Parra Mario A, Saarimäki Heini, Bastin Mark E, Londoño Ana C, Pettit Lewis, Lopera Francisco, Della Sala Sergio, Abrahams Sharon
1 Human Cognitive Neuroscience, Psychology, University of Edinburgh, Edinburgh, UK 2 Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK 3 UDP-INECO Foundation Core on Neuroscience (UIFCoN), Diego Portales University, Santiago, Chile 4 Alzheimer Scotland Dementia Research Centre and Scottish Dementia Clinical Research Network, NHS Scotland 5 Neuroscience Group, University of Antioquia, Antioquia, Colombia
1 Human Cognitive Neuroscience, Psychology, University of Edinburgh, Edinburgh, UK.
Brain. 2015 May;138(Pt 5):1355-69. doi: 10.1093/brain/awv048. Epub 2015 Mar 11.
Binding information in short-term and long-term memory are functions sensitive to Alzheimer's disease. They have been found to be affected in patients who meet criteria for familial Alzheimer's disease due to the mutation E280A of the PSEN1 gene. However, only short-term memory binding has been found to be affected in asymptomatic carriers of this mutation. The neural correlates of this dissociation are poorly understood. The present study used diffusion tensor magnetic resonance imaging to investigate whether the integrity of white matter structures could offer an account. A sample of 19 patients with familial Alzheimer's disease, 18 asymptomatic carriers and 21 non-carrier controls underwent diffusion tensor magnetic resonance imaging, neuropsychological and memory binding assessment. The short-term memory binding task required participants to detect changes across two consecutive screens displaying arrays of shapes, colours, or shape-colour bindings. The long-term memory binding task was a Paired Associates Learning Test. Performance on these tasks were entered into regression models. Relative to controls, patients with familial Alzheimer's disease performed poorly on both memory binding tasks. Asymptomatic carriers differed from controls only in the short-term memory binding task. White matter integrity explained poor memory binding performance only in patients with familial Alzheimer's disease. White matter water diffusion metrics from the frontal lobe accounted for poor performance on both memory binding tasks. Dissociations were found in the genu of corpus callosum which accounted for short-term memory binding impairments and in the hippocampal part of cingulum bundle which accounted for long-term memory binding deficits. The results indicate that white matter structures in the frontal and temporal lobes are vulnerable to the early stages of familial Alzheimer's disease and their damage is associated with impairments in two memory binding functions known to be markers for Alzheimer's disease.
短期和长期记忆中的绑定信息是对阿尔茨海默病敏感的功能。已发现它们在因PSEN1基因E280A突变而符合家族性阿尔茨海默病标准的患者中受到影响。然而，仅在这种突变的无症状携带者中发现短期记忆绑定受到影响。这种分离的神经关联尚不清楚。本研究使用扩散张量磁共振成像来研究白质结构的完整性是否能对此作出解释。19名家族性阿尔茨海默病患者、18名无症状携带者和21名非携带者对照样本接受了扩散张量磁共振成像、神经心理学和记忆绑定评估。短期记忆绑定任务要求参与者检测在连续两个屏幕上显示形状、颜色或形状 - 颜色组合阵列时的变化。长期记忆绑定任务是配对联想学习测试。这些任务的表现被纳入回归模型。相对于对照组，家族性阿尔茨海默病患者在两项记忆绑定任务上表现不佳。无症状携带者仅在短期记忆绑定任务中与对照组不同。白质完整性仅在家族性阿尔茨海默病患者中解释了记忆绑定表现不佳的原因。额叶的白质水扩散指标解释了两项记忆绑定任务的不佳表现。在胼胝体膝部发现了解离，其导致短期记忆绑定受损，在扣带束海马部分发现了解离，其导致长期记忆绑定缺陷。结果表明，额叶和颞叶的白质结构在家族性阿尔茨海默病早期阶段易受影响，其损伤与已知为阿尔茨海默病标志物的两种记忆绑定功能受损有关。
