Beason-Held L L, Kraut M A, Resnick S M
Laboratory of Personality and Cognition, National Institute on Aging, NIH.
Brain Imaging Behav. 2009 Jan 14;3(2):123-131. doi: 10.1007/s11682-008-9054-z.
Activity attributed to the default-mode occurs during the resting state and is thought to represent self-referential and other intrinsic processes. Although activity in default-associated regions changes across the lifespan, little is known about the stability of default-mode activity in the healthy aging brain. We investigated changes in rest-specific activity across an 8 year period in older participants in the Baltimore Longitudinal Study of Aging (BLSA) neuroimaging study. Comparison of resting-state and recognition memory PET regional cerebral blood flow conditions from baseline and 8-year follow-up shows relative stability of rest-specific activity over time in medial frontal/anterior cingulate, hippocampal and posterior cingulate regions commonly associated with the default-mode. In contrast, prefrontal, parahippocampal and occipital cortical regions, which are not typically associated with default-mode activity, show changes over time Overall, activity in the major components of the default-mode network remains stable in healthy older individuals, a finding which may assist in identifying factors that discriminate between normal and pathological aging.
默认模式相关的活动发生在静息状态期间，被认为代表自我参照及其他内在过程。尽管默认模式相关区域的活动在整个生命周期中会发生变化，但对于健康衰老大脑中默认模式活动的稳定性却知之甚少。我们在巴尔的摩纵向衰老研究（BLSA）神经影像学研究中，对老年参与者在8年期间的静息特异性活动变化进行了调查。对基线和8年随访时静息状态及识别记忆PET区域脑血流情况的比较显示，内侧额叶/前扣带回、海马体和后扣带回等通常与默认模式相关的区域，其静息特异性活动随时间相对稳定。相比之下，前额叶、海马旁回和枕叶皮质区域通常与默认模式活动无关，随时间会发生变化。总体而言，默认模式网络主要组成部分的活动在健康老年人中保持稳定，这一发现可能有助于识别区分正常衰老和病理性衰老的因素。
