香烟烟雾暴露对小鼠学习能力和神经发生的影响研究

发布时间：2018-06-30 04:46

本文选题：神经发生 + 小胶质细胞　；参考：《广西医科大学》2008年硕士论文

【摘要】： 为了探讨香烟烟雾暴露(cigarette smoking exposure,CSE,亦即被动吸烟)对发育中神经系统的影响及其作用机理,本实验研究了对幼年小鼠学习能力、神经发生和小胶质细胞的影响,首次发现CSE抑制了海马的神经发生并减少了激活的小胶质细胞数量,证明了神经发生在学习记忆中起着关键性的作用。阐明了香烟烟雾暴露对学习能力的影响是通过抑制神经发生进行的,为CSE对幼年神经系统的危害提供实验依据。实验分为两部份: 第一部分:香烟烟雾暴露对幼年小鼠学习能力、神经发生和小胶质细胞的影响【目的】研究香烟烟雾暴露对幼年小鼠学习能力、神经发生和小胶质细胞数量的影响。【材料和方法】选取出生后30天的SPF级昆明小鼠,经旋棒实验,方型水迷宫实验筛选以排除体力和学习能力上存在的差异后随机分成对照组、低强度组、高强度组,每组12只,CSE实验中两处理组被分别置于仿Younoszai的自制被动吸烟箱内接受共8天,3次/天,1支/次,10分钟/次(低强度组)和8天,3次/天,2支/次,30分钟/次(高强度组)的香烟烟雾暴露,而对照组亦被放置于没有香烟烟雾的同样环境中接受8天,3次/天,30分钟/次的处理。通过Morris水迷宫训练检测其学习记忆能力,采用5-溴脱氧尿苷(5-bromodeoxyuridine,BrdU)免疫细胞染色标记新生细胞,西非单叶豆同工凝集素(Bandeirae Simplicifolia Isolectin-B4,BSI-B4)亲和组织化学方法标记小胶质细胞。【结果】 CSE组动物较对照组花费更多的时间才能找到平台,其DG内的BrdU~+细胞数目的明显减少,BSUI-B4~+细胞数量也显著减少,其中分枝状的细胞(代表了激活的小胶质细胞)数量同样平行地减少。【结论】 1.CSE损害了幼年小鼠的空间学习能力。 2.CSE抑制了DG内的神经发生并使小胶质细胞尤其是激活的小胶质细胞数量减少。 3.空间学习能力与DG内神经发生、小胶质细胞数量存在着正相关的关系,提示它们之间可能存在着某种方式的相互作用。第二部分:神经发生对学习记忆的影响【目的】研究神经发生对学习记忆的影响,探讨香烟烟雾暴露损害幼年小鼠学习记忆的机理【材料和方法】用脑内埋管微量注射技术将细胞分裂促进剂-酸性成纤维细胞生长因子(acid fibroblast growth factor,aFGF)和细胞分裂抑制剂-甲氨蝶呤(Methotrexate,MTX)注入侧脑室内,之后使用神经行为学、免疫组织化学技术及亲和组织化学技术检测其空间学习记忆能力、神经发生及激活的小胶质细胞数量变化。【结果】细胞分裂促进剂aFGF组观察到了水迷宫训练中潜伏期的缩短,BrdU~+细胞数目的明显增多,BSI-B4~+细胞数量也显著增加;而抑制剂MTX组在水迷宫训练中的表现明显比对照组和aFGF组要差,BrdU~+细胞数目减少,但BSI-B4~+细胞数量同对照组相比并没有显著的变化。【结论】 1.aFGF有促神经发生和促小胶质细胞激活的作用。 2.MTX有抑制神经发生的作用,但对小胶质细胞影响不大。 3.本实验从正反两方面证明了神经发生对学习记忆起着重要的作用。【总结】 1.香烟烟雾暴露损害了幼年小鼠的空间学习能力。 2.香烟烟雾暴露抑制了幼年小鼠DG内的神经发生并使小胶质细胞尤其是激活的小胶质细胞数量减少。 3.香烟烟雾暴露对神经发生的抑制作用,可能是香烟烟雾暴露损害空间学习能力的作用机理。 4.神经发生在学习记忆过程中起着重要的作用。 5.小胶质细胞与神经发生和学习记忆之间可能存在着某种相互作用。 6.aFGF有促神经发生的作用,MTX有抑制神经发生的作用。
[Abstract]:In order to study the influence of cigarette smoke exposure ( Ck , i.e . , passive smoking ) on the nervous system in development , this paper studied the effects of cigarette smoke exposure on learning ability , neurogenesis and microglial cells . It was found that the neurogenesis plays a key role in learning and memory . The effect of cigarette smoke exposure on learning ability was demonstrated . The effect of cigarette smoke exposure on learning ability was demonstrated .

Part I : Effect of cigarette smoke exposure on learning ability , neurogenesis and microglial cells in young mice

Purpose of the project

To study the effects of cigarette smoke exposure on learning ability , neurogenesis and microglial cells in young mice .

Materials and methods therefor

SPF Kunming mice were randomly divided into two groups : control group , low - intensity group and high - strength group , and the control group was placed in the same environment without cigarette smoke for 8 days , 3 times / day , 30 minutes / time ( high - intensity group ) .

The result is not valid .

More time could be spent in the control group than in the control group to find the platform , and the number of cells in DG - B4 - B4 cells decreased significantly , and the number of dendritic cells ( representing the activated microglial cells ) decreased in parallel .

Conclusion

1 . The ability to learn space in young mice was impaired .

2 . Inhibition of neurogenesis in DG and reduced number of microglial cells , in particular activated microglial cells .

3 . There is a positive correlation between the spatial learning ability and the number of neurogenesis and microglial cells in DG , suggesting that there may be some kind of interaction between them .

Part Two : Effects of Neurogenesis on Learning and Memory

Purpose of the project

To study the effect of neurogenesis on learning and memory , and to explore the mechanism of cigarette smoke exposure damage to learning and memory of young mice

Materials and methods therefor

Cytokinin - acidic fibroblast growth factor ( aFGF ) and cell division inhibitor - methotrexate ( MTX ) were injected into the lateral ventricle using intracerebroventricular microinjection technique , followed by neurobehavioral , immunohistochemical techniques and immunohistochemistry techniques to detect the spatial learning and memory capacity , neurogenesis , and the number of activated microglial cells .

The result is not valid .

There was no significant change in BSI - B4 ~ + cells than in control group and aFGF group , but BSI - B4 ~ + cells did not change significantly compared with control group .

Conclusion

1 . aFGF has the effect of promoting neurogenesis and promoting the activation of microglial cells .

2 . MTX inhibited the neurogenesis , but had little effect on microglial cells .

3 . This experiment proves that the neurogenesis plays an important role in learning and memory .

Summary of summarization

1 . cigarette smoke exposure damages the spatial learning ability of young mice .

2 . Cigarette smoke exposure inhibited the neurogenesis in the young mouse DG and reduced the number of microglial cells , in particular activated microglial cells .

3 . The inhibitory effect of cigarette smoke exposure on neurogenesis may be the mechanism of cigarette smoke exposure damage spatial learning ability .

4 . Neurogenesis plays an important role in learning and memory .

5 . There may be some interaction between microglial cells and neurogenesis and learning and memory .

6 . aFGF has the effect of promoting neurogenesis , and MTX has the effect of inhibiting neurogenesis .
【学位授予单位】：广西医科大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R363

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