标题： 去甲肾上腺素能蓝斑核和黑质致密部年龄相关微结构变化的表征 显示英文标题

标题： Characterization of Age-related Microstructural Changes in Locus Coeruleus and Substantia Nigra Pars Compacta

摘要： 蓝斑（LC）和黑质致密部（SNpc）随着正常衰老而退化，但关于这些变化在MRI图像中的表现尚不清楚，或者这些标记物是否能预测认知的某些方面。 在这里，我们使用高分辨率扩散加权MRI来研究年轻和老年群体中LC和SNpc的微观结构和组成变化，以及它们与认知的关系。 在LC中，老年群体的平均扩散率和径向扩散率显著减少，但与年轻群体相比，部分各向异性显著增加。 我们观察到LC平均扩散率和径向扩散率的下降与延迟回忆之间存在显著相关性。 这一观察表明，LC参与保留认知能力。 此外，我们观察到SNpc中的铁沉积在生命早期就发生，并在正常衰老过程中持续进行。 由于神经元丢失发生在帕金森病的LC和SNpc中，而在阿尔茨海默病中仅发生在LC中，我们的结果可能有助于这些疾病的早期阶段影像生物标志物的开发。 显示英文摘要

摘要： Locus coeruleus (LC) and substantia nigra pars compacta (SNpc) degrade with normal aging, but not much is known regarding how these changes manifest in MRI images, or whether these markers predict aspects of cognition. Here, we use high-resolution diffusion-weighted MRI to investigate microstructural and compositional changes in LC and SNpc in young and aged cohorts, as well as their relationship with cognition. In LC, the older cohort exhibited a significant reduction in mean and radial diffusivity, but a significant increase in fractional anisotropy compared to the young cohort. We observed a significant correlation between the decrease in LC mean and radial diffusivities with delayed recall. This observation suggests that LC is involved in retaining cognitive abilities. In addition, we observed that iron deposition in SNpc occurs early in life and continues during normal aging. Since neuronal loss occurs in both LC and SNpc in Parkinson's disease, but occurs only in the LC in Alzheimer's disease, our results may lead to early stage imaging biomarkers for these diseases.