{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T07:08:20Z","timestamp":1789456100551,"version":"build-2803163510"},"reference-count":57,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T00:00:00Z","timestamp":1789430400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Neurosci."],"abstract":"<jats:p>Sleep is thought to modulate brain fluid transport; however, whether these physiological processes are reflected in regional diffusion magnetic resonance imaging (MRI) parameters and their interregional organization during sleep remains unclear. We performed simultaneous electroencephalography (EEG) and repeated multishell diffusion MRI during zolpidem-facilitated sleep in 12 healthy adults. Analyses included nine participants who maintained sleep throughout all diffusion acquisitions. Scan-wise sleep depth was quantified using the odds ratio product (ORP), which showed excellent agreement with EEG-defined arousal states and an expected inverse association with relative delta power. The diffusion tensor and kurtosis metrics were quantified within the JHU ICBM-DTI-81 white-matter and the Automated Anatomical Labeling atlas, v. 2 (AAL2) gray-matter regions. We examined regional sleep-depth associations and interregional correlation networks. Exploratory analyses showed that deeper sleep was associated with lower white-matter anisotropy, reflected in reduced fractional anisotropy and kurtosis fractional anisotropy within major projection and association pathways. In the gray matter, associations with sleep depth were more pronounced, with lower axial, mean, and radial diffusivities, whereas the corresponding kurtosis metrics showed associations in the opposite direction that reached nominal significance. These associations were primarily localized to the frontocentral sensorimotor and medial frontal\u2013cingulate regions. Correlation network analysis identified seven interregional correlations that were sensitive to sleep depth after controlling for global covariance. Four were located within the middle cerebral artery territory, two within the posterior circulation cerebellar and vermian regions, and one sensorimotor correlation spanned the anterior and middle cerebral artery territories. These findings demonstrate region-specific and coordinated diffusion changes during human sleep and establish an exploratory network-based framework for investigating diffusion patterns relevant to glymphatic physiology.<\/jats:p>","DOI":"10.3389\/fnins.2026.1889651","type":"journal-article","created":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T06:25:06Z","timestamp":1789453506000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Regional and network patterns of sleep-depth-associated brain diffusion changes: an EEG-informed multishell diffusion MRI study"],"prefix":"10.3389","volume":"20","author":[{"given":"Jehyeong","family":"Yeon","sequence":"first","affiliation":[{"name":"Department of Radiation Convergence Engineering, College of Software and Digital Healthcare Convergence, Yonsei University","place":["Wonju, Gangwon-State, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chul-Ho","family":"Sohn","sequence":"additional","affiliation":[{"name":"Department of Radiology, Seoul National University College of Medicine, Seoul National University Hospital","place":["Seoul, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chang-Soo","family":"Yun","sequence":"additional","affiliation":[{"name":"Neuroscience Research Institute, Gachon University Gil Medical Center","place":["Incheon, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kun-Jin","family":"Chung","sequence":"additional","affiliation":[{"name":"Department of Radiation Convergence Engineering, College of Software and Digital Healthcare Convergence, Yonsei University","place":["Wonju, Gangwon-State, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Byong-Ji","family":"Min","sequence":"additional","affiliation":[{"name":"Department of Radiation Convergence Engineering, College of Software and Digital Healthcare Convergence, Yonsei University","place":["Wonju, Gangwon-State, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chang-Ho","family":"Yun","sequence":"additional","affiliation":[{"name":"Department of Neurology, Seoul National University Bundang Hospital and Seoul National University College of Medicine","place":["Seongnam, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bong Soo","family":"Han","sequence":"additional","affiliation":[{"name":"Department of Radiation Convergence Engineering, College of Software and Digital Healthcare Convergence, Yonsei University","place":["Wonju, Gangwon-State, Republic of Korea"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,15]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"870","DOI":"10.1016\/S1053-8119(03)00336-7","article-title":"How to correct susceptibility distortions in spin-echo echo-planar images: application to diffusion tensor imaging","volume":"20","author":"Andersson","year":"2003","journal-title":"NeuroImage"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"1063","DOI":"10.1016\/j.neuroimage.2015.10.019","article-title":"An integrated approach to correction for off-resonance effects and subject movement in diffusion MR imaging","volume":"125","author":"Andersson","year":"2016","journal-title":"NeuroImage"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"232","DOI":"10.1038\/nature09613","article-title":"Glial and neuronal control of brain blood flow","volume":"468","author":"Attwell","year":"2010","journal-title":"Nature"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"e221848","DOI":"10.1148\/radiol.221848","article-title":"Altered brain Glymphatic flow at diffusion-tensor MRI in rapid eye movement sleep behavior disorder","volume":"307","author":"Bae","year":"2023","journal-title":"Radiology"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"259","DOI":"10.1016\/S0006-3495(94)80775-1","article-title":"MR diffusion tensor spectroscopy and imaging","volume":"66","author":"Basser","year":"1994","journal-title":"Biophys. 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