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Tamayo E, Mouland JW, Lucas RJ, Brown TM. Regulation of mouse exploratory behaviour by irradiance and cone-opponent signals. BMC Biol 2023; 21:178. [PMID: 37605163 PMCID: PMC10441731 DOI: 10.1186/s12915-023-01663-6] [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: 01/11/2023] [Accepted: 07/14/2023] [Indexed: 08/23/2023] Open
Abstract
BACKGROUND Animal survival depends on the ability to adjust behaviour according to environmental conditions. The circadian system plays a key role in this capability, with diel changes in the quantity (irradiance) and spectral content ('colour') of ambient illumination providing signals of time-of-day that regulate the timing of rest and activity. Light also exerts much more immediate effects on behaviour, however, that are equally important in shaping daily activity patterns. Hence, nocturnal mammals will actively avoid light and dramatically reduce their activity when light cannot be avoided. The sensory mechanisms underlying these acute effects of light are incompletely understood, particularly the importance of colour. RESULTS To define sensory mechanisms controlling mouse behaviour, we used photoreceptor-isolating stimuli and mice with altered cone spectral sensitivity (Opn1mwR), lacking melanopsin (Opn1mwR; Opn4-/-) or cone phototransduction (Cnga3-/-) in assays of light-avoidance and activity suppression. In addition to roles for melanopsin-dependent irradiance signals, we find a major influence of spectral content in both cases. Hence, remarkably, selective increases in S-cone irradiance (producing a blue-shift in spectrum replicating twilight) drive light-seeking behaviour and promote activity. These effects are opposed by signals from longer-wavelength sensitive cones, indicating a true spectrally-opponent mechanism. Using c-Fos-mapping and multielectrode electrophysiology, we further show these effects are associated with a selective cone-opponent modulation of neural activity in the key brain site implicated in acute effects of light on behaviour, the subparaventricular zone. CONCLUSIONS Collectively, these data reveal a mechanism whereby blue-shifts in the spectrum of environmental illumination, such as during twilight, promote mouse exploratory behaviour.
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Affiliation(s)
- E Tamayo
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - J W Mouland
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - R J Lucas
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - T M Brown
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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2
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Athanasouli C, Kalmbach K, Booth V, Diniz Behn CG. NREM-REM alternation complicates transitions from napping to non-napping behavior in a three-state model of sleep-wake regulation. Math Biosci 2023; 355:108929. [PMID: 36448821 DOI: 10.1016/j.mbs.2022.108929] [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: 06/12/2022] [Revised: 10/23/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022]
Abstract
The temporal structure of human sleep changes across development as it consolidates from the polyphasic sleep of infants to the single nighttime sleep episode typical in adults. Experimental studies have shown that changes in the dynamics of sleep need may mediate this developmental transition in sleep patterning, however, it is unknown how sleep architecture interacts with these changes. We employ a physiologically-based mathematical model that generates wake, rapid eye movement (REM) and non-REM (NREM) sleep states to investigate how NREM-REM alternation affects the transition in sleep patterns as the dynamics of the homeostatic sleep drive are varied. To study the mechanisms producing these transitions, we analyze the bifurcations of numerically-computed circle maps that represent key dynamics of the full sleep-wake network model by tracking the evolution of sleep onsets across different circadian (∼ 24 h) phases. The maps are non-monotonic and discontinuous, being composed of branches that correspond to sleep-wake cycles containing distinct numbers of REM bouts. As the rates of accumulation and decay of the homeostatic sleep drive are varied, we identify the bifurcations that disrupt a period-adding-like behavior of sleep patterns in the transition between biphasic and monophasic sleep. These bifurcations include border collision and saddle-node bifurcations that initiate new sleep patterns, period-doubling bifurcations leading to higher-order patterns of NREM-REM alternation, and intervals of bistability of sleep patterns with different NREM-REM alternations. Furthermore, patterns of NREM-REM alternation exhibit variable behaviors in different regimes of constant sleep-wake patterns. Overall, the sequence of sleep-wake behaviors, and underlying bifurcations, in the transition from biphasic to monophasic sleep in this three-state model is more complex than behavior observed in models of sleep-wake regulation that do not consider the dynamics of NREM-REM alternation. These results suggest that interactions between the dynamics of the homeostatic sleep drive and the dynamics of NREM-REM alternation may contribute to the wide interindividual variation observed when young children transition from napping to non-napping behavior.
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Affiliation(s)
- Christina Athanasouli
- Department of Mathematics University of Michigan, 530 Church Street, Ann Arbor, MI, 48109, USA.
| | - Kelsey Kalmbach
- Department of Applied Mathematics and Statistics Colorado School of Mines, 1500 Illinois Street, Golden, 80401, CO, USA.
| | - Victoria Booth
- Department of Mathematics University of Michigan, 530 Church Street, Ann Arbor, MI, 48109, USA; Department of Anesthesiology, University of Michigan, 1500 E Medical Center Drive, Ann Arbor, 48109-5048, MI, USA.
| | - Cecilia G Diniz Behn
- Department of Applied Mathematics and Statistics Colorado School of Mines, 1500 Illinois Street, Golden, 80401, CO, USA; Department of Pediatrics, University of Colorado Anschutz Medical Campus, 13001 East 17th Place, Aurora, 80045, CO, USA.
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3
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Giannetto C, Cerutti RD, Scaglione MC, Fazio F, Aragona F, Arfuso F, Zumbo A, Piccione G. Simultaneous recording of subcutaneous temperature and total locomotor activity in Bos taurus and Bos indicus raised in a subtropical region of Argentina. Trop Anim Health Prod 2022; 54:371. [DOI: 10.1007/s11250-022-03365-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022]
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4
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Cortical waste clearance in normal and restricted sleep with potential runaway tau buildup in Alzheimer's disease. Sci Rep 2022; 12:13740. [PMID: 35961995 PMCID: PMC9374764 DOI: 10.1038/s41598-022-15109-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 06/17/2022] [Indexed: 01/10/2023] Open
Abstract
Accumulation of waste in cortical tissue and glymphatic waste clearance via extracellular voids partly drives the sleep-wake cycle and modeling has reproduced much of its dynamics. Here, new modeling incorporates higher void volume and clearance in sleep, multiple waste compounds, and clearance obstruction by waste. This model reproduces normal sleep-wake cycles, sleep deprivation effects, and performance decreases under chronic sleep restriction (CSR). Once fitted to calibration data, it successfully predicts dynamics in further experiments on sleep deprivation, intermittent CSR, and recovery after restricted sleep. The results imply a central role for waste products with lifetimes similar to tau protein. Strong tau buildup is predicted if pathologically enhanced production or impaired clearance occur, with runaway buildup above a critical threshold. Predicted tau accumulation has timescales consistent with the development of Alzheimer’s disease. The model unifies a wide sweep of phenomena, clarifying the role of glymphatic clearance and targets for interventions against waste buildup.
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5
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Lin J, Sun X, Dai X, Zhang S, Zhang X, Wang Q, Zheng Q, Huang M, He Y, Lin R. Integrated Proteomics and Metabolomics Analysis in Pregnant Rat Hippocampus After Circadian Rhythm Inversion. Front Physiol 2022; 13:941585. [PMID: 35936909 PMCID: PMC9355539 DOI: 10.3389/fphys.2022.941585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/07/2022] [Indexed: 11/15/2022] Open
Abstract
To investigate the changes in proteins, metabolites, and related mechanisms in the hypothalamus of pregnant rats after circadian rhythm inversion during the whole pregnancy cycle. A total of 12 Wistar female rats aged 7 weeks were randomly divided into control (six rats) and experimental (six rats) groups at the beginning of pregnancy. The control group followed a 12-h light and dark cycle (6 a.m. to 6 p.m. light, 6 p.m. to 6 a.m. dark the next day), and the experimental group followed a completely inverted circadian rhythm (6 p.m. to 6 a.m. light the next day, 6 a.m. to 6 p.m. dark). Postpartum data were collected until 7–24 h after delivery, and hypothalamus samples were collected in two groups for quantitative proteomic and metabolism analyses. The differential proteins and metabolites of the two groups were screened by univariate combined with multivariate statistical analyses, and the differential proteins and metabolites enriched pathways were annotated with relevant databases to analyze the potential mechanisms after circadian rhythm inversion. A comparison of postpartum data showed that circadian rhythm inversion can affect the number of offspring and the average weight of offspring in pregnant rats. Compared with the control group, the expression of 20 proteins and 37 metabolites was significantly changed in the experimental group. The integrated analysis between proteins and metabolites found that RGD1562758 and lysophosphatidylcholine acyltransferase 1 (LPCAT1) proteins were closely associated with carbon metabolism (choline, NAD+, L-glutamine, theobromine, D-fructose, and pyruvate) and glycerophospholipid metabolism (choline, NAD+, L-glutamine, phosphatidylcholine, theobromine, D-fructose, pyruvate, and arachidonate). Moreover, the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the differential metabolites enriched in adenosine triphosphate (ATP)–binding cassette (ABC) transporters. Our study suggested that circadian rhythm inversion in pregnant rats may affect the numbers, the average weight of offspring, and the expressions of proteins and metabolism in the hypothalamus, which may provide a comprehensive overview of the molecular profile of circadian rhythm inversion in pregnant groups.
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Affiliation(s)
- Jingjing Lin
- School of Nursing Fujian Medical University, Fuzhou City, China
| | - Xinyue Sun
- The First Affiliated Hospital of Fujian Medical University, Fuzhou City, China
| | - Xiaofeng Dai
- The First Affiliated Hospital of Fujian Medical University, Fuzhou City, China
| | | | - Xueling Zhang
- School of Nursing Fujian Medical University, Fuzhou City, China
- The First Affiliated Hospital of Fujian Medical University, Fuzhou City, China
| | - Qiaosong Wang
- School of Nursing Fujian Medical University, Fuzhou City, China
| | - Qirong Zheng
- School of Nursing Fujian Medical University, Fuzhou City, China
| | - Minfang Huang
- School of Nursing Fujian Medical University, Fuzhou City, China
- The First Affiliated Hospital of Fujian Medical University, Fuzhou City, China
| | - Yuanyuan He
- School of Nursing Fujian Medical University, Fuzhou City, China
| | - Rongjin Lin
- School of Nursing Fujian Medical University, Fuzhou City, China
- The First Affiliated Hospital of Fujian Medical University, Fuzhou City, China
- *Correspondence: Rongjin Lin,
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6
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Öztürk M, Ingenwerth M, Sager M, von Gall C, Ali AAH. Does a Red House Affect Rhythms in Mice with a Corrupted Circadian System? Int J Mol Sci 2021; 22:2288. [PMID: 33669004 PMCID: PMC7956239 DOI: 10.3390/ijms22052288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/12/2021] [Accepted: 02/24/2021] [Indexed: 02/05/2023] Open
Abstract
The circadian rhythms of body functions in mammals are controlled by the circadian system. The suprachiasmatic nucleus (SCN) in the hypothalamus orchestrates subordinate oscillators. Time information is conveyed from the retina to the SCN to coordinate an organism's physiology and behavior with the light/dark cycle. At the cellular level, molecular clockwork composed of interlocked transcriptional/translational feedback loops of clock genes drives rhythmic gene expression. Mice with targeted deletion of the essential clock gene Bmal1 (Bmal1-/-) have an impaired light input pathway into the circadian system and show a loss of circadian rhythms. The red house (RH) is an animal welfare measure widely used for rodents as a hiding place. Red plastic provides light at a low irradiance and long wavelength-conditions which affect the circadian system. It is not known yet whether the RH affects rhythmic behavior in mice with a corrupted circadian system. Here, we analyzed whether the RH affects spontaneous locomotor activity in Bmal1-/- mice under standard laboratory light conditions. In addition, mPER1- and p-ERK-immunoreactions, as markers for rhythmic SCN neuronal activity, and day/night plasma corticosterone levels were evaluated. Our findings indicate that application of the RH to Bmal1-/- abolishes rhythmic locomotor behavior and dampens rhythmic SCN neuronal activity. However, RH had no effect on the day/night difference in corticosterone levels.
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Affiliation(s)
- Menekse Öztürk
- Institute for Anatomy II, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Dusseldorf, Germany; (M.Ö.); (M.I.); (A.A.H.A.)
| | - Marc Ingenwerth
- Institute for Anatomy II, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Dusseldorf, Germany; (M.Ö.); (M.I.); (A.A.H.A.)
- Institute of Pathology, Medical Faculty, University Duisburg-Essen, Hufelandstrasse 55, 45147 Essen, Germany
| | - Martin Sager
- Central Institute for Animal Research and Animal Protection (ZETT), Medical Faculty, Heinrich Heine University, Moorenstrasse 5, 40225 Dusseldorf, Germany;
| | - Charlotte von Gall
- Institute for Anatomy II, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Dusseldorf, Germany; (M.Ö.); (M.I.); (A.A.H.A.)
| | - Amira A. H. Ali
- Institute for Anatomy II, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Dusseldorf, Germany; (M.Ö.); (M.I.); (A.A.H.A.)
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7
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Octodon degus: a natural model of multimorbidity for ageing research. Ageing Res Rev 2020; 64:101204. [PMID: 33152453 DOI: 10.1016/j.arr.2020.101204] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/14/2022]
Abstract
Integrating the multifactorial processes co-occurring in both physiological and pathological human conditions still remains one of the main challenges in translational investigation. Moreover, the impact of age-associated disorders has increased, which underlines the urgent need to find a feasible model that could help in the development of successful therapies. In this sense, the Octodon degus has been indicated as a 'natural' model in many biomedical areas, especially in ageing. This rodent shows complex social interactions and high sensitiveness to early-stressful events, which have been used to investigate neurodevelopmental processes. Interestingly, a high genetic similarity with some key proteins implicated in human diseases, such as apolipoprotein-E, β-amyloid or insulin, has been demonstrated. On the other hand, the fact that this animal is diurnal has provided important contribution in the field of circadian biology. Concerning age-related diseases, this rodent could be a good model of multimorbidity since it naturally develops cognitive decline, neurodegenerative histopathological hallmarks, visual degeneration, type II diabetes, endocrinological and metabolic dysfunctions, neoplasias and kidneys alterations. In this review we have collected and summarized the studies performed on the Octodon degus through the years that support its use as a model for biomedical research, with a special focus on ageing.
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8
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Verra DM, Sajdak BS, Merriman DK, Hicks D. Diurnal rodents as pertinent animal models of human retinal physiology and pathology. Prog Retin Eye Res 2019; 74:100776. [PMID: 31499165 DOI: 10.1016/j.preteyeres.2019.100776] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/27/2019] [Accepted: 08/31/2019] [Indexed: 12/12/2022]
Abstract
This presentation will survey the retinal architecture, advantages, and limitations of several lesser-known rodent species that provide a useful diurnal complement to rats and mice. These diurnal rodents also possess unusually cone-rich photoreceptor mosaics that facilitate the study of cone cells and pathways. Species to be presented include principally the Sudanian Unstriped Grass Rat and Nile Rat (Arvicanthis spp.), the Fat Sand Rat (Psammomys obesus), the degu (Octodon degus) and the 13-lined ground squirrel (Ictidomys tridecemlineatus). The retina and optic nerve in several of these species demonstrate unusual resilience in the face of neuronal injury, itself an interesting phenomenon with potential translational value.
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Affiliation(s)
- Daniela M Verra
- Department of Neurobiology of Rhythms, Institut des Neurosciences Cellulaires et Intégratives (INCI), CNRS UPR 3212, Strasbourg, France
| | | | - Dana K Merriman
- Department of Biology, University of Wisconsin Oshkosh, Oshkosh, WI, USA
| | - David Hicks
- Department of Neurobiology of Rhythms, Institut des Neurosciences Cellulaires et Intégratives (INCI), CNRS UPR 3212, Strasbourg, France.
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9
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Activity patterns and temporal niche partitioning of dogs and medium-sized wild mammals in urban parks of Xalapa, Mexico. Urban Ecosyst 2019. [DOI: 10.1007/s11252-019-00878-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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10
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Abstract
Sleep and circadian rhythms are regulated across multiple functional, spatial and temporal levels: from genes to networks of coupled neurons and glial cells, to large scale brain dynamics and behaviour. The dynamics at each of these levels are complex and the interaction between the levels is even more so, so research have mostly focused on interactions within the levels to understand the underlying mechanisms—the so-called reductionist approach. Mathematical models were developed to test theories of sleep regulation and guide new experiments at each of these levels and have become an integral part of the field. The advantage of modelling, however, is that it allows us to simulate and test the dynamics of complex biological systems and thus provides a tool to investigate the connections between the different levels and study the system as a whole. In this paper I review key models of sleep developed at different physiological levels and discuss the potential for an integrated systems biology approach for sleep regulation across these levels. I also highlight the necessity of building mechanistic connections between models of sleep and circadian rhythms across these levels.
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Affiliation(s)
- Svetlana Postnova
- School of Physics, University of Sydney, Sydney 2006, NSW, Australia;
- Center of Excellence for Integrative Brain Function, University of Sydney, Sydney 2006, NSW, Australia
- Charles Perkins Center, University of Sydney, Sydney 2006, NSW, Australia
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11
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Caravaggi A, Gatta M, Vallely MC, Hogg K, Freeman M, Fadaei E, Dick JT, Montgomery WI, Reid N, Tosh DG. Seasonal and predator-prey effects on circadian activity of free-ranging mammals revealed by camera traps. PeerJ 2018; 6:e5827. [PMID: 30498626 PMCID: PMC6252065 DOI: 10.7717/peerj.5827] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 09/25/2018] [Indexed: 11/20/2022] Open
Abstract
Endogenous circadian and seasonal activity patterns are adapted to facilitate effective utilisation of environmental resources. Activity patterns are shaped by physiological constraints, evolutionary history, circadian and seasonal changes and may be influenced by other factors, including ecological competition and interspecific interactions. Remote-sensing camera traps allow the collection of species presence data throughout the 24 h period and for almost indefinite lengths of time. Here, we collate data from 10 separate camera trap surveys in order to describe circadian and seasonal activity patterns of 10 mammal species, and, in particular, to evaluate interspecific (dis)associations of five predator-prey pairs. We recorded 8,761 independent detections throughout Northern Ireland. Badgers, foxes, pine martens and wood mice were nocturnal; European and Irish hares and European rabbits were crepuscular; fallow deer and grey and red squirrels were diurnal. All species exhibited significant seasonal variation in activity relative to the timing of sunrise/sunset. Foxes in particular were more crepuscular from spring to autumn and hares more diurnal. Lagged regression analyses of predator-prey activity patterns between foxes and prey (hares, rabbits and wood mice), and pine marten and prey (squirrel and wood mice) revealed significant annual and seasonal cross-correlations. We found synchronised activity patterns between foxes and hares, rabbits and wood mice and pine marten and wood mice, and asynchrony between squirrels and pine martens. Here, we provide fundamental ecological data on endemic, invasive, pest and commercially valuable species in Ireland, as well as those of conservation importance and those that could harbour diseases of economic and/or zoonotic relevance. Our data will be valuable in informing the development of appropriate species-specific methodologies and processes and associated policies.
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Affiliation(s)
- Anthony Caravaggi
- School of Biological Sciences, Queen’s University Belfast, UK
- School of Biological Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - Maria Gatta
- School or Animal, Plant and Environmental Sciences, University of Witwatersrand, South Africa
| | - Marie-Claire Vallely
- School of Biological Sciences, Queen’s University Belfast, UK
- Northern Ireland Environment Agency, UK
| | - Kayleigh Hogg
- School of Biological Sciences, Queen’s University Belfast, UK
| | | | - Erfan Fadaei
- School of Biological Sciences, Queen’s University Belfast, UK
- Institute of Global Food Security (IGFS), Queen’s University Belfast, UK
| | - Jaimie T.A. Dick
- School of Biological Sciences, Queen’s University Belfast, UK
- Institute of Global Food Security (IGFS), Queen’s University Belfast, UK
| | - W. Ian Montgomery
- School of Biological Sciences, Queen’s University Belfast, UK
- Institute of Global Food Security (IGFS), Queen’s University Belfast, UK
| | - Neil Reid
- School of Biological Sciences, Queen’s University Belfast, UK
- Institute of Global Food Security (IGFS), Queen’s University Belfast, UK
| | - David G. Tosh
- School of Biological Sciences, Queen’s University Belfast, UK
- National Museums Northern Ireland, UK
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Kim SH, Goh S, Han K, Kim JW, Choi M. Numerical study of entrainment of the human circadian system and recovery by light treatment. Theor Biol Med Model 2018; 15:5. [PMID: 29743086 PMCID: PMC5944165 DOI: 10.1186/s12976-018-0077-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 04/23/2018] [Indexed: 11/26/2022] Open
Abstract
Background While the effects of light as a zeitgeber are well known, the way the effects are modulated by features of the sleep-wake system still remains to be studied in detail. Methods A mathematical model for disturbance and recovery of the human circadian system is presented. The model combines a circadian oscillator and a sleep-wake switch that includes the effects of orexin. By means of simulations, we characterize the period-locking zone of the model, where a stable 24-hour circadian rhythm exists, and the occurrence of circadian disruption due to both insufficient light and imbalance in orexin. We also investigate how daily bright light treatments of short duration can recover the normal circadian rhythm. Results It is found that the system exhibits continuous phase advance/delay at lower/higher orexin levels. Bright light treatment simulations disclose two optimal time windows, corresponding to morning and evening light treatments. Among the two, the morning light treatment is found effective in a wider range of parameter values, with shorter recovery time. Conclusions This approach offers a systematic way to determine the conditions under which circadian disruption occurs, and to evaluate the effects of light treatment. In particular, it could potentially offer a way to optimize light treatments for patients with circadian disruption, e.g., sleep and mood disorders, in clinical settings.
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Affiliation(s)
- Soon Ho Kim
- Department of Physics and Center for Theoretical Physics, Seoul National University, Gwanak-ro 1, Seoul, 08826, Korea
| | - Segun Goh
- Institut für Theoretische Physik II - Soft Matter, Heinrich-Heine- Universität Düsseldorf, Düsseldorf, D-40225, Germany
| | - Kyungreem Han
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, 20892, USA
| | - Jong Won Kim
- Department of Healthcare Information Technology, Inje University, Gimhae, 50834, Korea.
| | - MooYoung Choi
- Department of Physics and Center for Theoretical Physics, Seoul National University, Gwanak-ro 1, Seoul, 08826, Korea
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Modeling the adenosine system as a modulator of cognitive performance and sleep patterns during sleep restriction and recovery. PLoS Comput Biol 2017; 13:e1005759. [PMID: 29073206 PMCID: PMC5675465 DOI: 10.1371/journal.pcbi.1005759] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 11/07/2017] [Accepted: 09/01/2017] [Indexed: 11/18/2022] Open
Abstract
Sleep loss causes profound cognitive impairments and increases the concentrations of adenosine and adenosine A1 receptors in specific regions of the brain. Time courses for performance impairment and recovery differ between acute and chronic sleep loss, but the physiological basis for these time courses is unknown. Adenosine has been implicated in pathways that generate sleepiness and cognitive impairments, but existing mathematical models of sleep and cognitive performance do not explicitly include adenosine. Here, we developed a novel receptor-ligand model of the adenosine system to test the hypothesis that changes in both adenosine and A1 receptor concentrations can capture changes in cognitive performance during acute sleep deprivation (one prolonged wake episode), chronic sleep restriction (multiple nights with insufficient sleep), and subsequent recovery. Parameter values were estimated using biochemical data and reaction time performance on the psychomotor vigilance test (PVT). The model closely fit group-average PVT data during acute sleep deprivation, chronic sleep restriction, and recovery. We tested the model's ability to reproduce timing and duration of sleep in a separate experiment where individuals were permitted to sleep for up to 14 hours per day for 28 days. The model accurately reproduced these data, and also correctly predicted the possible emergence of a split sleep pattern (two distinct sleep episodes) under these experimental conditions. Our findings provide a physiologically plausible explanation for observed changes in cognitive performance and sleep during sleep loss and recovery, as well as a new approach for predicting sleep and cognitive performance under planned schedules.
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Swaminathan K, Klerman EB, Phillips AJK. Are Individual Differences in Sleep and Circadian Timing Amplified by Use of Artificial Light Sources? J Biol Rhythms 2017; 32:165-176. [PMID: 28367676 DOI: 10.1177/0748730417699310] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Within the human population, there is large interindividual variability in the timing of sleep and circadian rhythms. This variability has been attributed to individual differences in sleep physiology, circadian physiology, and/or light exposure. Recent experimental evidence suggests that the latter is necessary to evoke large interindividual differences in sleep and circadian timing. We used a validated model of human sleep and circadian physiology to test the hypothesis that intrinsic differences in sleep and circadian timing are amplified by self-selected use of artificial light sources. We tested the model under 2 conditions motivated by an experimental study (Wright et al., 2013): (1) a "natural" light cycle, and (2) a "realistic" light cycle that included attenuation of light due to living indoors when natural light levels are high and use of electric light when natural light levels are low. Within these conditions, we determined the relationship between intrinsic circadian period (within the range of 23.7-24.6 h) and timing of sleep onset, sleep offset, and circadian rhythms. In addition, we simulated a work week, with fixed wake time for 5 days and free sleep times on weekends. Under both conditions, a longer intrinsic period resulted in later sleep and circadian timing. Compared to the natural condition, the realistic condition evoked more than double the variation in sleep timing across the physiological range of intrinsic circadian periods. Model predictions closely matched data from the experimental study. We found that if the intrinsic circadian period was long (>24.2 h) under the realistic condition, there was significant mismatch in sleep timing between weekdays and weekends, which is known as social jetlag. These findings indicate that individual tendencies to have very delayed schedules can be greatly amplified by self-selected modifications to the natural light/dark cycle. This has important implications for therapeutic treatment of advanced or delayed sleep phase disorders.
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Affiliation(s)
- Krithika Swaminathan
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Elizabeth B Klerman
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Andrew J K Phillips
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
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15
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Enright T, Refinetti R. Chronotype, class times, and academic achievement of university students. Chronobiol Int 2017; 34:445-450. [PMID: 28272914 DOI: 10.1080/07420528.2017.1281287] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Numerous studies over the years have documented an effect of human chronotypes on physiological and psychological processes. Studies evaluating the impact of an individual's chronotype on his/her academic achievement have indicated that morning chronotypes have an academic advantage over evening chronotypes. However, these studies did not account for the time of day in which the participants were being evaluated. The goal of the present study was to examine whether morning chronotypes do have an academic advantage over evening chronotypes when the time of day of classes and exams is taken into consideration. We obtained morningness-eveningness scores and course grades from 207 university students who took classes (and exams) at different times of the day. We confirmed that morning chronotypes attain better grades than evening chronotypes, although the association is weak (r2 = 0.02). The difference persisted even after the time of day of classes and exams was taken into consideration. This is probably due to the fact that evening chronotypes are generally more sleep deprived than morning chronotypes as a result of the early schedule of most schools, which can impair their performance both early and late in the day.
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Affiliation(s)
- Tristan Enright
- a Circadian Rhythm Laboratory, Department of Psychological Science , Boise State University , Boise , ID , USA
| | - Roberto Refinetti
- a Circadian Rhythm Laboratory, Department of Psychological Science , Boise State University , Boise , ID , USA
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Tanaka S, Takizawa N, Honda Y, Koike T, Oe S, Toyoda H, Kodama T, Yamada H. Hypocretin/orexin loss changes the hypothalamic immune response. Brain Behav Immun 2016; 57:58-67. [PMID: 27318095 DOI: 10.1016/j.bbi.2016.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 12/26/2022] Open
Abstract
Hypocretin, also known as orexin, maintains the vigilance state and regulates various physiological processes, such as arousal, sleep, food intake, energy expenditure, and reward. Previously, we found that when wild-type mice and hypocretin/ataxin-3 littermates (which are depleted of hypothalamic hypocretin-expressing neurons postnatally) were administered lipopolysaccharide (LPS), the two genotypes exhibited significant differences in their sleep/wake cycle, including differences in the degree of increase in sleep periods and in recovery from sickness behaviour. In the present study, we examined changes in the hypothalamic vigilance system and in the hypothalamic expression of inflammatory factors in response to LPS in hypocretin/ataxin-3 mice. Peripheral immune challenge with LPS affected the hypothalamic immune response and vigilance states. This response was altered by the loss of hypocretin. Hypocretin expression was inhibited after LPS injection in both hypocretin/ataxin-3 mice and their wild-type littermates, but expression was completely abolished only in hypocretin/ataxin-3 mice. Increases in the number of histidine decarboxylase (HDC)-positive cells and in Hdc mRNA expression were found in hypocretin/ataxin-3 mice, and this increase was suppressed by LPS. Hypocretin loss did not impact the change in expression of hypothalamic inflammatory factors in response to LPS, except for interferon gamma and colony stimulating factor 3. The number of c-Fos-positive/HDC-positive cells in hypocretin/ataxin-3 mice administered LPS injections was elevated, even during the rest period, in all areas, suggesting that there is an increase in the activity of histaminergic neurons in hypocretin/ataxin-3 mice following LPS injection. Taken together, our results suggest a novel role for hypocretin in the hypothalamic response to peripheral immune challenge. Our findings contribute to the understanding of the pathophysiology of narcolepsy.
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Affiliation(s)
- Susumu Tanaka
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan; SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
| | - Nae Takizawa
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Yoshiko Honda
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Taro Koike
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Souichi Oe
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Hiromi Toyoda
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tohru Kodama
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Hisao Yamada
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
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Ortiz A, Bradler K, Radu L, Alda M, Rusak B. Exponential state transition dynamics in the rest-activity architecture of patients with bipolar disorder. Bipolar Disord 2016; 18:116-23. [PMID: 26934362 DOI: 10.1111/bdi.12372] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 11/06/2015] [Accepted: 12/11/2015] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Our goal was to model the temporal dynamics of sleep-wake transitions, represented by transitions between rest and activity obtained from actigraphic data, in patients with bipolar disorder using a probabilistic state transition approach. METHODS We collected actigraphic data for 14 days from 20 euthymic patients with bipolar disorder, who had been characterized clinically, demographically, and with respect to their circadian preferences (chronotype). We processed each activity record to generate a series of transitions in both directions between the states of rest (R) and activity (A) and plotted the estimated transition probabilities (pRA and pAR). Each 24-hour period was also divided into a rest phase consisting of the eight consecutive least active hours in each day and an active phase consisting of the 16 consecutive most active hours in each day. We then calculated separate transition probabilities for each of these phases for each participant. We subsequently modeled the rest phase data to find the best fit for rest-activity transitions using maximum likelihood estimation. We also examined the association of transition probabilities with clinical and demographic variables. RESULTS The best-fit model for rest-activity transitions during the rest phase was a mixture (bimodal) of exponential functions. Of those patients with rapid cycling, 75% had an evening-type chronotype. Patients with bipolar II disorder taking antidepressants had a lower probability of transitioning back to rest than those not on antidepressants [mean ± SD = 0.050 ± 0.006 versus 0.141 ± 0.058, F(1,15) = 3.40, p < 0.05]. CONCLUSIONS The dynamics of transitions between rest and activity in bipolar disorder can be accounted for by a mixture (bimodal) of exponential functions. Patients taking antidepressants had a reduced probability of sustaining and returning to sleep.
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Affiliation(s)
- Abigail Ortiz
- Department of Psychiatry, University of Ottawa, Ottawa, ON.,Department of Psychiatry, Dalhousie University, Halifax, NS
| | | | - Luiza Radu
- College of Pharmacy, Dalhousie University, Halifax, NS, Canada
| | - Martin Alda
- Department of Psychiatry, Dalhousie University, Halifax, NS.,National Institute of Mental Health, Klecany, Czech Republic
| | - Benjamin Rusak
- Department of Psychiatry, Dalhousie University, Halifax, NS.,Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada
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Distribution of histaminergic neuronal cluster in the rat and mouse hypothalamus. J Chem Neuroanat 2015; 68:1-13. [DOI: 10.1016/j.jchemneu.2015.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 06/11/2015] [Accepted: 07/01/2015] [Indexed: 01/03/2023]
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Ramkisoensing A, Gu C, van Engeldorp Gastelaars HMD, Michel S, Deboer T, Rohling JHT, Meijer JH. Enhanced phase resetting in the synchronized suprachiasmatic nucleus network. J Biol Rhythms 2014; 29:4-15. [PMID: 24492878 DOI: 10.1177/0748730413516750] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The suprachiasmatic nucleus (SCN) adapts to both the external light-dark (LD) cycle and seasonal changes in day length. In short photoperiods, single-cell activity patterns are tightly synchronized (i.e., in phase); in long photoperiods, these patterns are relatively dispersed, causing lower amplitude rhythms. The limit cycle oscillator has been used to describe the SCN's circadian rhythmicity and predicts that following a given perturbation, high-amplitude SCN rhythms will shift less than low-amplitude rhythms. Some studies reported, however, that phase delays are larger when animals are entrained to a short photoperiod. Because phase advances and delays are mediated by partially distinct (i.e., nonoverlapping) biochemical pathways, we investigated the effect of a 4-h phase advance of the LD cycle in mice housed in either short (LD 8:16) or long (LD 16:8) photoperiods. In vitro recordings revealed a significantly larger phase advance in the SCN of mice entrained to short as compared to long photoperiods (4.2 ± 0.3 h v. 1.4 ± 0.9 h, respectively). Surprisingly, in mice with long photoperiods, the behavioral phase shift was larger than the phase shift of the SCN (3.7 ± 0.4 h v. 1.4 ± 0.9 h, respectively). To exclude a confounding influence of running-wheel activity on the magnitude of the shifts of the SCN, we repeated the experiments in the absence of running wheels and found similar shifts in the SCN in vitro in short and long days (3.0 ± 0.5 h v. 0.4 ± 0.9 h, respectively). Interestingly, removal of the running wheel reduced the phase-shifting capacity of mice in long days, leading to similar behavioral shifts in short and long photoperiods (1.0 ± 0.1 h v. 1.0 ± 0.4 h). As the behavioral shifts in the presence of wheels were larger than the shift of the SCN, it is suggested that additional, non-SCN neuronal networks in the brain are involved in regulating the timing of behavioral activity. On the basis of the phase shifts observed in vitro, we conclude that highly synchronized SCN networks with high-amplitude rhythms show a larger phase-shifting capacity than desynchronized networks of low amplitude.
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Affiliation(s)
- Ashna Ramkisoensing
- Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
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Fulcher BD, Phillips AJK, Postnova S, Robinson PA. A physiologically based model of orexinergic stabilization of sleep and wake. PLoS One 2014; 9:e91982. [PMID: 24651580 PMCID: PMC3961294 DOI: 10.1371/journal.pone.0091982] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 02/15/2014] [Indexed: 01/09/2023] Open
Abstract
The orexinergic neurons of the lateral hypothalamus (Orx) are essential for regulating sleep-wake dynamics, and their loss causes narcolepsy, a disorder characterized by severe instability of sleep and wake states. However, the mechanisms through which Orx stabilize sleep and wake are not well understood. In this work, an explanation of the stabilizing effects of Orx is presented using a quantitative model of important physiological connections between Orx and the sleep-wake switch. In addition to Orx and the sleep-wake switch, which is composed of mutually inhibitory wake-active monoaminergic neurons in brainstem and hypothalamus (MA) and the sleep-active ventrolateral preoptic neurons of the hypothalamus (VLPO), the model also includes the circadian and homeostatic sleep drives. It is shown that Orx stabilizes prolonged waking episodes via its excitatory input to MA and by relaying a circadian input to MA, thus sustaining MA firing activity during the circadian day. During sleep, both Orx and MA are inhibited by the VLPO, and the subsequent reduction in Orx input to the MA indirectly stabilizes sustained sleep episodes. Simulating a loss of Orx, the model produces dynamics resembling narcolepsy, including frequent transitions between states, reduced waking arousal levels, and a normal daily amount of total sleep. The model predicts a change in sleep timing with differences in orexin levels, with higher orexin levels delaying the normal sleep episode, suggesting that individual differences in Orx signaling may contribute to chronotype. Dynamics resembling sleep inertia also emerge from the model as a gradual sleep-to-wake transition on a timescale that varies with that of Orx dynamics. The quantitative, physiologically based model developed in this work thus provides a new explanation of how Orx stabilizes prolonged episodes of sleep and wake, and makes a range of experimentally testable predictions, including a role for Orx in chronotype and sleep inertia.
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Affiliation(s)
- Ben D. Fulcher
- School of Physics, The University of Sydney, Sydney, New South Wales, Australia
- * E-mail:
| | - Andrew J. K. Phillips
- Division of Sleep Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Svetlana Postnova
- School of Physics, The University of Sydney, Sydney, New South Wales, Australia
- Center for Integrated Research and Understanding of Sleep, The University of Sydney, Sydney, New South Wales, Australia
- Brain Dynamics Center, The University of Sydney, Sydney, New South Wales, Australia
| | - Peter A. Robinson
- School of Physics, The University of Sydney, Sydney, New South Wales, Australia
- Center for Integrated Research and Understanding of Sleep, The University of Sydney, Sydney, New South Wales, Australia
- Brain Dynamics Center, The University of Sydney, Sydney, New South Wales, Australia
- Cooperative Research Center for Alertness, Safety and Productivity, The University of Sydney, Sydney, New South Wales, Australia
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