刺激养老穴激活脑功能区的不同阈值分析

目的为针刺的fMRI研究的统计分析选择合宜的的阈值。方法选取健康青年志愿者12例,进行刺激养老穴的fMRI研究,采用组块模式,使用SPM2对扫描后图像进行后处理,采用校正和非校正来统计分析脑功能激活情况。结果在校正象情况下（组分析,FWE,0．05,K≥10）,养老穴主要激活了左顶叶的顶下小叶BA40,右侧额叶的额下回BA45、BA46,其次为左侧颞中回、颞下回BA37,左额上回BA10。而非校正情况下,激活点非常广泛。结论在穴位的脑功能激活实验应选择校正像分析。     

耳鸣患者PET显像的相关脑区探讨

目的：探讨耳鸣患者脑PET18 F-FDG代谢的相关脑区。方法通过对41例耳鸣患者及40例健康对照组进行PET-CT检查,行踪剂为18 F-FDG,结果用统计参数图(SPM)软件进行统计分析,确定与耳鸣相关脑区的解剖部位(BA)。结果耳鸣患者相关脑区主要位于左侧颞下回(BA20)、左侧颞中回(BA21)、左侧颞上回(BA22)、左侧腹侧后扣带皮层(BA24)、左侧颞极区(BA38)及右侧后外侧前额叶皮层(BA9)、右侧额极区(BA10)、右侧眶额回(BA11)、右侧颞下回(BA20)、右侧背侧前扣带皮层(BA32)、右侧海马旁皮层(BA36)、右侧梭状回(BA37)。结论耳鸣患者在中枢神经系统可能存在特定的投射区,主要位于边缘系统及额叶联合区,与主次级听觉皮层有一定关系。PET 为耳鸣提供了客观证据,有望成为耳鸣的客观检测方法。     

人脑顶叶在空间记忆认知功能中的作用

目的:通过功能磁共振成像(fMRI)技术研究健康人脑顶叶在处理空间记忆信息时的作用。方法:在对10例右利手健康志愿者进行一项短时空间记忆任务作业的同时,进行fMRI扫描,实验采用组块设计并采用SPM99软件进行数据分析和脑功能区定位。结果:当统计阈值设为P<0.001时,大脑皮质所激活的脑区有双侧顶叶的楔前叶、顶上小叶、缘上回(BA7/40,BA:BrodmannArea,布鲁德曼分区,下同),双侧前额上中下回(BA6/9/47),双侧枕叶和枕颞交界处(BA17/18/19/37),右侧海马和右侧扣带回;左侧顶叶的激活强度最强,左侧顶叶与双侧前额叶以及右侧顶叶与左侧前额叶之间的激活强度差异均有统计学意义(P<0.05)。结论:人脑在处理短时空间记忆信息时,顶叶起主导性作用。     

听觉相关穴位刺激时中枢变化功能磁共振研究

目的利用血氧水平依赖效应功能磁共振成像（blood oxygenation level dependent-functional magnetic resonance imaging,BOLD-fMRI）观察正常人在针灸刺激听觉相关穴位时中枢的兴奋情况。方法正常人受试者30名。选取足少阴肾经的太溪穴和手少阳三焦经的中渚穴作为刺激穴位,穴位旁刺激作为对照。针灸刺激用专用电针治疗仪施加,频率2000Hz,电流强度以受试者能忍耐的最大值为限。功能成像采用组块设计,刺激持续时间1000ms,刺激间隔1000ms。结果受试者接受穴位电针刺激激活脑区有两侧半球的：初级体感中枢、次级体感中枢、颞上回、颞中回、枕叶、缘上回、额上回、额下回、扣带回前部、中央前回、小脑半球。对照实验中,非穴位刺激激活的脑区与穴位刺激基本相同。但两种刺激对脑区的激活强度存在很大的差异。比较针刺穴位和穴位旁区激活脑区的强度,表现为穴位刺激显著高于穴位旁刺激的脑区有：两侧次级体感中枢、两侧颞上回、两侧缘上回、左侧枕叶、右侧小脑半球。结论正常人太溪穴和中渚穴接受电针刺激比单纯体感刺激在部分脑区激活强度显著增高,认为是穴位刺激特殊效应所致。太溪、中渚两穴联合刺激较体感刺激更明显地激活听觉初级和次级皮层,提示这两个穴位通过听觉中枢调节听觉功能。     

早发性抑郁患者基于低频振幅比特低频振幅下脑区功能活动特征研究

目的利用静息态磁共振技术对早发性抑郁症患者特异性脑区进行定位。方法选择20例我院收治的早发抑郁症患者20例和性别、年龄、受教育年限与患者相匹配的20名健康受试者(对照组),分别给予功能磁共振(fMRI)扫描,分别应用低频振幅(ALFF)、比特低频振幅(fALFF)方法进行基于体素的组间比较,分析其静息态脑功能的差异。结果 (1)在右侧缘上回、左侧额中回、右侧中央沟盖、左侧额上回及右侧眶部额中回的ALFF值强于健康对照组,在舌回、左侧中央前回、左侧小脑10区、左侧颞中回区域的ALFF值弱于健康对照组;(2)在右侧眶部额中回、右侧眶部额下回、右侧缘上回、右侧中央沟盖、左侧眶部额下回、左侧扣带回及右侧枕中回的fALFF强于健康对照组,在左侧中央前回、左侧中央后回、右侧楔叶及右侧梭状回区域的fALFF值弱于健康对照组。结论早发性抑郁患者在前额叶、扣带回、边缘系统等多个区域脑自发活动强于健康受试者;在大脑额叶后部、颞叶前部、枕叶及小脑部分区域等多个区域脑自发活动弱于正常受试者;且ALFF及fALFF算法均存在相对一致性,显示这些特定脑区的脑自发活动异常可能是早发抑郁的神经生物学基础。     

健康成人大脑灰质体积年龄相关性变化的研究

目的探讨正常脑老化过程灰质体积年龄相关性的改变规律。方法应用MR采集124例健康志愿者全脑T1WI图像,利用VBM技术获得全脑灰质体积。采用双因素方差分析不同性别及年龄组间灰质体积的差异性。结果每2个年龄组间均存在显著的年龄主效应(P<0.05,FDR校正)。其中中年组与青年组比较,存在明显萎缩的脑区位于两侧额上回、两侧额下回三角部、右侧额下回眶部、双侧丘脑、双侧颞中回、右侧额上回眶面、右侧颞中极、右侧岛叶、右侧尾状核及右侧顶叶。老年组与中年组比较存在明显萎缩的脑区位于右侧颞中极、杏仁核、扣带回后部、两侧枕叶舌回、两侧海马/海马旁回及两侧颞下极。老年组与青年组比较,除枕叶外,老年组全脑灰质体积存在广泛下降。当不采用多重对比校正时,观察到青年组与中年组之间部分脑区,如右侧颞中回、右侧颞上回、左侧角回、右侧枕叶中部、左侧扣带回中部、右额下回三角部,存在年龄×性别交互效应(P<0.01,未校正)。结论在正常老化过程中,全脑灰质体积与年龄呈现为负相关性改变,不同脑区存在不同的萎缩模式,一般遵循"先进后出"的规律,其中额叶最易受年龄的影响;并且在部分脑区中,女性灰质萎缩进程较男性缓慢。     

感音神经性耳聋者的脑白质结构基于体素形态学研究

目的利用基于体素形态学技术比较听力正常人与感音神经性耳聋人的脑白质之间差异。方法分别对20例听力正常人及20例感音神经性耳聋人进行常规T2-WI与三维（3D）快速扰相梯度回波（FSPGR）采集脑结构图像。用VBM技术运算,然后观察2组脑质差异并显示出差异脑区的MNI坐标及差异容积,然后对所得数据进行相应统计学分析。结果听力正常组脑白质增多的区域有（P〈0.01,Clustersize=30）：左侧颞上回、左侧额中回、左侧顶叶（半卵圆中心）、左侧楔前叶、左侧额下回、左侧颞上回、左侧中央后回、左侧小脑半球、右侧颞上回。结论感音神经性聋人在左、右侧颞上回白质减少,提示其白质发生萎缩。     

感音神经性耳聋者的脑灰质结构基于体素形态学的研究

目的利用基于体素形态学技术分析听力正常人志愿者与感音神经性耳聋患者之间的脑灰质差异。方法分别对24例听力正常人及24例感音神经性耳聋人进行常规T2-WI与三维(3D)快速扰相梯度回波(fast spoiled gradient echo,FSPGR)采集脑结构图像。用VBM技术运算,然后观察两组之间的脑质差异并显示出差异脑区的MNI坐标及差异容积,然后对所得数据进行相应统计学分析。结果感音神经性耳聋组脑灰质增多的区域有(P<0.01,Cluster size=40):左侧颞上回、右侧颞上回、左侧额下回、左侧中央前回、左侧中央后回、左侧扣带回、左侧小脑半球、左侧顶下小叶、左侧屏状核、左侧小脑前叶、右侧小脑前叶、右侧小脑后叶、右侧额下回。结论感音神经性聋人在左、右侧颞上回灰质增多,提示其听觉中枢皮质有结构重组。     

氯胺酮成瘾者的静息态脑功能变化

目的:分析氯胺酮成瘾者的静息态脑功能活动变化情况,探索氯胺酮成瘾者的神经学机制。方法:采用静息态功能磁共振(resting-state f MRI)局部一致性(Regional Homogeneity,Re Ho)的方法,分析10名有氯胺酮成瘾者者与10名健康受试者的脑功能活动。结果:与健康受试者相比,氯胺酮成瘾者者双侧顶下缘角回、左侧顶上回、右背外侧额上回、左额中回、左内侧额上回、前扣带回、右侧丘脑、左侧尾状核、右梭状回的Re Ho信号显著升高(P<0.01,Alpha Sim校正,cluster size=18)。结论:证实氯胺酮成瘾者者额叶、顶叶、边缘系统、梭状回和尾状核存在脑功能活动异常。     

利用功能性磁共振成像针刺人中穴位所致大脑皮层神经生理兴奋的现象

目的在"针刺人中穴观察大脑皮层神经生理的兴奋性的现象"的指导下,开展人中穴特异性的fMRI脑功能成像研究,进一步探讨人中穴与脑区激活之间的联系。方法针刺6名健康志愿者人中穴,针刺得气后捻转30s后停止捻针30s,重复6次,同时利用功能性核磁共振成像(fMRIBOLD)技术进行全脑扫描,利用统计参数图软件包处理图像。结果针刺人中穴捻针状态,左右大脑皮层均有不同程度的激活,其中,左脑激活的区域相对集中在额下回、颞下回、顶下小叶和小脑,右脑激活的区域相对集中在额下回、颞上回、颞中回、顶下小叶、岛叶、边缘叶、脑干和小脑。结论通过利用功能性磁共振成像揭示出的针刺人中穴位所致大脑皮层神经生理兴奋的现象,说明人中穴与大脑皮层功能区存在着密切联系,针刺人中穴与脑部部分功能区的感受器有着相应的激活效应,为此能为以后针灸在临床工作中治疗某些疾病提供了有效的帮助。     

MDMA intoxication and verbal memory performance: a placebo-controlled pharmaco-MRI study

The aim of the present study was to identify the neural substrate underlying memory impairment due to a single dose of MDMA (3,4-methylenedioxymethamphetamine) by means of pharmaco-MRI. Based on previous behavioral results it was hypothesized that this deficit could be attributed to a specific influence of MDMA on encoding. Fourteen Ecstasy users participated in this double-blind, placebo-controlled, within-subject study with two treatment conditions: MDMA (75 mg) and placebo. Memory performance was tested by means of a word learning task including two words lists, one addressing reading processes (control task, CWL) and a second (experimental task, EWL) addressing encoding and reading processes. Behavioral data showed that under the influence of MDMA, EWL performance was worse than placebo. Imaging data showed that Encoding was situated mainly in (pre)frontal, temporal and parietal areas. MDMA by Encoding interaction was situated in three areas: the left middle frontal gyrus (BA10), the right fusiform gyrus (BA19), and the left cuneus (BA18). Behavioral and functional data only correlated in BA10. It appeared that EWL performance caused BOLD signal change in BA10 during placebo treatment but not during MDMA intoxication. It is concluded that MDMA influences middle frontal gyrus processes resulting in impoverished memory encoding.     

Now or Later? An fMRI study of the effects of endogenous opioid blockade on a decision-making network

Previously, we found that distinct brain areas predict individual selection bias in decisions between small immediate (“Now”) and larger delayed rewards (“Later”). Furthermore, such selection bias can be manipulated by endogenous opioid blockade. To test whether blocking endogenous opioids with naltrexone (NTX) alters brain activity during decision-making in areas predicting individual bias, we compared fMRI BOLD signal correlated with Now versus Later decision-making after acute administration of NTX (50 mg) or placebo. We tested abstinent alcoholics and control subjects in a double-blind two-session design. We defined regions of interest (ROIs) centered on activation peaks predicting Now versus Later selection bias. NTX administration significantly increased BOLD signal during decision-making in the right lateral orbital gyrus ROI, an area where enhanced activity during decision-making predicts Later bias. Exploratory analyses identified additional loci where BOLD signal during decision-making was enhanced (left orbitofrontal cortex, left inferior temporal gyrus, and cerebellum) or reduced (right superior temporal pole) by NTX. Additional analyses identified sites, including the right lateral orbital gyrus, in which NTX effects on BOLD signal predicted NTX effects on selection bias. These data agree with opioid receptor expression in human frontal and temporal cortices, and suggest possible mechanisms of NTX's therapeutic effects.     

首发抑郁症氟西汀治疗后脑葡萄糖代谢特点及与临床改善的相关分析

目的：探讨氟西汀治疗首发抑郁症的脑葡萄糖代谢特点及与临床症状改善的相关性。方法：14例首发抑郁症病人与11例健康者进行正电子发射断层显象(posifion emission tomography,PET),抑郁症组经氟西汀(20 mg·d~(-1))治疗12 wk后复查PET(8例)。汉密尔顿抑郁量表(HAMD_(17))、Montgomery-Asberg抑郁量表(MADS)、汉密尔顿焦虑量表(HAMA)、临床疗效总评量表(CGI)、中国修订韦克斯勒成人智力量表(WAIS- RC)、中国修订韦克斯勒记忆量表(WMS-RC)、威斯康星卡片分类测验(WCST)评价临床症状改善及神经心理变化。结果：(1)治疗前抑郁症组右侧额上回、右侧扣带回的脑葡萄糖代谢率(rCMRglc)显著低于健康对照组(P＜0.05)；(2)治疗有效的抑郁症组右侧额上回rCMRglc显著高于治疗前(P＜0.05)；(3)治疗后抑郁症病人病情严重程度(SI)的改善与右侧脑岛rCMRglc的变化呈正相关；WAIS-RC的总智商数(FIQ)改善与左侧额下回的变化呈正相关；WAIS-RC的语言商数(VIQ)改善与左侧丘脑rCMRglc的变化呈正相关；WMS- RC的记忆商数(MQ)改善与右侧额下回rCMRglc的变化呈负相关；WCST改善与右侧枕叶rCMRglc的变化呈正相关(P均＜0.05)；均入回归方程式。结论：氟西汀可有效改善首发抑郁症病人右侧额上回的rCMRglc降低；抑郁症病人临床症状的改善与局部脑葡萄糖代谢率改变有关。     

DRD4 VNTR polymorphism is associated with transient fMRI-BOLD responses to smoking cues

Rationale A dopamine receptor 4 variable number tandem repeat (DRD4 VNTR) polymorphism has been related to reactivity to smoking cues among smokers, but the effect of this genetic variation on brain responses to smoking cues has not been evaluated. Objectives The present study evaluated the relationship between carrying the DRD4 VNTR 7-repeat allele and transient functional magnetic resonance imaging (fMRI) blood-oxygen-level-dependent responses to smoking cues among adult dependent cigarette smokers. Materials and methods Smokers (n = 15) underwent fMRI scanning after 2-h abstinence. During scanning, they viewed visual smoking and control cues. A blood sample was assayed for the DRD4 VNTR polymorphism, and participants were categorized based on whether they carried one or two copies of the 7-repeat allele (DRD4 L, n = 7) or not (DRD4 S, n = 8). Results Contrasts in brain cue-reactivity (smoking minus control cues) between DRD4 groups were conducted using SPM2. Smoking cues as compared to control cues elicited transient brain responses in right superior frontal gyrus (BA 8/9/10/32), left anterior cingulate gyrus (BA 32), and right cuneus (BA 19). Exposure to smoking cues resulted in greater activation of right superior frontal gyrus (BA 10) and right insula in DRD4 L compared to DRD4 S individuals. By contrast, exposure to smoking cues among DRD4 S individuals resulted in no significant increases in activation compared to DRD4 L individuals. Conclusions These brain imaging results suggest that DRD4 VNTR polymorphism is related to transient brain responses to smoking cues in regions subserving executive and somatosensory processes.     

Modulation of neural response to happy and sad faces by acute tryptophan depletion

Background Central serotonin (5HT) plays a major role in emotional processing. We used functional neuroimaging (fMRI) to investigate the effects of experimental manipulation of central 5HT levels on the regional neural response to happy and sad facial expressions. Methods Ten healthy participants (eight men and two women) were scanned during an implicit emotional processing task after receiving a tryptophan-free (acute tryptophan depletion, ATD) or a balanced amino acid drink in a double-blind design. Results ATD lowered total plasma tryptophan concentration by 80%. There was no significant effect on subjective mood ratings, on response accuracy and on reaction times. Compared to sham depletion, ATD attenuated activation in the right medial/inferior frontal gyrus, the posterior cingulate cortex, the occipital and parietal cortex bilaterally, the right hippocampus, claustrum and insula. Conversely, ATD was associated with relatively increased activation in the left inferior frontal gyrus. ATD had differential effects on activation during the processing of happy and sad faces in the right putamen and in the left superior temporal gyrus. Conclusions In both cortical and sub-cortical regions, the neural response associated with processing emotional faces is significantly modulated by 5HT manipulation resulting from ATD. Moreover, in certain areas, this effect of 5HT depends on the emotional valence of the stimulus.     

Direction and magnitude of nicotine effects on the fMRI BOLD response are related to nicotine effects on behavioral performance

Considerable variability across individuals has been reported in both the behavioral and fMRI blood oxygen level-dependent (BOLD) response to nicotine. We aimed to investigate (1) whether there is a heterogeneous effect of nicotine on behavioral and BOLD responses across participants and (2) if heterogeneous BOLD responses are associated with behavioral performance measures. In this double-blind, placebo-controlled, cross-over study, 41 healthy participants (19 smokers)—drawn from a larger population-based sample—performed a visual oddball task after acute challenge with 1 mg nasal nicotine. fMRI data and reaction time were recorded during performance of the task. Across the entire group of subjects, we found increased activation in the anterior cingulate cortex, middle frontal gyrus, superior temporal gyrus, post-central gyrus, planum temporal and frontal pole in the nicotine condition compared with the placebo condition. However, follow-up analyses of this difference in activation between the placebo and nicotine conditions revealed that some participants showed an increase in activation while others showed a decrease in BOLD activation from the placebo to the nicotine condition. A reduction of BOLD activation from placebo to nicotine was associated with a decrease in reaction time and reaction time variability and vice versa, suggesting that it is the direction of BOLD response to nicotine which is related to task performance. We conclude that the BOLD response to nicotine is heterogeneous and that the direction of response to nicotine should be taken into account in future pharmaco-fMRI research on the central action of nicotine.