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Shumikhina SI, Kozhukhov SA, Bondar IV. Dose-dependent changes in orientation amplitude maps in the cat visual cortex after propofol bolus injections. IBRO Neurosci Rep 2024; 16:224-240. [PMID: 38352699 PMCID: PMC10862412 DOI: 10.1016/j.ibneur.2023.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/30/2023] [Indexed: 02/16/2024] Open
Abstract
A general intravenous anesthetic propofol (2,6-diisopropylphenol) is widely used in clinical, veterinary practice and animal experiments. It activates gamma- aminobutyric acid (GABAa) receptors. Though the cerebral cortex is one of the major targets of propofol action, no study of dose dependency of propofol action on cat visual cortex was performed yet. Also, no such investigation was done until now using intrinsic signal optical imaging. Here, we report for the first time on the dependency of optical signal in the visual cortex (area 17/area 18) on the propofol dose. Optical imaging of intrinsic responses to visual stimuli was performed in cats before and after propofol bolus injections at different doses on the background of continuous propofol infusion. Orientation amplitude maps were recorded. We found that amplitude of optical signal significantly decreased after a bolus dose of propofol. The effect was dose- and time-dependent producing stronger suppression of optical signal under the highest bolus propofol doses and short time interval after injection. In each hemisphere, amplitude at cardinal and oblique orientations decreased almost equally. However, surprisingly, amplitude at cardinal orientations in the ipsilateral hemisphere was depressed stronger than in contralateral cortex at most time intervals. As the magnitude of optical signal represents the strength of orientation tuned component, these our data give new insights on the mechanisms of generation of orientation selectivity. Our results also provide new data toward understanding brain dynamics under anesthesia and suggest a recommendation for conducting intrinsic signal optical imaging experiments on cortical functioning under propofol anesthesia.
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Affiliation(s)
- Svetlana I. Shumikhina
- Functional Neurocytology, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 5a Butlerova Street, 117485 Moscow, Russian Federation
| | - Sergei A. Kozhukhov
- Physiology of Sensory Systems, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 5a Butlerova Street, 117485 Moscow, Russian Federation
| | - Igor V. Bondar
- Physiology of Sensory Systems, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 5a Butlerova Street, 117485 Moscow, Russian Federation
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2
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Abstract
Neurological insults, such as congenital blindness, deafness, amputation, and stroke, often result in surprising and impressive behavioural changes. Cortical reorganisation, which refers to preserved brain tissue taking on a new functional role, is often invoked to account for these behavioural changes. Here, we revisit many of the classical animal and patient cortical remapping studies that spawned this notion of reorganisation. We highlight empirical, methodological, and conceptual problems that call this notion into doubt. We argue that appeal to the idea of reorganisation is attributable in part to the way that cortical maps are empirically derived. Specifically, cortical maps are often defined based on oversimplified assumptions of 'winner-takes-all', which in turn leads to an erroneous interpretation of what it means when these maps appear to change. Conceptually, remapping is interpreted as a circuit receiving novel input and processing it in a way unrelated to its original function. This implies that neurons are either pluripotent enough to change what they are tuned to or that a circuit can change what it computes. Instead of reorganisation, we argue that remapping is more likely to occur due to potentiation of pre-existing architecture that already has the requisite representational and computational capacity pre-injury. This architecture can be facilitated via Hebbian and homeostatic plasticity mechanisms. Crucially, our revised framework proposes that opportunities for functional change are constrained throughout the lifespan by the underlying structural 'blueprint'. At no period, including early in development, does the cortex offer structural opportunities for functional pluripotency. We conclude that reorganisation as a distinct form of cortical plasticity, ubiquitously evoked with words such as 'take-over'' and 'rewiring', does not exist.
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Affiliation(s)
- Tamar R Makin
- MRC Cognition and Brain Sciences Unit, University of CambridgeCambridgeUnited Kingdom
| | - John W Krakauer
- Department of Neuroscience, Johns Hopkins University School of MedicineBaltimoreUnited States
- Department of Neurology, Johns Hopkins University School of MedicineBaltimoreUnited States
- The Santa Fe InstituteSanta FeUnited States
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3
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Liang Y, Lu R, Borges K, Ji N. Stimulus edges induce orientation tuning in superior colliculus. Nat Commun 2023; 14:4756. [PMID: 37553352 PMCID: PMC10409754 DOI: 10.1038/s41467-023-40444-1] [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: 04/25/2022] [Accepted: 07/27/2023] [Indexed: 08/10/2023] Open
Abstract
Orientation columns exist in the primary visual cortex (V1) of cat and primates but not mouse. Intriguingly, some recent studies reported the presence of orientation and direction columns in the mouse superficial superior colliculus (sSC), while others reported a lack of columnar organization therein. Using in vivo calcium imaging of sSC in the awake mouse brain, we found that the presence of columns is highly stimulus dependent. Specifically, we observed orientation and direction columns formed by sSC neurons retinotopically mapped to the edge of grating stimuli. For both excitatory and inhibitory neurons in sSC, orientation selectivity can be induced by the edge with their preferred orientation perpendicular to the edge orientation. Furthermore, we found that this edge-induced orientation selectivity is associated with saliency encoding. These findings indicate that the tuning properties of sSC neurons are not fixed by circuit architecture but rather dependent on the spatiotemporal properties of the stimulus.
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Affiliation(s)
- Yajie Liang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20148, USA
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Rongwen Lu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20148, USA
| | - Katharine Borges
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA
| | - Na Ji
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20148, USA.
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA.
- Department of Physics, University of California, Berkeley, CA, 94720, USA.
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, 94720, USA.
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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4
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Li VJ, Chorghay Z, Ruthazer ES. A Guide for the Multiplexed: The Development of Visual Feature Maps in the Brain. Neuroscience 2023; 508:62-75. [PMID: 35952996 DOI: 10.1016/j.neuroscience.2022.07.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 07/21/2022] [Accepted: 07/27/2022] [Indexed: 01/17/2023]
Abstract
Neural maps are found ubiquitously in the brain, where they encode a wide range of behaviourally relevant features into neural space. Developmental studies have shown that animals devote a great deal of resources to establish consistently patterned organization in neural circuits throughout the nervous system, but what purposes maps serve beneath their often intricate appearance and composition is a topic of active debate and exploration. In this article, we review the general mechanisms of map formation, with a focus on the visual system, and then survey notable organizational properties of neural maps: the multiplexing of feature representations through a nested architecture, the interspersing of fine-scale heterogeneity within a globally smooth organization, and the complex integration at the microcircuit level that enables a high dimensionality of information encoding. Finally, we discuss the roles of maps in cortical functions, including input segregation, feature extraction and routing of circuit outputs for higher order processing, as well as the evolutionary basis for the properties we observe in neural maps.
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Affiliation(s)
- Vanessa J Li
- Montreal Neurological Institute-Hospital, McGill University, 3801 University St. Montreal, Quebec H3A 2B4, Canada
| | - Zahraa Chorghay
- Montreal Neurological Institute-Hospital, McGill University, 3801 University St. Montreal, Quebec H3A 2B4, Canada
| | - Edward S Ruthazer
- Montreal Neurological Institute-Hospital, McGill University, 3801 University St. Montreal, Quebec H3A 2B4, Canada
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5
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Natural scene sampling reveals reliable coarse-scale orientation tuning in human V1. Nat Commun 2022; 13:6469. [PMID: 36309512 PMCID: PMC9617970 DOI: 10.1038/s41467-022-34134-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 10/13/2022] [Indexed: 12/25/2022] Open
Abstract
Orientation selectivity in primate visual cortex is organized into cortical columns. Since cortical columns are at a finer spatial scale than the sampling resolution of standard BOLD fMRI measurements, analysis approaches have been proposed to peer past these spatial resolution limitations. It was recently found that these methods are predominantly sensitive to stimulus vignetting - a form of selectivity arising from an interaction of the oriented stimulus with the aperture edge. Beyond vignetting, it is not clear whether orientation-selective neural responses are detectable in BOLD measurements. Here, we leverage a dataset of visual cortical responses measured using high-field 7T fMRI. Fitting these responses using image-computable models, we compensate for vignetting and nonetheless find reliable tuning for orientation. Results further reveal a coarse-scale map of orientation preference that may constitute the neural basis for known perceptual anisotropies. These findings settle a long-standing debate in human neuroscience, and provide insights into functional organization principles of visual cortex.
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6
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Wright JJ, Bourke PD. Unification of free energy minimization, spatiotemporal energy, and dimension reduction models of V1 organization: Postnatal learning on an antenatal scaffold. Front Comput Neurosci 2022; 16:869268. [PMID: 36313813 PMCID: PMC9614369 DOI: 10.3389/fncom.2022.869268] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 09/27/2022] [Indexed: 11/23/2022] Open
Abstract
Developmental selection of neurons and synapses so as to maximize pulse synchrony has recently been used to explain antenatal cortical development. Consequences of the same selection process—an application of the Free Energy Principle—are here followed into the postnatal phase in V1, and the implications for cognitive function are considered. Structured inputs transformed via lag relay in superficial patch connections lead to the generation of circumferential synaptic connectivity superimposed upon the antenatal, radial, “like-to-like” connectivity surrounding each singularity. The spatiotemporal energy and dimension reduction models of cortical feature preferences are accounted for and unified within the expanded model, and relationships of orientation preference (OP), space frequency preference (SFP), and temporal frequency preference (TFP) are resolved. The emergent anatomy provides a basis for “active inference” that includes interpolative modification of synapses so as to anticipate future inputs, as well as learn directly from present stimuli. Neurodynamic properties are those of heteroclinic networks with coupled spatial eigenmodes.
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Affiliation(s)
- James Joseph Wright
- Centre for Brain Research, University of Auckland, Auckland, New Zealand
- Department of Psychological Medicine, School of Medicine, University of Auckland, Auckland, New Zealand
- *Correspondence: James Joseph Wright,
| | - Paul David Bourke
- Faculty of Arts, Business, Law and Education, School of Social Sciences, University of Western Australia, Perth, WA, Australia
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7
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Revisiting horizontal connectivity rules in V1: from like-to-like towards like-to-all. Brain Struct Funct 2022; 227:1279-1295. [PMID: 35122520 DOI: 10.1007/s00429-022-02455-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 01/03/2022] [Indexed: 01/15/2023]
Abstract
Horizontal connections in the primary visual cortex of carnivores, ungulates and primates organize on a near-regular lattice. Given the similar length scale for the regularity found in cortical orientation maps, the currently accepted theoretical standpoint is that these maps are underpinned by a like-to-like connectivity rule: horizontal axons connect preferentially to neurons with similar preferred orientation. However, there is reason to doubt the rule's explanatory power, since a growing number of quantitative studies show that the like-to-like connectivity preference and bias mostly observed at short-range scale, are highly variable on a neuron-to-neuron level and depend on the origin of the presynaptic neuron. Despite the wide availability of published data, the accepted model of visual processing has never been revised. Here, we review three lines of independent evidence supporting a much-needed revision of the like-to-like connectivity rule, ranging from anatomy to population functional measures, computational models and to theoretical approaches. We advocate an alternative, distance-dependent connectivity rule that is consistent with new structural and functional evidence: from like-to-like bias at short horizontal distance to like-to-all at long horizontal distance. This generic rule accounts for the observed high heterogeneity in interactions between the orientation and retinotopic domains, that we argue is necessary to process non-trivial stimuli in a task-dependent manner.
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8
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Mohan YS, Viswanathan S, Jayakumar J, Lloyd EKJ, Vidyasagar TR. Mechanism underpinning the sharpening of orientation and spatial frequency selectivities in the tree shrew (Tupaia belangeri) primary visual cortex. Brain Struct Funct 2022; 227:1265-1278. [PMID: 35118562 DOI: 10.1007/s00429-021-02445-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 12/16/2021] [Indexed: 11/02/2022]
Abstract
Most neurons in the primary visual cortex (V1) of mammals show sharp orientation selectivity and band-pass spatial frequency tuning. Here, we examine whether sharpening of the broad tuning that exists subcortically, namely in the retina and the lateral geniculate nucleus (LGN), underlie the sharper tuning seen for both the above features in tree shrew V1. Since the transition from poor feature selectivity to sharp tuning occurs entirely within V1 in tree shrews, we examined the orientation selectivity and spatial frequency tuning of neurons within individual electrode penetrations. We found that most layer 4 and layer 2/3 neurons in the same cortical column preferred the same stimulus orientation. However, a subset of layer 3c neurons close to the layer 4 border preferred near orthogonal orientations, suggesting that layer 2/3 neurons may inherit the orientation preferences of their layer 4 input neurons and also receive cross-orientation inhibition from layer 3c neurons. We also found that layer 4 neurons showed sharper orientation selectivity at higher spatial frequencies, suggesting that attenuation of low spatial frequency responses by spatially broad inhibition acting on layer 4 inputs to layer 2/3 neurons can enhance both orientation and spatial frequency selectivities. However, in a proportion of layer 2/3 neurons, the sharper tuning of layer 2/3 neurons appeared to arise also or even mainly from inhibition specific to high spatial frequencies acting on the layer 4 inputs to layer 2/3. Overall, our results are consistent with the suggestion that in tree shrews, sharp feature selectivity in layer 2/3 can be established by intracortical mechanisms that sharpen biases observed in layer 4, which are in turn inherited presumably from thalamic afferents.
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Affiliation(s)
- Yamni S Mohan
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Sivaram Viswanathan
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Jaikishan Jayakumar
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia.,Centre for Computational Brain Research, IIT Madras, Chennai, India
| | - Errol K J Lloyd
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Trichur R Vidyasagar
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia. .,ARC Centre of Excellence in Integrative Brain Function, Clayton, Australia.
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9
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Gămănuţ R, Shimaoka D. Anatomical and functional connectomes underlying hierarchical visual processing in mouse visual system. Brain Struct Funct 2021; 227:1297-1315. [PMID: 34846596 DOI: 10.1007/s00429-021-02415-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 10/08/2021] [Indexed: 10/19/2022]
Abstract
Over the last 10 years, there has been a surge in interest in the rodent visual system resulting from the discovery of visual processing functions shared with primates V1, and of a complex anatomical structure in the extrastriate visual cortex. This surprisingly intricate visual system was elucidated by recent investigations using rapidly growing genetic tools primarily available in the mouse. Here, we examine the structural and functional connections of visual areas that have been identified in mice mostly during the past decade, and the impact of these findings on our understanding of brain functions associated with vision. Special attention is paid to structure-function relationships arising from the hierarchical organization, which is a prominent feature of the primate visual system. Recent evidence supports the existence of a hierarchical organization in rodents that contains levels that are poorly resolved relative to those observed in primates. This shallowness of the hierarchy indicates that the mouse visual system incorporates abundant non-hierarchical processing. Thus, the mouse visual system provides a unique opportunity to study non-hierarchical processing and its relation to hierarchical processing.
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Affiliation(s)
- Răzvan Gămănuţ
- Department of Physiology, Monash University, Melbourne, Australia
| | - Daisuke Shimaoka
- Department of Physiology, Monash University, Melbourne, Australia.
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10
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Schmidt KE, Wolf F. Punctuated evolution of visual cortical circuits? Evidence from the large rodent Dasyprocta leporina, and the tiny primate Microcebus murinus. Curr Opin Neurobiol 2021; 71:110-118. [PMID: 34823047 DOI: 10.1016/j.conb.2021.10.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/22/2021] [Accepted: 10/26/2021] [Indexed: 11/30/2022]
Abstract
Recent reports of the lack of periodic orientation columns in a very large rodent species, the red-rumped agouti, and the existence of incompressible hypercolumns in the lineage of primates, as demonstrated in one of the smallest primates, the mouse lemur, strengthen the interpretation that salt-and-pepper and columns-and-pinwheel mosaics are two distinct functional layouts. These layouts do neither depend on lifestyle nor scale with body size, brain size, absolute neuron numbers, binocular overlap, or visual acuity, but are primarily distinguishable by phylogenetic traits. The predictive value of other biological signatures such as V1 neuronal surface density and the central-peripheral density ratio of retinal ganglion cells are reconsidered, and experiments elucidating the intracortical connectivity in rodents are proposed.
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Affiliation(s)
- Kerstin E Schmidt
- Neurobiology of Vision Lab, Brain Institute, Federal University of Rio Grande do Norte, 59078 970, Av. Sen. Salgado Filho, 3000, Lagoa Nova, Natal, RN, Brazil.
| | - Fred Wolf
- Göttingen Campus Institute for Dynamics of Biological Networks, Germany; Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany; Bernstein Center for Computational Neuroscience, University of Göttingen, Göttingen, Germany; Max Planck Institute of Experimental Medicine, Herrmann-Rein-Strasse, 37075 Göttingen, Germany
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11
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Correia ARA, Amorim AKJ, Soares JGM, Lima B, Fiorani M, Gattass R. The role of feedback projections in feature tuning and neuronal excitability in the early primate visual system. Brain Struct Funct 2021; 226:2881-2895. [PMID: 34089102 DOI: 10.1007/s00429-021-02311-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 05/26/2021] [Indexed: 11/29/2022]
Abstract
A general assumption in visual neuroscience is that basic receptive field properties such as orientation and direction selectivity are constructed within intrinsic neuronal circuits and feedforward projections. In addition, it is assumed that general neuronal excitability and responsiveness in early visual areas is to a great extent independent of feedback input originating in areas higher in the stream. Here, we review the contribution of feedback projections from MT, V4 and pulvinar to the receptive field properties of V2 neurons in the anesthetized and paralyzed monkey. Importantly, our results contradict both of these assumptions. We separately inactivated each of these three brain regions using GABA pressure injections, while simultaneously recording V2 single unit activity before and hours after inactivation. Recordings and GABA injections were carried out in topographically corresponding regions of the visual field. We outline the changes in V2 activity, responsiveness and receptive field properties for early, mid and late post-injection phases. Immediately after injection, V2 activity is globally suppressed. Subsequently, there is an increase in stimulus-driven relative to spontaneous neuronal activity, which improves the signal-to-noise coding for the oriented moving bars. Notably, V2 tuning properties change substantially relative to its pre-injection selectivity profile. The resulting increase or decrease in selectivity could not be readily predicted based on the selectivity profile of the inactivated site. Finally, V2 activity rebounds before returning to it pre-injection profile Our results show that feedback projections profoundly impact neuronal circuits in early visual areas, and may have been heretofore largely underestimated in their physiological role.
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Affiliation(s)
- A R A Correia
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, 21941-900, Rio de Janeiro, RJ, Brasil.,Programa de Pós-Graduação Em Ciências Cirúrgicas, Faculdade de Medicina, UFRJ, Rio de Janeiro, RJ, Brasil
| | - A K J Amorim
- Instituto de Ciências Biológicas, Universidade Federal Do Pará, Belém, PA, Brasil
| | - J G M Soares
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, 21941-900, Rio de Janeiro, RJ, Brasil
| | - B Lima
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, 21941-900, Rio de Janeiro, RJ, Brasil
| | - M Fiorani
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, 21941-900, Rio de Janeiro, RJ, Brasil
| | - R Gattass
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, 21941-900, Rio de Janeiro, RJ, Brasil.
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12
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Ibrahim BA, Murphy CA, Yudintsev G, Shinagawa Y, Banks MI, Llano DA. Corticothalamic gating of population auditory thalamocortical transmission in mouse. eLife 2021; 10:e56645. [PMID: 34028350 PMCID: PMC8186908 DOI: 10.7554/elife.56645] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/23/2021] [Indexed: 12/12/2022] Open
Abstract
The mechanisms that govern thalamocortical transmission are poorly understood. Recent data have shown that sensory stimuli elicit activity in ensembles of cortical neurons that recapitulate stereotyped spontaneous activity patterns. Here, we elucidate a possible mechanism by which gating of patterned population cortical activity occurs. In this study, sensory-evoked all-or-none cortical population responses were observed in the mouse auditory cortex in vivo and similar stochastic cortical responses were observed in a colliculo-thalamocortical brain slice preparation. Cortical responses were associated with decreases in auditory thalamic synaptic inhibition and increases in thalamic synchrony. Silencing of corticothalamic neurons in layer 6 (but not layer 5) or the thalamic reticular nucleus linearized the cortical responses, suggesting that layer 6 corticothalamic feedback via the thalamic reticular nucleus was responsible for gating stochastic cortical population responses. These data implicate a corticothalamic-thalamic reticular nucleus circuit that modifies thalamic neuronal synchronization to recruit populations of cortical neurons for sensory representations.
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Affiliation(s)
- Baher A Ibrahim
- Department of Molecular and Integrative Physiology, University of IllinoisUrbana-ChampaignUnited States
- Beckman Institute for Advanced Science and Technology, University of IllinoisUrbana-ChampaignUnited States
| | - Caitlin A Murphy
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
- Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
| | - Georgiy Yudintsev
- Neuroscience Program, University of IllinoisUrbana-ChampaignUnited States
| | - Yoshitaka Shinagawa
- Department of Molecular and Integrative Physiology, University of IllinoisUrbana-ChampaignUnited States
| | - Matthew I Banks
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
- Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
| | - Daniel A Llano
- Department of Molecular and Integrative Physiology, University of IllinoisUrbana-ChampaignUnited States
- Beckman Institute for Advanced Science and Technology, University of IllinoisUrbana-ChampaignUnited States
- Neuroscience Program, University of IllinoisUrbana-ChampaignUnited States
- College of Medicine, University of IllinoisUrbana-ChampaignUnited States
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13
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van den Berg CP, Hollenkamp M, Mitchell LJ, Watson EJ, Green NF, Marshall NJ, Cheney KL. More than noise: context-dependent luminance contrast discrimination in a coral reef fish ( Rhinecanthus aculeatus). J Exp Biol 2020; 223:jeb232090. [PMID: 32967998 DOI: 10.1242/jeb.232090] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/11/2020] [Indexed: 01/19/2023]
Abstract
Achromatic (luminance) vision is used by animals to perceive motion, pattern, space and texture. Luminance contrast sensitivity thresholds are often poorly characterised for individual species and are applied across a diverse range of perceptual contexts using over-simplified assumptions of an animal's visual system. Such thresholds are often estimated using the receptor noise limited model (RNL). However, the suitability of the RNL model to describe luminance contrast perception remains poorly tested. Here, we investigated context-dependent luminance discrimination using triggerfish (Rhinecanthus aculeatus) presented with large achromatic stimuli (spots) against uniform achromatic backgrounds of varying absolute and relative contrasts. 'Dark' and 'bright' spots were presented against relatively dark and bright backgrounds. We found significant differences in luminance discrimination thresholds across treatments. When measured using Michelson contrast, thresholds for bright spots on a bright background were significantly higher than for other scenarios, and the lowest threshold was found when dark spots were presented on dark backgrounds. Thresholds expressed in Weber contrast revealed lower thresholds for spots darker than their backgrounds, which is consistent with the literature. The RNL model was unable to estimate threshold scaling across scenarios as predicted by the Weber-Fechner law, highlighting limitations in the current use of the RNL model to quantify luminance contrast perception. Our study confirms that luminance contrast discrimination thresholds are context dependent and should therefore be interpreted with caution.
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Affiliation(s)
- Cedric P van den Berg
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Michelle Hollenkamp
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Laurie J Mitchell
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Erin J Watson
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Naomi F Green
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - N Justin Marshall
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Karen L Cheney
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
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14
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Vanni S, Hokkanen H, Werner F, Angelucci A. Anatomy and Physiology of Macaque Visual Cortical Areas V1, V2, and V5/MT: Bases for Biologically Realistic Models. Cereb Cortex 2020; 30:3483-3517. [PMID: 31897474 PMCID: PMC7233004 DOI: 10.1093/cercor/bhz322] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 12/02/2019] [Indexed: 12/22/2022] Open
Abstract
The cerebral cortex of primates encompasses multiple anatomically and physiologically distinct areas processing visual information. Areas V1, V2, and V5/MT are conserved across mammals and are central for visual behavior. To facilitate the generation of biologically accurate computational models of primate early visual processing, here we provide an overview of over 350 published studies of these three areas in the genus Macaca, whose visual system provides the closest model for human vision. The literature reports 14 anatomical connection types from the lateral geniculate nucleus of the thalamus to V1 having distinct layers of origin or termination, and 194 connection types between V1, V2, and V5, forming multiple parallel and interacting visual processing streams. Moreover, within V1, there are reports of 286 and 120 types of intrinsic excitatory and inhibitory connections, respectively. Physiologically, tuning of neuronal responses to 11 types of visual stimulus parameters has been consistently reported. Overall, the optimal spatial frequency (SF) of constituent neurons decreases with cortical hierarchy. Moreover, V5 neurons are distinct from neurons in other areas for their higher direction selectivity, higher contrast sensitivity, higher temporal frequency tuning, and wider SF bandwidth. We also discuss currently unavailable data that could be useful for biologically accurate models.
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Affiliation(s)
- Simo Vanni
- HUS Neurocenter, Department of Neurology, Helsinki University Hospital, 00290 Helsinki, Finland
- Department of Neurosciences, University of Helsinki, 00100 Helsinki, Finland
| | - Henri Hokkanen
- HUS Neurocenter, Department of Neurology, Helsinki University Hospital, 00290 Helsinki, Finland
- Department of Neurosciences, University of Helsinki, 00100 Helsinki, Finland
| | - Francesca Werner
- HUS Neurocenter, Department of Neurology, Helsinki University Hospital, 00290 Helsinki, Finland
- Department of Neurosciences, University of Helsinki, 00100 Helsinki, Finland
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy
| | - Alessandra Angelucci
- Department of Ophthalmology and Visual Sciences, Moran Eye Institute, University of Utah, Salt Lake City, UT 84132, USA
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15
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Ibbotson M, Jung YJ. Origins of Functional Organization in the Visual Cortex. Front Syst Neurosci 2020; 14:10. [PMID: 32194379 PMCID: PMC7063058 DOI: 10.3389/fnsys.2020.00010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 02/04/2020] [Indexed: 01/25/2023] Open
Abstract
How are the complex maps for orientation selectivity (OS) created in the primary visual cortex (V1)? Rodents and rabbits have a random distribution of OS preferences across V1 while in cats, ferrets, and all primates cells with similar OS preferences cluster together into relatively wide cortical columns. Given other clear similarities in the organization of the visual pathways, why is it that maps coding OS preferences are so radically different? Prominent models have been created of cortical OS mapping that incorporate Hebbian plasticity, intracortical interactions, and the properties of growing axons. However, these models suggest that the maps arise primarily through intracortical interactions. Here we focus on several other features of the visual system and brain that may influence V1 structure. These are: eye divergence, the total number of cells in V1, the thalamocortical networks, the topography of the retina and phylogeny. We outline the evidence for and against these factors contributing to map formation. One promising theory is that the central-to-peripheral ratio (CP ratio) of retinal cell density can be used to predict whether or not a species has pinwheel maps. Animals with high CP ratios (>7) have orientation columns while those with low CP ratios (<4) have random OS maps. The CP ratio is related to the total number of cells in cortex, which also appears to be a reasonable contributing factor. However, while these factors correlate with map structure to some extent, there is a gray area where certain species do not fit elegantly into the theory. A problem with the existing literature is that OS maps have been investigated in only a small number of mammals, from a small fraction of the mammalian phylogenetic tree. We suggest four species (agouti, fruit bat, sheep, and wallaby) that have a range of interesting characteristics, which sit at intermediate locations between primates and rodents, that make them good targets for filling in the missing gaps in the literature. We make predictions about the map structures of these species based on the organization of their brains and visual systems and, in doing so, set possible paths for future research.
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Affiliation(s)
- Michael Ibbotson
- Australian College of Optometry, National Vision Research Institute, Carlton, VIC, Australia.,Department of Optometry and Vision Science, The University of Melbourne, Parkville, VIC, Australia
| | - Young Jun Jung
- Australian College of Optometry, National Vision Research Institute, Carlton, VIC, Australia.,Department of Optometry and Vision Science, The University of Melbourne, Parkville, VIC, Australia
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16
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Mohan YS, Jayakumar J, Lloyd EKJ, Levichkina E, Vidyasagar TR. Diversity of Feature Selectivity in Macaque Visual Cortex Arising from a Limited Number of Broadly Tuned Input Channels. Cereb Cortex 2019; 29:5255-5268. [PMID: 31220214 DOI: 10.1093/cercor/bhz063] [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: 01/29/2023] Open
Abstract
Spike (action potential) responses of most primary visual cortical cells in the macaque are sharply tuned for the orientation of a line or an edge, and neurons preferring similar orientations are clustered together in cortical columns. The preferred stimulus orientation of these columns span the full range of orientations, as observed in recordings of spikes and in classical optical imaging of intrinsic signals. However, when we imaged the putative thalamic input to striate cortical cells that can be seen in imaging of intrinsic signals when they are analyzed on a larger spatial scale, we found that the orientation domain map of the primary visual cortex did not show the same diversity of orientations. This map was dominated by just the one orientation that is most commonly preferred by neurons in the retina and the lateral geniculate nucleus. This supports cortical feature selectivity and columnar architecture being built upon feed-forward signals transmitted from the thalamus in a very limited number of broadly tuned input channels.
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Affiliation(s)
- Yamni S Mohan
- Department of Optometry & Vision Science, University of Melbourne, Parkville, Victoria, Australia
| | - Jaikishan Jayakumar
- Department of Optometry & Vision Science, University of Melbourne, Parkville, Victoria, Australia.,Centre for Computational Brain Research, Indian Institute of Technology-Madras, Chennai, India
| | - Errol K J Lloyd
- Department of Optometry & Vision Science, University of Melbourne, Parkville, Victoria, Australia
| | - Ekaterina Levichkina
- Department of Optometry & Vision Science, University of Melbourne, Parkville, Victoria, Australia.,Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| | - Trichur R Vidyasagar
- Department of Optometry & Vision Science, University of Melbourne, Parkville, Victoria, Australia.,Melbourne Neuroscience Institute, University of Melbourne, Parkville, Victoria, Australia
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17
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Bressloff PC. Stochastic neural field model of stimulus-dependent variability in cortical neurons. PLoS Comput Biol 2019; 15:e1006755. [PMID: 30883546 PMCID: PMC6438587 DOI: 10.1371/journal.pcbi.1006755] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/28/2019] [Accepted: 02/26/2019] [Indexed: 01/03/2023] Open
Abstract
We use stochastic neural field theory to analyze the stimulus-dependent tuning of neural variability in ring attractor networks. We apply perturbation methods to show how the neural field equations can be reduced to a pair of stochastic nonlinear phase equations describing the stochastic wandering of spontaneously formed tuning curves or bump solutions. These equations are analyzed using a modified version of the bivariate von Mises distribution, which is well-known in the theory of circular statistics. We first consider a single ring network and derive a simple mathematical expression that accounts for the experimentally observed bimodal (or M-shaped) tuning of neural variability. We then explore the effects of inter-network coupling on stimulus-dependent variability in a pair of ring networks. These could represent populations of cells in two different layers of a cortical hypercolumn linked via vertical synaptic connections, or two different cortical hypercolumns linked by horizontal patchy connections within the same layer. We find that neural variability can be suppressed or facilitated, depending on whether the inter-network coupling is excitatory or inhibitory, and on the relative strengths and biases of the external stimuli to the two networks. These results are consistent with the general observation that increasing the mean firing rate via external stimuli or modulating drives tends to reduce neural variability.
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Affiliation(s)
- Paul C. Bressloff
- Department of Mathematics, University of Utah, Salt Lake City, Utah, USA
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18
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Milleret C, Bui Quoc E. Beyond Rehabilitation of Acuity, Ocular Alignment, and Binocularity in Infantile Strabismus. Front Syst Neurosci 2018; 12:29. [PMID: 30072876 PMCID: PMC6058758 DOI: 10.3389/fnsys.2018.00029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 06/15/2018] [Indexed: 11/13/2022] Open
Abstract
Infantile strabismus impairs the perception of all attributes of the visual scene. High spatial frequency components are no longer visible, leading to amblyopia. Binocularity is altered, leading to the loss of stereopsis. Spatial perception is impaired as well as detection of vertical orientation, the fastest movements, directions of movement, the highest contrasts and colors. Infantile strabismus also affects other vision-dependent processes such as control of postural stability. But presently, rehabilitative therapies for infantile strabismus by ophthalmologists, orthoptists and optometrists are restricted to preventing or curing amblyopia of the deviated eye, aligning the eyes and, whenever possible, preserving or restoring binocular vision during the critical period of development, i.e., before ~10 years of age. All the other impairments are thus ignored; whether they may recover after strabismus treatment even remains unknown. We argue here that medical and paramedical professionals may extend their present treatments of the perceptual losses associated with infantile strabismus. This hypothesis is based on findings from fundamental research on visual system organization of higher mammals in particular at the cortical level. In strabismic subjects (as in normal-seeing ones), information about all of the visual attributes converge, interact and are thus inter-dependent at multiple levels of encoding ranging from the single neuron to neuronal assemblies in visual cortex. Thus if the perception of one attribute is restored this may help to rehabilitate the perception of other attributes. Concomitantly, vision-dependent processes may also improve. This could occur spontaneously, but still should be assessed and validated. If not, medical and paramedical staff, in collaboration with neuroscientists, will have to break new ground in the field of therapies to help reorganize brain circuitry and promote more comprehensive functional recovery. Findings from fundamental research studies in both young and adult patients already support our hypothesis and are reviewed here. For example, presenting different contrasts to each eye of a strabismic patient during training sessions facilitates recovery of acuity in the amblyopic eye as well as of 3D perception. Recent data also demonstrate that visual recoveries in strabismic subjects improve postural stability. These findings form the basis for a roadmap for future research and clinical development to extend presently applied rehabilitative therapies for infantile strabismus.
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Affiliation(s)
- Chantal Milleret
- Center for Interdisciplinary Research in Biology, Centre National de la Recherche Scientifique, College de France, INSERM, PSL Research University, Paris, France
| | - Emmanuel Bui Quoc
- Department of Ophthalmology, Robert Debré University Hospital, Assistance Publique - Hôpitaux de Paris Paris, France
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19
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Pakan JM, Francioni V, Rochefort NL. Action and learning shape the activity of neuronal circuits in the visual cortex. Curr Opin Neurobiol 2018; 52:88-97. [PMID: 29727859 PMCID: PMC6562203 DOI: 10.1016/j.conb.2018.04.020] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 04/13/2018] [Indexed: 11/25/2022]
Abstract
Arousal and locomotion modulate neuronal activity in primary visual cortex. Neurons in primary visual cortex respond to visuomotor mismatch. Experience shapes neuronal responses to familiar stimuli, reward and object location. Neuronal representations of visual stimuli are modulated according to the behavioural relevance of the stimuli. Neuromodulatory, top-down and thalamocortical inputs convey arousal-related and motor-related signals to primary visual cortex.
Nonsensory variables strongly influence neuronal activity in the adult mouse primary visual cortex. Neuronal responses to visual stimuli are modulated by behavioural state, such as arousal and motor activity, and are shaped by experience. This dynamic process leads to neural representations in the visual cortex that reflect stimulus familiarity, expectations of reward and object location, and mismatch between self-motion and visual-flow. The recent development of genetic tools and recording techniques in awake behaving mice has enabled the investigation of the circuit mechanisms underlying state-dependent and experience-dependent neuronal representations in primary visual cortex. These neuronal circuits involve neuromodulatory, top-down cortico-cortical and thalamocortical pathways. The functions of nonsensory signals at this early stage of visual information processing are now beginning to be unravelled.
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Affiliation(s)
- Janelle Mp Pakan
- Center for Behavioral Brain Sciences, Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University, Magdeburg, Germany; German Center for Neurodegenerative Diseases, Magdeburg, Germany
| | - Valerio Francioni
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, Edinburgh, United Kingdom
| | - Nathalie L Rochefort
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, Edinburgh, United Kingdom; Simons Initiative for the Developing Brain, Edinburgh, United Kingdom.
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20
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Antinucci P, Hindges R. Orientation-Selective Retinal Circuits in Vertebrates. Front Neural Circuits 2018; 12:11. [PMID: 29467629 PMCID: PMC5808299 DOI: 10.3389/fncir.2018.00011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/23/2018] [Indexed: 11/24/2022] Open
Abstract
Visual information is already processed in the retina before it is transmitted to higher visual centers in the brain. This includes the extraction of salient features from visual scenes, such as motion directionality or contrast, through neurons belonging to distinct neural circuits. Some retinal neurons are tuned to the orientation of elongated visual stimuli. Such ‘orientation-selective’ neurons are present in the retinae of most, if not all, vertebrate species analyzed to date, with species-specific differences in frequency and degree of tuning. In some cases, orientation-selective neurons have very stereotyped functional and morphological properties suggesting that they represent distinct cell types. In this review, we describe the retinal cell types underlying orientation selectivity found in various vertebrate species, and highlight their commonalities and differences. In addition, we discuss recent studies that revealed the cellular, synaptic and circuit mechanisms at the basis of retinal orientation selectivity. Finally, we outline the significance of these findings in shaping our current understanding of how this fundamental neural computation is implemented in the visual systems of vertebrates.
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Affiliation(s)
- Paride Antinucci
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Robert Hindges
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom.,MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom
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21
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Abstract
The mechanisms underlying the emergence of orientation selectivity in the visual cortex have been, and continue to be, the subjects of intense scrutiny. Orientation selectivity reflects a dramatic change in the representation of the visual world: Whereas afferent thalamic neurons are generally orientation insensitive, neurons in the primary visual cortex (V1) are extremely sensitive to stimulus orientation. This profound change in the receptive field structure along the visual pathway has positioned V1 as a model system for studying the circuitry that underlies neural computations across the neocortex. The neocortex is characterized anatomically by the relative uniformity of its circuitry despite its role in processing distinct signals from region to region. A combination of physiological, anatomical, and theoretical studies has shed some light on the circuitry components necessary for generating orientation selectivity in V1. This targeted effort has led to critical insights, as well as controversies, concerning how neural circuits in the neocortex perform computations.
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Affiliation(s)
- Nicholas J Priebe
- Center for Learning and Memory, Center for Perceptual Systems, Department of Neuroscience, College of Natural Sciences, University of Texas, Austin, Texas 78712;
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22
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Towards building a more complex view of the lateral geniculate nucleus: Recent advances in understanding its role. Prog Neurobiol 2017. [DOI: 10.1016/j.pneurobio.2017.06.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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23
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Huang JY, Wang C, Dreher B. Silencing "Top-Down" Cortical Signals Affects Spike-Responses of Neurons in Cat's "Intermediate" Visual Cortex. Front Neural Circuits 2017; 11:27. [PMID: 28487637 PMCID: PMC5404610 DOI: 10.3389/fncir.2017.00027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 04/04/2017] [Indexed: 11/13/2022] Open
Abstract
We examined the effects of reversible inactivation of a higher-order, pattern/form-processing, postero-temporal visual (PTV) cortex on the background activities and spike-responses of single neurons in the ipsilateral cytoarchitectonic area 19 (putative area V3) of anesthetized domestic cats. Very occasionally (2/28), silencing recurrent “feedback” signals from PTV, resulted in significant and reversible reduction in background activity of area 19 neurons. By contrast, in large proportions of area 19 neurons, PTV inactivation resulted in: (i) significant reversible changes in the peak magnitude of their responses to visual stimuli (35.5%; 10/28); (ii) substantial reversible changes in direction selectivity indices (DSIs; 43%; 12/28); and (iii) reversible, upward shifts in preferred stimulus velocities (37%; 7/19). Substantial (≥20°) shifts in preferred orientation and/or substantial (≥20°) changes in width of orientation-tuning curves of area 19 neurons were however less common (26.5%; 4/15). In a series of experiments conducted earlier, inactivation of PTV also induced upward shifts in the preferred velocities of the ipsilateral cytoarchitectonic area 17 (V1) neurons responding optimally at low velocities. These upward shifts in preferred velocities of areas 19 and 17 neurons were often accompanied by substantial increases in DSIs. Thus, in both the primary visual cortex and the “intermediate” visual cortex (area 19), feedback from PTV plays a modulatory role in relation to stimulus velocity preferences and/or direction selectivity, that is, the properties which are usually believed to be determined by the inputs from the dorsal thalamus and/or feedforward inputs from the primary visual cortices. The apparent specialization of area 19 for processing information about stationary/slowly moving visual stimuli is at least partially determined, by the feedback from the higher-order pattern-processing visual area. Overall, the recurrent signals from the higher-order, pattern/form-processing visual cortex appear to play an important role in determining the magnitude of spike-responses and some “motion-related” receptive field properties of a substantial proportion of neurons in the intermediate form-processing visual area—area 19.
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Affiliation(s)
- Jin Y Huang
- Discipline of Anatomy and Histology, The University of SydneySydney, NSW, Australia.,Discipline of Biomedical Science, School of Medical Sciences, The University of SydneySydney, NSW, Australia.,The Bosch Institute, The University of SydneySydney, NSW, Australia
| | - Chun Wang
- Discipline of Anatomy and Histology, The University of SydneySydney, NSW, Australia.,The Bosch Institute, The University of SydneySydney, NSW, Australia
| | - Bogdan Dreher
- Discipline of Anatomy and Histology, The University of SydneySydney, NSW, Australia.,The Bosch Institute, The University of SydneySydney, NSW, Australia
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24
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Takahata T. What Does Cytochrome Oxidase Histochemistry Represent in the Visual Cortex? Front Neuroanat 2016; 10:79. [PMID: 27489537 PMCID: PMC4951485 DOI: 10.3389/fnana.2016.00079] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/06/2016] [Indexed: 11/13/2022] Open
Affiliation(s)
- Toru Takahata
- Laboratory of Comparative Molecular Neuroanatomy, Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University Hangzhou, China
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25
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Sweeney Y, Clopath C. Emergent spatial synaptic structure from diffusive plasticity. Eur J Neurosci 2016; 45:1057-1067. [DOI: 10.1111/ejn.13279] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 05/04/2016] [Accepted: 05/13/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Yann Sweeney
- Department of Bioengineering; Imperial College London, South Kensington Campus; London SW7 2AZ UK
| | - Claudia Clopath
- Department of Bioengineering; Imperial College London, South Kensington Campus; London SW7 2AZ UK
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26
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Abstract
Low-level perception results from neural-based computations, which build a multimodal skeleton of unconscious or self-generated inferences on our environment. This review identifies bottleneck issues concerning the role of early primary sensory cortical areas, mostly in rodent and higher mammals (cats and non-human primates), where perception substrates can be searched at multiple scales of neural integration. We discuss the limitation of purely bottom-up approaches for providing realistic models of early sensory processing and the need for identification of fast adaptive processes, operating within the time of a percept. Future progresses will depend on the careful use of comparative neuroscience (guiding the choices of experimental models and species adapted to the questions under study), on the definition of agreed-upon benchmarks for sensory stimulation, on the simultaneous acquisition of neural data at multiple spatio-temporal scales, and on the in vivo identification of key generic integration and plasticity algorithms validated experimentally and in simulations.
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