The Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK.
UK Dementia Research Institute at UCL, University College London, London, UK.
Alzheimers Dement. 2023 Jun;19(6):2750-2754. doi: 10.1002/alz.13011. Epub 2023 Mar 18.
In Alzheimer's disease (AD), hyperphosphorylated tau is closely associated with focal neurodegeneration, but the mechanism remains uncertain.
We quantified cortical microstructure using neurite orientation dispersion and density imaging in 14 individuals with young onset AD. Diffusion tensor imaging measured mean diffusivity (MD). Amyloid beta and tau positron emission tomography were acquired and associations with microstructural measures were assessed.
When regional volume was adjusted for, in the medial temporal lobe there was a significant negative association between neurite density and tau (partial R = 0.56, p = 0.008) and between orientation dispersion and tau (partial R = 0.66, p = 0.002), but not between MD and tau. In a wider cortical composite, there was an association between orientation dispersion and tau (partial R = 0.43, p = 0.030), but not between other measures and tau.
Our findings are consistent with tau causing first dendritic pruning (reducing dispersion/complexity) followed by neuronal loss. Advanced magnetic resonance imaging (MRI) microstructural measures have the potential to provide information relating to underlying tau deposition.
在阿尔茨海默病（AD）中，过度磷酸化的 tau 与局灶性神经退行性变密切相关，但机制仍不确定。
我们使用神经丝取向分散和密度成像技术对 14 名早发性 AD 患者的皮质微观结构进行了量化。弥散张量成像测量平均弥散度（MD）。获取淀粉样β和 tau 正电子发射断层扫描（PET），并评估其与微观结构测量的相关性。
当调整了区域体积后，在内侧颞叶中，tau 与神经丝密度之间存在显著的负相关（部分 R 为 0.56，p 为 0.008），tau 与取向分散之间也存在显著的负相关（部分 R 为 0.66，p 为 0.002），但 MD 与 tau 之间无相关性。在更广泛的皮质复合区域中，tau 与取向分散之间存在相关性（部分 R 为 0.43，p 为 0.030），但其他指标与 tau 之间无相关性。
我们的研究结果与 tau 首先引起树突修剪（降低分散/复杂性），然后导致神经元丢失的假说一致。先进的磁共振成像（MRI）微观结构测量有潜力提供与 tau 沉积相关的信息。
