Nair Vidhya Vijayakrishnan, Diorio Tyler C, Wen Qiuting, Rayz Vitaliy L, Tong Yunjie
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States.
Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States.
Imaging Neurosci (Camb). 2024 Jun 10;2. doi: 10.1162/imag_a_00192. eCollection 2024.
With growing evidence signifying the impact of cerebrospinal fluid (CSF) flow in facilitating waste clearance from the brain and potential pathophysiological links to neurodegenerative disorders, it is of vital importance to develop effective methods to modulate CSF flow in the brain. Here, we attempt this by means of simple commonly used respiratory challenges-paced breathing and breath holding. Functional Magnetic Resonance Imaging scans of the brain and neck respectively were used to record the craniad and caudad CSF movements at the fourth ventricle from eight healthy volunteers during paced breathing and breath holding. Further, we utilized a novel approach for the first time to combine these separately acquired unidirectional CSF movement signals to compare the CSF flow in both directions (in the fourth ventricle) with the respiratory stimuli as a physiological control. Our results demonstrate that these respiratory challenges enhance the magnitude as well as control the direction of CSF movement in the fourth ventricle. They also reveal the capability of blood COconcentration changes (induced by respiratory challenges) in the low-frequency range to bring about these CSF movement modulations. Finally, we also successfully report our novel approach where we use these breathing challenges as a unique control condition to detect the small net CSF flows from independently captured unidirectional signals.
随着越来越多的证据表明脑脊液（CSF）流动在促进大脑废物清除以及与神经退行性疾病潜在病理生理联系方面的影响，开发有效的方法来调节大脑中的脑脊液流动至关重要。在此，我们通过简单常用的呼吸挑战——定频呼吸和屏气来尝试实现这一点。分别对八名健康志愿者在定频呼吸和屏气过程中进行大脑和颈部的功能磁共振成像扫描，以记录第四脑室处脑脊液的头向和尾向运动。此外，我们首次采用一种新颖的方法，将这些分别获取的单向脑脊液运动信号进行合并，以比较第四脑室中两个方向（脑脊液流动方向）的脑脊液流动情况，并将呼吸刺激作为生理对照。我们的结果表明，这些呼吸挑战增强了第四脑室中脑脊液运动的幅度并控制了其方向。它们还揭示了低频范围内血液二氧化碳浓度变化（由呼吸挑战引起）引发这些脑脊液运动调节的能力。最后，我们还成功报告了我们的新颖方法，即利用这些呼吸挑战作为独特的对照条件，从独立捕获的单向信号中检测脑脊液的小净流量。
