海马CA3区琥珀酸脱氢酶和酸性磷酸酶的老龄性表达

目的:探讨老龄大鼠海马CA3区神经元琥珀酸脱氢酶(SDH)和酸性磷酸酶(ACP)表达的改变.方法:Wistar大鼠随机分为2组:青年组(3～5月龄)、老龄组(27月龄),各组分别进行海马CA3区神经元酶细胞化学显色,并对其含量进行显微图像分析及数据处理.结果:青年组海马CA3区神经元SDH含量较高,老龄组较青年组减少了32.3%;青年组海马CA3区神经元ACP含量较低,老龄组较青年组增加了41.5%.结论:老龄大鼠海马CA3区神经元SDH和ACP的表达发生了明显的改变,本研究为老龄大鼠SDH和ACP活性的改变提供了可靠的实验依据.     

人参皂甙对老龄大鼠Meynert核及大脑皮质脑源性神经营养因子含量的影响

目的观察Meyaert核（NBM）与大脑皮质神经元内脑源性神经营养因子（BDNF）的老龄性改变,探讨人参皂甙对BDNF蛋白含量表达的影响.方法雌性Wistar大鼠随机分为青年组、老龄组及老龄给药组.老龄给药组大鼠自18个月开始饲以人参皂甙至27月龄.对各组NBM及大脑皮层神经元进行免疫组织化学法染色、图像分析及统计学处理.结果老龄组大鼠NBM及大脑皮质内BDNF含量均显著低于青年组（P＜0.01）.给药组大脑皮质内BDNF含量较老龄组显著增加（P＜0.01）,但NBM内BDNF含量变化无统计学意义.结论老龄大鼠NBM及大脑皮质内BDNF含量显著降低,给予人参皂甙可显著提高大脑皮质神经元BDNF的表达.     

老年性痴呆模型大鼠海马结构nNOS神经元的变化

目的　研究老年性痴呆模型大鼠海马结构nNOS神经元的变化情况。方法　用 15月龄老年Wistar大鼠以D 半乳糖腹腔注射 4周加上鹅膏蕈氨酸 (ibotenicacid ,IBO)脑内Meynert核注射造模 ,然后运用免疫组织化学方法检测大鼠海马CA1、CA3和齿状回nNOS神经元数目。结果　老年性痴呆模型大鼠海马CA1、CA3和齿状回nNOS阳性神经元数目及其积分光密度较正常老年组和正常青年组有明显减少的趋势 ,组间比较有差异显著性。结论　大鼠海马结构nNOS神经元的减少是老年性痴呆病的主要病理变化之一     

人参皂甙降低老龄大鼠海马CA3区神经元酸性磷酸酶活性的光,电镜观察

实验选用健康的Ｗｉｓｔａｒ大鼠，应用光、电镜酶细胞化学方法结合图像分析观察了老龄大鼠海马ＣＡ３区神经元的酸性磷酸酶的衰老变化，同时对比观察了人参皂甙对上述改变的影响。光镜结果表明：酸性磷酸酶含量老龄组比青年组增加３６％，而给药组较老龄组减少２０％；电镜结果表明：酸性磷酸酶反应产物面积老龄组比青年组增加５倍，给药组较老龄组减少２．５倍（Ｐ〈０．０１）。光、电镜结果均提示老龄时海马ＣＡ３区神经元酸性磷     

慢性脑缺血大鼠海马CA_1区中的BDNF表达

为了观察慢性脑缺血时海马CA1区中BDNF的表达变化,探讨缺血性脑损伤及修复机制。我们将Wistar大鼠双侧颈总动脉结扎制成慢性脑缺血动物模型。分为三组:正常对照组、慢性脑缺血30d和120d组。分别于术后30d和120d处死动物,行BDNF免疫组化染色,计数各组大鼠海马CA1区中的阳性神经元数。结果显示:(1)在对照组的海马CA1区可见BDNF较强的表达;(2)在慢性脑缺血30d时,海马CA1区BDNF的表达高于缺血120d组及对照组(P<0.05)。而120d时,海马CA1区BDNF的表达与对照组无显著性差异(P>0.05)。结果提示:(1)在正常大鼠海马CA1区有BDNF表达,能维持神经元的存活;(2)慢性脑缺血时,BDNF在海马CA1区的表达先升后降。     

人参皂甙降低老龄大鼠海马CA3区神经元酸性磷酸酶活性的光、电镜观察

实验选用健康的Wistar大鼠,应用光、电镜酶细胞化学方法结合图像分析观察了老龄大鼠海马CA3区神经元的酸性磷酸酶的衰老变化,同时对比观察了人参皂甙对上述改变的影响.光镜结果表明:酸性磷酸酶含量老龄组比青年组增加36%,而给药组较老龄组减少20%;电镜结果表明:酸性磷酸酶反应产物面积老龄组比青年组增加5倍,给药组较老龄组减少2.5倍(P<0.01).光、电镜结果均提示老龄时海马CA3区神经元酸性磷酸酶活性增高,而人参皂甙具有降低酸性磷酸酶活性的作用.     

脑室内注射BDNF抗体对大鼠海马NOS表达的影响

探讨脑室内注射脑源性神经营养因子 (BDNF)抗体阻断内源性BDNF对大鼠海马一氧化氮合酶 (NOS)阳性神经元的影响。脑室内注射BDNF抗体一周后 ,采用Morris水迷宫进行行为检测 ;并用NADPH 黄递酶组化染色方法观察海马NOS阳性神经元数目的变化。与对照组相比 ,实验组大鼠空间学习和记忆能力明显下降 (P <0 0 1) ;实验组大鼠海马CA1区NOS阳性神经元数目 (38 37± 5 2 3)明显少于对照组 (4 9 5 3± 5 74 ) (P <0 0 1) ;实验组DG区NOS阳性神经元数目 (4 8 77± 5 5 1)明显少于对照组 (6 0 4 0± 7 39) (P <0 0 1)。脑室内注射BDNF抗体可导致大鼠空间学习记忆能力下降 ,海马NOS阳性神经元数目减少 ,提示BDNF对学习和记忆的影响可能与海马NOS阳性神经元数目的变化有关     

马桑内酯诱导惊厥发作海马结构内神经元损伤的观察

目的：观察国产中药制剂马桑内酯诱导惊厥发作后，海马结构内神经元损害的范围和特征。方法：采用SD大鼠，马桑内酯单次腹腔内注射诱发惊厥，在发作后不同时间点取脑，行H＆E染色和GFAP免疫组化染色观察海马结构内神经元和神经胶质细胞的改变。结果：海马结构内有显著的神经元损伤。其损伤次序表现为：齿状回、门区和CA3区、CA1区，损伤区周围有反应性星形胶质细胞增生。结论：马桑内酯致惊厥发作后海马神经元的损害与兴奋性细胞毒制剂海仁酸致惊厥具有相似的病理学改变特征，提示国产中药制剂马桑内酯致惊厥与兴奋性细胞毒有关。     

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。     

不同成熟期大鼠戊四氮反复惊厥模型与癫痫发病机制研究

目的：观察新生大鼠、成熟大鼠反复惊厥后海马结构的变化及NF-κB 表达，探索未成熟脑癫痫发病机制。 方法： 对生后10 d、60 d（P10、P60）两实验组大鼠用戊四氮(PTZ)反复腹腔注射5 d，设P10、P60生理盐水对照组；硫堇染色对CA1、CA3、DG及门区神经元进行细胞计数, 观察海马神经元坏死及凋亡；免疫组化技术检测NF-κB的表达；Timm组织化学染色观察苔藓纤维发芽并评分。 结果： (1) P10实验组与对照组比较，海马齿状回、CA1、CA3区无明显神经元丢失，DG区颗粒细胞数在实验组(23.25±3.06) 多于对照组（16.25±1.58）；P60实验组CA1、CA3区神经元计数（8.22±1.88、5.62±1.68）明显少于对照组（6.31±1.50、3.62±1.40），DG区无明显差异；（2）两实验组CA3区锥体层苔藓纤维发芽均多于对照组，但P60(3.25±1.03)较P10（1.50±0.92）更明显；（3）P10、P60实验组NF-κB 表达高于对照组，且P10组较P60组更为明显（P<0.05）。 结论： 新生大鼠致痫后海马神经元无明显丢失，脑内NF-κB 表达增加，可能是未成熟脑对惊厥性脑损伤具有耐受性的重要神经生物学基础。     

Spatial memory training modifies the expression of brain-derived neurotrophic factor tyrosine kinase receptors in young and aged rats

Aging leads to alterations in the function of the hippocampus, a brain structure largely involved in learning processes. This study aimed at examining the basal levels and the impact of a learning-associated task on brain-derived neurotrophic factor (BDNF), on BDNF full-length catalytic receptor (TrkB.FL) and on the truncated forms (TrkB.T1 and TrkB.T2) receptor expression (mRNA and protein) in the hippocampus of young (2-month-old) and aged (24-month-old) Wistar rats. Spatial memory was evaluated using a water-maze procedure involving visible and invisible platform location learning. Aged rats showed higher latencies during the first two training days but rapidly exhibited learning performances similar to patterns observed with young rats. Real-time PCR measurements showed that aged rats had significantly higher levels of trkB.FL mRNAs than young rats under basal conditions. In situ hybridization analysis indicated that the highest level of trkB.FL mRNA (mRNA encoding for TrkB.FL receptor) was noted in the dentate gyrus, and in the CA2 and CA3 hippocampal layers. In contrast, there was no marked difference in trkB.T1 signal in any hippocampal region. Training induced a significant reduction in trkB.FL mRNA levels solely in aged rats. In contrast, in young and aged rats, trkB.T2 mRNA levels were significantly increased after training. Measurements of proteins revealed that learning significantly increased TrkB.FL content in aged rats. Untrained aged rats presented higher levels of BDNF and brain-derived neurotrophic factor precursor (proBDNF) proteins than young rats. Training strongly increased precursor BDNF metabolism in young and aged rats, resulting in increased levels of proBDNF in the two groups but in old rats the mature BDNF level did not change. This study shows that Wistar rats present age-related differences in the levels of BDNF and TrkB isoforms and that spatial learning differentially modifies some of these parameters in the hippocampus.     

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。     

Effects of chronic forced swim stress on hippocampal brain-derived neutrophic factor (BDNF) and its receptor (TrkB) immunoreactive cells in juvenile and aged rats

A type of stress stimulation and age are claimed to affect the expression of brain-derived neurotrophic factor (BDNF) and its receptor - tyrosine kinase B (TrkB) in the hippocampal regions differentially. This study aimed to explore the influence of chronic (15 min daily for 21 days) forced swim stress (FS) exposure on the BDNF and TrkB containing neurons in the hippocampal CA1, CA3 pyramidal cell layers and dentate gyrus (DG) granule cell layer in juvenile (P28) and aged (P360) rats. An immunofluorescence (-ir) method was used to detect BDNF-ir and TrkB-ir cells. Under chronic FS exposure, in the group of juvenile rats a significant decrease in the density of BDNF immunoreactive neurons was observed in CA1 and DG (P less than <0.001), unlike CA3, where it remained unaltered just as the density of TrkB-ir cells in CA1 and DG, but in CA3 the number of TrkB-ir cells was found to grow (P less than 0.05) in comparison with control groups. After chronic FS exposure of aged (P360) rats, the density of BDNF-ir and TrkB-ir cells did not decline in any of the subregions of the hippocampus. In all subfields of the hippocampus, the denseness of BDNF-positive neurons was significantly higher in P360 stressed group, compared with P28 stressed group, but the density of TrkB-ir fell more markedly in P360 than in P28. In conclusion, chronic FS stress influenced the number of BDNF and TrkB immunoreactive neurons only in juvenile animals. The age of rats tested in the chronic forced swim test was a decisive factor determining changes in the density of BDNF-ir and TrkB-ir in the hippocampal structures.     

单侧磨牙缺失对老年记忆减退大鼠海马结构的影响

为了探讨单侧缺牙对不同学习记忆能力老年大鼠海马结构的影响 ,本研究用 Morris水迷宫筛选出老年记忆减退鼠和老年记忆正常鼠 ,拔除单侧磨牙后 2个月 ,观察其海马结构神经元和胆碱能纤维密度的影响变化。结果显示 :(1)海马 CA1 区锥体细胞密度 :老年记忆减退鼠拔牙组较对照组 (未拔牙 )明显下降 (P<0 .0 1) ;(2 )海马 CA1 区 ACh E阳性纤维密度 :老年记忆减退鼠拔牙组和老年记忆正常鼠拔牙组均较对照组 (未拔牙 )明显下降 (P<0 .0 1)。结果提示 :单侧磨牙缺失可加速老年性学习记忆减退鼠海马结构的损害。     

卵巢移植对去势大鼠海马神经元形态及BDNF表达的影响

目的:观察卵巢移植后大鼠海马神经元形态变化及BDNF的表达,评价卵巢移植对海马神经元的保护效果。方法:制作去势SD大鼠模型,卵巢移植干预组在其肾被膜下移植出生3 d内的SD乳鼠卵巢,外源性激素干预组隔天给予腹腔注射乙烯雌酚1 mg/kg。分别于干预后的4、7、14和28 d,电镜观察海马神经元形态及免疫组化观察BDNF的表达情况。结果:卵巢移植后随着移植时间的延长血清雌激素和孕酮水平都逐步升高,乙烯雌酚组仅雌激素水平升高;各组海马神经元形态逐渐好转,移植14 d和28 d组海马神经元的形态改善优于同期给药组。卵巢移植组和乙烯雌酚组BDNF的表达在各区均有所升高,卵巢移植14 d和28 d组CA3区尤为明显(P<0.05)。结论:卵巢移植可以恢复卵巢内分泌功能,对海马神经元形态有改善作用及促进BDNF的表达,其神经元保护作用优于单纯乙烯雌酚干预组。     

Age-related changes in glutamate release in the CA3 and dentate gyrus of the rat hippocampus

The present studies employed a novel microelectrode array recording technology to study glutamate release and uptake in the dentate gyrus, CA3 and CA1 hippocampal subregions in anesthetized young, late-middle aged and aged male Fischer 344 rats. The mossy fiber terminals in CA3 showed a significantly decreased amount of KCl-evoked glutamate release in aged rats compared to both young and late-middle-aged rats. Significantly more KCl-evoked glutamate release was seen from perforant path terminals in the DG of late-middle-aged rats compared young and aged rats. The DG of aged rats developed an increased glutamate uptake rate compared to the DG of young animals, indicating a possible age-related change in glutamate regulation to deal with increased glutamate release that occurred in late-middle age. No age-related changes in resting levels of glutamate were observed in the DG, CA3 and CA1. Taken together, these data support dynamic changes to glutamate regulation during aging in subregions of the mammalian hippocampus that are critical for learning and memory.     

酒精处理影响青春期大鼠海马CA1区BDNF和TrkB的表达

为探讨青春期饮酒致学习记忆力下降的可能机制,本研究观察了青春期大鼠酒精处理后海马CA1区脑源性神经营养因子(BDNF)和酪氨酸激酶受体B(TrkB)的表达变化。实验选用30d龄SD雄性大鼠,以25%的酒精按8g/kg/d灌胃,连续灌7d,动物分别在停酒后0d,3d,7d和14d处死;对照组以等量生理盐水代替酒精按同样方法处理。用免疫组织化学方法(ABC法)检测海马CA1区BDNF和TrkB的表达,Motic3.2图像分析系统测定免疫阳性产物的平均灰度值。结果显示,BDNF的表达在停酒后0d和14d,实验组与相应对照组相比差异无显著性(P>0.05);3d显著升高(P<0.05);7d明显下降(P<0.05)。TrkB的表达在停酒后0d,3d,7d,实验组与相应对照组相比差异无显著性(P>0.05);14d显著下降(P<0.05)。以上结果提示,BDNF表达的相对不足可能是青春期饮酒致学习记忆力持续性下降的原因之一。     

自噬水平变化对心脏骤停心肺复苏后大鼠海马神经元凋亡的影响

目的探讨自噬水平变化对心脏骤停心肺复苏(CA/CPR)后大鼠海马神经元凋亡的影响。方法将40只大鼠随机分为假手术组(sham)、CA/CPR模型组(model)、雷帕霉素(Rapa)组(CA/CPR+Rapa)及3-甲基腺嘌呤(3-MA)组(CA/CPR+3-MA)。采用呼气末夹闭气管窒息法复制大鼠CA/CPR动物模型,分别给予自噬激动剂Rapa 0.2 mg/kg及自噬抑制剂3-MA 10 mg/kg进行干预。采用神经功能缺陷评分(NDS)评价CA/CPR大鼠神经功能;用TUNEL染色法检测大鼠海马神经元的凋亡变化;用RT-PCR和Western blotting法检测大鼠海马内微管蛋白轻链3(LC3)、Beclin-1、Bax、Bcl-2及Caspase-3 mRNA和蛋白的表达水平。结果与假手术组比较,CA/CPR模型组大鼠NDS评分明显降低;海马神经元TUNEL染色阳性细胞数明显增多,凋亡率显著升高;海马内LC3、Beclin-1、Caspase-3、Bax表达上调,Bcl-2表达下调(P<0.05,P<0.01)。与模型组比较,CA/CPR+Rapa大鼠NDS评分明显降低,而海马神经元凋亡率明显有所增加,海马内LC3、Beclin-1、Caspase-3、Bax表达明显上调,而Bcl-2表达则明显有所下降;CA/CPR+3-MA大鼠NDS评分明显升高,而海马神经元凋亡率下降,海马内LC3、Beclin-1、Caspase-3、Bax表达明显下调,而Bcl-2表达则有所升高(P<0.05,P<0.01)。结论 CA/CPR后自噬水平升高促进海马神经元凋亡,自噬水平降低抑制海马神经凋亡,两者相互作用共同参与CA/CPR的病理过程。