嗅觉适应恢复后早期大脑皮层活化的功能性磁共振成像研究  

Functional magnetic resonance imaging of brain activation in early period after olfactory adaptation

作　　者：肖伟[1] 魏永祥[1] 顾华[2] 李坤艳[1] 张金峰[3] 司丽芳[2] 

机构地区：[1]首都医科大学附属北京朝阳医院耳鼻咽喉头颈外科,100020 [2]首都医科大学附属北京朝阳医院介入放射科,100020 [3]天津市第四中心医院耳鼻咽喉头颈外科

出　　处：《中华耳鼻咽喉头颈外科杂志》2011年第9期723-727,共5页Chinese Journal of Otorhinolaryngology Head and Neck Surgery

基　　金：国家自然科学基金（30973284）;首都医学发展科研基金（2007-1034）;高等学校博士学科点专项科研基金（2007125123）

摘　　要：目的应用功能性磁共振成像技术对嗅觉适应前以及恢复后早期大脑功能活化区进行研究，探讨嗅觉适应机制。方法给予10名右利手、无嗅觉障碍的受试荇2次间隔20min的相同的嗅觉刺激任务（分别称为任务1和任务2），刺激剂为异戊酸，功能性磁共振扫描获得图像数据，采用SPM5软件进行数据处理。利用视觉模拟黄表对2次任务进行气味强度和愉悦度评分，并将结果进行统计学分析。结果2次任务的强度评分分别为（6．50±1．11）、（5．40±2．11）分，差异无统计学意义（t=1．976，P=0．080）；愉悦度评分分别为（4．70±1．93）、（4．55±1．50）分，差异无统计学意义（t=0．225，P=0．804）。任务1中大脑活化区域位于双侧小脑、额叶（包括眶额回）、岛叶、丘脑、扣带回、壳、杏仁体、梨状皮层、左侧顶下小叶、中央前回、右侧海马、苍白球、颞中同、缘上同。任务2中，仅见右侧额巾回活化，且活化像素显著减少。任务1-任务2的活化区域位于左巾央前回、额叶（包括眶额回）、岛叶、右侧颞上回、小脑；任务2-任务1的活化区域位于左顶下小叶和右舌回。结论大脑的嗅觉适应较主观感觉有明显的“延时现象”，主观嗅觉适应已经恢复时，而大脑活化敏感性仍处于较低水平。接受重复嗅觉刺激时，高级嗅觉中枢在气味的感知及嗅觉高级处理过程中所起的作用有限。Objective To explore the brain activation before and in early period after olfactory adaptation using functional magnetic resonance imaging, and discuss the meehanisms of olfactory adaptation. Methods Ten right-handed, normosmic subjects underwent 2 times of olfactory stimulation tasks with the interval of 20 minutes. The odorant used was isovaleric acid. The fMRI data was processed by the SPM5 software. Rating odor intensity and valence using visual analogue scale （VAS） , and the results of 2 tasks were statistically analyzed. Results There was no significant difference between 2 tasks on both intensity and hedonicity scores. In task 1, the brain activation in bilateral cerebellum, frontal （including orbitofrontal gyms）, insula, thalamus, cingulate gyms, putamen, amygdala, piriform cortex, the left inferior parietal lobule, precentral gyms, right hippocampus, pallidum, middle temporal gyms, supramarginal gyms. In task 2, only the right middle frontal gyms activated, and the voxels decreased significantly. Paired t-test results showed that： （taskl -task2） activated regions in left precentral gyms, frontal lobe （including the orbitofl＇ontal gyrus） , insula, right superior temporal gyms, cerebellum; （ task2 - taskl ） activation in the left inferior parietal lobule and right lingual gyrus. Conclusions The sensitivity of brain activation is still at a low level, when subjects had recovered from adaptation in subjective olfactory pereeption. Underwent repeated olfactory stimulation, second olfactory cortex plays less role on olfactory perception and advanced processing.

关 键 词：嗅觉 大脑皮质 磁共振成像 

分 类 号：R445.2[医药卫生—影像医学与核医学]