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Benavides-Piccione R, Blazquez-Llorca L, Kastanauskaite A, Fernaud-Espinosa I, Tapia-González S, DeFelipe J. Key morphological features of human pyramidal neurons. Cereb Cortex 2024; 34:bhae180. [PMID: 38745556 PMCID: PMC11094408 DOI: 10.1093/cercor/bhae180] [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: 01/03/2024] [Revised: 04/01/2024] [Accepted: 04/18/2024] [Indexed: 05/16/2024] Open
Abstract
The basic building block of the cerebral cortex, the pyramidal cell, has been shown to be characterized by a markedly different dendritic structure among layers, cortical areas, and species. Functionally, differences in the structure of their dendrites and axons are critical in determining how neurons integrate information. However, within the human cortex, these neurons have not been quantified in detail. In the present work, we performed intracellular injections of Lucifer Yellow and 3D reconstructed over 200 pyramidal neurons, including apical and basal dendritic and local axonal arbors and dendritic spines, from human occipital primary visual area and associative temporal cortex. We found that human pyramidal neurons from temporal cortex were larger, displayed more complex apical and basal structural organization, and had more spines compared to those in primary sensory cortex. Moreover, these human neocortical neurons displayed specific shared and distinct characteristics in comparison to previously published human hippocampal pyramidal neurons. Additionally, we identified distinct morphological features in human neurons that set them apart from mouse neurons. Lastly, we observed certain consistent organizational patterns shared across species. This study emphasizes the existing diversity within pyramidal cell structures across different cortical areas and species, suggesting substantial species-specific variations in their computational properties.
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Affiliation(s)
- Ruth Benavides-Piccione
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid 28223, Spain
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Avda. Doctor Arce 37, Madrid 28002, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Valderrebollo 5, Madrid 28031, Spain
| | - Lidia Blazquez-Llorca
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid 28223, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Valderrebollo 5, Madrid 28031, Spain
- Departamento de Tecnología Fotónica y Bioingeniería, ETSI Telecomunicación, Universidad Politécnica de Madrid, Madrid 28040, Spain
| | - Asta Kastanauskaite
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid 28223, Spain
| | - Isabel Fernaud-Espinosa
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Avda. Doctor Arce 37, Madrid 28002, Spain
| | - Silvia Tapia-González
- Laboratorio de Neurofisiología Celular, Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Madrid, Spain
| | - Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid 28223, Spain
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Avda. Doctor Arce 37, Madrid 28002, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Valderrebollo 5, Madrid 28031, Spain
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2
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Garcia-Marin V, Kelly JG, Hawken MJ. Neuronal composition of processing modules in human V1: laminar density for neuronal and non-neuronal populations and a comparison with macaque. Cereb Cortex 2024; 34:bhad512. [PMID: 38183210 PMCID: PMC10839852 DOI: 10.1093/cercor/bhad512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 01/07/2024] Open
Abstract
The neuronal composition of homologous brain regions in different primates is important for understanding their processing capacities. Primary visual cortex (V1) has been widely studied in different members of the catarrhines. Neuronal density is considered to be central in defining the structure-function relationship. In human, there are large variations in the reported neuronal density from prior studies. We found the neuronal density in human V1 was 79,000 neurons/mm3, which is 35% of the neuronal density previously determined in macaque V1. Laminar density was proportionally similar between human and macaque. In V1, the ocular dominance column (ODC) contains the circuits for the emergence of orientation preference and spatial processing of a point image in many mammalian species. Analysis of the total neurons in an ODC and of the full number of neurons in macular vision (the central 15°) indicates that humans have 1.3× more neurons than macaques even though the density of neurons in macaque is 3× the density in human V1. We propose that the number of neurons in a functional processing unit rather than the number of neurons under a mm2 of cortex is more appropriate for cortical comparisons across species.
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Affiliation(s)
| | - Jenna G Kelly
- Center for Neural Science, New York University, New York City, NY 10003, United States
| | - Michael J Hawken
- Center for Neural Science, New York University, New York City, NY 10003, United States
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3
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Hoffman SJ, Dotson NM, Lima V, Gray CM. The Primate Cortical LFP Exhibits Multiple Spectral and Temporal Gradients and Widespread Task-Dependence During Visual Short-Term Memory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.29.577843. [PMID: 38352585 PMCID: PMC10862751 DOI: 10.1101/2024.01.29.577843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Although cognitive functions are hypothesized to be mediated by synchronous neuronal interactions in multiple frequency bands among widely distributed cortical areas, we still lack a basic understanding of the distribution and task dependence of oscillatory activity across the cortical map. Here, we ask how the spectral and temporal properties of the local field potential (LFP) vary across the primate cerebral cortex, and how they are modulated during visual short-term memory. We measured the LFP from 55 cortical areas in two macaque monkeys while they performed a visual delayed match to sample task. Analysis of peak frequencies in the LFP power spectra reveals multiple discrete frequency bands between 3-80 Hz that differ between the two monkeys. The LFP power in each band, as well as the Sample Entropy, a measure of signal complexity, display distinct spatial gradients across the cortex, some of which correlate with reported spine counts in layer 3 pyramidal neurons. Cortical areas can be robustly decoded using a small number of spectral and temporal parameters, and significant task dependent increases and decreases in spectral power occur in all cortical areas. These findings reveal pronounced, widespread and spatially organized gradients in the spectral and temporal activity of cortical areas. Task-dependent changes in cortical activity are globally distributed, even for a simple cognitive task.
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Affiliation(s)
- Steven J Hoffman
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
- Current address: Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Nicholas M Dotson
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
- Current address: Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Vinicius Lima
- Aix Marseille Université, INSERM, Systems Neuroscience Institute, Marseille, France
| | - Charles M Gray
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717, USA
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4
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Morales-Gregorio A, van Meegen A, van Albada SJ. Ubiquitous lognormal distribution of neuron densities in mammalian cerebral cortex. Cereb Cortex 2023; 33:9439-9449. [PMID: 37409647 PMCID: PMC10438924 DOI: 10.1093/cercor/bhad160] [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: 02/06/2023] [Revised: 04/13/2023] [Accepted: 04/14/2023] [Indexed: 07/07/2023] Open
Abstract
Numbers of neurons and their spatial variation are fundamental organizational features of the brain. Despite the large corpus of cytoarchitectonic data available in the literature, the statistical distributions of neuron densities within and across brain areas remain largely uncharacterized. Here, we show that neuron densities are compatible with a lognormal distribution across cortical areas in several mammalian species, and find that this also holds true within cortical areas. A minimal model of noisy cell division, in combination with distributed proliferation times, can account for the coexistence of lognormal distributions within and across cortical areas. Our findings uncover a new organizational principle of cortical cytoarchitecture: the ubiquitous lognormal distribution of neuron densities, which adds to a long list of lognormal variables in the brain.
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Affiliation(s)
- Aitor Morales-Gregorio
- Institute of Neuroscience and Medicine (INM-6) and Institute for Advanced Simulation (IAS-6) and JARA-Institut Brain Structure-Function Relationships (INM-10), Jülich Research Centre, Wilhelm-Johnen-Str., 52428 Jülich, Germany
- Institute of Zoology, University of Cologne, Zülpicher Str., 50674 Cologne, Germany
| | - Alexander van Meegen
- Institute of Neuroscience and Medicine (INM-6) and Institute for Advanced Simulation (IAS-6) and JARA-Institut Brain Structure-Function Relationships (INM-10), Jülich Research Centre, Wilhelm-Johnen-Str., 52428 Jülich, Germany
- Institute of Zoology, University of Cologne, Zülpicher Str., 50674 Cologne, Germany
| | - Sacha J van Albada
- Institute of Neuroscience and Medicine (INM-6) and Institute for Advanced Simulation (IAS-6) and JARA-Institut Brain Structure-Function Relationships (INM-10), Jülich Research Centre, Wilhelm-Johnen-Str., 52428 Jülich, Germany
- Institute of Zoology, University of Cologne, Zülpicher Str., 50674 Cologne, Germany
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5
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Froudist-Walsh S, Xu T, Niu M, Rapan L, Zhao L, Margulies DS, Zilles K, Wang XJ, Palomero-Gallagher N. Gradients of neurotransmitter receptor expression in the macaque cortex. Nat Neurosci 2023; 26:1281-1294. [PMID: 37336976 PMCID: PMC10322721 DOI: 10.1038/s41593-023-01351-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/01/2023] [Indexed: 06/21/2023]
Abstract
Dynamics and functions of neural circuits depend on interactions mediated by receptors. Therefore, a comprehensive map of receptor organization across cortical regions is needed. In this study, we used in vitro receptor autoradiography to measure the density of 14 neurotransmitter receptor types in 109 areas of macaque cortex. We integrated the receptor data with anatomical, genetic and functional connectivity data into a common cortical space. We uncovered a principal gradient of receptor expression per neuron. This aligns with the cortical hierarchy from sensory cortex to higher cognitive areas. A second gradient, driven by serotonin 5-HT1A receptors, peaks in the anterior cingulate, default mode and salience networks. We found a similar pattern of 5-HT1A expression in the human brain. Thus, the macaque may be a promising translational model of serotonergic processing and disorders. The receptor gradients may enable rapid, reliable information processing in sensory cortical areas and slow, flexible integration in higher cognitive areas.
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MESH Headings
- Aged
- Animals
- Female
- Humans
- Male
- Rats
- Autoradiography
- Brain Mapping
- Cerebral Cortex/cytology
- Cerebral Cortex/metabolism
- Cognition
- Dendritic Spines
- Gyrus Cinguli/cytology
- Gyrus Cinguli/metabolism
- Macaca fascicularis
- Rats, Inbred Lew
- Receptor, Serotonin, 5-HT1A/analysis
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptors, Cholinergic/analysis
- Receptors, Cholinergic/metabolism
- Receptors, Dopamine/analysis
- Receptors, Dopamine/metabolism
- Receptors, Neurotransmitter/analysis
- Receptors, Neurotransmitter/metabolism
- Serotonin/metabolism
- Species Specificity
- Myelin Sheath/metabolism
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Affiliation(s)
- Sean Froudist-Walsh
- Computational Neuroscience Unit, Faculty of Engineering, University of Bristol, Bristol, UK
- Center for Neural Science, New York University, New York, NY, USA
| | - Ting Xu
- Child Mind Institute, New York, NY, USA
| | - Meiqi Niu
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Lucija Rapan
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Ling Zhao
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Daniel S Margulies
- Integrative Neuroscience and Cognition Center, University of Paris Cité, Paris, France
| | | | - Xiao-Jing Wang
- Center for Neural Science, New York University, New York, NY, USA
| | - Nicola Palomero-Gallagher
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany.
- Cécile and Oskar Vogt Institute for Brain Research, Medical Faculty, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
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6
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Kell AJ, Bokor SL, Jeon YN, Toosi T, Issa EB. Marmoset core visual object recognition behavior is comparable to that of macaques and humans. iScience 2022; 26:105788. [PMID: 36594035 PMCID: PMC9804140 DOI: 10.1016/j.isci.2022.105788] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 10/13/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
Among the smallest simian primates, the common marmoset offers promise as an experimentally tractable primate model for neuroscience with translational potential to humans. However, given its exceedingly small brain and body, the gap in perceptual and cognitive abilities between marmosets and humans requires study. Here, we performed a comparison of marmoset behavior to that of three other species in the domain of high-level vision. We first found that marmosets outperformed rats - a marmoset-sized rodent - on a simple recognition task, with marmosets robustly recognizing objects across views. On a more challenging invariant object recognition task used previously in humans, marmosets also achieved high performance. Notably, across hundreds of images, marmosets' image-by-image behavior was highly similar to that of humans - nearly as human-like as macaque behavior. Thus, core aspects of visual perception are conserved across monkeys and humans, and marmosets present salient behavioral advantages over other small model organisms for visual neuroscience.
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Affiliation(s)
- Alexander J.E. Kell
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA,Department of Neuroscience, Columbia University, New York, NY 10027, USA
| | - Sophie L. Bokor
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA,Department of Neuroscience, Columbia University, New York, NY 10027, USA
| | - You-Nah Jeon
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA,Department of Neuroscience, Columbia University, New York, NY 10027, USA
| | - Tahereh Toosi
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA,Department of Neuroscience, Columbia University, New York, NY 10027, USA
| | - Elias B. Issa
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA,Department of Neuroscience, Columbia University, New York, NY 10027, USA,Corresponding author
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7
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Wallace MN, Zobay O, Hardman E, Thompson Z, Dobbs P, Chakrabarti L, Palmer AR. The large numbers of minicolumns in the primary visual cortex of humans, chimpanzees and gorillas are related to high visual acuity. Front Neuroanat 2022; 16:1034264. [PMID: 36439196 PMCID: PMC9681811 DOI: 10.3389/fnana.2022.1034264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 10/21/2022] [Indexed: 11/10/2022] Open
Abstract
Minicolumns are thought to be a fundamental neural unit in the neocortex and their replication may have formed the basis of the rapid cortical expansion that occurred during primate evolution. We sought evidence of minicolumns in the primary visual cortex (V-1) of three great apes, three rodents and representatives from three other mammalian orders: Eulipotyphla (European hedgehog), Artiodactyla (domestic pig) and Carnivora (ferret). Minicolumns, identified by the presence of a long bundle of radial, myelinated fibers stretching from layer III to the white matter of silver-stained sections, were found in the human, chimpanzee, gorilla and guinea pig V-1. Shorter bundles confined to one or two layers were found in the other species but represent modules rather than minicolumns. The inter-bundle distance, and hence density of minicolumns, varied systematically both within a local area that might represent a hypercolumn but also across the whole visual field. The distance between all bundles had a similar range for human, chimpanzee, gorilla, ferret and guinea pig: most bundles were 20-45 μm apart. By contrast, the space between bundles was greater for the hedgehog and pig (20-140 μm). The mean density of minicolumns was greater in tangential sections of the gorilla and chimpanzee (1,243-1,287 bundles/mm2) than in human (314-422 bundles/mm2) or guinea pig (643 bundles/mm2). The minicolumnar bundles did not form a hexagonal lattice but were arranged in thin curving and branched bands separated by thicker bands of neuropil/somata. Estimates of the total number of modules/minicolumns within V-1 were strongly correlated with visual acuity.
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Affiliation(s)
- Mark N. Wallace
- Medical Research Council (MRC) Institute of Hearing Research, University Park, Nottingham, United Kingdom
- Hearing Sciences, Mental Health and Clinical Neurosciences, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Oliver Zobay
- Medical Research Council (MRC) Institute of Hearing Research, University Park, Nottingham, United Kingdom
- School of Medicine, University of Nottingham, Hearing Sciences—Scottish Section, Glasgow Royal Infirmary, Glasgow, United Kingdom
| | - Eden Hardman
- Medical Research Council (MRC) Institute of Hearing Research, University Park, Nottingham, United Kingdom
| | - Zoe Thompson
- Medical Research Council (MRC) Institute of Hearing Research, University Park, Nottingham, United Kingdom
| | - Phillipa Dobbs
- Veterinary Department, Twycross Zoo, East Midland Zoological Society, Atherstone, United Kingdom
| | - Lisa Chakrabarti
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Nottingham, United Kingdom
| | - Alan R. Palmer
- Medical Research Council (MRC) Institute of Hearing Research, University Park, Nottingham, United Kingdom
- Hearing Sciences, Mental Health and Clinical Neurosciences, School of Medicine, University of Nottingham, Nottingham, United Kingdom
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8
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Mejías JF, Wang XJ. Mechanisms of distributed working memory in a large-scale network of macaque neocortex. eLife 2022; 11:72136. [PMID: 35200137 PMCID: PMC8871396 DOI: 10.7554/elife.72136] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 01/19/2022] [Indexed: 12/15/2022] Open
Abstract
Neural activity underlying working memory is not a local phenomenon but distributed across multiple brain regions. To elucidate the circuit mechanism of such distributed activity, we developed an anatomically constrained computational model of large-scale macaque cortex. We found that mnemonic internal states may emerge from inter-areal reverberation, even in a regime where none of the isolated areas is capable of generating self-sustained activity. The mnemonic activity pattern along the cortical hierarchy indicates a transition in space, separating areas engaged in working memory and those which do not. A host of spatially distinct attractor states is found, potentially subserving various internal processes. The model yields testable predictions, including the idea of counterstream inhibitory bias, the role of prefrontal areas in controlling distributed attractors, and the resilience of distributed activity to lesions or inactivation. This work provides a theoretical framework for identifying large-scale brain mechanisms and computational principles of distributed cognitive processes.
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Affiliation(s)
- Jorge F Mejías
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Xiao-Jing Wang
- Center for Neural Science, New York University, New York, United States
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9
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Remodeling of lateral geniculate nucleus projections to extrastriate area MT following long-term lesions of striate cortex. Proc Natl Acad Sci U S A 2022; 119:2117137119. [PMID: 35058366 PMCID: PMC8794847 DOI: 10.1073/pnas.2117137119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2021] [Indexed: 01/04/2023] Open
Abstract
Lesions of the primary visual area (V1) in primates cause blindness by severing the main pathway which brings information from the thalamus to the cortex. However, some visual abilities remain, which are hypothesized to be mediated by thalamic neurons that innervate surviving areas such as the middle temporal (MT) cortex. We found that V1 lesions trigger long-term plasticity in the connections between the thalamus and cortex, including the emergence of a pathway that brings information to MT from cell populations that would normally project to V1. These results reveal potential targets for rehabilitation strategies to ameliorate the consequences of cortical blindness. Here, we report on a previously unknown form of thalamocortical plasticity observed following lesions of the primary visual area (V1) in marmoset monkeys. In primates, lateral geniculate nucleus (LGN) neurons form parallel pathways to the cortex, which are characterized by the expression of different calcium-binding proteins. LGN projections to the middle temporal (MT) area only originate in the koniocellular layers, where many neurons express calbindin. In contrast, projections to V1 also originate in the magnocellular and parvocellular layers, where neurons express parvalbumin but not calbindin. Our results demonstrate that this specificity is disrupted following long-term (1 to 3 y) unilateral V1 lesions, indicating active rearrangement of the geniculocortical circuit. In lesioned animals, retrograde tracing revealed MT-projecting neurons scattered throughout the lesion projection zone (LPZ, the sector of the LGN that underwent retrograde degeneration following a V1 lesion). Many of the MT-projecting neurons had large cell bodies and were located outside the koniocellular layers. Furthermore, we found that a large percentage of magno- and parvocellular neurons expressed calbindin in addition to the expected parvalbumin expression and that this coexpression was present in many of the MT-projecting neurons within the LPZ. These results demonstrate that V1 lesions trigger neurochemical and structural remodeling of the geniculo-extrastriate pathway, leading to the emergence of nonkoniocellular input to MT. This has potential implications for our understanding of the neurobiological bases of the residual visual abilities that survive V1 lesions, including motion perception and blindsight, and reveals targets for rehabilitation strategies to ameliorate the consequences of cortical blindness.
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10
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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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11
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Ramdas T, Mel BW. Optimizing a Neuron for Reliable Dendritic Subunit Pooling. Neuroscience 2021; 489:216-233. [PMID: 34715265 DOI: 10.1016/j.neuroscience.2021.10.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 10/10/2021] [Accepted: 10/15/2021] [Indexed: 12/16/2022]
Abstract
In certain biologically relevant computing scenarios, a neuron "pools" the outputs of multiple independent functional subunits, firing if any one of them crosses threshold. Recent studies suggest that active dendrites could provide the thresholding mechanism, so that both the thresholding and pooling operations could take place within a single neuron. A pooling neuron faces a difficult task, however. Dendrites can produce highly variable responses depending on the density and spatial patterning of their synaptic inputs, and bona fide dendritic firing may be very rare, making it difficult for a neuron to reliably detect when one of its many dendrites has "gone suprathreshold". Our goal has been to identify biological adaptations that optimize a neuron's performance at the binary subunit pooling (BSP) task. Katz et al. (2009) pointed to the importance of spine density gradients in shaping dendritic responses. In a similar vein, we used a compartmental model to study how a neuron's performance at the BSP task is affected by different spine density layouts and other biological variables. We found BSP performance was optimized when dendrites have (1) a decreasing spine density gradient (true for many types of pyramidal neurons); (2) low-to-medium resistance spine necks; (3) strong NMDA currents; (4) fast spiking Na+ channels; and (5) powerful hyperpolarizing inhibition. Our findings provide a normative account that links several neuronal properties within the context of a behaviorally relevant task, and thus provide new insights into nature's subtle strategies for optimizing the computing capabilities of neural tissue.
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Affiliation(s)
- Tejas Ramdas
- Computational Neuroscience Program, USC, United States.
| | - Bartlett W Mel
- Biomedical Engineering Department and Neuroscience Graduate Program, USC, United States.
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12
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Rolls ET. The connections of neocortical pyramidal cells can implement the learning of new categories, attractor memory, and top-down recall and attention. Brain Struct Funct 2021; 226:2523-2536. [PMID: 34347165 PMCID: PMC8448704 DOI: 10.1007/s00429-021-02347-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 07/19/2021] [Indexed: 11/17/2022]
Abstract
Neocortical pyramidal cells have three key classes of excitatory input: forward inputs from the previous cortical area (or thalamus); recurrent collateral synapses from nearby pyramidal cells; and backprojection inputs from the following cortical area. The neocortex performs three major types of computation: (1) unsupervised learning of new categories, by allocating neurons to respond to combinations of inputs from the preceding cortical stage, which can be performed using competitive learning; (2) short-term memory, which can be performed by an attractor network using the recurrent collaterals; and (3) recall of what has been learned by top–down backprojections from the following cortical area. There is only one type of excitatory neuron involved, pyramidal cells, with these three types of input. It is proposed, and tested by simulations of a neuronal network model, that pyramidal cells can implement all three types of learning simultaneously, and can subsequently usefully categorise the forward inputs; keep them active in short-term memory; and later recall the representations using the backprojection input. This provides a new approach to understanding how one type of excitatory neuron in the neocortex can implement these three major types of computation, and provides a conceptual advance in understanding how the cerebral neocortex may work.
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Affiliation(s)
- Edmund T Rolls
- Oxford Centre for Computational Neuroscience, Oxford, UK. .,Department of Computer Science, University of Warwick, Coventry, CV4 7AL, UK.
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13
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Rolls ET. Learning Invariant Object and Spatial View Representations in the Brain Using Slow Unsupervised Learning. Front Comput Neurosci 2021; 15:686239. [PMID: 34366818 PMCID: PMC8335547 DOI: 10.3389/fncom.2021.686239] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/29/2021] [Indexed: 11/13/2022] Open
Abstract
First, neurophysiological evidence for the learning of invariant representations in the inferior temporal visual cortex is described. This includes object and face representations with invariance for position, size, lighting, view and morphological transforms in the temporal lobe visual cortex; global object motion in the cortex in the superior temporal sulcus; and spatial view representations in the hippocampus that are invariant with respect to eye position, head direction, and place. Second, computational mechanisms that enable the brain to learn these invariant representations are proposed. For the ventral visual system, one key adaptation is the use of information available in the statistics of the environment in slow unsupervised learning to learn transform-invariant representations of objects. This contrasts with deep supervised learning in artificial neural networks, which uses training with thousands of exemplars forced into different categories by neuronal teachers. Similar slow learning principles apply to the learning of global object motion in the dorsal visual system leading to the cortex in the superior temporal sulcus. The learning rule that has been explored in VisNet is an associative rule with a short-term memory trace. The feed-forward architecture has four stages, with convergence from stage to stage. This type of slow learning is implemented in the brain in hierarchically organized competitive neuronal networks with convergence from stage to stage, with only 4-5 stages in the hierarchy. Slow learning is also shown to help the learning of coordinate transforms using gain modulation in the dorsal visual system extending into the parietal cortex and retrosplenial cortex. Representations are learned that are in allocentric spatial view coordinates of locations in the world and that are independent of eye position, head direction, and the place where the individual is located. This enables hippocampal spatial view cells to use idiothetic, self-motion, signals for navigation when the view details are obscured for short periods.
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Affiliation(s)
- Edmund T Rolls
- Oxford Centre for Computational Neuroscience, Oxford, United Kingdom.,Department of Computer Science, University of Warwick, Coventry, United Kingdom
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14
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Theodoni P, Majka P, Reser DH, Wójcik DK, Rosa MGP, Wang XJ. Structural Attributes and Principles of the Neocortical Connectome in the Marmoset Monkey. Cereb Cortex 2021; 32:15-28. [PMID: 34274966 PMCID: PMC8634603 DOI: 10.1093/cercor/bhab191] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/23/2021] [Accepted: 06/01/2021] [Indexed: 12/12/2022] Open
Abstract
The marmoset monkey has become an important primate model in Neuroscience. Here, we characterize salient statistical properties of interareal connections of the marmoset cerebral cortex, using data from retrograde tracer injections. We found that the connectivity weights are highly heterogeneous, spanning 5 orders of magnitude, and are log-normally distributed. The cortico-cortical network is dense, heterogeneous and has high specificity. The reciprocal connections are the most prominent and the probability of connection between 2 areas decays with their functional dissimilarity. The laminar dependence of connections defines a hierarchical network correlated with microstructural properties of each area. The marmoset connectome reveals parallel streams associated with different sensory systems. Finally, the connectome is spatially embedded with a characteristic length that obeys a power law as a function of brain volume across rodent and primate species. These findings provide a connectomic basis for investigations of multiple interacting areas in a complex large-scale cortical system underlying cognitive processes.
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Affiliation(s)
- Panagiota Theodoni
- Center for Neural Science, New York University, New York, NY 10003, USA.,New York University Shanghai, Shanghai 200122, China.,NYU-ECNU Institute of Brain and Cognitive Science at New York University Shanghai, Shanghai 200062, China
| | - Piotr Majka
- Laboratory of Neuroinformatics, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw 02-093, Poland.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC 3800, Australia.,Neuroscience Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, VIC 3800, Australia
| | - David H Reser
- Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC 3800, Australia.,Graduate Entry Medicine Program, Monash Rural Health-Churchill, Monash University, Churchill, VIC 3842, Australia
| | - Daniel K Wójcik
- Laboratory of Neuroinformatics, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Marcello G P Rosa
- Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC 3800, Australia.,Neuroscience Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, VIC 3800, Australia
| | - Xiao-Jing Wang
- Center for Neural Science, New York University, New York, NY 10003, USA
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15
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Benavides-Piccione R, Rojo C, Kastanauskaite A, DeFelipe J. Variation in Pyramidal Cell Morphology Across the Human Anterior Temporal Lobe. Cereb Cortex 2021; 31:3592-3609. [PMID: 33723567 PMCID: PMC8258433 DOI: 10.1093/cercor/bhab034] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 02/03/2021] [Accepted: 02/04/2021] [Indexed: 11/13/2022] Open
Abstract
Pyramidal neurons are the most abundant and characteristic neuronal type in the cerebral cortex and their dendritic spines are the main postsynaptic elements of cortical excitatory synapses. Previous studies have shown that pyramidal cell structure differs across layers, cortical areas, and species. However, within the human cortex, the pyramidal dendritic morphology has been quantified in detail in relatively few cortical areas. In the present work, we performed intracellular injections of Lucifer Yellow at several distances from the temporal pole. We found regional differences in pyramidal cell morphology, which showed large inter-individual variability in most of the morphological variables measured. However, some values remained similar in all cases. The smallest and least complex cells in the most posterior temporal region showed the greatest dendritic spine density. Neurons in the temporal pole showed the greatest sizes with the highest number of spines. Layer V cells were larger, more complex, and had a greater number of dendritic spines than those in layer III. The present results suggest that, while some aspects of pyramidal structure are conserved, there are specific variations across cortical regions, and species.
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Affiliation(s)
- Ruth Benavides-Piccione
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid 28002, Spain.,Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28223, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid 28031, Spain
| | - Concepcion Rojo
- Sección Departamental de Anatomía y Embriología, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Asta Kastanauskaite
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid 28002, Spain.,Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28223, Spain
| | - Javier DeFelipe
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid 28002, Spain.,Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid 28223, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid 28031, Spain
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16
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Liu Y, Hu J, Yao S, Zhou Q, Li H, Takahata T. Multiple Visuotopically Organized Subdivisions of the Lateral Pulvinar/Central Lateral Inferior Pulvinar Project into Thin and Thick Stripe Compartments of V2 in Macaques. Cereb Cortex 2021; 31:3788-3803. [PMID: 33772553 DOI: 10.1093/cercor/bhab049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/30/2021] [Accepted: 02/13/2021] [Indexed: 11/13/2022] Open
Abstract
The lateral and central lateral inferior pulvinar (PL/PIcl) of primates has been implicated in playing an important role in visual processing, but its physiological and anatomical characteristics remain to be elucidated. It has been suggested that there are two complete visuotopic maps in the PL/PIcl, each of which sends afferents into V2 and V4 in primates. Given that functionally distinct thin and thick stripes of V2 both receive inputs from the PL/PIcl, this raises the possibility of a presence of parallel segregated pathways within the PL/PIcl. To address this question, we selectively injected three types of retrograde tracers (CTB-488, CTB-555, and BDA) into thin or thick stripes in V2 and examined labeling in the PL/PIcl in macaques. As a result, we found that every cluster of retrograde labeling in the PL/PIcl included all three types of signals next to each other, suggesting that thin stripe- and thick stripe-projecting compartments are not segregated into domains. Unexpectedly, we found at least five topographically organized retrograde labeling clusters in the PL/PIcl, indicating the presence of more than two V2-projecting maps. Our results suggest that the PL/PIcl exhibits greater compartmentalization than previously thought. They may be functionally similar but participate in multiple cortico-pulvinar-cortical loops.
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Affiliation(s)
- Ye Liu
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University School of Medicine, Hangzhou 310029, P. R. China
| | - Jiaming Hu
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University School of Medicine, Hangzhou 310029, P. R. China
| | - Songping Yao
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University School of Medicine, Hangzhou 310029, P. R. China.,Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University,Hangzhou 310029, P. R. China
| | - Qiuying Zhou
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University School of Medicine, Hangzhou 310029, P. R. China
| | - Hangqi Li
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University School of Medicine, Hangzhou 310029, P. R. China.,Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University,Hangzhou 310029, P. R. China
| | - Toru Takahata
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University School of Medicine, Hangzhou 310029, P. R. China.,Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University,Hangzhou 310029, P. R. China
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17
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Khalil R, Farhat A, Dłotko P. Developmental Changes in Pyramidal Cell Morphology in Multiple Visual Cortical Areas Using Cluster Analysis. Front Comput Neurosci 2021; 15:667696. [PMID: 34135746 PMCID: PMC8200563 DOI: 10.3389/fncom.2021.667696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 05/05/2021] [Indexed: 11/18/2022] Open
Abstract
Neuronal morphology is characterized by salient features such as complex axonal and dendritic arbors. In the mammalian brain, variations in dendritic morphology among cell classes, brain regions, and animal species are thought to underlie known differences in neuronal function. In this work, we obtained a large dataset from http://neuromorpho.org/ comprising layer III pyramidal cells in different cortical areas of the ventral visual pathway (V1, V2, V4, TEO, and TE) of the macaque monkey at different developmental stages. We performed an in depth quantitative analysis of pyramidal cell morphology throughout development in an effort to determine which aspects mature early in development and which features require a protracted period of maturation. We were also interested in establishing if developmental changes in morphological features occur simultaneously or hierarchically in multiple visual cortical areas. We addressed these questions by performing principal component analysis (PCA) and hierarchical clustering analysis on relevant morphological features. Our analysis indicates that the maturation of pyramidal cell morphology is largely based on early development of topological features in most visual cortical areas. Moreover, the maturation of pyramidal cell morphology in V1, V2, V4, TEO, and TE is characterized by unique developmental trajectories.
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Affiliation(s)
- Reem Khalil
- Biology, Chemistry, and Environmental Sciences Department, American University of Sharjah, Sharjah, United Arab Emirates
| | - Ahmad Farhat
- Dioscuri Centre in Topological Data Analysis, Mathematical Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Paweł Dłotko
- Dioscuri Centre in Topological Data Analysis, Mathematical Institute, Polish Academy of Sciences, Warsaw, Poland
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18
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Yang Y, Chen K, Rosa MGP, Yu HH, Kuang LR, Yang J. Visual response characteristics of neurons in the second visual area of marmosets. Neural Regen Res 2021; 16:1871-1876. [PMID: 33510095 PMCID: PMC8328785 DOI: 10.4103/1673-5374.303043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The physiological characteristics of the marmoset second visual area (V2) are poorly understood compared with those of the primary visual area (V1). In this study, we observed the physiological response characteristics of V2 neurons in four healthy adult marmosets using intracortical tungsten microelectrodes. We recorded 110 neurons in area V2, with receptive fields located between 8° and 15° eccentricity. Most (88.2%) of these neurons were orientation selective, with half-bandwidths typically ranging between 10° and 30°. A significant proportion of neurons (28.2%) with direction selectivity had a direction index greater than 0.5. The vast majority of V2 neurons had separable spatial frequency and temporal frequency curves and, according to this criterion, they were not speed selective. The basic functional response characteristics of neurons in area V2 resemble those found in area V1. Our findings show that area V2 together with V1 are important in primate visual processing, especially in locating objects in space and in detecting an object’s direction of motion. The methods used in this study were approved by the Monash University Animal Ethics Committee, Australia (MARP 2009-2011) in 2009.
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Affiliation(s)
- Yin Yang
- Department of Ophthalmology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital; College of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Ke Chen
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Marcello G P Rosa
- Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Hsin-Hao Yu
- Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Li-Rong Kuang
- Chengdu Medical College, Chengdu, Sichuan Province, China
| | - Jie Yang
- College of Medicine, University of Electronic Science and Technology of China; Department of Neurology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, Sichuan Province, China
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19
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Experience-Dependent Development of Dendritic Arbors in Mouse Visual Cortex. J Neurosci 2020; 40:6536-6556. [PMID: 32669356 DOI: 10.1523/jneurosci.2910-19.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 12/27/2022] Open
Abstract
The dendritic arbor of neurons constrains the pool of available synaptic partners and influences the electrical integration of synaptic currents. Despite these critical functions, our knowledge of the dendritic structure of cortical neurons during early postnatal development and how these dendritic structures are modified by visual experience is incomplete. Here, we present a large-scale dataset of 849 3D reconstructions of the basal arbor of pyramidal neurons collected across early postnatal development in visual cortex of mice of either sex. We found that the basal arbor grew substantially between postnatal day 7 (P7) and P30, undergoing a 45% increase in total length. However, the gross number of primary neurites and dendritic segments was largely determined by P7. Growth from P7 to P30 occurred primarily through extension of dendritic segments. Surprisingly, comparisons of dark-reared and typically reared mice revealed that a net gain of only 15% arbor length could be attributed to visual experience; most growth was independent of experience. To examine molecular contributions, we characterized the role of the activity-regulated small GTPase Rem2 in both arbor development and the maintenance of established basal arbors. We showed that Rem2 is an experience-dependent negative regulator of dendritic segment number during the visual critical period. Acute deletion of Rem2 reduced directionality of dendritic arbors. The data presented here establish a highly detailed, quantitative analysis of basal arbor development that we believe has high utility both in understanding circuit development as well as providing a framework for computationalists wishing to generate anatomically accurate neuronal models.SIGNIFICANCE STATEMENT Dendrites are the sites of the synaptic connections among neurons. Despite their importance for neural circuit function, only a little is known about the postnatal development of dendritic arbors of cortical pyramidal neurons and the influence of experience. Here we show that the number of primary basal dendritic arbors is already established before eye opening, and that these arbors primarily grow through lengthening of dendritic segments and not through addition of dendritic segments. Surprisingly, visual experience has a modest net impact on overall arbor length (15%). Experiments in KO animals revealed that the gene Rem2 is positive regulator of dendritic length and a negative regulator of dendritic segments.
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20
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Friedman R. Measurements of neuronal morphological variation across the rat neocortex. Neurosci Lett 2020; 734:135077. [PMID: 32485285 DOI: 10.1016/j.neulet.2020.135077] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/20/2020] [Indexed: 11/16/2022]
Abstract
Neuron morphology is highly variable across the mammalian brain. It is thought that these attributes of neuronal cell shape, such as soma surface area and branching frequency, are determined by biological function and information processing. In this study, a large data set of neurons across the rat neocortex were clustered by their anatomical characters for evidence of distinctiveness among neocortical regions and the somatosensory layers. This data set of neuronal morphologies was compiled from 31 different lab sources with a validation procedure so that data records are potentially comparable across research studies. With this large set of heterogeneous data and by clustering analysis, this study shows that neuronal morphological traits overlap among neocortical and somatosensory regions. In the context of past neuroanatomical studies, this result is not congruent with tissue level analysis and strongly suggests further sampling of neuronal data to lessen the effect of confounding factors, such as the influence of different methodologies from use of heterogeneous samples of neuronal data.
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Affiliation(s)
- Robert Friedman
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States.
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21
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Rosa MGP, Soares JGM, Chaplin TA, Majka P, Bakola S, Phillips KA, Reser DH, Gattass R. Cortical Afferents of Area 10 in Cebus Monkeys: Implications for the Evolution of the Frontal Pole. Cereb Cortex 2020; 29:1473-1495. [PMID: 29697775 DOI: 10.1093/cercor/bhy044] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/12/2018] [Accepted: 02/07/2018] [Indexed: 01/26/2023] Open
Abstract
Area 10, located in the frontal pole, is a unique specialization of the primate cortex. We studied the cortical connections of area 10 in the New World Cebus monkey, using injections of retrograde tracers in different parts of this area. We found that injections throughout area 10 labeled neurons in a consistent set of areas in the dorsolateral, ventrolateral, orbital, and medial parts of the frontal cortex, superior temporal association cortex, and posterior cingulate/retrosplenial region. However, sites on the midline surface of area 10 received more substantial projections from the temporal lobe, including clear auditory connections, whereas those in more lateral parts received >90% of their afferents from other frontal areas. This difference in anatomical connectivity reflects functional connectivity findings in the human brain. The pattern of connections in Cebus is very similar to that observed in the Old World macaque monkey, despite >40 million years of evolutionary separation, but lacks some of the connections reported in the more closely related but smaller marmoset monkey. These findings suggest that the clearer segregation observed in the human frontal pole reflects regional differences already present in early simian primates, and that overall brain mass influences the pattern of cortico-cortical connectivity.
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Affiliation(s)
- Marcello G P Rosa
- Department of Physiology, Monash University, Clayton, VIC, Australia.,Neuroscience Program, Biomedicine Research Institute, Monash University, Clayton, VIC, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC, Australia
| | - Juliana G M Soares
- Programa de Neurobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Tristan A Chaplin
- Department of Physiology, Monash University, Clayton, VIC, Australia.,Neuroscience Program, Biomedicine Research Institute, Monash University, Clayton, VIC, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC, Australia
| | - Piotr Majka
- Department of Physiology, Monash University, Clayton, VIC, Australia.,Neuroscience Program, Biomedicine Research Institute, Monash University, Clayton, VIC, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC, Australia.,Laboratory of Neuroinformatics, Department of Neurophysiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, Warsaw, Poland
| | - Sophia Bakola
- Department of Physiology, Monash University, Clayton, VIC, Australia.,Neuroscience Program, Biomedicine Research Institute, Monash University, Clayton, VIC, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC, Australia.,Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Kimberley A Phillips
- Department of Psychology, Trinity University, San Antonio, TX, USA.,USA Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - David H Reser
- Department of Physiology, Monash University, Clayton, VIC, Australia.,Neuroscience Program, Biomedicine Research Institute, Monash University, Clayton, VIC, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, VIC, Australia.,Monash Rural Health, Monash University, Churchill, VIC, Australia
| | - Ricardo Gattass
- Programa de Neurobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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22
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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: 22] [Impact Index Per Article: 5.5] [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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23
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BigBrain 3D atlas of cortical layers: Cortical and laminar thickness gradients diverge in sensory and motor cortices. PLoS Biol 2020; 18:e3000678. [PMID: 32243449 PMCID: PMC7159250 DOI: 10.1371/journal.pbio.3000678] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/15/2020] [Accepted: 03/18/2020] [Indexed: 11/19/2022] Open
Abstract
Histological atlases of the cerebral cortex, such as those made famous by Brodmann and von Economo, are invaluable for understanding human brain microstructure and its relationship with functional organization in the brain. However, these existing atlases are limited to small numbers of manually annotated samples from a single cerebral hemisphere, measured from 2D histological sections. We present the first whole-brain quantitative 3D laminar atlas of the human cerebral cortex. It was derived from a 3D histological atlas of the human brain at 20-micrometer isotropic resolution (BigBrain), using a convolutional neural network to segment, automatically, the cortical layers in both hemispheres. Our approach overcomes many of the historical challenges with measurement of histological thickness in 2D, and the resultant laminar atlas provides an unprecedented level of precision and detail. We utilized this BigBrain cortical atlas to test whether previously reported thickness gradients, as measured by MRI in sensory and motor processing cortices, were present in a histological atlas of cortical thickness and which cortical layers were contributing to these gradients. Cortical thickness increased across sensory processing hierarchies, primarily driven by layers III, V, and VI. In contrast, motor-frontal cortices showed the opposite pattern, with decreases in total and pyramidal layer thickness from motor to frontal association cortices. These findings illustrate how this laminar atlas will provide a link between single-neuron morphology, mesoscale cortical layering, macroscopic cortical thickness, and, ultimately, functional neuroanatomy. Using deep learning to segment the layers of the cerebral cortex, this study presents the first whole brain quantitative atlas of cortical and laminar structure. This laminar atlas provides a novel framework for bridging between the scales of neuroscience.
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24
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Parra A, Baker CA, Bolton MM. Regional Specialization of Pyramidal Neuron Morphology and Physiology in the Tree Shrew Neocortex. Cereb Cortex 2019; 29:4488-4505. [PMID: 30715235 DOI: 10.1093/cercor/bhy326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 10/12/2018] [Accepted: 12/07/2018] [Indexed: 01/08/2023] Open
Abstract
The mammalian cerebral cortex is divided into different areas according to their function and pattern of connections. Studies comparing primary visual (V1) and prefrontal cortex (PFC) of primates have demonstrated striking pyramidal neuron (PN) specialization not present in comparable areas of the mouse neocortex. To better understand PFC evolution and regional PN specialization, we studied the tree shrew, a species with a close phylogenetic relationship to primates. We defined the tree shrew PFC based on cytoarchitectonic borders, thalamic connectivity and characterized the morphology and electrophysiology of layer II/III PNs in V1 and PFC. Similar to primates, the PFC PNs in the tree shrew fire with a regular spiking pattern and have larger dendritic tree and spines than those in V1. However, V1 PNs showed strikingly large basal dendritic arbors with high spine density, firing at higher rates and in a more varied pattern than PFC PNs. Yet, unlike in the mouse and unreported in the primate, medial prefrontal PN are more easily recruited than either the dorsolateral or V1 neurons. This specialization of PN morphology and physiology is likely to be a significant factor in the evolution of cortex, contributing to differences in the computational capacities of individual cortical areas.
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Affiliation(s)
- Andres Parra
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, USA.,Functional Architecture of the Cerebral Cortex, Max Planck Florida Institute for Neuroscience, Jupiter, USA.,Cellular and Systems Neurobiology, Instituto de Neurociencias de Alicante, Alicante, Spain
| | - Christopher A Baker
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, USA
| | - M McLean Bolton
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, USA
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25
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Beul SF, Hilgetag CC. Neuron density fundamentally relates to architecture and connectivity of the primate cerebral cortex. Neuroimage 2019; 189:777-792. [PMID: 30677500 DOI: 10.1016/j.neuroimage.2019.01.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/05/2019] [Indexed: 12/16/2022] Open
Abstract
Studies of structural brain connectivity have revealed many intriguing features of complex cortical networks. To advance integrative theories of cortical organization, an understanding is required of how connectivity interrelates with other aspects of brain structure. Recent studies have suggested that interareal connectivity may be related to a variety of macroscopic as well as microscopic architectonic features of cortical areas. However, it is unclear how these features are inter-dependent and which of them most strongly and fundamentally relate to structural corticocortical connectivity. Here, we systematically investigated the relation of a range of microscopic and macroscopic architectonic features of cortical organization, namely layer III pyramidal cell soma cross section, dendritic synapse count, dendritic synapse density and dendritic tree size as well as area neuron density, to multiple properties of cortical connectivity, using a comprehensive, up-to-date structural connectome of the primate brain. Importantly, relationships were investigated by multi-variate analyses to account for the interrelations of features. Of all considered factors, the classical architectonic parameter of neuron density most strongly and consistently related to essential features of cortical connectivity (existence and laminar patterns of projections, area degree), and in conjoint analyses largely abolished effects of cellular morphological features. These results confirm neuron density as a central architectonic indicator of the primate cerebral cortex that is closely related to essential aspects of brain connectivity and is also highly indicative of further features of the architectonic organization of cortical areas, such as the considered cellular morphological measures. Our findings integrate several aspects of cortical micro- and macroscopic organization, with implications for cortical development and function.
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Affiliation(s)
- Sarah F Beul
- Institute of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Claus C Hilgetag
- Institute of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany; Department of Health Sciences, Boston University, 02215, Boston, MA, USA.
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26
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Atapour N, Majka P, Wolkowicz IH, Malamanova D, Worthy KH, Rosa MGP. Neuronal Distribution Across the Cerebral Cortex of the Marmoset Monkey (Callithrix jacchus). Cereb Cortex 2018; 29:3836-3863. [DOI: 10.1093/cercor/bhy263] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 09/13/2018] [Accepted: 09/19/2018] [Indexed: 01/18/2023] Open
Abstract
Abstract
Using stereological analysis of NeuN-stained sections, we investigated neuronal density and number of neurons per column throughout the marmoset cortex. Estimates of mean neuronal density encompassed a greater than 3-fold range, from >150 000 neurons/mm3 in the primary visual cortex to ~50 000 neurons/mm3 in the piriform complex. There was a trend for density to decrease from posterior to anterior cortex, but also local gradients, which resulted in a complex pattern; for example, in frontal, auditory, and somatosensory cortex neuronal density tended to increase towards anterior areas. Anterior cingulate, motor, premotor, insular, and ventral temporal areas were characterized by relatively low neuronal densities. Analysis across the depth of the cortex revealed greater laminar variation of neuronal density in occipital, parietal, and inferior temporal areas, in comparison with other regions. Moreover, differences between areas were more pronounced in the supragranular layers than in infragranular layers. Calculations of the number of neurons per unit column revealed a pattern that was distinct from that of neuronal density, including local peaks in the posterior parietal, superior temporal, precuneate, frontopolar, and temporopolar regions. These results suggest that neuronal distribution in adult cortex result from a complex interaction of developmental/ evolutionary determinants and functional requirements.
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Affiliation(s)
- Nafiseh Atapour
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, 770 Blackburn Road, Clayton, Melbourne, VIC, Australia
| | - Piotr Majka
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, 770 Blackburn Road, Clayton, Melbourne, VIC, Australia
- Laboratory of Neuroinformatics, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, Warsaw, Poland
| | - Ianina H Wolkowicz
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
| | - Daria Malamanova
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
| | - Katrina H Worthy
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
| | - Marcello G P Rosa
- Neuroscience Program, Monash Biomedicine Discovery Institute, 19 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Melbourne, VIC, Australia
- Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, 770 Blackburn Road, Clayton, Melbourne, VIC, Australia
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27
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Burt JB, Demirtaş M, Eckner WJ, Navejar NM, Ji JL, Martin WJ, Bernacchia A, Anticevic A, Murray JD. Hierarchy of transcriptomic specialization across human cortex captured by structural neuroimaging topography. Nat Neurosci 2018; 21:1251-1259. [PMID: 30082915 PMCID: PMC6119093 DOI: 10.1038/s41593-018-0195-0] [Citation(s) in RCA: 311] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 05/30/2018] [Indexed: 12/18/2022]
Abstract
Hierarchy provides a unifying principle for the macroscale organization of anatomical and functional properties across primate cortex, yet microscale bases of specialization across human cortex are poorly understood. Anatomical hierarchy is conventionally informed by invasive tract-tracing measurements, creating a need for a principled proxy measure in humans. Moreover, cortex exhibits marked interareal variation in gene expression, yet organizing principles of cortical transcription remain unclear. We hypothesized that specialization of cortical microcircuitry involves hierarchical gradients of gene expression. We found that a noninvasive neuroimaging measure-MRI-derived T1-weighted/T2-weighted (T1w/T2w) mapping-reliably indexes anatomical hierarchy, and it captures the dominant pattern of transcriptional variation across human cortex. We found hierarchical gradients in expression profiles of genes related to microcircuit function, consistent with monkey microanatomy, and implicated in neuropsychiatric disorders. Our findings identify a hierarchical axis linking cortical transcription and anatomy, along which gradients of microscale properties may contribute to the macroscale specialization of cortical function.
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Affiliation(s)
- Joshua B Burt
- Department of Physics, Yale University, New Haven, CT, USA
| | - Murat Demirtaş
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | | | | | - Jie Lisa Ji
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
| | | | | | - Alan Anticevic
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - John D Murray
- Department of Physics, Yale University, New Haven, CT, USA.
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
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28
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García-Cabezas MÁ, Barbas H, Zikopoulos B. Parallel Development of Chromatin Patterns, Neuron Morphology, and Connections: Potential for Disruption in Autism. Front Neuroanat 2018; 12:70. [PMID: 30174592 PMCID: PMC6107687 DOI: 10.3389/fnana.2018.00070] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 07/30/2018] [Indexed: 12/27/2022] Open
Abstract
The phenotype of neurons and their connections depend on complex genetic and epigenetic processes that regulate the expression of genes in the nucleus during development and throughout life. Here we examined the distribution of nuclear chromatin patters in relation to the epigenetic landscape, phenotype and connections of neurons with a focus on the primate cerebral cortex. We show that nuclear patterns of chromatin in cortical neurons are related to neuron size and cortical connections. Moreover, we point to evidence that reveals an orderly sequence of events during development, linking chromatin and gene expression patterns, neuron morphology, function, and connections across cortical areas and layers. Based on this synthesis, we posit that systematic studies of changes in chromatin patterns and epigenetic marks across cortical areas will provide novel insights on the development and evolution of cortical networks, and their disruption in connectivity disorders of developmental origin, like autism. Achieving this requires embedding and interpreting genetic, transcriptional, and epigenetic studies within a framework that takes into consideration distinct types of neurons, local circuit interactions, and interareal pathways. These features vary systematically across cortical areas in parallel with laminar structure and are differentially affected in disorders. Finally, based on evidence that autism-associated genetic polymorphisms are especially prominent in excitatory neurons and connectivity disruption affects mostly limbic cortices, we employ this systematic approach to propose novel, targeted studies of projection neurons in limbic areas to elucidate the emergence and time-course of developmental disruptions in autism.
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Affiliation(s)
- Miguel Á García-Cabezas
- Neural Systems Laboratory, Department of Health Sciences, Boston University, Boston, MA, United States
| | - Helen Barbas
- Neural Systems Laboratory, Department of Health Sciences, Boston University, Boston, MA, United States.,Graduate Program in Neuroscience, Boston University, Boston, MA, United States
| | - Basilis Zikopoulos
- Graduate Program in Neuroscience, Boston University, Boston, MA, United States.,Human Systems Neuroscience Laboratory, Department of Health Sciences, Boston University, Boston, MA, United States
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29
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Wagstyl K, Lepage C, Bludau S, Zilles K, Fletcher PC, Amunts K, Evans AC. Mapping Cortical Laminar Structure in the 3D BigBrain. Cereb Cortex 2018; 28:2551-2562. [PMID: 29901791 PMCID: PMC5998962 DOI: 10.1093/cercor/bhy074] [Citation(s) in RCA: 43] [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] [Received: 10/27/2017] [Revised: 03/08/2018] [Accepted: 03/13/2018] [Indexed: 11/30/2022] Open
Abstract
Histological sections offer high spatial resolution to examine laminar architecture of the human cerebral cortex; however, they are restricted by being 2D, hence only regions with sufficiently optimal cutting planes can be analyzed. Conversely, noninvasive neuroimaging approaches are whole brain but have relatively low resolution. Consequently, correct 3D cross-cortical patterns of laminar architecture have never been mapped in histological sections. We developed an automated technique to identify and analyze laminar structure within the high-resolution 3D histological BigBrain. We extracted white matter and pial surfaces, from which we derived histologically verified surfaces at the layer I/II boundary and within layer IV. Layer IV depth was strongly predicted by cortical curvature but varied between areas. This fully automated 3D laminar analysis is an important requirement for bridging high-resolution 2D cytoarchitecture and in vivo 3D neuroimaging. It lays the foundation for in-depth, whole-brain analyses of cortical layering.
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Affiliation(s)
- Konrad Wagstyl
- Department of Psychiatry, University of Cambridge, Cambridge, UK
- Department of Neurology and Neurosurgery, Montreal Neurological Institute (MNI), McGill University, Montreal, Canada
| | - Claude Lepage
- Department of Neurology and Neurosurgery, Montreal Neurological Institute (MNI), McGill University, Montreal, Canada
| | - Sebastian Bludau
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Karl Zilles
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen, Germany
- JARA—Translational Brain Medicine, Aachen, Aachen, Germany
| | - Paul C Fletcher
- Department of Psychiatry, University of Cambridge, Cambridge, UK
- Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, UK
| | - Katrin Amunts
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
- C. and O. Vogt-Institute for Brain Research, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Alan C Evans
- Department of Neurology and Neurosurgery, Montreal Neurological Institute (MNI), McGill University, Montreal, Canada
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30
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31
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Zhuang C, Wang Y, Yamins D, Hu X. Deep Learning Predicts Correlation between a Functional Signature of Higher Visual Areas and Sparse Firing of Neurons. Front Comput Neurosci 2017; 11:100. [PMID: 29163117 PMCID: PMC5670118 DOI: 10.3389/fncom.2017.00100] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 10/13/2017] [Indexed: 11/21/2022] Open
Abstract
Visual information in the visual cortex is processed in a hierarchical manner. Recent studies show that higher visual areas, such as V2, V3, and V4, respond more vigorously to images with naturalistic higher-order statistics than to images lacking them. This property is a functional signature of higher areas, as it is much weaker or even absent in the primary visual cortex (V1). However, the mechanism underlying this signature remains elusive. We studied this problem using computational models. In several typical hierarchical visual models including the AlexNet, VggNet, and SHMAX, this signature was found to be prominent in higher layers but much weaker in lower layers. By changing both the model structure and experimental settings, we found that the signature strongly correlated with sparse firing of units in higher layers but not with any other factors, including model structure, training algorithm (supervised or unsupervised), receptive field size, and property of training stimuli. The results suggest an important role of sparse neuronal activity underlying this special feature of higher visual areas.
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Affiliation(s)
- Chengxu Zhuang
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, China.,Department of Psychology, Stanford University, Stanford, CA, United States
| | - Yulong Wang
- Tsinghua National Laboratory for Information Science and Technology, Department of Computer Science and Technology, Tsinghua University, Beijing, China
| | - Daniel Yamins
- Department of Psychology, Stanford University, Stanford, CA, United States.,Computer Science Department, Stanford Neurosciences Institute, Stanford University, Stanford, CA, United States
| | - Xiaolin Hu
- Tsinghua National Laboratory for Information Science and Technology, Department of Computer Science and Technology, Tsinghua University, Beijing, China.,Center for Brain-Inspired Computing Research, Tsinghua University, Beijing, China
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32
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Similarity in Neuronal Firing Regimes across Mammalian Species. J Neurosci 2017; 36:5736-47. [PMID: 27225764 DOI: 10.1523/jneurosci.0230-16.2016] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/12/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED The architectonic subdivisions of the brain are believed to be functional modules, each processing parts of global functions. Previously, we showed that neurons in different regions operate in different firing regimes in monkeys. It is possible that firing regimes reflect differences in underlying information processing, and consequently the firing regimes in homologous regions across animal species might be similar. We analyzed neuronal spike trains recorded from behaving mice, rats, cats, and monkeys. The firing regularity differed systematically, with differences across regions in one species being greater than the differences in similar areas across species. Neuronal firing was consistently most regular in motor areas, nearly random in visual and prefrontal/medial prefrontal cortical areas, and bursting in the hippocampus in all animals examined. This suggests that firing regularity (or irregularity) plays a key role in neural computation in each functional subdivision, depending on the types of information being carried. SIGNIFICANCE STATEMENT By analyzing neuronal spike trains recorded from mice, rats, cats, and monkeys, we found that different brain regions have intrinsically different firing regimes that are more similar in homologous areas across species than across areas in one species. Because different regions in the brain are specialized for different functions, the present finding suggests that the different activity regimes of neurons are important for supporting different functions, so that appropriate neuronal codes can be used for different modalities.
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33
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Abstract
Structural plasticity of the axon initial segment (AIS), the site of action potential initiation, is observed as part of the normal early development of the cortex, as well as in association with injury and disease. Here, we show that structural AIS plasticity also occurs with normal aging in adult marmosets. Immunohistochemical techniques were used to reveal the extent of the AIS of layer 2/3A pyramidal cells in 8 neocortical areas. We found that the AIS length varied significantly between areas in young adult (2-3 years old) marmosets, with neurons in frontal area 14C having the longest AIS, and those in the primary visual cortex the shortest. Similar interareal differences were observed in aged (12-14 year old) monkeys, but the AIS was significantly shortened in many areas, relative to the corresponding length in young adults. Shortening of the AIS is likely to represent a compensatory response to changes in the excitation-inhibition balance, associated with the loss of GABAergic interneurons in the aged cortex.
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Affiliation(s)
- Nafiseh Atapour
- Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Victoria, Australia; Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Melbourne, Victoria, Australia.
| | - Marcello G P Rosa
- Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Victoria, Australia; Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Melbourne, Victoria, Australia
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34
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Wang Q, Tanigawa H, Fujita I. Postnatal Development of Intrinsic Horizontal Axons in Macaque Inferior Temporal and Primary Visual Cortices. Cereb Cortex 2017; 27:2708-2726. [PMID: 27114175 DOI: 10.1093/cercor/bhw105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Two distinct areas along the ventral visual stream of monkeys, the primary visual (V1) and inferior temporal (TE) cortices, exhibit different projection patterns of intrinsic horizontal axons with patchy terminal fields in adult animals. The differences between the patches in these 2 areas may reflect differences in cortical representation and processing of visual information. We studied the postnatal development of patches by injecting an anterograde tracer into TE and V1 in monkeys of various ages. At 1 week of age, labeled patches with distribution patterns reminiscent of those in adults were already present in both areas. The labeling intensity of patches decayed exponentially with projection distance in monkeys of all ages in both areas, but this trend was far less evident in TE. The number and extent of patches gradually decreased with age in V1, but not in TE. In V1, axonal and bouton densities increased postnatally only in patches with short projection distances, whereas in TE this density change occurred in patches with various projection distances. Thus, patches with area-specific distribution patterns are formed early in life, and area-specific postnatal developmental processes shape the connectivity of patches into adulthood.
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Affiliation(s)
- Quanxin Wang
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Toyonaka, Osaka 560-8537, Japan
- The Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Hisashi Tanigawa
- Department of Cognitive Neuroscience, Osaka University Medical School, Suita, Osaka 565-0871, Japan
- Center for Transdisciplinary Research, Niigata University, Niigata, Niigata 950-2181, Japan
| | - Ichiro Fujita
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Toyonaka, Osaka 560-8537, Japan
- Department of Cognitive Neuroscience, Osaka University Medical School, Suita, Osaka 565-0871, Japan
- Graduate School of Frontier Biosciences and Center for Information and Neural Networks, Osaka University and National Institute of Information and Communications Technology, Suita, Osaka 565-0871, Japan
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35
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Oga T, Elston GN, Fujita I. Postnatal Dendritic Growth and Spinogenesis of Layer-V Pyramidal Cells Differ between Visual, Inferotemporal, and Prefrontal Cortex of the Macaque Monkey. Front Neurosci 2017; 11:118. [PMID: 28348514 PMCID: PMC5347257 DOI: 10.3389/fnins.2017.00118] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/27/2017] [Indexed: 12/29/2022] Open
Abstract
Pyramidal cells in the primate cerebral cortex, particularly those in layer III, exhibit regional variation in both the time course and magnitude of postnatal growth and pruning of dendrites and spines. Less is known about the development of pyramidal cell dendrites and spines in other cortical layers. Here we studied dendritic morphology of layer-V pyramidal cells in primary visual cortex (V1, sensory), cytoarchitectonic area TE in the inferotemporal cortex (sensory association), and granular prefrontal cortex (Walker's area 12, executive) of macaque monkeys at the ages of 2 days, 3 weeks, 3.5 months, and 4.5 years. We found that changes in the basal dendritic field area of pyramidal cells were different across the three areas. In V1, field size became smaller over time (largest at 2 days, half that size at 4.5 years), in TE it did not change, and in area 12 it became larger over time (smallest at 2 days, 1.5 times greater at 4.5 years). In V1 and TE, the total number of branch points in the basal dendritic trees was similar between 2 days and 4.5 years, while in area 12 the number was greater in the adult monkeys than in the younger ones. Spine density peaked at 3 weeks and declined in all areas by adulthood, with V1 exhibiting a faster decline than area TE or area 12. Estimates of the total number of spines in the dendritic trees revealed that following the onset of visual experience, pyramidal cells in V1 lose more spines than they grow, whereas those in TE and area 12 grow more spines than they lose during the same period. These data provide further evidence that the process of synaptic refinement in cortical pyramidal cells differs not only according to time, but also location within the cortex. Furthermore, given the previous finding that layer-III pyramidal cells in all these areas exhibit the highest density and total number of spines at 3.5 months, the current results indicate that pyramidal cells in layers III and V develop spines at different rates.
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Affiliation(s)
- Tomofumi Oga
- Laboratory for Cognitive Neuroscience, Graduate School of Frontier Biosciences, Osaka University Suita, Japan
| | - Guy N Elston
- Centre for Cognitive Neuroscience Sunshine Coast, QLD, Australia
| | - Ichiro Fujita
- Laboratory for Cognitive Neuroscience, Graduate School of Frontier Biosciences, Osaka UniversitySuita, Japan; Center for Information and Neural Networks, National Institute of Information and Communications Technology and Osaka UniversitySuita, Japan
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36
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Oga T, Okamoto T, Fujita I. Basal Dendrites of Layer-III Pyramidal Neurons do not Scale with Changes in Cortical Magnification Factor in Macaque Primary Visual Cortex. Front Neural Circuits 2016; 10:74. [PMID: 27708563 PMCID: PMC5030257 DOI: 10.3389/fncir.2016.00074] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 09/08/2016] [Indexed: 11/13/2022] Open
Abstract
Neurons in the mammalian primary visual cortex (V1) are systematically arranged across the cortical surface according to the location of their receptive fields (RFs), forming a visuotopic (or retinotopic) map. Within this map, the foveal visual field is represented by a large cortical surface area, with increasingly peripheral visual fields gradually occupying smaller cortical areas. Although cellular organization in the retina, such as the spatial distribution of ganglion cells, can partially account for the eccentricity-dependent differences in the size of cortical representation, whether morphological differences exist across V1 neurons representing different eccentricities is unclear. In particular, morphological differences in dendritic field diameter might contribute to the magnified representation of the central visual field. Here, we addressed this question by measuring the basal dendritic arbors of pyramidal neurons of layer-IIIC and adjoining layer III sublayers (in the Hassler's nomenclature) in macaque V1. We labeled layer-III pyramidal neurons at various retinotopic positions in V1 by injecting lightly fixed brain tissue with intracellular dye, and then compared dendritic morphology across regions in the retinotopic map representing 0-20° of eccentricity. The dendritic field area, total dendritic length, number of principal dendrites, branching complexity, spine density and total number of spines were all consistent across different retinotopic regions of V1. These results indicate that dendrites in layer-III pyramidal neurons are relatively homogeneous according to these morphometric parameters irrespective of their locations in this portion of the retinotopic map. The homogeneity of dendritic morphology in these neurons suggests that the emphasis of central visual field representation is not attributable to changes in the basal dendritic arbors of pyramidal neurons in layer III, but is likely the result of successive processes earlier in the retino-geniculo-striate pathway.
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Affiliation(s)
- Tomofumi Oga
- Graduate School of Frontier Biosciences, Osaka UniversitySuita, Osaka, Japan
| | - Tsuguhisa Okamoto
- Graduate School of Frontier Biosciences, Osaka UniversitySuita, Osaka, Japan
| | - Ichiro Fujita
- Graduate School of Frontier Biosciences, Osaka UniversitySuita, Osaka, Japan
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology and Osaka UniversitySuita, Osaka, Japan
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37
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Mamah D, Wen J, Luo J, Ulrich X, Barch DM, Yablonskiy D. Subcomponents of brain T2* relaxation in schizophrenia, bipolar disorder and siblings: A Gradient Echo Plural Contrast Imaging (GEPCI) study. Schizophr Res 2015; 169:36-45. [PMID: 26603058 PMCID: PMC4681636 DOI: 10.1016/j.schres.2015.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 10/02/2015] [Accepted: 10/06/2015] [Indexed: 11/30/2022]
Abstract
Investigating brain tissue T2* relaxation properties in vivo can potentially guide the uncovering of neuropathology in psychiatric illness, which is traditionally examined post mortem. We use an MRI-based Gradient Echo Plural Contrast Imaging (GEPCI) technique that produces inherently co-registered images allowing quantitative assessment of tissue cellular and hemodynamic properties. Usually described as R2* (=1/T2*) relaxation rate constant, recent developments in GEPCI allow the separation of cellular-specific (R2*C) and hemodynamic (BOLD) contributions to the MRI signal decay. We characterize BOLD effect in terms of tissue concentration of deoxyhemoglobin, i.e. CDEOXY, which reflects brain activity. 17 control (CON), 17 bipolar disorder (BPD), 16 schizophrenia (SCZ), and 12 unaffected schizophrenia sibling (SIB) participants were scanned and post-processed using GEPCI protocols. A MANOVA of 38gray matter regions ROIs showed significant group effects for CDEOXY but not for R2*C. In the three non-control groups, 71-92% of brain regions had increased CDEOXY. Group effects were observed in the superior temporal cortex and the thalamus. Increased superior temporal cortex CDEOXY was found in SCZ (p=0.01), BPD (p=0.01) and SIB (p=0.02), with bilateral effects in SCZ and only left hemisphere effects in BPD and SIB. Thalamic CDEOXY abnormalities were observed in SCZ (p=0.003), BPD (p=0.03) and SIB (p=0.02). Our results suggest that increased activity in certain brain regions is part of the underlying pathophysiology of specific psychiatric disorders. High CDEOXY in the superior temporal cortex suggests abnormal activity with auditory, language and/or social cognitive processing. Larger studies are needed to clarify the clinical significance of relaxometric abnormalities.
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Affiliation(s)
- Daniel Mamah
- Department of Psychiatry, Washington University Medical School, St. Louis, United States.
| | - Jie Wen
- Department of Radiology, Washington University Medical School, St. Louis, United States
| | - Jie Luo
- Department of Radiology, Washington University Medical School, St. Louis, United States
| | - Xialing Ulrich
- Department of Radiology, Washington University Medical School, St. Louis, United States
| | - Deanna M. Barch
- Department of Psychiatry, Washington University Medical School, St. Louis, United States, Department of Psychology, Washington University in St. Louis, United States, Department of Anatomy and Neurobiology, Washington University in St. Louis, United States
| | - Dmitriy Yablonskiy
- Department of Radiology, Washington University Medical School, St. Louis, United States
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38
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Böhm MRR, Melkonyan H, Thanos S. Life-time expression of the proteins peroxiredoxin, beta-synuclein, PARK7/DJ-1, and stathmin in the primary visual and primary somatosensory cortices in rats. Front Neuroanat 2015; 9:16. [PMID: 25788877 PMCID: PMC4349188 DOI: 10.3389/fnana.2015.00016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 02/04/2015] [Indexed: 11/16/2022] Open
Abstract
Four distinct proteins are regulated in the aging neuroretina and may be regulated in the cerebral cortex, too: peroxiredoxin, beta-synuclein, PARK[Parkinson disease(autosomal recessive, early onset)]7/DJ-1, and Stathmin. Thus, we performed a comparative analysis of these proteins in the the primary somatosensory cortex (S1) and primary visual cortex (V1) in rats, in order to detect putative common development-, maturation- and age-related changes. The expressions of peroxiredoxin, beta-synuclein, PARK[Parkinson disease (autosomal recessive, early onset)]7/DJ-1, and Stathmin were compared in the newborn, juvenile, adult, and aged S1 and V1. Western blot (WB), quantitative reverse-transcription polymerase chain reaction (qRT-PCR), and immunohistochemistry (IHC) analyses were employed to determine whether the changes identified by proteomics were verifiable at the cellular and molecular levels. All of the proteins were detected in both of the investigated cortical areas. Changes in the expressions of the four proteins were found throughout the life-time of the rats. Peroxiredoxin expression remained unchanged over life-time. Beta-Synuclein expression was massively increased up to the adult stage of life in both the S1 and V1. PARK[Parkinson disease (autosomal recessive, early onset)]7/DJ-1 exhibited a massive up-regulation in both the S1 and V1 at all ages. Stathmin expression was massively down regulated after the neonatal period in both the S1 and V1. The detected protein alterations were analogous to their retinal profiles. This study is the first to provide evidence that peroxiredoxin, beta-synuclein, PARK[Parkinson disease (autosomal recessive, early onset)]7/DJ-1, and Stathmin are associated with postnatal maturation and aging in both the S1 and V1 of rats. These changes may indicate their involvement in key functional pathways and may account for the onset or progression of age-related pathologies.
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Affiliation(s)
- Michael R R Böhm
- Institute of Experimental Ophthalmology and DFG-Center of Excellence Cells in Motion (CiM), area C.4, School of Medicine, Westfalian-Wilhelms-University of Münster Münster, Germany ; Department of Ophthalmology, St. Franziskus Hospital Münster Münster, Germany
| | - Harutyun Melkonyan
- Institute of Experimental Ophthalmology and DFG-Center of Excellence Cells in Motion (CiM), area C.4, School of Medicine, Westfalian-Wilhelms-University of Münster Münster, Germany
| | - Solon Thanos
- Institute of Experimental Ophthalmology and DFG-Center of Excellence Cells in Motion (CiM), area C.4, School of Medicine, Westfalian-Wilhelms-University of Münster Münster, Germany
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Jain R, Millin R, Mel BW. Multimap formation in visual cortex. J Vis 2015; 15:3. [PMID: 26641946 PMCID: PMC4675321 DOI: 10.1167/15.16.3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 09/29/2015] [Indexed: 12/12/2022] Open
Abstract
An extrastriate visual area such as V2 or V4 contains neurons selective for a multitude of complex shapes, all sharing a common topographic organization. Simultaneously developing multiple interdigitated maps--hereafter a "multimap"--is challenging in that neurons must compete to generate a diversity of response types locally, while cooperating with their dispersed same-type neighbors to achieve uniform visual field coverage for their response type at all orientations, scales, etc. Previously proposed map development schemes have relied on smooth spatial interaction functions to establish both topography and columnar organization, but by locally homogenizing cells' response properties, local smoothing mechanisms effectively rule out multimap formation. We found in computer simulations that the key requirements for multimap development are that neurons are enabled for plasticity only within highly active regions of cortex designated "learning eligibility regions" (LERs), but within an LER, each cell's learning rate is determined only by its activity level with no dependence on location. We show that a hybrid developmental rule that combines spatial and activity-dependent learning criteria in this way successfully produces multimaps when the input stream contains multiple distinct feature types, or in the degenerate case of a single feature type, produces a V1-like map with "salt-and-pepper" structure. Our results support the hypothesis that cortical maps containing a fine mixture of different response types, whether in monkey extrastriate cortex, mouse V1 or elsewhere in the cortex, rather than signaling a breakdown of map formation mechanisms at the fine scale, are a product of a generic cortical developmental scheme designed to map cells with a diversity of response properties across a shared topographic space.
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Mancuso JJ, Cheng J, Yin Z, Gilliam JC, Xia X, Li X, Wong STC. Integration of multiscale dendritic spine structure and function data into systems biology models. Front Neuroanat 2014; 8:130. [PMID: 25429262 PMCID: PMC4228840 DOI: 10.3389/fnana.2014.00130] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 10/22/2014] [Indexed: 12/27/2022] Open
Abstract
Comprising 1011 neurons with 1014 synaptic connections the human brain is the ultimate systems biology puzzle. An increasing body of evidence highlights the observation that changes in brain function, both normal and pathological, consistently correlate with dynamic changes in neuronal anatomy. Anatomical changes occur on a full range of scales from the trafficking of individual proteins, to alterations in synaptic morphology both individually and on a systems level, to reductions in long distance connectivity and brain volume. The major sites of contact for synapsing neurons are dendritic spines, which provide an excellent metric for the number and strength of signaling connections between elements of functional neuronal circuits. A comprehensive model of anatomical changes and their functional consequences would be a holy grail for the field of systems neuroscience but its realization appears far on the horizon. Various imaging technologies have advanced to allow for multi-scale visualization of brain plasticity and pathology, but computational analysis of the big data sets involved forms the bottleneck toward the creation of multiscale models of brain structure and function. While a full accounting of techniques and progress toward a comprehensive model of brain anatomy and function is beyond the scope of this or any other single paper, this review serves to highlight the opportunities for analysis of neuronal spine anatomy and function provided by new imaging technologies and the high-throughput application of older technologies while surveying the strengths and weaknesses of currently available computational analytical tools and room for future improvement.
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Affiliation(s)
- James J Mancuso
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Jie Cheng
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Zheng Yin
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Jared C Gilliam
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Xiaofeng Xia
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Xuping Li
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
| | - Stephen T C Wong
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute Houston, TX, USA ; TT and WF Chao Center for Bioinformatics Research and Imaging for Neurosciences, Houston Methodist Research Institute Houston, TX, USA
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Linking macroscale graph analytical organization to microscale neuroarchitectonics in the macaque connectome. J Neurosci 2014; 34:12192-205. [PMID: 25186762 DOI: 10.1523/jneurosci.0752-14.2014] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Macroscale connectivity of the mammalian brain has been shown to display several characteristics of an efficient communication network architecture. In parallel, at the microscopic scale, histological studies have extensively revealed large interregional variation in cortical neural architectonics. However, how these two "scales" of cerebrum organization are linked remains an open question. Collating and combining data across multiple studies on the cortical cytoarchitecture of the macaque cortex with information on macroscale anatomical wiring derived from tract tracing studies, this study focuses on examining the interplay between macroscale organization of the macaque connectome and microscale cortical neuronal architecture. Our findings show that both macroscale degree as well as the topological role in the overall network are related to the level of neuronal complexity of cortical regions at the microscale, showing (among several effects) a positive overall association between macroscale degree and metrics of microscale pyramidal complexity. Macroscale hub regions, together forming a densely interconnected "rich club," are noted to display a high level of neuronal complexity, findings supportive of a high level of integrative neuronal processes to occur in these regions. Together, we report on cross-scale observations that jointly suggest that a region's microscale neuronal architecture is tuned to its role in the global brain network.
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Hanson KL, Hrvoj-Mihic B, Semendeferi K. A dual comparative approach: integrating lines of evidence from human evolutionary neuroanatomy and neurodevelopmental disorders. BRAIN, BEHAVIOR AND EVOLUTION 2014; 84:135-55. [PMID: 25247986 DOI: 10.1159/000365409] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The evolution of the human brain has been marked by a nearly 3-fold increase in size since our divergence from the last common ancestor shared with chimpanzees and bonobos. Despite increased interest in comparative neuroanatomy and phylogenetic methods, relatively little is known regarding the effects that this enlargement has had on its internal organization, and how certain areas of the brain have differentially expanded over evolutionary time. Analyses of the microstructure of several regions of the human cortex and subcortical structures have demonstrated subtle changes at the cellular and molecular level, suggesting that the human brain is more than simply a 'scaled-up' primate brain. Ongoing research in comparative neuroanatomy has much to offer regarding our understanding of human brain evolution. Through analysis of the neuroanatomical phenotype at the level of reorganization in cytoarchitecture and cellular morphology, new data continue to highlight changes in cell density and organization associated with volumetric changes in discrete regions. An understanding of the functional significance of variation in neural circuitry can further be approached through studies of atypical human development. Many neurodevelopmental disorders cause disruption in systems associated with uniquely human features of cognition, including language and social cognition. Understanding the genetic and developmental mechanisms that underlie variation in the human cognitive phenotype can help to clarify the functional significance of interspecific variation. By uniting approaches from comparative neuroanatomy and neuropathology, insights can be gained that clarify trends in human evolution. Here, we explore these lines of evidence and their significance for understanding functional variation between species as well as within neuropathological variation in the human brain.
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Affiliation(s)
- Kari L Hanson
- Department of Anthropology, University of California, San Diego, La Jolla, Calif., USA
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Morgan JT, Amaral DG. Comparative analysis of the dendritic organization of principal neurons in the lateral and central nuclei of the rhesus macaque and rat amygdala. J Comp Neurol 2014; 522:689-716. [PMID: 24114951 DOI: 10.1002/cne.23467] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 08/23/2013] [Accepted: 09/13/2013] [Indexed: 11/10/2022]
Abstract
The amygdala plays a critical role in emotional processing and has been implicated in the etiology of numerous psychiatric disorders. It is an evolutionarily ancient structure that is enlarged in primates relative to rodents. Certain amygdala nuclei, such as the lateral nucleus, show relatively greater phylogenetic expansion than other nuclei. However, it is unknown whether there is also differential alteration in neuronal features. To address this question, we examined the dendritic arbors of principal neurons, visualized by using the Golgi method, in the lateral and central nuclei of young adult rhesus macaques and rats. Total dendritic length is greater in the macaque than in the rat. Dendritic trees are increased by 250% in length in the lateral nucleus of the monkey compared with the rat (6,009 μm vs. 2,473 μm); dendritic tree length in the central nucleus is increased by 50% (1,786 μm vs. 1,232 μm). Somal volume is increased 62% between species in the lateral nucleus and 48% in the central nucleus. Spine density is lower on macaque lateral nucleus dendrites compared with rat (-22%) but equivalent in the central nucleus. Spines are equally long in the lateral nucleus of rat and macaque, but spines are longer by about 20% in the central nucleus of the macaque. The alterations in dendritic structure that we observed between the two species suggest differences in the number and spacing of inputs into these nuclei that undoubtedly influence amygdala function.
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Affiliation(s)
- John T Morgan
- Department of Psychiatry and Behavioral Sciences, The M.I.N.D. Institute, Center for Neuroscience and California National Primate Research Center, University of California, Davis, Sacramento, California, 95817
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Elston GN, Fujita I. Pyramidal cell development: postnatal spinogenesis, dendritic growth, axon growth, and electrophysiology. Front Neuroanat 2014; 8:78. [PMID: 25161611 PMCID: PMC4130200 DOI: 10.3389/fnana.2014.00078] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 07/22/2014] [Indexed: 01/12/2023] Open
Abstract
Here we review recent findings related to postnatal spinogenesis, dendritic and axon growth, pruning and electrophysiology of neocortical pyramidal cells in the developing primate brain. Pyramidal cells in sensory, association and executive cortex grow dendrites, spines and axons at different rates, and vary in the degree of pruning. Of particular note is the fact that pyramidal cells in primary visual area (V1) prune more spines than they grow during postnatal development, whereas those in inferotemporal (TEO and TE) and granular prefrontal cortex (gPFC; Brodmann's area 12) grow more than they prune. Moreover, pyramidal cells in TEO, TE and the gPFC continue to grow larger dendritic territories from birth into adulthood, replete with spines, whereas those in V1 become smaller during this time. The developmental profile of intrinsic axons also varies between cortical areas: those in V1, for example, undergo an early proliferation followed by pruning and local consolidation into adulthood, whereas those in area TE tend to establish their territory and consolidate it into adulthood with little pruning. We correlate the anatomical findings with the electrophysiological properties of cells in the different cortical areas, including membrane time constant, depolarizing sag, duration of individual action potentials, and spike-frequency adaptation. All of the electrophysiological variables ramped up before 7 months of age in V1, but continued to ramp up over a protracted period of time in area TE. These data suggest that the anatomical and electrophysiological profiles of pyramidal cells vary among cortical areas at birth, and continue to diverge into adulthood. Moreover, the data reveal that the “use it or lose it” notion of synaptic reinforcement may speak to only part of the story, “use it but you still might lose it” may be just as prevalent in the cerebral cortex.
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Affiliation(s)
- Guy N Elston
- Centre for Cognitive Neuroscience Sunshine Coast, QLD, Australia
| | - Ichiro Fujita
- Graduate School of Frontier Biosciences and Center for Information and Neural Networks, Osaka University and National Institute of Communication Technology Suita, Japan
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Butti C, Janeway CM, Townshend C, Wicinski BA, Reidenberg JS, Ridgway SH, Sherwood CC, Hof PR, Jacobs B. The neocortex of cetartiodactyls: I. A comparative Golgi analysis of neuronal morphology in the bottlenose dolphin (Tursiops truncatus), the minke whale (Balaenoptera acutorostrata), and the humpback whale (Megaptera novaeangliae). Brain Struct Funct 2014; 220:3339-68. [PMID: 25100560 DOI: 10.1007/s00429-014-0860-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 07/25/2014] [Indexed: 12/12/2022]
Abstract
The present study documents the morphology of neurons in several regions of the neocortex from the bottlenose dolphin (Tursiops truncatus), the North Atlantic minke whale (Balaenoptera acutorostrata), and the humpback whale (Megaptera novaeangliae). Golgi-stained neurons (n = 210) were analyzed in the frontal and temporal neocortex as well as in the primary visual and primary motor areas. Qualitatively, all three species exhibited a diversity of neuronal morphologies, with spiny neurons including typical pyramidal types, similar to those observed in primates and rodents, as well as other spiny neuron types that had more variable morphology and/or orientation. Five neuron types, with a vertical apical dendrite, approximated the general pyramidal neuron morphology (i.e., typical pyramidal, extraverted, magnopyramidal, multiapical, and bitufted neurons), with a predominance of typical and extraverted pyramidal neurons. In what may represent a cetacean morphological apomorphy, both typical pyramidal and magnopyramidal neurons frequently exhibited a tri-tufted variant. In the humpback whale, there were also large, star-like neurons with no discernable apical dendrite. Aspiny bipolar and multipolar interneurons were morphologically consistent with those reported previously in other mammals. Quantitative analyses showed that neuronal size and dendritic extent increased in association with body size and brain mass (bottlenose dolphin < minke whale < humpback whale). The present data thus suggest that certain spiny neuron morphologies may be apomorphies in the neocortex of cetaceans as compared to other mammals and that neuronal dendritic extent covaries with brain and body size.
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Affiliation(s)
- Camilla Butti
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA.
| | - Caroline M Janeway
- Laboratory of Quantitative Neuromorphology, Psychology, Colorado College, 14 E. Cache La Poudre, Colorado Springs, CO, 80903, USA
| | - Courtney Townshend
- Laboratory of Quantitative Neuromorphology, Psychology, Colorado College, 14 E. Cache La Poudre, Colorado Springs, CO, 80903, USA
| | - Bridget A Wicinski
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Joy S Reidenberg
- Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Sam H Ridgway
- National Marine Mammal Foundation, 2240 Shelter Island Drive, San Diego, CA, 92106, USA
| | - Chet C Sherwood
- Department of Anthropology, The George Washington University, 2110 G Street NW, Washington, DC, 20052, USA
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, Box 1639, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Bob Jacobs
- Laboratory of Quantitative Neuromorphology, Psychology, Colorado College, 14 E. Cache La Poudre, Colorado Springs, CO, 80903, USA
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The neocortex of cetartiodactyls. II. Neuronal morphology of the visual and motor cortices in the giraffe (Giraffa camelopardalis). Brain Struct Funct 2014; 220:2851-72. [PMID: 25048683 DOI: 10.1007/s00429-014-0830-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Accepted: 06/21/2014] [Indexed: 12/24/2022]
Abstract
The present quantitative study extends our investigation of cetartiodactyls by exploring the neuronal morphology in the giraffe (Giraffa camelopardalis) neocortex. Here, we investigate giraffe primary visual and motor cortices from perfusion-fixed brains of three subadults stained with a modified rapid Golgi technique. Neurons (n = 244) were quantified on a computer-assisted microscopy system. Qualitatively, the giraffe neocortex contained an array of complex spiny neurons that included both "typical" pyramidal neuron morphology and "atypical" spiny neurons in terms of morphology and/or orientation. In general, the neocortex exhibited a vertical columnar organization of apical dendrites. Although there was no significant quantitative difference in dendritic complexity for pyramidal neurons between primary visual (n = 78) and motor cortices (n = 65), there was a significant difference in dendritic spine density (motor cortex > visual cortex). The morphology of aspiny neurons in giraffes appeared to be similar to that of other eutherian mammals. For cross-species comparison of neuron morphology, giraffe pyramidal neurons were compared to those quantified with the same methodology in African elephants and some cetaceans (e.g., bottlenose dolphin, minke whale, humpback whale). Across species, the giraffe (and cetaceans) exhibited less widely bifurcating apical dendrites compared to elephants. Quantitative dendritic measures revealed that the elephant and humpback whale had more extensive dendrites than giraffes, whereas the minke whale and bottlenose dolphin had less extensive dendritic arbors. Spine measures were highest in the giraffe, perhaps due to the high quality, perfusion fixation. The neuronal morphology in giraffe neocortex is thus generally consistent with what is known about other cetartiodactyls.
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de Sousa AA, Proulx MJ. What can volumes reveal about human brain evolution? A framework for bridging behavioral, histometric, and volumetric perspectives. Front Neuroanat 2014; 8:51. [PMID: 25009469 PMCID: PMC4069365 DOI: 10.3389/fnana.2014.00051] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Accepted: 06/03/2014] [Indexed: 11/25/2022] Open
Abstract
An overall relationship between brain size and cognitive ability exists across primates. Can more specific information about neural function be gleaned from cortical area volumes? Numerous studies have found significant relationships between brain structures and behaviors. However, few studies have speculated about brain structure-function relationships from the microanatomical to the macroanatomical level. Here we address this problem in comparative neuroanatomy, where the functional relevance of overall brain size and the sizes of cortical regions have been poorly understood, by considering comparative psychology, with measures of visual acuity and the perception of visual illusions. We outline a model where the macroscopic size (volume or surface area) of a cortical region (such as the primary visual cortex, V1) is related to the microstructure of discrete brain regions. The hypothesis developed here is that an absolutely larger V1 can process more information with greater fidelity due to having more neurons to represent a field of space. This is the first time that the necessary comparative neuroanatomical research at the microstructural level has been brought to bear on the issue. The evidence suggests that as the size of V1 increases: the number of neurons increases, the neuron density decreases, and the density of neuronal connections increases. Thus, we describe how information about gross neuromorphology, using V1 as a model for the study of other cortical areas, may permit interpretations of cortical function.
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Affiliation(s)
| | - Michael J Proulx
- Crossmodal Cognition Lab, Department of Psychology, University of Bath Bath, UK
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Elston GN, Manger P. Pyramidal cells in V1 of African rodents are bigger, more branched and more spiny than those in primates. Front Neuroanat 2014; 8:4. [PMID: 24574977 PMCID: PMC3918685 DOI: 10.3389/fnana.2014.00004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 01/20/2014] [Indexed: 01/21/2023] Open
Abstract
Pyramidal cells are characterized by markedly different sized dendritic trees, branching patterns, and spine density across the cortical mantle. Moreover, pyramidal cells have been shown to differ in structure among homologous cortical areas in different species; however, most of these studies have been conducted in primates. Whilst pyramidal cells have been quantified in a few cortical areas in some other species there are, as yet, no uniform comparative data on pyramidal cell structure in a homologous cortical area among species in different Orders. Here we studied layer III pyramidal cells in V1 of three species of rodents, the greater cane rat, highveld gerbil, and four-striped mouse, by the same methodology used to sample data from layer III pyramidal cells in primates. The data reveal markedly different trends between rodents and primates: there is an appreciable increase in the size, branching complexity, and number of spines in the dendritic trees of pyramidal cells with increasing size of V1 in the brain in rodents, whereas there is relatively little difference in primates. Moreover, pyramidal cells in rodents are larger, more branched and more spinous than those in primates. For example, the dendritic trees of pyramidal cells in V1 of the adult cane rat are nearly three times larger, and have more than 10 times the number of spines in their basal dendritic trees, than those in V1 of the adult macaque (7900 and 600, respectively), which has a V1 40 times the size that of the cane rat. It remains to be determined to what extent these differences may result from development or reflect evolutionary and/or processing specializations.
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Affiliation(s)
- Guy N Elston
- Centre for Cognitive Neuroscience Sunshine Coast, QLD, Australia
| | - Paul Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand Johannesburg, South Africa
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Bianchi S, Stimpson CD, Bauernfeind AL, Schapiro SJ, Baze WB, McArthur MJ, Bronson E, Hopkins WD, Semendeferi K, Jacobs B, Hof PR, Sherwood CC. Dendritic morphology of pyramidal neurons in the chimpanzee neocortex: regional specializations and comparison to humans. Cereb Cortex 2013; 23:2429-36. [PMID: 22875862 PMCID: PMC3767963 DOI: 10.1093/cercor/bhs239] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The primate cerebral cortex is characterized by regional variation in the structure of pyramidal neurons, with more complex dendritic arbors and greater spine density observed in prefrontal compared with sensory and motor cortices. Although there are several investigations in humans and other primates, virtually nothing is known about regional variation in the morphology of pyramidal neurons in the cerebral cortex of great apes, humans' closest living relatives. The current study uses the rapid Golgi stain to quantify the dendritic structure of layer III pyramidal neurons in 4 areas of the chimpanzee cerebral cortex: Primary somatosensory (area 3b), primary motor (area 4), prestriate visual (area 18), and prefrontal (area 10) cortex. Consistent with previous studies in humans and macaque monkeys, pyramidal neurons in the prefrontal cortex of chimpanzees exhibit greater dendritic complexity than those in other cortical regions, suggesting that prefrontal cortical evolution in primates is characterized by increased potential for integrative connectivity. Compared with chimpanzees, the pyramidal neurons of humans had significantly longer and more branched dendritic arbors in all cortical regions.
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Affiliation(s)
- Serena Bianchi
- Department of Anthropology, The George Washington University, Washington, DC
| | - Cheryl D. Stimpson
- Department of Anthropology, The George Washington University, Washington, DC
| | - Amy L. Bauernfeind
- Department of Anthropology, The George Washington University, Washington, DC
| | - Steven J. Schapiro
- Department of Veterinary Sciences, The University of Texas M.D. Anderson Cancer Center, Bastrop, TX 78602
| | - Wallace B. Baze
- Department of Veterinary Sciences, The University of Texas M.D. Anderson Cancer Center, Bastrop, TX 78602
| | - Mark J. McArthur
- Department of Veterinary Sciences, The University of Texas M.D. Anderson Cancer Center, Bastrop, TX 78602
| | | | - William D. Hopkins
- Neuroscience Institute, Georgia State University, Atlanta, Georgia 30302
- Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30322
| | - Katerina Semendeferi
- Department of Anthropology and Neuroscience Graduate Program, University of California, San Diego, La Jolla, CA 92093
| | - Bob Jacobs
- Department of Psychology, Colorado College, Colorado Springs, CO 80903
| | - Patrick R. Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Mount Sinai School of Medicine, New York, NY 10029 and
- New York Consortium in Evolutionary Primatology, New York, NY, USA
| | - Chet C. Sherwood
- Department of Anthropology, The George Washington University, Washington, DC
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