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Fei Y, Wu Q, Zhao S, Song K, Han J, Liu C. Diverse and asymmetric patterns of single-neuron projectome in regulating interhemispheric connectivity. Nat Commun 2024; 15:3403. [PMID: 38649683 PMCID: PMC11035633 DOI: 10.1038/s41467-024-47762-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 04/11/2024] [Indexed: 04/25/2024] Open
Abstract
The corpus callosum, historically considered primarily for homotopic connections, supports many heterotopic connections, indicating complex interhemispheric connectivity. Understanding this complexity is crucial yet challenging due to diverse cell-specific wiring patterns. Here, we utilized public AAV bulk tracing and single-neuron tracing data to delineate the anatomical connection patterns of mouse brains and conducted wide-field calcium imaging to assess functional connectivity across various brain states in male mice. The single-neuron data uncovered complex and dense interconnected patterns, particularly for interhemispheric-heterotopic connections. We proposed a metric "heterogeneity" to quantify the complexity of the connection patterns. Computational modeling of these patterns suggested that the heterogeneity of upstream projections impacted downstream homotopic functional connectivity. Furthermore, higher heterogeneity observed in interhemispheric-heterotopic projections would cause lower strength but higher stability in functional connectivity than their intrahemispheric counterparts. These findings were corroborated by our wide-field functional imaging data, underscoring the important role of heterotopic-projection heterogeneity in interhemispheric communication.
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Affiliation(s)
- Yao Fei
- School of Automation, Northwestern Polytechnical University, Xi'an, China
- CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Qihang Wu
- CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shijie Zhao
- School of Automation, Northwestern Polytechnical University, Xi'an, China.
- Research & Development, Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, China.
| | - Kun Song
- CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Junwei Han
- School of Automation, Northwestern Polytechnical University, Xi'an, China.
- Research & Development, Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, China.
| | - Cirong Liu
- CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, 200031, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Key Laboratory of Genetic Evolution & Animal Models, Chinese Academy of Sciences, Shanghai, China.
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2
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Pal S, Lim JWC, Richards LJ. Diverse axonal morphologies of individual callosal projection neurons reveal new insights into brain connectivity. Curr Opin Neurobiol 2024; 84:102837. [PMID: 38271848 DOI: 10.1016/j.conb.2023.102837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 12/20/2023] [Indexed: 01/27/2024]
Abstract
In the mature brain, functionally distinct areas connect to specific targets, mediating network activity required for function. New insights are still occurring regarding how specific connectivity occurs in the developing brain. Decades of work have revealed important insights into the molecular and genetic mechanisms regulating cell type specification in the brain. This work classified long-range projection neurons of the cerebral cortex into three major classes based on their primary target (e.g. subcortical, intracortical, and interhemispheric projections). However, painstaking single-cell mapping reveals that long-range projection neurons of the corpus callosum connect to multiple and overlapping ipsilateral and contralateral targets with often highly branched axons. In addition, their scRNA transcriptomes are highly variable, making it difficult to identify meaningful subclasses. This work has prompted us to reexamine how cortical projection neurons that comprise the corpus callosum are currently classified and how this stunning array of variability might be achieved during development.
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Affiliation(s)
- Suranjana Pal
- Department of Neuroscience, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA. https://twitter.com/PalSuranjana
| | - Jonathan W C Lim
- Department of Neuroscience, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Linda J Richards
- Department of Neuroscience, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA.
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3
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Szczupak D, Schaeffer DJ, Tian X, Choi SH, Fang-Cheng, Iack PM, Campos VP, Mayo JP, Patsch J, Mitter C, Haboosheh A, Kwon HS, Vieira MAC, Reich DS, Jacobson S, Kasprian G, Tovar-Moll F, Lent R, Silva AC. Direct interhemispheric cortical communication via thalamic commissures: a new white matter pathway in the primate brain. Cereb Cortex 2024; 34:bhad394. [PMID: 37950874 PMCID: PMC10793074 DOI: 10.1093/cercor/bhad394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 11/13/2023] Open
Abstract
Cortical neurons of eutherian mammals project to the contralateral hemisphere, crossing the midline primarily via the corpus callosum and the anterior, posterior, and hippocampal commissures. We recently reported and named the thalamic commissures (TCs) as an additional interhemispheric axonal fiber pathway connecting the cortex to the contralateral thalamus in the rodent brain. Here, we demonstrate that TCs also exist in primates and characterize the connectivity of these pathways with high-resolution diffusion-weighted MRI, viral axonal tracing, and fMRI. We present evidence of TCs in both New World (Callithrix jacchus and Cebus apella) and Old World primates (Macaca mulatta). Further, like rodents, we show that the TCs in primates develop during the embryonic period, forming anatomical and functionally active connections of the cortex with the contralateral thalamus. We also searched for TCs in the human brain, showing their presence in humans with brain malformations, although we could not identify TCs in healthy subjects. These results pose the TCs as a vital fiber pathway in the primate brain, allowing for more robust interhemispheric connectivity and synchrony and serving as an alternative commissural route in developmental brain malformations.
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Affiliation(s)
- Diego Szczupak
- University of Pittsburgh Brain Institute, Department of Neurobiology, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - David J Schaeffer
- University of Pittsburgh Brain Institute, Department of Neurobiology, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Xiaoguang Tian
- University of Pittsburgh Brain Institute, Department of Neurobiology, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Sang-Ho Choi
- University of Pittsburgh Brain Institute, Department of Neurobiology, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Fang-Cheng
- Department of Neurological Surgery, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15261, USA
| | - Pamela Meneses Iack
- Biomedical Sciences Institute, Federal University of Rio de Janeiro, 373 Carlos Chagas Filho Avenue, Rio de Janeiro, Rio de Janeiro 21941-853, Brazil
| | - Vinicius P Campos
- Department of Electrical and Computer Engineering, 400 Trabalhador São-Carlense Avenue, University of São Paulo, São Carlos, SP 13565-905, Brazil
| | - J Patrick Mayo
- Department of Ophthalmology, University of Pittsburgh, 1622 Locust Street, Pittsburgh, PA 15261, USA
| | - Janina Patsch
- Department of Biomedical Imaging and Image-Guided Therapy of the Medical University of Vienna, 18-20 Währinger Gürtel, 1090, Vienna, Austria
| | - Christian Mitter
- Department of Biomedical Imaging and Image-Guided Therapy of the Medical University of Vienna, 18-20 Währinger Gürtel, 1090, Vienna, Austria
| | - Amit Haboosheh
- Department of Radiology Hadassah Ein Karem Hospital, Kalman Ya'akov Man St, Jerusalem 9112001, Israel
| | - Ha Seung Kwon
- University of Pittsburgh Brain Institute, Department of Neurobiology, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Marcelo A C Vieira
- Department of Electrical and Computer Engineering, 400 Trabalhador São-Carlense Avenue, University of São Paulo, São Carlos, SP 13565-905, Brazil
| | - Daniel S Reich
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, 10 Center Drive, Bethesda, MD 20814, USA
| | - Steve Jacobson
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, 10 Center Drive, Bethesda, MD 20814, USA
| | - Gregor Kasprian
- Department of Biomedical Imaging and Image-Guided Therapy of the Medical University of Vienna, 18-20 Währinger Gürtel, 1090, Vienna, Austria
| | - Fernanda Tovar-Moll
- D’Or Institute of Research and Education, 30 Rua Diniz Cordeiro Street, Rio de Janeiro, Rio de Janeiro 22281-100, Brazil
| | - Roberto Lent
- Biomedical Sciences Institute, Federal University of Rio de Janeiro, 373 Carlos Chagas Filho Avenue, Rio de Janeiro, Rio de Janeiro 21941-853, Brazil
- D’Or Institute of Research and Education, 30 Rua Diniz Cordeiro Street, Rio de Janeiro, Rio de Janeiro 22281-100, Brazil
| | - Afonso C Silva
- University of Pittsburgh Brain Institute, Department of Neurobiology, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
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Montanari R, Alegre-Cortés J, Alonso-Andrés A, Cabrera-Moreno J, Navarro I, García-Frigola C, Sáez M, Reig R. Callosal inputs generate side-invariant receptive fields in the barrel cortex. Sci Adv 2023; 9:eadi3728. [PMID: 38019920 PMCID: PMC10686559 DOI: 10.1126/sciadv.adi3728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023]
Abstract
Barrel cortex integrates contra- and ipsilateral whiskers' inputs. While contralateral inputs depend on the thalamocortical innervation, ipsilateral ones are thought to rely on callosal axons. These are more abundant in the barrel cortex region bordering with S2 and containing the row A-whiskers representation, the row lying nearest to the facial midline. Here, we ask what role this callosal axonal arrangement plays in ipsilateral tactile signaling. We found that novel object exploration with ipsilateral whiskers confines c-Fos expression within the highly callosal subregion. Targeting this area with in vivo patch-clamp recordings revealed neurons with uniquely strong ipsilateral responses dependent on the corpus callosum, as assessed by tetrodotoxin silencing and by optogenetic activation of the contralateral hemisphere. Still, in this area, stimulation of contra- or ipsilateral row A-whiskers evoked an indistinguishable response in some neurons, mostly located in layers 5/6, indicating their involvement in the midline representation of the whiskers' sensory space.
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Affiliation(s)
| | | | | | - Jorge Cabrera-Moreno
- Instituto de Neurociencias UMH-CSIC (Alicante), Avenida Santiago Ramón y Cajal s.n., 03550, Spain
| | | | - Cristina García-Frigola
- Instituto de Neurociencias UMH-CSIC (Alicante), Avenida Santiago Ramón y Cajal s.n., 03550, Spain
| | - María Sáez
- Instituto de Neurociencias UMH-CSIC (Alicante), Avenida Santiago Ramón y Cajal s.n., 03550, Spain
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Stanton-Turcotte D, Hsu K, Moore SA, Yamada M, Fawcett JP, Iulianella A. Mllt11 Regulates Migration and Neurite Outgrowth of Cortical Projection Neurons during Development. J Neurosci 2022; 42:3931-3948. [PMID: 35379703 PMCID: PMC9097781 DOI: 10.1523/jneurosci.0124-22.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/13/2022] [Accepted: 03/30/2022] [Indexed: 11/22/2022] Open
Abstract
The formation of connections within the mammalian neocortex is highly regulated by both extracellular guidance mechanisms and intrinsic gene expression programs. There are two types of cortical projection neurons (CPNs): those that project locally and interhemispherically and those that project to subcerebral structures such as the thalamus, hindbrain, and spinal cord. The regulation of cortical projection morphologies is not yet fully understood at the molecular level. Here, we report a role for Mllt11 (Myeloid/lymphoid or mixed-lineage leukemia; translocated to chromosome 11/All1 Fused Gene From Chromosome 1q) in the migration and neurite outgrowth of callosal projection neurons during mouse brain formation. We show that Mllt11 expression is exclusive to developing neurons and is enriched in the developing cortical plate (CP) during the formation of the superficial cortical layers. In cultured primary cortical neurons, Mllt11 is detected in varicosities and growth cones as well as the soma. Using conditional loss-of-function and gain-of-function analysis we show that Mllt11 is required for neuritogenesis and proper migration of upper layer CPNs. Loss of Mllt11 in the superficial cortex of male and female neonates leads to a severe reduction in fibers crossing the corpus callosum (CC), a progressive loss in the maintenance of upper layer projection neuron gene expression, and reduced complexity of dendritic arborization. Proteomic analysis revealed that Mllt11 associates with stabilized microtubules, and Mllt11 loss affected microtubule staining in callosal axons. Taken together, our findings support a role for Mllt11 in promoting the formation of mature upper-layer neuron morphologies and connectivity in the cerebral cortex.SIGNIFICANCE STATEMENT The regulation of cortical projection neuron (CPN) morphologies is an area of active investigation since the time of Cajal. Yet the molecular mechanisms of how the complex dendritic and axonal morphologies of projection neurons are formed remains incompletely understood. Although conditional mutagenesis analysis in the mouse, coupled with overexpression assays in the developing fetal brain, we show that a novel protein called Mllt11 is sufficient and necessary to regulate the dendritic and axonal characteristics of callosal projection neurons in the developing mammalian neocortex. Furthermore, we show that Mllt11 interacts with microtubules, likely accounting for its role in neuritogenesis.
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Affiliation(s)
- Danielle Stanton-Turcotte
- Department of Medical Neuroscience, and Brain Repair Centre, Faculty of Medicine, Dalhousie University. Life Science Research Institute, Halifax, Nova Scotia B3H-4R2, Canada
| | - Karolynn Hsu
- Department of Medical Neuroscience, and Brain Repair Centre, Faculty of Medicine, Dalhousie University. Life Science Research Institute, Halifax, Nova Scotia B3H-4R2, Canada
| | - Samantha A Moore
- Department of Medical Neuroscience, and Brain Repair Centre, Faculty of Medicine, Dalhousie University. Life Science Research Institute, Halifax, Nova Scotia B3H-4R2, Canada
| | - Makiko Yamada
- Department of Medical Neuroscience, and Brain Repair Centre, Faculty of Medicine, Dalhousie University. Life Science Research Institute, Halifax, Nova Scotia B3H-4R2, Canada
| | - James P Fawcett
- Departments of Phamacology, Surgery, and Brain Repair Centre, Faculty of Medicine, Dalhousie University. Life Science Research Institute, Halifax, Nova Scotia B3H-4R2, Canada
| | - Angelo Iulianella
- Department of Medical Neuroscience, and Brain Repair Centre, Faculty of Medicine, Dalhousie University. Life Science Research Institute, Halifax, Nova Scotia B3H-4R2, Canada
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6
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Cho H, Lee H, Gong Y, Kim YR, Cho J, Cho HJ. Quantitative susceptibility mapping and R1 measurement: Determination of the myelin volume fraction in the aging ex vivo rat corpus callosum. NMR Biomed 2022; 35:e4645. [PMID: 34739153 DOI: 10.1002/nbm.4645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 10/03/2021] [Accepted: 10/16/2021] [Indexed: 06/13/2023]
Abstract
In studies of the white matter (WM) in aging brains, both quantitative susceptibility mapping (QSM) and direct R1 measurement offer potentially useful ex vivo MRI tools that allow volumetric characterization of myelin content changes. Despite the technical importance of such MRI methods in numerous age-related diseases, the supposed linear relationship between the estimates of either the QSM or R1 method and age-affected myelin contents has not been validated. In this study, the absolute myelin volume fraction (MVF) was determined by transmission electron microscopy (TEM) as a gold standard measure for comparison with the values obtained by the aforementioned MR methods. To theoretically evaluate and understand the MR signal characteristics, QSM simulations were performed using the finite perturber method (FPM). Specifically, the simulation geometry modeling was based on TEM-derived structures aligned orthogonally to the main magnetic field, the construct of which was used to estimate the magnetic field shift (ΔB) changes arising from the conjectured myelin structures. Experimentally, ex vivo corpus callosum (CC) samples from rat brains obtained at 6 weeks (n = 3), 4 months (n = 3), and 20 months (n = 3) after birth were used to establish the relationship between changes quantified by either QSM or R1 with the absolute MVF by TEM. From the ex vivo brain samples, the scatterplot of mean MVF versus R1 was fitted to a linear equation, where R1mean = 0.7948 × MVFmean + 0.8118 (Pearson's correlation coefficient r = 0.9138; p < 0.01), while the scatterplot of mean MVF versus MRI-derived magnetic susceptibility (χ) was also fitted to a line where χmeasured,mean = -0.1218 × MVFmean - 0.006345 (r = -0.8435; p < 0.01). As a result of the FPM-based QSM simulations, a linearly proportional relationship between the simulated magnetic susceptibility, χsimulated,mean , and MVF (r = -0.9648; p < 0.01) was established. Such a statistically significant linear correlation between MRI-derived values by the QSM (or R1 ) method and MVF demonstrated that variable myelin contents in the WM (i.e., CC) can be quantified across multiple stages of aging. These findings further support that both techniques based on QSM and R1 provide an efficient means of studying the brain-aging process with accurate volumetric quantification of the myelin content in WM.
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Affiliation(s)
- Hwapyeong Cho
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Hansol Lee
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Yelim Gong
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Young Ro Kim
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - Junghun Cho
- Department of Radiology, Weill Cornell Medical College, New York, New York, USA
| | - Hyung Joon Cho
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
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Marshall AT, McConnell R, Lanphear BP, Thompson WK, Herting MM, Sowell ER. Risk of lead exposure, subcortical brain structure, and cognition in a large cohort of 9- to 10-year-old children. PLoS One 2021; 16:e0258469. [PMID: 34648580 PMCID: PMC8516269 DOI: 10.1371/journal.pone.0258469] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 09/26/2021] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Lead, a toxic metal, affects cognitive development at the lowest measurable concentrations found in children, but little is known about its direct impact on brain development. Recently, we reported widespread decreases in cortical surface area and volume with increased risks of lead exposure, primarily in children of low-income families. METHODS AND FINDINGS We examined associations of neighborhood-level risk of lead exposure with cognitive test performance and subcortical brain volumes. We also examined whether subcortical structure mediated associations between lead risk and cognitive performance. Our analyses employed a cross-sectional analysis of baseline data from the observational Adolescent Brain Cognitive Development (ABCD) Study. The multi-center ABCD Study used school-based enrollment to recruit a demographically diverse cohort of almost 11,900 9- and 10-year-old children from an initial 22 study sites. The analyzed sample included data from 8,524 typically developing child participants and their parents or caregivers. The primary outcomes and measures were subcortical brain structure, cognitive performance using the National Institutes of Health Toolbox, and geocoded risk of lead exposure. Children who lived in neighborhoods with greater risks of environmental lead exposure exhibited smaller volumes of the mid-anterior (partial correlation coefficient [rp] = -0.040), central (rp = -0.038), and mid-posterior corpus callosum (rp = -0.035). Smaller volumes of these three callosal regions were associated with poorer performance on cognitive tests measuring language and processing speed. The association of lead exposure risk with cognitive performance was partially mediated through callosal volume, particularly the mid-posterior corpus callosum. In contrast, neighborhood-level indicators of disadvantage were not associated with smaller volumes of these brain structures. CONCLUSIONS Environmental factors related to the risk of lead exposure may be associated with certain aspects of cognitive functioning via diminished subcortical brain structure, including the anterior splenium (i.e., mid-posterior corpus callosum).
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Affiliation(s)
- Andrew T. Marshall
- Children’s Hospital Los Angeles, and the Department of Pediatrics, University of Southern California, Los Angeles, California, United States of America
| | - Rob McConnell
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Bruce P. Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
| | - Wesley K. Thompson
- Department of Biostatistics, Department of Family Medicine and Public Health, University of California, San Diego, San Diego, California, United States of America
| | - Megan M. Herting
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Elizabeth R. Sowell
- Children’s Hospital Los Angeles, and the Department of Pediatrics, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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Krupnik R, Yovel Y, Assaf Y. Inner Hemispheric and Interhemispheric Connectivity Balance in the Human Brain. J Neurosci 2021; 41:8351-8361. [PMID: 34465598 PMCID: PMC8496194 DOI: 10.1523/jneurosci.1074-21.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 07/25/2021] [Accepted: 08/08/2021] [Indexed: 11/21/2022] Open
Abstract
The connectome of the brain has a great impact on the function of the brain as the structure of the connectome affects the speed and efficiency of information transfer. As a highly energy-consuming organ, an efficient network structure is essential. A previous study has shown consistent overall brain connectivity across a large variety of species. This connectivity conservation was explained by a balance between interhemispheric and intrahemispheric connections; that is, spices with highly connected hemispheres appear to have weaker interhemisphere connections. This study examines this connectivity trade-off in the human brain using diffusion-based tractography and network analysis in the Human Connectome Project (970 subjects, 527 female). We explore the biological origins of this phenomenon, heritability, and the effect on cognitive measures.The proportion of commissural fibers in the brain had a negative correlation to hemispheric efficiency, pointing to a trade-off between inner hemispheric and interhemispheric connectivity. Network hubs including anterior and middle cingulate cortex, superior frontal areas, medial occipital areas, the parahippocampal gyrus, post- and precentral gyri, and the precuneus had the strongest contribution to this phenomenon. Other results show a high heritability as well as a strong connection to crystalized intelligence. This work presents cohort-based network analysis research, spanning a large variety of samples and exploring the overall architecture of the human connectome. Our results show a connectivity conservation phenomenon at the base of the overall brain network architecture. This network structure may explain much of the functional, behavioral, and cognitive variability among different brains.SIGNIFICANCE STATEMENT The network structure of the brain is at the basis of every brain function as it dictates the characteristics of information transfer. Understanding the patterns and mechanisms that guide the connectome structure is crucial to understanding the brain itself. Here we unravel the mechanism at the base of the connectivity conservation phenomenon by exploring the interaction between hemispheric and commissural connectivity in a large-scale cohort-based connectivity study. We describe the trade-off between the two components and examine the origins of the trade-off and observe the effect on cognitive abilities and behavior.
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Affiliation(s)
- Ronnie Krupnik
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yossi Yovel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
- Steinhardt Museum of Natural History, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yaniv Assaf
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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9
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Gooijers J, De Luca A, Zivari Adab H, Leemans A, Roebroeck A, Swinnen SP. Indices of callosal axonal density and radius from diffusion MRI relate to upper and lower limb motor performance. Neuroimage 2021; 241:118433. [PMID: 34324975 DOI: 10.1016/j.neuroimage.2021.118433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 07/15/2021] [Accepted: 07/26/2021] [Indexed: 11/16/2022] Open
Abstract
Understanding the relationship between human brain structure and functional outcome is of critical importance in systems neuroscience. Diffusion MRI (dMRI) studies show that fractional anisotropy (FA) is predictive of motor control, underscoring the importance of white matter (WM). However, as FA is a surrogate marker of WM, we aim to shed new light on the structural underpinnings of this relationship by applying a multi-compartment microstructure model providing axonal density/radius indices. Sixteen young adults (7 males / 9 females), performed a hand/foot tapping task and a Multi Limb Reaction Time task. Furthermore, diffusion (STEAM &HARDI) and fMRI (localizer hand/foot activations) data were obtained. Sphere ROIs were placed on activation clusters with highest t value to guide interhemispheric WM tractography. Axonal radius/density indices of callosal parts intersecting with tractography were calculated from STEAM, using the diffusion-time dependent AxCaliber model, and correlated with behavior. Results indicated a possible association between larger apparent axonal radii of callosal motor fibers of the hand and higher tapping scores of both hands, and faster selection-related processing (normalized reaction) times (RTs) on diagonal limb combinations. Additionally, a trend was present for faster selection-related processing (normalized reaction) times for lower limbs being related with higher axonal density of callosal foot motor fibers, and for higher FA values of callosal motor fibers in general being related with better tapping and faster selection-related processing (normalized reaction) times. Whereas FA is sensitive in demonstrating associations with motor behavior, axon radius/density (i.e., fiber geometry) measures are promising to explain the physiological source behind the observed FA changes, contributing to deeper insights into brain-behavior interactions.
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Affiliation(s)
- J Gooijers
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven (3000), Belgium; LBI-KU Leuven Brain Institute, Leuven (3000), Belgium.
| | - A De Luca
- PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht, Utrecht 3584 CX, Netherlands; Neurology Department, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht 3584 CX, Netherlands
| | - H Zivari Adab
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven (3000), Belgium; LBI-KU Leuven Brain Institute, Leuven (3000), Belgium
| | - A Leemans
- PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht, Utrecht 3584 CX, Netherlands
| | - A Roebroeck
- Department of Cognitive Neuroscience, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht 6229 EV, Netherlands
| | - S P Swinnen
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven (3000), Belgium; LBI-KU Leuven Brain Institute, Leuven (3000), Belgium
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10
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Oran Y, Katz Y, Sokoletsky M, Malina KCK, Lampl I. Reduction of corpus callosum activity during whisking leads to interhemispheric decorrelation. Nat Commun 2021; 12:4095. [PMID: 34215734 PMCID: PMC8253780 DOI: 10.1038/s41467-021-24310-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 06/09/2021] [Indexed: 11/20/2022] Open
Abstract
Interhemispheric correlation between homotopic areas is a major hallmark of cortical physiology and is believed to emerge through the corpus callosum. However, how interhemispheric correlations and corpus callosum activity are affected by behavioral states remains unknown. We performed laminar extracellular and intracellular recordings simultaneously from both barrel cortices in awake mice. We find robust interhemispheric correlations of both spiking and synaptic activities that are reduced during whisking compared to quiet wakefulness. Accordingly, optogenetic inactivation of one hemisphere reveals that interhemispheric coupling occurs only during quiet wakefulness, and chemogenetic inactivation of callosal terminals reduces interhemispheric correlation especially during quiet wakefulness. Moreover, in contrast to the generally elevated firing rate observed during whisking epochs, we find a marked decrease in the activity of imaged callosal fibers. Our results indicate that the reduction in interhemispheric coupling and correlations during active behavior reflects the specific reduction in the activity of callosal neurons.
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Affiliation(s)
- Yael Oran
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Yonatan Katz
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Michael Sokoletsky
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | | | - Ilan Lampl
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel.
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11
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Sivaramakrishnan A, Madhavan S. Reliability of transcallosal inhibition measurements for the lower limb motor cortex in stroke. Neurosci Lett 2021; 743:135558. [PMID: 33352282 PMCID: PMC7855415 DOI: 10.1016/j.neulet.2020.135558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 11/29/2022]
Abstract
Transcallosal inhibition (TCI) is a measure of between-hemisphere inhibitory control that can be evaluated with the ipsilateral silent period (iSP) transcranial magnetic stimulation (TMS) paradigm. The study of iSP for the lower extremity has been limited possibly due to the close orientation of the lower extremity motor representations. Change in TCI can provide insights into pathophysiological mechanisms underlying the asymmetry in corticomotor excitability in stroke. Here, we describe a method for iSP quantification and report reliability of iSP parameters for the tibialis anterior (TA) muscle in stroke. 26 individuals with stroke attended three sessions where single pulse TMS was used to measure TCI from the lesioned to non-lesioned hemisphere. A double cone coil was used for stimulating the ipsilateral motor cortex while the participant maintained an isometric contraction of the non-paretic TA. Absolute and relative reliability were computed for iSP latency, duration and area. iSP latency showed the lowest measurement error (absolute reliability) and iSP latency, duration and area showed good relative reliability (intraclass correlation coefficients > 0.6). This study suggests that iSP parameters for the tibialis anterior are reliable and attempts to provide a guideline for evaluating TCI for the lower extremity in stroke and other clinical populations.
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Affiliation(s)
- Anjali Sivaramakrishnan
- Brain Plasticity Lab, Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago (UIC), USA; Graduate Program in Rehabilitation Sciences, College of Applied Health Sciences, UIC, USA
| | - Sangeetha Madhavan
- Brain Plasticity Lab, Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago (UIC), USA.
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12
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Wang P, Wang J, Tang Q, Alvarez TL, Wang Z, Kung YC, Lin CP, Chen H, Meng C, Biswal BB. Structural and functional connectivity mapping of the human corpus callosum organization with white-matter functional networks. Neuroimage 2020; 227:117642. [PMID: 33338619 DOI: 10.1016/j.neuroimage.2020.117642] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/28/2020] [Accepted: 12/03/2020] [Indexed: 11/13/2022] Open
Abstract
The corpus callosum serves as a crucial organization for understanding the information integration between the two hemispheres. Our previous study explored the functional connectivity between the corpus callosum and white-matter functional networks (WM-FNs), but the corresponding physical connectivity remains unknown. The current study uses the resting-state fMRI of Human Connectome Project data to identify ten WM-FNs in 108 healthy subjects, and then independently maps the structural and functional connectivity between the corpus callosum and above WM-FNs using the diffusion tensor images (DTI) tractography and resting-state functional connectivity (RSFC). Our results demonstrated that the structural and functional connectivity between the human corpus callosum and WM-FNs have the following high overall correspondence: orbitofrontal WM-FN, DTI map = 89% and RSFC map = 92%; sensorimotor middle WM-FN, DTI map = 47% and RSFC map = 77%; deep WM-FN, DTI map = 50% and RSFC map = 79%; posterior corona radiata WM-FN, DTI map = 82% and RSFC map = 73%. These findings reinforce the notion that the corpus callosum has unique spatial distribution patterns connecting to distinct WM-FNs. However, important differences between the structural and functional connectivity mapping results were also observed, which demonstrated a synergy between DTI tractography and RSFC toward better understanding the information integration of primary and higher-order functional systems in the human brain.
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Affiliation(s)
- Pan Wang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Jianlin Wang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Qin Tang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Tara L Alvarez
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Zedong Wang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Yi-Chia Kung
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan
| | - Ching-Po Lin
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan
| | - Huafu Chen
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Chun Meng
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Bharat B Biswal
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China; Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA.
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13
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Labache L, Mazoyer B, Joliot M, Crivello F, Hesling I, Tzourio-Mazoyer N. Typical and atypical language brain organization based on intrinsic connectivity and multitask functional asymmetries. eLife 2020; 9:e58722. [PMID: 33064079 PMCID: PMC7605859 DOI: 10.7554/elife.58722] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 10/16/2020] [Indexed: 01/23/2023] Open
Abstract
Based on the joint investigation in 287 healthy volunteers (150 left-Handers (LH)) of language task-induced asymmetries and intrinsic connectivity strength of the sentence-processing supramodal network, we show that individuals with atypical rightward language lateralization (N = 30, 25 LH) do not rely on an organization that simply mirrors that of typical leftward lateralized individuals. Actually, the resting-state organization in the atypicals showed that their sentence processing was underpinned by left and right networks both wired for language processing and highly interacting by strong interhemispheric intrinsic connectivity and larger corpus callosum volume. Such a loose hemispheric specialization for language permits the hosting of language in either the left and/or right hemisphere as assessed by a very high incidence of dissociations across various language task-induced asymmetries in this group.
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Affiliation(s)
- Loïc Labache
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CNRS, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CEA, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- Université de Bordeaux, Institut de Mathématiques de Bordeaux, UMR 5251BordeauxFrance
- Bordeaux INP, Institut de Mathématiques de Bordeaux, UMR 5251BordeauxFrance
- INRIA Bordeaux Sud-Ouest, Institut de Mathématiques de Bordeaux, UMR 5251, Contrôle de Qualité et Fiabilité DynamiqueTalenceFrance
| | - Bernard Mazoyer
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CNRS, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CEA, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- Centre Hospitalier Universitaire de BordeauxBordeauxFrance
| | - Marc Joliot
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CNRS, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CEA, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
| | - Fabrice Crivello
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CNRS, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CEA, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
| | - Isabelle Hesling
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CNRS, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CEA, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
| | - Nathalie Tzourio-Mazoyer
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CNRS, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
- CEA, Institut des Maladies Neurodégéneratives, UMR 5293, Groupe d’Imagerie NeurofonctionnelleBordeauxFrance
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14
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Lynn JD, Anand C, Arshad M, Homayouni R, Rosenberg DR, Ofen N, Raz N, Stanley JA. Microstructure of Human Corpus Callosum across the Lifespan: Regional Variations in Axon Caliber, Density, and Myelin Content. Cereb Cortex 2020; 31:1032-1045. [PMID: 32995843 DOI: 10.1093/cercor/bhaa272] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 08/21/2020] [Accepted: 08/21/2020] [Indexed: 12/13/2022] Open
Abstract
The myeloarchitecture of the corpus callosum (CC) is characterized as a mosaic of distinct differences in fiber density of small- and large-diameter axons along the anterior-posterior axis; however, regional and age differences across the lifespan are not fully understood. Using multiecho T2 magnetic resonance imaging combined with multi-T2 fitting, the myelin water fraction (MWF) and geometric-mean of the intra-/extracellular water T2 (geomT2IEW) in 395 individuals (7-85 years; 41% males) were examined. The approach was validated where regional patterns along the CC closely resembled the histology; MWF matched mean axon diameter and geomT2IEW mirrored the density of large-caliber axons. Across the lifespan, MWF exhibited a quadratic association with age in all 10 CC regions with evidence of a positive linear MWF-age relationship among younger participants and minimal age differences in the remainder of the lifespan. Regarding geomT2IEW, a significant linear age × region interaction reflected positive linear age dependence mostly prominent in the regions with the highest density of small-caliber fibers-genu and splenium. In all, these two indicators characterize distinct attributes that are consistent with histology, which is a first. In addition, these results conform to rapid developmental progression of CC myelination leveling in middle age as well as age-related degradation of axon sheaths in older adults.
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Affiliation(s)
- Jonathan D Lynn
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit MI 48201, USA
- Institute of Gerontology, Wayne State University, Detroit MI 48202, USA
| | - Chaitali Anand
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit MI 48201, USA
- Institute of Gerontology, Wayne State University, Detroit MI 48202, USA
| | - Muzamil Arshad
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit MI 48201, USA
| | - Roya Homayouni
- Institute of Gerontology, Wayne State University, Detroit MI 48202, USA
- Department of Psychology, Wayne State University, Detroit MI 48201, USA
| | - David R Rosenberg
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit MI 48201, USA
| | - Noa Ofen
- Institute of Gerontology, Wayne State University, Detroit MI 48202, USA
- Department of Psychology, Wayne State University, Detroit MI 48201, USA
- Lifespan Cognitive Neuroscience, Merrill Palmer Skillman Institute, Wayne State University, Detroit MI 14195, USA
| | - Naftali Raz
- Institute of Gerontology, Wayne State University, Detroit MI 48202, USA
- Department of Psychology, Wayne State University, Detroit MI 48201, USA
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin 14195, Germany
| | - Jeffrey A Stanley
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit MI 48201, USA
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15
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Petrus E, Dembling S, Usdin T, Isaac JTR, Koretsky AP. Circuit-Specific Plasticity of Callosal Inputs Underlies Cortical Takeover. J Neurosci 2020; 40:7714-7723. [PMID: 32913109 PMCID: PMC7531555 DOI: 10.1523/jneurosci.1056-20.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/13/2020] [Accepted: 08/21/2020] [Indexed: 02/06/2023] Open
Abstract
Injury induces synaptic, circuit, and systems reorganization. After unilateral amputation or stroke, this functional loss disrupts the interhemispheric interaction between intact and deprived somatomotor cortices to recruit deprived cortex in response to intact limb stimulation. This recruitment has been implicated in enhanced intact sensory function. In other patients, maladaptive consequences such as phantom limb pain can occur. We used unilateral whisker denervation in male and female mice to detect circuitry alterations underlying interhemispheric cortical reorganization. Enhanced synaptic strength from the intact cortex via the corpus callosum (CC) onto deep neurons in deprived primary somatosensory barrel cortex (S1BC) has previously been detected. It was hypothesized that specificity in this plasticity may depend on to which area these neurons projected. Increased connectivity to somatomotor areas such as contralateral S1BC, primary motor cortex (M1) and secondary somatosensory cortex (S2) may underlie beneficial adaptations, while increased connectivity to pain areas like anterior cingulate cortex (ACC) might underlie maladaptive pain phenotypes. Neurons from the deprived S1BC that project to intact S1BC were hyperexcitable, had stronger responses and reduced inhibitory input to CC stimulation. M1-projecting neurons also showed increases in excitability and CC input strength that was offset with enhanced inhibition. S2 and ACC-projecting neurons showed no changes in excitability or CC input. These results demonstrate that subgroups of output neurons undergo dramatic and specific plasticity after peripheral injury. The changes in S1BC-projecting neurons likely underlie enhanced reciprocal connectivity of S1BC after unilateral deprivation consistent with the model that interhemispheric takeover supports intact whisker processing.SIGNIFICANCE STATEMENT Amputation, peripheral injury, and stroke patients experience widespread alterations in neural activity after sensory loss. A hallmark of this reorganization is the recruitment of deprived cortical space which likely aids processing and thus enhances performance on intact sensory systems. Conversely, this recruitment of deprived cortical space has been hypothesized to underlie phenotypes like phantom limb pain and hinder recovery. A mouse model of unilateral denervation detected remarkable specificity in alterations in the somatomotor circuit. These changes underlie increased reciprocal connectivity between intact and deprived cortical hemispheres. This increased connectivity may help explain the enhanced intact sensory processing detected in humans.
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Affiliation(s)
- Emily Petrus
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
| | - Sarah Dembling
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
| | - Ted Usdin
- Systems Neuroscience Imaging Resource, National Institute of Mental Health, Bethesda, Maryland 20892
| | - John T R Isaac
- Janssen Neuroscience, J&J Innovations, London W1G 0BG, United Kingdom
| | - Alan P Koretsky
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
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16
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Avelar-Pereira B, Bäckman L, Wåhlin A, Nyberg L, Salami A. Increased functional homotopy of the prefrontal cortex is associated with corpus callosum degeneration and working memory decline. Neurobiol Aging 2020; 96:68-78. [PMID: 32949903 DOI: 10.1016/j.neurobiolaging.2020.08.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 06/29/2020] [Accepted: 08/10/2020] [Indexed: 11/18/2022]
Abstract
Functional homotopy reflects the link between spontaneous activity in a voxel and its counterpart in the opposite hemisphere. Alterations in homotopic functional connectivity (FC) are seen in normal aging, with highest and lowest homotopy being present in sensory-motor and higher-order regions, respectively. Homotopic FC relates to underlying structural connections, but its neurobiological underpinnings remain unclear. The genu of the corpus callosum joins symmetrical parts of the prefrontal cortex (PFC) and is susceptible to age-related degeneration, suggesting that PFC homotopic connectivity is linked to changes in white-matter integrity. We investigated homotopic connectivity changes and whether these were associated with white-matter integrity in 338 individuals. In addition, we examined whether PFC homotopic FC was related to changes in the genu over 10 years and working memory over 5 years. There were increases and decreases in functional homotopy, with the former being prevalent in subcortical and frontal regions. Increased PFC homotopic FC was partially driven by structural degeneration and negatively associated with working memory, suggesting that it reflects detrimental age-related changes.
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Affiliation(s)
- Bárbara Avelar-Pereira
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden; Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden.
| | - Lars Bäckman
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Anders Wåhlin
- Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden; Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - Lars Nyberg
- Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden; Department of Radiation Sciences, Umeå University, Umeå, Sweden; Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | - Alireza Salami
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden; Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden; Department of Radiation Sciences, Umeå University, Umeå, Sweden; Department of Integrative Medical Biology, Umeå University, Umeå, Sweden; Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
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17
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Paolino A, Fenlon LR, Kozulin P, Haines E, Lim JWC, Richards LJ, Suárez R. Differential timing of a conserved transcriptional network underlies divergent cortical projection routes across mammalian brain evolution. Proc Natl Acad Sci U S A 2020; 117:10554-10564. [PMID: 32312821 PMCID: PMC7229759 DOI: 10.1073/pnas.1922422117] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A unique combination of transcription factor expression and projection neuron identity demarcates each layer of the cerebral cortex. During mouse and human cortical development, the transcription factor CTIP2 specifies neurons that project subcerebrally, while SATB2 specifies neuronal projections via the corpus callosum, a large axon tract connecting the two neocortical hemispheres that emerged exclusively in eutherian mammals. Marsupials comprise the sister taxon of eutherians but do not have a corpus callosum; their intercortical commissural neurons instead project via the anterior commissure, similar to egg-laying monotreme mammals. It remains unknown whether divergent transcriptional networks underlie these cortical wiring differences. Here, we combine birth-dating analysis, retrograde tracing, gene overexpression and knockdown, and axonal quantification to compare the functions of CTIP2 and SATB2 in neocortical development, between the eutherian mouse and the marsupial fat-tailed dunnart. We demonstrate a striking degree of structural and functional homology, whereby CTIP2 or SATB2 of either species is sufficient to promote a subcerebral or commissural fate, respectively. Remarkably, we reveal a substantial delay in the onset of developmental SATB2 expression in mice as compared to the equivalent stage in dunnarts, with premature SATB2 overexpression in mice to match that of dunnarts resulting in a marsupial-like projection fate via the anterior commissure. Our results suggest that small alterations in the timing of regulatory gene expression may underlie interspecies differences in neuronal projection fate specification.
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Affiliation(s)
- Annalisa Paolino
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Laura R Fenlon
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia;
| | - Peter Kozulin
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Elizabeth Haines
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jonathan W C Lim
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Linda J Richards
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia;
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rodrigo Suárez
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia;
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18
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Charvet CJ, Das A, Song JW, Tindal-Burgess DJ, Kabaria P, Dai G, Kane T, Takahashi E. High Angular Resolution Diffusion MRI Reveals Conserved and Deviant Programs in the Paths that Guide Human Cortical Circuitry. Cereb Cortex 2020; 30:1447-1464. [PMID: 31667494 PMCID: PMC7132938 DOI: 10.1093/cercor/bhz178] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/13/2019] [Accepted: 07/10/2019] [Indexed: 02/07/2023] Open
Abstract
Diffusion magnetic resonance (MR) tractography represents a novel opportunity to investigate conserved and deviant developmental programs between humans and other species such as mice. To that end, we acquired high angular resolution diffusion MR scans of mice [embryonic day (E) 10.5 to postnatal week 4] and human brains [gestational week (GW) 17-30] at successive stages of fetal development to investigate potential evolutionary changes in radial organization and emerging pathways between humans and mice. We compare radial glial development as well as commissural development (e.g., corpus callosum), primarily because our findings can be integrated with previous work. We also compare corpus callosal growth trajectories across primates (i.e., humans and rhesus macaques) and rodents (i.e., mice). One major finding is that the developing cortex of humans is predominated by pathways likely associated with a radial glial organization at GW 17-20, which is not as evident in age-matched mice (E 16.5, 17.5). Another finding is that, early in development, the corpus callosum follows a similar developmental timetable in primates (i.e., macaques and humans) as in mice. However, the corpus callosum grows for an extended period of time in primates compared with rodents. Taken together, these findings highlight deviant developmental programs underlying the emergence of cortical pathways in the human brain.
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Affiliation(s)
| | - Avilash Das
- Medical Sciences in the College of Arts and Sciences, Boston University, Boston, MA 02215, USA
- Division of Newborn Medicine, Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02215, USA
- Fetal-Neonatal Brain Imaging and Developmental Science Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02215, USA
| | - Jae W Song
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, USA
| | | | - Priya Kabaria
- Department of Behavioral Neuroscience, Northeastern University, Boston, MA 02115, USA
| | - Guangping Dai
- Science Center, Wellesley College, Wellesley, MA 02481, USA
| | - Tara Kane
- Department of Behavioral Neuroscience, Northeastern University, Boston, MA 02115, USA
| | - Emi Takahashi
- Division of Newborn Medicine, Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02215, USA
- Fetal-Neonatal Brain Imaging and Developmental Science Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02215, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
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19
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Barnes-Davis ME, Williamson BJ, Merhar SL, Holland SK, Kadis DS. Rewiring the extremely preterm brain: Altered structural connectivity relates to language function. Neuroimage Clin 2020; 25:102194. [PMID: 32032818 PMCID: PMC7005506 DOI: 10.1016/j.nicl.2020.102194] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 11/26/2022]
Abstract
Children born preterm are at increased risk for cognitive impairment, with higher-order functions such as language being especially vulnerable. Previously, we and others have reported increased interhemispheric functional connectivity in children born extremely preterm; the finding appears at odds with literature showing decreased integrity of the corpus callosum, the primary commissural bundle, in preterm children. We address the apparent discrepancy by obtaining advanced measures of structural connectivity in twelve school-aged children born extremely preterm (<28 weeks) and ten term controls. We hypothesize increased extracallosal structural connectivity might support the functional hyperconnectivity we had previously observed. Participants were aged four to six years at time of study and groups did not differ in age, sex, race, ethnicity, or socioeconomic status. Whole-brain and language-network-specific (functionally-constrained) connectometry analyses were performed. At the whole-brain level, preterm children had decreased connectivity in the corpus callosum and increased connectivity in the cerebellum versus controls. Functionally-constrained analyses revealed significantly increased extracallosal connectivity between bilateral temporal regions in preterm children (FDRq <0.05). Connectivity within these extracallosal pathways was positively correlated with performance on standardized language assessments in children born preterm (FDRq <0.001), but unrelated to performance in controls. This is the first study to identify anatomical substrates for increased interhemispheric functional connectivity in children born preterm; increased reliance on an extracallosal pathway may represent a biomarker for resiliency following extremely preterm birth.
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Affiliation(s)
- Maria E Barnes-Davis
- Perinatal Institute, Cincinnati Children's Hospital Medical Center, United States; Department of Pediatrics, University of Cincinnati College of Medicine, United States.
| | - Brady J Williamson
- Department of Psychology, University of Cincinnati, United States; Pediatric Neuroimaging Research Consortium, Cincinnati Children's Hospital Medical Center, United States
| | - Stephanie L Merhar
- Perinatal Institute, Cincinnati Children's Hospital Medical Center, United States; Department of Pediatrics, University of Cincinnati College of Medicine, United States
| | - Scott K Holland
- Department of Physics, University of Cincinnati, United States; Medpace Imaging Core Laboratory, Medpace Inc., United States
| | - Darren S Kadis
- Neurosciences and Mental Health Research Institute, Hospital for Sick Children, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Canada
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20
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Mortamais M, Pujol J, Martínez-Vilavella G, Fenoll R, Reynes C, Sabatier R, Rivas I, Forns J, Vilor-Tejedor N, Alemany S, Cirach M, Alvarez-Pedrerol M, Nieuwenhuijsen M, Sunyer J. Effects of prenatal exposure to particulate matter air pollution on corpus callosum and behavioral problems in children. Environ Res 2019; 178:108734. [PMID: 31539824 PMCID: PMC6892268 DOI: 10.1016/j.envres.2019.108734] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 09/06/2019] [Accepted: 09/06/2019] [Indexed: 05/17/2023]
Abstract
OBJECTIVE Air pollution (AP) may affect neurodevelopment, but studies about the effects of AP on the growing human brain are still scarce. We aimed to investigate the effects of prenatal exposure to AP on lateral ventricles (LV) and corpus callosum (CC) volumes in children and to determine whether the induced brain changes are associated with behavioral problems. METHODS Among the children recruited through a set of representative schools of the city of Barcelona, (Spain) in the Brain Development and Air Pollution Ultrafine Particles in School Children (BREATHE) study, 186 typically developing participants aged 8-12 years underwent brain MRI on the same 1.5 T MR unit over a 1.5-year period (October 2012-April 2014). Brain volumes were derived from structural MRI scans using automated tissue segmentation. Behavioral problems were assessed using the Strengths and Difficulties Questionnaire (SDQ) and the criteria of the Attention Deficit Hyperactivity Disorder DSM-IV list. Prenatal fine particle (PM2.5) levels were retrospectively estimated at the mothers' residential addresses during pregnancy with land use regression (LUR) models. To determine whether brain structures might be affected by prenatal PM2.5 exposure, linear regression models were run and adjusted for age, sex, intracranial volume (ICV), maternal education, home socioeconomic vulnerability index, birthweight and mothers' smoking status during pregnancy. To test for associations between brain changes and behavioral outcomes, negative binomial regressions were performed and adjusted for age, sex, ICV. RESULTS Prenatal PM2.5 levels ranged from 11.8 to 39.5 μg/m3 during the third trimester of pregnancy. An interquartile range increase in PM2.5 level (7 μg/m3) was significantly linked to a decrease in the body CC volume (mm3) (β = -53.7, 95%CI [-92.0, -15.5] corresponding to a 5% decrease of the mean body CC volume) independently of ICV, age, sex, maternal education, socioeconomic vulnerability index at home, birthweight and mothers' smoking status during the third trimester of pregnancy. A 50 mm3 decrease in the body CC was associated with a significant higher hyperactivity subscore (Rate Ratio (RR) = 1.09, 95%CI [1.01, 1.17) independently of age, sex and ICV. The statistical significance of these results did not survive to False Discovery Rate correction for multiple comparisons. CONCLUSIONS Prenatal exposure to PM2.5 may be associated with CC volume decrease in children. The consequences might be an increase in behavioral problems.
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Affiliation(s)
- Marion Mortamais
- ISGLOBAL, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Pompeu Fabra University, Barcelona, Catalonia, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain; Institut National de la Santé et de la Recherche Médicale U1061, Neuropsychiatry: Epidemiological and Clinical Research, University of Montpellier, Montpellier, France.
| | - Jesus Pujol
- MRI Research Unit, Hospital del Mar, Barcelona, Spain; Centro Investigación Biomédica en Red de Salud Mental, CIBERSAM G21, Barcelona, Spain
| | | | - Raquel Fenoll
- MRI Research Unit, Hospital del Mar, Barcelona, Spain
| | - Christelle Reynes
- University of Montpellier, Montpellier, France; 3 EA 2415, Faculté de Pharmacie, Montpellier, France
| | - Robert Sabatier
- University of Montpellier, Montpellier, France; 3 EA 2415, Faculté de Pharmacie, Montpellier, France
| | - Ioar Rivas
- ISGLOBAL, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Pompeu Fabra University, Barcelona, Catalonia, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain; MRC-PHE Centre for Environment & Health, Environmental Research Group, King's College London, SE1 9NH, London, UK
| | - Joan Forns
- ISGLOBAL, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Pompeu Fabra University, Barcelona, Catalonia, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Natàlia Vilor-Tejedor
- ISGLOBAL, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Pompeu Fabra University, Barcelona, Catalonia, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Silvia Alemany
- ISGLOBAL, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Pompeu Fabra University, Barcelona, Catalonia, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Marta Cirach
- ISGLOBAL, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Pompeu Fabra University, Barcelona, Catalonia, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Mar Alvarez-Pedrerol
- ISGLOBAL, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Pompeu Fabra University, Barcelona, Catalonia, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Mark Nieuwenhuijsen
- ISGLOBAL, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Pompeu Fabra University, Barcelona, Catalonia, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Jordi Sunyer
- ISGLOBAL, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Pompeu Fabra University, Barcelona, Catalonia, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain; Institut Hospital del Mar d'Investigacions Mèdiques-Parc de Salut Mar, Barcelona, Catalonia, Spain
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21
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Mount CW, Yalçın B, Cunliffe-Koehler K, Sundaresh S, Monje M. Monosynaptic tracing maps brain-wide afferent oligodendrocyte precursor cell connectivity. eLife 2019; 8:e49291. [PMID: 31625910 PMCID: PMC6800000 DOI: 10.7554/elife.49291] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 10/06/2019] [Indexed: 12/20/2022] Open
Abstract
Neurons form bona fide synapses with oligodendrocyte precursor cells (OPCs), but the circuit context of these neuron to OPC synapses remains incompletely understood. Using monosynaptically-restricted rabies virus tracing of OPC afferents, we identified extensive afferent synaptic inputs to OPCs residing in secondary motor cortex, corpus callosum, and primary somatosensory cortex of adult mice. These inputs primarily arise from functionally-interconnecting cortical areas and thalamic nuclei, illustrating that OPCs have strikingly comprehensive synaptic access to brain-wide projection networks. Quantification of these inputs revealed excitatory and inhibitory components that are consistent in number across brain regions and stable in barrel cortex despite whisker trimming-induced sensory deprivation.
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Affiliation(s)
- Christopher W Mount
- Department of NeurologyStanford UniversityStanfordUnited States
- Medical Scientist Training ProgramStanford UniversityStanfordUnited States
- Neurosciences Graduate ProgramStanford UniversityStanfordUnited States
| | - Belgin Yalçın
- Department of NeurologyStanford UniversityStanfordUnited States
| | | | - Shree Sundaresh
- Department of NeurologyStanford UniversityStanfordUnited States
| | - Michelle Monje
- Department of NeurologyStanford UniversityStanfordUnited States
- Institute for Stem Cell Biology and Regenerative MedicineStanford UniversityStanfordUnited States
- Department of PathologyStanford UniversityStanfordUnited States
- Department of PediatricsStanford UniversityStanfordUnited States
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22
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Evans TA, Bury LA, Huang AY, Sabo SL. Spatio-temporal dynamics of neocortical presynaptic terminal development using multi-photon imaging of the corpus callosum in vivo. Sci Rep 2019; 9:14028. [PMID: 31575884 PMCID: PMC6773694 DOI: 10.1038/s41598-019-50431-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 09/12/2019] [Indexed: 11/25/2022] Open
Abstract
Within the developing central nervous system, the dynamics of synapse formation and elimination are insufficiently understood. It is ideal to study these processes in vivo, where neurons form synapses within appropriate behavioral and anatomical contexts. In vivo analysis is particularly important for long-range connections, since their development cannot be adequately studied in vitro. The corpus callosum (CC) represents a clinically-relevant long-range connection since several neurodevelopmental diseases involve CC defects. Here, we present a novel strategy for in vivo longitudinal and rapid time-lapse imaging of CC presynaptic terminal development. In postnatal mice, the time-course of CC presynaptic terminal formation and elimination was highly variable between axons or groups of axons. Young presynaptic terminals were remarkably dynamic - moving, dividing to generate more boutons, and merging to consolidate small terminals into large boutons. As synaptic networks matured, presynaptic mobility decreased. These rapid dynamics may be important for establishing initial synaptic contacts with postsynaptic partners, refining connectivity patterns or modifying synapse strength during development. Ultimately, this in vivo imaging approach will facilitate investigation of synapse development in other long-range connections and neurodevelopmental disease models.
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Affiliation(s)
- Teresa A Evans
- Departments of Pharmacology and Neuroscience, Case Western Reserve University School of Medicine, Cleveland, USA
- Department of Pediatrics, Stanford University, Stanford, USA
| | - Luke A Bury
- Departments of Pharmacology and Neuroscience, Case Western Reserve University School of Medicine, Cleveland, USA
| | - Alex Y Huang
- Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, USA
| | - Shasta L Sabo
- Departments of Pharmacology and Neuroscience, Case Western Reserve University School of Medicine, Cleveland, USA.
- Department of Biology, Central Michigan University, Mount Pleasant, USA.
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23
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Drakesmith M, Harms R, Rudrapatna SU, Parker GD, Evans CJ, Jones DK. Estimating axon conduction velocity in vivo from microstructural MRI. Neuroimage 2019; 203:116186. [PMID: 31542512 PMCID: PMC6854468 DOI: 10.1016/j.neuroimage.2019.116186] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 11/19/2022] Open
Abstract
The conduction velocity (CV) of action potentials along axons is a key neurophysiological property central to neural communication. The ability to estimate CV in humans in vivo from non-invasive MRI methods would therefore represent a significant advance in neuroscience. However, there are two major challenges that this paper aims to address: (1) Much of the complexity of the neurophysiology of action potentials cannot be captured with currently available MRI techniques. Therefore, we seek to establish the variability in CV that can be captured when predicting CV purely from parameters that have been reported to be estimatable from MRI: inner axon diameter (AD) and g-ratio. (2) errors inherent in existing MRI-based biophysical models of tissue will propagate through to estimates of CV, the extent to which is currently unknown. Issue (1) is investigated by performing a sensitivity analysis on a comprehensive model of axon electrophysiology and determining the relative sensitivity to various morphological and electrical parameters. The investigations suggest that 85% of the variance in CV is accounted for by variation in AD and g-ratio. The observed dependency of CV on AD and g-ratio is well characterised by the previously reported model by Rushton. Issue (2) is investigated through simulation of diffusion and relaxometry MRI data for a range of axon morphologies, applying models of restricted diffusion and relaxation processes to derive estimates of axon volume fraction (AVF), AD and g-ratio and estimating CV from the derived parameters. The results show that errors in the AVF have the biggest detrimental impact on estimates of CV, particularly for sparse fibre populations (AVF<0.3). For our equipment set-up and acquisition protocol, CV estimates are most accurate (below 5% error) where AVF is above 0.3, g-ratio is between 0.6 and 0.85 and AD is high (above 4μm). CV estimates are robust to errors in g-ratio estimation but are highly sensitive to errors in AD estimation, particularly where ADs are small. We additionally show CV estimates in human corpus callosum in a small number of subjects. In conclusion, we demonstrate accurate CV estimates are possible in regions of the brain where AD is sufficiently large. Problems with estimating ADs for smaller axons presents a problem for estimating CV across the whole CNS and should be the focus of further study.
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Affiliation(s)
- Mark Drakesmith
- Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, United Kingdom; Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom.
| | - Robbert Harms
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands
| | - Suryanarayana Umesh Rudrapatna
- Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, United Kingdom; Phillips Inovation Campus, Bangalore, India
| | - Greg D Parker
- Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, United Kingdom; Experimental MRI Centre (EMRIC), School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - C John Evans
- Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, United Kingdom; Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
| | - Derek K Jones
- Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, United Kingdom; Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom; Mary McKillop Institute for Health Research, Faculty of Health Sciences, Australian Catholic University, Melbourne, Victoria, 3065, Australia
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24
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Skumlien M, Sederevicius D, Fjell AM, Walhovd KB, Westerhausen R. Parallel but independent reduction of emotional awareness and corpus callosum connectivity in older age. PLoS One 2018; 13:e0209915. [PMID: 30596756 PMCID: PMC6312250 DOI: 10.1371/journal.pone.0209915] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 12/13/2018] [Indexed: 11/19/2022] Open
Abstract
Differential functional specialization of the left and right hemispheres for linguistic and emotional functions, respectively, suggest that interhemispheric communication via the corpus callosum is critical for emotional awareness. Accordingly, it has been hypothesized that the age-related decline in callosal connectivity mediates the frequently demonstrated reduction in emotional awareness in older age. The present study tests this hypothesis in a sample of 307 healthy individuals between 20-89 years using combined structural and diffusion-tensor magnetic resonance imaging (MRI) of the corpus callosum. As assumed, inter-hemispheric connectivity (midsagittal callosal area and thickness, as well as fractional anisotropy, FA) and emotional awareness (i.e., increase in externally-oriented thinking, EOT; assessed with the Toronto Alexithymia Scale, TAS-20) were found to be reduced in older (> 60 years) compared to younger participants. Furthermore, relating callosal measures to emotional awareness, FA in the genu of the corpus callosum was found to be negatively correlated with EOT in male participants. Thus, "stronger" structural connectivity (higher FA) was related with higher emotional awareness (lower EOT). However, a formal mediation analysis did not support the notion that age-related decline in emotional awareness is mediated by the corpus callosum. Thus, the observed reduction of emotional awareness and callosal connectivity in older age likely reflects parallel but not inter-dependent processes.
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Affiliation(s)
- Martine Skumlien
- Center for Lifespan Changes in Brain and Cognition (LCBC), Department of Psychology, University of Oslo, Oslo, Norway
| | - Donatas Sederevicius
- Center for Lifespan Changes in Brain and Cognition (LCBC), Department of Psychology, University of Oslo, Oslo, Norway
| | - Anders M. Fjell
- Center for Lifespan Changes in Brain and Cognition (LCBC), Department of Psychology, University of Oslo, Oslo, Norway
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Kristine B. Walhovd
- Center for Lifespan Changes in Brain and Cognition (LCBC), Department of Psychology, University of Oslo, Oslo, Norway
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - René Westerhausen
- Center for Lifespan Changes in Brain and Cognition (LCBC), Department of Psychology, University of Oslo, Oslo, Norway
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway
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25
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Suárez R, Paolino A, Fenlon LR, Morcom LR, Kozulin P, Kurniawan ND, Richards LJ. A pan-mammalian map of interhemispheric brain connections predates the evolution of the corpus callosum. Proc Natl Acad Sci U S A 2018; 115:9622-9627. [PMID: 30181276 PMCID: PMC6156618 DOI: 10.1073/pnas.1808262115] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The brain of mammals differs from that of all other vertebrates, in having a six-layered neocortex that is extensively interconnected within and between hemispheres. Interhemispheric connections are conveyed through the anterior commissure in egg-laying monotremes and marsupials, whereas eutherians evolved a separate commissural tract, the corpus callosum. Although the pattern of interhemispheric connectivity via the corpus callosum is broadly shared across eutherian species, it is not known whether this pattern arose as a consequence of callosal evolution or instead corresponds to a more ancient feature of mammalian brain organization. Here we show that, despite cortical axons using an ancestral commissural route, monotremes and marsupials share features of interhemispheric connectivity with eutherians that likely predate the origin of the corpus callosum. Based on ex vivo magnetic resonance imaging and tractography, we found that connections through the anterior commissure in both fat-tailed dunnarts (Marsupialia) and duck-billed platypus (Monotremata) are spatially segregated according to cortical area topography. Moreover, cell-resolution retrograde and anterograde interhemispheric circuit mapping in dunnarts revealed several features shared with callosal circuits of eutherians. These include the layered organization of commissural neurons and terminals, a broad map of connections between similar (homotopic) regions of each hemisphere, and regions connected to different areas (heterotopic), including hyperconnected hubs along the medial and lateral borders of the cortex, such as the cingulate/motor cortex and claustrum/insula. We therefore propose that an interhemispheric connectome originated in early mammalian ancestors, predating the evolution of the corpus callosum. Because these features have been conserved throughout mammalian evolution, they likely represent key aspects of neocortical organization.
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Affiliation(s)
- Rodrigo Suárez
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4070, Australia;
| | - Annalisa Paolino
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4070, Australia
| | - Laura R Fenlon
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4070, Australia
| | - Laura R Morcom
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4070, Australia
| | - Peter Kozulin
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4070, Australia
| | - Nyoman D Kurniawan
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD 4070, Australia
| | - Linda J Richards
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4070, Australia;
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4070, Australia
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26
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Chang CL, Chiu NC, Yang YC, Ho CS, Hung KL. Normal Development of the Corpus Callosum and Evolution of Corpus Callosum Sexual Dimorphism in Infancy. J Ultrasound Med 2018; 37:869-877. [PMID: 28990212 DOI: 10.1002/jum.14420] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/16/2017] [Accepted: 07/05/2017] [Indexed: 06/07/2023]
Abstract
OBJECTIVES The aim of this study was to establish reference ranges for the corpus callosum in infancy and to clarify how sexual dimorphism evolves between the fetal stage and infancy. METHODS Normal sonograms from cerebral ultrasonographic examinations of 1- to 6-month-old healthy full-term infants were selected. The length and thickness of the corpus callosum were determined, and the effect of sex on these values was analyzed. Studies on corpus callosum sexual dimorphism were reviewed. RESULTS In total, sonograms from 236 1- to 6-month-old infants (120 male and 116 female) were collected, and the typical values (5th-95th percentiles) of the corpus callosum were determined for each group. During the first 2 months, with and without brain size adjustment, the corpus callosum in female infants was significantly thicker than that in male infants (mean thickness ± SD: 1 month, male infant, 1.8 ± 0.3 mm; female infant, 2.1 ± 0.3 mm; P = .005; 2 months, male infant, 1.8 ± 0.2 mm; female infant, 2.0 ± 0.3 mm; P = .002). The corpus callosum thickness of male and female infants had no significant differences after 2 months of age. Sexual dimorphism was not detected in corpus callosum length. CONCLUSIONS Our study provides reference data on typical corpus callosum development in infants. In the fetal period and early infancy, the corpus callosum in female infants is thicker than that in male infants. From 3 months onward, the corpus callosum sexual dimorphism becomes insignificant throughout childhood. The evolvement of corpus callosum sexual dimorphism suggests that maternal factors may influence brain development.
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Affiliation(s)
- Chaw-Liang Chang
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan
- Department of Pediatrics, Cathay General Hospital, Hsinchu, Taiwan
- Department of Center for Medical Education and Research, Cathay General Hospital, Hsinchu, Taiwan
| | - Nan-Chang Chiu
- Department of Pediatrics, MacKay Children's Hospital, Taipei, Taiwan
- Department of Pediatrics, Mackay Junior College of Medicine, Nursing, and Management, New Taipei City, Taiwan Department of Pediatrics (K.-L.H.), Cathay General Hospital, Taipei, Taiwan
| | - Yi-Chen Yang
- Department of Center for Medical Education and Research, Cathay General Hospital, Hsinchu, Taiwan
| | - Che-Sheng Ho
- Department of Pediatrics, MacKay Children's Hospital, Taipei, Taiwan
- Department of Pediatrics, Mackay Junior College of Medicine, Nursing, and Management, New Taipei City, Taiwan Department of Pediatrics (K.-L.H.), Cathay General Hospital, Taipei, Taiwan
| | - Kun-Long Hung
- Department of Pediatrics, Cathay General Hospital, Hsinchu, Taiwan
- Department of Pediatrics School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
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27
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Iordanova B, Vazquez A, Kozai TDY, Fukuda M, Kim SG. Optogenetic investigation of the variable neurovascular coupling along the interhemispheric circuits. J Cereb Blood Flow Metab 2018; 38:627-640. [PMID: 29372655 PMCID: PMC5888863 DOI: 10.1177/0271678x18755225] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 01/03/2018] [Indexed: 12/13/2022]
Abstract
The interhemispheric circuit connecting the left and the right mammalian brain plays a key role in integration of signals from the left and the right side of the body. The information transfer is carried out by modulation of simultaneous excitation and inhibition. Hemodynamic studies of this circuit are inconsistent since little is known about neurovascular coupling of mixed excitatory and inhibitory signals. We investigated the variability in hemodynamic responses driven by the interhemispheric circuit during optogenetic and somatosensory activation. We observed differences in the neurovascular response based on the stimulation site - cell bodies versus distal projections. In half of the experiments, optogenetic stimulation of the cell bodies evoked a predominant post-synaptic inhibition in the other hemisphere, accompanied by metabolic oxygen consumption without coupled functional hyperemia. When the same transcallosal stimulation resulted in predominant post-synaptic excitation, the hemodynamic response was biphasic, consisting of metabolic dip followed by functional hyperemia. Optogenetic suppression of the postsynaptic excitation abolished the coupled functional hyperemia. In contrast, light stimulation at distal projections evoked consistently a metabolic response. Our findings suggest that functional hyperemia requires signals originating from the cell body and the hemodynamic response variability appears to reflect the balance between the post-synaptic excitation and inhibition.
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Affiliation(s)
- Bistra Iordanova
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alberto Vazquez
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Takashi DY Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mitsuhiro Fukuda
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Seong-Gi Kim
- Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Korea
- Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea
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28
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Katagiri N, Pantelis C, Nemoto T, Tsujino N, Saito J, Hori M, Yamaguchi T, Funatogawa T, Mizuno M. Symptom recovery and relationship to structure of corpus callosum in individuals with an 'at risk mental state'. Psychiatry Res Neuroimaging 2018; 272:1-6. [PMID: 29232635 DOI: 10.1016/j.pscychresns.2017.11.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 11/09/2017] [Accepted: 11/22/2017] [Indexed: 01/14/2023]
Abstract
Previous studies have revealed that changes in sub-threshold psychotic symptoms observed in individuals with an 'at risk mental state' (ARMS) are associated with biological changes in the corpus callosum (CC). To elucidate the biological background for resilience against transition to psychosis, we investigated the relationship between CC structural changes and recovery of sub-threshold psychotic symptom in subjects with ARMS who did not develop psychosis (ARMS-N). Sixteen healthy controls and 42 ARMS (37 ARMS-N) subjects participated this study. The volumes of five sub-regions of the CC were analyzed using MRI. The sub-threshold psychotic symptoms of the ARMS were measured using the Scale of Prodromal Symptoms (SOPS). Imaging and symptoms were re-administered in the ARMS group 52 weeks later. Significant baseline volume differences in the mid-posterior CC, central CC and mid-anterior CC were found between the controls and the ARMS-N subjects. These findings suggest that biological abnormalities are present in a so-called "false-positive" group of individuals. For the ARMS-N subjects, improvement in negative symptoms significantly correlated with an increase in the volume of the central CC at follow-up. This finding may suggest that a neurobiological 'resilience' is associated with symptom recovery.
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Affiliation(s)
- Naoyuki Katagiri
- Department of Neuropsychiatry, School of Medicine, Toho University, Tokyo, Japan.
| | - Christos Pantelis
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne & Melbourne Health, South Carlton, Victoria, Australia; Centre for Neural Engineering, Department of Electrical and Electronic Engineering, University of Melbourne, Carlton South, Victoria, Australia
| | - Takahiro Nemoto
- Department of Neuropsychiatry, School of Medicine, Toho University, Tokyo, Japan
| | - Naohisa Tsujino
- Department of Neuropsychiatry, School of Medicine, Toho University, Tokyo, Japan
| | - Junichi Saito
- Department of Neuropsychiatry, School of Medicine, Toho University, Tokyo, Japan
| | - Masaaki Hori
- Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan
| | - Taiju Yamaguchi
- Department of Neuropsychiatry, School of Medicine, Toho University, Tokyo, Japan
| | - Tomoyuki Funatogawa
- Department of Neuropsychiatry, School of Medicine, Toho University, Tokyo, Japan
| | - Masafumi Mizuno
- Department of Neuropsychiatry, School of Medicine, Toho University, Tokyo, Japan
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Liang JG, Kim NY, Ko A, Kim HD, Lee D. Changes in functional brain network topology after successful and unsuccessful corpus callosotomy for Lennox-Gastaut Syndrome. Sci Rep 2018; 8:3414. [PMID: 29467376 PMCID: PMC5821858 DOI: 10.1038/s41598-018-21764-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 02/09/2018] [Indexed: 12/16/2022] Open
Abstract
Corpus callosotomy (CC) is an effective palliative surgical treatment for patients with Lennox-Gastaut Syndrome (LGS). However, research on the long-term functional effects of CC is sparse. We aimed to investigate these effects and their associated clinical conditions over the two years after CC. Long-term clinical EEG recordings of 30 patients with LGS who had good and bad seizure outcome after CC were collected and retrospectively studied. It was found that CC caused brain network 'hubs' to shift from paramedian to lateral regions in the good-recovery group, which reorganized the brain network into a more homogeneous state. We also found increased local clustering coefficients in patients with bad outcomes and decreases, implying enhanced network integration, in patients with good outcomes. The small worldness of brain networks in patients with good outcomes increased in the two years after CC, whereas it decreased in patients with bad outcomes. The covariation of small-worldness with the rate of reduction in seizure frequency suggests that this can be used as an indicator of CC outcome. Local and global network changes during the long-term state might be associated with the postoperative recovery process and could serve as indicators for CC outcome and long-term LGS recovery.
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Affiliation(s)
- Jun-Ge Liang
- RFIC Center, Kwangwoon University, Seoul, Republic of Korea
| | - Nam-Young Kim
- RFIC Center, Kwangwoon University, Seoul, Republic of Korea.
| | - Ara Ko
- Department of Pediatrics, Pediatric Epilepsy Clinic, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Heung Dong Kim
- Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
- Department of Pediatrics, Pediatric Epilepsy Clinic, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
| | - Dongpyo Lee
- Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
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Abstract
Cognition is supported by a network of axonal connections between gray matter regions within and between right and left cerebral cortex. Global organizing principles of this circuitry were examined with network analysis tools applied to monosynaptic association (within one side) and commissural (between sides) connections between all 77 cortical gray matter regions in each hemisphere of the rat brain. The analysis used 32,350 connection reports expertly collated from published pathway tracing experiments, and 5,394 connections of a possible 23,562 were identified, for a connection density of 23%-of which 20% (1,084) were commissural. Network community detection yielded a stable bihemispheric six-module solution, with an identical set in each hemisphere of three modules topographically forming a lateral core and medial shell arrangement of cortical regions. Functional correlations suggest the lateral module deals preferentially with environmental sensory-motor interactions and the ventromedial module deals preferentially with visceral control, affect, and short-term memory, whereas the dorsomedial module resembles the default mode network. Analysis of commissural connections revealed a set of unexpected rules to help generate hypotheses. Most notably, there is an order of magnitude more heterotopic than homotopic projections; all cortical regions send more association than commissural connections, and for each region, the latter are always a subset of the former; the number of association connections from each cortical region strongly correlates with the number of its commissural connections; and the module (dorsomedial) lying closest to the corpus callosum has the most complete set of commissural connections-and apparently the most complex function.
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Affiliation(s)
- Larry W Swanson
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089;
| | - Joel D Hahn
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089
| | - Olaf Sporns
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405
- Indiana University Network Science Institute, Indiana University, Bloomington, IN 47405
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31
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Ferizi U, Scherrer B, Schneider T, Alipoor M, Eufracio O, Fick RH, Deriche R, Nilsson M, Loya‐Olivas AK, Rivera M, Poot DH, Ramirez‐Manzanares A, Marroquin JL, Rokem A, Pötter C, Dougherty RF, Sakaie K, Wheeler‐Kingshott C, Warfield SK, Witzel T, Wald LL, Raya JG, Alexander DC. Diffusion MRI microstructure models with in vivo human brain Connectome data: results from a multi-group comparison. NMR Biomed 2017. [PMID: 28643354 PMCID: PMC5563694 DOI: 10.1002/nbm.3734] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A large number of mathematical models have been proposed to describe the measured signal in diffusion-weighted (DW) magnetic resonance imaging (MRI). However, model comparison to date focuses only on specific subclasses, e.g. compartment models or signal models, and little or no information is available in the literature on how performance varies among the different types of models. To address this deficiency, we organized the 'White Matter Modeling Challenge' during the International Symposium on Biomedical Imaging (ISBI) 2015 conference. This competition aimed to compare a range of different kinds of models in their ability to explain a large range of measurable in vivo DW human brain data. Specifically, we assessed the ability of models to predict the DW signal accurately for new diffusion gradients and b values. We did not evaluate the accuracy of estimated model parameters, as a ground truth is hard to obtain. We used the Connectome scanner at the Massachusetts General Hospital, using gradient strengths of up to 300 mT/m and a broad set of diffusion times. We focused on assessing the DW signal prediction in two regions: the genu in the corpus callosum, where the fibres are relatively straight and parallel, and the fornix, where the configuration of fibres is more complex. The challenge participants had access to three-quarters of the dataset and their models were ranked on their ability to predict the remaining unseen quarter of the data. The challenge provided a unique opportunity for a quantitative comparison of diverse methods from multiple groups worldwide. The comparison of the challenge entries reveals interesting trends that could potentially influence the next generation of diffusion-based quantitative MRI techniques. The first is that signal models do not necessarily outperform tissue models; in fact, of those tested, tissue models rank highest on average. The second is that assuming a non-Gaussian (rather than purely Gaussian) noise model provides little improvement in prediction of unseen data, although it is possible that this may still have a beneficial effect on estimated parameter values. The third is that preprocessing the training data, here by omitting signal outliers, and using signal-predicting strategies, such as bootstrapping or cross-validation, could benefit the model fitting. The analysis in this study provides a benchmark for other models and the data remain available to build up a more complete comparison in the future.
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Affiliation(s)
- Uran Ferizi
- Centre for Medical Image ComputingDepartment of Computer Science, University College LondonUK
- Department of RadiologyNew York University School of MedicineUSA
- Department of Neuroinflammation, Institute of NeurologyUniversity College LondonUK
| | - Benoit Scherrer
- Computational Radiology Laboratory, Boston Children's Hosp.Harvard UniversityUSA
| | - Torben Schneider
- Department of Neuroinflammation, Institute of NeurologyUniversity College LondonUK
- Philips HealthcareGuildfordSurreyUK
| | | | - Odin Eufracio
- Centro de Investigacion en Matematicas ACGuanajuatoMexico
| | | | - Rachid Deriche
- Athena Project‐TeamINRIA Sophia Antipolis ‐ MéditerranéeFrance
| | | | | | - Mariano Rivera
- Centro de Investigacion en Matematicas ACGuanajuatoMexico
| | - Dirk H.J. Poot
- Erasmus Medical Center and Delft University of Technologythe Netherlands
| | | | | | - Ariel Rokem
- eScience InstituteUniversity of WashingtonUSA
- Center for Cognitive and Neurobiological ImagingStanford UniversityUSA
| | - Christian Pötter
- Center for Cognitive and Neurobiological ImagingStanford UniversityUSA
| | | | - Ken Sakaie
- Imaging InstituteThe Cleveland ClinicClevelandUSA
| | | | - Simon K. Warfield
- Computational Radiology Laboratory, Boston Children's Hosp.Harvard UniversityUSA
| | - Thomas Witzel
- A.A. Martinos Center for Biomedical Imaging, MGHHarvard UniversityUSA
| | - Lawrence L. Wald
- A.A. Martinos Center for Biomedical Imaging, MGHHarvard UniversityUSA
| | - José G. Raya
- Department of RadiologyNew York University School of MedicineUSA
| | - Daniel C. Alexander
- Centre for Medical Image ComputingDepartment of Computer Science, University College LondonUK
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Nagy B, Hovhannisyan A, Barzan R, Chen TJ, Kukley M. Different patterns of neuronal activity trigger distinct responses of oligodendrocyte precursor cells in the corpus callosum. PLoS Biol 2017; 15:e2001993. [PMID: 28829781 PMCID: PMC5567905 DOI: 10.1371/journal.pbio.2001993] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 07/18/2017] [Indexed: 12/28/2022] Open
Abstract
In the developing and adult brain, oligodendrocyte precursor cells (OPCs) are influenced by neuronal activity: they are involved in synaptic signaling with neurons, and their proliferation and differentiation into myelinating glia can be altered by transient changes in neuronal firing. An important question that has been unanswered is whether OPCs can discriminate different patterns of neuronal activity and respond to them in a distinct way. Here, we demonstrate in brain slices that the pattern of neuronal activity determines the functional changes triggered at synapses between axons and OPCs. Furthermore, we show that stimulation of the corpus callosum at different frequencies in vivo affects proliferation and differentiation of OPCs in a dissimilar way. Our findings suggest that neurons do not influence OPCs in “all-or-none” fashion but use their firing pattern to tune the response and behavior of these nonneuronal cells. Oligodendrocytes are glial cells of the central nervous system. One of their major tasks is to enwrap neuronal axons with myelin, providing electrical insulation of axons and a dramatic increase in the speed of nerve impulse propagation. Oligodendrocytes develop from oligodendrocyte precursor cells (OPCs). Self-renewal of OPCs, their differentiation into oligodendrocytes, and the process of myelin synthesis are influenced by neuronal activity. Furthermore, OPCs receive glutamatergic synaptic input from neurons. Neuronal activity in vivo is highly variable depending on the brain region, input stimulus, and/or behavioral task that an animal or human has to perform in everyday life. Therefore, it is important to understand whether different types of neuronal activity affect development and function of oligodendrocyte lineage cells in a distinct way. In this study, we demonstrate that the amount and the timing of glutamate release at synapses between neurons and OPCs, the properties of the subsequent ionic current through glutamate receptors in OPC membrane, as well as the extent of OPCs’ self-renewal and differentiation into oligodendrocytes differ depending on the frequency and duration of neuronal activity. Hence, the pattern of neuronal activity rather than just presence or absence of activity is an important parameter that determines development and function of oligodendroglial cells.
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Affiliation(s)
- Balint Nagy
- Group of Neuron Glia Interaction, Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
- * E-mail: (MK); (BN)
| | - Anahit Hovhannisyan
- Group of Neuron Glia Interaction, Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Ruxandra Barzan
- Group of Neuron Glia Interaction, Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Ting-Jiun Chen
- Group of Neuron Glia Interaction, Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Maria Kukley
- Group of Neuron Glia Interaction, Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- * E-mail: (MK); (BN)
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Martino D, Delorme C, Pelosin E, Hartmann A, Worbe Y, Avanzino L. Abnormal lateralization of fine motor actions in Tourette syndrome persists into adulthood. PLoS One 2017; 12:e0180812. [PMID: 28708864 PMCID: PMC5510833 DOI: 10.1371/journal.pone.0180812] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/21/2017] [Indexed: 12/14/2022] Open
Abstract
Youth with Tourette syndrome (TS) exhibit, compared to healthy, abnormal ability to lateralize digital sequential tasks. It is unknown whether this trait is related to inter-hemispheric connections, and whether it is preserved or lost in patients with TS persisting through adult life. We studied 13 adult TS patients and 15 age-matched healthy volunteers. All participants undertook: 1) a finger opposition task, performed with the right hand (RH) only or with both hands, using a sensor-engineered glove in synchrony with a metronome at 2 Hz; we calculated a lateralization index [(single RH-bimanual RH)/single RH X 100) for percentage of correct movements (%CORR); 2) MRI-based diffusion tensor imaging and probabilistic tractography of inter-hemispheric corpus callosum (CC) connections between supplementary motor areas (SMA) and primary motor cortices (M1). We confirmed a significant increase in the %CORR in RH in the bimanual vs. single task in TS patients (p<0.001), coupled to an abnormal ability to lateralize finger movements (significantly lower lateralization index for %CORR in TS patients, p = 0.04). The %CORR lateralization index correlated positively with tic severity measured with the Yale Global Tic Severity Scale (R = 0.55;p = 0.04). We detected a significantly higher fractional anisotropy (FA) in both the M1-M1 (p = 0.036) and the SMA-SMA (p = 0.018) callosal fibre tracts in TS patients. In healthy subjects, the %CORR lateralization index correlated positively with fractional anisotropy of SMA-SMA fibre tracts (R = 0.63, p = 0.02); this correlation was not significant in TS patients. TS patients exhibited an abnormal ability to lateralize finger movements in sequential tasks, which increased in accuracy when the task was performed bimanually. This abnormality persists throughout different age periods and appears dissociated from the transcallosal connectivity of motor cortical regions. The altered interhemispheric transfer of motor abilities in TS may be the result of compensatory processes linked to self-regulation of motor control.
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Affiliation(s)
- D. Martino
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
| | - C. Delorme
- UMR S 975, CNRS UMR 7225, ICM, Sorbonne Universités, UPMC University Paris 06, Paris, France
- Department of Neurology, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, 47–83 boulevard de l'Hôpital, Paris, France, and French National Reference Centre for Gilles de la Tourette Syndrome, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - E. Pelosin
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal Child Health, University of Genoa Genoa, Italy
| | - A. Hartmann
- UMR S 975, CNRS UMR 7225, ICM, Sorbonne Universités, UPMC University Paris 06, Paris, France
- Department of Neurology, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, 47–83 boulevard de l'Hôpital, Paris, France, and French National Reference Centre for Gilles de la Tourette Syndrome, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - Y. Worbe
- UMR S 975, CNRS UMR 7225, ICM, Sorbonne Universités, UPMC University Paris 06, Paris, France
- Department of Neurology, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, 47–83 boulevard de l'Hôpital, Paris, France, and French National Reference Centre for Gilles de la Tourette Syndrome, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
- Department of Neurophysiology, Saint-Antoine Hospital, Paris, France
| | - L. Avanzino
- Section of Human Physiology and Centro Polifunzionale di Scienze Motorie, Department of Experimental Medicine, University of Genoa Genoa, Italy
- * E-mail:
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Sun X, Song S, Liang X, Xie Y, Zhao C, Zhang Y, Shu H, Gong G. ROBO1 polymorphisms, callosal connectivity, and reading skills. Hum Brain Mapp 2017; 38:2616-2626. [PMID: 28240421 PMCID: PMC6866921 DOI: 10.1002/hbm.23546] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 02/10/2017] [Accepted: 02/10/2017] [Indexed: 11/10/2022] Open
Abstract
The genetic effects on specific behavioral phenotypes are putatively mediated by specific neural functions. It remains unexplored how the axon-guidance-receptor gene ROBO1 influences reading performance through the neural system despite the identification of ROBO1 as a susceptibility gene for dyslexia. To address this issue, the present study recruited a group of children with a wide range of reading abilities. Two previously identified reading-related ROBO1 polymorphisms were genotyped, and diffusion and structural MRI were acquired to measure the fiber microstructure of the corpus callosum (CC), the major white-matter tract that connects inter-hemispheric cortical regions. The results confirmed the significant influence of the ROBO1 polymorphisms on reading scores. The fiber microstructures of the midline-CC segments around the genu and splenium were also affected by the ROBO1 polymorphisms. Moreover, a mediation analysis further revealed that the genu could significantly mediate the effects of the ROBO1 polymorphisms on word-list reading performance, which suggests a ROBO1-to-genu-to-reading pathway. The genu-linked cortical morphology, however, was not associated with either the ROBO1 polymorphisms or reading performance. These findings offer direct evidence supporting ROBO1-callosum association in humans and also provide valuable insight into the functions of ROBO1 and the gene-to-brain mechanisms that underlie human reading. Hum Brain Mapp 38:2616-2626, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Xiaochen Sun
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain ResearchBeijing Normal UniversityBeijing100875China
| | - Shuang Song
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain ResearchBeijing Normal UniversityBeijing100875China
| | - Xinyu Liang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain ResearchBeijing Normal UniversityBeijing100875China
| | - Yachao Xie
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain ResearchBeijing Normal UniversityBeijing100875China
| | - Chenxi Zhao
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain ResearchBeijing Normal UniversityBeijing100875China
| | - Yuping Zhang
- Department of PsychologyChengdu Medical CollegeChengdu610550China
| | - Hua Shu
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain ResearchBeijing Normal UniversityBeijing100875China
| | - Gaolang Gong
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain ResearchBeijing Normal UniversityBeijing100875China
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35
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Hopkins WD, Hopkins AM, Misiura M, Latash EM, Mareno MC, Schapiro SJ, Phillips KA. Sex differences in the relationship between planum temporale asymmetry and corpus callosum morphology in chimpanzees (Pan troglodytes): A combined MRI and DTI analysis. Neuropsychologia 2016; 93:325-334. [PMID: 27055947 PMCID: PMC5050170 DOI: 10.1016/j.neuropsychologia.2016.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 02/23/2016] [Accepted: 04/03/2016] [Indexed: 12/31/2022]
Abstract
Increases brain size has been hypothesized to be inversely associated with the expression of behavioral and brain asymmetries within and between species. We tested this hypothesis by analyzing the relation between asymmetries in the planum temporale (PT) and different measures of the corpus callosum (CC) including surface area, streamline count as measured from diffusion tensor imaging, fractional anisotropy values and the ratio in the number of fibers to surface area in a sample of chimpanzees. We found that chimpanzees with larger PT asymmetries in absolute terms had smaller CC surface areas, fewer streamlines and a smaller ratio of fibers to surface area. These results were largely specific to male but not female chimpanzees. Our results partially support the hypothesis that brain asymmetries are linked to variation in corpus callosum morphology, although these associations may be sex-dependent.
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Affiliation(s)
- William D Hopkins
- Neuroscience Institute and Language Research Center, Georgia State University, Atlanta, GA 30302, USA; Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30329, USA.
| | - Anna M Hopkins
- Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30329, USA
| | - Maria Misiura
- Department of Psychology, Georgia State University, Atlanta, GA 30302, USA
| | - Elitaveta M Latash
- Neuroscience Institute and Language Research Center, Georgia State University, Atlanta, GA 30302, USA
| | - Mary Catherine Mareno
- Department of Veterinary Science, The University of Texas MD Anderson Cancer Center, Bastrop, TX 78602, USA
| | - Steven J Schapiro
- Department of Veterinary Science, The University of Texas MD Anderson Cancer Center, Bastrop, TX 78602, USA
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Deng Y, Han Q, Shen F, Chen M, Zeng H. [Effect of axonal developmental disorders in the corpus callosum on the neurological function after birth in septic neonatal rats]. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue 2016; 28:683-7. [PMID: 27434556 DOI: 10.3760/cma.j.issn.2095-4352.2016.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To observe the axonal development in the corpus callosum of septic neonatal rats, and its effect on the neurological function after birth. METHODS Forty-eight 1-day-old Sprague-Dawley (SD) rats were randomly divided into two groups: control group and sepsis group, with 24 rats in each group. The rat model of sepsis was reproduced by intraperitoneal injection of 1 mg/kg lipopolysaccharide (LPS), and the rats in control group were injected with an equal volume of phosphate buffered saline (PBS). The corpus callosum in brain was harvested at 7, 14, and 28 days after model reproduction, and double immunofluorescence staining and Western Blot were used to observe the expression of neurofilament heavy chain (NFH), neurofilament medium chain (NFM) and neurofilament light chain (NFL) in the corpus callosum. The morphology and number of axon were observed in the corpus callosum of rats at 28 days using electron microscopy. The number of myelin basic protein (MBP) positive cells in the corpus callosum of rats was determined by in situ hybridization. RESULTS The immunofluorescence intensities of NFH, NFM, and NFL in the corpus callosum of rats at 7, 14, and 28 days after model reproduction in sepsis group were significantly lower than those of control group. In addition, it was revealed by Western Blot results that the protein expression levels of NFH, NFM, and NFL in sepsis group were significantly lower than those of control group [NFH (gray value): 0.16±0.03 vs. 0.34±0.04 at 7 days, 1.75±0.11 vs. 2.42±0.17 at 14 days, 3.39±0.25 vs. 5.11±0.23 at 28 days; NFM (gray value): 0.34±0.04 vs. 0.53±0.04 at 7 days, 0.74±0.04 vs. 1.12±0.07 at 14 days, 0.92±0.06 vs. 1.52±0.07 at 28 days; NFL (gray value): 0.12±0.02 vs. 0.26±0.14 at 7 days, 0.32±0.03 vs. 0.81±0.04 at 14 days, 0.85±0.08 vs. 1.81±0.05 at 28 days; P < 0.05 or P <0.01]. In the control group, an obvious myelination was found in the corpus callosum of rats on the 28th day after the birth, and the nodes of Ranvier were clearly distinguishable, with intact structure and smooth edges. The number of myelinated axons was reduced and the nodes of Ranvier were impaired in the corpus callosum of rats at 28 days after LPS injection. The expression of MBP in the corpus callosum of rats at 28 days after LPS injection was obviously decreased compared with control group (cells/LP: 23.67±3.21 vs. 35.00±3.61, P < 0.01). CONCLUSIONS The axonal development in the corpus callosum of septic neonatal rats on the 28th day after the birth was impaired, and lead to reduced myelination and further deterioration of neurological function.
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Affiliation(s)
- Yiyu Deng
- Department of Critical Care and Emergency, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, Guangdong, China (Deng YY, Han QP, Chen MM, Zeng HK); Department of Rheumatology, the First Affiliated Hospital, Shantou University Medical College, Shantou 515000, Guangdong, China (Shen FC). Corresponding author: Deng Yiyu,
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Abstract
The organisational and architectural configuration of white matter pathways connecting brain regions has ramifications for all facets of the human condition, including manifestations of incipient neurodegeneration. Although diffusion tensor imaging (DTI) has been used extensively to visualise white matter connectivity, due to the widespread presence of crossing fibres, the lateral projections of the corpus callosum are not normally detected using this methodology. Detailed knowledge of the transcallosal connectivity of the human cortical motor network has, therefore, remained elusive. We employed constrained spherical deconvolution (CSD) tractography—an approach that is much less susceptible to the influence of crossing fibres, in order to derive complete in vivo characterizations of white matter pathways connecting specific motor cortical regions to their counterparts and other loci in the opposite hemisphere. The revealed patterns of connectivity closely resemble those derived from anatomical tracing in primates. It was established that dorsal premotor cortex (PMd) and supplementary motor area (SMA) have extensive interhemispheric connectivity—exhibiting both dense homologous projections, and widespread structural relations with every other region in the contralateral motor network. Through this in vivo portrayal, the importance of non-primary motor regions for interhemispheric communication is emphasised. Additionally, distinct connectivity profiles were detected for the anterior and posterior subdivisions of primary motor cortex. The present findings provide a comprehensive representation of transcallosal white matter projections in humans, and have the potential to inform the development of models and hypotheses relating structural and functional brain connectivity.
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Affiliation(s)
- Kathy L Ruddy
- School of Psychology, Queen's University Belfast, Belfast, BT7 1NN, UK.
- Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, Dublin, Ireland.
- Neural Control of Movement Lab, Department of Health Sciences and Technology, ETH Zurich, Y36 M 12, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
| | - Alexander Leemans
- Image Sciences Institute, University Medical Center Utrecht, 85500, Utrecht, The Netherlands
| | - Richard G Carson
- School of Psychology, Queen's University Belfast, Belfast, BT7 1NN, UK
- Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, Dublin, Ireland
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Moshrefi-Ravasdjani B, Dublin P, Seifert G, Jennissen K, Steinhäuser C, Kafitz KW, Rose CR. Changes in the proliferative capacity of NG2 cell subpopulations during postnatal development of the mouse hippocampus. Brain Struct Funct 2016; 222:831-847. [PMID: 27306788 DOI: 10.1007/s00429-016-1249-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/05/2016] [Indexed: 12/29/2022]
Abstract
Besides astrocytes and oligodendrocytes, NG2 proteoglycan-expressing cells (NG2 glia) represent a third subtype of macroglia in the brain. Originally described as oligodendrocyte precursor cells, they feature several characteristics not expected from mere progenitor cells, including synaptic connections with neurons. There is accumulating evidence that the properties of NG2 glia differ between different brain regions and developmental stages. To further analyze this proposed heterogeneity, we studied electrophysiological properties, transcript and protein expression, distribution and proliferative capacity of NG2 glia during postnatal development, focusing on the hippocampus and corpus callosum. All NG2 glia displayed a 'complex' current pattern consisting of voltage- and time-dependent in- and outward currents. In juvenile mice, Kir current densities and rectification index were highly variable and on average significantly lower than in adult animals. Single cell RT-PCR analyses of electrophysiologically characterized cells demonstrated that different glial genes were expressed at variable extent, independent of developmental stage and genetic background. In the hippocampus proper and the corpus callosum, the density of NG2 glia was highest at postnatal days (P)10-12, decreased by ~50 % at P25-35 and then remained stable in adults (P80-90). Interestingly, co-expression of NG2 and S100β, a marker for mature astrocytes, increased from 7 % at P10-12 to 27 % at P25-35 in the hippocampus proper, and then dropped again in the stratum radiatum at P80-90. In the dentate gyrus and corpus callosum, co-expression of NG2 and S100β was very low (3 %) and constant throughout development. Age-related differences were also observed with Ki-67, a proliferation marker. In NG2 glia of the CA1 region, its expression decreased from 16 % at P10-12 to 9 % (P25-35) and then 3 % (P80-90). Triple-stainings revealed that Ki-67 was also expressed in 2-3 % of NG2/S100β-positive cells in the juvenile and mature stratum radiatum, indicating that the latter, in contrast to S100β-positive astrocytes, still host proliferative potential. Taken together, we found significant differences in transcript and protein expression, electrophysiological properties and proliferative capacity of NG2 glia in the mouse forebrain, suggesting the co-existence of several subpopulations of NG2 glia. Our data thus support the idea of a substantial regional and developmental heterogeneity in this subtype of macroglia.
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Affiliation(s)
| | - Pavel Dublin
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Gerald Seifert
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53105, Bonn, Germany
| | - Katja Jennissen
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53105, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53105, Bonn, Germany
| | - Karl W Kafitz
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Christine R Rose
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
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Braun CMJ, Achim A, Roberge C, Gauvin G. Callosal Sensitivity to Short-Range Stimulus Orientation and Long-Range Stimulus Context Orientation: Tachistoscopic Evidence. Am J Psychol 2015; 128:355-65. [PMID: 26442342 DOI: 10.5406/amerjpsyc.128.3.0355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
To study local-global relationships in interhemispheric interactions, tachistoscopically presented pairs of lines (1.15 degrees) were compared for their relative orientation by 48 neurotypical adults. Orientations of line stimuli (local aspect of the task) were vertical, horizontal, forward slash or backslash, as were those of the interstimulus axes. The latter created a global context that could influence line discrimination. Stimulus pairs were presented within a field (not requiring callosal participation for line orientation comparison) or one on each side of the visual field meridian (requiring callosal participation). The primary purpose of the design was to determine whether local or global violations of stimulus "homotopy" across the meridian would impose costs of interhemispheric integration. The rationale for this expectation is that the fiber projection of the corpus callosum is highly symmetric across the midsagittal plane (i.e., homotopic). The expected "callosal homotopy" effect was significantly upheld as a whole but broke down or became extravagant in certain specific conditions, with specific costs of interhemispheric integration varying from null to a highly significant 20-ms as a function of interactions of interstimulus and stimulus orientations. The corpus callosum seems to be particularly sensitive to local stimulus orientation in interaction with long-range stimulus context orientation.
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Burunat I, Brattico E, Puoliväli T, Ristaniemi T, Sams M, Toiviainen P. Action in Perception: Prominent Visuo-Motor Functional Symmetry in Musicians during Music Listening. PLoS One 2015; 10:e0138238. [PMID: 26422790 PMCID: PMC4589413 DOI: 10.1371/journal.pone.0138238] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 08/27/2015] [Indexed: 12/23/2022] Open
Abstract
Musical training leads to sensory and motor neuroplastic changes in the human brain. Motivated by findings on enlarged corpus callosum in musicians and asymmetric somatomotor representation in string players, we investigated the relationship between musical training, callosal anatomy, and interhemispheric functional symmetry during music listening. Functional symmetry was increased in musicians compared to nonmusicians, and in keyboardists compared to string players. This increased functional symmetry was prominent in visual and motor brain networks. Callosal size did not significantly differ between groups except for the posterior callosum in musicians compared to nonmusicians. We conclude that the distinctive postural and kinematic symmetry in instrument playing cross-modally shapes information processing in sensory-motor cortical areas during music listening. This cross-modal plasticity suggests that motor training affects music perception.
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Affiliation(s)
- Iballa Burunat
- Finnish Centre for Interdisciplinary Music Research, Department of Music, University of Jyväskylä, Finland
- Department of Mathematical Information Technology, University of Jyväskylä, Jyväskylä, Finland
- * E-mail:
| | - Elvira Brattico
- Center for Music in the Brain (MIB), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Cognitive Brain Research Unit (CBRU), Institute of Behavioral Sciences, University of Helsinki, Helsinki, Finland
- Advanced Magnetic Imaging (AMI) Centre, Aalto University School of Science, Espoo, Finland
| | - Tuomas Puoliväli
- Department of Mathematical Information Technology, University of Jyväskylä, Jyväskylä, Finland
| | - Tapani Ristaniemi
- Department of Mathematical Information Technology, University of Jyväskylä, Jyväskylä, Finland
| | - Mikko Sams
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Petri Toiviainen
- Finnish Centre for Interdisciplinary Music Research, Department of Music, University of Jyväskylä, Finland
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Platas-Neri D, Hidalgo-Tobón S, da Celis Alonso B, de León FCP, Muñoz-Delgado J, Phillips KA. Tractography of the spider monkey (Ateles geoffroyi) corpus callosum using diffusion tensor magnetic resonance imaging. PLoS One 2015; 10:e0117367. [PMID: 25693078 PMCID: PMC4333290 DOI: 10.1371/journal.pone.0117367] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 12/22/2014] [Indexed: 11/30/2022] Open
Abstract
The objective of this research was to describe the organization, connectivity and microstructure of the corpus callosum of the spider monkey (Ateles geoffroyi). Non-invasive magnetic resonance imaging and diffusion-tensor imaging were obtained from three subjects using a 3T Philips scanner. We hypothesized that the arrangement of fibers in spider monkeys would be similar to that observed in other non-human primates. A repeated measure (n = 3) of fractional anisotropy values was obtained of each subject and for each callosal subdivision. Measurements of the diffusion properties of corpus callosum fibers exhibited a similar pattern to those reported in the literature for humans and chimpanzees. No statistical difference was reached when comparing this parameter between the different CC regions (p = 0.066). The highest fractional anisotropy values corresponded to regions projecting from the corpus callosum to the posterior cortical association areas, premotor and supplementary motor cortices. The lowest fractional anisotropy corresponded to projections to motor and sensory cortical areas. Analyses indicated that approximately 57% of the fibers projects to the frontal cortex and 43% to the post-central cortex. While this study had a small sample size, the results provided important information concerning the organization of the corpus callosum in spider monkeys.
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Affiliation(s)
- Diana Platas-Neri
- Instituto Profesional de la Región Sur, Universidad Autónoma del Estado de Morelos, Jojutla, Morelos, Mexico
| | - Silvia Hidalgo-Tobón
- Departamento de Neurocirugía, Hospital Infantil de México Federico Gómez, Mexico City, Distrito Federal, Mexico
- Departamento de Física, Universidad Autónoma Metropolitana, Iztapalapa, Mexico City, Distrito Federal, Mexico
| | - Benito da Celis Alonso
- Facultad de Ciencias Físico-Matemáticas, Benemérita Universidad de Puebla, Puebla, Puebla, Mexico
| | | | - Jairo Muñoz-Delgado
- Dirección de Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Mexico City, Distrito Federal, Mexico
- Facultad de Psicología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Distrito Federal, Mexico
| | - Kimberley A. Phillips
- Psychology Department, Trinity University, San Antonio, Texas, United States of America
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Azimi Alamouti M, Bakhtiyari M, Moradi F, Mokhtari T, Hedayatpour A, Zafari F, Barbarestani M. Remyelination of the Corpus Callosum by Olfactory Ensheathing Cell in an Experimental Model of Multiple Sclerosis. Acta Med Iran 2015; 53:533-539. [PMID: 26553080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2015] [Indexed: 06/05/2023] Open
Abstract
Multiple Sclerosis (MS) causes loss of the myelin sheath, which leads to loss of neurons. Regeneration of myelin sheath stimulates axon regeneration and neurons' survival. In this study, olfactory ensheathing cell (OEC) transplantation is investigated to restore myelin sheath in an experimental model of MS in male mice.OECs were isolated from the olfactory mucosa of seven-day-old infant rats and cultured. Then, cells were evaluated and approved by flow cytometry by p75 and GFAP markers. A total of 32 mice (C57BL /6) were studied in four groups; 1) without any treatment (control), 2) Sham (receiving PBS), 3) MS model and 4) MS and OEC transplantation. MS was induced by adding Cuprizon in the diet of animals for six weeks. After the expiration of 20 days, histologic analysis was performed with approval of the presence of cells in the graft area and the removal of myelin and myelin regeneration with two types of luxal fast blue (LFB) staining and immunohistochemistry. The purity of the cells ensheathing the olfactory was 90%. There was a significant difference in Myelin percentage of PBS and OEC recipient groups (P≤0.05). MBP and PLP of the myelin sheath in the group receiving OECs were more than MS group.According to the findings, in MS model MBP and PLP of the myelin sheath is reduced. In the group receiving OECs, it was returned to a normal level significantly compared to the sham group received only PBS significant differences were observed. The OECs transplantation can improve myelin restoration.
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Affiliation(s)
- Mohammad Azimi Alamouti
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehrdad Bakhtiyari
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Moradi
- Department of Anatomy, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Tahmineh Mokhtari
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Azim Hedayatpour
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Fariba Zafari
- Department of Anatomy, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Barbarestani
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Moreno MB, Concha L, González-Santos L, Ortiz JJ, Barrios FA. Correlation between corpus callosum sub-segmental area and cognitive processes in school-age children. PLoS One 2014; 9:e104549. [PMID: 25170897 PMCID: PMC4149349 DOI: 10.1371/journal.pone.0104549] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 07/15/2014] [Indexed: 12/13/2022] Open
Abstract
We assessed the relationship between structural characteristics (area) and microstructure (apparent diffusion coefficient; ADC) of the corpus callosum (CC) in 57 healthy children aged 7.0 to 9.1 years, with diverse cognitive and academic abilities as well as executive functions evaluated with a neuropsychological battery for children. The CC was manually delineated and sub-segmented into six regions, and their ADC and area were measured. There were no significant differences between genders in the callosal region area or in ADC. The CC area and ADC, mainly of anterior regions, correlated with different cognitive abilities for each gender. Our results suggest that the relationship between cognitive abilities and CC characteristics is different between girls and boys and between the anterior and posterior regions of the CC. Furthermore, these findings strenghten the idea that regardless of the different interhemispheric connectivity schemes per gender, the results of cognitive tasks are very similar for girls and boys throughout childhood.
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Affiliation(s)
- Martha Beatriz Moreno
- Universidad Nacional Autónoma de México, Instituto de Neurobiología, Querétaro, México
| | - Luis Concha
- Universidad Nacional Autónoma de México, Instituto de Neurobiología, Querétaro, México
| | | | - Juan Jose Ortiz
- Universidad Nacional Autónoma de México, Instituto de Neurobiología, Querétaro, México
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Fothergill T, Donahoo ALS, Douglass A, Zalucki O, Yuan J, Shu T, Goodhill GJ, Richards LJ. Netrin-DCC signaling regulates corpus callosum formation through attraction of pioneering axons and by modulating Slit2-mediated repulsion. Cereb Cortex 2014; 24:1138-51. [PMID: 23302812 DOI: 10.1093/cercor/bhs395] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The left and right sides of the nervous system communicate via commissural axons that cross the midline during development using evolutionarily conserved molecules. These guidance cues have been particularly well studied in the mammalian spinal cord, but it remains unclear whether these guidance mechanisms for commissural axons are similar in the developing forebrain, in particular for the corpus callosum, the largest and most important commissure for cortical function. Here, we show that Netrin1 initially attracts callosal pioneering axons derived from the cingulate cortex, but surprisingly is not attractive for the neocortical callosal axons that make up the bulk of the projection. Instead, we show that Netrin-deleted in colorectal cancer signaling acts in a fundamentally different manner, to prevent the Slit2-mediated repulsion of precrossing axons thereby allowing them to approach and cross the midline. These results provide the first evidence for how callosal axons integrate multiple guidance cues to navigate the midline.
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MESH Headings
- Animals
- Animals, Newborn
- Axons/physiology
- Cells, Cultured
- Cerebral Cortex/cytology
- Coculture Techniques
- Corpus Callosum/physiology
- DCC Receptor
- Embryo, Mammalian
- Female
- Functional Laterality/genetics
- Functional Laterality/physiology
- Humans
- In Vitro Techniques
- Intercellular Signaling Peptides and Proteins/metabolism
- Male
- Mice, Inbred C57BL
- Mice, Neurologic Mutants
- Nerve Growth Factors/genetics
- Nerve Growth Factors/metabolism
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Netrin-1
- Pregnancy
- Rats, Wistar
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Signal Transduction/genetics
- Signal Transduction/physiology
- Tumor Suppressor Proteins/genetics
- Tumor Suppressor Proteins/metabolism
- Roundabout Proteins
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Affiliation(s)
- Thomas Fothergill
- The University of Queensland, Queensland Brain Institute, Brisbane, Qld., Australia
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45
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Ihori N, Kawamura M. [Corpus callosum and somesthetic transfer]. Brain Nerve 2014; 66:341-350. [PMID: 24748081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Here we describe somesthetic disconnection in 3 patients with callosal lesions. The results suggest the importance of the anterior and/or dorsal part of the posterior truncus of the corpus callosum for interhemispheric transfer of discriminative sensations and integrated somesthetic information necessary to tactile naming and somesthetic reading. We provide a hypothesis for the neural mechanisms underlying somesthetic communication.
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Affiliation(s)
- Nami Ihori
- Department of Rehabilitation, Kawasaki Cooperative Hospital
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Abstract
High quality segmentation of diffusion tensor images (DTI) is of key interest in biomedical research and clinical application. In previous studies, most efforts have been made to construct predefined metrics for different DTI segmentation tasks. These methods require adequate prior knowledge and tuning parameters. To overcome these disadvantages, we proposed to automatically learn an adaptive distance metric by a graph based semi-supervised learning model for DTI segmentation. An original discriminative distance vector was first formulated by combining both geometry and orientation distances derived from diffusion tensors. The kernel metric over the original distance and labels of all voxels were then simultaneously optimized in a graph based semi-supervised learning approach. Finally, the optimization task was efficiently solved with an iterative gradient descent method to achieve the optimal solution. With our approach, an adaptive distance metric could be available for each specific segmentation task. Experiments on synthetic and real brain DTI datasets were performed to demonstrate the effectiveness and robustness of the proposed distance metric learning approach. The performance of our approach was compared with three classical metrics in the graph based semi-supervised learning framework.
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Affiliation(s)
- Youyong Kong
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- Research Center for Medical Image Computing, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Defeng Wang
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- Research Center for Medical Image Computing, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Biomedical Engineering and Shun Hing Institute of Advanced Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- * E-mail: (DW); (WCWC)
| | - Lin Shi
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- Research Center for Medical Image Computing, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Steve C. N. Hui
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- Research Center for Medical Image Computing, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Winnie C. W. Chu
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- Research Center for Medical Image Computing, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- * E-mail: (DW); (WCWC)
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Tkachenko LA, Toronova NO, Krasnoshchekova EI, Aleksandrov TA, Zykin PA, Ialfimov AN. [Comparative MRI morphometric study of the corpus callosum at term and preterm infants]. Fiziol Cheloveka 2014; 40:36-42. [PMID: 25272766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A comparative morphometric analysis of MRI brain tomograms of term ant preterm born children was conducted. Common morphometric indexes and a novel quantitative parameter, a coefficient of corpus callosum (kCC), developed with regard to prenatal cortex ontogenesis pattern were applied to the study in order to get objective structural characteristics of the brain. All these quantitative indexes display anatomical features of the preterm brain. Reduced values of corpus callosum coefficient at preterm born children are known to associate with altered proportion between its rostral and caudal segments. A threshold coefficient value was established to differentiate preterm brain from the term one and it has proven its statistical significance.
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48
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Frederiksen KS. Corpus callosum in aging and dementia. Dan Med J 2013; 60:B4721. [PMID: 24083533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The overarching objective of the thesis was to investigate the morphological changes in the corpus callosum (CC) in aging and dementia in relation to its role in cognitive and motor decline. The CC is the largest white matter tract in the brain, containing upwards of 200 million axons, and is believed important for communication and interaction between the two cerebral hemispheres. Historically, the role of white matter, including the CC, in relation to cognitive function has often been eclipsed by the predominance of the cortex, and led to a "corticocentric" view of the brain and cognitive function. However, from the 1960s and onwards, the role of lesions in the white matter in the appearence of cognitive deficits and diseases such as dementia has become increasingly evident. Many studies have indicated that AD is associated with CC atrophy, but the precise pattern of subregional CC atrophy in different disease stages remains undetermined. In study I, we establish that atrophy is present primarily in the posterior CC early in AD, and that atrophy of the CC is associated with faster disease progression. This finding supports a model where posterior atrophy is the earliest changes in the CC in AD patients, with atrophy of anterior CC being a later pathological event. To further elucidate the role of CC atrophy in dementia, we examined a population of 329 elderly subjects, and found that a higher rate of tissue loss in posterior CC is associated with an increased risk of dementia. This study represents the first to examine CC in elderly subjects longitudinally. In the same cohort, we investigated whether impairment in specific cognitive domains was associated with CC tissue loss. Previous studies had shown that processing speed and executive functions may be particularly reliant on the CC. Our findings indicated that CC tissue loss leads to selective impairment of processing speed but not memory or executive function deficits. Finally, CC tissue loss was also associated with impairment of motor function. Overall, the present findings confirm and extend the role of the CC in dementia and age-associated cognitive and motor deficits.
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Affiliation(s)
- Kristian Steen Frederiksen
- Danish Dementia Research Center, Department of Neurology, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark.
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49
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Keller J, Rulseh AM, Komárek A, Latnerová I, Rusina R, Brožová H, Vymazal J. New non-linear color look-up table for visualization of brain fractional anisotropy based on normative measurements - principals and first clinical use. PLoS One 2013; 8:e71431. [PMID: 23990954 PMCID: PMC3750032 DOI: 10.1371/journal.pone.0071431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 06/28/2013] [Indexed: 12/14/2022] Open
Abstract
Fractional anisotropy (FA) is the most commonly used quantitative measure of diffusion in the brain. Changes in FA have been reported in many neurological disorders, but the implementation of diffusion tensor imaging (DTI) in daily clinical practice remains challenging. We propose a novel color look-up table (LUT) based on normative data as a tool for screening FA changes. FA was calculated for 76 healthy volunteers using 12 motion-probing gradient directions (MPG), a subset of 59 subjects was additionally scanned using 30 MPG. Population means and 95% prediction intervals for FA in the corpus callosum, frontal gray matter, thalamus and basal ganglia were used to create the LUT. Unique colors were assigned to inflection points with continuous ramps between them. Clinical use was demonstrated on 17 multiple system atrophy (MSA) patients compared to 13 patients with Parkinson disease (PD) and 17 healthy subjects. Four blinded radiologists classified subjects as MSA/non-MSA. Using only the LUT, high sensitivity (80%) and specificity (84%) were achieved in differentiating MSA subjects from PD subjects and controls. The LUTs generated from 12 and 30 MPG were comparable and accentuate FA abnormalities.
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Affiliation(s)
- Jiří Keller
- Department of Neurology, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
- * E-mail:
| | - Aaron M. Rulseh
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
| | - Arnošt Komárek
- Department of Probability and Mathematical Statistics, Faculty of Mathematics and Physics, Charles University in Prague, Prague, Czech Republic
| | - Iva Latnerová
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
| | - Robert Rusina
- Department of Neurology, Thomayer Hospital, Prague, Czech Republic
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | - Hana Brožová
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | - Josef Vymazal
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
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Ziegler E, Foret A, Mascetti L, Muto V, Le Bourdiec-Shaffii A, Stender J, Balteau E, Dideberg V, Bours V, Maquet P, Phillips C. Altered white matter architecture in BDNF met carriers. PLoS One 2013; 8:e69290. [PMID: 23935975 PMCID: PMC3729843 DOI: 10.1371/journal.pone.0069290] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 06/07/2013] [Indexed: 01/19/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) modulates the pruning of synaptically silent axonal arbors. The Met allele of the BDNF gene is associated with a reduction in the neurotrophin's activity-dependent release. We used diffusion-weighted imaging to construct structural brain networks for 36 healthy subjects with known BDNF genotypes. Through permutation testing we discovered clear differences in connection strength between subjects carrying the Met allele and those homozygotic for the Val allele. We trained a Gaussian process classifier capable of identifying the subjects' allelic group with 86% accuracy and high predictive value. In Met carriers structural connectivity was greatly increased throughout the forebrain, particularly in connections corresponding to the anterior and superior corona radiata as well as corticothalamic and corticospinal projections from the sensorimotor, premotor, and prefrontal portions of the internal capsule. Interhemispheric connectivity was also increased via the corpus callosum and anterior commissure, and extremely high connectivity values were found between inferior medial frontal polar regions via the anterior forceps. We propose that the decreased availability of BDNF leads to deficits in axonal maintenance in carriers of the Met allele, and that this produces mesoscale changes in white matter architecture.
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Affiliation(s)
- Erik Ziegler
- Cyclotron Research Centre, Université de Liège, Liège, Belgium
| | - Ariane Foret
- Cyclotron Research Centre, Université de Liège, Liège, Belgium
| | - Laura Mascetti
- Cyclotron Research Centre, Université de Liège, Liège, Belgium
| | - Vincenzo Muto
- Cyclotron Research Centre, Université de Liège, Liège, Belgium
| | | | - Johan Stender
- Cyclotron Research Centre, Université de Liège, Liège, Belgium
| | - Evelyne Balteau
- Cyclotron Research Centre, Université de Liège, Liège, Belgium
| | | | - Vincent Bours
- Department of Human Genetics, CHU Sart Tilman, Liège, Belgium
| | - Pierre Maquet
- Cyclotron Research Centre, Université de Liège, Liège, Belgium
- Department of Neurology, CHU Liège, Liège, Belgium
| | - Christophe Phillips
- Cyclotron Research Centre, Université de Liège, Liège, Belgium
- Department of Electrical Engineering and Computer Science, University of Liège, Liège, Belgium
- * E-mail:
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