Center for BrainHealth, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 2200 W. Mockingbird Ln, Dallas, TX 75235, USA.
Neuropsychol Rev. 2009 Dec;19(4):436-50. doi: 10.1007/s11065-009-9118-x. Epub 2009 Nov 12.
A central issue in cognitive neuroscience of aging research is pinpointing precise neural mechanisms that determine cognitive outcome in late adulthood as well as identifying early markers of less successful cognitive aging. One promising biomarker is beta amyloid (Abeta) deposition. Several new radiotracers have been developed that bind to fibrillar Abeta providing sensitive estimates of amyloid deposition in various brain regions. Abeta imaging has been primarily used to study patients with Alzheimer's Disease (AD) and individuals with Mild Cognitive Impairment (MCI); however, there is now building data on Abeta deposition in healthy controls that suggest at least 20% and perhaps as much as a third of healthy older adults show significant deposition. Considerable evidence suggests amyloid deposition precedes declines in cognition and may be the initiator in a cascade of events that indirectly leads to age-related cognitive decline. We review studies of Abeta deposition imaging in AD, MCI, and normal adults, its cognitive consequences, and the role of genetic risk and cognitive reserve.
认知神经科学老龄化研究的一个核心问题是确定决定晚年认知结果的精确神经机制，并确定认知老化不成功的早期标志物。一个有前途的生物标志物是β淀粉样蛋白（Aβ）沉积。已经开发了几种新的放射性示踪剂，它们与纤维状 Aβ结合，提供了对各种大脑区域中淀粉样蛋白沉积的敏感估计。Aβ成像主要用于研究阿尔茨海默病（AD）患者和轻度认知障碍（MCI）个体；然而，现在有越来越多的关于健康对照组中 Aβ沉积的数据表明，至少有 20%，甚至可能高达三分之一的健康老年人有明显的沉积。大量证据表明，淀粉样蛋白沉积先于认知能力下降，并且可能是一连串事件的启动因素，这些事件间接导致与年龄相关的认知能力下降。我们回顾了 AD、MCI 和正常成年人中 Aβ沉积成像的研究、其认知后果以及遗传风险和认知储备的作用。
