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Bharmauria V, Ramezanpour H, Ouelhazi A, Yahia Belkacemi Y, Flouty O, Molotchnikoff S. KETAMINE: Neural- and network-level changes. Neuroscience 2024; 559:188-198. [PMID: 39245312 DOI: 10.1016/j.neuroscience.2024.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 08/30/2024] [Accepted: 09/03/2024] [Indexed: 09/10/2024]
Abstract
Ketamine is a widely used clinical drug that has several functional and clinical applications, including its use as an anaesthetic, analgesic, anti-depressive, anti-suicidal agent, among others. Among its diverse behavioral effects, it influences short-term memory and induces psychedelic effects. At the neural level across different brain areas, it modulates neural firing rates, neural tuning, brain oscillations, and modularity, while promoting hypersynchrony and random connectivity between neurons. In our recent studies we demonstrated that topical application of ketamine on the visual cortex alters neural tuning and promotes vigorous connectivity between neurons by decreasing their firing variability. Here, we begin with a brief review of the literature, followed by results from our lab, where we synthesize a dendritic model of neural tuning and network changes following ketamine application. This model has potential implications for focused modulation of cortical networks in clinical settings. Finally, we identify current gaps in research and suggest directions for future studies, particularly emphasizing the need for more animal experiments to establish a platform for effective translation and synergistic therapies combining ketamine with other protocols such as training and adaptation. In summary, investigating ketamine's broader systemic effects, not only provides deeper insight into cognitive functions and consciousness but also paves the way to advance therapies for neuropsychiatric disorders.
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Affiliation(s)
- Vishal Bharmauria
- The Tampa Human Neurophysiology Lab & Department of Neurosurgery and Brain Repair, Morsani College of Medicine, 2 Tampa General Circle, University of South Florida, Tampa, FL 33606, USA; Centre for Vision Research and Centre for Integrative and Applied Neuroscience, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada.
| | - Hamidreza Ramezanpour
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
| | - Afef Ouelhazi
- Neurophysiology of the Visual system, Département de Sciences Biologiques, 1375 Av. Thérèse-Lavoie-Roux, Université de Montréal, Montréal, Québec H2V 0B3, Canada
| | - Yassine Yahia Belkacemi
- Neurophysiology of the Visual system, Département de Sciences Biologiques, 1375 Av. Thérèse-Lavoie-Roux, Université de Montréal, Montréal, Québec H2V 0B3, Canada
| | - Oliver Flouty
- The Tampa Human Neurophysiology Lab & Department of Neurosurgery and Brain Repair, Morsani College of Medicine, 2 Tampa General Circle, University of South Florida, Tampa, FL 33606, USA
| | - Stéphane Molotchnikoff
- Neurophysiology of the Visual system, Département de Sciences Biologiques, 1375 Av. Thérèse-Lavoie-Roux, Université de Montréal, Montréal, Québec H2V 0B3, Canada
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2
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Ouelhazi A, Bharmauria V, Molotchnikoff S. Adaptation-induced sharpening of orientation tuning curves in the mouse visual cortex. Neuroreport 2024; 35:291-298. [PMID: 38407865 DOI: 10.1097/wnr.0000000000002012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
OBJECTIVE Orientation selectivity is an emergent property of visual neurons across species with columnar and noncolumnar organization of the visual cortex. The emergence of orientation selectivity is more established in columnar cortical areas than in noncolumnar ones. Thus, how does orientation selectivity emerge in noncolumnar cortical areas after an adaptation protocol? Adaptation refers to the constant presentation of a nonoptimal stimulus (adapter) to a neuron under observation for a specific time. Previously, it had been shown that adaptation has varying effects on the tuning properties of neurons, such as orientation, spatial frequency, motion and so on. BASIC METHODS We recorded the mouse primary visual neurons (V1) at different orientations in the control (preadaptation) condition. This was followed by adapting neurons uninterruptedly for 12 min and then recording the same neurons postadaptation. An orientation selectivity index (OSI) for neurons was computed to compare them pre- and post-adaptation. MAIN RESULTS We show that 12-min adaptation increases the OSI of visual neurons ( n = 113), that is, sharpens their tuning. Moreover, the OSI postadaptation increases linearly as a function of the OSI preadaptation. CONCLUSION The increased OSI postadaptation may result from a specific dendritic neural mechanism, potentially facilitating the rapid learning of novel features.
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Affiliation(s)
- Afef Ouelhazi
- Département de Sciences Biologiques, Neurophysiology of the Visual system, Université de Montréal, Montréal, Québec
| | - Vishal Bharmauria
- Department of Psychology, Centre for Vision Research and Vision: Science to Applications (VISTA) Program, York University, Toronto, Ontario, Canada
| | - Stéphane Molotchnikoff
- Département de Sciences Biologiques, Neurophysiology of the Visual system, Université de Montréal, Montréal, Québec
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3
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Afef O, Rudy L, Stéphane M. Ketamine promotes adaption-induced orientation plasticity and vigorous network changes. Brain Res 2022; 1797:148111. [PMID: 36183793 DOI: 10.1016/j.brainres.2022.148111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/16/2022] [Accepted: 09/27/2022] [Indexed: 11/22/2022]
Abstract
Adult primary visual cortex features well demonstrated orientation selectivities. However, the imposition of a non-preferred stimulus for many minutes (adaptation) or the application of an antidepressant drug, such as ketamine, shifts the peak of the tuning curve, assigning a novel selectivity to a neuron. The effect of ketamine on V1 neural circuitry is not yet ascertained. The present investigation explores (in control, post-adaptation, and following local ketamine application) the modification of orientation selectivities and its outcome on functional relationships between neurons in mouse and cat. Two main results are revealed. Electrophysiological neuronal responses of monocular stimulation show that in cells exhibiting large orientation shifts after adaptation, ketamine facilitates the cell's recovery. Whereas in units displaying small shifts following adaptation, the drug increases the magnitude of orientation shifts. In addition, pair-wise cross correlogram analyses show modifications of functional relationships between neurons revealing updated micro-circuits as a consequence of ketamine application. We report in cat but not in mouse, that ketamine significantly increases the connectivity rate, their strengths, and an enhancement of neuronal synchrony.
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Affiliation(s)
- Ouelhazi Afef
- Université de Montréal, 1375 Avenue Thérèse-Lavoie-Roux, Montréal, Quebec H2V 0B3, Canada
| | - Lussiez Rudy
- Université de Montréal, 1375 Avenue Thérèse-Lavoie-Roux, Montréal, Quebec H2V 0B3, Canada
| | - Molotchnikoff Stéphane
- Université de Montréal, 1375 Avenue Thérèse-Lavoie-Roux, Montréal, Quebec H2V 0B3, Canada.
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4
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Thakkar KN, Ghermezi L, Silverstein SM, Slate R, Yao B, Achtyes ED, Brascamp JW. Stronger tilt aftereffects in persons with schizophrenia. JOURNAL OF ABNORMAL PSYCHOLOGY 2020; 130:186-197. [PMID: 33301337 DOI: 10.1037/abn0000653] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Individuals with schizophrenia may fail to appropriately use temporal context and apply past environmental regularities to the interpretation of incoming sensory information. Here we use the visual system as a test bed for investigating how prior experience shapes perception in individuals with schizophrenia. Specifically, we use visual aftereffects, illusory percepts resulting from prior exposure to visual input, to measure the influence of prior events on current processing. At a neural level, visual aftereffects arise due to attenuation in the responses of neurons that code the features of the prior stimulus (neuronal adaptation) and subsequent disinhibition of neurons signaling activity at the opposite end of the feature dimension. In the current study, we measured tilt aftereffects and negative afterimages, 2 types of aftereffects that reflect, respectively, adaptation of cortical orientation-coding neurons and adaptation of subcortical and retinal luminance-coding cells in persons with schizophrenia (PSZ; n = 36) and demographically matched healthy controls (HC; n = 22). We observed stronger tilt aftereffects in PSZ compared to HC, but no difference in negative afterimages. Stronger tilt aftereffects were related to more severe negative symptoms. These data suggest oversensitivity to recent regularities, in the form of stronger visual adaptation, at cortical, but not subcortical, levels in schizophrenia. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
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Baroncelli L, Lunghi C. Neuroplasticity of the visual cortex: in sickness and in health. Exp Neurol 2020; 335:113515. [PMID: 33132181 DOI: 10.1016/j.expneurol.2020.113515] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/14/2020] [Accepted: 10/21/2020] [Indexed: 01/18/2023]
Abstract
Brain plasticity refers to the ability of synaptic connections to adapt their function and structure in response to experience, including environmental changes, sensory deprivation and injuries. Plasticity is a distinctive, but not exclusive, property of the developing nervous system. This review introduces the concept of neuroplasticity and describes classic paradigms to illustrate cellular and molecular mechanisms underlying synapse modifiability. Then, we summarize a growing number of studies showing that the adult cerebral cortex retains a significant degree of plasticity highlighting how the identification of strategies to enhance the plastic potential of the adult brain could pave the way for the development of novel therapeutic approaches aimed at treating amblyopia and other neurodevelopmental disorders. Finally, we analyze how the visual system adjusts to neurodegenerative conditions leading to blindness and we discuss the crucial role of spared plasticity in the visual system for sight recovery.
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Affiliation(s)
- Laura Baroncelli
- Institute of Neuroscience, National Research Council (CNR), I-56124 Pisa, Italy; Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, I-56128 Pisa, Italy.
| | - Claudia Lunghi
- Laboratoire des systèmes perceptifs, Département d'études cognitives, École normale supérieure, PSL University, CNRS, 75005 Paris, France
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6
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Lussiez R, Chanauria N, Ouelhazi A, Molotchnikoff S. Effects of visual adaptation on orientation selectivity in cat secondary visual cortex. Eur J Neurosci 2020; 53:588-600. [PMID: 32916020 DOI: 10.1111/ejn.14967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 08/20/2020] [Accepted: 09/02/2020] [Indexed: 11/28/2022]
Abstract
Neuron orientation selectivity, otherwise known as the ability to respond optimally to a preferred orientation, has been extensively described in both primary and secondary visual cortices. This orientation selectivity, conserved through all cortical layers of a given column, is the primary basis for cortical organization and functional network emergence. While this selectivity is programmed and acquired since critical period, it has always been believed that in a mature brain, neurons' inherent functional features could not be changed. However, a plurality of studies has investigated the mature brain plasticity in V1, by changing the cells' orientation selectivity with visual adaptation. Using electrophysiological data in both V1 and V2 areas, this study aims to investigate the effects of adaptation on simultaneously recorded cells in both areas. Visual adaptation had an enhanced effect on V2 units, as they exhibited greater tuning curve shifts and a more pronounced decrease of their OSI. Not only did adaptation have a different effect on V2 neurons, it also elicited a different response depending on the neuron's cortical depth. Indeed, in V2, cells in layers II-III were more affected by visual adaptation, while infragranular layer V units exhibited little to no effect at all.
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7
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Hansen HD, Lindberg U, Ozenne B, Fisher PM, Johansen A, Svarer C, Keller SH, Hansen AE, Knudsen GM. Visual stimuli induce serotonin release in occipital cortex: A simultaneous positron emission tomography/magnetic resonance imaging study. Hum Brain Mapp 2020; 41:4753-4763. [PMID: 32813903 PMCID: PMC7555083 DOI: 10.1002/hbm.25156] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 06/25/2020] [Accepted: 07/21/2020] [Indexed: 12/27/2022] Open
Abstract
Endogenous serotonin (5-HT) release can be measured noninvasively using positron emission tomography (PET) imaging in combination with certain serotonergic radiotracers. This allows us to investigate effects of pharmacological and nonpharmacological interventions on brain 5-HT levels in living humans. Here, we study the neural responses to a visual stimulus using simultaneous PET/MRI. In a cross-over design, 11 healthy individuals were PET/MRI scanned with the 5-HT1B receptor radioligand [11 C]AZ10419369, which is sensitive to changes in endogenous 5-HT. During the last part of the scan, participants either viewed autobiographical images with positive valence (n = 11) or kept their eyes closed (n = 7). The visual stimuli increased cerebral blood flow (CBF) in the occipital cortex, as measured with pseudo-continuous arterial spin labeling. Simultaneously, we found decreased 5-HT1B receptor binding in the occipital cortex (-3.6 ± 3.6%), indicating synaptic 5-HT release. Using a linear regression model, we found that the change in 5-HT1B receptor binding was significantly negatively associated with change in CBF in the occipital cortex (p = .004). For the first time, we here demonstrate how cerebral 5-HT levels change in response to nonpharmacological stimuli in humans, as measured with PET. Our findings more directly support a link between 5-HT signaling and visual processing and/or visual attention.
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Affiliation(s)
- Hanne Demant Hansen
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Massachusetts, Massachusetts
| | - Ulrich Lindberg
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Brice Ozenne
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Department of Public Health, Section of Biostatistics, University of Copenhagen, Copenhagen K, Denmark
| | - Patrick MacDonald Fisher
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Annette Johansen
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Claus Svarer
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Sune Høgild Keller
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Adam Espe Hansen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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8
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Ouelhazi A, Bharmauria V, Chanauria N, Bachatene L, Lussiez R, Molotchnikoff S. Effects of ketamine on orientation selectivity and variability of neuronal responses in primary visual cortex. Brain Res 2019; 1725:146462. [PMID: 31539548 DOI: 10.1016/j.brainres.2019.146462] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 09/03/2019] [Accepted: 09/13/2019] [Indexed: 11/16/2022]
Abstract
The plasticity of the adult brain is one of the most highly evolving areas of recent neuroscience research. It has been acknowledged that the visual cortex in adulthood can adapt and restructure the neuronal connections in response to a sensory experience or to an imposed input such as in adaptation or ocular deprivation protocols. In order to understand the basic cellular mechanisms of plasticity in the primary visual cortex (V1), we examined the effects of ketamine, a non-competitive, glutamatergic NMDAR (N-methyl-D-aspartate receptor) antagonist, on the orientation of cortical cells by measuring their response variability and the Gaussian tuning curves in adult anesthetised mouse and cat. Neurons were recorded extracellularly using glass electrodes. The ketamine was applied locally by placing a custom-cut filter paper (1x1mm) soaked in ketamine solution (10 mg/ml) on the cortical surface next the site of the recording tip, in both species. Our results show that the local and acute exposure of ketamine on V1 changes the preferred orientation of the visual neurons established during the critical period of development. Furthermore, ketamine also leads to a decrease in the orientation selectivity (measured by orientation selectivity index, OSI) and the variability of neuronal evoked responses (measured by Fano factor), but does not affect spontaneous activity. These results suggest that ketamine induces plasticity in V1 neurons that might be operated by a different pathway than that of NMDARs.
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Affiliation(s)
- A Ouelhazi
- Department of Biological Sciences, University of Montreal, Montreal, QC, Canada.
| | - V Bharmauria
- Department of Biological Sciences, University of Montreal, Montreal, QC, Canada; Department of Psychology, Faculty of Health, York University, Toronto, Ontario, Canada
| | - N Chanauria
- Department of Biological Sciences, University of Montreal, Montreal, QC, Canada.
| | - L Bachatene
- University of Sherbrook, Sherbrook, QC, Canada.
| | - R Lussiez
- Department of Biological Sciences, University of Montreal, Montreal, QC, Canada.
| | - S Molotchnikoff
- Department of Biological Sciences, University of Montreal, Montreal, QC, Canada.
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9
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Chanauria N, Bharmauria V, Bachatene L, Cattan S, Rouat J, Molotchnikoff S. Sound Induces Change in Orientation Preference of V1 Neurons: Audio-Visual Cross-Influence. Neuroscience 2019; 404:48-61. [PMID: 30703505 DOI: 10.1016/j.neuroscience.2019.01.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 01/18/2019] [Accepted: 01/21/2019] [Indexed: 10/27/2022]
Abstract
In the cortex, demarcated unimodal sensory regions often respond to unforeseen sensory stimuli and exhibit plasticity. The goal of the current investigation was to test evoked responses of primary visual cortex (V1) neurons when an adapting auditory stimulus is applied in isolation. Using extracellular recordings in anesthetized cats, we demonstrate that, unlike the prevailing observation of only slight modulations in the firing rates of the neurons, sound imposition in isolation entirely shifted the peaks of orientation tuning curves of neurons in both supra- and infragranular layers of V1. Our results suggest that neurons specific to either layer dynamically integrate features of sound and modify the organization of the orientation map of V1. Intriguingly, these experiments present novel findings that the mere presentation of a prolonged auditory stimulus may drastically recalibrate the tuning properties of the visual neurons and highlight the phenomenal neuroplasticity of V1 neurons.
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Affiliation(s)
- Nayan Chanauria
- Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Vishal Bharmauria
- Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Lyes Bachatene
- Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Sarah Cattan
- Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Jean Rouat
- Departement de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Stéphane Molotchnikoff
- Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale Centre-Ville, Montréal, QC H3C 3J7, Canada.
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10
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Shumikhina SI, Bondar IV, Svinov MM. Dynamics of Stability of Orientation Maps Recorded with Optical Imaging. Neuroscience 2018; 374:49-60. [PMID: 29391133 DOI: 10.1016/j.neuroscience.2018.01.030] [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: 07/14/2017] [Revised: 01/11/2018] [Accepted: 01/12/2018] [Indexed: 10/18/2022]
Abstract
Orientation selectivity is an important feature of visual cortical neurons. Optical imaging of the visual cortex allows for the generation of maps of orientation selectivity that reflect the activity of large populations of neurons. To estimate the statistical significance of effects of experimental manipulations, evaluation of the stability of cortical maps over time is required. Here, we performed optical imaging recordings of the visual cortex of anesthetized adult cats. Monocular stimulation with moving clockwise square-wave gratings that continuously changed orientation and direction was used as the mapping stimulus. Recordings were repeated at various time intervals, from 15 min to 16 h. Quantification of map stability was performed on a pixel-by-pixel basis using several techniques. Map reproducibility showed clear dynamics over time. The highest degree of stability was seen in maps recorded 15-45 min apart. Averaging across all time intervals and all stimulus orientations revealed a mean shift of 2.2 ± 0.1°. There was a significant tendency for larger shifts to occur at longer time intervals. Shifts between 2.8° (mean ± 2SD) and 5° were observed more frequently at oblique orientations, while shifts greater than 5° appeared more frequently at cardinal orientations. Shifts greater than 5° occurred rarely overall (5.4% of cases) and never exceeded 11°. Shifts of 10-10.6° (0.7%) were seen occasionally at time intervals of more than 4 h. Our findings should be considered when evaluating the potential effect of experimental manipulations on orientation selectivity mapping studies.
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Affiliation(s)
- S I Shumikhina
- Functional Neurocytology, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 5a Butlerova Street, 117485, Russia.
| | - I V Bondar
- Sensory Physiology, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 5a Butlerova Street, 117485, Russia.
| | - M M Svinov
- Functional Neurocytology, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 5a Butlerova Street, 117485, Russia.
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11
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Serotonin Decreases the Gain of Visual Responses in Awake Macaque V1. J Neurosci 2017; 37:11390-11405. [PMID: 29042433 PMCID: PMC5700422 DOI: 10.1523/jneurosci.1339-17.2017] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/09/2017] [Accepted: 09/12/2017] [Indexed: 11/21/2022] Open
Abstract
Serotonin, an important neuromodulator in the brain, is implicated in affective and cognitive functions. However, its role even for basic cortical processes is controversial. For example, in the mammalian primary visual cortex (V1), heterogenous serotonergic modulation has been observed in anesthetized animals. Here, we combined extracellular single-unit recordings with iontophoresis in awake animals. We examined the role of serotonin on well-defined tuning properties (orientation, spatial frequency, contrast, and size) in V1 of two male macaque monkeys. We find that in the awake macaque the modulatory effect of serotonin is surprisingly uniform: it causes a mainly multiplicative decrease of the visual responses and a slight increase in the stimulus-selective response latency. Moreover, serotonin neither systematically changes the selectivity or variability of the response, nor the interneuronal correlation unexplained by the stimulus ("noise-correlation"). The modulation by serotonin has qualitative similarities with that for a decrease in stimulus contrast, but differs quantitatively from decreasing contrast. It can be captured by a simple additive change to a threshold-linear spiking nonlinearity. Together, our results show that serotonin is well suited to control the response gain of neurons in V1 depending on the animal's behavioral or motivational context, complementing other known state-dependent gain-control mechanisms.SIGNIFICANCE STATEMENT Serotonin is an important neuromodulator in the brain and a major target for drugs used to treat psychiatric disorders. Nonetheless, surprisingly little is known about how it shapes information processing in sensory areas. Here we examined the serotonergic modulation of visual processing in the primary visual cortex of awake behaving macaque monkeys. We found that serotonin mainly decreased the gain of the visual responses, without systematically changing their selectivity, variability, or covariability. This identifies a simple computational function of serotonin for state-dependent sensory processing, depending on the animal's affective or motivational state.
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12
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The Effect of Citalopram Versus a Placebo on Central Auditory Processing in the Elderly. Otol Neurotol 2017; 38:1233-1239. [DOI: 10.1097/mao.0000000000001531] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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Beyeler M, Rokem A, Boynton GM, Fine I. Learning to see again: biological constraints on cortical plasticity and the implications for sight restoration technologies. J Neural Eng 2017; 14:051003. [PMID: 28612755 DOI: 10.1088/1741-2552/aa795e] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The 'bionic eye'-so long a dream of the future-is finally becoming a reality with retinal prostheses available to patients in both the US and Europe. However, clinical experience with these implants has made it apparent that the visual information provided by these devices differs substantially from normal sight. Consequently, the ability of patients to learn to make use of this abnormal retinal input plays a critical role in whether or not some functional vision is successfully regained. The goal of the present review is to summarize the vast basic science literature on developmental and adult cortical plasticity with an emphasis on how this literature might relate to the field of prosthetic vision. We begin with describing the distortion and information loss likely to be experienced by visual prosthesis users. We then define cortical plasticity and perceptual learning, and describe what is known, and what is unknown, about visual plasticity across the hierarchy of brain regions involved in visual processing, and across different stages of life. We close by discussing what is known about brain plasticity in sight restoration patients and discuss biological mechanisms that might eventually be harnessed to improve visual learning in these patients.
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Affiliation(s)
- Michael Beyeler
- Department of Psychology, University of Washington, Seattle, WA, United States of America. Institute for Neuroengineering, University of Washington, Seattle, WA, United States of America. eScience Institute, University of Washington, Seattle, WA, United States of America
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14
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Chanauria N, Bharmauria V, Bachatene L, Cattan S, Rouat J, Molotchnikoff S. Comparative effects of adaptation on layers II-III and V-VI neurons in cat V1. Eur J Neurosci 2016; 44:3094-3104. [PMID: 27740707 DOI: 10.1111/ejn.13439] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 10/04/2016] [Accepted: 10/06/2016] [Indexed: 12/23/2022]
Abstract
V1 is fundamentally grouped into columns that descend from layers II-III to V-VI. Neurons inherent to visual cortex are capable of adapting to changes in the incoming stimuli that drive the cortical plasticity. A principle feature called orientation selectivity can be altered by the presentation of non-optimal stimulus called 'adapter'. When triggered, LGN cells impinge upon layer IV and further relay the information to deeper layers via layers II-III. Using different adaptation protocols, neuronal plasticity can be investigated. Superficial neurons in area V1 are well acknowledged to exhibit attraction and repulsion by shifting their tuning peaks when challenged by a non-optimal stimulus called 'adapter'. Layers V-VI neurons in spite of partnering layers II-III neurons in cortical computation have not been explored simultaneously toward adaptation. We believe that adaptation not only affects cells specific to a layer but modifies the entire column. In this study, through simultaneous multiunit recordings in anesthetized cats using a multichannel depth electrode, we show for the first time how layers V-VI neurons (1000-1200 μm) along with layers II-III neurons (300-500 μm) exhibit plasticity in response to adaptation. Our results demonstrate that superficial and deeper layer neurons react synonymously toward adapter by exhibiting similar behavioral properties. The neurons displayed similar amplitude of shift and maintained equivalent sharpness of Gaussian tuning peaks before and the following adaptation. It appears that a similar mechanism, belonging to all layers, is responsible for the analog outcome of the neurons' experience with adapter.
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Affiliation(s)
- Nayan Chanauria
- Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale Centre-Ville, Montréal, QC, H3C 3J7, Canada
| | - Vishal Bharmauria
- Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale Centre-Ville, Montréal, QC, H3C 3J7, Canada.,The Visuomotor Neuroscience Lab, Centre for Vision Research, Faculty of Health, York University, Toronto, ON, Canada
| | - Lyes Bachatene
- Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale Centre-Ville, Montréal, QC, H3C 3J7, Canada.,Department of Nuclear Medicine and Radiobiology, Faculty of Medicine and Health Sciences (CHUS), SNAIL
- Sherbrooke Neuro Analysis and Imaging Lab, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Sarah Cattan
- Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale Centre-Ville, Montréal, QC, H3C 3J7, Canada
| | - Jean Rouat
- Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale Centre-Ville, Montréal, QC, H3C 3J7, Canada.,Département de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Stéphane Molotchnikoff
- Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale Centre-Ville, Montréal, QC, H3C 3J7, Canada
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15
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Bharmauria V, Bachatene L, Ouelhazi A, Cattan S, Chanauria N, Etindele-Sosso FA, Rouat J, Molotchnikoff S. Interplay of orientation selectivity and the power of low- and high-gamma bands in the cat primary visual cortex. Neurosci Lett 2016; 620:14-9. [PMID: 27033667 DOI: 10.1016/j.neulet.2016.03.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 03/01/2016] [Accepted: 03/21/2016] [Indexed: 01/28/2023]
Abstract
Gamma oscillations are ubiquitous in brain and are believed to be inevitable for information processing in brain. Here, we report that distinct bands (low, 30-40Hz and high gamma, 60-80Hz) of stimulus-triggered gamma oscillations are systematically linked to the orientation selectivity index (OSI) of neurons in the cat primary visual cortex. The gamma-power is high for the highly selective neurons in the low-gamma band, whereas it is high for the broadly selective neurons in the high-gamma band. We suggest that the low-gamma band is principally implicated in feed-forward excitatory flow, whereas the high-gamma band governs the flow of this excitation.
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Affiliation(s)
- Vishal Bharmauria
- Neurophysiology of Visual System, Université de Montréal, Département de Sciences Biologiques, Montréal, QC, Canada
| | - Lyes Bachatene
- Neurophysiology of Visual System, Université de Montréal, Département de Sciences Biologiques, Montréal, QC, Canada
| | - Afef Ouelhazi
- Neurophysiology of Visual System, Université de Montréal, Département de Sciences Biologiques, Montréal, QC, Canada
| | - Sarah Cattan
- Neurophysiology of Visual System, Université de Montréal, Département de Sciences Biologiques, Montréal, QC, Canada
| | - Nayan Chanauria
- Neurophysiology of Visual System, Université de Montréal, Département de Sciences Biologiques, Montréal, QC, Canada
| | - Faustin Armel Etindele-Sosso
- Neurophysiology of Visual System, Université de Montréal, Département de Sciences Biologiques, Montréal, QC, Canada
| | - Jean Rouat
- Neurophysiology of Visual System, Université de Montréal, Département de Sciences Biologiques, Montréal, QC, Canada; Département de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Stéphane Molotchnikoff
- Neurophysiology of Visual System, Université de Montréal, Département de Sciences Biologiques, Montréal, QC, Canada; Département de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada.
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16
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Bharmauria V, Bachatene L, Cattan S, Brodeur S, Chanauria N, Rouat J, Molotchnikoff S. Network-selectivity and stimulus-discrimination in the primary visual cortex: cell-assembly dynamics. Eur J Neurosci 2015; 43:204-19. [DOI: 10.1111/ejn.13101] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 10/06/2015] [Accepted: 10/10/2015] [Indexed: 12/24/2022]
Affiliation(s)
- Vishal Bharmauria
- Neurophysiology of Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale Centre-Ville Montréal QC Canada H3C 3J7
- Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS); Sherbrooke QC Canada
| | - Lyes Bachatene
- Neurophysiology of Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale Centre-Ville Montréal QC Canada H3C 3J7
- Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS); Sherbrooke QC Canada
| | - Sarah Cattan
- Neurophysiology of Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale Centre-Ville Montréal QC Canada H3C 3J7
- Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS); Sherbrooke QC Canada
| | - Simon Brodeur
- Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS); Sherbrooke QC Canada
- Département de Génie Électrique et Génie Informatique; Université de Sherbrooke; Sherbrooke QC Canada
| | - Nayan Chanauria
- Neurophysiology of Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale Centre-Ville Montréal QC Canada H3C 3J7
- Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS); Sherbrooke QC Canada
| | - Jean Rouat
- Neurophysiology of Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale Centre-Ville Montréal QC Canada H3C 3J7
- Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS); Sherbrooke QC Canada
- Département de Génie Électrique et Génie Informatique; Université de Sherbrooke; Sherbrooke QC Canada
| | - Stéphane Molotchnikoff
- Neurophysiology of Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale Centre-Ville Montréal QC Canada H3C 3J7
- Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS); Sherbrooke QC Canada
- Département de Génie Électrique et Génie Informatique; Université de Sherbrooke; Sherbrooke QC Canada
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17
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Bachatene L, Bharmauria V, Cattan S, Chanauria N, Rouat J, Molotchnikoff S. Summation of connectivity strengths in the visual cortex reveals stability of neuronal microcircuits after plasticity. BMC Neurosci 2015; 16:64. [PMID: 26453336 PMCID: PMC4600218 DOI: 10.1186/s12868-015-0203-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 09/30/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Within sensory systems, neurons are continuously affected by environmental stimulation. Recently, we showed that, on cell-pair basis, visual adaptation modulates the connectivity strength between similarly tuned neurons to orientation and we suggested that, on a larger scale, the connectivity strength between neurons forming sub-networks could be maintained after adaptation-induced-plasticity. In the present paper, based on the summation of the connectivity strengths, we sought to examine how, within cell-assemblies, functional connectivity is regulated during an exposure-based adaptation. RESULTS Using intrinsic optical imaging combined with electrophysiological recordings following the reconfiguration of the maps of the primary visual cortex by long stimulus exposure, we found that within functionally connected cells, the summed connectivity strengths remain almost equal although connections among individual pairs are modified. Neuronal selectivity appears to be strongly associated with neuronal connectivity in a "homeodynamic" manner which maintains the stability of cortical functional relationships after experience-dependent plasticity. CONCLUSIONS Our results support the "homeostatic plasticity concept" giving new perspectives on how the summation in visual cortex leads to the stability within labile neuronal ensembles, depending on the newly acquired properties by neurons.
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Affiliation(s)
- Lyes Bachatene
- Laboratoire de Neurosciences de la vision, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succ. Centre-Ville, Montréal, QC, H3C 3J7, Canada. .,Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS), Département de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Vishal Bharmauria
- Laboratoire de Neurosciences de la vision, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succ. Centre-Ville, Montréal, QC, H3C 3J7, Canada. .,Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS), Département de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Sarah Cattan
- Laboratoire de Neurosciences de la vision, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succ. Centre-Ville, Montréal, QC, H3C 3J7, Canada. .,Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS), Département de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Nayan Chanauria
- Laboratoire de Neurosciences de la vision, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succ. Centre-Ville, Montréal, QC, H3C 3J7, Canada. .,Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS), Département de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Jean Rouat
- Laboratoire de Neurosciences de la vision, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succ. Centre-Ville, Montréal, QC, H3C 3J7, Canada. .,Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS), Département de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada.
| | - Stéphane Molotchnikoff
- Laboratoire de Neurosciences de la vision, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succ. Centre-Ville, Montréal, QC, H3C 3J7, Canada. .,Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS), Département de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada.
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18
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Bocci T, Caleo M, Vannini B, Vergari M, Cogiamanian F, Rossi S, Priori A, Sartucci F. An unexpected target of spinal direct current stimulation: Interhemispheric connectivity in humans. J Neurosci Methods 2015. [DOI: 10.1016/j.jneumeth.2015.07.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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19
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Bharmauria V, Bachatene L, Cattan S, Chanauria N, Rouat J, Molotchnikoff S. Stimulus-dependent augmented gamma oscillatory activity between the functionally connected cortical neurons in the primary visual cortex. Eur J Neurosci 2015; 41:1587-96. [DOI: 10.1111/ejn.12912] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/18/2015] [Accepted: 04/01/2015] [Indexed: 12/25/2022]
Affiliation(s)
- Vishal Bharmauria
- Neurophysiology of the Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale centre-ville Montréal QC H3C 3J7 Canada
| | - Lyes Bachatene
- Neurophysiology of the Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale centre-ville Montréal QC H3C 3J7 Canada
| | - Sarah Cattan
- Neurophysiology of the Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale centre-ville Montréal QC H3C 3J7 Canada
| | - Nayan Chanauria
- Neurophysiology of the Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale centre-ville Montréal QC H3C 3J7 Canada
| | - Jean Rouat
- Neurophysiology of the Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale centre-ville Montréal QC H3C 3J7 Canada
- Département de Génie Électrique et Génie Informatique; Université de Sherbrooke; Sherbrooke QC Canada
| | - Stéphane Molotchnikoff
- Neurophysiology of the Visual System; Département de Sciences Biologiques; Université de Montréal; CP 6128 Succursale centre-ville Montréal QC H3C 3J7 Canada
- Département de Génie Électrique et Génie Informatique; Université de Sherbrooke; Sherbrooke QC Canada
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20
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Reprogramming of orientation columns in visual cortex: a domino effect. Sci Rep 2015; 5:9436. [PMID: 25801392 PMCID: PMC4371149 DOI: 10.1038/srep09436] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 03/02/2015] [Indexed: 02/06/2023] Open
Abstract
Cortical organization rests upon the fundamental principle that neurons sharing similar properties are co-located. In the visual cortex, neurons are organized into orientation columns. In a column, most neurons respond optimally to the same axis of an oriented edge, that is, the preferred orientation. This orientation selectivity is believed to be absolute in adulthood. However, in a fully mature brain, it has been established that neurons change their selectivity following sensory experience or visual adaptation. Here, we show that after applying an adapter away from the tested cells, neurons whose receptive fields were located remotely from the adapted site also exhibit a novel selectivity in spite of the fact that they were not adapted. These results indicate a robust reconfiguration and remapping of the orientation domains with respect to each other thus removing the possibility of an orientation hole in the new hypercolumn. These data suggest that orientation columns transcend anatomy, and are almost strictly functionally dynamic.
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21
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Bachatene L, Bharmauria V, Cattan S, Rouat J, Molotchnikoff S. Modulation of functional connectivity following visual adaptation: homeostasis in V1. Brain Res 2015; 1594:136-53. [PMID: 25451112 DOI: 10.1016/j.brainres.2014.10.054] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 10/24/2014] [Accepted: 10/26/2014] [Indexed: 11/28/2022]
Abstract
Sensory neurons exhibit remarkable adaptability in acquiring new optimal selectivity to unfamiliar features when a new stimulus becomes prevalent in the environment. In conventionally prepared adult anesthetized cats, we used visual adaptation to change the preferred orientation selectivity in V1 neurons. Cortical circuits are dominated by complex and intricate connections between neurons. Cross-correlation of cellular spike-trains discloses the putative functional connection between two neurons. We sought to investigate changes in these links following a 12 min uninterrupted application of a specific, usually non-preferred, orientation. We report that visual adaptation, mimicking training, modulates the magnitude of crosscorrelograms suggesting that the strength of inter-neuronal relationships is modified. While individual cell-pairs exhibit changes in their response correlation strength, the average correlation of the recorded cell cluster remains unchanged. Hence, visual adaptation induces plastic changes that impact the connectivity between neurons.
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Affiliation(s)
- L Bachatene
- Laboratoire de Neurosciences de la Vision, Département de Sciences Biologiques, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC, Canada H3C 3J7; Neurosciences Computationnelles et Traitement Intelligent des Signaux-NECOTIS, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - V Bharmauria
- Laboratoire de Neurosciences de la Vision, Département de Sciences Biologiques, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC, Canada H3C 3J7; Neurosciences Computationnelles et Traitement Intelligent des Signaux-NECOTIS, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - S Cattan
- Laboratoire de Neurosciences de la Vision, Département de Sciences Biologiques, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC, Canada H3C 3J7; Neurosciences Computationnelles et Traitement Intelligent des Signaux-NECOTIS, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - J Rouat
- Laboratoire de Neurosciences de la Vision, Département de Sciences Biologiques, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC, Canada H3C 3J7; Neurosciences Computationnelles et Traitement Intelligent des Signaux-NECOTIS, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - S Molotchnikoff
- Laboratoire de Neurosciences de la Vision, Département de Sciences Biologiques, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC, Canada H3C 3J7; Neurosciences Computationnelles et Traitement Intelligent des Signaux-NECOTIS, Université de Sherbrooke, Sherbrooke, QC, Canada.
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22
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Cattan S, Bachatene L, Bharmauria V, Jeyabalaratnam J, Milleret C, Molotchnikoff S. Comparative analysis of orientation maps in areas 17 and 18 of the cat primary visual cortex following adaptation. Eur J Neurosci 2014; 40:2554-63. [DOI: 10.1111/ejn.12616] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/07/2014] [Accepted: 04/10/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Sarah Cattan
- Département de sciences biologiques; Université de Montréal; Pavillon Marie-Victorin, C.P. 6128, succ. Centre-ville Montréal QC H3C 3J7 Canada
| | - Lyes Bachatene
- Département de sciences biologiques; Université de Montréal; Pavillon Marie-Victorin, C.P. 6128, succ. Centre-ville Montréal QC H3C 3J7 Canada
| | - Vishal Bharmauria
- Département de sciences biologiques; Université de Montréal; Pavillon Marie-Victorin, C.P. 6128, succ. Centre-ville Montréal QC H3C 3J7 Canada
| | - Jeyadarshan Jeyabalaratnam
- Département de sciences biologiques; Université de Montréal; Pavillon Marie-Victorin, C.P. 6128, succ. Centre-ville Montréal QC H3C 3J7 Canada
| | - Chantal Milleret
- Neural Bases of Spatial Memory and Navigation; CIRB - Collège de France (CNRS UMR 7241, INSERM U1050, UPMC ED 158, MEMOLIFE PSL); Paris France
| | - Stéphane Molotchnikoff
- Département de sciences biologiques; Université de Montréal; Pavillon Marie-Victorin, C.P. 6128, succ. Centre-ville Montréal QC H3C 3J7 Canada
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23
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Bharmauria V, Bachatene L, Cattan S, Rouat J, Molotchnikoff S. Synergistic activity between primary visual neurons. Neuroscience 2014; 268:255-64. [DOI: 10.1016/j.neuroscience.2014.03.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 03/12/2014] [Accepted: 03/13/2014] [Indexed: 01/16/2023]
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Activity-dependent NPAS4 expression and the regulation of gene programs underlying plasticity in the central nervous system. Neural Plast 2013; 2013:683909. [PMID: 24024041 PMCID: PMC3759247 DOI: 10.1155/2013/683909] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 07/09/2013] [Indexed: 11/17/2022] Open
Abstract
The capability of the brain to change functionally in response to sensory experience is most active during early stages of development but it decreases later in life when major alterations of neuronal network structures no longer take place in response to experience. This view has been recently challenged by experimental strategies based on the enhancement of environmental stimulation levels, genetic manipulations, and pharmacological treatments, which all have demonstrated that the adult brain retains a degree of plasticity that allows for a rewiring of neuronal circuitries over the entire life course. A hot spot in the field of neuronal plasticity centres on gene programs that underlie plastic phenomena in adulthood. Here, I discuss the role of the recently discovered neuronal-specific and activity-dependent transcription factor NPAS4 as a critical mediator of plasticity in the nervous system. A better understanding of how modifications in the connectivity of neuronal networks occur may shed light on the treatment of pathological conditions such as brain damage or disease in adult life, some of which were once considered untreatable.
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