吗啡依赖戒断焦虑大鼠海马突触结构的可塑性

目的:通过对吗啡依赖戒断后焦虑模型大鼠海马突触形态结构可塑性的观察,探讨其焦虑情绪的发生机制。方法:采用剂量递增法建立大鼠吗啡依赖戒断后焦虑模型。取海马CA1、CA3区组织进行透射电镜观察和体视学定量分析。结果:焦虑模型组大鼠海马CA1、CA3区均可见突触密集、数量多,但体积比较小。CA1区突触数密度、面密度均较对照组显著增高,而突触连接带平均面积显著减小;CA3区突触数密度、面密度较对照组同样明显增高,而突触连接带平均面积明显减小。结论:突触形态结构的可塑性变化可能参与了吗啡依赖戒断后焦虑情绪的发生。     

老年记忆减退大鼠海马CA1区锥体细胞和神经毡线粒体的视学研究

目的 应用电镜观察老年记忆损害大鼠海马线粒体的开矿学改变。方法 青年（３月龄）和老年（２６月龄）ＳＤ大鼠经Ｍｏｒｒｉｓ水迷宫测试后,以青年鼠平均逃潜伏期正常值上限的９５％和９９％上限值 蚧将老年鼠分为老年记忆正常组和老年记忆减退组。和透射电镜观察海马ＣＡ１锥体细胞和神经毡内线粒本视学参数。结果 １．与青年大鼠相比,老年记忆正常大鼠海马线粒体数密度（Ｎｖ）、比膜面（Ｓｍ）、比表面（Ｓｓ）下降显著,但     

雌激素撤退大鼠海马和基底前脑神经元线粒体超微结构的观察

目的观察在去卵巢后海马CA1区锥体细胞和基底前脑外侧隔核神经元线粒体超微结构的变化情况。方法雌性SD大鼠8只,随机分为正常对照组(4只)和OVX组(4只)。采用去卵巢(ovariectomized,OVX)SD大鼠模型,OVX组行双侧卵巢切除术,术后第12天,常规固定、包埋,透射电镜观察海马CA1区锥体细胞和基底前脑外侧隔核神经元线粒体结构。结果与正常对照组相比,OVX组海马CA1区锥体细胞部分线粒体肿胀较明显,嵴出现断裂和脱落,部分线粒体空泡化;但基底前脑线粒体基本正常。结论大鼠去势12d后,其海马易感区神经元线粒体超微结构发生改变,并可能引起神经元退变,为女性更年期后老年性痴呆易感性增加提供了有益的线索。     

去卵巢对大鼠海马神经元线粒体超微结构的影响

目的:观察去卵巢(OVX)后不同时相点上大鼠海马CA1区锥体细胞线粒体超微结构的变化。方法:雌性SD大鼠分为:正常对照组、OVX-6 d组、OVX-9 d组、OVX-12 d组和OVX-15 d组,正常对照组未给予任何处理即处死,其余4组分别于术后第6、9、12、15天处死进行电镜观察并做体视学分析。结果:随着去卵巢后天数的延长,线粒体变性逐渐明显,OVX-12 d组线粒体的体积密度(Vv)、平均表面积(S)、粒子分散度(Cλz)和比表面(δ)与其他组相比,差异显著或非常显著,但OVX-15 d组有所减轻。另外,各组的数密度(Nv)相比差别均无统计学意义。结论:大鼠去卵巢后海马CA1区神经元线粒体第12天变性最明显,提示线粒体变性可能导致女性更年期后神经元退变或与阿尔茨海默病发病有关。     

植物雌激素对去卵巢大鼠海马神经元线粒体超微结构的保护作用

采用去卵巢(OVX)SD大鼠模拟女性绝经后神经元的退变来观察雌激素、植物雌激素对海马神经元线粒体的保护作用。雌性SD大鼠分为5组:(1)正常对照组;(2)去卵巢对照组;(3)雌激素治疗组;(4)金雀异黄酮治疗组;(5)依普拉芬治疗组,并于术后12d取材进行超微结构观察和体视学定量分析。结果显示:(1)去卵巢后海马神经元的线粒体肿胀明显,嵴断裂明显,空泡化显著;3个治疗组细胞和线粒体相对于去卵巢对照组均有明显改善;(2)与去卵巢对照组相比较,3个治疗组线粒体的体积密度(Vv)、平均直径(D)、平均表面积(S)明显减小(P<0.05);3个治疗组的比表面(δ)、数密度(Nv)和粒子分散度(Cλz)较去卵巢对照组明显增大(P<0.05)。以上结果表明:雌激素和植物雌激素对去卵巢后大鼠的海马神经元线粒体具有保护作用。本研究结果为雌激素和植物雌激素以线粒体为靶点防治女性更年期后神经元的退变及老年性痴呆可能的作用机制提供了一定的形态学资料。     

三七总皂甙对大鼠脑出血灶周围神经元线粒体超微结构的影响

目的:研究三七总皂甙对大鼠脑出血后神经元线粒体超微结构的保护作用。方法:用鼠脑立体定位仪将肝素化Ⅶ型胶原酶注入实验大鼠基底节区制备大鼠脑出血模型;用透射电镜观察线粒体超微结构并对其进行体视学分析;用免疫组织化学方法检测Bcl-2和Bax蛋白表达;利用神经功能评分标准检测各组大鼠的神经行为学变化。结果:神经行为学检测,模型组大鼠的神经功能评分分值升高,治疗组大鼠分值较模型组下降(P0.01);线粒体体视学分析,治疗组线粒体的比表面积、比膜面积、体密度、数密度均较模型组增大,差异有统计学意义(P0.01);与模型组比较,治疗组Bax的阳性表达降低(P0.01)、Bcl-2的阳性表达升高(P0.01),Bcl-2/Bax蛋白比值增高。结论:三七总皂甙能够保护脑出血后神经元线粒体,促进神经功能恢复。     

吗啡对大鼠海马神经元钾、钙通道的作用

吗啡是常见的阿片类镇痛药,长时间应用可导致吗啡耐受和依赖,其作用机制十分复杂。海马中同时包含μ,κ,δ阿片受体,与吗啡耐受及依赖有一定的关系,并参与机体的痛觉调制过程,因而了解吗啡对海马神经元离子通道的作用对阐明吗啡的镇痛、耐受及依赖机制具有重要的理论及实际意义。本文报导吗啡对培养的海马神经元电压门控性钾、钙     

糖尿病大鼠海马毛细血管超微结构观察

目的:观察实验性糖尿病大鼠海马毛细血管超微结构改变。方法:将成年SD大鼠随机分为正常对照组（5只）、糖尿病组（12只,经腹腔注射链脲佐菌素制备实验性糖尿病大鼠模型）、糖尿病治疗组（12只,给予部分成模大鼠长效胰岛素2-3U/日治疗,使血糖低于10mmol/L）,于成模第3月末及第6月末灌注固定取脑,透射电镜下观察海马CA1区毛细血管。结果:糖尿病大鼠海马毛细血管基底膜增厚、内皮细胞与周细胞退变。6月组病变较3月组更显著,各治疗组改变较轻微。结论:糖尿病可导致大鼠海马毛细血管基底膜增厚,早期应用胰岛素治疗可延缓其发生。     

脑缺血大鼠海马超微结构的形态定量研究

对大鼠双侧颈总动脉夹闭2小时,经透射电镜观察海马,用Weibel氏形态定量法分别测量了海马1区和3区的线粒体和突触的表面积密度(Svi)、表面积—体积比(Si/Vi),并与对照组进行了比较。结果表明:缺血时海马1区受损较严重,表现为线粒体体积缩小,数量减少,Svi下降;突触数量有增多的趋势,但突触的Svi与Si/Vi变化不明显。缺血组海马3区受损较轻,线粒体和突触的结构基本正常,其Svi、Si/Vi与对照组差别不显著,提示了3区对缺血有较强的耐受性。     

衰老晚期海马CA1区锥体细胞线粒体改变──电镜定量分析

选用成年健康SD大鼠20只.分为青年组（3个月）和老年组（34～36个月）二个实验组，每组10只。应用透射电镜结合体视学方法观察并比较了海马CA1区锥体细胞线粒体的变化，结果如下：和青年组相比，老年组肿胀、变性线粒体增多，体视学分析显示老年组线粒体密度和平均体积增大，线粒体数密度和比表面减少，线粒体切面积大小频数分布图向右侧迁移，显示到衰老晚期较小的线粒体数减少.较大的线粒体数增多。本研究结果表明，衰老晚期海马CA1区锥体细胞线粒体严重退变，进入失代偿状态。     

大鼠脑出血后神经元线粒体的体视学分析及黄芪的神经保护作用研究

目的　探讨黄芪对大鼠脑出血后神经元线粒体的保护作用。 方法　用Ⅶ型胶原酶脑内注入法制作大鼠脑出血模型,利用Narrow-alley Test检测各组大鼠的神经行为学指标;用透射电镜观察各组大鼠脑出血灶周围神经元线粒体的超微结构并对其进行体视学分析;用免疫组织化学方法检测Caspase-3蛋白表达。 结果　神经行为学检测,模型组大鼠的不对称分值明显升高,治疗组大鼠不对称分值较模型组明显下降;神经元线粒体体视学分析,与模型组相比,治疗组线粒体的体密度、数密度、比表面积和比膜面积均较模型组增大,差异有显著性（P＜0.05);与模型组比较,治疗组Caspase-3的阳性表达明显降低（P＜0.01)。 结论　黄芪能够减轻出血后神经元线粒体的损伤,抑制神经元凋亡,促进神经功能恢复。     

Histopathological study on neuroapoptotic alterations induced by etomidate in rat hippocampus

In human, there is substantial neurogenesis in the hippocampus that is implicated in memory formation and learning. These new-born neurons can be affected by neuropathological conditions. Anesthesia and surgical procedures are associated with postoperative cognitive changes particularly, impaired memory and learning. Therefore, the aim of this study was to evaluate the possible neurodegenerative effects of etomidate in rat hippocampus. Thirty male Wistar rats weighing 250 ± 30 g were randomly divided into 3 groups: 1) Etomidate group; four times 20 mg intraperitoneal injection with 1-h intervals, 2) Control group; the equal volume of normal saline, and 3) Normal group; without any intervention. 6 h after the last injection, the brains were removed and processed according to routine histological methods. TUNEL assay and toluidine blue staining were performed to evaluate neuro-histopathological changes in different regions of hippocampus. Our results showed that the number of TUNEL positive cells and dark neurons (DNs) in etomidate group were significantly higher in the CA1, CA2, CA3, and dentate gyrus (DG) of hippocampus compared with the control and normal groups (p < 0.05). While, there was no significant difference between the various regions of hippocampus in control and normal groups. Our findings showed that etomidate can increase apoptotic cells and dark neurons induction in different regions of hippocampus mainly in DG.     

胍丁胺对吗啡镇痛耐受大鼠脊髓和海马锌含量变化的影响

目的观察胍丁胺对吗啡耐受大鼠脊髓和海马组织中锌(Zn2+)含量变化的影响。方法采用SD成年雄性大鼠,建立慢性吗啡耐受大鼠模型,用热水甩尾法测定甩尾潜伏期观察痛反应的变化。动物随机分为4组:生理盐水(NS-NS)组、吗啡(NS-Mor)组、胍丁胺(Ag-NS)组、胍丁胺-吗啡(Ag-Mor)组。用原子吸收光谱法测定各组大鼠的脊髓和海马Zn2+含量。结果胍丁胺(10mg/kg)与吗啡合用具有显著的抗吗啡耐受作用,并阻断慢性吗啡耐受引起的脊髓和海马Zn2+含量的降低(P<0.001)。结论逆转吗啡耐受时脊髓和海马组织中Zn2+含量的减少,可能是胍丁胺抗吗啡耐受的机制之一。     

The impact of maternal separation on adult mouse behaviour and on the total neuron number in the mouse hippocampus

The maternal separation paradigm has been applied to C57BL/6J mice as an animal developmental model for understanding structural deficits leading to abnormal behaviour. A maternal separation (MS) model was used on postnatal day (PND) 9, where the pups were removed from their mother for 24 h (MS24). When the pups were 10 weeks old, the level of anxiety and fear was measured with two behavioural tests; an open field test and an elevated plus maze test. The Barnes platform maze was used to test spatial learning, and memory by using acquisition trials followed by reverse trial sessions. The MS24 mice spent more time in the open arms of the elevated plus maze compared to controls, but no other treatment differences were found in the emotional behavioural tests. However, in the reverse trial for the Barnes maze test there was a significant difference in the frequency of visits to the old goal, the number of errors made by the MS24 mice compared to controls and in total distance moved. The mice were subsequently sacrificed and the total number of neurons estimated in the hippocampus using the optical fractionator. We found a significant loss of neurons in the dentate gyrus in MS mice compared to controls. Apparently a single maternal separation can impact the number of neurons in mouse hippocampus either by a decrease of neurogenesis or as an increase in neuron apoptosis. This study is the first to assess the result of maternal separation combining behaviour and stereology.     

皮质发育障碍大鼠海马神经元的体视学方法定量研究

目的　用体视学方法计数比较X射线制作的大脑皮质发育障碍（DCDs）模型大鼠海马神经元数量变化和测量海马体积变化。 方法　选择2月龄正常SD大鼠和DCDs模型鼠各5 只,取脑后石蜡包埋、连续冠状切片。根据均匀系统随机抽样原则,从含海马结构的切片中随机抽取一组切片,组织化学染色,在体视学设备下计数大鼠海马CA1、CA3和DG区的神经元数目和测量海马体积。 结果　正常大鼠单侧海马CA1、CA3和DG区的神经元的数目分别是（8.35×104±1.44×104）、（8.23×104±1.60×104）和（1.43×105±2.24×104）,DCDs模型大鼠单侧海马CA1、CA3和DG区的神经元的数目分别是（3.70×104±　1.96×104）、（3.57×104±1.47×104）和（6.86×104±4.85×104）;正常大鼠和DCDs模型鼠单侧海马的体积分别是(14.18±1.52)mm3和(8.49±3.41)mm3。DCDs大鼠海马结构各亚区的神经元数量和海马体积均较正常鼠明显减小（P＜0.05）。 结论　X射线制作的DCDs模型鼠海马CA1、CA3和DG的神经元数目和海马体积都较正常大鼠减少。     

Microglia and neurons in the hippocampus of migratory sandpipers

The semipalmated sandpiper Calidris pusilla and the spotted sandpiper Actitis macularia are long- and short-distance migrants, respectively. C. pusilla breeds in the sub-arctic and mid-arctic tundra of Canada and Alaska and winters on the north and east coasts of South America. A. macularia breeds in a broad distribution across most of North America from the treeline to the southern United States. It winters in the southern United States, and Central and South America. The autumn migration route of C. pusilla includes a non-stop flight over the Atlantic Ocean, whereas autumn route of A. macularia is largely over land. Because of this difference in their migratory paths and the visuo-spatial recognition tasks involved, we hypothesized that hippocampal volume and neuronal and glial numbers would differ between these two species. A. macularia did not differ from C. pusilla in the total number of hippocampal neurons, but the species had a larger hippocampal formation and more hippocampal microglia. It remains to be investigated whether these differences indicate interspecies differences or neural specializations associated with different strategies of orientation and navigation.     

An immunocytochemical study of calpain II in the hippocampus of rats injected with kainate

The distributions of the kainate/dl-alpha-amino-3-hydroxy-5-methylisoxazolepropionic acid (KA/AMPA) receptors GluR1 and calcium-activated neutral protease II (calpain II) in the hippocampus of normal and kainate-lesioned rats were studied by immunocytochemistry. There was a reduction in GluR1 immunoreactivity and a slight increase in calpain II immunoreactivity on the dendrites of pyramidal neurons in CA fields affected by the kainate at 18 h postinjection. Calpain II immunoreactivity was associated with amyloid fibrils at electron microscopy. These fibrils were most often intracellular, in membrane-bound profiles, some of which were contacted by axon terminals and were identified as degenerating dendrites. There was extensive destruction of mitochondrial membranes in degenerating profiles, and accumulations of amyloid fibrils were often localised in mitochondria in a calpain-positive profile. This was unlike other, calpain-negative degenerating profiles, that contained tubulovesicular profiles or multilamellar bodies, where mitochondrial membranes were preserved. Many more calpain-positive profiles were observed at electron microscopy 6 days after kainate injection. The enzyme was present in macrophages and astrocytes in lesioned areas.     

吗啡成瘾戒断对大鼠海马CA1区P-CREB表达的影响

目的探讨吗啡成瘾戒断后大鼠海马CA1区P-CREB的表达变化。方法48只健康雄性成年SD大鼠,随机分为实验组和对照组:实验组腹腔注射吗啡起始剂量5mg/kg,1d2次,逐日递增,连续10d;对照组:以生理盐水代替吗啡。停药后7d、14d和21d处死。用免疫组织化学方法(ABC法)检测海马CA1区P-CREB的表达,图像分析系统测定阳性反应产物的平均灰度值。结果P-CREB表达在7d、14d实验组与对照组相比表达上调(P<0.05),21d与对照组比较无显著差异(P>0.05)。结论海马CA1区CREB磷酸化在吗啡依赖的形成中发挥作用。     

Mitochondrial dysfunction and ultrastructural damage in the hippocampus of pilocarpine-induced epileptic rat

Mitochondrial dysfunction has been implicated as a contributing factor in epileptic seizures. Present studies were carried out to decipher seizure-dependent changes in mitochondrial function and ultrastructure in the chronic condition of temporal lobe epilepsy (TLE) induced by pilocarpine in rat hippocampus. Enzyme assay revealed significant depression of the activity of mitochondrial- and nuclear-encoded cytochrome oxidase (COX). Conversely, the activity of nuclear-encoded succinate dehydrogenase (SDH) remained unchanged. Discernible mitochondrial ultrastructural damage, varying from swelling to disruption of membrane, was observed in the hippocampus. Quantitative real-time PCR and Western blotting showed the expression of mitochondrial-encoded COX subunit III (COXIII) dropped significantly during the chronic seizure activity; the corresponding expression of COX subunit IV (COXIV) displayed no significant change. Most likely, our results suggest that dysfunction of mitochondrial COX respiratory enzyme and mitochondrial ultrastructural damage in the hippocampus are associated with prolonged seizure during experimental TLE and mitochondria are more vulnerable to epilepsy.