PDF(Pubmed)
Abstract：
BACKGROUND: The combination of apolipoprotein E ε4 (ApoE ε4) status, odor identification, and odor familiarity predicts conversion to mild cognitive impairment (MCI) and Alzheimer\'s disease (AD).
METHODS: To further understand olfactory disturbances and AD risk, ApoE ε4 carrier (mean age 76.38 ± 5.21) and ε4 non-carrier (mean age 76.8 ± 3.35) adults were given odor familiarity and identification tests and performed an odor identification task during fMRI scanning. Five task-related functional networks were detected using independent components analysis. Main and interaction effects of mean odor familiarity ratings, odor identification scores, and ε4 status on network activation and task-modulation of network functional connectivity (FC) during correct and incorrect odor identification (hits and misses), controlling for age and sex, were explored using multiple linear regression.
RESULTS: Findings suggested that sensory-olfactory network activation was positively associated with odor identification scores in ε4 carriers with intact odor familiarity. The FC of sensory-olfactory, multisensory-semantic integration, and occipitoparietal networks was altered in ε4 carriers with poorer odor familiarity and identification. In ε4 carriers with poorer familiarity, connectivity between superior frontal areas and the sensory-olfactory network was negatively associated with odor identification scores.
CONCLUSIONS: The results contribute to the clarification of the neurocognitive structure of odor identification processing and suggest that poorer odor familiarity and identification in ε4 carriers may signal multi-network dysfunction. Odor familiarity and identification assessment in ε4 carriers may contribute to the predictive value of risk for MCI and AD due to the breakdown of sensory-cognitive network integration. Additional research on olfactory processing in those at risk for AD is warranted.
METHODS: To further understand olfactory disturbances and AD risk, ApoE ε4 carrier (mean age 76.38 ± 5.21) and ε4 non-carrier (mean age 76.8 ± 3.35) adults were given odor familiarity and identification tests and performed an odor identification task during fMRI scanning. Five task-related functional networks were detected using independent components analysis. Main and interaction effects of mean odor familiarity ratings, odor identification scores, and ε4 status on network activation and task-modulation of network functional connectivity (FC) during correct and incorrect odor identification (hits and misses), controlling for age and sex, were explored using multiple linear regression.
RESULTS: Findings suggested that sensory-olfactory network activation was positively associated with odor identification scores in ε4 carriers with intact odor familiarity. The FC of sensory-olfactory, multisensory-semantic integration, and occipitoparietal networks was altered in ε4 carriers with poorer odor familiarity and identification. In ε4 carriers with poorer familiarity, connectivity between superior frontal areas and the sensory-olfactory network was negatively associated with odor identification scores.
CONCLUSIONS: The results contribute to the clarification of the neurocognitive structure of odor identification processing and suggest that poorer odor familiarity and identification in ε4 carriers may signal multi-network dysfunction. Odor familiarity and identification assessment in ε4 carriers may contribute to the predictive value of risk for MCI and AD due to the breakdown of sensory-cognitive network integration. Additional research on olfactory processing in those at risk for AD is warranted.
摘要：
背景：载脂蛋白Eε4（ApoEε4）状态的组合，气味识别,气味熟悉度可预测转化为轻度认知障碍（MCI）和阿尔茨海默病（AD）。
方法：为了进一步了解嗅觉障碍和AD风险，对ApoEε4携带者（平均年龄76.38±5.21）和ε4非携带者（平均年龄76.8±3.35）的成年人进行了气味熟悉度和识别测试，并在fMRI扫描期间执行了气味识别任务。使用独立成分分析检测了五个与任务相关的功能网络。平均气味熟悉度等级的主要影响和相互作用影响，气味识别评分,以及在正确和不正确的气味识别（命中和未命中）期间网络激活和网络功能连接（FC）的任务调制的ε4状态，控制年龄和性别，使用多元线性回归进行了探索。
结果：研究结果表明，在气味熟悉完整的ε4携带者中，感觉-嗅觉网络激活与气味识别评分呈正相关。感官嗅觉的FC，多感官语义整合，ε4携带者的枕顶顶网络发生了变化，气味熟悉和识别较差。在熟悉度差的ε4载波中，额叶上区和感觉-嗅觉网络之间的连通性与气味识别评分呈负相关.
结论：结果有助于澄清气味识别过程的神经认知结构，并表明ε4携带者对气味的熟悉和识别较差可能是多网络功能障碍的信号。由于感觉-认知网络整合的破坏，ε4携带者的气味熟悉和识别评估可能有助于MCI和AD风险的预测价值。有必要对有AD风险的人进行嗅觉处理的其他研究。
方法：为了进一步了解嗅觉障碍和AD风险，对ApoEε4携带者（平均年龄76.38±5.21）和ε4非携带者（平均年龄76.8±3.35）的成年人进行了气味熟悉度和识别测试，并在fMRI扫描期间执行了气味识别任务。使用独立成分分析检测了五个与任务相关的功能网络。平均气味熟悉度等级的主要影响和相互作用影响，气味识别评分,以及在正确和不正确的气味识别（命中和未命中）期间网络激活和网络功能连接（FC）的任务调制的ε4状态，控制年龄和性别，使用多元线性回归进行了探索。
结果：研究结果表明，在气味熟悉完整的ε4携带者中，感觉-嗅觉网络激活与气味识别评分呈正相关。感官嗅觉的FC，多感官语义整合，ε4携带者的枕顶顶网络发生了变化，气味熟悉和识别较差。在熟悉度差的ε4载波中，额叶上区和感觉-嗅觉网络之间的连通性与气味识别评分呈负相关.
结论：结果有助于澄清气味识别过程的神经认知结构，并表明ε4携带者对气味的熟悉和识别较差可能是多网络功能障碍的信号。由于感觉-认知网络整合的破坏，ε4携带者的气味熟悉和识别评估可能有助于MCI和AD风险的预测价值。有必要对有AD风险的人进行嗅觉处理的其他研究。
