Brosnan Méadhbh B, Shalev Nir, Ramduny Jivesh, Sotiropoulos Stamatios N, Chechlacz Magdalena
Department of Experimental Psychology, University of Oxford, Oxford, UK.
Oxford Centre for Human Brain Activity, University of Oxford, Oxford, UK.
Brain Commun. 2022 Mar 28;4(2):fcac080. doi: 10.1093/braincomms/fcac080. eCollection 2022.
Exposure to enriched environments throughout a lifetime, providing so-called reserve, protects against cognitive decline in later years. It has been hypothesized that high levels of alertness necessitated by enriched environments might strengthen the right fronto-parietal networks to facilitate this neurocognitive resilience. We have previously shown that enriched environments offset age-related deficits in selective attention by preserving grey matter within right fronto-parietal regions. Here, using neurite orientation dispersion and density imaging, we examined the relationship between enriched environments, microstructural properties of fronto-parietal white matter association pathways (three branches of the superior longitudinal fasciculus), structural brain health (atrophy), and attention (alertness, orienting and executive control) in a group of older adults. We show that exposure to enriched environments is associated with a lower orientation dispersion index within the right superior longitudinal fasciculus 1 which in turn mediates the relationship between enriched environments and alertness, as well as grey and white matter atrophy. This suggests that enriched environments may induce white matter plasticity (and prevent age-related dispersion of axons) within the right fronto-parietal networks to facilitate the preservation of neurocognitive health in later years.
终生置身于丰富环境中，即所谓的储备，可预防晚年认知能力下降。据推测，丰富环境所必需的高警觉性可能会强化右侧额顶叶网络，以促进这种神经认知弹性。我们之前已经表明，丰富环境通过保留右侧额顶叶区域内的灰质来抵消与年龄相关的选择性注意力缺陷。在此，我们使用神经突方向离散度和密度成像技术，研究了一组老年人中丰富环境、额顶叶白质联合通路（上纵束的三个分支）的微观结构特性、脑结构健康（萎缩）与注意力（警觉性、定向和执行控制）之间的关系。我们发现，置身于丰富环境与右侧上纵束1内较低的方向离散度指数相关，而该指数反过来又介导了丰富环境与警觉性以及灰质和白质萎缩之间的关系。这表明，丰富环境可能会在右侧额顶叶网络内诱导白质可塑性（并防止与年龄相关的轴突离散），以促进晚年神经认知健康的维持。
