Duffy Charles J
Departmentsof Neurology, The University of Rochester Medical Center, Rochester, New York 14642, USA.
Ann N Y Acad Sci. 2009 Jul;1170:736-44. doi: 10.1111/j.1749-6632.2009.04021.x.
Aging and Alzheimer's disease (AD) are accompanied by impairments of autonomous navigation and spatial orientation that commonly demand the abandonment of driving and independent living. We have studied the neuronal mechanisms of navigation using single neurons in monkey cerebral cortex, finding a specific population of cells that processes the visual motion patterns of optic flow that provide important cues about self-movement. We have found that AD patients show pronounced deficits in the perceptual processing of optic flow, with different patterns of less severe impairment in mild cognitive impairment and cognitive aging. These perceptual deficits occur in subjects who show difficulties in real-world navigation that can be linked to visual associative processing impairments. Human neurophysiological recordings reveal a robust link between navigational capacity and cortical information processing in aging and AD. We conclude that visual information processing is progressively impaired in aging and AD. We speculate that these behavioral impairments reflect the progress of mechanistically linked cortical pathophysiologies that are manifestations of the fateful transition from cognitive aging to AD.
衰老和阿尔茨海默病（AD）伴随着自主导航和空间定向能力的损害，这通常导致人们放弃驾驶和独立生活。我们利用猴子大脑皮层中的单个神经元研究了导航的神经机制，发现了一个特定的细胞群体，它们处理视觉运动模式的光流，这些光流提供了关于自我运动的重要线索。我们发现，AD患者在光流的感知处理方面存在明显缺陷，轻度认知障碍和认知衰老患者的损伤模式较轻且有所不同。这些感知缺陷出现在现实世界导航有困难的受试者中，这些困难可能与视觉联想处理障碍有关。人类神经生理学记录揭示了衰老和AD中导航能力与皮层信息处理之间的紧密联系。我们得出结论，视觉信息处理在衰老和AD中逐渐受损。我们推测，这些行为障碍反映了机械性关联的皮层病理生理学的进展，这些病理生理学是从认知衰老到AD这一致命转变的表现。
