發(fā)布時間：2018-04-20 05:09

  本文選題：嗅球 + 乙酰膽堿��； 參考：《桂林醫(yī)學(xué)院》2016年碩士論文

【摘要】：目的:乙酰膽堿是中樞神經(jīng)系統(tǒng)內(nèi)一種重要的神經(jīng)遞質(zhì)�；浊澳X膽堿能神經(jīng)元通過釋放乙酰膽堿來調(diào)節(jié)注意、學(xué)習(xí)和記憶等功能。主嗅球接受來自基底前腦斜角帶核水平支大量的膽堿能和GABA能離心纖維的投射,這一投射系統(tǒng)已經(jīng)被證明在嗅覺信息的處理和嗅覺記憶中發(fā)揮至關(guān)重要的作用。動物行為學(xué)實驗表明乙酰膽堿影響動物的嗅覺分辨和嗅覺記憶能力。但是,基底前腦斜角帶核水平支膽堿能神經(jīng)元對嗅球中神經(jīng)元以及神經(jīng)環(huán)路的調(diào)控作用仍然未知。近來研究發(fā)現(xiàn),阿爾茨海默病等神經(jīng)退行性疾病的患者早期多伴有膽堿能神經(jīng)元的損傷和嗅覺的減退缺失。因此,了解乙酰膽堿在嗅覺信息處理中所起的作用對探索神經(jīng)退行性疾病的發(fā)病機(jī)制有一定的臨床意義。本文的主要目的是探索乙酰膽堿對嗅球內(nèi)部神經(jīng)環(huán)路的作用。方法:通過腦立體定位注射,將腺相關(guān)病毒注射到小鼠的基底前腦,待病毒穩(wěn)定表達(dá)后,通過灌流取材和冰凍切片觀察膽堿能纖維在嗅球中的分布。采用離體腦片的膜片鉗記錄,制備厚度為300?m的嗅球腦片用于記錄。使用含有生物素的記錄電極記錄位于嗅小球?qū)拥那蛑芗?xì)胞和僧帽細(xì)胞層的僧帽細(xì)胞,再利用給藥電極在細(xì)胞附近局部噴射乙酰膽堿等藥物。記錄完成之后,將腦片用4%PFA固定,用Cy3的紅色二抗進(jìn)行免疫染色,用激光共聚焦顯微鏡掃描圖像,確定細(xì)胞形態(tài)和類型。所有的電生理數(shù)據(jù)用Clampex10.2軟件(Axon)進(jìn)行分析處理。結(jié)果:膽堿能神經(jīng)纖維在嗅球各層都有投射,主要集中在嗅小球?qū)�。局部給予乙酰膽堿使表達(dá)VGAT的球周細(xì)胞自發(fā)放電和誘發(fā)放電頻率顯著增加,并產(chǎn)生內(nèi)向電流,這一反應(yīng)可被mAChR的拮抗劑阿托品阻斷,突觸傳遞的阻斷劑不能消除該反應(yīng)。尼古丁則對球周細(xì)胞無此作用。乙酰膽堿還可通過激活mAChR使球周細(xì)胞接受的興奮性輸入的頻率增加。嗅球的投射神經(jīng)元僧帽細(xì)胞放電被乙酰膽堿抑制,這種抑制可被GABAA受體的阻斷劑和mAChR的拮抗劑阻斷。嗅球中另一類多巴胺能的球周細(xì)胞,其放電可被乙酰膽堿直接抑制。結(jié)論:乙酰膽堿通過激活mAChR從而增加GABA能球周細(xì)胞的興奮性,這一興奮性的增加不依賴于任何突觸傳遞。乙酰膽堿通過興奮GABA能球周細(xì)胞間接抑制僧帽細(xì)胞,從而調(diào)節(jié)嗅球的信息輸出。多巴胺能的球周細(xì)胞則受到乙酰膽堿的抑制。乙酰膽堿對嗅球神經(jīng)環(huán)路的調(diào)節(jié)作用,可能影響到動物的嗅覺分辨和嗅覺記憶能力。
[Abstract]:Objective: acetylcholine is an important neurotransmitter in the central nervous system. Basal forebrain cholinergic neurons regulate attention, learning and memory by releasing acetylcholine. The main olfactory bulb receives a large number of cholinergic and GABA energy centrifugal fibers from the horizontal branch of the basal diagonal band nucleus. This projection system has been shown to play a crucial role in the processing of olfactory information and olfactory memory. Animal behavioral experiments show that acetylcholine affects olfactory resolution and olfactory memory in animals. However, the regulation of horizontal cholinergic neurons on the olfactory bulb neurons and the neural loop is still unknown. Recent studies have found that patients with neurodegenerative diseases such as Alzheimer's disease are associated with cholinergic neuron damage and loss of olfaction. Therefore, understanding the role of acetylcholine in olfactory information processing has a certain clinical significance in exploring the pathogenesis of neurodegenerative diseases. The main purpose of this paper is to explore the effect of acetylcholine on the neural loop in olfactory bulb. Methods: adeno-associated virus was injected into the basal forebrain of mice by stereotactic injection. After stable expression of the virus, the distribution of cholinergic fibers in olfactory bulb was observed by perfusion and frozen sections. Using patch-clamp recording of isolated brain slices, the olfactory bulb slices with thickness of 300 m were prepared for recording. A recording electrode containing biotin was used to record the peribulbar cells located in the olfactory pellet layer and the mitral cells in the mitral cell layer. The acetylcholine and other drugs were sprayed near the cells by the administration electrode. After the recording was completed, the brain slices were fixed with 4%PFA and stained with the red second antibody of Cy3. The images were scanned by laser confocal microscope to determine the morphology and type of cells. All electrophysiological data were analyzed with Clampex10.2 software. Results: cholinergic nerve fibers were projected in all layers of olfactory bulb, mainly in the layer of olfactory bulb. Local administration of acetylcholine significantly increased the frequency of spontaneous and evoked discharges in peripheral cells expressing VGAT and produced inward currents, which could be blocked by atropine, an antagonist of mAChR, which could not be eliminated by synaptic transmitters. Nicotine had no such effect on peribulbar cells. Acetylcholine can also increase the frequency of excitatory inputs accepted by peribulbar cells by activating mAChR. The firing of mitral cells of olfactory bulb projecting neurons was inhibited by acetylcholine, which could be blocked by antagonists of GABAA receptor and mAChR. In the olfactory bulb, another type of dopaminergic peribulbar cells whose discharges are directly inhibited by acetylcholine. Conclusion: acetylcholine increases the excitability of GABA peracyclic cells by activating mAChR, which is independent of any synaptic transmission. Acetylcholine regulates the information output of olfactory bulb by stimulating GABA and inhibiting mitral cells indirectly. Dopaminergic peribulbar cells were inhibited by acetylcholine. The effect of acetylcholine on olfactory bulb loop may affect olfactory resolution and olfactory memory.
【學(xué)位授予單位】：桂林醫(yī)學(xué)院
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：R741

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 徐祖才;陳恒勝;劉靚;周艷;唐波;陳國俊;王學(xué)峰;;膜片鉗技術(shù)在成年大鼠海馬腦片應(yīng)用的初步研究[J];重慶醫(yī)科大學(xué)學(xué)報;2012年09期

2 譚潔;羅敏敏;;嗅球?qū)π嵊X信息的處理[J];生物物理學(xué)報;2010年03期

3 邱前輝,陳少華,蒙翠原,廖鳳英,黃曉明,李添應(yīng);放療對鼻咽癌患者嗅覺的影響[J];臨床耳鼻咽喉科雜志;2001年02期

4 檀進(jìn)發(fā),張德興,潘文珊,柯銘華;大鼠嗅球乙酰膽堿酯酶陽性傳入纖維起源的實驗研究[J];解剖學(xué)雜志;1991年04期

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