【作者】 傅小云；

【导师】 常业恬；

【作者基本信息】 中南大学 ， 麻醉， 2009， 博士

【摘要】 本研究通过比较四种不同麻醉药物腹腔注射,对比观察麻醉效果及血流动力学、血气变化,探讨适合本研究的最佳腹腔注射麻醉药物;调试并建立大鼠全脑的fMRI扫描序列参数、鼠脑空间标准化的方法;运用fMRI脑功能成像技术观察在重复的伤害性电刺激下,中枢伤害性刺激加工网络的激活变化特点,为连续、动态的监测伤害性刺激加工网络提供方法学上的支持并奠定前期的试验基础,同时也为全麻药物、镇痛药物中枢效应的可视化监测提供前期方法学上的探索。第一部分不同全麻药物腹腔注射麻醉效果及血流动力学、血气变化目的比较四种麻醉药物腹腔注射麻醉效果及血流动力学、血气变化,确定适用本研究的最佳麻醉药物。方法随机表法将SD大鼠分为4组,每组12只。A组大鼠以丙泊酚腹腔注射麻醉,剂量80mg/kg;B组以氯胺酮腹腔注射麻醉,剂量75mg/kg;C组以2%戊巴比妥钠腹腔注射麻醉,剂量40mg/kg;D组大鼠以10%水合氯醛腹腔注射麻醉,剂量300mg/kg。行鼠尾连续伤害性电刺激,刺激参数:脉冲宽度300μs,恒定电流3.8mA（产生伤害性刺激电流）,刺激频率3Hz。观察在麻醉后10min、刺激后15min、30min、清醒后5min记录体温（T）、呼吸（R）、平均动脉压（MAP）、心率（HR）,经股动脉抽血0.3ml检测pH、PaO₂、PaCO₂,观察麻醉后、电刺激期间的呼吸、心率、MAP及血气的改变。结果1.四组大鼠麻醉前后体温均维持在37℃—38℃之间。A组呼吸频率在刺激后15min明显低于清醒后呼吸频率（P＜0.05）;C组、D组呼吸频率在麻醉后10min,均低于其他各时间点的呼吸频率（P＜0.05）;B组大鼠各时间点的呼吸频率稳定,差异无统计学意义（P＜0.05）。A、C、D组大鼠麻醉后10min HR明显低于清醒后心率（P＜0.05）;B组麻醉后及刺激期间心率明显高于清醒后心率（P＜0.05）。A、C、D组麻醉后10min的MAP明显低于刺激后15min、刺激后30min、清醒后30min的MAP（P＜0.05）;B组麻醉后及刺激期间MAP明显高于清醒后MAP（P＜0.05）。2.各组pH值在各时间点均无明显变化,差异无统计学意义（P＜0.05）。A、C、D组的PaO₂在麻醉后10min较清醒后明显降低,差异有统计学意义（P＜0.05）。各组PaCO₂在各时间点比较,差异无显著性意义（P＞0.05）。C组麻醉后10min于其他各组同时间点比较PaO₂明显降低,PaCO₂明显增高（P＜0.05）。3.D组的起效时间为（3.56±1.01）min,明显较A、B、C组起效时间短,差异有统计学意义（P＜0.01）;C组的起效时间明显较A组和B组起效时间短,差异有统计学意义（P＜0.05）。D组的苏醒时间为（76.54±15.48）min,明显长于A、B、C组,差异有统计学意义（P＜0.01）;C组的苏醒时间明显长于A组和B组（P＜0.05）。结论四种麻醉药物腹腔注射,均安全有效,大鼠的HR、MAP、血气分析均在正常范围。10%水合氯醛300mg/kg腹腔注射麻醉效果确切,麻醉维持时间最长,麻醉期间呼吸、循环、血气分析结果稳定,是大鼠磁共振扫描的很好的麻醉方法。第二部分fMRI用于伤害性刺激加工网络的可视化研究目的本研究拟采用连续的fMRI成像方法,探讨在全麻状态不同麻醉间期伤害性电刺激时中枢加工网络的激活规律。方法根据经皮电刺激的部位将SD大鼠随机分为两组（n=24）,T组刺激鼠尾,LF组刺激左前爪。10%水合氯醛腹腔注射麻醉后行fMRI脑功能成像。采用组块设计的fMRI试验方法,每次fMRI成像共扫描110个全脑图象,组成5个Block,每次扫描时间3分55秒。电刺激方由有静息和刺激交替进行（off-on-off-on-off）,即:静息30个scan,刺激10个scan,静息30个scan,刺激10个scan,静息30个scan。每次扫描结束后,间歇5min,行下一次扫描,刺激方式相同,重复扫描4个循环。采用SPM统计软件行功能像分析处理,比较不同麻醉间期伤害性刺激中枢处理网络的激活情况。结果1各组试验前后HR、MAP、血气的变化2组试验大鼠均顺利完成试验,实验过程麻醉平稳,连续4个循环的伤害性刺激头动均在可以控制的范围之内。2组试验前HR、MAP、pH、PaO2、PaCO2均处于同一水平,试验结束时2组的HR、MAP均明显高于试验前,差异有统计学意义（P＜0.05）。2组试验前后的pH、PaO2、PaCO2均在正常范围,差异无统计学意义（P＞0.05）。表明2组MRI扫描期间生理指标处于稳定状态,大鼠脑血流的灌注均在同一水平,试验数据具有可比性。2不同麻醉间期鼠尾、左前爪伤害性刺激脑中枢激活情况本研究表明,在不同的麻醉间期,对大鼠尾、左前爪行伤害性电刺激,脑中枢的激活均不完全一致。SPM统计参数图在阈值0.005水平,伤害性电刺激在中枢激活的主要脑区包括:初级感觉皮质（primarysomatosensory cortex,SⅠ）、次级感觉皮质（sencondly somatosensorycortex,SⅡ）、运动皮质（Motor cortex,MC）、中脑（midbrain）、纹状体（caudate putamen（striatum）,Cpu）、视觉皮质（visualcortex,VC）、前扣带回（anterior cingutate,Cg）、后扣带回皮质（retrosplenial granular cortex,RSG）、丘脑（thamulus,Th）、海马（Hippocamps,HIP）、杏仁核（amygdaloid nucleus,AN）、伏膈核（accumbens nucleus,Acb）、桥脑（Pons,Po）、延髓（medullaoblogata,MO）、下丘（inferior colliculus,IC）、小脑（Cerebellum）。3 2组不同时间段各脑区激活发生率及激活脑区数目比较本研究表明,2组不同时间段的各脑区激活的发生率不是完全一致的,广义混合线性模型统计学分析可以得到:两组Cg、Cpu、Hip、SⅡ、Th在A时间段的激活率明显高于D时间段,差异有统计学意义（P＜0.05）;T组AN、Cerebellum在A时间段的激活率明显高于D时间段,差异有统计学意义（P＜0.05）;LF组VC的激活率在A时间段的激活率明显高于D时间段,差异有统计学意义（P＜0.05）;LF组Th的激活率在A时间段的激活率明显高于C时间段,差异有统计学意义（P＜0.05）。广义混合线性模型统计学分析两组不同时间段激活数目情况:两组D时间段的总的激活数目明显低于A、B、C时间段,差异有统计学意义;两组C时间段总的激活数目明显低于A、B时间段,差异有统计学意义（P＜0.05）。LF组的D时间段的激活数目明显低于同组A、B、C时间段,差异有统计学意义（P＜0.05）;LF组的C时间段的激活数目明显低于同组A、B时间段,差异有统计学意义（P＜0.05）;LF组的B时间段的激活数目明显低于同组A时间段,差异有统计学意义（P＜0.05）。T组的D时间段的激活数目明显低于同组A、B、C时间段,差异有统计学意义（P＜0.05）。4 2组不同麻醉间期fMRI图像的组分析结果SPM组分析结果:T组在不同麻醉间期均存在右侧SⅠ、SⅡ、后扣带回皮质（RSG）、杏仁核（AN）的激活,其中在A时间段还可以见到右侧腹后外侧丘脑核（ventral posterolateral thalamic nucleus,VPL）的激活;LF组在不同麻醉间期均存在伏膈核（AcASH）、右侧SⅠ、右侧腹后外侧丘脑核（ventral posterolateral thalamic nucleus,VPL）及后扣带回皮质（RSG）的激活;2组大鼠在D时间段各激活脑区的体积在四个时间段中比较最小,提示在连续3个时间段的电刺激后,中枢对电刺激引起的躯体感觉传导通路及加工网络的BOLD信号响应减弱。5 2组A、D时间段激活差异比较本研究运用SPM的减法原则,分析2组A、D时间段激活的差异,在threshhold 0.05水平,T组A时间段fMRI激活区减去D时间段fMRI激活区,有差异的激活区为苍白球（ventral pallidum,VP）、左侧SⅡ、海马CA1区（field CA1 of the hippocampus,CA1）;LF组A时间段fMRI激活区减去D时间段fMRI激活区,有差异的激活区为基底外侧杏仁核（BLA）、导水管灰质（PAG）、中央杏仁核（CMe）、顶盖前核（anterior pretectal nucleus,APtn）。而2组D时间段fMRI激活区减去A时间段fMRI激活区,则基本没有差异的激活。结论不同麻醉间期、不同刺激部位大鼠中枢痛觉处理网络的激活不完全一致。刺激鼠尾以右侧SⅠ、SⅡ、后扣带回皮质（RSG）、杏仁核（AN）的激活为主,刺激左前爪以伏膈核（AcbSH）、右侧SⅠ、右侧腹后外侧丘脑核（ventral posterolateral thalamic nucleus,VPL）及后扣带回皮质（RSG）为主。在伤害性刺激的早期,即有中枢下行抑制系统的激活,这些区域包括:苍白球（ventral pallidum,VP）、左侧SⅡ、海马CA1区（field CA1 of the hippocampus,CA1）;基底外侧杏仁核（BLA）、导水管灰质（PAG）、中央杏仁核（CMe）、项盖前核（anterior pretectal nucleus,APtN）。在连续的经皮电刺激后,中枢伤害性刺激加工网络BOLD信号响应会出现减弱的情况,这可能与中枢的痛觉下行调制系统的抗痛效应有关。SⅠ、SⅡ、后扣带回皮质（RSG）、杏仁核（AN）及伏膈核（AcbSH）、右侧SⅠ、右侧腹后外侧丘脑核（ventral posterolateral thalamicnucleus,VPL）及后扣带回皮质（RSG）可作为fMRI可视化监测麻醉状态下伤害性加工网络的主要脑区;做为一种为整体、动态的监测全麻状态下中枢伤害性刺激加工网络的可视化监测方法,有很好的开发应用前景。更多还原

【Abstract】 Firstly,our researsh was to establish a stable methods for anaesthesia in rats during fMRI to compare the effects of diffirent anaesthetics;Secondly,rats fMRI scanning sequence and the methods of whole brain normalization were to be constructed;Finally,our research was to characterize the cerebral network of nociception stimulas proccessing with fMRI during diffirent anaesthetic intervals and to provide a new methods to monitor somatosensory pathway and establish prior research groundwork.Chapter 1 The comparison of the ananesthesia effects and the changes of hemodynamics and blood gas level in treatment with diffirent anesthetic agents in ratsObjectiveTo compare the ananesthesia effects and the changes of hemodynamics and blood gas level in treatment with diffirent anesthetic agents in rats for MRI scanning in this study.Methods48 SD rats were randomized into 4 groups(n=12),the rats of group A,B,C and D were intraperitoneally injected propofol(80mg/kg), ketamine(75mg/kg),2%sodium pentobarbital(40mg/kg) and 10%Chloral Hydrate(300mg/kg) respectively.A TENS supplied 3.8 mA,300μs,3Hz to the rat tail in the enviorment to simulate MRI scanning house.The body temprature,R,HR,MAP,pH,PaO2 and PaCO2 were monitored 10 min before anaesthesia,15 min after stimulation,30 min after stimulation and 5 rain after recovery.Results1.All rats rectal temprature were maintaned at 37℃-38℃.The ration of respiration of 15 min after stimulation of group A was significantly deceased when compared with those of other timepoints in same group (P＜0.05).The ration of respiration of 10 min after anaesthesia of group C and D were deceased significantly when compared with those of other timepoints in same group(P＜0.05).The HR of group A,C and D were inhibited significantly 10 min after anaesthesia when compared with those of 5 min after recovery(P＜0.05).The HR of group B were increased significantly when compared those of 5 min after recovery (P＜0.05).MAP of 10 min after anaesthesia in group A,C and D were decareased significantly when compared withe those of 15 min after stimulation,30 min after stimulation and 5 min after recobery (P＜0.05),but MAP of 10 min after anaesthesia in group B were higher than those of 5 min after recobery(P＜0.05)2.The pH of all rats had no significant changes in each timepoint(P＜0.05).PaO2 of 10 min after anaesthesia in group A,C and D were decreased significantly when compared those of 10 min after recvery.PaCO2 of 10 min after anaesthesia in group A,B and D had not been influenced at the each timepoint(P＞0.05).PaO2 of 10 min after anaesthesia in group C was lower than that of other timepoint whtin same group and PaCO2 of 10 min after anaesthesia in group C was increased at the same time(P＜0.05).3.The onset time of 10%Chloral Hydrate was shorter than that of propofol,ketamine and 2%sodium pentobarbital(P＜0.05).The onset time of 2%sodium pentobarbitalwas shorter than that of propofol,ketamine (P＜0.05).The time of recovery of group D was longer than that of group A,B and C(P＜0.05).The time of recovery of group C was longer than that of group A and B(P＜0.05).ConlusionsFour anesthetic agents are safe and effective in rats during magnetic resonance imaging.HR,MAP and blood gas datas are mantained in a normal level.Single intraperitoneal injection with 10%Chloral Hydrate(300mg/kg) is a nice method in rats during magnetic resonance imaging especialy longtime MRI scanning. Chapter 2 Functional MRI of the cerebral processing network of nociception stimulation at different anaesthesia intervalsObjectiveTo investigate the characterizations of cerebral processing network activation of nociception stimulation at different anaesthesia intervals using Functional MRI.Methods48 rats were randomized into 2 groups:the tail of nociceptive electric stimulus to rats in group T(n=24) and the left forepaw of nociceptive electric stimulus to rats in group LF n=24).All animals were anaesthetised with 10%Chloral Hydrate(300mg/kg) by single intraperitoneal injection.Using block design model,110 whole brain scanning imaging were acquired[Coil selection:SENSE-Torso;FOV: RL(mm) 50,AP(mm) 41,FH(mm) 20;TR:2000ms,TE:28ms, slice thickness:1mm;ACQ voxel matrix MPS(mm):0.63/0.49/2.0; REC voxel matrix MPS(mm):0.21/0.21/1.0;flip angle):90°]."rest" and "stimulation" were alternately carried out(off-on-off-on-off).Every tests included 30 rest whole brain scanning,10 stimulation whole brain scanning,30 rest whole brain scanning,10 stimulation whole brain scanning and 30 rest whole brain scanning.The same test was repeated 3 times 5 min later.Post-processed images were analysed with SPM2 using a multi-subject fixed effects general linear model to characterise brain specific activations and visualise cerebral processing network activation of nociception stimulation at different anaesthesia intervals.Results1 The changes of HR,MAP and blood gas analysis in 2 groups There were no significantly differences in HR、MAP、pH、PaO2、PaCO2 between 2 groups before fMRI sanning after anaesthesia (P＞0.05).HR and MAP of both groups were higher than those of 2 groups before the test(P＜0.05).There were no differences in pH、PaO2、PaCO2 which were all in normal ranges between those of before the test and after the test(P＜0.05).The datas show the physiological index of all rats are stable and brain blood perfusion are in same level.2 The changes of brain activations of rats induced by nociceptive stimulation in different anaesthesia interval2.1 SPMs for nociceptive stimulation of tail and left fore pawThe threshold of SPM was 0.005.Constant current electrical stimulation of the tail and forepaw produced rbust and localised BOLD contrast changes.These activation areas includes:primary somatosensory cortex(SⅠ),sencondly somatosensory cortex(SⅡ),Motor cortex(MC), midbrain,caudate putamen(striatum)(Cpu),visual cortex(VC),anterior cingutate(Cg),retrosplenial granular cortex(RSG),thamulus(Th), Hippoc-amps(HIP),amygdaloid nucleus(AN),accumbens nucleus(Acb), Pons(Po),medulla oblogata(MO),inferior colliculus(IC),Cerebellum.2.2 The comparision of incidence and numbers of brain activation in different anaesthesia intervalThe incidences of brain areas in 2 groups were not completely homologous.General linear mixed model determined that incidences of Cg、Cpu、Hip、SⅡ、Th of both groups during A stage were higher than those of D stage(P＜0.05) and incidences of AN、Cerebellum of T group during A stage were higher than those of D stage(P＜0.05) and incidences of Th of LF group during A stage were higher than those of C stage (P＜0.05).The sum amounts of activation during C stage were deceased significantly after 2 stage-constant current electrical stimulationin in both group(P＜0.05).The sum amounts of activation during D stage were deceased significantly after 3 stage-constant current electrical stimulationin in both group(P＜0.05).The amounts of activation during D stage in LF group and D goup were deceased significantly after 3 stage-constant current electrical stimulationin(P＜0.05).The amounts of activation during C stage in LF group were decreased significantly after 2 stage-constant current electrical stimulationin(P＜0.05).The amounts of activation during B stage in LF group were lower than that of A stage (P＜0.05).2.3 SPM group analysis for brain activations of rats induced by nociception stimulation in different anaesthesia intervalRandom-effects analysises were conducted in SPM to accounts for inter-group variation.One Sample t-tests were conducted to evaluate all your subjects for having a zero effect.The brain activation of T group invluded SⅠand SⅡ(right),RSG,AN and VPL(only A stage activation).The brain activation of LF group invluded AcbSH, SⅠ(right),VPL and RSG.2.4 SPMs for A stage minus D stage(differential) changesOne way Anova was conducted to test the fifference between A stage and B stage in 2 groups.The activation of T_A minus T_D included VP, SⅡ(left) and CA1;The activation of LF_A minus LF_D included included BLA,PAG,CMe and APtN.ConclusionsThe incidences of brain areas in 2 groups were not completely homologous in the different anaesthesia stage.The brain activation of T group invluded SⅠand SⅡ(right),RSG,AN and VPL(only A stage activation).The brain activation of LF group invluded AcbSH, SⅠ(right),VPL and RSG.In the early stage of nociceptive stimulation,The activations of T_A minus T_D include VP,SⅡ(left) and CA1 and the activation sof LF_A minus LF_D include included BLA,PAG;CMe and APtN,which is corelation with the pain descending inhibitory effects.fMRI is a good tool to monitor the central network invoving pain perception and processing,which shows perfect perspective to visualize the central effects of anaesthetics and analgesitcs.更多还原