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bioRxiv · 10.64898/2025.12.24.696312

Effects of different slow paced breathing regimes on cerebrospinal fluid (CSF) oscillations

Nasseri, P.·Banks, M.·Li, A. Y.·Lewis, L. D.·Yoo, H. J.·Mather, M.
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Abstract

Cerebrospinal fluid (CSF) transport is crucial for clearing waste from the brain and is largely driven by blood vessel oscillatory dynamics. During non-REM sleep, large oscillations occur in the infraslow range around 0.02-0.03 Hz, where noradrenergically driven vasomotion, blood volume and CSF flow are tightly coupled. Whether an infraslow oscillation induced by respiration can engage comparable dynamics during wakefulness is unknown. Utilizing a fast neuroimaging technique, we investigated the effects of four different slow paced respiratory conditions on CSF oscillations in 35 healthy adults (aged 18-30): paced breathing at 0.09-0.11 Hz and 0.05-0.07 Hz, and paced sighing at 0.05-0.07 Hz and 0.02-0.03 Hz. All four conditions increased respiratory volume, low-frequency respiratory power, CSF oscillatory power and BOLD global signal amplitude relative to rest, and CSF power did not differ among them. However, the infraslow slow sighing produced significantly higher CSF-BOLD coupling than all the other conditions, together with the largest global signal amplitude, an index associated with reduced arousal. This effect of infraslow sighing was not linked with respiratory power, as paced breathing at 0.05-0.07 Hz had the greatest respiratory power yet the weakest CSF-BOLD coupling, falling below rest. Cardiac spectral power was also lower during infraslow sighing than during any other breathing manipulation. Stimulating oscillatory dynamics via respiration during wakefulness therefore may recruit neurovascular-CSF coupling due to the same infraslow-specific dynamics that are believed to drive sleep-dependent waste clearance. Our study provides evidence that slow paced breathing increases CSF oscillations during wakefulness. Furthermore, we found that sighing at the frequency of the infraslow band linked to glymphatic clearance increases the coupling between blood and CSF dynamics.

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Nasseri, P., Banks, M., Li, A. Y., Lewis, L. D., Yoo, H. J., Mather, M.. 2025-12-26. Effects of different slow paced breathing regimes on cerebrospinal fluid (CSF) oscillations. https://doi.org/10.64898/2025.12.24.696312

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