戊四唑点燃大鼠模型海马结构蛋白激酶C阳性细胞的变化

目的　利用戊四唑点燃大鼠模型 ,研究癫痫大鼠海马结构蛋白激酶C(PKC)阳性细胞的变化。方法　将大鼠分为对照组和模型组 ,模型组大鼠又分为完全点燃组和完全点燃后间歇 2 4h组。用免疫组织化学方法检测了海马和齿状回PKC阳性细胞的变化。结果　PKC阳性细胞主要分布于齿状回的颗粒层 ,在海马的分布主要在分子层 ,数量较少。点燃组大鼠海马和齿状回PKC阳性细胞数量与对照组相比 ,均显著增加 (P <0 0 5 ) ;点燃后间歇 2 4h组与对照组相比 ,无显著性变化 (P >0 0 5 )。结论　PKC阳性细胞表达的增加可能在诱导大鼠点燃中起重要的作用。     

大鼠海马结构在空间辨别性学习记忆时突触素表达的变化

目的:探讨空间辨别性学习记忆活动与突触可塑性的关系。方法:用免疫组织化学方法对具有空间辨别性学习记忆功能的模型大鼠与对照组大鼠海马结构内突触素I的表达进行对比研究。结果:(1)对照组大鼠海马结构内未见明显的突触素颗粒产物;在模型组,经水迷宫训练1周的大鼠海马切片上见到齿状回、CA4和CA3区出现深染的颗粒分布,CA2和CA1区颗粒较少;训练2周的大鼠海马结构内的染色显示颗粒与训练1周的比较无明显差异,但染色加深;(2)模型组大鼠的突触素反应产物的光密度值明显大于对照组(P＜0.05);模型组大鼠海马结构内突触素光密度值在训练的1~2周内随训练时间增加而增加,训练2~3周则增加不明显;模型组大鼠海马结构CA3、CA4区和齿状回突触素反应产物的光密度值较CA1和CA2区的大,差异有显著(P＜0.05)。结论:(1)大鼠经水迷宫训练获得空间辨别性学习记忆功能时在海马结构内有新突触形成;(2)海马结构的CA3、CA4区和齿状回与空间辨别性学习记忆的关系密切。     

雌激素对自发性高血压大鼠颅内动脉血管壁TNF-α和MMP-9表达的影响

目的: 探讨雌激素对颅内动脉血管壁炎症反应和血管重塑的可能作用。方法: 雌性自发性高血压大鼠(SHR)32只,随机分为4组:自发性高血压模型对照组、卵巢切除去势组、去势后雌激素替代组和卵巢切除去势对照组,每组8只。放射免疫法检测各组静脉血的雌激素水平,获取标本后光镜下观察血管壁的病理变化,运用Western blotting 检测颅内动脉Willis环血管壁组织TNF-α和MMP-9蛋白的含量。结果: 自发性高血压模型对照组雌激素水平明显高于卵巢切除去势组(P<0.01);卵巢切除去势后雌二醇替代组的雌激素水平较卵巢切除去势对照组明显增高(P<0.01)。所有大鼠均未见进展期动脉瘤。在自发性高血压模型对照组中未见动脉瘤样改变,在卵巢切除去势组、卵巢切除去势对照组和卵巢去势后雌激素替代组中分别发现2个、3个和1个早期动脉瘤样改变。自发性高血压模型对照组颅内动脉血管壁TNF-α和MMP-9的含量明显低于卵巢切除去势组,雌二醇替代治疗组颅内动脉血管壁的TNF-α和MMP-9表达明显低于卵巢去势对照组(P<0.01)。结论: 雌激素能通过抑制颅内动脉的炎性反应,降低血管壁MMP-9的表达,影响颅内动脉的血管重塑。     

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。     

空间辨别性学习记忆活动与大鼠海马结构基质细胞衍生因子 1表达的关系

目的 探讨大鼠空间辨别性学习记忆活动与趋化因子基质细胞衍生因子.1(SDF-1)的关系. 方法用免疫组织化学方法、免疫印迹法和RT-PCR方法对获得空间辨别性学习记忆大鼠海马结构内SDF-1表达进行研究,并与游水组和对照组比较.结果 1.免疫组织化学方法显示,对照组大鼠海马结构内趋化因子SDF-1阳性细胞分布在海马结构各亚区和各层.阳性细胞的形态以圆形为主,少见锥体形和梭形.阳性产物主要分布在细胞膜上;游水组大鼠海马结构内SDF-1阳性细胞的形态和分布与对照组相比未见组间差异;训练组大鼠海马结构内SDF-1免疫阳性细胞的数量比对照组增多(P<0.01).阳性细胞的形态以锥体形和三角形居多,在分布上有向齿状回聚集的趋势.2.免疫印迹方法检测训练组大鼠海马结构内SDF-1蛋白质的表达明显高于对照组(P<0.01).而且在训练组内则随着训练时间的延长表达量随之增加.3.RT-PCR方法检测训练组大鼠海马结构内SDF-1mRNA的量明显高于对照组(P<0.01),且随着训练时间的延长表达增加.在水盆中漫游的游水组大鼠,不论是免疫组织化学方法,还是免疫印迹法以及RT-PCR方法获得的结果与对照组相比均未见组间差异. 结论 经水迷宫训练使大鼠获得空间辨别性学习记忆功能,致使海马结构内细胞导向因子SDF-1表达上调,上调的SDF-1蛋白质可能与所获功能需要的形态基础.神经微环路的形成有关.     

植物雌激素对去卵巢大鼠海马NOS阳性神经元及学习记忆的影响

目的 :观察植物雌激素对去卵巢大鼠海马NOS阳性神经元及学习、记忆的影响 ,对中枢神经系统的保护作用。方法 :采用NADPH d酶组化观测各组大鼠海马各功能亚区NOS阳性神经元数目和Morris水迷宫行为学方法。结果 :定位航行实验显示各组大鼠的平均逃避潜伏期无明显差异 ,而空间探索实验显示植物雌激素组平台象限的游泳距离百分比和穿台次数均高于去卵巢对照组。在海马CA1和齿状回 (DG) ,植物雌激素组NOS阳性神经元数目较去卵巢对照组明显增多 (P <0 .0 5 )。结论 :植物雌激素能增加海马神经元NOS的表达 ,改善去卵巢大鼠的学习记忆能力 ,提示对中枢神经系统退行性病变具有保护作用。     

雌激素与辛伐他汀序贯法干预对去势大鼠骨质疏松的治疗作用

背景:Frost根据骨重建的概念创建了骨重建干预理论——序贯疗法,即在骨吸收抑制剂之后可给予刺激骨形成的药物。目的:基于骨重建干预理论,序贯应用雌激素与辛伐他汀干预骨重建吸收期和形成期,观察其对去势大鼠骨质疏松的治疗作用。方法:3月龄雄性SD大鼠40只,以随机数字表法分为去势组与正常对照组。去势组切除双侧卵巢,正常对照组只进行下腹部皮肤单纯切开术。大鼠去势后1个月,将去势组随机分为3组:序贯组、雌激素组、去势对照组,并开始药物干预:序贯组,皮下注射苯甲酸雌二醇0.1mg/kg,3d给药1次,2周后,灌胃给予辛伐他汀5mg/(kg·d)2周,停药5周,再应用辛伐他汀5mg/(kg·d)灌胃2周;雌激素组,皮下注射苯甲酸雌二醇0.1mg/kg,每3d给药1次,连续用药11周;去势对照组,单纯的饲料喂养,无药物干预。11周后,双能X射线骨密度仪测定股骨骨密度,放射免疫法检测血清白细胞介素6、骨钙素水平。结果与结论:各治疗组大鼠股骨骨密度、骨钙素水平高于去势对照组(P0.05),并且序贯组明显高于雌激素组(P0.05)。各治疗组白细胞介素6水平低于去势对照组(P0.05),并且序贯组低于雌激素组(P0.05)。说明雌激素和辛伐他汀序贯疗法可以通过抑制骨吸收,促进骨形成有效地治疗骨质疏松。     

电针对脑梗塞大鼠海马结构内GFAP免疫阳性细胞的形态学影响

目的观察电针对脑梗塞大鼠海马结构内胶质纤维酸性蛋白(GFAP)免疫阳性细胞形态学的影响,为探讨针刺治病机制的胶质细胞机制提供实验依据。方法线栓法建立大鼠脑梗塞模型,用免疫细胞化学方法显示针刺对大鼠海马结构内GFAP免疫阳性细胞的形态、分布及数量,并与非针刺组、假手术组和对照组的比较,电针对大鼠海马结构GFAP阳性细胞的形态。结果①对照组大鼠海马结构内可见散在多角形和椭圆形的GFAP阳性细胞。前者分布多见于CA4区,胞体较大,突起少而短,GFAP免疫反应产物沉积胞膜和胞体一侧;后者多见与CA1区,胞体较小,突起多而长,GFAP免疫产物充满胞体。假手术组大鼠海马结构内GFAP免疫反应阳性细胞的分布和形态与对照组的比未见明显组间差异。非电针组大鼠海马结构内可见大量GFAP免疫阳性细胞,GFAP免疫反应较对照组明显增强。但其形态和分布与对照组的比未见明显差异。电针组大鼠海马结构内GFAP免疫阳性细胞的数量、体积和免疫反应的程度均比非电针组的增多、增大和增强。②对照组大鼠海马结构内GFAP阳性细胞数量与假手术组的差异无统计学意义(P0.05);非电针组的GFAP阳性细胞比对照组的明显增加,差异有统计学意义(P0.01);电针组的GFAP阳性细胞比非电针组的增加,差异有统计学意义(P0.01)。③大鼠海马结构内GFAP免疫产物的相对量在对照组与假手术组的比较差异无统计学意义(P0.05);非电针组的比对照组的明显增加,差异有统计学意义(P0.01);电针组的比非电针组的增加,差异有统计学意义(P0.01)。结论1～2mA强度的电刺激"曲池"和"足三里"穴位能影响大鼠海马结构内星形胶质细胞的激活并上调GFAP的表达,参与缺血性神经元生存或死亡归宿的调节过程。     

外源性雌激素对去势后大鼠下丘脑视上核一氧化氮合酶阳性神经元分布的影响

目的观察外源性雌激素对去势后雌性大鼠下丘脑视上核(SON)一氧化氮合酶(NOS)阳性神经元分布的影响。方法选用2～3月龄、健康未交配的雌性大鼠40只;动物分组如下:对照组大鼠20只,分为正常对照组(n=10)和实验对照组(卵巢切除术后,n=10)。实验组(即卵巢切除术后肌肉注射雌激素组)20只,造模成功后,分别于术后40d(即给药一个月)和术后70d(即给药两个月)陆续灌注取材。采用SABC法在光学显微镜下对下丘脑视上核内NOS阳性神经元进行形态学观察和细胞计数,采用图像分析系统测定NOS阳性神经元内免疫反应产物的平均灰度值。结果卵巢切除术后对照组大鼠下丘脑视上核NOS阳性神经元的密度明显增高,细胞比正常对照组有所增大(P0.05)。去势后补充雌激素1个月组的大鼠与正常对照组和卵巢切除组相比较,视上核内NOS阳性神经元的密度及形态均无明显改变(P0.05)。去势后补充雌激素两个月组与实验对照组相比较,无论NOS阳性神经元的密度还是阳性神经元胞体的大小均显著下降(P0.05),细胞着色变浅。结论外源性雌激素可能影响去势雌性大鼠下丘脑视上核NOS阳性神经元的分布和表达。     

Meynert核毁损后大鼠海马结构内生长抑素阳性神经元的变化

目的 观察Meynert核毁损后大鼠海马结构内生长抑素(SS)阳性神经元变化,探讨SS参与学习记忆的机制.方法以海人酸(1μg/每侧)毁损双侧Meynert(NBM)核建立学习记忆障碍模型,用避暗回避实验进行行为学检测,免疫组织化学染色后光镜下观察并计数海马结构内SS阳性神经元.结果 1.NBM受损后大鼠记忆力明显下降,与正常组比较具有显著性差异;2.NBM受损后各组海马结构内SS阳性神经元数量明显减少,与正常组比较具有高度显著性差异.细胞形态的改变主要表现为胞质着色减弱,阳性突起变短.结论 NBM损毁后大鼠海马结构内SS阳性神经元数量显著减少,此过程参与了NBM毁损导致的大鼠学习记忆障碍.     

金雀异黄酮对去卵巢大鼠海马突触体素表达的影响

目的：研究金雀异黄酮对去卵巢大鼠海马突触体素的影响,以探讨金雀异黄酮对女性更年期后中枢神经系统退行性变的作用机制。方法：用免疫组化结合图像分析的方法,测量分析去卵巢后不同时间点以及给予金雀异黄酮替代治疗后海马CA1～3区辐射层和齿状回分子层突触体素免疫阳性产物的平均光密度变化。结果：去卵巢后大鼠CA1～3区辐射层和DG分子层突触体素免疫阳性产物的平均光密度值逐渐降低,4周后与假手术组和苯甲酸雌二醇组相比有显著差异;金雀异黄酮组治疗后海马突触体素免疫阳性产物平均光密度恢复。结论：金雀异黄酮能恢复去卵巢大鼠海马突触密度,延缓女性更年期后中枢神经系统的退行性变。     

吗啡依赖小鼠海马神经元c-fos的表达

目的:探讨吗啡依赖小鼠海马不同亚区神经元c-fos表达的差异。方法:以剂量递增法皮下注射吗啡建立吗啡依赖小鼠模型,腹腔注射纳洛酮诱发戒断症状。根据小鼠戒断反应中出现的跳跃次数、体重下降等指标评定戒断反应强度。采用免疫组织化学法显示吗啡依赖小鼠和正常对照组小鼠海马神经元c-fos的表达。结果:吗啡依赖组海马CA1区和齿状回Fos阳性神经元数目明显增加(P<0.05),CA3区无明显改变(P>0.05)。纳洛酮催促戒断组海马CA1和CA3区Fos阳性神经元数目明显增加(P<0.05),齿状回Fos阳性神经元数目增加更为明显(P<0.01)。吗啡依赖组与纳洛酮催促戒断组CA3区阳性神经元数目有显著性差异(P<0.05)。结论:海马神经元c-fos的表达增强可能与吗啡依赖对神经元的损伤有关。     

Short term treatment with estradiol decreases the rate of newly generated cells in the subventricular zone and main olfactory bulb of adult female mice

Adult neurogenesis occurs most notably in the subgranular zone (SGZ) of the hippocampal dentate gyrus and in the olfactory bulb (OB) where new neurons are generated from neural progenitors cells produced in the subventricular zone (SVZ) of the forebrain. As it is well known that gonadal steroid hormones, primarily estradiol, modulate neurogenesis in the hippocampus of adult female rodents, we wanted to determine whether estradiol would also affect the proliferation of progenitor cells in the SVZ and by consequence the rate of newly generated cells in the main OB. Thus a first group of adult female C57Bl6/J mice was ovariectomized and received a short term treatment with estradiol (single injection of 1 or 10 μg 17β-estradiol or Silastic capsule of estradiol during 2 days) before receiving a single injection with BrdU to determine whether estradiol would modulate the cell proliferation in the SVZ. A second group of adult ovariectomized female mice was submitted to the same estradiol treatment before receiving four BrdU injections, and was sacrificed 21 days later to determine whether a modulation in cell proliferation actually leads to a modulation in the number of newborn cells in the main OB. We observed a decrease in cell proliferation in the SVZ following either dose of estradiol compared to the controls. Furthermore, 21 days after their generation in the SVZ, the number of BrdU labeled cells was also lower in the main OB, both in the granular and periglomerular cell layers of estradiol-treated animals. These results show that a short term treatment with estradiol actually downregulates cell proliferation leading to a decreased number of newborn cells in the OB.     

马桑内酯致痫大鼠海马神经元丢失及化学性质的研究

为观察癫痫发作过程海马神经元丢失细胞的主要死亡方式 ,用马桑内酯建立慢性致痫大鼠模型 ,以 Nissl染色、免疫组化、TUNEL法以及后二者相结合的技术 ,对海马神经元及其中的抑制性神经元的丢失进行了分区观察、统计、分析。结果发现 :致痫组海马各区神经元较对照组明显减少 ,不同区域减少程度不同 ,以齿状回减少最为明显 ;免疫组化结果显示 ,致痫组的抑制性神经元 GABA-IR神经元、PV-IR神经元、CB-IR神经元在海马各区有不同程度的减少 ,其中 GABA-IR神经元减少最明显。在海马各区所有丢失的神经元中 ,三种抑制性神经元所占的比例不同 ;并在海马各区均可见到 TUNEL -GABA、TUNEL-PV、TU NEL-CB双重反应阳性神经元。提示 :马桑内酯所致的癫痫发作 ,可引起海马神经元丢失 ,且不同区域丢失的程度不同 ,丢失的神经元可能以凋亡方式为主 ;海马抑制性神经元 GABA-IR、PV-IR、CB-IR神经元在癫痫发作过程中也有不同程度的丢失 ,丢失很可能也是以凋亡形式为主     

The histological validation of post mortem magnetic resonance imaging-determined hippocampal volume in Alzheimer's disease

For 11 AD cases and four normal elderly controls, post mortem volumes of the hippocampal subdivisions were calculated by using magnetic resonance imaging and histological sections. After at least six weeks of fixation in formalin, brains were examined on a 1.5-T Philips Gyroscan imager producing T1-weighted coronal images with a 3-mm slice thickness. Brains were then processed and embedded in paraffin. Serial coronal sections, 3 mm apart and stained with Cresyl Violet, were used for the planimetry and unbiased estimation of the total numbers of neurons in the hippocampal subdivisions. For all 15 cases, magnetic resonance imaging- and histology-based measurements were performed along the whole rostrocaudal extent of the hippocampal formation and included three subvolumes: (i) the hippocampus (CA1-CA4 and the dentate gyrus); (ii) hippocampus/subiculum; and (iii) hippocampus/parahippocampal gyrus. After controlling for shrinkage, strong correlations were found between magnetic resonance imaging and histological measurements for the hippocampus (r = 0.97, P < 0.001), hippocampus/subiculum (r = 0.95, P < 0.001) and hippocampus/parahippocampal gyrus (r = 0.89, P < 0.001). We also calculated the total number of neurons in the hippocampus and hippocampus/subiculum subvolumes. Strong correlations between the magnetic resonance imaging subvolumes and neuronal counts were found for the hippocampus (r = 0.90, P < 0.001) and the hippocampus/subiculum subvolume (r = 0.84, P < 0.001). We conclude that very accurate volumetric measurements of the whole hippocampal formation can be obtained by using a magnetic resonance imaging protocol. Moreover, the strong correlations between magnetic resonance imaging-based hippocampal volumes and neuronal numbers suggest the anatomical validity of magnetic resonance imaging volume measurements.     

Effects of estrogen and raloxifene on neuroglia number and morphology in the hippocampus of aged female mice

Hormone replacement therapy with the gonadal steroid estrogen or synthetic agents such as raloxifene, a selective estrogen receptor modulator, may affect cellular function in brains of postmenopausal women. In vitro studies suggest that 17beta estradiol and raloxifene can alter the microglial and astrocyte expression of immuno-neuronal modulators, such as cytokines, complement factors, chemokines, and other molecules involved in neuroinflammation and neurodegeneration. To directly test whether exogenous 17beta estradiol and raloxifene affect the number of glial cells in brain, C57BL/6NIA female mice aged 20-24 months received bilateral ovariectomy followed by s.c. placement of a 60-day release pellet containing 17beta estradiol (1.7 mg), raloxifene (10 mg), or placebo (cholesterol). After 60 days, numbers of microglia and astrocytes were quantified in dentate gyrus and CA1 regions of the hippocampal formation using immunocytochemistry and design-based stereology. The results show that long-term 17beta estradiol treatment in aged female mice significantly lowered the numbers of astrocytes and microglial cells in dentate gyrus and CA1 regions compared with placebo. After long-term treatment with raloxifene, a similar reduction was observed in numbers of astrocytes and microglial cells in the hippocampal formation. These findings indicate that estrogen and selective estrogen receptor modulators can influence glial-mediated inflammatory pathways and possibly protect against age- and disease-related neuropathology.     

Role of Estrogen in Regulation of Morphology and Synaptic Connectivity in Female Rat Subiculum

Estrogen is reported to exert neuroprotective influences on the cornu ammonis as well as the dentate gyrus, two of the three components of the hippocampal memory system. Subiculum, the third and the output component of this system, plays a vital role in retrieval of previously learnt information (recall tasks). We undertook these studies to understand estrogen's role in regulating the synaptic connectivity, neurotransmission and neural degeneration in subiculum. For this, we used brains of aged (16–18 months) post-estropausal female Wistar rats, and compared them with those of adult (4–5 months) ovary-intact, ovariectomized, ova riectomized-vehicle treated and ova riectomized-estrogen treated rats. The vehicle (sesame oil) and estrogen therapy. (17β estradiol, E2) were administered as daily subcutaneous injections (0.1 mg/kg of E2 in 0.1 ml vehicle) for 30 days. Serum estradiol assay was done to determine the levels of circulating serum estradiol levels. Brains were processed for Cresyl Violet, Golgi staining and Immunohistochemical studies [using anti-synaptophysin antibody].Our results indicate that estrogen deficiency (induced by normal ageing or by ovariectomy) results in subicular neuronal degenerative changes, decreased synaptic connectivity and reduced dendritic arborization, most of which are reasonably reversed with estrogen replenishment. These studies suggest a unique role of estrogen in preventing and even reversing the senile neurodegenerative changes in female subiculum.     

金雀异黄酮对去卵巢大鼠脑抗氧化作用的影响

目的研究金雀异黄酮对去卵巢大鼠大脑抗氧化作用的影响,为使用植物雌激素防治女性更年期后老年性痴呆提供依据。方法40只3月龄雌性SD大鼠,随机分为假手术组、去卵巢对照组、金雀异黄酮组和苯甲酸雌二醇组,给予相应手术和治疗。术后6周分析大鼠额叶、颞叶、海马和基底前脑的SOD和MDA值。结果假手术组颞叶和海马的SOD值低于基底前脑(P<0.05);额叶和颞叶的MDA值高于海马和基底前脑(P<0.05);去卵巢对照组基底前脑的SOD值显著低于假手术组、金雀异黄酮组和苯甲酸雌二醇组(P<0.05),MDA值显著高于假手术组、金雀异黄酮组和苯甲酸雌二醇组(P<0.05);假手术组、金雀异黄酮组及苯甲酸雌二醇组之间SOD值和MDA值差异无统计学意义(P>0.05)。结论去卵巢对照组大鼠基底前脑抗氧化能力显著降低,氧化损伤程度显著升高,金雀异黄酮替代治疗可增加去卵巢大鼠基底前脑的抗氧化能力,降低基底前脑的氧化损伤,可用于女性更年期后老年性痴呆的防治。