Tauopathy被定义为中枢神经系统中异常磷酸化的微管相关蛋白Tau的异常积累,最能使用抗Tau抗体证明免疫细胞化学。位于17染色体上的TAU基因突变的新公认的家族状况介体证实该过程直接导致神经元变性。TAU由六种同种型组成,从单个基因的替代剪接转换。They are classified into three repeat (3R) and four repeat (4R) subtypes, by the number of microtubulus-binding domain from the reading or skipping of the exon 10. In sporadic tauopathy, 3R + 4R accumulate in Alzehimer’s disease (AD), 3R in Pick’s disease, and 4R in progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). In familial tauopathy, the mutations affecting the splicing of the exon 10 accumulate 4R and phenotypically mimick CBD/PSP, while majority of others simulate neurofibrillary tangle-predominant form of dementia (NFTD). Argyrophlic grains (AG) are tau-immunoreactive comma-shaped or filiform structure, and argyrophilic grain dementia (AGD) is a form of senile dementia carrying AG as only morphological substrate explaining dementia. In our consecutive autopsy cases from the oldest old, AGD is the second leading cause of degenerative type of dementia, highlighting the importance of tauopathy in the aging and dementia.