正常成年人嗅觉神经环路激活与行为学的相关性研究

The correlation study of olfactory behavior and the neural activation under olfactory stim uli in normal adult

目的:嗅觉障碍是阿尔茨海默病(Alzheimer disease,AD)中最早期的临床表现,早于记忆和认知功能减退,但是关于嗅觉神经环路的研究比较少。本研究将利用嗅觉刺激任务态功能磁共振(f MRI)探讨正常成人嗅觉神经环路激活与行为学的相关性,为进一步研究AD嗅觉障碍奠定方法学和理论基础。方法:招募30名年轻志愿者,进行嗅觉行为学测试、任务态fMRI扫描以及神经心理学测试。分析嗅觉行为学的重复性及其与任务态fMRI脑激活之间的相关性。结果:本研究结果显示正常年轻人嗅觉阈值为10.1±2.7,识别及回忆功能正确率平均约为75.5～80%。在嗅觉任务态fMRI中显著激活的脑区包括:双侧杏仁核、海马及海马旁回、眶额回(Orbito frontal cortex, OFC)、岛叶、梨状皮层,仅在眶额回具有偏侧性。男女之间嗅觉行为学及脑功能激活强度未见明显差异(p>0.05),嗅觉行为学与脑激活程度之间未见明显相关性。结论:正常年轻人嗅觉行为学及脑功能均未见明确性别差异,为后续研究AD患者排除了性别的干扰;在嗅觉任务态fMRI中显著激活的脑区构成了正常成人初级到高级的嗅觉神经环路,且在眶额回有明显偏侧性,为进一步研究AD患者的嗅觉神经环破坏机制提供了参考标准。

Objective The earliest and most common manifestation were olfactory dysfunction,early in memory and cognitive dysfunction.The main goal of this study was therefore to explore the correlation between the behavior and the activation of olfactory neural circuits in normal adult by task-bold fMRI. Methods 30 students of Nanjing university were recruited as volunteer. All participants underwentneuropsychological assessment and olfactory test. After that all participant take a olfactory related task-BOLD MRI scanning. Then olfactory test performance and brain activation were analyzed. Result The results of this study show the scores of olfactory function threshold of the normal young people is 10.1±2.7, the correct rate of identification and recall functions are from75.5 percent-80 percent, while studies have shown that men and women olfactory function was no statistically significant difference, Both sides of the amygdala, hippocampus and parahippocampal gyrus, the both sides of frontal and entorhinal cortex, insular cortex on both sides, both sides of the amygdala/piriform cortex in odor stimuli task(p<0.05). Only in the orbito frontal cortex has laterality. Conclusion The basic olfactory functions of normal young people was no significant difference about sex, excluding gender interference for the further study AD patients. The result of using olfactory threshold analyzer are reliability, repeatability, economically viable, and laid a methodology foundation for further study of AD patients’ olfactory function. only in the orbito frontal cortex has laterality. These structures completely and clearly show the primary-advanced olfactory neural circuits of young adults. laid the theoretical and methodological foundation for the further study of olfactory nerve ring failure mechanism of AD patients.