Neuronal Migration and Axonal Pathways Linked to Human Fetal Insular Development Revealed by Diffusion MR Tractography

Das, Avilash; Takahashi, Emi

doi:10.1093/cercor/bhx224

Cited by 13 publications

(10 citation statements)

References 59 publications

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“…Spatiotemporal developmental time courses of the maturation of the fornix, cingulum bundle, corpus callosal and thalamocortical pathways, inferior longitudinal, inferior fronto-occipital, uncinate, and arcuate fasciculi, as well as insular, cerebellar, and many other pathways in human fetal ages have been described with the use of HARDI (Takahashi et al ., 2012, 2014; Song et al ., 2015; Wilkinson et al ., 2016; Vasung et al ., 2017; Das and Takahashi, 2017). Although ex vivo dMRI has produced an exceptional resolution of fiber pathways, it is possible to achieve comparable results using in vivo imaging (e.g.…”

Section: Technological Considerations Of Ex Vivo Fetal Mrimentioning

confidence: 99%

“…We have recently further differentially identified radial pathways between different fetal transient zones (Vasung et al ., 2017), as well as pathways likely originating from the VZ to the insular and surrounding cortices (Das and Takahashi 2017) and the thalamus (Fig. 7; Wilkinson et al ., 2016).…”

Section: Neuronal Migration Pathwaysmentioning

confidence: 99%

“…Therefore, with new MR image acquisition and reconstruction techniques (e.g. Alexander et al, 2017; Hamilton et al, 2017; Liu et al, 2017; Poser and Setsompop, 2018), a detailed high resolution histological and MRI ex vivo atlases of the developing fetal brain (Kostovic et al , 2002, Huang et al , 2006, 2009, Vasung et al , 2010, 2016, 2017; Takahashi et al , 2012, Xu et al , 2014, Wang et al , 2015, Wilkinson et al , 2016, Das and Takahashi, 2017) can offer valuable information for interpretation of in vivo fetal MRI findings, and can identify areas where technical improvements in MRI acquisition, reconstruction, or analysis are still necessity.…”

Section: Future Directionsmentioning

confidence: 99%

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Ex vivo fetal brain MRI: Recent advances, challenges, and future directions

et al. 2019

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During early development, the fetal brain undergoes dynamic morphological changes. These changes result from neurogenic events, such as neuronal proliferation, migration, axonal elongation, retraction, and myelination. The duration and intensity of these events vary across species. Comparative assessments of these neurogenic events give us insight into evolutionary changes and the complexity of human brain development. Recent advances in magnetic resonance imaging (MRI), especially ex vivo MRI, permit characterizing and comparing fetal brain development across species. Comparative ex vivo MRI studies support the detection of speciesspecific differences that occur during early brain development. In this review, we provide a comprehensive overview of ex vivo MRI studies that characterize early brain development in humans, monkeys, cats, as well as rats/mice. Finally, we discuss the current advantages and limitations of ex vivo fetal brain MRI.

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Section: Technological Considerations Of Ex Vivo Fetal Mrimentioning

confidence: 99%

Section: Neuronal Migration Pathwaysmentioning

confidence: 99%

Section: Future Directionsmentioning

confidence: 99%

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Ex vivo fetal brain MRI: Recent advances, challenges, and future directions

et al. 2019

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“…This technique, theoretically, provides an advantage over DTI (Frank, 2002;Tournier et al, 2004), because there are many places throughout the brain where WM tracts cross and project in many different directions (Tournier et al, 2007). We have previously successfully applied HARDI tractography to insular development in fetal human brains (Das and Takahashi, 2017).…”

Section: Introductionmentioning

confidence: 99%

Asymmetric Insular Connectomics Revealed by Diffusion Magnetic Resonance Imaging Analysis of Healthy Brain Development

et al. 2019

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The insula has been implicated in playing important roles in various brain functions including consciousness, homeostasis, perception, self-awareness, language processing, and interpersonal experience. Abnormalities of the insula have been observed in patients suffering from addiction, deteriorating language function, anorexia, and emotional dysregulation. We analyzed typical development of insular connections in a large-scale pediatric population using 642 magnetic resonance imaging examinations. Interpreting large quantities of acquired data is one of the major challenges in connectomics. This article focuses its analysis on the connectivity observed between the insula and many other regions throughout the brain and performs a hemispheric asymmetry analysis comparing localized connectome measurements. Results demonstrate asymmetries in the pathways connecting the insula to the superior temporal region, pars opercularis, etc. that may be representative of language lateralization in the brain. Results also demonstrate multiple fiber pathways that exhibit hemispheric dominance in tract length and an inverted hemispheric dominance in tract counts, implying the presence of asymmetric lateralization of some of the brain's insular pathways. This study illustrates the investigative potential of performing connectomics-style analyses in a clinical context across a large population of children as part of routine imaging, demonstrating the feasibility of using current technologies to perform regionally focused clinical connectivity studies.

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“…No threshold of fractional anisotropy (FA) was used for the fiber reconstruction. Brain mask volumes were used to terminate tractography structures instead of the standard FA threshold (Takahash et al, 2010 ; Takahashi et al, 2011 , 2012 , 2014 ; Song et al, 2015 ; Das and Takahashi, 2017 ; Vasung et al, 2017 ), because progressive myelination and crossing fibers in the developing brain can result in low FA values that may potentially incorrectly terminate tractography tracing in brain regions with low FA values.…”

Section: Methodsmentioning

confidence: 99%

Convergence of Cortical, Thalamocortical, and Callosal Pathways during Human Fetal Development Revealed by Diffusion MRI Tractography

et al. 2017

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There has been evidence that during brain development, emerging thalamocortical (TC) and corticothalamic (CT) pathways converge in some brain regions and follow each other's trajectories to their final destinations. Corpus callosal (CC) pathways also emerge at a similar developmental stage, and are known to converge with TC pathways in specific cortical regions in mature brains. Given the functional relationships between TC and CC pathways, anatomical convergence of the two pathways are likely important for their functional integration. However, it is unknown (1) where TC and CT subcortically converge in the human brain, and (2) where TC and CC converge in the cortex of the human brain, due to the limitations of non-invasive methods. The goals of this study were to describe the spatio-temporal relationships in the development of the TC/CT and CC pathways in the human brain, using high-angular resolution diffusion MR imaging (HARDI) tractography. Emerging cortical, TC and CC pathways were identified in postmortem fetal brains ranging from 17 gestational weeks (GW) to 30 GW, as well as in vivo 34–40 GW newborns. Some pathways from the thalami were found to be converged with pathways from the cerebral cortex as early as 17 GW. Such convergence was observed mainly in anterior and middle regions of the brain until 21 GW. At 22 GW and onwards, posterior pathways from the thalami also converged with cortical pathways. Many CC pathways reached the full length up to the cortical surface as early as 17 GW, while pathways linked to thalami (not only TC axons but also including pathways linked to thalamic neuronal migration) reached the cortical surface at and after 20 GW. These results suggest that CC pathways developed earlier than the TC pathways. The two pathways were widespread at early stages, but by 40 GW they condensed and formed groups of pathways that projected to specific regions of the cortex and overlapped in some brain regions. These results suggest that HARDI tractography has the potential to identify developing TC/CT and CC pathways with the timing and location of their convergence in fetal stages persisting in postnatal development.

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Neuronal Migration and Axonal Pathways Linked to Human Fetal Insular Development Revealed by Diffusion MR Tractography

Cited by 13 publications

References 59 publications

Ex vivo fetal brain MRI: Recent advances, challenges, and future directions

Ex vivo fetal brain MRI: Recent advances, challenges, and future directions

Asymmetric Insular Connectomics Revealed by Diffusion Magnetic Resonance Imaging Analysis of Healthy Brain Development

Convergence of Cortical, Thalamocortical, and Callosal Pathways during Human Fetal Development Revealed by Diffusion MRI Tractography

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