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Gulbinaite R, Nazari M, Rule ME, Bermudez-Contreras EJ, Cohen MX, Mohajerani MH, Heimel JA. Spatiotemporal resonance in mouse primary visual cortex. Curr Biol 2024; 34:4184-4196.e7. [PMID: 39255789 DOI: 10.1016/j.cub.2024.07.091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 07/08/2024] [Accepted: 07/29/2024] [Indexed: 09/12/2024]
Abstract
Human primary visual cortex (V1) responds more strongly, or resonates, when exposed to ∼10, ∼15-20, and ∼40-50 Hz rhythmic flickering light. Full-field flicker also evokes the perception of hallucinatory geometric patterns, which mathematical models explain as standing-wave formations emerging from periodic forcing at resonant frequencies of the simulated neural network. However, empirical evidence for such flicker-induced standing waves in the visual cortex was missing. We recorded cortical responses to flicker in awake mice using high-spatial-resolution widefield imaging in combination with high-temporal-resolution glutamate-sensing fluorescent reporter (iGluSnFR). The temporal frequency tuning curves in the mouse V1 were similar to those observed in humans, showing a banded structure with multiple resonance peaks (8, 15, and 33 Hz). Spatially, all flicker frequencies evoked responses in V1 corresponding to retinotopic stimulus location, but some evoked additional peaks. These flicker-induced cortical patterns displayed standing-wave characteristics and matched linear wave equation solutions in an area restricted to the visual cortex. Taken together, the interaction of periodic traveling waves with cortical area boundaries leads to spatiotemporal activity patterns that may affect perception.
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Affiliation(s)
- Rasa Gulbinaite
- Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands.
| | - Mojtaba Nazari
- Canadian Centre for Behavioral Neuroscience, University of Lethbridge Lethbridge, AB T1K 3M4, Canada
| | - Michael E Rule
- School of Engineering Mathematics and Technology, University of Bristol, Queen's Building, Bristol BS8 1TR, UK
| | | | - Michael X Cohen
- Radboud University Medical Center, Donders Institute for Brain, Cognition, and Behaviour, 6525 EN Nijmegen, the Netherlands
| | - Majid H Mohajerani
- Canadian Centre for Behavioral Neuroscience, University of Lethbridge Lethbridge, AB T1K 3M4, Canada; Department of Psychiatry, Douglas Hospital Research Centre, McGill University, 6875 Boulevard LaSalle, Montréal, QC H4H 1R3, Canada
| | - J Alexander Heimel
- Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands
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2
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Samonds JM, Szinte M, Barr C, Montagnini A, Masson GS, Priebe NJ. Mammals Achieve Common Neural Coverage of Visual Scenes Using Distinct Sampling Behaviors. eNeuro 2024; 11:ENEURO.0287-23.2023. [PMID: 38164577 PMCID: PMC10860624 DOI: 10.1523/eneuro.0287-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/24/2023] [Accepted: 10/30/2023] [Indexed: 01/03/2024] Open
Abstract
Most vertebrates use head and eye movements to quickly change gaze orientation and sample different portions of the environment with periods of stable fixation. Visual information must be integrated across fixations to construct a complete perspective of the visual environment. In concert with this sampling strategy, neurons adapt to unchanging input to conserve energy and ensure that only novel information from each fixation is processed. We demonstrate how adaptation recovery times and saccade properties interact and thus shape spatiotemporal tradeoffs observed in the motor and visual systems of mice, cats, marmosets, macaques, and humans. These tradeoffs predict that in order to achieve similar visual coverage over time, animals with smaller receptive field sizes require faster saccade rates. Indeed, we find comparable sampling of the visual environment by neuronal populations across mammals when integrating measurements of saccadic behavior with receptive field sizes and V1 neuronal density. We propose that these mammals share a common statistically driven strategy of maintaining coverage of their visual environment over time calibrated to their respective visual system characteristics.
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Affiliation(s)
- Jason M Samonds
- Center for Learning and Memory and the Institute for Neuroscience, The University of Texas at Austin, Austin 78712, Texas
| | - Martin Szinte
- Institut de Neurosciences de la Timone (UMR 7289), Centre National de la Recherche Scientifique and Aix-Marseille Université, 13385 Marseille, France
| | - Carrie Barr
- Center for Learning and Memory and the Institute for Neuroscience, The University of Texas at Austin, Austin 78712, Texas
| | - Anna Montagnini
- Institut de Neurosciences de la Timone (UMR 7289), Centre National de la Recherche Scientifique and Aix-Marseille Université, 13385 Marseille, France
| | - Guillaume S Masson
- Institut de Neurosciences de la Timone (UMR 7289), Centre National de la Recherche Scientifique and Aix-Marseille Université, 13385 Marseille, France
| | - Nicholas J Priebe
- Center for Learning and Memory and the Institute for Neuroscience, The University of Texas at Austin, Austin 78712, Texas
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3
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Newman BA, D’Angelo GJ. A Review of Cervidae Visual Ecology. Animals (Basel) 2024; 14:420. [PMID: 38338063 PMCID: PMC10854973 DOI: 10.3390/ani14030420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/21/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
This review examines the visual systems of cervids in relation to their ability to meet their ecological needs and how their visual systems are specialized for particular tasks. Cervidae encompasses a diverse group of mammals that serve as important ecological drivers within their ecosystems. Despite evidence of highly specialized visual systems, a large portion of cervid research ignores or fails to consider the realities of cervid vision as it relates to their ecology. Failure to account for an animal's visual ecology during research can lead to unintentional biases and uninformed conclusions regarding the decision making and behaviors for a species or population. Our review addresses core behaviors and their interrelationship with cervid visual characteristics. Historically, the study of cervid visual characteristics has been restricted to specific areas of inquiry such as color vision and contains limited integration into broader ecological and behavioral research. The purpose of our review is to bridge these gaps by offering a comprehensive review of cervid visual ecology that emphasizes the interplay between the visual adaptations of cervids and their interactions with habitats and other species. Ultimately, a better understanding of cervid visual ecology allows researchers to gain deeper insights into their behavior and ecology, providing critical information for conservation and management efforts.
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Affiliation(s)
- Blaise A. Newman
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
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4
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Boissonnet T, Tripodi M, Asari H. Awake responses suggest inefficient dense coding in the mouse retina. eLife 2023; 12:e78005. [PMID: 37922200 PMCID: PMC10624425 DOI: 10.7554/elife.78005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 09/28/2023] [Indexed: 11/05/2023] Open
Abstract
The structure and function of the vertebrate retina have been extensively studied across species with an isolated, ex vivo preparation. Retinal function in vivo, however, remains elusive, especially in awake animals. Here, we performed single-unit extracellular recordings in the optic tract of head-fixed mice to compare the output of awake, anesthetized, and ex vivo retinas. While the visual response properties were overall similar across conditions, we found that awake retinal output had in general (1) faster kinetics with less variability in the response latencies; (2) a larger dynamic range; and (3) higher firing activity, by ~20 Hz on average, for both baseline and visually evoked responses. Our modeling analyses further showed that such awake response patterns convey comparable total information but less efficiently, and allow for a linear population decoder to perform significantly better than the anesthetized or ex vivo responses. These results highlight distinct retinal behavior in awake states, in particular suggesting that the retina employs dense coding in vivo, rather than sparse efficient coding as has been often assumed from ex vivo studies.
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Affiliation(s)
- Tom Boissonnet
- Epigenetics and Neurobiology Unit, EMBL Rome, European Molecular Biology LaboratoryMonterotondoItaly
- Collaboration for joint PhD degree between EMBL and Université Grenoble Alpes, Grenoble Institut des NeurosciencesLa TroncheFrance
| | - Matteo Tripodi
- Epigenetics and Neurobiology Unit, EMBL Rome, European Molecular Biology LaboratoryMonterotondoItaly
| | - Hiroki Asari
- Epigenetics and Neurobiology Unit, EMBL Rome, European Molecular Biology LaboratoryMonterotondoItaly
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5
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Samonds JM, Szinte M, Barr C, Montagnini A, Masson GS, Priebe NJ. Mammals achieve common neural coverage of visual scenes using distinct sampling behaviors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.20.533210. [PMID: 36993477 PMCID: PMC10055212 DOI: 10.1101/2023.03.20.533210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Most vertebrates use head and eye movements to quickly change gaze orientation and sample different portions of the environment with periods of stable fixation. Visual information must be integrated across several fixations to construct a more complete perspective of the visual environment. In concert with this sampling strategy, neurons adapt to unchanging input to conserve energy and ensure that only novel information from each fixation is processed. We demonstrate how adaptation recovery times and saccade properties interact, and thus shape spatiotemporal tradeoffs observed in the motor and visual systems of different species. These tradeoffs predict that in order to achieve similar visual coverage over time, animals with smaller receptive field sizes require faster saccade rates. Indeed, we find comparable sampling of the visual environment by neuronal populations across mammals when integrating measurements of saccadic behavior with receptive field sizes and V1 neuronal density. We propose that these mammals share a common statistically driven strategy of maintaining coverage of their visual environment over time calibrated to their respective visual system characteristics.
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6
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Allen AE. Circadian Regulation of the Rod Contribution to Mesopic Vision in Mice. J Neurosci 2022; 42:8795-8806. [PMID: 36216501 PMCID: PMC9698662 DOI: 10.1523/jneurosci.0486-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 07/27/2022] [Accepted: 09/21/2022] [Indexed: 12/29/2022] Open
Abstract
At intermediate (mesopic) light levels, rods and cones are both active and can contribute to vision. This presents a challenge to the retina because the visual responses originating with rods and cones are distinct, yet their visual responses must be seamlessly combined. The current study aimed to establish how the circadian clock regulates rod and/or cone vision in these conditions, given the strong time-of-day change in the reliance on each photoreceptor. Visual responses were recorded in the retina and visual thalamus of anaesthetized male mice at distinct circadian time points, and the method of receptor silent substitution was used to selectively stimulate different photoreceptor types. With stimuli designed to only activate rods, responses in the mesopic range were highly rhythmic and peaked in amplitude in the subjective night. This rhythm was abolished following intravitreal injection of the gap junction blocker meclofenamic acid, consistent with a circadian variation in the strength of electrical coupling of photoreceptors. In contrast, responses to stimuli designed to only activate cones were arrhythmic within the mesopic to photopic range when adapted to the background irradiance. The outcome was that combined rod-plus-cone responses showed a stable contrast-response relationship across mesopic-photopic backgrounds in the circadian day, whereas at night, responses were significantly amplified at lower light levels. These data support the idea that the circadian clock is a key regulator of vision, in this case defining the relative amplitude of rod/cone vision across the mesopic transition according to time of day.SIGNIFICANCE STATEMENT Although the importance of circadian clocks in regulating vision has been long recognized, less is known about how the clock shapes vision in conditions where both rods and cones are active (mesopic conditions). Here, the novel approach of receptor silent substitution has been applied to trace rod and cone visual responses in mice across the circadian cycle and has identified pronounced rhythms in rod, but not cone, vision. This has the effect of boosting responses in dimmer backgrounds at night at the cost of impaired contrast-response stability across the mesopic to photopic range. Thus, the circadian clock drives anticipatory changes in the relative contribution of rods versus cones to vision, which match the prevailing visual environment.
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Affiliation(s)
- Annette E Allen
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PT, United Kingdom
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7
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Lankford CK, Umino Y, Poria D, Kefalov V, Solessio E, Baker SA. Cone-Driven Retinal Responses Are Shaped by Rod But Not Cone HCN1. J Neurosci 2022; 42:4231-4249. [PMID: 35437278 PMCID: PMC9145265 DOI: 10.1523/jneurosci.2271-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 04/01/2022] [Accepted: 04/07/2022] [Indexed: 11/21/2022] Open
Abstract
Signal integration of converging neural circuits is poorly understood. One example is in the retina where the integration of rod and cone signaling is responsible for the large dynamic range of vision. The relative contribution of rods versus cones is dictated by a complex function involving background light intensity and stimulus temporal frequency. One understudied mechanism involved in coordinating rod and cone signaling onto the shared retinal circuit is the hyperpolarization activated current (Ih) mediated by hyperpolarization-activated cyclic nucleotide-gated 1 (HCN1) channels expressed in rods and cones. Ih opposes membrane hyperpolarization driven by activation of the phototransduction cascade and modulates the strength and kinetics of the photoreceptor voltage response. We examined conditional knock-out (KO) of HCN1 from mouse rods using electroretinography (ERG). In the absence of HCN1, rod responses are prolonged in dim light which altered the response to slow modulation of light intensity both at the level of retinal signaling and behavior. Under brighter intensities, cone-driven signaling was suppressed. To our surprise, conditional KO of HCN1 from mouse cones had no effect on cone-mediated signaling. We propose that Ih is dispensable in cones because of the high level of temporal control of cone phototransduction. Thus, HCN1 is required for cone-driven retinal signaling only indirectly by modulating the voltage response of rods to limit their output.SIGNIFICANCE STATEMENT Hyperpolarization gated hyperpolarization-activated cyclic nucleotide-gated 1 (HCN1) channels carry a feedback current that helps to reset light-activated photoreceptors. Using conditional HCN1 knock-out (KO) mice we show that ablating HCN1 from rods allows rods to signal in bright light when they are normally shut down. Instead of enhancing vision this results in suppressing cone signaling. Conversely, ablating HCN1 from cones was of no consequence. This work provides novel insights into the integration of rod and cone signaling in the retina and challenges our assumptions about the role of HCN1 in cones.
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Affiliation(s)
- Colten K Lankford
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, Iowa 52242
| | - Yumiko Umino
- Center for Vision Research, Department of Ophthalmology and Visual Sciences, State University of New York Upstate Medical University, Syracuse, New York 13210
| | - Deepak Poria
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, California 92697
| | - Vladimir Kefalov
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, California 92697
- Department of Physiology and Biophysics, University of California, Irvine, California 92697
| | - Eduardo Solessio
- Center for Vision Research, Department of Ophthalmology and Visual Sciences, State University of New York Upstate Medical University, Syracuse, New York 13210
| | - Sheila A Baker
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, Iowa 52242
- Department of Ophthalmology and Visual Sciences and Institute for Vision Research, University of Iowa, Iowa City, Iowa 52242
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8
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You 游文愷 WK, Mysore SP. Dynamics of Visual Perceptual Decision-Making in Freely Behaving Mice. eNeuro 2022; 9:ENEURO.0161-21.2022. [PMID: 35228308 DOI: 10.1101/2020.02.20.958652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 02/14/2022] [Accepted: 02/17/2022] [Indexed: 05/25/2023] Open
Abstract
The temporal dynamics of perceptual decisions offer a key window into the cognitive processes contributing to decision-making. Investigating perceptual dynamics in a genetically tractable animal model can facilitate the subsequent unpacking of the underlying neural mechanisms. Here, we investigated the time course as well as fundamental psychophysical constants governing visual perceptual decision-making in freely behaving mice. We did so by analyzing response accuracy against reaction time (RT), i.e., conditional accuracy, in a series of two-alternative forced choice (2-AFC) orientation discrimination tasks in which we varied target size, luminance, duration, and presence of a foil. Our results quantified two distinct stages in the time course of mouse visual decision-making: a "sensory encoding" stage in which conditional accuracy exhibits a classic trade-off with response speed, and a subsequent "short-term memory (STM)-dependent" stage in which conditional accuracy exhibits a classic asymptotic decay following stimulus offset. We estimated the duration of visual sensory encoding as 200-320 ms across tasks, the lower bound of the duration of STM as ∼1700 ms, and the briefest duration of visual stimulus input that is informative as ≤50 ms. Separately, by varying stimulus onset delay, we demonstrated that the conditional accuracy function (CAF) and RT distribution can be independently modulated, and found that the duration for which mice naturally withhold from responding is a quantitative metric of impulsivity. Taken together, our results establish a quantitative foundation for investigating the neural circuit bases of visual decision dynamics in mice.
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Affiliation(s)
- Wen-Kai You 游文愷
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21205
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205
| | - Shreesh P Mysore
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21205
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205
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9
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Dynamics of Visual Perceptual Decision-Making in Freely Behaving Mice. eNeuro 2022; 9:ENEURO.0161-21.2022. [PMID: 35228308 PMCID: PMC8925649 DOI: 10.1523/eneuro.0161-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 02/14/2022] [Accepted: 02/17/2022] [Indexed: 11/21/2022] Open
Abstract
The temporal dynamics of perceptual decisions offer a key window into the cognitive processes contributing to decision-making. Investigating perceptual dynamics in a genetically tractable animal model can facilitate the subsequent unpacking of the underlying neural mechanisms. Here, we investigated the time course as well as fundamental psychophysical constants governing visual perceptual decision-making in freely behaving mice. We did so by analyzing response accuracy against reaction time (RT), i.e., conditional accuracy, in a series of two-alternative forced choice (2-AFC) orientation discrimination tasks in which we varied target size, luminance, duration, and presence of a foil. Our results quantified two distinct stages in the time course of mouse visual decision-making: a “sensory encoding” stage in which conditional accuracy exhibits a classic trade-off with response speed, and a subsequent “short-term memory (STM)-dependent” stage in which conditional accuracy exhibits a classic asymptotic decay following stimulus offset. We estimated the duration of visual sensory encoding as 200–320 ms across tasks, the lower bound of the duration of STM as ∼1700 ms, and the briefest duration of visual stimulus input that is informative as ≤50 ms. Separately, by varying stimulus onset delay, we demonstrated that the conditional accuracy function (CAF) and RT distribution can be independently modulated, and found that the duration for which mice naturally withhold from responding is a quantitative metric of impulsivity. Taken together, our results establish a quantitative foundation for investigating the neural circuit bases of visual decision dynamics in mice.
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10
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Vit JP, Fuchs DT, Angel A, Levy A, Lamensdorf I, Black KL, Koronyo Y, Koronyo-Hamaoui M. Color and contrast vision in mouse models of aging and Alzheimer's disease using a novel visual-stimuli four-arm maze. Sci Rep 2021; 11:1255. [PMID: 33441984 PMCID: PMC7806734 DOI: 10.1038/s41598-021-80988-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 12/31/2020] [Indexed: 12/14/2022] Open
Abstract
We introduce a novel visual-stimuli four-arm maze (ViS4M) equipped with spectrally- and intensity-controlled LED emitters and dynamic grayscale objects that relies on innate exploratory behavior to assess color and contrast vision in mice. Its application to detect visual impairments during normal aging and over the course of Alzheimer’s disease (AD) is evaluated in wild-type (WT) and transgenic APPSWE/PS1∆E9 murine models of AD (AD+) across an array of irradiance, chromaticity, and contrast conditions. Substantial color and contrast-mode alternation deficits appear in AD+ mice at an age when hippocampal-based memory and learning is still intact. Profiling of timespan, entries and transition patterns between the different arms uncovers variable AD-associated impairments in contrast sensitivity and color discrimination, reminiscent of tritanomalous defects documented in AD patients. Transition deficits are found in aged WT mice in the absence of alternation decline. Overall, ViS4M is a versatile, controlled device to measure color and contrast-related vision in aged and diseased mice.
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Affiliation(s)
- Jean-Philippe Vit
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA.,Biobehavioral Research Core, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Dieu-Trang Fuchs
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Ariel Angel
- Pharmaseed Ltd., 9 Hamazmera St., 74047, Ness Ziona, Israel
| | - Aharon Levy
- Pharmaseed Ltd., 9 Hamazmera St., 74047, Ness Ziona, Israel
| | | | - Keith L Black
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Yosef Koronyo
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Maya Koronyo-Hamaoui
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA. .,Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
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11
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Camillo D, Ahmadlou M, Heimel JA. Contrast-Dependence of Temporal Frequency Tuning in Mouse V1. Front Neurosci 2020; 14:868. [PMID: 32982668 PMCID: PMC7477338 DOI: 10.3389/fnins.2020.00868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 07/27/2020] [Indexed: 11/13/2022] Open
Abstract
The perception of speed is influenced by visual contrast. In primary visual cortex (V1), an early stage in the visual perception pathway, the neural tuning to speed is directly related to the neural tuning to temporal frequency of stimulus changes. The influence of contrast on speed perception can be caused by the joint dependency of neural responses in V1 on temporal frequency and contrast. Here, we investigated how tuning to contrast and temporal frequency in V1 of anesthetized mice are related. We found that temporal frequency tuning is contrast-dependent. V1 was more responsive at lower temporal frequencies than the dLGN, consistent with previous work at high contrast. The temporal frequency tuning moves toward higher temporal frequencies with increasing contrast. The low half-maximum temporal frequency does not change with contrast. The Heeger divisive normalization equation provides a good fit to many response characteristics in V1, but does not fit the dependency of temporal frequency and contrast with set of parameters for all temporal frequencies. Different mechanisms for normalization in the visual cortex may predict different relationships between temporal frequency and contrast non-linearity. Our data could help to make a model selection.
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12
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Rod Photoreceptors Signal Fast Changes in Daylight Levels Using a Cx36-Independent Retinal Pathway in Mouse. J Neurosci 2019; 40:796-810. [PMID: 31776212 DOI: 10.1523/jneurosci.0455-19.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 11/11/2019] [Accepted: 11/17/2019] [Indexed: 11/21/2022] Open
Abstract
Temporal contrast detected by rod photoreceptors is channeled into multiple retinal rod pathways that ultimately connect to cone photoreceptor pathways via Cx36 gap junctions or via chemical synapses. However, we do not yet understand how the different rod pathways contribute to the perception of temporal contrast (changes in luminance with time) at mesopic light levels, where both rods and cones actively respond to light. Here, we use a forced-choice, operant behavior assay to investigate rod-driven, temporal contrast sensitivity (TCS) in mice of either sex. Transgenic mice with desensitized cones (GNAT2 cpfl3 line) were used to identify rod contributions to TCS in mesopic lights. We found that at low mesopic lights (400 photons/s/μm2 at the retina), control and GNAT2 cpfl3 mice had similar TCS. Surprisingly, at upper mesopic lights (8000 photons/s/μm2), GNAT2 cpfl3 mice exhibited a relative reduction in TCS to low (<12 Hz) while maintaining normal TCS to high (12-36 Hz) temporal frequencies. The rod-driven responses to high temporal frequencies developed gradually over time (>30 min). Furthermore, the TCS of GNAT2 cpfl3 and GNAT2 cpfl3 ::Cx36-/- mice matched closely, indicating that transmission of high-frequency signals (1) does not require the rod-cone Cx36 gap junctions as has been proposed in the past; and (2) a Cx36-independent rod pathway(s) (e.g., direct rod to OFF cone bipolar cell synapses and/or glycinergic synapses from AII amacrine cells to OFF ganglion cells) is sufficient for fast, mesopic rod-driven vision. These findings extend our understanding of the link between visual circuits and perception in mouse.SIGNIFICANCE STATEMENT The contributions of specific retinal pathways to visual perception are not well understood. We found that the temporal processing properties of rod-driven vision in mice change significantly with light level. In dim lights, rods relay relatively slow temporal variations. However, in daylight conditions, rod pathways exhibit high sensitivity to fast but not to slow temporal variations, whereas cone-driven responses supplement the loss in rod-driven sensitivity to slow temporal variations. Our findings highlight the dynamic interplay of rod- and cone-driven vision as light levels rise from night to daytime levels. Furthermore, the fast, rod-driven signals do not require the rod-to-cone Cx36 gap junctions as proposed in the past, but rather, can be relayed by alternative Cx36-independent rod pathways.
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13
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Rod Photoresponse Kinetics Limit Temporal Contrast Sensitivity in Mesopic Vision. J Neurosci 2019; 39:3041-3056. [PMID: 30737308 DOI: 10.1523/jneurosci.1404-18.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 01/29/2019] [Accepted: 01/30/2019] [Indexed: 11/21/2022] Open
Abstract
The mammalian visual system operates over an extended range of ambient light levels by switching between rod and cone photoreceptors. Rod-driven vision is sluggish, highly sensitive, and operates in dim or scotopic lights, whereas cone-driven vision is brisk, less sensitive, and operates in bright or photopic lights. At intermediate or mesopic lights, vision transitions seamlessly from rod-driven to cone-driven, despite the profound differences in rod and cone response dynamics. The neural mechanisms underlying such a smooth handoff are not understood. Using an operant behavior assay, electrophysiological recordings, and mathematical modeling we examined the neural underpinnings of the mesopic visual transition in mice of either sex. We found that rods, but not cones, drive visual sensitivity to temporal light variations over much of the mesopic range. Surprisingly, speeding up rod photoresponse recovery kinetics in transgenic mice improved visual sensitivity to slow temporal variations, in the range where perceptual sensitivity is governed by Weber's law of sensation. In contrast, physiological processes acting downstream from phototransduction limit sensitivity to high frequencies and temporal resolution. We traced the paradoxical control of visual temporal sensitivity to rod photoresponses themselves. A scenario emerges where perceptual sensitivity is limited by: (1) the kinetics of neural processes acting downstream from phototransduction in scotopic lights, (2) rod response kinetics in mesopic lights, and (3) cone response kinetics as light levels rise into the photopic range.SIGNIFICANCE STATEMENT Our ability to detect flickering lights is constrained by the dynamics of the slowest step in the visual pathway. Cone photoresponse kinetics limit visual temporal sensitivity in bright (photopic) lights, whereas mechanisms in the inner retina limit sensitivity in dim (scotopic) lights. The neural mechanisms underlying the transition between scotopic and photopic vision in mesopic lights, when both rods are cones are active, are unknown. This study provides a missing link in this mechanism by establishing that rod photoresponse kinetics limit temporal sensitivity during the mesopic transition. Surprisingly, this range is where Weber's Law of Sensation governs temporal contrast sensitivity in mouse. Our results will help guide future studies of complex and dynamic interactions between rod-cone signals in the mesopic retina.
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