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Moser C, Spencer-Smith MM, Anderson PJ, McIlroy A, Wood AG, Leventer RJ, Anderson VA, Siffredi V. Language and communication functioning in children and adolescents with agenesis of the corpus callosum. BRAIN AND LANGUAGE 2024; 255:105448. [PMID: 39083998 DOI: 10.1016/j.bandl.2024.105448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 07/19/2024] [Accepted: 07/22/2024] [Indexed: 08/02/2024]
Abstract
The corpus callosum, the largest white matter inter-hemispheric pathway, is involved in language and communication. In a cohort of 15 children and adolescents (8-15 years) with developmental absence of the corpus callosum (AgCC), this study aimed to describe language and everyday communication functioning, and explored the role of anatomical factors, social risk, and non-verbal IQ in these outcomes. Standardised measures of language and everyday communication functioning, intellectual ability and social risk were used. AgCC classification and anterior commissure volume, a potential alternative pathway, were extracted from T1-weighted images. Participants with AgCC showed reduced receptive and expressive language compared with test norms, and high rates of language and communication impairments. Complete AgCC, higher social risk and lower non-verbal IQ were associated with communication difficulties. Anterior commissure volume was not associated with language and communication. Recognising heterogeneity in language and communication functioning enhances our understanding and suggests specific focuses for potential interventions.
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Affiliation(s)
| | - Megan M Spencer-Smith
- School of Psychological Sciences, Monash University, Melbourne, Australia; Clinical Sciences, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Peter J Anderson
- School of Psychological Sciences, Monash University, Melbourne, Australia
| | - Alissandra McIlroy
- Clinical Sciences, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Amanda G Wood
- Clinical Sciences, Murdoch Children's Research Institute, Parkville, Victoria, Australia; School of Psychology, Deakin University, Burwood, Victoria, Australia; Aston Institute for Health and Neurodevelopment, Aston University, Birmingham, UK
| | - Richard J Leventer
- Clinical Sciences, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Australia; Department of Neurology, Royal Children's Hospital, Melbourne, Australia
| | - Vicki A Anderson
- Clinical Sciences, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Australia; The Royal Children's Hospital, Melbourne, Australia
| | - Vanessa Siffredi
- Clinical Sciences, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Division of Development and Growth, Department of Paediatrics, Gynaecology and Obstetrics, Geneva University Hospitals and University of Geneva, Geneva, Switzerland; Department of Radiology, Lausanne University Hospital and University of Lausanne, Switzerland.
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2
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Urbanik A, Guz W, Gołębiowski M, Szurowska E, Majos A, Sąsiadek M, Stajgis M, Ostrogórska M. Assessment of the corpus callosum size in male individuals with high intelligence quotient (members of Mensa International). RADIOLOGIE (HEIDELBERG, GERMANY) 2023; 63:49-54. [PMID: 37160478 PMCID: PMC10689507 DOI: 10.1007/s00117-023-01146-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/27/2023] [Indexed: 05/11/2023]
Abstract
OBJECTIVES The aim of this study was to assess the size of the corpus callosum in members of Mensa International, which is the world's largest and oldest high-intelligence quotient (IQ) society. METHODS We performed T2-weighted magnetic resonance imaging (Repetition Time, TR = 3200 ms, Time of Echo, TE = 409 ms) to examine the brain of members of Mensa International (Polish national group) in order to assess the size of the corpus callosum. Results from 113 male MENSA members and 96 controls in the age range of 21-40 years were analyzed. RESULTS The comparative analysis showed that the mean length of the corpus callosum and the thickness of the isthmus were significantly greater in the Mensa members compared to the control groups. A statistically significant difference was also identified in the largest linear dimension of the brain from the frontal lobe to the occipital lobe. The mean corpus callosum cross-sectional area and its ratio to the brain area were significantly greater in the Mensa members. CONCLUSIONS The results show that the dimensions (linear measures and midsagittal cross-sectional surface area) of the corpus callosum were significantly greater in the group of Mensa members than in the controls.
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Affiliation(s)
- Andrzej Urbanik
- Department of Radiology, Collegium Medicum, Jagiellonian University, Kopernika 19, 31-501, Krakow, Poland
| | - Wiesław Guz
- Department of Electroradiology, University of Rzeszów, Rzeszów, Poland
| | - Marek Gołębiowski
- I-st Department of Clinical Radiology, Medical University of Warsaw, Warszawa, Poland
| | - Edyta Szurowska
- 2nd Department of Radiology, Medical University of Gdańsk, Gdańsk, Poland
| | - Agata Majos
- Chair of Radiology and Imaging Diagnostics, Medical University of Łódź, Łódź, Poland
| | - Marek Sąsiadek
- Department of Radiology, Wroclaw Medical University, Wrocław, Poland
| | - Marek Stajgis
- Department of General Radiology and Neuroradiology, Poznan University of Medical Sciences, Poznań, Poland
| | - Monika Ostrogórska
- Department of Radiology, Collegium Medicum, Jagiellonian University, Kopernika 19, 31-501, Krakow, Poland.
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3
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Radwan AM, Sunaert S, Schilling K, Descoteaux M, Landman BA, Vandenbulcke M, Theys T, Dupont P, Emsell L. An atlas of white matter anatomy, its variability, and reproducibility based on constrained spherical deconvolution of diffusion MRI. Neuroimage 2022; 254:119029. [PMID: 35231632 DOI: 10.1016/j.neuroimage.2022.119029] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/19/2022] [Accepted: 02/21/2022] [Indexed: 11/17/2022] Open
Abstract
Virtual dissection of white matter (WM) using diffusion MRI tractography is confounded by its poor reproducibility. Despite the increased adoption of advanced reconstruction models, early region-of-interest driven protocols based on diffusion tensor imaging (DTI) remain the dominant reference for virtual dissection protocols. Here we bridge this gap by providing a comprehensive description of typical WM anatomy reconstructed using a reproducible automated subject-specific parcellation-based approach based on probabilistic constrained-spherical deconvolution (CSD) tractography. We complement this with a WM template in MNI space comprising 68 bundles, including all associated anatomical tract selection labels and associated automated workflows. Additionally, we demonstrate bundle inter- and intra-subject variability using 40 (20 test-retest) datasets from the human connectome project (HCP) and 5 sessions with varying b-values and number of b-shells from the single-subject Multiple Acquisitions for Standardization of Structural Imaging Validation and Evaluation (MASSIVE) dataset. The most reliably reconstructed bundles were the whole pyramidal tracts, primary corticospinal tracts, whole superior longitudinal fasciculi, frontal, parietal and occipital segments of the corpus callosum and middle cerebellar peduncles. More variability was found in less dense bundles, e.g., the fornix, dentato-rubro-thalamic tract (DRTT), and premotor pyramidal tract. Using the DRTT as an example, we show that this variability can be reduced by using a higher number of seeding attempts. Overall inter-session similarity was high for HCP test-retest data (median weighted-dice = 0.963, stdev = 0.201 and IQR = 0.099). Compared to the HCP-template bundles there was a high level of agreement for the HCP test-retest data (median weighted-dice = 0.747, stdev = 0.220 and IQR = 0.277) and for the MASSIVE data (median weighted-dice = 0.767, stdev = 0.255 and IQR = 0.338). In summary, this WM atlas provides an overview of the capabilities and limitations of automated subject-specific probabilistic CSD tractography for mapping white matter fasciculi in healthy adults. It will be most useful in applications requiring a reproducible parcellation-based dissection protocol, and as an educational resource for applied neuroimaging and clinical professionals.
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Affiliation(s)
- Ahmed M Radwan
- KU Leuven, Department of Imaging and pathology, Translational MRI, Leuven, Belgium; KU Leuven, Leuven Brain Institute (LBI), Department of Neurosciences, Leuven, Belgium.
| | - Stefan Sunaert
- KU Leuven, Department of Imaging and pathology, Translational MRI, Leuven, Belgium; KU Leuven, Leuven Brain Institute (LBI), Department of Neurosciences, Leuven, Belgium; UZ Leuven, Department of Radiology, Leuven, Belgium
| | - Kurt Schilling
- Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, TN, USA
| | | | - Bennett A Landman
- Vanderbilt University, Department of Electrical Engineering and Computer Engineering, Nashville, TN, USA
| | - Mathieu Vandenbulcke
- KU Leuven, Leuven Brain Institute (LBI), Department of Neurosciences, Leuven, Belgium; KU Leuven, Department of Neurosciences, Neuropsychiatry, Leuven, Belgium; KU Leuven, Department of Geriatric Psychiatry, University Psychiatric Center (UPC), Leuven, Belgium
| | - Tom Theys
- KU Leuven, Leuven Brain Institute (LBI), Department of Neurosciences, Leuven, Belgium; KU Leuven, Department of Neurosciences, Research Group Experimental Neurosurgery and Neuroanatomy, Leuven, Belgium; UZ Leuven, Department of Neurosurgery, Leuven, Belgium
| | - Patrick Dupont
- KU Leuven, Leuven Brain Institute (LBI), Department of Neurosciences, Leuven, Belgium; KU Leuven, Laboratory for Cognitive Neurology, Department of Neurosciences, Leuven, Belgium
| | - Louise Emsell
- KU Leuven, Department of Imaging and pathology, Translational MRI, Leuven, Belgium; KU Leuven, Leuven Brain Institute (LBI), Department of Neurosciences, Leuven, Belgium; KU Leuven, Department of Neurosciences, Neuropsychiatry, Leuven, Belgium; KU Leuven, Department of Geriatric Psychiatry, University Psychiatric Center (UPC), Leuven, Belgium
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4
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Mather D. Preventing the Development of Dyslexia: A Premature Writing Hypothesis. Percept Mot Skills 2022; 129:468-487. [PMID: 35084244 PMCID: PMC9198397 DOI: 10.1177/00315125221075001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
It has been argued that dyslexia may develop in strongly left eye dominant children through learning to write using ipsilateral, right hemisphere motor pathways. New light on this theory has been cast by recent findings of atypical enhanced corpus callosum white matter in children with dyslexia, reflecting right to left hemisphere communication that is resistant to intensive remedial reading intervention. Enhanced corpus callosum white matter is consistent with uninhibited right to left hemisphere ipsilateral mirror-motor innervation, manifested as frequent mirror-letter writing errors in children with dyslexia. Delaying writing instruction until 7-8 years of age may prevent these errors and as well as the development of dyslexia. During the 7-8 year age period, visual-proprioceptive integration enables a child to mentally map whole word visual images onto kinaesthetic/proprioceptive letter engrams (memory representations). Hypothetically, this process is facilitated by anterior commissure activity involving inter-hemispheric transfer of ipsilateral mirror-to-non mirror motor movement. This postulate, involving delayed writing instruction pending further maturation, also receives indirect support from the remarkable proficiency leap among second graders reading Hebrew as Hebrew involves a leftward orthography in which ipsilateral right to left hemisphere innervation is uninhibited. Additionally, and more directly, normal reading comprehension for learning English among children with agenesis of the corpus callosum suggests that letter-sound decoding is not the sole route to proficient reading comprehension. In this paper, I make recommendations for obtaining empirical evidence of premature writing as a cause of dyslexia.
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Affiliation(s)
- David Mather
- Curriculum and Instruction8205University of Victoria
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5
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Three-dimensional anatomy of the anterior commissure: A tractography and anatomical study. World Neurosurg 2021; 159:e365-e374. [PMID: 34952222 DOI: 10.1016/j.wneu.2021.12.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 11/22/2022]
Abstract
The anterior commissure (AC) is one of the main commissural fibers of the brain. Commissural fibers are involved in bilateral integration and coordination of any normal brain activity. The AC is an important interhemispheric structure which forms a bidirectional communication channel between the frontal, temporal, parietal and occipital lobes bilaterally. In this article, we focus on describing the morphology, relations, and distribution of the AC through diffusion spectrum imaging (DSI) DSI-based fiber tracking. Tractographies were compared with gross anatomical dissection of the anterior commissure of adult's brains. Our study suggests that the AC found by tracking methods is bigger in comparison to the one found by dissection. In summary, the tractography added extensions to the main AC structure.
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6
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Innocenti GM, Schmidt K, Milleret C, Fabri M, Knyazeva MG, Battaglia-Mayer A, Aboitiz F, Ptito M, Caleo M, Marzi CA, Barakovic M, Lepore F, Caminiti R. The functional characterization of callosal connections. Prog Neurobiol 2021; 208:102186. [PMID: 34780864 PMCID: PMC8752969 DOI: 10.1016/j.pneurobio.2021.102186] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 11/05/2021] [Accepted: 11/11/2021] [Indexed: 12/12/2022]
Abstract
The functional characterization of callosal connections is informed by anatomical data. Callosal connections play a conditional driving role depending on the brain state and behavioral demands. Callosal connections play a modulatory function, in addition to a driving role. The corpus callosum participates in learning and interhemispheric transfer of sensorimotor habits. The corpus callosum contributes to language processing and cognitive functions.
The brain operates through the synaptic interaction of distant neurons within flexible, often heterogeneous, distributed systems. Histological studies have detailed the connections between distant neurons, but their functional characterization deserves further exploration. Studies performed on the corpus callosum in animals and humans are unique in that they capitalize on results obtained from several neuroscience disciplines. Such data inspire a new interpretation of the function of callosal connections and delineate a novel road map, thus paving the way toward a general theory of cortico-cortical connectivity. Here we suggest that callosal axons can drive their post-synaptic targets preferentially when coupled to other inputs endowing the cortical network with a high degree of conditionality. This might depend on several factors, such as their pattern of convergence-divergence, the excitatory and inhibitory operation mode, the range of conduction velocities, the variety of homotopic and heterotopic projections and, finally, the state-dependency of their firing. We propose that, in addition to direct stimulation of post-synaptic targets, callosal axons often play a conditional driving or modulatory role, which depends on task contingencies, as documented by several recent studies.
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Affiliation(s)
- Giorgio M Innocenti
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden; Signal Processing Laboratory (LTS5), École Polytechnique Fédérale (EPFL), Lausanne, Switzerland
| | - Kerstin Schmidt
- Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil
| | - Chantal Milleret
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U 1050, Label Memolife, PSL Research University, Paris, France
| | - Mara Fabri
- Department of Life and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Maria G Knyazeva
- Laboratoire de Recherche en Neuroimagerie (LREN), Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland; Leenaards Memory Centre and Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | | | - Francisco Aboitiz
- Centro Interdisciplinario de Neurociencias and Departamento de Psiquiatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Maurice Ptito
- Harland Sanders Chair in Visual Science, École d'Optométrie, Université de Montréal, Montréal, Qc, Canada; Department of Neurology and Neurosurgery, Montréal Neurological Institute, McGill University, Montréal, Qc, Canada; Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Matteo Caleo
- Department of Biomedical Sciences, University of Padua, Italy; CNR Neuroscience Institute, Pisa, Italy
| | - Carlo A Marzi
- Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Muhamed Barakovic
- Signal Processing Laboratory (LTS5), École Polytechnique Fédérale (EPFL), Lausanne, Switzerland
| | - Franco Lepore
- Department of Psychology, Centre de Recherche en Neuropsychologie et Cognition, University of Montréal, Montréal, QC, Canada
| | - Roberto Caminiti
- Department of Physiology and Pharmacology, University of Rome SAPIENZA, Rome, Italy; Neuroscience and Behavior Laboratory, Istituto Italiano di Tecnologia, Rome, Italy.
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7
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Interlimb Transfer of Reach Adaptation Does Not Require an Intact Corpus Callosum: Evidence from Patients with Callosal Lesions and Agenesis. eNeuro 2021; 8:ENEURO.0190-20.2021. [PMID: 33632816 PMCID: PMC8318344 DOI: 10.1523/eneuro.0190-20.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 12/14/2020] [Accepted: 01/11/2021] [Indexed: 11/26/2022] Open
Abstract
Generalization of sensorimotor adaptation across limbs, known as interlimb transfer, is a well-demonstrated phenomenon in humans, yet the underlying neural mechanisms remain unclear. Theoretical models suggest that interlimb transfer is mediated by interhemispheric transfer of information via the corpus callosum. We thus hypothesized that lesions of the corpus callosum, especially to its midbody connecting motor, supplementary motor, and premotor areas of the two cerebral hemispheres, would impair interlimb transfer of sensorimotor adaptation. To test this hypothesis, we recruited three patients: two rare stroke patients with recent, extensive callosal lesions including the midbody and one patient with complete agenesis. A prismatic adaptation paradigm involving unconstrained arm reaching movements was designed to assess interlimb transfer from the prism-exposed dominant arm (DA) to the unexposed non-dominant arm (NDA) for each participant. Baseline results showed that spatial performance of each patient did not significantly differ from controls, for both limbs. Further, each patient adapted to the prismatic perturbation, with no significant difference in error reduction compared with controls. Crucially, interlimb transfer was found in each patient. The absolute magnitude of each patient’s transfer did not significantly differ from controls. These findings show that sensorimotor adaptation can transfer across limbs despite extensive lesions or complete absence of the corpus callosum. Therefore, callosal pathways connecting homologous motor, premotor, and supplementary motor areas are not necessary for interlimb transfer of prismatic reach adaptation. Such interlimb transfer could be mediated by transcallosal splenium pathways (connecting parietal, temporal and visual areas), ipsilateral cortico-spinal pathways or subcortical structures such as the cerebellum.
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8
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Fenlon LR, Suarez R, Lynton Z, Richards LJ. The evolution, formation and connectivity of the anterior commissure. Semin Cell Dev Biol 2021; 118:50-59. [PMID: 33958283 DOI: 10.1016/j.semcdb.2021.04.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/08/2021] [Accepted: 04/10/2021] [Indexed: 10/21/2022]
Abstract
The anterior commissure is the most ancient of the forebrain interhemispheric connections among all vertebrates. Indeed, it is the predominant pallial commissure in all non-eutherian vertebrates, universally subserving basic functions related to olfaction and survival. A key feature of the anterior commissure is its ability to convey connections from diverse brain areas, such as most of the neocortex in non-eutherian mammals, thereby mediating the bilateral integration of diverse functions. Shared developmental mechanisms between the anterior commissure and more evolutionarily recent commissures, such as the corpus callosum in eutherians, have led to the hypothesis that the former may have been a precursor for additional expansion of commissural circuits. However, differences between the formation of the anterior commissure and other telencephalic commissures suggest that independent developmental mechanisms underlie the emergence of these connections in extant species. Here, we review the developmental mechanisms and connectivity of the anterior commissure across evolutionarily distant species, and highlight its potential functional importance in humans, both in the course of normal neurodevelopment, and as a site of plastic axonal rerouting in the absence or damage of other connections.
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Affiliation(s)
- Laura R Fenlon
- The University of Queensland, The Queensland Brain Institute, Brisbane, Australia.
| | - Rodrigo Suarez
- The University of Queensland, The Queensland Brain Institute, Brisbane, Australia
| | - Zorana Lynton
- The University of Queensland, The Queensland Brain Institute, Brisbane, Australia; The Faculty of Medicine, Brisbane, Australia
| | - Linda J Richards
- The University of Queensland, The Queensland Brain Institute, Brisbane, Australia; The School of Biomedical Sciences, Brisbane, Australia.
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9
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Ghulam-Jelani Z, Barrios-Martinez J, Eguiluz-Melendez A, Gomez R, Anania Y, Yeh FC. Redundancy circuits of the commissural pathways in human and rhesus macaque brains. Hum Brain Mapp 2021; 42:2250-2261. [PMID: 33559959 PMCID: PMC8046059 DOI: 10.1002/hbm.25363] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 01/06/2021] [Accepted: 01/21/2021] [Indexed: 12/25/2022] Open
Abstract
It has been hypothesized that the human brain has less redundancy than animals, but the structural evidence has not been identified to confirm this claim. Here, we report three redundancy circuits of the commissural pathways in primate brains, namely the orbitofrontal, temporal, and occipital redundancy circuits of the anterior commissure and corpus callosum. Each redundancy circuit has two distinctly separated routes connecting a common pair of cortical regions. We mapped their trajectories in human and rhesus macaque brains using individual and population‐averaged tractography. The dissection results confirmed the existence of these redundancy circuits connecting the orbitofrontal lobe, amygdala, and visual cortex. The volume analysis showed a significant reduction in the orbitofrontal and occipital redundancy circuits of the human brain, whereas the temporal redundancy circuit had a substantial organizational difference between the human and rhesus macaque. Our results support the hypothesis that the human brain has less redundancy in the commissural pathways than that of the rhesus macaque brain. Further studies are needed to explore its neuropathological implications.
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Affiliation(s)
- Zulfar Ghulam-Jelani
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.,Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Jessica Barrios-Martinez
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Aldo Eguiluz-Melendez
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Ricardo Gomez
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Yury Anania
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Fang-Cheng Yeh
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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10
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Effect of corpus callosum agenesis on the language network in children and adolescents. Brain Struct Funct 2021; 226:701-713. [PMID: 33496825 PMCID: PMC7981296 DOI: 10.1007/s00429-020-02203-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 12/16/2020] [Indexed: 12/17/2022]
Abstract
The present study is interested in the role of the corpus callosum in the development of the language network. We, therefore, investigated language abilities and the language network using task-based fMRI in three cases of complete agenesis of the corpus callosum (ACC), three cases of partial ACC and six controls. Although the children with complete ACC revealed impaired functions in specific language domains, no child with partial ACC showed a test score below average. As a group, ACC children performed significantly worse than healthy controls in verbal fluency and naming. Furthermore, whole-brain ROI-to-ROI connectivity analyses revealed reduced intrahemispheric and right intrahemispheric functional connectivity in ACC patients as compared to controls. In addition, stronger functional connectivity between left and right temporal areas was associated with better language abilities in the ACC group. In healthy controls, no association between language abilities and connectivity was found. Our results show that ACC is associated not only with less interhemispheric, but also with less right intrahemispheric language network connectivity in line with reduced verbal abilities. The present study, thus, supports the excitatory role of the corpus callosum in functional language network connectivity and language abilities.
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11
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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] [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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12
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Cavaliere C, Aiello M, Soddu A, Laureys S, Reislev NL, Ptito M, Kupers R. Organization of the commissural fiber system in congenital and late-onset blindness. NEUROIMAGE-CLINICAL 2019; 25:102133. [PMID: 31945651 PMCID: PMC6965724 DOI: 10.1016/j.nicl.2019.102133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 12/04/2019] [Accepted: 12/13/2019] [Indexed: 11/13/2022]
Abstract
Larger anterior commissure (AC) in congenitally (CB) and late blind (LB) subjects. Decreased fractional anisotropy (FA) of the posterior part of AC (pAC) in CB and LB. Decreased FA in pAC is paralleled by increased number of pAC streamlines in CB only. Selective reduction of the splenium of the corpus callosum (CC) in CB and LB. Reduction of splenium correlated with decrease in streamlines and tract volume.
We investigated the effects of blindness on the structural and functional integrity of the corpus callosum and the anterior commissure (AC), which together form the two major components of the commissural pathways. Twelve congenitally blind (CB), 15 late blind (LB; mean onset of blindness of 16.6 ± 8.9 years), and 15 matched normally sighted controls (SC) participated in a multimodal brain imaging study. Magnetic resonance imaging(MRI) data were acquired using a 3T scanner, and included a structural brain scan, resting state functional MRI, and diffusion-weighted imaging. We used tractography to divide the AC into its anterior (aAC) and posterior (pAC) branch. Virtual tract dissection was performed using a deterministic spherical deconvolution tractography algorithm. The corpus callosum was subdivided into five subregions based on the criteria described by Witelson and modified by Bermudez and Zatorre. Our data revealed decreased fractional anisotropy of the pAC in CB and LB compared to SC, together with an increase in the number of streamlines in CB only. In addition, the AC surface area was significantly larger in CB compared to SC and LB, and correlated with the number of streamlines in pAC (rho = 0.55) and tract volume (rho = 0.46). As for the corpus callosum, the splenial part was significantly smaller in CB and LB, and fewer streamlines passed through it. We did not find group differences in functional connectivity of cortical areas connected by fibers crossing any of the five callosal subregions. The present data suggest that the two main components of the commissural system undergo neuroplastic changes, irrespective of the age of onset of blindness, although the alterations observed in the AC are more important in congenital than late-onset blindness.
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Affiliation(s)
- Carlo Cavaliere
- IRCCS SDN, Via E. Gianturco 113, 80143 Naples, Italy; GIGA-Consciousness - Coma Science Group, GIGA-Research and Neurology Department, University and University Hospital of Liège, Liège, Belgium.
| | - Marco Aiello
- IRCCS SDN, Via E. Gianturco 113, 80143 Naples, Italy
| | - Andrea Soddu
- Brain and Mind Institute, The Department of Physics and Astronomy, University of Western Ontario London, ON, Canada
| | - Steven Laureys
- GIGA-Consciousness - Coma Science Group, GIGA-Research and Neurology Department, University and University Hospital of Liège, Liège, Belgium
| | - Nina L Reislev
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
| | - Maurice Ptito
- Ecole d'Optométrie, Université de Montréal, Montréal, Québec, Canada; Department of nuclear Medicine, University of Southern Denmark, Odense, Denmark; BRAINlab, Institute of Neuroscience, Panum Institute, Faculty of Health and Medical Sciences, University of Copenhagen, Nørre Allé 10, 2200 Copenhagen,Denmark
| | - Ron Kupers
- Ecole d'Optométrie, Université de Montréal, Montréal, Québec, Canada; BRAINlab, Institute of Neuroscience, Panum Institute, Faculty of Health and Medical Sciences, University of Copenhagen, Nørre Allé 10, 2200 Copenhagen,Denmark; Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium.
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13
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Anterior and posterior commissures in agenesis of the corpus callosum: Alternative pathways for attention processes? Cortex 2019; 121:454-467. [DOI: 10.1016/j.cortex.2019.09.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 04/18/2019] [Accepted: 09/24/2019] [Indexed: 11/20/2022]
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14
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Structural and functional brain correlates of theory of mind impairment post-stroke. Cortex 2019; 121:427-442. [DOI: 10.1016/j.cortex.2019.09.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 07/20/2019] [Accepted: 09/26/2019] [Indexed: 12/19/2022]
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15
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de Vin T, Ten Tusscher M. Inter-occipital communication through the anterior commissure in callosal agenesis: a necessary prerequisite for normal binocularity? Acta Neurol Belg 2019; 119:657-658. [PMID: 31642051 DOI: 10.1007/s13760-019-01221-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 10/09/2019] [Indexed: 11/24/2022]
Affiliation(s)
- Tessa de Vin
- Department of Ophthalmology, University Hospital, Vrije Universiteit Brussel, Brussels, Belgium
| | - Marcel Ten Tusscher
- Department of Ophthalmology, University Hospital, Vrije Universiteit Brussel, Brussels, Belgium.
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16
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Ten Tusscher MPM, Houtman AC, De Mey J, Van Schuerbeek P. Cortical Visual Connections via the Corpus Callosum are Asymmetrical in Human Infantile Esotropia. Strabismus 2017; 26:22-27. [PMID: 29279026 DOI: 10.1080/09273972.2017.1418898] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE Besides chiasmal hemidecussation, interhemispheric connections are likely important in human binocularity. The corpus callosum (CC) is the major fiber bundle in the mammalian brain which mostly connects homologous cortical areas in the two hemispheres. Visual interhemispheric connections were found abnormal in strabismic cats. No studies have investigated these pathways in humans with infantile strabismus. METHODS Diffusion tensor imaging was used in four subjects with infantile esotropia (IE) and nine control subjects with normal binocularity, in order to study interhemispheric fibers in the CC connecting the right and left primary visual cortical areas. RESULTS The number of callosal fibers linking both visual cortical areas between the hemispheres was found to be higher in subjects with IE. Also in IE, the amount of visual callosal fibers found after analysis from the primary visual cortical areas on one side appeared significantly different from the amount starting from the contralateral primary visual areas. The distribution area on one side is wider. CONCLUSION We show callosal visual fibers to be abnormal in human IE. Subjects with IE showed abnormal numbers of transcallosal fibers connecting the visual cortical areas on both sides which likely results from an abnormal elimination process during development. Pruning of these fibers in IE favors the side of the visual cortex ipsilateral to the dominant eye. This study underlines the likely role of the CC in the development of human binocularity.
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Affiliation(s)
- Marcel P M Ten Tusscher
- a Department of Ophthalmology , Universitair Ziekenhuis Vrije Universiteit Brussel , Brussels , Belgium
| | - Anne Cees Houtman
- a Department of Ophthalmology , Universitair Ziekenhuis Vrije Universiteit Brussel , Brussels , Belgium
| | - Johan De Mey
- b Department of Radiology , Universitair Ziekenhuis Vrije Universiteit Brussel , Brussels , Belgium
| | - Peter Van Schuerbeek
- b Department of Radiology , Universitair Ziekenhuis Vrije Universiteit Brussel , Brussels , Belgium
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