We propose to use magnetic resonance imaging (MRI) and histology to determine the time course of development of radial pathways, thalamo-cortical fibers, short- and long-range cortico-cortical fibers and cortical efferent projection fibers in the brain of the human fetus ex vivo. Amajor challenge in MR tractography is to distinguish different fiber tracts at locations where they cross one another. When two or more fiber tracts cross within a voxel, conventional diffusion tensor imaging (DTI) often fail to resolve the multiple angles with peak water diffusion. This leads to errors such as missing fiber crossings when they exist or misconnecting incorrect fiber tracts. To overcome this problem, our colleagues have developed high-angular resolution techniques. They resolve the water diffusion angles along 60-200 directions and detect fiber crossings by the presence of multiple peaks in the water diffusion spectrum. Even with these high-resolution techniques, however, there is an additional problem when one tries to apply these techniques to determine the fiber pathways in developing fetal brains. Because myelination is incomplete, and the pattern of myelination dynamically changes during development, accurate tractography on human fetal brains has been challenging. We have recently shown that this problem can be overcome with HARDI and DSI by further refining scanning conditions and data analysis technique. We are now able to perform tractography in the developing brain without using a water diffusion anisotropy threshold. This has enabled us to visualize detailed coherent structures in the developing brain even in the areas with low myelination. This R21 proposal takes advantage of these recent technical developments to address an important issue in developmental human neuroscience, namely the time course of development of fiber pathways in human fetal brains. Although this issue has been addressed by others with diffusion tractography, these studies thus far have used DTI with incomplete pathway tracking. Therefore, we still know very little about the spatio-temporal course of fiber development in human brain. We believe that our technical developments will enable us to demonstrate that important developmental issues can be addressed in ex vivo preparations. For this first systematic high-resolution study of fiber development in the whole human fetal brain, we will use postmortem samples. This approach will provide crucial normative data with high signal-to-noise ratios, since movement artifact will be completely absent. Moreover, we will be able to validate our tractography results by comparing with histology. As discussed in the proposal, we believe that this research has potential for important clinical applications in perinatal brain injury or malformation as well as understanding of subtle abnormality of folding/connectivity that affect higher cognitive functions after birth.

Public Health Relevance

We propose to use magnetic resonance imaging (MRI) and histology to determine the time course of development of brain connectivity and gyral formation. As this will be the first systematic high-resolution study of fiber development in the whole human brain, the results should lead to a novel, precise spatio-temporal maps of fiber development and allow precise comparison of fiber and gyral development that will contribute not only for basic neuroscience but also for accurate diagnose and understanding of the implications of abnormal folding and connectivity in infants with perinatal brain injury or malformation.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21HD069001-01A1
Application #
8244245
Study Section
Developmental Brain Disorders Study Section (DBD)
Program Officer
Freund, Lisa S
Project Start
2012-03-01
Project End
2014-02-28
Budget Start
2012-03-01
Budget End
2013-02-28
Support Year
1
Fiscal Year
2012
Total Cost
$261,000
Indirect Cost
$111,000
Name
Children's Hospital Boston
Department
Type
DUNS #
076593722
City
Boston
State
MA
Country
United States
Zip Code
02115
Kang, Dong-Wha; Kim, Dongho; Chang, Li-Hung et al. (2018) Structural and Functional Connectivity Changes Beyond Visual Cortex in a Later Phase of Visual Perceptual Learning. Sci Rep 8:5186
Das, Avilash; Takahashi, Emi (2018) Neuronal Migration and Axonal Pathways Linked to Human Fetal Insular Development Revealed by Diffusion MR Tractography. Cereb Cortex 28:3555-3563
Re, Thomas J; Levman, Jacob; Lim, Ashley R et al. (2017) High-angular resolution diffusion imaging tractography of cerebellar pathways from newborns to young adults. Brain Behav 7:e00589
Kanamaru, Yuri; Li, Jianxue; Stewart, Natalie et al. (2017) Cerebellar Pathways in Mouse Model of Purkinje Cell Degeneration Detected by High-Angular Resolution Diffusion Imaging Tractography. Cerebellum 16:648-655
Wilkinson, Molly; Kane, Tara; Wang, Rongpin et al. (2017) Migration Pathways of Thalamic Neurons and Development of Thalamocortical Connections in Humans Revealed by Diffusion MR Tractography. Cereb Cortex 27:5683-5695
Charvet, Christine J; Hof, Patrick R; Raghanti, Mary Ann et al. (2017) Combining diffusion magnetic resonance tractography with stereology highlights increased cross-cortical integration in primates. J Comp Neurol 525:1075-1093
Charvet, Christine J; Šimi?, Goran; Kostovi?, Ivica et al. (2017) Coevolution in the timing of GABAergic and pyramidal neuron maturation in primates. Proc Biol Sci 284:
Wilkinson, Molly; Lim, Ashley R; Cohen, Andrew H et al. (2017) Detection and Growth Pattern of Arcuate Fasciculus from Newborn to Adult. Front Neurosci 11:389
Vasung, Lana; Raguz, Marina; Kostovic, Ivica et al. (2017) Spatiotemporal Relationship of Brain Pathways during Human Fetal Development Using High-Angular Resolution Diffusion MR Imaging and Histology. Front Neurosci 11:348
Wang, Rongpin; Wilkinson, Molly; Kane, Tara et al. (2017) Convergence of Cortical, Thalamocortical, and Callosal Pathways during Human Fetal Development Revealed by Diffusion MRI Tractography. Front Neurosci 11:576

Showing the most recent 10 out of 29 publications