Linking white matter tracts to associated cortical grey matter: A tract extension methodology

Modality specific encoding habits account for a significant portion of individual differences reflected in functional activation during cognitive processing. Yet, little is known about how these habits of thought influence long-term structural changes in the brain. Traditionally, habits of thought have been assessed using self-report questionnaires such as the visualizer-verbalizer questionnaire. Here, rather than relying on subjective reports, we measured habits of thought using a novel behavioral task assessing attentional biases toward picture and word stimuli. Hypothesizing that verbal habits of thought are reflected in the structural integrity of white matter tracts and cortical regions of interest, we used diffusion tensor imaging and volumetric analyses to assess this prediction. Using a whole-brain approach, we show that word bias is associated with increased volume in several bilateral language regions, in both white and grey matter parcels. Additionally, connectivity within white matter tracts within an a priori speech production network increased as a function of word bias. These results demonstrate long-term structural and morphological differences associated with verbal habits of thought.

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Exploring the laminar connectome

10.1101/2021.03.17.21253439 ◽

2021 ◽

Author(s):

Ittai Shamir ◽

Omri Tomer ◽

Ronnie Krupnik ◽

Yaniv Assaf

Keyword(s):

White Matter ◽

Grey Matter ◽

Structural Description ◽

Mri Imaging ◽

Healthy Human ◽

Cortical Grey Matter ◽

Cortical Laminar ◽

White Matter Connectivity ◽

Human Brains

The human connectome is the complete structural description of the network of connections and elements that form the wiring diagram of the brain. Because of the current scarcity of information regarding laminar end points of white matter tracts inside cortical grey matter, tractography remains focused on cortical partitioning into regions, while ignoring radial partitioning into laminar components. To overcome this biased representation of the cortex as a single homogenous unit, we use a recent data-derived model of cortical laminar connectivity, which has been further explored and corroborated in the macaque brain by comparison to published studies. The model integrates multimodal MRI imaging datasets regarding both white matter connectivity and grey matter laminar composition into a laminar-level connectome. In this study we model the laminar connectome of healthy human brains (N=20) and explore them via a set of neurobiologically meaningful complex network measures. Our analysis demonstrates a subdivision of network hubs that appear in the standard connectome into each individual component of the laminar connectome, giving a fresh look into the role of laminar components in cortical connectivity and offering new prospects in the fields of both structural and functional connectivity.

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Regional brain volumes, microstructure and neurodevelopment in moderate–late preterm children

Archives of Disease in Childhood - Fetal and Neonatal Edition ◽

10.1136/archdischild-2019-317941 ◽

2020 ◽

Vol 105 (6) ◽

pp. 593-599 ◽

Cited By ~ 1

Author(s):

Claire E Kelly ◽

Deanne K Thompson ◽

Alicia J Spittle ◽

Jian Chen ◽

Marc L Seal ◽

...

Keyword(s):

White Matter ◽

Grey Matter ◽

Diffusion Tensor ◽

Brain Mri ◽

Developmental Outcomes ◽

Late Preterm ◽

Brain Volumes ◽

Regional Brain ◽

White Matter Microstructure ◽

Cortical Grey Matter

ObjectiveTo explore whether regional brain volume and white matter microstructure at term-equivalent age (TEA) are associated with development at 2 years of age in children born moderate–late preterm (MLPT).Study designA cohort of MLPT infants had brain MRI at approximately TEA (38–44 weeks’ postmenstrual age) and had a developmental assessment (Bayley Scales of Infant and Toddler Development and Infant Toddler Social Emotional Assessment) at 2 years’ corrected age. Relationships between cortical grey matter and white matter volumes and 2-year developmental outcomes were explored using voxel-based morphometry. Relationships between diffusion tensor measures of white matter microstructure (fractional anisotropy (FA) and axial (AD), radial (RD) and mean (MD) diffusivities) and 2-year developmental outcomes were explored using tract-based spatial statistics.Results189 MLPT children had data from at least one MRI modality (volumetric or diffusion) and data for at least one developmental domain. Larger cortical grey and white matter volumes in many brain regions, and higher FA and lower AD, RD and MD in several major white matter regions, were associated with better cognitive and language scores. There was little evidence that cortical grey matter and white matter volumes and white matter microstructure were associated with motor and behavioural outcomes.ConclusionsRegional cortical grey matter and white matter volumes and white matter microstructure are associated with cognitive and language development at 2 years of age in MLPT children. Thus, early alterations to brain volumes and microstructure may contribute to some of the developmental deficits described in MLPT children.

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Grey matter abnormality in progressive multifocal leucoencephalopathy

Practical Neurology ◽

10.1136/practneurol-2020-002852 ◽

2021 ◽

pp. practneurol-2020-002852

Author(s):

Christopher Yuki Itoh ◽

Han Sung Lee ◽

Alan Howe Yee

Keyword(s):

White Matter ◽

Gold Standard ◽

Grey Matter ◽

Jc Virus ◽

White Matter Disease ◽

Viral Dna ◽

Progressive Multifocal Leucoencephalopathy ◽

Cerebral Grey Matter ◽

Cortical Grey Matter

Progressive multifocal leucoencephalopathy (PML) is a demyelinating white matter disease that most often affects immunocompromised people infected by JC virus. The diagnostic gold standard is demonstrable viral DNA or protein from histopathological tissue. However, there are few detailed descriptions of cortical grey matter involvement on neuroimaging. Here we describe the histopathological correlate of cerebral grey matter involvement and radiological accompaniment in a patient with biopsy proven PML.

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Abstract WP98: Characterizing Cerebral Morphometry Changes and Effects of 3K3A-APC in Ischemic Stroke

Stroke ◽

10.1161/str.51.suppl_1.wp98 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Matthew M Padrick ◽

Ryan Cabeen ◽

Arthur Toga ◽

Patrick Lyden ◽

Keyword(s):

White Matter ◽

Feasibility Study ◽

Treatment Effect ◽

Large Scale ◽

Grey Matter ◽

Small Sample Size ◽

Activated Protein C ◽

Small Sample ◽

Stroke Treatment ◽

Cortical Grey Matter

Introduction: Acute stroke treatment trials have long used radiological endpoints of infarct size and hemorrhage burden to quantify treatment effect. Automated imaging pipelines analyzing cerebral morphometry have become more ubiquitous and can provide more comprehensive insight by measuring specific brain compartments. We piloted a feasibility study to integrate these imaging analyses into an established multicenter stroke trial, the NeuroNEXT trial NN104 (RHAPSODY), which investigated the effect of 3K3A-APC, a recombinant variant of activated protein C active at PAR-1. Methods: Using a well-validated Advanced Normalization Tools (ANTs) pipeline and the MindBoggle OASIS-30 Atropos template, gross compartments of hemispheric white matter, cortical grey matter, and subcortical grey matter were calculated from MRIs from participants >7 days post stroke. Fourteen participants treated with placebo were included, and eleven treated with 3K3A-APC. Results: Participants treated with placebo had mean volumes of 220.0mL, 276.5mL, and 21.7mL in ipsilateral cortical grey matter, white matter, and subcortical grey matter, respectively. Participants in the treatment arm had mean volumes of 227.4mL, 243.7mL, and 21.4mL. Discussion: We present a novel application of dynamic cerebral morphometry software that can be implemented in future large scale multi center stroke trials. This study is limited by its small sample size, and while no treatment effect was observed in this feasibility study, we plan to further refine our algorithm to include more heterogenous, clinically acquired imaging protocols, define more specific compartments, and to ultimately correlate with clinical outcomes.

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Dementia in multiple sclerosis: report of a case with cortical grey matter involvement and frontal-type-like clinical features

European Psychiatry ◽

10.1016/s0924-9338(11)72192-7 ◽

2011 ◽

Vol 26 (S2) ◽

pp. 485-485

Author(s):

R. Correia ◽

D. Dias ◽

A.J. Bastos-Leite ◽

E. Rio ◽

R. Curral

Keyword(s):

Multiple Sclerosis ◽

Case Report ◽

White Matter ◽

Frontal Lobe ◽

Cognitive Dysfunction ◽

Clinical Features ◽

Grey Matter ◽

Psychiatric Symptoms ◽

Eating Behaviour ◽

Cortical Grey Matter

Background/introductionAlthough multiple sclerosis (MS), a demyelinating disease of unknown aetiology, is primarily a white matter disease, it may also involve the grey matter, a feature not often demonstrated in vivo by means of magnetic resonance imaging (MRI). The involvement of cortical grey matter in MS may account for cognitive dysfunction and behavioural abnormalities.ObjectiveThe purpose of this report is to present the case of a patient with MS and clinical features mimicking dementia of the frontal type due to clear-cut cortical grey matter involvement in the left frontal lobe.Case reportA 55-year-old woman with relapsing remitting MS developed a clinical picture characterized by frontal deficits (e.g. attention, verbal fluency, and speed processing), disinhibition, loss of insight, perseveration, abnormal eating behaviour, agitation, insomnia, and depersonalization phenomena. Neuropsychological evaluation also revealed abnormal performance on the Trail Making and the Stroop tests. Besides typical demyelinating lesions and “black holes”, MRI showed a striking pattern of left frontal opercular involvement including cortical thinning, focal knife-edge appearance of the gyri, and marked gliosis in the adjacent white matter.DiscussionCognitive deficits in MS are typically subcortical, due to the expected predominance of white matter lesions. Nonetheless, the involvement of grey matter structures may contribute to a different pattern of cognitive dysfunction. For example, hippocampal involvement has been linked to memory impairment. This particular case report additionally illustrates how cortical grey matter involvement in the frontal lobe may lead (not unexpectedly) to a clinical condition mostly characterised by frontal deficits and psychiatric symptoms.

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Increase of blood-brain barrier leakage is related to cognitive decline in vascular mild cognitive impairment

BMC Neurology ◽

10.1186/s12883-021-02189-6 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Man Li ◽

Yue Li ◽

Long Zuo ◽

Wenli Hu ◽

Tao Jiang

Keyword(s):

Cognitive Impairment ◽

Cognitive Function ◽

White Matter ◽

Grey Matter ◽

Leakage Rate ◽

White Matter Hyperintensity ◽

Normal Appearing White Matter ◽

Cortical Grey Matter ◽

Deep Grey Matter ◽

The Relationship

Abstract Background Blood-brain barrier (BBB) breakdown, as an early biomarker for vascular mild cognitive impairment (vMCI), has only been validated by a few studies. The aim of this study was to investigate whether compromised BBB integrity is involved in vMCI patients, and detect the relationship between BBB breakdown and cognitive function. BBB leakage in vMCI was explored, and the relationship between BBB leakage and cognitive function was discussed in this study. Methods This is a cross-sectional study involving 26 vMCI patients and 21 sex- and age-matched healthy controls. Dynamic contrast-enhanced-magnetic resonance imaging was performed for all participants, to determine BBB leakage. Leakage volume, leakage rate, and fractional blood plasma volume (Vp) in the grey and white matter were evaluated. Neuropsychological tests were used to determine cognitive function. Leakage rate, leakage volume, and Vp in different brain locations, including deep grey matter, cortical grey matter, white matter hyperintensity, and normal-appearing white matter were compared between the two groups. Results Multivariable linear regression analyses revealed that in all regions of interest, the leakage rate was significantly higher in vMCI patients relative to controls. Leakage volume in normal-appearing white matter and white matter hyperintensity were significantly higher, while Vp in normal-appearing white matter, deep grey matter, and cortical grey matter were significantly lower in vMCI patients. Moreover, Montreal Cognitive Assessment scores decreased with the increase of leakage rate in white matter hyperintensity. Conclusion Increased BBB permeability was detected in vMCI patients and was related to cognitive decline, which suggested that BBB breakdown might be involved in cognitive dysfunction pathogenesis.

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Differences in the molecular structure of the blood-brain barrier in the cerebral cortex and white matter: an in silico, in vitro, and ex vivo study

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00774.2015 ◽

2016 ◽

Vol 310 (11) ◽

pp. H1702-H1714 ◽

Cited By ~ 19

Author(s):

Ádám Nyúl-Tóth ◽

Maria Suciu ◽

Judit Molnár ◽

Csilla Fazakas ◽

János Haskó ◽

...

Keyword(s):

Endothelial Cells ◽

Cerebral Cortex ◽

White Matter ◽

Blood Brain Barrier ◽

In Silico ◽

Grey Matter ◽

Ex Vivo ◽

Cortical Grey Matter ◽

The Brain

The blood-brain barrier (BBB) is the main interface controlling molecular and cellular traffic between the central nervous system (CNS) and the periphery. It consists of cerebral endothelial cells (CECs) interconnected by continuous tight junctions, and closely associated pericytes and astrocytes. Different parts of the CNS have diverse functions and structures and may be subject of different pathologies, in which the BBB is actively involved. It is largely unknown, however, what are the cellular and molecular differences of the BBB in different regions of the brain. Using in silico, in vitro, and ex vivo techniques we compared the expression of BBB-associated genes and proteins (i.e., markers of CECs, brain pericytes, and astrocytes) in the cortical grey matter and white matter. In silico human database analysis (obtained from recalculated data of the Allen Brain Atlas), qPCR, Western blot, and immunofluorescence studies on porcine and mouse brain tissue indicated an increased expression of glial fibrillary acidic protein in astrocytes in the white matter compared with the grey matter. We have also found increased expression of genes of the junctional complex of CECs (occludin, claudin-5, and α-catenin) in the white matter compared with the cerebral cortex. Accordingly, occludin, claudin-5, and α-catenin proteins showed increased expression in CECs of the white matter compared with endothelial cells of the cortical grey matter. In parallel, barrier properties of white matter CECs were superior as well. These differences might be important in the pathogenesis of diseases differently affecting distinct regions of the brain.

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Clinical experience with the E.M.I. scanner

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1977.0009 ◽

1977 ◽

Vol 195 (1119) ◽

pp. 291-297

Keyword(s):

White Matter ◽

Grey Matter ◽

Wide Spectrum ◽

Three Dimensional ◽

Cerebral Atrophy ◽

Ventricular System ◽

Presenile Dementia ◽

Dimensional Reconstruction ◽

Cortical Grey Matter ◽

The Brain

Computerized tomography of the head using the E.M.I. scanner is a revolutionary method for diagnosing a wide spectrum of intracranial diseases. Because small differences in tissue density can be measured accurately the technique is sufficiently sensitive to demonstrate the ventricular system and major subarachnoid cisterns. The cortical grey matter, basal ganglia and thalami can be distinguished from white matter. A three-dimensional reconstruction of the brain is possible by examining a vertical sequence of transverse ‘slices’. Dilatation of the ventricular system is readily seen and since cortical sulcal enlargement is also shown, a diagnosis of cerebral atrophy can be made. This removes the need for pneumoencephalography in the majority of patients presenting with presenile dementia.

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Modelling white matter in gyral blades as a continuous vector field

10.1101/2020.07.27.222778 ◽

2020 ◽

Author(s):

Michiel Cottaar ◽

Matteo Bastiani ◽

Nikhil Boddu ◽

Matthew Glasser ◽

Suzanne Haber ◽

...

Keyword(s):

Vector Field ◽

White Matter ◽

Grey Matter ◽

Structural Connectivity ◽

Cortical Surface ◽

Divergence Free Vector ◽

Human Connectome Project ◽

Cortical Grey Matter ◽

Tractography Data

1AbstractMany brain imaging studies aim to measure structural connectivity with diffusion tractography. However, biases in tractography data, particularly near the boundary between white matter and cortical grey matter can limit the accuracy of such studies. When seeding from the white matter, streamlines tend to travel parallel to the convoluted cortical surface, largely avoiding sulcal fundi and terminating preferentially on gyral crowns. When seeding from the cortical grey matter, streamlines generally run near the cortical surface until reaching deep white matter. These so-called “gyral biases” limit the accuracy and effective resolution of cortical structural connectivity profiles estimated by tractography algorithms, and they do not reflect the expected distributions of axonal densities seen in invasive tracer studies or stains of myelinated fibres. We propose an algorithm that concurrently models fibre density and orientation using a divergence-free vector field within gyral blades to encourage an anatomically-justified streamline density distribution along the cortical white/grey-matter boundary while maintaining alignment with the diffusion MRI estimated fibre orientations. Using in vivo data from the Human Connectome Project, we show that this algorithm reduces tractography biases. We compare the structural connectomes to functional connectomes from resting-state fMRI, showing that our model improves cross-modal agreement. Finally, we find that after parcellation the changes in the structural connectome are very minor with slightly improved interhemispheric connections (i.e, more homotopic connectivity) and slightly worse intrahemispheric connections when compared to tracers.

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