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Zhang Y, Paik SS, Kim IB. Changes in Retinal Structure and Function in Mice Exposed to Flickering Blue Light: Electroretinographic and Optical Coherence Tomographic Analyses. Exp Neurobiol 2024; 33:152-164. [PMID: 38993082 PMCID: PMC11247282 DOI: 10.5607/en24011] [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: 04/26/2024] [Revised: 05/27/2024] [Accepted: 06/01/2024] [Indexed: 07/13/2024] Open
Abstract
The harmful effects of blue light on the retina and health issues attributed to flickering light have been researched extensively. However, reports on the effects of flickering blue light at a frequency in the visible range on the retina are limited. This study aimed to non-invasively investigate the structural and functional changes in mice retinas following exposure to flickering blue light. BALB/c mice were subjected to non-flickering and flickering blue light, and changes in the retinal function and structure were assessed using electroretinography (ERG) and spectral-domain optical coherence tomography (SD-OCT), respectively. Retinal damage progression was monitored on days 3, 7, 14, and 42 following light exposure. Significant reductions in scotopic and photopic ERG responses were observed on day 3 (p<0.05). On day 7, the non-flickering and flickering groups demonstrated different functional changes: the flickering group showed further ERG response reduction, while the non-flickering group showed no reduction or slight improvement that was statistically insignificant (p>0.05). A similar trend lasted by day 14. On day 42, however, the difference between the non-flickering and flickering groups was significant, which was corroborated by the normalized amplitudes at 0, 0.5, and 1 log cd s/m2 (p<0.05). Quantitative and qualitative SD-OCT assays revealed more severe and progressive retinal damage in the flickering group throughout the study. Flickering blue light causes more persistent and severe retinal damage than non-flickering blue light and may be a risk factor for retinal degeneration even at frequencies as low as 20 Hz.
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Affiliation(s)
- Yan Zhang
- Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul 06591, Korea
| | - Sun-Sook Paik
- Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - In-Beom Kim
- Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul 06591, Korea
- Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
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2
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Gil R, Valente M, Shemesh N. Rat superior colliculus encodes the transition between static and dynamic vision modes. Nat Commun 2024; 15:849. [PMID: 38346973 PMCID: PMC10861507 DOI: 10.1038/s41467-024-44934-8] [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: 06/23/2023] [Accepted: 01/09/2024] [Indexed: 02/15/2024] Open
Abstract
The visual continuity illusion involves a shift in visual perception from static to dynamic vision modes when the stimuli arrive at high temporal frequency, and is critical for recognizing objects moving in the environment. However, how this illusion is encoded across the visual pathway remains poorly understood, with disparate frequency thresholds at retinal, cortical, and behavioural levels suggesting the involvement of other brain areas. Here, we employ a multimodal approach encompassing behaviour, whole-brain functional MRI, and electrophysiological measurements, for investigating the encoding of the continuity illusion in rats. Behavioural experiments report a frequency threshold of 18±2 Hz. Functional MRI reveal that superior colliculus signals transition from positive to negative at the behaviourally-driven threshold, unlike thalamic and cortical areas. Electrophysiological recordings indicate that these transitions are underpinned by neural activation/suppression. Lesions in the primary visual cortex reveal this effect to be intrinsic to the superior colliculus (under a cortical gain effect). Our findings highlight the superior colliculus' crucial involvement in encoding temporal frequency shifts, especially the change from static to dynamic vision modes.
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Affiliation(s)
- Rita Gil
- Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal
| | - Mafalda Valente
- Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal
| | - Noam Shemesh
- Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal.
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3
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Bailey MCD, du Hoffmann JF, Dalley JW. A multimodal approach connecting cortical and behavioural responses to the visual continuity illusion. Brain Neurosci Adv 2024; 8:23982128241251685. [PMID: 38720796 PMCID: PMC11077936 DOI: 10.1177/23982128241251685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 04/08/2024] [Indexed: 05/12/2024] Open
Abstract
In their recently published study, Gil, Valente and Shemesh combined behaviour, functional magnetic resonance imaging, electroencephalography and causal interventions to establish and validate a cortical processing substrate underlying the transition from static to dynamic visual states in the rat. Their research highlights the superior colliculus as the primary mediator of visual temporal discrimination by showing a direct correlation between behavioural and cortically derived flicker fusion frequency thresholds. This work provides the first empirical evidence addressing the previously established disparity between behavioural and cortically derived flicker fusion frequency thresholds. It demonstrates how important convergent multimodal approaches are to mapping and validating previously disputed cortical pathways. Here, we discuss and evaluate their work, suggesting possible future applications in the field of behavioural neuroscience.
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Affiliation(s)
- Matthew C. D. Bailey
- Department of Psychology, University of Cambridge, Cambridge, UK
- Boehringer Ingelheim Pharma GmbH & Co, Biberach an der Riss, Germany
| | | | - Jeffrey W. Dalley
- Department of Psychology, University of Cambridge, Cambridge, UK
- Boehringer Ingelheim Pharma GmbH & Co, Biberach an der Riss, Germany
- Department of Psychiatry, Herchel Smith Building for Brain and Mind Sciences, University of Cambridge, Cambridge, UK
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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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Muth T, Schipke JD, Brebeck AK, Dreyer S. Assessing Critical Flicker Fusion Frequency: Which Confounders? A Narrative Review. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:medicina59040800. [PMID: 37109758 PMCID: PMC10141404 DOI: 10.3390/medicina59040800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/13/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023]
Abstract
The critical flicker fusion frequency (cFFF) refers to the frequency at which a regularly recurring change of light stimuli is perceived as steady. The cFFF threshold is often assessed in clinics to evaluate the temporal characteristics of the visual system, making it a common test for eye diseases. Additionally, it serves as a helpful diagnostic tool for various neurological and internal diseases. In the field of diving/hyperbaric medicine, cFFF has been utilized to determine alertness and cognitive functions. Changes in the cFFF threshold have been linked to the influence of increased respiratory gas partial pressures, although there exist inconsistent results regarding this effect. Moreover, the use of flicker devices has produced mixed outcomes in previous studies. This narrative review aims to explore confounding factors that may affect the accuracy of cFFF threshold measurements, particularly in open-field studies. We identify five broad categories of such factors, including (1) participant characteristics, (2) optical factors, (3) smoking/drug use, (4) environmental aspects, and (5) breathing gases and partial pressures. We also discuss the application of cFFF measurements in the field of diving and hyperbaric medicine. In addition, we provide recommendations for interpreting changes in the cFFF threshold and how they are reported in research studies.
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Affiliation(s)
- Thomas Muth
- Institute of Occupational, Social, Environmental Medicine, Faculty of Medicine, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany
| | - Jochen D Schipke
- Research Group Experimental Surgery, University Hospital Düsseldorf, 40225 Düsseldorf, Germany
| | | | - Sven Dreyer
- Hyperbaric Oxygen Therapy, University Hospital Düsseldorf, 40225 Düsseldorf, Germany
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Klioutchnikov A, Wallace DJ, Sawinski J, Voit KM, Groemping Y, Kerr JND. A three-photon head-mounted microscope for imaging all layers of visual cortex in freely moving mice. Nat Methods 2023; 20:610-616. [PMID: 36443485 PMCID: PMC10089923 DOI: 10.1038/s41592-022-01688-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 10/19/2022] [Indexed: 11/30/2022]
Abstract
Advances in head-mounted microscopes have enabled imaging of neuronal activity using genetic tools in freely moving mice but these microscopes are restricted to recording in minimally lit arenas and imaging upper cortical layers. Here we built a 2-g, three-photon excitation-based microscope, containing a z-drive that enabled access to all cortical layers while mice freely behaved in a fully lit environment. The microscope had on-board photon detectors, robust to environmental light, and the arena lighting was timed to the end of each line-scan, enabling functional imaging of activity from cortical layer 4 and layer 6 neurons expressing jGCaMP7f in mice roaming a fully lit or dark arena. By comparing the neuronal activity measured from populations in these layers we show that activity in cortical layer 4 and layer 6 is differentially modulated by lit and dark conditions during free exploration.
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Affiliation(s)
- Alexandr Klioutchnikov
- Department of Behavior and Brain Organization, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn, Germany
| | - Damian J Wallace
- Department of Behavior and Brain Organization, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn, Germany
| | - Juergen Sawinski
- Department of Behavior and Brain Organization, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn, Germany
| | - Kay-Michael Voit
- Department of Behavior and Brain Organization, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn, Germany
| | - Yvonne Groemping
- Department of Behavior and Brain Organization, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn, Germany
| | - Jason N D Kerr
- Department of Behavior and Brain Organization, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn, Germany.
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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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8
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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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9
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Lopez-Cruz L, Bussey TJ, Saksida LM, Heath CJ. Using touchscreen-delivered cognitive assessments to address the principles of the 3Rs in behavioral sciences. Lab Anim (NY) 2021; 50:174-184. [PMID: 34140683 DOI: 10.1038/s41684-021-00791-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 05/11/2021] [Indexed: 02/05/2023]
Abstract
Despite considerable advances in both in silico and in vitro approaches, in vivo studies that involve animal model systems remain necessary in many research disciplines. Neuroscience is one such area, with studies often requiring access to a complete nervous system capable of dynamically selecting between and then executing a full range of cognitive and behavioral outputs in response to a given stimulus or other manipulation. The involvement of animals in research studies is an issue of active public debate and concern and is therefore carefully regulated. Such regulations are based on the principles of the 3Rs of Replacement, Reduction and Refinement. In the sub-specialty of behavioral neuroscience, Full/Absolute Replacement remains a major challenge, as the complete ex vivo recapitulation of a system as complex and dynamic as the nervous system has yet to be achieved. However, a number of very positive developments have occurred in this area with respect to Relative Replacement and to both Refinement and Reduction. In this review, we discuss the Refinement- and Reduction-related benefits yielded by the introduction of touchscreen-based behavioral assessment apparatus. We also discuss how data generated by a specific panel of behavioral tasks developed for this platform might substantially enhance monitoring of laboratory animal welfare and provide robust, quantitative comparisons of husbandry techniques to define and ensure maintenance of best practice.
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Affiliation(s)
- Laura Lopez-Cruz
- Department of Psychology and MRC/Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK. .,School of Life, Health and Chemical Sciences, The Open University, Milton Keynes, UK.
| | - Timothy J Bussey
- Department of Psychology and MRC/Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.,Robarts Research Institute & Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.,The Brain and Mind Institute, Western University, London, Ontario, Canada
| | - Lisa M Saksida
- Department of Psychology and MRC/Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.,Robarts Research Institute & Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.,The Brain and Mind Institute, Western University, London, Ontario, Canada
| | - Christopher J Heath
- School of Life, Health and Chemical Sciences, The Open University, Milton Keynes, UK
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10
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Michelson NJ, Vanni MP, Murphy TH. Comparison between transgenic and AAV-PHP.eB-mediated expression of GCaMP6s using in vivo wide-field functional imaging of brain activity. NEUROPHOTONICS 2019; 6:025014. [PMID: 31763351 PMCID: PMC6864505 DOI: 10.1117/1.nph.6.2.025014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/22/2019] [Indexed: 05/13/2023]
Abstract
We employ transcranial wide-field single-photon imaging to compare genetically encoded calcium sensors under transgenic or viral vector expression strategies. Awake, head-fixed animals and brief visual flash stimuli are used to assess function. The use of awake transcranial imaging may reduce confounds attributed to cranial window implantation or anesthesia states. We report differences in wide-field epifluorescence brightness and peak Δ F / F 0 response to visual stimulation between expression strategies. Other metrics for indicator performance include fluctuation analysis (standard deviation) and regional correlation maps made from spontaneous activity. We suggest that multiple measures, such as stimulus-evoked signal-to-noise ratio, brightness, and averaged visual Δ F / F 0 response, may be necessary to characterize indicator sensitivity and methods of expression. Furthermore, we show that strategies using blood brain barrier-permeable viruses, such as PHP.eB, yield comparable expression and function as those derived from transgenic mice. We suggest that testing of new genetically engineered activity sensors could employ a single-photon, wide-field imaging pipeline involving visual stimulation in awake mice that have been intravenously injected with PHP.eB.
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Affiliation(s)
- Nicholas J. Michelson
- Kinsmen Laboratory of Neurological Research, Department of Psychiatry, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
| | - Matthieu P. Vanni
- Kinsmen Laboratory of Neurological Research, Department of Psychiatry, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
- Université de Montréal, School of Optometry, Montréal, Québec, Canada
| | - Timothy H. Murphy
- Kinsmen Laboratory of Neurological Research, Department of Psychiatry, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
- Address all correspondence to Timothy H. Murphy E-mail:
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