正常老化对视皮层静息状态脑活动的影响  

Health aging modulation of the resting state human brain activity in visual cortex

作　　者：吴义根[1] 赵小虎[2] 王培军[2] 

机构地区：[1]南京信息工程大学数理学院,江苏南京210044 [2]同济大学附属同济医院放射科,上海200065

出　　处：《中国医学影像技术》2007年第9期1270-1273,共4页Chinese Journal of Medical Imaging Technology

基　　金：国家自然科学基金(30570538和30470517);南京信息工程大学科研启动基金(QD64)资助

摘　　要：目的利用fMRI技术初步探讨年龄对人类视皮层静息状态活动的影响。方法10名健康青年志愿者及10名老年健康志愿者参加实验。任务通过听觉呈现。任务期要求受试者听汉语真词词组并作词语属性判断(具体或抽象)。静息期要求受试者闭眼、静卧,不做任何主动思维活动。利用SPM 2软件进行数据处理,采用反减法获得负激活图。结果两组受试者负激活脑区部位基本一致,主要包括扣带回后部/楔前叶(BA 7),前额叶中内侧(BA 32/10),两侧前额叶背外侧(BA 9),两侧顶下小叶(BA 39/40),两侧枕叶视皮层(BA 18/19),左侧基底节区及两侧岛叶(BA 13)。该负激活脑区模式与Raichle等提出的脑默认活动网络基本一致。进一步组间分析发现,老年人视皮层静息期fMR信号强度明显高于青年人组。结论本研究进一步验证了静息状态人脑默认活动假说,并发现静息状态时老年人视皮层活动比青年人活跃。Objective To investigate the effect of aging on resting state human brain activity in visual cortex by using functional magnetic resonance imaging technique （fMRI）. Methods Ten healthy old and ten healthy young volunteers participated in our block design fMRI experiments. Subjects were instructed to listen carefully and make silently the valence of the words （abstract or concrete）during task conditions. In rest condition, subjects were told lying quietly with eyes closed. Data were analyzed with SPM 2 software. We used reverse subtracting method to obtain the group averaged deactivation map and make further analysis with mask function. Results Our data revealed nearly the same deactivated brain pattern between the old and young group,which nearly overlapping with the default mode networks. These brain regions included posterior cingulate and precuneous cortex （BA 7）, medial prefrontal cortex （BA 32/10）, bilateral dorsal prefrontal gyrus （BA 9）, bilateral inferior parietal cortex （BA 39/40）, bilateral visual cortex（BA 18,19） and insula （BA 13）. With further analysis,we found significantly great magnitude of deactivation in visual cortex of old subjects than that in young subjects. Conclusion Our findings supported the default mode network hypothesis and revealed that the old subjects might have great neural activity in visual cortex than young subjects during rest state.

关 键 词：功能磁共振成像 负激活 脑默认活动网络 视皮层 正常老化 

分 类 号：R445.2[医药卫生—影像医学与核医学] R817.4[医药卫生—诊断学]