本文關鍵詞：年輕小鼠海馬攜帶人ApoE4基因導致突觸和神經網絡異常的研究　出處：《河北醫(yī)科大學》2017年碩士論文　論文類型：學位論文

  更多相關文章： ApoE4 海馬 輸入/輸出曲線 雙脈沖易化 突觸后長時程增強 θ波

【摘要】：目的:通過觀察年輕(4月齡)的ApoE4轉基因小鼠腦片海馬腦片樹突形態(tài)及興奮性突觸后電位變化,探討ApoE4基因對年輕小鼠海馬突觸功能和神經網絡活動的影響。方法:雄性4個月ApoE4轉基因小鼠(年輕ApoE4TG組)22只,體重35g±5g,12個月ApoE4轉基因小鼠20只。雄性4個月ApoE3轉基因小鼠(ApoE3TG組)22只,分別異氟烷吸入麻醉后,斷頭處死,開顱取腦,取背側海馬區(qū)冠狀腦片,置于人工腦脊液中孵育至少1小時后轉移到水浴槽內,記錄在海馬CA1區(qū)放射層誘發(fā)和記錄興奮性突觸后電位(field excitatory postsynaptic potential,f EPSP),比較輸入/輸出曲線(Input-output relationship curve,I/O)、配對脈沖引起的雙脈沖易化(paired-pulse facilitation,PPF)、長時程增強(Long-term Potentiation,LTP)、三組高頻刺激(high frequency stimulations,HFSs)以及卡巴膽堿誘發(fā)的θ波的不同。雄性4個月ApoE4轉基因小鼠和12個月ApoE4轉基因小鼠(老年ApoE4TG組)比較I/O、PPF、LTP、突觸囊泡循環(huán)和θ波。用熒光染料注射到4個月ApoE4轉基因小鼠海馬CA1區(qū)錐體細胞層,然后重建染色神經元并分析樹突長度和樹突棘數(shù)量。結果:1 ApoE4TG組與ApoE3TG組樹突棘密度的比較ApoE4TG組與ApoE3TG組相比,海馬CA1區(qū)神經元樹突長度減短(P0.05),樹突棘數(shù)量明顯減少(P0.01),樹突棘密度整體減少(9.2±0.31,13.7±0.9,P0.05)(Fig.2)。2興奮性突觸后電位2.1年輕ApoE4TG組和年輕ApoE3TG組I/O、PPF、LTP的比較2.1.1海馬Schaffer側枝單個測試刺激的輸入/輸出曲線ApoE4TG組海馬CA1區(qū)單個4-10V電刺激后所得到的輸入輸出曲線斜率大于ApoE3TG組(0.89±0.08,0.49±0.04,P0.0001)(Fig.3)。2.1.2配對脈沖引起的雙脈沖易化ApoE4TG組雙脈沖易化與ApoE3TG組相比增強(P0.05)(Fig.4)。2.1.3突觸后長時程增強ApoE4TG組與ApoE3TG組相比,海馬CA1區(qū)突觸后LTP誘導期減弱(1.38±0.02,1.52±0.02,P0.0001)。在LTP維持ApoE4 T組仍低于ApoE3TG組(1.31±0.01,1.47±0.01,P0.0001)(Fig.5)。2.2年輕ApoE4TG組和老年ApoE4TG組I/O、PPF、LTP的比較。年輕ApoE4TG組海馬CA1區(qū)單個4-10V電刺激后所得到的輸入輸出曲線斜率大于老年ApoE4TG組(年輕ApoE4:0.89±0.07,老年ApoE4:0.49±0.04,P0.0001)。老年ApoE4TG組雙脈沖易化與年輕ApoE3TG組相比(P0.01)。老年ApoE4TG組與年輕ApoE3TG組相比LTP誘發(fā)(LTP強直刺激后0-10min)沒有明顯差別(老年ApoE4:1.34±0.04,年輕ApoE4:1.38±0.02,P0.05),但LTP維持(強直刺激后50-60min)明顯減弱(老年ApoE4:1.20±0.006,年輕ApoE4:1.31±0.007,P0.0001)(Fig.6)。2.3 ApoE4TG組與ApoE3TG組卡巴膽堿誘發(fā)的θ波ApoE4TG組與ApoE3TG組相比,卡巴膽堿誘發(fā)的θ波的潛伏時間長(P0.05),誘發(fā)的波數(shù)量少(P0.01)(Fig.7)。2.4年輕ApoE4TG組和年輕ApoE3TG組突觸囊泡循環(huán)年輕ApoE4TG組和年輕ApoE3TG組相比,突觸囊泡循環(huán)沒有統(tǒng)計學差異(Fig.8)。結論:1年輕ApoE4轉基因小鼠與相同年齡組ApoE3轉基因小鼠相比較神經突觸長度及樹突棘密度減少。2年輕ApoE4轉基因小鼠與年輕ApoE3轉基因小鼠相比較海馬CA3-CA1區(qū)輸入輸出曲線、雙脈沖易化增強,突觸囊泡循環(huán)明顯變化,但是突觸后長時程增強有減弱;老年ApoE4轉基因小鼠神海馬區(qū)神經元的突觸后增強減弱。年輕ApoE4小鼠與年輕ApoE3轉基因小鼠相比較海馬區(qū)θ波已有減弱。3在年輕ApoE4轉基因小鼠的海馬區(qū)樹突形態(tài)及神經網絡功能已經有降低,可能預示著阿爾茨海默病患者在出現(xiàn)臨床癥狀前海馬區(qū)樹突及神經元電生理活動已經發(fā)生病理學變化。
[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.

【學位授予單位】：河北醫(yī)科大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：R749.16

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相關期刊論文 前1條

1 Shreaya CHAKROBORTY;Grace E.STUTZMANN;;Early calcium dysregulation in Alzheimer's disease:setting the stage for synaptic dysfunction[J];Science China(Life Sciences);2011年08期

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本文編號：1423058