脑缺血诱导大鼠皮层和海马二价金属离子转运体1表达增加的研究

目的:探讨脑缺血对大鼠皮层、海马二价金属离子转运体1(DMT1)表达的影响。方法:雄性Wistar大鼠随机分为脑缺血1、3、7、28 d和假手术组。结扎双侧颈总动脉建立脑缺血模型组,假手术组仅分离双侧颈总动脉但不结扎。采用RT-PCR测定DMT1+/-IRE mRNA的表达;采用免疫组化染色测定大鼠皮层及海马组织DMT1的表达。结果:大鼠皮层和海马DMT1+/-IRE mRNA的表达随缺血时间的延长逐渐增加。与假手术组比较,皮层DMT1+/-IRE mRNA的表达在缺血1、3 d时无差异(P>0.05);缺血7 d时表达增加(P<0.01),缺血28d时增加更明显(P<0.01)。海马DMT1-IRE mRNA表达除在缺血1 d时与假手术组无差异外(P>0.05),其余时间点DMT1+/-IRE mRNA表达均高于假手术组(P<0.01)。随缺血时间的延长,大鼠皮层、海马的锥体细胞、颗粒细胞及血管内皮细胞DMT1的表达逐渐增加。DMT1的表达除缺血1 d组与假手术组无差别外(P>0.05),其余各组均高于假手术组(P<0.05)。结论:脑缺血可诱导大鼠皮层及海马DMT1表达升高,DMT1表达的改变可能参与了脑缺血引起大鼠脑铁含量升高及神经元铁沉积过程。     

慢性脑缺血大鼠大脑皮质中的神经生长因子表达

目的：研究慢性脑缺血时大鼠大脑皮质中神经生长因子（NGF）的表达变化,探讨缺血性脑损伤及修复机制。方法：永久性结扎Wistar大鼠双侧颈总动脉,取慢性脑缺血30、120d组。行为学测试,免疫组化ABC法染色,计数大鼠大脑皮质中的NGF阳性神经元数及测量平均灰度值。结果：大鼠慢性脑缺血时,大脑皮质中NGF的表达,第120d比第30d及对照组显著增强,而30d与对照组无显著性差异,同时伴有学习和记忆力下降。结论：慢性脑缺血时,NGF在大脑皮质中的表达将随时间逐渐增强,对坏死神经元起保护作用。     

局灶性脑缺血对大鼠前额叶皮质神经型一氧化氮合酶的影响

目的:探讨局灶性脑缺血对大鼠前额叶皮质损伤区域神经型一氧化氮合酶(nNOS)表达以及氧化应激水平的影响。方法:8周龄雄性健康SD大鼠12只,随机分为两组,分别为假手术组(sham)和缺血组(ischemia),通过光化学诱导法建立大鼠局灶性脑缺血模型。采用Nissl染色观察大鼠前额叶皮质神经元损伤情况,免疫组织化学染色检测损伤区域nNOS的表达,商品化试剂盒检测大鼠血清中氧化应激水平。结果:与sham组相比,ischemia组的神经元明显损伤且数量显著降低,nNOS阳性细胞比例显著升高,血清中各氧化应激指标有不同程度变化。结论:局灶性脑缺血可导致大鼠前额叶皮质区神经元损伤及nNOS的表达升高,机体氧化应激水平上升。     

The effects of selenium against cerebral ischemia-reperfusion injury in rats

It is known that the brain tissue is extremely sensitive to ischemia-reperfusion (IR) injury and therefore, brain ischemia and consecutive reperfusion result in neural damage and apoptosis. The proinflammatory cytokines such as tumor necrosis factor alfa (TNF-α) and interleukin-1 beta (IL-1β) are produced during neurological disorders including cerebral ischemia. On the other hand, nerve growth factor (NGF), which is essential for the differentiation, survival and functions of neuronal cells in the central nervous system, regulate neuronal development through cell survival and cell death signaling. In the present study, we aimed to investigate the effect of selenium (Se) on prefrontal cortex and hippocampal damage in rats subjected to cerebral IR injury. Selenium was injected intraperitoneally at the doses of 0.625 mg/(kg day) after induction of IR injury. Prefrontal cortex and hippocampal damage was examined by cresyl-violet staining. Apostain and caspase-3 immune staining were used to detect apoptosis. TNF-α, IL-1β and NGF levels were also evaluated. Histopathological evaluation showed that treatment with selenium after ischemia significantly attenuated IR-induced neuronal death in prefrontal cortex and hippocampal CA1 regions of rats. Apoptotic cells stained with apostain and caspase-3 were significantly decreased in treatment group when compared with the IR group. Additionally, treatment with selenium decreased the TNF-α and IL-1β levels and increased the NGF levels in prefrontal cortex and hippocampal tissue of animals subjected to IR. The present results suggest that selenium is potentially a beneficial agent in treating IR-induced brain injury in rats.     

家兔急性不完全性脑缺血及重灌流的实验研究

采用低压低灌流方法造成家兔急性不完全性脑缺血60分钟,缺血后进行重灌流。检测了脑电图(EEG)、心输出量、平均动脉血压及脑静脉血乳酸脱氢酶(LDH)、磷酸肌酸激酶(CPK)活性以及大脑皮质水、钠、钾及环核苷酸含量,观察组织形态学改变。实验结果表明通过低压低灌流成功地复制了兔急性不完全性脑缺血模型。其特点为EEG严重抑制、大脑皮质水、钠含量升高、LDH及CPK活性显著升高。并见脑组织出现脑水肿改变。重灌流期间EEG先有所恢复后严重抑制,LDH及CPK活性仍显著升高。大脑皮质cAMP含量进一步升高,水肿程度加重。组织形态学呈现明显的缺血性损伤尤以亚微结构更为严重,表明重灌流后组织损伤加重。作者分析了上述改变发生的可能机制。     

糖尿病大鼠脑缺血再灌后神经元损伤与细胞死亡

目的:研究脑缺血/再灌后迟发性神经元损伤的细胞死亡形式,以及在糖尿病作为附加因素时,对于神经细胞死亡的影响。方法:在糖尿病模型及中脑动脉阻塞(MCAO)/再灌模型的基础上,通过病理形态,FCM,TUNEL,琼脂糖凝胶电泳等检测手段对脑缺血及再灌后脑细胞死亡形式进行综合判定。结果:局灶脑缺血再灌损伤过程中既存在细胞坏死,又存在细胞凋亡。其凋亡的神经细胞主要分布在重度缺血区域的边缘(半影区)附近。缺血中心区主要表现为坏死。另外还证明了合并糖尿病组可明显加重缺血性脑损伤,而且与诱导半影区、中线区的细胞凋亡发生发展有密切关系。结论:局灶脑缺血/再灌后神经元损伤包括坏死与凋亡,中心区以前者为主,而半影区则以后者为主,二者具有紧密的内在联系。合并有糖尿病时,可以明显加重缺血再灌性脑损伤的进程。     

Activation of leukocyte-endothelial interactions and reduction of selective neuronal death after global cerebral ischemia

The role of leukocyte-endothelial interactions (LEI) as part of the inflammatory response after global cerebral ischemia (GCI) is hardly understood and may be detrimental as well as beneficial. Objective of the current study was to investigate the cause-effect relationship of activated leukocytes for the development of ischemic brain damage. Mongolian gerbils were subjected to 15 min of global cerebral ischemia. A cranial window was implanted for quantitative analysis of the pial microcirculation focusing on leukocyte-endothelium interactions by intravital fluorescence microscopy up to 3 h of reperfusion. Subsequently the animals were daily screened for neurological deficits and the evolving brain damage was assessed histologically after 4 days. After global cerebral ischemia the number of rolling and adherent leukocytes increased 20- and >23-fold, respectively upon 3 h of reperfusion as compared to controls (P<0.05). Ischemic animals developed neurological deficits and showed a significant loss of neurons in selective vulnerable areas of the brain. The extent of leukocyte activation, i.e. the maximum number of rollers and stickers directly correlated to the number of viable neurons on day 4 in hippocampus, cortex, and striatum. We conclude that there is a relationship between activation of leukocyte-endothelium interactions and the reduction of ischemic brain damage after global cerebral ischemia. Activation of leukocytes may have neuroprotective potential or indicate regenerative processes.     

Rapamycin保护大鼠缺血性脑损伤和特定脑区神经新生有关

目的:探讨缺血前给予自噬诱导剂对脑缺血损伤的保护效应及可能机制。方法:双侧颈总动脉结扎建立全脑缺血模型,再灌注后24 h,评价动物神经行为功能,连续脑切片,采用Nissl染色定量检测皮层及海马CA1区细胞密度;通过免疫荧光技术检测Caspase-3阳性神经元,计数皮层及海马CA1凋亡细胞数量;激光共聚焦显微镜观察并计数海马齿状回颗粒下层内呈Ki67阳性、GFAP(胶质纤维酸性蛋白)阴性(Ki67+/GFAP-)细胞的数量。结果:Rapamycin术前预处理可以改善缺血导致的神经功能缺陷(P<0.05)。Nissl染色结果表明Ra-pamincy术前1 h给药可以减轻缺血导致的皮层(P<0.01)及海马CA1区(P<0.01)细胞丢失。同时,Rapamycin术前给药也显著减少了缺血导致的皮层及海马CA1区内Caspase-3阳性细胞的数量,组间比较有显著性差异(P<0.05)。Rapamycin术前1 h给药增加了海马齿状回内Ki67+/GFAP-细胞的数量,和缺血组比较差异有显著性(P<0.05)。结论:在全脑缺血模型上,通过自噬活化途径的缺血预处理可以保护缺血性脑损伤,这一作用和Rapamycin减少凋亡、增加新生神经细胞的数量有关。     

Ischemic preconditioning prevents protein aggregation after transient cerebral ischemia

Transient cerebral ischemia leads to protein aggregation mainly in neurons destined to undergo delayed neuronal death after ischemia. This study utilized a rat transient cerebral ischemia model to investigate whether ischemic preconditioning is able to alleviate neuronal protein aggregation, thereby protecting neurons from ischemic neuronal damage. Ischemic preconditioning was introduced by a sublethal 3 min period of ischemia followed by 48 h of recovery. Brains from rats with either ischemic preconditioning or sham-surgery were then subjected to a subsequent 7 min period of ischemia followed by 30 min, 4, 24, 48 and 72 h of reperfusion. Protein aggregation and neuronal death were studied by electron and confocal microscopy, as well as by biochemical analyses. Seven minutes of cerebral ischemia alone induced severe protein aggregation after 4 h of reperfusion mainly in CA1 neurons destined to undergo delayed neuronal death (which took place after 72 h of reperfusion). Ischemic preconditioning reduced significantly protein aggregation and virtually eliminated neuronal death in CA1 neurons. Biochemical analyses revealed that ischemic preconditioning decreased accumulation of ubiquitin-conjugated proteins (ubi-proteins) and reduced free ubiquitin depletion after brain ischemia. Furthermore, ischemic preconditioning also reduced redistribution of heat shock cognate protein 70 and Hdj1 from cytosolic fraction to protein aggregate-containing fraction after brain ischemia. These results suggest that ischemic preconditioning decreases protein aggregation after brain ischemia.     

大鼠星形胶质细胞在高血糖脑缺血再灌注损伤中的变化

目的:探讨星形胶质细胞在高血糖脑缺血再灌注损伤中的变化规律。方法:采用链脲佐菌素(STZ)诱导Ⅰ型糖尿病高血糖大鼠模型,通过双侧颈总动脉夹闭联合股动脉放血法建立全脑缺血再灌注模型,应用组织学、免疫荧光、组织化学及Western Blot方法,对比观察糖尿病高血糖脑缺血再灌注组(简称糖尿病组)与正常血糖脑缺血再灌注组(简称正常血糖组)在脑缺血15 min、再灌注1 h和6 h大脑额叶皮质区神经元、星形胶质细胞组织学变化及GFAP的表达。结果:正常血糖组再灌注1 h脑组织出现轻度水肿;再灌注6 h脑水肿加重,出现神经元固缩;再灌注1 h,糖尿病组病变与正常血糖组基本相同,再灌注6 h脑水肿加重,固缩神经元进一步增加。再灌注1 h和6 h,糖尿病组Nissl体平均光密度值明显低于正常血糖组(P<0.05)。脑组织GFAP免疫荧光检查可见,再灌注6 h正常血糖组GFAP免疫阳性细胞明显增加。糖尿病组再灌注1 h和6 h,出现GFAP阳性星形胶质细胞数目增加(P<0.05),胞体显著增大,突起增长、增粗。Western Blot结果可见,糖尿病组GFAP的表达明显高于正常血糖组。结论:糖尿病高血糖脑缺血再灌注能够加重神经元损伤,星形胶质细胞出现更明显的数量增加和GFAP表达。     

依达拉奉干预永久性脑缺血大鼠神经干细胞增殖及分化

目的 探讨依达拉奉对永久性脑缺血大鼠脑内内源性神经干细胞的影响。 方法 采用电凝法建立大鼠永久性脑缺血模型。将30只SD大鼠随机分为假手术组、脑损伤组与依达拉奉组,每组10只,模型制作成功后6 h,1.5 g/L依达拉奉组腹腔注射依达拉奉（10 ml/kg）,每天1次,假手术组与脑缺血组腹腔注射等体积的生理盐水,连续注射7 d。末次给药后24 h,免疫荧光染色观察损伤侧脑室下区与缺血周围脑皮质区BrdU标记阳性细胞、Nestin/BrdU标记阳性细胞、神经元Ⅲ型β-微管蛋白（Tuj1）/BrdU标记阳性细胞与胶质纤维酸性蛋白（GFAP）/BrdU标记阳性细胞,Western blotting 检测缺血周围脑皮质区Tuj1与GFAP蛋白表达。 结果 与脑缺血组比较,依达拉奉组损伤侧脑室下区与缺血周围脑皮质区的BrdU标记阳性细胞、Nestin/BrdU标记阳性细胞、Tuj1/BrdU标记阳性细胞与GFAP/BrdU标记阳性细胞明显增加(P<0.05)。与脑缺血组比较,依达拉奉组缺血周围脑皮质区的Tuj1与GFAP蛋白表达量增加(P<0.05)。 结论 依达拉奉可促进缺血损伤侧脑室下区与缺血周围脑皮质内源性神经干细胞与星形胶质细胞的增殖,促进内源性神经干细胞分化为神经元。     

Iron deposition in the brain following the ischemia in a rat model of ischemic tolerance

Preconditioning of the brain by short-term ischemia increases brain tolerance to the subsequent severer ischemia. In this study, we investigated iron deposition in the cerebral cortex and the ischemic tolerance in a rat model of cerebral ischemia. Forebrain ischemia was induced by four-vessel occlusion for 5 min as ischemic preconditioning. Two days after preconditioning or after the sham-operation, the second ischemia was induced for 20 min. Changes in the cerebral cortex were examined after 1 to 8 weeks of recirculation following 20 min ischemia with or without preconditioning using the iron histochemistry. Granular deposits of the iron were found in the cytoplasm of the pyramidal cells in the layers III and V of the frontal cortex after 1 week of recirculation. When the rats were exposed to 5 min ischemia 2 days before 20 min lasting ischemia, the deposition of iron in the cytoplasm of the pyramidal cells in layers III and V of the frontal cortex was significantly lower during all periods of reperfusion. Preconditioning 5 min ischemia followed by 2 days of reperfusion before 20 min ischemia also prevented degeneration of the pyramidal neurons in layers III and V of the frontal cortex.     

电针上调脑梗塞大鼠皮质缺血半影区Bcl-2蛋白质的表达

目的观察电针对脑缺血大鼠皮质缺血半影区Bcl-2蛋白质表达的影响,为探讨电针治疗脑梗塞的机理提供实验依据。方法线栓雄性SD大鼠大脑中动脉建立脑梗塞动物模型,随机分为电针组和非电针组。用免疫组化的方法显示大脑皮质缺血半影区Bcl-2阳性细胞并观察细胞形态和分布,计数阳性细胞数量;用Western-blot方法定量皮质缺血半影区Bcl-2蛋白表达的变化。结果①对照组和假手术组大鼠脑皮质未显示出Bcl-2免疫阳性细胞。非电针组的大鼠皮质缺血半影区在缺血6h即在皮质中间带见圆形,偶见椭圆形和梭形Bcl-2免疫阳性细胞分布。阳性细胞的数量在缺血1d最多,3d呈减少的趋势。电针组的阳性细胞形态与分布与非电针组比未见明显差异,在数量上亦随电针的时间增加而增多。②Western-blot方法未在对照组和假手术组大鼠额叶皮质检出Bcl-2蛋白质。电针组大鼠皮质缺血半影区的Bcl-2的表达比非电针组的呈上调的趋势。结论电针刺激内关和足三里穴位可以上调脑梗塞大鼠皮质缺血半影区内Bcl-2蛋白质的表达,参与脑缺血性细胞凋亡的病理过程。     

Changes in Serum Ghrelin and Small Intestinal Motility in Rats with Ischemic Stroke

Ischemic stroke occurs as a result of an obstruction within a blood vessel supplying blood to the brain. Gastrointestinal mucosal damage not only induces local and systemic inflammatory reactions but may also result in multiple organ dysfunction syndrome. We studied whether the changes in serum ghrelin and small intestinal motility occur in cerebral ischemia. The focal cerebral ischemia rat models were produced by the middle cerebral artery occlusion (MCAO) method. The MCAO group was further equally divided into five subgroups at 3, 6, 12, 24, and 48 hr, and the sham operated rats were used as controls. Serum ghrelin level was analyzed using enzyme‐linked immunosorbent assay, and small intestinal motility was measured by methylene blue staining. The ileum tissue was examined by light and electron microscopy. The neurologic scores were 0 for all the rats in the control group and 2–3 for those in the MCAO group, suggesting that rat models were established successfully. The serum ghrelin level was higher in the MCAO group when compared with the control group (P < 0.05). However, the impelling force in MCAO rats was significantly lower than that of the control group (P < 0.05), reaching the lowest level at 24 hr. Damage to the intestinal mucosa, including villus intestinalis, vacuolar degeneration of organelles, widened cell–cell junctions, and apoptotic cells could be found under the light and electron microscopy. Our results showed that higher level of serum ghrelin decreased gastrointestinal motility and damage to the intestinal mucosa existed in rats with MCAO. Anat Rec, 2012. © 2011 Wiley Periodicals, Inc.     

Modulation of microglial activation enhances neuroprotection and functional recovery derived from bone marrow mononuclear cell transplantation after cortical ischemia

Activated microglia may exacerbate damage in neural disorders; however, it is unknown how they affect stem cells transplanted after stroke. Focal ischemia was induced by microinjections of 40 pmol of endothelin-1 into the motor cortex of adult rats. Ischemic animals were treated with sterile saline (n = 5), bone marrow mononuclear cells (BMMCs, n = 8), minocycline (n = 5) or concomitantly with minocycline and BMMCs (n = 5). BMMC-treated animals received 5 × 10(6)BMMCs through the caudal vein 24h post-ischemia. Behavioral tests were performed to evaluate functional recovery. Morphometric and histological analyses were performed to assess infarct area, neuronal loss and microglia/macrophage activation up to 21 days post-ischemia. Treatments with minocycline, BMMCs or minocycline-BMMCs reduced infarct area, increased neuronal survival and decreased the number of caspase-3+ and ED-1+ cells, but these effects were more prominent in the minocycline-BMMC group. Behavioral analyses using the modified sticky-tape and open-field tests showed that ischemic rats concomitantly treated with BMMCs and minocycline showed better motor performance than rats treated with BMMCs or minocycline only. The results suggest that proper modulation of the inflammatory response through the blockage of microglia activation enhances neuroprotection and functional recovery induced by intravenous transplantation of BMMCs after motor cortex ischemia.     

高血糖加重缺血性脑损伤

目的：探讨高血糖对脑缺血损伤的影响。方法：采用大鼠高血糖全脑缺血模型,用HE和TUNEL染色,对比检测脑细胞损伤和凋亡。结果：高血糖组在缺血再灌注后与血糖正常组相比,纹状皮质脑水肿和神经元变性、死亡明显加重;海马CA1区损伤神经元计数无显著性差异;海马CA3区损伤神经细胞数明显多于血糖正常组。TUNEL染色可见,在纹状皮质、海马CA1区和CA3区高血糖组和血糖正常组阳性细胞明显多于对照组;在缺血或再灌注后,正常血糖组和高血糖组的TUNEL阳性细胞数均无显著性差异。结论：高血糖可加重缺血引起的神经元损伤。     

CGRP和NGF对全脑缺血再灌注大鼠脑组织Erk表达的调节作用

目的 :检测大鼠脑缺血再灌注后细胞外调节蛋白激酶 (Erk)的表达 ,探讨降钙素基因相关肽 (CGRP)和神经生长因子 (NGF)对脑组织的保护作用及机制。方法 :采用颈动脉负压分流法制作大鼠脑缺血再灌注模型 ,采用免疫组织化学SABC法及显微图像分析检测海马及皮质内Erk的表达。结果 :大鼠缺血再灌注海马及皮质内Erk免疫反应阳性产物较正常组增多 (P <0 .0 5 ) ,而注射CGRP或NGF后阳性产物明显高于缺血再灌注组 (P <0 .0 1 ) ,二者联合应用效果更加显著 (P <0 .0 5 )。结论 :CGRP及NGF参与缺血神经元Erk的调节 ,二者对缺血神经元有协同修复作用     

Abnormalities in glucose and energy metabolism are more severe in the hippocampus than in cerebral cortex in postischemic recovery in aged rats

After brain ischemia, dissimilar disturbances in morphology and energy metabolism have become evident in cortex and hippocampus the reason of which has not been completely elucidated as yet. Aged male Wistar rats underwent a 15 min complete cerebral ischemia induced by occlusion of the carotid and vertebral arteries and by hypovolemic hypotension. Thereafter, normotensive recirculation of the brain was established and the animals were allowed to recover for either 60 min, or 24 h, or 48 h, or 72 h, or 96 h. In cerebral cortex and hippocampus, the concentrations of glucose, lactate, and energy-rich compounds were measured by means of standard enzymatic methods. After ischemia, the ischemia induced metabolic abnormalities as measured as concentrations of glucose and lactate, and as energy-rich compounds normalized rapidly. After 48 and 72 h recirculation, a disturbance in glucose breakdown and an imbalance in energy metabolism became manifest in cerebral cortex, and even earlier (24 h) and longer (96 h), and more severe, in hippocampus. These changes may contribute to delayed neuronal damage and cell death in the areas studied.     

大豆异黄酮对脑缺血/再灌注诱导的线粒体损伤和脑细胞凋亡的影响

 目的:研究大豆异黄酮（SI）对全脑缺血/再灌注大鼠脑组织线粒体超微结构、细胞凋亡和细胞色素C（Cyt-C）、caspase-3及caspase-9表达的影响,探讨大豆异黄酮对脑缺血/再灌注损伤的作用及机制。方法: 60只健康成年SD 大鼠随机分为假手术组（sham）、缺血再灌注组（I/R）和大豆异黄酮预处理组（SI）。SI组给予SI 120 mg·kg-1·d-1连续灌胃21 d,其余2组用等体积生理盐水灌胃,每天1次,第22天I/R组和SI组行手术阻断三血管制备全脑缺血/再灌注模型。缺血1 h,再灌1 h后处死,取大脑皮层,光镜观察脑细胞形态学变化,透射电镜观察线粒体超微结构变化,流式细胞术检测细胞凋亡率,半定量RT-PCR法和免疫组织化学法测定脑组织中Cyt-C、caspase-9及caspase-3的表达。结果: I/R组线粒体膜崩解、嵴消失,脑细胞大量凋亡。与I/R组相比,大豆异黄酮预处理能明显改善线粒体超微结构的损伤,减少脑细胞凋亡率（P<0.01）。I/R组Cyt-C、caspase-9和caspase-3 mRNA的表达和蛋白的含量高于sham 组（P<0.01）,与I/R组相比,SI组Cyt-C、 caspase-9及caspase-3 mRNA 和蛋白的表达显著降低（P<0.01）。结论: 大豆异黄酮可能通过稳定线粒体结构,减少线粒体释放Cyt-C,降低caspase-9和caspase-3的表达,抑制细胞凋亡,从而减轻脑缺血/再灌注损伤。     

骨髓间充质干细胞移植对大鼠脑缺血区血管新生及神经前体细胞增殖的影响

目的：探讨骨髓问充质千细胞（MSC）移植促进大鼠脑缺血后神经功能恢复的可能机制。方法：用线栓法复制大鼠脑缺血再灌注动物模型,分缺血对照组和移植治疗组（经颈动脉移植体外培养异体MSC）。采用免疫组织化学染色及原位杂交技术观察缺血区脑组织的新生血管、细胞增殖及巢蛋白表达的变化。结果：（1）移植组比对照组缺血区皮层微血管密度（MVD）明显增高,血管内皮生长因子（VEGF）mRNA阳性信号明显增强。（2）缺血区顶叶皮层、尾壳核、室管膜、室管膜下区均可见大量Nestin阳性细胞及BrdU阳性细胞．各时间段移植组两种阳性细胞数均比对照组显著增多。结论：MSC可能通过改善缺血区血运及促进缺血区神经前体细胞再生达到修复缺粗区损伤组织．从而改善脑缺血大鼠神经功能。