2-BFI对EAE小鼠血脑屏障通透性和AQP4 mRNA表达的影响

目的观察2-(2-苯并呋喃基)-2-咪唑啉(2-BFI)对实验性自身免疫性脑脊髓炎(EAE)小鼠血脑屏障和水通道蛋白4(AQP4)mRNA表达的影响。方法 C57BL/6小鼠39只随机分为正常对照组、EAE组和2-BFI干预组。各组每日进行神经功能缺损评分;第20天进行病理学检查;伊文思蓝荧光定量方法检测血脑屏障通透性;电子显微镜观察血脑屏障的超微结构变化;Real-time PCR法测定AQP4 mRNA的表达水平。结果与EAE组比较,2-BFI干预组小鼠神经功能缺损及血脑屏障病理损伤减轻,AQP4 mRNA的表达水平明显降低,均差异有统计学意义。结论 2-BFI对EAE小鼠的神经保护作用与减少AQP4 mRNA的表达、减轻血脑屏障通透性有关。     

2-(2-苯并呋喃基)-2-咪唑啉对实验性自身免疫性脑脊髓炎小鼠小胶质细胞活化及氧化应激的影响

目的观察2-(2-苯并呋喃基)-2-咪唑啉(2-BFI)对实验性自身免疫性脑脊髓炎(EAE)小鼠CNS小胶质细胞活化及氧化应激的影响。方法将27只C57BL/6小鼠随机分为正常对照组、EAE组和2-BFI干预组,每组9只。采用MOG_(35-55)免疫法制作经典EAE模型。2-BFI干预组小鼠于EAE造模后当日起腹腔注射2-BFI 20 mg/kg,2次/d,连续14 d。正常对照组和EAE组以等量生理盐水代替。每日观察并记录动物的行为学变化、进行神经功能缺损评分。免疫后第20 d处死各组小鼠,采用HE染色和LFB染色观察组织学变化;免疫组化法测定诱导型小鼠CNS中一氧化氮合成酶(iNOS)蛋白和离子钙接头分子(Iba-1)的表达,比色法检测丙二醛(MDA)的含量;并对活化的小胶质细胞数量和iNOS蛋白表达水平进行线性相关分析。结果正常对照组小鼠未见神经系统受损的表现。与EAE组相比,2-BFI干预组日均神经功能缺损评分明显降低,CNS脊髓炎性细胞浸润明显减少,髓鞘脱失严重程度明显减轻,活化的小胶质细胞数量减少,iNOS蛋白表达明显减少,MDA含量降低(P0.05~0.01)。相关分析结果显示,iNOS表达水平与活化的小胶质细胞数量呈正相关(r=0.596,P0.01)。结论 2-BFI能减轻EAE小鼠临床症状和组织学改变,2-BFI对EAE小鼠的神经保护作用于小胶质细胞激活和减轻氧化应激相关。     

2-BFI对EAE小鼠iNOS和COX-2 mRNA表达的影响

目的探讨咪唑啉2受体(I2R)高选择性高亲和力配体2-BFI对实验性自身免疫性脑脊髓炎(EAE)小鼠诱导型一氧化氮合酶(iNOS)和环氧化酶-2(COX-2)mRNA表达的影响。方法使用髓鞘少突胶质细胞糖蛋白(MOG35-55)抗原诱导EAE小鼠模型。采用临床症状评分、病理学检查和反转录-聚合酶链反应(RT-PCR)观察完全福氏佐剂(CFA)对照组、EAE组和2-BFI干预组小鼠行为学、中枢炎性细胞浸润及iNOS和COX-2mRNA表达变化。结果 2-BFI干预组较EAE组临床症状明显减轻(P<0.01),中枢炎性细胞浸润显著减少(P<0.01),iNOS和COX-2的mRNA表达水平降低(P<0.05,P<0.01)。结论 I2R高选择性配体2-BFI对EAE小鼠具有一定保护作用,其作用机制可能与降低iNOS和COX-2 mRNA表达有关。     

2-BFI、阿米洛利和咪唑克生对实验性自身免疫性脑脊髓炎小鼠行为学和病理学变化的药效作用比较

目的比较3种咪唑啉Ⅱ类受体(I2R)高选择性配体2-(2-苯并呋喃基)-2-咪唑啉(2-BFI)、阿米洛利和咪唑克生对实验性自身免疫性脑脊髓炎(EAE)模型小鼠行为学和病理学变化的干预效果。方法在相同实验条件下,髓鞘少突胶质细胞糖蛋白35-55多肽诱导EAE小鼠模型后,分为空白对照组、EAE-生理盐水组、EAE-2-BFI组(2-BFI干预)、EAE-阿米洛利组(阿米洛利干预)、EAE-咪唑克生组(咪唑克生干预),每组8只。均采用经实验证实的有效剂量,用动物神经功能评分评价各组间小鼠行为学表现。苏木精-伊红染色和LFB髓鞘染色,观察中枢组织炎性细胞浸润和髓鞘脱失程度。结果 3个不同配体干预组小鼠的神经行为学和炎症病理学改变与EAE-生理盐水组比较均明显减轻,差异有显著统计学意义(P0.01);而3个不同干预组之间的行为学和病理学变化比较无显著差异,2-BFI保护作用具微弱优势。结论 2-BFI、阿米洛利和咪唑克生均能明显减缓小鼠EAE发生与发展,均具有较好抑制中枢炎症反应的药理作用,3者间的药效作用强度未见明显差异。     

经不同咪唑啉类药物长期处理后大鼠脑内I_2R密度及胶质纤维酸性蛋白的变化

目的:观察咪唑啉类药物长期处理后大脑组织中咪唑啉2受体(I_2R)密度和亲和力的变化以及对胶质纤维酸性蛋白(GFAP)表达的影响。方法:将大鼠随机分成生理盐水组、胍丁胺组、育亨宾组、咪唑克生组、左旋咪唑组及2-(2-苯并呋喃基)-2-咪唑啉(2-BFI)组,腹腔注射×2周。采用放射性配体结合试验检测大脑和脑干匀浆中I_2R B_(max)和K_d变化,免疫组化测定小脑和颈髓中GFAP的表达。结果:反映I_2R密度的B_(max)值,咪唑克生、2-BFI和左旋咪唑组较NS组分别上调了80%、93%和122%(均P<0.01)。反映受体亲和力的K_d值,各组间无明显差异。咪唑克生、2-BFI和左旋咪唑组中GFAP表达比生理盐水组明显增加(均P<0.01)。结论:咪唑克生、2-BFI和左旋咪唑表现为拮抗剂特性;I_2R可能参与调节GFAP表达。     

实验性自身免疫性脑脊髓炎小鼠脊髓中细胞色素C和凋亡诱导因子表达的变化

目的观察实验性自身免疫性脑脊髓炎(EAE)小鼠脊髓中细胞色素C(CytC)和凋亡诱导因子(AIF)表达的变化。方法 C57BL/6小鼠12只随机分为EAE组和正常对照组。使用髓鞘少突胶质细胞糖蛋白和完全弗氏佐剂混合抗原乳剂免疫C57BL/6小鼠制作EAE模型。每天2次记录各组小鼠体重和神经功能评分的变化。采用苏木精-伊红染色、髓鞘LFB染色、免疫组化染色,检测发病高峰期(免疫后第19天)小鼠脊髓的病理变化、髓鞘脱失程度、CytC和AIF的变化。结果与正常对照组比较,EAE组神经功能评分增加(P<0.01)、炎症细胞浸润增加(P<0.01)、脱髓鞘程度严重(P<0.01)、CytC和AIF表达均增加(P<0.01),而且与EAE的病情变化指标(最高症状评分、病理评分)均呈正相关关系。结论 EAE小鼠发病高峰期脊髓中CytC和AIF表达增加,提示EAE小鼠的病情变化与中枢神经系统的线粒体损伤有关。     

2-（2-苯并呋喃基）-2-咪唑啉对大鼠局灶性脑缺血再灌注损伤的初步观察

目的：初步观察咪唑啉I2受体的高选择性配体2-（2-苯并呋喃基）-2-咪唑啉（2-BFI）对大鼠局灶性脑缺血再灌注损伤的影响。方法：建立SD大鼠大脑中动脉局灶性脑缺血模型。在脑缺血后即通过大鼠尾静脉给予生理盐水、2-BFI或咪唑克生。通过2,3,5-三苯基氯化四唑染色检测梗死体积并评价大鼠的神经功能缺损。通过免疫组化方法检测caspase-3蛋白和原位细胞凋亡法检测缺血半暗带中凋亡神经细胞数。结果：在局灶性脑缺血24h后,2-BFI和咪唑克生都能够显著提高神经功能评分。给予2-BFI或咪唑克生都可以显著降低梗死体积、减少caspase-3阳性细胞数（P〈0．01）和凋亡细胞数（P〈0．05）。结论：2-BFI和咪唑克生对局灶性脑缺血再灌注损伤大鼠有神经保护作用,为脑卒中的治疗提供了新的治疗方法。     

实验性自身免疫性脑脊髓炎小鼠血脑屏障通透性与紧密连接蛋白-5的变化

目的观察实验性自身免疫性脑脊髓炎(EAE)小鼠血脑屏障(BBB)通透性与紧密连接蛋白-5(claudin-5)表达的变化。方法 40只C57BL/6小鼠随机分为EAE组和正常对照组,应用髓鞘少突胶质细胞糖蛋白35-55诱导制作小鼠EAE模型,每日进行神经功能缺损评分。采用苏木精-伊红、髓鞘染色和免疫组化法观察炎症细胞浸润、髓鞘脱失及轴索损坏程度。伊文思蓝染色和Western blot法观察BBB通透性和claudin-5表达的变化。结果与正常对照组比较,EAE组小鼠神经功能缺损评分、炎症细胞浸润、髓鞘脱失、轴索损坏和BBB通透性均明显增加;而claudin-5表达显著降低(均P0.01)。BBB通透性的变化与平均神经功能缺损评分、炎症细胞浸润和轴索损坏均呈正相关(P0.01);而与claudin-5表达水平呈负相关(P0.05)。结论 EAE发病过程中claudin-5表达减少,可能导致BBB通透性增加,使外周大量的炎症反应细胞向中枢迁移,继而进一步加重中枢的炎症反应。     

不同剂量甲泼尼龙治疗实验性变态反应性脑脊髓炎大鼠的疗效及其与大鼠脊髓糖皮质激素受体亚型表达的关系

目的探讨不同剂量甲泼尼龙(MP)治疗实验性变态反应性脑脊髓炎(EAE)大鼠的疗效及其与大鼠脊髓糖皮质激素受体(GR)亚型表达的关系。方法健康雌性Wistar大鼠28只,随机分为大剂量MP治疗组(8只)、小剂量MP治疗组(8只)、EAE模型组(7只)和正常对照组(5只)。大、小剂量MP治疗组及EAE模型组接种豚鼠全脊髓制成的抗原乳剂,制作EAE模型。免疫接种后每日对大鼠进行神经功能缺损评分。接种后第12 d,大、小剂量MP治疗组分别予以MP 100 mg/(kg.d)或25 mg/(kg.d)尾静脉注射,连续3d后减半量再给药2 d;EAE模型组及正常对照组大鼠予等容量生理盐水。给药结束后次日,采用免疫组化法检测大鼠脊髓组织GRα及GRβ的表达。结果两MP治疗组大鼠治疗后的神经功能缺损评分比治疗前明显降低(均P<0.01);并且明显低于EAE模型组(均P<0.001),但两组间差异无统计学意义。大、小剂量MP治疗组大鼠脊髓组织GRα表达均明显低于EAE模型组与正常对照组(P<0.05～0.01);各组大鼠脊髓组织GRβ表达的差异无统计学意义。相关性分析显示,EAE大鼠治疗前后神经功能缺损评分的差值与脊髓组织GRα、GRβ的表达不相关,与GRα/GRβ比值呈正相关(r=0.550,P=0.027)。结论 MP治疗EAE大鼠的疗效与剂量无关,而与脊髓组织GRα/GRβ比值有关。     

载脂蛋白E拟肽对实验性变态反应性脑脊髓炎小鼠基质金属蛋白酶-9和基质金属蛋白酶组织抑制因子-1表达的影响

目的探讨载脂蛋白E(Apo E)拟肽对实验性变态反应性脑脊髓炎(EAE)小鼠基质金属蛋白酶-9(MMP-9)和基质金属蛋白酶组织抑制因子-1(TIMP-1)表达的影响。方法将30只雌性C57BL/6J小鼠随机分为Apo E拟肽组、EAE组和正常组,每组10只小鼠。EAE模型通过以髓鞘少突胶质细胞糖蛋白多肽35-55为抗原诱导。Apo E拟肽组在免疫后第2 d到30 d每隔2 d按5 mg/(kg·d)背部皮下注射Apo E拟肽。EAE组和正常组均以等体积生理盐水替代。免疫后第0~35 d每日对小鼠进行神经功能评分。免疫后第35d解剖小鼠,分离大脑和脊髓并行HE染色。采用免疫组化染色法检测各组小鼠大脑、脑干和脊髓的MMP-9和TIMP-1的表达。结果正常组小鼠均未发病。Apo E拟肽组、EAE组的小鼠全部发病,但各有1只小鼠发病后死亡。Apo E拟肽组与EAE组的发病潜伏期差异无统计学意义(P=0.72)。Apo E拟肽组的神经功能评分在峰值和慢性期(第35 d)均明显低于EAE组(均P0.05)。HE染色示,正常组未见炎症细胞浸润;EAE组小鼠大脑、脑干和脊髓均有不同程度的炎性细胞浸润,以脑干和脊髓较为明显;Apo E拟肽组小鼠CNS炎性细胞浸润相对于EAE组明显减少。EAE组小鼠大脑、脑干和脊髓的MMP-9表达均高于正常组(均P0.05)。Apo E拟肽组小鼠大脑和脊髓的MMP-9表达要明显低于EAE组(均P0.05),其中Apo E拟肽组小鼠中脑和脊髓的MMP-9表达与正常组相比无明显差异(均P0.05)。正常组小鼠脊髓TIMP-1的表达明显高于EAE组和Apo E拟肽组(均P0.05)。而Apo E拟肽组与EAE组小鼠大脑、脑干和脊髓TIMP-1表达的差异均无统计学意义(均P0.05)。结论 Apo E拟肽能通过抑制大脑和脊髓MMP-9的表达改善EAE小鼠的症状。     

肉苁蓉多糖通过Shh通路缓解EAE小鼠的临床症状

目的探讨音猬因子(Sonic hedgehog,Shh)通路在实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)小鼠发病过程中的作用,及肉苁蓉多糖(cistanche deserticola polysaccharide,CDPS)能否通过该通路缓解EAE小鼠临床症状。方法给予C57BL/6小鼠皮下注射髓鞘少突细胞糖蛋白35-55多肽(myelin oligodendrocyte glycoprotein 35-55,MOG35-55)抗原制备EAE动物模型。将60只小鼠随机分为正常对照组、EAE模型组、CDPS治疗组以及CDPS+Smo受体阻断剂环王巴明(cyc)治疗组(以下简称CDPS+cyc治疗组)4组,每组各15只。观察各组小鼠免疫注射后0~26d的临床症状评分,采用勒克斯光蓝染色(Luxol Fast Blue,LFB)检测各组小鼠脊髓组织内髓鞘脱失情况,Western blot法检测脊髓组织内Shh、碎片蛋白-1(Patched-1,Ptc-1)蛋白表达,采用RT-PCR检测脊髓组织内平滑蛋白(Smoothened,Smo)mRNA、神经胶质瘤相关癌基因1(Glioma-associated oncogene-1,Gli1)mRNA表达。结果自CDPS治疗第9天开始,CDPS治疗组小鼠临床症状评分低于EAE模型组(P<0.05),而CDPS+cyc治疗组临床症状评分高于CDPS组(P <0.05)。CDPS治疗组小鼠脊髓LFB评分较EAE模型组降低(t=9.64,P<0.01),而CDPS+cyc治疗组其LFB评分与EAE模型组比较差异无统计学意义(P>0.05)。EAE模型组小鼠脊髓组织内Shh、Ptc-1蛋白以及Smo mRNA、Gli1mRNA表达水平较正常组升高(均P<0.01),经CDPS治疗后,上述因子表达进一步升高(均P<0.01),而经cyc干预后,上述因子表达较CDPS治疗组降低(均P<0.01)。结论 CDPS对EAE小鼠临床症状有改善作用,其作用途径可能与Shh信号通路有关。     

实验性自身免疫性脑脊髓炎模型的建立和长期观察研究

目的 建立实验性自身免疫性脑脊髓炎小鼠模型(EAE)并长期观察研究.方法 C57BL/6小鼠30只,随机分为EAE模型组、PBS对照组和正常对照组.应用神经功能评分进行临床评估,通过HE和髓鞘染色观察组织病理变化.结果 小鼠在诱导后的12±3d急性起病,16±2d内达到高峰,严重度评分为3.2±0.6分.半年观察期内复发1次,复发率为25%.光镜下可见EAE组以脊髓组织病变为主,表现为大量炎性细胞浸润和白质脱髓鞘.结论 采用MOG_(35-55)诱导C57BL/6小鼠建立的模型既往被认为是一种慢性迁延EAE模型,本研究通过长期观察发现其存在缓解复发现象.

Abstract：

Objective To establish a mice model of experimental autoimmune encephalomyelitis (EAE) and perform a long term study. Methods C57BL/6 mice were immunized with 300μg MOG_(35-55) in complete Freund' s adjuvant (CFA) to establish EAE model in EAE group (n = 10). Mice in adjuvant group( n = 10)were treated with CFA without MOG_(35-55) and control group( n = 10)were treated with normal saline. The pathologic changes of the central nervous system were studied by HE staining and myelin staining. Results The clinic symptoms of EAE were present in the 12±3th day post-immunization,and went to the peek in the 16±2 th day post-immunization. The severity score was 3.2±0.6. One relapse was observed in the term of 6 months, and the rate was 25%. Light microscopy showed there were abundant inflammatory cells infiltrated especially in spinal cord tissues in EAE mice,with evident demyelination in white matter. Conclusion The relapse of this EAE model was observed in the study, though it was believed to be a chronic persistent model without relapse.     

人脑出血后血肿周围组织HO-1、GFAP和cyclinD1的表达研究

目的探讨脑出血后血肿周围组织血红素氧合酶-1(HO-1)、胶质纤维酸性蛋白(GFAP)和细胞周期蛋白D1(cvclinD1)表达规律,及其与神经修复之间的关系。方法 HE染色观察脑出血后神经元和星形胶质细胞形态变化,免疫组织化学染色检测脑出血后不同时间点血肿周围组织H0-1、GFAP和cycIinD1表达水平。结果脑出血后2h星形胶质细胞胞质内即开始表达HO-1[(5.30±1.00)个/高倍视野]、GFAP[(22.60±1.40)个/高倍视野]和cvclinD1[(11.50±1.20)个/高倍视野],达峰值水平后逐渐下降,脑出血后不同时间点表达水平均高于健侧正常脑组织,且差异具有统计学意义(均P=0.000)。结论人脑出血后血肿周围组织HO-1、GFAP和cvclinD1表达变化呈"抛物线"样,HO-1和cvclinD1共同参与了脑出血后星形胶质细胞的增生与活化,以及脑出血后的继发性损伤和修复。     

法舒地尔通过诱导EAE小鼠Occludin表达抑制其炎性细胞浸润

目的观察法舒地尔(Fasudil)对实验性自身免疫性脑脊髓炎(EAE)小鼠模型的治疗效果并探讨其作用机制。方法采用髓鞘少突胶质细胞糖蛋白35-55(MOG35-55)免疫建立国际标准的小鼠EAE模型。将免疫后的42只雌性C57BL/6小鼠随机分为EAE组、Fasudil早期治疗组和Fasudil晚期治疗组。Fasudil早期治疗组即免疫后第3天按体质量40mg/(kg.d)腹腔注射Fasudil,1次/d,至免疫后30d;Fasudil晚期治疗组即免疫后首只小鼠出现症状即开始腹腔注射Fasudil,注射方法和剂量同Fasudil早期治疗组;与晚期治疗组给药同一时间,给予EAE组等量生理盐水作为对照。免疫后隔天观察各组小鼠临床评分和体质量变化。于免疫30d后处死动物,分离小鼠脊髓腰膨大和脑冠状位中部1/3处做冷冻切片,行HE染色和免疫荧光染色。同时提取小鼠脊髓蛋白检测Occludin蛋白的表达。结果 Fasudil可改善EAE的临床症状,抑制脑血管内皮细胞Rho激酶(ROCK)活性。与EAE组相比,Fasudil早期治疗组和晚期治疗组CD31阳性内皮细胞上p-MYPT1表达均减弱(P<0.01,P<0.05),起病时间均延长(P<0.01,P<0.05),脊髓Occludin蛋白表达均增加(P<0.05)。结论 Fasudil对EAE具有治疗的潜能,其机制可能为通过抑制血管内皮细胞ROCK活性,参与诱导内皮细胞紧密连接蛋白Occludin的表达,从而抑制炎性细胞的中枢浸润,最终阻止疾病的发生和发展。     

雌激素对实验性自身免疫性脑脊髓炎小鼠的治疗作用及对基质金属蛋白酶-9表达的影响

目的 探讨雌激素对实验性自身免疫性脑脊髓炎(EAE)小鼠中枢神经系统(CNS)中基质金属蛋白酶-9(MMP-9)表达的影响.方法 用MeG35-55多肽诱发60只EAE小鼠模型,做去卵巢术.分为治疗组和对照组,治疗组予雌激素治疗.比较2组EAE小鼠的临床症状评分.取脑和脊髓,行HE染色观察各组EAE小鼠炎症反应;实时荧光定量PCR及免疫荧光染色法检测各组EAE小鼠CNS中MMP-9的表达.结果 治疗组EAE小鼠与对照组相比临床症状减轻(治疗组3.23±0.83,对照组1.62±1.00,t=3.811,P＜0 05)、发病率降低(治疗组8/30,对照组28/30);HE染色显示治疗组炎症细胞浸润(急性期0.895±0.206,缓解期0.752±0.302,慢性期0.732±0.183)较对照组(急性期3.472±0.635,缓解期2.881±0.662,慢性期1.891±0.482)减少(t=8.622、6.543、5.027,均P＜0.01),实时荧光定量PCR及免疫荧光染色结果示治疗组EAE小鼠CNS中MMP-9表达降低.结论 雌激素能抑制EAE小鼠CNS中MMP-9的表达,减轻EAE小鼠临床症状及炎症反应.

Abstract：

Objective To study the regulation effect of estrogen in expression of matrix metalloproteinase-9 (MMP-9) in the central nervous system (CNS) in mice with experimental autoimmune encephalomyelitis ( EAE).Methods The 60 mice were overiectomized and 2 weeks later EAE was induced with MOG35-55 peptide in these mice.They were divided into a treatment group and a control group.The treatment group was treated with estrogen and the control group was given PBS.Clinical symptoms in these two groups were scored and compared.HE staining was used to observe inflammation in the brain and spinal cord.The MMP-9 expression in the CNS was examined by quantitative real-time PCR and immunofluorescence staining.Results The incidence of disease was lower (treatment and control group were 8/30 and 28/30 respectively) and clinical symptoms were milder (treatment and control group were 3.23±0.83 and 1.62 ±1.00 respectively,t=3.811 and P＜0.05) in the treatment group than those in the control group.HE staining showed the decreased infiltration of inflammatory cell in the treatment group (Treatment group:inflammatory score were 0.895 ±0.206,0.752 ±0.302,0.732 ±0.183 in acute,relief and chronic phase respectively;Control group:inflammatory score were 3.472 ±0.635,2.881 ±0.662,1.891 ± 0.482 in acute,relief and chronic phase respectively.t = 8.622,6.543 and 5.027,all P ＜ 0.05).The quantitative real-time PCR and immunofluorescence staining showed that the expression of MMP9 in the CNS was decreased in the treatment group.Conclusion Estrogen may decrease MMP-9 expression in the CNS,reduce inflammation and clinical symptoms in mice with EAE.     

GFAP mRNA fluctuates in synchrony with chronic relapsing EAE symptoms in SJL/J mice

Activation of astrocytes and hypertrophy of their processes is a result of a number of pathological conditions in the central nervous system. Astrocytic gliosis is especially prominent in multiple sclerosis (MS), where astrocytic fibers form a dense matrix around demyelinated axons. Experimental allergic encephalomyelitis (EAE), a laboratory model for MS, is also accompanied by astrocytic hyperactivity. We have previously shown the formation of plaque-like structures which stain heavily for glial fibrillary acidic protein (GFAP) in the brains and spinal cords of SJL/J mice after several episodes of chronic relapsing EAE (Smith and Eng: J Neurosci Res 18:203, 1987). To further investigate the mechanisms of this phenomenon, we have measured the levels of mRNA for GFAP throughout the course of three episodes and recoveries of EAE in the SJL/J mouse. Mice were immunized with spinal cord homogenate and subsequently developed EAE. After recovery they were again immunized at appropriate intervals, resulting in successive episodes of EAE, with partial or complete recovery between the paralytic stages. At appropriate times in the course of the different stages of EAE, spinal cords were dissected and RNA was prepared from each spinal cord. RNA Was analyzed by Northern blots to determine the levels of mRNA for GFAP and, as a control, for the 70 kDa neurofilament (NF-L). With the onset of the first EAE episode GFAP mRNA in spinal cords from animals with mild symptoms increased to sixfold the control level (P < 0.02) and to 20-fold in those with paralysis (P < 0.01). With recovery, the GFAP mRNA level decreased to twice the control. With each subsequent episodes, a chronic but stable neurological deficit was established, with GFAP mRNA at about eightfold the control levels (P < 0.01). Over the course of several episodes, the GFAP rose to about 2.8 times the control, while vimentin increased by a factor of 3.6. Thus multiple episodes of EAE resulted in upregulation of GFAP mRNA and accumulation of GFAP, which are associated with astrocyte activation and hypertrophy. Similar events may occur in the human demyelinative disease MS, where multiple episodes of inflammatory cell invasion occur, resulting in a neurological deficit. © 1995 Wiley-Liss, Inc.