前扣带回参与痛觉调控的功能磁共振成像研究  

Anterior cingulate cortex involving in pain modulation -an functional magnetic resonance imaging study

作　　者：张明[1] 王渊[1] 刘海[2] 章士正[2] 鱼博浪[1] 

机构地区：[1]西安交通大学医学院第一附属医院影像中心,710061 [2]浙江大学医学院附属邵逸夫医院放射科博士后流动站

出　　处：《中华医学杂志》2006年第30期2127-2130,共4页National Medical Journal of China

基　　金：中国博士后科学基金资助项目(2004035718)

摘　　要：目的利用功能磁共振成像(fMRI)技术研究健康志愿者接受不同强度电刺激时前扣带回(ACC)各亚区的激活模式,探讨该脑区在痛觉调控网络中的作用。方法对10名右利手健康志愿者分别施加1倍痛阈(P1)、2倍痛阈(P2)、3倍痛阈(P3)三个不同强度的电刺激任务,同期采用GE Signa 1．5T超导型磁共振成像系统进行脑功能活动的数据采集,应用功能神经成像分析(AFNI)软件包进行后处理以获取ACC的激活图像,根据10名受试者的平均脑功能激活图分析ACC各亚区独特的刺激反应特性。结果前扣带回前部(aACC)在不同强度电刺激时均呈中度激活,该亚区在P1、P2、P3时平均激活像素分别为324、429、562,BOLD信号差异不大,表现出痛觉注意相关性反应;前扣带回背后部(dpACC)在P1、P2、P3时平均激活象素为311、964、1414,其BOLD信号与刺激强度基本呈线性正相关,表现出刺激强度依赖性反应,提示该区与刺激强度编码有关;前扣带回腹后部(vpACC)在P1、P2时无明显激活(平均激活像素为262、375),但当刺激强度增大到P3时,该区BOLD信号显著增强(平均激活像素为1781),提示该区参与痛觉强度编码。结论前扣带回各亚区在痛觉调控网络中发挥了重要作用。在不同强度电刺激作用下,该区表现出分离性激活特性,各亚区的激活曲线显示出各自的痛觉调控特点。Objective To investigate the functional activation patterns of the subregions of anterior cingnlate cortex （ACC） in human to electrical stimulation of different intensity with functional Magnetic Resonance Imaging （fMRI） and probe the contribution of this area in pain modulation network. Methods 10 healthy right-handed volunteers were studied with different electrical intensity stimulation of 1-, 2-, or 3- time pain threshold. The fMRI data were collected by GE signa 1.5T MRI system and postprocessed with software of Analysis of Functional Neuroimages （AFNI） to generate the regional activation maps of ACC, furthermore, the distinctive characteristics of stimulation-BOLD signal in ACC subregions were analyzed according to the fMRI maps from the average of the 10 subjects. Results The anterior portion of ACC （aACC） showed moderate pain-attention-related activation but not statistically related to the strength of stimulation （ average activated pixels of P1, P2, P3 amounted to 324,429,562 respectively）. The BOLD signal showed a positive linear relation with the increasing stimulation at the dorsal-posterlor portion of ACC （average activated pixels of P1, P2, P3 were 311, 964, 1414）, which indicated stimulus intensity-dependent responses. The ventral-posterior area of ACC （ vpACC ） demonstrated pain intensity encoding because the BOLD signal had no significant difference during innocuous condition but displayed remarkable distinction during noxious stimulation in this area （ average activated pixels of P1, P2, P3 were 324, 429, 562）. Conclusion Subregions in ACC may play a varied role in the network of pain modulation. Each area of ACC displays segregated activation patterns in response to electrical stimulation with different strength.

关 键 词：磁共振成像 痛阈 电刺激 

分 类 号：R445.2[医药卫生—影像医学与核医学] R338.3[医药卫生—诊断学]