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Magrou L, Joyce MKP, Froudist-Walsh S, Datta D, Wang XJ, Martinez-Trujillo J, Arnsten AFT. The meso-connectomes of mouse, marmoset, and macaque: network organization and the emergence of higher cognition. Cereb Cortex 2024; 34:bhae174. [PMID: 38771244 PMCID: PMC11107384 DOI: 10.1093/cercor/bhae174] [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: 01/31/2024] [Revised: 03/29/2024] [Accepted: 04/08/2024] [Indexed: 05/22/2024] Open
Abstract
The recent publications of the inter-areal connectomes for mouse, marmoset, and macaque cortex have allowed deeper comparisons across rodent vs. primate cortical organization. In general, these show that the mouse has very widespread, "all-to-all" inter-areal connectivity (i.e. a "highly dense" connectome in a graph theoretical framework), while primates have a more modular organization. In this review, we highlight the relevance of these differences to function, including the example of primary visual cortex (V1) which, in the mouse, is interconnected with all other areas, therefore including other primary sensory and frontal areas. We argue that this dense inter-areal connectivity benefits multimodal associations, at the cost of reduced functional segregation. Conversely, primates have expanded cortices with a modular connectivity structure, where V1 is almost exclusively interconnected with other visual cortices, themselves organized in relatively segregated streams, and hierarchically higher cortical areas such as prefrontal cortex provide top-down regulation for specifying precise information for working memory storage and manipulation. Increased complexity in cytoarchitecture, connectivity, dendritic spine density, and receptor expression additionally reveal a sharper hierarchical organization in primate cortex. Together, we argue that these primate specializations permit separable deconstruction and selective reconstruction of representations, which is essential to higher cognition.
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Affiliation(s)
- Loïc Magrou
- Department of Neural Science, New York University, New York, NY 10003, United States
| | - Mary Kate P Joyce
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, United States
| | - Sean Froudist-Walsh
- School of Engineering Mathematics and Technology, University of Bristol, Bristol, BS8 1QU, United Kingdom
| | - Dibyadeep Datta
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06510, United States
| | - Xiao-Jing Wang
- Department of Neural Science, New York University, New York, NY 10003, United States
| | - Julio Martinez-Trujillo
- Departments of Physiology and Pharmacology, and Psychiatry, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A 3K7, Canada
| | - Amy F T Arnsten
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, United States
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Franken TP, Reynolds JH. Grouping cells in primate visual cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.16.575953. [PMID: 38293172 PMCID: PMC10827172 DOI: 10.1101/2024.01.16.575953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Our perception of how objects are laid out in visual scenes is remarkably stable, despite rapid shifts in the patterns of light that fall on the retina with each saccade. One mechanism that may help establish perceptual stability is border ownership assignment. Studies in macaque area V2 have identified border ownership neurons that signal which side of a border belongs to a foreground surface. This signal persists for hundreds of milliseconds after border ownership has been rendered ambiguous by deleting the stimulus features that distinguish foreground from background. Remarkably, this signal survives eye movements: border ownership neurons also exhibit border ownership signals de novo when an eye movement places the newly ambiguous border within their receptive field. The grouping cell hypothesis proposes the existence of hypothetical grouping cells in a downstream brain area. These cells would compute persistent proto-object representations and therefore have the properties to endow cells in upstream brain areas with selectivity for border ownership. Such grouping cells have been predicted to show a centripetal and persistent pattern of preferred side of ownership for a border placed parallel to the perimeter of their classical receptive field, and such a centripetal ownership preference pattern should also occur de novo in these same cells if an ambiguous border lands in their receptive field after a saccade. It is unknown if grouping cells exist. Here we used laminar multielectrodes in area V4 - the main source of feedback to V2 - of behaving macaques to determine whether such grouping cells exist. Consistent with the model prediction we find a substantial population of neurons with these properties, in all laminar compartments, and they exhibit a response latency that is short enough to act as the source that endows neurons in V2 with selectivity for border ownership. While grouping cell activity provides information about the location of foreground surfaces, these neurons are, counterintuitively, not as strongly tuned for luminance contrast polarity, a feature of those surfaces, as are border ownership cells. Our data suggest a division of labor in which these newly discovered grouping cells provide spatiotemporal continuity of segmented surfaces whereas border ownership cells link this location information with surface features such as luminance contrast.
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Affiliation(s)
- Tom P. Franken
- Systems Neurobiology Laboratory, The Salk Institute for Biological Studies, San Diego, California, USA
- Department of Neuroscience, Washington University School of Medicine, St. Louis, Missouri, USA
- Lead contact
| | - John H. Reynolds
- Systems Neurobiology Laboratory, The Salk Institute for Biological Studies, San Diego, California, USA
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3
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Wang X, Nandy AS, Jadi MP. Laminar compartmentalization of attention modulation in area V4 aligns with the demands of visual processing hierarchy in the cortex. Sci Rep 2023; 13:19558. [PMID: 37945642 PMCID: PMC10636153 DOI: 10.1038/s41598-023-46722-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 11/04/2023] [Indexed: 11/12/2023] Open
Abstract
Attention selectively enhances neural responses to low contrast stimuli in visual area V4, a critical hub that sends projections both up and down the visual hierarchy. Veridical encoding of contrast information is a key computation in early visual areas, while later stages encoding higher level features benefit from improved sensitivity to low contrast. How area V4 meets these distinct information processing demands in the attentive state is unknown. We found that attentional modulation in V4 is cortical layer and cell-class specific. Putative excitatory neurons in the superficial layers show enhanced boosting of low contrast information, while those of deep layers exhibit contrast-independent scaling. Computational modeling suggested the extent of spatial integration of inhibitory neurons as the mechanism behind such laminar differences. Considering that superficial neurons are known to project to higher areas and deep layers to early visual areas, our findings suggest that the interactions between attention and contrast in V4 are compartmentalized, in alignment with the demands of the visual processing hierarchy.
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Affiliation(s)
- Xiang Wang
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, 06511, USA
| | - Anirvan S Nandy
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, 06511, USA
- Department of Neuroscience, Yale University, New Haven, CT, 06511, USA
| | - Monika P Jadi
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, 06511, USA.
- Department of Psychiatry, Yale University, New Haven, CT, 06511, USA.
- Department of Neuroscience, Yale University, New Haven, CT, 06511, USA.
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4
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Rockland KS. Notes on Visual Cortical Feedback and Feedforward Connections. Front Syst Neurosci 2022; 16:784310. [PMID: 35153685 PMCID: PMC8831541 DOI: 10.3389/fnsys.2022.784310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 01/06/2022] [Indexed: 11/29/2022] Open
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5
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Ferro D, van Kempen J, Boyd M, Panzeri S, Thiele A. Directed information exchange between cortical layers in macaque V1 and V4 and its modulation by selective attention. Proc Natl Acad Sci U S A 2021; 118:e2022097118. [PMID: 33723059 PMCID: PMC8000025 DOI: 10.1073/pnas.2022097118] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Achieving behavioral goals requires integration of sensory and cognitive information across cortical laminae and cortical regions. How this computation is performed remains unknown. Using local field potential recordings and spectrally resolved conditional Granger causality (cGC) analysis, we mapped visual information flow, and its attentional modulation, between cortical layers within and between macaque brain areas V1 and V4. Stimulus-induced interlaminar information flow within V1 dominated upwardly, channeling information toward supragranular corticocortical output layers. Within V4, information flow dominated from granular to supragranular layers, but interactions between supragranular and infragranular layers dominated downwardly. Low-frequency across-area communication was stronger from V4 to V1, with little layer specificity. Gamma-band communication was stronger in the feedforward V1-to-V4 direction. Attention to the receptive field of V1 decreased communication between all V1 layers, except for granular-to-supragranular layer interactions. Communication within V4, and from V1 to V4, increased with attention across all frequencies. While communication from V4 to V1 was stronger in lower-frequency bands (4 to 25 Hz), attention modulated cGCs from V4 to V1 across all investigated frequencies. Our data show that top-down cognitive processes result in reduced communication within cortical areas, increased feedforward communication across all frequency bands, and increased gamma-band feedback communication.
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Affiliation(s)
- Demetrio Ferro
- Neural Computation Laboratory, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy
- Center for Mind and Brain Sciences, University of Trento, 38068 Rovereto, Italy
- Center for Brain and Cognition, Universitat Pompeu Fabra, 08002 Barcelona, Spain
- Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08002 Barcelona, Spain
| | - Jochem van Kempen
- Biosciences Institute, Newcastle University, NE1 7RU Newcastle upon Tyne, United Kingdom
| | - Michael Boyd
- Biosciences Institute, Newcastle University, NE1 7RU Newcastle upon Tyne, United Kingdom
| | - Stefano Panzeri
- Neural Computation Laboratory, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy;
| | - Alexander Thiele
- Biosciences Institute, Newcastle University, NE1 7RU Newcastle upon Tyne, United Kingdom
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6
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Pan H, Zhang S, Pan D, Ye Z, Yu H, Ding J, Wang Q, Sun Q, Hua T. Characterization of Feedback Neurons in the High-Level Visual Cortical Areas That Project Directly to the Primary Visual Cortex in the Cat. Front Neuroanat 2021; 14:616465. [PMID: 33488364 PMCID: PMC7820340 DOI: 10.3389/fnana.2020.616465] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 12/04/2020] [Indexed: 12/17/2022] Open
Abstract
Previous studies indicate that top-down influence plays a critical role in visual information processing and perceptual detection. However, the substrate that carries top-down influence remains poorly understood. Using a combined technique of retrograde neuronal tracing and immunofluorescent double labeling, we characterized the distribution and cell type of feedback neurons in cat's high-level visual cortical areas that send direct connections to the primary visual cortex (V1: area 17). Our results showed: (1) the high-level visual cortex of area 21a at the ventral stream and PMLS area at the dorsal stream have a similar proportion of feedback neurons back projecting to the V1 area, (2) the distribution of feedback neurons in the higher-order visual area 21a and PMLS was significantly denser than in the intermediate visual cortex of area 19 and 18, (3) feedback neurons in all observed high-level visual cortex were found in layer II-III, IV, V, and VI, with a higher proportion in layer II-III, V, and VI than in layer IV, and (4) most feedback neurons were CaMKII-positive excitatory neurons, and few of them were identified as inhibitory GABAergic neurons. These results may argue against the segregation of ventral and dorsal streams during visual information processing, and support "reverse hierarchy theory" or interactive model proposing that recurrent connections between V1 and higher-order visual areas constitute the functional circuits that mediate visual perception. Also, the corticocortical feedback neurons from high-level visual cortical areas to the V1 area are mostly excitatory in nature.
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Affiliation(s)
- Huijun Pan
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Shen Zhang
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Deng Pan
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Zheng Ye
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Hao Yu
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Jian Ding
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Qin Wang
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Qingyan Sun
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Tianmiao Hua
- College of Life Sciences, Anhui Normal University, Wuhu, China
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7
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Ashaber M, Zalányi L, Pálfi E, Stuber I, Kovács T, Roe A, Friedman R, Négyessy L. Synaptic organization of cortico-cortical communication in primates. Eur J Neurosci 2020; 52:4037-4056. [PMID: 32654301 PMCID: PMC7874932 DOI: 10.1111/ejn.14905] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 07/01/2020] [Accepted: 07/01/2020] [Indexed: 01/11/2023]
Abstract
In cortical circuitry, synaptic communication across areas is based on two types of axon terminals, small and large, with modulatory and driving roles, respectively. In contrast, it is not known whether similar synaptic specializations exist for intra-areal projections. Using anterograde tracing and three-dimensional reconstruction by electron microscopy (3D-EM), we asked whether large boutons form synapses in the circuit of somatosensory cortical areas 3b and 1. In contrast to observations in macaque visual cortex, light microscopy showed both small and large boutons not only in inter-areal pathways, but also in long-distance intrinsic connections. 3D-EM showed that correlation of surface and volume provides a powerful tool for classifying cortical endings. Principal component analysis supported this observation and highlighted the significance of the size of mitochondria as a distinguishing feature of bouton type. The larger mitochondrion and higher degree of perforated postsynaptic density associated with large rather than to small boutons support the driver-like function of large boutons. In contrast to bouton size and complexity, the size of the postsynaptic density appeared invariant across the bouton types. Comparative studies in human supported that size is a major distinguishing factor of bouton type in the cerebral cortex. In conclusion, the driver-like function of the large endings could facilitate fast dissemination of tactile information within the intrinsic and inter-areal circuitry of areas 3b and 1.
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Affiliation(s)
- M. Ashaber
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - L. Zalányi
- Complex Systems and Computational Neuroscience Group, Department of Computational Sciences, Wigner Research Centre for Physics, Budapest, Hungary
| | - E. Pálfi
- Complex Systems and Computational Neuroscience Group, Department of Computational Sciences, Wigner Research Centre for Physics, Budapest, Hungary
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - I Stuber
- Three-dimensional morphology and motion analyses laboratory, University of Physical Education, Budapest, Hungary
| | - T. Kovács
- Nokia Hungary Ltd., Nokia Software Department, Budapest, Hungary
| | - A.W. Roe
- Division of Neuroscience, Oregon National Primate Research Center, OHSU, Beaverton OR, USA
- Department of Behavioral Neuroscience, OHSU, Portland OR, USA
- Interdisciplinary Institute of Neuroscience & Technology, Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, China
| | - R.M. Friedman
- Division of Neuroscience, Oregon National Primate Research Center, OHSU, Beaverton OR, USA
| | - L. Négyessy
- Complex Systems and Computational Neuroscience Group, Department of Computational Sciences, Wigner Research Centre for Physics, Budapest, Hungary
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8
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Barron HC, Auksztulewicz R, Friston K. Prediction and memory: A predictive coding account. Prog Neurobiol 2020; 192:101821. [PMID: 32446883 PMCID: PMC7305946 DOI: 10.1016/j.pneurobio.2020.101821] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 02/26/2020] [Accepted: 04/29/2020] [Indexed: 01/27/2023]
Abstract
The hippocampus is crucial for episodic memory, but it is also involved in online prediction. Evidence suggests that a unitary hippocampal code underlies both episodic memory and predictive processing, yet within a predictive coding framework the hippocampal-neocortical interactions that accompany these two phenomena are distinct and opposing. Namely, during episodic recall, the hippocampus is thought to exert an excitatory influence on the neocortex, to reinstate activity patterns across cortical circuits. This contrasts with empirical and theoretical work on predictive processing, where descending predictions suppress prediction errors to 'explain away' ascending inputs via cortical inhibition. In this hypothesis piece, we attempt to dissolve this previously overlooked dialectic. We consider how the hippocampus may facilitate both prediction and memory, respectively, by inhibiting neocortical prediction errors or increasing their gain. We propose that these distinct processing modes depend upon the neuromodulatory gain (or precision) ascribed to prediction error units. Within this framework, memory recall is cast as arising from fictive prediction errors that furnish training signals to optimise generative models of the world, in the absence of sensory data.
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Affiliation(s)
- Helen C Barron
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Mansfield Road, Oxford, OX1 3TH, UK; Wellcome Centre for Integrative Neuroimaging, University of Oxford, FMRIB, John Radcliffe Hospital, Oxford, OX3 9DU, UK.
| | - Ryszard Auksztulewicz
- Max Planck Institute for Empirical Aesthetics, Frankfurt Am Main, 60322, Germany; Department of Biomedical Sciences, City University of Hong Kong, Hong Kong
| | - Karl Friston
- The Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, WC1N 3BG, UK
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9
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Rockland KS. What we can learn from the complex architecture of single axons. Brain Struct Funct 2020; 225:1327-1347. [DOI: 10.1007/s00429-019-02023-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 12/30/2019] [Indexed: 12/22/2022]
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10
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Moyal R, Edelman S. Dynamic Computation in Visual Thalamocortical Networks. ENTROPY (BASEL, SWITZERLAND) 2019; 21:E500. [PMID: 33267214 PMCID: PMC7514988 DOI: 10.3390/e21050500] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/10/2019] [Accepted: 05/14/2019] [Indexed: 02/06/2023]
Abstract
Contemporary neurodynamical frameworks, such as coordination dynamics and winnerless competition, posit that the brain approximates symbolic computation by transitioning between metastable attractive states. This article integrates these accounts with electrophysiological data suggesting that coherent, nested oscillations facilitate information representation and transmission in thalamocortical networks. We review the relationship between criticality, metastability, and representational capacity, outline existing methods for detecting metastable oscillatory patterns in neural time series data, and evaluate plausible spatiotemporal coding schemes based on phase alignment. We then survey the circuitry and the mechanisms underlying the generation of coordinated alpha and gamma rhythms in the primate visual system, with particular emphasis on the pulvinar and its role in biasing visual attention and awareness. To conclude the review, we begin to integrate this perspective with longstanding theories of consciousness and cognition.
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Affiliation(s)
- Roy Moyal
- Department of Psychology, Cornell University, Ithaca, NY 14853, USA
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11
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Sun R, Chen X, Yin CY, Qi L, Lau PM, Han H, Bi GQ. Correlative light and electron microscopy for complex cellular structures on PDMS substrates with coded micro-patterns. LAB ON A CHIP 2018; 18:3840-3848. [PMID: 30417906 DOI: 10.1039/c8lc00703a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Fluorescence light microscopy (FLM) is commonly used for localizing specific cellular and subcellular targets. Electron microscopy (EM), on the other hand, can reveal ultrastructural details of cellular architectures beyond the limit of optical resolution. Correlative light and electron microscopy (CLEM) that combines the two techniques has proven valuable in various cell biological applications that require both specificity and resolution. Here, we report an efficient and easy-to-use CLEM system, and its applications in studying neuronal synapses. The system utilizes patterned symbols to encode coordinates on micro-fabricated polydimethylsiloxane (PDMS) substrates, on which dissociated primary hippocampal neurons grow and form synaptic connections. After imaging and localizing specifically labeled synapses with FLM, samples are embedded in resin blocks and sectioned for EM analysis. The patterned symbols on PDMS substrates provide coordinate information, allowing efficient co-registration between FLM and EM images with high precision. A custom-developed software package achieves automated EM image collection, FLM/EM alignment, and EM navigation. With this CLEM system, we have obtained high quality electron tomograms of fluorescently labeled synapses along dendrites of hippocampal neurons and analyzed docking statistics of synaptic vesicles (SVs) in different subtypes of excitatory synapses. This technique provides an efficient approach to combine functional studies with ultrastructural analysis of heterogeneous neuronal synapses, as well as other subcellular structures in general.
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Affiliation(s)
- Rong Sun
- Center for Integrative Imaging, National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
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12
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Abstract
Predictive coding theories of sensory brain function interpret the hierarchical construction of the cerebral cortex as a Bayesian, generative model capable of predicting the sensory data consistent with any given percept. Predictions are fed backward in the hierarchy and reciprocated by prediction error in the forward direction, acting to modify the representation of the outside world at increasing levels of abstraction, and so to optimize the nature of perception over a series of iterations. This accounts for many ‘illusory’ instances of perception where what is seen (heard, etc.) is unduly influenced by what is expected, based on past experience. This simple conception, the hierarchical exchange of prediction and prediction error, confronts a rich cortical microcircuitry that is yet to be fully documented. This article presents the view that, in the current state of theory and practice, it is profitable to begin a two-way exchange: that predictive coding theory can support an understanding of cortical microcircuit function, and prompt particular aspects of future investigation, whilst existing knowledge of microcircuitry can, in return, influence theoretical development. As an example, a neural inference arising from the earliest formulations of predictive coding is that the source populations of forward and backward pathways should be completely separate, given their functional distinction; this aspect of circuitry – that neurons with extrinsically bifurcating axons do not project in both directions – has only recently been confirmed. Here, the computational architecture prescribed by a generalized (free-energy) formulation of predictive coding is combined with the classic ‘canonical microcircuit’ and the laminar architecture of hierarchical extrinsic connectivity to produce a template schematic, that is further examined in the light of (a) updates in the microcircuitry of primate visual cortex, and (b) rapid technical advances made possible by transgenic neural engineering in the mouse. The exercise highlights a number of recurring themes, amongst them the consideration of interneuron diversity as a spur to theoretical development and the potential for specifying a pyramidal neuron’s function by its individual ‘connectome,’ combining its extrinsic projection (forward, backward or subcortical) with evaluation of its intrinsic network (e.g., unidirectional versus bidirectional connections with other pyramidal neurons).
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Affiliation(s)
- Stewart Shipp
- Laboratory of Visual Perceptual Mechanisms, Institute of Neuroscience, Chinese Academy of SciencesShanghai, China; INSERM U1208, Stem Cell and Brain Research InstituteBron, France; Department of Visual Neuroscience, UCL Institute of OphthalmologyLondon, UK
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13
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Spratling MW. A review of predictive coding algorithms. Brain Cogn 2016; 112:92-97. [PMID: 26809759 DOI: 10.1016/j.bandc.2015.11.003] [Citation(s) in RCA: 154] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 11/09/2015] [Accepted: 11/13/2015] [Indexed: 10/22/2022]
Abstract
Predictive coding is a leading theory of how the brain performs probabilistic inference. However, there are a number of distinct algorithms which are described by the term "predictive coding". This article provides a concise review of these different predictive coding algorithms, highlighting their similarities and differences. Five algorithms are covered: linear predictive coding which has a long and influential history in the signal processing literature; the first neuroscience-related application of predictive coding to explaining the function of the retina; and three versions of predictive coding that have been proposed to model cortical function. While all these algorithms aim to fit a generative model to sensory data, they differ in the type of generative model they employ, in the process used to optimise the fit between the model and sensory data, and in the way that they are related to neurobiology.
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Affiliation(s)
- M W Spratling
- King's College London, Department of Informatics, London, UK.
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14
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Markov NT, Vezoli J, Chameau P, Falchier A, Quilodran R, Huissoud C, Lamy C, Misery P, Giroud P, Ullman S, Barone P, Dehay C, Knoblauch K, Kennedy H. Anatomy of hierarchy: feedforward and feedback pathways in macaque visual cortex. J Comp Neurol 2014; 522:225-59. [PMID: 23983048 PMCID: PMC4255240 DOI: 10.1002/cne.23458] [Citation(s) in RCA: 419] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 04/10/2013] [Accepted: 08/14/2013] [Indexed: 12/18/2022]
Abstract
The laminar location of the cell bodies and terminals of interareal connections determines the hierarchical structural organization of the cortex and has been intensively studied. However, we still have only a rudimentary understanding of the connectional principles of feedforward (FF) and feedback (FB) pathways. Quantitative analysis of retrograde tracers was used to extend the notion that the laminar distribution of neurons interconnecting visual areas provides an index of hierarchical distance (percentage of supragranular labeled neurons [SLN]). We show that: 1) SLN values constrain models of cortical hierarchy, revealing previously unsuspected areal relations; 2) SLN reflects the operation of a combinatorial distance rule acting differentially on sets of connections between areas; 3) Supragranular layers contain highly segregated bottom-up and top-down streams, both of which exhibit point-to-point connectivity. This contrasts with the infragranular layers, which contain diffuse bottom-up and top-down streams; 4) Cell filling of the parent neurons of FF and FB pathways provides further evidence of compartmentalization; 5) FF pathways have higher weights, cross fewer hierarchical levels, and are less numerous than FB pathways. Taken together, the present results suggest that cortical hierarchies are built from supra- and infragranular counterstreams. This compartmentalized dual counterstream organization allows point-to-point connectivity in both bottom-up and top-down directions.
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Affiliation(s)
- Nikola T Markov
- Stem Cell and Brain Research Institute, INSERM U846, 69500, Bron, France; Université de Lyon, Université Lyon I, 69003, Lyon, France; Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut, 06520-8001, USA
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15
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Medalla M, Barbas H. Specialized prefrontal "auditory fields": organization of primate prefrontal-temporal pathways. Front Neurosci 2014; 8:77. [PMID: 24795553 PMCID: PMC3997038 DOI: 10.3389/fnins.2014.00077] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 03/27/2014] [Indexed: 12/14/2022] Open
Abstract
No other modality is more frequently represented in the prefrontal cortex than the auditory, but the role of auditory information in prefrontal functions is not well understood. Pathways from auditory association cortices reach distinct sites in the lateral, orbital, and medial surfaces of the prefrontal cortex in rhesus monkeys. Among prefrontal areas, frontopolar area 10 has the densest interconnections with auditory association areas, spanning a large antero-posterior extent of the superior temporal gyrus from the temporal pole to auditory parabelt and belt regions. Moreover, auditory pathways make up the largest component of the extrinsic connections of area 10, suggesting a special relationship with the auditory modality. Here we review anatomic evidence showing that frontopolar area 10 is indeed the main frontal “auditory field” as the major recipient of auditory input in the frontal lobe and chief source of output to auditory cortices. Area 10 is thought to be the functional node for the most complex cognitive tasks of multitasking and keeping track of information for future decisions. These patterns suggest that the auditory association links of area 10 are critical for complex cognition. The first part of this review focuses on the organization of prefrontal-auditory pathways at the level of the system and the synapse, with a particular emphasis on area 10. Then we explore ideas on how the elusive role of area 10 in complex cognition may be related to the specialized relationship with auditory association cortices.
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Affiliation(s)
- Maria Medalla
- Department of Anatomy and Neurobiology, Boston University Boston, MA, USA ; Neural Systems Laboratory, Department of Health Sciences, Boston University Boston, MA, USA
| | - Helen Barbas
- Department of Anatomy and Neurobiology, Boston University Boston, MA, USA ; Neural Systems Laboratory, Department of Health Sciences, Boston University Boston, MA, USA ; Department of Health Sciences, Boston University Boston, MA, USA
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Experience-dependent rewiring of specific inhibitory connections in adult neocortex. PLoS Biol 2014; 12:e1001798. [PMID: 24586113 PMCID: PMC3934820 DOI: 10.1371/journal.pbio.1001798] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 01/15/2014] [Indexed: 11/24/2022] Open
Abstract
Optogenetic mapping of connectivity in the primary somatosensory cortex shows that mature cortical circuits adapt to sensory deprivation by selectively altering specific network motifs. Although neocortical connectivity is remarkably stereotyped, the abundance of some wiring motifs varies greatly between cortical areas. To examine if regional wiring differences represent functional adaptations, we have used optogenetic raster stimulation to map the laminar distribution of GABAergic interneurons providing inhibition to pyramidal cells in layer 2/3 (L2/3) of adult mouse barrel cortex during sensory deprivation and recovery. Whisker trimming caused large, motif-specific changes in inhibitory synaptic connectivity: ascending inhibition from deep layers 4 and 5 was attenuated to 20%–45% of baseline, whereas inhibition from superficial layers remained stable (L2/3) or increased moderately (L1). The principal mechanism of deprivation-induced plasticity was motif-specific changes in inhibitory-to-excitatory connection probabilities; the strengths of extant connections were left unaltered. Whisker regrowth restored the original balance of inhibition from deep and superficial layers. Targeted, reversible modifications of specific inhibitory wiring motifs thus contribute to the adaptive remodeling of cortical circuits. Many natural and engineered networks contain recurring patterns of local connectivity. Although these so-called network motifs are thought to have functional significance, direct tests of the idea that network topology reflects function remain scarce. We have performed such a test in the area of mammalian neocortex that is devoted to the sensory representation of touch. To this end, we equipped inhibitory interneurons in the mouse with light-activated ion channels that allowed us to stimulate interneuron activity optically and record light-evoked inhibitory currents in their postsynaptic partners, thereby revealing maps of connectivity. We find that excitatory pyramidal cells in layer 2/3 of primary somatosensory cortex receive inhibition from GABAergic interneurons located in different cortical layers, with a characteristic balance of inhibitory connections from deep and superficial layers. Trimming the whiskers to remove sensory input in adult animals alters this balance—inhibitory connections from deep cortical layers are depleted, while inhibitory connections from superficial layers are augmented. These changes revert when the whiskers regrow, restoring the original balance between wiring motifs. This see-saw relationship between deep and superficial inhibition demonstrates that mature cortical circuits adapt to functional change by selectively altering specific network motifs.
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The emerging role of GABAB receptors as regulators of network dynamics: fast actions from a 'slow' receptor? Curr Opin Neurobiol 2013; 26:15-21. [PMID: 24650499 DOI: 10.1016/j.conb.2013.10.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 10/10/2013] [Accepted: 10/11/2013] [Indexed: 12/25/2022]
Abstract
Convention holds that ionotropic receptors mediate fast neurotransmission and that 'slow' G-protein coupled metabotropic receptors have a secondary, modulatory role in the control of neuronal networks. Here, we discuss recent evidence showing that activation of metabotropic GABAB receptors in cortical layer 1 can powerfully inhibit principal cell activity and that their activation can rapidly halt ongoing network activity. Inputs from both within and without the cortex converge upon layer 1 where they target various populations of interneurons, including neurogliaform cells. We argue that neurogliaform cells are the main effector of a powerful inhibitory circuit that, acting through GABAB receptors, can be differentially recruited by long-range connections to serve in roles as diverse as conscious perception and memory consolidation.
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18
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da Costa NM. Diversity of thalamorecipient spine morphology in cat visual cortex and its implication for synaptic plasticity. J Comp Neurol 2013. [PMID: 23184851 DOI: 10.1002/cne.23272] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A feature of spine synapses is the existence of a neck connecting the synapse on the spine head to the dendritic shaft. As with a cable, spine neck resistance (R(neck)) increases with increasing neck length and is inversely proportional to the cross-sectional area of the neck. A synaptic current entering a spine with a high R(neck) will lead to greater local depolarization in the spine head than would a similar input applied to a spine with a lower R(neck). This could make spines with high R(neck) more sensitive to plastic changes since voltage sensitive conductances, such as N-methyl-D-aspartic acid (NMDA) channels can be more easily activated. This hypothesis was tested using serial section electron microscopic reconstructions of thalamocortical spine synapses and spine necks located on spiny stellate cells and corticothalamic cells from area 17 of cats. Thalamic axons and corticothalamic neurons were labeled by injections of the tracer biotinylated dextran amine (BDA) in the dorsal lateral geniculate nucleus (dLGN) of anesthetized cats and spiny stellates were filled intracellularly in vivo with horseradish peroxidase. Twenty-eight labeled spines that formed synapses with dLGN boutons were collected from three spiny stellate and four corticothalamic cells and reconstructed in 3D from serial electron micrographs. Spine length, spine diameter, and the area of the postsynaptic density were measured from the 3D reconstructions and R(neck) of the spine was estimated. No correlation was found between the postsynaptic density size and the estimated spine R(neck). This suggests that forms of plasticity that lead to larger synapses are independent of spine neck resistance.
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Affiliation(s)
- Nuno Maçarico da Costa
- Institute for Neuroinformatics, University of Zürich and ETH Zürich, 8057 Zürich, Switzerland.
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19
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Rockland KS. Collateral branching of long-distance cortical projections in monkey. J Comp Neurol 2013; 521:4112-23. [DOI: 10.1002/cne.23414] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 05/24/2013] [Accepted: 05/28/2013] [Indexed: 12/19/2022]
Affiliation(s)
- Kathleen S. Rockland
- Department of Anatomy and Neurobiology; Boston University School of Medicine; Boston Massachusetts 02118
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20
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da Costa NM, Martin KA. Sparse reconstruction of brain circuits: Or, how to survive without a microscopic connectome. Neuroimage 2013; 80:27-36. [DOI: 10.1016/j.neuroimage.2013.04.054] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 04/10/2013] [Accepted: 04/15/2013] [Indexed: 11/30/2022] Open
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21
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Corticocortical feedback contributes to surround suppression in V1 of the alert primate. J Neurosci 2013; 33:8504-17. [PMID: 23658187 DOI: 10.1523/jneurosci.5124-12.2013] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Feedback connections are prevalent throughout the cerebral cortex, yet their function remains poorly understood. Previous studies in anesthetized monkeys found that inactivating feedback from extrastriate visual cortex produced effects in striate cortex that were relatively weak, generally suppressive, largest for visual stimuli confined to the receptive field center, and detectable only at low stimulus contrast. We studied the influence of corticocortical feedback in alert monkeys using cortical cooling to reversibly inactivate visual areas 2 (V2) and 3 (V3) while characterizing receptive field properties in primary visual cortex (V1). We show that inactivation of feedback from areas V2 and V3 results in both response suppression and facilitation for stimuli restricted to the receptive field center, in most cases leading to a small reduction in the degree of orientation selectivity but no change in orientation preference. For larger-diameter stimuli that engage regions beyond the center of the receptive field, eliminating feedback from V2 and V3 results in strong and consistent response facilitation, effectively reducing the strength of surround suppression in V1 for stimuli of both low and high contrast. For extended contours, eliminating feedback had the effect of reducing end stopping. Inactivation effects were largest for neurons that exhibited strong surround suppression before inactivation, and their timing matched the dynamics of surround suppression under control conditions. Our results provide direct evidence that feedback contributes to surround suppression, which is an important source of contextual influences essential to vision.
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22
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Craig MT, Mayne EW, Bettler B, Paulsen O, McBain CJ. Distinct roles of GABAB1a- and GABAB1b-containing GABAB receptors in spontaneous and evoked termination of persistent cortical activity. J Physiol 2012; 591:835-43. [PMID: 23266934 PMCID: PMC3591701 DOI: 10.1113/jphysiol.2012.248088] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
During slow-wave sleep, cortical neurons display synchronous fluctuations between periods of persistent activity (‘UP states’) and periods of relative quiescence (‘DOWN states’). Such UP and DOWN states are also seen in isolated cortical slices. Recently, we reported that both spontaneous and evoked termination of UP states in slices from the rat medial entorhinal cortex (mEC) involves GABAB receptors. Here, in order to dissociate the roles of GABAB1a- and GABAB1b-containing receptors in terminating UP states, we used mEC slices from mice in which either the GABAB1a or the GABAB1b subunit had been genetically ablated. Pharmacological blockade of GABAB receptors using the antagonist CGP55845 prolonged the UP state duration in both wild-type mice and those lacking the GABAB1b subunit, but not in those lacking the GABAB1a subunit. Conversely, electrical stimulation of layer 1 could terminate an ongoing UP state in both wild-type mice and those lacking the GABAB1a subunit, but not in those lacking the GABAB1b subunit. Together with previous reports, indicating a preferential presynaptic location of GABAB1a- and postsynaptic location of GABAB1b-containing receptors, these results suggest that presynaptic GABAB receptors contribute to spontaneous DOWN state transitions, whilst postsynaptic GABAB receptors are essential for the afferent termination of the UP state. Inputs to layer 1 from other brain regions could thus provide a powerful mechanism for synchronizing DOWN state transitions across cortical areas via activation of GABAergic interneurons targeting postsynaptic GABAB receptors.
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Affiliation(s)
- Michael T Craig
- Program in Developmental Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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23
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Bastos AM, Usrey WM, Adams RA, Mangun GR, Fries P, Friston KJ. Canonical microcircuits for predictive coding. Neuron 2012; 76:695-711. [PMID: 23177956 PMCID: PMC3777738 DOI: 10.1016/j.neuron.2012.10.038] [Citation(s) in RCA: 1337] [Impact Index Per Article: 111.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2012] [Indexed: 11/19/2022]
Abstract
This Perspective considers the influential notion of a canonical (cortical) microcircuit in light of recent theories about neuronal processing. Specifically, we conciliate quantitative studies of microcircuitry and the functional logic of neuronal computations. We revisit the established idea that message passing among hierarchical cortical areas implements a form of Bayesian inference-paying careful attention to the implications for intrinsic connections among neuronal populations. By deriving canonical forms for these computations, one can associate specific neuronal populations with specific computational roles. This analysis discloses a remarkable correspondence between the microcircuitry of the cortical column and the connectivity implied by predictive coding. Furthermore, it provides some intuitive insights into the functional asymmetries between feedforward and feedback connections and the characteristic frequencies over which they operate.
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Affiliation(s)
- Andre M Bastos
- Center for Neuroscience, University of California, Davis, Davis, CA 95618, USA
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24
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Berezovskii VK, Nassi JJ, Born RT. Segregation of feedforward and feedback projections in mouse visual cortex. J Comp Neurol 2012; 519:3672-83. [PMID: 21618232 DOI: 10.1002/cne.22675] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hierarchical organization is a common feature of mammalian neocortex. Neurons that send their axons from lower to higher areas of the hierarchy are referred to as "feedforward" (FF) neurons, whereas those projecting in the opposite direction are called "feedback" (FB) neurons. Anatomical, functional, and theoretical studies suggest that these different classes of projections play fundamentally different roles in perception. In primates, laminar differences in projection patterns often distinguish the two projection streams. In rodents, however, these differences are less clear, despite an established hierarchy of visual areas. Thus the rodent provides a strong test of the hypothesis that FF and FB neurons form distinct populations. We tested this hypothesis by injecting retrograde tracers into two different hierarchical levels of mouse visual cortex (area 17 and anterolateral area [AL]) and then determining the relative proportions of double-labeled FF and FB neurons in an area intermediate to them (lateromedial area [LM]). Despite finding singly labeled neurons densely intermingled with no laminar segregation, we found few double-labeled neurons (≈5% of each singly labeled population). We also examined the development of FF and FB connections. FF connections were present at the earliest timepoint we examined (postnatal day 2, P2), while FB connections were not detectable until P11. Our findings indicate that, even in cortices without laminar segregation of FF and FB neurons, the two projection systems are largely distinct at the neuronal level and also differ with respect to the timing of their axonal outgrowth.
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Affiliation(s)
- Vladimir K Berezovskii
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115-5701, USA
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25
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Pathways of attention: synaptic relationships of frontal eye field to V4, lateral intraparietal cortex, and area 46 in macaque monkey. J Neurosci 2011; 31:10872-81. [PMID: 21795539 DOI: 10.1523/jneurosci.0622-11.2011] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The frontal eye field (FEF) of the primate neocortex occupies a pivotal position in the matrix of inter-areal projections. In addition to its role in directing saccadic eye movements, it is the source of an attentional signal that modulates the activity of neurons in extrastriate and parietal cortex. Here, we tested the prediction that FEF preferentially excites inhibitory neurons in target areas during attentional modulation. Using the anterograde tracer biotinylated dextran amine, we found that the projections from FEF terminate in all cortical layers of area 46, lateral intraparietal area (LIP), and visual area V4. Axons in layer 1 spread extensively, those in layer 2/3 were most numerous, individual axons in layer 4 formed sprays of collaterals, and those of the deep layers were the finest caliber and irregular. All labeled synapses were the typical asymmetric morphology of excitatory synapses of pyramidal neurons. Dendritic spines were the most frequent synaptic target in all areas (95% in area 46, 89% in V4, 84% in LIP, 78% intrinsic local FEF). The remaining targets were one soma and dendritic shafts, most of which showed characteristics of inhibitory neurons with smooth dendrites (5% of all targets in area 46, 2% in V4, 9% in LIP, and 13% in FEF).
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26
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Wozny C, Williams SR. Specificity of synaptic connectivity between layer 1 inhibitory interneurons and layer 2/3 pyramidal neurons in the rat neocortex. Cereb Cortex 2011; 21:1818-26. [PMID: 21220765 PMCID: PMC3138515 DOI: 10.1093/cercor/bhq257] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Understanding the structure and function of the neocortical microcircuit requires a description of the synaptic connectivity between identified neuronal populations. Here, we investigate the electrophysiological properties of layer 1 (L1) neurons of the rat somatosensory neocortex (postnatal day 24-36) and their synaptic connectivity with supragranular pyramidal neurons. The active and passive properties of visually identified L1 neurons (n = 266) suggested division into 4 groups according to the Petilla classification scheme with characteristics of neurogliaform cells (NGFCs) (n = 72), classical-accommodating (n = 137), fast-spiking (n = 23), and burst-spiking neurons (n = 34). Anatomical reconstructions of L1 neurons supported the existence of 4 major neuronal groups. Multiparameter unsupervised cluster analysis confirmed the existence of 4 groups, revealing a high degree of similarity with the Petilla scheme. Simultaneous recordings between synaptically connected L1 neurons and L2/3 pyramidal neurons (n = 384) demonstrated neuronal class specificity in both excitatory and inhibitory connectivity and the properties of synaptic potentials. Notably, all groups of L1 neurons received monosynaptic excitatory input from L2/3 pyramidal neurons (n = 33), with the exception of NGFCs (n = 68 pairs tested). In contrast, NGFCs strongly inhibited L2/3 pyramidal neurons (n = 12 out 27 pairs tested). These data reveal a high specificity of excitatory and inhibitory connections in the superficial layers of the neocortex.
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Affiliation(s)
| | - Stephen R. Williams
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
- The Queensland Brain Institute, St Lucia, QLD 4072, Australia
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27
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Kononenko NL, Witter MP. Presubiculum layer III conveys retrosplenial input to the medial entorhinal cortex. Hippocampus 2011; 22:881-95. [DOI: 10.1002/hipo.20949] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2011] [Indexed: 12/17/2022]
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28
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Deco G, Thiele A. Cholinergic control of cortical network interactions enables feedback-mediated attentional modulation. Eur J Neurosci 2011; 34:146-57. [PMID: 21692884 DOI: 10.1111/j.1460-9568.2011.07749.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Attention increases our ability to detect behaviorally relevant stimuli. At the neuronal level this is supported by increased firing rates of neurons representing the attended object. In primary visual cortex an attention-mediated activity increase depends on the presence of the neuromodulator acetylcholine. Using a spiking network model of visual cortex we have investigated how acetylcholine interacts with biased feedback to enable attentional processing. Although acetylcholine affects cortical processing in a multitude of manners, we restricted our analysis to four of its main established actions. These were (i) a reduction in firing rate adaptation by reduction in M-currents (muscarinic), (ii) an increase in thalamocortical synaptic efficacy by nicotinic presynaptic receptors, (iii) a reduction in lateral interactions by muscarinic presynaptic receptors, and (iv) an increase in inhibitory drive by muscarinic receptors located on inhibitory interneurons. We found that acetylcholine contributes to feedback-mediated attentional modulation, mostly by reducing intracortical interactions and also to some extent by increasing the inhibitory drive. These findings help explain why acetylcholine is necessary for top-down-driven attentional modulation, and suggest a close interdependence of cholinergic and feedback drive in mediating cognitive function.
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Affiliation(s)
- Gustavo Deco
- Department of Technology, Computational Neuroscience, Institució Catalana de Recerca i Estudis Avançats (ICREA), Universitat Pompeu Fabra, Roc Boronat, 138, 08018 Barcelona, Spain.
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29
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Anterior cingulate synapses in prefrontal areas 10 and 46 suggest differential influence in cognitive control. J Neurosci 2011; 30:16068-81. [PMID: 21123554 DOI: 10.1523/jneurosci.1773-10.2010] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Dorsolateral prefrontal areas 46 and 10 are involved in distinct aspects of cognition. Area 46 has a key role in working memory tasks, and frontopolar area 10 is recruited in complex multitask operations. Both areas are innervated by the anterior cingulate cortex (ACC), a region associated with emotions and memory but is also important for attentional control through unknown synaptic mechanisms. Here, we found that in rhesus monkeys (Macaca mulatta) most axon terminals labeled from tracers injected into ACC area 32 innervated spines of presumed excitatory neurons, but ∼20-30% formed mostly large synapses with dendritic shafts of presumed inhibitory neurons in the upper layers (I-IIIa) of dorsolateral areas 10, 46, and 9. Moreover, area 32 terminals targeted preferentially calbindin and, to a lesser extent, calretinin neurons, which are thought to be inhibitory neurons that modulate the gain of task-relevant activity during working memory tasks. Area 46 was distinguished as a recipient of more (by ∼40%) area 32 synapses on putative inhibitory neurons. Area 10 stood apart as recipient of significantly larger (by ∼40% in volume) area 32 terminals on spines of putative excitatory neurons. These synaptic specializations suggest that area 32 has complementary roles, potentially enhancing inhibition in area 46 and strengthening excitation in area 10, which may help direct attention to new tasks while temporarily holding in memory another task.
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30
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Abstract
The claustrum is a subcortical structure reciprocally connected with most areas of neocortex. This strategic location suggests an integrative role of the claustrum across different sensory modalities. However, our knowledge of the synaptic relationship between the neocortex and the claustrum is basic. In this study, we address this question through a structural investigation of the claustral projection to the ipsilateral primary visual cortex of the cat. Light microscopic reconstructions of axons from the entire thickness of cortex showed a very sparse innervation of the entire cortical depth, with most synaptic boutons in layers 2/3 and 6. Axons bearing numerous boutons terminaux and boutons en passant branched in these laminae. The sparse innervation did not seem to be compensated by particularly large synapses, given that the postsynaptic densities in the superficial layers are of comparable sizes (0.1 μm(2)) to other cortical synapses. All claustral synapses were asymmetric and in most cases targeted spines (87% in layer 4, 94% in layers 2/3 and 97% in layer 6). The pattern of innervation together with the known physiology of this projection suggests that the claustrum has a modulatory effect on visual cortex.
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31
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Voges N, Schüz A, Aertsen A, Rotter S. A modeler's view on the spatial structure of intrinsic horizontal connectivity in the neocortex. Prog Neurobiol 2010; 92:277-92. [PMID: 20685378 DOI: 10.1016/j.pneurobio.2010.05.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 04/10/2010] [Accepted: 05/27/2010] [Indexed: 10/19/2022]
Abstract
Most current computational models of neocortical networks assume a homogeneous and isotropic arrangement of local synaptic couplings between neurons. Sparse, recurrent connectivity is typically implemented with simple statistical wiring rules. For spatially extended networks, however, such random graph models are inadequate because they ignore the traits of neuron geometry, most notably various distance dependent features of horizontal connectivity. It is to be expected that such non-random structural attributes have a great impact, both on the spatio-temporal activity dynamics and on the biological function of neocortical networks. Here we review the neuroanatomical literature describing long-range horizontal connectivity in the neocortex over distances of up to eight millimeters, in various cortical areas and mammalian species. We extract the main common features from these data to allow for improved models of large-scale cortical networks. Such models include, next to short-range neighborhood coupling, also long-range patchy connections. We show that despite the large variability in published neuroanatomical data it is reasonable to design a generic model which generalizes over different cortical areas and mammalian species. Later on, we critically discuss this generalization, and we describe some examples of how to specify the model in order to adapt it to specific properties of particular cortical areas or species.
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Affiliation(s)
- Nicole Voges
- Faculty of Biology, Albert-Ludwig University Freiburg, Germany.
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Anderson JC, da Costa NM, Martin KAC. The W cell pathway to cat primary visual cortex. J Comp Neurol 2009; 516:20-35. [PMID: 19562768 DOI: 10.1002/cne.22085] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The thalamic input to area 17 in the cat can be divided into at least three parallel pathways, the W, X, and Y. Although the latter two are some of the best studied synaptic connections in the brain, the former remains poorly understood both in structure and in function. By combining light and electron microscopy, we have reconstructed in 3-D single W axons and described quantitatively the synapses that they form. We have also made a structural comparison of reconstructed synapses from the three visual pathways. Thalamic axons were labeled in vivo by injections of biotinylated dextran amine into the dLGN. W axons originating from C laminae injections arborized in layers 1, 2/3, and 5. Axons that traversed layer 1 supplied a few descending collaterals to layer 2/3, but the most extensive innervation in layer 2/3 was provided by axons ascending from the white matter. Most W boutons formed a single synapse, dendritic spines being the most common target, with dendritic shafts forming the remaining targets. In layer 1, the area of the postsynaptic density of spine synapses (0.16 microm(2)) was significantly larger than that of layers 2/3 (0.11 microm(2)) and 5 (0.09 microm(2)). Synapses from X and Y axons in layer 4 were similar in size to synapses formed by W boutons in layer 1. In layer 1, the main targets of the W axons are likely the apical dendrites of pyramidal cells, so that both proximal and distal regions of pyramidal cell dendritic trees can be excited by the W pathway.
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Affiliation(s)
- John C Anderson
- Institute for Neuroinformatics, University of Zürich, ETH Zürich, Zürich, Switzerland
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33
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The synaptic connections between cortical areas V1 and V2 in macaque monkey. J Neurosci 2009; 29:11283-93. [PMID: 19741135 DOI: 10.1523/jneurosci.5757-08.2009] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The primary visual cortex (V1) and V2 together form approximately 24% of the total neocortex of the macaque monkey and have each other as their major partners. The major target of the V1 projection to V2 is layer 4, where it forms clusters of boutons, which form asymmetric (excitatory) synapses mainly with dendritic spines (75%). The remainder form synapses with dendritic shafts. The synapses found on spines were often more complex, perforated postsynaptic densities than those found on dendritic shafts. The reciprocal projection from V2 to V1 targeted layers 1, 2/3, and 5 and was formed of axons of different morphologies. One axon type, originating from superficial layer pyramidal cells, had a morphology resembling those of local pyramidal cell collaterals. These axons arborized in layers 1, 2/3, and 5 of V1. Another type of axon, arborizing in layer 1, was slender (0.3 microm), unbranched, unmyelinated, and uniformly covered with boutons terminaux and formed asymmetric synapses mainly with slender spines. Yet a third type of axon also confined to layer 1, was thick (>1 microm), branched, heavily myelinated, and formed separate small clusters of large ( approximately 1 microm) en passant multisynaptic boutons that formed asymmetric synapses mainly with large flat spines. These data show the existence of a reciprocal excitatory loop between V1 and V2 that is formed by different axonal types, each with preferred layers of termination.
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34
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Schmid MC, Panagiotaropoulos T, Augath MA, Logothetis NK, Smirnakis SM. Visually driven activation in macaque areas V2 and V3 without input from the primary visual cortex. PLoS One 2009; 4:e5527. [PMID: 19436733 PMCID: PMC2677457 DOI: 10.1371/journal.pone.0005527] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 03/17/2009] [Indexed: 11/18/2022] Open
Abstract
Creating focal lesions in primary visual cortex (V1) provides an opportunity to study the role of extra-geniculo-striate pathways for activating extrastriate visual cortex. Previous studies have shown that more than 95% of neurons in macaque area V2 and V3 stop firing after reversibly cooling V1. However, no studies on long term recovery in areas V2, V3 following permanent V1 lesions have been reported in the macaque. Here we use macaque fMRI to study area V2, V3 activity patterns from 1 to 22 months after lesioning area V1. We find that visually driven BOLD responses persist inside the V1-lesion projection zones (LPZ) of areas V2 and V3, but are reduced in strength by approximately 70%, on average, compared to pre-lesion levels. Monitoring the LPZ activity over time starting one month following the V1 lesion did not reveal systematic changes in BOLD signal amplitude. Surprisingly, the retinotopic organization inside the LPZ of areas V2, V3 remained similar to that of the non-lesioned hemisphere, suggesting that LPZ activation in V2, V3 is not the result of input arising from nearby (non-lesioned) V1 cortex. Electrophysiology recordings of multi-unit activity corroborated the BOLD observations: visually driven multi-unit responses could be elicited inside the V2 LPZ, even when the visual stimulus was entirely contained within the scotoma induced by the V1 lesion. Restricting the stimulus to the intact visual hemi-field produced no significant BOLD modulation inside the V2, V3 LPZs. We conclude that the observed activity patterns are largely mediated by parallel, V1-bypassing, subcortical pathways that can activate areas V2 and V3 in the absence of V1 input. Such pathways may contribute to the behavioral phenomenon of blindsight.
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Affiliation(s)
- Michael C. Schmid
- Max Planck Institut für biologische Kybernetik, Tübingen, Germany
- * E-mail: (MCS); (SMS)
| | | | - Mark A. Augath
- Max Planck Institut für biologische Kybernetik, Tübingen, Germany
| | - Nikos K. Logothetis
- Max Planck Institut für biologische Kybernetik, Tübingen, Germany
- Imaging Science and Biomedical Engineering, University of Manchester, Manchester, United Kingdom
| | - Stelios M. Smirnakis
- Max Planck Institut für biologische Kybernetik, Tübingen, Germany
- Departments of Neuroscience and Neurology, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail: (MCS); (SMS)
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Medalla M, Barbas H. Synapses with inhibitory neurons differentiate anterior cingulate from dorsolateral prefrontal pathways associated with cognitive control. Neuron 2009; 61:609-20. [PMID: 19249280 DOI: 10.1016/j.neuron.2009.01.006] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 01/07/2009] [Accepted: 01/08/2009] [Indexed: 11/30/2022]
Abstract
The primate dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) focus attention on relevant signals and suppress noise in cognitive tasks. However, their synaptic interactions and unique roles in cognitive control are unknown. We report that two distinct pathways to DLPFC area 9, one from the neighboring area 46 and the other from the functionally distinct ACC, similarly innervate excitatory neurons associated with selecting relevant stimuli. However, ACC has more prevalent and larger synapses with inhibitory neurons and preferentially innervates calbindin inhibitory neurons, which reduce noise by inhibiting excitatory neurons. In contrast, area 46 mostly innervates calretinin inhibitory neurons, which disinhibit excitatory neurons. These synaptic specializations suggest that ACC has a greater impact in reducing noise in dorsolateral areas during challenging cognitive tasks involving conflict, error, or reversing decisions, mechanisms that are disrupted in schizophrenia. These observations highlight the unique roles of the DLPFC and ACC in cognitive control.
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Affiliation(s)
- Maria Medalla
- Department of Health Sciences, Boston University and School of Medicine, Boston, MA 02215, USA
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Shipp S, Adams DL, Moutoussis K, Zeki S. Feature binding in the feedback layers of area V2. ACTA ACUST UNITED AC 2009; 19:2230-9. [PMID: 19153106 DOI: 10.1093/cercor/bhn243] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The visual features of an object are processed by multiple, functionally specialized areas of cerebral cortex. When several objects are seen simultaneously, what mechanism preserves the association of features that belong to a single item? We address this question-known as the "binding problem"-by examining combinatorial feature selectivity of neurons in area V2. In recording from anesthetized macaques, we estimate that dual selectivity for chromatic and spatiotemporal attributes is 50% more common (27% vs. 18% sampling frequency) in superficial and deep layer neurons receiving feedback connections from higher areas, compared with layer 4-3 neurons relaying ascending signals. The operation of feedback pathways is thought to mediate attentional modulation of activity that may achieve binding through acting to select one single object for higher representation and filtering out competing objects. We propose that dual-selective neurons perform a "bridging" function, mediating the transfer of feedback-induced bias between feature dimensions. The bias can be propagated through V2 output neurons (of unitary selectivity) to higher levels of specialized processing and so promote selection of the target object's representation among multiple feature maps. The bridging function would thus act to unify the outcome of parallel, object-selective processes taking place along segregated visual pathways.
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Affiliation(s)
- Stewart Shipp
- Laboratory of Neurobiology, Department of Cell and Developmental Biology, University College London, London, UK.
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37
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Affiliation(s)
- Rodney J Douglas
- Institute of Neuroinformatics, Winterthurerstrasse 190, Zurich, Switzerland
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38
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Affiliation(s)
- Stewart Shipp
- Department of Anatomy and Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK.
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39
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Aoto J, Ting P, Maghsoodi B, Xu N, Henkemeyer M, Chen L. Postsynaptic ephrinB3 promotes shaft glutamatergic synapse formation. J Neurosci 2007; 27:7508-19. [PMID: 17626212 PMCID: PMC6672605 DOI: 10.1523/jneurosci.0705-07.2007] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Excitatory synapses in the CNS are formed on both dendritic spines and shafts. Recent studies show that the density of shaft synapses may be independently regulated by behavioral learning and the induction of synaptic plasticity, suggesting that distinct mechanisms are involved in regulating these two types of synapses. Although the molecular mechanisms underlying spinogenesis and spine synapse formation are being delineated, those regulating shaft synapses are still unknown. Here, we show that postsynaptic ephrinB3 expression promotes the formation of glutamatergic synapses specifically on the shafts, not on spines. Reducing or increasing postsynaptic ephrinB3 expression selectively decreases or increases shaft synapse density, respectively. In the ephrinB3 knock-out mouse, although spine synapses are normal, shaft synapse formation is reduced in the hippocampus. Overexpression of glutamate receptor-interacting protein 1 (GRIP1) rescues ephrinB3 knockdown phenotype by restoring shaft synapse density. GRIP1 knockdown prevents the increase in shaft synapse density induced by ephrinB3 overexpression. Together, our results reveal a novel mechanism for independent modulation of shaft synapses through ephrinB3 reverse signaling.
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Affiliation(s)
- Jason Aoto
- Department of Molecular and Cell Biology and
| | - Pamela Ting
- Department of Molecular and Cell Biology and
| | | | - Nanjie Xu
- Department of Developmental Biology and Kent Waldrep Center for Basic Research on Nerve Growth and Regeneration, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Mark Henkemeyer
- Department of Developmental Biology and Kent Waldrep Center for Basic Research on Nerve Growth and Regeneration, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Lu Chen
- Department of Molecular and Cell Biology and
- Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720-3200, and
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Kiper D, Martin KAC, Scherberger H. Cortical plasticity: a view from nonhuman primates. NEURODEGENER DIS 2007; 4:34-42. [PMID: 17429217 DOI: 10.1159/000100357] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The primate's large brain-to-body weight ratio and high complexity are unusual in the animal kingdom. There is compelling evidence that it is an evolutionary adaptation that allows its owner to live a long life because of its competence in solving a wide range of problems. How primates use their brain to achieve such competence is of course of central interest to us. Here we review some key aspects of the neocortex that can be explored in nonhuman primates. Studies of the cortical circuits in the visual cortex reveal that the two major types of pathways, called feedforward and feedback, involve a very small fraction of the total synapses that any area contains. Nevertheless these pathways may be critical for some important forms of cortical plasticity, like perceptual learning and tasks involving perception and action.
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Affiliation(s)
- Daniel Kiper
- Institute of Neuroinformatics, University and ETH Zurich, Zurich, Switzerland
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