scholarly journals Coupled electrophysiological, hemodynamic, and cerebrospinal fluid oscillations in human sleep

Science ◽  
2019 ◽  
Vol 366 (6465) ◽  
pp. 628-631 ◽  
Author(s):  
Nina E. Fultz ◽  
Giorgio Bonmassar ◽  
Kawin Setsompop ◽  
Robert A. Stickgold ◽  
Bruce R. Rosen ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Brain Function ◽  
Slow Waves ◽  
Neural Dynamics ◽  
Rapid Eye Movement Sleep ◽  
Csf Flow ◽  
Csf Dynamics ◽  
Macroscopic Scale ◽  
Waste Products ◽  
The Brain

Sleep is essential for both cognition and maintenance of healthy brain function. Slow waves in neural activity contribute to memory consolidation, whereas cerebrospinal fluid (CSF) clears metabolic waste products from the brain. Whether these two processes are related is not known. We used accelerated neuroimaging to measure physiological and neural dynamics in the human brain. We discovered a coherent pattern of oscillating electrophysiological, hemodynamic, and CSF dynamics that appears during non–rapid eye movement sleep. Neural slow waves are followed by hemodynamic oscillations, which in turn are coupled to CSF flow. These results demonstrate that the sleeping brain exhibits waves of CSF flow on a macroscopic scale, and these CSF dynamics are interlinked with neural and hemodynamic rhythms.

scholarly journals Immediate Impact of Yogic Breathing on Pulsatile Cerebrospinal Fluid Dynamics

2021 ◽  
Author(s):  
Selda Yildiz ◽  
John Grinstead ◽  
Andrea Hildebrand ◽  
John Oshinski ◽  
William D. Rooney ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Spontaneous Breathing ◽  
Controlled Trial ◽  
Critical Role ◽  
Csf Dynamics ◽  
Waste Products ◽  
Yogic Breathing ◽  
Abdominal Breathing ◽  
The Impact ◽  
The Brain

Cerebrospinal fluid (CSF), a clear fluid bathing the central nervous system (CNS), undergoes pulsatile movements, and plays a critical role for the removal of waste products from the brain including amyloid beta, a protein associated with Alzheimer's disease. Regulation of CSF dynamics is critical for maintaining CNS health, and increased pulsatile CSF dynamics may alter brain's waste clearance due to increased mixing and diffusion. As such, understanding the mechanisms driving CSF movement, and interventions that influence its resultant removal of wastes from the brain is of high scientific and clinical impact. Since pulsatile CSF dynamics is sensitive and synchronous to respiratory movements, we are interested in identifying potential integrative therapies such as yogic breathing to regulate and enhance CSF dynamics, which has not been reported before. Here, we investigated the pre-intervention baseline data from our ongoing randomized controlled trial, and examined whether yogic breathing immediately impacts pulsatile CSF dynamics compared to spontaneous breathing. We utilized our previously established non-invasive real-time phase contrast magnetic resonance imaging (RT-PCMRI) approach using a 3T MRI instrument, and computed and rigorously tested differences in CSF velocities (instantaneous, respiratory, cardiac 1st and 2nd harmonics) at the level of foramen magnum during spontaneous versus four yogic breathing patterns. In examinations of 18 healthy participants (eight females, ten males; mean age 34.9 ± 14 (SD) years; age range: 18-61 years), we discovered immediate increase in cranially-directed velocities of instantaneous-CSF 16% - 28% and respiratory-CSF 60% - 118% during yogic versus spontaneous breathing, with most statistically significant changes during deep abdominal breathing (28%, p=0.0008, and 118%, p=0.0001, respectively). Further, cardiac pulsation was the primary source of pulsatile CSF during all breathing conditions except during deep abdominal breathing, when there was a comparable contribution of respiratory and cardiac 1st harmonic power [0.59 ± 0.78], demonstrating respiration can be the primary regulator of CSF depending on individual differences in breath depth and location. Further work is needed to investigate the impact of sustained training yogic breathing on increased pulsatile CSF dynamics and brain waste clearance for CNS health.

scholarly journals The orthopedic characterization of cfap298tm304 mutants validate zebrafish to faithfully model human AIS

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marie-Hardy Laura ◽  
Cantaut-Belarif Yasmine ◽  
Pietton Raphaël ◽  
Slimani Lotfi ◽  
Pascal-Moussellard Hugues
Keyword(s):  
Cerebrospinal Fluid ◽  
Three Dimensional ◽  
Fluid Circulation ◽  
Micro Computed Tomography ◽  
Csf Flow ◽  
Cerebrospinal Fluid Circulation ◽  
Clinical Criteria ◽  
Brain And Spinal Cord ◽  
The Brain

AbstractCerebrospinal fluid (CSF) circulation relies on the beating of motile cilia projecting in the lumen of the brain and spinal cord cavities Mutations in genes involved in cilia motility disturb cerebrospinal fluid circulation and result in scoliosis-like deformities of the spine in juvenile zebrafish. However, these defects in spine alignment have not been validated with clinical criteria used to diagnose adolescent idiopathic scoliosis (AIS). The aim of this study was to describe, using orthopaedic criteria the spinal deformities of a zebrafish mutant model of AIS targeting a gene involved in cilia polarity and motility, cfap298tm304. The zebrafish mutant line cfap298tm304, exhibiting alteration of CSF flow due to defective cilia motility, was raised to the juvenile stage. The analysis of mutant animals was based on micro-computed tomography (micro-CT), which was conducted in a QUANTUM FX CALIPER, with a 59 µm-30 mm protocol. 63% of the cfap298tm304 zebrafish analyzed presented a three-dimensional deformity of the spine, that was evolutive during the juvenile phase, more frequent in females, with a right convexity, a rotational component and involving at least one dislocation. We confirm here that cfap298tm304 scoliotic individuals display a typical AIS phenotype, with orthopedic criteria mirroring patient’s diagnosis.

Amplitude and phase of cerebrospinal fluid pulsations: experimental studies and review of the literature

2006 ◽  
Vol 104 (5) ◽  
pp. 810-819 ◽  
Author(s):  
Mark E. Wagshul ◽  
John J. Chen ◽  
Michael R. Egnor ◽  
Erin J. McCormack ◽  
Patricia E. Roche
Keyword(s):  
Cerebrospinal Fluid ◽  
Stroke Volume ◽  
Experimental Studies ◽  
Volume Ratio ◽  
Communicating Hydrocephalus ◽  
Phase Lag ◽  
Review Of The Literature ◽  
Csf Flow ◽  
Prepontine Cistern ◽  
The Brain

Object A recently developed model of communicating hydrocephalus suggests that ventricular dilation may be related to the redistribution of pulsations in the cranium from the subarachnoid spaces (SASs) into the ventricles. Based on this model, the authors have developed a method for analyzing flow pulsatility in the brain by using the ratio of aqueductal to cervical subarachnoid stroke volume and the phase of cerebrospinal fluid (CSF) flow, which is obtained at multiple locations throughout the cranium, relative to the phase of arterial flow. Methods Flow data were collected in a group of 15 healthy volunteers by using a series of images acquired with cardiac-gated, phase-contrast magnetic resonance imaging. The stroke volume ratio was 5.1 ± 1.8% (mean ± standard deviation). The phase lag in the aqueduct was −52.5 ± 16.5° and the phase lag in the prepontine cistern was −22.1 ± 8.2°. The flow phase at the level of C-2 was +5.1 ± 10.5°, which was consistent with flow synchronous with the arterial pulse. The subarachnoid phase lag ventral to the pons was shown to decrease progressively to zero at the craniocervical junction. Flow in the posterior cervical SAS preceded the anterior space flow. Conclusions Under normal conditions, pulsatile ventricular CSF flow is a small fraction of the net pulsatile CSF flow in the cranium. A thorough review of the literature supports the view that modified intracranial compliance can lead to redistribution of pulsations and increased intraventricular pulsations. The phase of CSF flow may also reflect the local and global compliance of the brain.

A Nonlinear Biphasic Hyperelastic Model for Acute Hydrocephalus

2008 ◽  
Author(s):  
Joshua H. Smith ◽  
Jose Jaime García
Keyword(s):  
Central Nervous System ◽  
Cerebrospinal Fluid ◽  
Nervous System ◽  
Ventricular Pressure ◽  
Csf Flow ◽  
Acute Hydrocephalus ◽  
The Central Nervous System ◽  
Hyperelastic Model ◽  
The Brain ◽  
Significant Increment

The cerebrospinal fluid present in the central nervous system plays an important role in the physiological activities and protection of the brain. Disruptions of CSF flow lead to different forms of a disease known as hydrocephalus, characterized by a significant increment of the ventricular space. In acute hydrocephalus the Sylvius aqueduct is blocked and ventricular pressure is greatly increased.

scholarly journals Fluid dynamics of cerebrospinal fluid flow in perivascular spaces

2019 ◽  
Vol 16 (159) ◽  
pp. 20190572 ◽  
Author(s):  
John H. Thomas
Keyword(s):  
Fluid Dynamics ◽  
Cerebrospinal Fluid ◽  
Dynamic Models ◽  
Fluid Dynamic ◽  
Critical Evaluation ◽  
Amyloid Β ◽  
Perivascular Spaces ◽  
Waste Products ◽  
Basic Fluid ◽  
The Brain

The flow of cerebrospinal fluid along perivascular spaces (PVSs) is an important part of the brain’s system for delivering nutrients and eliminating metabolic waste products (such as amyloid-β); it also offers a pathway for the delivery of therapeutic drugs to the brain parenchyma. Recent experimental results have resolved several important questions about this flow, setting the stage for advances in our understanding of its fluid dynamics. This review summarizes the new experimental evidence and provides a critical evaluation of previous fluid-dynamic models of flows in PVSs. The review also discusses some basic fluid-dynamic concepts relevant to these flows, including the combined effects of diffusion and advection in clearing solutes from the brain.

scholarly journals Anthropomorphic Model of Intrathecal Cerebrospinal Fluid Dynamics Within the Spinal Subarachnoid Space: Spinal Cord Nerve Roots Increase Steady-Streaming

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Mohammadreza Khani ◽  
Lucas R. Sass ◽  
Tao Xing ◽  
M. Keith Sharp ◽  
Olivier Balédent ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Spinal Cord ◽  
Cerebrospinal Fluid ◽  
Cfd Model ◽  
Csf Flow ◽  
Nerve Roots ◽  
Csf Dynamics ◽  
Steady Streaming ◽  
Spinal Subarachnoid Space ◽  
The Impact

Cerebrospinal fluid (CSF) dynamics are thought to play a vital role in central nervous system (CNS) physiology. The objective of this study was to investigate the impact of spinal cord (SC) nerve roots (NR) on CSF dynamics. A subject-specific computational fluid dynamics (CFD) model of the complete spinal subarachnoid space (SSS) with and without anatomically realistic NR and nonuniform moving dura wall deformation was constructed. This CFD model allowed detailed investigation of the impact of NR on CSF velocities that is not possible in vivo using magnetic resonance imaging (MRI) or other noninvasive imaging methods. Results showed that NR altered CSF dynamics in terms of velocity field, steady-streaming, and vortical structures. Vortices occurred in the cervical spine around NR during CSF flow reversal. The magnitude of steady-streaming CSF flow increased with NR, in particular within the cervical spine. This increase was located axially upstream and downstream of NR due to the interface of adjacent vortices that formed around NR.

scholarly journals Cerebrospinal Fluid and Interstitial Fluid Motion via the Glymphatic Pathway Modelled by Optimal Mass Transport

2016 ◽  
Author(s):  
Vadim Ratner ◽  
Yi Gao ◽  
Hedok Lee ◽  
Maikan Nedergaard ◽  
Helene Benveniste ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Interstitial Fluid ◽  
Initial Conditions ◽  
Fluid Motion ◽  
Flow Patterns ◽  
Brain Parenchyma ◽  
Fluid Exchange ◽  
Waste Products ◽  
Glymphatic Pathway ◽  
The Brain

It was recently shown that the brain-wide cerebrospinal fluid (CSF) and interstitial fluid exchange system designated the `glymphatic pathway' plays a key role in removing waste products from the brain, similarly to the lymphatic system in other body organs [1,2]. It is therefore important to study the flow patterns of glymphatic transport through the live brain in order to better understand its functionality in normal and pathological states. Unlike blood, the CSF does not flow rapidly through a network of dedicated vessels, but rather through peri-vascular channels and brain parenchyma in a slower time-domain, and thus conventional fMRI or other blood-flow sensitive MRI sequences do not provide much useful information about the desired flow patterns. We have accordingly analyzed a series of MRI images, taken at different times, of the brain of a live rat, which was injected with a paramagnetic tracer into the CSF via the lumbar intrathecal space of the spine. Our goal is twofold: (a) find glymphatic (tracer) flow directions in the live rodent brain; and (b) provide a model of a (healthy) brain that will allow the prediction of tracer concentrations given initial conditions. We model the liquid flow through the brain by the diffusion equation. We then use the Optimal Mass Transfer (OMT) approach [3] to model the glymphatic flow vector field, and estimate the diffusion tensors by analyzing the (changes in the) flow. Simulations show that the resulting model successfully reproduces the dominant features of the experimental data.

scholarly journals Memory formation: from network structure to neural dynamics

2010 ◽  
Vol 368 (1918) ◽  
pp. 2251-2267 ◽  
Author(s):  
Sarah Feldt ◽  
Jane X. Wang ◽  
Vaughn L. Hetrick ◽  
Joshua D. Berke ◽  
Michal Żochowski
Keyword(s):  
Brain Function ◽  
Cognitive Process ◽  
Neural Correlates ◽  
Memory Formation ◽  
Neural Dynamics ◽  
Formation Processes ◽  
Neuronal Dynamics ◽  
Neuronal Ensembles ◽  
Derived Data ◽  
The Brain

Understanding the neural correlates of brain function is an extremely challenging task, since any cognitive process is distributed over a complex and evolving network of neurons that comprise the brain. In order to quantify observed changes in neuronal dynamics during hippocampal memory formation, we present metrics designed to detect directional interactions and the formation of functional neuronal ensembles. We apply these metrics to both experimental and model-derived data in an attempt to link anatomical network changes with observed changes in neuronal dynamics during hippocampal memory formation processes. We show that the developed model provides a consistent explanation of the anatomical network modifications that underlie the activity changes observed in the experimental data.

scholarly journals Paravascular spaces at the brain surface: Low resistance pathways for cerebrospinal fluid flow

2017 ◽  
Vol 38 (4) ◽  
pp. 719-726 ◽  
Author(s):  
Beatrice Bedussi ◽  
Mitra Almasian ◽  
Judith de Vos ◽  
Ed VanBavel ◽  
Erik NTP Bakker
Keyword(s):  
Cerebrospinal Fluid ◽  
Fluid Flow ◽  
Confocal Imaging ◽  
Waste Products ◽  
Cerebrospinal Fluid Flow ◽  
Low Resistance ◽  
Cranial Window ◽  
Brain Surface ◽  
Antegrade Flow ◽  
The Brain

Clearance of waste products from the brain is of vital importance. Recent publications suggest a potential clearance mechanism via paravascular channels around blood vessels. Arterial pulsations might provide the driving force for paravascular flow, but its flow pattern remains poorly characterized. In addition, the relationship between paravascular flow around leptomeningeal vessels and penetrating vessels is unclear. In this study, we determined blood flow and diameter pulsations through a thinned-skull cranial window. We observed that microspheres moved preferentially in the paravascular space of arteries rather than in the adjacent subarachnoid space or around veins. Paravascular flow was pulsatile, generated by the cardiac cycle, with net antegrade flow. Confocal imaging showed microspheres distributed along leptomeningeal arteries, while their presence along penetrating arteries was limited to few vessels. These data suggest that paravascular spaces around leptomeningeal arteries form low resistance pathways on the surface of the brain that facilitate cerebrospinal fluid flow.

scholarly journals Peering through the Windows of the Brain

1987 ◽  
Vol 7 (6) ◽  
pp. 663-672 ◽  
Author(s):  
Paul M. Gross ◽  
Adolf Weindl ◽  
Karl M. Knigge
Keyword(s):  
Cerebrospinal Fluid ◽  
Brain Function ◽  
Structural Characteristics ◽  
Mammalian Brain ◽  
Intimate Contact ◽  
The Brain

These seven specialized circumventricular structures of the mammalian brain represent windows with individualized structural characteristics permitting intimate contact between blood and cerebrospinal fluid, neurones and specialized ependyma-glia. These “Seven Windows of the Brain”, like the seven lucky deities of Japan, may each have a specific patron of body -brain function which they serve.1

Sign in / Sign up

Export Citation Format

Share Document