【作者】 伍建林； 张清； 张竞文； 宋清伟； 苗延巍；

【Author】 WU Jian lin, ZHANG Qing, ZHANG Jing-wen, et al. Department of Radiology, The first affiliated hospital of Dalian Medical University, Dalian 116011, China

【机构】 大连医科大学附属第一医院放射科；

【摘要】 目的:采用功能磁共振成像(fMRI)观察和研究愉快及非愉快气体激活相应脑区的情况并对嗅觉中枢及其通路进行功能定位。方法:12名右利手、无嗅觉障碍健康志愿者参加实验。采用乙酸戊酯为刺激的愉快气体,吡啶为非愉快气体,组块设计(block design),1.5T MRI行EPI序列扫描,用Matlab5.3及SPM99、Talairach等软件对数据后处理。结果:愉快及非愉快气体刺激海马回钩、丘脑内侧背核、眶额回皮质均出现明显激活,并且两种气味均表现为右侧大脑半球优势激活,即右侧额叶上、中、下回、右侧眶额回、右侧海马回钩以及右侧丘脑背内侧核均较左侧半球相应脑区激活明显;在与情绪相关脑区亦发现激活,即额内侧回、海马旁回、扣带回、颞上回以及右侧额叶上、中、下回。大脑前部区域以愉快气体激活明显,大脑后部区域以不愉快气体激活明显,后者还可引起脑干、小脑、胼胝体明显激活。结论:Bold-fMRI是研究人类嗅觉功能的有效方法。本研究进一步验证了海马回钩、丘脑内侧背核和眶额回为嗅觉中枢及其重要通路,并且右侧大脑半球为嗅觉“优势半球”;气味嗅觉还可以引起与情绪相关的脑区激活,并且愉快情绪主要与大脑前部区域有关,不愉快情绪主要与大脑后部区域关系密切。更多还原

【Abstract】 Objective:To identify regional activation of the human cerebral cortex in response to pleasant and unpleasant odors with functional MRI(fMRI), and to localize the olfactory center and its tracts. Methods: Twelve right-handed, healthy volunteers underwent this study. Two types of odors were given to them through the personally developed instrument. One was amyl acetate, which was regarded as pleasant odor , and the unpleasant one was pyridine. Block design was adopted in this experiment, and EPI was performed on 1.5TMRI, the raw fMRI data were dealed with Matlab5.3, SPM99 and Talairach tool software.Results: Activation was present in the olfactory center and important tract during administration of pleasant and unpleasant odors, such as uncus of hippocampus, lateral medial nucleus of thalamus and orbitofrontal gyru, and both of the two odors had more activation in the right hemisphere than the left, ie the superior, middle, inferior gyrus of right frontal lobe, right orbitofrontal gyrus, right uncus of hippocampus and right lateral medial nucleus of thalamus were activated more prominently than the contralateral corresponding region. The mood related region were also found activated, including medial frontal gyrus, parahippocampal gyrus, cingulate gyrus, superior temporal gyrus and the superior, middle, inferior gyrus of right frontal lobe. Further, it was found that the anterior part of the cerebrum was activated by the pleasant odor and that a more posterior part was activated by the unpleasant odor. Otherwise, activation occurred in the brain stem, cerebellum and corpus callosum during administration of unpleasant odor, which were not activated by pleasant odor. Conclusion: Bold-fMRI is an useful method for studying of human olfactory system.The uncus of hippocampus, lateral medial nucleus of thalamus and orbitofrontal gyrus are further proved the olfactory center and important tract, and presented dominant in the right hemisphere. In the same time, odors can activate the mood related regions, the pleasant feeling is mainly concerned with the anterior part of the cerebrum, while the unpleasant feeling is involved in the posterior part of the cerebrum.更多还原