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本文意在通过观察适宜游泳运动后大鼠海马脑源性神经营养因子(BDNF)表达的变化,探讨有氧运动促进大脑健康的神经生物学机制。研究将24只SD大鼠随机分为对照组和运动组,运动组又分为3,7,12天三个亚组。采用SABC免疫组化染色法观察分析海马CA1区神经元BDNF阳性表达的数量。结果表明CG大鼠海马有BDNF阳性细胞的蛋白表达,并以神经元表达为主。与CG相比,7SG大鼠海马CA1区BDNF阳性细胞数量增加达显著水平(P<0.05),12SG大鼠海马CA1区BDNF阳性细胞数量增加达极显著水平(P<0.01)。因此,适量的有氧运动可增加BDNF的表达,促进大脑神经可塑性。  相似文献   
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目的:观察戊四氮(PTZ)致痫大鼠海马神经元caspase-3表达以及中药复方AAP的脑保护作用.方法:144只健康成年雄性Wistar大鼠随机分为对照组(CK组)、模型组(PTZ组)、中药大剂量组(AAPl组)、中药中剂量组(AAPm组)、中药小剂量组(AAPs组)和丙戊酸钠组(VPA组);每组各6只.CK组和PTZ组分别给予生理盐水(4mL/kg.d)灌胃;中药各组分别给予中药复方大、中、小剂量(10.26g/kg、5.13g/kg、2.56g/kg)灌胃,每天1次;VPA组腹腔注射VPA(20mg/kg.d).造模第一天,除CK组外,其余各组大鼠均腹腔注射戊四氮(PTZ)75mg/kg,观察记录大鼠行为学变化;于致痫后12h、2d、5d、7d相应时间点取材,制备脑标本;免疫组化检测caspase-3表达.结果:致痫后,除CK组外,其余各组海马区caspase-3阳性表达增强;7天,与PTZ组相比,AAPl组、AAPm组和AAPs组海马CA3区caspase-3阳性表达减弱(P〈0.05).结论:caspase-3参与致痫大鼠海马神经元凋亡过程;AAP能降低caspase-3表达,减少神经元凋亡,有神经保护作用.  相似文献   
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Lead is found in small but appreciable quantities in air, soil drinking water and food. Exposure to such amounts of lead does not cause acute lead toxicity, but produces subtle effects, particularly in children. The CDC advocates “safe” or “acceptable” levels of blood lead up to 10 μg/dl, while OSHA declares blood lead levels up to 40 μg/dl as “safe” or “acceptable” in the occupationally exposed. The objective of the study was to see if blood levels considered “safe” can cause changes in the biogenic neurotransmitters in the developing brain which may cause neurobehavioral defects like hyperactivity and other cognitive disorders. Albino Wistar rats were divided into the control and lead-treated groups. The control group was given unleaded water, while the lead-treated group was fed with 50 ppm lead acetate in drinking water. On day 45 the animals were subjected to a passive avoidance test, their blood analysed for ZPP and lead. They were then sacrificed and the neurotransmitters—Norepinephrine (NE) and its metabolite—methoxyhydroxyphenylglycol (MHPG) estimated in the brain areas associated with learning and memory—the frontal cortex, hippocampus and the striatum by HPLC-ECD. Our results showed significant increases in blood lead, NE and MHPG, while ZPP increase was insignificant. The rats showed neurobehavioral abnormalities as assessed by the passive avoidance test. We concluded that low blood levels of lead cannot be considered “safe” or “acceptable” as it causes neurotransmitter alterations. Increased NE turnover is implicated in hyperactivity disorders such as ADHD and Tourette syndrome.  相似文献   
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目的:探讨有氧运动对老年大鼠学习记忆能力、血清睾酮及海马CA1区nNOS表达的影响.方法:选择SD雄性老年大鼠,分成老年对照组及有氧训练组.对照组不运动,有氧训练组采用递增负荷训练,连续8周.8周后检测血清睾酮,测试大鼠空间学习记忆能力,对海马CA1区nNOS神经元的数量、面积及灰度进行测量和分析.结果:1)与老年对照组比较,有氧运动组大鼠血清睾酮水平增高(P<0.05),完成八臂迷宫时间缩短,错误次数显著减少(P<0.05);2)与老年对照组比较,有氧运动组海马CAl区nNOS免疫阳性细胞数量和阳性产物面积均增加(P<0.05).结论:有氧运动可提高老年大鼠的记忆能力,机理可能与长期有氧运动提高老年大鼠的血清睾酮水平及增强大脑海马CA1区nNOS的表达有关.  相似文献   
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本文以不同强度训练大鼠停训28周为对象,应用免疫组织化学技术探讨长期停训对大鼠脑组织的影响。采用雄性SD大鼠(3月龄,由西安交通大学医学院动物管理中心提供)24只,体重248±24g,国家标准啮齿类动物干燥饲料喂养,自由饮食,温度22℃~27℃,湿度40%~60%。适应性喂养1周后进行实验。将大鼠随机分为安静对照组、有氧训练组和疲劳训练组,每组各8只。有氧训练组和疲劳训练组运动负荷参照B ed ford跑台训练模型训练8周。8周后疲劳训练组和有氧训练组停训,与对照组同处于正常笼内生活状态,再饲养28周。各组大鼠依次用乌拉坦腹腔麻醉,开胸行左心室穿刺灌注,同时剪破右心耳放血.灌注过程中,先用加3‰肝素生理盐水灌注15m in左右,直至流出液体为粉红色时换用中性甲醛固定液灌注40m in左右,pH=7.4,将灌注好的标本置于事先准备的冰盘上并迅速取材。得出结论为大鼠恢复28周后有氧、疲劳训练使海马CA1区的表达增强,未见显著性差异。显示该区在训练恢复后VEGF阳性表达基本恢复。海马CA3区,VEGF的表达下降趋势显著。  相似文献   
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Study on the neurotoxic effects of low-level lead exposure in rats   总被引:10,自引:0,他引:10  
Objective: To investigate effects of developmental lead exposure on nitric oxide synthase (NOS) activity in different brain regions and on N-methyl-D-aspartate (NMDA) receptor mRNA expression in the hippocampus of rats. On the basis of these observations, we explored possible mechanisms by which lead exposure leads to impaired learning and memorizing abilities in children. Methods: A series of rat animal models exposed to low levels of lead during the developing period was established (drinking water containing 0.025%, 0.05% and 0.075% lead acetate). NOS activities in the hippocampus, the cerebral cortex, the cerebellum and the brain stem were determined with fluorescence measurement and levels of mRNA expression of the NMDA receptor 2A (NR2A) subunit and NMDA receptor 2B (NR2B) subunit in the rat hippocampus were measured with Retro-translation (RT-PCR). Results: There were no differences in the body weight of rat pups between any of the groups at any given time (P>0.05). The blood lead level of Pb-exposed rat pups showed a systematic pattern of change: at 14 d of age, it was lower than that at 7 d of age, then rising to the peak level at 21 d and finally falling to lower levels at 28 d. The hippocampal NOS activities of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.01). NOS activities in the cerebellum of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.001) and the NOS activity of the 0.025% group was significantly lower than that of the 0.05% and 0.075% groups on the 28th day (P<0.05). NOS activity in the cerebral cortex of the 0.075% group was significantly lower than that of the control, 0.025% and 0.05% groups on the four day spans (P<0.001). There was no significant difference of NOS activity in the brain stem between any lead-exposed group and the control group on the four day spans. In the 0.05% and the 0.075% groups, the level of NR2A mRNA expression was higher than that in the control group at 7 d and 14 d of age (P<0.05). In the 0.025% group, the level of NR2A was found to be higher than that in the control group at 7 d of age only (P<0.05). No significant differences were found for the levels of NR2B mRNA expression between any of the groups at any given time. Conclusions: NOS activity in the hippocampus, the cerebral cortex and the cerebellum are inhibited by lead exposure. The degree of the inhibitory effect depends on the time span of exposure and the lead concentration. Developmental low-level lead exposure was found to raise the level of NR2A mRNA expression in the hippocampus of rats. Developmental low-level lead exposure does not affect the level of NR2B mRNA expression in the hippocampus.  相似文献   
7.
Objective: To directly examine the effects of carnosine on neuronal excitation and inhibition in rat hippocampus in vivo. Methods: Artificial cerebrospinal fluid with carnosine was directly administrated over the exposed rat hippocampus. The changes of neuron activity in the CA1 region of hippocampus were evaluated by orthodromically- and antidromically-evoked potentials, as well as paired-pulse stimulation paradigm. Results: In both orthodromic and antidromic response potentials, carnosine transformed population spikes (PSs) with single spike into epileptiform multiple spikes. In addition, similar to the effect of γ-aminobutyric acidA (GABAA) antagonist picrotoxin, carnosine decreased paired-pulse stimulating depression significantly.However, no significant change was observed in the spontaneous field potentials during the application of carnosine. Conclusion:The results indicate a disinhibition-induced excitation effect of carnosine on the CA1 pyramidal neurons. It provides important information against the application of carnosine as a potential anticonvulsant in clinical treatment.  相似文献   
8.
学习与记忆是脑的重要生理功能,是现代生命科学研究的前沿.文章就学习记忆有关的脑区、神经元机理、电生理研究、神经生理机制及神经生化机制几个方面的研究进展作一综述.  相似文献   
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