Ohara S, Tsukada M, Ikeda S
Department of Neurology, National Chushin-Matsumoto Hospital, Matsumoto, Japan.
Acta Neuropathol. 1999 Jan;97(1):85-90. doi: 10.1007/s004010050959.
We report on the autopsy of a 52-year-old Down's syndrome patient with a 9-year history of progressive dementia. Histologically, there was a marked neuronal loss in the cerebral cortices with numerous neurofibrillary tangles and senile plaques and congophilic angiopathy. The second cortical layer was spongy in appearance and the frontal and temporal white matter showed marked myelin pallor. Immunohistochemistry for MAP2 of the frontal and temporal cortices revealed great reduction in the number of large pyramidal neurons. On the other hand, a much stronger MAP2 immunoreactivity than that seen in the controls was observed in the second layer, which consisted of many small pyramidal neurons with features of aberrant sprouting. They were recognized in the frontal cortices but not in the temporal cortices, and were not immunolabeled with phosphorylated-tau nor MAP5. On double immunolabeling with MAP2 and beta-amyloid antibodies, these neurons were found to be not directly associated with the formation of senile plaques. Ultrastructurally, MAP2 was immunolocalized in an amorphous granular form in the neuronal somata and processes, and paired helical filaments were not immunolabeled. The observation may indicate the occurrence of a remarkable plastic response of small pyramidal cortical neurons in this patient with Down's syndrome.
我们报告了一名患有9年进行性痴呆病史的52岁唐氏综合征患者的尸检情况。组织学上，大脑皮质存在明显的神经元丢失，伴有大量神经原纤维缠结、老年斑和嗜刚果红血管病。第二层皮质外观呈海绵状，额叶和颞叶白质显示明显的髓鞘苍白。额叶和颞叶皮质的MAP2免疫组织化学显示大锥体神经元数量大幅减少。另一方面，在由许多具有异常发芽特征的小锥体神经元组成的第二层中，观察到MAP2免疫反应性比对照组更强。它们在额叶皮质中可见，但在颞叶皮质中未见，且未被磷酸化tau或MAP5免疫标记。在用MAP2和β-淀粉样蛋白抗体进行双重免疫标记时，发现这些神经元与老年斑的形成没有直接关联。超微结构上，MAP2以无定形颗粒形式免疫定位在神经元胞体和突起中，成对螺旋丝未被免疫标记。该观察结果可能表明该唐氏综合征患者的小锥体皮质神经元发生了显著的可塑性反应。
