Tuunanen Johanna, Helakari Heta, Huotari Niko, Väyrynen Tommi, Järvelä Matti, Kananen Janne, Kivipää Annastiina, Raitamaa Lauri, Ebrahimi Seyed-Mohsen, Kallio Mika, Piispala Johanna, Kiviniemi Vesa, Korhonen Vesa
Department of Diagnostic Radiology, Oulu Functional NeuroImaging (OFNI), Oulu University Hospital, Oulu, Finland.
Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland.
Front Neurosci. 2024 Oct 8;18:1457732. doi: 10.3389/fnins.2024.1457732. eCollection 2024.
The cerebrospinal fluid dynamics in the human brain are driven by physiological pulsations, including cardiovascular pulses and very low-frequency (< 0.1 Hz) vasomotor waves. Ultrafast functional magnetic resonance imaging (fMRI) facilitates the simultaneous measurement of these signals from venous and arterial compartments independently with both classical venous blood oxygenation level dependent (BOLD) and faster arterial spin-phase contrast.
In this study, we compared the interaction of these two pulsations in awake and sleep using fMRI and peripheral fingertip photoplethysmography in both arterial and venous signals in 10 healthy subjects (5 female).
Sleep increased the power of brain cardiovascular pulsations, decreased peripheral pulsation, and desynchronized them. However, vasomotor waves increase power and synchronicity in both brain and peripheral signals during sleep. Peculiarly, lag between brain and peripheral vasomotor signals reversed in sleep within the default mode network. Finally, sleep synchronized cerebral arterial vasomotor waves with venous BOLD waves within distinct parasagittal brain tissue.
These changes in power and pulsation synchrony may reflect systemic sleep-related changes in vascular control between the periphery and brain vasculature, while the increased synchrony of arterial and venous compartments may reflect increased convection of regional neurofluids in parasagittal areas in sleep.
人类大脑中的脑脊液动力学由生理搏动驱动，包括心血管搏动和极低频（<0.1Hz）血管舒缩波。超快功能磁共振成像（fMRI）有助于通过经典的静脉血氧水平依赖（BOLD）和更快的动脉自旋相位对比，独立地同时测量来自静脉和动脉腔室的这些信号。
在本研究中，我们使用fMRI和外周指尖光电容积描记术，比较了10名健康受试者（5名女性）在清醒和睡眠状态下这两种搏动在动脉和静脉信号中的相互作用。
睡眠增加了脑血管搏动的功率，降低了外周搏动，并使其去同步化。然而，血管舒缩波在睡眠期间增加了大脑和外周信号的功率和同步性。特别的是，在默认模式网络中，睡眠期间大脑和外周血管舒缩信号之间的延迟发生了逆转。最后，睡眠使大脑动脉血管舒缩波与矢状旁脑区不同脑组织中的静脉BOLD波同步。
这些功率和搏动同步性的变化可能反映了外周和脑血管系统之间与睡眠相关的系统性血管控制变化，而动脉和静脉腔室同步性的增加可能反映了睡眠期间矢状旁区域局部神经流体对流的增加。
