年轻小鼠海马携带人ApoE4基因导致突触和神经网络异常的研究

发布时间：2018-01-14 09:40

  本文关键词：年轻小鼠海马携带人ApoE4基因导致突触和神经网络异常的研究　出处：《河北医科大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： ApoE4 海马 输入/输出曲线 双脉冲易化 突触后长时程增强 θ波

【摘要】：目的:通过观察年轻(4月龄)的ApoE4转基因小鼠脑片海马脑片树突形态及兴奋性突触后电位变化,探讨ApoE4基因对年轻小鼠海马突触功能和神经网络活动的影响。方法:雄性4个月ApoE4转基因小鼠(年轻ApoE4TG组)22只,体重35g±5g,12个月ApoE4转基因小鼠20只。雄性4个月ApoE3转基因小鼠(ApoE3TG组)22只,分别异氟烷吸入麻醉后,断头处死,开颅取脑,取背侧海马区冠状脑片,置于人工脑脊液中孵育至少1小时后转移到水浴槽内,记录在海马CA1区放射层诱发和记录兴奋性突触后电位(field excitatory postsynaptic potential,f EPSP),比较输入/输出曲线(Input-output relationship curve,I/O)、配对脉冲引起的双脉冲易化(paired-pulse facilitation,PPF)、长时程增强(Long-term Potentiation,LTP)、三组高频刺激(high frequency stimulations,HFSs)以及卡巴胆碱诱发的θ波的不同。雄性4个月ApoE4转基因小鼠和12个月ApoE4转基因小鼠(老年ApoE4TG组)比较I/O、PPF、LTP、突触囊泡循环和θ波。用荧光染料注射到4个月ApoE4转基因小鼠海马CA1区锥体细胞层,然后重建染色神经元并分析树突长度和树突棘数量。结果:1 ApoE4TG组与ApoE3TG组树突棘密度的比较ApoE4TG组与ApoE3TG组相比,海马CA1区神经元树突长度减短(P0.05),树突棘数量明显减少(P0.01),树突棘密度整体减少(9.2±0.31,13.7±0.9,P0.05)(Fig.2)。2兴奋性突触后电位2.1年轻ApoE4TG组和年轻ApoE3TG组I/O、PPF、LTP的比较2.1.1海马Schaffer侧枝单个测试刺激的输入/输出曲线ApoE4TG组海马CA1区单个4-10V电刺激后所得到的输入输出曲线斜率大于ApoE3TG组(0.89±0.08,0.49±0.04,P0.0001)(Fig.3)。2.1.2配对脉冲引起的双脉冲易化ApoE4TG组双脉冲易化与ApoE3TG组相比增强(P0.05)(Fig.4)。2.1.3突触后长时程增强ApoE4TG组与ApoE3TG组相比,海马CA1区突触后LTP诱导期减弱(1.38±0.02,1.52±0.02,P0.0001)。在LTP维持ApoE4 T组仍低于ApoE3TG组(1.31±0.01,1.47±0.01,P0.0001)(Fig.5)。2.2年轻ApoE4TG组和老年ApoE4TG组I/O、PPF、LTP的比较。年轻ApoE4TG组海马CA1区单个4-10V电刺激后所得到的输入输出曲线斜率大于老年ApoE4TG组(年轻ApoE4:0.89±0.07,老年ApoE4:0.49±0.04,P0.0001)。老年ApoE4TG组双脉冲易化与年轻ApoE3TG组相比(P0.01)。老年ApoE4TG组与年轻ApoE3TG组相比LTP诱发(LTP强直刺激后0-10min)没有明显差别(老年ApoE4:1.34±0.04,年轻ApoE4:1.38±0.02,P0.05),但LTP维持(强直刺激后50-60min)明显减弱(老年ApoE4:1.20±0.006,年轻ApoE4:1.31±0.007,P0.0001)(Fig.6)。2.3 ApoE4TG组与ApoE3TG组卡巴胆碱诱发的θ波ApoE4TG组与ApoE3TG组相比,卡巴胆碱诱发的θ波的潜伏时间长(P0.05),诱发的波数量少(P0.01)(Fig.7)。2.4年轻ApoE4TG组和年轻ApoE3TG组突触囊泡循环年轻ApoE4TG组和年轻ApoE3TG组相比,突触囊泡循环没有统计学差异(Fig.8)。结论:1年轻ApoE4转基因小鼠与相同年龄组ApoE3转基因小鼠相比较神经突触长度及树突棘密度减少。2年轻ApoE4转基因小鼠与年轻ApoE3转基因小鼠相比较海马CA3-CA1区输入输出曲线、双脉冲易化增强,突触囊泡循环明显变化,但是突触后长时程增强有减弱;老年ApoE4转基因小鼠神海马区神经元的突触后增强减弱。年轻ApoE4小鼠与年轻ApoE3转基因小鼠相比较海马区θ波已有减弱。3在年轻ApoE4转基因小鼠的海马区树突形态及神经网络功能已经有降低,可能预示着阿尔茨海默病患者在出现临床症状前海马区树突及神经元电生理活动已经发生病理学变化。
[Abstract]:Objective: To observe the young (April age) potential changes in ApoE4 transgenic mice brain slices of hippocampal dendritic morphology and postsynaptic excitability, to investigate the effect of ApoE4 gene on young mouse hippocampal synaptic and neural network activity. Methods: male ApoE4 transgenic mice 4 months (young group ApoE4TG) 22 rats, weighing 35g. 5g, 12 months and 20 ApoE4 transgenic mice. Male 4 months ApoE3 transgenic mice (ApoE3TG group) 22 rats respectively after isoflurane inhalation and decapitated, the brain was collected from the dorsal hippocampus, coronal slices, placed in artificial cerebrospinal fluid were incubated for at least 1 hours after the transfer to the water bath. Recorded in the CA1 region of the hippocampus induced by radiation layer and recording the excitatory postsynaptic potential (field excitatory postsynaptic potential, f EPSP), compared with the input / output curve (Input-output relationship curve, I/O), paired pulse facilitation (double pulse caused by paired-pul Se facilitation, PPF), long term potentiation (Long-term Potentiation, LTP), group three (high frequency stimulations, high frequency stimulation HFSs) and different Kaba choline evoked theta. 4 month male ApoE4 transgenic mice and ApoE4 transgenic mice (12 month old ApoE4TG group) I/O, PPF, LTP. Synaptic vesicle cycle and theta wave. By using the fluorescent dye injection to 4 months ApoE4 transgenic mice hippocampus CA1 pyramidal cell layer, and then the reconstruction of neurons and analysis of dendritic length and number of dendritic spines. Results: compared to ApoE4TG group and ApoE3TG group, 1 ApoE4TG group and ApoE3TG group, the density of dendritic spines and dendrites of neurons in hippocampus CA1 region length (P0.05), significantly reduced the number of dendritic spines (P0.01), an overall reduction in the density of dendritic spines (9.2 + 0.31,13.7 + 0.9, P0.05) (Fig.2).2 excitatory postsynaptic potentials of 2.1 young ApoE4TG group and young group ApoE3TG I/O, PPF, 2.1. LTP 1 hippocampal Schaffer single test stimulus collateral input / output curve of single ApoE4TG group in hippocampus CA1 area by 4-10V after electrical stimulation of the input and output curve slope is higher than that of group ApoE3TG (0.89 + 0.08,0.49 + 0.04, P0.0001) (Fig.3).2.1.2 paired pulse double pulse induced facilitation of paired pulse facilitation in ApoE4TG group compared with ApoE3TG group increased (P0.05) (Fig.4).2.1.3 postsynaptic LTP in ApoE4TG group compared with ApoE3TG group, hippocampal CA1 synapses after LTP induction period decreased (1.38 + 0.02,1.52 + 0.02, P0.0001). Still lower than that of ApoE3TG group in LTP T group to maintain ApoE4 (1.31 + 0.01,1.47 + 0.01, P0.0001) (Fig.5).2.2 young ApoE4TG the elderly group and ApoE4TG group I/O, PPF, LTP. ApoE4TG young single group in CA1 region of hippocampus by 4-10V after electrical stimulation of the input and output curve slope is greater than ApoE4TG in the elderly group (young ApoE4:0.89 + 0.07, ApoE4: + 0.04 P0.0001 0.49 elderly, aged ApoE4T). G group of paired pulse facilitation compared with young group ApoE3TG (P0.01). The group of patients with ApoE4TG induced by LTP compared with the young group ApoE3TG (LTP after tetanic stimulation (0-10min) there was no significant difference between elderly ApoE4:1.34 + 0.04, ApoE4:1.38 + 0.02 young, P0.05), but the LTP maintain (after tetanic stimulation (50-60min) significantly decreased ApoE4:1.20 in the elderly. 0.006, young ApoE4:1.31 + 0.007, P0.0001) (Fig.6) theta ApoE4TG group compared with ApoE3TG group,.2.3 ApoE4TG group and ApoE3TG group induced by Kaba Kaba choline, choline evoked theta long latency time (P0.05), induced by the wave number (P0.01) (Fig.7).2.4 ApoE4TG group and ApoE3TG group of young young the synaptic vesicle cycle compared to young ApoE4TG group and young group ApoE3TG, synaptic vesicle cycle was not statistically significant (Fig.8). Conclusion: 1 young ApoE4 transgenic mice with the same age group in ApoE3 transgenic mice compared to synaptic length and density of dendritic spines Reduce.2 young ApoE4 transgenic mice and ApoE3 transgenic mice compared with young hippocampal area CA3-CA1 curve of input and output, paired pulse facilitation enhancement, synaptic vesicle cycle significantly, but postsynaptic LTP has weakened; aged ApoE4 transgenic mice God hippocampal neurons postsynaptic enhancement decreased. Young ApoE4 mice and young ApoE3 transgenic mice compared to hippocampal theta.3 in hippocampus has weakened the dendritic morphology and neural network function in young ApoE4 transgenic mice have been reduced, may indicate that patients with Alzheimer's disease in clinical symptoms before the hippocampus neuron dendrites and electrophysiological activity has occurred pathological changes.

【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R749.16

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