A Ultra-fast magnetic resonance encephalography of physiological brain activity - Glymphatic pulsation mechanisms?
A Ultra-fast magnetic resonance encephalography of physiological brain activity - Glymphatic pulsation mechanisms?
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DOI：
10.1177/0271678x15622047
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发表时间：
2016-06-01
影响因子：
6.3
通讯作者：
Nedergaard, Maiken
中科院分区：
文献类型：
--
作者：
Kiviniemi, Vesa;Wang, Xindi;Nedergaard, Maiken
关于脑脊液的胶质淋巴对流机制的理论认为，心脏搏动部分地将脑脊液从动脉周围空间通过细胞外组织泵送到静脉周围空间中，这是由水通道蛋白水通道促进的。由于心脏脉冲不能是胶质淋巴推进的唯一机制，我们用超快磁共振脑成像在人脑中寻找额外的脑脊液脉冲。我们检测到三种类型的生理机制影响脑脑脊液脉动：心脏，呼吸，和非常低的频率脉动。心脏搏动在动脉周围区域引起负磁共振脑成像信号变化，其以大约1 Hz的周期离心延伸并覆盖大脑。近似0.3Hz的呼吸脉动是主要发生在静脉周围区域的向心周期性脉动。第三种类型的脉动是非常低频（VLF 0.001-0.023 Hz）和低频（LF 0.023-0.73 Hz）波，两者都以独特的时空模式传播。我们的研究结果使用批判性采样磁共振脑成像打开了一个新的视角到脑流体动力学。由于胶质淋巴系统故障可能先于阿尔茨海默氏症等疾病中的蛋白质积累，因此这种方法学上的进步提供了一种新的脑流体动力学成像方法，可能能够早期检测和干预神经退行性疾病。
The theory on the glymphatic convection mechanism of cerebrospinal fluid holds that cardiac pulsations in part pump cerebrospinal fluid from the peri-arterial spaces through the extracellular tissue into the peri-venous spaces facilitated by aquaporin water channels. Since cardiac pulses cannot be the sole mechanism of glymphatic propulsion, we searched for additional cerebrospinal fluid pulsations in the human brain with ultra-fast magnetic resonance encephalography. We detected three types of physiological mechanisms affecting cerebral cerebrospinal fluid pulsations: cardiac, respiratory, and very low frequency pulsations. The cardiac pulsations induce a negative magnetic resonance encephalography signal change in peri-arterial regions that extends centrifugally and covers the brain in approximate to 1 Hz cycles. The respiratory approximate to 0.3 Hz pulsations are centripetal periodical pulses that occur dominantly in peri-venous areas. The third type of pulsation was very low frequency (VLF 0.001-0.023 Hz) and low frequency (LF 0.023-0.73 Hz) waves that both propagate with unique spatiotemporal patterns. Our findings using critically sampled magnetic resonance encephalography open a new view into cerebral fluid dynamics. Since glymphatic system failure may precede protein accumulations in diseases such as Alzheimer's dementia, this methodological advance offers a novel approach to image brain fluid dynamics that potentially can enable early detection and intervention in neurodegenerative diseases.