基于多模态神经影像学的人海马毕生变化曲线

研究背景近20年来,越来越多的研究者采用fMRI技术研究海马结构与功能,以揭示海马功能与记忆力之间的关系。对正常人海马结构与功能毕生变化曲线的研究和建模,是监测个体发育情况和辅助预测相关疾病的关键环节,能够反映正常人脑自然变化的普适性结构变量(即体积),以及反映功能活动的指标低频振荡振幅、分数低频振荡振幅和局部功能一致性。方法采用fMRI技术,通过连接组计算机系统对125例7~85岁正常个体的海马体积、低频振荡振幅、分数低频振荡振幅和局部功能一致性进行评价。结果双侧海马体积随年龄的增长而显著减小(校正后Ps=0.000),左侧海马低频振荡振幅(校正后P=0.034,β=-0.314)、分数低频振荡振幅(校正后P=0.059,β=-0.687)和局部功能一致性(校正后P=0.005,β=-0.330)与年龄呈显著负相关及负相关趋势。结论从一个侧面揭示了人毕生发展过程中海马结构与功能之间的相互关系。

The developmental trajectory of hippocampus across the human lifespan based on multimodal neuroimaging

Background During the last 2 decades, more and more functional MRI （fMRI） researches have increasingly focused on both structures and functions of the hippocampal region to discover the relationship between hippocampus and memory. In order to reveal the normative pattern of individual development or aging processes of the hippocampus or further memory,-related disease prediction, an investigation on such a brain structure＇s trajectory across the human lifespan is necessary. Methods Regional volume is the most commonly used variable for the structural change of normal brain. The regional homogeneity （ReHo） and amplitude of low-frequency fluctuation （ALFF） are the two test-retest reliable metrics for detection of functional changes. We here investigate ReHo, ALFF and fractional ALFF （fALFF） based upon both structural and resting state fMRI of 125 subjects from 7 to 85 years old. Results As results, significant age-related decreases were detected for volumes of bilateral hippoeampus （corrected Ps = 0.000）. In contrast, ALFF （corrected P = 0.034,β= - 0.314）, fALFF （corrected P = 0.059, β= - 0.687） and ReHo （corrected P = 0.005, β=- 0.330） demonstrated a trend of negative linear correlation with age in the left hippocampus. Conclusions Our findings partly reflect the structure-function relationship of the hippoeampus during the human lifespan.