Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, Düsseldorf 40225, Germany.
Institute of Neuroscience and Medicine (INM-1, INM-7), Research Centre Jülich, Jülich, Germany.
Brain. 2020 Sep 1;143(9):2788-2802. doi: 10.1093/brain/awaa222.
The hippocampus is a plastic region and highly susceptible to ageing and dementia. Previous studies explicitly imposed a priori models of hippocampus when investigating ageing and dementia-specific atrophy but led to inconsistent results. Consequently, the basic question of whether macrostructural changes follow a cytoarchitectonic or functional organization across the adult lifespan and in age-related neurodegenerative disease remained open. The aim of this cross-sectional study was to identify the spatial pattern of hippocampus differentiation based on structural covariance with a data-driven approach across structural MRI data of large cohorts (n = 2594). We examined the pattern of structural covariance of hippocampus voxels in young, middle-aged, elderly, mild cognitive impairment and dementia disease samples by applying a clustering algorithm revealing differentiation in structural covariance within the hippocampus. In all the healthy and in the mild cognitive impaired participants, the hippocampus was robustly divided into anterior, lateral and medial subregions reminiscent of cytoarchitectonic division. In contrast, in dementia patients, the pattern of subdivision was closer to known functional differentiation into an anterior, body and tail subregions. These results not only contribute to a better understanding of co-plasticity and co-atrophy in the hippocampus across the lifespan and in dementia, but also provide robust data-driven spatial representations (i.e. maps) for structural studies.
海马体是一个具有可塑性的区域，对衰老和痴呆非常敏感。以前的研究在研究衰老和痴呆特异性萎缩时明确地预先设定了海马体的模型，但导致了不一致的结果。因此，关于宏观结构变化是否遵循成年期和与年龄相关的神经退行性疾病的细胞构筑或功能组织的基本问题仍然没有答案。本横断面研究的目的是通过对大型队列的结构 MRI 数据（n=2594）进行数据驱动的方法，基于结构协方差来确定海马体分化的空间模式。我们通过应用聚类算法来揭示海马体体素结构协方差的分化，来检查年轻、中年、老年、轻度认知障碍和痴呆疾病样本中海马体结构协方差的模式。在所有健康和轻度认知障碍的参与者中，海马体都被稳健地分为前、侧和内侧亚区，这让人联想到细胞构筑的划分。相比之下，在痴呆患者中，细分的模式更接近已知的功能分化为前、体和尾亚区。这些结果不仅有助于更好地理解整个生命周期和痴呆中海马体的共可塑性和共萎缩，还为结构研究提供了强大的基于数据的空间表示（即图谱）。
