Department of Cell Biology, Center for Glial Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Neurobiol Aging. 2011 Sep;32(9):1651-61. doi: 10.1016/j.neurobiolaging.2009.10.008. Epub 2009 Nov 11.
Recently it has been shown that over 3-year-old wild-type South American rodents, Octodon degus, the "common degu" or degu, of their own accord develop Alzheimer's disease neuropathological hallmarks: amyloid-β-peptide depositions and accumulation of tau-protein. Here we analyzed brains of 1-, 3- and 6-year-old degu's, bred in standard animal facilities. Significant amounts of Aβ and tau deposits are present in the hippocampal formation of 6-year-old O. degus, primarily in the white matter, but these hippocampal Aβ and tau deposits are not present in younger ones. In contrast, significant Aβ deposits in blood vessel walls are already found in 3-year-old animals. The tau deposits in the hippocampal formation coincide with a significant decrease in staining for myelin in the same areas, indicating hippocampal disconnection and, likely, dysfunction. Our findings indicate that (1) cerebral amyloid angiopathy precedes brain parenchyma pathology in aged degu's and (2) the onset of disease seems to be delayed in the laboratory vs. wild-type degu's.
最近的研究表明，3 岁以上的野生南美的啮齿动物——八齿鼠（俗称“普通八齿鼠”或八齿鼠）会自行发展出阿尔茨海默病的神经病理学特征：β-淀粉样蛋白沉积和 tau 蛋白的积累。在这里，我们分析了在标准动物设施中饲养的 1 岁、3 岁和 6 岁八齿鼠的大脑。在 6 岁的 O. degus 的海马结构中存在大量的 Aβ 和 tau 沉积，主要存在于白质中，但在年幼的八齿鼠中不存在这些海马 Aβ 和 tau 沉积。相比之下，在 3 岁的动物中已经发现了明显的血管壁中的 Aβ 沉积。海马结构中的 tau 沉积与同一区域髓鞘染色的显著减少相吻合，表明海马区的断开，可能还有功能障碍。我们的发现表明：（1）大脑淀粉样血管病先于老年八齿鼠的脑实质病变；（2）与野生型八齿鼠相比，疾病的发作似乎在实验室中被延迟了。
