Filters








1,026 Hits in 9.0 sec

Evidence for wakefulness-related changes to extracellular space in human brain white matter from diffusion-weighted MRI

Irene Voldsbekk, Ivan I. Maximov, Nathalia Zak, Daniel Roelfs, Oliver Geier, Paulina Due-Tønnessen, Torbjørn Elvsåshagen, Marie Strømstad, Atle Bjørnerud, Inge Groote
2020 NeuroImage  
In addition, the current study assessed whether time-of-day effects were driven by changes to extracellular space, by including estimations of non-Gaussian diffusion metrics obtained from diffusion kurtosis  ...  These results suggest that an increase in the intra-axonal space relative to the extra-axonal volume underlies time-of-day effects in human white matter, which is in line with activity-induced reductions  ...  We thank Lise-Linn Løkken, Taran Blakstvedt and Yvonne Kuiper for assistance with data acquisition.  ... 
doi:10.1016/j.neuroimage.2020.116682 pmid:32114147 fatcat:poofuiwswzafvnngkl55cgtmmm

The Emerging Relationship Between Interstitial Fluid–Cerebrospinal Fluid Exchange, Amyloid-β, and Sleep

Erin L. Boespflug, Jeffrey J. Iliff
2018 Biological Psychiatry  
These changes may underlie the diurnal fluctuations in interstitial and CSF Aβ levels observed in both the rodent and human.  ...  Glymphatic function is primarily a feature of the sleeping, rather than the waking brain, and is slowed in the aging and post-traumatic brain.  ...  If validated in human subjects, then sleep-wake changes in the dimensions of the brain extracellular space will have important implications not only for the clearance of interstitial solutes such as Aβ  ... 
doi:10.1016/j.biopsych.2017.11.031 pmid:29279202 pmcid:PMC5767516 fatcat:42s7wp2g7jc2flstyxawckh2pm

Sleep-related and diurnal effects on brain diffusivity and cerebrospinal fluid flow

Ruth O'Gorman Tuura, Carina Volk, Fraser Callaghan, Valeria Jaramillo, Reto Huber
2021 NeuroImage  
The purpose of this study was to investigate whether overnight changes in diffusivity, brain volumes, and cerebrospinal fluid flow measured with MRI are associated with sleep parameters from overnight  ...  These results provide evidence for both sleep related and diurnal effects on water compartmentalisation within the brain.  ...  The authors gratefully acknowledge the support of Lea Scherer and Benjamin Stucky for providing the algorithm used for analysis of the actimetry data.  ... 
doi:10.1016/j.neuroimage.2021.118420 pmid:34302966 fatcat:ju727rnpdfg3jjogtdm32pkmdi

Diffusion MRI and the detection of alterations following traumatic brain injury

Elizabeth B. Hutchinson, Susan C. Schwerin, Alexandru V. Avram, Sharon L. Juliano, Carlo Pierpaoli
2017 Journal of Neuroscience Research  
In particular, quantitative MRI methods have the potential to distinguish and evaluate the complex collection of neurobiological responses to TBI arising from pathology, neuroprotection, and recovery.  ...  Although well-established approaches such as diffusion tensor imaging are known to be highly sensitive to changes in the tissue environment, more advanced dMRI techniques have been developed that may offer  ...  These models directly relate the MRI signal for each DWI to the diffusion weighting (i.e., b-value in seconds per millimeter squared) and the orientation of the applied diffusion sensitizing gradients,  ... 
doi:10.1002/jnr.24065 pmid:28609579 pmcid:PMC5729069 fatcat:5wmsqpm3tjfvjbv6abmob2s2u4

Relating Imaging Indices of White Matter Integrity and Volume in Healthy Older Adults

C. E. Hugenschmidt, A. M. Peiffer, R. A. Kraft, R. Casanova, A. R. Deibler, J. H. Burdette, J. A. Maldjian, P. J. Laurienti
2007 Cerebral Cortex  
FA appears to be more sensitive than volume loss to changes in normal appearing tissue, and these FA changes may actually precede white matter atrophy in some brain areas.  ...  Confounding these results are imaging studies demonstrating age-related white matter atrophy in some areas displaying altered FA, suggesting changes in diffusion may be simply an epiphenomenon of tissue  ...  White matter has traditionally been characterized in human studies using conventional clinical MRI sequences, such as T 1and T 2 -weighted images.  ... 
doi:10.1093/cercor/bhm080 pmid:17575289 fatcat:rugzwagpr5d7zi35iyqerppe5u

The glymphatic system: Current understanding and modeling

Douglas H. Kelley, Tomas Bohr, Poul G. Hjorth, Sebastian C. Holst, Sabina Hrabětová, Vesa Kiviniemi, Tuomas Lilius, Iben Lundgaard, Kent-Andre Mardal, Erik A. Martens, Yuki Mori, U. Valentin Nägerl (+7 others)
2022 iScience  
We sort existing models into broad categories by anatomical function: Perivascular flow, transport in brain parenchyma, interfaces to perivascular spaces, efflux routes, and links to neuronal activity.  ...  Needs and opportunities for future work are highlighted wherever possible; new models, expanded models, and novel experiments to inform models could all have tremendous value for advancing the field.  ...  One study in human brain was not able to detect changes in the mean diffusivity between wakefulness and sleep after sleep deprivation, thereby not corroborating extracellular space volume changes [46]  ... 
doi:10.1016/j.isci.2022.104987 pmid:36093063 pmcid:PMC9460186 fatcat:j6cioyycxzfgregdvpe6bc4nhi

Neurofluid Dynamics and the Glymphatic System: A Neuroimaging Perspective

Toshiaki Taoka, Shinji Naganawa
2020 Korean Journal of Radiology  
being drained from the brain.  ...  CSF guided to the perivascular space around the arteries enters the interstitium of brain tissue via aquaporin-4 water channels to clear waste proteins into the perivascular space around the veins before  ...  Thus, in this region, diffusion along the perivascular spaces of the medullary arteries and veins can be measured separately from the diffusion along large white matter fibers.  ... 
doi:10.3348/kjr.2020.0042 pmid:32783417 pmcid:PMC7462760 fatcat:hdn42apkurdnlb7rjvzni3isby

Sleep reverts changes in human gray and white matter caused by wake-dependent training

Giulio Bernardi, Luca Cecchetti, Francesca Siclari, Andreas Buchmann, Xiaoqian Yu, Giacomo Handjaras, Michele Bellesi, Emiliano Ricciardi, Steven R. Kecskemeti, Brady A. Riedner, Andrew L. Alexander, Ruth M. Benca (+4 others)
2016 NeuroImage  
Learning leads to rapid microstructural changes in grey (GM) and white (WM) matter. Do these changes continue to accumulate if task training continues, and can they be reverted by sleep?  ...  and strength, as well as to its recently discovered ability to enhance the extracellular space and the clearance of brain metabolites.  ...  Acknowledgments Supported by NIH (grant R01MH099231 to CC and GT), McDonnell Foundation (to MFG and GT), the Waisman Brain Imaging Core (supported by NIH P30 HD003352), the Swiss National Foundation and  ... 
doi:10.1016/j.neuroimage.2016.01.020 pmid:26812659 pmcid:PMC4803519 fatcat:46kgo3ox2ncsbnztrxfiotfa2m

Perivascular spaces and brain waste clearance systems: relevance for neurodegenerative and cerebrovascular pathology

Kaylene Gouveia-Freitas, António J. Bastos-Leite
2021 Neuroradiology  
AbstractPerivascular spaces (PVS) of the brain, often called Virchow-Robin spaces, comprise fluid, cells and connective tissue, and are externally limited by astrocytic endfeet.  ...  In addition, distinct topographic patterns of enlarged PVS are related to different types of microangiopathy: CAA is linked to enlarged juxtacortical PVS, whereas subjects with vascular risk factors tend  ...  État criblé is frequently associated with white matter changes (Fig. 4) . In fact, Maclullich et al.  ... 
doi:10.1007/s00234-021-02718-7 pmid:34019111 pmcid:PMC8460534 fatcat:7xixcvjytvf4zkicfancas4uke

Short-Term Learning Induces White Matter Plasticity in the Fornix

S. Hofstetter, I. Tavor, S. Tzur Moryosef, Y. Assaf
2013 Journal of Neuroscience  
These results, which provide the first indication of short-term white matter plasticity in the human brain, suggest that the adult brain white matter preserves dynamic characteristics and can be modified  ...  Between tasks, subjects were scanned with DTI, a diffusion MRI framework sensitive to tissue microstructure.  ...  Discussion Our results provide the first indication of short-term white matter plasticity in the human brain.  ... 
doi:10.1523/jneurosci.4520-12.2013 pmid:23904619 pmcid:PMC6618548 fatcat:hbyvcrnmzncaznmpzpronz6i2u

Brain intra- and extracellular sodium concentration in multiple sclerosis: a 7 T MRI study

Maria Petracca, Roxana O. Vancea, Lazar Fleysher, Laura E. Jonkman, Niels Oesingmann, Matilde Inglese
2016 Brain  
and white matter regions when patients were compared with healthy controls (P 5 0.05 family-wise error corrected for total sodium concentration, P 5 0.05 uncorrected for multiple comparisons for intracellular  ...  Global grey matter and white matter total sodium concentration (respectively P 5 0.05 and P 5 0.01), and intracellular sodium concentration (both P 5 0.001) were higher while grey matter and white matter  ...  Funding This study was supported in part by research funds from the Noto Foundation to M.I. and by a research fellowship grant from Fondazione Italiana Sclerosi Multipla (FISM 2013/B/7) to M.P.  ... 
doi:10.1093/brain/awv386 pmid:26792552 fatcat:bfru6vaglfcddellzp7tt6pcxm

Sleep and sleep deprivation differentially alter white matter microstructure: a mixed model design utilising advanced diffusion modelling [article]

Irene Voldsbekk, Inge Groote, Nathalia Zak, Daniel Roelfs, Oliver Geier, Paulina Due-Tonnessen, Lise-Linn Lokken, Marie Stromstad, Taran Y. Blakstvedt, Yvonne S. Kuiper, Torbjorn Elvsashagen, Lars T. Westlye (+2 others)
2020 biorxiv/medrxiv   pre-print
Sleep deprivation influences several critical functions, yet how it affects human brain white matter (WM) is not well understood.  ...  The aim of the present work was to investigate the effect of 32 hours of sleep deprivation on WM microstructure compared to changes observed in a normal sleep-wake cycle (SWC).  ...  foundation, and a research grant from Mrs.  ... 
doi:10.1101/2020.08.24.259432 fatcat:fnuvkeazqzfopdvjptdaejtpxq

Advanced Neuroimaging in Traumatic Brain Injury

Ona Wu, Brian Edlow
2013 Seminars in neurology  
Novel techniques for measuring cerebral blood flow, metabolism, white matter connectivity, and neural network activation have great potential to improve the accuracy of diagnosis and prognosis for patients  ...  with traumatic brain injury (TBI), while also providing biomarkers to guide the development of new therapies.  ...  Acknowledgments This work was supported by the National Institutes of Health (R25NS065743 and P41RR14075) and the Center for Integration of Medicine & Innovative Technology (Boston, MA).  ... 
doi:10.1055/s-0032-1331810 pmid:23361483 pmcid:PMC3779469 fatcat:ecxuxhf3obefngigwjg6ebjrd4

White Matter Tract Alterations in Drug-Naïve Parkinson's Disease Patients With Excessive Daytime Sleepiness

Amir Ashraf-Ganjouei, Ghazaleh Kheiri, Maryam Masoudi, Bahram Mohajer, Mahtab Mojtahed Zadeh, Pejman Saberi, Mehdi Shirin Shandiz, Mohammad Hadi Aarabi
2019 Frontiers in Neurology  
Therefore, this study investigated brain white matter microstructure alterations in patients with Parkinson's disease with EDS (PD-EDS) compared to healthy controls and PD patients without EDS (PD-nEDS  ...  These differences between PD-EDS and PD-nEDS patients reflects microstructural changes with respect to sleep-related circuits, which can pave the way for future investigations considering EDS pathogenesis  ...  Data Acquisition Diffusion MRI Data Processing Diffusion MRI data were corrected for subject motion, eddy current distortions, and susceptibility artifacts due to the magnetic field inhomogeneity using  ... 
doi:10.3389/fneur.2019.00378 pmid:31057475 pmcid:PMC6477886 fatcat:pt53iza3y5ectafsoyalahvwoq

Diffusion Tensor Imaging of the Evolving Response to Mild Traumatic Brain Injury in Rats

Wouter S Hoogenboom, Todd G Rubin, Kenny Ye, Min-Hui Cui, Kelsey C Branch, Jinyuan Liu, Craig A Branch, Michael L Lipton
2019 Journal of Experimental Neuroscience  
More specifically, we observed increased fractional anisotropy in combination with decreased radial diffusivity and mean diffusivity, in the absence of changes in axial diffusivity, within the white matter  ...  Diffusion tensor imaging changes within the white matter were most noticeable 1 week following injury and returned to baseline values after 2 weeks.  ...  Given that the signal detected by DTI arises from the extracellular space, directionally restricted diffusion (high FA, low RD, and low MD) is consistent with compression of the extracellular space possibly  ... 
doi:10.1177/1179069519858627 pmid:31308735 pmcid:PMC6613065 fatcat:4ki2gwlmajfipmzsa5srcncequ
« Previous Showing results 1 — 15 out of 1,026 results