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Antolik J, Sabatier Q, Galle C, Frégnac Y, Benosman R. Assessment of optogenetically-driven strategies for prosthetic restoration of cortical vision in large-scale neural simulation of V1. Sci Rep 2021; 11:10783. [PMID: 34031442 PMCID: PMC8144184 DOI: 10.1038/s41598-021-88960-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/01/2021] [Indexed: 02/04/2023] Open
Abstract
The neural encoding of visual features in primary visual cortex (V1) is well understood, with strong correlates to low-level perception, making V1 a strong candidate for vision restoration through neuroprosthetics. However, the functional relevance of neural dynamics evoked through external stimulation directly imposed at the cortical level is poorly understood. Furthermore, protocols for designing cortical stimulation patterns that would induce a naturalistic perception of the encoded stimuli have not yet been established. Here, we demonstrate a proof of concept by solving these issues through a computational model, combining (1) a large-scale spiking neural network model of cat V1 and (2) a virtual prosthetic system transcoding the visual input into tailored light-stimulation patterns which drive in situ the optogenetically modified cortical tissue. Using such virtual experiments, we design a protocol for translating simple Fourier contrasted stimuli (gratings) into activation patterns of the optogenetic matrix stimulator. We then quantify the relationship between spatial configuration of the imposed light pattern and the induced cortical activity. Our simulations in the absence of visual drive (simulated blindness) show that optogenetic stimulation with a spatial resolution as low as 100 [Formula: see text]m, and light intensity as weak as [Formula: see text] photons/s/cm[Formula: see text] is sufficient to evoke activity patterns in V1 close to those evoked by normal vision.
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Affiliation(s)
- Jan Antolik
- Faculty of Mathematics and Physics, Charles University, Malostranské nám. 25, 118 00, Prague 1, Czechia.
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.
| | - Quentin Sabatier
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
| | - Charlie Galle
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
| | - Yves Frégnac
- Unité de Neurosciences, Information et Complexité (UNIC), NeuroPSI, Gif-sur-Yvette, France
| | - Ryad Benosman
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012, Paris, France
- University of Pittsburgh, McGowan Institute, 3025 E Carson St, Pittsburgh, PA, USA
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2
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Tang R, Chen W, Wang Y. Different roles of subcortical inputs in V1 responses to luminance and contrast. Eur J Neurosci 2021; 53:3710-3726. [PMID: 33848389 DOI: 10.1111/ejn.15233] [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: 09/14/2020] [Revised: 04/02/2021] [Accepted: 04/09/2021] [Indexed: 01/01/2023]
Abstract
Cells in the primary visual cortex (V1) generally respond weakly to large uniform luminance stimuli. Only a subset of V1 cells is thought to encode uniform luminance information. In natural scenes, local luminance is an important feature for defining an object that varies and coexists with local spatial contrast. However, the strategies used by V1 cells to encode local mean luminance for spatial contrast stimuli remain largely unclear. Here, using extracellular recordings in anesthetized cats, we investigated the responses of V1 cells by comparing with those of retinal ganglion (RG) cells and lateral geniculate nucleus (LGN) cells to simultaneous and rapid changes in luminance and spatial contrast. Almost all V1 cells exhibited a strong monotonic increasing luminance tuning when they were exposed to high spatial contrast. Thus, V1 cells encode the luminance carried by spatial contrast stimuli with the monotonically increasing response function. Moreover, high contrast decreased luminance tuning of OFF cells but increased that of in ON cells in RG and LGN. The luminance and contrast tunings of LGN ON cells were highly separable as V1 cells, whereas those of LGN OFF cells were lowly separable. These asymmetrical effects of spatial contrast on ON/OFF channels might underlie the robust ability of V1 cells to perform luminance tuning when exposed to spatial contrast stimuli.
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Affiliation(s)
- Rendong Tang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Wenzhen Chen
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yi Wang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
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3
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Niu X, Huang S, Yang S, Wang Z, Li Z, Shi L. Comparison of pop-out responses to luminance and motion contrasting stimuli of tectal neurons in pigeons. Brain Res 2020; 1747:147068. [PMID: 32827547 DOI: 10.1016/j.brainres.2020.147068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/20/2020] [Accepted: 08/17/2020] [Indexed: 11/30/2022]
Abstract
The emergence of visual saliency has been widely studied in the primary visual cortex and the superior colliculus (SC) in mammals. There are fewer studies on the pop-out response to motion direction contrasting stimuli taken in the optic tectum (OT, homologous to mammalian SC), and these are mainly of owls and fish. To our knowledge the influence of spatial luminance has not been reported. In this study, we have recorded multi-units in pigeon OT and analyzed the tectal response to spatial luminance contrasting, motion direction contrasting, and contrasting stimuli from both feature dimensions. The comparison results showed that 1) the tectal response would pop-out in either motion direction or spatial luminance contrasting conditions. 2) The modulation from motion direction contrasting was independent of the temporal luminance variation of the visual stimuli. 3) When both spatial luminance and motion direction were salient, the response of tectal neurons was modulated more intensely by motion direction than by spatial luminance. The phenomenon was consistent with the innate instinct of avians in their natural environment. This study will help to deepen the understanding of mechanisms involved in bottom-up visual information processing and selective attention in the avian.
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Affiliation(s)
- Xiaoke Niu
- Henan Key Laboratory of Brain-Computer Interface Technology, School of Electrical Engineering, ZhengZhou University, Zhengzhou 450001, China; College of Basic Medicine, Zhengzhou University, Zhengzhou 450001, China.
| | - Shuman Huang
- Henan Key Laboratory of Brain-Computer Interface Technology, School of Electrical Engineering, ZhengZhou University, Zhengzhou 450001, China
| | - Shangfei Yang
- Henan Key Laboratory of Brain-Computer Interface Technology, School of Electrical Engineering, ZhengZhou University, Zhengzhou 450001, China
| | - Zhizhong Wang
- Henan Key Laboratory of Brain-Computer Interface Technology, School of Electrical Engineering, ZhengZhou University, Zhengzhou 450001, China
| | - Zhihui Li
- Henan Key Laboratory of Brain-Computer Interface Technology, School of Electrical Engineering, ZhengZhou University, Zhengzhou 450001, China
| | - Li Shi
- Henan Key Laboratory of Brain-Computer Interface Technology, School of Electrical Engineering, ZhengZhou University, Zhengzhou 450001, China; Department of Automation, Tsinghua University, Beijing 100000, China.
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4
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Abstract
Our visual system is tasked with transforming variations in light within our environment into a coherent percept, typically described using properties such as luminance and contrast. Models of vision often downplay the importance of luminance in shaping cortical responses, instead prioritizing representations that do not covary with overall luminance (i.e., contrast), and yet visuocortical response properties that may reflect luminance encoding remain poorly understood. In this study, we examined whether well-established visuocortical response properties may also reflect luminance encoding, challenging the idea that luminance information itself plays no significant role in supporting visual perception. To do so, we measured functional activity in human visual cortex when presenting stimuli varying in contrast and mean luminance, and found that luminance response functions are strongly contrast dependent between 50 and 250 cd/m2, confirmed with a subsequent experiment. High-contrast stimuli produced linearly increasing responses as luminance increased logarithmically for all early visual areas, whereas low-contrast stimuli produced either flat (V1) or assorted positive linear (V2 and V3) response profiles. These results reveal that the mean luminance information of a visual signal persists within visuocortical representations, potentially reflecting an inherent imbalance of excitatory and inhibitory components that can be either contrast dependent (V1 and V2) or contrast invariant (V3). The role of luminance should be considered when the aim is to drive potent visually evoked responses and when activity is compared across studies. More broadly, overall luminance should be weighed heavily as a core feature of the visual system and should play a significant role in cortical models of vision.NEW & NOTEWORTHY This neuroimaging study investigates the influence of overall luminance on population activity in human visual cortex. We discovered that the response to a particular stimulus contrast level is reliant, in part, on the mean luminance of a signal, revealing that the mean luminance information of our environment is represented within the visual cortex. The results challenge a long-standing misconception about the role of luminance information in the processing of visual information at the cortical level.
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Affiliation(s)
- Louis N Vinke
- Graduate Program for Neuroscience, Boston University, Boston, Massachusetts.,Center for Systems Neuroscience, Boston University, Boston, Massachusetts
| | - Sam Ling
- Psychological and Brain Sciences, Boston University, Boston, Massachusetts.,Center for Systems Neuroscience, Boston University, Boston, Massachusetts
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5
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Prefrontal neural dynamics in consciousness. Neuropsychologia 2019; 131:25-41. [DOI: 10.1016/j.neuropsychologia.2019.05.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 05/17/2019] [Accepted: 05/20/2019] [Indexed: 12/11/2022]
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6
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Comparison of Neurochemical and BOLD Signal Contrast Response Functions in the Human Visual Cortex. J Neurosci 2019; 39:7968-7975. [PMID: 31358655 DOI: 10.1523/jneurosci.3021-18.2019] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 07/16/2019] [Accepted: 07/20/2019] [Indexed: 01/20/2023] Open
Abstract
We investigated the relationship between neurochemical and hemodynamic responses as a function of image contrast in the human primary visual cortex (V1). Simultaneously acquired BOLD-fMRI and single voxel proton MR spectroscopy signals were measured in V1 of 24 healthy human participants of either sex at 7 tesla field strength, in response to presentations (64 s blocks) of different levels of image contrast (3%, 12.5%, 50%, 100%). Our results suggest that complementary measures of neurotransmission and energy metabolism are in partial agreement: BOLD and glutamate signals were linear with image contrast; however, a significant increase in glutamate concentration was evident only at the highest intensity level. In contrast, GABA signals were steady across all intensity levels. These results suggest that neurochemical concentrations are maintained at lower ranges of contrast levels, which match the statistics of natural vision, and that high stimulus intensity may be critical to increase sensitivity to visually modulated glutamate signals in the early visual cortex using MR spectroscopy.SIGNIFICANCE STATEMENT Glutamate and GABA are the major excitatory and inhibitory neurotransmitters of the brain. To better understand the relationship between MRS-visible neurochemicals, the BOLD signal change, and stimulus intensity, we measured combined neurochemical and BOLD signals (combined fMRI-MRS) to different image contrasts in human V1 at 7 tesla. While a linear change to contrast was present for both signals, the increase in glutamate was significant only at the highest stimulus intensity. These results suggest that hemodynamic and neurochemical signals reflect common metabolic markers of neural activity, whereas the mismatch at lower contrast levels may indicate a sensitivity threshold for detecting neurochemical changes during visual processing. Our results highlight the challenge and importance of reconciling cellular and metabolic measures of neural activity in the human brain.
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7
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Dai J, Wang Y. Contrast coding in the primary visual cortex depends on temporal contexts. Eur J Neurosci 2018; 47:947-958. [DOI: 10.1111/ejn.13893] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 02/06/2018] [Accepted: 02/20/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Ji Dai
- State Key Laboratory of Brain and Cognitive Sciences; Institute of Biophysics; Chinese Academy of Sciences; Beijing 100101 China
- Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science; CAS Center for Excellence in Brain Science and Intelligence Technology; the Brain Cognition and Brain Disease Institute; Shenzhen Institutes of Advanced Technology; Chinese Academy of Sciences; Shenzhen 518055 China
| | - Yi Wang
- State Key Laboratory of Brain and Cognitive Sciences; Institute of Biophysics; Chinese Academy of Sciences; Beijing 100101 China
- University of Chinese Academy of Sciences; Beijing 100101 China
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Ghodrati M, Alwis DS, Price NSC. Orientation selectivity in rat primary visual cortex emerges earlier with low-contrast and high-luminance stimuli. Eur J Neurosci 2016; 44:2759-2773. [PMID: 27563930 DOI: 10.1111/ejn.13379] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 08/20/2016] [Accepted: 08/20/2016] [Indexed: 11/25/2022]
Abstract
In natural vision, rapid and sustained variations in luminance and contrast change the reliability of information available about a visual scene, and markedly affect both neuronal and behavioural responses. The hallmark property of neurons in primary visual cortex (V1), orientation selectivity, is unaffected by changes in stimulus contrast, but it remains unclear how sustained differences in mean luminance and contrast affect the time-course of orientation selectivity, and the amount of information that neurons carry about orientation. We used reverse correlation with characterize the temporal dynamics of orientation selectivity in rat V1 neurons under four luminance-contrast conditions. We show that orientation selectivity and mutual information between neuronal responses and stimulus orientation are invariant to contrast or mean luminance. Critically, the time-course of the emergence of orientation selectivity was affected by both factors; response latencies were longer for low- than high-luminance gratings, and surprisingly, response latencies were also longer for high- than low-contrast gratings. Modelling suggests that luminance-modulated changes in feedforward gain, in combination with hyperpolarization caused by high contrasts can account for our physiological data. The hyperpolarization at high contrasts may increase signal-to-noise ratios, whereas a more depolarized membrane may lead to greater sensitivity to weak stimuli.
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Affiliation(s)
- Masoud Ghodrati
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Vic., 3800, Australia.,Neuroscience Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Dasuni S Alwis
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Vic., 3800, Australia.,Neuroscience Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Nicholas S C Price
- Department of Physiology, Monash University, 26 Innovation Walk, Clayton, Vic., 3800, Australia.,Neuroscience Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia.,ARC Centre of Excellence for Integrative Brain Function, Monash University Node, Clayton, Vic., Australia
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