阿尔茨海默病转基因小鼠早期记忆功能障碍与氧化应激损伤关系的实验研究

Objective To investigate the spatial learning and memory ability,the changes of indicators of oxidative stress,and their relationship in transgenic APP/PS1 mouse model of Alzheimer's disease(APP/PS1 mice). Methods The spatial learning and memory ability were assessed by Morris water maze test,and the activity or content of SOD, GSH-PX, MDA, and protein carbonyl in brain tissues were measured by ELISA in the APP/PS1 and wild type (WT) mice. Furthermore, the relationship between the learning and memory performances and the indicators of oxidative stress was examined. Results No significant difference in the spatial learning was observed between the APP/PS1 and WT mice (P ＜0. 05). The spatial memory which was measured as the percentage of time traveling in the targeted quadrant to the total traveling time was significantlydeclined in the APP/PS1 mice(29. 02 ± 4. 27) % as compared with the WT mice(47. 39 ± 6. 01) %(t =0. 000 ,P ＜0. 05). The percentage of length of traveling in the targeted quadrant to the total length traveled was significantly lower in the APP/PS1 mice(28. 85 ±3.77)% compared with the WT mice(46. 70 ±5.60)% (t =0. 000,P ＜0. 05). These findings indicated that the spatial learning and memory ability of APP/PS1 mice was significantly decreased compared to WT mice. There was no significant difference in activity or content of SOD,GSH-PX,and MDA in brain tissues between the APP/PS1 and WT mice (P ＜ 0. 05), while the content of protein carbonyl was significantly elevated in the APP/PS1 mice (2. 67 ±0. 19) than in the WT mice (2. 38 ±0. 15)(t = 0. 008, P ＜ 0. 05). Correlation analysis revealed that the elevated protein carbonyl was negatively correlated with the percentage of length traveled in the targeted quadrant(r = - 0. 639, P ＜ 0. 05) and the percentage of time traveled in the targeted quadrant(r = - 0. 636 ,P ＜ 0. 05). Conclusion The spatial memory impairment was negatively correlated with the elevated protein carbonyl in the APP/PS1 mice, suggesting that protein carbonylation caused by oxidative stress might play an important role in the development of memory impairment in the early stage of Alzheimer's disease.     

转基因阿尔茨海默病小鼠脑内炎症反应的诱发因素研究

目的 观察炎症反应在转基因阿尔茨海默病(AD)小鼠脑组织中的变化,探讨AD脑内炎症反应的诱发因素.方法 选用3、12个月龄转人β-淀粉样前体蛋白/早老素-1(APP/PS1)基因AD小鼠及正常野生型(WT)小鼠,分别应用免疫组织化学法和ELISA法观察脑内淀粉样斑块、炎性因子[白细胞介素(IL)-1β、IL-6、肿瘤坏死因子(TNF)α、前列腺素(PGE)2]的变化.结果 3个月龄APP/PS1基因AD小鼠脑组织中无淀粉样斑块沉积,未发现激活的星型胶质细胞和小胶质细胞,炎性因子IL-1β、IL-6、TNFα、PGE2的含量与WT小鼠差异无统计学意义(P均＞0.05).12个月龄转APP/PS1基因AD小鼠脑组织中有大量淀粉样斑块沉积,并伴有大量激活的星型胶质细胞和小胶质细胞,炎性因子IL-1β、IL-6、TNFα、PGE2的含量[分别为(56.02±9.04)、(8.66±0.83)、(97.48±26.58)、(72.18±21.01)ng/g]较WT小鼠[分别为(29.81±6.03)、(7.73±0.74)、(61.98±11.11)、(37.23±10.96)ng/g]及3个月龄转APP/PS1基因AD小鼠[分别为(30.05±3.53)、(7.43±1.17)、(59.34±10.47)、(42.56±5.93)ng/g]显著增加(P＜0.05或P＜0.01).结论 在淀粉样斑块形成之前,转APP/PS1基因AD小鼠脑组织中无明确的炎症反应;而淀粉样斑块沉积之后,脑组织中有显著的炎症反应;AD脑内炎症反应与淀粉样斑块形成密切相关,淀粉样蛋白(Aβ)沉积是导致脑内炎症反应的直接诱发因素.

Abstract：

Objective To observe the changes of cerebral inflammation-related markers in brain of a transgenic mouse model of Alzheimer's disease (AD) ,and to determine the causative factor to the development of cerebral inflammation in AD. Methods 3- and 12-month-old β-amyloid protein precursor ( APP)/presenilin (PSI) transgenic mice and age-matched wild-type mice (WT) were used in the study. The changes of amyloid plaques, inflammatory factors ( interleukin 1β ( IL-1β ); interleukin 6( IL-6 ); tumor necrosis factor α (TNFα) ;prostaglandin E2 (PGE2)) in the brains among these mice were measured by immunohistochemistry and ELISA. Results Immunohistochemical analysis revealed that no amyloid plaques and activated astrocytes as well as microglia were observed in the 3-month-old APP/PS1 mice. There were no significant differences in the levels of inflammatory factors (IL-1β, IL-6 ,TNFα,and PGE2) between the 3-month-old APP/PS1 and WT mice ( Ps ＞ 0. 05 ). However, abundant amyloid plaques accompanied by a remarkable increase of activated astrocytes and microglia were found in the brain of the 12-month-old APP/PS1 mice. The levels of inflammatory factors (IL-1β,IL-6,TNFα, and PGE2 ) were significantly increased in the 12-month-old APP/PS1 mice ([56. 02 ±9. 04] ng/g, [8. 66 ±0.83] ng/g, [97.48 ±26.58] ng/g, [72. 18 ±21.01] ng/g) than in the WT mice ([29. 18 ± 6. 03] ng/g, [7. 73 ± 0. 74] ng/g, [61.98 ±11.11] ng/g, [37. 23 ± 10. 96] ng/g) and the 3-month-old APP/PS1 mice ( [30. 05 ± 3.53] ng/g, [7.43 ± 1.17] ng/g, [59.34 ± 10. 07] ng/g, [42. 56 ±5.93] ng/g) (P＜0.05,or P＜0.01,respectively). Conclusion This study demonstrates that the APP/PS1mice did not show cerebral inflammation before the appearance of amyloid plaques, and exhibited remarkable inflammation after amyloid plaque deposition. These findings suggest that the induction of cerebral inflammation is tightly associated with amyloid plaque formation, and deposition of amyloid-beta protein (Aβ) may be the direct causative factor to the development of cerebral inflammation in AD.     

运动对快速老化小鼠海马β-淀粉样蛋白及淀粉样蛋白前体蛋白的影响

目的 研究运动对快速老化小鼠(SAMP)8海马β-淀粉样蛋白(Aβ)及淀粉样蛋白前体蛋白(APP)的影响,以探讨运动改善阿尔茨海默病(AD)学习记忆功能的机制.方法 将40只3月龄SAMP8小鼠采用单纯随机抽样法分为运动组和对照组,运动组进行跑笼运动训练,第1个月每周训练5 d,每天10 min,第2个月每周训练5 d,每天20 min.2个月后采用H-E染色观察2组小鼠海马神经元形态改变;免疫组织化学技术检测海马Aβ免疫阳性细胞的表达;逆转录-聚合酶链反应(RT-PCR)技术检测海马APP mRNA的表达水平.结果 对照组5月龄SAMP8小鼠海马部分神经元细胞变性、死亡,核浓缩,空泡变性;运动组偶有神经元细胞变性、死亡,大部分细胞形态正常.运动组海马Aβ免疫阳性细胞表达水平为(0.192±0.018),明显低于对照组的(0.274±0.017)(P＜0.05);运动组海马APP mRNA表达水平为(0.168±0.059),明显低于对照组的(0.574±0.115)(P＜0.01).结论 运动可以延缓SAMP8小鼠海马神经元变性,降低海马Aβ及APP的表达,这可能是运动改善AD学习记忆功能的重要机制之一.

Abstract：

Objective To explore the effects of movement on hippocampal β-amyloid protein ( Aβ ) and amyloid precursor protein (APP) in senescence-accelerated and senescence-prone (SAMP8) mice, and the mechanism by which movement improves learning and memory in mice with a model of Alzheimer's disease. Methods Forty 3-month-old SAMP8 mice were divided randomly into a movement group and a control group. The movement group was trained with a running wheel 10 min daily, 5 days a week in the first month, and 20 min daily in the second month. Morphological changes in the hippocampus were observed under the microscope after HE staining. The expression of Aβ in the hippocampus was detected by immumohistochemical methods and APP mRNA expression was detected by RT-PCR two months later. Results HE staining showed neuron degeneration and death, chromatin condensation and vacuolar degeneration in the hippocampus of the 5-mouth-old SAMP8 mice of the control group. The movement group showed less neuron degeneration and death, and the morphology of most cells was normal The expression of Aβ in the hippocampus of the 5-month-old SAMP8 mice in the movement group was significantly lower than that in the control group. APP mRNA expression levels in the movement group were also significantly lower.Conclusions Movement can delay neuron degeneration and down-regulate Aβ and APP mRNA expression levels in the hippocampus of SAMP8 mice. It may be an important mechanism by which movement improves learning and memory in mice with a model of Alzheimer's disease.     

电针配合神经生长因子对脑缺血大鼠学习记忆能力的影响

Objective To observe the effect of nerve growth factor(NGF)and electro-acupuncture(EA) on learning and memory in rats with cerebral ischemia.Methods An experimental model of cerebral ischemiareperfusion was established in 40 rats,who were then randomly divided into a model group,a sham operated group,a NGF group,an acupuncture group and a NGF plus acupuncture group.Three weeks were allowed for the recovery of the blood-brain barrier lesion caused by ischemia-reperfusion before intravenous injection of NGF(10μg/kg,once daily for 15 days)via the vena caudalis.In the two acupuncture groups,this was administered in combination with EA at the Baihui(DU20)and Yamen(DU15)acupoints(frequency 100 Hz,2 mA,20 min/time,once daily for 15 days).Morris' water maze test was used to assess any changes in spatial learning and memory abilities.Results The ischemic rats showed significant learning and memory disorders compared with the sham-operated group.In the NGF group,the rats' learning and memory abilities did not impmve significantly compared with the model group and the EA group.Significantly better learning was observed in the NGF+EA group compared with the model group,the EA group and the NGF group.Conclusion NGF combined with EA can improve the learning and memory abilities of rats with learning and memory dysfunction caused by cerebral ischemia-repedusion.     

电针配合神经生长因子对脑缺血大鼠学习记忆能力的影响

Objective To observe the effect of nerve growth factor(NGF)and electro-acupuncture(EA) on learning and memory in rats with cerebral ischemia.Methods An experimental model of cerebral ischemiareperfusion was established in 40 rats,who were then randomly divided into a model group,a sham operated group,a NGF group,an acupuncture group and a NGF plus acupuncture group.Three weeks were allowed for the recovery of the blood-brain barrier lesion caused by ischemia-reperfusion before intravenous injection of NGF(10μg/kg,once daily for 15 days)via the vena caudalis.In the two acupuncture groups,this was administered in combination with EA at the Baihui(DU20)and Yamen(DU15)acupoints(frequency 100 Hz,2 mA,20 min/time,once daily for 15 days).Morris' water maze test was used to assess any changes in spatial learning and memory abilities.Results The ischemic rats showed significant learning and memory disorders compared with the sham-operated group.In the NGF group,the rats' learning and memory abilities did not impmve significantly compared with the model group and the EA group.Significantly better learning was observed in the NGF+EA group compared with the model group,the EA group and the NGF group.Conclusion NGF combined with EA can improve the learning and memory abilities of rats with learning and memory dysfunction caused by cerebral ischemia-repedusion.     

电针配合神经生长因子对脑缺血大鼠学习记忆能力的影响

Objective To observe the effect of nerve growth factor(NGF)and electro-acupuncture(EA) on learning and memory in rats with cerebral ischemia.Methods An experimental model of cerebral ischemiareperfusion was established in 40 rats,who were then randomly divided into a model group,a sham operated group,a NGF group,an acupuncture group and a NGF plus acupuncture group.Three weeks were allowed for the recovery of the blood-brain barrier lesion caused by ischemia-reperfusion before intravenous injection of NGF(10μg/kg,once daily for 15 days)via the vena caudalis.In the two acupuncture groups,this was administered in combination with EA at the Baihui(DU20)and Yamen(DU15)acupoints(frequency 100 Hz,2 mA,20 min/time,once daily for 15 days).Morris' water maze test was used to assess any changes in spatial learning and memory abilities.Results The ischemic rats showed significant learning and memory disorders compared with the sham-operated group.In the NGF group,the rats' learning and memory abilities did not impmve significantly compared with the model group and the EA group.Significantly better learning was observed in the NGF+EA group compared with the model group,the EA group and the NGF group.Conclusion NGF combined with EA can improve the learning and memory abilities of rats with learning and memory dysfunction caused by cerebral ischemia-repedusion.     

电针配合神经生长因子对脑缺血大鼠学习记忆能力的影响

Objective To observe the effect of nerve growth factor(NGF)and electro-acupuncture(EA) on learning and memory in rats with cerebral ischemia.Methods An experimental model of cerebral ischemiareperfusion was established in 40 rats,who were then randomly divided into a model group,a sham operated group,a NGF group,an acupuncture group and a NGF plus acupuncture group.Three weeks were allowed for the recovery of the blood-brain barrier lesion caused by ischemia-reperfusion before intravenous injection of NGF(10μg/kg,once daily for 15 days)via the vena caudalis.In the two acupuncture groups,this was administered in combination with EA at the Baihui(DU20)and Yamen(DU15)acupoints(frequency 100 Hz,2 mA,20 min/time,once daily for 15 days).Morris' water maze test was used to assess any changes in spatial learning and memory abilities.Results The ischemic rats showed significant learning and memory disorders compared with the sham-operated group.In the NGF group,the rats' learning and memory abilities did not impmve significantly compared with the model group and the EA group.Significantly better learning was observed in the NGF+EA group compared with the model group,the EA group and the NGF group.Conclusion NGF combined with EA can improve the learning and memory abilities of rats with learning and memory dysfunction caused by cerebral ischemia-repedusion.     

电针配合神经生长因子对脑缺血大鼠学习记忆能力的影响

Objective To observe the effect of nerve growth factor(NGF)and electro-acupuncture(EA) on learning and memory in rats with cerebral ischemia.Methods An experimental model of cerebral ischemiareperfusion was established in 40 rats,who were then randomly divided into a model group,a sham operated group,a NGF group,an acupuncture group and a NGF plus acupuncture group.Three weeks were allowed for the recovery of the blood-brain barrier lesion caused by ischemia-reperfusion before intravenous injection of NGF(10μg/kg,once daily for 15 days)via the vena caudalis.In the two acupuncture groups,this was administered in combination with EA at the Baihui(DU20)and Yamen(DU15)acupoints(frequency 100 Hz,2 mA,20 min/time,once daily for 15 days).Morris' water maze test was used to assess any changes in spatial learning and memory abilities.Results The ischemic rats showed significant learning and memory disorders compared with the sham-operated group.In the NGF group,the rats' learning and memory abilities did not impmve significantly compared with the model group and the EA group.Significantly better learning was observed in the NGF+EA group compared with the model group,the EA group and the NGF group.Conclusion NGF combined with EA can improve the learning and memory abilities of rats with learning and memory dysfunction caused by cerebral ischemia-repedusion.     

电针配合神经生长因子对脑缺血大鼠学习记忆能力的影响

Objective To observe the effect of nerve growth factor(NGF)and electro-acupuncture(EA) on learning and memory in rats with cerebral ischemia.Methods An experimental model of cerebral ischemiareperfusion was established in 40 rats,who were then randomly divided into a model group,a sham operated group,a NGF group,an acupuncture group and a NGF plus acupuncture group.Three weeks were allowed for the recovery of the blood-brain barrier lesion caused by ischemia-reperfusion before intravenous injection of NGF(10μg/kg,once daily for 15 days)via the vena caudalis.In the two acupuncture groups,this was administered in combination with EA at the Baihui(DU20)and Yamen(DU15)acupoints(frequency 100 Hz,2 mA,20 min/time,once daily for 15 days).Morris' water maze test was used to assess any changes in spatial learning and memory abilities.Results The ischemic rats showed significant learning and memory disorders compared with the sham-operated group.In the NGF group,the rats' learning and memory abilities did not impmve significantly compared with the model group and the EA group.Significantly better learning was observed in the NGF+EA group compared with the model group,the EA group and the NGF group.Conclusion NGF combined with EA can improve the learning and memory abilities of rats with learning and memory dysfunction caused by cerebral ischemia-repedusion.     

电针配合神经生长因子对脑缺血大鼠学习记忆能力的影响

Objective To observe the effect of nerve growth factor(NGF)and electro-acupuncture(EA) on learning and memory in rats with cerebral ischemia.Methods An experimental model of cerebral ischemiareperfusion was established in 40 rats,who were then randomly divided into a model group,a sham operated group,a NGF group,an acupuncture group and a NGF plus acupuncture group.Three weeks were allowed for the recovery of the blood-brain barrier lesion caused by ischemia-reperfusion before intravenous injection of NGF(10μg/kg,once daily for 15 days)via the vena caudalis.In the two acupuncture groups,this was administered in combination with EA at the Baihui(DU20)and Yamen(DU15)acupoints(frequency 100 Hz,2 mA,20 min/time,once daily for 15 days).Morris' water maze test was used to assess any changes in spatial learning and memory abilities.Results The ischemic rats showed significant learning and memory disorders compared with the sham-operated group.In the NGF group,the rats' learning and memory abilities did not impmve significantly compared with the model group and the EA group.Significantly better learning was observed in the NGF+EA group compared with the model group,the EA group and the NGF group.Conclusion NGF combined with EA can improve the learning and memory abilities of rats with learning and memory dysfunction caused by cerebral ischemia-repedusion.     

淀粉样β蛋白42及其亚单位疫苗预防接种对APPSWE转基因小鼠学习记忆能力的保护作用

背景研究表明,淀粉样β蛋白42疫苗接种可以诱导阿尔茨海默病转基因小鼠产生特异性抗淀粉样β蛋白42抗体,清除其脑内的淀粉样β蛋白沉积,改善其学习记忆能力,在对阿尔茨海默病的防治中具有良好的应用前景.目的研究淀粉样β蛋白42及其亚单位肽疫苗预防接种对APPSWE转基因小鼠学习记忆能力的影响.设计以动物为研究对象,完全随机分组实验.单位一所大学医学院人体解剖学教研室脑研究室.材料实验于2003-04/2004-02在中山大学实验动物中心和人体解剖学教研室脑研究室进行.5月龄APPSWE转基因小鼠32只,购自美国Taconic company,在本室繁育成功.实验随机分成对照组、淀粉样β蛋白42组、淀粉样β蛋白1-15组和淀粉样β蛋白36-42组,每组8只.干预淀粉样β蛋白42.及其亚单位疫苗配伍MF59佐剂,基础接种采用皮下注射,加强接种采用鼻黏膜免疫,共接种8个月.疫苗接种前用Y迷宫作行为学测试,接种后用Morris水迷宫作行为学测试.主要观察指标空间学习记忆能力,平均逃避潜伏期,穿过平台次数,第一象限游泳距离百分率,20%边缘区游泳距离百分率.结果疫苗接种前对照组、淀粉样β蛋白42组、淀粉样β蛋白1-15组和淀粉样β蛋白36-42组APPSWE转基因小鼠Y迷宫作行为学测试10次中正确反应的次数分别为7.50±0.81,7.06±0.71,7.19±0.91,7.50±0.86,各组小鼠间的空间学习记忆能力差异无显著性意义(P＞0.05);疫苗接种8个月后,对照组、淀粉样β蛋白42组、淀粉样β蛋白1-15组和淀粉样β蛋白36-42组小鼠定位航行试验8个单元训练的平均逃避潜伏期分别为(67.3±2.8)s,(23.6±1.6)s,(26.4±2.0)s和(36.5±2.2)s,淀粉样β蛋白42组、淀粉样β蛋白1-15组和淀粉样β蛋白36-42组较对照组明显缩短,淀粉样β蛋白42组、淀粉样β蛋白1-15组和淀粉样β蛋白36-42组之间差异无显著性意义(P＞0.05);对照组、淀粉样β蛋白42组、淀粉样β蛋白1-15组和淀粉样β蛋白36-42组小鼠空间探索试验穿过平台次数分别为0.71±0.29,8.14±1.37,7.28±1.34和3.29±0.67,第一象限游泳距离百分率分别为(24.3±2.9)%,(50.6±11.6)%,(49.9±9.3)%和(35.4±7.0)%,20%边缘区游泳距离百分率分别为(46.4±7.3)%,(11.6±3.9)%,(14.4±2.6)%和(25.8±3.3)%,淀粉样β蛋白42组、淀粉样β蛋白1-15组和淀粉样β蛋白36-42组较对照组穿过平台次数显著增多、第一象限游泳距离百分率升高和20%边缘区游泳距离百分率降低,其中淀粉样β蛋白42组、淀粉样β蛋白1-15组和淀粉样β蛋白36-42组比较差异无显著性意义(P＜0.05).结论淀粉样β蛋白42及其亚单位疫苗预防接种可有效减轻APPSWE转基因小鼠学习记忆能力的损害.     

Memantine improves spatial learning in a transgenic mouse model of Alzheimer's disease

Memantine, a low- to moderate-affinity uncompetitive N-methyl-D-aspartate receptor antagonist, has been shown to improve learning and memory in several pharmacological models of Alzheimer's disease (AD). In the present study, the effect of memantine on locomotor activity, social behavior, and spatial learning was assessed in a transgenic mouse model of AD. Eight-month-old male C57BL/6J mice carrying mutated human APP and PS1 genes (APP/PS1) and their nontransgenic (NT) litter mates were administered a therapeutic dose of memantine (30 mg/kg/day p.o.) for 2 to 3 weeks. At this age, APP/PS1 mice show elevated levels of beta-amyloid peptides in several brain regions. APP/PS1 mice exhibited less exploratory rearing and increased aggressive behavior compared with NT mice. In the water maze test for spatial learning, APP/PS1 mice had longer escape latencies to both hidden and visible platforms, but they did not differ from NT mice in their swimming speed. Memantine significantly improved the acquisition of the water maze in APP/PS1 mice without affecting swimming speed. Memantine did not affect either locomotor activity or aggressive behavior in either genotype. These data indicate that memantine improves hippocampus-based spatial learning in a transgenic mouse model of AD without producing nonspecific effects on locomotion/exploratory activity.     

电针百会穴对APP/PS1双转基因痴呆模型小鼠18F-FDGPET/CT成像及学习记忆的影响

目的:观察电针百会穴对APP/PS1双转基因小鼠葡萄糖代谢水平以及学习记忆的影响,探讨电针治疗阿尔茨海默病的作用机制。方法:将30只雌性12月龄APP/PS1双转基因小鼠随机分为模型组、百会组和非穴组,每组10只,另取10只同窝阴性野生小鼠为野生组。百会组电针百会穴,非穴组电针非穴,每次30min,每天1次,每周5天,共治疗4周,野生组和模型组不干预。采用正电子发射断层扫描技术(PET)观察各组小鼠大脑18F-FDG摄取率的水平;Morris水迷宫实验观察小鼠学习记忆。结果:与模型组相比,百会组小鼠逃避潜伏期缩短(P0.05),跨越平台次数增加(P0.01);非穴组小鼠逃避潜伏期与模型组相比无显著性差异(P0.05);百会组小鼠18F-FDG摄取率高于野生组、模型组以及非穴组。结论:电针百会穴可改善APP/PS1双转基因小鼠的学习记忆功能,其作用机制可能是通过改善小鼠脑内葡萄糖代谢从而发挥神经保护作用。     

一氧化氮合酶阳性神经元与小鼠学习记忆障碍的关系

背景通过竞争性抑制一氧化氮合酶(nitric oxide synthase,NOS),可损害大鼠的学习记忆行为,表明NO/NOS对维持正常的学习记忆功能是必需的,但有关学习记忆障碍时NOS神经元的变化尚不十分清楚.目的探讨NOS神经元与学习记忆障碍的关系.设计完全随机设计,对照实验研究.地点和材料本研究地点为中南大学湘雅医学院人体解剖学和神经生物学系,材料为健康昆明雄性小鼠32只,6～8周龄,体质量20～25 g,购于湖南医科大学动物学部.干预32只小鼠随机分为模型组和对照组,每组各取7 d和14 d两个时间点,每个时间点各8只小鼠.采用辐射式三等份Y型迷宫测试装置,检测动物的空间辨别性学习记忆能力.应用免疫组化结合组织化学方法显示学习记忆障碍小鼠脑中NOS神经元的变化.主要观察指标检测动物的空间辨别性学习记忆能力,观察切片NOS神经元形态并计数.结果随训练次数的增加,对照组小鼠在Y型迷宫中的正确次数逐渐增加(术前第1天8.3±1.2,术后第7天10.1±1.0),而模型组小鼠术后在Y型迷宫测试中的正确次数较术前(8.3±1.2)明显减少(术后第7天4.7±2.4,P＜0.05),与对照组同时间点相比,差异有显著性意义(P＜0.01).但术后14 d模型组小鼠在迷宫测试中的正确次数渐有增加(9.3±0.7).学习记忆障碍小鼠海马CA1-4区NOS神经元数目显著减少,齿状回颗粒细胞层和梨状区皮质外颗粒细胞层内出现大量新的NOS神经元.结论海马内NOS神经元与小鼠学习记忆有重要关系;梨状区皮质和齿状回颗粒细胞层内出现新的NOS神经元可能是学习记忆障碍后的代偿性反应.它们可能在随后的学习记忆功能恢复中发挥了重要作用.     

神经节苷酯对鼠脑放射性损伤后空间学习记忆力下降的影响

背景记忆力下降是放射性脑病早期的主要临床表现,已有许多人认为神经节苷酯在神经修复中对记忆功能具有改善作用.目的研究神经节苷酯对鼠脑放射性损伤后空间学习记忆能力减退的影响.设计以动物为观察对象的随机对照实验.单位中山大学第二附属医院的神经科和放射科.材料实验于2001-03/2002-05在中山大学附属第二医院实验室完成.选取SD大鼠80只,分为空白对照组、神经节苷酯治疗组、生理盐水治疗组、未干预组,20只/组.干预神经节苷酯治疗组、生理盐水治疗组、未干预组大鼠麻醉后头部接受60Coγ射线照射,7 Gy/次,1次/d,连续照射6 d,总剂量42 Gy.空白对照组麻醉后不予照射.接受照射的3组每天照射后隔1 h给药,神经节苷酯治疗组腹腔注射神经节苷酯30 mg/kg;生理盐水治疗组注射等量的生理盐水,1次/d,连续6 d;空白对照组和未干预组不给药.评估①照射结束后采用Morris水迷宫的定位航行实验,通过记录大鼠寻找平台所需时间(潜伏期)来测定大鼠对水迷宫的学习记忆能力.②采用空间搜索实验,通过记录大鼠在120s内搜索平台的路线图,测量其平台象限的游泳距离占总距离的百分比,从而测定大鼠学会寻找平台后,对平台空间位置记忆的能力.③迷宫试验结束后将神经节苷酯治疗组、生理盐水治疗组、未干预组大鼠断头取脑,观察各组大鼠的脑组织病理改变.结果①各组第4天起潜伏期渐趋平稳,第5天时神经节苷酯治疗组寻找平台潜伏期(13.6±1.4)s,短于生理盐水治疗组和未干预组[(17.1±2.9),(15.8±2.2)s,P＜O.05].②神经节苷酯治疗组和空白对照组能依靠空间搜索寻找平台,运动轨迹多位于原平台所在象限,而生理盐水治疗组及未干预组多绕池壁游泳,运动轨迹呈随机分布于各象限中.神经节苷酯治疗组平台象限游泳距离百分比高于生理盐水治疗组及未干预组,但较空白对照组低.③组织学检查显示,生理盐水治疗组神经元轻度变性,部分细胞呈空泡变性,出现细胞皱缩,染色质浓缩,核边聚,星形细胞数量减少;未干预组病理改变与生理盐水治疗组基本相似;神经节苷酯治疗组部分神经元出现胞体变小,胞浆红染等变性改变,但数量、核皱缩、核边聚、空泡现象较前两组少.结论放射性脑损伤使大鼠的学习记忆能力明显下降,神经节苷酯治疗可减轻照射后脑组织病理改变,对放射所致的空间学习记忆能力减退有明显改善作用.     

丹参大黄合剂对拟老年痴呆大鼠学习记忆能力及海马β淀粉样前体蛋白、早老素1mRNA表达的影响

目的探讨丹参大黄合剂对拟老年性痴呆（AD）大鼠学习记忆能力的影响及其机制。方法用D-半乳糖和三氯化铝联合用药制备拟AD动物模型。从造模的第20天开始,丹参大黄组灌胃给予丹参大黄合剂,连续70d。给药结束后,通过方形水迷宫、逆转录聚合酶链反应来观察丹参大黄合剂对拟AD模型大鼠学习记忆和海马β淀粉样前体蛋白（APP）、早老素1（PS1）基因表达的影响。结果丹参大黄合剂可以缩短拟AD模型大鼠水迷宫测试的潜伏期（P〈0.05）,减少其错误次数（P〈0.05）,同时降低海马APP、PS1 mRNA的表达（P〈0.05）。结论丹参大黄合剂能提高拟AD大鼠学习、记忆能力,可能与降低APP、PS1 mRNA的表达有关。     

老年痴呆症模型小鼠蛋白磷酸化与短期丰富环境刺激的影响

背景:丰富环境刺激可提高对神经可塑性、学习记忆很重要的CAMKII、CREB蛋白的转录。目的:探讨短期丰富环境刺激对老年痴呆模型小鼠海马CAMKII和CREB蛋白磷酸化的影响。方法:实验分3组:长期环境组(以APP/PS1转基因C57/BL6小鼠作为老年痴呆症动物模型,从小鼠6月龄时开始进行长期的丰富环境刺激)、对照组(未进行长期环境刺激的APP/PS1转基因C57/BL6小鼠)与野生型组(非转基因的野生型C57/BL6小鼠)。在3组小鼠18月龄时,每组又随机分为基线组和刺激后两个亚组,对刺激后亚组施以为期1d的短期丰富环境刺激。结果与结论:野生型组的刺激后亚组海马CREB磷酸化水平显著高于基线亚组(P<0.05),CAMKII的磷酸化水平也有所升高;丰富环境组的刺激后亚组海马CAMKII磷酸化水平稍高于基线亚组,CREB磷酸化水平的区别不明显;对照组两个亚组海马的CAMKII和CREB磷酸化水平无明显区别。说明短期丰富环境刺激仅提高了丰富环境刺激后老年痴呆症小鼠的CAMKII磷酸化水平,但显著提高了野生型小鼠的CAMKII和CREB磷酸化水平。     

人源化抗Aβ抗体治疗APP／PS1转基因鼠的实验研究

目的：初步探讨人源化抗Aβ抗体对APP/PS1转基因鼠被动免疫治疗效果。方法选取36只APP/PS1转基因鼠,随机分为3组,每组各12只,分别予腹腔注射人源化抗Aβ抗体、鼠源性单克隆抗体、磷酸盐缓冲液（PBS）,观察3组小鼠脑内淀粉样斑块积聚情况,测试其学习记忆能力,同时检测血清及脑内TNF-α含量。结果人源化抗Aβ抗体组、鼠源性单克隆抗体组小鼠空间辨别学习记忆能力均优于PBS对照组（P＜0．05）,人源化抗Aβ抗体组与鼠源性单克隆抗体组间比较差异无统计学意义（P＞0．05）;治疗后人源化抗Aβ抗体组与鼠源性单克隆抗体组小鼠大脑皮质、海马区棕色斑块沉积明显形态变小、数量变少、范围分散。人源化抗Aβ抗体组与鼠源性单克隆抗体组脑内TNF-α含量均较PBS对照组明显减少（P＜0．05）。结论人源化抗Aβ抗体治疗转基因小鼠后明显改善其学习记忆能力,同时使其脑内TNF-α含量减少。     

老年痴呆症模型小鼠蛋白磷酸化与短期丰富环境刺激的影响

背景：丰富环境刺激可提高对神经可塑性、学习记忆很重要的CAMKII、CREB蛋白的转录。目的：探讨短期丰富环境刺激对老年痴呆模型小鼠海马CAMKII和CREB蛋白磷酸化的影响。方法：实验分3组：长期环境组（以APP/PS1转基因C57/BL6小鼠作为老年痴呆症动物模型,从小鼠6月龄时开始进行长期的丰富环境刺激）、对照组（未进行长期环境刺激的APP/PS1转基因C57/BL6小鼠）与野生型组（非转基因的野生型C57/BL6小鼠）。在3组小鼠18月龄时,每组又随机分为基线组和刺激后两个亚组,对刺激后亚组施以为期1d的短期丰富环境刺激。结果与结论：野生型组的刺激后亚组海马CREB磷酸化水平显著高于基线亚组（P〈0.05）,CAMKII的磷酸化水平也有所升高;丰富环境组的刺激后亚组海马CAMKII磷酸化水平稍高于基线亚组,CREB磷酸化水平的区别不明显;对照组两个亚组海马的CAMKII和CREB磷酸化水平无明显区别。说明短期丰富环境刺激仅提高了丰富环境刺激后老年痴呆症小鼠的CAMKII磷酸化水平,但显著提高了野生型小鼠的CAMKII和CREB磷酸化水平。