Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Kanazawa, Japan.
Commun Biol. 2022 Jun 2;5(1):529. doi: 10.1038/s42003-022-03464-z.
The detrimental effects of high-level mercury exposure on the central nervous system as well as effects of low-level exposure during early development have been established. However, no previous studies have investigated the effects of mercury level on brain morphometry using advance imaging techniques in young adults. Here, utilizing hair analysis which has been advocated as a method for biological monitoring, data of regional gray matter volume (rGMV), regional white matter volume (rWMV), fractional anisotropy (FA) and mean diffusivity (MD), cognitive functions, and depression among 920 healthy young adults in Japan, we showed that greater hair mercury levels were weakly but significantly associated with diminished cognitive performance, particularly on tasks requiring rapid processing (speed measures), lower depressive tendency, lower rGMV in areas of the thalamus and hippocampus, lower rWMV in widespread areas, greater FA in bilaterally distributed white matter areas overlapping with areas of significant rWMV reductions and lower MD of the widely distributed gray and white matter areas particularly in the bilateral frontal lobe and the right basal ganglia. These results suggest that even normal mercury exposure levels in Japan are weakly associated with differences of brain structures and lower neurobehavioral performance and altered mood among young adults.
高水平汞暴露对中枢神经系统的有害影响以及早期发育过程中低水平暴露的影响已得到证实。然而，以前没有研究利用先进的成像技术调查汞水平对年轻人脑形态计量学的影响。在这里，我们利用头发分析（头发分析被提倡作为生物监测的一种方法），分析了日本 920 名健康年轻人的区域灰质体积 (rGMV)、区域白质体积 (rWMV)、各向异性分数 (FA) 和平均弥散度 (MD)、认知功能和抑郁的数据，结果表明，头发中的汞含量越高，与认知能力下降越显著相关，尤其是在需要快速处理的任务（速度指标）上，抑郁倾向越低，丘脑和海马体等区域的 rGMV 越低，广泛区域的 rWMV 越低，双侧分布的白质区域的 FA 越高，与 rWMV 降低区域重叠，双侧额叶和右侧基底节等广泛分布的灰质和白质区域的 MD 越低。这些结果表明，即使在日本，正常的汞暴露水平也与年轻人的大脑结构差异、神经行为表现下降和情绪改变有关。
