氨对星形胶质细胞超微结构的影响

目的：在体外实验条件下观察氨对星状胶质细胞超微结构的影响。材料与方法：用ＮＨ４Ｃｌ造成高高ＮＨ４环境，对体外培养之星形胶质细胞的形态变化进行了超微结构观察。结果：高ＮＨ４环境下，星菜胶质细胞首先表现出损伤性变化，细胞电子密度降低，线粒体、内质网等细胞器肿胀，在胞质内形成许多单位膜包绕的电子密度降低的空泡区域，以后随着氨浓度加大或／和氨作用的时间延长，细胞内成份开始出现增生修复现象，次级溶酶体数量增     

大鼠大脑中动脉缺血后海马星形胶质细胞反应的研究

目的:观察大鼠大脑中动脉缺血后皮层损伤侧海马星形胶质细胞反应的变化。方法:采用大鼠大脑中动脉阻塞再灌流模型,应用免疫印迹和免疫组织化学方法测定脑缺血后3 d、7 d以及30 d皮层损伤侧海马胶质纤维酸性蛋白(GFAP)以及增殖细胞核抗原(PCNA)蛋白的表达,观察星形胶质细胞增殖的变化。结果: GFAP免疫组化结果显示,脑缺血后7d皮层损伤侧海马CA1、CA2区星形胶质细胞数量较假手术组增加且胞体增大;脑缺血后30 d皮层损伤侧海马CA1、CA2区呈胶质疤痕样改变。同时,免疫印迹法显示脑缺血后7 d皮层损伤侧海马GFAP表达增强;脑缺血后30 d皮层损伤侧海马GFAP表达增高更加明显。此外,免疫印迹法显示脑缺血后3 d皮层损伤侧海马PCNA蛋白表达水平升高;脑缺血后7 d PCNA蛋白表达水平达到峰值;脑缺血后30 d,PCNA蛋白表达水平降低,但仍高于假手术组。结论: 大鼠大脑中动脉缺血后可引起其皮层损伤侧海马星形胶质细胞过度反应和增殖。     

活化小胶质细胞致星形胶质细胞激活

目的探讨活化小胶质细胞培养液对星形胶质细胞的影响。方法 LPS激活原代培养小胶质细胞,采用活化的小胶质细胞条件培养液刺激星形胶质细胞,观察星形胶质细胞GFAP及IL-1β和TNFα的表达。结果 LPS刺激后,小胶质细胞OX42表达量上升,IL-1β和TNFα的表达量增高;小胶质细胞条件培养液可致星形胶质细胞激活,GFAP表达量上升,IL-1β和TNFα的表达量增加。结论活化小胶质细胞的条件培养液可致星形胶质细胞激活,激活的小胶质细胞和星形胶质细胞表达前炎症介质IL-1β和TNFα。     

罗格列酮对大鼠脑出血急性期小胶质细胞和星形胶质细胞的影响

目的:研究罗格列酮对大鼠脑出血后小胶质细胞、星形胶质细胞的影响。方法:雄性SD大鼠随机分为对照组、大剂量干预组、小剂量干预组和假手术组。采用Ⅳ型胶原酶肝素生理盐水尾状核立体定向注射法建立大鼠脑出血模型,大剂量干预组给予罗格列酮2 mg·kg~(-1)·d~(-1)灌胃,小剂量干预组给予罗格列酮0.2 mg·kg~(-1)·d~(-1)灌胃,连续7 d。在术前和术后每日进行1次Longa神经功能缺损评分和尾部微量血糖测量,在术后第2天和第7天采用免疫组织化学检测脑小胶质细胞和星形胶质细胞。结果:大剂量干预组在术后第4天到第7天,小剂量干预组在术后第5天到第7天的Longa神经功能缺损评分低于对照组;大剂量干预组在术后第4天到第7天,小剂量干预组在术后第6天和第7天的微量血糖低于对照组;大剂量干预组术后第2天和第7天血肿周边活化的小胶质细胞较对照组增加,小剂量干预组术后第7天血肿周边活化的小胶质细胞较对照组增加;大剂量干预组和小剂量干预组术后第7天星形胶质细胞较对照组明显增加。结论:罗格列酮可以部分改善大鼠脑出血急性期神经功能,这可能与调节小胶质细胞和星形胶质细胞激活和功能有关。     

苯丙胺对大鼠学习能力和海马结构GFAP阳性细胞结构的影响

目的观察苯丙胺对大鼠学习能力、GFAP免疫阳性细胞结构和亚细胞结构的影响。方法苯丙胺腹腔注射SD大鼠,用水迷宫检测其空间辨别性学习能力,用免疫组织化学方法观察海马结构胶质纤维酸性蛋白(GFAP)免疫阳性细胞的形态变化;用电镜方法检测GFAP免疫阳性细胞超微结构变化。结果学习能力检测发现,在14d以前,苯丙胺组大鼠较生理盐水组的平均运行时间和平均潜伏期缩短(P0.05);在15～28d,苯丙胺组大鼠较生理盐水组正确率降低(P0.05);在29～42d,苯丙胺组大鼠较生理盐水组正确率降低、平均运行时间延长(P0.05)。GFAP阳性细胞形态学观察发现,正常对照组大鼠海马结构星形胶质细胞主要分布在海马以及齿状回的多形层和分子层;生理盐水组大鼠海马结构星形胶质细胞分布与游水组相似,但细胞突起变长及增粗,分支增多,且各亚区比正常对照组相应亚区的星形胶质细胞数量增多(P0.05);苯丙胺组大鼠海马星形胶质细胞分布与正常对照组相似,但细胞突起变长、增粗和分支增多更明显,各亚区的星形胶质细胞比正常对照组和生理盐水组相应亚区增多(P0.05);电镜观察发现苯丙胺组大鼠脑内星形胶质细胞增生肥大,亦可见退变星形胶质细胞。结论在本实验条件下,苯丙胺导致大鼠空间辨别性学习记忆能力下降,引起大鼠海马结构星形胶质细胞增生和损害。     

大鼠束缚后脑内星形胶质细胞的反应

为了探讨束缚后大鼠脑内星形胶质细胞的反应,本实验将大鼠束缚于小的塑料桶内1、3或6 h,于解束后30 min处死,正常大鼠不被束缚作为对照。脑组织进行抗glial fibrillary acidic-protein(GFAP)免疫组织化学染色。结果显示:在正常大鼠脑内有少数散在静止状态的星形胶质细胞,表现为胞体小、突起细、GFAP淡染,缺乏机能定位分布特点;束缚后脑内星形胶质细胞表现为胞体肥大、突起变粗、GFAP深染、形成激活状态,其分布有明显的机能定位特点,表达于与应激反应调节相关的核团,主要有(1)端脑:扣带回、新皮质(尤其是第Ⅲ和V层)、隔外侧核、杏仁中央核;(2)间脑:丘脑室旁核、外侧膝状体、内侧膝状体、下丘脑的视上核、室旁核、第三脑室室周区、弓状核;(3)脑干:中脑的上丘浅层、中脑导水管周围灰质、下丘的皮质部;脑桥的臂旁外侧核、蓝斑、A5区;延髓的耳蜗核、延髓内脏带(MVZ)等处。反应性星形胶质细胞表达的时程变化是束缚1 h最高,3 h次之,6 h最少。本文结果表明,大鼠被束缚后全脑多处核团的星形胶质细胞发生不同程度的改变,随着束缚时间的延长,动物产生适应性,星形胶质细胞表达减少。     

皮质酮对大鼠脊髓背角星形胶质细胞活动的影响

目的:探讨皮质酮(corticosterone,CORT)对培养的大鼠脊髓背角星形胶质细胞活性的调节作用。方法:培养纯化新生SD大鼠脊髓背角星形胶质细胞,荧光双重标记技术检测培养的星形胶质细胞糖皮质激素受体(glucocorticoid receptor,GR)及胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)共表达;免疫印迹技术检测星形胶质细胞GFAP表达的变化;高效液相色谱法(high performance liquid chromatography,HPLC)检测星形胶质细培养液中谷氨酸含量。结果:培养的脊髓背角星形胶质细胞均表达GR;CORT孵育3 h可降低脊髓背角星形胶质细胞GFAP表达,GR拮抗剂RU38486可阻断CORT的作用;但CORT对星形胶质细胞谷氨酸释放无显著影响。结论:CORT可降低脊髓背角星形胶质细胞GFAP表达,但对谷氨酸释放无显著影响。     

帕金森病大鼠黑质小胶质细胞及星形胶质细胞的变化

目的探讨帕金森病(PD)发病中黑质小胶质细胞和星形胶质细胞的变化。方法采用立体定向术将神经毒素6-羟基多巴胺(6-OHDA)注入大鼠右侧黑质和内侧前脑束内,制备大鼠PD模型。将制模成功的16只PD大鼠随机分为2周和8周模型组,另6只正常大鼠作为对照组。观察各组大鼠黑质致密带内多巴胺(DA)能神经元、OX-42(小胶质细胞的特异性标志物)及神经胶质纤维酸性蛋白(GFAP,星形胶质细胞的特异性标志物)阳性细胞的分布和形态变化。结果 2周和8周模型组损毁侧黑质致密部DA能神经元较健侧显著减少(P0.01),损毁侧OX-42阳性细胞的数量较健侧明显增加(P0.01),形态呈"阿米巴状"。损毁侧GFAP阳性细胞数量较健侧明显增加(P0.01),突起变短,染色加深。2周模型组和8周模型组DA能神经元及两种胶质细胞的变化情况相似。结论 PD大鼠模型中存在着小胶质细胞和星形胶质细胞的激活,且两种胶质细胞的活化程度在PD发病过程中的不同时间无明显差别。     

Minimosymptomatic occlusion of the middle cerebral artery

Minimosymptomatic occlusion of the MCA before the origin of the perforating branches is an exceedingly rare occurrence. We report two cases of MCA occlusion at its origin, the second case proven by the CT scan in vivo. Published work rules out the possibility of a functionally effective deep collateral circulation in the distribution of the capsular rami of the MCA. In view of this we argue that there may be cases — admittedly very rare — in which, given the individual variability of the vascular supply, the MCA may be of negligïble functional importance to the circulation of the internal capsule. In such cases occlusion of the MCA would be relatively well tolerated.     

L-丝氨酸对永久性大脑中动脉栓塞大鼠的神经保护作用

目的: 研究L-丝氨酸对大鼠永久性脑梗死的神经保护作用、治疗剂量及有效治疗时间窗,并探讨相关作用机制。方法: 制作大鼠永久性大脑中动脉栓塞(pMCAO)模型,腹腔注射L-丝氨酸,通过神经行为学评分、脑梗死体积测定和尼氏染色法,观察L-丝氨酸的治疗剂量效应(56 mg/kg、168 mg/kg和504 mg/kg治疗组)和治疗时间窗(1 h、3 h、6 h、12 h和24 h治疗组);并测定丝氨酸消旋酶抑制剂对L-丝氨酸疗效的影响。利用激光多普勒血流监测仪观察缺血区血供及L-丝氨酸对缺血区局部脑血流量的影响。结果: 与pMCAO组相比,L-丝氨酸于pMCAO后3 h使用,168 mg/kg和504 mg/kg两个剂量都能较好地降低神经行为学评分,减少脑梗死体积,抑制海马CA1区神经细胞的丢失。在治疗时间窗的研究中,L-丝氨酸在pMCAO后6 h内治疗具有明显的神经保护作用,12 h及以后使用,神经保护作用不明显。丝氨酸消旋酶抑制剂不改变L-丝氨酸的疗效。脑缺血30 min时注射L-丝氨酸可明显增加缺血区局部脑血流量,并且这一作用不受甘氨酸受体阻断剂士的宁的影响。结论: L-丝氨酸对永久性脑梗死具有神经保护作用,其机制可能部分与增加缺血区皮质的血供有关。     

The neuroprotective effects of caffeic acid phenethyl ester (CAPE) in the hippocampal formation of cigarette smoke exposed rabbits

BACKGROUND: In this study, the neuroprotective effects of caffeic acid phenethyl ester (CAPE) in the hippocampus of cigarette smoke exposed rabbits were investigated. MATERIALS AND METHODS: Eighteen rabbits were used as experimental subjects and divided into three equal groups. The control group (Group A) was exposed to clean air. Rabbits in the cigarette smoke (CS) group (Group B) were exposed to cigarette smoke 1 hour daily in a room within a glass chamber for 4 weeks. Animals in the CS+CAPE group (Group C) were exposed to cigarette smoke as in Group B and administered CAPE (10 micromol/kg/day) intraperitoneally for 4 weeks just before the exposure to cigarette smoke. Rabbits in all three groups were sacrificed with intraperitoneal administration of 100 mg/kg sodium pentothal and their brains were removed immediately. In the hippocampal formation samples of left hemispheres, the levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were measured and the number of apoptotic neurons was counted by 'terminal transferase dUTP nick end labelling' (TUNEL) assay in the right hippocampal formation. RESULTS: We found that MDA levels increased significantly in the Group B rabbits compared with the control group (Group A; p = 0.001). In contrast, SOD activities decreased significantly in Group B rabbits compared with the control group (p = 0.001). In the CAPE treated rabbits (Group C), MDA levels decreased and SOD activities increased significantly as compared with Group B rabbits (p = 0.002, p = 0.002, respectively). The number of apoptotic neurons (TUNEL+) in the CA1, CA2, CA3 and dentate gyrus areas of rabbits' hippocampal formation were significantly increased in Group B rabbits compared with the control group. On the other hand, the number of apoptotic neurons in the hippocampus areas was decreased significantly in Group C rabbits compared with Group B rabbits. CONCLUSION: These findings suggest that cigarette smoking induces apoptosis in the hippocampal formation of rabbits and CAPE has a protective role against this induction.     

Protective effect of estrogen in endothelin-induced middle cerebral artery occlusion in female rats

Estrogen is a powerful endogenous and exogenous neuroprotective agent in animal models of brain injury, including focal cerebral ischemia. Although this protection has been demonstrated in several different treatment and injury paradigms, it has not been demonstrated in focal cerebral ischemia induced by intraparenchymal endothelin-1 injection, a model with many advantages over other models of experimental focal ischemia. Reproductively mature female Sprague–Dawley rats were ovariectomized and divided into placebo and estradiol-treated groups. Two weeks later, halothane-anesthetized rats underwent middle cerebral artery (MCA) occlusion by interparenchymal stereotactic injection of the potent vasoconstrictor endothelin 1 (180 pmoles/2 μl) near the middle cerebral artery. Laser-Doppler flowmetry (LDF) revealed similar reductions in cerebral blood flow in both groups. Animals were behaviorally evaluated before, and 2 days after, stroke induction, and infarct size was evaluated. In agreement with other models, estrogen treatment significantly reduced infarct size evaluated by both TTC and Fluoro-Jade staining and behavioral deficits associated with stroke. Stroke size was significantly correlated with LDF in both groups, suggesting that cranial perfusion measures can enhance success in this model.     

The effects of TRH analogues on cerebral ischaemia produced by middle cerebral artery occlusion in the rat

Summary This study examined the effects of two stabilised analogues of TRH, RX 77368 and CG 3509, in a rat cerebral ischaemia model produced by unilateral occlusion of the middle cerebral artery. The analogues were given intraventricularly after artery occlusion. The extent of the cortical ischaemia was evaluated after 10 days by somatosensory evoked potential (SEP) recording, followed by tetrazolium staining of brain slices for NADH-diaphorase activity. RX 77368 (2×10 g; 15 min, 24 h) significantly improved the survival rate, protected the SEP and reduced the area of infarct. In contrast, neither a smaller dose of RX 77368 (2×3 g) nor a 4 h delay in the treatment had any significant beneficial effects. Although CG 3509 (2×10 g) resulted in an apparent improvement in survival, its overall effects were not statistically significant. The findings indicate that stabilised TRH analogues may have beneficial effects when given to animals with focal cerebral ischaemia.     

Nylon filament coated with paraffin for intraluminal permanent middle cerebral artery occlusion in rats

A variety of intraluminal nylon filament has been used in rat middle cerebral artery occlusion (MCAO) models. However the lesion extent and its reproducibility vary among laboratories. The properties of nylon filament play a part of reasons for these variations. In the present study, we used paraffin-coated nylon filament for rat MCAO model, tested the effects and advanced improvement for making the rat MCAO. Forty male Sprague-Dawley (SD) rats were randomized into two groups, MCAO with traditional uncoated nylon filament (uMCAO) and MCAO with paraffin-coated nylon filament (cMCAO), three rats as normal group and sham group respectively. Assessment included mortality rates, model success rates, neurological deficit evaluation, and infarct volume. The study showed two rats died in uMCAO group, no rat died in cMCAO group within the 12 h. The model success rate of uMCAO was 100%, while the uMCAO group was 55% (n = 20, two died within 12 h, seven rats were excluded as the brain slices showed no TTC staining due to subarachanoid hemorrhage). Neurological evaluation demonstrated group cMCAO had more worse neurological outcomes than group uMCAO, and the difference was statistically signification (p < 0.05). TTC staining cMCAO group had significantly larger infarct volumes than uMCAO group, and also showed statistically significant difference (p < 0.05). The result demonstrated that the paraffin-coated nylon filament intraluminal occlusion provide better occlusion of middle cerebral artery than the uncoated nylon filament, improve the consistent of model, and raise the success rate to reduce the number of experimental animals. These positive results are much encouraging and interesting.     

亚甲蓝对APP/PS1转基因小鼠学习记忆及海马结构内GFAP表达的影响

目的:观察亚甲蓝对APP/PS1转基因小鼠学习记忆及胶质纤维酸性蛋白(Glial fibrillary acidic pro-tein,GFAP)在海马结构表达变化的影响。方法:20只3月龄APP/PS1小鼠,随机分2组,每组10只,对照组:自由饮水;治疗组:根据小鼠饮水量将亚甲蓝加入日常饮水中(25 mg/kg/d)连用4个月至7月龄。水迷宫测试观察其行为学的改变,免疫组化、Western Blot和TUNEL染色法观察GFAP在海马结构的表达及神经元的凋亡情况。结果:水迷宫测试结果显示亚甲蓝喂养组APP/PS1转基因小鼠第2～4 d的平均潜伏期显著低于对照组小鼠的潜伏期,说明治疗组与对照组相比在7个月时出现明显差异(P<0.05);免疫组化和Western结果显示治疗组海马结构内的GFAP在APP/PS1转基因小鼠的表达下调(P<0.05)。TUNEL染色法显示治疗组海马CA1、CA3区和齿状回TUNEL阳性细胞数较对照组明显减少(P<0.05)。结论:亚甲蓝能够下调APP/PS1小鼠海马结构内GFAP蛋白的表达,并通过抑制海马结构神经元的凋亡,提高APP/PS1小鼠的认知能力。     

健康成人海马结构体积的磁共振测量

目的:探讨正常成人海马结构体积的平均值范围,为与海马结构形态改变相关的疾病提供线性测量指标。方法:使用GE3.0T核磁共振仪采集海马结构图像,观测海马结构体积、纵轴长度、宽度、高度等指标,分析各线性指标与海马结构体积的相关性及海马结构体积随年龄变化的规律。结果:健康成人海马结构的体积随着年龄的增长而减小。海马结构体积左、右侧差异有统计学意义(左侧右侧),性别差异亦有统计学意义(男性女性)。Pearson分析显示,海马结构纵轴长度、海马结构宽度、海马结构高度、侧脑室颞角间距与海马结构体积呈正相关,侧脑室颞角宽度与海马结构体积呈负相关。结论:海马结构体积随着年龄增长而减小,且存在侧别及性别上的差异。海马结构纵轴长度、海马结构宽度、海马结构高度、侧脑室颞角间距、侧脑室颞角宽度可作为海马结构形态变化的初筛指标。     

Ketamine-induced rotational asymmetry in evaluation of motor disturbances in rats with middle cerebral artery occlusion

Intraperitoneal injection of ketamine in subanesthetic doses to Wistar rats with unilateral occlusion of the middle cerebral artery caused ipsilateral rotation (2-10 rpm), which was recorded in an automatic rotameter. The optimal dose of ketamine was 50 mg/kg. The animals were examined in an automatic rotameter for 40 min. Motor asymmetry persisted for no less than 2 months after surgery. According to the neurological test (Menzies scale) motor asymmetry in animals with focal brain ischemia persisted for no more than 30 days. The degree of ketamine-induced motor asymmetry in intact rats was 0.10±0.03 rpm.