Department of Family Medicine, University of Southern California, Los Angeles, California, USA.
Department of Neurology, University of Southern California, Los Angeles, California, USA.
Hum Brain Mapp. 2022 Nov;43(16):5044-5052. doi: 10.1002/hbm.26070. Epub 2022 Sep 6.
While there has been a proliferation of neuroimaging studies on cognitive decline in older non-Hispanic White adults, there is a dearth of knowledge regarding neuroimaging correlates of cognitive decline in Black adults. Resting-state functional neuroimaging approaches may be particularly sensitive to early cognitive decline, but there are no studies that we know of that apply this approach to examining associations of brain function to cognition in older Black adults. We investigated the association of cognitive decline with whole-brain voxel-wise functional connectivity to the hippocampus, a key brain region functionally implicated in early Alzheimer's dementia, in 132 older Black adults without dementia participating in the Minority Aging Research Study and Rush Memory and Aging Project, two longitudinal studies of aging that include harmonized annual cognitive assessments and magnetic resonance imaging brain imaging. In models adjusted for demographic factors (age, education, sex), global cognitive decline was associated with functional connectivity of the hippocampus to three clusters in the right and left frontal regions of the dorsolateral prefrontal cortex. In domain-specific analyses, decline in semantic memory was associated with functional connectivity of the hippocampus to bilateral clusters in the precentral gyrus, and decline in perceptual speed was inversely associated with connectivity of the hippocampus to the bilateral intracalcarine cortex and the right fusiform gyrus. These findings elucidate neurobiological mechanisms underlying cognitive decline in older Black adults and may point to specific targets of intervention for Alzheimer's disease.
虽然有大量关于老年非西班牙裔白种人认知能力下降的神经影像学研究，但关于黑种人认知能力下降的神经影像学相关性的知识却很少。静息态功能神经影像学方法可能对早期认知能力下降特别敏感，但我们还没有研究应用这种方法来检查大脑功能与老年黑人认知能力之间的关联。我们调查了认知能力下降与全脑体素功能连接的关联，这些体素与海马体有关，海马体是一个在早期阿尔茨海默病中具有关键功能的大脑区域，共有 132 名没有痴呆的老年黑人参与者参加了少数族裔衰老研究和拉什记忆和衰老项目，这两项纵向衰老研究包括年度认知评估和磁共振成像脑成像的协调。在调整了人口统计学因素（年龄、教育、性别）的模型中，整体认知能力下降与海马体与右侧和左侧背外侧前额叶皮质三个区域的功能连接有关。在特定领域的分析中，语义记忆的下降与海马体与双侧中央前回的功能连接有关，而知觉速度的下降则与海马体与双侧内距状皮层和右侧梭状回的功能连接呈负相关。这些发现阐明了老年黑人认知能力下降的神经生物学机制，并可能为阿尔茨海默病的特定干预靶点指明方向。
