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Marins TF, Russo M, Rodrigues EC, Monteiro M, Moll J, Felix D, Bouzas J, Arcanjo H, Vargas CD, Tovar‐Moll F. Reorganization of thalamocortical connections in congenitally blind humans. Hum Brain Mapp 2023; 44:2039-2049. [PMID: 36661404 PMCID: PMC9980890 DOI: 10.1002/hbm.26192] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 11/14/2022] [Accepted: 11/24/2022] [Indexed: 01/21/2023] Open
Abstract
Cross-modal plasticity in blind individuals has been reported over the past decades showing that nonvisual information is carried and processed by "visual" brain structures. However, despite multiple efforts, the structural underpinnings of cross-modal plasticity in congenitally blind individuals remain unclear. We mapped thalamocortical connectivity and assessed the integrity of white matter of 10 congenitally blind individuals and 10 sighted controls. We hypothesized an aberrant thalamocortical pattern of connectivity taking place in the absence of visual stimuli from birth as a potential mechanism of cross-modal plasticity. In addition to the impaired microstructure of visual white matter bundles, we observed structural connectivity changes between the thalamus and occipital and temporal cortices. Specifically, the thalamic territory dedicated to connections with the occipital cortex was smaller and displayed weaker connectivity in congenitally blind individuals, whereas those connecting with the temporal cortex showed greater volume and increased connectivity. The abnormal pattern of thalamocortical connectivity included the lateral and medial geniculate nuclei and the pulvinar nucleus. For the first time in humans, a remapping of structural thalamocortical connections involving both unimodal and multimodal thalamic nuclei has been demonstrated, shedding light on the possible mechanisms of cross-modal plasticity in humans. The present findings may help understand the functional adaptations commonly observed in congenitally blind individuals.
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Affiliation(s)
- Theo F. Marins
- D'Or Institute for Research and Education (IDOR)Rio de JaneiroBrazil,Post‐Graduation Program in Morphological Sciences (PCM) of the Institute of Biomedical Sciences (ICB)Federal University of Rio de Janeiro (UFRJ)Rio de JaneiroBrazil
| | - Maite Russo
- Institute of Biophysics Carlos Chagas Filho (IBCCF)Federal University of Rio de Janeiro (UFRJ)Rio de JaneiroBrazil
| | | | - Marina Monteiro
- D'Or Institute for Research and Education (IDOR)Rio de JaneiroBrazil
| | - Jorge Moll
- D'Or Institute for Research and Education (IDOR)Rio de JaneiroBrazil
| | - Daniel Felix
- D'Or Institute for Research and Education (IDOR)Rio de JaneiroBrazil
| | - Julia Bouzas
- D'Or Institute for Research and Education (IDOR)Rio de JaneiroBrazil
| | - Helena Arcanjo
- Centro de Oftalmologia EspecializadaRio de JaneiroBrazil
| | - Claudia D. Vargas
- Institute of Biophysics Carlos Chagas Filho (IBCCF)Federal University of Rio de Janeiro (UFRJ)Rio de JaneiroBrazil
| | - Fernanda Tovar‐Moll
- D'Or Institute for Research and Education (IDOR)Rio de JaneiroBrazil,Post‐Graduation Program in Morphological Sciences (PCM) of the Institute of Biomedical Sciences (ICB)Federal University of Rio de Janeiro (UFRJ)Rio de JaneiroBrazil
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2
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Khalil R, Gonzalez C, Alsuwaidi S, Levitt JB. Developmental refinement of visual callosal inputs to ferret area 17. J Comp Neurol 2021; 530:804-816. [PMID: 34611910 DOI: 10.1002/cne.25246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 09/03/2021] [Accepted: 09/07/2021] [Indexed: 12/22/2022]
Abstract
Corticocortical connections link visual cortical areas in both the ipsilateral and contralateral hemispheres. We studied the postnatal refinement of callosal connections linking multiple cortical areas with ferret area 17 during the period from just before eye opening (4 weeks) to 10 weeks of age. We aimed to determine (1) whether callosal projections from multiple visual cortical areas to area 17 refine with a similar rate and (2) whether the refinement of callosal projections parallels that of intrahemispheric cortical circuits. We injected the bidirectional tracer CTb into area 17, and mapped the areal and laminar distribution of labeled cells in visual areas of the contralateral hemisphere. Like intrahemispheric projections, callosal inputs to area 17 before eye opening are dominated by Suprasylvian area Ssy (with lesser and comparable input from areas 17, 18, 19, and 21), but within 2 weeks of eye opening are jointly dominated by area 18 and Ssy inputs; however, there are fewer labeled cells in the contralateral hemisphere. Unlike intrahemispheric projections, there is no laminar reorganization of callosal inputs; in all visual areas and at all ages studied, the greatest proportion of callosal projections arises from the infragranular layers. Also, unlike intrahemispheric projections, the peak density of callosal cells in each area projecting to area 17 declines more modestly. These results reveal important similarities and differences in the postnatal reorganization of inter- and intrahemispheric projections to area 17.
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Affiliation(s)
- Reem Khalil
- Biology, Chemistry, and Environmental Sciences Department, American University of Sharjah, Sharjah, UAE.,Department of Biology MR526, City College of New York, New York, New York, USA.,Graduate Center of the City University of New York, New York, New York, USA
| | - Cyndi Gonzalez
- Department of Biology MR526, City College of New York, New York, New York, USA
| | - Shaima Alsuwaidi
- Biology, Chemistry, and Environmental Sciences Department, American University of Sharjah, Sharjah, UAE.,Douglas Mental Health University Institute, McGill University, Montreal, Quebec, Canada
| | - Jonathan B Levitt
- Department of Biology MR526, City College of New York, New York, New York, USA.,Graduate Center of the City University of New York, New York, New York, USA
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3
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Deng R, Kao JPY, Kanold PO. Aberrant development of excitatory circuits to inhibitory neurons in the primary visual cortex after neonatal binocular enucleation. Sci Rep 2021; 11:3163. [PMID: 33542365 PMCID: PMC7862622 DOI: 10.1038/s41598-021-82679-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 01/22/2021] [Indexed: 11/09/2022] Open
Abstract
The development of GABAergic interneurons is important for the functional maturation of cortical circuits. After migrating into the cortex, GABAergic interneurons start to receive glutamatergic connections from cortical excitatory neurons and thus gradually become integrated into cortical circuits. These glutamatergic connections are mediated by glutamate receptors including AMPA and NMDA receptors and the ratio of AMPA to NMDA receptors decreases during development. Since previous studies have shown that retinal input can regulate the early development of connections along the visual pathway, we investigated if the maturation of glutamatergic inputs to GABAergic interneurons in the visual cortex requires retinal input. We mapped the spatial pattern of glutamatergic connections to layer 4 (L4) GABAergic interneurons in mouse visual cortex at around postnatal day (P) 16 by laser-scanning photostimulation and investigated the effect of binocular enucleations at P1/P2 on these patterns. Gad2-positive interneurons in enucleated animals showed an increased fraction of AMPAR-mediated input from L2/3 and a decreased fraction of input from L5/6. Parvalbumin-expressing (PV) interneurons showed similar changes in relative connectivity. NMDAR-only input was largely unchanged by enucleation. Our results show that retinal input sculpts the integration of interneurons into V1 circuits and suggest that the development of AMPAR- and NMDAR-only connections might be regulated differently.
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Affiliation(s)
- Rongkang Deng
- Department of Biology, University of Maryland, College Park, MD, 20742, USA.,Biological Sciences Graduate Program, University of Maryland, College Park, 20742, MD, USA
| | - Joseph P Y Kao
- Center for Biomedical Engineering and Technology, and Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Patrick O Kanold
- Department of Biomedical Engineering, Johns Hopkins University, 379 Miller Res. Bldg, Baltimore, MD, 21205, USA. .,Department of Biology, University of Maryland, College Park, MD, 20742, USA.
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4
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Touj S, Gallino D, Chakravarty MM, Bronchti G, Piché M. Structural brain plasticity induced by early blindness. Eur J Neurosci 2020; 53:778-795. [PMID: 33113245 DOI: 10.1111/ejn.15028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/28/2020] [Accepted: 10/20/2020] [Indexed: 11/30/2022]
Abstract
It is well established that early blindness results in behavioural adaptations. While the functional effects of visual deprivation have been well researched, anatomical studies are scarce. The aim of this study was to investigate whole brain structural plasticity in a mouse model of congenital blindness. Volumetric analyses were conducted on high-resolution MRI images and histological sections from the same brains. These morphometric measurements were compared between anophthalmic and sighted ZRDBA mice obtained by breeding ZRDCT and DBA mice. Results from MRI analyses using the Multiple Automatically Generated Templates (MAGeT) method showed smaller volume for the primary visual cortex and superior colliculi in anophthalmic compared with sighted mice. Deformation-based morphometry revealed smaller volumes within the dorsal lateral geniculate nuclei and the lateral secondary visual cortex and larger volumes within olfactory areas, piriform cortex, orbital areas and the amygdala, in anophthalmic compared with sighted mice. Histological analyses revealed a larger volume for the amygdala and smaller volume for the superior colliculi, primary visual cortex and medial secondary visual cortex, in anophthalmic compared with sighted mice. The absence of superficial visual layers of the superior colliculus and the thinner cortical layer IV of the primary and secondary visual cortices may explain the smaller volume of these areas, although this was observed in a limited sample. The present study shows large-scale brain plasticity in a mouse model of congenital blindness. In addition, the congruence of MRI and histological findings support the use of MRI to investigate structural brain plasticity in the mouse.
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Affiliation(s)
- Sara Touj
- Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.,CogNAC Research Group, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Daniel Gallino
- Computational Brain Anatomy Laboratory, Brain Imaging Center, Douglas Mental Health University Institute, Verdun, QC, Canada
| | - Mallar M Chakravarty
- Computational Brain Anatomy Laboratory, Brain Imaging Center, Douglas Mental Health University Institute, Verdun, QC, Canada.,Department of Biological and Biomedical Engineering, McGill, Montréal, QC, Canada.,Department of Psychiatry, McGill, Montréal, QC, Canada
| | - Gilles Bronchti
- Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.,CogNAC Research Group, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Mathieu Piché
- Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.,CogNAC Research Group, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
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5
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Andelin AK, Olavarria JF, Fine I, Taber EN, Schwartz D, Kroenke CD, Stevens AA. The Effect of Onset Age of Visual Deprivation on Visual Cortex Surface Area Across-Species. Cereb Cortex 2020; 29:4321-4333. [PMID: 30561529 DOI: 10.1093/cercor/bhy315] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/25/2018] [Accepted: 11/23/2018] [Indexed: 12/21/2022] Open
Abstract
Blindness early in life induces permanent alterations in brain anatomy, including reduced surface area of primary visual cortex (V1). Bilateral enucleation early in development causes greater reductions in primary visual cortex surface area than at later times. However, the time at which cortical surface area expansion is no longer sensitive to enucleation is not clearly established, despite being an important milestone for cortical development. Using histological and MRI techniques, we investigated how reductions in the surface area of V1 depends on the timing of blindness onset in rats, ferrets and humans. To compare data across species, we translated ages of all species to a common neuro-developmental event-time (ET) scale. Consistently, blindness during early cortical expansion induced large (~40%) reductions in V1 surface area, in rats and ferrets, while blindness occurring later had diminishing effects. Longitudinal measurements on ferrets confirmed that early enucleation disrupted cortical expansion, rather than inducing enhanced pruning. We modeled the ET associated with the conclusion of the effect of blindness on surface area at maturity (ETc), relative to the normal conclusion of visual cortex surface area expansion, (ETdev). A final analysis combining our data with extant published data confirmed that ETc occurred well before ETdev.
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Affiliation(s)
- Adrian K Andelin
- Department of Psychology, University of Washington, Seattle, WA, USA
| | - Jaime F Olavarria
- Department of Psychology, University of Washington, Seattle, WA, USA
| | - Ione Fine
- Department of Psychology, University of Washington, Seattle, WA, USA
| | - Erin N Taber
- Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, USA
| | - Daniel Schwartz
- Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, USA
| | - Christopher D Kroenke
- Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, USA.,Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA.,Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, USA
| | - Alexander A Stevens
- Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, USA
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6
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Hutchinson EB, Schwerin SC, Radomski KL, Sadeghi N, Jenkins J, Komlosh ME, Irfanoglu MO, Juliano SL, Pierpaoli C. Population based MRI and DTI templates of the adult ferret brain and tools for voxelwise analysis. Neuroimage 2017; 152:575-589. [PMID: 28315740 PMCID: PMC6409125 DOI: 10.1016/j.neuroimage.2017.03.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/27/2017] [Accepted: 03/05/2017] [Indexed: 01/26/2023] Open
Abstract
Non-invasive imaging has the potential to play a crucial role in the characterization and translation of experimental animal models to investigate human brain development and disorders, especially when employed to study animal models that more accurately represent features of human neuroanatomy. The purpose of this study was to build and make available MRI and DTI templates and analysis tools for the ferret brain as the ferret is a well-suited species for pre-clinical MRI studies with folded cortical surface, relatively high white matter volume and body dimensions that allow imaging with pre-clinical MRI scanners. Four ferret brain templates were built in this study – in-vivo MRI and DTI and ex-vivo MRI and DTI – using brain images across many ferrets and region of interest (ROI) masks corresponding to established ferret neuroanatomy were generated by semi-automatic and manual segmentation. The templates and ROI masks were used to create a web-based ferret brain viewing software for browsing the MRI and DTI volumes with annotations based on the ROI masks. A second objective of this study was to provide a careful description of the imaging methods used for acquisition, processing, registration and template building and to demonstrate several voxelwise analysis methods including Jacobian analysis of morphometry differences between the female and male brain and bias-free identification of DTI abnormalities in an injured ferret brain. The templates, tools and methodological optimization presented in this study are intended to advance non-invasive imaging approaches for human-similar animal species that will enable the use of pre-clinical MRI studies for understanding and treating brain disorders.
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Affiliation(s)
- E B Hutchinson
- Section on Quantitative Imaging and Tissue Science, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA; The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA.
| | - S C Schwerin
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA; Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - K L Radomski
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA; Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - N Sadeghi
- Section on Quantitative Imaging and Tissue Science, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - J Jenkins
- Section on Quantitative Imaging and Tissue Science, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA; Dept. of Electrical Engineering and Computer Science, The Catholic University of America, Washington D.C., USA
| | - M E Komlosh
- Section on Quantitative Imaging and Tissue Science, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA; The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - M O Irfanoglu
- Section on Quantitative Imaging and Tissue Science, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA; The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - S L Juliano
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - C Pierpaoli
- Section on Quantitative Imaging and Tissue Science, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
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7
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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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8
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Effects of developmental alcohol and valproic acid exposure on play behavior of ferrets. Int J Dev Neurosci 2016; 52:75-81. [PMID: 27208641 DOI: 10.1016/j.ijdevneu.2016.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 03/11/2016] [Accepted: 03/15/2016] [Indexed: 01/27/2023] Open
Abstract
Exposure to alcohol and valproic acid (VPA) during pregnancy can lead to fetal alcohol spectrum disorders and fetal valproate syndrome, respectively. Altered social behavior is a hallmark of both these conditions and there is ample evidence showing that developmental exposure to alcohol and VPA affect social behavior in rodents. However, results from rodent models are somewhat difficult to translate to humans owing to the substantial differences in brain development, morphology, and connectivity. Since the cortex folding pattern is closely related to its specialization and that social behavior is strongly influenced by cortical structures, here we studied the effects of developmental alcohol and VPA exposure on the play behavior of the ferret, a gyrencephalic animal known for its playful nature. Animals were injected with alcohol (3.5g/kg, i.p.), VPA (200mg/kg, i.p.) or saline (i.p) every other day during the brain growth spurt period, between postnatal days 10 and 30. The play behavior of pairs of the same experimental group was evaluated 3 weeks later. Both treatments induced significant behavioral differences compared to controls. Alcohol and VPA exposed ferrets played less than saline treated ones, but while animals from the alcohol group displayed a delay in start playing with each other, VPA treated ones spent most of the time close to one another without playing. These findings not only extend previous results on the effects of developmental exposure to alcohol and VPA on social behavior, but make the ferret a great model to study the underlying mechanisms of social interaction.
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9
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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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10
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Bock AS, Fine I. Anatomical and functional plasticity in early blind individuals and the mixture of experts architecture. Front Hum Neurosci 2014; 8:971. [PMID: 25566016 PMCID: PMC4269126 DOI: 10.3389/fnhum.2014.00971] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 11/14/2014] [Indexed: 12/22/2022] Open
Abstract
As described elsewhere in this special issue, recent advances in neuroimaging over the last decade have led to a rapid expansion in our knowledge of anatomical and functional correlations within the normal and abnormal human brain. Here, we review how early blindness has been used as a model system for examining the role of visual experience in the development of anatomical connections and functional responses. We discuss how lack of power in group comparisons may provide a potential explanation for why extensive anatomical changes in cortico-cortical connectivity are not observed. Finally we suggest a framework-cortical specialization via hierarchical mixtures of experts-which offers some promise in reconciling a wide range of functional and anatomical data.
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Affiliation(s)
- Andrew S. Bock
- Department of Psychology, University of WashingtonSeattle, WA, USA
| | - Ione Fine
- Department of Psychology, University of WashingtonSeattle, WA, USA
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11
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Ackman JB, Crair MC. Role of emergent neural activity in visual map development. Curr Opin Neurobiol 2013; 24:166-75. [PMID: 24492092 DOI: 10.1016/j.conb.2013.11.011] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 11/12/2013] [Accepted: 11/22/2013] [Indexed: 11/24/2022]
Abstract
The initial structural and functional development of visual circuits in reptiles, birds, and mammals happens independent of sensory experience. After eye opening, visual experience further refines and elaborates circuits that are critical for normal visual function. Innate genetic programs that code for gradients of molecules provide gross positional information for developing nerve cells, yet much of the cytoarchitectural complexity and synaptogenesis of neurons depends on calcium influx, neurotransmitter release, and neural activity before the onset of vision. In fact, specific spatiotemporal patterns of neural activity, or 'retinal waves', emerge amidst the development of the earliest connections made between excitable cells in the developing eye. These patterns of spontaneous activity, which have been observed in all amniote retinae examined to date, may be an evolved adaptation for species with long gestational periods before the onset of functional vision, imparting an informational robustness and redundancy to guide development of visual maps across the nervous system. Recent experiments indicate that retinal waves play a crucial role in the development of interconnections between different parts of the visual system, suggesting that these spontaneous patterns serve as a template-matching mechanism to prepare higher-order visually associative circuits for the onset of visuomotor learning and behavior. Key questions for future studies include determining the exact sources and nature of spontaneous activity during development, characterizing the interactions between neural activity and transcriptional gene regulation, and understanding the extent of circuit connectivity governed by retinal waves within and between sensory-motor systems.
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Affiliation(s)
- James B Ackman
- Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510, United States
| | - Michael C Crair
- Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510, United States; Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, CT 06510, United States; Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT 06510, United States.
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12
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Neural pathways conveying novisual information to the visual cortex. Neural Plast 2013; 2013:864920. [PMID: 23840972 PMCID: PMC3690246 DOI: 10.1155/2013/864920] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Accepted: 05/22/2013] [Indexed: 11/18/2022] Open
Abstract
The visual cortex has been traditionally considered as a stimulus-driven, unimodal system with a hierarchical organization. However, recent animal and human studies have shown that the visual cortex responds to non-visual stimuli, especially in individuals with visual deprivation congenitally, indicating the supramodal nature of the functional representation in the visual cortex. To understand the neural substrates of the cross-modal processing of the non-visual signals in the visual cortex, we firstly showed the supramodal nature of the visual cortex. We then reviewed how the nonvisual signals reach the visual cortex. Moreover, we discussed if these non-visual pathways are reshaped by early visual deprivation. Finally, the open question about the nature (stimulus-driven or top-down) of non-visual signals is also discussed.
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13
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Bock AS, Saenz M, Tungaraza R, Boynton GM, Bridge H, Fine I. Visual callosal topography in the absence of retinal input. Neuroimage 2013; 81:325-334. [PMID: 23684881 DOI: 10.1016/j.neuroimage.2013.05.038] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 05/02/2013] [Accepted: 05/05/2013] [Indexed: 01/03/2023] Open
Abstract
Using probabilistic diffusion tractography, we examined the retinotopic organization of splenial callosal connections within early blind, anophthalmic, and control subjects. Early blind subjects experienced prenatal retinal "waves" of spontaneous activity similar to those of sighted subjects, and only lack postnatal visual experience. In anophthalmia, the eye is either absent or arrested at an early prenatal stage, depriving these subjects of both pre- and postnatal visual input. Therefore, comparing these two groups provides a way of separating the influence of pre- and postnatal retinal input on the organization of visual connections across hemispheres. We found that retinotopic mapping within the splenium was not measurably disrupted in early blind or anophthalmic subjects compared to visually normal controls. No significant differences in splenial volume were observed across groups. No significant differences in diffusivity were found between early blind subjects and sighted controls, though some differences in diffusivity were noted between anophthalmic subjects and controls. These results suggest that neither prenatal retinal activity nor postnatal visual experience plays a role in the large-scale topographic organization of visual callosal connections within the splenium.
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Affiliation(s)
- Andrew S Bock
- Department of Psychology, University of Washington, Seattle, WA 98195, USA.
| | - Melissa Saenz
- Department of Clinical Neuroscience, University of Lausanne, 1011 Lausanne, Switzerland
| | - Rosalia Tungaraza
- Integrated Brain Imaging Center (IBIC), Department of Radiology, University of Washington, Seattle, WA 98195, USA
| | - Geoffrey M Boynton
- Department of Psychology, University of Washington, Seattle, WA 98195, USA
| | - Holly Bridge
- FMRIB Centre, Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, United Kingdom
| | - Ione Fine
- Department of Psychology, University of Washington, Seattle, WA 98195, USA
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Altered white matter integrity in the congenital and late blind people. Neural Plast 2013; 2013:128236. [PMID: 23710371 PMCID: PMC3654351 DOI: 10.1155/2013/128236] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 04/01/2013] [Indexed: 11/18/2022] Open
Abstract
The blind subjects have experienced a series of brain structural and functional alterations due to the visual deprivation. It remains unclear as to whether white matter changes differ between blind subjects with visual deprivation before and after a critical developmental period. The present study offered a direct comparison in changes of white matter fractional anisotropy (FA) between congenital blind (CB) and late blind (LB) individuals. Twenty CB, 21 LB (blindness onset after 18 years old), and 40 sight control (SC) subjects were recruited. Both the tract-based spatial statistics (TBSS) and voxel-based analysis (VBA) showed lower FA in the bilateral optic radiations in both blind groups, suggesting that the loss of white matter integrity was the prominent hallmark in the blind people. The LB group showed more extensive white matter impairment than the CB group, indicating the mechanisms of white matter FA changes are different between the CB and LB groups. Using a loose threshold, a trend of an increased FA was found in the bilateral corticospinal tracts in the LB but with a smaller spatial extent relative to the CB. These results suggest that white matter FA changes in the blind subjects are the reflection of multiple mechanisms, including the axonal degeneration, deafferentation, and plasticity.
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15
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Laing RJ, Bock AS, Lasiene J, Olavarria JF. Role of retinal input on the development of striate-extrastriate patterns of connections in the rat. J Comp Neurol 2013; 520:3256-76. [PMID: 22430936 DOI: 10.1002/cne.23096] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Previous studies have shown that retinal input plays an important role in the development of interhemispheric callosal connections, but little is known about the role retinal input plays on the development of ipsilateral striate-extrastriate connections and the interplay that might exist between developing ipsilateral and callosal pathways. We analyzed the effects of bilateral enucleation performed at different ages on both the distribution of extrastriate projections originating from restricted loci in medial, acallosal striate cortex, and the overall pattern of callosal connections revealed following multiple tracer injections. As in normal rats, striate-extrastriate projections in rats enucleated at birth consisted of multiple, well-defined fields that were largely confined to acallosal regions throughout extrastriate cortex. However, these projections were highly irregular and variable, and they tended to occupy correspondingly anomalous and variable acallosal regions. Moreover, area 17, but not area 18a, was smaller in enucleates compared to controls, resulting in an increase in the divergence of striate projections. Anomalies in patterns of striate-extrastriate projections were not observed in rats enucleated at postnatal day (P)6, although the size of area 17 was still reduced in these rats. These results indicate that the critical period during which the eyes influence the development of striate-extrastriate, but not the size of striate cortex, ends by P6. Finally, enucleation did not change the time course and definition of the initial invasion of axons into gray matter, suggesting that highly variable striate projections patterns do not result from anomalous pruning of exuberant distributions of 17-18a fibers in gray matter.
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Affiliation(s)
- R J Laing
- Department of Psychology, and Behavior and Neuroscience program, University of Washington, Seattle, Washington 98195-1525, USA
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16
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Qin W, Liu Y, Jiang T, Yu C. The development of visual areas depends differently on visual experience. PLoS One 2013; 8:e53784. [PMID: 23308283 PMCID: PMC3538632 DOI: 10.1371/journal.pone.0053784] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 12/05/2012] [Indexed: 11/29/2022] Open
Abstract
Visual experience plays an important role in the development of the visual cortex; however, recent functional imaging studies have shown that the functional organization is preserved in several higher-tier visual areas in congenitally blind subjects, indicating that maturation of visual areas depend unequally on visual experience. In this study, we aim to validate this hypothesis using a multimodality MRI approach. We found increased cortical thickness in the congenitally blind was present in the early visual areas and absent in the higher-tier ones, suggesting that the structural development of the visual cortex depends hierarchically on visual experience. In congenitally blind subjects, the decreased resting-state functional connectivity with the primary somatosensory cortex was more prominent in the early visual areas than in the higher-tier ones and were more pronounced in the ventral stream than in the dorsal one, suggesting that the development of functional organization of the visual cortex also depends differently on visual experience. Moreover, congenitally blind subjects showed normal or increased functional connectivity between ipsilateral higher-tier and early visual areas, suggesting an indirect corticocortical pathway through which somatosenroy information can reach the early visual areas. These findings support our hypothesis that the development of visual areas depends differently on visual experience.
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Affiliation(s)
- Wen Qin
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Yong Liu
- LIAMA Center for Computational Medicine, National Laboratory of Pattern Recognition Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Tianzi Jiang
- LIAMA Center for Computational Medicine, National Laboratory of Pattern Recognition Institute of Automation, Chinese Academy of Sciences, Beijing, China
- * E-mail: (CY); (TJ)
| | - Chunshui Yu
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China
- Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China
- * E-mail: (CY); (TJ)
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17
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Deafferentation-induced plasticity of visual callosal connections: predicting critical periods and analyzing cortical abnormalities using diffusion tensor imaging. Neural Plast 2012; 2012:250196. [PMID: 23213572 PMCID: PMC3504471 DOI: 10.1155/2012/250196] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 10/01/2012] [Indexed: 12/23/2022] Open
Abstract
Callosal connections form elaborate patterns that bear close association with striate and extrastriate visual areas. Although it is known that retinal input is required for normal callosal development, there is little information regarding the period during which the retina is critically needed and whether this period correlates with the same developmental stage across species. Here we review the timing of this critical period, identified in rodents and ferrets by the effects that timed enucleations have on mature callosal connections, and compare it to other developmental milestones in these species. Subsequently, we compare these events to diffusion tensor imaging (DTI) measurements of water diffusion anisotropy within developing cerebral cortex. We observed that the relationship between the timing of the critical period and the DTI-characterized developmental trajectory is strikingly similar in rodents and ferrets, which opens the possibility of using cortical DTI trajectories for predicting the critical period in species, such as humans, in which this period likely occurs prenatally. Last, we discuss the potential of utilizing DTI to distinguish normal from abnormal cerebral cortical development, both within the context of aberrant connectivity induced by early retinal deafferentation, and more generally as a potential tool for detecting abnormalities associated with neurodevelopmental disorders.
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Knutsen AK, Kroenke CD, Chang YV, Taber LA, Bayly PV. Spatial and temporal variations of cortical growth during gyrogenesis in the developing ferret brain. ACTA ACUST UNITED AC 2012; 23:488-98. [PMID: 22368085 DOI: 10.1093/cercor/bhs042] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Spatial and temporal variations in cortical growth were studied in the neonatal ferret to illuminate the mechanisms of folding of the cerebral cortex. Cortical surface representations were created from magnetic resonance images acquired between postnatal day 4 and 35. Global measures of shape (e.g., surface area, normalized curvature, and sulcal depth) were calculated. In 2 ferrets, relative cortical growth was calculated between surfaces created from in vivo images acquired at P14, P21, and P28. The isocortical surface area transitions from a slower (12.7 mm(2)/day per hemisphere) to a higher rate of growth (36.7 mm(2)/day per hemisphere) approximately 13 days after birth, which coincides with the time of transition from neuronal proliferation to cellular morphological differentiation. Relative cortical growth increases as a function of relative geodesic distance from the origin of the transverse neurogenetic gradient and is related to the change in fractional diffusion anisotropy over the same time period. The methods presented here can be applied to study cortical growth during development in other animal models or human infants. Our results provide a quantitative spatial and temporal description of folding in cerebral cortex of the developing ferret brain, which will be important to understand the underlying mechanisms that drive folding.
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Affiliation(s)
- Andrew K Knutsen
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, Saint Louis, MO 63130, USA.
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Bock AS, Olavarria JF. Neonatal enucleation during a critical period reduces the precision of cortico-cortical projections in visual cortex. Neurosci Lett 2011; 501:152-6. [PMID: 21782890 DOI: 10.1016/j.neulet.2011.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Revised: 06/29/2011] [Accepted: 07/05/2011] [Indexed: 10/18/2022]
Abstract
Previous studies have reported that intrahemispheric connections between area 17 (V1, striate cortex) and other cortical visual areas are not point-to-point, but instead have some degree of convergence and divergence. Many pathological conditions can interfere with the normal development of patterns of cortico-cortical connections, but there is little information regarding whether or not early pathological insults can also induce permanent changes in the convergence and divergence of cortical connections. Obtaining this information is important because loss of precision in neural projections can contribute to functional deficits and behavioral impairment. In the present study we investigated whether retinal input is required for the development of normal values of convergence and divergence in the visual callosal pathway. We found that enucleation performed at birth induced significant increases in convergence and divergence compared to control animals. In contrast, values of convergence and divergence in rats enucleated at postnatal day 7 (P7) were similar to those in controls. Previous studies have shown that retinal input during the first postnatal week is required for the specification of the overall distribution and internal topography of visual callosal pathways. Our present results therefore extend these previous finding by showing that retinal input during the first postnatal week also specifies the precision of cortico-cortical projections. These findings raise the possibility that the precision of neural connections may be reduced in other pathological conditions that affect early development of neural connections.
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Affiliation(s)
- A S Bock
- Department of Psychology, Behavioral Neuroscience Program, University of Washington, Seattle, WA 98195-1525, USA
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