达成反比，差异有统计学意义（p〈0．05）。结论Caspase-3蛋白的表达水平在癫痫发作后神经元的损伤中占有重要的作用，参与其凋亡的发生及其它功能的调控。Bcl-2可通过抑制Caspase-3的活性而抑制神经元的损伤，但是这种抑制作用是有限的。     

自噬水平变化对心脏骤停心肺复苏后大鼠海马神经元凋亡的影响

目的探讨自噬水平变化对心脏骤停心肺复苏(CA/CPR)后大鼠海马神经元凋亡的影响。方法将40只大鼠随机分为假手术组(sham)、CA/CPR模型组(model)、雷帕霉素(Rapa)组(CA/CPR+Rapa)及3-甲基腺嘌呤(3-MA)组(CA/CPR+3-MA)。采用呼气末夹闭气管窒息法复制大鼠CA/CPR动物模型,分别给予自噬激动剂Rapa 0.2 mg/kg及自噬抑制剂3-MA 10 mg/kg进行干预。采用神经功能缺陷评分(NDS)评价CA/CPR大鼠神经功能;用TUNEL染色法检测大鼠海马神经元的凋亡变化;用RT-PCR和Western blotting法检测大鼠海马内微管蛋白轻链3(LC3)、Beclin-1、Bax、Bcl-2及Caspase-3 mRNA和蛋白的表达水平。结果与假手术组比较,CA/CPR模型组大鼠NDS评分明显降低;海马神经元TUNEL染色阳性细胞数明显增多,凋亡率显著升高;海马内LC3、Beclin-1、Caspase-3、Bax表达上调,Bcl-2表达下调(P<0.05,P<0.01)。与模型组比较,CA/CPR+Rapa大鼠NDS评分明显降低,而海马神经元凋亡率明显有所增加,海马内LC3、Beclin-1、Caspase-3、Bax表达明显上调,而Bcl-2表达则明显有所下降;CA/CPR+3-MA大鼠NDS评分明显升高,而海马神经元凋亡率下降,海马内LC3、Beclin-1、Caspase-3、Bax表达明显下调,而Bcl-2表达则有所升高(P<0.05,P<0.01)。结论 CA/CPR后自噬水平升高促进海马神经元凋亡,自噬水平降低抑制海马神经凋亡,两者相互作用共同参与CA/CPR的病理过程。     

抗坏血酸对癫痫大鼠海马分子伴侣介导的自噬激活的影响

目的: 探讨癫痫大鼠海马氧化应激反应和分子伴侣介导的自噬(chaperone-mediated autophagy,CMA)活性的变化,以及抗氧化剂抗坏血酸 (ascorbic acid, AA)神经保护作用的可能机制。方法: 实验大鼠分为空白对照组、癫痫24 h组、AA预处理癫痫组和AA对照组。应用RT-PCR和免疫印迹法检测海马组织2a型溶酶体相关膜蛋白(lysosome-associated membrane protein type 2a,LAMP2a)mRNA和蛋白的变化,采用化学法检测海马组织丙二醛(malondialdehyde, MDA)和超氧化物歧化酶(superoxide dismutase,SOD)的水平。结果: 癫痫组大鼠海马组织LAMP2a转录和合成明显高于空白对照组,MDA含量明显升高,而SOD的水平显著下降。AA预处理可显著减低癫痫大鼠海马LAMP2a的转录和合成,并明显降低MDA的含量,却显著提高SOD的水平。结论: 癫痫发作导致的海马损伤时存在CMA激活现象和显著的氧化应激反应;抗氧化剂AA通过抑制CMA活性和降低氧化应激反应来减轻癫痫发作中的海马损伤,具有神经保护作用。     

增强自噬减轻大鼠造影剂所致急性肾损伤的实验研究

目的 建立造影剂所致急性肾损伤(CI-AKI)大鼠模型,探讨自噬在CI-AKI中的作用及机制.方法 将18只雄性Sprague-Dawley大鼠随机分为对照组(Con组)、CI-AKI组和雷帕霉素+造影剂组(Rapa组).CI-AKI组腹腔注射超大剂量的碘海醇(12.25 g/kg I),Rapa组于碘海醇注射前1周连续腹腔注射雷帕霉素(5 mg/(kg·d)),Con组腹腔注射等剂量的生理盐水.注射后24 h观察大鼠血肌酐水平、肾组织病理、肾组织中LC3Ⅱ/Ⅰ和Beclin-1表达水平及过氧化氢酶(CAT)含量的变化.结果 与Con组比较,CI-AKI组大鼠血肌酐水平明显升高((239.93±27.00) μmol/L比(51.70±10.59)μmol/L,P＜0.05),肾小管重度损伤,肾组织中自噬相关蛋白LC3Ⅱ/Ⅰ和Beclin-1表达均增加(均P＜0.05),而CAT含量减少((14.86±0.32)U/mg比(18.72±1.46)U/mg),差异具有统计学意义(P＜0.05).与CI-AKI组比较,雷帕霉素预处理增加了肾组织中LC3Ⅱ/Ⅰ和Beclin-1的表达及CAT含量((17.62±1.86)U/mg比(14.86±0.32)U/mg,P＜0.05),减轻了造影剂所致的肾小管损伤,并降低了血肌酐水平((187.62±47.76) μmol/L比(239.93±27.00) μmol/L),差异具有统计学意义(P＜0.05).结论 造影剂可诱导自噬激活,增强自噬可减轻造影剂所致氧化应激损伤及肾损伤.     

硫化氢通过抑制自噬减轻心脏停搏后脑损伤

 目的: 观察硫化氢在心肺复苏后脑保护中的作用,并探讨其对神经元细胞自噬的影响。方法: 窒息法建立大鼠心脏停搏模型。72只雄性Wistar大鼠随机分为假手术(sham)组、模型(model)组和硫氢化钠(NaHS)组。自主循环恢复(ROSC)后2 h、4 h、12 h和24 h用Western blot方法检测神经元自噬标志物beclin-1的表达和微管相关蛋白1轻链3(LC3)的转换;ROSC后12 h,用免疫组化方法观察LC3颗粒的表达;透射电镜观察神经元自噬现象;ROSC后72 h,TUNEL染色计数顶叶皮层凋亡神经元。ROSC后24 h、48 h和72 h行神经功能缺损评分(NDS)评价神经功能。结果: ROSC后2 h、4 h、12 h和24 h,model组自噬标志物beclin- 1的表达持续增加,而NaHS组beclin-1的表达先增加,然后逐渐降低(P < 0.05)。自噬标志物LC3 II/I的表达也是同样趋势。免疫组化显示,ROSC后12 h,model组神经元胞浆和胞核LC3颗粒的比例较NaHS组明显增多(P < 0.05)。电镜显示,model组自噬泡明显多于NaHS组及sham组(P < 0.05)。TUNEL染色显示,ROSC后72 h凋亡神经元数量model组明显多于NaHS组及sham组(P < 0.05)。NDS评分显示,NaHS组在各时点神经功能优于model组(P < 0.05)。结论: 硫化氢可以抑制心脏停搏模型大鼠ROSC后神经元自噬,减少神经元凋亡,改善神经功能。     

Effect of inherent epileptic seizures on brain injury after transient cerebral ischemia in Mongolian gerbils

Subthreshold excitotoxic stimuli such as brief cerebral ischemia or chemically induced seizures modulate brain injury resulting from subsequent transient ischemia. Depending on the delay between the two insults, either tolerance or cumulative damage will develop. We were interested whether non-chemically induced inherent epileptic seizures as they occur in Mongolian gerbils have an effect on the outcome of a transient global ischemia, i.e., whether they are an interfering variable in ischemia experiments. Occurrence of spontaneous seizures in adult male gerbils was registered with a video-controlled seizure monitoring system. Bilateral occlusion of common carotid arteries was carried out 2 h or 24 h after the last generalized seizure. After 4 days survival, the extent of ischemia-induced neuronal damage and glial activation were assessed in the hippocampus and striatum. No significant difference in the ischemia induced nerve cell loss was observed in cresyl violet stained sections between the 2-h or 24-h interval gerbils. Neuronal expression of endothelial nitric oxide synthase in CA1 disappeared with neuronal degeneration. Distribution and degree of upregulation of glial fibrillary acidic protein as marker for astrocytes did not differ between the two groups. We concluded that non-chemically induced inherent epileptic seizures neither protect the gerbil brain from injury nor augment the degree of damage resulting from transient forebrain ischemia. Thus, inherent epileptic seizures do not influence the outcome of the insult, making the gerbil a reliable model for studies on transient brain ischemia.     

Vitamin E inhibits activated chaperone-mediated autophagy in rats with status epilepticus

Seizures and status epilepticus induce an excessive production of reactive oxygen species leading to oxidative stress. Vitamin E, a classic antioxidant, has a neuroprotective effect on rats with seizures by regulating reactive oxygen species production. The activity of chaperone-mediated autophagy, a selective pathway for the degradation of cytosolic proteins in lysosomes, is enhanced during oxidative stress. Whether chaperone-mediated autophagy is induced during status epilepticus is not established. To address this problem, we used pilocarpine to elicit status epilepticus in rats. Lysosome-associated membrane protein 2a was used to estimate chaperone-mediated autophagy. We showed that compared to control animals, lysosome-associated membrane protein 2a at lysosomal membranes increased significantly in rats at 8 h, 16 h, and 24 h after induction of status epilepticus, which directly correlated with chaperone-mediated autophagy activity. Since reactive oxygen species are believed to be important in the pathogenesis of status epilepticus and are essential for the process of chaperone-mediated autophagy, we also sought to determine if pretreatment with vitamin E reduced chaperone-mediated autophagy. Pretreatment with vitamin E reduced oxidative stress and partially inhibited chaperone-mediated autophagy in brain at 24 h after status epilepticus versus vehicle. Taken together, these data show that chaperone-mediated autophagy is increased in rats with pilocarpine-induced status epilepticus through upregulation of de novo synthesis of lysosome-associated membrane protein 2a. Antioxidants such as vitamin E may partially inhibit activated chaperone-mediated autophagy.     

roTOR信号在KA诱导幼鼠癎性发作后的表达变化研究

目的：研究哺乳动物雷帕霉索靶蛋白（mammalian target of rapamycin,mTOR）信号在幼鼠癎性发作后的表达变化。方法：海人藻酸（KA）诱导幼鼠癎性发作,根据疝性发作后不同的时间点（1h、3h、16h、24h、3d、5d、1w、2w、6w）进行取材,从大脑中分离KA注射侧海马组织,提取全蛋白进行westernblot检测观察癎性发作后mTOR信号通路活化的标志物核糖体蛋白56（p-S6）蛋白的表达变化。免疫组织化学检测海马区P-S6免疫阳性细胞的表达。结果：KA海马内注射1h、3h、16h、24h,3d,5d,1w,2w,6w大鼠海马组织进行westernblot检测,发现在急性期P-S6的表达量呈现持续升高的表达变化。KA致癎1w后,海马区p-S6阳性细胞表达相对于手术对照组明显增高（76±12VS25±5）。在大鼠大脑皮层神经元亦可见到致癎后大量表达的p-S6阳性神经元（88±13 VS 15±3）。结论：mTOR信号活化标志物p-S6蛋白在KA诱导幼鼠癎性发作后表达明显增加,抑制mTOR信号的异常活化或许成为预防癫癎形成的新靶点。     

Cellular hybridization for BDNF. trkB, and NGF mRNAs and BDNF-immunoreactivity in rat forebrain after pilocarpine-induced status epilepticus

The messenger RNAs (mRNAs) for the neurotrophins, brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF), are upregulated during epileptic seizure activity, as visualized by in situ hybridization techniques. Neurotrophins might be protective against excitotoxic cell stress, and the upregulation during seizures might provide such cell protection. In this study, a high dose of pilocarpine (300 mg/kg) was used to induce long-lasting, limbic motor status epilepticus and a selective pattern of brain damage. The regulation of BDNF, trkB, and NGF mRNA was studied by in situ hybridization at 1, 3, 6, and 24 h after induction of limbic motor status epilepticus. BDNF immunoreactivity was examined with an anti-peptide antibody and the neuropathological process studied in parallel. BDNF mRNA increased in hippocampus, neocortex, piriform cortex, striatum, and thalamus with a maximum at 3–6 h. Hybridization levels increased earlier in the resistant granule and CA1 cells as compared to the vulnerable CA3 neurons. BDNF immunoreactivity was elevated in dentate gyrus at 3–6 h. trKB mRNA increased in the entire hippocampus. NGF mRNA in hippocampus appeared in dentate gyrus at 3–6 h and declined in hilar neurons at 6–24 h. Cell damage was found in the CA3 area, entire basal cortex, and layers II/III of neocortex. Endogenous neurotrophins are upregulated during status epilepticus caused by pilocarpine, which is related to the coupling between neuronal excitation and trophic factor expression. This upregulation of neurotrophic factors may serve endogenous protective effects; however, the excessive levels of neuronal hyperexcitation resulting from pilocarpine seizures lead to cell damage which cannot be prevented by endogenous neurotrophins.     

排斥性导向分子a抑制剂6FNⅢ对大鼠大脑皮质神经元缺血再灌注后自噬的作用

目的 探讨排斥性导向分子a(RGMa)特异性抑制剂6FNⅢ对大鼠大脑皮质神经元缺血再灌注引发的自噬及对神经功能恢复的影响。 方法 雄性成年SD大鼠立体定位侧脑室注射不同浓度6FNⅢ后建立大脑中动脉闭塞（MCAO）/再灌注模型,Western blotting检测RGMa下游分子脑衰反应调节蛋白-2（CRMP-2）蛋白表达水平,确定最佳6FNⅢ干预浓度。将72只雄性成年SD大鼠随机分成4组：假手术组（sham）、脑缺血再灌注组（I/R）、生理盐水干预组（I/R+NS）、6FNⅢ干预组（I/R+6FNⅢ）,每组18只。缺血2h再灌注后24h,采用神经功能缺损评分评估各组大鼠神经功能恢复情况;Western blotting检测自噬相关蛋白LC3Ⅱ/Ⅰ水平;免疫荧光双标检测LC3在神经元内的表达情况;透射电子显微镜观察自噬体的形成情况。 结果 根据各浓度6FNⅢ干预组CRMP-2表达,确定中浓度（0.5 g/L）为本实验的最适浓度。缺血再灌注后24h,I/R组较sham组神经功能评分降低(P＜0.05)、自噬相关蛋白LC3Ⅱ/Ⅰ水平升高(P＜0.05)、自噬体形成增多;I/R+6FNⅢ组较I/R组神经功能评分增高(P＜0.05)、自噬相关蛋白LC3Ⅱ/Ⅰ水平降低(P＜0.05)、自噬体形成减少;而I/R+NS组与I/R组以上各项均无统计学意义(P＞0.05)。 结论 RGMa特异性抑制剂6FNⅡ可在缺血再灌注急性期抑制自噬发生,促进神经功能恢复。     

Repeated brief epileptic seizures by pentylenetetrazole cause neurodegeneration and promote neurogenesis in discrete brain regions of freely moving adult rats

Recurrent epileptic seizures are known to provoke various forms of cellular reorganization in the brains of humans and experimental animals. However, little is known about the mechanism of neuronal cell death resulting from epileptic seizures elicited by GABA antagonists. In the present study, we explored the effect on the central nervous systems of freely moving adult rats, of repeated brief epileptic seizures induced by systemic injection of pentylenetetrazole, a GABA-A receptor antagonist. Starting with minor convulsions, repeated epileptic seizures elicited a progressive increase in seizure severity, culminating in the fully kindled state. Histological examination showed that the epileptic seizures caused overt neuronal cell death in the limbic system, including the hippocampus and amygdala, and its adjoining cortex. During the recurrent epileptic seizures, neurogenesis occurred in the subgranular zone of the hippocampus, the subventricular zone of the lateral ventricle, and the amygdala. This type of pentylenetetrazole-induced neurogenesis was seen at an early stage of epileptogenesis in some regions in which massive cell loss was not evident. This suggests that neurogenesis is not a secondary consequence of neuronal cell death, but rather an independent effect of recurrent epileptic seizures.     

Lipoic acid effects on monoaminergic system after pilocarpine-induced seizures

Systemic injection of pilocarpine has been shown to induce recurrent seizures and epileptic discharges demonstrated by EEG monitoring. It also has been reported that antioxidants are able to diminish or prevent the occurrence of epileptic discharges induced by pilocarpine through the inhibition of free radical formation and neurotransmitter metabolic alterations. The purpose of this work was to determine the effects of lipoic acid (LA) on the levels of dopamine (DA), serotonin (5-HT), norepinephrine (NE) and subsequent metabolites in the hippocampus of rats after seizure induction by pilocarpine. Seizures dramatically decreased the levels of DA, 5-hydroxyindoleacetic acid (5-HIAA) and NE, whereas significantly increased the levels of neurotransmitter metabolites. The administration of lipoic acid before seizure induction resulted in normalized levels of DA and 5-HA. However, the lipoic acid administration in similar conditions produced a reduction of the metabolites levels when compared with the pilocarpine group. These results suggest that the establishment of acute phase of seizures induced by pilocarpine might be produced by consequent the activation of serotonergic neurons. In addition, the lipoic acid inhibits hyperactivity of this system during the installation of pilocarpine-induced seizures.