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Tapia ML, Nascimento-dos-Santos G, Park KK. Subtype-specific survival and regeneration of retinal ganglion cells in response to injury. Front Cell Dev Biol 2022; 10:956279. [PMID: 36035999 PMCID: PMC9411869 DOI: 10.3389/fcell.2022.956279] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 06/28/2022] [Indexed: 11/19/2022] Open
Abstract
Retinal ganglion cells (RGCs) are a heterogeneous population of neurons that function synchronously to convey visual information through the optic nerve to retinorecipient target areas in the brain. Injury or disease to the optic nerve results in RGC degeneration and loss of visual function, as few RGCs survive, and even fewer can be provoked to regenerate their axons. Despite causative insults being broadly shared, regeneration studies demonstrate that RGC types exhibit differential resilience to injury and undergo selective survival and regeneration of their axons. While most early studies have identified these RGC types based their morphological and physiological characteristics, recent advances in transgenic and gene sequencing technologies have further enabled type identification based on unique molecular features. In this review, we provide an overview of the well characterized RGC types and identify those shown to preferentially survive and regenerate in various regeneration models. Furthermore, we discuss cellular characteristics of both the resilient and susceptible RGC types including the combinatorial expression of different molecular markers that identify these specific populations. Lastly, we discuss potential molecular mechanisms and genes found to be selectively expressed by specific types that may contribute to their reparative capacity. Together, we describe the studies that lay the important groundwork for identifying factors that promote neural regeneration and help advance the development of targeted therapy for the treatment of RGC degeneration as well as neurodegenerative diseases in general.
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2
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Chen CK, Kiyama T, Weber N, Whitaker CM, Pan P, Badea TC, Massey SC, Mao CA. Characterization of Tbr2-expressing retinal ganglion cells. J Comp Neurol 2021; 529:3513-3532. [PMID: 34245014 DOI: 10.1002/cne.25208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 05/27/2021] [Accepted: 06/28/2021] [Indexed: 12/19/2022]
Abstract
The mammalian retina contains more than 40 retinal ganglion cell (RGC) subtypes based on their unique morphologies, functions, and molecular profiles. Among them, intrinsically photosensitive RGCs (ipRGCs) are the first specified RGC type emerging from a common retinal progenitor pool during development. Previous work has shown that T-box transcription factor T-brain 2 (Tbr2) is essential for the formation and maintenance of ipRGCs, and that Tbr2-expressing RGCs activate Opn4 expression upon native ipRGC ablation, suggesting that Tbr2+ RGCs contain a reservoir for ipRGCs. However, the identity of Tbr2+ RGCs has not been fully vetted. Here, using genetic sparse labeling and single cell recording, we showed that Tbr2-expressing retinal neurons include RGCs and a subset of GABAergic displaced amacrine cells (dACs). Most Tbr2+ RGCs are intrinsically photosensitive and morphologically resemble native ipRGCs with identical retinofugal projections. Tbr2+ RGCs also include a unique and rare Pou4f1-expressing OFF RGC subtype. Using a loss-of-function strategy, we have further demonstrated that Tbr2 is essential for the survival of these RGCs and dACs, as well as maintaining the expression of Opn4. These data set a strong foundation to study how Tbr2 regulates ipRGC development and survival, as well as the expression of molecular machinery regulating intrinsic photosensitivity.
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Affiliation(s)
- Ching-Kang Chen
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - Takae Kiyama
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | - Nicole Weber
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - Christopher M Whitaker
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | - Ping Pan
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | - Tudor C Badea
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA.,Research and Development Institute, Transilvania University of Brasov, School of Medicine, Brasov, Romania
| | - Stephen C Massey
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA.,The MD Anderson Cancer Center/UTHealth Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - Chai-An Mao
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA.,The MD Anderson Cancer Center/UTHealth Graduate School of Biomedical Sciences, Houston, Texas, USA
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3
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Hannibal J. Comparative Neurology of Circadian Photoreception: The Retinohypothalamic Tract (RHT) in Sighted and Naturally Blind Mammals. Front Neurosci 2021; 15:640113. [PMID: 34054403 PMCID: PMC8160255 DOI: 10.3389/fnins.2021.640113] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/29/2021] [Indexed: 11/13/2022] Open
Abstract
The mammalian eye contains two systems for light perception: an image detecting system constituted primarily of the classical photoreceptors, rods and cones, and a non-image forming system (NIF) constituted of a small group of intrinsically photosensitive retinal ganglion cells driven by melanopsin (mRGCs). The mRGCs receive input from the outer retina and NIF mediates light entrainment of circadian rhythms, masking behavior, light induced inhibition of nocturnal melatonin secretion, pupillary reflex (PLR), and affect the sleep/wake cycle. This review focuses on the mammalian NIF and its anatomy in the eye as well as its neuronal projection to the brain. This pathway is known as the retinohypothalamic tract (RHT). The development and functions of the NIF as well as the knowledge gained from studying gene modified mice is highlighted. Furthermore, the similarities of the NIF between sighted (nocturnal and diurnal rodent species, monkeys, humans) and naturally blind mammals (blind mole rats Spalax ehrenbergi and the Iberian mole, Talpa occidentalis) are discussed in relation to a changing world where increasing exposure to artificial light at night (ALAN) is becoming a challenge for humans and animals in the modern society.
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Affiliation(s)
- Jens Hannibal
- Department of Clinical Biochemistry, Bispebjerg Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark
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4
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Bray ER, Yungher BJ, Levay K, Ribeiro M, Dvoryanchikov G, Ayupe AC, Thakor K, Marks V, Randolph M, Danzi MC, Schmidt TM, Chaudhari N, Lemmon VP, Hattar S, Park KK. Thrombospondin-1 Mediates Axon Regeneration in Retinal Ganglion Cells. Neuron 2019; 103:642-657.e7. [PMID: 31255486 DOI: 10.1016/j.neuron.2019.05.044] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 02/11/2019] [Accepted: 05/28/2019] [Indexed: 12/20/2022]
Abstract
Neuronal subtypes show diverse injury responses, but the molecular underpinnings remain elusive. Using transgenic mice that allow reliable visualization of axonal fate, we demonstrate that intrinsically photosensitive retinal ganglion cells (ipRGCs) are both resilient to cell death and highly regenerative. Using RNA sequencing (RNA-seq), we show genes that are differentially expressed in ipRGCs and that associate with their survival and axon regeneration. Strikingly, thrombospondin-1 (Thbs1) ranked as the most differentially expressed gene, along with the well-documented injury-response genes Atf3 and Jun. THBS1 knockdown in RGCs eliminated axon regeneration. Conversely, RGC overexpression of THBS1 enhanced regeneration in both ipRGCs and non-ipRGCs, an effect that was dependent on syndecan-1, a known THBS1-binding protein. All structural domains of the THBS1 were not equally effective; the trimerization and C-terminal domains promoted regeneration, while the THBS type-1 repeats were dispensable. Our results identify cell-type-specific induction of Thbs1 as a novel gene conferring high regenerative capacity.
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Affiliation(s)
- Eric R Bray
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Benjamin J Yungher
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Konstantin Levay
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Marcio Ribeiro
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Gennady Dvoryanchikov
- Department of Physiology & Biophysics, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Ana C Ayupe
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Kinjal Thakor
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Victoria Marks
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Michael Randolph
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Matt C Danzi
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Tiffany M Schmidt
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | - Nirupa Chaudhari
- Department of Physiology & Biophysics, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Vance P Lemmon
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Samer Hattar
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Kevin K Park
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
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5
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Bertolesi GE, McFarlane S. Seeing the light to change colour: An evolutionary perspective on the role of melanopsin in neuroendocrine circuits regulating light-mediated skin pigmentation. Pigment Cell Melanoma Res 2018; 31:354-373. [PMID: 29239123 DOI: 10.1111/pcmr.12678] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 12/05/2017] [Indexed: 12/17/2022]
Abstract
Melanopsin photopigments, Opn4x and Opn4m, were evolutionary selected to "see the light" in systems that regulate skin colour change. In this review, we analyse the roles of melanopsins, and how critical evolutionary developments, including the requirement for thermoregulation and ultraviolet protection, the emergence of a background adaptation mechanism in land-dwelling amphibian ancestors and the loss of a photosensitive pineal gland in mammals, may have helped sculpt the mechanisms that regulate light-controlled skin pigmentation. These mechanisms include melanopsin in skin pigment cells directly inducing skin darkening for thermoregulation/ultraviolet protection; melanopsin-expressing eye cells controlling neuroendocrine circuits to mediate background adaptation in amphibians in response to surface-reflected light; and pineal gland secretion of melatonin phased to environmental illuminance to regulate circadian and seasonal variation in skin colour, a process initiated by melanopsin-expressing eye cells in mammals, and by as yet unknown non-visual opsins in the pineal gland of non-mammals.
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Affiliation(s)
- Gabriel E Bertolesi
- Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB, Canada
| | - Sarah McFarlane
- Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB, Canada
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6
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Hannibal J, Christiansen AT, Heegaard S, Fahrenkrug J, Kiilgaard JF. Melanopsin expressing human retinal ganglion cells: Subtypes, distribution, and intraretinal connectivity. J Comp Neurol 2017; 525:1934-1961. [PMID: 28160289 DOI: 10.1002/cne.24181] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/24/2017] [Accepted: 01/25/2017] [Indexed: 12/15/2022]
Abstract
Intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin belong to a heterogenic population of RGCs which regulate the circadian clock, masking behavior, melatonin suppression, the pupillary light reflex, and sleep/wake cycles. The different functions seem to be associated to different subtypes of melanopsin cells. In rodents, subtype classification has associated subtypes to function. In primate and human retina such classification has so far, not been applied. In the present study using antibodies against N- and C-terminal parts of human melanopsin, confocal microscopy and 3D reconstruction of melanopsin immunoreactive (-ir) RGCs, we applied the criteria used in mouse on human melanopsin-ir RGCs. We identified M1, displaced M1, M2, and M4 cells. We found two other subtypes of melanopsin-ir RGCs, which were named "gigantic M1 (GM1)" and "gigantic displaced M1 (GDM1)." Few M3 cells and no M5 subtypes were labeled. Total cell counts from one male and one female retina revealed that the human retina contains 7283 ± 237 melanopsin-ir (0.63-0.75% of the total number of RGCs). The melanopsin subtypes were unevenly distributed. Most significant was the highest density of M4 cells in the nasal retina. We identified input to the melanopsin-ir RGCs from AII amacrine cells and directly from rod bipolar cells via ribbon synapses in the innermost ON layer of the inner plexiform layer (IPL) and from dopaminergic amacrine cells and GABAergic processes in the outermost OFF layer of the IPL. The study characterizes a heterogenic population of human melanopsin-ir RGCs, which most likely are involved in different functions.
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Affiliation(s)
- Jens Hannibal
- Department of Clinical Biochemistry, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | | | - Steffen Heegaard
- Department of Ophalmology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Pathology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Jan Fahrenkrug
- Department of Clinical Biochemistry, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jens Folke Kiilgaard
- Department of Ophalmology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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7
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T-box transcription regulator Tbr2 is essential for the formation and maintenance of Opn4/melanopsin-expressing intrinsically photosensitive retinal ganglion cells. J Neurosci 2014; 34:13083-95. [PMID: 25253855 DOI: 10.1523/jneurosci.1027-14.2014] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Opsin 4 (Opn4)/melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) play a major role in non-image-forming visual system. Although advances have been made in understanding their morphological features and functions, the molecular mechanisms that regulate their formation and survival remain unknown. Previously, we found that mouse T-box brain 2 (Tbr2) (also known as Eomes), a T-box-containing transcription factor, was expressed in a subset of newborn RGCs, suggesting that it is involved in the formation of specific RGC subtypes. In this in vivo study, we used complex mouse genetics, single-cell dye tracing, and behavioral analyses to determine whether Tbr2 regulates ipRGC formation and survival. Our results show the following: (1) Opn4 is expressed exclusively in Tbr2-positive RGCs; (2) no ipRGCs are detected when Tbr2 is genetically ablated before RGC specification; and (3) most ipRGCs are eliminated when Tbr2 is deleted in established ipRGCs. The few remaining ipRGCs display abnormal dendritic morphological features and functions. In addition, some Tbr2-expressing RGCs can activate Opn4 expression on the loss of native ipRGCs, suggesting that Tbr2-expressing RGCs may serve as a reservoir of ipRGCs to regulate the number of ipRGCs and the expression levels of Opn4.
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8
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Daytime light exposure: effects on biomarkers, measures of alertness, and performance. Behav Brain Res 2014; 274:176-85. [PMID: 25131505 DOI: 10.1016/j.bbr.2014.08.017] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 08/04/2014] [Accepted: 08/08/2014] [Indexed: 12/25/2022]
Abstract
Light can elicit an alerting response in humans, independent from acute melatonin suppression. Recent studies have shown that red light significantly increases daytime and nighttime alertness. The main goal of the present study was to further investigate the effects of daytime light exposure on performance, biomarkers and measures of alertness. It was hypothesized that, compared to remaining in dim light, daytime exposure to narrowband long-wavelength (red) light or polychromatic (2568K) light would induce greater alertness and shorter response times. Thirteen subjects experienced three lighting conditions: dim light (<5lux), red light (λmax=631nm, 213lux, 1.1W/m(2)), and white light (2568K, 361lux, 1.1W/m(2)). The presentation order of the lighting conditions was counterbalanced across the participants and each participant saw a different lighting condition each week. Our results demonstrate, for the first time, that red light can increase short-term performance as shown by the significant (p<0.05) reduced response time and higher throughput in performance tests during the daytime. There was a significant decrease (p<0.05) in alpha power and alpha-theta power after exposure to the white light, but this alerting effect did not translate to better performance. Alpha power was significantly reduced after red light exposure in the middle of the afternoon. There was no significant effect of light on cortisol and alpha amylase. The present results suggest that red light can be used to increase daytime performance.
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9
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Hong J, Zeng Q, Wang H, Kuo DS, Baldridge WH, Wang N. Controlling the number of melanopsin-containing retinal ganglion cells by early light exposure. Exp Eye Res 2013; 111:17-26. [DOI: 10.1016/j.exer.2013.03.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 03/08/2013] [Accepted: 03/14/2013] [Indexed: 11/28/2022]
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10
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Non-circadian direct effects of light on sleep and alertness: lessons from transgenic mouse models. Sleep Med Rev 2013; 17:445-52. [PMID: 23602126 DOI: 10.1016/j.smrv.2012.12.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 12/27/2012] [Accepted: 12/29/2012] [Indexed: 01/16/2023]
Abstract
Light exerts a strong non-visual influence on human physiology and behavior. Additionally light is known to affect sleep indirectly through the phase shifting of circadian rhythms, and directly, promoting alertness in humans and sleep in nocturnal species. Little attention has been paid to the direct non-image-forming influence of light until recently with the discovery and emerging knowledge on melanopsin, a photopigment which is maximally sensitive to the blue spectrum of light and expressed in a subset of intrinsically photosensitive retinal ganglion cells. Indeed, the development of transgenic mouse models targeting different phototransduction pathways has allowed researchers to decipher the mechanisms by which mammals adapt sleep to their light environment. This review summarizes the novel concepts and discrepancies from recent publications relating to the non-circadian effects of light on sleep and waking. Specifically, we discuss whether darkness, in addition to light, affects their quality. Furthermore, we seek to understand whether longer sustained periods of light exposure can influence sleep, if the direct photic regulation depends on time of day, and whether this affects the homeostatic sleep process. Moreover, the neural pathways by which light exerts a direct influence on sleep will be discussed including the respective role of rods/cones and melanopsin. Finally, we suggest that light weighs on the components of the flip-flop switch model to induce respectively sleep or waking, in nocturnal and diurnal animals. Taking these data into account we therefore propose a novel model of sleep regulation based on three processes; the direct photic regulation interacting with the circadian and homeostatic drives to determine the timing and quality of sleep and waking. An outlook of promising clinical and non-clinical applications of these findings will be considered as well as directions for future animal and human research.
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11
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Roecklein KA, Wong PM, Franzen PL, Hasler BP, Wood-Vasey WM, Nimgaonkar VL, Miller MA, Kepreos KM, Ferrell RE, Manuck SB. Melanopsin gene variations interact with season to predict sleep onset and chronotype. Chronobiol Int 2012; 29:1036-47. [PMID: 22881342 DOI: 10.3109/07420528.2012.706766] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The human melanopsin gene has been reported to mediate risk for seasonal affective disorder (SAD), which is hypothesized to be caused by decreased photic input during winter when light levels fall below threshold, resulting in differences in circadian phase and/or sleep. However, it is unclear if melanopsin increases risk of SAD by causing differences in sleep or circadian phase, or if those differences are symptoms of the mood disorder. To determine if melanopsin sequence variations are associated with differences in sleep-wake behavior among those not suffering from a mood disorder, the authors tested associations between melanopsin gene polymorphisms and self-reported sleep timing (sleep onset and wake time) in a community sample (N = 234) of non-Hispanic Caucasian participants (age 30-54 yrs) with no history of psychological, neurological, or sleep disorders. The authors also tested the effect of melanopsin variations on differences in preferred sleep and activity timing (i.e., chronotype), which may reflect differences in circadian phase, sleep homeostasis, or both. Daylength on the day of assessment was measured and included in analyses. DNA samples were genotyped for melanopsin gene polymorphisms using fluorescence polarization. P10L genotype interacted with daylength to predict self-reported sleep onset (interaction p < .05). Specifically, sleep onset among those with the TT genotype was later in the day when individuals were assessed on longer days and earlier in the day on shorter days, whereas individuals in the other genotype groups (i.e., CC and CT) did not show this interaction effect. P10L genotype also interacted in an analogous way with daylength to predict self-reported morningness (interaction p < .05). These results suggest that the P10L TT genotype interacts with daylength to predispose individuals to vary in sleep onset and chronotype as a function of daylength, whereas other genotypes at P10L do not seem to have effects that vary by daylength. A better understanding of how melanopsin confers heightened responsivity to daylength may improve our understanding of a broad range of behavioral responses to light (i.e., circadian, sleep, mood) as well as the etiology of disorders with seasonal patterns of recurrence or exacerbation.
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Affiliation(s)
- Kathryn A Roecklein
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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12
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Danilenko KV, Plisov IL, Cooper HM, Wirz-Justice A, Hébert M. Human Cone Light Sensitivity and Melatonin Rhythms Following 24-hour Continuous Illumination. Chronobiol Int 2011; 28:407-14. [DOI: 10.3109/07420528.2011.567425] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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13
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Sans-Fuentes MA, Díez-Noguera A, Cambras T. Light responses of the circadian system in leptin deficient mice. Physiol Behav 2010; 99:487-94. [DOI: 10.1016/j.physbeh.2009.12.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 11/25/2009] [Accepted: 12/17/2009] [Indexed: 01/19/2023]
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14
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Ingham ES, Günhan E, Fuller PM, Fuller CA. Immunotoxin-induced ablation of melanopsin retinal ganglion cells in a non-murine mammalian model. J Comp Neurol 2009; 516:125-40. [PMID: 19575450 DOI: 10.1002/cne.22103] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In mammals, non-image-forming visual functions, including circadian photoentrainment and the pupillary light reflex, are thought to be mediated by the combination of rods, cones, and the melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs). Although several genetic models have been developed to clarify the individual roles of the rod, cone, and ipRGC systems in mediating non-image visual function, assessing the in vivo role(s) of the ipRGCs has been complicated by the possibility of ontogenetic issues in these genetically modified animal models. In the present study, we describe the development and validation of an immunotoxin that specifically targets the ipRGC population in the mature mammalian retina. This ipRGC immunotoxin, consisting of saporin conjugated to a melanopsin polyclonal antibody, was evaluated with respect to its effectiveness and specificity in depleting the ipRGC population in the fully developed rat retina. The results showed that the ipRGC toxin rapidly and permanently depleted approximately 70% of the ipRGC population, without inducing appreciable changes in the cell number or morphology of any of the non-melanopsin-containing retinal cell populations investigated. These findings suggest that the newly developed ipRGC immunotoxin provides a potent method for achieving relatively rapid, permanent, and selective depletion of the ipRGC population in a non-murine model system. The development of this ipRGC-ablation method is the next step in elucidating the role of ipRGCs in mediating non-visual and circadian light-resetting responses in a wide range of non-murine mammalian models.
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Affiliation(s)
- Elizabeth S Ingham
- Department of Neurobiology, Physiology & Behavior, University of California, Davis, California 95616, USA
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15
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Revell VL, Skene DJ. Light‐Induced Melatonin Suppression in Humans with Polychromatic and Monochromatic Light. Chronobiol Int 2009; 24:1125-37. [DOI: 10.1080/07420520701800652] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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16
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Higuchi S, Motohashi Y, Ishibashi K, Maeda T. Less Exposure to Daily Ambient Light in Winter Increases Sensitivity of Melatonin to Light Suppression. Chronobiol Int 2009; 24:31-43. [PMID: 17364578 DOI: 10.1080/07420520601139805] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
This study was carried out to examine the seasonal difference in the magnitude of the suppression of melatonin secretion induced by exposure to light in the late evening. The study was carried out in Akita (39 degrees North, 140 degrees East), in the northern part of Japan, where the duration of sunshine in winter is the shortest. Ten healthy male university students (mean age: 21.9+/-1.2 yrs) volunteered to participate twice in the study in winter (from January to February) and summer (from June to July) 2004. According to Japanese meteorological data, the duration of sunshine in Akita in the winter (50.5 h/month) is approximately one-third of that in summer (159.7 h/month). Beginning one week prior to the start of the experiment, the level of daily ambient light to which each subject was exposed was recorded every minute using a small light sensor that was attached to the subject's wrist. In the first experiment, saliva samples were collected every hour over a period of 24 h in a dark experimental room (<15 lux) to determine peak salivary melatonin concentration. The second experiment was conducted after the first experiment to determine the percentage of melatonin suppression induced by exposure to light. The starting time of exposure to light was set 2 h before the time of peak salivary melatonin concentration detected in the first experiment. The subjects were exposed to light (1000 lux) for 2 h using white fluorescent lamps (4200 K). The percentage of suppression of melatonin by light was calculated on the basis of the melatonin concentration determined before the start of exposure to light. The percentage of suppression of melatonin 2 h after the start of exposure to light was significantly greater in winter (66.6+/-18.4%) than summer (37.2+/-33.2%), p<0.01). The integrated level of daily ambient light from rising time to bedtime in summer was approximately twice that in winter. The results suggest that the increase in suppression of melatonin by light in winter is caused by less exposure to daily ambient light.
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Affiliation(s)
- Shigekazu Higuchi
- Department of Public Health, Akita University School of Medicine, Akita, Japan.
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Danilenko KV, Plisov IL, Wirz‐Justice A, Hébert M. Human Retinal Light Sensitivity and Melatonin Rhythms Following Four Days in Near Darkness. Chronobiol Int 2009; 26:93-107. [DOI: 10.1080/07420520802689814] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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18
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Abstract
The circadian clock in the suprachiasmatic nuclei (SCN) is composed of thousands of oscillator neurons, each dependent on the cell-autonomous action of a defined set of circadian clock genes. A major question is still how these individual oscillators are organized into a biological clock that produces a coherent output capable of timing all the different daily changes in behavior and physiology. We investigated which anatomical connections and neurotransmitters are used by the biological clock to control the daily release pattern of a number of hormones. The picture that emerged shows projections contacting target neurons in the medial hypothalamus surrounding the SCN. The activity of these pre-autonomic and neuro-endocrine target neurons is controlled by differentially timed waves of vasopressin, GABA, and glutamate release from SCN terminals, among other factors. Together our data indicate that, with regard to the timing of their main release period within the LD cycle, at least four subpopulations of SCN neurons should be discernible. The different subgroups do not necessarily follow the phenotypic differences among SCN neurons. Thus, different subgroups can be found within neuron populations containing the same neurotransmitter. Remarkably, a similar distinction of four differentially timed subpopulations of SCN neurons was recently also discovered in experiments determining the temporal patterns of rhythmicity in individual SCN neurons by way of the electrophysiology or clock gene expression. Moreover, the specialization of the SCN may go as far as a single body structure, i.e., the SCN seems to contain neurons that specifically target the liver, pineal gland, and adrenal gland.
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Affiliation(s)
- A Kalsbeek
- Netherlands Institute for Brain Research, Hypothalamic Integration Mechanisms, Amsterdam, The Netherlands.
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19
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Abstract
The circadian clock in the suprachiasmatic nuclei (SCN) is composed of thousands of oscillator neurons, each of which is dependent on the cell-autonomous action of a defined set of circadian clock genes. A major question is still how these individual oscillators are organized into a biological clock producing a coherent output that is able to time all the different daily changes in behavior and physiology. We investigated which anatomical connections and neurotransmitters are used by the biological clock to control the daily release pattern of a number of hormones. The picture that emerged shows projections contacting target neurons in the medial hypothalamus surrounding the SCN. The activity of these pre-autonomic and neuro-endocrine target neurons is controlled by differentially timed waves of, among others, vasopressin, GABA, and glutamate release from SCN terminals. Together our data indicate that, with regard to the timing of their main release period within the light-dark (LD) cycle, at least 4 subpopulations of SCN neurons should be discerned. The different subgroups do not necessarily follow the phenotypic differences among SCN neurons. Thus, different subgroups can be found within neuron populations containing the same neurotransmitter. Remarkably, a similar distinction of 4 differentially timed subpopulations of SCN neurons was recently also discovered in experiments determining the temporal patterns of rhythmicity in individual SCN neurons by way of the electrophysiology or clock gene expression. Moreover, the specialization of the SCN may go as far as a single body structure; i.e., the SCN seems to contain neurons that specifically target the liver, pineal, and adrenal.
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Affiliation(s)
- A Kalsbeek
- Netherlands Institute for Brain Research, Hypothalamic Integration Mechanisms, Amsterdam, The Netherlands.
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Portaluppi F. Consistency and Accuracy of the Medical Subject Headings® Thesaurus for Electronic Indexing and Retrieval of Chronobiologic References. Chronobiol Int 2009; 24:1213-29. [DOI: 10.1080/07420520701791570] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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21
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Tsai JW, Hannibal J, Hagiwara G, Colas D, Ruppert E, Ruby NF, Heller HC, Franken P, Bourgin P. Melanopsin as a sleep modulator: circadian gating of the direct effects of light on sleep and altered sleep homeostasis in Opn4(-/-) mice. PLoS Biol 2009; 7:e1000125. [PMID: 19513122 PMCID: PMC2688840 DOI: 10.1371/journal.pbio.1000125] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Accepted: 04/28/2009] [Indexed: 11/18/2022] Open
Abstract
Analyses in mice deficient for the blue-light-sensitive photopigment melanopsin show that direct effects of light on behavior and EEG depend on the time of day. The data further suggest an unexpected role for melanopsin in sleep homeostasis. Light influences sleep and alertness either indirectly through a well-characterized circadian pathway or directly through yet poorly understood mechanisms. Melanopsin (Opn4) is a retinal photopigment crucial for conveying nonvisual light information to the brain. Through extensive characterization of sleep and the electrocorticogram (ECoG) in melanopsin-deficient (Opn4−/−) mice under various light–dark (LD) schedules, we assessed the role of melanopsin in mediating the effects of light on sleep and ECoG activity. In control mice, a light pulse given during the habitual dark period readily induced sleep, whereas a dark pulse given during the habitual light period induced waking with pronounced theta (7–10 Hz) and gamma (40–70 Hz) activity, the ECoG correlates of alertness. In contrast, light failed to induce sleep in Opn4−/− mice, and the dark-pulse-induced increase in theta and gamma activity was delayed. A 24-h recording under a LD 1-h∶1-h schedule revealed that the failure to respond to light in Opn4−/− mice was restricted to the subjective dark period. Light induced c-Fos immunoreactivity in the suprachiasmatic nuclei (SCN) and in sleep-active ventrolateral preoptic (VLPO) neurons was importantly reduced in Opn4−/− mice, implicating both sleep-regulatory structures in the melanopsin-mediated effects of light. In addition to these acute light effects, Opn4−/− mice slept 1 h less during the 12-h light period of a LD 12∶12 schedule owing to a lengthening of waking bouts. Despite this reduction in sleep time, ECoG delta power, a marker of sleep need, was decreased in Opn4−/− mice for most of the (subjective) dark period. Delta power reached after a 6-h sleep deprivation was similarly reduced in Opn4−/− mice. In mice, melanopsin's contribution to the direct effects of light on sleep is limited to the dark or active period, suggesting that at this circadian phase, melanopsin compensates for circadian variations in the photo sensitivity of other light-encoding pathways such as rod and cones. Our study, furthermore, demonstrates that lack of melanopsin alters sleep homeostasis. These findings call for a reevaluation of the role of light on mammalian physiology and behavior. Light affects sleep in two ways: indirectly through the phase adjustment of circadian rhythms and directly through nonvisual mechanisms that are independent of the circadian system. The direct effects of light include the promotion of sleep in night-active animals and of alertness in diurnal species. We analyzed sleep and the electroencephalogram (EEG) under various light–dark regimens in mice lacking melanopsin (Opn4−/−), a retinal photopigment crucial for conveying light-level information to the brain, to determine the role of melanopsin, as opposed to rod and cones, in mediating these direct effects of light. We show that melanopsin mediates the direct effects of light during the subjective dark period, whereas rods and cones contribute to these effects in the light period. Our finding that “sleep-active” (i.e., galanin-positive) neurons of the anterior hypothalamus are not activated by light in Opn4−/− mice suggests that these neurons are part of the circuitry whereby light promotes sleep. Also, the alerting effects of transitions into darkness were less pronounced in Opn4−/− mice judged on the reduced increase in EEG theta and gamma activity. Finally, and unexpectedly, the rate at which the need for sleep, quantified as EEG delta power, accumulated during wakefulness was found to be reduced in Opn4−/− mice both during baseline and sleep deprivation conditions, implicating a photopigment in the homeostatic regulation of sleep. We conclude that melanopsin contributes to the direct effects of light and darkness, and in interaction with circadian and homeostatic drive, determines the occurrence and quality of both sleep and waking. If confirmed in humans, our observations will have applications for the clinical use of light as well as for societal lighting conditions.
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Affiliation(s)
- Jessica W. Tsai
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Jens Hannibal
- Department of Clinical Biochemistry, Rigshopitalet, Copenhagen, Denmark
| | - Grace Hagiwara
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Damien Colas
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Elisabeth Ruppert
- Laboratory of Rhythms - CNRS UMR 7168/LC2, Louis Pasteur University and Department of Neurology - School of Medicine, Strasbourg, France
| | - Norman F. Ruby
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - H. Craig Heller
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Paul Franken
- Department of Biology, Stanford University, Stanford, California, United States of America
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne-Dorigny, Switzerland
- * E-mail: (PF); (PB)
| | - Patrice Bourgin
- Department of Biology, Stanford University, Stanford, California, United States of America
- Laboratory of Rhythms - CNRS UMR 7168/LC2, Louis Pasteur University and Department of Neurology - School of Medicine, Strasbourg, France
- * E-mail: (PF); (PB)
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Shalchi Z, Sandhu H, Butt A, Smith S, Powrie J, Swaminathan R. Retina-Specific mRNA in the Assessment of Diabetic Retinopathy. Ann N Y Acad Sci 2008; 1137:253-7. [DOI: 10.1196/annals.1448.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Mathes A, Engel L, Holthues H, Wolloscheck T, Spessert R. Daily profile in melanopsin transcripts depends on seasonal lighting conditions in the rat retina. J Neuroendocrinol 2007; 19:952-7. [PMID: 18001324 DOI: 10.1111/j.1365-2826.2007.01608.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The retinal photopigment melanopsin (Opn4) mediates photoentrainment of the circadian system. In the present study, seasonal regulation of the melanopsin gene was investigated in comparison with the arylalkylamine N-acetyltransferase (AA-NAT) gene as an indicator of retinal pacemaker output. For this purpose, the daily profiles in the amount of melanopsin mRNA and AA-NAT mRNA were monitored under 8 : 16 h light/dark, 12 : 12 h light/dark and 16 : 8 h light/dark photoperiods using real-time polymerase chain reaction analysis. We found that, under all of the lighting regimes, melanopsin and AA-NAT expression oscillated with a peak around dark onset and the middle of the dark phase, respectively. The lighting regime influenced both genes, but in an opposing manner. Under long photoperiods, the duration of peak expression was prolonged for melanopsin, whereas it was shortened for AA-NAT. Under constant darkness, the rhythm of mRNA was abolished for melanopsin, but persisted for AA-NAT whereas, under constant light, the rhythm of mRNA was abolished for both genes. Our findings suggest that, in contrast to the AA-NAT gene, the daily and photoperiod-dependent regulation of the melanopsin gene does not rely on a circadian oscillator but is directly illumination-dependent.
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Affiliation(s)
- A Mathes
- Department of Anaesthesiology, Critical Care Medicine and Pain Management, Saarland University Hospital, Homburg (Saar), Germany
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Hannibal J, Georg B, Fahrenkrug J. Melanopsin changes in neonatal albino rat independent of rods and cones. Neuroreport 2007; 18:81-5. [PMID: 17259866 DOI: 10.1097/wnr.0b013e328010ff56] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Intrinsically photosensitive retinal ganglion cells employ the photopigment melanopsin and provide light information to brain areas responsible for the regulation of circadian rhythms. The expression of melanopsin is regulated by environmental illumination, but it remains to be clarified whether the rods and cones are involved. Here, we examined the influence of 5 days of constant light and dark conditions on melanopsin mRNA and protein expression in newborn albino rats, in which functional rods and cones have not yet been developed. We found that the melanopsin mRNA level was unaffected, whereas the melanopsin protein level was more than two-fold higher in the darkness-adapted group than in pups raised in constant light. In pups raised during 12 : 12 h light/dark cycles, the melanopsin protein level was significantly higher during the day than at night. Our findings indicate that melanopsin protein changes are independent of input from the rods and cones.
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Affiliation(s)
- Jens Hannibal
- Department of Clinical Biochemistry, Bispebjerg Hospital, University of Copenhagen, Copenhagen NV, Denmark.
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