Semel Institute for Neuroscience & Human Behavior, Department of Psychiatry, UCLA School of Medicine, Los Angeles, USA.
Centre for Research on Ageing Health and Wellbeing, Australian National University, Canberra, Australia.
Neuroimage. 2017 Dec;163:296-300. doi: 10.1016/j.neuroimage.2017.09.016. Epub 2017 Sep 14.
The hippocampal complex, an anatomical composite of several subregions, is known to decrease in size with increasing age. However, studies investigating which subregions are particularly prone to age-related tissue loss revealed conflicting findings. Possible reasons for such inconsistencies may reflect differences between studies in terms of the cohorts examined or techniques applied to define and measure hippocampal subregions. In the present study, we enhanced conventional MR-based information with microscopically defined cytoarchitectonic probabilities to investigate aging effects on the hippocampal complex in a carefully selected sample of 96 healthy subjects (48 males/48 females) aged 18-69 years. We observed significant negative correlations between age and volumes of the cornu ammonis, fascia dentata, subiculum, and hippocampal-amygdaloid transition area, but not the entorhinal cortex. The estimated age-related annual atrophy rates were most pronounced in the left and right subiculum with -0.23% and -0.22%, respectively. These findings suggest age-related atrophy of the hippocampal complex overall, but with differential effects in its subregions. If confirmed in future studies, such region-specific information may prove useful for the assessment of diseases and disorders known to modulate age-related hippocampal volume loss.
海马复合体是由几个亚区组成的解剖复合结构，其体积会随着年龄的增长而减小。然而，研究发现哪些亚区特别容易受到与年龄相关的组织损失的影响，这些研究结果存在矛盾。造成这种不一致的原因可能反映了研究之间在研究对象或用于定义和测量海马亚区的技术方面的差异。在本研究中，我们使用显微镜定义的细胞构筑概率增强了传统的基于 MRI 的信息，以在一个精心挑选的 96 名健康受试者（48 名男性/48 名女性）样本中调查年龄对海马复合体的影响，年龄为 18-69 岁。我们观察到年龄与角回、齿状回、下托和海马杏仁核过渡区的体积之间存在显著的负相关，但与内嗅皮层无关。估计的与年龄相关的每年萎缩率在左侧和右侧下托最为明显，分别为-0.23%和-0.22%。这些发现表明海马复合体整体上存在与年龄相关的萎缩，但在其亚区中存在差异效应。如果在未来的研究中得到证实，这种特定于区域的信息可能对评估已知调节与年龄相关的海马体积损失的疾病和障碍有用。
