scholarly journals Catch me if you can: Least myelinated white matter develops fastest during early infancy

2021 ◽  
Author(s):  
Mareike Grotheer ◽  
Mona Rosenke ◽  
Hua Wu ◽  
Holly Kular ◽  
Francesca R. Querdasi ◽  
...  
Keyword(s):  
White Matter ◽  
Nerve Fibers ◽  
Developmental Trajectory ◽  
Quantitative Mri ◽  
Early Infancy ◽  
Longitudinal Diffusion ◽  
Neural Communication ◽  
White Matter Development ◽  
Catch Up ◽  
The Brain

Development of myelin, a fatty sheath that insulates nerve fibers, is critical for brain function. Myelination during infancy has been studied in postmortem histology, but such data cannot evaluate the developmental trajectory of the white matter bundles of the brain. To address this gap in knowledge, we (i) obtained longitudinal diffusion MRI measures and quantitative MRI measures of T1, which is sensitive to myelin, from newborns to 6-months-old infants, and (ii) developed an automated fiber quantification method that identifies bundles from dMRI and quantifies their T1 development in infants. Here we show that both along the length of each bundle and across bundles, T1 decreases from newborns to 6 months-old’s and the rate of T1 decrease is inversely correlated with T1 at birth. As lower T1 indicates more myelin, these data suggest that in early infancy white matter bundles myelinate at different rates such that less mature bundles at birth develop faster to catch-up with the other bundles. We hypothesize that this development reflects experience-dependent myelination, which may promote efficient and coordinated neural communication. These findings open new avenues to measure typical and atypical white matter development in early infancy, which has important implications for early identification of neurodevelopmental disorders.

scholarly journals Development of white matter tracts between and within the dorsal and ventral streams

2021 ◽  
Author(s):  
S. Vinci-Booher ◽  
B. Caron ◽  
D. Bullock ◽  
K. James ◽  
F. Pestilli
Keyword(s):  
White Matter ◽  
Sensory Information ◽  
Dorsal Stream ◽  
Developmental Trajectory ◽  
Microstructural Development ◽  
Perceptual Task ◽  
Visual Stream ◽  
White Matter Tracts ◽  
Feed Forward ◽  
White Matter Development

AbstractThe degree of interaction between the ventral and dorsal visual streams has been discussed in multiple scientific domains for decades. Recently, several white matter tracts that directly connect the dorsal and ventral streams have become possible to study using automated and reproducible methods. The developmental trajectory of this set of tracts, the posterior vertical pathway (PVP), is yet to be described. We propose an input-driven model of white matter development and provide evidence for the model by focusing on PVP development. We used reproducible cloud-computing methods and diffusion imaging from adults and children (ages 5-8 years) to compare PVP development to that of tracts within the ventral and dorsal pathways. PVP microstructure was more adult-like than dorsal stream microstructure but less adult-like than ventral stream microstructure. Additionally, PVP microstructure was more similar to the microstructure of the ventral than dorsal stream and was predicted by performance on a perceptual task in children. Overall, results suggest a key role for the PVP in the development of the dorsal visual stream that may be related to its ability to facilitate interactions between ventral and dorsal streams during learning. The results are consistent with the proposed model, suggesting that the microstructural development of major white matter pathways is related, at least in part, to the feed-forward propagation of sensory information within the visual system.Significance StatementUnderstanding white matter development is important to building predictive models that can inform interventions and targeted educational methods. We propose and provide evidence for an input-driven model of white matter development. We tested an uncharted aspect of human brain development. Namely, how the recently described posterior vertical white matter tracts develop. Our results suggest a feed-forward developmental progression along the known direct anatomical connections from posterior visual areas to anterior ventral and dorsal areas. Our results suggest fundamental biological mechanisms that clarify the role of white matter in predicting human learning and behavior.

scholarly journals Quantification of Gadolinium Deposition in the Brain Using Quantitative MRI

2021 ◽  
Author(s):  
Angie Landgren Liu ◽  
Ida Blystad ◽  
Anders Tisell
Keyword(s):  
White Matter ◽  
Grey Matter ◽  
T Test ◽  
Quantitative Mri ◽  
Paired Samples ◽  
Quantitative Measurements ◽  
Conventional Mri ◽  
Observational Cohort ◽  
The Brain

Abstract Gadolinium depositions in the brain caused by Gadolinium Based Contrast Agents (GBCAs) represent a topical issue since depositions have been confirmed, but their potential effects remain unknown. The purpose of this study is to show that quantitative MRI provides an alternative to conventional MRI for detection of gadolinium depositions without the need for reference areas, while also avoiding methodological limitations associated with conventional MRI, facilitating future studies on the subject. This retrospective observational cohort study of longitudinally acquired data uses quantitative MRI to quantify gadolinium depositions in six areas of the brain; the dentate nuclei, globus pallidi, thalami, pons, white matter and frontal cortex grey matter of 43 patients who received two to five doses of Magnevist (a linear GBCA) from 2009 to 2015. R1 was measured at baseline and after four years in the six areas of the brain of each patient. The changes in R1 were examined using a Paired-Samples T test. The correlation between doses of Magnevist and R1 was analysed using an Independent-Samples T test. There was a significant increase in R1 (p<0.05), consistent with gadolinium depositions in the dentate nuclei, globus pallidi and grey matter. No significant increase of R1 was found in the thalami, white matter or pons. A correlation between doses of Magnevist and R1 was found in the dentate nuclei and grey matter, but not in the globus pallidus. The results suggest that quantitative MRI is an alternative to conventional MRI for early detection of gadolinium depositions, while additionally providing quantitative measurements for comparison and follow-up.

126-OR: Fat Catch-Up Growth in Early Infancy and Cardiometabolic Outcomes at 5 Years of Age

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 126-OR
Author(s):  
GREGERS S. ANDERSEN ◽  
RASMUS WIBAEK ◽  
BITIYA ADMASSU ◽  
DORTE VISTISEN ◽  
MARIT E. JØRGENSEN ◽  
...  
Keyword(s):  
Early Infancy ◽  
Catch Up

Characterization of Ischemic Stroke in CT Images using Image Processing

2017 ◽  
Vol 7 (9) ◽  
pp. 18
Author(s):  
Amal Alzain ◽  
Suhaib Alameen ◽  
Rani Elmaki ◽  
Mohamed E. M. Gar-Elnabi
Keyword(s):  
Ischemic Stroke ◽  
White Matter ◽  
Classification Accuracy ◽  
Ct Images ◽  
Gray Level ◽  
Level Variation ◽  
Interactive Data ◽  
The Brain ◽  
Brain Tissues

This study concern to characterize the brain tissues to ischemic stroke, gray matter, white matter and CSF using texture analysisto extract classification features from CT images. The First Order Statistic techniques included sevenfeatures. To find the gray level variation in CT images it complements the FOS features extracted from CT images withgray level in pixels and estimate the variation of thesubpatterns. analyzing the image with Interactive Data Language IDL software to measure the grey level of images. The results show that the Gray Level variation and   features give classification accuracy of ischemic stroke 97.6%, gray matter95.2%, white matter 97.3% and the CSF classification accuracy 98.0%. The overall classification accuracy of brain tissues 97.0%.These relationships are stored in a Texture Dictionary that can be later used to automatically annotate new CT images with the appropriate brain tissues names.

What Has Direct Cortical and Subcortical Electrostimulation Taught Us about Neurolinguistics?

2019 ◽  
pp. 185-211
Author(s):  
Hugues Duffau
Keyword(s):  
White Matter ◽  
Large Scale ◽  
Functional Neuroimaging ◽  
Great Accuracy ◽  
Subcortical White Matter ◽  
Cerebral Lesions ◽  
Physiological Basis ◽  
Postoperative Mri ◽  
The Brain

Investigating the neural and physiological basis of language is one of the most important challenges in neurosciences. Direct electrical stimulation (DES), usually performed in awake patients during surgery for cerebral lesions, is a reliable tool for detecting both cortical and subcortical (white matter and deep grey nuclei) regions crucial for cognitive functions, especially language. DES transiently interacts locally with a small cortical or axonal site, but also nonlocally, as the focal perturbation will disrupt the entire subnetwork sustaining a given function. Thus, in contrast to functional neuroimaging, DES represents a unique opportunity to identify with great accuracy and reproducibility, in vivo in humans, the structures that are actually indispensable to the function, by inducing a transient virtual lesion based on the inhibition of a subcircuit lasting a few seconds. Currently, this is the sole technique that is able to directly investigate the functional role of white matter tracts in humans. Thus, combining transient disturbances elicited by DES with the anatomical data provided by pre- and postoperative MRI enables to achieve reliable anatomo-functional correlations, supporting a network organization of the brain, and leading to the reappraisal of models of language representation. Finally, combining serial peri-operative functional neuroimaging and online intraoperative DES allows the study of mechanisms underlying neuroplasticity. This chapter critically reviews the basic principles of DES, its advantages and limitations, and what DES can reveal about the neural foundations of language, that is, the large-scale distribution of language areas in the brain, their connectivity, and their ability to reorganize.

scholarly journals Listening to Mom in the NICU: effects of increased maternal speech exposure on language outcomes and white matter development in infants born very preterm

Trials ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Edith Brignoni-Pérez ◽  
Maya Chan Morales ◽  
Virginia A. Marchman ◽  
Melissa Scala ◽  
Heidi M. Feldman ◽  
...  
Keyword(s):  
White Matter ◽  
Structural Connectivity ◽  
Receptive Language ◽  
Secondary Outcome ◽  
Language Outcomes ◽  
Theoretical Understanding ◽  
Very Preterm ◽  
White Matter Development ◽  
Maternal Speech

Abstract Background Infants born very preterm (< 32 weeks gestational age (GA)) are at risk for developmental language delays. Poor language outcomes in children born preterm have been linked to neurobiological factors, including impaired development of the brain’s structural connectivity (white matter), and environmental factors, including decreased exposure to maternal speech in the neonatal intensive care unit (NICU). Interventions that enhance preterm infants’ exposure to maternal speech show promise as potential strategies for improving short-term health outcomes. Intervention studies have yet to establish whether increased exposure to maternal speech in the NICU offers benefits beyond the newborn period for brain and language outcomes. Methods This randomized controlled trial assesses the long-term effects of increased maternal speech exposure on structural connectivity at 12 months of age (age adjusted for prematurity (AA)) and language outcomes between 12 and 18 months of age AA. Study participants (N = 42) will include infants born very preterm (24–31 weeks 6/7 days GA). Newborns are randomly assigned to the treatment (n = 21) or standard medical care (n = 21) group. Treatment consists of increased maternal speech exposure, accomplished by playing audio recordings of each baby’s own mother reading a children’s book via an iPod placed in their crib/incubator. Infants in the control group have the identical iPod setup but are not played recordings. The primary outcome will be measures of expressive and receptive language skills, obtained from a parent questionnaire collected at 12–18 months AA. The secondary outcome will be measures of white matter development, including the mean diffusivity and fractional anisotropy derived from diffusion magnetic resonance imaging scans performed at around 36 weeks postmenstrual age during the infants’ routine brain imaging session before hospital discharge and 12 months AA. Discussion The proposed study is expected to establish the potential impact of increased maternal speech exposure on long-term language outcomes and white matter development in infants born very preterm. If successful, the findings of this study may help to guide NICU clinical practice for promoting language and brain development. This clinical trial has the potential to advance theoretical understanding of how early language exposure directly changes brain structure for later language learning. Trial registration NIH Clinical Trials (ClinicalTrials.gov) NCT04193579. Retrospectively registered on 10 December 2019.

THE METABOLISM OF NORMAL BRAIN AND HUMAN GLIOMAS IN RELATION TO CELL TYPE AND DENSITY

1955 ◽  
Vol 33 (3) ◽  
pp. 395-403 ◽  
Author(s):  
Irving H. Heller ◽  
K. A. C. Elliott
Keyword(s):  
Cerebral Cortex ◽  
White Matter ◽  
Brain Tumors ◽  
Corpus Callosum ◽  
Oxygen Uptake ◽  
Glial Cells ◽  
Cerebellar Cortex ◽  
Unit Weight ◽  
Uptake Rates ◽  
The Brain

Per unit weight, cerebral and cerebellar cortex respire much more actively than corpus callosum. The rate per cell nucleus is highest in cerebral cortex, lower in corpus callosum, and still lower in cerebellar cortex. The oxygen uptake rates of the brain tumors studied, with the exception of an oligodendroglioma, were about the same as that of white matter on the weight basis but lower than that of cerebral cortex or white matter on the cell basis. In agreement with previous work, an oligodendroglioma respired much more actively than the other tumors. The rates of glycolysis of the brain tumors per unit weight were low but, relative to their respiration rate, glycolysis was higher than in normal gray or white matter. Consideration of the figures obtained leads to the following tentative conclusions: Glial cells of corpus callosum respire more actively than the neurons of the cerebellar cortex. Neurons of the cerebral cortex respire on the average much more actively than neurons of the cerebellar cortex or glial cells. Considerably more than 70% of the oxygen uptake by cerebral cortex is due to neurons. The oxygen uptake rates of normal oligodendroglia and astrocytes are probably about the same as the rates found per nucleus in an oligodendroglioma and in astrocytomas; oligodendroglia respire much more actively than astrocytes.

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