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Mesoscopic structure of neuronal tracts from time-dependent diffusion

Lauren M. Burcaw, Els Fieremans, Dmitry S. Novikov
2015 NeuroImage  
Our results relate the measured diffusion to the mesoscopic structure of neuronal tissue, uncovering the sensitivity of diffusion metrics to axonal arrangement within a fiber tract, and providing an alternative  ...  Interpreting brain diffusion MRI measurements in terms of neuronal structure at a micrometer level is an exciting unresolved problem.  ...  This work was supported by the Fellowship from Raymond and Beverly Sackler Laboratories for Convergence of Physical, Engineering and Biomedical Sciences, by the Litwin Foundation for Alzheimer's  ... 
doi:10.1016/j.neuroimage.2015.03.061 pmid:25837598 pmcid:PMC4446209 fatcat:xsrmkloubbaczh2nt3wlsktghy

What We Know About the Brain Structure–Function Relationship

Karla Batista-García-Ramó, Caridad Fernández-Verdecia
2018 Behavioral Sciences  
The goal of the present article is to discuss about the progress made to elucidate the structure-function relationship of the Central Nervous System, particularly at the brain level, based on results from  ...  The current novel systems and neuroimaging techniques with high resolutive physio-structural capacity have brought about the development of an integral framework of different structural and morphometric  ...  Mesoscopic refers to neuronal populations under the assumption that the neurons of a population have similar properties with the aim of explaining macroscopic spatio-temporal dynamics from mesoscopic approximations  ... 
doi:10.3390/bs8040039 pmid:29670045 pmcid:PMC5946098 fatcat:nahupzt2enfarcaa5ju3qrbbwm

In vivo observation and biophysical interpretation of time-dependent diffusion in human white matter

Els Fieremans, Lauren M. Burcaw, Hong-Hsi Lee, Gregory Lemberskiy, Jelle Veraart, Dmitry S. Novikov
2016 NeuroImage  
We perform stimulated echo diffusion tensor imaging on 5 healthy volunteers and observe a relatively weak time-dependence in diffusion transverse to major fiber tracts.  ...  Comparing models of diffusion in ordered, confined and disordered media, we argue that the time-dependence in both directions can arise due to structural disorder, such as axonal beads in the longitudinal  ...  Acknowledgments We would like to thank Kecheng Liu, Christopher Glielmi and Thorsten Feiweier from Siemens Healthcare for providing support and guidance related to the STEAM acquisition.  ... 
doi:10.1016/j.neuroimage.2016.01.018 pmid:26804782 pmcid:PMC4803645 fatcat:vqqvs2dcmzayde4qwaaxdx2czu

Unraveling the multiscale structural organization and connectivity of the human brain: the role of diffusion MRI

Matteo Bastiani, Alard Roebroeck
2015 Frontiers in Neuroanatomy  
The aim of this review is to illustrate and discuss the structural architecture and the anatomical connectivity of the human brain at different spatial scales and how recently developed diffusion MRI techniques  ...  The structural architecture and the anatomical connectivity of the human brain show different organizational principles at distinct spatial scales.  ...  To study the brain's structural connectivity profile, several animal studies have used tract tracing techniques that are based on the axonal transport of injected neuronal tracers, either anterogradely  ... 
doi:10.3389/fnana.2015.00077 pmid:26106304 pmcid:PMC4460430 fatcat:4oxgpn5adrgrbbip3nzanpj2xm

Quantifying brain microstructure with diffusion MRI: Theory and parameter estimation

Dmitry S. Novikov, Els Fieremans, Sune N. Jespersen, Valerij G. Kiselev
2018 NMR in Biomedicine  
The first avenue 9 focusses on the transient, or time-dependent, effects in diffusion.  ...  6 We review, systematize and discuss models of diffusion in neuronal tissue, by putting them into an overarching 7 physical context of coarse-graining over an increasing diffusion length scale.  ...  relaxation rate would depend 43 on time t because of the presence of the mesoscopic 44 structure (such as D inst (t) decaying from D(0) down 45 to D ∞ in our example of Fig. 2).  ... 
doi:10.1002/nbm.3998 pmid:30321478 fatcat:l6bq5enb7zguzccywuepk4eiuu

Detection of aberrant hippocampal mossy fiber connections: Ex vivo mesoscale diffusion MRI and microtractography with histological validation in a patient with uncontrolled temporal lobe epilepsy

Michel Modo, T. Kevin Hitchens, Jessie R. Liu, R. Mark Richardson
2015 Human Brain Mapping  
Mesoscopic ex vivo MR imaging hence provides an exciting new avenue to study hippocampi from treatment-resistant patients and allows exploration of existing hypotheses, as well as the development of new  ...  Mossy fiber sprouting in the dentate gyrus (DG), with evidence of glutamatergic synapses in the stratum moleculare (SM) putatively originating from granule cell neurons, may also be observed.  ...  Investigating temporal scaling characteristics of the diffusion signal by using diffusion times could indeed lead to a more robust delineation of different structures [ € Ozarslan et al., 2013] .  ... 
doi:10.1002/hbm.23066 pmid:26611565 pmcid:PMC4718824 fatcat:wg577ebcw5byzmtuwlywhusrgi

Integrative Models of Brain Structure and Dynamics: Concepts, Challenges, and Methods

Siva Venkadesh, John Darrell Van Horn
2021 Frontiers in Neuroscience  
diffusion along axonal fibers, from which structural connections are estimated.  ...  This microstructural adaptation facilitates coordinated dynamics of populations of neurons (mesoscopic scale) and brain regions (macroscopic scale).  ...  AUTHOR CONTRIBUTIONS SV and JV contributed to the conception of this work and manuscript revision. SV wrote the first draft of the manuscript. Both authors approved the submitted version.  ... 
doi:10.3389/fnins.2021.752332 pmid:34776853 pmcid:PMC8585845 fatcat:rgcwmry7tjfa3ciqo6fggnnaea

Microstructural imaging of human neocortex in vivo

Luke J. Edwards, Evgeniya Kirilina, Siawoosh Mohammadi, Nikolaus Weiskopf
2018 NeuroImage  
From these studies, we know that the scale of important neocortical structure spans six orders of magnitude, ranging from the size of axonal diameters (microns), to the size of cortical areas responsible  ...  Neuronal fibre mapping in the cortex remains challenging in vivo, but recent improvements in diffusion MRI hold promise for exciting applications in the near future.  ...  length of water over the diffusion time scale that can be probed with516 MRI covers the micro-and mesoscopic scales (Novikov et al., 2016) .  ... 
doi:10.1016/j.neuroimage.2018.02.055 pmid:29588229 fatcat:bqpmgy66xbchpfjllfdoapg374

Glioma follow white matter tracts: a multiscale DTI-based model

Christian Engwer, Thomas Hillen, Markus Knappitsch, Christina Surulescu
2014 Journal of Mathematical Biology  
The tumor diffusion tensor and the tumor drift velocity depend on both, the directions of the white matter tracts as well as the binding dynamics of the adhesion molecules.  ...  Using formal computations similar to those in the work of Painter and Hillen (2013) we show that the tumor diffusion tensor depends on the structure of the underlying fibre network, while the drift velocity  ...  Acknowledgments We thank Carsten Wolters and Felix Lucka (Institute of Biomagnetism and Biosignalanalysis, University of Münster) for a lot of preprocessed DTI data and much advice with the visualization  ... 
doi:10.1007/s00285-014-0822-7 pmid:25212910 fatcat:yuljbjum4jef3hvpwylt4ffixm

A Proposal for a Coordinated Effort for the Determination of Brainwide Neuroanatomical Connectivity in Model Organisms at a Mesoscopic Scale

Jason W. Bohland, Caizhi Wu, Helen Barbas, Hemant Bokil, Mihail Bota, Hans C. Breiter, Hollis T. Cline, John C. Doyle, Peter J. Freed, Ralph J. Greenspan, Suzanne N. Haber, Michael Hawrylycz (+26 others)
2009 PLoS Computational Biology  
Here we advocate for a concerted effort to fill this gap, through systematic, experimental mapping of neural circuits at a mesoscopic scale of resolution suitable for comprehensive, brain-wide coverage  ...  , using injections of tracers or viral vectors.  ...  of scientists who are listed alphabetically as middle authors.  ... 
doi:10.1371/journal.pcbi.1000334 pmid:19325892 pmcid:PMC2655718 fatcat:zhc7iea7bbfjbbrr4domy5xho4

A systematic review on the quantitative relationship between structural and functional network connectivity strength in mammalian brains

Milou Straathof, Michel RT Sinke, Rick M Dijkhuizen, Willem M Otte
2018 Journal of Cerebral Blood Flow and Metabolism  
We included network studies in which functional connectivity was measured with resting-state fMRI, and structural connectivity with either diffusion-weighted MRI or neuronal tract tracers.  ...  Two functional datasets demonstrated lower structure-function correlations with neuronal tracer-based (r = 0.22 and r = 0.30) than with diffusion-based measures (r = 0.49 and r = 0.65).  ...  The Declaration of conflicting interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.  ... 
doi:10.1177/0271678x18809547 pmid:30375267 pmcid:PMC6360487 fatcat:rl42rz4by5exfmdj7piiv5jlaq

The Virtual Brain Integrates Computational Modeling and Multimodal Neuroimaging

Petra Ritter, Michael Schirner, Anthony R. McIntosh, Viktor K. Jirsa
2013 Brain Connectivity  
Brain function is thought to emerge from the interactions among neuronal populations.  ...  Apart from traditional efforts to reproduce brain dynamics from the micro-to macroscopic scales, complementary approaches develop phenomenological models of lower complexity.  ...  .; the German Ministry of Education and Research (Bernstein Focus State Dependencies of Learning 01GQ0971) granted to P.R.; and the Max-Planck Society (Minerva Program) granted to P.R.  ... 
doi:10.1089/brain.2012.0120 pmid:23442172 pmcid:PMC3696923 fatcat:i6677e3cubaqzcbikvczz2uvba

Spin-glass model predicts metastable brain states that diminish in anesthesia

Anthony G. Hudetz, Colin J. Humphries, Jeffrey R. Binder
2014 Frontiers in Systems Neuroscience  
We implemented a modified spin glass model to describe UP/DOWN state transitions of neuronal populations at a mesoscopic scale based on resting state BOLD fMRI data.  ...  Cross-correlation matrices of the mapped BOLD time courses of the set of sites were calculated and averaged across subjects.  ...  The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.  ... 
doi:10.3389/fnsys.2014.00234 pmid:25565989 pmcid:PMC4263076 fatcat:p2avuhvh6zfglb2tfxoomczssy

Making Sense of Brain Waves: The Most Baffling Frontier in Neuroscience [chapter]

Walter J. Freeman
2002 Biocomputing  
It was the action potential of single neurons that provided the foundation of neurobiology for the 20th century, and in its time it supported the development of digital computers, neural networks, and  ...  of interfacing between finite state automata and the infinite complexity of the real world.  ...  Acknowledgments This research was supported by grants from the National Institute of Mental Health MH 06686 & Office of Naval Research N00014-90-J-4054.  ... 
doi:10.1007/978-1-4613-0259-9_1 fatcat:f5anp7iguvdsbgbt3p3f57qnh4

Towards a theory of cortical columns: From spiking neurons to interacting neural populations of finite size

Tilo Schwalger, Moritz Deger, Wulfram Gerstner, Lyle J. Graham
2017 PLoS Computational Biology  
Here we derive an equation for several interacting populations at the mesoscopic scale starting from a microscopic model of randomly connected generalized integrate-and-fire neuron models.  ...  Efficient integration of the stochastic mesoscopic equations reproduces the statistical behavior of the population activities obtained from microscopic simulations of a full spiking neural network model  ...  However, trial-averaging reveals that the mean time-dependent activities that can be estimated from a peri-stimulus-time histogram (PSTH) obtained from microscopic and mesoscopic simulations indeed agree  ... 
doi:10.1371/journal.pcbi.1005507 pmid:28422957 pmcid:PMC5415267 fatcat:dxz2ilgoqvbjpghcte67cwtdde
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