本文選題：可塑性 + 深部腦刺激��； 參考：《廣州醫(yī)科大學》2017年碩士論文

【摘要】：【研究背景】抑郁癥嚴重影響人類健康與社會發(fā)展,世界衛(wèi)生組織估計至2020年抑郁癥將成為全球第二大疾病。當前針對抑郁癥的治療以藥物治療以及心理治療為主,然而僅有三分之一的患者取得較滿意療效。臨床上把久治不愈的的抑郁癥病人稱為難治性抑郁(treatment-resistant depression,TRD),對于這類患者,臨床上往往采用深部腦刺激(Deep Brain Stimulation,DBS)的治療方式,并取得了顯著的療效。外側韁核(Lateral Habenula,LHb)是連接基底節(jié)與邊緣系統(tǒng)的核團,參與調控獎賞系統(tǒng)及單胺類神經(jīng)遞質的分泌。深部腦刺激外側韁核(LHb-DBS)是治療難治性抑郁的主要方式之一,但其機制目前仍不明確。Malinow.R、Hongmei Meng等認為,DBS通過調控LHb神經(jīng)元的放電,上調腦內單胺類遞質的釋放從而改善抑郁癥狀,然而這一提高單胺類神經(jīng)遞質的假說與DBS運用于對單胺類藥物不敏感患者的臨床現(xiàn)象以及DBS快速起效的臨床特點不相符合,提示LHb-DBS治療抑郁存在其它機制。目前研究發(fā)現(xiàn)快速抗抑郁效果是由哺乳動物雷帕霉素位點(mTOR,mammalian target of rapamycin)激活介導的,而在下邊緣皮層進行深部腦刺激能上調mTOR磷酸化水平,提示LHb-DBS可能通過激活mTOR達到治療抑郁。Duman等發(fā)現(xiàn)L型電壓依賴鈣通道(L-type voltage-dependent calcium channel,L-VDCC)阻斷劑能有效阻斷mTO R的激活與KET的快速抗抑郁作用,提示L-VDCC也可能參與了LHb-DBS治療抑郁的過程。同時其它研究表明,DBS能誘導長時間的突觸改變,而mTOR的激活常常伴隨著樹棘突發(fā)生、突觸重構等突觸改變。進一步提示LHb-DBS可能通過激活mTOR改善突觸可塑性達到抗抑郁效果的機制。本研究采用免疫印跡、行為學和膜片鉗等技術,揭示并探討mTOR激活以及相關突觸可塑性在LHb-DBS治療抑郁的機制�！狙芯磕康摹框炞C激活mTOR與改善神經(jīng)可塑性是LHb-DBS治療抑郁在重要途徑,明確L-VDCC是否參與了LHb-DBS治療抑郁癥的過程,探討LHb-DBS上調神經(jīng)可塑性的具體機制。為DBS治療抑郁癥的臨床運用提供可靠的實驗依據(jù),并針對其機制開發(fā)抗抑郁新藥提供理論依據(jù)。【研究方法】LHb-DBS對LH大鼠的抑郁樣行為的影響參照Daniela Schulz等的方法,建立大鼠習得性無助(LH,learned helplessness)抑郁模型。觀察LH大鼠與正常大鼠行為差別,評價LH造模的可行性;對LH大鼠進行外側韁核深部腦刺激,觀察LHb-DBS對習得性無助大鼠抑郁樣行為的影響。同時給予側腦室注射L-VDCC阻斷劑(硝苯地平,nifedipine),觀察其對LHb-DBS抗抑郁作用的影響。LHb-DBS對mTOR磷酸化及其表達的作用參照Daniela Schulz等的方法,建立大鼠LH抑郁模型,通過手術安放電極于LHb,深部腦刺激為實驗組,深部腦假刺激為陽性對照組,未接受LH造模的正常老鼠為陰性對照組。通過western-blot,觀察外側韁核深部腦刺激后,海馬內mTOR磷酸化的表達變化。同時給予側腦室注射L-VDCC阻斷劑(硝苯地平,nifedipine),觀察其能否改變外側韁核深部腦刺激對mTOR磷酸化的調節(jié)。通過腦片模擬深部腦刺激觀察其對突觸可塑性影響急性分離LH大鼠冠狀位腦片于人工腦脊液中孵育,采用體外模擬LHb-DBS技術(具體詳見方法)刺激LHb,在海馬CA1 stratum radiatum(SR)亞區(qū)記錄由刺激聯(lián)合纖維引起的興奮性突觸后場電位(Shaffer collateral-CA1 field excitatory postsynaptic potentials,SC-CA1 fEPSP),觀察外側韁核刺激對SC-CA1 fEPSP的影響;給予20uM硝苯地平灌流腦片,觀察其對外側韁核刺激引起SC-CA1 fEPSP變化的影響;給予冠狀腦片模擬外側韁核深部腦刺激情況下,記錄海馬CA1區(qū)椎體神經(jīng)元的自發(fā)放電,探討LHb-DBS激活L-VDCC的機制�！狙芯拷Y果與結論】LHb-DBS能顯著改善LH大鼠的抑郁樣行為,而硝苯地平能有效阻斷外側韁核深部腦刺激的抗抑郁作用,提示L-VDCC參與了LHb-DBS的抗抑郁機制。同時LHb-DBS能激活海馬mTOR并引起海馬SC-CA1 fEPSP長時程升高,這一現(xiàn)象也能被硝苯地平阻斷,證明LHb-DBS能通過激活mTOR、改善突觸可塑性達到抗抑郁作用,且這一機制依賴L-VDCC的激活;LHb-DBS能顯著提高海馬CA1區(qū)椎體細胞自發(fā)動作電位的頻率以及寬度,增加L-VDCC的開放次數(shù)與時間,進一步證明了L-VDCC參與其抗抑郁的機制。
[Abstract]:[background] depression seriously affects human health and social development. The WHO estimates that depression will become the second largest disease in the world by 2020. At present, the treatment of depression is mainly drug therapy and psychotherapy, but only 1/3 of the patients have a satisfactory effect. The patients with depression are called treatment-resistant depression (TRD). For these patients, the treatment of Deep Brain Stimulation (DBS) is often used in this kind of patients. The lateral habenular nucleus (Lateral Habenula, LHb) is a nucleus connecting the basal ganglia and the marginal system and participates in the regulation of reward system. And the secretion of monoamine neurotransmitters. Deep brain stimulation of the lateral habenular nucleus (LHb-DBS) is one of the main ways to treat refractory depression, but its mechanism is still not clear.Malinow.R, Hongmei Meng and so on. DBS can improve depressive symptoms by regulating the discharge of LHb neurons and raising the release of monoamine neurotransmitters in the brain. The hypothesis of aminergic neurotransmitters is not consistent with the clinical characteristics of DBS in patients with monoamine drug insensitivity and the rapid onset of DBS, suggesting that LHb-DBS has other mechanisms for depression. The current study found that the rapid antidepressant effect was induced by the mammalian rapamycin site (mTOR, mammalian target of rapamycin). Deep brain stimulation in the lower marginal cortex can increase the level of mTOR phosphorylation, suggesting that LHb-DBS may be activated by activating mTOR to treat depression.Duman, such as the L type voltage dependent calcium channel (L-type voltage-dependent calcium channel, L-VDCC) blocking agent can effectively block the activation of mTO R and the rapid antidepressant effect. L-VDCC may also be involved in the process of depression in the treatment of LHb-DBS. Other studies have shown that DBS can induce long synaptic changes, and the activation of mTOR is often accompanied by synaptic changes such as the occurrence of tree spines and synaptic remodeling. Further hints that LHb-DBS may improve the mechanism of synaptic plasticity to improve the antidepressant effect by activating mTOR. Immunoblotting, behavioural and patch clamp techniques were used to reveal and explore the mechanism of mTOR activation and related synaptic plasticity in the treatment of depression in LHb-DBS. [Objective] to verify that activation of mTOR and improvement of nerve plasticity is an important way to treat depression in the treatment of LHb-DBS, whether L-VDCC is involved in the process of LHb-DBS treatment of depression, and to explore LHb- DBS provides a reliable experimental basis for the clinical application of DBS in the treatment of depression, and provides a theoretical basis for the development of new antidepressants for its mechanism. [Methods] the effects of LHb-DBS on the depressive behavior of LH rats refer to the methods of Daniela Schulz, and establish the acquired helplessness of rats (LH, learned he) Lplessness) depression model. Observe the behavior difference between LH rats and normal rats, evaluate the feasibility of the LH model, and observe the effect of LHb-DBS on the depressive behavior of the Acquired Helplessness rats by the deep brain stimulation of the lateral habenular nucleus in LH rats. At the same time, a L-VDCC blocker (nifedipine, nifedipine) is injected into the lateral ventricle, and the anti depressive effect of LHb-DBS on LHb-DBS is observed. The effects of.LHb-DBS on the phosphorylation and expression of mTOR in the rat model of LH depression were established by using the methods of Daniela Schulz and so on. Through the operation, the experimental group was placed on the electrode at LHb, the deep brain stimulation was the experimental group, the deep brain stimulation was the positive control group, and the normal mice without the LH model were negative control group. Through Western-blot, the lateral habenon was observed. Changes in the expression of phosphorylation of mTOR in the hippocampus after deep brain stimulation. The L-VDCC blocker (nifedipine, nifedipine) was injected into the lateral ventricle to observe the changes in the regulation of mTOR phosphorylation in the deep brain stimulation of the lateral habenular nucleus. The effects of the synaptic plasticity on the coronary position of the acute LH rats were observed by the brain slices simulated deep brain stimulation. The brain slices were incubated in the artificial cerebrospinal fluid. In vitro simulated LHb-DBS technique (detailed method) was used to stimulate the LHb. The excitatory postsynaptic potential (Shaffer collateral-CA1 field excitatory postsynaptic potentials) was recorded in the CA1 stratum radiatum (SR) subregion of the hippocampus (Shaffer collateral-CA1 field excitatory postsynaptic potentials), and the lateral habenular nucleus was observed. The effects of irritation on SC-CA1 fEPSP, 20uM nifedipine perfusion brain slices were given to observe the effect of the external habenular nucleus stimulation on the changes of SC-CA1 fEPSP. The spontaneous discharge of the vertebral neurons in the hippocampal CA1 region was recorded and the mechanism of LHb-DBS activation of L-VDCC in the hippocampus of the lateral habenular nucleus was given, and the mechanism of LHb-DBS activation of L-VDCC was discussed. LHb-DBS can significantly improve the depressive behavior of LH rats, while nifedipine can effectively block the antidepressant effect of the deep brain stimulation of the lateral habenular nucleus, suggesting that L-VDCC participates in the antidepressant mechanism of LHb-DBS. LHb-DBS can activate hippocampus mTOR and cause the long time course of SC-CA1 fEPSP in the hippocampus. This phenomenon can also be blocked by nifedipine, proving LHb-DB S can improve the synaptic plasticity to achieve antidepressant effect by activating mTOR, and this mechanism depends on the activation of L-VDCC. LHb-DBS can significantly increase the frequency and width of spontaneous action potential of the vertebral body cells in the CA1 region of the hippocampus, increase the opening times and time of L-VDCC, and further prove that L-VDCC is involved in its antidepressant mechanism.

【學位授予單位】：廣州醫(yī)科大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：R749.4

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相關期刊論文 前1條

1 張婷;蘇園林;王寧;王錦琰;羅非;;深部腦刺激治療疼痛的基礎研究與臨床應用進展[J];中國疼痛醫(yī)學雜志;2011年12期

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本文編號：1830395