Near-infrared spectroscopy (fNIRS) measures concentrations of oxygenated (HbO) and deoxygenated (HbR) hemoglobin in the brain. Recently, we demonstrated its potential also for measuring concentrations of cerebral water (\(\hbox {cH}_{2}\hbox {O}\)). We performed fNIRS measurements during rest to study fluctuations in concentrations of \(\hbox {cH}_{2}\hbox {O}\), HbO and HbR in 33 well-rested healthy control subjects (HC) and 18 acutely sleep-deprived HC. Resting-state fNIRS signal was filtered in full-band, cardiac, respiratory, low-, and very-low-frequency bands. The sum of HbO and HbR constitutes the regional cerebral blood volume (CBV). CBV and \(\hbox {cH}_{2}\hbox {O}\) concentrations were analyzed via temporal correlation and phase synchrony. Fluctuation in concentrations of \(\hbox {cH}_{2}\hbox {O}\) and CBV was strongly anti-correlated across all frequency bands in both frontal and parietal cortices. Fluctuation in concentrations of \({\hbox {cH}}_{2}{\hbox {O}}\) and CBV showed neither a completely synchronous nor a random phase relationship in both frontal and parietal cortices. Acutely sleep-deprived subjects did not show significant differences in temporal correlation or phase synchrony between fluctuations in \({\hbox {cH}}_{2}{\hbox {O}}\) and CBV concentrations compared with well-rested HC. The reciprocal interrelation between fluctuations in CBV and \({\hbox {cH}}_{2}{\hbox {O}}\) concentrations is consistent with the Munro–Kellie doctrine of constant intracranial volume. This coupling may constitute a functional mechanism underlying glymphatic circulation, which persists despite acutely disturbed sleep patterns.

近红外光谱（fNIRS）可测量大脑中氧合（HbO）和脱氧（HbR）血红蛋白的浓度。最近，我们证明了其在测量脑水浓度中的潜力（\（\ hbox {cH} _ {2} \ hbox {O} \））。我们在休息期间进行了fNIRS测量，以研究33名健康良好的健康对照受试者（HC）和18名急性睡眠-健康受试者的\（\ hbox {cH} _ {2} \ hbox {O} \），HbO和HbR浓度的波动。剥夺了HC。静息状态的fNIRS信号在全频带，心脏，呼吸，低和非常低的频带中被过滤。HbO和HbR的总和构成区域脑血容量（CBV）。CBV和\（\ hbox {cH} _ {2} \ hbox {O} \）通过时间相关性和相位同步分析浓度。\（\ hbox {cH} _ {2} \ hbox {O} \）和CBV的浓度波动在额叶和顶叶皮质的所有频带上都具有很强的反相关性。\（{\ hbox {cH}} _ {2} {\ hbox {O}} \）和CBV的浓度波动在额叶和顶叶皮质均未显示完全同步或随机相位关系。与安静的HC相比，缺乏睡眠的受试者在\（{{hbox {cH}} _ {2} {\ hbox {O}} \）和CBV浓度波动之间，在时间相关性或相位同步性方面没有显示出显着差异。CBV波动与\（{\ hbox {cH}} _ {2} {\ hbox {O}} \）之间的相互关系浓度与恒定颅内体积的Munro-Kellie学说相符。这种耦合可能构成了淋巴循环的基础功能机制，尽管睡眠模式受到严重干扰，这种机制仍持续存在。