Significant densities of neurofibrillary tangles (NFT) often occur in regions of the cerebral cortex and hippocampus in cases of Alzheimer’s disease (AD). To investigate the spatial fluctuations of NFT in these regions, variations in the density of Gallyas-stained NFT were recorded in ‘transects’ of contiguous sample fields aligned parallel with the tissue boundary. Fourier (spectral) analysis was used to analyse the fluctuations in density of NFT and to interpret them in relation to the underlying neuroanatomy. The Fourier analysis suggested that NFT exhibited complex sinusoidal fluctuations in density in the cerebral cortex and hippocampus in AD. The fluctuations occurred at different scales, the most common pattern being a small-scale sinusoidal fluctuation repeating every 500-1000 mm and a larger-scale pattern repeating at distances greater than 1000 mm. These fluctuations in density may reflect the association of NFT with the modular structure of the cortex and hippocampus. Fourier analysis may be a useful statistical method for studying the patterns of NFT and other abundant cellular inclusions in neurodegenerative disease.

中文翻译：

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傅立叶（光谱）分析揭示阿尔茨海默病神经原纤维缠结密度的波动

在阿尔茨海默病 (AD) 的病例中，神经原纤维缠结 (NFT) 的显着密度通常出现在大脑皮层和海马区。为了研究这些区域中 NFT 的空间波动，在与组织边界平行的连续样本场的“横断面”中记录了 Gallyas 染色的 NFT 密度的变化。傅里叶（光谱）分析用于分析 NFT 密度的波动，并根据潜在的神经解剖学解释它们。傅立叶分析表明，NFT 在 AD 的大脑皮层和海马中表现出复杂的正弦波密度波动。波动发生在不同的尺度上，最常见的模式是每 500-1000 毫米重复一次的小规模正弦波动和距离大于 1000 毫米重复的大规模模式。这些密度的波动可能反映了 NFT 与皮质和海马的模块化结构的关联。傅里叶分析可能是研究神经退行性疾病中 NFT 和其他丰富细胞内含物模式的有用统计方法。