Parcellation of motor cortex-associated regions in the human corpus callosum on the basis of Human Connectome Project data

BACKGROUND: The corpus callosum in the midsagittal plane plays a crucial role in the early diagnosis of diseases. When the anisotropy of the diffusion tensor in the midsagittal plane is calculated, the anisotropy of corpus callosum is close to that of the fornix, which leads to blurred boundary of the segmentation region. OBJECTIVE: To apply a fuzzy clustering algorithm combined with new spatial information to achieve accurate segmentation of the corpus callosum in the midsagittal plane in diffusion tensor images. METHODS: In this algorithm, a fixed region of interest is selected from the midsagittal plane, and the anisotropic filtering algorithm based on tensor is implemented by replacing the gradient direction of the structural tensor with an eigenvector, thus filtering the diffusion tensor of region of interest. Then, the iterative clustering center based on K-means clustering is used as the initial clustering center of tensor fuzzy clustering algorithm. Taking filtered diffusion tensor as input data and different metrics as similarity measures, the neighborhood diffusion tensor pixel calculation method of Log Euclidean framework is introduced in the membership function calculation, and tensor fuzzy clustering algorithm is proposed. In this study, MGH35 data from the Human Connectome Project (HCP) are tested and the variance, accuracy and specificity of the experimental results are discussed. RESULTS: Segmentation results of three groups of subjects in MGH35 data are reported. The average segmentation accuracy is 97.34%, and the average specificity is 98.43%. CONCLUSIONS: When segmenting the corpus callosum of diffusion tensor imaging, our method cannot only effective denoise images, but also achieve high accuracy and specificity.

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Body mass variability is represented by distinct functional connectivity patterns

10.31232/osf.io/b9ahw ◽

2018 ◽

Author(s):

Jennifer R Sadler ◽

Grace Elisabeth Shearrer ◽

Kyle Stanley Burger

Keyword(s):

Functional Connectivity ◽

Body Mass ◽

Visual Processing ◽

Weight Status ◽

Design Sensitivity ◽

Human Connectome Project ◽

Connectivity Patterns ◽

Discordant Twins ◽

Project Data ◽

Discordant Twin

Understanding weight-related differences in functional connectivity provides key insight into neurocognitive factors implicated in obesity. Here, we sampled three groups from human connectome project data: 1) 47 pairs of BMI-discordant twins (n=94; average BMI-discordancy 6.7 3.1 kg/m2), 2) 47 pairs of gender and BMI matched BMI-discordant, unrelated individuals, and 3) 47 pairs of BMI-similar twins to test for body mass dependent differences in between network functional connectivity. Across BMI discordant samples, three networks appeared to be highly sensitivity to weight status; specifically, a network compromised of gustatory processing regions, a visual processing network, and the default mode network (DMN). Further, individuals with a lower BMI relative to their twin had stronger connectivity between striatal/thalamic and prefrontal networks (pFWE = 0.04) in the BMI-discordant twin sample. Cortical-striatal-thalamic networks underlie regulation of hedonically motivated behaviors. Stronger connectivity may facilitate increased regulation of decision-making when presented with highly rewarding, energy-dense foods. We also observed that individuals with a higher BMI than their twin had stronger connectivity between cerebellar and insular networks (pFWE = 0.04). Increased cerebellar-insula connectivity is associated with caloric deprivation and, in high BMI individuals, is associated compromised satiation signaling, thereby increasing risk for postprandial food intake. Connectivity patterns observed in the BMI-discordant twin sample were not see in a BMI-similar sample, providing evidence that the results are specific to BMI discordance. Beyond the involvement of gustatory and visual networks and the DMN, little overlap in results were seen between the two BMI-discordant samples. This may be a function of the higher study design sensitivity in the BMI-discordant twin sample, relative to the more generalizable results in the unrelated sample. These findings demonstrate that distinct connectivity patterns can represent weight variability, adding to mounting evidence that implicates atypical brain functioning with the accumulation and/or maintenance of elevated weight.

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Combining Hypothermia and Oleuropein Subacutely Protects Subcortical White Matter in a Swine Model of Neonatal Hypoxic-Ischemic Encephalopathy

Journal of Neuropathology & Experimental Neurology ◽

10.1093/jnen/nlaa132 ◽

2020 ◽

Author(s):

Jennifer K Lee ◽

Polan T Santos ◽

May W Chen ◽

Caitlin E O’Brien ◽

Ewa Kulikowicz ◽

...

Keyword(s):

White Matter ◽

Motor Cortex ◽

Corpus Callosum ◽

Internal Capsule ◽

Subcortical White Matter ◽

White Matter Injury ◽

Swine Model ◽

Cortex Neuron ◽

Motor Cortex Neuron ◽

Ischemic Encephalopathy

Abstract Neonatal hypoxia-ischemia (HI) causes white matter injury that is not fully prevented by therapeutic hypothermia. Adjuvant treatments are needed. We compared myelination in different piglet white matter regions. We then tested whether oleuropein (OLE) improves neuroprotection in 2- to 4-day-old piglets randomized to undergo HI or sham procedure and OLE or vehicle administration beginning at 15 minutes. All groups received overnight hypothermia and rewarming. Injury in the subcortical white matter, corpus callosum, internal capsule, putamen, and motor cortex gray matter was assessed 1 day later. At baseline, piglets had greater subcortical myelination than in corpus callosum. Hypothermic HI piglets had scant injury in putamen and cerebral cortex. However, hypothermia alone did not prevent the loss of subcortical myelinating oligodendrocytes or the reduction in subcortical myelin density after HI. Combining OLE with hypothermia improved post-HI subcortical white matter protection by preserving myelinating oligodendrocytes, myelin density, and oligodendrocyte markers. Corpus callosum and internal capsule showed little HI injury after hypothermia, and OLE accordingly had minimal effect. OLE did not affect putamen or motor cortex neuron counts. Thus, OLE combined with hypothermia protected subcortical white matter after HI. As an adjuvant to hypothermia, OLE may subacutely improve regional white matter protection after HI.

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Effective connectivity during animacy perception – dynamic causal modelling of Human Connectome Project data

Scientific Reports ◽

10.1038/srep06240 ◽

2014 ◽

Vol 4 (1) ◽

Cited By ~ 25

Author(s):

Hauke Hillebrandt ◽

Karl J. Friston ◽

Sarah-Jayne Blakemore

Keyword(s):

Effective Connectivity ◽

Causal Modelling ◽

Human Connectome Project ◽

Project Data ◽

Dynamic Causal Modelling

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Stereotactic linac-based radiosurgery in the treatment of cerebral arteriovenous malformations located deep, involving corpus callosum, motor cortex, or brainstem

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/j.ijrobp.2005.09.024 ◽

2006 ◽

Vol 64 (4) ◽

pp. 1044-1048 ◽

Cited By ~ 41

Author(s):

Angelika Zabel-du Bois ◽

Stefanie Milker-Zabel ◽

Peter Huber ◽

Wolfgang Schlegel ◽

Jürgen Debus

Keyword(s):

Motor Cortex ◽

Corpus Callosum ◽

Arteriovenous Malformations ◽

Cerebral Arteriovenous Malformations

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Clinically-Feasible Brain Morphometric Similarity Network Construction Approaches with Restricted Magnetic Resonance Imaging Acquisitions and their Relationship with Cognition

10.31234/osf.io/vks3u ◽

2019 ◽

Author(s):

Daniel J. King ◽

Amanda Wood

Keyword(s):

Developmentally Appropriate ◽

Structural Connectivity ◽

Developmental Neuroscience ◽

Architectural Features ◽

Human Connectome Project ◽

Valid Estimate ◽

Mri Sequences ◽

Project Data ◽

Potential Tool

Morphometric Similarity Networks (MSNs) estimate structural 'connectivity' as a biologically meaningful set of statistical similarities between cyto-architectural features derived in-vivo from multiple MRI sequences. These networks have shown to be clinically relevant, predicting 40% variance in IQ. However, the sequences required (T1w and T2w 3D anatomical, DWI) to produce these networks typically have long acquisition times, which are less feasible in some populations. Thus, estimating MSNs using features from only a T1w MRI is attractive to both clinical and developmental neuroscience. We aimed to determine whether reduced-feature approaches approximate the original MSN model as a potential tool to investigate brain structure. Using Human Connectome Project data, we extended previous investigations of reduced-feature MSNs by comparing not only T1w-derived networks but additional MSNs generated with fewer MR sequences to their full acquisition counterparts. We produce MSNs which are highly similar at the edge-level, to those generated with multi-modal imaging. We also find that, regardless of the number of features, these networks have limited predictive validity of generalised cognitive ability scores in contrast to previous research. Overall, settings in which multi-modal imaging is not available or clinically/developmentally appropriate, T1w-restricted MSN construction provides a valid estimate of the MSN.

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Paradoxical facilitation alongside interhemispheric inhibition

Experimental Brain Research ◽

10.1007/s00221-021-06183-9 ◽

2021 ◽

Author(s):

Michel Belyk ◽

Russell Banks ◽

Anna Tendera ◽

Robert Chen ◽

Deryk S. Beal

Keyword(s):

Motor Cortex ◽

Corpus Callosum ◽

Primary Motor Cortex ◽

Conditioning Stimulus ◽

Future Research ◽

Homologous Region ◽

Inhibitory Influence ◽

Interhemispheric Inhibition ◽

Opposite Hemisphere ◽

Surprising Effect

AbstractNeurophysiological experiments using transcranial magnetic stimulation (TMS) have sought to probe the function of the motor division of the corpus callosum. Primary motor cortex sends projections via the corpus callosum with a net inhibitory influence on the homologous region of the opposite hemisphere. Interhemispheric inhibition (IHI) experiments probe this inhibitory pathway. A test stimulus (TS) delivered to the motor cortex in one hemisphere elicits motor evoked potentials (MEPs) in a target muscle, while a conditioning stimulus (CS) applied to the homologous region of the opposite hemisphere modulates the effect of the TS. We predicted that large CS MEPs would be associated with increased IHI since they should be a reliable index of how effectively contralateral motor cortex was stimulated and therefore of the magnitude of interhemispheric inhibition. However, we observed a strong tendency for larger CS MEPs to be associated with reduced interhemispheric inhibition which in the extreme lead to a net effect of facilitation. This surprising effect was large, systematic, and observed in nearly all participants. We outline several hypotheses for mechanisms which may underlie this phenomenon to guide future research.

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