本文關(guān)鍵詞：Ahi1基因敲除造成小鼠腦內(nèi)神經(jīng)遞質(zhì)釋放改變，由筆耕文化傳播整理發(fā)布。

        目的觀察Ahi1基因敲除(Ahi1KO)小鼠是否存在抑郁樣表型，進(jìn)一步探討神經(jīng)遞質(zhì)改變在抑郁樣行為發(fā)生機(jī)制中的作用。方法采用Western blot法測定Ahi1KO小鼠以及對照小鼠(Ahi1雜合子)腦組織中Ahi1蛋白的表達(dá)水平；利用懸尾實(shí)驗(yàn)(TST)、強(qiáng)迫游泳實(shí)驗(yàn)(FST)、糖水偏好實(shí)驗(yàn)等行為學(xué)實(shí)驗(yàn)觀察Ahi1KO小鼠是否存在抑郁樣表型；采用高效液相色譜法(HPLC)測定腦組織中五羥色胺(5-HT)、五羥基吲哚乙酸(5-HIAA)、多巴胺(DA)、高香草酸(HVA)、二羥基苯乙酸(DOPAC)、谷氨酸(glutamate)、γ-氨基丁酸(GABA)等神經(jīng)遞質(zhì)的含量；采用ELISA法測定腦組織單胺類神經(jīng)遞質(zhì)代謝相關(guān)酶單胺氧化酶(MAO)的活性。為研究抗抑郁藥對這種抑郁樣行為是否存在治療作用，將Ahi1KO小鼠隨機(jī)分為2組，實(shí)驗(yàn)組、鹽水組。實(shí)驗(yàn)組給予每天腹腔注射丙咪嗪(20mg/kg體重)，鹽水組給予腹腔注射相同劑量生理鹽水，3周后觀察行為學(xué)改變，并應(yīng)用HPLC測定腦組織中神經(jīng)遞質(zhì)的改變。結(jié)果Western blot結(jié)果顯示：與對照組相比，Ahi1KO小鼠基本無Ahi1蛋白表達(dá)。懸尾實(shí)驗(yàn)和強(qiáng)迫游泳實(shí)驗(yàn)表明Ahi1KO小鼠的不動時(shí)間較對照組明顯增長(P＜0.05)。在糖水偏好實(shí)驗(yàn)中，Ahi1KO小鼠的總飲水量以及糖水占總飲水量的百分比是明顯降低的(P＜0.05)。出生4天的小鼠腦組織中，Ahi1KO小鼠與對照組的5-HT的含量沒有明顯差別，出生10天、1月、2月的小鼠腦組織中，對照組的5-HT的含量明顯增加(P＜0.05)，而Ahi1KO小鼠增加不明顯；同樣DA的水平在出生4天的Ahi1KO小鼠腦組織中也沒有明顯差別，出生10天及1月的小鼠腦組織中的DA的含量Ahi1KO小鼠較對照組降低(P＜0.05)。出生4天和10天的小鼠腦組織中的谷氨酸和GABA的含量，Ahi1KO小鼠與對照組相比卻無明顯差別(P>0.05)。取1月齡小鼠不同部位腦組織(杏仁核、海馬、皮層、下丘腦、腦干)進(jìn)行5-HT和DA等神經(jīng)遞質(zhì)檢測，發(fā)現(xiàn)Ahi1KO小鼠的腦組織的5-HT及其代謝產(chǎn)物5-HIAA較對照組含量明顯降低(P＜0.05)，，5-HIAA與5-HT的比值（代謝率）則比對照組增高(P＜0.05)。同5-HT類似，DA及其代謝產(chǎn)物HVA、DOPAC也觀察到同樣結(jié)果。ELISA法檢測腦組織中腦干MAO的活性結(jié)果顯示Ahi1KO小鼠的MAO的活性與對照組相比明顯升高(P＜0.05)。Ahi1KO小鼠注射丙咪嗪3周后，在TST、FST中不動時(shí)間較鹽水組明顯縮短(P＜0.05)，五羥色胺的水平較鹽水組升高(P＜0.05)，而多巴胺的含量卻沒有明顯變化(P>0.05)。結(jié)論敲除Ahi1基因可在小鼠中造成抑郁樣行為。Ahi1KO小鼠不同腦組織中抑郁相關(guān)單胺類神經(jīng)遞質(zhì)如5-HT、DA含量降低，但氨基酸類神經(jīng)遞質(zhì)如谷氨酸、GABA的含量無明顯改變。在Ahi1KO小鼠腦組織中，MAO的活性增高可能是引起單胺類神經(jīng)遞質(zhì)含量降低的一個(gè)原因。丙咪嗪治療可以減輕抑郁樣癥狀，Ahi1KO小鼠腦組織中5-HT的含量可以部分恢復(fù)，因此Ahi1KO小鼠是研究抑郁機(jī)制的一個(gè)理想模型，并可用于抗抑郁藥物篩選。

    Objective To investigate whether Ahi1KO mice have depressive phenotype andfurther explore the role of neurotransmitters in the mechanisms of depressive behaviors.Methods Western blot analysis was used to determine the expression levels of Ahi1inAhi1KO mice and control mice (Ahi1heterozygote). Tail suspension test, forcedswimming test, and sucrose preference test were used to examine depressive phenotype inmice. The contents of neurotransmitters including serotonin (5-HT),5-hydroxy indoleacetic acid (5-HIAA), dopamine (DA),4-hydroxy-3-methoxyphenylacetic (HVA),dihydroxyphenylacetic acid (DOPAC), glutamate and gamma amino acid butyric acid(GABA) were measured by high performance liquid chromatography (HPLC). Wemeasured the monoamine oxidase activity (MAO) in the brainstem of control and Ahi1KOmice by an enzyme linked immunosorbent assay method (ELISA). In order to studywhether these mice responded to known anti-depressant impramine, Mice were treatedwith imipramine or normal saline intraperitoneally for3weeks. Three weeks later, thechange of behaviors was evaluated by forced swimming test and tail suspension test, thechanges of neurotransmitters were examined by HPLC.Results Western blot analysis revealed that there was almost no Ahi1expression inAhi1KO mice (P＜0.05).Tail suspension test and forced swimming test shown thatsignificant decrease of immobility time was found in Ahi1KO mice compared with controlmice (P＜0.05). In sucrose preference test, total consumed liquid and the percentage ofconsumed sucrose water was markedly decreased in Ahi1KO mice (P＜0.05).At postnatalday4, there was no difference for the content of serotonin in control and Ahi1KO mice(P>0.05). However, after postnatal day10、1month and2month，serotonin level wassignificantly increased in control mice, while only a slight increase of serotonin wasobserved in Ahi1KO mice. Similarly, dopamine level was not significantly elevated inAhi1KO mice as in control mice after postnatal day4, but dopamine level was muchlower in Ahi1KO mice after postnatal day10d、1m compared with control mice (P＜0.05). Glutamate and GABA levels were not influenced in control and Ahi1KO mice at4d,10d(P>0.05). We further measured serotonin levels in the cortex, hippocampus, hypothalamus,brainstem, and amygdale at1-m-old mice, the level of serotonin and the metabolite ofserotonin5-HIAA was decreased in Ahi1KO mice compared with control mice (P＜0.05).However, the ratio of5-HIAA to serotonin, namely serotonin turnover, was markedlyelevated in Ahi1KO mice(P＜0.05). Similar tendency was also observed in dopamine, themetabolite of dopamine (DOPAC and HVA).MAO activity was significantly increased inAhi1KO mice compared with control mice(P＜0.05).After imipramine treatment for3weeks, immobility time of Ahi1KO mice in forced swimming test and tail suspension testwas significantly decreased(P＜0.05). Serotonin level was elevated(P＜0.05), however,dopamine level was not changed (P>0.05).Conclusion Ahi1KO caused depressive behaviors in mice.In Ahi1KO mice, thecontent of depression-related neurotransmitter such as5-HT and DA was decreased,however, the level of amino acid neurotransmitters (such as glutamate and GABA) werenot influenced. MAO activity was elevated in Ahi1KO mice, which may result in thedecrease of monoamine in brains. Imipramine alleviated the depressive phenotype;moreover, the content of5-HT in Ahi1KO mice was partly restored. Therefore, Ahi1KOmice are a genetic model of depression for the mechanistic study and a useful tool toscreen anti-depressants.

Ahi1基因敲除造成小鼠腦內(nèi)神經(jīng)遞質(zhì)釋放改變

中文摘要4-6Abstract6-7前言9-11第一部分 AHI1 基因敲除對小鼠行為學(xué)的影響11-20    材料和方法11-16    結(jié)果16-19    小結(jié)19-20第二部分 AHI1 敲除小鼠腦內(nèi)神經(jīng)遞質(zhì)水平及單胺氧化酶活性的改變20-31    材料和方法20-25    結(jié)果25-29    小結(jié)29-31第三部分 抗抑郁藥對 AHI1 KO 小鼠抑郁樣癥狀以及神經(jīng)遞質(zhì)水平的影響31-36    材料和方法31-32    結(jié)果32-35    小結(jié)35-36討論36-39結(jié)論39-40參考文獻(xiàn)40-43綜述：五羥色胺與抑郁治療43-50    參考文獻(xiàn)47-50英文縮寫詞表50-51攻讀學(xué)位期間公開發(fā)表的論文51-52致謝52-53

  本文關(guān)鍵詞：Ahi1基因敲除造成小鼠腦內(nèi)神經(jīng)遞質(zhì)釋放改變，由筆耕文化傳播整理發(fā)布。