摘除颈上神经节对成年大鼠海马齿状回神经再生及学习记忆的影响

发布时间：2018-06-29 15:20

本文选题：颈上神经节 + 大鼠　；参考：《兰州大学》2008年博士论文

【摘要】： 一方面,认知科学是当前生命科学中最引人瞩目、发展最迅速的学科之一。随着神经科学的发展,神经发生现象逐渐在啮齿类、灵长类动物和人类得以广泛证实。很多学者认为,在成人海马齿状回中神经元的再生伴随着人的一生。另一方面,交感神经是神经系统中的一个重要的组成部分,而颈上神经节则是通往脑颅的主要交感输入纤维,这些纤维包含着胺类、氨基酸类、肽类等多种神经递质,发挥着各自不同的功能,对靶器官进行精确的调控以适应机体的需求。目前,除了对已知的颈上神经节参与特殊神经递质的分泌和运输、运动及血压节律性的调控等方面的作用外,还不断有新的发现。但是,交感神经系统还有很多未知的生理功能有待于进一步的研究。本论文通过摘除成年大鼠颈上神经节手术,探讨去颈上神经节(SCG)对成年大鼠海马齿状回神经再生及学习记忆的影响,进而探索交感神经节对哺乳动物学习记忆的调节机制,为交感神经系统临床研究提供实验资料。本实验将大鼠分为双侧摘除神经节组(B SCGe)、单侧摘除神经节组(USCGe)和对照组(C)。手术后大鼠呈现Homer综合症:手术侧面部瞳孔缩小、睑裂变小、眼球后陷,大鼠食欲不振。运用Morris水迷宫测定手术后学习记忆能力的改变。结果显示:在定位航行实验中,通过5d的训练,三组大鼠均获取了对平台位置的参考记忆,搜索平台的策略都由边缘式变为趋向式或直线式,训练潜伏期下降。统计分析结果表明,BSCGe组潜伏期值显著高于U SCGe和C组的(P＜0.05),而单侧摘除手术组和对照组五天内的训练潜伏期则无差异(P＞0.05)。在空间搜索实验中,C组和U SCGe组大鼠由于能够记住原平台的位置,反复穿越原平台所在象限(第Ⅳ象限),运动轨迹主要集中在原平台所在位置,而B SCGe组大鼠由于不能准确记忆平台的位置,则在其它象限运动相对较其他两组多。以平台为靶心,统计三组大鼠轨迹分布在靶心和9环靶的百分率,比较记忆得分率,结果显示B SCGe组大鼠记忆得分率显著低于C组和U SCGe组(P＜0.05)。本实验还运用神经元前体细胞的标志物DCX(Doublecortin)免疫组织化学染色方法检测海马齿状回神经元前体细胞的增殖情况。结果显示:DCX阳性细胞呈黄色或棕黄色颗粒,而且在齿状回分子层(ML)、颗粒层(GCL)和颗粒下层(SGZ)的分布是不均匀的。DCX标记细胞胞体位于SGZ或者GCL,树突沿着板层的垂直方向穿行,跨越GCL,内分子层和中分子层。C组大鼠颗粒下层的DCX阳性细胞有不少排列成簇;U SCGe组大鼠呈簇排列较C组少;BSCGe组的DCX阳性细胞较少,而绝大多数都是单个散在分布。通过DCX免疫组化染色定量分析结果显示,与C组大鼠相比,U SCGe组和B SCGe组大鼠DCX阳性细胞数目及密度均减少,其中B SCGe组与C组DCX阳性细胞数目差异极显著(P＜0.01)。从以上实验结果得知,与C组比较,U SCGe组大鼠的Morris水迷宫成绩比B SCGe组好,且DCX阳性细胞数量、密度比B SCGe组大,这似乎说明单侧SCG切除后,其对侧的SCG能进行了某种功能上的补偿,所以我们进一步切除大鼠单侧颈上神经节,将其对侧SCG(手术组)进行石蜡、半薄切片制作,运用光镜观察、体视学方法与正常SCG进行比较来探讨其中的原因,为颈上神经节损伤的研究提供实验依据。结果发现手术30天后,手术组SCG的主细胞的神经节体积(Vg),神经元的数密度(Nv)、神经元细胞数量(N)、体密度(Vv)等参数与对照组相比均未出现显著差异,但是非神经元的数密度(Nv)、细胞数量(N)及体密度则发生极显著性增多(P＜0.01)。由以上的实验结果我们得出这样的推论:SCG摘除对成年大鼠的海马齿状回神经元的再生和学习和记忆能力有一定的影响,而且双侧摘除的影响更为显著,其原因可能是因为单侧切除SCG后,其对侧的卫星细胞的繁殖增多,以此增加SCG的活性进行代偿;也可能是周围的白细胞渗入到SCG中,对这种神经退行性疾病进行某种补偿性地免疫修复。
[Abstract]:On the one hand, cognitive science is one of the most noticeable and rapidly developing subjects in the current life science. With the development of neuroscience, neurogenesis is gradually confirmed in rodents, primates and humans. Many scholars believe that the regeneration of neurons in the adult sea horse dentate gyrus is accompanied by human life.
On the other hand, the sympathetic nerve is an important component of the nervous system, and the superior cervical ganglion is the main sympathetic input fiber to the brain. These fibers contain various neurotransmitters, such as amines, amino acids, peptides, and other functions, and regulate the target organs accurately to meet the needs of the body. In addition to the role of the known superior cervical ganglion involved in the secretion and transport of special neurotransmitters, movement and regulation of rhythmic blood pressure, there are still new discoveries. However, there are many unknown physiological functions in the sympathetic nervous system to be further studied.
In this paper, the effect of the removal of the superior cervical ganglion (SCG) on the regeneration of the dentate gyrus and learning and memory in adult rats was investigated by removing the superior cervical ganglion in the adult rat, and the mechanism of the learning and memory of the sympathetic ganglion to the mammalian learning and memory was explored to provide experimental data for the study of the sympathetic nervous system.
The rats were divided into bilateral extirpation ganglion group (B SCGe), unilateral extirpate ganglion group (USCGe) and control group (C). After operation, the rats showed Homer syndrome: the pupil in the side of the operation was narrowed, the eyelid fission was small, the eyeball was depressed, and the appetite was inexorpant in the rats.
The Morris water maze was used to determine the changes of learning and memory ability after operation. The results showed that in the navigation experiment, the three groups of rats obtained the reference memory of the platform position through the training of 5D. The strategy of the search platform changed from the edge to the trend or the straight line, and the training latency decreased. The statistical analysis showed that the BSCGe group dive. The value of volt period was significantly higher than that of U SCGe and C group (P < 0.05), but there was no difference in the training latency in the unilateral extirpation group and the control group (P > 0.05). In the space search experiment, the C and U SCGe group rats were able to remember the original platform's position and cross the quadrant of the original platform (the fourth quadrant), and the track was mainly concentrated in Yuanping. The position of the platform in the B SCGe group was more than the other two groups because of the inability to remember the position of the platform. With the platform as the target, the percentage of the three groups of rats in the target center and the 9 target were compared, and the score of memory was compared. The results showed that the memory score of the B SCGe group was significantly lower than that of the C group and the U SCGe group (P). < 0.05).
The proliferation of neuronal precursor cells in hippocampal dentate gyrus was detected by DCX (Doublecortin) immuno histochemical staining of neuronal precursor cells. The results showed that the DCX positive cells were yellow or brown yellow granules, and at the dentate gyrus (ML), and the distribution of the granular layer (GCL) and the subgranular layer (SGZ) was uneven. The cell bodies of.DCX labeled cells are located in SGZ or GCL, and the dendrites go along the vertical direction of the plate layer and cross the GCL. The DCX positive cells in the lower layer of the.C group of the.C group of the inner molecular layer and the middle molecular layer are arranged in a lot of clusters; the U SCGe group rats are smaller in cluster arrangement than in the C group; the DCX positive cells in the BSCGe group are less, and the vast majority are single scattered distribution. The quantitative analysis of DCX immunohistochemical staining showed that the number and density of DCX positive cells in the U SCGe group and the B SCGe group decreased, and the number of DCX positive cells in the B SCGe group and the C group was very significant (P < 0.01).
From the above experimental results, we found that compared with the C group, the Morris water maze of the U SCGe group was better than the B SCGe group, and the number and density of the DCX positive cells were larger than that of the B SCGe group. This seems to indicate that the unilateral SCG excision is a kind of functional compensation for the lateral SCG energy of the unilateral SCG, so we further excised the unilateral superior cervical ganglion and put it on the side SC. G (operation group) was made with paraffin and semi thin section, using light microscopy and comparing with normal SCG to compare the reasons. The results provided experimental basis for the study of the injury of the superior cervical ganglia. Results 30 days after operation, the nerve volume (Vg), the number density of neurons (Nv), the number of neuron cells in the main cells of the operation group SCG, the number of neurons (Nv), and the number of neuron cells were found. There was no significant difference in quantity (N), volume density (Vv) and other parameters, but the number density (Nv) of non neuron (Nv), the number of cells (N) and body density increased significantly (P < 0.01).
From the experimental results, we conclude that SCG extirpation has a certain effect on the regeneration and learning and memory ability of the hippocampal dentate gyrus in adult rats, and the effect of bilateral extirpation is more significant, which may be due to the increase in the reproduction of the opposite satellite cells after unilateral removal of SCG to increase the activity of SCG. Sexual compensation is also made. It may also be the infiltration of leukocytes around the SCG into a compensatory immune repair of this neurodegenerative disease.
【学位授予单位】：兰州大学
【学位级别】：博士
【学位授予年份】：2008
【分类号】：R33

【参考文献】