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Inamdar SM, Lankford CK, Poria D, Laird JG, Solessio E, Kefalov VJ, Baker SA. Differential impact of Kv8.2 loss on rod and cone signaling and degeneration. Hum Mol Genet 2022; 31:1035-1050. [PMID: 34652420 PMCID: PMC8976434 DOI: 10.1093/hmg/ddab301] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/27/2021] [Accepted: 10/11/2021] [Indexed: 12/17/2022] Open
Abstract
Heteromeric Kv2.1/Kv8.2 channels are voltage-gated potassium channels localized to the photoreceptor inner segment. They carry IKx, which is largely responsible for setting the photoreceptor resting membrane potential. Mutations in Kv8.2 result in childhood-onset cone dystrophy with supernormal rod response (CDSRR). We generated a Kv8.2 knockout (KO) mouse and examined retinal signaling and photoreceptor degeneration to gain deeper insight into the complex phenotypes of this disease. Using electroretinograms, we show that there were delayed or reduced signaling from rods depending on the intensity of the light stimulus, consistent with reduced capacity for light-evoked changes in membrane potential. The delayed response was not seen ex vivo where extracellular potassium levels were controlled by the perfusion buffer, so we propose the in vivo alteration is influenced by genotype-associated ionic imbalance. We observed mild retinal degeneration. Signaling from cones was reduced but there was no loss of cone density. Loss of Kv8.2 altered responses to flickering light with responses attenuated at high frequencies and altered in shape at low frequencies. The Kv8.2 KO line on an all-cone retina background had reduced cone-driven ERG b wave amplitudes and underwent degeneration. Altogether, we provide insight into how a deficit in the dark current affects the health and function of photoreceptors.
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Affiliation(s)
- Shivangi M Inamdar
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa, IA 52252, USA
| | - Colten K Lankford
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa, IA 52252, USA
| | - Deepak Poria
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO 63110, USA
- Gavin Herbert Eye Institute, School of Medicine, Irvine, CA 92697, USA
| | - Joseph G Laird
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa, IA 52252, USA
| | - Eduardo Solessio
- Department of Ophthalmology and Visual Sciences, Center for Vision Research, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Vladimir J Kefalov
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO 63110, USA
- Gavin Herbert Eye Institute, School of Medicine, Irvine, CA 92697, USA
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA
| | - Sheila A Baker
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa, IA 52252, USA
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa, IA 52252, USA
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Wang M, Mason BN, Sowers LP, Kuburas A, Rea BJ, Russo AF. Investigating Migraine-Like Behavior using Light Aversion in Mice. J Vis Exp 2021. [PMID: 34459825 DOI: 10.3791/62839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Migraine is a complex neurological disorder characterized by headache and sensory abnormalities, such as hypersensitivity to light, observed as photophobia. Whilst it is impossible to confirm that a mouse is experiencing migraine, light aversion can be used as a behavioral surrogate for the migraine symptom of photophobia. To test for light aversion, we utilize the light/dark assay to measure the time mice freely choose to spend in either a light or dark environment. The assay has been refined by introducing two critical modifications: pre-exposures to the chamber prior to running the test procedure and adjustable chamber lighting, permitting the use of a range of light intensities from 55 lux to 27,000 lux. Because the choice to spend more time in the dark is also indicative of anxiety, we also utilize a light-independent anxiety test, the open field assay, to distinguish anxiety from light-aversive behavior. Here, we describe a modified test paradigm for the light/dark and open field assays. The application of these assays is described for intraperitoneal injection of calcitonin gene-related peptide (CGRP) in two mouse strains and for optogenetic brain stimulation studies.
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Affiliation(s)
- Mengya Wang
- Department of Neuroscience and Pharmacology, University of Iowa
| | - Bianca N Mason
- School of Behavioral and Brain Sciences, University of Texas at Dallas
| | - Levi P Sowers
- Center for the Prevention and Treatment of Visual Loss, Veterans Administration Health Center, Iowa City, IA; Department of Molecular Physiology and Biophysics, University of Iowa
| | - Adisa Kuburas
- Department of Molecular Physiology and Biophysics, University of Iowa
| | - Brandon J Rea
- Center for the Prevention and Treatment of Visual Loss, Veterans Administration Health Center, Iowa City, IA; Department of Molecular Physiology and Biophysics, University of Iowa
| | - Andrew F Russo
- Center for the Prevention and Treatment of Visual Loss, Veterans Administration Health Center, Iowa City, IA; Department of Molecular Physiology and Biophysics, University of Iowa; Department of Neurology, University of Iowa;
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Contreras EO, Dearing CG, Ashinhurst CA, Fish BA, Hossain SN, Rey AM, Silva PD, Thompson S. Pupillary reflex and behavioral masking responses to light as functional measures of retinal degeneration in mice. PLoS One 2021; 16:e0244702. [PMID: 33493166 PMCID: PMC7833141 DOI: 10.1371/journal.pone.0244702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 01/09/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Pre-clinical testing of retinal pathology and treatment efficacy depends on reliable and valid measures of retinal function. The electroretinogram (ERG) and tests of visual acuity are the ideal standard, but can be unmeasurable while useful vision remains. Non-image-forming responses to light such as the pupillary light reflex (PLR) are attractive surrogates. However, it is not clear how accurately such responses reflect changes in visual capability in specific disease models. The purpose of this study was to test whether measures of non-visual responses to light correlate with previously determined visual function in two photoreceptor degenerations. METHODS The sensitivity of masking behavior (light induced changes in running wheel activity) and the PLR were measured in 3-month-old wild-type mice (WT) with intact inner retinal circuitry, Pde6b-rd1/rd1 mice (rd1) with early and rapid loss of rods and cones, and Prph2-Rd2/Rd2 mice (Rd2) with a slower progressive loss of rods and cones. RESULTS In rd1 mice, negative masking had increased sensitivity, positive masking was absent, and the sensitivity of the PLR was severely reduced. In Rd2 mice, positive masking identified useful vision at higher light levels, but there was a limited decrease in the irradiance sensitivity of negative masking and the PLR, and the amplitude of change for both underestimated the reduction in irradiance sensitivity of image-forming vision. CONCLUSIONS Together these data show that in a given disease, two responses to light can be affected in opposite ways, and that for a given response to light, the change in the response does not accurately represent the degree of pathology. However, the extent of the deficit in the PLR means that even a limited rescue of rod/cone function might be measured by increased PLR amplitude. In addition, positive masking has the potential to measure effective treatment in both models by restoring responses or shifting thresholds to lower irradiances.
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Affiliation(s)
- Ethan O. Contreras
- Department of Psychology, New Mexico Tech, Socorro, NM, United States of America
- Department of Biology, New Mexico Tech, Socorro, NM, United States of America
| | - Carley G. Dearing
- Department of Psychology, New Mexico Tech, Socorro, NM, United States of America
- Department of Biology, New Mexico Tech, Socorro, NM, United States of America
- College of Veterinary Medicine and Biomedical Science, Colorado State University, Fort Collins, CO, United States of America
| | - Crystal A. Ashinhurst
- Department of Psychology, New Mexico Tech, Socorro, NM, United States of America
- Department of Biology, New Mexico Tech, Socorro, NM, United States of America
| | - Betty A. Fish
- Department of Psychology, New Mexico Tech, Socorro, NM, United States of America
- Department of Biology, New Mexico Tech, Socorro, NM, United States of America
| | - Sajila N. Hossain
- Department of Psychology, New Mexico Tech, Socorro, NM, United States of America
- Department of Biology, New Mexico Tech, Socorro, NM, United States of America
| | - Ariana M. Rey
- Department of Psychology, New Mexico Tech, Socorro, NM, United States of America
- Department of Biology, New Mexico Tech, Socorro, NM, United States of America
| | - Primal D. Silva
- Department of Psychology, New Mexico Tech, Socorro, NM, United States of America
- Department of Biology, New Mexico Tech, Socorro, NM, United States of America
| | - Stewart Thompson
- Department of Psychology, New Mexico Tech, Socorro, NM, United States of America
- Department of Biology, New Mexico Tech, Socorro, NM, United States of America
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Sowers LP, Wang M, Rea BJ, Taugher RJ, Kuburas A, Kim Y, Wemmie JA, Walker CS, Hay DL, Russo AF. Stimulation of Posterior Thalamic Nuclei Induces Photophobic Behavior in Mice. Headache 2020; 60:1961-1981. [PMID: 32750230 DOI: 10.1111/head.13917] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/15/2020] [Accepted: 06/24/2020] [Indexed: 02/03/2023]
Abstract
OBJECTIVE A hallmark of migraine is photophobia. In mice, photophobia-like behavior is induced by calcitonin gene-related peptide (CGRP), a neuropeptide known to be a key player in migraine. In this study, we sought to identify sites within the brain from which CGRP could induce photophobia. DESIGN We focused on the posterior thalamic region, which contains neurons responsive to both light and dural stimulation and has CGRP binding sites. We probed this area with both optogenetic stimulation and acute CGRP injections in wild-type mice. Since the light/dark assay has historically been used to investigate anxiety-like responses in animals, we measured anxiety in a light-independent open field assay and asked if stimulation of a brain region, the periaqueductal gray, that induces anxiety would yield similar results to posterior thalamic stimulation. The hippocampus was used as an anatomical control to ensure that light-aversive behaviors could not be induced by the stimulation of any brain region. RESULTS Optogenetic activation of neuronal cell bodies in the posterior thalamic nuclei elicited light aversion in both bright and dim light without an anxiety-like response in an open field assay. Injection of CGRP into the posterior thalamic region triggered similar light-aversive behavior without anxiety. In contrast to the posterior thalamic nuclei, optogenetic stimulation of dorsal periaqueductal gray cell bodies caused both light aversion and an anxiety-like response, while CGRP injection had no effect. In the dorsal hippocampus, neither optical stimulation nor CGRP injection affected light aversion or open field behaviors. CONCLUSION Stimulation of posterior thalamic nuclei is able to initiate light-aversive signals in mice that may be modulated by CGRP to cause photophobia in migraine.
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Affiliation(s)
- Levi P Sowers
- Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, USA.,Veterans Administration Health Center, Iowa City, IA, USA.,Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | - Mengya Wang
- Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Brandon J Rea
- Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, USA.,Veterans Administration Health Center, Iowa City, IA, USA.,Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | - Rebecca J Taugher
- Veterans Administration Health Center, Iowa City, IA, USA.,Department of Psychiatry, University of Iowa, Iowa City, IA, USA
| | - Adisa Kuburas
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | - Youngcho Kim
- Department of Neurology, University of Iowa, Iowa City, IA, USA
| | - John A Wemmie
- Veterans Administration Health Center, Iowa City, IA, USA.,Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA.,Department of Psychiatry, University of Iowa, Iowa City, IA, USA.,Department of Neurosurgery, University of Iowa, Iowa City, IA, USA
| | | | - Debbie L Hay
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Andrew F Russo
- Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, USA.,Veterans Administration Health Center, Iowa City, IA, USA.,Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA.,Department of Neurology, University of Iowa, Iowa City, IA, USA
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Thompson S, Blodi FR, Larson DR, Anderson MG, Stasheff SF. The Efemp1R345W Macular Dystrophy Mutation Causes Amplified Circadian and Photophobic Responses to Light in Mice. Invest Ophthalmol Vis Sci 2019; 60:2110-2117. [PMID: 31095679 PMCID: PMC6735810 DOI: 10.1167/iovs.19-26881] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Purpose The R345W mutation in EFEMP1 causes malattia leventinese, an autosomal dominant eye disease with pathogenesis similar to an early-onset age-related macular degeneration. In mice, Efemp1R345W does not cause detectable degeneration but small subretinal deposits do accumulate. The purpose of this study was to determine whether there were abnormal responses to light at this presymptomatic stage in Efemp1R345W mice. Methods Responses to light were assessed by visual water task, circadian phase shifting, and negative masking behavior. The mechanism of abnormal responses was investigated by anterior eye exam, electroretinogram, melanopsin cell quantification, and multielectrode recording of retinal ganglion cell activity. Results Visual acuity was not different in Efemp1R345W mice. However, amplitudes of circadian phase shifting (P = 0.016) and negative masking (P < 0.0001) were increased in Efemp1R345W mice. This phenotype was not explained by anterior eye defects or amplified outer retina responses. Instead, we identified increased melanopsin-generated responses to light in the ganglion cell layer of the retina (P < 0.01). Conclusions Efemp1R345W increases the sensitivity to light of behavioral responses driven by detection of irradiance. An amplified response to light in melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) is consistent with this phenotype. The major concern with this effect of the malattia leventinese mutation is the potential for abnormal regulation of physiology by light to negatively affect health.
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Affiliation(s)
- Stewart Thompson
- Department of Psychology, New Mexico Tech, Socorro, New Mexico, United States.,Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States.,Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States
| | - Frederick R Blodi
- Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States.,Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States.,Pediatrics, University of Iowa, Iowa City, Iowa, United States.,Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, United States
| | - Demelza R Larson
- Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States.,Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, United States.,Biology Department, College of St. Benedict & St. John's University, Collegeville, Minnesota, United States
| | - Michael G Anderson
- Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States.,Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States.,Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, United States.,VA Center for Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States
| | - Steven F Stasheff
- Institute for Vision Research, University of Iowa, Iowa City, Iowa, United States.,Pediatrics, University of Iowa, Iowa City, Iowa, United States.,Unit on Retinal Neurophysiology, National Eye Institute, Bethesda, Maryland, United States.,Center for Neurosciences and Behavioral Medicine, Children's National Medical Center, Washington, DC, United States.,George Washington University School of Medicine and Health Sciences, Washington, DC, United States
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6
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Kostic C, Crippa SV, Martin C, Kardon RH, Biel M, Arsenijevic Y, Kawasaki A. Determination of Rod and Cone Influence to the Early and Late Dynamic of the Pupillary Light Response. Invest Ophthalmol Vis Sci 2017; 57:2501-8. [PMID: 27152964 PMCID: PMC4868103 DOI: 10.1167/iovs.16-19150] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study aims to identify which aspects of the pupil light reflex are most influenced by rods and cones independently by analyzing pupil recordings from different mouse models of photoreceptor deficiency. METHODS One-month-old wild type (WT), rodless (Rho-/-), coneless (Cnga3-/-), or photoreceptor less (Cnga3-/-; Rho-/- or Gnat1-/-) mice were subjected to brief red and blue light stimuli of increasing intensity. To describe the initial dynamic response to light, the maximal pupillary constriction amplitudes and the derivative curve of the first 3 seconds were determined. To estimate the postillumination phase, the constriction amplitude at 9.5 seconds after light termination was related to the maximal constriction amplitude. RESULTS Rho-/- mice showed decreased constriction amplitude but more prolonged pupilloconstriction to all blue and red light stimuli compared to wild type mice. Cnga3-/- mice had constriction amplitudes similar to WT however following maximal constriction, the early and rapid dilation to low intensity blue light was decreased. To high intensity blue light, the Cnga3-/- mice demonstrated marked prolongation of the pupillary constriction. Cnga3-/-; Rho-/- mice had no pupil response to red light of low and medium intensity. CONCLUSIONS From specific gene defective mouse models which selectively voided the rod or cone function, we determined that mouse rod photoreceptors are highly contributing to the pupil response to blue light stimuli but also to low and medium red stimuli. We also observed that cone cells mainly drive the partial rapid dilation of the initial response to low blue light stimuli. Thus photoreceptor dysfunction can be derived from chromatic pupillometry in mouse models.
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Affiliation(s)
- Corinne Kostic
- Department of Ophthalmology University Lausanne, Hôpital Ophtalmique Jules Gonin, Lausanne, Switzerland
| | - Sylvain V Crippa
- Department of Ophthalmology University Lausanne, Hôpital Ophtalmique Jules Gonin, Lausanne, Switzerland
| | - Catherine Martin
- Department of Ophthalmology University Lausanne, Hôpital Ophtalmique Jules Gonin, Lausanne, Switzerland
| | - Randy H Kardon
- Department of Ophthalmology, University of Iowa School of Medicine and Iowa City VA Center for Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States
| | - Martin Biel
- Center for Integrated Protein Science Munich CiPS at the Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Yvan Arsenijevic
- Department of Ophthalmology University Lausanne, Hôpital Ophtalmique Jules Gonin, Lausanne, Switzerland
| | - Aki Kawasaki
- Department of Ophthalmology University Lausanne, Hôpital Ophtalmique Jules Gonin, Lausanne, Switzerland
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Bushnell M, Umino Y, Solessio E. A system to measure the pupil response to steady lights in freely behaving mice. J Neurosci Methods 2016; 273:74-85. [PMID: 27494989 DOI: 10.1016/j.jneumeth.2016.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 06/27/2016] [Accepted: 08/02/2016] [Indexed: 01/17/2023]
Abstract
BACKGROUND Transgenic mice are widely used for the study of basic visual function and retinal disease, including in psychophysical tests. Mice have a robust pupillary light reflex that controls the amount of light that enters the eye, and the attenuating effects of the pupil must be considered during such tests. Measurement of the size of pupils at various luminance levels requires that mice remain stable over prolonged periods of time; however, sedation of mice with anesthesia and/or manual restraint can influence the size of their pupils. NEW METHOD We present a system to measure the pupillary light response to steady lights of freely behaving mice using a custom-built, portable device that automatically acquires close-up images of their eyes. The device takes advantage of the intrinsic nature of mice to inspect objects of interest and can be used to measure pupillary responses in optomotor or operant behavior testing chambers. RESULTS The size of the pupils in freely behaving mice decreased gradually with luminance from a maximal area in the dark of 3.8mm2 down to a minimum 0.14mm2 at 80 scotopic cd/m2. The data was well fit with a Hill equation with Lo equal to 0.21cd/m2 and coefficient h=0.48. COMPARISON WITH EXISTING METHODS These values agree with prior measurements of the pupillary response of unrestrained mice that use more laborious and time consuming approaches. CONCLUSIONS Our new method facilitates practical, straightforward and accurate measurements of pupillary responses made under the same experimental conditions as those used during psychophysical testing.
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Affiliation(s)
- Mark Bushnell
- Center for Vision Research and SUNY Eye Institute, Department of Ophthalmology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, New York 13210, USA
| | - Yumiko Umino
- Center for Vision Research and SUNY Eye Institute, Department of Ophthalmology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, New York 13210, USA
| | - Eduardo Solessio
- Center for Vision Research and SUNY Eye Institute, Department of Ophthalmology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, New York 13210, USA.
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Light aversion and corneal mechanical sensitivity are altered by intrinscally photosensitive retinal ganglion cells in a mouse model of corneal surface damage. Exp Eye Res 2015; 137:57-62. [PMID: 26070985 DOI: 10.1016/j.exer.2015.05.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 05/13/2015] [Accepted: 05/29/2015] [Indexed: 02/03/2023]
Abstract
Animal models of corneal surface damage reliably exhibit altered tear quality and quantity, apoptosis, nerve degeneration, immune responses and many other symptoms of dry eye disease. An important clinical symptom of dry eye disease is photoallodynia (photophobia), which can be modeled in mice using behavioral light aversion as a surrogate. Intrinsically photosensitive retinal ganglion cells (ipRGCs) function as irradiance detectors. They have been shown to mediate innate light aversion and are ideal candidates to initiate or modulate light aversion in disease or dysfunctional states. This study addresses the relationship between light aversion, corneal mechanical sensitivity and corneal surface damage in a preclinical mouse model using bilateral topical application of benzalkonium chloride (BAC). Corneal application of BAC resulted in similar levels of corneal surface damage by fluorescein staining in both wild type mice and mice lacking ipRGCs. Light aversion was an early symptom of corneal surface damage, was proportional to the level of corneal damage and dependent on melanopsin-expressing cells. A decrease in both corneal mechanosensitivity and light aversion was observed in mice lacking melanopsin-expressing cells, suggesting a connection in the neural circuits mediating the two most common symptoms of corneal surface damage.
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