Williamson John B, Lamb Damon G, Porges Eric C, Bottari Sarah, Woods Adam J, Datta Somnath, Langer Kailey, Cohen Ronald A
Center for Cognitive Aging and Memory, Clinical Translational Research Program, College of Medicine, University of Florida, Gainesville, FL, United States.
Center for OCD and Anxiety Related Disorders, Department of Psychiatry, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, United States.
Front Aging Neurosci. 2021 Feb 3;12:587104. doi: 10.3389/fnagi.2020.587104. eCollection 2020.
Cerebral metabolites are associated with different physiological processes in brain aging. Cortical and limbic structures play important roles in cognitive aging; however, the relationship between these structures and age remains unclear with respect to physiological underpinnings. Regional differences in metabolite levels may be related to different structural and cognitive changes in aging.
Magnetic resonance imaging and spectroscopy were obtained from 117 cognitively healthy older adults. Limbic and other key structural volumes were measured. Concentrations of N-acetylaspartate (NAA) and choline-containing compounds (Cho) were measured in frontal and parietal regions. Neuropsychological testing was performed including measures of crystallized and fluid intelligence and memory.
NAA in the frontal voxel was associated with limbic and cortical volumes, whereas Cho in parietal cortex was negatively associated with hippocampal and other regional volumes. Hippocampal volume was associated with forgetting, independent of age. Further, parietal Cho and hippocampal volume contributed independent variance to age corrected discrepancy between fluid and crystallized abilities.
These findings suggest that physiological changes with age in the frontal and parietal cortices may be linked to structural changes in other connected brain regions. These changes are differentially associated with cognitive performance, suggesting potentially divergent mechanisms.
脑代谢物与脑衰老过程中的不同生理过程相关。皮质和边缘系统结构在认知衰老中起重要作用；然而，就生理基础而言，这些结构与年龄之间的关系仍不明确。代谢物水平的区域差异可能与衰老过程中不同的结构和认知变化有关。
对117名认知健康的老年人进行磁共振成像和波谱分析。测量边缘系统和其他关键结构的体积。在额叶和顶叶区域测量N-乙酰天门冬氨酸（NAA）和含胆碱化合物（Cho）的浓度。进行神经心理学测试，包括对晶体智力、流体智力和记忆的测量。
额叶体素中的NAA与边缘系统和皮质体积相关，而顶叶皮质中的Cho与海马体及其他区域体积呈负相关。海马体体积与遗忘相关，与年龄无关。此外，顶叶Cho和海马体体积对年龄校正后的流体和晶体能力差异有独立的贡献。
这些发现表明，额叶和顶叶皮质随年龄的生理变化可能与其他相连脑区的结构变化有关。这些变化与认知表现有不同的关联，提示可能存在不同的机制。
