1
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Arcaro MJ, Livingstone MS, Kay KN, Weiner KS. The retrocalcarine sulcus maps different retinotopic representations in macaques and humans. Brain Struct Funct 2022; 227:1227-1245. [PMID: 34921348 PMCID: PMC9046316 DOI: 10.1007/s00429-021-02427-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 11/09/2021] [Indexed: 11/30/2022]
Abstract
Primate cerebral cortex is highly convoluted with much of the cortical surface buried in sulcal folds. The origins of cortical folding and its functional relevance have been a major focus of systems and cognitive neuroscience, especially when considering stereotyped patterns of cortical folding that are shared across individuals within a primate species and across multiple species. However, foundational questions regarding organizing principles shared across species remain unanswered. Taking a cross-species comparative approach with a careful consideration of historical observations, we investigate cortical folding relative to primary visual cortex (area V1). We identify two macroanatomical structures-the retrocalcarine and external calcarine sulci-in 24 humans and 6 macaque monkeys. We show that within species, these sulci are identifiable in all individuals, fall on a similar part of the V1 retinotopic map, and thus, serve as anatomical landmarks predictive of functional organization. Yet, across species, the underlying eccentricity representations corresponding to these macroanatomical structures differ strikingly across humans and macaques. Thus, the correspondence between retinotopic representation and cortical folding for an evolutionarily old structure like V1 is species-specific and suggests potential differences in developmental and experiential constraints across primates.
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Affiliation(s)
- Michael J Arcaro
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, 19146, USA
| | | | - Kendrick N Kay
- Center for Magnetic Resonance Research (CMRR), Department of Radiology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Kevin S Weiner
- Department of Psychology, University of California, Berkeley, Berkeley, CA, 94720, USA.
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, 94720, USA.
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2
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Takemura H, Rosa MGP. Understanding structure-function relationships in the mammalian visual system: part two. Brain Struct Funct 2022; 227:1167-1170. [PMID: 35419751 DOI: 10.1007/s00429-022-02495-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Hiromasa Takemura
- Division of Sensory and Cognitive Brain Mapping, Department of System Neuroscience, National Institute for Physiological Sciences, Okazaki, Japan. .,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Japan. .,Center for Information and Neural Networks (CiNet), Advanced ICT Research Institute, National Institute of Information and Communications Technology, Suita, Japan.
| | - Marcello G P Rosa
- Biomedicine Discovery Institute, Neuroscience Program, Monash University, Clayton, VIC, 3800, Australia.,Department of Physiology, Monash University, Clayton, VIC, 3800, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Melbourne, VIC, 3800, Australia
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3
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Receptor architecture of macaque and human early visual areas: not equal, but comparable. Brain Struct Funct 2021; 227:1247-1263. [PMID: 34931262 PMCID: PMC9046358 DOI: 10.1007/s00429-021-02437-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 11/28/2021] [Indexed: 11/16/2022]
Abstract
Existing cytoarchitectonic maps of the human and macaque posterior occipital cortex differ in the number of areas they display, thus hampering identification of homolog structures. We applied quantitative in vitro receptor autoradiography to characterize the receptor architecture of the primary visual and early extrastriate cortex in macaque and human brains, using previously published cytoarchitectonic criteria as starting point of our analysis. We identified 8 receptor architectonically distinct areas in the macaque brain (mV1d, mV1v, mV2d, mV2v, mV3d, mV3v, mV3A, mV4v), and their respective counterpart areas in the human brain (hV1d, hV1v, hV2d, hV2v, hV3d, hV3v, hV3A, hV4v). Mean densities of 14 neurotransmitter receptors were quantified in each area, and ensuing receptor fingerprints used for multivariate analyses. The 1st principal component segregated macaque and human early visual areas differ. However, the 2nd principal component showed that within each species, area-specific differences in receptor fingerprints were associated with the hierarchical processing level of each area. Subdivisions of V2 and V3 were found to cluster together in both species and were segregated from subdivisions of V1 and from V4v. Thus, comparative studies like this provide valuable architectonic insights into how differences in underlying microstructure impact evolutionary changes in functional processing of the primate brain and, at the same time, provide strong arguments for use of macaque monkey brain as a suitable animal model for translational studies.
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4
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Ribeiro FL, Bollmann S, Puckett AM. Predicting the retinotopic organization of human visual cortex from anatomy using geometric deep learning. Neuroimage 2021; 244:118624. [PMID: 34607019 DOI: 10.1016/j.neuroimage.2021.118624] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 09/13/2021] [Accepted: 09/27/2021] [Indexed: 10/20/2022] Open
Abstract
Whether it be in a single neuron or a more complex biological system like the human brain, form and function are often directly related. The functional organization of human visual cortex, for instance, is tightly coupled with the underlying anatomy with cortical shape having been shown to be a useful predictor of the retinotopic organization in early visual cortex. Although the current state-of-the-art in predicting retinotopic maps is able to account for gross individual differences, such models are unable to account for any idiosyncratic differences in the structure-function relationship from anatomical information alone due to their initial assumption of a template. Here we developed a geometric deep learning model capable of exploiting the actual structure of the cortex to learn the complex relationship between brain function and anatomy in human visual cortex such that more realistic and idiosyncratic maps could be predicted. We show that our neural network was not only able to predict the functional organization throughout the visual cortical hierarchy, but that it was also able to predict nuanced variations across individuals. Although we demonstrate its utility for modeling the relationship between structure and function in human visual cortex, our approach is flexible and well-suited for a range of other applications involving data structured in non-Euclidean spaces.
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Affiliation(s)
- Fernanda L Ribeiro
- School of Psychology, The University of Queensland, Saint Lucia, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Steffen Bollmann
- School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Alexander M Puckett
- School of Psychology, The University of Queensland, Saint Lucia, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
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5
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Meikle SJ, Wong YT. Neurophysiological considerations for visual implants. Brain Struct Funct 2021; 227:1523-1543. [PMID: 34773502 DOI: 10.1007/s00429-021-02417-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 10/17/2021] [Indexed: 11/26/2022]
Abstract
Neural implants have the potential to restore visual capabilities in blind individuals by electrically stimulating the neurons of the visual system. This stimulation can produce visual percepts known as phosphenes. The ideal location of electrical stimulation for achieving vision restoration is widely debated and dependent on the physiological properties of the targeted tissue. Here, the neurophysiology of several potential target structures within the visual system will be explored regarding their benefits and downfalls in producing phosphenes. These regions will include the lateral geniculate nucleus, primary visual cortex, visual area 2, visual area 3, visual area 4 and the middle temporal area. Based on the existing engineering limitations of neural prostheses, we anticipate that electrical stimulation of any singular brain region will be incapable of achieving high-resolution naturalistic perception including color, texture, shape and motion. As improvements in visual acuity facilitate improvements in quality of life, emulating naturalistic vision should be one of the ultimate goals of visual prostheses. To achieve this goal, we propose that multiple brain areas will need to be targeted in unison enabling different aspects of vision to be recreated.
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Affiliation(s)
- Sabrina J Meikle
- Department of Electrical and Computer Systems Engineering, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia
- Department of Physiology and Biomedicine Discovery Institute, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia
- Monash Vision Group, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia
| | - Yan T Wong
- Department of Electrical and Computer Systems Engineering, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia.
- Department of Physiology and Biomedicine Discovery Institute, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia.
- Monash Vision Group, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia.
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6
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Strasburger H. Seven Myths on Crowding and Peripheral Vision. Iperception 2020; 11:2041669520913052. [PMID: 32489576 PMCID: PMC7238452 DOI: 10.1177/2041669520913052] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 02/13/2020] [Indexed: 12/03/2022] Open
Abstract
Crowding has become a hot topic in vision research, and some fundamentals are now widely agreed upon. For the classical crowding task, one would likely agree with the following statements. (1) Bouma's law can be stated, succinctly and unequivocally, as saying that critical distance for crowding is about half the target's eccentricity. (2) Crowding is predominantly a peripheral phenomenon. (3) Peripheral vision extends to at most 90° eccentricity. (4) Resolution threshold (the minimal angle of resolution) increases strongly and linearly with eccentricity. Crowding increases at an even steeper rate. (5) Crowding is asymmetric as Bouma has shown. For that inner-outer asymmetry, the peripheral flanker has more effect. (6) Critical crowding distance corresponds to a constant cortical distance in primary visual areas like V1. (7) Except for Bouma's seminal article in 1970, crowding research mostly became prominent starting in the 2000s. I propose the answer is "not really" or "not quite" to these assertions. So should we care? I think we should, before we write the textbook chapters for the next generation.
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Affiliation(s)
- Hans Strasburger
- Georg-August-Universität, Göttingen, Germany
Ludwig-Maximilians-Universität, München, Germany
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7
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Castaldi E, Cicchini GM, Falsini B, Binda P, Morrone MC. Residual Visual Responses in Patients With Retinitis Pigmentosa Revealed by Functional Magnetic Resonance Imaging. Transl Vis Sci Technol 2019; 8:44. [PMID: 31867144 PMCID: PMC6922275 DOI: 10.1167/tvst.8.6.44] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 09/24/2019] [Indexed: 01/20/2023] Open
Abstract
PURPOSE We evaluated the potential of magnetic resonance imaging in identifying signs of cortical visual processing with greater sensitivity than standard ophthalmological measures in patients with retinitis pigmentosa (RP) at advanced stages. METHODS Eight patients affected with RP with only bare light perception and weak or absent visual evoked potential (VEP) or electroretinogram (ERG) responses to flashes of light were tested. Visual impairment was evaluated by means of psychophysical testing, where patients were asked to discriminate the drifting direction of a contrast modulated grating. Patients underwent magnetic resonance imaging scanning, and the behavioral performance was correlated with both blood oxygenation level-dependent (BOLD) signal elicited by flashes of lights and cortical thickness measured in primary visual area. RESULTS Contrast sensitivity to drifting gratings of very low spatial and temporal frequency was greatly impaired, yet measurable in all patients. Weak luminance flashes elicited significant BOLD responses in the striate and extrastriate cortex, despite that the stimuli were not perceived during scanning. Importantly, patients with less severe impairment of contrast sensitivity showed stronger V1 BOLD responses. Striate cortical thickness did not correlate with visual sensitivity. CONCLUSIONS BOLD responses provide a sensitive and reliable index of visual sparing more than VEPs or ERGs, which are often absent in RP patients. The minimal residual vision can be assessed by optimal visual stimulation in two alternative forced choice discrimination tasks and by BOLD responses. Imaging techniques provide useful information to monitor progressive vision loss. TRANSLATIONAL RELEVANCE Functional magnetic resonance imaging might be a practical tool for assessing visual sparing, as it is more feasible and sensitive than psychophysical or ophthalmological testing.
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Affiliation(s)
- Elisa Castaldi
- Department of Neuroscience, Psychology, Pharmacology and Child Health, University of Florence, Florence, Italy
| | | | - Benedetto Falsini
- Department of Ophthalmology, Policlinico Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Paola Binda
- Institute of Neuroscience CNR, Pisa, Italy
- Department of Translational Research and New technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Maria Concetta Morrone
- Department of Translational Research and New technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- IRCCS Stella Maris, Calambrone, Pisa, Italy
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8
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Vascular effects on the BOLD response and the retinotopic mapping of hV4. PLoS One 2019; 14:e0204388. [PMID: 31194745 PMCID: PMC6563965 DOI: 10.1371/journal.pone.0204388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 05/29/2019] [Indexed: 11/30/2022] Open
Abstract
Despite general acceptance that the retinotopic organisation of human V4 (hV4) takes the form of a single, uninterrupted ventral hemifield, measured retinotopic maps of this visual area are often incomplete. Here, we test hypotheses that artefact from draining veins close to hV4 cause inverted BOLD responses that may serve to obscure a portion of the lower visual quarterfield—including the lower vertical meridian—in some hemispheres. We further test whether correcting such responses can restore the ‘missing’ retinotopic coverage in hV4. Subjects (N = 10) viewed bowtie, ring, drifting bar and full field flash stimuli. Functional EPIs were acquired over approximately 1.5h and analysed to reveal retinotopic maps of early visual cortex, including hV4. Normalised mean maps (which show the average EPI signal amplitude) were constructed by voxel-wise averaging of the EPI time course and used to locate venous eclipses, which can be identified by a decrease in the EPI signal caused by deoxygenated blood. Inverted responses are shown to cluster in these regions and correcting these responses improves maps of hV4 in some hemispheres, including restoring a complete hemifield map in one. A leftwards bias was found whereby 6/10 left hemisphere hV4 maps were incomplete, while this was the case in only 1/10 right hemisphere maps. Incomplete hV4 maps did not correspond with venous artefact in every instance, with incomplete maps being present in the absence of a venous eclipse and complete maps coexisting with a proximate venous eclipse. We also show that mean maps of upper surfaces (near the boundary between cortical grey matter and CSF) provide highly detailed maps of veins on the cortical surface. Results suggest that venous eclipses and inverted voxels can explain some incomplete hV4 maps, but cannot explain the remainder nor the leftwards bias in hV4 coverage reported here.
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9
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Rossion B, Taubert J. What can we learn about human individual face recognition from experimental studies in monkeys? Vision Res 2019; 157:142-158. [DOI: 10.1016/j.visres.2018.03.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 03/22/2018] [Accepted: 03/29/2018] [Indexed: 10/28/2022]
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10
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Marcondes M, Rosa MGP, Fiorani M, Lima B, Gattass R. Distribution of cytochrome oxidase-rich patches in human primary visual cortex. J Comp Neurol 2018; 527:614-624. [PMID: 29574727 DOI: 10.1002/cne.24435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 01/10/2018] [Accepted: 01/23/2018] [Indexed: 11/10/2022]
Abstract
We studied the tangential distribution of cytochrome oxidase (CytOx)-rich patches (blobs) in the striate cortex (V1) of normally sighted Homo sapiens. We analyzed the spatial density and cross-sectional area of patches in CytOx-reacted tangential sections of flat-mounted preparations of V1 and surrounding areas. CytOx-rich patches were most clearly defined in the supragranular cortical layers of V1, particularly at middle levels of layer III. Variations in patch spatial density were subtle across different visual eccentricity representations. Within the binocular representation of V1, the average patch spatial density decreased slightly with increasing cortical eccentricity, from around 1.0 patch/mm2 in the foveal representation to 0.6 patch/mm2 at the representation of ∼60° eccentricity, but seemed to increase again at the representation of the monocular crescent. Across the entire sample, the cross-sectional area of patches (i.e., patch size) varied from approximately 0.2-0.8 mm2 , with a mean value of 0.32 mm2 . Notably, there was no significant variation in the mean patch size across eccentricity representations. Human patches are on average larger than those reported for nonhuman primate brains, and analysis of species with different brain sizes suggests an approximately linear relationship between V1 area and patch size. The relative constancy of patch metrics across eccentricities is in stark contrast with the exponential variation in V1 cortical magnification, suggesting a nearly invariant modular organization throughout human V1.
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Affiliation(s)
- Marco Marcondes
- Programa de Neurobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941, Brazil.,Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, DF, Brazil
| | - Marcello G P Rosa
- Programa de Neurobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941, Brazil.,Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC, 3800, Australia
| | - Mario Fiorani
- Programa de Neurobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941, Brazil
| | - Bruss Lima
- Programa de Neurobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941, Brazil
| | - Ricardo Gattass
- Programa de Neurobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941, Brazil
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11
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Castaldi E, Cicchini GM, Cinelli L, Biagi L, Rizzo S, Morrone MC. Visual BOLD Response in Late Blind Subjects with Argus II Retinal Prosthesis. PLoS Biol 2016; 14:e1002569. [PMID: 27780207 PMCID: PMC5079588 DOI: 10.1371/journal.pbio.1002569] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 09/19/2016] [Indexed: 11/19/2022] Open
Abstract
Retinal prosthesis technologies require that the visual system downstream of the retinal circuitry be capable of transmitting and elaborating visual signals. We studied the capability of plastic remodeling in late blind subjects implanted with the Argus II Retinal Prosthesis with psychophysics and functional MRI (fMRI). After surgery, six out of seven retinitis pigmentosa (RP) blind subjects were able to detect high-contrast stimuli using the prosthetic implant. However, direction discrimination to contrast modulated stimuli remained at chance level in all of them. No subject showed any improvement of contrast sensitivity in either eye when not using the Argus II. Before the implant, the Blood Oxygenation Level Dependent (BOLD) activity in V1 and the lateral geniculate nucleus (LGN) was very weak or absent. Surprisingly, after prolonged use of Argus II, BOLD responses to visual input were enhanced. This is, to our knowledge, the first study tracking the neural changes of visual areas in patients after retinal implant, revealing a capacity to respond to restored visual input even after years of deprivation.
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Affiliation(s)
- E. Castaldi
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | | | - L. Cinelli
- Azienda Ospedaliero-Universitaria Careggi, SOD Oculistica, Florence, Italy
| | - L. Biagi
- Stella Maris Scientific Institute, Pisa, Italy
| | - S. Rizzo
- Azienda Ospedaliero-Universitaria Careggi, SOD Oculistica, Florence, Italy
| | - M. C. Morrone
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- Stella Maris Scientific Institute, Pisa, Italy
- * E-mail:
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12
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Hagan MA, Rosa MGP, Lui LL. Neural plasticity following lesions of the primate occipital lobe: The marmoset as an animal model for studies of blindsight. Dev Neurobiol 2016; 77:314-327. [PMID: 27479288 DOI: 10.1002/dneu.22426] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 07/21/2016] [Accepted: 07/29/2016] [Indexed: 12/15/2022]
Abstract
For nearly a century it has been observed that some residual visually guided behavior can persist after damage to the primary visual cortex (V1) in primates. The age at which damage to V1 occurs leads to different outcomes, with V1 lesions in infancy allowing better preservation of visual faculties in comparison with those incurred in adulthood. While adult V1 lesions may still allow retention of some limited visual abilities, these are subconscious-a characteristic that has led to this form of residual vision being referred to as blindsight. The neural basis of blindsight has been of great interest to the neuroscience community, with particular focus on understanding the contributions of the different subcortical pathways and cortical areas that may underlie this phenomenon. More recently, research has started to address which forms of neural plasticity occur following V1 lesions at different ages, including work using marmoset monkeys. The relatively rapid postnatal development of this species, allied to the lissencephalic brains and well-characterized visual cortex provide significant technical advantages, which allow controlled experiments exploring visual function in the absence of V1. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 314-327, 2017.
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Affiliation(s)
- Maureen A Hagan
- Department of Physiology, Monash University, Victoria, 3800, Australia.,Neuroscience Program, Biomedicine Discovery Institute, Monash University, Victoria, 3800, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Victoria, 3800, Australia
| | - Marcello G P Rosa
- Department of Physiology, Monash University, Victoria, 3800, Australia.,Neuroscience Program, Biomedicine Discovery Institute, Monash University, Victoria, 3800, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Victoria, 3800, Australia
| | - Leo L Lui
- Department of Physiology, Monash University, Victoria, 3800, Australia.,Neuroscience Program, Biomedicine Discovery Institute, Monash University, Victoria, 3800, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Victoria, 3800, Australia
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13
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Yu HH, Chaplin TA, Rosa MGP. Representation of central and peripheral vision in the primate cerebral cortex: Insights from studies of the marmoset brain. Neurosci Res 2014; 93:47-61. [PMID: 25242578 DOI: 10.1016/j.neures.2014.09.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 08/27/2014] [Accepted: 08/28/2014] [Indexed: 01/06/2023]
Abstract
How the visual field is represented by neurons in the cerebral cortex is one of the most basic questions in visual neuroscience. However, research to date has focused heavily on the small part of the visual field within, and immediately surrounding the fovea. Studies on the cortical representation of the full visual field in the primate brain are still scarce. We have been investigating this issue with electrophysiological and anatomical methods, taking advantage of the small and lissencephalic marmoset brain, which allows easy access to the representation of the full visual field in many cortical areas. This review summarizes our main findings to date, and relates the results to a broader question: is the peripheral visual field processed in a similar manner to the central visual field, but with lower spatial acuity? Given the organization of the visual cortex, the issue can be addressed by asking: (1) Is visual information processed in the same way within a single cortical area? and (2) Are different cortical areas specialized for different parts of the visual field? The electrophysiological data from the primary visual cortex indicate that many aspects of spatiotemporal computation are remarkably similar across the visual field, although subtle variations are detectable. Our anatomical and electrophysiological studies of the extrastriate cortex, on the other hand, suggest that visual processing in the far peripheral visual field is likely to involve a distinct network of specialized cortical areas, located in the depths of the calcarine sulcus and interhemispheric fissure.
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Affiliation(s)
- H-H Yu
- Department of Physiology, Monash University, Clayton, VIC 3800, Australia; Australian Research Council Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC 3800, Australia.
| | - T A Chaplin
- Department of Physiology, Monash University, Clayton, VIC 3800, Australia; Monash Vision Group, Monash University, Clayton, VIC 3800, Australia
| | - M G P Rosa
- Department of Physiology, Monash University, Clayton, VIC 3800, Australia; Australian Research Council Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC 3800, Australia; Monash Vision Group, Monash University, Clayton, VIC 3800, Australia
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14
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Solomon SG, Rosa MGP. A simpler primate brain: the visual system of the marmoset monkey. Front Neural Circuits 2014; 8:96. [PMID: 25152716 PMCID: PMC4126041 DOI: 10.3389/fncir.2014.00096] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 07/22/2014] [Indexed: 12/15/2022] Open
Abstract
Humans are diurnal primates with high visual acuity at the center of gaze. Although primates share many similarities in the organization of their visual centers with other mammals, and even other species of vertebrates, their visual pathways also show unique features, particularly with respect to the organization of the cerebral cortex. Therefore, in order to understand some aspects of human visual function, we need to study non-human primate brains. Which species is the most appropriate model? Macaque monkeys, the most widely used non-human primates, are not an optimal choice in many practical respects. For example, much of the macaque cerebral cortex is buried within sulci, and is therefore inaccessible to many imaging techniques, and the postnatal development and lifespan of macaques are prohibitively long for many studies of brain maturation, plasticity, and aging. In these and several other respects the marmoset, a small New World monkey, represents a more appropriate choice. Here we review the visual pathways of the marmoset, highlighting recent work that brings these advantages into focus, and identify where additional work needs to be done to link marmoset brain organization to that of macaques and humans. We will argue that the marmoset monkey provides a good subject for studies of a complex visual system, which will likely allow an important bridge linking experiments in animal models to humans.
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Affiliation(s)
- Samuel G Solomon
- Department of Experimental Psychology, University College London London, UK
| | - Marcello G P Rosa
- Department of Physiology, Monash University, Clayton, VIC Australia ; Monash Vision Group, Monash University, Clayton, VIC Australia ; Australian Research Council Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC Australia
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15
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Correction of distortion in flattened representations of the cortical surface allows prediction of V1-V3 functional organization from anatomy. PLoS Comput Biol 2014; 10:e1003538. [PMID: 24676149 PMCID: PMC3967932 DOI: 10.1371/journal.pcbi.1003538] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 02/06/2014] [Indexed: 11/19/2022] Open
Abstract
Several domains of neuroscience offer map-like models that link location on the cortical surface to properties of sensory representation. Within cortical visual areas V1, V2, and V3, algebraic transformations can relate position in the visual field to the retinotopic representation on the flattened cortical sheet. A limit to the practical application of this structure-function model is that the cortex, while topologically a two-dimensional surface, is curved. Flattening of the curved surface to a plane unavoidably introduces local geometric distortions that are not accounted for in idealized models. Here, we show that this limitation is overcome by correcting the geometric distortion induced by cortical flattening. We use a mass-spring-damper simulation to create a registration between functional MRI retinotopic mapping data of visual areas V1, V2, and V3 and an algebraic model of retinotopy. This registration is then applied to the flattened cortical surface anatomy to create an anatomical template that is linked to the algebraic retinotopic model. This registered cortical template can be used to accurately predict the location and retinotopic organization of these early visual areas from cortical anatomy alone. Moreover, we show that prediction accuracy remains when extrapolating beyond the range of data used to inform the model, indicating that the registration reflects the retinotopic organization of visual cortex. We provide code for the mass-spring-damper technique, which has general utility for the registration of cortical structure and function beyond the visual cortex.
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