Why musical memory can be preserved in advanced Alzheimer's disease
Why musical memory can be preserved in advanced Alzheimer's disease
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DOI：
10.1093/brain/awv135
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发表时间：
2015-08-01
期刊：
影响因子：
14.5
通讯作者：
Turner, Robert
中科院分区：
文献类型：
--
作者：
Jacobsen, Jorn-Henrik;Stelzer, Johannes;Turner, Robert
音乐记忆被认为是部分独立于其他记忆系统的。在阿尔茨海默氏症和不同类型的痴呆症中，音乐记忆出人意料地强大，影响其他类型记忆的大脑损伤也是如此。然而，音乐记忆的机制和神经基础仍然知之甚少。在一组32名正常的年轻人(16名男性和16名女性，平均年龄28.0+/-2.2岁)中，我们进行了一项7T功能磁共振成像研究，研究了大脑对未知的、最近知道的(扫描前一小时听到的)和长期知道的音乐片段的反应。我们使用多变量模式分类来识别编码长期音乐记忆的大脑区域。结果表明，与最近已知和未知的音乐相比，尾侧前扣带回和腹侧前辅助运动区在长期已知音乐的神经编码中起着至关重要的作用。在研究的第二部分，我们分析了20名阿尔茨海默病患者(10名男性和10名女性，平均年龄68.9±9.0岁)和34名健康对照组(14名男性和20名女性，平均年龄68.1±7.2岁)阿尔茨海默病患者的兴趣区域(尾侧扣带前皮质和腹侧辅助运动区)中三个基本阿尔茨海默病生物标志物的数据。有趣的是，与大脑的其他部分相比，被识别为编码音乐记忆的区域对应于表现出实质上最轻微的皮质萎缩(通过磁共振成像测量)和最轻微的葡萄糖代谢干扰(通过F-18-氟代脱氧葡萄糖正电子发射断层扫描测量)的区域。然而，当前观察到的感兴趣区域中的淀粉样β沉积(用F-18-Flobetapir正电子发射断层扫描测量)并不比大脑的其余部分少很多，这表明感兴趣区域仍处于这些区域生物标记物发展的预期过程的非常早期阶段(淀粉样蛋白积累->；代谢不足->；皮质萎缩)，因此保存相对完好。鉴于观察到的音乐记忆区域与阿尔茨海默病中相对幸免的区域重叠，目前的发现可能因此解释了这种神经退行性疾病中音乐记忆的惊人保存。
Musical memory is considered to be partly independent from other memory systems. In Alzheimer's disease and different types of dementia, musical memory is surprisingly robust, and likewise for brain lesions affecting other kinds of memory. However, the mechanisms and neural substrates of musical memory remain poorly understood. In a group of 32 normal young human subjects (16 male and 16 female, mean age of 28.0 +/- 2.2 years), we performed a 7 T functional magnetic resonance imaging study of brain responses to music excerpts that were unknown, recently known (heard an hour before scanning), and long-known. We used multivariate pattern classification to identify brain regions that encode long-term musical memory. The results showed a crucial role for the caudal anterior cingulate and the ventral pre-supplementary motor area in the neural encoding of long-known as compared with recently known and unknown music. In the second part of the study, we analysed data of three essential Alzheimer's disease biomarkers in a region of interest derived from our musical memory findings (caudal anterior cingulate cortex and ventral pre-supplementary motor area) in 20 patients with Alzheimer's disease (10 male and 10 female, mean age of 68.9 +/- 9.0 years) and 34 healthy control subjects (14 male and 20 female, mean age of 68.1 +/- 7.2 years). Interestingly, the regions identified to encode musical memory corresponded to areas that showed substantially minimal cortical atrophy (as measured with magnetic resonance imaging), and minimal disruption of glucose-metabolism (as measured with F-18-fluorodeoxyglucose positron emission tomography), as compared to the rest of the brain. However, amyloid-beta deposition (as measured with F-18-flobetapir positron emission tomography) within the currently observed regions of interest was not substantially less than in the rest of the brain, which suggests that the regions of interest were still in a very early stage of the expected course of biomarker development in these regions (amyloid accumulation -> hypometabolism -> cortical atrophy) and therefore relatively well preserved. Given the observed overlap of musical memory regions with areas that are relatively spared in Alzheimer's disease, the current findings may thus explain the surprising preservation of musical memory in this neurodegenerative disease.