scholarly journals Short Association Fibre Tractography

2021 ◽  
Author(s):  
Dmitri Shastin ◽  
Sila Genc ◽  
Greg D. Parker ◽  
Kristin Koller ◽  
Chantal M.W. Tax ◽  
...  
Keyword(s):  
White Matter ◽  
Surface Coverage ◽  
Cortical Surface ◽  
Complex Structures ◽  
Surface Representation ◽  
Voxel Grid

Through advancing the existing and introducing novel methodological developments in streamlines tractography, this work proposes an approach that is meant to specifically interrogate an important yet relatively understudied population of the human white matter - the short association fibres. By marrying tractography with surface representation of the cortex, the framework: (1) ensures a greater cortical surface coverage through spreading streamline seeds more uniformly; (2) relies on precise filtering mechanics which are particularly important when dealing with small, morphologically complex structures; (3) allows to make use of surface-based registration for dataset comparisons which can be superior in the vicinity of the cortex. The indexation of surface vertices at each streamline end enables direct interfacing between streamlines and the cortical surface without dependence on the voxel grid. Short association fibre tractograms generated using recent test-retest data from our institution are carefully characterised and measures of consistency using streamline-, voxel-, surface- and network-wise comparisons calculated.

scholarly journals The Concurrence of Cortical Surface Area Expansion and White Matter Myelination in Human Brain Development

2018 ◽  
Vol 29 (2) ◽  
pp. 827-837 ◽  
Author(s):  
Riccardo Cafiero ◽  
Jens Brauer ◽  
Alfred Anwander ◽  
Angela D Friederici
Keyword(s):  
White Matter ◽  
Human Brain ◽  
Brain Development ◽  
Surface Area ◽  
Cortical Surface ◽  
Cortical Surface Area ◽  
Human Brain Development ◽  
Area Expansion

White matter architecture rather than cortical surface area correlates with the EEG alpha rhythm

NeuroImage ◽  
2010 ◽  
Vol 49 (3) ◽  
pp. 2328-2339 ◽  
Author(s):  
Pedro A. Valdés-Hernández ◽  
Alejandro Ojeda-González ◽  
Eduardo Martínez-Montes ◽  
Agustín Lage-Castellanos ◽  
Trinidad Virués-Alba ◽  
...  
Keyword(s):  
White Matter ◽  
Surface Area ◽  
Alpha Rhythm ◽  
Cortical Surface ◽  
Cortical Surface Area ◽  
Eeg Alpha

scholarly journals Birth weight is associated with brain tissue volumes seven decades later, but not with age-associated changes to brain structure

2020 ◽  
Author(s):  
Emily N. W. Wheater ◽  
Susan D. Shenkin ◽  
Susana Muñoz Maniega ◽  
Maria Valdés Hernández ◽  
Joanna M. Wardlaw ◽  
...  
Keyword(s):  
Birth Weight ◽  
White Matter ◽  
Cognitive Ability ◽  
Brain Tissue ◽  
Brain Structure ◽  
Early Life ◽  
Later Life ◽  
Cortical Surface ◽  
Age Related ◽  
Mri Features

AbstractBirth weight, an indicator of fetal growth, is associated with cognitive outcomes in early life and risk of metabolic and cardiovascular disease across the life course. Cognitive ability in early life is predictive of cognitive ability in later life. Brain health in older age, defined by MRI features, is associated with cognitive performance. However, little is known about how variation in normal birth weight impacts on brain structure in later life. In a community dwelling cohort of participants in their early seventies we tested the hypothesis that birthweight is associated with the following MRI features: total brain (TB), grey matter (GM) and normal appearing white matter (NAWM) volumes; whiter matter hyperintensity (WMH) volume; a general factor of fractional anisotropy (gFA) and peak width skeletonised mean diffusivity (PSMD) across the white matter skeleton. We also investigated the associations of birthweight with cortical surface area, volume and thickness. Birthweight was positively associated with TB, GM and NAWM volumes in later life (β ≥ 0.194), and with regional cortical surface area but not gFA, PSMD, WMH volume, or cortical volume or thickness. These positive relationships appear to be explained by larger intracranial volume rather than by age-related tissue atrophy, and are independent of body height and weight in adulthood. This suggests that larger birthweight is linked to increased brain tissue reserve in older life, rather than a resilience to age-related changes in brain structure, such as tissue atrophy or WMH volume.Significance StatementCognitive brain ageing carries a high personal, societal and financial cost and understanding its developmental origins is important for identifying possible preventative strategies. In a sample of older participants from the Lothian Birth Cohort 1936 we were able to explore the neurobiological correlates of birth weight, which is indicative of the fetal experience. We find that higher birth weight is related to larger brain tissue volumes in later life, but does not modify the trajectory of age-related change. This suggests that early life growth confers preserved differentiation, rather than differential preservation with regards to brain reserve. That these effects are detectable into later life indicates that this variable may be valuable biomarker in the epidemiology of ageing.

scholarly journals Correction: Anatomical Abnormalities in Gray and White Matter of the Cortical Surface in Persons with Schizophrenia

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
Author(s):  
Tiziano Colibazzi ◽  
Bruce E. Wexler ◽  
Ravi Bansal ◽  
Xuejun Hao ◽  
Jun Liu ◽  
...  
Keyword(s):  
White Matter ◽  
Cortical Surface ◽  
Persons With Schizophrenia

scholarly journals How the flow and processing of information shapes the cerebrum

2015 ◽  
Author(s):  
Marc H.E. de Lussanet
Keyword(s):  
White Matter ◽  
Long Range ◽  
Information Flow ◽  
Information Transfer ◽  
Regular Structure ◽  
Cortical Surface ◽  
Local Networks ◽  
Trade Off ◽  
Processing Power ◽  
Underlying Mechanisms

The cerebrum of mammals spans a vast range of sizes and yet has a very regular structure. The amount of folding of the cortical surface and the proportion of white matter gradually increase with size, but the underlying mechanisms remain elusive. Here, two laws are derived to fully explain these cerebral scaling relations. The two general laws are derived from the notion that total processing power of the cortex is determined by the total cortical surface (i.e., the number of neurons), whereas the most efficient over-all flow of information is governed by the size of local networks (cortical columns). Since information is transferred by axonal connections which have a definite volume, a trade-off can be formulated from theoretical considerations between local, inter-gyral information transfer and long-range information transfer. It can be shown that this trade-off is governed by a single parameter describing the size of local networks, tlocal. Despite having just one free parameter, the first law fits the mammalian cerebrum better than any existing function, both across species and within humans. According to the second law, the scaling of white matter volume is also determined by the information principles. It follows that large cerebrums have much local processing and little global information flow. Moreover, paradoxically, a further increase in long-range connections would decrease the efficiency of information flow. These theoretical scaling principles help to compare the cerebrums across mammals regardless their size.

scholarly journals Brain structural differences between 73- and 92-year olds matched for childhood intelligence, social background, and intracranial volume

2017 ◽  
Author(s):  
Stuart J. Ritchie ◽  
David Alexander Dickie ◽  
Simon R. Cox ◽  
Maria del C. Valdés Hernández ◽  
Alison Pattie ◽  
...  
Keyword(s):  
White Matter ◽  
Cognitive Ability ◽  
Surface Area ◽  
Cortical Thickness ◽  
White Matter Hyperintensity ◽  
Socioeconomic Background ◽  
Intracranial Volume ◽  
Cortical Surface ◽  
Age Cohorts ◽  
Cortical Surface Area

AbstractFully characterizing age differences in the brain is a key task for combatting ageing-related cognitive decline. Using propensity score matching on two independent, narrow-age cohorts, we used data on childhood cognitive ability, socioeconomic background, and intracranial volume to match participants at mean age 92 years (n = 42) to very similar participants at mean age 73 (n = 126). Examining a variety of global and regional structural neuroimaging variables, there were large differences in grey and white matter volumes, cortical surface area, cortical thickness, and white matter hyperintensity volume and spatial extent. In a mediation analysis, the total volume of white matter hyperintensities and total cortical surface area jointly mediated 24.9% of the relation between age and general cognitive ability (tissue volumes and cortical thickness were not significant mediators in this analysis). These findings provide an unusual and valuable perspective on neurostructural ageing, in which brains from the eighth and tenth decades of life differ widely despite the same cognitive, socio-economic, and brain-volumetric starting points.

274. MIR137 Influences White Matter Fractional Anisotropy and Cortical Surface Area in Individuals with High Genetic Risk for Psychosis

2017 ◽  
Vol 81 (10) ◽  
pp. S112-S113
Author(s):  
Bob Vogel ◽  
Tristram Lett ◽  
Susanne Erk ◽  
Sebastian Mohnke ◽  
Carolin Wackerhagen ◽  
...  
Keyword(s):  
White Matter ◽  
Surface Area ◽  
Fractional Anisotropy ◽  
Genetic Risk ◽  
Cortical Surface ◽  
Cortical Surface Area ◽  
High Genetic Risk

scholarly journals Asymmetry Map of Human Brain in Young Adults

2020 ◽  
Author(s):  
Maryam Malekzadeh ◽  
Alireza Kashani
Keyword(s):  
Young Adults ◽  
White Matter ◽  
Human Brain ◽  
Surface Area ◽  
Gray Matter ◽  
Gray Matter Volume ◽  
Cortical Surface ◽  
Cortical Surface Area ◽  
Matter Volume ◽  
Cortical Regions

AbstractAlthough, asymmetry is a central organizational aspect of human brain, it has not been clearly described yet. Here, we have studied structural brain asymmetry in 1113 young adults using data obtained from Human Connectome Project. A significant rightward asymmetry in mean global cerebral cortical thickness, surface area and gray matter volume as well as volumes of cerebral white matter, cerebellar cortex and white matter, hippocampus, putamen, caudate nucleus, nucleus accumbens and amygdala was observed. Thalamus showed a leftward asymmetry. Regionally, most cerebral cortical regions show a significant rightward asymmetry in thickness. However, cortical surface area and gray matter volume are more evenly distributed between two hemispheres with almost half of the regions showing a leftward asymmetry. In addition, a strong correlation between cortical surface area and gray matter volume as well as their asymmetry indices was noted which results in concordant asymmetry patterns between cortical surface area and gray matter volume in most cortical regions.

scholarly journals How the flow and processing of information shapes the cerebrum

2014 ◽  
Author(s):  
Marc HE de Lussanet
Keyword(s):  
White Matter ◽  
Long Range ◽  
Information Flow ◽  
Information Transfer ◽  
Regular Structure ◽  
Cortical Surface ◽  
Local Networks ◽  
Trade Off ◽  
Processing Power ◽  
Underlying Mechanisms

The cerebrum of mammals spans a vast range of sizes and yet has a very regular structure. The amount of folding of the cortical surface and the proportion of white matter gradually increase with size, but the underlying mechanisms remain elusive. Here, two laws are derived to fully explain these cerebral scaling relations. The two general laws are derived from the notion that total processing power of the cortex is determined by the total cortical surface (i.e., the number of neurons), whereas the most efficient over-all flow of information is governed by the size of local networks (cortical columns). Since information is transferred by axonal connections which have a definite volume, a trade-off can be formulated from theoretical considerations between local, inter-gyral information transfer and long-range information transfer. It can be shown that this trade-off is governed by a single parameter describing the size of local networks, \(t_{local}\). Despite having just one free parameter, the first law fits the mammalian cerebrum better than any existing function, both across species and within humans. According to the second law, the scaling of white matter volume is also determined by the information principles. It follows that large cerebrums have much local processing and little global information flow. Moreover, paradoxically, a further increase in long-range connections would decrease the efficiency of information flow. These theoretical scaling principles help to compare the cerebrums across mammals regardless their size.

scholarly journals Superficial white matter fiber systems impede detection of long-range cortical connections in diffusion MR tractography

2015 ◽  
Vol 112 (21) ◽  
pp. E2820-E2828 ◽  
Author(s):  
Colin Reveley ◽  
Anil K. Seth ◽  
Carlo Pierpaoli ◽  
Afonso C. Silva ◽  
David Yu ◽  
...  
Keyword(s):  
White Matter ◽  
High Resolution ◽  
Human Brain ◽  
Long Range ◽  
Ex Vivo ◽  
Cortical Surface ◽  
Tracer Injection ◽  
Axonal Projections ◽  
Probabilistic Tracking

In vivo tractography based on diffusion magnetic resonance imaging (dMRI) has opened new doors to study structure–function relationships in the human brain. Initially developed to map the trajectory of major white matter tracts, dMRI is used increasingly to infer long-range anatomical connections of the cortex. Because axonal projections originate and terminate in the gray matter but travel mainly through the deep white matter, the success of tractography hinges on the capacity to follow fibers across this transition. Here we demonstrate that the complex arrangement of white matter fibers residing just under the cortical sheet poses severe challenges for long-range tractography over roughly half of the brain. We investigate this issue by comparing dMRI from very-high-resolution ex vivo macaque brain specimens with histological analysis of the same tissue. Using probabilistic tracking from pure gray and white matter seeds, we found that ∼50% of the cortical surface was effectively inaccessible for long-range diffusion tracking because of dense white matter zones just beneath the infragranular layers of the cortex. Analysis of the corresponding myelin-stained sections revealed that these zones colocalized with dense and uniform sheets of axons running mostly parallel to the cortical surface, most often in sulcal regions but also in many gyral crowns. Tracer injection into the sulcal cortex demonstrated that at least some axonal fibers pass directly through these fiber systems. Current and future high-resolution dMRI studies of the human brain will need to develop methods to overcome the challenges posed by superficial white matter systems to determine long-range anatomical connections accurately.

Sign in / Sign up

Export Citation Format

Share Document