嗅觉与阿尔茨海默病相互关系的研究进展

Research Progress on the Relationship between Olfaction and Alzheimer’s Disease

阿尔茨海默病(Alzheimer’s disease,AD)是一种复杂的神经退行性疾病,严重影响患者的认知能力和记忆力,其病理特征为细胞外淀粉样斑块沉积和细胞内神经纤维缠结。AD患者嗅觉减退,且嗅觉障碍出现时间早于认知障碍,嗅觉系统的初级神经元直接与外界环境接触,可能会将有害物质传递到大脑。暴露于金属物质后,啮齿类动物嗅觉减退、学习记忆损伤、tau蛋白磷酸化水平升高、脑组织中Aβ积累等,这与AD症状相似。嗅觉障碍与AD病理程度密切相关,AD患者嗅觉相关脑区在AD核心症状出现之前即发生嗅球萎缩、神经元丢失等病理改变,且嗅觉相关脑区的病理改变程度与AD病理程度呈正相关。进一步深入了解嗅觉损伤与AD发病之间的关系对AD发病机制研究及AD早期诊断有重要意义。

AD(Alzheimer’s disease)is a complex neurodegenerative disease,which seriously affects cognition and memory.The pathological characteristics of AD are extracellular amyloid plaque deposition and intracellular neurofibrillary tangles.Olfactory impairment occurs earlier than cognitive impairment in AD.The primary sensory neurons of the olfactory system are in direct contact with the external environment,which may transfer harmful substances to the brain.Rodents show olfactory dysfunction,learning and memory impairment,elevated tau protein phosphorylation level and Aβaccumulation in the brain after mental expose,which are similar to AD characteristics.Olfactory dysfunction is closely related to the degree of AD pathology.Olfactory bulb atrophy,neuron loss and other pathological changes occur in olfactory-related brain areas before the occurrence of core symptoms of AD,and the degree of pathological changes in olfactory-related brain areas is positively related to the pathological degree of AD.Further understanding of the relationship between olfactory impairment and AD pathogenesis is of great significance for the study of the pathogenesis of AD and the early diagnosis of AD.