Cognitive aging varies tremendously across individuals and is often accompanied by regionally specific reductions in gray matter (GM) volume, even in the absence of disease. Rhesus monkeys provide a primate model unconfounded by advanced neurodegenerative disease, and the current study used a recognition memory test (delayed non-matching to sample; DNMS) in conjunction with structural imaging and voxel-based morphometry (VBM) to characterize age-related differences in GM volume and brain-behavior relationships. Consistent with expectations from a long history of neuropsychological research, DNMS performance in young animals prominently correlated with the volume of multiple structures in the medial temporal lobe memory system. Less anticipated correlations were also observed in the cingulate and cerebellum. In aged monkeys, significant volumetric correlations with DNMS performance were largely restricted to the prefrontal cortex and striatum. Importantly, interaction effects in an omnibus analysis directly confirmed that the associations between volume and task performance in the MTL and prefrontal cortex are age-dependent. These results demonstrate that the regional distribution of GM volumes coupled with DNMS performance changes across the lifespan, consistent with the perspective that the aged primate brain retains a substantial capacity for structural reorganization.

中文翻译：

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识别记忆与年轻和年老猴子区域灰质体积的不同模式有关

认知老化在个体之间差异很大，并且通常伴随着特定区域灰质 (GM) 体积的减少，即使在没有疾病的情况下也是如此。恒河猴提供了一种不受晚期神经退行性疾病影响的灵长类动物模型，目前的研究使用识别记忆测试（延迟与样本不匹配；DNMS）结合结构成像和基于体素的形态计量学（VBM）来表征与年龄相关的差异在 GM 体积和大脑行为关系中。与长期以来神经心理学研究的预期一致，年轻动物的 DNMS 表现与内侧颞叶记忆系统中多个结构的体积显着相关。在扣带回和小脑中也观察到较少预期的相关性。在年老的猴子身上，与 DNMS 性能的显着体积相关性主要局限于前额叶皮层和纹状体。重要的是，综合分析中的交互效应直接证实了 MTL 和前额叶皮层的容量和任务表现之间的关联是年龄依赖性的。这些结果表明，GM 体积的区域分布与 DNMS 性能在整个生命周期中发生变化，这与老年灵长类动物大脑保留大量结构重组能力的观点一致。