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Jiao S, Wang K, Luo Y, Zeng J, Han Z. Plastic reorganization of the topological asymmetry of hemispheric white matter networks induced by congenital visual experience deprivation. Neuroimage 2024; 299:120844. [PMID: 39260781 DOI: 10.1016/j.neuroimage.2024.120844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 09/01/2024] [Accepted: 09/08/2024] [Indexed: 09/13/2024] Open
Abstract
Congenital blindness offers a unique opportunity to investigate human brain plasticity. The influence of congenital visual loss on the asymmetry of the structural network remains poorly understood. To address this question, we recruited 21 participants with congenital blindness (CB) and 21 age-matched sighted controls (SCs). Employing diffusion and structural magnetic resonance imaging, we constructed hemispheric white matter (WM) networks using deterministic fiber tractography and applied graph theory methodologies to assess topological efficiency (i.e., network global efficiency, network local efficiency, and nodal local efficiency) within these networks. Statistical analyses revealed a consistent leftward asymmetry in global efficiency across both groups. However, a different pattern emerged in network local efficiency, with the CB group exhibiting a symmetric state, while the SC group showed a leftward asymmetry. Specifically, compared to the SC group, the CB group exhibited a decrease in local efficiency in the left hemisphere, which was caused by a reduction in the nodal properties of some key regions mainly distributed in the left occipital lobe. Furthermore, interhemispheric tracts connecting these key regions exhibited significant structural changes primarily in the splenium of the corpus callosum. This result confirms the initial observation that the reorganization in asymmetry of the WM network following congenital visual loss is associated with structural changes in the corpus callosum. These findings provide novel insights into the neuroplasticity and adaptability of the brain, particularly at the network level.
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Affiliation(s)
- Saiyi Jiao
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Ke Wang
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; School of System Science, Beijing Normal University, Beijing 100875, China
| | - Yudan Luo
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; Department of Psychology and Art Education, Chengdu Education Research Institute, Chengdu 610036, China
| | - Jiahong Zeng
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Zaizhu Han
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China.
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Jiao S, Wang K, Zhang L, Luo Y, Lin J, Han Z. Developmental plasticity of the structural network of the occipital cortex in congenital blindness. Cereb Cortex 2023; 33:11526-11540. [PMID: 37851850 DOI: 10.1093/cercor/bhad385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 10/20/2023] Open
Abstract
The occipital cortex is the visual processing center in the mammalian brain. An unanswered scientific question pertains to the impact of congenital visual deprivation on the development of various profiles within the occipital network. To address this issue, we recruited 30 congenitally blind participants (8 children and 22 adults) as well as 31 sighted participants (10 children and 21 adults). Our investigation focused on identifying the gray matter regions and white matter connections within the occipital cortex, alongside behavioral measures, that demonstrated different developmental patterns between blind and sighted individuals. We discovered significant developmental changes in the gray matter regions and white matter connections of the occipital cortex among blind individuals from childhood to adulthood, in comparison with sighted individuals. Moreover, some of these structures exhibited cognitive functional reorganization. Specifically, in blind adults, the posterior occipital regions (left calcarine fissure and right middle occipital gyrus) showed reorganization of tactile perception, and the forceps major tracts were reorganized for braille reading. These plastic changes in blind individuals may be attributed to experience-dependent neuronal apoptosis, pruning, and myelination. These findings provide valuable insights into the longitudinal neuroanatomical and cognitive functional plasticity of the occipital network following long-term visual deprivation.
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Affiliation(s)
- Saiyi Jiao
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, No. 19 Xinjiekouwai Street, Haidian District, Beijing 100875, China
| | - Ke Wang
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, No. 19 Xinjiekouwai Street, Haidian District, Beijing 100875, China
| | - Linjun Zhang
- School of Chinese as a Second Language, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing 100871, China
| | - Yudan Luo
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, No. 19 Xinjiekouwai Street, Haidian District, Beijing 100875, China
| | - Junfeng Lin
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, No. 19 Xinjiekouwai Street, Haidian District, Beijing 100875, China
| | - Zaizhu Han
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, No. 19 Xinjiekouwai Street, Haidian District, Beijing 100875, China
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Paré S, Bleau M, Dricot L, Ptito M, Kupers R. Brain structural changes in blindness: a systematic review and an anatomical likelihood estimation (ALE) meta-analysis. Neurosci Biobehav Rev 2023; 150:105165. [PMID: 37054803 DOI: 10.1016/j.neubiorev.2023.105165] [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: 09/22/2022] [Revised: 03/23/2023] [Accepted: 04/09/2023] [Indexed: 04/15/2023]
Abstract
In recent decades, numerous structural brain imaging studies investigated purported morphometric changes in early (EB) and late onset blindness (LB). The results of these studies have not yielded very consistent results, neither with respect to the type, nor to the anatomical locations of the brain morphometric alterations. To better characterize the effects of blindness on brain morphometry, we performed a systematic review and an Anatomical-Likelihood-Estimation (ALE) coordinate-based-meta-analysis of 65 eligible studies on brain structural changes in EB and LB, including 890 EB, 466 LB and 1257 sighted controls. Results revealed atrophic changes throughout the whole extent of the retino-geniculo-striate system in both EB and LB, whereas changes in areas beyond the occipital lobe occurred in EB only. We discuss the nature of some of the contradictory findings with respect to the used brain imaging methodologies and characteristics of the blind populations such as the onset, duration and cause of blindness. Future studies should aim for much larger sample sizes, eventually by merging data from different brain imaging centers using the same imaging sequences, opt for multimodal structural brain imaging, and go beyond a purely structural approach by combining functional with structural connectivity network analyses.
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Affiliation(s)
- Samuel Paré
- School of Optometry, University of Montreal, Montreal, Qc, Canada
| | - Maxime Bleau
- School of Optometry, University of Montreal, Montreal, Qc, Canada
| | - Laurence Dricot
- Institute of NeuroScience (IoNS), Université catholique de Louvain (UCLouvain), Bruxelles, Belgium
| | - Maurice Ptito
- School of Optometry, University of Montreal, Montreal, Qc, Canada; Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Qc, Canada; Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Ron Kupers
- School of Optometry, University of Montreal, Montreal, Qc, Canada; Institute of NeuroScience (IoNS), Université catholique de Louvain (UCLouvain), Bruxelles, Belgium; Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.
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Isiklar S, Ozdemir ST, Ozkaya G, Ozpar R. Three dimensional development and asymmetry of the corpus callosum in the 0-18 age group: A retrospective magnetic resonance imaging study. Clin Anat 2022; 36:581-598. [PMID: 36527384 DOI: 10.1002/ca.23996] [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: 10/19/2022] [Revised: 12/07/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
Most of the corpus callosum (CC) developmental studies are concerned with its two-dimensional structure. Linear and area measurements do not directly assess the CC size but estimate the overall structure from the cross-sectional image. This study investigated age- and sex-related changes in volumetric development and asymmetry of CC from birth to 18. For this retrospective study, we selected 696 patients (329 [47.27%] females) with both 3D-T1-weighted sequence and normal radiological anatomy from patients 0-18 years of age who had brain magnetic resonance imaging (MRI) between 2012 and 2020. The genu, body, splenium, and total volume of CC were calculated using MRICloud. The measurement results of 23 age groups were analyzed with SPSS (ver.28). Total CC volume was 18740.76 ± 4314.06 mm3 between 0 and 18 years of age, and its ratio to total brain volume (TBV) was 1.70% ± 0.23%. We observed that the total CC volume has six developmental periods 0 years, 1, 2-4, 5-9, 10-16, and 17-18 years. Genu and body grew in five developmental periods, while splenium in seven. There was intermittent sexual dimorphism in the CC volume in the first 4 years of life (p < 0.05). However, sex factor was insignificant in CC ratio to TBV. Total CC was right lateralized on average 1.81% (ranging -0.59% to 4.52%). Genu was 8.70% lateralized to the right, the body was 2.99% to the left, and the splenium was 1.41% to the right. The three-dimensional development of CC agreed with the two-dimensional developmental data of CC except for some differences.
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Affiliation(s)
- Sefa Isiklar
- Medical Imaging Techniques Program, Vocational School of Health Services, Bursa Uludag University, Bursa, Turkey
| | - Senem Turan Ozdemir
- Department of Anatomy, Faculty of Medicine, Bursa Uludag University, Bursa, Turkey
| | - Güven Ozkaya
- Department of Biostatistics, Faculty of Medicine, Bursa Uludag University, Bursa, Turkey
| | - Rıfat Ozpar
- Department of Radiology, Faculty of Medicine, Bursa Uludag University, Bursa, Turkey
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Arend I, Yuen K, Yizhar O, Chebat DR, Amedi A. Gyrification in relation to cortical thickness in the congenitally blind. Front Neurosci 2022; 16:970878. [DOI: 10.3389/fnins.2022.970878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 10/14/2022] [Indexed: 11/11/2022] Open
Abstract
Greater cortical gyrification (GY) is linked with enhanced cognitive abilities and is also negatively related to cortical thickness (CT). Individuals who are congenitally blind (CB) exhibits remarkable functional brain plasticity which enables them to perform certain non-visual and cognitive tasks with supranormal abilities. For instance, extensive training using touch and audition enables CB people to develop impressive skills and there is evidence linking these skills to cross-modal activations of primary visual areas. There is a cascade of anatomical, morphometric and functional-connectivity changes in non-visual structures, volumetric reductions in several components of the visual system, and CT is also increased in CB. No study to date has explored GY changes in this population, and no study has explored how variations in CT are related to GY changes in CB. T1-weighted 3D structural magnetic resonance imaging scans were acquired to examine the effects of congenital visual deprivation in cortical structures in a healthy sample of 11 CB individuals (6 male) and 16 age-matched sighted controls (SC) (10 male). In this report, we show for the first time an increase in GY in several brain areas of CB individuals compared to SC, and a negative relationship between GY and CT in the CB brain in several different cortical areas. We discuss the implications of our findings and the contributions of developmental factors and synaptogenesis to the relationship between CT and GY in CB individuals compared to SC. F.
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Grégoire A, Deggouj N, Dricot L, Decat M, Kupers R. Brain Morphological Modifications in Congenital and Acquired Auditory Deprivation: A Systematic Review and Coordinate-Based Meta-Analysis. Front Neurosci 2022; 16:850245. [PMID: 35418829 PMCID: PMC8995770 DOI: 10.3389/fnins.2022.850245] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 03/01/2022] [Indexed: 12/02/2022] Open
Abstract
Neuroplasticity following deafness has been widely demonstrated in both humans and animals, but the anatomical substrate of these changes is not yet clear in human brain. However, it is of high importance since hearing loss is a growing problem due to aging population. Moreover, knowing these brain changes could help to understand some disappointing results with cochlear implant, and therefore could improve hearing rehabilitation. A systematic review and a coordinate-based meta-analysis were realized about the morphological brain changes highlighted by MRI in severe to profound hearing loss, congenital and acquired before or after language onset. 25 papers were included in our review, concerning more than 400 deaf subjects, most of them presenting prelingual deafness. The most consistent finding is a volumetric decrease in gray matter around bilateral auditory cortex. This change was confirmed by the coordinate-based meta-analysis which shows three converging clusters in this region. The visual areas of deaf children is also significantly impacted, with a decrease of the volume of both gray and white matters. Finally, deafness is responsible of a gray matter increase within the cerebellum, especially at the right side. These results are largely discussed and compared with those from deaf animal models and blind humans, which demonstrate for example a much more consistent gray matter decrease along their respective primary sensory pathway. In human deafness, a lot of other factors than deafness could interact on the brain plasticity. One of the most important is the use of sign language and its age of acquisition, which induce among others changes within the hand motor region and the visual cortex. But other confounding factors exist which have been too little considered in the current literature, such as the etiology of the hearing impairment, the speech-reading ability, the hearing aid use, the frequent associated vestibular dysfunction or neurocognitive impairment. Another important weakness highlighted by this review concern the lack of papers about postlingual deafness, whereas it represents most of the deaf population. Further studies are needed to better understand these issues, and finally try to improve deafness rehabilitation.
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Affiliation(s)
- Anaïs Grégoire
- Department of ENT, Cliniques Universitaires Saint-Luc, Brussels, Belgium
- Institute of NeuroScience (IoNS), UCLouvain, Brussels, Belgium
| | - Naïma Deggouj
- Department of ENT, Cliniques Universitaires Saint-Luc, Brussels, Belgium
- Institute of NeuroScience (IoNS), UCLouvain, Brussels, Belgium
| | - Laurence Dricot
- Institute of NeuroScience (IoNS), UCLouvain, Brussels, Belgium
| | - Monique Decat
- Department of ENT, Cliniques Universitaires Saint-Luc, Brussels, Belgium
- Institute of NeuroScience (IoNS), UCLouvain, Brussels, Belgium
| | - Ron Kupers
- Institute of NeuroScience (IoNS), UCLouvain, Brussels, Belgium
- Department of Neuroscience, Panum Institute, University of Copenhagen, Copenhagen, Denmark
- Ecole d’Optométrie, Université de Montréal, Montréal, QC, Canada
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Qu 曲晓霞 X, Ding 丁静文 J, Wang 王倩 Q, Cui 崔靖 J, Dong J, Guo 郭健 J, Li 李婷 T, Xie 解立志 L, Li 李冬梅 D, Xian 鲜军舫 J. Effect of the long-term lack of half visual inputs on the white matter microstructure in congenital monocular blindness. Brain Res 2022; 1781:147832. [DOI: 10.1016/j.brainres.2022.147832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 02/05/2022] [Accepted: 02/08/2022] [Indexed: 01/31/2023]
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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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Ptito M, Paré S, Dricot L, Cavaliere C, Tomaiuolo F, Kupers R. A quantitative analysis of the retinofugal projections in congenital and late-onset blindness. NEUROIMAGE-CLINICAL 2021; 32:102809. [PMID: 34509923 PMCID: PMC8435915 DOI: 10.1016/j.nicl.2021.102809] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 07/14/2021] [Accepted: 08/24/2021] [Indexed: 01/22/2023]
Abstract
Congenital (CB) and late blind (LB) affects the integrity brain visual structures. We measured the integrity of the retino-fugal system using structural MRI images. Optic nerve, optic tract, optic chiasm and LGN were reduced by 50 to 60% in CB and LB. There were no differences between CB and LB. In LB, optic nerve volume correlated negatively with blindness duration.
Vision loss early in life has dramatic consequences on the organization of the visual system and hence on structural plasticity of its remnant components. Most of the studies on the anatomical changes in the brain following visual deprivation have focused on the re-organization of the visual cortex and its afferent and efferent projections. In this study, we performed a quantitative analysis of the volume and size of the optic chiasm, optic nerve, optic tract and the lateral geniculate nucleus (LGN), the retino recipient thalamic nucleus. Analysis was carried out on structural T1-weighted MRIs from 22 congenitally blind (CB), 14 late blind (LB) and 29 age -and sex-matched sighted control (SC) subjects. We manually segmented the optic nerve, optic chiasm and optic tract, while LGN volumes were extracted using in-house software. We also measured voxel intensity of optic nerve, optic chiasm and optic tract. Mean volumes of the optic nerve, optic tract and optic chiasm were reduced by 50 to 60% in both CB and LB participants. No significant differences were found between the congenitally and late-onset blind participants for any of the measures. Our data further revealed reduced white matter voxel intensities in optic nerve, optic chiasm and optic tract in blind compared to sighted participants, suggesting decreased myelin content in the atrophied white matter. The LGN was reduced by 50% and 44% in CB and LB, respectively. In LB, optic nerve volume correlated negatively with the blindness duration index; no such correlation was found for optic chiasm, optic tract and LGN. The observation that despite the absence of visual input about half of the subcortical retinofugal projections are structurally preserved raises the question of their functional role. One possibility is that the surviving fibers play a role in the maintenance of circadian rhythms in the blind through the intrinsically photosensitive melanopsin-containing retinal ganglion cells.
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Affiliation(s)
- Maurice Ptito
- School of Optometry, University of Montreal, Montreal, QC, Canada; BRAINlab, University of Copenhagen, Copenhagen, Denmark; Danish Research Center for Magnetic Resonance (DRCMR), Copenhagen University Hospital, Hvidovre, Denmark
| | - Samuel Paré
- School of Optometry, University of Montreal, Montreal, QC, Canada
| | - Laurence Dricot
- Institute of NeuroScience (IoNS), Université catholique de Louvain (UCLouvain), Belgium
| | - Carlo Cavaliere
- IRCCS SDN, Naples, Italy; Coma Science Group, Cyclotron Research Center and Neurology Department, University and University Hospital of Liège, Liège, Belgium
| | - Francesco Tomaiuolo
- Univesità degli Studi di Messina, Dipartimento di Medicina Clinica e Sperimentale
| | - Ron Kupers
- School of Optometry, University of Montreal, Montreal, QC, Canada; BRAINlab, University of Copenhagen, Copenhagen, Denmark; Institute of NeuroScience (IoNS), Université catholique de Louvain (UCLouvain), Belgium.
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Guerreiro MJS, Linke M, Lingareddy S, Kekunnaya R, Röder B. The effect of congenital blindness on resting-state functional connectivity revisited. Sci Rep 2021; 11:12433. [PMID: 34127748 PMCID: PMC8203782 DOI: 10.1038/s41598-021-91976-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 06/03/2021] [Indexed: 02/05/2023] Open
Abstract
Lower resting-state functional connectivity (RSFC) between 'visual' and non-'visual' neural circuits has been reported as a hallmark of congenital blindness. In sighted individuals, RSFC between visual and non-visual brain regions has been shown to increase during rest with eyes closed relative to rest with eyes open. To determine the role of visual experience on the modulation of RSFC by resting state condition-as well as to evaluate the effect of resting state condition on group differences in RSFC-, we compared RSFC between visual and somatosensory/auditory regions in congenitally blind individuals (n = 9) and sighted participants (n = 9) during eyes open and eyes closed conditions. In the sighted group, we replicated the increase of RSFC between visual and non-visual areas during rest with eyes closed relative to rest with eyes open. This was not the case in the congenitally blind group, resulting in a lower RSFC between 'visual' and non-'visual' circuits relative to sighted controls only in the eyes closed condition. These results indicate that visual experience is necessary for the modulation of RSFC by resting state condition and highlight the importance of considering whether sighted controls should be tested with eyes open or closed in studies of functional brain reorganization as a consequence of blindness.
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Affiliation(s)
- Maria J S Guerreiro
- Biological Psychology and Neuropsychology, Institute for Psychology, University of Hamburg, Von-Melle-Park 11, 20146, Hamburg, Germany.
- Biological Psychology, Department of Psychology, Carl Von Ossietzky University of Oldenburg, 26111, Oldenburg, Germany.
| | - Madita Linke
- Biological Psychology and Neuropsychology, Institute for Psychology, University of Hamburg, Von-Melle-Park 11, 20146, Hamburg, Germany
| | - Sunitha Lingareddy
- Department of Radiology, Lucid Medical Diagnostics, Banjara Hills, Hyderabad, Telengana, 500082, India
| | - Ramesh Kekunnaya
- Child Sight Institute, Jasti V. Ramanamma Children's Eye Care Center, Department of Pediatric Ophthalmology, Strabismus, and Neuro-Ophthalmology, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telengana, 500034, India
| | - Brigitte Röder
- Biological Psychology and Neuropsychology, Institute for Psychology, University of Hamburg, Von-Melle-Park 11, 20146, Hamburg, Germany
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Ptito M, Bleau M, Djerourou I, Paré S, Schneider FC, Chebat DR. Brain-Machine Interfaces to Assist the Blind. Front Hum Neurosci 2021; 15:638887. [PMID: 33633557 PMCID: PMC7901898 DOI: 10.3389/fnhum.2021.638887] [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: 12/07/2020] [Accepted: 01/19/2021] [Indexed: 12/31/2022] Open
Abstract
The loss or absence of vision is probably one of the most incapacitating events that can befall a human being. The importance of vision for humans is also reflected in brain anatomy as approximately one third of the human brain is devoted to vision. It is therefore unsurprising that throughout history many attempts have been undertaken to develop devices aiming at substituting for a missing visual capacity. In this review, we present two concepts that have been prevalent over the last two decades. The first concept is sensory substitution, which refers to the use of another sensory modality to perform a task that is normally primarily sub-served by the lost sense. The second concept is cross-modal plasticity, which occurs when loss of input in one sensory modality leads to reorganization in brain representation of other sensory modalities. Both phenomena are training-dependent. We also briefly describe the history of blindness from ancient times to modernity, and then proceed to address the means that have been used to help blind individuals, with an emphasis on modern technologies, invasive (various type of surgical implants) and non-invasive devices. With the advent of brain imaging, it has become possible to peer into the neural substrates of sensory substitution and highlight the magnitude of the plastic processes that lead to a rewired brain. Finally, we will address the important question of the value and practicality of the available technologies and future directions.
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Affiliation(s)
- Maurice Ptito
- École d’Optométrie, Université de Montréal, Montréal, QC, Canada
- Department of Nuclear Medicine, University of Southern Denmark, Odense, Denmark
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Maxime Bleau
- École d’Optométrie, Université de Montréal, Montréal, QC, Canada
| | - Ismaël Djerourou
- École d’Optométrie, Université de Montréal, Montréal, QC, Canada
| | - Samuel Paré
- École d’Optométrie, Université de Montréal, Montréal, QC, Canada
| | - Fabien C. Schneider
- TAPE EA7423 University of Lyon-Saint Etienne, Saint Etienne, France
- Neuroradiology Unit, University Hospital of Saint-Etienne, Saint-Etienne, France
| | - Daniel-Robert Chebat
- Visual and Cognitive Neuroscience Laboratory (VCN Lab), Department of Psychology, Faculty of Social Sciences and Humanities, Ariel University, Ariel, Israël
- Navigation and Accessibility Research Center of Ariel University (NARCA), Ariel, Israël
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12
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Özen Ö, Aslan F. Morphometric evaluation of cerebellar structures in late monocular blindness. Int Ophthalmol 2020; 41:769-776. [PMID: 33180280 DOI: 10.1007/s10792-020-01629-5] [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: 06/16/2020] [Accepted: 10/29/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Only a few studies have investigated structural and functional changes in monocular blind individuals. Our aim in this study was to segmentally investigate the cerebellar structures of subjects with late-onset monocular blindness (LMB) using a Voxel-based volumetric analysis system. METHODS The segmental volumetric values, cortical thickness, gray matter volumes and percentage ratios of the cerebellar lobules of individuals with LMB due to trauma and in healthy individuals with bilateral sight as the control group were calculated at the volBrain CERES 1.0 website ( https://volbrain.upv.es/ ) by using brain 3D fast spoiled gradient recall acquisition in steady-state (3D T1 FSPGR) MRI sequence images in our prospective study. RESULTS We studied 11 subjects with LMB (8 males/3 females) and 11 healthy control subjects (8 males/3 females). The mean age was 41.45 ± 14.15 and 40 ± 11.11 years, respectively (p > 0.05). The mean duration of the LMB status was 20.8 ± 11.2 years. Cerebellar lobule crus II volume and cerebellar lobule VIIB/VIIIA volume/percentage were higher in the LMB group, and mean cerebellar cortical thickness, cerebellar lobule VI-cerebellar lobule crus I-II cortical thickness, and cerebellar lobule VI gray matter volume values were lower in the LMB group (p < 0.05). CONCLUSION In this study, cerebellar lobule VIIB/VIIIA volume/total percent ratio, cerebellar cortical thickness and cerebellar gray matter volume in the LMB group were found to be different from the control group. To our knowledge, this is the first study to report cerebellar anatomical changes in patients with LMB.
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Affiliation(s)
- Özkan Özen
- Department of Radiology, Alaaddin Keykubat University Alanya Education and Research Hospital, Antalya, 07400, Turkey
| | - Fatih Aslan
- Department of Ophthalmology, Alaaddin Keykubat University Alanya Education and Research Hospital, Antalya, 07400, Turkey.
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13
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Tomaiuolo F, Cerasa A, Lerch JP, Bivona U, Carlesimo GA, Ciurli P, Raffa G, Quattropani MC, Germanò A, Caltagirone C, Formisano R, Nigro S. Brain Neurodegeneration in the Chronic Stage of the Survivors from Severe Non-Missile Traumatic Brain Injury: A Voxel-Based Morphometry Within-Group at One versus Nine Years from a Head Injury. J Neurotrauma 2020; 38:283-290. [PMID: 32962533 DOI: 10.1089/neu.2020.7203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The long-term time course of neuropathological changes occurring in survivors from severe traumatic brain injury (TBI) remains uncertain. We investigated the brain morphometry and memory performance modifications within the same group of severe non-missile traumatic brain injury patients (nmTBI) after about ∼one year and at ∼ nine years from injury. Brain magnetic resonance imaging (MRI) measurements were performed with voxel-based morphometry (VBM) to determine specific changes in the gray matter (GM) and white matter (WM) and the overall gray matter volume modifications (GMV) and white matter volume modifications (WMV). Contemporarily, memory-tests were also administered. In comparison with healthy control subjects (HC), those with nmTBI showed a significant change and volume reduction in the GM and WM and also in the GMV and WMV after ∼one year; conversely, ∼nine years after injury, neurodegenerative changes spared the GM and GMV, but a prominent loss was detected in WMV and in WM sites, such as the superior longitudinal fasciculi, the body of the corpus callosum, the optic radiation, and the uncinate fasciculus. Memory performance at ∼one year in comparison with ∼nine years was stable with a subtle but significant trend toward recovery. These data demonstrate that patients with nmTBI undergo neurodegenerative processes during the chronic stage affecting mainly the cerebral WM rather than GM. Despite these anatomical brain parenchyma losses, memory performance tends to be stable or even slightly recovered. These results suggest possible correlations between progressive demyelinization and/or neuropsychiatric changes other than memory performance, and support possible treatments to prevent long-term WM degeneration of the examined nmTBI.
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Affiliation(s)
- Francesco Tomaiuolo
- Department of Clinical and Experimental Medicine and Department BIOMORF, University of Messina, Messina, Italy
| | - Antonio Cerasa
- IRIB, National Research Council, Cosenza, Italy, and S. Anna Institute and Research in Advanced Neurorehabilitation (RAN), Crotone, Italy
| | - Jason P Lerch
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, The University of Oxford, Oxford, United Kingdom
| | | | - Giovanni Augusto Carlesimo
- IRCCS Fondazione 'Santa Lucia', Rome, Italy.,Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Rome, Italy
| | | | - Giovanni Raffa
- Division of Neurosurgery, Department BIOMORF, University of Messina, Messina, Italy
| | - Marina Catena Quattropani
- Department of Clinical and Experimental Medicine and Department BIOMORF, University of Messina, Messina, Italy
| | - Antonino Germanò
- Division of Neurosurgery, Department BIOMORF, University of Messina, Messina, Italy
| | | | | | - Salvatore Nigro
- Institute of Nanotechnology (NANOTEC), National Research Council, Lecce, Italy
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14
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Chebat DR, Schneider FC, Ptito M. Spatial Competence and Brain Plasticity in Congenital Blindness via Sensory Substitution Devices. Front Neurosci 2020; 14:815. [PMID: 32848575 PMCID: PMC7406645 DOI: 10.3389/fnins.2020.00815] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/10/2020] [Indexed: 12/22/2022] Open
Abstract
In congenital blindness (CB), tactile, and auditory information can be reinterpreted by the brain to compensate for visual information through mechanisms of brain plasticity triggered by training. Visual deprivation does not cause a cognitive spatial deficit since blind people are able to acquire spatial knowledge about the environment. However, this spatial competence takes longer to achieve but is eventually reached through training-induced plasticity. Congenitally blind individuals can further improve their spatial skills with the extensive use of sensory substitution devices (SSDs), either visual-to-tactile or visual-to-auditory. Using a combination of functional and anatomical neuroimaging techniques, our recent work has demonstrated the impact of spatial training with both visual to tactile and visual to auditory SSDs on brain plasticity, cortical processing, and the achievement of certain forms of spatial competence. The comparison of performances between CB and sighted people using several different sensory substitution devices in perceptual and sensory-motor tasks uncovered the striking ability of the brain to rewire itself during perceptual learning and to interpret novel sensory information even during adulthood. We discuss here the implications of these findings for helping blind people in navigation tasks and to increase their accessibility to both real and virtual environments.
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Affiliation(s)
- Daniel-Robert Chebat
- Visual and Cognitive Neuroscience Laboratory (VCN Lab), Department of Psychology, Faculty of Social Sciences and Humanities, Ariel University, Ariel, Israel
- Navigation and Accessibility Research Center of Ariel University (NARCA), Ariel, Israel
| | - Fabien C. Schneider
- Department of Radiology, University of Lyon, Saint-Etienne, France
- Neuroradiology Unit, University Hospital of Saint-Etienne, Saint-Etienne, France
| | - Maurice Ptito
- BRAIN Lab, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Chaire de Recherche Harland Sanders en Sciences de la Vision, École d’Optométrie, Université de Montréal, Montréal, QC, Canada
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15
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Abstract
Background Several neuroimaging studies demonstrated that visual deprivation led to significant cross-modal plasticity in the brain’s functional and anatomical architecture. Purpose To investigate the pattern of the interhemispheric functional connectivity in individuals with late blindness using the voxel-mirrored homotopic connectivity (VMHC) and seed-based functional connectivity (FC) methods. Material and Methods Forty-four individuals with late blindness (22 men, 22 women; mean age = 39.88 ± 12.84 years) and 55 sighted control individuals (35 men, 20 women; mean age = 43.13 ± 13.98 years)—closely matched for age, sex, and education—underwent resting-state magnetic resonance imaging scans. The VMHC and seed-based FC methods were applied to assess interhemispheric coordination in a voxel-wise manner. Results Compared with the sighted control groups, the late blindness groups showed decreased VMHC values in the bilateral cuneus/calcarine/lingual gyrus (CUN/CAL/LING) (BA 17/18/19) (voxel level: P < 0.001, Gaussian random field [GRF] correction, cluster level: P < 0.005). Meanwhile, for seed-based FC analysis, compared with the sighted control group, the late blindness group showed a decreased FC between the right lower VMHC regions and the bilateral CUN/LING/CAL/precuneus (PreCUN)/left middle occipital gyrus (MOG) (BA 18/19/30/31) and left precentral gyrus (PreCG) and postcentral gyrus (PostCG) (BA 2/3/4/6). The late blindness group showed a decreased FC between the left lower VMHC regions and the bilateral CUN/LING/CAL/PreCUN (BA 18/19/31) and left PreCG and PostCG (BA 2/3/4/6) relative to the sighted control group (voxel level: P < 0.001, GRF correction, cluster level: P < 0.005). Moreover, a negative correlation was observed between the duration of blindness and VMHC values in the bilateral CUN/CAL/LING (r = −0.393, P = 0.008) in individuals with late blindness. Conclusion Our results indicated that late blindness induced substantial impairment of interhemispheric coordination in the visual cortex. This might reflect impaired visual fusion, visual recognition function, and top-down modulations in individuals with late blindness.
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Affiliation(s)
- Xin Huang
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, PR China
| | - Fu-Qing Zhou
- Department of Radiology, The First Affiliated Hospital of Nanchang University, Jiangxi Province Medical Imaging Research Institute, Nanchang, PR China
| | - Han-Dong Dan
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, PR China
| | - Yin Shen
- Eye Center, Renmin Hospital of Wuhan University, Wuhan, PR China
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16
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Chebat DR, Schneider FC, Ptito M. Neural Networks Mediating Perceptual Learning in Congenital Blindness. Sci Rep 2020; 10:495. [PMID: 31949207 PMCID: PMC6965659 DOI: 10.1038/s41598-019-57217-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/19/2019] [Indexed: 11/25/2022] Open
Abstract
Despite the fact that complete visual deprivation leads to volumetric reductions in brain structures associated with spatial learning, blind individuals are still able to navigate. The neural structures involved in this function are not fully understood. Our study aims to correlate the performance of congenitally blind individuals (CB) and blindfolded sighted controls (SC) in a life-size obstacle-course using a visual-to-tactile sensory substitution device, with the size of brain structures (voxel based morphometry-VBM-) measured through structural magnetic resonance Imaging (MRI). VBM was used to extract grey matter volumes within several a-priori defined brain regions in all participants. Principal component analysis was utilized to group brain regions in factors and orthogonalize brain volumes. Regression analyses were then performed to link learning abilities to these factors. We found that (1) both CB and SC were able to learn to detect and avoid obstacles; (2) their learning rates for obstacle detection and avoidance correlated significantly with the volume of brain structures known to be involved in spatial skills. There is a similar relation between regions of the dorsal stream network and avoidance for both SC and CB whereas for detection, SC rely more on medial temporal lobe structures and CB on sensorimotor areas.
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Affiliation(s)
- Daniel-Robert Chebat
- Visual and Cognitive Neuroscience Laboratory (VCN Lab), Department of Psychology, Faculty of Social Sciences and Humanities, Ariel University, Ariel, Israel. .,Navigation and Accessibility Research Center of Ariel University (NARCA), Ariel, Israel.
| | - Fabien C Schneider
- University of Lyon, Saint-Etienne, F-42023, France.,Neuroradiology Unit, University Hospital of Saint-Etienne, Saint-Etienne, France
| | - Maurice Ptito
- BRAINlab, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark.,Chaire de recherche Harland Sanders en Sciences de la Vision, École d'Optométrie, Université de Montréal, Montréal, Canada
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17
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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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18
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Alterations of the Brain Microstructure and Corresponding Functional Connectivity in Early-Blind Adolescents. Neural Plast 2019; 2019:2747460. [PMID: 30996726 PMCID: PMC6408999 DOI: 10.1155/2019/2747460] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 10/17/2018] [Accepted: 12/27/2018] [Indexed: 11/17/2022] Open
Abstract
Although evidence from studies on blind adults indicates that visual deprivation early in life leads to structural and functional disruption and reorganization of the brain, whether young blind people show similar patterns remains unknown. Therefore, this study is aimed at exploring the structural and functional alterations of the brain of early-blind adolescents (EBAs) compared to normal-sighted controls (NSCs) and investigating the effects of residual light perception on brain microstructure and function in EBAs. We obtained magnetic resonance imaging (MRI) data from 23 EBAs (8 with residual light perception (LPs), 15 without light perception (NLPs)) and 21 NSCs (age range 11-19 years old). Whole-brain voxel-based analyses of diffusion tensor imaging metrics and region-of-interest analyses of resting-state functional connectivity (RSFC) were performed to compare patterns of brain microstructure and the corresponding RSFC between the groups. The results showed that structural disruptions of LPs and NLPs were mainly located in the occipital visual pathway. Compared with NLPs, LPs showed increased fractional anisotropy (FA) in the superior frontal gyrus and reduced diffusivity in the caudate nucleus. Moreover, the correlations between FA of the occipital cortices or mean diffusivity of the lingual gyrus and age were consistent with the development trajectory of the brain in NSCs, but inconsistent or even opposite in EBAs. Additionally, we found functional, but not structural, reorganization in NLPs compared with NSCs, suggesting that functional neuroplasticity occurs earlier than structural neuroplasticity in EBAs. Altogether, these findings provided new insights into the mechanisms underlying the neural reorganization of the brain in adolescents with early visual deprivation.
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19
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Aubin S, Christensen JAE, Jennum P, Nielsen T, Kupers R, Ptito M. Preserved sleep microstructure in blind individuals. Sleep Med 2017; 42:21-30. [PMID: 29458742 DOI: 10.1016/j.sleep.2017.11.1135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 11/10/2017] [Accepted: 11/22/2017] [Indexed: 10/18/2022]
Abstract
The loss of vision, particularly when it occurs early in life, is associated with compensatory cortical plasticity not only in the visual cortical areas, but throughout the entire brain. The absence of visual input to the retina can also induce changes in entrainment of the circadian rhythm, as light is the primary zeitgeber of the master biological clock found in the suprachiasmatic nucleus of the hypothalamus. In addition, a greater number of sleep disturbances is often reported in blind individuals. Here, we examined various electroencephalographic microstructural components of sleep, both during rapid-eye-movement (REM) sleep and non-REM (NREM) sleep, between blind individuals, including both of early and late onset, and normal-sighted controls. During wakefulness, occipital alpha oscillations were lower, or absent in blind individuals. During sleep, differences were observed across electrode derivations between the early and late blind samples, which may reflect altered cortical networking in early blindness. Despite these differences in power spectra density, the electroencephalography microstructure of sleep, including sleep spindles, slow wave activity, and sawtooth waves, remained present in the absence of vision.
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Affiliation(s)
- Sébrina Aubin
- Department of Neuroscience, University of Montreal, Montreal, Quebec, Canada; Brain Research and Integrative Neuroscience Laboratory, Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark; Harland Sanders Chair in Visual Science, School of Optometry, University of Montreal, Montreal, Quebec, Canada
| | - Julie A E Christensen
- Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark
| | - Poul Jennum
- Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark
| | - Tore Nielsen
- Dream and Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Department of Psychiatry, University of Montreal, Montreal, Quebec, Canada
| | - Ron Kupers
- Brain Research and Integrative Neuroscience Laboratory, Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark; Department of Radiology & Biomedical Imaging, Yale University, 300 Cedar Street, New Haven, CT 06520, USA; Laboratory of Neuropsychiatry and Psychiatric Centre Copenhagen, University of Copenhagen, Copenhagen, Denmark.
| | - Maurice Ptito
- Brain Research and Integrative Neuroscience Laboratory, Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark; Harland Sanders Chair in Visual Science, School of Optometry, University of Montreal, Montreal, Quebec, Canada; Laboratory of Neuropsychiatry and Psychiatric Centre Copenhagen, University of Copenhagen, Copenhagen, Denmark
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20
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Le Meur G, Lebranchu P, Billaud F, Adjali O, Schmitt S, Bézieau S, Péréon Y, Valabregue R, Ivan C, Darmon C, Moullier P, Rolling F, Weber M. Safety and Long-Term Efficacy of AAV4 Gene Therapy in Patients with RPE65 Leber Congenital Amaurosis. Mol Ther 2017; 26:256-268. [PMID: 29033008 DOI: 10.1016/j.ymthe.2017.09.014] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 09/05/2017] [Accepted: 09/09/2017] [Indexed: 11/17/2022] Open
Abstract
The aim of this study was the evaluation of the safety and efficacy of unilateral subretinal injection of the adeno-associated vector (AAV) serotypes 2 and 4 (AAV2/4) RPE65-RPE65 vector in patients with Leber congenital amaurosis (LCA) associated with RPE65 gene deficiency. We evaluated ocular and general tolerance and visual function up to 1 year after vector administration in the most severely affected eye in nine patients with retinal degeneration associated with mutations in the RPE65 gene. Patients received either low (1.22 × 1010 to 2 × 1010 vector genomes [vg]) or high (between 3.27 × 1010 and 4.8 × 1010 vg) vector doses. An ancillary study, in which six of the original nine patients participated, extended the follow-up period to 2-3.5 years. All patients showed good ophthalmological and general tolerance to the rAAV2/4-RPE65-RPE65 vector. We observed a trend toward improved visual acuity in patients with nystagmus, stabilization and improvement of the visual field, and cortical activation along visual pathways during fMRI analysis. OCT analysis after vector administration revealed no retinal thinning, except in cases of macular detachment. Our findings show that the rAAV2/4.RPE65.RPE65 vector was well tolerated in nine patients with RPE65-associated LCA. Efficacy parameters varied between patients during follow-up.
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Affiliation(s)
- Guylène Le Meur
- Ophthalmology Department, University Hospital Centre (CHU) de Nantes, Nantes, France; INSERM UMR 1089, University of Nantes, CHU de Nantes, Nantes France.
| | - Pierre Lebranchu
- Ophthalmology Department, University Hospital Centre (CHU) de Nantes, Nantes, France; UMR 6597 CNRS, Image and Video Communication Team, Institute for Research into Communications and Cybernetics of Nantes, Polytech Nantes, Nantes, France
| | - Fanny Billaud
- Ophthalmology Department, University Hospital Centre (CHU) de Nantes, Nantes, France
| | - Oumeya Adjali
- INSERM UMR 1089, University of Nantes, CHU de Nantes, Nantes France
| | | | | | - Yann Péréon
- Reference Centre for Neuromuscular Disorders, FILNEMUS, CHU de Nantes, Nantes, France
| | - Romain Valabregue
- Institut du Cerveau et de la Moelle épinière ICM, Centre for NeuroImaging Research (CENIR), Paris, France
| | - Catherine Ivan
- Ophthalmology Department, University Hospital Centre (CHU) de Nantes, Nantes, France
| | | | | | - Fabienne Rolling
- INSERM UMR 1089, University of Nantes, CHU de Nantes, Nantes France
| | - Michel Weber
- Ophthalmology Department, University Hospital Centre (CHU) de Nantes, Nantes, France; INSERM UMR 1089, University of Nantes, CHU de Nantes, Nantes France
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21
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Aubin S, Jennum P, Nielsen T, Kupers R, Ptito M. Sleep structure in blindness is influenced by circadian desynchrony. J Sleep Res 2017. [PMID: 28621018 DOI: 10.1111/jsr.12548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
We examined the structure, duration and quality of sleep, including non-rapid eye movement sleep and rapid eye movement sleep, in 11 blind individuals without conscious light perception and 11 age- and sex-matched sighted controls. Because blindness is associated with a greater incidence of free-running circadian rhythms, we controlled for circadian phase by a measure of melatonin onset timing. When circadian rhythm was entrained and melatonin onset occurred at normal times, sleep structure did not differ between blind and sighted individuals. On the other hand, an abnormal timing of the circadian phase, including delayed, shifted and unclassifiable melatonin onsets, led to larger rapid eye movement sleep latencies and increased wake times. No differences were observed for stages of non-rapid eye movement sleep, either between congenital and late blind and sighted individuals, or across the different circadian phases. Moreover, abnormal circadian phases were more common in the blind (n = 5) than the sighted (n = 2) sample. Our findings suggest that the sleep structure of blind individuals depends on entrainment of circadian phase, rather than on the absence of vision.
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Affiliation(s)
- Sébrina Aubin
- Department of Neuroscience, University of Montreal, Montreal, QC, Canada.,Brain Research and Integrative Neurosciences (BRAINlab) and Danish Center for Sleep Medicine, Rigshospitalet, Glostrup, Denmark
| | - Poul Jennum
- Brain Research and Integrative Neurosciences (BRAINlab) and Danish Center for Sleep Medicine, Rigshospitalet, Glostrup, Denmark.,Department of Clinical Neurophysiology, University of Copenhagen, Copenhagen, Denmark
| | - Tore Nielsen
- Dream and Nightmare Laboratory, Center for Advanced Research in Sleep Medicine, Montreal, QC, Canada.,Department of Psychiatry, University of Montreal, Montreal, QC, Canada
| | - Ron Kupers
- Brain Research and Integrative Neurosciences (BRAINlab) and Danish Center for Sleep Medicine, Rigshospitalet, Glostrup, Denmark.,Harland Sanders Chair in Visual Science, School of Optometry, University of Montreal, Montreal, QC, Canada
| | - Maurice Ptito
- Brain Research and Integrative Neurosciences (BRAINlab) and Danish Center for Sleep Medicine, Rigshospitalet, Glostrup, Denmark.,Harland Sanders Chair in Visual Science, School of Optometry, University of Montreal, Montreal, QC, Canada.,Laboratory of Neuropsychiatry and Psychiatric Centre Copenhagen, University of Copenhagen, Copenhagen, Denmark
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22
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Bauer CM, Hirsch GV, Zajac L, Koo BB, Collignon O, Merabet LB. Multimodal MR-imaging reveals large-scale structural and functional connectivity changes in profound early blindness. PLoS One 2017; 12:e0173064. [PMID: 28328939 PMCID: PMC5362049 DOI: 10.1371/journal.pone.0173064] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 02/14/2017] [Indexed: 11/21/2022] Open
Abstract
In the setting of profound ocular blindness, numerous lines of evidence demonstrate the existence of dramatic anatomical and functional changes within the brain. However, previous studies based on a variety of distinct measures have often provided inconsistent findings. To help reconcile this issue, we used a multimodal magnetic resonance (MR)-based imaging approach to provide complementary structural and functional information regarding this neuroplastic reorganization. This included gray matter structural morphometry, high angular resolution diffusion imaging (HARDI) of white matter connectivity and integrity, and resting state functional connectivity MRI (rsfcMRI) analysis. When comparing the brains of early blind individuals to sighted controls, we found evidence of co-occurring decreases in cortical volume and cortical thickness within visual processing areas of the occipital and temporal cortices respectively. Increases in cortical volume in the early blind were evident within regions of parietal cortex. Investigating white matter connections using HARDI revealed patterns of increased and decreased connectivity when comparing both groups. In the blind, increased white matter connectivity (indexed by increased fiber number) was predominantly left-lateralized, including between frontal and temporal areas implicated with language processing. Decreases in structural connectivity were evident involving frontal and somatosensory regions as well as between occipital and cingulate cortices. Differences in white matter integrity (as indexed by quantitative anisotropy, or QA) were also in general agreement with observed pattern changes in the number of white matter fibers. Analysis of resting state sequences showed evidence of both increased and decreased functional connectivity in the blind compared to sighted controls. Specifically, increased connectivity was evident between temporal and inferior frontal areas. Decreases in functional connectivity were observed between occipital and frontal and somatosensory-motor areas and between temporal (mainly fusiform and parahippocampus) and parietal, frontal, and other temporal areas. Correlations in white matter connectivity and functional connectivity observed between early blind and sighted controls showed an overall high degree of association. However, comparing the relative changes in white matter and functional connectivity between early blind and sighted controls did not show a significant correlation. In summary, these findings provide complimentary evidence, as well as highlight potential contradictions, regarding the nature of regional and large scale neuroplastic reorganization resulting from early onset blindness.
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Affiliation(s)
- Corinna M. Bauer
- Laboratory for Visual Neuroplasticity. Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, United States of America
| | - Gabriella V. Hirsch
- Laboratory for Visual Neuroplasticity. Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, United States of America
| | - Lauren Zajac
- Center for Biomedical Imaging. Boston University School of Medicine, Boston, MA, United States of America
| | - Bang-Bon Koo
- Center for Biomedical Imaging. Boston University School of Medicine, Boston, MA, United States of America
| | - Olivier Collignon
- Crossmodal Perception and Plasticity Laboratory. University of Trento, Trento, Italy
| | - Lotfi B. Merabet
- Laboratory for Visual Neuroplasticity. Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, United States of America
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23
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Rokem A, Takemura H, Bock AS, Scherf KS, Behrmann M, Wandell BA, Fine I, Bridge H, Pestilli F. The visual white matter: The application of diffusion MRI and fiber tractography to vision science. J Vis 2017; 17:4. [PMID: 28196374 PMCID: PMC5317208 DOI: 10.1167/17.2.4] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 12/12/2016] [Indexed: 12/19/2022] Open
Abstract
Visual neuroscience has traditionally focused much of its attention on understanding the response properties of single neurons or neuronal ensembles. The visual white matter and the long-range neuronal connections it supports are fundamental in establishing such neuronal response properties and visual function. This review article provides an introduction to measurements and methods to study the human visual white matter using diffusion MRI. These methods allow us to measure the microstructural and macrostructural properties of the white matter in living human individuals; they allow us to trace long-range connections between neurons in different parts of the visual system and to measure the biophysical properties of these connections. We also review a range of findings from recent studies on connections between different visual field maps, the effects of visual impairment on the white matter, and the properties underlying networks that process visual information supporting visual face recognition. Finally, we discuss a few promising directions for future studies. These include new methods for analysis of MRI data, open datasets that are becoming available to study brain connectivity and white matter properties, and open source software for the analysis of these data.
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Affiliation(s)
- Ariel Rokem
- The University of Washington eScience Institute, Seattle, WA, ://arokem.org
| | - Hiromasa Takemura
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Suita-shi, JapanGraduate School of Frontier Biosciences, Osaka University, Suita-shi,
| | | | | | | | | | - Ione Fine
- University of Washington, Seattle, WA,
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24
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Restani L, Caleo M. Reorganization of Visual Callosal Connections Following Alterations of Retinal Input and Brain Damage. Front Syst Neurosci 2016; 10:86. [PMID: 27895559 PMCID: PMC5107575 DOI: 10.3389/fnsys.2016.00086] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 10/25/2016] [Indexed: 01/16/2023] Open
Abstract
Vision is a very important sensory modality in humans. Visual disorders are numerous and arising from diverse and complex causes. Deficits in visual function are highly disabling from a social point of view and in addition cause a considerable economic burden. For all these reasons there is an intense effort by the scientific community to gather knowledge on visual deficit mechanisms and to find possible new strategies for recovery and treatment. In this review, we focus on an important and sometimes neglected player of the visual function, the corpus callosum (CC). The CC is the major white matter structure in the brain and is involved in information processing between the two hemispheres. In particular, visual callosal connections interconnect homologous areas of visual cortices, binding together the two halves of the visual field. This interhemispheric communication plays a significant role in visual cortical output. Here, we will first review the essential literature on the physiology of the callosal connections in normal vision. The available data support the view that the callosum contributes to both excitation and inhibition to the target hemisphere, with a dynamic adaptation to the strength of the incoming visual input. Next, we will focus on data showing how callosal connections may sense visual alterations and respond to the classical paradigm for the study of visual plasticity, i.e., monocular deprivation (MD). This is a prototypical example of a model for the study of callosal plasticity in pathological conditions (e.g., strabismus and amblyopia) characterized by unbalanced input from the two eyes. We will also discuss the findings of callosal alterations in blind subjects. Noteworthy, we will discuss data showing that inter-hemispheric transfer mediates recovery of visual responsiveness following cortical damage. Finally, we will provide an overview of how callosal projections dysfunction could contribute to pathologies such as neglect and occipital epilepsy. A particular focus will be on reviewing noninvasive brain stimulation techniques and optogenetic approaches that allow to selectively manipulate callosal function and to probe its involvement in cortical processing and plasticity. Overall, the data indicate that experience can potently impact on transcallosal connectivity, and that the callosum itself is crucial for plasticity and recovery in various disorders of the visual pathway.
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Affiliation(s)
- Laura Restani
- Neuroscience Institute, National Research Council (CNR) Pisa, Italy
| | - Matteo Caleo
- Neuroscience Institute, National Research Council (CNR) Pisa, Italy
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25
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Aguirre GK, Datta R, Benson NC, Prasad S, Jacobson SG, Cideciyan AV, Bridge H, Watkins KE, Butt OH, Dain AS, Brandes L, Gennatas ED. Patterns of Individual Variation in Visual Pathway Structure and Function in the Sighted and Blind. PLoS One 2016; 11:e0164677. [PMID: 27812129 PMCID: PMC5094697 DOI: 10.1371/journal.pone.0164677] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/28/2016] [Indexed: 11/18/2022] Open
Abstract
Many structural and functional brain alterations accompany blindness, with substantial individual variation in these effects. In normally sighted people, there is correlated individual variation in some visual pathway structures. Here we examined if the changes in brain anatomy produced by blindness alter the patterns of anatomical variation found in the sighted. We derived eight measures of central visual pathway anatomy from a structural image of the brain from 59 sighted and 53 blind people. These measures showed highly significant differences in mean size between the sighted and blind cohorts. When we examined the measurements across individuals within each group we found three clusters of correlated variation, with V1 surface area and pericalcarine volume linked, and independent of the thickness of V1 cortex. These two clusters were in turn relatively independent of the volumes of the optic chiasm and lateral geniculate nucleus. This same pattern of variation in visual pathway anatomy was found in the sighted and the blind. Anatomical changes within these clusters were graded by the timing of onset of blindness, with those subjects with a post-natal onset of blindness having alterations in brain anatomy that were intermediate to those seen in the sighted and congenitally blind. Many of the blind and sighted subjects also contributed functional MRI measures of cross-modal responses within visual cortex, and a diffusion tensor imaging measure of fractional anisotropy within the optic radiations and the splenium of the corpus callosum. We again found group differences between the blind and sighted in these measures. The previously identified clusters of anatomical variation were also found to be differentially related to these additional measures: across subjects, V1 cortical thickness was related to cross-modal activation, and the volume of the optic chiasm and lateral geniculate was related to fractional anisotropy in the visual pathway. Our findings show that several of the structural and functional effects of blindness may be reduced to a smaller set of dimensions. It also seems that the changes in the brain that accompany blindness are on a continuum with normal variation found in the sighted.
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Affiliation(s)
- Geoffrey K. Aguirre
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States of America
- * E-mail:
| | - Ritobrato Datta
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States of America
| | - Noah C. Benson
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States of America
| | - Sashank Prasad
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States of America
| | - Samuel G. Jacobson
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States of America
| | - Artur V. Cideciyan
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States of America
| | - Holly Bridge
- FMRIB Centre, Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, United Kingdom
| | - Kate E. Watkins
- Department of Experimental Psychology, University of Oxford, Oxford, OX1 3UD, United Kingdom
| | - Omar H. Butt
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States of America
| | - Aleksandra S. Dain
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States of America
| | - Lauren Brandes
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States of America
| | - Efstathios D. Gennatas
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States of America
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26
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Shi J, Collignon O, Xu L, Wang G, Kang Y, Leporé F, Lao Y, Joshi AA, Leporé N, Wang Y. Impact of Early and Late Visual Deprivation on the Structure of the Corpus Callosum: A Study Combining Thickness Profile with Surface Tensor-Based Morphometry. Neuroinformatics 2016; 13:321-336. [PMID: 25649876 DOI: 10.1007/s12021-014-9259-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Blindness represents a unique model to study how visual experience may shape the development of brain organization. Exploring how the structure of the corpus callosum (CC) reorganizes ensuing visual deprivation is of particular interest due to its important functional implication in vision (e.g., via the splenium of the CC). Moreover, comparing early versus late visually deprived individuals has the potential to unravel the existence of a sensitive period for reshaping the CC structure. Here, we develop a novel framework to capture a complete set of shape differences in the CC between congenitally blind (CB), late blind (LB) and sighted control (SC) groups. The CCs were manually segmented from T1-weighted brain MRI and modeled by 3D tetrahedral meshes. We statistically compared the combination of local area and thickness at each point between subject groups. Differences in area are found using surface tensor-based morphometry; thickness is estimated by tracing the streamlines in the volumetric harmonic field. Group differences were assessed on this combined measure using Hotelling's T(2) test. Interestingly, we observed that the total callosal volume did not differ between the groups. However, our fine-grained analysis reveals significant differences mostly localized around the splenium areas between both blind groups and the sighted group (general effects of blindness) and, importantly, specific dissimilarities between the LB and CB groups, illustrating the existence of a sensitive period for reorganization. The new multivariate statistics also gave better effect sizes for detecting morphometric differences, relative to other statistics. They may boost statistical power for CC morphometric analyses.
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Affiliation(s)
- Jie Shi
- School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, AZ, USA
| | | | - Liang Xu
- School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Gang Wang
- School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, AZ, USA
- School of Information and Electrical Engineering, Ludong University, Yantai, China
| | - Yue Kang
- Department of Radiology, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Franco Leporé
- Department of Psychology, University of Montreal, Montreal, QC, Canada
| | - Yi Lao
- Department of Radiology, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Anand A Joshi
- Signal and Image Processing Institute, Brain and Creativity Institute, University of Southern California, Los Angeles, CA, USA
| | - Natasha Leporé
- Department of Radiology, Children's Hospital Los Angeles, Los Angeles, CA, USA
- Department of Radiology & Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Yalin Wang
- School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, AZ, USA
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27
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Hasson U, Andric M, Atilgan H, Collignon O. Congenital blindness is associated with large-scale reorganization of anatomical networks. Neuroimage 2016; 128:362-372. [PMID: 26767944 PMCID: PMC4767220 DOI: 10.1016/j.neuroimage.2015.12.048] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 12/29/2015] [Accepted: 12/30/2015] [Indexed: 11/15/2022] Open
Abstract
Blindness is a unique model for understanding the role of experience in the development of the brain's functional and anatomical architecture. Documenting changes in the structure of anatomical networks for this population would substantiate the notion that the brain's core network-level organization may undergo neuroplasticity as a result of life-long experience. To examine this issue, we compared whole-brain networks of regional cortical-thickness covariance in early blind and matched sighted individuals. This covariance is thought to reflect signatures of integration between systems involved in similar perceptual/cognitive functions. Using graph-theoretic metrics, we identified a unique mode of anatomical reorganization in the blind that differed from that found for sighted. This was seen in that network partition structures derived from subgroups of blind were more similar to each other than they were to partitions derived from sighted. Notably, after deriving network partitions, we found that language and visual regions tended to reside within separate modules in sighted but showed a pattern of merging into shared modules in the blind. Our study demonstrates that early visual deprivation triggers a systematic large-scale reorganization of whole-brain cortical-thickness networks, suggesting changes in how occipital regions interface with other functional networks in the congenitally blind.
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Affiliation(s)
- Uri Hasson
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy.
| | - Michael Andric
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy
| | - Hicret Atilgan
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy
| | - Olivier Collignon
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy; CERNEC, Département de Psychologie, Université de Montréal, Montreal, QC, Canada
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28
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Simultaneous Assessment of White Matter Changes in Microstructure and Connectedness in the Blind Brain. Neural Plast 2016; 2016:6029241. [PMID: 26881120 PMCID: PMC4736370 DOI: 10.1155/2016/6029241] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/28/2015] [Indexed: 12/24/2022] Open
Abstract
Magnetic resonance imaging (MRI) of the human brain has provided converging evidence that visual deprivation induces regional changes in white matter (WM) microstructure. It remains unclear how these changes modify network connections between brain regions. Here we used diffusion-weighted MRI to relate differences in microstructure and structural connectedness of WM in individuals with congenital or late-onset blindness relative to normally sighted controls. Diffusion tensor imaging (DTI) provided voxel-specific microstructural features of the tissue, while anatomical connectivity mapping (ACM) assessed the connectedness of each voxel with the rest of the brain. ACM yielded reduced anatomical connectivity in the corpus callosum in individuals with congenital but not late-onset blindness. ACM did not identify any brain region where blindness resulted in increased anatomical connectivity. DTI revealed widespread microstructural differences as indexed by a reduced regional fractional anisotropy (FA). Blind individuals showed lower FA in the primary visual and the ventral visual processing stream relative to sighted controls regardless of the blindness onset. The results show that visual deprivation shapes WM microstructure and anatomical connectivity, but these changes appear to be spatially dissociated as changes emerge in different WM tracts. They also indicate that regional differences in anatomical connectivity depend on the onset of blindness.
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29
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Heine L, Bahri MA, Cavaliere C, Soddu A, Laureys S, Ptito M, Kupers R. Prevalence of increases in functional connectivity in visual, somatosensory and language areas in congenital blindness. Front Neuroanat 2015; 9:86. [PMID: 26190978 PMCID: PMC4486836 DOI: 10.3389/fnana.2015.00086] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 06/15/2015] [Indexed: 12/16/2022] Open
Abstract
There is ample evidence that congenitally blind individuals rely more strongly on non-visual information compared to sighted controls when interacting with the outside world. Although brain imaging studies indicate that congenitally blind individuals recruit occipital areas when performing various non-visual and cognitive tasks, it remains unclear through which pathways this is accomplished. To address this question, we compared resting state functional connectivity in a group of congenital blind and matched sighted control subjects. We used a seed-based analysis with a priori specified regions-of-interest (ROIs) within visual, somato-sensory, auditory and language areas. Between-group comparisons revealed increased functional connectivity within both the ventral and the dorsal visual streams in blind participants, whereas connectivity between the two streams was reduced. In addition, our data revealed stronger functional connectivity in blind participants between the visual ROIs and areas implicated in language and tactile (Braille) processing such as the inferior frontal gyrus (Broca's area), thalamus, supramarginal gyrus and cerebellum. The observed group differences underscore the extent of the cross-modal reorganization in the brain and the supra-modal function of the occipital cortex in congenitally blind individuals.
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Affiliation(s)
- Lizette Heine
- Coma Science Group, Cyclotron Research Center and Neurology Department, University and University Hospital of Liège Liège, Belgium
| | - Mohamed A Bahri
- Cyclotron Research Centre, University of Liège Liège, Belgium
| | - Carlo Cavaliere
- Coma Science Group, Cyclotron Research Center and Neurology Department, University and University Hospital of Liège Liège, Belgium ; IRCCS SDN, Istituto di Ricerca Diagnostica e Nucleare Naples, Italy
| | - Andrea Soddu
- Physics and Astronomy Department, Brain and Mind Institute, Western University London, ON, Canada
| | - Steven Laureys
- Coma Science Group, Cyclotron Research Center and Neurology Department, University and University Hospital of Liège Liège, Belgium
| | - Maurice Ptito
- Harland Sanders Chair, School of Optometry, University of Montreal Montreal, QC, Canada ; Brain Research and Integrative Neuroscience Laboratory, Department of Neuroscience and Pharmacology, University of Copenhagen Copenhagen, Denmark ; Laboratory of Neuropsychiatry, Psychiatric Centre Copenhagen and Department of Neuroscience and Pharmacology, University of Copenhagen Copenhagen, Denmark
| | - Ron Kupers
- Harland Sanders Chair, School of Optometry, University of Montreal Montreal, QC, Canada ; Brain Research and Integrative Neuroscience Laboratory, Department of Neuroscience and Pharmacology, University of Copenhagen Copenhagen, Denmark
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30
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Ansado J, Collins L, Fonov V, Garon M, Alexandrov L, Karama S, Evans A, Beauchamp MH. A new template to study callosal growth shows specific growth in anterior and posterior regions of the corpus callosum in early childhood. Eur J Neurosci 2015; 42:1675-84. [PMID: 25864842 DOI: 10.1111/ejn.12869] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/29/2015] [Accepted: 02/06/2015] [Indexed: 11/28/2022]
Abstract
Most of the studies conducted on the development of the corpus callosum (CC) have been limited to a relatively simple assessment of callosal area, providing an estimation of the size of the CC in two dimensions rather than its actual measurement. The goal of this study was to revisit callosal development in childhood and adolescence by using a three-dimensional (3D) magnetic resonance imaging template of the CC that considers the horizontal width of the CC and compares this with the two-dimensional (2D) callosal area. We mapped callosal growth in a large sample of youths followed longitudinally (N = 370 at T1; N = 304 at T2; and N = 246 at T3). Both techniques were based on a five-section subdivision of the CC. The results obtained with the 3D method revealed that the rate of CC growth over a 4-year period in the rostrum, the genu, the anterior body and the splenium was significantly higher in the youngest age group (< 7 years) than in older groups, indicating an intense period of development in early childhood for the anterior and posterior parts of the CC. Similar results were obtained when 2D callosal area was used for the anterior and posterior parts of the CC. However, divergent results were found in the mid-body and the caudal body of the CC. As shown by differences between 2D estimations and actual 3D measurements of callosal growth, our study highlights the importance of considering the horizontal width in measuring developmental changes in the CC.
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Affiliation(s)
- Jennyfer Ansado
- Ste-Justine Hospital Research Center, Montreal, QC, Canada.,Department of Psychology, University of Montreal, Montreal, QC, H3C 3J7, Canada.,Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Louis Collins
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada.,McConnell Brain Imaging Center, McGill University, Montreal, QC, Canada
| | - Vladimir Fonov
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada.,McConnell Brain Imaging Center, McGill University, Montreal, QC, Canada
| | - Mathieu Garon
- Ste-Justine Hospital Research Center, Montreal, QC, Canada.,Department of Psychology, University of Montreal, Montreal, QC, H3C 3J7, Canada
| | | | - Sherif Karama
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada.,McConnell Brain Imaging Center, McGill University, Montreal, QC, Canada
| | - Alan Evans
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada.,McConnell Brain Imaging Center, McGill University, Montreal, QC, Canada
| | - Miriam H Beauchamp
- Ste-Justine Hospital Research Center, Montreal, QC, Canada.,Department of Psychology, University of Montreal, Montreal, QC, H3C 3J7, Canada
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31
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Congenital blindness affects diencephalic but not mesencephalic structures in the human brain. Brain Struct Funct 2015; 221:1465-80. [DOI: 10.1007/s00429-014-0984-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 12/28/2014] [Indexed: 11/26/2022]
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