枸杞对慢性心理应激大鼠海马CA3区锥体细胞的影响

目的探讨枸杞对慢性心理应激大鼠海马CA3区锥体细胞数量和形态的影响。方法选择健康成年SD大鼠96只,雌雄各半,随机分为8组。采用慢性复合应激的方法,通过HE染色方法观察枸杞对实验大鼠海马锥体细胞的影响。结果应激组、枸杞低剂量+应激组和枸杞高剂量+应激组血清皮质醇含量明显升高,与对照组比较,差异有统计学意义(P0.01)。枸杞低剂量组、枸杞中剂量组、枸杞高剂量组、枸杞中剂量+应激组和枸杞高剂量+应激组血清皮质醇含量明显降低,与应激组比较,差异有统计学意义(P0.01)。应激组CA3区细胞数明显减少,与对照组比较,差异有统计学意义(P0.01)。枸杞低剂量+应激组、枸杞中剂量+应激组和枸杞高剂量+应激组CA3区细胞数明显增多,与应激组比较,差异有统计学意义(P0.05)。光镜下观察应激组细胞排列不整齐、间隙增宽,部分胞核固缩呈三角形或不规则形;枸杞低剂量组、枸杞中剂量组、枸杞高剂量组海马细胞形态与对照组基本相同,枸杞低剂量+应激组、枸杞中剂量+应激组、枸杞高剂量+应激组海马细胞形态介于对照组和应激组之间。结论慢性心理应激引起血清皮质醇含量升高,导致大鼠海马CA3区锥体细胞受损;枸杞能够降低应激大鼠的血清皮质醇水平,减缓应激损伤海马,对受损伤的神经元具有一定的保护作用。     

规律运动对慢性心理应激大鼠海马锥体细胞形态的影响

目的探讨规律运动对慢性心理应激大鼠海马锥体细胞形态的影响。方法建立慢性心理应激模型结合6周游泳训练后,采用HE染色和透射电镜技术观察海马锥体细胞形态和结构变化。结果应激组大鼠海马CA3区锥体细胞胞浆凝固、胞核固缩、染色质边集,核膜皱褶,核内外可见空泡变性,线粒体变性、嵴数量明显减少,粗面内质网模糊不清、网腔局部扩张;30min运动组与对照组相似,60min运动组较对照组轻度改变,应激+30min运动组变化介于对照组和应激组之间;应激+60min运动组与应激组相似。结论心理应激导致大鼠海马CA3区锥体细胞形态和超微结构改变,适量运动调节可减缓慢性心理应激引起的损伤,对海马锥体细胞有保护作用。     

运动对慢性心理应激大鼠影响

目的研究运动对慢性心理应激大鼠血清皮质醇、白细胞介素-2（IL-2）、白细胞介素-6（IL-6）的影响。方法建立慢性心理应激模型,进行6周游泳训练：测定各组大鼠血清皮质醇、IL-2、IL-6的含量。结果（1）应激组大鼠血清皮质醇含量显著高于对照组（P〈0.01）,血清IL-2I、L-6水平显著低于对照组（P〈0.01）;（2）30min运动组血清IL-2水平显著高于对照组（P〈0.01）,60 min运动组血清IL-2I、L-6水平均显著高于对照组（P〈0.01）,血清皮质醇含量显著低于对照组（P〈0.05）;（3）应激＋30 min运动组、应激＋60 min运动组血清皮质醇含量显著低于应激组（P〈0.01）,IL-2和IL-6水平显著高于应激组（P〈0.01）。结论慢性心理应激引起大鼠下丘脑-垂体-肾上腺皮质（HPA）轴释放过量皮质醇,使免疫功能受到抑制;适量运动能够调节HPA轴适应性,降低皮质醇的过量释放,维护免疫功能稳定。     

枸杞对慢性心理应激大鼠海马CA3区谷氨酸受体NMDAR2表达的影响

目的通过测定枸杞对慢性心理应激大鼠海马CA3区谷氨酸受体NMDAR2表达水平的影响,探讨慢性心理应激对大鼠中枢海马损伤的分子机制。方法健康成年SD大鼠96只,雌雄各半,随机分为8组:对照组;心理应激组;枸杞低、中、高剂量组(分别枸杞干果2.0、4.0和6.0g/kg);枸杞低、中、高剂量组+心理应激组。枸杞干果浸泡喂饲,慢性心理应激采用复合应激(束缚应激+噪声应激)法。采用免疫组织化法检测海马组织各亚区NMDAR2的表达。结果 (1)经单因素方差分析,与对照组相比,心理应激组、枸杞低剂量+心理应激组大鼠血清皮质醇含量明显升高(P<0.01);与心理应激组相比,枸杞中剂量+心理应激组和枸杞高剂量+心理应激组大鼠血清皮质醇含量显著降低(P<0.01或P<0.05)。(2)经免疫组化法检测,NMDAR2免疫反应阳性细胞多呈棕黄色,广泛分布在大鼠海马各个亚区。与对照组相比,心理应激组大鼠海马CA1区、CA3区和DG区NMDAR2表达均明显增多(P<0.01);与心理应激组相比,枸杞低剂量+心理应激组、枸杞中剂量+心理应激组和枸杞高剂量+心理应激组大鼠海马CA1区、CA3区和DG区NMDAR2表达均明显减少(P<0.01)。结论慢性心理应激使大鼠HPA轴功能紊乱,释放过量皮质醇,导致海马组织NMDAR2表达增加;枸杞可以有效调节大鼠HPA轴,降低应激大鼠血清皮质醇水平,使海马组织NMDAR2表达降低,减轻脑损害。     

高频电磁场对雌性大鼠海马细胞形态学的影响

目的 研究短期及亚慢性暴露高频电磁场(HF-EMF,30MHz,电场强度0～1600V/m)对雌性大鼠海马细胞凋亡及超微结构的影响,探讨HF-EMF对雌性大鼠海马细胞损伤的作用.方法 选用清洁级Wistar雌性大鼠120只,按体重随机分为10组,大鼠置于HF-EMF辐射源,频率30MHz,各组辐射剂量平均电场强度为0、25、100、400、1600 V/m,短期实验是连续辐射8 h/d,连续3 d后取海马;亚慢性实验是8 h,d,每周连续5 d,停2 d,共暴露56 d后取海马,HE染色法光学显微镜下观察海马细胞病理改变,脱氧核苷酸转移酶介导的dUTP缺口末端标记法(TUNEL)系统检测海马细胞凋亡情况,电子显微镜下观察细胞的超微结构.结果 (1)短期实验:各组大鼠海马细胞病理改变不明显,细胞凋亡率的差异无统计学意义(P>0.05).(2)亚慢性实验:与对照组(0.052%±0.016%)比较,400、1600 V/m组DG区颗粒细胞凋亡率(分别为0.165%±0.049%、0.189%±0.049%)明显增加,差异有统计学意义(P<0.01);光学显微镜下可见,400、1600 V/m组大鼠海马细胞核固缩明显增多,电子显微镜下可见,100 V/m以上剂量组的神经元细胞超微结构有轻微改变,1600 V/m组大鼠海马神经元细胞超微结构改变较明显.结论 短期暴露HF-EMF(30 MHz,25～1600 V/m)对雌性大鼠海马细胞形态学影响不明显;亚慢性高剂量暴露HF-EMF(400～1600 V/m)对大鼠海马细胞形态学影响较明显,低剂量暴露(25～100 V/m)对大鼠海马细胞形态学影响不明显.     

高频电磁场对雌性大鼠海马细胞形态学的影响

Objective To analyze the effects of high-frequency electromagnetic field (HF-EMF, 30 MHz,0～1600 V/m) on the apoptosis and ultramicrostructure of the hippocamp and demonstrate the cytotoxici-ty of hippocamp. Methods 120 Wistar female adult rats were randomly divided into ten groups based on body weight with different levels of 30 MHz electromagnetic field (0, 25, 100, 400, 1600 V/m) for eight hours daily. Five group rats were irradiated for three days. The other five group rats were irradiated for fifty-six days. Weekly the rats were continuously exposed five days. The apoptotic rate of the hippocamp was detected with TUNEL System. Meanwhile, the ultramicrostructure was observed with the transmission electron microscope. Results (1)There was no significant difference on the apoptotic rate and pathological change of the hip-pocamp cell between the exposure and the control groups through short term experiment (P>0.05). (2) The apoptotic rate of the granulocyte on the DG campus of the hippocamp in the 400 V/m group and the 1600 V/m group (0.165%±0.049%, 0.189%±0.049% respectively) were increased significantly(P<0.01) through inferior chronic experiment compared with the control group (0.052%±0.016%). Along with the increase of radiation dose, the ultramicrostructure of the neuron cell appeared more abnormal cells. Especially there were marked change on the neuron in the 1600 V/m group. Conclusions There is no association between cell apoptotic rate of the hippocamp and short period exposure to HF-KMF(30 MHz,25～1600 V/m). However inferior chron-ic exposures to HF-EMF might induce the cytotoxicity, especially in the high dose exposure (1600 V/m) under our experiment.     

高频电磁场对雌性大鼠海马细胞形态学的影响

Objective To analyze the effects of high-frequency electromagnetic field (HF-EMF, 30 MHz,0～1600 V/m) on the apoptosis and ultramicrostructure of the hippocamp and demonstrate the cytotoxici-ty of hippocamp. Methods 120 Wistar female adult rats were randomly divided into ten groups based on body weight with different levels of 30 MHz electromagnetic field (0, 25, 100, 400, 1600 V/m) for eight hours daily. Five group rats were irradiated for three days. The other five group rats were irradiated for fifty-six days. Weekly the rats were continuously exposed five days. The apoptotic rate of the hippocamp was detected with TUNEL System. Meanwhile, the ultramicrostructure was observed with the transmission electron microscope. Results (1)There was no significant difference on the apoptotic rate and pathological change of the hip-pocamp cell between the exposure and the control groups through short term experiment (P>0.05). (2) The apoptotic rate of the granulocyte on the DG campus of the hippocamp in the 400 V/m group and the 1600 V/m group (0.165%±0.049%, 0.189%±0.049% respectively) were increased significantly(P<0.01) through inferior chronic experiment compared with the control group (0.052%±0.016%). Along with the increase of radiation dose, the ultramicrostructure of the neuron cell appeared more abnormal cells. Especially there were marked change on the neuron in the 1600 V/m group. Conclusions There is no association between cell apoptotic rate of the hippocamp and short period exposure to HF-KMF(30 MHz,25～1600 V/m). However inferior chron-ic exposures to HF-EMF might induce the cytotoxicity, especially in the high dose exposure (1600 V/m) under our experiment.     

慢性温和应激对大鼠海马区胶质细胞蛋白影响

目的 探讨慢性温和应激对抑郁模型大鼠海马星形胶质细胞内胶质纤维酸性蛋白(GFAP)和酸性钙结合蛋白(S100β)表达的影响.方法 选用Wistar成年雄性大鼠30只,应用慢性不可预知的温和应激(CUMS)建立抑郁模型,随机分为对照组和抑郁组,刺激时间8周,跳台实验测试大鼠的学习记忆能力,免疫组化法检测海马GFAP和S100β蛋白的表达.结果 抑郁组GFAP和S100β免疫反应产物阳性细胞计数值(32.85±5.57,35.64±9.84)均较对照组(27.03±5.47,27.44±9.46)显著增高(P<0.05),细胞形态有所改变;大鼠跳台实验成绩显示,随着应激时间的延长,反应期明显延长,潜伏期缩短,而错误次数从第4周开始明显增加.结论 慢性温和应激可影响大鼠的学习记忆能力,诱发抑郁并引起海马GFAP和S100β蛋白表达的增加.     

慢性心理应激对大鼠行为及血清皮质醇影响及运动的调节作用

目的了解慢性心理应激对大鼠行为和血清皮质醇的影响,探讨适宜运动对慢性心理应激的调节作用。方法采用慢性束缚心理应激模型,将60只成年雄性Sprague-Dawley(SD)大鼠随机均分为正常对照组、应激模型组、30 min运动组、60 min运动组、应激 30 min运动组及应激 60 min运动组,通过对大鼠的行为观察、悬尾试验及旷场活动试验的测定,动态观察各组大鼠在应激及运动调节前后的行为学方面的变化;采用放射免疫学方法测定大鼠应激及运动调节前后血清中皮质醇浓度的改变。结果应激模型组的血清皮质醇浓度最高,与正常对照组比较,差异有统计学意义(P<0.05)。应激 30 min运动组及应激 60 min运动组的血清皮质醇浓度均低于应激模型组(P<0.05),而与正常对照组及运动对照组比较,差异无统计学意义(P>0.05);旷场实验结果显示,应激模型组的中央格停留时间最长,穿格次数、直立次数及修饰时间最少,与正常对照组、应激 30 min运动组及应激 60 min运动组比较,差异有统计学意义(P<0.05);悬尾实验结果显示,慢性心理应激模型组的静止时间较长、挣扎次数较少,与正常对照组大鼠比较,差异有统计学意义(P<0.05)。结论适宜运动调节能够有效抵抗机体皮质醇的过量释放,减缓心理及行为的应激水平。     

运动对慢性应激大鼠不同脑区ERK-CREB表达影响

目的探讨运动对慢性应激大鼠不同脑区磷酸化细胞外信号调节蛋白激酶(p-ERK)-环磷酸腺苷反应元件结合蛋白(p-CREB)信号通路的作用。方法雄性SD大鼠40只随机分为对照组、应激组、运动+应激组及运动组;采用慢性束缚方式建立应激模型;运动方式为无负重游泳;免疫组织化学方法检测海马、额叶皮层、纹状体p-ERK/p-CREB表达变化。结果应激组海马、额叶皮层、纹状体区p-ERK表达分别为(11.25±3.68),(19.26±6.03),(18.22±4.70),p-CREB表达分别为(2.13±0.38),(2.32±0.49),(2.91±0.54),对照组各脑区p-ERK表达分别为(22.53±2.96),(30.64±5.89),(29.46±4.54),p-CREB表达分别为(3.32±0.33),(3.56±0.44),(3.94±0.51),应激组表达低于对照组,差异有统计学意义(P<0.01);运动+应激组海马、额叶皮层p-ERK表达为(17.59±4.30),(25.31±5.57),p-CREB表达为(2.76±0.40),(2.98±0.53),表达高于应激组,差异有统计学意义(P<0.05)。结论运动锻炼作为一种有效的防护和干预手段,可能通过上调ERK-CREB通路提高慢性应激状态下的学习记忆能力。     

Transitory gliosis in the CA3 hippocampal region in rats fed on a ketogenic diet

The ketogenic diet (KD) is a high-fat, low-protein and low-carbohydrate diet included as medical practice against seizure disorders, particularly in children refractory to conventional anti-epileptic drug treatment. However, the molecular basis of its therapeutic effect remains unclear. Considering the growing evidence for the importance of glial cells for neuronal development, survival and plasticity, we investigated astrocyte protein markers from KD fed rats, in different regions of hippocampus, a brain structure commonly involved in seizure disorders. We found a transitory increment in GFAP in the CA3 hippocampal region, but not in the CA1 or dentate gyrus (DG). This change was not accompanied by changes in S100B content or glutamine synthetase activity. In order to evaluate possible hippocampal involvement we investigated spatial-cognitive behavior using the water-maze task. No changes were observed. This transitory gliosis in CA3 could be related to, or precede, other associated changes proposed to be involved in the attenuation of seizure disorders. These data reinforce the importance of hippocampal astrocytes as cell targets during KD feeding.     

Transitory gliosis in the CA3 hippocampal region in rats fed on a ketogenic diet

Abstract

The ketogenic diet (KD) is a high-fat, low-protein and low-carbohydrate diet included as medical practice against seizure disorders, particularly in children refractory to conventional anti-epileptic drug treatment. However, the molecular basis of its therapeutic effect remains unclear. Considering the growing evidence for the importance of glial cells for neuronal development, survival and plasticity, we investigated astrocyte protein markers from KD fed rats, in different regions of hippocampus, a brain structure commonly involved in seizure disorders. We found a transitory increment in GFAP in the CA3 hippocampal region, but not in the CA1 or dentate gyrus (DG). This change was not accompanied by changes in S100B content or glutamine synthetase activity. In order to evaluate possible hippocampal involvement we investigated spatial-cognitive behavior using the water-maze task. No changes were observed. This transitory gliosis in CA3 could be related to, or precede, other associated changes proposed to be involved in the attenuation of seizure disorders. These data reinforce the importance of hippocampal astrocytes as cell targets during KD feeding.     

核转录因子κB和小清蛋白阳性神经元在丙戊酸钠孤独症模型鼠海马CA1区的表达

目的 建立丙戊酸钠(valproic acid,VPA)孤独症动物模型,观察核转录因子κB和小清蛋白阳性神经元在VPA孤独症模型鼠海马CA1区的表达,探讨孤独症可能的发病机制,为完善其治疗方案提供理论依据。方法 按Schneider方法制作VPA孤独症动物模型,采用免疫组化和图像分析技术检测孤独症模型鼠海马CA1区核转录因子κB和小清蛋白阳性神经元的表达。结果 与正常对照组比较,孤独症模型组海马CA1区核转录因子κB阳性神经元数目增加(4.67±1.56 vs 3.00±1.54,t=2.639,P=0.015);海马CA1区小清蛋白表阳性神经元数目增加(5.33±0.99 vs 2.83±1.27,t=5.378,P=0.000)。结论 孤独症的发病可能与海马CA1区核转录因子κB和小清蛋白的表达水平有关。     

蛋氨酸胆碱对染铅大鼠海马神经元影响

目的 探讨蛋氨酸胆碱对刚断乳SD大鼠铅染毒后海马神经元形态及超微结构损伤的改善作用。方法 40只SPF级SD雄性大鼠随机分为5组:空白组、染铅组、蛋氨酸胆碱组、铅+低、高剂量蛋氨酸胆碱组,4和8周后分别麻醉动物,尾尖采血,原子吸收法测血铅含量;心脏灌注内固定,取海马做石蜡切片、硫堇染色观察海马神经元形态结构,戊二醛再固定,透射电镜观察超微结构。结果 铅染毒4、8周后,染铅组大鼠血铅含量分别升高至(274.85±19.51)、(294.32±11.00)μg/L,与染铅组比较,铅+高剂量蛋氨酸胆碱组血铅含量(187.25±16.02,192.68±14.17)μg/L明显降低,差异有统计学意义(P<0.05);硫堇染色和透射电镜结果显示,4周时海马神经元无明显改变;8周时CA1区神经元有缺失、坏死,细胞数量由每3个视野(光镜400×)(306.00±43.05)个减少至(234.86±20.88)个,且超微结构发生改变,蛋氨酸胆碱干预后形态和结构均得到改善,且存在剂量-效应关系。结论 铅对海马神经元形态和结构损伤出现较晚,蛋氨酸胆碱可改善铅染毒大鼠海马神经元的形态和结构损伤。     

慢性铅暴露对幼鼠海马CA1区长时程增强的影响

OBJECTIVE: To study the effects of chronic exposure to lead on learning and memory function in young rats, based on the plasticity of their synapse function. METHODS: With method of extracellular glass microelectrode recording, effects of exposure to lead at different concentrations on long term potentiation (LTP) induction in hippocampal CA(1) area of young rats in vivo were observed. RESULTS: Incidence of LTP and mean amplitude increase after application of high frequency stimulus decreased, as blood lead in rats reached (3.28 +/- 0.88) micromol/L, even causing long term depression. To the exposed rats, their mean increase ratio in their population spike amplitudes after high-frequency stimulation correlated inversely with their brain lead load. CONCLUSION: Chronic lead exposure could damage in vivo LTP induction and maintenance in the CA(1) area in hippocampus of rats, and the severity of damage increased with the extent of exposure to lead.     

断乳前丰富环境对大鼠空间参考记忆及海马CA1区神经元形态学的影响

[目的]探讨断乳前丰富环境对大鼠空间参考记忆和海马CA1区锥体神经元树突结构可塑性的影响.[方法]3窝共30只新生SD大鼠,每窝均随机分为对照组(n=14)和实验组(n=16).实验组大鼠生后10日龄至24日龄每天予以丰富环境暴露20 min,对照组大鼠除不予以丰富环境暴露外,余处理均与实验组相同.生后5周,两组大鼠予以Morris水迷宫测试评估空间参考学习记忆能力.同时,采用高尔基染色法观察断乳前丰富环境对大鼠海马CA1区锥体神经元树突形态的影响,并进行统计分析. [结果]在Morris水迷宫测试中,丰富环境组大鼠的空间参考记忆成绩显著高于对照组.在训练阶段,两组到达平台的平均时间均呈下降趋势.在测试阶段,丰富环境组大鼠的空间记忆保持能力优于对照组[(31.41±5.91)%vs(26.17±5.66)%,F=4.470,P<0.05).高尔基染色显示断乳前丰富环境增加海马CA1区锥体神经元顶树突和基树突的长度[(3.46±0.65)mm vs(2.48±0.57)mm;(2.30±0.48)mm vs(1.93±0.53)mm;F=29.838,P<0.01;F=6.222;P<0.053. [结论]断乳前丰富环境可以促进大鼠空间参考记忆能力,增加海马CA1区锥体神经元顶树突和基树突的长度.     

脑源性神经营养因子对皮质酮诱导新生大鼠海马神经元凋亡的保护作用

目的 探讨脑源性神经营养因子(brain-derived neurotrophic factor, BDNF)对皮质酮诱导新生大鼠海马神经元凋亡的保护作用。 方法 原代培养新生大鼠海马神经元,并分成对照组、皮质酮组、皮质酮+BDNF组,皮质酮造模浓度为100 μM,分别采用浓度为0.1、1、10、25、50、100 ng/ml的BDNF干预,造模及干预时间均为24 h。CCK8法测定细胞活力,分析BDNF的最佳作用浓度,流式细胞术和 Hoechst荧光染色检测细胞的凋亡情况,免疫印迹(Western-blotting)法检测细胞Caspase-3、Caspase-9的表达水平。 结果 与对照组比较,皮质酮组神经元凋亡率由(10.7±1.2)%上升为(33.9±3.5)%(t=18.707,P<0.01),胞体透亮,部分细胞核碎裂,凋亡特征明显,Caspase-3、Caspase-9表达显著上调(t₁=27.098,P₁＜0.01;t₂=24.311,P₂＜0.01);BDNF作用后,细胞活力显著上升,在浓度为1 ng/ml时与皮质酮组比较差异有统计学意义(t=3.562,P＜0.05),分析得出BDNF最佳浓度为48 ng/ml;BDNF(48 ng/ml)干预完成后,细胞凋亡率较皮质酮组下降至(18.7±2.1)%,差异有统计学意义(t=11.478,P＜0.01),细胞形态基本恢复正常,Caspase-3、Caspase-9表达明显下调(t₁=17.341,P₁=0.002;t₂=14.993,P₂=0.005)。 结论 BDNF能有效拮抗皮质酮诱导的海马神经元凋亡,保护神经元细胞。     

刘瑞莹;胡丹丹;王涤新;

目的研究运动对慢性心理应激大鼠行为及血清皮质醇、IL-2、IL-8的影响方法建立慢性心理应激模型,进行6周游泳训练;通过旷场实验及悬尾实验观察各组大鼠在应激及运动调节前后的行为学变化;测定血清皮质醇、IL-2、IL-8的含量。结果（1）应激组大鼠血清皮质醇含量显著高于对照组（P〈0．01）,而IL-2、IL-8含量显著低于对照组（P〈0．05）;60min运动组血清皮质醇含量显著低于对照组（P〈0．05）,而血清IL-2和IL-8含量均显著高于对照组（P〈0．05）;应激＋30min运动组、应激＋60min运动组血清皮质醇含量显著低于应激组（P〈0．01）,IL-2和IL-8含量显著高于应激组（P〈0．01）。（2）旷场实验结果显示,与对照组相比,应激组大鼠中央格停留时间最长,穿格次数、直立次数及修饰时间最少,有统计学意义;与应激组相比,应激＋30min运动组及应激＋60min运动组均存在统计学意义（P〈0．01）。（3）悬尾实验结果显示,应激组大鼠静止时间最长,挣扎次数最少,与对照组相比有统计学意义（P〈0．01）;与应激组相比,应激＋30min运动组及应激＋60min运动组均存在统计学意义（P〈0．01）。结论慢性心理应激可引起大鼠行为异常,可能与HPA轴释放过量皮质醇,从而使免疫功能受到抑制有关。适量运动能够调节HPA轴适应性,降低皮质醇的过量释放,维持免疫功能稳定,调节心理应激水平。