Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, North Jianshe Road, Chengdu, Sichuan, China.
Chin Med J (Engl). 2012 Feb;125(4):604-10.
Successful aging (SA) and mild cognitive impairment (MCI) are heterogeneous groups of aging. To explore the heterogeneity, the functional connectivity was studied in these populations.
The present study utilized functional connectivity magnetic resonance imaging (fcMRI) to investigate default mode network (DMN) in 8 healthy subjects of SA, 8 subjects of usual aging (UA), and 8 MCI patients during verbal fluency tests (VFTs). Functional connectivity (based seeds) of different groups was analyzed by using statistical test.
Compared with SA and UA groups, MCI subjects exhibited decreased functional connectivity in the DMN regions, including the inferior parietal lobule and left angular gyrus (t = 3.53, P < 0.001). Compared with UA and MCI groups, the SA elderly exhibited increased functional connectivity in the precuneus (t = 3.53, P < 0.001).
These findings suggested that abnormalities of functional connectivity in DMN might be related with semantic memory impairment in aging. Left angular gyrus and precuneus might be the potential imaging-based biomarker for distinguishing heterogeneous process of elderly.
成功老龄化（SA）和轻度认知障碍（MCI）是老龄化的异质群体。为了探索其异质性，对这些人群的功能连接进行了研究。
本研究采用功能连接磁共振成像（fcMRI）技术，在言语流畅性测试（VFT）期间，对 8 名 SA 健康受试者、8 名正常老化（UA）受试者和 8 名 MCI 患者的默认模式网络（DMN）进行了研究。使用统计检验对不同组的功能连接（基于种子）进行了分析。
与 SA 和 UA 组相比，MCI 受试者的 DMN 区域，包括下顶叶和左角回的功能连接减少（t=3.53，P<0.001）。与 UA 和 MCI 组相比，SA 老年人的楔前叶的功能连接增加（t=3.53，P<0.001）。
这些发现表明，DMN 中功能连接的异常可能与衰老过程中的语义记忆损伤有关。左角回和楔前叶可能是区分老年人异质过程的潜在基于影像学的生物标志物。
