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Jiang H, Rowland BA, Stein BE. Reversing Hemianopia by Multisensory Training Under Anesthesia. Front Syst Neurosci 2020; 14:4. [PMID: 32076401 PMCID: PMC7006460 DOI: 10.3389/fnsys.2020.00004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 01/13/2020] [Indexed: 02/04/2023] Open
Abstract
Hemianopia is characterized by blindness in one half of the visual field and is a common consequence of stroke and unilateral injury to the visual cortex. There are few effective rehabilitative strategies that can relieve it. Using the cat as an animal model of hemianopia, we found that blindness induced by lesions targeting all contiguous areas of the visual cortex could be rapidly reversed by a non-invasive, multisensory (auditory-visual) exposure procedure even while animals were anesthetized. Surprisingly few trials were required to reinstate vision in the previously blind hemisphere. That rehabilitation was possible under anesthesia indicates that the visuomotor behaviors commonly believed to be essential are not required for this recovery, nor are factors such as attention, motivation, reward, or the various other cognitive features that are generally thought to facilitate neuro-rehabilitative therapies.
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Affiliation(s)
- Huai Jiang
- Department of Neurobiology and Anatomy, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, United States
| | - Benjamin A Rowland
- Department of Neurobiology and Anatomy, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, United States
| | - Barry E Stein
- Department of Neurobiology and Anatomy, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, United States
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2
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Benedek G, Keri S, Nagy A, Braunitzer G, Norita M. A multimodal pathway including the basal ganglia in the feline brain. Physiol Int 2019; 106:95-113. [PMID: 31271309 DOI: 10.1556/2060.106.2019.09] [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] [Indexed: 11/19/2022]
Abstract
The purpose of this paper is to give an overview of our present knowledge about the feline tecto-thalamo-basal ganglia cortical sensory pathway. We reviewed morphological and electrophysiological studies of the cortical areas, located in ventral bank of the anterior ectosylvian sulcus as well as the region of the insular cortex, the suprageniculate nucleus of the thalamus, caudate nucleus, and the substantia nigra. Microelectrode studies revealed common receptive field properties in all these structures. The receptive fields were extremely large and multisensory, with pronounced sensitivity to motion of visual stimuli. They often demonstrated directional and velocity selectivity. Preference for small visual stimuli was also a frequent finding. However, orientation sensitivity was absent. It became obvious that the structures of the investigated sensory loop exhibit a unique kind of information processing, not found anywhere else in the feline visual system.
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Affiliation(s)
- G Benedek
- 1 Department of Physiology, University of Szeged , Szeged, Hungary
| | - S Keri
- 1 Department of Physiology, University of Szeged , Szeged, Hungary.,2 Nyirő Gyula Hospital, Laboratory for Perception & Cognition and Clinical Neuroscience , Budapest, Hungary
| | - A Nagy
- 1 Department of Physiology, University of Szeged , Szeged, Hungary
| | - G Braunitzer
- 3 Department of Anatomy, Niigata University , Niigata, Japan
| | - M Norita
- 3 Department of Anatomy, Niigata University , Niigata, Japan
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3
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Galindo-Leon EE, Stitt I, Pieper F, Stieglitz T, Engler G, Engel AK. Context-specific modulation of intrinsic coupling modes shapes multisensory processing. SCIENCE ADVANCES 2019; 5:eaar7633. [PMID: 30989107 PMCID: PMC6457939 DOI: 10.1126/sciadv.aar7633] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 02/14/2019] [Indexed: 06/05/2023]
Abstract
Intrinsically generated patterns of coupled neuronal activity are associated with the dynamics of specific brain states. Sensory inputs are extrinsic factors that can perturb these intrinsic coupling modes, creating a complex scenario in which forthcoming stimuli are processed. Studying this intrinsic-extrinsic interplay is necessary to better understand perceptual integration and selection. Here, we show that this interplay leads to a reconfiguration of functional cortical connectivity that acts as a mechanism to facilitate stimulus processing. Using audiovisual stimulation in anesthetized ferrets, we found that this reconfiguration of coupling modes is context specific, depending on long-term modulation by repetitive sensory inputs. These reconfigured coupling modes lead to changes in latencies and power of local field potential responses that support multisensory integration. Our study demonstrates that this interplay extends across multiple time scales and involves different types of intrinsic coupling. These results suggest a previously unknown large-scale mechanism that facilitates multisensory integration.
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Affiliation(s)
- Edgar E. Galindo-Leon
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Iain Stitt
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Florian Pieper
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Thomas Stieglitz
- Department of Microsystems Engineering, University of Freiburg, 79110 Freiburg, Germany
| | - Gerhard Engler
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Andreas K. Engel
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
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4
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Xu AG, Qian M, Tian F, Xu B, Friedman RM, Wang J, Song X, Sun Y, Chernov MM, Cayce JM, Jansen ED, Mahadevan-Jansen A, Zhang X, Chen G, Roe AW. Focal infrared neural stimulation with high-field functional MRI: A rapid way to map mesoscale brain connectomes. SCIENCE ADVANCES 2019; 5:eaau7046. [PMID: 31032400 PMCID: PMC6482007 DOI: 10.1126/sciadv.aau7046] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 03/14/2019] [Indexed: 05/13/2023]
Abstract
We have developed a way to map brain-wide networks using focal pulsed infrared neural stimulation in ultrahigh-field magnetic resonance imaging (MRI). The patterns of connections revealed are similar to those of connections previously mapped with anatomical tract tracing methods. These include connections between cortex and subcortical locations and long-range cortico-cortical connections. Studies of local cortical connections reveal columnar-sized laminar activation, consistent with feed-forward and feedback projection signatures. This method is broadly applicable and can be applied to multiple areas of the brain in different species and across different MRI platforms. Systematic point-by-point application of this method may lead to fundamental advances in our understanding of brain connectomes.
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Affiliation(s)
- Augix Guohua Xu
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310029, China
| | - Meizhen Qian
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310029, China
| | - Feiyan Tian
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310029, China
| | - Bin Xu
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310029, China
| | - Robert M. Friedman
- Department of Psychology, Vanderbilt University, Nashville, TN 37203, USA
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97239-3098, USA
| | - Jianbao Wang
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310029, China
| | - Xuemei Song
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310029, China
| | - Yi Sun
- MR Collaboration Northeast Asia, Siemens Healthcare, Shanghai 200001, China
| | - Mykyta M. Chernov
- Department of Psychology, Vanderbilt University, Nashville, TN 37203, USA
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97239-3098, USA
| | - Jonathan M. Cayce
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37203, USA
- Biophotonics Center, Vanderbilt University, Nashville, TN 37232, USA
| | - E. Duco Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37203, USA
- Biophotonics Center, Vanderbilt University, Nashville, TN 37232, USA
| | - Anita Mahadevan-Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37203, USA
- Biophotonics Center, Vanderbilt University, Nashville, TN 37232, USA
- Medical Center, Vanderbilt University, Nashville, TN 37232, USA
| | - Xiaotong Zhang
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310029, China
- Corresponding author. (A.W.R.); (G.C.); (X.Z.)
| | - Gang Chen
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310029, China
- Corresponding author. (A.W.R.); (G.C.); (X.Z.)
| | - Anna Wang Roe
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310029, China
- Department of Psychology, Vanderbilt University, Nashville, TN 37203, USA
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97239-3098, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37203, USA
- Corresponding author. (A.W.R.); (G.C.); (X.Z.)
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Distribution and Morphology of Cortical Terminals in the Cat Thalamus from the Anterior Ectosylvian Sulcus. Sci Rep 2019; 9:3075. [PMID: 30816175 PMCID: PMC6395774 DOI: 10.1038/s41598-019-39327-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 01/22/2019] [Indexed: 11/08/2022] Open
Abstract
Two main types of cortical terminals have been identified in the cat thalamus. Large (type II) have been proposed to drive the response properties of thalamic cells while smaller (type I) are believed to modulate those properties. Among the cat's visual cortical areas, the anterior ectosylvian visual area (AEV) is considered as one of the highest areas in the hierarchical organization of the visual system. Whereas the connections from the AEV to the thalamus have been recognized, their nature (type I or II) is presently not known. In this study, we assessed and compared the relative contribution of type I and type II inputs to thalamic nuclei originating from the AEV. The anterograde tracer BDA was injected in the AEV of five animals. Results show that (1) both type I and II terminals from AEV are present in the Lateral Posterior- Pulvinar complex, the lateral median suprageniculate complex and the medial and dorsal geniculate nuclei (2) type I terminals significantly outnumber the type II terminals in almost all nuclei studied. Our results indicate that neurons in the AEV are more likely to modulate response properties in the thalamus rather than to determine basic organization of receptive fields of thalamic cells.
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6
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Modified Origins of Cortical Projections to the Superior Colliculus in the Deaf: Dispersion of Auditory Efferents. J Neurosci 2018; 38:4048-4058. [PMID: 29610441 DOI: 10.1523/jneurosci.2858-17.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 03/13/2018] [Accepted: 03/16/2018] [Indexed: 11/21/2022] Open
Abstract
Following the loss of a sensory modality, such as deafness or blindness, crossmodal plasticity is commonly identified in regions of the cerebrum that normally process the deprived modality. It has been hypothesized that significant changes in the patterns of cortical afferent and efferent projections may underlie these functional crossmodal changes. However, studies of thalamocortical and corticocortical connections have refuted this hypothesis, instead revealing a profound resilience of cortical afferent projections following deafness and blindness. This report is the first study of cortical outputs following sensory deprivation, characterizing cortical projections to the superior colliculus in mature cats (N = 5, 3 female) with perinatal-onset deafness. The superior colliculus was exposed to a retrograde pathway tracer, and subsequently labeled cells throughout the cerebrum were identified and quantified. Overall, the percentage of cortical projections arising from auditory cortex was substantially increased, not decreased, in early-deaf cats compared with intact animals. Furthermore, the distribution of labeled cortical neurons was no longer localized to a particular cortical subregion of auditory cortex but dispersed across auditory cortical regions. Collectively, these results demonstrate that, although patterns of cortical afferents are stable following perinatal deafness, the patterns of cortical efferents to the superior colliculus are highly mutable.SIGNIFICANCE STATEMENT When a sense is lost, the remaining senses are functionally enhanced through compensatory crossmodal plasticity. In deafness, brain regions that normally process sound contribute to enhanced visual and somatosensory perception. We demonstrate that hearing loss alters connectivity between sensory cortex and the superior colliculus, a midbrain region that integrates sensory representations to guide orientation behavior. Contrasting expectation, the proportion of projections from auditory cortex increased in deaf animals compared with normal hearing, with a broad distribution across auditory fields. This is the first description of changes in cortical efferents following sensory loss and provides support for models predicting an inability to form a coherent, multisensory percept of the environment following periods of abnormal development.
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7
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Meredith MA, Wallace MT, Clemo HR. Do the Different Sensory Areas Within the Cat Anterior Ectosylvian Sulcal Cortex Collectively Represent a Network Multisensory Hub? Multisens Res 2018; 31:793-823. [PMID: 31157160 PMCID: PMC6542292 DOI: 10.1163/22134808-20181316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Current theory supports that the numerous functional areas of the cerebral cortex are organized and function as a network. Using connectional databases and computational approaches, the cerebral network has been demonstrated to exhibit a hierarchical structure composed of areas, clusters and, ultimately, hubs. Hubs are highly connected, higher-order regions that also facilitate communication between different sensory modalities. One region computationally identified network hub is the visual area of the Anterior Ectosylvian Sulcal cortex (AESc) of the cat. The Anterior Ectosylvian Visual area (AEV) is but one component of the AESc that also includes the auditory (Field of the Anterior Ectosylvian Sulcus - FAES) and somatosensory (Fourth somatosensory representation - SIV). To better understand the nature of cortical network hubs, the present report reviews the biological features of the AESc. Within the AESc, each area has extensive external cortical connections as well as among one another. Each of these core representations is separated by a transition zone characterized by bimodal neurons that share sensory properties of both adjoining core areas. Finally, core and transition zones are underlain by a continuous sheet of layer 5 neurons that project to common output structures. Altogether, these shared properties suggest that the collective AESc region represents a multiple sensory/multisensory cortical network hub. Ultimately, such an interconnected, composite structure adds complexity and biological detail to the understanding of cortical network hubs and their function in cortical processing.
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Affiliation(s)
- M. Alex Meredith
- Department of Anatomy and Neurobiology, Virginia
Commonwealth University School of Medicine, Richmond, VA 23298 USA
| | - Mark T. Wallace
- Vanderbilt Brain Institute, Vanderbilt University,
Nashville, TN 37240 USA
| | - H. Ruth Clemo
- Department of Anatomy and Neurobiology, Virginia
Commonwealth University School of Medicine, Richmond, VA 23298 USA
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8
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Xu J, Bi T, Keniston L, Zhang J, Zhou X, Yu L. Deactivation of Association Cortices Disrupted the Congruence of Visual and Auditory Receptive Fields in Superior Colliculus Neurons. Cereb Cortex 2017; 27:5568-5578. [PMID: 27797831 DOI: 10.1093/cercor/bhw324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Indexed: 11/13/2022] Open
Abstract
Physiological and behavioral studies in cats show that corticotectal inputs play a critical role in the information-processing capabilities of neurons in the deeper layers of the superior colliculus (SC). Among them, the sensory inputs from functionally related associational cortices are especially critical for SC multisensory integration. However, the underlying mechanism supporting this influence is still unclear. Here, results demonstrate that deactivation of relevant cortices can both dislocate SC visual and auditory spatial receptive fields (RFs) and decrease their overall size, resulting in reduced alignment. Further analysis demonstrated that this RF separation is significantly correlated with the decrement of neurons' multisensory enhancement and is most pronounced in low stimulus intensity conditions. In addition, cortical deactivation could influence the degree of stimulus effectiveness, thereby illustrating the means by which higher order cortices may modify the multisensory activity of SC.
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Affiliation(s)
- Jinghong Xu
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), School of Life Science, East China Normal University, Shanghai, 200062, China
| | - Tingting Bi
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), School of Life Science, East China Normal University, Shanghai, 200062, China
| | - Les Keniston
- Department of Physical Therapy, University of Maryland Eastern Shore, Princess Anne, MD 21853, USA
| | - Jiping Zhang
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), School of Life Science, East China Normal University, Shanghai, 200062, China
| | - Xiaoming Zhou
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), School of Life Science, East China Normal University, Shanghai, 200062, China.,Collaborative Innovation Center for Brain Science, East China Normal University, Shanghai 200062, China
| | - Liping Yu
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), School of Life Science, East China Normal University, Shanghai, 200062, China
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9
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Meredith MA, Clemo HR, Lomber SG. Is territorial expansion a mechanism for crossmodal plasticity? Eur J Neurosci 2017; 45:1165-1176. [PMID: 28370755 DOI: 10.1111/ejn.13564] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 02/07/2017] [Accepted: 03/13/2017] [Indexed: 01/08/2023]
Abstract
Crossmodal plasticity is the phenomenon whereby, following sensory damage or deprivation, the lost sensory function of a brain region is replaced by one of the remaining senses. One of several proposed mechanisms for this phenomenon involves the expansion of a more active brain region at the expense of another whose sensory inputs have been damaged or lost. This territorial expansion hypothesis was examined in the present study. The cat ectosylvian visual area (AEV) borders the auditory field of the anterior ectosylvian sulcus (FAES), which becomes visually reorganized in the early deaf. If this crossmodal effect in the FAES is due to the expansion of the adjoining AEV into the territory of the FAES after hearing loss, then the reorganized FAES should exhibit connectional features characteristic of the AEV. However, tracer injections revealed significantly different patterns of cortical connectivity between the AEV and the early deaf FAES, and substantial cytoarchitectonic and behavioral distinctions occur as well. Therefore, the crossmodal reorganization of the FAES cannot be mechanistically attributed to the expansion of the adjoining cortical territory of the AEV and an overwhelming number of recent studies now support unmasking of existing connections as the operative mechanism underlying crossmodal plasticity.
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Affiliation(s)
- M A Meredith
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, 1101 E. Marshall St., Sanger Hall Rm. 12-067, Richmond, VA, 23298, USA
| | - H R Clemo
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, 1101 E. Marshall St., Sanger Hall Rm. 12-067, Richmond, VA, 23298, USA
| | - S G Lomber
- Departments of Physiology and Pharmacology, & Psychology, University of Western Ontario, London, ON, Canada
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10
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Bauer J, Magg S, Wermter S. Attention modeled as information in learning multisensory integration. Neural Netw 2015; 65:44-52. [PMID: 25688997 DOI: 10.1016/j.neunet.2015.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 01/14/2015] [Accepted: 01/18/2015] [Indexed: 11/30/2022]
Abstract
Top-down cognitive processes affect the way bottom-up cross-sensory stimuli are integrated. In this paper, we therefore extend a successful previous neural network model of learning multisensory integration in the superior colliculus (SC) by top-down, attentional input and train it on different classes of cross-modal stimuli. The network not only learns to integrate cross-modal stimuli, but the model also reproduces neurons specializing in different combinations of modalities as well as behavioral and neurophysiological phenomena associated with spatial and feature-based attention. Importantly, we do not provide the model with any information about which input neurons are sensory and which are attentional. If the basic mechanisms of our model-self-organized learning of input statistics and divisive normalization-play a major role in the ontogenesis of the SC, then this work shows that these mechanisms suffice to explain a wide range of aspects both of bottom-up multisensory integration and the top-down influence on multisensory integration.
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Affiliation(s)
- Johannes Bauer
- University of Hamburg, Department of Informatics, Knowledge Technology, WTM, Vogt-Kölln-Straße 30, 22527 Hamburg, Germany.
| | - Sven Magg
- University of Hamburg, Department of Informatics, Knowledge Technology, WTM, Vogt-Kölln-Straße 30, 22527 Hamburg, Germany.
| | - Stefan Wermter
- University of Hamburg, Department of Informatics, Knowledge Technology, WTM, Vogt-Kölln-Straße 30, 22527 Hamburg, Germany.
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11
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Stein BE, Stanford TR, Rowland BA. Development of multisensory integration from the perspective of the individual neuron. Nat Rev Neurosci 2014; 15:520-35. [PMID: 25158358 DOI: 10.1038/nrn3742] [Citation(s) in RCA: 211] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The ability to use cues from multiple senses in concert is a fundamental aspect of brain function. It maximizes the brain’s use of the information available to it at any given moment and enhances the physiological salience of external events. Because each sense conveys a unique perspective of the external world, synthesizing information across senses affords computational benefits that cannot otherwise be achieved. Multisensory integration not only has substantial survival value but can also create unique experiences that emerge when signals from different sensory channels are bound together. However, neurons in a newborn’s brain are not capable of multisensory integration, and studies in the midbrain have shown that the development of this process is not predetermined. Rather, its emergence and maturation critically depend on cross-modal experiences that alter the underlying neural circuit in such a way that optimizes multisensory integrative capabilities for the environment in which the animal will function.
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12
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Barone P, Lacassagne L, Kral A. Reorganization of the connectivity of cortical field DZ in congenitally deaf cat. PLoS One 2013; 8:e60093. [PMID: 23593166 PMCID: PMC3625188 DOI: 10.1371/journal.pone.0060093] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 02/25/2013] [Indexed: 02/07/2023] Open
Abstract
Psychophysics and brain imaging studies in deaf patients have revealed a functional crossmodal reorganization that affects the remaining sensory modalities. Similarly, the congenital deaf cat (CDC) shows supra-normal visual skills that are supported by specific auditory fields (DZ-dorsal zone and P-posterior auditory cortex) but not the primary auditory cortex (A1). To assess the functional reorganization observed in deafness we analyzed the connectivity pattern of the auditory cortex by means of injections of anatomical tracers in DZ and A1 in both congenital deaf and normally hearing cats. A quantitative analysis of the distribution of the projecting neurons revealed the presence of non-auditory inputs to both A1 and DZ of the CDC which were not observed in the hearing cats. Firstly, some visual (areas 19/20) and somatosensory (SIV) areas were projecting toward DZ of the CDC but not in the control. Secondly, A1 of the deaf cat received a weak projection from the visual lateral posterior nuclei (LP). Most of these abnormal projections to A1 and DZ represent only a small fraction of the normal inputs to these areas. In addition, most of the afferents to DZ and A1 appeared normal in terms of areal specificity and strength of projection, with preserved but smeared nucleotopic gradient of A1 in CDCs. In conclusion, while the abnormal projections revealed in the CDC can participate in the crossmodal compensatory mechanisms, the observation of a limited reorganization of the connectivity pattern of the CDC implies that functional reorganization in congenital deafness is further supported also by normal cortico-cortical connectivity.
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Affiliation(s)
- Pascal Barone
- Université Toulouse, CerCo, Université Paul Sabatier, Toulouse, France.
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13
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Different properties of visual relearning after damage to early versus higher-level visual cortical areas. J Neurosci 2012; 32:5414-25. [PMID: 22514305 DOI: 10.1523/jneurosci.0316-12.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The manipulation of visual perceptual learning is emerging as an important rehabilitation tool following visual system damage. Specificity of visual learning for training stimulus and task attributes has been used in prior work to infer a differential contribution of higher-level versus lower-level visual cortical areas to this process. The present study used a controlled experimental paradigm in felines to examine whether relearning of motion discrimination and the specificity of such relearning are differently influenced by damage at lower versus higher levels of the visual cortical hierarchy. Cats with damage to either early visual areas 17,18, and 19, or to higher-level, motion-processing lateral suprasylvian (LS) cortex were trained to perform visual tasks with controlled fixation. Animals with either type of lesion could relearn to discriminate the direction of motion of both drifting gratings and random dot stimuli in their impaired visual field. However, two factors emerged as critical for allowing transfer of learning to untrained motion stimuli: (1) an intact LS cortex and (2) more complex visual stimuli. Thus, while the hierarchical level of visual cortex damage did not seem to limit the ability to relearn motion discriminations, generalizability of relearning with a damaged visual system appeared to be influenced by both the areas damaged and the nature of the stimulus used during training.
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14
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Meredith MA, Lomber SG. Somatosensory and visual crossmodal plasticity in the anterior auditory field of early-deaf cats. Hear Res 2011; 280:38-47. [PMID: 21354286 PMCID: PMC3134631 DOI: 10.1016/j.heares.2011.02.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 02/08/2011] [Accepted: 02/10/2011] [Indexed: 01/28/2023]
Abstract
It is well known that the post-natal loss of sensory input in one modality can result in crossmodal reorganization of the deprived cortical areas, but deafness fails to induce crossmodal effects in cat primary auditory cortex (A1). Because the core auditory regions (A1, and anterior auditory field AAF) are arranged as separate, parallel processors, it cannot be assumed that early-deafness affects one in the same manner as the other. The present experiments were conducted to determine if crossmodal effects occur in the anterior auditory field (AAF). Using mature cats (n = 3), ototoxically deafened postnatally, single-unit recordings were made in the gyral and sulcal portions of the AAF. In contrast to the auditory responsivity found in the hearing controls, none of the neurons in early-deafened AAF were activated by auditory stimulation. Instead, the majority (78%) were activated by somatosensory cues, while fewer were driven by visual stimulation (44%; values include unisensory and bimodal neurons). Somatosensory responses could be activated from all locations on the body surface but most often occurred on the head, were often bilateral (e.g., occupied portions of both sides of the body), and were primarily excited by low-threshold hair receptors. Visual receptive fields were large, collectively represented the contralateral visual field, and exhibited conventional response properties such as movement direction and velocity preferences. These results indicate that, following post-natal deafness, both somatosensory and visual modalities participate in crossmodal reinnervation of the AAF, consistent with the growing literature that documents deafness-induced crossmodal plasticity outside A1.
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Affiliation(s)
- M Alex Meredith
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, School of Medicine, Richmond VA 23298-0709, USA.
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Clemo H, Keniston L, Meredith M. Structural Basis of Multisensory Processing. Front Neurosci 2011. [DOI: 10.1201/b11092-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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16
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Meredith M, Allman B, Keniston L, Clemo H. Are Bimodal Neurons the Same throughout the Brain? Front Neurosci 2011. [DOI: 10.1201/b11092-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Meredith M, Allman B, Keniston L, Clemo H. Are Bimodal Neurons the Same throughout the Brain? Front Neurosci 2011. [DOI: 10.1201/9781439812174-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Nagy AJ, Berényi A, Gulya K, Norita M, Benedek G, Nagy A. Direct projection from the visual associative cortex to the caudate nucleus in the feline brain. Neurosci Lett 2011; 503:52-7. [PMID: 21864648 DOI: 10.1016/j.neulet.2011.08.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 07/30/2011] [Accepted: 08/06/2011] [Indexed: 11/28/2022]
Abstract
Recent morphological and physiological studies support the assumption that the extrageniculate ascending tectofugal pathways send visual projection to the caudate nucleus (CN) in amniotes. In the present study we investigate the anatomical connection between the visual associative cortex along the anterior ectosylvian sulcus (AES) and the CN in adult domestic cats. An anterograde tracer - fluoro-dextrane-amine - was injected into the AES cortex. The distribution of labeled axons was not uniform in the CN. The majority of labeled axons and terminal like puncta was found only in a limited area in the dorsal part of the CN between the coordinates anterior 12-15. Furthermore, a retrograde tracer - choleratoxin-B - was injected into the dorsal part of the CN between anterior 12 and 13. We detected a large number of labeled neurons in the fundus and the dorsal part of the AES between the coordinates anterior 12-14. Based upon our recent results we argue that there is a direct monosynaptic connection between the visual associative cortex along the AES and the CN. Beside the posterior thalamus, the AES cortex should also participate in the transmission of the tectal visual information to the CN. This pathway is likely to convey complex information containing both sensory and motor components toward the basal ganglia, which supports their integrative function in visuomotor actions such as motion and novelty detection and saccade generation.
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Affiliation(s)
- Anett Júlia Nagy
- Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary
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Meredith MA, Kryklywy J, McMillan AJ, Malhotra S, Lum-Tai R, Lomber SG. Crossmodal reorganization in the early deaf switches sensory, but not behavioral roles of auditory cortex. Proc Natl Acad Sci U S A 2011; 108:8856-61. [PMID: 21555555 PMCID: PMC3102418 DOI: 10.1073/pnas.1018519108] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
It is well known that early disruption of sensory input from one modality can induce crossmodal reorganization of a deprived cortical area, resulting in compensatory abilities in the remaining senses. Compensatory effects, however, occur in selected cortical regions and it is not known whether such compensatory phenomena have any relation to the original function of the reorganized area. In the cortex of hearing cats, the auditory field of the anterior ectosylvian sulcus (FAES) is largely responsive to acoustic stimulation and its unilateral deactivation results in profound contralateral acoustic orienting deficits. Given these functional and behavioral roles, the FAES was studied in early-deafened cats to examine its crossmodal sensory properties as well as to assess the behavioral role of that reorganization. Recordings in the FAES of early-deafened adults revealed robust responses to visual stimulation as well as receptive fields that collectively represented the contralateral visual field. A second group of early-deafened cats was trained to localize visual targets in a perimetry array. In these animals, cooling loops were surgically placed on the FAES to reversibly deactivate the region, which resulted in substantial contralateral visual orienting deficits. These results demonstrate that crossmodal plasticity can substitute one sensory modality for another while maintaining the functional repertoire of the reorganized region.
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Affiliation(s)
- M Alex Meredith
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA.
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Bajo VM, Nodal FR, Bizley JK, King AJ. The non-lemniscal auditory cortex in ferrets: convergence of corticotectal inputs in the superior colliculus. Front Neuroanat 2010; 4:18. [PMID: 20640247 PMCID: PMC2904598 DOI: 10.3389/fnana.2010.00018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 04/23/2010] [Indexed: 11/19/2022] Open
Abstract
Descending cortical inputs to the superior colliculus (SC) contribute to the unisensory response properties of the neurons found there and are critical for multisensory integration. However, little is known about the relative contribution of different auditory cortical areas to this projection or the distribution of their terminals in the SC. We characterized this projection in the ferret by injecting tracers in the SC and auditory cortex. Large pyramidal neurons were labeled in layer V of different parts of the ectosylvian gyrus after tracer injections in the SC. Those cells were most numerous in the anterior ectosylvian gyrus (AEG), and particularly in the anterior ventral field, which receives both auditory and visual inputs. Labeling was also found in the posterior ectosylvian gyrus (PEG), predominantly in the tonotopically organized posterior suprasylvian field. Profuse anterograde labeling was present in the SC following tracer injections at the site of acoustically responsive neurons in the AEG or PEG, with terminal fields being both more prominent and clustered for inputs originating from the AEG. Terminals from both cortical areas were located throughout the intermediate and deep layers, but were most concentrated in the posterior half of the SC, where peripheral stimulus locations are represented. No inputs were identified from primary auditory cortical areas, although some labeling was found in the surrounding sulci. Our findings suggest that higher level auditory cortical areas, including those involved in multisensory processing, may modulate SC function via their projections into its deeper layers.
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Affiliation(s)
- Victoria M Bajo
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, UK
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Mellott JG, Van der Gucht E, Lee CC, Carrasco A, Winer JA, Lomber SG. Areas of cat auditory cortex as defined by neurofilament proteins expressing SMI-32. Hear Res 2010; 267:119-36. [PMID: 20430082 DOI: 10.1016/j.heares.2010.04.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 02/22/2010] [Accepted: 04/05/2010] [Indexed: 10/19/2022]
Abstract
The monoclonal antibody SMI-32 was used to characterize and distinguish individual areas of cat auditory cortex. SMI-32 labels non-phosphorylated epitopes on the high- and medium-molecular weight subunits of neurofilament proteins in cortical pyramidal cells and dendritic trees with the most robust immunoreactivity in layers III and V. Auditory areas with unique patterns of immunoreactivity included: primary auditory cortex (AI), second auditory cortex (AII), dorsal zone (DZ), posterior auditory field (PAF), ventral posterior auditory field (VPAF), ventral auditory field (VAF), temporal cortex (T), insular cortex (IN), anterior auditory field (AAF), and the auditory field of the anterior ectosylvian sulcus (fAES). Unique patterns of labeling intensity, soma shape, soma size, layers of immunoreactivity, laminar distribution of dendritic arbors, and labeled cell density were identified. Features that were consistent in all areas included: layers I and IV neurons are immunonegative; nearly all immunoreactive cells are pyramidal; and immunoreactive neurons are always present in layer V. To quantify the results, the numbers of labeled cells and dendrites, as well as cell diameter, were collected and used as tools for identifying and differentiating areas. Quantification of the labeling patterns also established profiles for ten auditory areas/layers and their degree of immunoreactivity. Areal borders delineated by SMI-32 were highly correlated with tonotopically-defined areal boundaries. Overall, SMI-32 immunoreactivity can delineate ten areas of cat auditory cortex and demarcate topographic borders. The ability to distinguish auditory areas with SMI-32 is valuable for the identification of auditory cerebral areas in electrophysiological, anatomical, and/or behavioral investigations.
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Affiliation(s)
- Jeffrey G Mellott
- Centre for Brain and Mind, Department of Physiology & Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, Medical Sciences Building, Room 216, 1151 Richmond Street North, London, Ontario N6A 5C1, Canada
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Rokszin A, Márkus Z, Braunitzer G, Berényi A, Benedek G, Nagy A. Visual pathways serving motion detection in the mammalian brain. SENSORS (BASEL, SWITZERLAND) 2010; 10:3218-42. [PMID: 22319295 PMCID: PMC3274219 DOI: 10.3390/s100403218] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 03/16/2010] [Accepted: 03/17/2010] [Indexed: 11/16/2022]
Abstract
Motion perception is the process through which one gathers information on the dynamic visual world, in terms of the speed and movement direction of its elements. Motion sensation takes place from the retinal light sensitive elements, through the visual thalamus, the primary and higher visual cortices. In the present review we aim to focus on the extrageniculo-extrastriate cortical and subcortical visual structures of the feline and macaque brain and discuss their functional role in visual motion perception. Special attention is paid to the ascending tectofugal system that may serve for detection of the visual environment during self-motion.
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Affiliation(s)
- Alice Rokszin
- Department of Physiology, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; E-Mails: (A.R.); (Z.M.); (G.B.); (A.B.); (G.B.)
| | - Zita Márkus
- Department of Physiology, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; E-Mails: (A.R.); (Z.M.); (G.B.); (A.B.); (G.B.)
| | - Gábor Braunitzer
- Department of Physiology, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; E-Mails: (A.R.); (Z.M.); (G.B.); (A.B.); (G.B.)
| | - Antal Berényi
- Department of Physiology, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; E-Mails: (A.R.); (Z.M.); (G.B.); (A.B.); (G.B.)
| | - György Benedek
- Department of Physiology, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; E-Mails: (A.R.); (Z.M.); (G.B.); (A.B.); (G.B.)
| | - Attila Nagy
- Department of Physiology, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; E-Mails: (A.R.); (Z.M.); (G.B.); (A.B.); (G.B.)
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Hoshino K, Horie M, Nagy A, Berényi A, Benedek G, Norita M. Direct synaptic connections between superior colliculus afferents and thalamo-insular projection neurons in the feline suprageniculate nucleus: A double-labeling study with WGA-HRP and kainic acid. Neurosci Res 2010; 66:7-13. [DOI: 10.1016/j.neures.2009.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 09/08/2009] [Accepted: 09/09/2009] [Indexed: 11/29/2022]
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Krueger J, Royal DW, Fister MC, Wallace MT. Spatial receptive field organization of multisensory neurons and its impact on multisensory interactions. Hear Res 2009; 258:47-54. [PMID: 19698773 DOI: 10.1016/j.heares.2009.08.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 08/05/2009] [Accepted: 08/12/2009] [Indexed: 11/18/2022]
Abstract
Previous work has established that the spatial receptive fields (SRFs) of multisensory neurons in the cerebral cortex are strikingly heterogeneous, and that SRF architecture plays an important deterministic role in sensory responsiveness and multisensory integrative capacities. The initial part of this contribution serves to review these findings detailing the key features of SRF organization in cortical multisensory populations by highlighting work from the cat anterior ectosylvian sulcus (AES). In addition, we have recently conducted parallel studies designed to examine SRF architecture in the classic model for multisensory studies, the cat superior colliculus (SC), and we present some of the preliminary observations from the SC here. An examination of individual SC neurons revealed marked similarities between their unisensory (i.e., visual and auditory) SRFs, as well as between these unisensory SRFs and the multisensory SRF. Despite these similarities within individual neurons, different SC neurons had SRFs that ranged from a single area of greatest activation (hot spot) to multiple and spatially discrete hot spots. Similar to cortical multisensory neurons, the interactive profile of SC neurons was correlated strongly to SRF architecture, closely following the principle of inverse effectiveness. Thus, large and often superadditive multisensory response enhancements were typically seen at SRF locations where visual and auditory stimuli were weakly effective. Conversely, subadditive interactions were seen at SRF locations where stimuli were highly effective. Despite the unique functions characteristic of cortical and subcortical multisensory circuits, our results suggest a strong mechanistic interrelationship between SRF microarchitecture and integrative capacity.
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Affiliation(s)
- Juliane Krueger
- Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN 37232, USA.
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Multisensory integration in the superior colliculus requires synergy among corticocollicular inputs. J Neurosci 2009; 29:6580-92. [PMID: 19458228 DOI: 10.1523/jneurosci.0525-09.2009] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Influences from the visual (AEV), auditory (FAES), and somatosensory (SIV) divisions of the cat anterior ectosylvian sulcus (AES) play a critical role in rendering superior colliculus (SC) neurons capable of multisensory integration. However, it is not known whether this is accomplished via their independent sensory-specific action or via some cross-modal cooperative action that emerges as a consequence of their convergence on SC neurons. Using visual-auditory SC neurons as a model, we examined how selective and combined deactivation of FAES and AEV affected SC multisensory (visual-auditory) and unisensory (visual-visual) integration capabilities. As noted earlier, multisensory integration yielded SC responses that were significantly greater than those evoked by the most effective individual component stimulus. This multisensory "response enhancement" was more evident when the component stimuli were weakly effective. Conversely, unisensory integration was dominated by the lack of response enhancement. During cryogenic deactivation of FAES and/or AEV, the unisensory responses of SC neurons were only modestly affected; however, their multisensory response enhancement showed a significant downward shift and was eliminated. The shift was similar in magnitude for deactivation of either AES subregion and, in general, only marginally greater when both were deactivated simultaneously. These data reveal that SC multisensory integration is dependent on the cooperative action of distinct subsets of unisensory corticofugal afferents, afferents whose sensory combination matches the multisensory profile of their midbrain target neurons, and whose functional synergy is specific to rendering SC neurons capable of synthesizing information from those particular senses.
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Hoshino K, Eördegh G, Nagy A, Benedek G, Norita M. Overlap of nigrothalamic terminals and thalamostriatal neurons in the feline lateralis medialis-suprageniculate nucleus. ACTA PHYSIOLOGICA HUNGARICA 2009; 96:203-11. [PMID: 19457764 DOI: 10.1556/aphysiol.96.2009.2.5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The lateralis medialis-suprageniculate nucleus (LM-Sg) of the feline posterior thalamus is a relay nucleus with a clear visuomotor function. In this study, we examined the distribution of axon terminals of the nigral afferent to the LM-Sg following injection of an anterograde tracer, biocytin, into the substantia nigra pars reticulata, and the distribution of the thalamostriatal projection neurons in the LM-Sg following the injection of wheat germ agglutinin conjugated with horseradish peroxidase (WGA-HRP) as a retrograde tracer into the caudate nucleus. The biocytin-labeled terminal-like puncta were located in the ventromedial portion of this nucleus in such a way that most of the labeled elements took the form of swellings having boutons in places, while a minority appeared in clusters of 3-5 large terminal-like puncta. The retrograde WGA-HRP-labeled neurons were also found in the ventromedial part of the LM-Sg, and the distributions of labeled nigrothalamic axon terminals and labeled thalamostriatal projection neurons therefore overlapped in this region. The present results indicate that the nigral afferent may make synaptic contacts directly with the thalamostriatal projection neurons within the LM-Sg.
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Affiliation(s)
- Kaeko Hoshino
- Niigata University Graduate School of Medical and Dental Sciences, Department of Sensory and Integrative Medicine, Division of Neurobiology and Anatomy, Asahimachi, Chuo-ku Niigata 951-8510 Japan.
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Fuentes-Santamaria V, Alvarado JC, McHaffie JG, Stein BE. Axon morphologies and convergence patterns of projections from different sensory-specific cortices of the anterior ectosylvian sulcus onto multisensory neurons in the cat superior colliculus. Cereb Cortex 2009; 19:2902-15. [PMID: 19359347 DOI: 10.1093/cercor/bhp060] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Corticofugal projections to the thalamus reveal 2 axonal morphologies, each associated with specific physiological attributes. These determine the functional characteristics of thalamic neurons. It is not clear, however, whether such features characterize the corticofugal projections that mediate multisensory integration in superior colliculus (SC) neurons. The cortico-collicular projections from cat anterior ectosylvian sulcus (AES) are derived from its visual, auditory, and somatosensory representations and are critical for multisensory integration. Following tracer injections into each subdivision, 2 types of cortico-collicular axons were observed. Most were categorized as type I and consisted of small-caliber axons traversing long distances without branching, bearing mainly small boutons. The less frequent type II had thicker axons, more complex branching patterns, larger boutons, and more complex terminal boutons. Following combinatorial injections of 2 different fluorescent tracers into defined AES subdivisions, fibers from each were seen converging onto individual SC neurons and indicate that such convergence, like that in the corticothalamic system, is mediated by 2 distinct morphological types of axon terminals. Nevertheless, and despite the conservation of axonal morphologies across different subcortical systems, it is not yet clear if the concomitant physiological attributes described in the thalamus are directly applicable to multisensory integration.
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Affiliation(s)
- Veronica Fuentes-Santamaria
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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Royal DW, Carriere BN, Wallace MT. Spatiotemporal architecture of cortical receptive fields and its impact on multisensory interactions. Exp Brain Res 2009; 198:127-36. [PMID: 19308362 DOI: 10.1007/s00221-009-1772-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Accepted: 03/05/2009] [Indexed: 11/29/2022]
Abstract
Recent electrophysiology studies have suggested that neuronal responses to multisensory stimuli may possess a unique temporal signature. To evaluate this temporal dynamism, unisensory and multisensory spatiotemporal receptive fields (STRFs) of neurons in the cortex of the cat anterior ectosylvian sulcus were constructed. Analyses revealed that the multisensory STRFs of these neurons differed significantly from the component unisensory STRFs and their linear summation. Most notably, multisensory responses were found to have higher peak firing rates, shorter response latencies, and longer discharge durations. More importantly, multisensory STRFs were characterized by two distinct temporal phases of enhanced integration that reflected the shorter response latencies and longer discharge durations. These findings further our understanding of the temporal architecture of cortical multisensory processing, and thus provide important insights into the possible functional role(s) played by multisensory cortex in spatially directed perceptual processes.
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Affiliation(s)
- David W Royal
- Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN 37232, USA.
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Fuentes-Santamaria V, Alvarado JC, Stein BE, McHaffie JG. Cortex contacts both output neurons and nitrergic interneurons in the superior colliculus: direct and indirect routes for multisensory integration. Cereb Cortex 2007; 18:1640-52. [PMID: 18003596 DOI: 10.1093/cercor/bhm192] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The ability of cat superior colliculus (SC) neurons to integrate information from different senses is thought to depend on direct projections from regions along the anterior ectosylvian sulcus (AES). However, electrical stimulation of AES also activates SC output neurons polysynaptically. In the present study, we found that nitric oxide (NO)-containing (nitrergic) interneurons are a target of AES projections, forming a component of this cortico-SC circuitry. The dendritic and axonal processes of these corticorecipient nitrergic interneurons apposed the soma and dendrites of presumptive SC output neurons. Often, an individual cortical fiber targeted both an output neuron and a neighboring nitrergic interneuron that, in turn, contacted the output neuron. Many (46%) nitrergic neurons also colocalized with gamma-aminobutyric acid (GABA), suggesting that a substantial subset have the potential for inhibiting output neurons. These observations suggest that nitrergic interneurons are positioned to convey cortical influences onto SC output neurons disynaptically via nitrergic mechanisms as well as conventional neurotransmitter systems utilizing GABA and other, possibly excitatory, neurotransmitters. In addition, because NO also acts as a retrograde messenger, cortically mediated NO release from the postsynaptic elements of nitrergic interneurons could influence presynaptic cortico-SC terminals that directly contact output neurons.
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Affiliation(s)
- Veronica Fuentes-Santamaria
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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Carriere BN, Royal DW, Perrault TJ, Morrison SP, Vaughan JW, Stein BE, Wallace MT. Visual deprivation alters the development of cortical multisensory integration. J Neurophysiol 2007; 98:2858-67. [PMID: 17728386 DOI: 10.1152/jn.00587.2007] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It has recently been demonstrated that the maturation of normal multisensory circuits in the cortex of the cat takes place over an extended period of postnatal life. Such a finding suggests that the sensory experiences received during this time may play an important role in this developmental process. To test the necessity of sensory experience for normal cortical multisensory development, cats were raised in the absence of visual experience from birth until adulthood, effectively precluding all visual and visual-nonvisual multisensory experiences. As adults, semichronic single-unit recording experiments targeting the anterior ectosylvian sulcus (AES), a well-defined multisensory cortical area in the cat, were initiated and continued at weekly intervals in anesthetized animals. Despite having very little impact on the overall sensory representations in AES, dark-rearing had a substantial impact on the integrative capabilities of multisensory AES neurons. A significant increase was seen in the proportion of multisensory neurons that were modulated by, rather than driven by, a second sensory modality. More important, perhaps, there was a dramatic shift in the percentage of these modulated neurons in which the pairing of weakly effective and spatially and temporally coincident stimuli resulted in response depressions. In normally reared animals such combinations typically give rise to robust response enhancements. These results illustrate the important role sensory experience plays in shaping the development of mature multisensory cortical circuits and suggest that dark-rearing shifts the relative balance of excitation and inhibition in these circuits.
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Affiliation(s)
- Brian N Carriere
- Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, Tennessee, USA.
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Waleszczyk WJ, Nagy A, Wypych M, Berényi A, Paróczy Z, Eördegh G, Ghazaryan A, Benedek G. Spectral receptive field properties of neurons in the feline superior colliculus. Exp Brain Res 2007; 181:87-98. [PMID: 17431601 DOI: 10.1007/s00221-007-0908-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Accepted: 02/09/2007] [Indexed: 10/23/2022]
Abstract
The spatio-temporal frequency response profiles of 73 neurons located in the superficial, retino-recipient layers of the feline superior colliculus (SC) were investigated. The majority of the SC cells responded optimally to very low spatial frequencies with a mean of 0.1 cycles/degree (c/deg). The spatial resolution was also low with a mean of 0.31 c/deg. The spatial frequency tuning functions were either low-pass or band-pass with a mean spatial frequency bandwidth of 1.84 octaves. The cells responded optimally to a range of temporal frequencies between 0.74 cycles/s (c/s) and 26.41 c/s with a mean of 6.84 c/s. The majority (68%) of the SC cells showed band-pass temporal frequency tuning with a mean temporal frequency bandwidth of 2.4 octaves, while smaller proportions of the SC units displayed high-pass (19%), low-pass (8%) or broad-band (5%) temporal tuning. Most of the SC units exhibited simple spectral tuning with a single maximum in the spatio-temporal frequency domain, while some neurons were tuned for spatial or temporal frequencies or speed tuned. Further, we found cells excited by gratings moving at high temporal and low spatial frequencies and cells whose activity was suppressed by high velocity movement. The spatio-temporal filter properties of the SC neurons show close similarities to those of their retinal Y and W inputs as well as those of their inputs from the cortical visual motion detector areas, suggesting their common role in motion analysis and related behavioral actions.
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Affiliation(s)
- Wioletta J Waleszczyk
- Department of Neurophysiology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093, Warsaw, Poland
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Lomber SG, Malhotra S, Hall AJ. Functional specialization in non-primary auditory cortex of the cat: areal and laminar contributions to sound localization. Hear Res 2007; 229:31-45. [PMID: 17329050 DOI: 10.1016/j.heares.2007.01.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Revised: 11/29/2006] [Accepted: 01/03/2007] [Indexed: 10/23/2022]
Abstract
The purpose of this study is to: (1) examine the relative contributions of the 13 acoustically-responsive regions of the cerebral cortex to sound localization; (2) examine the laminar contributions to spatial localization behavior for each of the cortical areas identified to be critical for accurately determining the position of a sound source; and (3) synthesize the findings from sound localization studies and the underlying corticocortical and corticotectal connections to develop a processing system for sound localization information within and between the cerebral cortex and the superior colliculus. First, we examined performance on a sound localization task before, during, and after unilateral or bilateral reversible cooling deactivation of each region of acoustically-responsive cortex. Overall, unilateral deactivation of primary auditory cortex and the dorsal zone (AI/DZ), the posterior auditory field (PAF), or the auditory field of the anterior ectosylvian sulcus (AES) yielded profound sound localization deficits in the contralateral field. Bilateral deactivations of the same regions yielded bilateral sound localization deficits. Second, graded cooling of AI/DZ or PAF showed that deactivation of only the superficial layers was required to elicit sound localization deficits. However, graded cooling of AES revealed that cooling of the superficial layers alone does not cause significant sound localization deficits. Profound deficits were identified only when cooling extended through the full thickness of AES cortex. Therefore, we propose that the superficial layers of AI/DZ or PAF and the deeper layers of AES are necessary for determining the precise location of a sound source. Finally, when these results are combined with data on corticocortical and corticotectal projections, we propose that signals processed in the superficial layers of AI, DZ, or PAF feed forward to the auditory field of AES. In turn, neurons in the deeper layers of AES project to the intermediate and deeper layers of the superior colliculus. Therefore, we propose that sound localization signals processed in primary and non-primary auditory cortex are transmitted to the superior colliculus by means of the auditory field of the AES.
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Affiliation(s)
- Stephen G Lomber
- Centre for Brain and Mind, Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada.
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Wallace MT, Carriere BN, Perrault TJ, Vaughan JW, Stein BE. The development of cortical multisensory integration. J Neurosci 2006; 26:11844-9. [PMID: 17108157 PMCID: PMC6674880 DOI: 10.1523/jneurosci.3295-06.2006] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2006] [Revised: 09/07/2006] [Accepted: 10/10/2006] [Indexed: 11/21/2022] Open
Abstract
Although there are many perceptual theories that posit particular maturational profiles in higher-order (i.e., cortical) multisensory regions, our knowledge of multisensory development is primarily derived from studies of a midbrain structure, the superior colliculus. Therefore, the present study examined the maturation of multisensory processes in an area of cat association cortex [i.e., the anterior ectosylvian sulcus (AES)] and found that these processes are rudimentary during early postnatal life and develop only gradually thereafter. The AES comprises separate visual, auditory, and somatosensory regions, along with many multisensory neurons at the intervening borders between them. During early life, sensory responsiveness in AES appears in an orderly sequence. Somatosensory neurons are present at 4 weeks of age and are followed by auditory and multisensory (somatosensory-auditory) neurons. Visual neurons and visually responsive multisensory neurons are first seen at 12 weeks of age. The earliest multisensory neurons are strikingly immature, lacking the ability to synthesize the cross-modal information they receive. With postnatal development, multisensory integrative capacity matures. The delayed maturation of multisensory neurons and multisensory integration in AES suggests that the higher-order processes dependent on these circuits appear comparatively late in ontogeny.
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Affiliation(s)
- Mark T Wallace
- Department of Hearing and Speech Sciences, Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, Tennessee 37232, USA.
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Malhotra S, Lomber SG. Sound localization during homotopic and heterotopic bilateral cooling deactivation of primary and nonprimary auditory cortical areas in the cat. J Neurophysiol 2006; 97:26-43. [PMID: 17035367 DOI: 10.1152/jn.00720.2006] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although the contributions of primary auditory cortex (AI) to sound localization have been extensively studied in a large number of mammals, little is known of the contributions of nonprimary auditory cortex to sound localization. Therefore the purpose of this study was to examine the contributions of both primary and all the recognized regions of acoustically responsive nonprimary auditory cortex to sound localization during both bilateral and unilateral reversible deactivation. The cats learned to make an orienting response (head movement and approach) to a 100-ms broad-band noise stimulus emitted from a central speaker or one of 12 peripheral sites (located in front of the animal, from left 90 degrees to right 90 degrees , at 15 degrees intervals) along the horizontal plane after attending to a central visual stimulus. Twenty-one cats had one or two bilateral pairs of cryoloops chronically implanted over one of ten regions of auditory cortex. We examined AI [which included the dorsal zone (DZ)], the three other tonotopic fields [anterior auditory field (AAF), posterior auditory field (PAF), ventral posterior auditory field (VPAF)], as well as six nontonotopic regions that included second auditory cortex (AII), the anterior ectosylvian sulcus (AES), the insular (IN) region, the temporal (T) region [which included the ventral auditory field (VAF)], the dorsal posterior ectosylvian (dPE) gyrus [which included the intermediate posterior ectosylvian (iPE) gyrus], and the ventral posterior ectosylvian (vPE) gyrus. In accord with earlier studies, unilateral deactivation of AI/DZ caused sound localization deficits in the contralateral field. Bilateral deactivation of AI/DZ resulted in bilateral sound localization deficits throughout the 180 degrees field examined. Of the three other tonotopically organized fields, only deactivation of PAF resulted in sound localization deficits. These deficits were virtually identical to the unilateral and bilateral deactivation results obtained during AI/DZ deactivation. Of the six nontonotopic regions examined, only deactivation of AES resulted in sound localization deficits in the contralateral hemifield during unilateral deactivation. Although bilateral deactivation of AI/DZ, PAF, or AES resulted in profound sound localization deficits throughout the entire field, the cats were generally able to orient toward the hemifield that contained the acoustic stimulus, but not accurately identify the location of the stimulus. Neither unilateral nor bilateral deactivation of areas AAF, VPAF, AII, IN, T, dPE, nor vPE had any effect on the sound localization task. Finally, bilateral heterotopic deactivations of AI/DZ, PAF, or AES yielded deficits that were as profound as bilateral homotopic cooling of any of these sites. The fact that deactivation of any one region (AI/DZ, PAF, or AES) was sufficient to produce a deficit indicated that normal function of all three regions was necessary for normal sound localization. Neither unilateral nor bilateral deactivation of AI/DZ, PAF, or AES affected the accurate localization of a visual target. The results suggest that hemispheric deactivations contribute independently to sound localization deficits.
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Affiliation(s)
- Shveta Malhotra
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
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Meredith MA, Keniston LR, Dehner LR, Clemo HR. Crossmodal projections from somatosensory area SIV to the auditory field of the anterior ectosylvian sulcus (FAES) in Cat: further evidence for subthreshold forms of multisensory processing. Exp Brain Res 2006; 172:472-84. [PMID: 16501962 DOI: 10.1007/s00221-006-0356-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2005] [Accepted: 12/30/2005] [Indexed: 10/25/2022]
Abstract
To date, evaluation of the neuronal basis for multisensory processing has focused on the convergence pattern that provides excitation from more than one sensory modality. However, a recent study (Dehner et al. in Cereb Cortex 14:387-401, 2004) has demonstrated excitatory-inhibitory multisensory effects that do not follow this conventional pattern and the present investigation documented a similar example of subthreshold cross-modal effects. Neuroanatomical tracers revealed that pyramidal neurons of the somatosensory area SIV project to the auditory field of the anterior ectosylvian sulcus (FAES), but subsequent electrophysiological tests showed that stimulation of SIV failed to elicit the expected orthodromic responses in FAES. Instead, combined auditory-SIV stimulation significantly suppressed FAES responses to auditory cues in approximately 25% of the neurons tested, and facilitated responses in another 5%. These modulatory responses in auditory FAES were similar in kind to those observed in somatosensory SIV and, as such, comprise further evidence for subthreshold forms of multisensory processing in cortex. Consequently, it seems likely that subthreshold cross-modal effects may impact other apparently 'unimodal' areas of the brain.
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Affiliation(s)
- M Alex Meredith
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA.
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Eördegh G, Nagy A, Berényi A, Benedek G. Processing of spatial visual information along the pathway between the suprageniculate nucleus and the anterior ectosylvian cortex. Brain Res Bull 2006; 67:281-9. [PMID: 16182935 DOI: 10.1016/j.brainresbull.2005.06.036] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Revised: 05/05/2005] [Accepted: 06/21/2005] [Indexed: 10/25/2022]
Abstract
This study describes the visual information coding ability of single neurons in the suprageniculate nucleus (Sg), and provides new data concerning the visual information flow in the suprageniculate/anterior ectosylvian pathways of the feline brain. The visual receptive fields of the Sg neurons have an internal structure rather similar to that described earlier in the anterior ectosylvian visual area (AEV). The majority of the Sg units can provide information via their discharge rate at the site of the visual stimulus within their large receptive fields. This suggests that they may serve as panoramic localizers. The sites of maximum responsivity of the Sg neurons are distributed over the whole investigated part of the visual field. There is no significant difference between the distributions of spatial location of maximum sensitivity of the AEV and the Sg neurons. The mean visual response latency of the Sg units was found to be significantly shorter than the mean latency of the AEV neurons, but there was no difference between the shortest latency values of the thalamic and the cortical single-units. This suggests that the visual information flows predominantly from the Sg to the AEV, though the cortico-thalamic route is also active. The Sg seems to represent a thalamic nucleus rather similar in function to both the first-order relays and the higher-order thalamic nuclei. These results, together with the fact that the superior colliculus provides the common ascending source of information to the suprageniculate/anterior ectosylvian pathway, suggest a unique function of the AEV and the Sg in sensorimotor integration.
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Affiliation(s)
- Gabriella Eördegh
- Department of Physiology, Faculty of Medicine, Albert Szent-Györgyi Medical and Pharmaceutical Centre, University of Szeged, Hungary
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Paróczy Z, Nagy A, Márkus Z, Waleszczyk WJ, Wypych M, Benedek G. Spatial and temporal visual properties of single neurons in the suprageniculate nucleus of the thalamus. Neuroscience 2006; 137:1397-404. [PMID: 16359815 DOI: 10.1016/j.neuroscience.2005.10.068] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 10/12/2005] [Accepted: 10/14/2005] [Indexed: 11/18/2022]
Abstract
The spatial and temporal visual sensitivity to drifting sinusoidal gratings was studied in 105 neurons of the suprageniculate nucleus of the feline thalamus. Extracellular single-unit recordings were performed in halothane-anesthetized, immobilized, artificially ventilated cats. Most suprageniculate nucleus cells were strongly sensitive to the direction of drifting gratings. The suprageniculate nucleus units had a clear preference for very low spatial frequencies with a mean of 0.05 cycle/deg. The spatial resolution was also very low with a mean of 0.16 cycle/deg. Most of the cells displayed low-pass spatial tuning characteristics, while the remainder of the units were band-pass tuned. The suprageniculate nucleus units were extremely narrowly tuned, to spatial frequencies with a mean spatial bandwidth of 1.07 octaves. A majority of the units responded optimally to high temporal frequencies, with a mean of 8.53 Hz. The temporal frequency tuning functions predominantly revealed a band-pass character, with a mean temporal bandwidth of 1.66 octaves. These results demonstrate that the neurons in the suprageniculate nucleus display particular spatial and temporal characteristics. The spatial and temporal tuning properties of the suprageniculate nucleus neurons are very similar to those of the superior colliculus and the anterior ectosylvian cortex, structures that provide the main visual afferentation toward the suprageniculate nucleus. This suggests their common function in motion perception, and especially in the recording of movements of the visual environment relative to the body, and the related behavioral action.
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Affiliation(s)
- Z Paróczy
- Department of Physiology, Faculty of Medicine, Albert Szent-Györgyi Medical and Pharmaceutical Centre, University of Szeged, Dóm tér 10., H-6720 Szeged, P.O. 427, Hungary
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Jiang W, Jiang H, Stein BE. Neonatal cortical ablation disrupts multisensory development in superior colliculus. J Neurophysiol 2005; 95:1380-96. [PMID: 16267111 PMCID: PMC1538963 DOI: 10.1152/jn.00880.2005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The ability of cat superior colliculus (SC) neurons to synthesize information from different senses depends on influences from two areas of the cortex: the anterior ectosylvian sulcus (AES) and the rostral lateral suprasylvian sulcus (rLS). Reversibly deactivating the inputs to the SC from either of these areas in normal adults severely compromises this ability and the SC-mediated behaviors that depend on it. In this study, we found that removal of these areas in neonatal animals precluded the normal development of multisensory SC processes. At maturity there was a substantial decrease in the incidence of multisensory neurons, and those multisensory neurons that did develop were highly abnormal. Their cross-modal receptive field register was severely compromised, as was their ability to integrate cross-modal stimuli. Apparently, despite the impressive plasticity of the neonatal brain, it cannot compensate for the early loss of these cortices. Surprisingly, however, neonatal removal of either AES or rLS had comparatively minor consequences on these properties. At maturity multisensory SC neurons were quite common: they developed the characteristic spatial register among their unisensory receptive fields and exhibited normal adult-like multisensory integration. These observations suggest that during early ontogeny, when the multisensory properties of SC neurons are being crafted, AES and rLS may have the ability to compensate for the loss of one another's cortico-collicular influences so that normal multisensory processes can develop in the SC.
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Affiliation(s)
- Wan Jiang
- Dept. of Neurobiology and Anatomy, Wake Forest Univ. School of Medicine, Winston-Salem, NC 27157-1010, USA
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40
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Manger PR, Engler G, Moll CKE, Engel AK. The anterior ectosylvian visual area of the ferret: a homologue for an enigmatic visual cortical area of the cat? Eur J Neurosci 2005; 22:706-14. [PMID: 16101752 DOI: 10.1111/j.1460-9568.2005.04246.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The present paper describes the results of electrophysiological mapping experiments focused on the anterior limb of the ectosylvian gyrus of the ferret (Mustela putorius). The aim was to determine if the ferret possessed a homologous cortical area to the anterior ectosylvian visual area (AEV) of the domestic cat, but not clearly delineated in any other mammal studied to date. We were able to gather data on the visuotopic organization of a region that we consider to be a homologue of cat AEV. The visual map in this area showed a distinct visuotopic organization and covered a large extent of the visual field. Within the ferret AEV there were clusters of bimodal recording sites (somato-visual and audio-visual) that were located adjacent to surrounding unimodal cortical areas (such as the second somatosensory area and primary and secondary auditory areas). The ferret AEV, like that of the cat, was topographically isolated from other visual cortical areas by intervening auditory and somatosensory areas. Taken together these features suggest that the region described here as AEV in the ferret is indeed a direct homologue of the previously described cat AEV.
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Affiliation(s)
- Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, Republic of South Africa.
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Stein BE. The development of a dialogue between cortex and midbrain to integrate multisensory information. Exp Brain Res 2005; 166:305-15. [PMID: 15988596 DOI: 10.1007/s00221-005-2372-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2004] [Accepted: 08/31/2004] [Indexed: 10/25/2022]
Abstract
The anterior ectosylvian (AES) and rostral lateral suprasylvian (rLS) sulci send critical signals to multisensory superior colliculus (SC) neurons that enable them to integrate information from different senses. When either of these areas is temporarily deactivated in adult animals, the ability of SC neurons to integrate multisensory information and, thereby, enhance their responses to cross-modal stimuli is temporarily compromised. As a consequence, the ability to use cross-modal stimuli to enhance SC-mediated behavioral performance is also compromised. In contrast, removal of either one of these areas during early life has little effect on the development of multisensory processes in the SC or on SC-mediated multisensory behaviors and these animals seem very similar to normal controls. These observations suggest that there is considerable plasticity in these cortico-collicular systems during early life, with each area able to compensate for the early loss of the other. However, when both AES and rLS are removed early in life, there appears to be no compensation. The SC neurons now deal with sensory stimuli, even those embedded in multisensory complexes, as if they were there alone, precluding any SC-mediated behavioral benefit to cross-modal stimuli.
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Affiliation(s)
- Barry E Stein
- Department of Neurobiology and Anatomy, School of Medicine, Wake Forest University, Winston-Salem, NC, 27157-1010, USA.
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Malhotra S, Hall AJ, Lomber SG. Cortical control of sound localization in the cat: unilateral cooling deactivation of 19 cerebral areas. J Neurophysiol 2004; 92:1625-43. [PMID: 15331649 DOI: 10.1152/jn.01205.2003] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We examined the ability of mature cats to accurately orient to, and approach, an acoustic stimulus during unilateral reversible cooling deactivation of primary auditory cortex (AI) or 1 of 18 other cerebral loci. After attending to a central visual stimulus, the cats learned to orient to a 100-ms broad-band, white-noise stimulus emitted from a central speaker or 1 of 12 peripheral sites (at 15 degrees intervals) positioned along the horizontal plane. Twenty-eight cats had two to six cryoloops implanted over multiple cerebral loci. Within auditory cortex, unilateral deactivation of AI, the posterior auditory field (PAF) or the anterior ectosylvian sulcus (AES) resulted in orienting deficits throughout the contralateral field. However, unilateral deactivation of the anterior auditory field, the second auditory cortex, or the ventroposterior auditory field resulted in no deficits on the orienting task. In multisensory cortex, unilateral deactivation of neither ventral or dorsal posterior ectosylvian cortices nor anterior or posterior area 7 resulted in any deficits. No deficits were identified during unilateral cooling of the five visual regions flanking auditory or multisensory cortices: posterior or anterior ii suprasylvian sulcus, posterior suprasylvian sulcus or dorsal or ventral posterior suprasylvian gyrus. In motor cortex, we identified contralateral orienting deficits during unilateral cooling of lateral area 5 (5L) or medial area 6 (6m) but not medial area 5 or lateral area 6. In a control visual-orienting task, areas 5L and 6m also yielded deficits to visual stimuli presented in the contralateral field. Thus the sound-localization deficits identified during unilateral deactivation of area 5L or 6m were not unimodal and are most likely the result of motor rather than perceptual impairments. Overall, three regions in auditory cortex (AI, PAF, AES) are critical for accurate sound localization as assessed by orienting.
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Affiliation(s)
- Shveta Malhotra
- Cerebral Systems Laboratory, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 2601 N. Floyd Road, GR41, Richardson, TX 75080, USA
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Benedek G, Eördegh G, Chadaide Z, Nagy A. Distributed population coding of multisensory spatial information in the associative cortex. Eur J Neurosci 2004; 20:525-9. [PMID: 15233761 DOI: 10.1111/j.1460-9568.2004.03496.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This study describes a possible mechanism of coding of multisensory information in the anterior ectosylvian visual area of the feline cortex. Extracellular microelectrode recordings on 168 cells were carried out in the anterior ectosylvian sulcal region of halothane-anaesthetized, immobilized, artificially ventilated cats. Ninety-five neurons were found to respond to visual stimuli, 96 responded to auditory stimuli and 45 were bimodal, reacting to both visual and auditory modalities. A large proportion of the neurons exhibited significantly different responses to stimuli appearing in different regions of their huge receptive field. These neurons have the ability to provide information via their discharge rate on the site of the stimulus within their receptive field. This suggests that they may serve as panoramic localizers. The ability of the bimodal neurons to localize bimodal stimulus sources is better than any of the unimodal localizing functions. Further, the sites of maximal responsivity of the visual, auditory and bimodal neurons are distributed over the whole extent of the large receptive fields. Thus, a large population of such panoramic visual, auditory and multisensory neurons could accurately code the locations of the sensory stimuli. Our findings support the notion that there is a distributed population code of multisensory information in the feline associative cortex.
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Affiliation(s)
- György Benedek
- Department of Physiology, Faculty of Medicine, Albert Szent-Györgyi Medical and Pharmaceutical Center, University of Szeged, Szeged, Hungary.
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Burnett LR, Stein BE, Chaponis D, Wallace MT. Superior colliculus lesions preferentially disrupt multisensory orientation. Neuroscience 2004; 124:535-47. [PMID: 14980725 DOI: 10.1016/j.neuroscience.2003.12.026] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/11/2003] [Indexed: 11/27/2022]
Abstract
The general involvement of the superior colliculus (SC) in orientation behavior and the striking parallels between the multisensory responses of SC neurons and overt orientation behaviors have led to assumptions that these neural and behavioral changes are directly linked. However, deactivation of two areas of cortex which also contain multisensory neurons, the anterior ectosylvian sulcus and rostral lateral suprasylvian sulcus have been shown to eliminate multisensory orientation behaviors, suggesting that this behavior may not involve the SC. To determine whether the SC contributes to this behavior, cats were tested in a multisensory (i.e. visual-auditory) orientation task before and after excitotoxic lesions of the SC. For unilateral SC lesions, modality-specific (i.e. visual or auditory) orientation behaviors had returned to pre-lesion levels after several weeks of recovery. In contrast, the enhancements and depressions in behavior normally seen with multisensory stimuli were severely compromised in the contralesional hemifield. No recovery of these behaviors was observed within the 6 month testing period. Immunohistochemical labeling of the SC revealed a preferential loss of parvalbumin-immunoreactive pyramidal neurons in the intermediate layers, a presumptive multisensory population that targets premotor areas of the brainstem and spinal cord. These results highlight the importance of the SC for multisensory behaviors, and suggest that the multisensory orientation deficits produced by cortical lesions are a result of the loss of cortical influences on multisensory SC neurons.
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Affiliation(s)
- L R Burnett
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
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45
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Ouellette BG, Minville K, Faubert J, Casanova C. Simple and complex visual motion response properties in the anterior medial bank of the lateral suprasylvian cortex. Neuroscience 2004; 123:231-45. [PMID: 14667458 DOI: 10.1016/j.neuroscience.2003.09.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The cortical regions surrounding the suprasylvian sulcus have previously been associated with motion processing. Of the six areas originally described by Palmer et al. [J Comp Neurol 177 (1978) 237], the posteromedial lateral suprasylvian (PMLS) cortex has attracted the greatest attention. Very little physiological information is available concerning other suprasylvian visual areas, and in particular, the anteromedial lateral suprasylvian cortex (AMLS). Based on its cortical and sub-cortical connectivity patterns, the AMLS cortex is a likely candidate for higher-order motion processing in cat visual cortex. We have investigated this possibility by studying the receptive field sensitivity of AMLS neurons to complex motion stimuli. Neurons in AMLS cortex exhibited large (mean of 354 degrees (2)) and complex-like receptive fields, and most of them (74%) were classified as direction selective on the basis of their responses to sinusoidal drifting gratings. Most importantly, direction selectivity was present for complex motion stimuli. A subset of the neurons sampled (eight of 38 cells; 21%) exhibited pattern-motion selectivity in response to moving plaid patterns. The capacity of AMLS neurons to signal higher-order stimuli was further supported by their selectivity to moving complex random-dot kinematograms. Finally, 45% of 20 neurons were direction selective to a radial optic flow stimulus. Overall, these results suggest that AMLS cortex is involved in higher-order analyses of visual motion. It is possible that the AMLS cortex represents a region between PMLS and the anterior ectosylvian visual area in a functional hierarchy of areas involved in motion integration.
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Affiliation(s)
- B G Ouellette
- Visual Neuroscience Laboratory, School of Optometry, Université de Montréal, CP 6128, Succ. Centre-ville, H3C 3J7, Montréal, Quebec, Canada
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Abstract
Multisensory depression is a fundamental index of multisensory integration in superior colliculus (SC) neurons. It is initiated when one sensory stimulus (auditory) located outside its modality-specific receptive field degrades or eliminates the neuron's responses to another sensory stimulus (visual) presented within its modality-specific receptive field. The present experiments demonstrate that the capacity of SC neurons to engage in multisensory depression is strongly dependent on influences from two cortical areas (the anterior ectosylvian and rostral lateral suprasylvian sulci). When these cortices are deactivated, the ability of SC neurons to synthesize visual-auditory inputs in this way is compromised; multisensory responses are disinhibited, becoming more vigorous and in some cases indistinguishable from responses to the visual stimulus alone. Although obtaining a more robust multisensory SC response when cortex is nonfunctional than when it is functional may seem paradoxical, these data may help explain previous observations that the loss of these cortical influences permits visual orientation behavior in the presence of a normally disruptive auditory stimulus.
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Affiliation(s)
- Wan Jiang
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
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Lomber SG, Payne BR. Cerebral areas mediating visual redirection of gaze: Cooling deactivation of 15 loci in the cat. J Comp Neurol 2004; 474:190-208. [PMID: 15164422 DOI: 10.1002/cne.20123] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In humans, damage to posterior parietal or frontal cortices often induces a severe impairment of the ability to redirect gaze to visual targets introduced into the contralateral field. In cats, unilateral deactivation of the posterior middle suprasylvian (pMS) sulcus in the posterior inferior parietal region also results in an equally severe impairment of visually mediated redirection of gaze. In this study we tested the contributions of the pMS cortex and 14 other cortical regions in mediating redirection of gaze to visual targets in 31 adult cats. Unilateral cooling deactivation of three adjacent regions along the posterior bend of the suprasylvian sulcus (posterior middle suprasylvian sulcus, posterior suprasylvian sulcus, and dorsal posterior ectosylvian gyrus at the confluence of the occipital, parietal, and temporal cortices) eliminated visually mediated redirection of gaze towards stimuli introduced into the contralateral hemifield, while the redirection of gaze toward the ipsilateral hemifield remained highly proficient. Additional cortical loci critical for visually mediated redirection of gaze include the anterior suprasylvian gyrus (lateral area 5, anterior inferior parietal cortex) and medial area 6 in the frontal region. Cooling deactivation of: 1) dorsal or 2) ventral posterior suprasylvian gyrus; 3) ventral posterior ectosylvian gyrus, 4) middle ectosylvian gyrus; 5) anterior or 6) posterior middle suprasylvian gyrus (area 7); 7) anterior middle suprasylvian sulcus; 8) medial area 5; 9) the visual portion of the anterior ectosylvian sulcus (AES); 10) or lateral area 6 were all without impact on the ability to redirect gaze. In summary, we identified a prominent field of cortex at the junction of the temporo-occipito-parietal cortices (regions pMS, dPE, PS), an anterior inferior parietal field (region 5L), and a frontal field (region 6M) that all contribute critically to the ability to redirect gaze to novel stimuli introduced into the visual field during fixation. These loci have several features in common with cortical fields in monkey and human brains that contribute to the visually guided redirection of the head and eyes.
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Affiliation(s)
- Stephen G Lomber
- Cerebral Systems Laboratory, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas 75080, USA.
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Hoshino K, Nagy A, Eördegh G, Benedek G, Norita M. Two types of neuron are found within the PPT, a small percentage of which project to both the LM-SG and SC. Exp Brain Res 2003; 155:421-6. [PMID: 14685806 DOI: 10.1007/s00221-003-1756-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2003] [Accepted: 10/14/2003] [Indexed: 12/21/2022]
Abstract
The pedunculopontine tegmental nucleus (PPT) projects its cholinergic fibers to both the lateralis medialis-suprageniculate nucleus (LM-Sg) and the superior colliculus (SC). For the purpose of verification of whether a single neuron in the PPT projects to both the LM-Sg and the SC, we injected dextran tetramethylrhodamine (DR) into the LM-Sg and dextran fluorescein (DF) into the ipsilateral SC. The DR-positive neurons labeled retrogradely in the PPT are small (mean: 27.13+/-1.22 micro m) and distributed in the rostral two-thirds of this nucleus, whereas the DF-positive neurons are small (mean: 27.54+/-1.16 micro m) or medium-sized (mean: 40.18+/-1.43 micro m), and are located throughout the PPT. Thirty-five percent of all labeled neurons are double-labeled and small. The present study indicates that the PPT projection to the LM-Sg in part involves neurons bifurcating to the SC.
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Affiliation(s)
- Kaeko Hoshino
- Division of Neurobiology and Anatomy, Department of Sensory and Integrative Medicine, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi, 951-8510 Niigata, Japan.
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Nagy A, Eördegh G, Benedek G. Extents of visual, auditory and bimodal receptive fields of single neurons in the feline visual associative cortex. ACTA ACUST UNITED AC 2003; 90:305-12. [PMID: 14708872 DOI: 10.1556/aphysiol.90.2003.4.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Extracellular microelectrode recordings were carried out on 150 neurons in the anterior ectosylvian sulcal region of halothane-anesthetized, immobilized, artificially ventilated cats. Fifty-nine neurons were visual, 60 were auditory and 31 were bimodal visual-auditory. As the extent of the receptive fields has never been exactly determined, we introduced a quasi-objective, computer-based, statistical method in order to estimate the receptive field sizes in the anterior half of the perimeter. The visual, auditory and bimodal cells had very large receptive fields, often with portions extending well into the ipsilateral hemifield. The mean extents of the visual and auditory receptive fields in the horizontal plane were 75.75 degrees (N=59, SD: +/- 28.620, range: 15-135 degrees), and 132.5 degrees (N=60, SD: +/- 46.72 degrees, range: 15-165 degrees) respectively. These data suggest that a single visual neuron can carry information from the whole visual field of the right eye and a single auditory unit can carry information of azimuths throughout the whole area of the horizontal plane studied. The mean extent of the bimodal receptive fields in the horizontal plane was 82.1 degrees (N=31, SD: +/- 24.24 degrees, range: 30-135 degrees). In 21 of the 31 bimodal cells we observed a facilitatory interaction between visual and auditory stimuli. The mean extent of the facilitatory interactions in these cells was 75.75 degrees (N=21, SD: +/- 24.56 degrees, range: 45-135 degrees).
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Affiliation(s)
- A Nagy
- Department of Physiology, Faculty of Medicine, Albert Szent-Györgyi Medical and Pharmaceutical Center, University of Szeged, Szeged, Hungary
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Payne BR, Rushmore RJ. Functional circuitry underlying natural and interventional cancellation of visual neglect. Exp Brain Res 2003; 154:127-53. [PMID: 14625667 DOI: 10.1007/s00221-003-1660-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2003] [Accepted: 07/28/2003] [Indexed: 10/26/2022]
Abstract
A large body of work demonstrates that lesions at multiple levels of the visual system induce neglect of stimuli in the contralesional visual field and that the neglect dissipates as neural compensations naturally emerge. Other studies show that interventional manipulations of cerebral cortex, superior colliculus or deep-lying midbrain structures have the power to attenuate, or cancel, the neglect and reinstate orienting into a neglected hemifield, and even into a profound cortically blind field. These results, and those derived from experiments on the behavioral impacts of unilateral and bilateral lesions, lead us to evaluate the repercussions of unilateral and bilateral deactivations, neural compensations and cancellations of attentional deficits in terms of an overarching hypothesis of neglect. The cancellations can be both striking and enduring, and they suggest that therapeutic strategies can be developed to reverse or ameliorate neglect in human patients. Animal studies show that in many instances of neglect adequate representations and the accompanying motor mechanisms are present despite the lesion and they simply need to be unmasked and brought into use to effect a remedy.
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Affiliation(s)
- Bertram R Payne
- Cerebral Dynamics, Department of Anatomy and Neurobiology, Boston University School of Medicine, W702, Boston, MA 02118, USA.
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