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Eysel UT, Jancke D. Induction of excitatory brain state governs plastic functional changes in visual cortical topology. Brain Struct Funct 2024; 229:531-547. [PMID: 38041743 PMCID: PMC10978694 DOI: 10.1007/s00429-023-02730-y] [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: 08/09/2023] [Accepted: 11/03/2023] [Indexed: 12/03/2023]
Abstract
Adult visual plasticity underlying local remodeling of the cortical circuitry in vivo appears to be associated with a spatiotemporal pattern of strongly increased spontaneous and evoked activity of populations of cells. Here we review and discuss pioneering work by us and others about principles of plasticity in the adult visual cortex, starting with our study which showed that a confined lesion in the cat retina causes increased excitability in the affected region in the primary visual cortex accompanied by fine-tuned restructuring of neuronal function. The underlying remodeling processes was further visualized with voltage-sensitive dye (VSD) imaging that allowed a direct tracking of retinal lesion-induced reorganization across horizontal cortical circuitries. Nowadays, application of noninvasive stimulation methods pursues the idea further of increased cortical excitability along with decreased inhibition as key factors for the induction of adult cortical plasticity. We used high-frequency transcranial magnetic stimulation (TMS), for the first time in combination with VSD optical imaging, and provided evidence that TMS-amplified excitability across large pools of neurons forms the basis for noninvasively targeting reorganization of orientation maps in the visual cortex. Our review has been compiled on the basis of these four own studies, which we discuss in the context of historical developments in the field of visual cortical plasticity and the current state of the literature. Overall, we suggest markers of LTP-like cortical changes at mesoscopic population level as a main driving force for the induction of visual plasticity in the adult. Elevations in excitability that predispose towards cortical plasticity are most likely a common property of all cortical modalities. Thus, interventions that increase cortical excitability are a promising starting point to drive perceptual and potentially motor learning in therapeutic applications.
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Affiliation(s)
- Ulf T Eysel
- Department of Neurophysiology, Ruhr University Bochum, 44780, Bochum, Germany.
| | - Dirk Jancke
- Optical Imaging Group, Institut für Neuroinformatik, Ruhr University Bochum, 44780, Bochum, Germany.
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2
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Brewer AA, Barton B. Cortical field maps across human sensory cortex. Front Comput Neurosci 2023; 17:1232005. [PMID: 38164408 PMCID: PMC10758003 DOI: 10.3389/fncom.2023.1232005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 11/07/2023] [Indexed: 01/03/2024] Open
Abstract
Cortical processing pathways for sensory information in the mammalian brain tend to be organized into topographical representations that encode various fundamental sensory dimensions. Numerous laboratories have now shown how these representations are organized into numerous cortical field maps (CMFs) across visual and auditory cortex, with each CFM supporting a specialized computation or set of computations that underlie the associated perceptual behaviors. An individual CFM is defined by two orthogonal topographical gradients that reflect two essential aspects of feature space for that sense. Multiple adjacent CFMs are then organized across visual and auditory cortex into macrostructural patterns termed cloverleaf clusters. CFMs within cloverleaf clusters are thought to share properties such as receptive field distribution, cortical magnification, and processing specialization. Recent measurements point to the likely existence of CFMs in the other senses, as well, with topographical representations of at least one sensory dimension demonstrated in somatosensory, gustatory, and possibly olfactory cortical pathways. Here we discuss the evidence for CFM and cloverleaf cluster organization across human sensory cortex as well as approaches used to identify such organizational patterns. Knowledge of how these topographical representations are organized across cortex provides us with insight into how our conscious perceptions are created from our basic sensory inputs. In addition, studying how these representations change during development, trauma, and disease serves as an important tool for developing improvements in clinical therapies and rehabilitation for sensory deficits.
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Affiliation(s)
- Alyssa A. Brewer
- mindSPACE Laboratory, Departments of Cognitive Sciences and Language Science (by Courtesy), Center for Hearing Research, University of California, Irvine, Irvine, CA, United States
| | - Brian Barton
- mindSPACE Laboratory, Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, United States
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3
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Demirayak P, Kıyı İ, İşbitiren YÖ, Yener G. Cognitive load associates prolonged P300 latency during target stimulus processing in individuals with mild cognitive impairment. Sci Rep 2023; 13:15956. [PMID: 37743392 PMCID: PMC10518304 DOI: 10.1038/s41598-023-43132-8] [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: 05/30/2023] [Accepted: 09/20/2023] [Indexed: 09/26/2023] Open
Abstract
Alterations in P300 amplitude and latency, as well as neuropsychological tests, are informative to detect early signs of the affected high cognitive processing in Mild Cognitive Impairment (MCI). In the present study, we examined P300 latency and amplitude elicited by visual oddball paradigm in 20 participants with MCI and age, education, and sex-matched healthy controls from frontal, central, and parietal midline electrodes. We performed a mixed-design ANOVA to compare P300 amplitude and latency between groups during target and non-target stimulus presentation. We also assessed the correlation between our electrophysiology findings and neuropsychological tests. Our results indicated that in healthy individuals P300 is elicited earlier in target stimulus processing compared to non-target stimulus processing. On the contrary, in the MCI group, P300 latency was increased during target processing compared to non-target stimulus processing. Moreover, P300 latency in target processing is prolonged in the MCI group compared to controls. Also, our correlation results showed a significant correlation between P300 peak latency and amplitude, and attention required cognitive tasks. In conclusion, our results provide evidence that high-order cognitive processes that are involved in stimulus processing slows down in individuals with MCI due to the high working memory demand for neural processing.
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Affiliation(s)
- Pinar Demirayak
- Civitan International Research Center, University of Alabama at Birmingham, 1719 6th Ave S Suite:252B, Birmingham, AL, 35233, USA.
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - İlayda Kıyı
- Department of Neurosciences, Institute of Health Sciences, Dokuz Eylül University, İzmir, Turkey
| | - Yağmur Özbek İşbitiren
- Department of Neurosciences, Institute of Health Sciences, Dokuz Eylül University, İzmir, Turkey
| | - Görsev Yener
- Brain Dynamics Multidisciplinary Research Center, Dokuz Eylül University, İzmir, Turkey
- Faculty of Medicine, İzmir University of Economics, İzmir, Turkey
- İzmir International Biomedicine and Genome Institute, Dokuz Eylül University, Izmir, Turkey
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4
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Defenderfer MK, Demirayak P, Fleming LL, DeCarlo DK, Stewart P, Visscher KM. Cortical plasticity in central vision loss: Cortical thickness and neurite structure. Hum Brain Mapp 2023; 44:4120-4135. [PMID: 37195035 PMCID: PMC10258531 DOI: 10.1002/hbm.26334] [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: 09/23/2022] [Revised: 04/24/2023] [Accepted: 04/28/2023] [Indexed: 05/18/2023] Open
Abstract
Late-stage macular degeneration (MD) often causes retinal lesions depriving an individual of central vision, forcing them to learn to use peripheral vision for daily tasks. To compensate, many patients develop a preferred retinal locus (PRL), an area of peripheral vision used more often than equivalent regions of spared vision. Thus, associated portions of cortex experience increased use, while portions of cortex associated with the lesion are deprived of sensory input. Prior research has not well examined the degree to which structural plasticity depends on the amount of use across the visual field. Cortical thickness, neurite density, and orientation dispersion were measured at portions of cortex associated with the PRL, the retinal lesion, and a control region in participants with MD as well as age-matched, gender-matched, and education-matched controls. MD participants had significantly thinner cortex in both the cortical representation of the PRL (cPRL) and the control region, compared with controls, but no significant differences in thickness, neurite density, or orientation dispersion were found between the cPRL and the control region as functions of disease or onset. This decrease in thickness is driven by a subset of early-onset participants whose patterns of thickness, neurite density, and neurite orientation dispersion are distinct from matched control participants. These results suggest that people who develop MD earlier in adulthood may undergo more structural plasticity than those who develop it late in life.
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Affiliation(s)
- Matthew K. Defenderfer
- Civitan International Research CenterUniversity of Alabama at BirminghamBirminghamAlabamaUSA
- Department of Neurobiology, Heersink School of MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Pinar Demirayak
- Civitan International Research CenterUniversity of Alabama at BirminghamBirminghamAlabamaUSA
- Department of Neurobiology, Heersink School of MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Leland L. Fleming
- Civitan International Research CenterUniversity of Alabama at BirminghamBirminghamAlabamaUSA
- Department of Neurobiology, Heersink School of MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Dawn K. DeCarlo
- Department of Ophthalmology, Heersink School of MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Paul Stewart
- Civitan International Research CenterUniversity of Alabama at BirminghamBirminghamAlabamaUSA
- Department of Neurobiology, Heersink School of MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Kristina M. Visscher
- Civitan International Research CenterUniversity of Alabama at BirminghamBirminghamAlabamaUSA
- Department of Neurobiology, Heersink School of MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
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5
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Carvalho J, Invernizzi A, Martins J, Renken RJ, Cornelissen FW. Local neuroplasticity in adult glaucomatous visual cortex. Sci Rep 2022; 12:21981. [PMID: 36539453 PMCID: PMC9767937 DOI: 10.1038/s41598-022-24709-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 11/18/2022] [Indexed: 12/24/2022] Open
Abstract
The degree to which the adult human visual cortex retains the ability to functionally adapt to damage at the level of the eye remains ill-understood. Previous studies on cortical neuroplasticity primarily focused on the consequences of foveal visual field defects (VFD), yet these findings may not generalize to peripheral defects such as occur in glaucoma. Moreover, recent findings on neuroplasticity are often based on population receptive field (pRF) mapping, but interpreting these results is complicated in the absence of appropriate control conditions. Here, we used fMRI-based neural modeling to assess putative changes in pRFs associated with glaucomatous VFD. We compared the fMRI-signals and pRF in glaucoma participants to those of controls with case-matched simulated VFD. We found that the amplitude of the fMRI-signal is reduced in glaucoma compared to control participants and correlated with disease severity. Furthermore, while coarse retinotopic structure is maintained in all participants with glaucoma, we observed local pRF shifts and enlargements in early visual areas, relative to control participants. These differences suggest that the adult brain retains some degree of local neuroplasticity. This finding has translational relevance, as it is consistent with VFD masking, which prevents glaucoma patients from noticing their VFD and seeking timely treatment.
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Affiliation(s)
- Joana Carvalho
- grid.4494.d0000 0000 9558 4598Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands ,grid.421010.60000 0004 0453 9636Pre-Clinical MRI Laboratory, Champalimaud Centre for the Unknown, Avenida de Brasilia, 1400-038 Lisbon, Portugal
| | - Azzurra Invernizzi
- grid.4494.d0000 0000 9558 4598Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands ,grid.59734.3c0000 0001 0670 2351Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Joana Martins
- grid.4494.d0000 0000 9558 4598Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Remco J. Renken
- grid.4494.d0000 0000 9558 4598Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands ,grid.4494.d0000 0000 9558 4598Cognitive Neuroscience Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Frans W. Cornelissen
- grid.4494.d0000 0000 9558 4598Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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6
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Caravaca-Rodriguez D, Gaytan SP, Suaning GJ, Barriga-Rivera A. Implications of Neural Plasticity in Retinal Prosthesis. Invest Ophthalmol Vis Sci 2022; 63:11. [PMID: 36251317 DOI: 10.1167/iovs.63.11.11] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Retinal degenerative diseases such as retinitis pigmentosa cause a progressive loss of photoreceptors that eventually prevents the affected person from perceiving visual sensations. The absence of a visual input produces a neural rewiring cascade that propagates along the visual system. This remodeling occurs first within the retina. Then, subsequent neuroplastic changes take place at higher visual centers in the brain, produced by either the abnormal neural encoding of the visual inputs delivered by the diseased retina or as the result of an adaptation to visual deprivation. While retinal implants can activate the surviving retinal neurons by delivering electric current, the unselective activation patterns of the different neural populations that exist in the retinal layers differ substantially from those in physiologic vision. Therefore, artificially induced neural patterns are being delivered to a brain that has already undergone important neural reconnections. Whether or not the modulation of this neural rewiring can improve the performance for retinal prostheses remains a critical question whose answer may be the enabler of improved functional artificial vision and more personalized neurorehabilitation strategies.
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Affiliation(s)
- Daniel Caravaca-Rodriguez
- Department of Applied Physics III, Technical School of Engineering, Universidad de Sevilla, Sevilla, Spain
| | - Susana P Gaytan
- Department of Physiology, Universidad de Sevilla, Sevilla, Spain
| | - Gregg J Suaning
- School of Biomedical Engineering, University of Sydney, Sydney, Australia
| | - Alejandro Barriga-Rivera
- Department of Applied Physics III, Technical School of Engineering, Universidad de Sevilla, Sevilla, Spain.,School of Biomedical Engineering, University of Sydney, Sydney, Australia
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7
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Mendoza M, Shotbolt M, Faiq MA, Parra C, Chan KC. Advanced Diffusion MRI of the Visual System in Glaucoma: From Experimental Animal Models to Humans. BIOLOGY 2022; 11:biology11030454. [PMID: 35336827 PMCID: PMC8945790 DOI: 10.3390/biology11030454] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 03/10/2022] [Indexed: 11/18/2022]
Abstract
Simple Summary This review summarizes current applications of advanced diffusion magnetic resonance imaging (MRI) throughout the glaucomatous visual system, focusing on the eye, optic nerve, optic tract, subcortical visual brain nuclei, optic radiations, and visual cortex. Glaucoma continues to be the leading cause of irreversible blindness worldwide and often remains undetected until later disease stages. The development of non-invasive methods for early detection of visual pathway integrity could pave the way for timely intervention and targeted treatment strategies. Principles of diffusion have been integrated with MRI protocols to produce a diffusion-weighted imaging modality for studying changes to tissue microstructures by quantifying the movement of water molecules in vivo. The development and applications of diffusion MRI in ophthalmology have allowed a better understanding of neural pathway changes in glaucoma. The feasibility of translating diffusion MRI techniques to assess both humans and experimental animal models of glaucoma and other optic neuropathies or neurodegenerative diseases is discussed. Recent research focuses on overcoming limitations in imaging quality, acquisition times, and biological interpretation suggest that diffusion MRI can provide an important tool for the non-invasive evaluation of glaucomatous changes in the visual system. Abstract Glaucoma is a group of ophthalmologic conditions characterized by progressive retinal ganglion cell death, optic nerve degeneration, and irreversible vision loss. While intraocular pressure is the only clinically modifiable risk factor, glaucoma may continue to progress at controlled intraocular pressure, indicating other major factors in contributing to the disease mechanisms. Recent studies demonstrated the feasibility of advanced diffusion magnetic resonance imaging (dMRI) in visualizing the microstructural integrity of the visual system, opening new possibilities for non-invasive characterization of glaucomatous brain changes for guiding earlier and targeted intervention besides intraocular pressure lowering. In this review, we discuss dMRI methods currently used in visual system investigations, focusing on the eye, optic nerve, optic tract, subcortical visual brain nuclei, optic radiations, and visual cortex. We evaluate how conventional diffusion tensor imaging, higher-order diffusion kurtosis imaging, and other extended dMRI techniques can assess the neuronal and glial integrity of the visual system in both humans and experimental animal models of glaucoma, among other optic neuropathies or neurodegenerative diseases. We also compare the pros and cons of these methods against other imaging modalities. A growing body of dMRI research indicates that this modality holds promise in characterizing early glaucomatous changes in the visual system, determining the disease severity, and identifying potential neurotherapeutic targets, offering more options to slow glaucoma progression and to reduce the prevalence of this world’s leading cause of irreversible but preventable blindness.
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Affiliation(s)
- Monica Mendoza
- Department of Biomedical Engineering, Tandon School of Engineering, New York University, New York, NY 11201, USA; (M.M.); (M.S.)
| | - Max Shotbolt
- Department of Biomedical Engineering, Tandon School of Engineering, New York University, New York, NY 11201, USA; (M.M.); (M.S.)
| | - Muneeb A. Faiq
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY 10017, USA; (M.A.F.); (C.P.)
| | - Carlos Parra
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY 10017, USA; (M.A.F.); (C.P.)
| | - Kevin C. Chan
- Department of Biomedical Engineering, Tandon School of Engineering, New York University, New York, NY 11201, USA; (M.M.); (M.S.)
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY 10017, USA; (M.A.F.); (C.P.)
- Department of Radiology, Neuroscience Institute, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY 10016, USA
- Correspondence:
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8
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Keliris GA, Shao Y, Schmid MC, Augath M, Logothetis NK, Smirnakis SM. Macaque Area V2/V3 Reorganization Following Homonymous Retinal Lesions. Front Neurosci 2022; 16:757091. [PMID: 35153666 PMCID: PMC8832035 DOI: 10.3389/fnins.2022.757091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 01/07/2022] [Indexed: 01/24/2023] Open
Abstract
In the adult visual system, topographic reorganization of the primary visual cortex (V1) after retinal lesions has been extensively investigated. In contrast, the plasticity of higher order extrastriate areas following retinal lesions is less well studied. Here, we used fMRI to study reorganization of visual areas V2/V3 following the induction of permanent, binocular, homonymous retinal lesions in 4 adult macaque monkeys. We found that the great majority of voxels that did not show visual modulation on the day of the lesion in the V2/V3 lesion projection zone (LPZ) demonstrated significant visual modulations 2 weeks later, and the mean modulation strength remained approximately stable thereafter for the duration of our observations (4-5 months). The distribution of eccentricities of visually modulated voxels inside the V2/V3 LPZ spanned a wider range post-lesion than pre-lesion, suggesting that neurons inside the LPZ reorganize by receiving input either from the foveal or the peripheral border of the LPZ, depending on proximity. Overall, we conclude that area V2/V3 of adult rhesus macaques displays a significant capacity for topographic reorganization following retinal lesions markedly exceeding the corresponding capacity of area V1.
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Affiliation(s)
- Georgios A. Keliris
- Physiology of Cognitive Processes, Max-Planck Institute for Biological Cybernetics, Tübingen, Germany,Bio-Imaging Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium,*Correspondence: Georgios A. Keliris,
| | - Yibin Shao
- Physiology of Cognitive Processes, Max-Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Michael C. Schmid
- Physiology of Cognitive Processes, Max-Planck Institute for Biological Cybernetics, Tübingen, Germany,Schmid Research Group, Medicine Section, University of Fribourg, Fribourg, Switzerland
| | - Mark Augath
- Physiology of Cognitive Processes, Max-Planck Institute for Biological Cybernetics, Tübingen, Germany,Institute of Biomedical Engineering, ETH Zurich, Zurich, Switzerland
| | - Nikos K. Logothetis
- Physiology of Cognitive Processes, Max-Planck Institute for Biological Cybernetics, Tübingen, Germany,International Center for Primate Brain Research, Shanghai, China,Division of Imaging Science and Biomedical Engineering, University of Manchester, Manchester, United Kingdom
| | - Stelios M. Smirnakis
- Department of Neurology, Brigham and Women’s Hospital and Jamaica Plain Veterans Administration Hospital, Harvard Medical School, Boston, MA, United States,Stelios M. Smirnakis,
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9
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Esquenazi RB, Meier K, Beyeler M, Boynton GM, Fine I. Learning to see again: Perceptual learning of simulated abnormal on- off-cell population responses in sighted individuals. J Vis 2021; 21:10. [PMID: 34935878 PMCID: PMC8727313 DOI: 10.1167/jov.21.13.10] [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] [Indexed: 11/24/2022] Open
Abstract
Many forms of artificial sight recovery, such as electronic implants and optogenetic proteins, generally cause simultaneous, rather than complementary firing of on- and off-center retinal cells. Here, using virtual patients—sighted individuals viewing distorted input—we examine whether plasticity might compensate for abnormal neuronal population responses. Five participants were dichoptically presented with a combination of original and contrast-reversed images. Each image (I) and its contrast-reverse (Iʹ) was filtered using a radial checkerboard (F) in Fourier space and its inverse (Fʹ). [I * F′] + [Iʹ * F] was presented to one eye, and [I * F] + [Iʹ * F′] was presented to the other, such that regions of the image that produced on-center responses in one eye produced off-center responses in the other eye, and vice versa. Participants continuously improved in a naturalistic object discrimination task over 20 one-hour sessions. Pre-training and post-training tests suggest that performance improvements were due to two learning processes: learning to recognize objects with reduced visual information and learning to suppress contrast-reversed image information in a non–eye-selective manner. These results suggest that, with training, it may be possible to adapt to the unnatural on- and off-cell population responses produced by electronic and optogenetic sight recovery technologies.
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Affiliation(s)
| | - Kimberly Meier
- Department of Psychology, University of Washington, USA.,
| | - Michael Beyeler
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, USA.,Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, California, USA.,
| | | | - Ione Fine
- Department of Psychology, University of Washington, USA.,
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10
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Carvalho J, Renken RJ, Cornelissen FW. Predictive masking of an artificial scotoma is associated with a system-wide reconfiguration of neural populations in the human visual cortex. Neuroimage 2021; 245:118690. [PMID: 34758382 DOI: 10.1016/j.neuroimage.2021.118690] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/19/2021] [Accepted: 10/28/2021] [Indexed: 11/29/2022] Open
Abstract
The visual brain has the remarkable capacity to complete our percept of the world even when the information extracted from the visual scene is incomplete. This ability to predict missing information based on information from spatially adjacent regions is an intriguing attribute of healthy vision. Yet, it gains particular significance when it masks the perceptual consequences of a retinal lesion, leaving patients unaware of their partial loss of vision and ultimately delaying diagnosis and treatment. At present, our understanding of the neural basis of this masking process is limited which hinders both quantitative modeling as well as translational application. To overcome this, we asked the participants to view visual stimuli with and without superimposed artificial scotoma (AS). We used fMRI to record the associated cortical activity and applied model-based analyzes to track changes in cortical population receptive fields and connectivity in response to the introduction of the AS. We found that throughout the visual field and cortical hierarchy, pRFs shifted their preferred position towards the AS border. Moreover, extrastriate areas biased their sampling of V1 towards sections outside the AS projection zone, thereby effectively masking the AS with signals from spared portions of the visual field. We speculate that the signals that drive these system-wide population modifications originate in extrastriate visual areas and, through feedback, also reconfigure the neural populations in the earlier visual areas.
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Affiliation(s)
- Joana Carvalho
- Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Laboratory of Preclinical MRI, Champalimaud Centre for the Unknown, Avenida de Brasília, Lisbon, Portugal 1400-038.
| | - Remco J Renken
- Cognitive Neuroscience Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Frans W Cornelissen
- Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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11
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Brown HDH, Gouws AD, Vernon RJW, Lawrence SJD, Donnelly G, Gill L, Gale RP, Baseler HA, Morland AB. Assessing functional reorganization in visual cortex with simulated retinal lesions. Brain Struct Funct 2021; 226:2855-2867. [PMID: 34529124 PMCID: PMC8541975 DOI: 10.1007/s00429-021-02366-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 08/23/2021] [Indexed: 11/07/2022]
Abstract
Macular
degeneration (MD) causes central vision loss, removing input to corresponding representations in the primary visual cortex. There is disagreement concerning whether the cortical regions deprived of input can remain responsive, and the source of reported cortical responses is still debated. To simulate MD in controls, normally sighted participants viewed a bright central disk to adapt the retina, creating a transient ‘retinal lesion’ during a functional MRI experiment. Participants viewed blocks of faces, scrambled faces and uniform grey stimuli, either passively or whilst performing a one-back task. To assess the impact of the simulated lesion, participants repeated the paradigm using a more conventional mean luminance simulated scotoma without adaptation. Our results suggest our attempt to create a more realistic simulation of a lesion did not impact on responses in the representation of the simulated lesion. While most participants showed no evidence of stimulus-driven activation within the lesion representation, a few individuals (22%) exhibited responses similar to a participant with juvenile MD who completed the same paradigm (without adaptation). Reliability analysis showed that responses in the representation of the lesion were generally consistent irrespective of whether positive or negative. We provide some evidence that peripheral visual stimulation can also produce responses in central representations in controls while performing a task. This suggests that the ‘signature of reorganization of visual processing’, is not found solely in patients with retinal lesions, consistent with the idea that activity may be driven by unmasked top–down feedback.
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Affiliation(s)
- Holly D H Brown
- Department of Psychology, University of York, York, UK.,York Neuroimaging Centre, University of York, York, UK.,York Biomedical Research Institute, University of York, York, UK
| | - André D Gouws
- Department of Psychology, University of York, York, UK.,York Neuroimaging Centre, University of York, York, UK
| | - Richard J W Vernon
- Department of Psychology, University of York, York, UK.,York Neuroimaging Centre, University of York, York, UK.,York Biomedical Research Institute, University of York, York, UK
| | - Samuel J D Lawrence
- Department of Psychology, University of York, York, UK.,York Neuroimaging Centre, University of York, York, UK
| | - Gemma Donnelly
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK
| | - Lorraine Gill
- Department of Psychology, University of York, York, UK
| | - Richard P Gale
- Department of Health Sciences, University of York, York, UK.,Academic Unit of Ophthalmology, York Teaching Hospital NHS Foundation Trust, York, UK
| | - Heidi A Baseler
- Department of Psychology, University of York, York, UK.,York Biomedical Research Institute, University of York, York, UK.,Hull York Medical School, University of York, York, UK
| | - Antony B Morland
- Department of Psychology, University of York, York, UK. .,York Neuroimaging Centre, University of York, York, UK. .,York Biomedical Research Institute, University of York, York, UK.
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12
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Klink PC, Aubry JF, Ferrera VP, Fox AS, Froudist-Walsh S, Jarraya B, Konofagou EE, Krauzlis RJ, Messinger A, Mitchell AS, Ortiz-Rios M, Oya H, Roberts AC, Roe AW, Rushworth MFS, Sallet J, Schmid MC, Schroeder CE, Tasserie J, Tsao DY, Uhrig L, Vanduffel W, Wilke M, Kagan I, Petkov CI. Combining brain perturbation and neuroimaging in non-human primates. Neuroimage 2021; 235:118017. [PMID: 33794355 PMCID: PMC11178240 DOI: 10.1016/j.neuroimage.2021.118017] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 03/07/2021] [Accepted: 03/22/2021] [Indexed: 12/11/2022] Open
Abstract
Brain perturbation studies allow detailed causal inferences of behavioral and neural processes. Because the combination of brain perturbation methods and neural measurement techniques is inherently challenging, research in humans has predominantly focused on non-invasive, indirect brain perturbations, or neurological lesion studies. Non-human primates have been indispensable as a neurobiological system that is highly similar to humans while simultaneously being more experimentally tractable, allowing visualization of the functional and structural impact of systematic brain perturbation. This review considers the state of the art in non-human primate brain perturbation with a focus on approaches that can be combined with neuroimaging. We consider both non-reversible (lesions) and reversible or temporary perturbations such as electrical, pharmacological, optical, optogenetic, chemogenetic, pathway-selective, and ultrasound based interference methods. Method-specific considerations from the research and development community are offered to facilitate research in this field and support further innovations. We conclude by identifying novel avenues for further research and innovation and by highlighting the clinical translational potential of the methods.
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Affiliation(s)
- P Christiaan Klink
- Department of Vision & Cognition, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands.
| | - Jean-François Aubry
- Physics for Medicine Paris, Inserm U1273, CNRS UMR 8063, ESPCI Paris, PSL University, Paris, France
| | - Vincent P Ferrera
- Department of Neuroscience & Department of Psychiatry, Columbia University Medical Center, New York, NY, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Andrew S Fox
- Department of Psychology & California National Primate Research Center, University of California, Davis, CA, USA
| | | | - Béchir Jarraya
- NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Institut National de la Santé et de la Recherche Médicale (INSERM), Cognitive Neuroimaging Unit, Université Paris-Saclay, France; Foch Hospital, UVSQ, Suresnes, France
| | - Elisa E Konofagou
- Ultrasound and Elasticity Imaging Laboratory, Department of Biomedical Engineering, Columbia University, New York, NY, USA; Department of Radiology, Columbia University, New York, NY, USA
| | - Richard J Krauzlis
- Laboratory of Sensorimotor Research, National Eye Institute, Bethesda, MD, USA
| | - Adam Messinger
- Laboratory of Brain and Cognition, National Institute of Mental Health, Bethesda, MD, USA
| | - Anna S Mitchell
- Department of Experimental Psychology, Oxford University, Oxford, United Kingdom
| | - Michael Ortiz-Rios
- Newcastle University Medical School, Newcastle upon Tyne NE1 7RU, United Kingdom; German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Hiroyuki Oya
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Department of Neurosurgery, University of Iowa, Iowa city, IA, USA
| | - Angela C Roberts
- Department of Physiology, Development and Neuroscience, Cambridge University, Cambridge, United Kingdom
| | - Anna Wang Roe
- Interdisciplinary Institute of Neuroscience and Technology, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | | | - Jérôme Sallet
- Department of Experimental Psychology, Oxford University, Oxford, United Kingdom; Univ Lyon, Université Lyon 1, Inserm, Stem Cell and Brain Research Institute, U1208 Bron, France; Wellcome Centre for Integrative Neuroimaging, Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Michael Christoph Schmid
- Newcastle University Medical School, Newcastle upon Tyne NE1 7RU, United Kingdom; Faculty of Science and Medicine, University of Fribourg, Chemin du Musée 5, CH-1700 Fribourg, Switzerland
| | - Charles E Schroeder
- Nathan Kline Institute, Orangeburg, NY, USA; Columbia University, New York, NY, USA
| | - Jordy Tasserie
- NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Institut National de la Santé et de la Recherche Médicale (INSERM), Cognitive Neuroimaging Unit, Université Paris-Saclay, France
| | - Doris Y Tsao
- Division of Biology and Biological Engineering, Tianqiao and Chrissy Chen Institute for Neuroscience; Howard Hughes Medical Institute; Computation and Neural Systems, Caltech, Pasadena, CA, USA
| | - Lynn Uhrig
- NeuroSpin, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Institut National de la Santé et de la Recherche Médicale (INSERM), Cognitive Neuroimaging Unit, Université Paris-Saclay, France
| | - Wim Vanduffel
- Laboratory for Neuro- and Psychophysiology, Neurosciences Department, KU Leuven Medical School, Leuven, Belgium; Leuven Brain Institute, KU Leuven, Leuven Belgium; Harvard Medical School, Boston, MA, USA; Massachusetts General Hospital, Martinos Center for Biomedical Imaging, Charlestown, MA, USA
| | - Melanie Wilke
- German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany; Department of Cognitive Neurology, University Medicine Göttingen, Göttingen, Germany
| | - Igor Kagan
- German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany.
| | - Christopher I Petkov
- Newcastle University Medical School, Newcastle upon Tyne NE1 7RU, United Kingdom.
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13
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van den Boom M, Miller KJ, Gregg NM, Ojeda Valencia G, Lee KH, Richner TJ, Ramsey NF, Worrell GA, Hermes D. Typical somatomotor physiology of the hand is preserved in a patient with an amputated arm: An ECoG case study. Neuroimage Clin 2021; 31:102728. [PMID: 34182408 PMCID: PMC8253998 DOI: 10.1016/j.nicl.2021.102728] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/17/2021] [Accepted: 05/10/2021] [Indexed: 12/03/2022]
Abstract
Electrophysiological signals in the human motor system may change in different ways after deafferentation, with some studies emphasizing reorganization while others propose retained physiology. Understanding whether motor electrophysiology is retained over longer periods of time can be invaluable for patients with paralysis (e.g. ALS or brainstem stroke) when signals from sensorimotor areas may be used for communication or control over neural prosthetic devices. In addition, a maintained electrophysiology can potentially benefit the treatment of phantom limb pains through prolonged use of these signals in a brain-machine interface (BCI). Here, we were presented with the unique opportunity to investigate the physiology of the sensorimotor cortex in a patient with an amputated arm using electrocorticographic (ECoG) measurements. While implanted with an ECoG grid for clinical evaluation of electrical stimulation for phantom limb pain, the patient performed attempted finger movements with the contralateral (lost) hand and executed finger movements with the ipsilateral (healthy) hand. The electrophysiology of the sensorimotor cortex contralateral to the amputated hand remained very similar to that of hand movement in healthy people, with a spatially focused increase of high-frequency band (65-175 Hz; HFB) power over the hand region and a distributed decrease in low-frequency band (15-28 Hz; LFB) power. The representation of the three different fingers (thumb, index and little) remained intact and HFB patterns could be decoded using support vector learning at single-trial classification accuracies of >90%, based on the first 1-3 s of the HFB response. These results indicate that hand representations are largely retained in the motor cortex. The intact physiological response of the amputated hand, the high distinguishability of the fingers and fast temporal peak are encouraging for neural prosthetic devices that target the sensorimotor cortex.
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Affiliation(s)
- Max van den Boom
- Department of Physiology and Biomedical Engineering, Mayo Clinic Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA; Department of Neurology & Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
| | - Kai J Miller
- Department of Neurosurgery, Mayo Clinic Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Nicholas M Gregg
- Department of Neurology, Mayo Clinic Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Gabriela Ojeda Valencia
- Department of Physiology and Biomedical Engineering, Mayo Clinic Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Kendall H Lee
- Department of Neurosurgery, Mayo Clinic Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Thomas J Richner
- Department of Neurosurgery, Mayo Clinic Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Nick F Ramsey
- Department of Neurology & Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Greg A Worrell
- Department of Neurology, Mayo Clinic Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
| | - Dora Hermes
- Department of Physiology and Biomedical Engineering, Mayo Clinic Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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14
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Morland AB, Brown HDH, Baseler HA. Cortical Reorganization: Reallocated Responses without Rewiring. Curr Biol 2021; 31:R76-R78. [PMID: 33497635 DOI: 10.1016/j.cub.2020.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Is the brain able to reorganise following loss of sensory input? New work on individuals with sight loss shows that, while brain areas normally allocated to vision respond to other sensory stimuli, those responses are unlikely to mean the brain has rewired.
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Affiliation(s)
- Antony B Morland
- Department of Psychology, University of York, York, UK; York Biomedical Research Institute, University of York, York, UK.
| | - Holly D H Brown
- Department of Psychology, University of York, York, UK; York Biomedical Research Institute, University of York, York, UK
| | - Heidi A Baseler
- York Biomedical Research Institute, University of York, York, UK; Hull-York Medical School, York, UK
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15
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Levi DM. Amblyopia. HANDBOOK OF CLINICAL NEUROLOGY 2021; 178:13-30. [PMID: 33832673 DOI: 10.1016/b978-0-12-821377-3.00002-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Amblyopia is a neurodevelopmental abnormality that results in physiological alterations in the visual pathways and impaired vision in one eye, less commonly in both. It reflects a broad range of neural, perceptual, oculomotor, and clinical abnormalities that can occur when normal visual development is disrupted early in life. Aside from refractive error, amblyopia is the most common cause of vision loss in infants and young children. It causes a constellation of perceptual deficits in the vision of the amblyopic eye, including a loss of visual acuity, position acuity, and contrast sensitivity, particularly at high spatial frequencies, as well as increased internal noise and prolonged manual and saccadic reaction times. There are also perceptual deficits in the strong eye, such as certain types of motion perception, reflecting altered neural responses and functional connectivity in visual cortex (Ho et al., 2005). Treatment in young children consists of correction of any refractive error and patching of the strong eye. Compliance with patching is challenging and a substantial proportion of amblyopic children fail to achieve normal acuity or stereopsis even after extended periods of treatment. There are a number of promising experimental treatments that may improve compliance and outcomes, such as the playing of action video games with the strong eye patched. Although there may be a sensitive period for optimal effects of treatment, there is evidence that amblyopic adults may still show some benefit of treatment. However, there is as yet no consensus on the treatment of adults with amblyopia.
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Affiliation(s)
- Dennis M Levi
- School of Optometry & Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, United States.
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16
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Chen Y, Ko H, Zemelman BV, Seidemann E, Nauhaus I. Uniform spatial pooling explains topographic organization and deviation from receptive-field scale invariance in primate V1. Nat Commun 2020; 11:6390. [PMID: 33319775 PMCID: PMC7738493 DOI: 10.1038/s41467-020-19954-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 11/06/2020] [Indexed: 11/29/2022] Open
Abstract
Receptive field (RF) size and preferred spatial frequency (SF) vary greatly across the primary visual cortex (V1), increasing in a scale invariant fashion with eccentricity. Recent studies reveal that preferred SF also forms a fine-scale periodic map. A fundamental open question is how local variability in preferred SF is tied to the overall spatial RF. Here, we use two-photon imaging to simultaneously measure maps of RF size, phase selectivity, SF bandwidth, and orientation bandwidth—all of which were found to be topographically organized and correlate with preferred SF. Each of these newly characterized inter-map relationships strongly deviate from scale invariance, yet reveal a common motif—they are all accounted for by a model with uniform spatial pooling from scale invariant inputs. Our results and model provide novel and quantitative understanding of the output from V1 to downstream circuits. Two-photon imaging in macaque V1 captured maps of tuning selectivity for four spatial parameters, all of which correlated with peak spatial frequency. These inter-map relationships reveal a common motif—they are described by uniform spatial pooling from a family of scale invariant Gabor receptive fields.
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Affiliation(s)
- Y Chen
- Department of Psychology, University of Texas, Austin, TX, USA.,Department of Neuroscience, University of Texas, Austin, TX, USA.,Center for Perceptual Systems, University of Texas, Austin, TX, USA
| | - H Ko
- Department of Psychology, University of Texas, Austin, TX, USA.,Center for Perceptual Systems, University of Texas, Austin, TX, USA
| | - B V Zemelman
- Department of Neuroscience, University of Texas, Austin, TX, USA.,Center for Learning and Memory, University of Texas, Austin, TX, USA
| | - E Seidemann
- Department of Psychology, University of Texas, Austin, TX, USA.,Department of Neuroscience, University of Texas, Austin, TX, USA.,Center for Perceptual Systems, University of Texas, Austin, TX, USA
| | - I Nauhaus
- Department of Psychology, University of Texas, Austin, TX, USA. .,Department of Neuroscience, University of Texas, Austin, TX, USA. .,Center for Perceptual Systems, University of Texas, Austin, TX, USA.
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17
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Muret D, Makin TR. The homeostatic homunculus: rethinking deprivation-triggered reorganisation. Curr Opin Neurobiol 2020; 67:115-122. [PMID: 33248404 DOI: 10.1016/j.conb.2020.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/15/2020] [Accepted: 08/16/2020] [Indexed: 12/16/2022]
Abstract
While amputation was considered a prominent model for cortical reorganisation, recent evidence highlights persistent representation of the missing hand. We offer a new perspective on the literature of amputation-triggered sensorimotor plasticity, by emphasising the need for homeostasis and emerging evidence of latent activity distributed across the homunculus. We argue that deprivation uncovers pre-existing latent activity, which can manifest as remapping, but that since this activity was already there, remapping could in some instances correspond to functional stability of the system rather than reorganisation. Adaptive behaviour and Hebbian-like plasticity may also play crucial roles in maintaining the functional organisation of the homunculus when deprivation occurs in adulthood or in early development. Collectively, we suggest that the brain's need for stability may underlie several key phenotypes for brain remapping, previously interpreted as consequential to reorganisation. Nevertheless, reorganisation may still be possible, especially when cortical changes contribute to the stability of the system.
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Affiliation(s)
- Dollyane Muret
- Institute of Cognitive Neuroscience, University College London, London, United Kingdom
| | - Tamar R Makin
- Institute of Cognitive Neuroscience, University College London, London, United Kingdom.
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18
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V1 Projection Zone Signals in Human Macular Degeneration Depend on Task Despite Absence of Visual Stimulus. Curr Biol 2020; 31:406-412.e3. [PMID: 33157025 DOI: 10.1016/j.cub.2020.10.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/12/2020] [Accepted: 10/12/2020] [Indexed: 11/23/2022]
Abstract
Identifying the plastic and stable components of the visual cortex after retinal loss is an important topic in visual neuroscience and neuro-ophthalmology.1-5 Humans with juvenile macular degeneration (JMD) show significant blood-oxygen-level-dependent (BOLD) responses in the primary visual area (V1) lesion projection zone (LPZ),6 despite the absence of the feedforward signals from the degenerated retina. Our previous study7 reported that V1 LPZ responds to full-field visual stimuli during the one-back task (OBT), not during passive viewing, suggesting the involvement of task-related feedback signals. Aiming to clarify whether visual inputs to the intact retina are necessary for the LPZ responses, here, we measured BOLD responses to tactile and auditory stimuli for both JMD patients and control participants with and without OBT. Participants were instructed to close their eyes during the experiment for the purpose of eliminating retinal inputs. Without OBT, no V1 responses were detected in both groups of participants. With OBT, to the contrary, both stimuli caused substantial V1 responses in JMD patients, but not controls. Furthermore, we also found that the task-dependent activity in V1 LPZ became less pronounced when JMD patients opened their eyes, suggesting that task-related feedback signals can be partially suppressed by residual feedforward signals. Modality-independent V1 LPZ responses only in the task condition suggest that V1 LPZ responses reflect task-related feedback signals rather than reorganized feedforward visual inputs.
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19
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Abstract
Recent work has transformed our ideas about the neural mechanisms, behavioral consequences and effective therapies for amblyopia. Since the 1700's, the clinical treatment for amblyopia has consisted of patching or penalizing the strong eye, to force the "lazy" amblyopic eye, to work. This treatment has generally been limited to infants and young children during a sensitive period of development. Over the last 20 years we have learned much about the nature and neural mechanisms underlying the loss of spatial and binocular vision in amblyopia, and that a degree of neural plasticity persists well beyond the sensitive period. Importantly, the last decade has seen a resurgence of research into new approaches to the treatment of amblyopia both in children and adults, which emphasize that monocular therapies may not be the most effective for the fundamentally binocular disorder that is amblyopia. These approaches include perceptual learning, video game play and binocular methods aimed at reducing inhibition of the amblyopic eye by the strong fellow eye, and enhancing binocular fusion and stereopsis. This review focuses on the what we've learned over the past 20 years or so, and will highlight both the successes of these new treatment approaches in labs around the world, and their failures in clinical trials. Reconciling these results raises important new questions that may help to focus future directions.
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Affiliation(s)
- Dennis M Levi
- University of California, Berkeley, School of Optometry & Helen Wills Neuroscience Institute, Berkeley, CA, USA.
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20
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Maniglia M, Soler V, Trotter Y. Combining fixation and lateral masking training enhances perceptual learning effects in patients with macular degeneration. J Vis 2020; 20:19. [PMID: 33064123 PMCID: PMC7571291 DOI: 10.1167/jov.20.10.19] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Macular degeneration (MD), a retinal disease affecting central vision, represents the leading cause of visual impairment in the Western world, and MD patients face severe limitations in daily activities like reading and face recognition. A common compensation strategy adopted by these patients involves the use of a region in the spared peripheral retina as a new fixation spot and oculomotor reference (preferred retinal locus, or PRL). Still, peripheral vision is characterized by poorer visual acuity, fixation stability, and larger crowding zones that further hinder processes like object recognition, visual search, and reading. Perceptual learning (PL) has been successfully used to improve visual acuity in mild visual conditions (e.g., presbyopia, amblyopia and myopia), but results in MD are less clear, often showing limited generalization of learning, unlike what is observed in a healthy population. A possible reason is the suboptimal fixation in the PRL that might prevent patients from processing the briefly presented training stimuli. Following this hypothesis, we trained five MD patients and four age- and eccentricity-matched controls with a protocol that combined contrast detection and a task previously used to train fixation stability. Results showed transfer of learning to crowding reduction, reading speed, and visual acuity in both MD patients and controls. These results suggest that in the case of central vision loss, PL training might benefit from the integration of oculomotor components to optimize the effect of training and promote transfer of learning to other visual functions.
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Affiliation(s)
- Marcello Maniglia
- UC Riverside, Riverside, CA, USA.,Université de Toulouse-UPS, Centre de Recherche Cerveau et Cognition, Toulouse, France.,Centre National de la Recherche Scientifique, Toulouse Cedex, France.,
| | - Vincent Soler
- Unité de rétine, consultation d'ophtalmologie, hôpital Pierre-Paul-Riquet, CHU de Toulouse, Toulouse Cedex, France.,
| | - Yves Trotter
- Université de Toulouse-UPS, Centre de Recherche Cerveau et Cognition, Toulouse, France.,Centre National de la Recherche Scientifique, Toulouse Cedex, France.,
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21
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van de Ven GM, Siegelmann HT, Tolias AS. Brain-inspired replay for continual learning with artificial neural networks. Nat Commun 2020; 11:4069. [PMID: 32792531 PMCID: PMC7426273 DOI: 10.1038/s41467-020-17866-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 07/23/2020] [Indexed: 01/18/2023] Open
Abstract
Artificial neural networks suffer from catastrophic forgetting. Unlike humans, when these networks are trained on something new, they rapidly forget what was learned before. In the brain, a mechanism thought to be important for protecting memories is the reactivation of neuronal activity patterns representing those memories. In artificial neural networks, such memory replay can be implemented as ‘generative replay’, which can successfully – and surprisingly efficiently – prevent catastrophic forgetting on toy examples even in a class-incremental learning scenario. However, scaling up generative replay to complicated problems with many tasks or complex inputs is challenging. We propose a new, brain-inspired variant of replay in which internal or hidden representations are replayed that are generated by the network’s own, context-modulated feedback connections. Our method achieves state-of-the-art performance on challenging continual learning benchmarks (e.g., class-incremental learning on CIFAR-100) without storing data, and it provides a novel model for replay in the brain. One challenge that faces artificial intelligence is the inability of deep neural networks to continuously learn new information without catastrophically forgetting what has been learnt before. To solve this problem, here the authors propose a replay-based algorithm for deep learning without the need to store data.
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Affiliation(s)
- Gido M van de Ven
- Center for Neuroscience and Artificial Intelligence, Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA. .,Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK.
| | - Hava T Siegelmann
- College of Computer and Information Sciences, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Andreas S Tolias
- Center for Neuroscience and Artificial Intelligence, Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Electrical and Computer Engineering, Rice University, Houston, TX, 77251, USA
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22
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Care RA, Kastner DB, De la Huerta I, Pan S, Khoche A, Della Santina L, Gamlin C, Santo Tomas C, Ngo J, Chen A, Kuo YM, Ou Y, Dunn FA. Partial Cone Loss Triggers Synapse-Specific Remodeling and Spatial Receptive Field Rearrangements in a Mature Retinal Circuit. Cell Rep 2020; 27:2171-2183.e5. [PMID: 31091454 PMCID: PMC6624172 DOI: 10.1016/j.celrep.2019.04.065] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/11/2019] [Accepted: 04/12/2019] [Indexed: 11/30/2022] Open
Abstract
Resilience of neural circuits has been observed in the persistence of function despite neuronal loss. In vision, acuity and sensitivity can be retained after 50% loss of cones. While neurons in the cortex can remodel after input loss, the contributions of cell-type-specific circuits to resilience are unknown. Here, we study the effects of partial cone loss in mature mouse retina where cell types and connections are known. At first-order synapses, bipolar cell dendrites remodel and synaptic proteins diminish at sites of input loss. Sites of remaining inputs preserve synaptic proteins. Second-order synapses between bipolar and ganglion cells remain stable. Functionally, ganglion cell spatio-temporal receptive fields retain center-surround structure following partial cone loss. We find evidence for slower temporal filters and expanded receptive field surrounds, derived mainly from inhibitory inputs. Surround expansion is absent in partially stimulated control retina. Results demonstrate functional resilience to input loss beyond pre-existing mechanisms in control retina. Care et al. find that photoreceptor ablation causes structural rearrangement of bipolar cell input synapses while output synapses endure. Functionally, recipient ganglion cells show altered receptive field sizes, an effect not seen after partial stimulation of control retina, demonstrating de novo changes that occur in inhibitory circuitry after photoreceptor loss.
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Affiliation(s)
- Rachel A Care
- Graduate Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA
| | - David B Kastner
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Irina De la Huerta
- Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Simon Pan
- Graduate Program in Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Atrey Khoche
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Luca Della Santina
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Clare Gamlin
- Program in Neuroscience, Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Chad Santo Tomas
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Jenita Ngo
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Allen Chen
- Department of Neuroscience, University of Rochester, Rochester, NY 14627, USA
| | - Yien-Ming Kuo
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Yvonne Ou
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Felice A Dunn
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, USA.
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23
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Rapid topographic reorganization in adult human primary visual cortex (V1) during noninvasive and reversible deprivation. Proc Natl Acad Sci U S A 2020; 117:11059-11067. [PMID: 32354998 DOI: 10.1073/pnas.1921860117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Can the primary visual cortex (V1), once wired up in development, change in adulthood? Although numerous studies have demonstrated topographic reorganization in adult V1 following the loss of bottom-up input, others have challenged such findings, offering alternative explanations. Here we use a noninvasive and reversible deprivation paradigm and converging neural and behavioral approaches to address these alternatives in the experimental test case of short-term topographic reorganization in adult human V1. Specifically, we patched one eye in typical adults, thereby depriving the cortical representation of the other eye's blind spot (BS), and immediately tested for topographic reorganization using functional magnetic resonance imaging and psychophysics. Strikingly, within just minutes of eye-patching, the BS representation in V1 began responding to stimuli presented outside of the BS, and these same stimuli were perceived as elongated toward the BS. Thus, we provide converging neural and behavioral evidence of rapid topographic reorganization in adult human V1, and the strongest evidence yet that visual deprivation produces bona fide cortical change.
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24
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Castaldi E, Lunghi C, Morrone MC. Neuroplasticity in adult human visual cortex. Neurosci Biobehav Rev 2020; 112:542-552. [DOI: 10.1016/j.neubiorev.2020.02.028] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 12/30/2019] [Accepted: 02/20/2020] [Indexed: 12/27/2022]
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25
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Persic D, Thomas ME, Pelekanos V, Ryugo DK, Takesian AE, Krumbholz K, Pyott SJ. Regulation of auditory plasticity during critical periods and following hearing loss. Hear Res 2020; 397:107976. [PMID: 32591097 PMCID: PMC8546402 DOI: 10.1016/j.heares.2020.107976] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/15/2020] [Accepted: 04/14/2020] [Indexed: 02/07/2023]
Abstract
Sensory input has profound effects on neuronal organization and sensory maps in the brain. The mechanisms regulating plasticity of the auditory pathway have been revealed by examining the consequences of altered auditory input during both developmental critical periods—when plasticity facilitates the optimization of neural circuits in concert with the external environment—and in adulthood—when hearing loss is linked to the generation of tinnitus. In this review, we summarize research identifying the molecular, cellular, and circuit-level mechanisms regulating neuronal organization and tonotopic map plasticity during developmental critical periods and in adulthood. These mechanisms are shared in both the juvenile and adult brain and along the length of the auditory pathway, where they serve to regulate disinhibitory networks, synaptic structure and function, as well as structural barriers to plasticity. Regulation of plasticity also involves both neuromodulatory circuits, which link plasticity with learning and attention, as well as ascending and descending auditory circuits, which link the auditory cortex and lower structures. Further work identifying the interplay of molecular and cellular mechanisms associating hearing loss-induced plasticity with tinnitus will continue to advance our understanding of this disorder and lead to new approaches to its treatment. During CPs, brain plasticity is enhanced and sensitive to acoustic experience. Enhanced plasticity can be reinstated in the adult brain following hearing loss. Molecular, cellular, and circuit-level mechanisms regulate CP and adult plasticity. Plasticity resulting from hearing loss may contribute to the emergence of tinnitus. Modifying plasticity in the adult brain may offer new treatments for tinnitus.
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Affiliation(s)
- Dora Persic
- University of Groningen, University Medical Center Groningen, Groningen, Department of Otorhinolaryngology and Head/Neck Surgery, 9713, GZ, Groningen, the Netherlands
| | - Maryse E Thomas
- Eaton-Peabody Laboratories, Massachusetts Eye & Ear and Department of Otorhinolaryngology and Head/Neck Surgery, Harvard Medical School, Boston, MA, USA
| | - Vassilis Pelekanos
- Hearing Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, University Park, Nottingham, UK
| | - David K Ryugo
- Hearing Research, Garvan Institute of Medical Research, Sydney, NSW, 2010, Australia; School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia; Department of Otolaryngology, Head, Neck & Skull Base Surgery, St Vincent's Hospital, Sydney, NSW, 2010, Australia
| | - Anne E Takesian
- Eaton-Peabody Laboratories, Massachusetts Eye & Ear and Department of Otorhinolaryngology and Head/Neck Surgery, Harvard Medical School, Boston, MA, USA
| | - Katrin Krumbholz
- Hearing Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, University Park, Nottingham, UK
| | - Sonja J Pyott
- University of Groningen, University Medical Center Groningen, Groningen, Department of Otorhinolaryngology and Head/Neck Surgery, 9713, GZ, Groningen, the Netherlands.
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26
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Raffin E, Salamanca-Giron RF, Hummel FC. Perspectives: Hemianopia-Toward Novel Treatment Options Based on Oscillatory Activity? Neurorehabil Neural Repair 2019; 34:13-25. [PMID: 31858874 DOI: 10.1177/1545968319893286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Stroke has become one of the main causes of visual impairment, with more than 15 million incidences of first-time strokes, per year, worldwide. One-third of stroke survivors exhibit visual impairment, and most of them will not fully recover. Some recovery is possible, but this usually happens in the first few weeks after a stroke. Most of the rehabilitation options that are offered to patients are compensatory, such as optical aids or eye training. However, these techniques do not seem to provide a sufficient amount of improvement transferable to everyday life. Based on the relatively recent idea that the visual system can actually recover from a chronic lesion, visual retraining protocols have emerged, sometimes even in combination with noninvasive brain stimulation (NIBS), to further boost plastic changes in the residual visual tracts and network. The present article reviews the underlying mechanisms supporting visual retraining and describes the first clinical trials that applied NIBS combined with visual retraining. As a further perspective, it gathers the scientific evidence demonstrating the relevance of interregional functional synchronization of brain networks for visual field recovery, especially the causal role of α and γ oscillations in parieto-occipital regions. Because transcranial alternating current stimulation (tACS) can induce frequency-specific entrainment and modulate spike timing-dependent plasticity, we present a new promising interventional approach, consisting of applying physiologically motivated tACS protocols based on multifocal cross-frequency brain stimulation of the visuoattentional network for visual field recovery.
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Affiliation(s)
- Estelle Raffin
- Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland.,Swiss Federal Institute of Technology (EPFL Valais), Sion, Switzerland.,Clinique Romande de Réadaptation, Sion, Switzerland
| | | | - Friedhelm Christoph Hummel
- Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland.,Swiss Federal Institute of Technology (EPFL Valais), Sion, Switzerland.,Clinique Romande de Réadaptation, Sion, Switzerland.,University of Geneva Medical School, Geneva, Switzerland
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27
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Mancini F, Wang AP, Schira MM, Isherwood ZJ, McAuley JH, Iannetti GD, Sereno MI, Moseley GL, Rae CD. Fine-Grained Mapping of Cortical Somatotopies in Chronic Complex Regional Pain Syndrome. J Neurosci 2019; 39:9185-9196. [PMID: 31570533 PMCID: PMC6855684 DOI: 10.1523/jneurosci.2005-18.2019] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 08/13/2019] [Accepted: 08/19/2019] [Indexed: 01/21/2023] Open
Abstract
It has long been thought that severe chronic pain conditions, such as complex regional pain syndrome (CRPS), are not only associated with, but even maintained by a reorganization of the somatotopic representation of the affected limb in primary somatosensory cortex (S1). This notion has driven treatments that aim to restore S1 representations in CRPS patients, such as sensory discrimination training and mirror therapy. However, this notion is based on both indirect and incomplete evidence obtained with imaging methods with low spatial resolution. Here, we used fMRI to characterize the S1 representation of the affected and unaffected hand in humans (of either sex) with unilateral CRPS. The cortical area, location, and geometry of the S1 representation of the CRPS hand were largely comparable with those of both the unaffected hand and healthy controls. We found no differential relation between affected versus unaffected hand map measures and clinical measures (pain severity, upper limb disability, disease duration). Thus, if any map reorganization occurs, it does not appear to be directly related to pain and disease severity. These findings compel us to reconsider the cortical mechanisms underlying CRPS and the rationale for interventions that aim to "restore" somatotopic representations to treat pain.SIGNIFICANCE STATEMENT This study shows that the spatial map of the fingers in somatosensory cortex is largely preserved in chronic complex regional pain syndrome (CRPS). These findings challenge the treatment rationale for restoring somatotopic representations in complex regional pain syndrome patients.
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Affiliation(s)
- Flavia Mancini
- Computational and Biological Learning, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom,
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Audrey P Wang
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- Faculty of Medicine and Health and Faculty of Health Sciences, University of Sydney, Sydney, New South Wales 2145, Australia
| | - Mark M Schira
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Psychology, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Zoey J Isherwood
- School of Psychology, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - James H McAuley
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Giandomenico D Iannetti
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
- Neuroscience and Behaviour Laboratory, Istituto Italiano di Tecnologia, Rome 00161, Italy
| | - Martin I Sereno
- Department of Psychology, University College London, London WC1E 6BT, United Kingdom
- Department of Psychology, San Diego State University, San Diego, California 92182, and
| | - G Lorimer Moseley
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- IMPACT in Health, University of South Australia, Adelaide, South Australia, Australia
| | - Caroline D Rae
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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28
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Haak KV, Beckmann CF. Plasticity versus stability across the human cortical visual connectome. Nat Commun 2019; 10:3174. [PMID: 31320643 PMCID: PMC6639412 DOI: 10.1038/s41467-019-11113-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 06/18/2019] [Indexed: 11/09/2022] Open
Abstract
Whether and how the balance between plasticity and stability varies across the brain is an important open question. Within a processing hierarchy, it is thought that plasticity is increased at higher levels of cortical processing, but direct quantitative comparisons between low- and high-level plasticity have not been made so far. Here, we address this issue for the human cortical visual system. We quantify plasticity as the complement of the heritability of resting-state functional connectivity and thereby demonstrate a non-monotonic relationship between plasticity and hierarchical level, such that plasticity decreases from early to mid-level cortex, and then increases further of the visual hierarchy. This non-monotonic relationship argues against recent theory that the balance between plasticity and stability is governed by the costs of the "coding-catastrophe", and can be explained by a concurrent decline of short-term adaptation and rise of long-term plasticity up the visual processing hierarchy.
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Affiliation(s)
- Koen V Haak
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6500HB, Nijmegen, The Netherlands.
| | - Christian F Beckmann
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6500HB, Nijmegen, The Netherlands.,Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), University of Oxford, Oxford, OX3 9DU, UK
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29
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Abstract
The noninvasive estimation of neuronal receptive field (RF) properties in vivo allows a detailed understanding of brain organization as well as its plasticity by longitudinal following of potential changes. Visual RFs measured invasively by electrophysiology in animal models have traditionally provided a great extent of our current knowledge about the visual brain and its disorders. Voxel-based estimates of population RF (pRF) by functional magnetic resonance imaging (fMRI) in humans revolutionized the field and have been used extensively in numerous studies. However, current methods cannot estimate single-neuron RF sizes as they reflect large populations of neurons with individual RF scatter. Here, we introduce an approach to estimate RF size using spatial frequency selectivity to checkerboard patterns. This method allowed us to obtain noninvasive, average single-neuron RF estimates over a large portion of human early visual cortex. These estimates were significantly smaller compared with prior pRF methods. Furthermore, fMRI and electrophysiology experiments in nonhuman primates demonstrated an exceptionally good match, validating the approach.
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30
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Maniglia M, Seitz AR. A New Look at Visual System Plasticity. Trends Cogn Sci 2019; 23:82-83. [DOI: 10.1016/j.tics.2018.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 11/08/2018] [Indexed: 11/29/2022]
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31
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Monegato M, Cattaneo Z, Pece A, Vecchi T. Comparing the Effects of Congenital and Late Visual Impairments on Visuospatial Mental Abilities. JOURNAL OF VISUAL IMPAIRMENT & BLINDNESS 2019. [DOI: 10.1177/0145482x0710100503] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study compared participants who were congenitally visually impaired and those who became visually impaired later in life in a spatial memory task. The latter showed less efficient visuospatial processes than did the former. However, these differences were of a quantitative nature only, indicating common cognitive mechanisms that can be clearly differentiated from those of people who are congenitally blind.
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Affiliation(s)
- Maura Monegato
- Department of Psychology, University of Pavia, Piazza Botta 6, 27100 Pavia, Italy, and optometrist, Ophthalmology Unit, Melegnano Hospital, Via Pandina 1, Vizzolo Predabissi (MI), Italy
| | | | - Alfredo Pece
- Department chair, Ophthalmology Unit, Melegnano Hospital, Italy
| | - Tomaso Vecchi
- Professor of experimental psychology, Department of Psychology, University of Pavia, Italy
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32
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Takahata T, Patel NB, Balaram P, Chino YM, Kaas JH. Long-term histological changes in the macaque primary visual cortex and the lateral geniculate nucleus after monocular deprivation produced by early restricted retinal lesions and diffuser induced form deprivation. J Comp Neurol 2018; 526:2955-2972. [PMID: 30004587 DOI: 10.1002/cne.24494] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 06/02/2018] [Accepted: 06/15/2018] [Indexed: 12/12/2022]
Abstract
Ocular dominance (OD) plasticity has been extensively studied in various mammalian species. While robust OD shifts are typically observed after monocular eyelid suture, relatively poor OD plasticity is observed for early eye removal or after tetrodotoxin (TTX) injections in mice. Hence, abnormal binocular signal interactions in the visual cortex may play a critical role in eliciting OD plasticity. Here, we examined the histochemical changes in the lateral geniculate nucleus (LGN) and the striate cortex (V1) in macaque monkeys that experienced two different monocular sensory deprivations in the same eye beginning at 3 weeks of age: restricted laser lesions in macular or peripheral retina and form deprivation induced by wearing a diffuser lens during the critical period. The monkeys were subsequently reared for 5 years under a normal visual environment. In the LGN, atrophy of neurons and a dramatic increase of GFAP expression were observed in the lesion projection zones (LPZs). In V1, although no obvious shift of the LPZ border was found, the ocular dominance columns (ODCs) for the lesioned eye shrunk and those for the intact eye expanded over the entirety of V1. This ODC size change was larger in the area outside the LPZ and in the region inside the LPZ near the border compared to that in the LPZ center. These developmental changes may reflect abnormal binocular interactions in V1 during early infancy. Our observations provide insights into the nature of degenerative and plastic changes in the LGN and V1 following early chronic monocular sensory deprivations.
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Affiliation(s)
- Toru Takahata
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.,Department of Psychology, Vanderbilt University, Nashville, Tennessee
| | - Nimesh B Patel
- Department of Vision Sciences, College of Optometry, University of Houston, Houston, Texas
| | - Pooja Balaram
- Department of Psychology, Vanderbilt University, Nashville, Tennessee.,Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
| | - Yuzo M Chino
- Department of Vision Sciences, College of Optometry, University of Houston, Houston, Texas
| | - Jon H Kaas
- Department of Psychology, Vanderbilt University, Nashville, Tennessee
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33
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Dumoulin SO, Knapen T. How Visual Cortical Organization Is Altered by Ophthalmologic and Neurologic Disorders. Annu Rev Vis Sci 2018; 4:357-379. [DOI: 10.1146/annurev-vision-091517-033948] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Receptive fields are a core property of cortical organization. Modern neuroimaging allows routine access to visual population receptive fields (pRFs), enabling investigations of clinical disorders. Yet how the underlying neural circuitry operates is controversial. The controversy surrounds observations that measurements of pRFs can change in healthy adults as well as in patients with a range of ophthalmological and neurological disorders. The debate relates to the balance between plasticity and stability of the underlying neural circuitry. We propose that to move the debate forward, the field needs to define the implied mechanism. First, we review the pRF changes in both healthy subjects and those with clinical disorders. Then, we propose a computational model that describes how pRFs can change in healthy humans. We assert that we can correctly interpret the pRF changes in clinical disorders only if we establish the capabilities and limitations of pRF dynamics in healthy humans with mechanistic models that provide quantitative predictions.
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Affiliation(s)
- Serge O. Dumoulin
- Spinoza Centre for Neuroimaging, 1105 BK Amsterdam, Netherlands
- Department of Experimental and Applied Psychology, VU University Amsterdam, 1181 BT Amsterdam, Netherlands
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University, 3584 CS Utrecht, Netherlands
| | - Tomas Knapen
- Spinoza Centre for Neuroimaging, 1105 BK Amsterdam, Netherlands
- Department of Experimental and Applied Psychology, VU University Amsterdam, 1181 BT Amsterdam, Netherlands
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34
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Abstract
AbstractIn age-related macular degeneration (AMD), the processing of fine details in a visual scene, based on a high spatial frequency processing, is impaired, while the processing of global shapes, based on a low spatial frequency processing, is relatively well preserved. The present fMRI study aimed to investigate the residual abilities and functional brain changes of spatial frequency processing in visual scenes in AMD patients. AMD patients and normally sighted elderly participants performed a categorization task using large black and white photographs of scenes (indoors vs. outdoors) filtered in low and high spatial frequencies, and nonfiltered. The study also explored the effect of luminance contrast on the processing of high spatial frequencies. The contrast across scenes was either unmodified or equalized using a root-mean-square contrast normalization in order to increase contrast in high-pass filtered scenes. Performance was lower for high-pass filtered scenes than for low-pass and nonfiltered scenes, for both AMD patients and controls. The deficit for processing high spatial frequencies was more pronounced in AMD patients than in controls and was associated with lower activity for patients than controls not only in the occipital areas dedicated to central and peripheral visual fields but also in a distant cerebral region specialized for scene perception, the parahippocampal place area. Increasing the contrast improved the processing of high spatial frequency content and spurred activation of the occipital cortex for AMD patients. These findings may lead to new perspectives for rehabilitation procedures for AMD patients.
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35
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Najarpour Foroushani A, Pack CC, Sawan M. Cortical visual prostheses: from microstimulation to functional percept. J Neural Eng 2018; 15:021005. [DOI: 10.1088/1741-2552/aaa904] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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36
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Abstract
Much remains to be understood about visual system malfunction following injury. The resulting deficits range from dense, visual field scotomas to mild dysfunction of visual perception. Despite the predictive value of anatomical localization studies, much patient-to-patient variability remains regarding (a) perceptual abilities following injury and (b) the capacity of individual patients for visual rehabilitation. Visual field perimetry is used to characterize the visual field deficits that result from visual system injury. However, standard perimetry mapping does not always precisely correspond to underlying anatomical or functional deficits. Functional magnetic resonance imaging can be used to probe the function of surviving visual circuits, allowing us to classify better how the pattern of injury relates to residual visual perception. Identifying pathways that are potentially modifiable by training may guide the development of improved strategies for visual rehabilitation. This review discusses primary visual cortex lesions, which cause dense contralateral scotomas.
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Affiliation(s)
- Stelios M Smirnakis
- Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts 02115.,Department of Neurology, Jamaica Plain Campus, Veterans Administration Boston Healthcare System, Boston, Massachusetts 02130.,Harvard Medical School, Boston, Massachusetts 02115;
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37
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Maniglia M, Soler V, Cottereau B, Trotter Y. Spontaneous and training-induced cortical plasticity in MD patients: Hints from lateral masking. Sci Rep 2018; 8:90. [PMID: 29311565 PMCID: PMC5758612 DOI: 10.1038/s41598-017-18261-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 12/04/2017] [Indexed: 12/04/2022] Open
Abstract
Macular degeneration (MD) affects central vision and represents the leading cause of visual diseases in elderly population worldwide. As a consequence of central vision loss, MD patients develop a preferred retinal locus (PRL), an eccentric fixation point that replaces the fovea. Here, our aim was to determine whether and to what extent spontaneous plasticity takes place in the cortical regions formerly responding to central vision and whether a visual training based on perceptual learning (PL) can boost this plasticity within the PRL area. Spontaneous and PL-induced cortical plasticity were characterized by using lateral masking, a contrast sensitivity modulation induced by collinear flankers. This configuration is known to be sensitive to neural plasticity and underlies several rehabilitation trainings. Results in a group of 4 MD patients showed that collinear facilitation was similar to what observed in age- and eccentricity-matched controls. However, MD patients exhibited significantly reduced collinear inhibition, a sign of neural plasticity, consistent with the hypothesis of partial cortical reorganization. Three AMD patients from the same group showed a further reduction of inhibition after training, but not controls. This result suggests that PL might further boost neural plasticity, opening promising perspectives for the development of rehabilitation protocols for MD patients.
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Affiliation(s)
- Marcello Maniglia
- UC Riverside, Riverside, California, USA. .,Université de Toulouse-UPS, Centre de Recherche Cerveau et Cognition, Toulouse, France. .,Centre National de la Recherche Scientifique, Toulouse, Cedex, France.
| | - Vincent Soler
- Unité de rétine, consultation d'ophtalmologie, hôpital Pierre-Paul-Riquet, CHU de Toulouse, place Baylac, 31059, Toulouse, cedex, France
| | - Benoit Cottereau
- Université de Toulouse-UPS, Centre de Recherche Cerveau et Cognition, Toulouse, France.,Centre National de la Recherche Scientifique, Toulouse, Cedex, France
| | - Yves Trotter
- Université de Toulouse-UPS, Centre de Recherche Cerveau et Cognition, Toulouse, France.,Centre National de la Recherche Scientifique, Toulouse, Cedex, France
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38
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Simmons AB, Bloomsburg SJ, Sukeena JM, Miller CJ, Ortega-Burgos Y, Borghuis BG, Fuerst PG. DSCAM-mediated control of dendritic and axonal arbor outgrowth enforces tiling and inhibits synaptic plasticity. Proc Natl Acad Sci U S A 2017; 114:E10224-E10233. [PMID: 29114051 PMCID: PMC5703318 DOI: 10.1073/pnas.1713548114] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mature mammalian neurons have a limited ability to extend neurites and make new synaptic connections, but the mechanisms that inhibit such plasticity remain poorly understood. Here, we report that OFF-type retinal bipolar cells in mice are an exception to this rule, as they form new anatomical connections within their tiled dendritic fields well after retinal maturity. The Down syndrome cell-adhesion molecule (Dscam) confines these anatomical rearrangements within the normal tiled fields, as conditional deletion of the gene permits extension of dendrite and axon arbors beyond these borders. Dscam deletion in the mature retina results in expanded dendritic fields and increased cone photoreceptor contacts, demonstrating that DSCAM actively inhibits circuit-level plasticity. Electrophysiological recordings from Dscam-/- OFF bipolar cells showed enlarged visual receptive fields, demonstrating that expanded dendritic territories comprise functional synapses. Our results identify cell-adhesion molecule-mediated inhibition as a regulator of circuit-level neuronal plasticity in the adult retina.
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Affiliation(s)
- Aaron B Simmons
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844
| | | | - Joshua M Sukeena
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844
| | - Calvin J Miller
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844
| | - Yohaniz Ortega-Burgos
- Department of Chemistry, University of Puerto Rico-Humacao, Humacao Puerto Rico, 00792
| | - Bart G Borghuis
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40202;
| | - Peter G Fuerst
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844;
- Washington-Wyoming-Alaska-Montana-Idaho Medical Education Program, University of Washington School of Medicine, Moscow, ID 83844
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39
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Zhang W, Jiang X, Zhang S, Howell BR, Zhao Y, Zhang T, Guo L, Sanchez MM, Hu X, Liu T. Connectome-scale functional intrinsic connectivity networks in macaques. Neuroscience 2017; 364:1-14. [PMID: 28842187 DOI: 10.1016/j.neuroscience.2017.08.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 08/10/2017] [Accepted: 08/11/2017] [Indexed: 01/06/2023]
Abstract
There have been extensive studies of intrinsic connectivity networks (ICNs) in the human brains using resting-state functional magnetic resonance imaging (fMRI) in the literature. However, the functional organization of ICNs in macaque brains has been less explored so far, despite growing interests in the field. In this work, we propose a computational framework to identify connectome-scale group-wise consistent ICNs in macaques via sparse representation of whole-brain resting-state fMRI data. Experimental results demonstrate that 70 group-wise consistent ICNs are successfully identified in macaque brains via the proposed framework. These 70 ICNs are interpreted based on two publicly available parcellation maps of macaque brains and our work significantly expand currently known macaque ICNs already reported in the literature. In general, this set of connectome-scale group-wise consistent ICNs can potentially benefit a variety of studies in the neuroscience and brain-mapping fields, and they provide a foundation to better understand brain evolution in the future.
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Affiliation(s)
- Wei Zhang
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA
| | - Xi Jiang
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA
| | - Shu Zhang
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA
| | - Brittany R Howell
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA; Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA; Institute of Child Development, University of Minnesota, Minneapolis, MN, USA
| | - Yu Zhao
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA
| | - Tuo Zhang
- School of Automation, Northwestern Polytechnical University, Xi'an, PR China; Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA
| | - Lei Guo
- School of Automation, Northwestern Polytechnical University, Xi'an, PR China
| | - Mar M Sanchez
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA; Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | - Xiaoping Hu
- Department of Bioengineering, UC Riverside, CA, USA
| | - Tianming Liu
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA.
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40
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Brown HDH, Woodall RL, Kitching RE, Baseler HA, Morland AB. Using magnetic resonance imaging to assess visual deficits: a review. Ophthalmic Physiol Opt 2017; 36:240-65. [PMID: 27112223 PMCID: PMC4855621 DOI: 10.1111/opo.12293] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/15/2016] [Indexed: 01/25/2023]
Abstract
Purpose Over the last two decades, magnetic resonance imaging (MRI) has been widely used in neuroscience research to assess both structure and function in the brain in health and disease. With regard to vision research, prior to the advent of MRI, researchers relied on animal physiology and human post‐mortem work to assess the impact of eye disease on visual cortex and connecting structures. Using MRI, researchers can non‐invasively examine the effects of eye disease on the whole visual pathway, including the lateral geniculate nucleus, striate and extrastriate cortex. This review aims to summarise research using MRI to investigate structural, chemical and functional effects of eye diseases, including: macular degeneration, retinitis pigmentosa, glaucoma, albinism, and amblyopia. Recent Findings Structural MRI has demonstrated significant abnormalities within both grey and white matter densities across both visual and non‐visual areas. Functional MRI studies have also provided extensive evidence of functional changes throughout the whole of the visual pathway following visual loss, particularly in amblyopia. MR spectroscopy techniques have also revealed several abnormalities in metabolite concentrations in both glaucoma and age‐related macular degeneration. GABA‐edited MR spectroscopy on the other hand has identified possible evidence of plasticity within visual cortex. Summary Collectively, using MRI to investigate the effects on the visual pathway following disease and dysfunction has revealed a rich pattern of results allowing for better characterisation of disease. In the future MRI will likely play an important role in assessing the impact of eye disease on the visual pathway and how it progresses over time.
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Affiliation(s)
| | | | | | - Heidi A Baseler
- Department of Psychology, University of York, York, UK.,Hull York Medical School, University of York, York, UK
| | - Antony B Morland
- Department of Psychology, University of York, York, UK.,Hull York Medical School, University of York, York, UK
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41
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Beyeler M, Rokem A, Boynton GM, Fine I. Learning to see again: biological constraints on cortical plasticity and the implications for sight restoration technologies. J Neural Eng 2017; 14:051003. [PMID: 28612755 DOI: 10.1088/1741-2552/aa795e] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The 'bionic eye'-so long a dream of the future-is finally becoming a reality with retinal prostheses available to patients in both the US and Europe. However, clinical experience with these implants has made it apparent that the visual information provided by these devices differs substantially from normal sight. Consequently, the ability of patients to learn to make use of this abnormal retinal input plays a critical role in whether or not some functional vision is successfully regained. The goal of the present review is to summarize the vast basic science literature on developmental and adult cortical plasticity with an emphasis on how this literature might relate to the field of prosthetic vision. We begin with describing the distortion and information loss likely to be experienced by visual prosthesis users. We then define cortical plasticity and perceptual learning, and describe what is known, and what is unknown, about visual plasticity across the hierarchy of brain regions involved in visual processing, and across different stages of life. We close by discussing what is known about brain plasticity in sight restoration patients and discuss biological mechanisms that might eventually be harnessed to improve visual learning in these patients.
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Affiliation(s)
- Michael Beyeler
- Department of Psychology, University of Washington, Seattle, WA, United States of America. Institute for Neuroengineering, University of Washington, Seattle, WA, United States of America. eScience Institute, University of Washington, Seattle, WA, United States of America
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42
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Barton B, Brewer AA. Visual Field Map Clusters in High-Order Visual Processing: Organization of V3A/V3B and a New Cloverleaf Cluster in the Posterior Superior Temporal Sulcus. Front Integr Neurosci 2017; 11:4. [PMID: 28293182 PMCID: PMC5329644 DOI: 10.3389/fnint.2017.00004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Accepted: 02/10/2017] [Indexed: 11/13/2022] Open
Abstract
The cortical hierarchy of the human visual system has been shown to be organized around retinal spatial coordinates throughout much of low- and mid-level visual processing. These regions contain visual field maps (VFMs) that each follows the organization of the retina, with neighboring aspects of the visual field processed in neighboring cortical locations. On a larger, macrostructural scale, groups of such sensory cortical field maps (CFMs) in both the visual and auditory systems are organized into roughly circular cloverleaf clusters. CFMs within clusters tend to share properties such as receptive field distribution, cortical magnification, and processing specialization. Here we use fMRI and population receptive field (pRF) modeling to investigate the extent of VFM and cluster organization with an examination of higher-level visual processing in temporal cortex and compare these measurements to mid-level visual processing in dorsal occipital cortex. In human temporal cortex, the posterior superior temporal sulcus (pSTS) has been implicated in various neuroimaging studies as subserving higher-order vision, including face processing, biological motion perception, and multimodal audiovisual integration. In human dorsal occipital cortex, the transverse occipital sulcus (TOS) contains the V3A/B cluster, which comprises two VFMs subserving mid-level motion perception and visuospatial attention. For the first time, we present the organization of VFMs in pSTS in a cloverleaf cluster. This pSTS cluster contains four VFMs bilaterally: pSTS-1:4. We characterize these pSTS VFMs as relatively small at ∼125 mm2 with relatively large pRF sizes of ∼2-8° of visual angle across the central 10° of the visual field. V3A and V3B are ∼230 mm2 in surface area, with pRF sizes here similarly ∼1-8° of visual angle across the same region. In addition, cortical magnification measurements show that a larger extent of the pSTS VFM surface areas are devoted to the peripheral visual field than those in the V3A/B cluster. Reliability measurements of VFMs in pSTS and V3A/B reveal that these cloverleaf clusters are remarkably consistent and functionally differentiable. Our findings add to the growing number of measurements of widespread sensory CFMs organized into cloverleaf clusters, indicating that CFMs and cloverleaf clusters may both be fundamental organizing principles in cortical sensory processing.
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Affiliation(s)
- Brian Barton
- Department of Cognitive Sciences, University of California, Irvine, Irvine CA, USA
| | - Alyssa A Brewer
- Department of Cognitive Sciences, University of California, Irvine, IrvineCA, USA; Department of Linguistics, University of California, Irvine, IrvineCA, USA; Center for Hearing Research, University of California, Irvine, IrvineCA, USA
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43
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Makin TR, Bensmaia SJ. Stability of Sensory Topographies in Adult Cortex. Trends Cogn Sci 2017; 21:195-204. [PMID: 28214130 DOI: 10.1016/j.tics.2017.01.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 12/30/2016] [Accepted: 01/03/2017] [Indexed: 01/03/2023]
Abstract
Textbooks teach us that the removal of sensory input to sensory cortex, for example, following arm amputation, results in massive reorganisation in the adult brain. In this opinion article, we critically examine evidence for functional reorganisation of sensory cortical representations, focusing on the sequelae of arm amputation on somatosensory topographies. Based on literature from human and non-human primates, we conclude that the cortical representation of the limb remains remarkably stable despite the loss of its main peripheral input. Furthermore, the purportedly massive reorganisation results primarily from the formation or potentiation of new pathways in subcortical structures and does not produce novel functional sensory representations. We discuss the implications of the stability of sensory representations on the development of upper-limb neuroprostheses.
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Affiliation(s)
- Tamar R Makin
- FMRIB Centre, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX39DU, UK; Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, UK.
| | - Sliman J Bensmaia
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA
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44
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Adaptation, perceptual learning, and plasticity of brain functions. Graefes Arch Clin Exp Ophthalmol 2017; 255:435-447. [PMID: 28091782 PMCID: PMC5323482 DOI: 10.1007/s00417-016-3580-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 12/06/2016] [Accepted: 12/28/2016] [Indexed: 12/16/2022] Open
Abstract
The capacity for functional restitution after brain damage is quite different in the sensory and motor systems. This series of presentations highlights the potential for adaptation, plasticity, and perceptual learning from an interdisciplinary perspective. The chances for restitution in the primary visual cortex are limited. Some patterns of visual field loss and recovery after stroke are common, whereas others are impossible, which can be explained by the arrangement and plasticity of the cortical map. On the other hand, compensatory mechanisms are effective, can occur spontaneously, and can be enhanced by training. In contrast to the human visual system, the motor system is highly flexible. This is based on special relationships between perception and action and between cognition and action. In addition, the healthy adult brain can learn new functions, e.g. increasing resolution above the retinal one. The significance of these studies for rehabilitation after brain damage will be discussed.
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45
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Maniglia M, Cottereau BR, Soler V, Trotter Y. Rehabilitation Approaches in Macular Degeneration Patients. Front Syst Neurosci 2016; 10:107. [PMID: 28082876 PMCID: PMC5187382 DOI: 10.3389/fnsys.2016.00107] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 12/12/2016] [Indexed: 11/13/2022] Open
Abstract
Age related macular degeneration (AMD) is a visual disease that affects elderly population. It entails a progressive loss of central vision whose consequences are dramatic for the patient's quality of life. Current rehabilitation programs are restricted to technical aids based on visual devices. They only temporarily improve specific visual functions such as reading skills. Considering the rapid increase of the aging population worldwide, it is crucial to intensify clinical research on AMD in order to develop simple and efficient methods that improve the patient's visual performances in many different contexts. One very promising approach to face this challenge is based on perceptual learning (PL). Through intensive practice, PL can induce neural plasticity in sensory cortices and result in long-lasting enhancements for various perceptual tasks in both normal and visually impaired populations. A growing number of studies showed how appropriate PL protocols improve visual functions in visual disorders, namely amblyopia, presbyopia or myopia. In order to successfully apply these approaches to more severe conditions such as AMD, numerous challenges have to be overcome. Indeed, the overall elderly age of patients and the reduced cortical surface that is devoted to peripheral vision potentially limit neural plasticity in this population. In addition, ocular fixation becomes much less stable because patients have to rely on peripheral fixation spots outside the scotoma whose size keeps on evolving. The aim of this review article is to discuss the recent literature on this topic and to offer a unified approach for developing new rehabilitation programs of AMD using PL. We argue that with an appropriate experimental and training protocol that is adapted to each patient needs, PL can offer fascinating opportunities for the development of simple, non-expensive rehabilitation approaches a large spectrum of visual functions in AMD patients.
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Affiliation(s)
- Marcello Maniglia
- Centre de Recherche Cerveau et Cognition, Université de Toulouse-UPSToulouse, France; Centre National de la Recherche ScientifiqueToulouse, France; Department of Psychology, University of CaliforniaRiverside, CA, USA
| | - Benoit R Cottereau
- Centre de Recherche Cerveau et Cognition, Université de Toulouse-UPSToulouse, France; Centre National de la Recherche ScientifiqueToulouse, France
| | - Vincent Soler
- Department of Ophthalmology, Hopital CHU Purpan Toulouse, France
| | - Yves Trotter
- Centre de Recherche Cerveau et Cognition, Université de Toulouse-UPSToulouse, France; Centre National de la Recherche ScientifiqueToulouse, France
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Ferreira S, Pereira AC, Quendera B, Reis A, Silva ED, Castelo-Branco M. Primary visual cortical remapping in patients with inherited peripheral retinal degeneration. NEUROIMAGE-CLINICAL 2016; 13:428-438. [PMID: 28116235 PMCID: PMC5233796 DOI: 10.1016/j.nicl.2016.12.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 11/10/2016] [Accepted: 12/14/2016] [Indexed: 12/17/2022]
Abstract
Human studies addressing the long-term effects of peripheral retinal degeneration on visual cortical function and structure are scarce. Here we investigated this question in patients with Retinitis Pigmentosa (RP), a genetic condition leading to peripheral visual degeneration. We acquired functional and anatomical magnetic resonance data from thirteen patients with different levels of visual loss and twenty-two healthy participants to study primary (V1) visual cortical retinotopic remapping and cortical thickness. We identified systematic visual field remapping in the absence of structural changes in the primary visual cortex of RP patients. Remapping consisted in a retinotopic eccentricity shift of central retinal inputs to more peripheral locations in V1. Importantly, this was associated with changes in visual experience, as assessed by the extent of the visual loss, with more constricted visual fields resulting in larger remapping. This pattern of remapping is consistent with expansion or shifting of neuronal receptive fields into the cortical regions with reduced retinal input. These data provide evidence for functional changes in V1 that are dependent on the magnitude of peripheral visual loss in RP, which may be explained by rapid cortical adaptation mechanisms or long-term cortical reorganization. This study highlights the importance of analyzing the retinal determinants of brain functional and structural alterations for future visual restoration approaches.
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Key Words
- FPZ, Function Projection Zone
- Functional magnetic resonance imaging (fMRI)
- Human
- LE, Left Eye
- LH, Left Hemisphere
- LPZ, Lesion Projection Zone
- MRI, Magnetic Resonance Imaging
- Plasticity
- Primary visual cortex
- RE, Right Eye
- RH, Right Hemisphere
- RNFL, Retinal Nerve Fiber Layer
- RP, Retinitis Pigmentosa
- Reorganization
- Retinitis pigmentosa
- Retinotopy
- fMRI, functional Magnetic Resonance Imaging
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Affiliation(s)
- Sónia Ferreira
- Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Andreia Carvalho Pereira
- Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Bruno Quendera
- Institute of Nuclear Sciences Applied to Health (ICNAS), Brain Imaging Network of Portugal, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Aldina Reis
- Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; Ophthalmology Unit, Centro Hospitalar e Universitário de Coimbra (CHUC), 3000-075 Coimbra, Portugal
| | - Eduardo Duarte Silva
- Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Miguel Castelo-Branco
- Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; Institute of Nuclear Sciences Applied to Health (ICNAS), Brain Imaging Network of Portugal, University of Coimbra, 3000-548 Coimbra, Portugal
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47
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Kikkert S, Kolasinski J, Jbabdi S, Tracey I, Beckmann CF, Johansen-Berg H, Makin TR. Revealing the neural fingerprints of a missing hand. eLife 2016; 5. [PMID: 27552053 PMCID: PMC5040556 DOI: 10.7554/elife.15292] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 08/22/2016] [Indexed: 01/06/2023] Open
Abstract
The hand area of the primary somatosensory cortex contains detailed finger topography, thought to be shaped and maintained by daily life experience. Here we utilise phantom sensations and ultra high-field neuroimaging to uncover preserved, though latent, representation of amputees’ missing hand. We show that representation of the missing hand’s individual fingers persists in the primary somatosensory cortex even decades after arm amputation. By demonstrating stable topography despite amputation, our finding questions the extent to which continued sensory input is necessary to maintain organisation in sensory cortex, thereby reopening the question what happens to a cortical territory once its main input is lost. The discovery of persistent digit topography of amputees’ missing hand could be exploited for the development of intuitive and fine-grained control of neuroprosthetics, requiring neural signals of individual digits. DOI:http://dx.doi.org/10.7554/eLife.15292.001 The brain has a remarkable ability to adapt to changes in circumstances. But what happens to the brain when it loses a key source of input, for example, following the amputation of a limb? A region of the brain known as primary somatosensory cortex processes sensory inputs from all over the body. The more sensitive an area of the body is, the more fine-grained its representation is in the cortex. For example, the hand is represented with a highly detailed map, with each finger represented seperately. The brain is thought to require ongoing sensory signals from the body to maintain these detailed representations in the cortex. Indeed, textbooks typically state that the brain will ‘overwrite’ its representation of a body part if input from that area no longer arrives. According to this view, people who have lost a hand should show little or no activity in the area of primary somatosensory cortex that used to represent it. However, many people who have had a limb amputated continue to experience vivid sensations of the missing limb long after its loss. When asked to move their so-called ‘phantom’ limb, these individuals report being able to feel the movement. Kikkert, Kolasinski et al. now show, using advanced imaging techniques, that the brains of individuals with phantom hands continue to represent the missing hand several decades after its loss. Indeed, asking the subjects to move individual fingers of their phantom hand activates fine-grained representations of those fingers, similar to those seen in two-handed controls. By showing that the brain ‘remembers’ an amputated hand, Kikkert, Kolasinski et al. demonstrate that ongoing sensory input is not required to maintain representations of the body in somatosensory cortex. This, in turn, offers new hope for developing prosthetic limbs that are under direct brain control. If the brain continues to represent individual fingers many years after their loss, it should be possible to exploit those pathways to achieve intuitive fine-grained control of artificial fingers. DOI:http://dx.doi.org/10.7554/eLife.15292.002
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Affiliation(s)
- Sanne Kikkert
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - James Kolasinski
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,University College, Oxford, United Kingdom
| | - Saad Jbabdi
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Irene Tracey
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Nuffield Division of Anaesthetics, University of Oxford, Oxford, United Kingdom
| | - Christian F Beckmann
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands.,Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Heidi Johansen-Berg
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Tamar R Makin
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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48
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Lemos J, Pereira D, Castelo-Branco M. Visual Cortex Plasticity Following Peripheral Damage To The Visual System: fMRI Evidence. Curr Neurol Neurosci Rep 2016; 16:89. [DOI: 10.1007/s11910-016-0691-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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49
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Adams DL, Economides JR, Horton JC. Cortical Representation of a Myopic Peripapillary Crescent. Ophthalmology 2016; 123:1494-9. [PMID: 27129902 DOI: 10.1016/j.ophtha.2016.03.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 03/15/2016] [Accepted: 03/16/2016] [Indexed: 10/21/2022] Open
Abstract
PURPOSE To determine how formation of an acquired myopic crescent adjacent to the optic disc affects metabolic activity in the primary visual cortex. DESIGN Laboratory animal study. PARTICIPANTS Three macaque monkeys. METHODS The blind spot region in the primary visual cortex was labeled by cytochrome oxidase (CO) histochemistry analysis or [(3)H]proline autoradiography. MAIN OUTCOME MEASURES Visualization of the representation of the blind spot and myopic peripapillary crescent in the visual cortex. RESULTS In high myopia, a region resembling the myopic peripapillary crescent was visible in cortical sections processed for CO. In this region, metabolic activity was reduced in ocular dominance columns that normally would be driven by input from retina corresponding to the myopic peripapillary crescent. CONCLUSIONS The formation of a myopic crescent is accompanied by loss of metabolic activity in the cortex supplied by the affected retina. This observation confirms that retinal tissue is damaged by the development of a myopic crescent, rather than simply translocated in a temporal direction. The cortical defect matches the myopic peripapillary crescent in size and shape, indicating that fill-in of the retinotopic map by healthy, surrounding retina does not occur.
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Affiliation(s)
- Daniel L Adams
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California; Center for Mind/Brain Sciences, The University of Trento, Trento, Italy
| | - John R Economides
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California
| | - Jonathan C Horton
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California.
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50
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Clara C, Elisa D, Luisa P, Giovanni S, Luca B. Hyper-vision of mirror symmetry in patients with macular degenerationreflects parafoveal cortical reorganization. Restor Neurol Neurosci 2015; 34:67-77. [PMID: 26599474 DOI: 10.3233/rnn-150562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE This study aims at comparing participants with juvenile macular degeneration (MD) and normally sighted observers in their sensitivity to mirror and translational symmetry. METHODS We measured in 25 normal sighted and 9 MD participants sensitivity (d') to detect the symmetry of two dot patterns presented at the opposite sides of their central scotoma. RESULTS At a large dot patterns separation (13.3 deg), at which detection failed in normally sighted observers, MD patients had high sensitivity to mirror symmetry, whereas translational symmetry was undetected. CONCLUSIONS The mirror-translational dissociation is not predicted by the well-known phenomenon of shrinking the location of images surrounding the scotoma. Our results indicate higher capacity of MD with respect to normally sighted observers to organize mirror symmetric dot patterns far apart into a unique percept. Our results suggest that MD have acquired the capability to use information only present in mirror symmetry, i.e., the co-aligned position of the centre of low-frequency filters connecting symmetric dot pairs on opposite sides of the scotoma. This relevant functional change in vision of MD patients may find its explanation in a functionally acquired high-level cortical representation of visual input.
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Affiliation(s)
- Casco Clara
- Department of General Psychology, University of Padova, Padova, Italy
| | - DeStefani Elisa
- Department of Neuroscience, University of Parma, Parma, Italy
| | - Pinello Luisa
- Department of Paediatrics, University of Padova, Padova, Italy
| | - Sato Giovanni
- Centro di Riabilitazione Visiva per Ipovedenti, c/o Istituto L. Configliachi, Padova, Italy
| | - Battaglini Luca
- Department of General Psychology, University of Padova, Padova, Italy
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