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Michel S, Kervezee L. One seasonal clock fits all? J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2024; 210:641-647. [PMID: 37947808 PMCID: PMC11226558 DOI: 10.1007/s00359-023-01680-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/02/2023] [Accepted: 10/12/2023] [Indexed: 11/12/2023]
Abstract
Adaptation of physiology and behavior to seasonal changes in the environment are for many organisms essential for survival. Most of our knowledge about the underlying mechanisms comes from research on photoperiodic regulation of reproduction in plants, insects and mammals. However, even humans, who mostly live in environments with minimal seasonal influences, show annual rhythms in physiology (e.g., immune activity, brain function), behavior (e.g., sleep-wake cycles) and disease prevalence (e.g., infectious diseases). As seasonal variations in environmental conditions may be drastically altered due to climate change, the understanding of the mechanisms underlying seasonal adaptation of physiology and behavior becomes even more relevant. While many species have developed specific solutions for dedicated tasks of photoperiodic regulation, we find a number of common principles and mechanisms when comparing insect and mammalian systems: (1) the circadian system contributes to photoperiodic regulation; (2) similar signaling molecules (VIP and PDF) are used for transferring information from the circadian system to the neuroendocrine system controlling the photoperiodic response; (3) the hormone melatonin participates in seasonal adaptation in insects as well as mammals; and (4) changes in photoperiod affect neurotransmitter function in both animal groups. The few examples of overlap elaborated in this perspective article, as well as the discussion on relevance for humans, should be seen as encouragement to unravel the machinery of seasonal adaptation in a multitude of organisms.
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Affiliation(s)
- Stephan Michel
- Department of Cell and Chemical Biology, Leiden University Medical Center, Postzone S5-P, 2300 RC, PO Box 9600, Leiden, The Netherlands.
| | - Laura Kervezee
- Department of Cell and Chemical Biology, Leiden University Medical Center, Postzone S5-P, 2300 RC, PO Box 9600, Leiden, The Netherlands
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2
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Zhang R, Tomasi D, Shokri-Kojori E, Manza P, Demiral SB, Wang GJ, Volkow ND. Seasonality in regional brain glucose metabolism. Psychol Med 2024:1-9. [PMID: 38634486 DOI: 10.1017/s0033291724000436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
BACKGROUND Daylength and the rates of changes in daylength have been associated with seasonal fluctuations in psychiatric symptoms and in cognition and mood in healthy adults. However, variations in human brain glucose metabolism in concordance with seasonal changes remain under explored. METHODS In this cross-sectional study, we examined seasonal effects on brain glucose metabolism, which we measured using 18F-fluorodeoxyglucose-PET in 97 healthy participants. To maximize the sensitivity of regional effects, we computed relative metabolic measures by normalizing the regional measures to white matter metabolism. Additionally, we explored the role of rest-activity rhythms/sleep-wake activity measured with actigraphy in the seasonal variations of regional brain metabolic activity. RESULTS We found that seasonal variations of cerebral glucose metabolism differed across brain regions. Glucose metabolism in prefrontal regions increased with longer daylength and with greater day-to-day increases in daylength. The cuneus and olfactory bulb had the maximum and minimum metabolic values around the summer and winter solstice respectively (positively associated with daylength), whereas the temporal lobe, brainstem, and postcentral cortex showed maximum and minimum metabolic values around the spring and autumn equinoxes, respectively (positively associated with faster daylength gain). Longer daylength was associated with greater amplitude and robustness of diurnal activity rhythms suggesting circadian involvement. CONCLUSIONS The current findings advance our knowledge of seasonal patterns in a key indicator of brain function relevant for mood and cognition. These data could inform treatment interventions for psychiatric symptoms that peak at specific times of the year.
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Affiliation(s)
- Rui Zhang
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Dardo Tomasi
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ehsan Shokri-Kojori
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter Manza
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sukru Baris Demiral
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gene-Jack Wang
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nora D Volkow
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
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3
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Zhang X, Huang S, Kim JY. Cell-type specific circadian transcription factor BMAL1 roles in excitotoxic hippocampal lesions to enhance neurogenesis. iScience 2024; 27:108829. [PMID: 38303690 PMCID: PMC10831945 DOI: 10.1016/j.isci.2024.108829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/11/2023] [Accepted: 01/03/2024] [Indexed: 02/03/2024] Open
Abstract
Circadian clocks, generating daily rhythms in biological processes, maintain homeostasis in physiology, so clock alterations are considered detrimental. Studies in brain pathology support this by reporting abnormal circadian phenotypes in patients, but restoring the abnormalities by light therapy shows no dramatic effects. Recent studies on glial clocks report the complex effects of altered clocks by showing their beneficial effects on brain repairs. However, how neuronal clocks respond to brain pathology is elusive. This study shows that neuronal BMAL1, a core of circadian clocks, reduces its expression levels in neurodegenerative excitotoxicity. In the dentate gyrus of excitotoxic hippocampal lesions, reduced BMAL1 in granule cells precedes apoptosis. This subsequently reduces BMAL1 levels in neighbor neural stem cells and progenitors in the subgranular zone, enhancing proliferation. This shows the various BMAL1 roles depending on cell types, and its alterations can benefit brain repair. Thus, cell-type-specific BMAL1 targeting is necessary to treat brain pathology.
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Affiliation(s)
- Xuebing Zhang
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
| | - Suihong Huang
- Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong SAR, China
| | - Jin Young Kim
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
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Li Y, Lu L, Androulakis IP. The Physiological and Pharmacological Significance of the Circadian Timing of the HPA Axis: A Mathematical Modeling Approach. J Pharm Sci 2024; 113:33-46. [PMID: 37597751 PMCID: PMC10840710 DOI: 10.1016/j.xphs.2023.08.005] [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: 04/13/2023] [Revised: 08/02/2023] [Accepted: 08/02/2023] [Indexed: 08/21/2023]
Abstract
As a potent endogenous regulator of homeostasis, the circadian time-keeping system synchronizes internal physiology to periodic changes in the external environment to enhance survival. Adapting endogenous rhythms to the external time is accomplished hierarchically with the central pacemaker located in the suprachiasmatic nucleus (SCN) signaling the hypothalamus-pituitary-adrenal (HPA) axis to release hormones, notably cortisol, which help maintain the body's circadian rhythm. Given the essential role of HPA-releasing hormones in regulating physiological functions, including immune response, cell cycle, and energy metabolism, their daily variation is critical for the proper function of the circadian timing system. In this review, we focus on cortisol and key fundamental properties of the HPA axis and highlight their importance in controlling circadian dynamics. We demonstrate how systems-driven, mathematical modeling of the HPA axis complements experimental findings, enhances our understanding of complex physiological systems, helps predict potential mechanisms of action, and elucidates the consequences of circadian disruption. Finally, we outline the implications of circadian regulation in the context of personalized chronotherapy. Focusing on the chrono-pharmacology of synthetic glucocorticoids, we review the challenges and opportunities associated with moving toward personalized therapies that capitalize on circadian rhythms.
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Affiliation(s)
- Yannuo Li
- Chemical & Biochemical Engineering Department, Piscataway, NJ 08854, USA
| | - Lingjun Lu
- Chemical & Biochemical Engineering Department, Piscataway, NJ 08854, USA
| | - Ioannis P Androulakis
- Chemical & Biochemical Engineering Department, Piscataway, NJ 08854, USA; Biomedical Engineering Department, Rutgers University, Piscataway, NJ 08540, USA.
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5
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Ren S, Zhu J, Xie X, Liu X, Jiang H, Ying C, Hu J, Di H, Hu N. The visual stimulation in disorders of consciousness. APPLIED NEUROPSYCHOLOGY. ADULT 2023:1-8. [PMID: 38104423 DOI: 10.1080/23279095.2023.2292244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Severe brain damage usually leads to disorders of consciousness (DOC), which include coma, unresponsive wakefulness syndrome (UWS) and a minimally conscious state (MCS). Visual stimulation is widely used, especially in the diagnosis and treatment and treatment of DOC. Researchers have indicated that tests based on visual stimulation including visual pursuit, when used in conjunction with the Coma Recovery Scale-Revised, are able to differentiate between UWS from an MCS. Recently, targeting patients' circadian rhythms has been proposed to be a possible treatment target for DOC. Indeed, light therapy has been applied in some other fields, including treating seasonal affective disorder, sleep problems, and Parkinson's disease. However, at present, although visual stimulation and light therapy are frequently used in DOC, there is still no international unified standard. Therefore, we recommend the development of an international consensus in regard to the definitions, operational criteria and assessment procedures of visual stimulation and light therapy. This review combines visual stimulation, circadian rhythm recovery, and light therapy in DOC patients and presents the mechanisms and current advances in applications related to light therapy and visual stimulation in an attempt to provide additional ideas for future research and treatment of DOC.
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Affiliation(s)
- Siyan Ren
- International Unresponsive Wakefulness Syndrome and Consciousness Science Institute, Hangzhou Normal University, Hangzhou, China
| | - Jiajie Zhu
- Department of Pediatric Surgery, Children's Hospital of Fudan University, Shanghai Key Laboratory of Birth Defect, Shanghai, China
| | - Xiangyu Xie
- International Unresponsive Wakefulness Syndrome and Consciousness Science Institute, Hangzhou Normal University, Hangzhou, China
| | - Ximeng Liu
- International Unresponsive Wakefulness Syndrome and Consciousness Science Institute, Hangzhou Normal University, Hangzhou, China
| | - Hui Jiang
- International Unresponsive Wakefulness Syndrome and Consciousness Science Institute, Hangzhou Normal University, Hangzhou, China
| | - Chenxi Ying
- International Unresponsive Wakefulness Syndrome and Consciousness Science Institute, Hangzhou Normal University, Hangzhou, China
| | - Jia Hu
- International Unresponsive Wakefulness Syndrome and Consciousness Science Institute, Hangzhou Normal University, Hangzhou, China
| | - Haibo Di
- International Unresponsive Wakefulness Syndrome and Consciousness Science Institute, Hangzhou Normal University, Hangzhou, China
| | - Nantu Hu
- International Unresponsive Wakefulness Syndrome and Consciousness Science Institute, Hangzhou Normal University, Hangzhou, China
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6
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Bussi IL, Neitz AF, Sanchez REA, Casiraghi LP, Moldavan M, Kunda D, Allen CN, Evans JA, de la Iglesia HO. Expression of the vesicular GABA transporter within neuromedin S + neurons sustains behavioral circadian rhythms. Proc Natl Acad Sci U S A 2023; 120:e2314857120. [PMID: 38019855 PMCID: PMC10710084 DOI: 10.1073/pnas.2314857120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
The suprachiasmatic nucleus (SCN) of the hypothalamus is the site of a central circadian clock that orchestrates overt rhythms of physiology and behavior. Circadian timekeeping requires intercellular communication among SCN neurons, and multiple signaling pathways contribute to SCN network coupling. Gamma-aminobutyric acid (GABA) is produced by virtually all SCN neurons, and previous work demonstrates that this transmitter regulates coupling in the adult SCN but is not essential for the nucleus to sustain overt circadian rhythms. Here, we show that the deletion of the gene that codes for the GABA vesicular transporter Vgat from neuromedin-S (NMS)+ neurons-a subset of neurons critical for SCN function-causes arrhythmia of locomotor activity and sleep. Further, NMS-Vgat deletion impairs intrinsic clock gene rhythms in SCN explants cultured ex vivo. Although vasoactive intestinal polypeptide (VIP) is critical for SCN function, Vgat deletion from VIP-expressing neurons did not lead to circadian arrhythmia in locomotor activity rhythms. Likewise, adult SCN-specific deletion of Vgat led to mild impairment of behavioral rhythms. Our results suggest that while the removal of GABA release from the adult SCN does not affect the pacemaker's ability to sustain overt circadian rhythms, its removal from a critical subset of neurons within the SCN throughout development removes the nucleus ability to sustain circadian rhythms. Our findings support a model in which SCN GABA release is critical for the developmental establishment of intercellular network properties that define the SCN as a central pacemaker.
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Affiliation(s)
- Ivana L. Bussi
- Department of Biology, University of Washington, Seattle, WA98195-1800
| | - Alexandra F. Neitz
- Department of Biology, University of Washington, Seattle, WA98195-1800
- Molecular and Cellular Biology in Seattle, University of Washington and Fred Hutch, Seattle, WA98195-7275
| | - Raymond E. A. Sanchez
- Department of Biology, University of Washington, Seattle, WA98195-1800
- Graduate Program in Neuroscience, University of Washington, Seattle, WA98195
| | | | - Michael Moldavan
- Oregon Institute for Occupational Health Sciences, Oregon Health & Science University, Portland, OR97239
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR97239
| | - Divya Kunda
- Department of Biology, University of Washington, Seattle, WA98195-1800
| | - Charles N. Allen
- Oregon Institute for Occupational Health Sciences, Oregon Health & Science University, Portland, OR97239
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR97239
| | - Jennifer A. Evans
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI53233
| | - Horacio O. de la Iglesia
- Department of Biology, University of Washington, Seattle, WA98195-1800
- Molecular and Cellular Biology in Seattle, University of Washington and Fred Hutch, Seattle, WA98195-7275
- Graduate Program in Neuroscience, University of Washington, Seattle, WA98195
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7
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Li Y, Androulakis IP. The SCN-HPA-Periphery Circadian Timing System: Mathematical Modeling of Clock Synchronization and the Effects of Photoperiod on Jetlag Adaptation. J Biol Rhythms 2023; 38:601-616. [PMID: 37529986 PMCID: PMC10615703 DOI: 10.1177/07487304231188541] [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] [Indexed: 08/03/2023]
Abstract
Synchronizing the circadian timing system (CTS) to external light/dark cycles is crucial for homeostasis maintenance and environmental adaptation. The CTS is organized hierarchically, with the central pacemaker located in the suprachiasmatic nuclei (SCN) generating coherent oscillations that are entrained to light/dark cycles. These oscillations regulate the release of glucocorticoids by the hypothalamus-pituitary-adrenal (HPA) axis, which acts as a systemic entrainer of peripheral clocks throughout the body. The SCN adjusts its network plasticity in response to variations in photoperiod, leading to changes in the rhythmic release of glucocorticoids and ultimately impacting peripheral clocks. However, the effects of photoperiod-induced variations of glucocorticoids on the synchronization of peripheral clocks are not fully understood, and the interaction between jetlag adaption and photoperiod changes is unclear. This study presents a semi-mechanistic mathematical model to investigate how the CTS responds to changes in photoperiod. Specifically, the study focuses on the entrainment properties of a system composed of the SCN, HPA axis, and peripheral clocks. The results show that high-amplitude glucocorticoid rhythms lead to a more coherent phase distribution in the periphery. In addition, our study investigates the effect of photoperiod exposure on jetlag recovery time and phase shift, proposing different interventional strategies for eastward and westward jetlag. The findings suggest that decreasing photic exposure before jetlag during eastward traveling and after jetlag during westward traveling can accelerate jetlag readaptation. The study provides insights into the mechanisms of CTS organization and potential recovery strategies for transitions between time zones and lighting zones.
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Affiliation(s)
- Yannuo Li
- Department of Chemical & Biochemical Engineering, Rutgers University-New Brunswick, New Brunswick, New Jersey, USA
| | - Ioannis P Androulakis
- Department of Chemical & Biochemical Engineering, Rutgers University-New Brunswick, New Brunswick, New Jersey, USA
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey, USA
- Department of Surgery, Robert Wood Johnson Medical School, Rutgers University-New Brunswick, New Brunswick, New Jersey, USA
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8
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He SK, Wang JH, Li T, Yin S, Cui JW, Xiao YF, Tang Y, Wang J, Bai YJ. Sleep and circadian rhythm disturbance in kidney stone disease: a narrative review. Front Endocrinol (Lausanne) 2023; 14:1293685. [PMID: 38089624 PMCID: PMC10711275 DOI: 10.3389/fendo.2023.1293685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 11/08/2023] [Indexed: 12/18/2023] Open
Abstract
The circadian rhythm generated by circadian clock genes functions as an internal timing system. Since the circadian rhythm controls abundant physiological processes, the circadian rhythm evolved in organisms is salient for adaptation to environmental change. A disturbed circadian rhythm is a trigger for numerous pathological events. Recently, accumulated data have indicated that kidney stone disease (KSD) is related to circadian rhythm disturbance. However, the mechanism between them has not been fully elucidated. In this narrative review, we summarized existing evidence to illustrate the possible association between circadian rhythm disturbance and KSD based on the epidemiological studies and risk factors that are linked to circadian rhythm disturbance and discuss some chronotherapies for KSD. In summary, KSD is associated with systemic disorders. Metabolic syndrome, inflammatory bowel disease, and microbiome dysbiosis are the major risk factors supported by sufficient data to cause KSD in patients with circadian rhythm disturbance, while others including hypertension, vitamin D deficiency, parathyroid gland dysfunction, and renal tubular damage/dysfunction need further investigation. Then, some chronotherapies for KSD were confirmed to be effective, but the molecular mechanism is still unclear.
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Affiliation(s)
- Si-Ke He
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China
| | - Jia-Hao Wang
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China
| | - Tao Li
- Department of Urology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Shan Yin
- Department of Urology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Jian-Wei Cui
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China
| | - Yun-Fei Xiao
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China
| | - Yin Tang
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China
| | - Jia Wang
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China
| | - Yun-Jin Bai
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China
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9
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Zhang R, Shokri-Kojori E, Volkow ND. Seasonal effect-an overlooked factor in neuroimaging research. Transl Psychiatry 2023; 13:238. [PMID: 37400428 DOI: 10.1038/s41398-023-02530-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 06/16/2023] [Accepted: 06/19/2023] [Indexed: 07/05/2023] Open
Abstract
In neuroimaging research, seasonal effects are often neglected or controlled as confounding factors. However, seasonal fluctuations in mood and behavior have been observed in both psychiatric disorders and healthy participants. There are vast opportunities for neuroimaging studies to understand seasonal variations in brain function. In this study, we used two longitudinal single-subject datasets with weekly measures over more than a year to investigate seasonal effects on intrinsic brain networks. We found that the sensorimotor network displayed a strong seasonal pattern. The sensorimotor network is not only relevant for integrating sensory inputs and coordinating movement, but it also affects emotion regulation and executive function. Therefore, the observed seasonality effects in the sensorimotor network could contribute to seasonal variations in mood and behavior. Genetic analyses revealed seasonal modulation of biological processes and pathways relevant to immune function, RNA metabolism, centrosome separation, and mitochondrial translation that have a significant impact on human physiology and pathology. In addition, we revealed critical factors such as head motion, caffeine use, and scan time that could interfere with seasonal effects and need to be considered in future studies.
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Affiliation(s)
- Rui Zhang
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892-1013, USA.
| | - Ehsan Shokri-Kojori
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892-1013, USA
| | - Nora D Volkow
- Laboratory of Neuroimaging, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892-1013, USA.
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10
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Crodelle J, Vanty C, Booth V. Modeling homeostatic and circadian modulation of human pain sensitivity. Front Neurosci 2023; 17:1166203. [PMID: 37360178 PMCID: PMC10285085 DOI: 10.3389/fnins.2023.1166203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/18/2023] [Indexed: 06/28/2023] Open
Abstract
Introduction Mathematical modeling has played a significant role in understanding how homeostatic sleep pressure and the circadian rhythm interact to influence sleep-wake behavior. Pain sensitivity is also affected by these processes, and recent experimental results have measured the circadian and homeostatic components of the 24 h rhythm of thermal pain sensitivity in humans. To analyze how rhythms in pain sensitivity are affected by disruptions in sleep behavior and shifts in circadian rhythms, we introduce a dynamic mathematical model for circadian and homeostatic regulation of sleep-wake states and pain intensity. Methods The model consists of a biophysically based, sleep-wake regulation network model coupled to data-driven functions for the circadian and homeostatic modulation of pain sensitivity. This coupled sleep-wake-pain sensitivity model is validated by comparison to thermal pain intensities in adult humans measured across a 34 h sleep deprivation protocol. Results We use the model to predict dysregulation of pain sensitivity rhythms across different scenarios of sleep deprivation and circadian rhythm shifts, including entrainment to new environmental light and activity timing as occurs with jet lag and chronic sleep restriction. Model results show that increases in pain sensitivity occur under conditions of increased homeostatic sleep drive with nonlinear modulation by the circadian rhythm, leading to unexpected decreased pain sensitivity in some scenarios. Discussion This model provides a useful tool for pain management by predicting alterations in pain sensitivity due to varying or disrupted sleep schedules.
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Affiliation(s)
- Jennifer Crodelle
- Department of Mathematics, Middlebury College, Middlebury, VT, United States
| | - Carolyn Vanty
- Department of Mathematics, Middlebury College, Middlebury, VT, United States
| | - Victoria Booth
- Departments of Mathematics and Anesthesiology, University of Michigan, Ann Arbor, MI, United States
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11
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Tomotani BM, Timpen F, Spoelstra K. Ingrained city rhythms: flexible activity timing but more persistent circadian pace in urban birds. Proc Biol Sci 2023; 290:20222605. [PMID: 37192668 PMCID: PMC10188242 DOI: 10.1098/rspb.2022.2605] [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: 12/31/2022] [Accepted: 04/24/2023] [Indexed: 05/18/2023] Open
Abstract
Urbanization dramatically increases the amount of light at night, which may disrupt avian circadian organization. We measured activity patterns of great tits breeding in the city and forest, and subsequently measured two clock properties of these birds under controlled conditions: tau (endogenous circadian clock speed) and after-effects (history dependency of the clock relative to previous conditions). City and forest birds showed a high repeatability of activity onset (0.60 and 0.41, respectively), with no difference between habitats after controlling for date effects. Activity duration and offset showed more variance, without a difference between birds from the two habitats. Tau did not differ between city and forest birds, however, city birds showed stronger after-effects, taking more days to revert to their endogenous circadian period. Finally, onset of activity was correlated with clocks speed in both habitats. Our results suggest that potential differences in activity timing of city birds is not caused by different clock speeds, but by a direct response to light. Persistence in after-effects suggests a reduced sensitivity of the clock to light at night. Urbanization may select for clock properties that increase the inertia of the endogenous circadian system to improve accuracy of activity rhythms when exposed to noisier lighting cues.
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Affiliation(s)
- Barbara M. Tomotani
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Fabian Timpen
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Kamiel Spoelstra
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
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12
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Chrobok L, Ahern J, Piggins HD. Ticking and talking in the brainstem satiety centre: Circadian timekeeping and interactions in the diet-sensitive clock of the dorsal vagal complex. Front Physiol 2022; 13:931167. [PMID: 36117684 PMCID: PMC9481231 DOI: 10.3389/fphys.2022.931167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
The dorsal vagal complex (DVC) is a key hub for integrating blood-borne, central, and vagal ascending signals that convey important information on metabolic and homeostatic state. Research implicates the DVC in the termination of food intake and the transition to satiety, and consequently it is considered a brainstem satiety centre. In natural and laboratory settings, animals have distinct times of the day or circadian phases at which they prefer to eat, but if and how circadian signals affect DVC activity is not well understood. Here, we evaluate how intrinsic circadian signals regulate molecular and cellular activity in the area postrema (AP), nucleus of the solitary tract (NTS), and dorsal motor nucleus of the vagus (DMV) of the DVC. The hierarchy and potential interactions among these oscillators and their response to changes in diet are considered a simple framework in which to model these oscillators and their interactions is suggested. We propose possible functions of the DVC in the circadian control of feeding behaviour and speculate on future research directions including the translational value of knowledge of intrinsic circadian timekeeping the brainstem.
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13
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Grant AD, Wilbrecht L, Kriegsfeld LJ. Sex Differences in Pubertal Circadian and Ultradian Rhythmic Development Under Semi-naturalistic Conditions. J Biol Rhythms 2022; 37:442-454. [PMID: 35502708 PMCID: PMC9329191 DOI: 10.1177/07487304221092715] [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] [Indexed: 01/23/2023]
Abstract
Biological rhythms in core body temperature (CBT) provide informative markers of adolescent development under controlled laboratory conditions. However, it is unknown whether these markers are preserved under more variable, semi-naturalistic conditions, and whether CBT may therefore prove useful in a real-world setting. To evaluate this possibility, we examined fecal steroid concentrations and CBT rhythms from pre-adolescence (p26) through early adulthood (p76) in intact male and female Wistar rats under natural light and climate at the Stephen Glickman Field Station for the Study of Behavior, Ecology and Reproduction. Despite greater environmental variability, CBT markers of pubertal onset and its rhythmic progression were comparable with those previously reported in laboratory conditions in female rats and extend actigraphy-based findings in males. Specifically, sex differences emerged in CBT circadian rhythm (CR) power and amplitude prior to pubertal onset and persisted into early adulthood, with females exhibiting elevated CBT and decreased CR power compared with males. Within-day (ultradian rhythm [UR]) patterns also exhibited a pronounced sex difference associated with estrous cyclicity. Pubertal onset, defined by vaginal opening, preputial separation, and sex steroid concentrations, occurred later than previously reported under lab conditions for both sexes. Vaginal opening and increased fecal estradiol concentrations were closely tied to the commencement of 4-day oscillations in CBT and UR power. By contrast, preputial separation and the first rise in testosterone concentration were not associated with adolescent changes to CBT rhythms in male rats. Together, males and females exhibited unique temporal patterning of CBT and sex steroids across pubertal development, with tractable associations between hormonal concentrations, external development, and temporal structure in females. The preservation of these features outside the laboratory supports CBT as a strong candidate for translational pubertal monitoring under semi-naturalistic conditions in females.
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Affiliation(s)
- Azure D. Grant
- The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, 94720, United States
| | - Linda Wilbrecht
- The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, 94720, United States
- Department of Psychology, University of California, Berkeley, CA, 94720, United States
| | - Lance J. Kriegsfeld
- The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, 94720, United States
- Department of Psychology, University of California, Berkeley, CA, 94720, United States
- Department of Integrative Biology, University of California, Berkeley, CA, 94720, United States
- Graduate Group in Endocrinology, University of California, Berkeley, CA, 94720, United States
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14
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Goltsev AV, Wright EAP, Mendes JFF, Yoon S. Generation and Disruption of Circadian Rhythms in the Suprachiasmatic Nucleus: A Core-Shell Model. J Biol Rhythms 2022; 37:545-561. [PMID: 35848398 PMCID: PMC9452856 DOI: 10.1177/07487304221107834] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We focus our research on how the core-shell organization controls behavior of the
suprachiasmatic nucleus (SCN), how the core and shell are synchronized to the
environment, what impact they have on the behavior of the SCN under different
lighting conditions, and what mechanisms disrupt synchronization. To this end,
we use a reduced Kuramoto model, with parameters inferred from experimental
observations and calibrated for mice, and perform a detailed comparison between
the model and experimental data under light-dark (LD), dark-dark (DD), and
light-light (LL) conditions. The operating limits of free-running and entrained
SCN activity under symmetric LD cycles are analyzed, with particular focus on
the phenomena of anticipation and dissociation. Results reveal that the
core-shell organization of the SCN enables anticipation of future events over
circadian cycles. The model predicts the emergence of a second (dissociated)
rhythm for large and small LD periods. Our results are in good qualitative and
quantitative agreement with experimental observations of circadian dissociation.
We further describe SCN activity under LL conditions and show that our model
satisfies Aschoff’s first rule, according to which the endogenous free-running
circadian period observed under complete darkness will shorten in diurnal
animals and lengthen in nocturnal animals under constant light. Our results
strongly suggest that the Kuramoto model captures essential features of
synchronization and entrainment in the SCN. Moreover, our approach is easily
extendible to an arbitrary number of groups, with dynamics described by explicit
equations for the group phase and synchronization index. Viewed together, the
reduced Kuramoto model presents itself as a useful tool for exploring open
problems in the study of circadian rhythms, one that can account for evolving
views of the circadian system’s organization, including peripheral clocks and
inter-hemispheric interaction, and can be translated to other nocturnal and
diurnal animals, including humans.
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Affiliation(s)
| | - Edgar A P Wright
- Department of Physics & I3N, University of Aveiro, Aveiro, Portugal
| | - José F F Mendes
- Department of Physics & I3N, University of Aveiro, Aveiro, Portugal
| | - Sooyeon Yoon
- Department of Physics & I3N, University of Aveiro, Aveiro, Portugal
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15
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Abstract
The molecular mechanism of circadian clocks depends on transcription-translation feedback loops (TTFLs) that have known effects on key cellular processes. However, the distinct role of circadian TTFLs in mammalian stem cells and other less differentiated cells remains poorly understood. Neural stem cells (NSCs) of the brain generate neurons and glia postnatally but also may become cancer stem cells (CSCs), particularly in astrocytomas. Evidence indicates clock TTFL impairment is needed for tumor growth and progression; although, this issue has been examined primarily in more differentiated cancer cells rather than CSCs. Similarly, few studies have examined circadian rhythms in NSCs. After decades of research, it is now well recognized that tumors consist of CSCs and a range of other cancer cells along with noncancerous stromal cells. The circadian properties of these many contributors to tumor properties and treatment outcome are being widely explored. New molecular tools and ones in development will likely enable greater discrimination of important circadian and non-circadian cells within malignancies at multiple stages of cancer progression and following therapy. Here, we focus on adult NSCs and glioma CSCs to address how cells at different stages of differentiation may harbor unique states of the molecular circadian clock influencing differentiation and cell fate.
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16
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Tacad DKM, Tovar AP, Richardson CE, Horn WF, Keim NL, Krishnan GP, Krishnan S. Satiety Associated with Calorie Restriction and Time-Restricted Feeding: Central Neuroendocrine Integration. Adv Nutr 2022; 13:758-791. [PMID: 35134815 PMCID: PMC9156369 DOI: 10.1093/advances/nmac011] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 12/08/2021] [Accepted: 02/02/2022] [Indexed: 02/06/2023] Open
Abstract
This review focuses on summarizing current knowledge on how time-restricted feeding (TRF) and continuous caloric restriction (CR) affect central neuroendocrine systems involved in regulating satiety. Several interconnected regions of the hypothalamus, brainstem, and cortical areas of the brain are involved in the regulation of satiety. Following CR and TRF, the increase in hunger and reduction in satiety signals of the melanocortin system [neuropeptide Y (NPY), proopiomelanocortin (POMC), and agouti-related peptide (AgRP)] appear similar between CR and TRF protocols, as do the dopaminergic responses in the mesocorticolimbic circuit. However, ghrelin and leptin signaling via the melanocortin system appears to improve energy balance signals and reduce hyperphagia following TRF, which has not been reported in CR. In addition to satiety systems, CR and TRF also influence circadian rhythms. CR influences the suprachiasmatic nucleus (SCN) or the primary circadian clock as seen by increased clock gene expression. In contrast, TRF appears to affect both the SCN and the peripheral clocks, as seen by phasic changes in the non-SCN (potentially the elusive food entrainable oscillator) and metabolic clocks. The peripheral clocks are influenced by the primary circadian clock but are also entrained by food timing, sleep timing, and other lifestyle parameters, which can supersede the metabolic processes that are regulated by the primary circadian clock. Taken together, TRF influences hunger/satiety, energy balance systems, and circadian rhythms, suggesting a role for adherence to CR in the long run if implemented using the TRF approach. However, these suggestions are based on only a few studies, and future investigations that use standardized protocols for the evaluation of the effect of these diet patterns (time, duration, meal composition, sufficiently powered) are necessary to verify these preliminary observations.
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Affiliation(s)
- Debra K M Tacad
- Obesity and Metabolism Research Unit, USDA–Western Human Nutrition Research Center, Davis, CA, USA,Department of Nutrition, University of California, Davis, Davis, CA, USA
| | - Ashley P Tovar
- Department of Nutrition, University of California, Davis, Davis, CA, USA
| | | | - William F Horn
- Obesity and Metabolism Research Unit, USDA–Western Human Nutrition Research Center, Davis, CA, USA
| | - Nancy L Keim
- Obesity and Metabolism Research Unit, USDA–Western Human Nutrition Research Center, Davis, CA, USA,Department of Nutrition, University of California, Davis, Davis, CA, USA
| | - Giri P Krishnan
- Department of Medicine, School of Medicine, University of California, San Diego, San Diego, CA, USA
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17
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Li Y, Androulakis IP. Light-induced synchronization of the SCN coupled oscillators and implications for entraining the HPA axis. Front Endocrinol (Lausanne) 2022; 13:960351. [PMID: 36387856 PMCID: PMC9648564 DOI: 10.3389/fendo.2022.960351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
The suprachiasmatic nucleus (SCN) synchronizes the physiological rhythms to the external light-dark cycle and tunes the dynamics of circadian rhythms to photoperiod fluctuations. Changes in the neuronal network topologies are suggested to cause adaptation of the SCN in different photoperiods, resulting in the broader phase distribution of neuron activities in long photoperiods (LP) compared to short photoperiods (SP). Regulated by the SCN output, the level of glucocorticoids is elevated in short photoperiod, which is associated with peak disease incidence. The underlying coupling mechanisms of the SCN and the interplay between the SCN and the HPA axis have yet to be fully elucidated. In this work, we propose a mathematical model including a multiple-cellular SCN compartment and the HPA axis to investigate the properties of the circadian timing system under photoperiod changes. Our model predicts that the probability-dependent network is more energy-efficient than the distance-dependent network. Coupling the SCN network by intra-subpopulation and inter-subpopulation forces, we identified the negative correlation between robustness and plasticity of the oscillatory network. The HPA rhythms were predicted to be strongly entrained to the SCN rhythms with a pro-inflammatory high-amplitude glucocorticoid profile under SP. The fast temporal topology switch of the SCN network was predicted to enhance synchronization when the synchronization is not complete. These synchronization and circadian dynamics alterations might govern the seasonal variation of disease incidence and its symptom severity.
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Affiliation(s)
- Yannuo Li
- Chemical & Biochemical Engineering Department, Rutgers University, Piscataway, NJ, United States
| | - Ioannis P. Androulakis
- Chemical & Biochemical Engineering Department, Rutgers University, Piscataway, NJ, United States
- Biomedical Engineering Department, Rutgers University, Piscataway, NJ, United States
- *Correspondence: Ioannis P. Androulakis,
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18
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Lu Q, Kim JY. Mammalian circadian networks mediated by the suprachiasmatic nucleus. FEBS J 2021; 289:6589-6604. [PMID: 34657394 DOI: 10.1111/febs.16233] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 10/09/2021] [Accepted: 10/15/2021] [Indexed: 12/28/2022]
Abstract
The brain has a complex structure composed of hundreds of regions, forming networks to cooperate body functions. Therefore, understanding how various brain regions communicate with each other and with peripheral organs is important to understand human physiology. The suprachiasmatic nucleus (SCN) in the brain is the circadian pacemaker. The SCN receives photic information from the environment and conveys this to other parts of the brain and body to synchronize all circadian clocks. The circadian clock is an endogenous oscillator that generates daily rhythms in metabolism and physiology in almost all cells via a conserved transcriptional-translational negative feedback loop. So, the information flow from the environment to the SCN to other tissues synchronizes locally distributed circadian clocks to maintain homeostasis. Thus, understanding the circadian networks and how they adjust to environmental changes will better understand human physiology. This review will focus on circadian networks mediated by the SCN to understand how the environment, brain, and peripheral tissues form networks for cooperation.
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Affiliation(s)
- Qingqing Lu
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Jin Young Kim
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.,Tung Foundation Biomedical Sciences Centre, Hong Kong, China.,Shenzhen Research Institute, City University of Hong Kong, Shenzhen, China
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19
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Gu C, Li J, Zhou J, Yang H, Rohling J. Network Structure of the Master Clock Is Important for Its Primary Function. Front Physiol 2021; 12:678391. [PMID: 34483953 PMCID: PMC8415478 DOI: 10.3389/fphys.2021.678391] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 07/22/2021] [Indexed: 11/13/2022] Open
Abstract
A master clock located in the suprachiasmatic nucleus (SCN) regulates the circadian rhythm of physiological and behavioral activities in mammals. The SCN has two main functions in the regulation: an endogenous clock produces the endogenous rhythmic signal in body rhythms, and a calibrator synchronizes the body rhythms to the external light-dark cycle. These two functions have been determined to depend on either the dynamic behaviors of individual neurons or the whole SCN neuronal network. In this review, we first introduce possible network structures for the SCN, as revealed by time series analysis from real experimental data. It was found that the SCN network is heterogeneous and sparse, that is, the average shortest path length is very short, some nodes are hubs with large node degrees but most nodes have small node degrees, and the average node degree of the network is small. Secondly, the effects of the SCN network structure on the SCN function are reviewed based on mathematical models of the SCN network. It was found that robust rhythms with large amplitudes, a high synchronization between SCN neurons and a large entrainment ability exists mainly in small-world and scale-free type networks, but not other types. We conclude that the SCN most probably is an efficient small-world type or scale-free type network, which drives SCN function.
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Affiliation(s)
- Changgui Gu
- Business School, University of Shanghai for Science and Technology, Shanghai, China
| | - Jiahui Li
- Business School, University of Shanghai for Science and Technology, Shanghai, China
| | - Jian Zhou
- Business School, University of Shanghai for Science and Technology, Shanghai, China
| | - Huijie Yang
- Business School, University of Shanghai for Science and Technology, Shanghai, China
| | - Jos Rohling
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
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20
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Anna G, Kannan NN. Post-transcriptional modulators and mediators of the circadian clock. Chronobiol Int 2021; 38:1244-1261. [PMID: 34056966 PMCID: PMC7611477 DOI: 10.1080/07420528.2021.1928159] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/26/2021] [Accepted: 05/03/2021] [Indexed: 01/04/2023]
Abstract
The endogenous circadian timekeeping system drives ~24-h rhythms in gene expression and rhythmically coordinates the physiology, metabolism and behavior in a wide range of organisms. Regulation at various levels is important for the accurate functioning of this circadian timing system. The core circadian oscillator consists of an interlocked transcriptional-translational negative feedback loop (TTFL) that imposes a substantial delay between the accumulation of clock gene mRNA and its protein to generate 24-h oscillations. This TTFL mediated daily oscillation of clock proteins is further fine-tuned by post-translational modifications that regulate the clock protein stability, interaction with other proteins and subcellular localization. Emerging evidence from various studies indicates that besides TTFL and post-translational modifications, post-transcriptional regulation plays a key role in shaping the rhythmicity of mRNAs and to delay the accumulation of clock proteins in relation to their mRNAs. In this review, we summarize the current knowledge on the importance of post-transcriptional regulatory mechanisms such as splicing, polyadenylation, the role of RNA-binding proteins, RNA methylation and microRNAs in the context of shaping the circadian rhythmicity in Drosophila and mammals. In particular, we discuss microRNAs, an important player in post-transcriptional regulation of core-clock machinery, circadian neural circuit, clock input, and output pathways. Furthermore, we provide an overview of the microRNAs that exhibit diurnal rhythm in expression and their role in mediating rhythmic physiological processes.
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Affiliation(s)
- Geo Anna
- Chronobiology Laboratory, School of Biology, Indian Institute of Science Education and Research (IISER), Thiruvananthapuram, Kerala 695551, India
| | - Nisha N Kannan
- Chronobiology Laboratory, School of Biology, Indian Institute of Science Education and Research (IISER), Thiruvananthapuram, Kerala 695551, India
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21
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Oviposition-promoting pars intercerebralis neurons show period-dependent photoperiodic changes in their firing activity in the bean bug. Proc Natl Acad Sci U S A 2021; 118:2018823118. [PMID: 33622784 DOI: 10.1073/pnas.2018823118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Animals show photoperiodic responses in physiology and behavior to adapt to seasonal changes. Recent genetic analyses have demonstrated the significance of circadian clock genes in these responses. However, the importance of clock genes in photoperiodic responses at the cellular level and the physiological roles of the cellular responses are poorly understood. The bean bug Riptortus pedestris shows a clear photoperiodic response in its reproduction. In the bug, the pars intercerebralis (PI) is an important brain region for promoting oviposition. Here, we analyzed the role of the photoperiodic neuronal response and its relationship with clock genes, focusing on PI neurons. Large PI neurons exhibited photoperiodic firing changes, and high firing activities were primarily found under photoperiodic conditions suitable for oviposition. RNA interference-mediated knockdown of the clock gene period abolished the photoperiodic response in PI neurons, as well as the response in ovarian development. To clarify whether the photoperiodic response in the PI was dependent on ovarian development, we performed an ovariectomy experiment. Ovariectomy did not have significant effects on the firing activity of PI neurons. Finally, we identified the output molecules of the PI neurons and analyzed the relevance of the output signals in oviposition. PI neurons express multiple neuropeptides-insulin-like peptides and diuretic hormone 44-and RNA interference of these neuropeptides reduced oviposition. Our results suggest that oviposition-promoting peptidergic neurons in the PI exhibit a circadian clock-dependent photoperiodic firing response, which contributes to the photoperiodic promotion of oviposition.
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22
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Rohr KE, Telega A, Savaglio A, Evans JA. Vasopressin regulates daily rhythms and circadian clock circuits in a manner influenced by sex. Horm Behav 2021; 127:104888. [PMID: 33202247 PMCID: PMC7855892 DOI: 10.1016/j.yhbeh.2020.104888] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/30/2020] [Accepted: 11/04/2020] [Indexed: 12/17/2022]
Abstract
Arginine vasopressin (AVP) is a neurohormone that alters cellular physiology through both endocrine and synaptic signaling. Circadian rhythms in AVP release and other biological processes are driven by the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. Loss of vasopressin signaling alters circadian behavior, but the basis of these effects remains unclear. Here we investigate the role of AVP signaling in circadian timekeeping by analyzing behavior and SCN function in a novel AVP-deficient mouse model. Consistent with previous work, loss of AVP signaling increases water consumption and accelerates recovery to simulated jetlag. We expand on these results to show that loss of AVP increases period, imprecision and plasticity of behavioral rhythms under constant darkness. Interestingly, the effect of AVP deficiency on circadian period was influenced by sex, with loss of AVP lengthening period in females but not males. Examining SCN function directly with ex vivo bioluminescence imaging of clock protein expression, we demonstrate that loss of AVP signaling modulates the period, precision, and phase relationships of SCN neurons in both sexes. This pattern of results suggests that there are likely sex differences in downstream targets of the SCN. Collectively, this work indicates that AVP signaling modulates circadian circuits in a manner influenced by sex, which provides new insight into sexual dimorphisms in the regulation of daily rhythms.
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Affiliation(s)
- Kayla E Rohr
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Adam Telega
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Alexandra Savaglio
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Jennifer A Evans
- Marquette University, Department of Biomedical Sciences, United States of America.
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23
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Sharma A, Sethi G, Tambuwala MM, Aljabali AAA, Chellappan DK, Dua K, Goyal R. Circadian Rhythm Disruption and Alzheimer's Disease: The Dynamics of a Vicious Cycle. Curr Neuropharmacol 2020; 19:248-264. [PMID: 32348224 PMCID: PMC8033974 DOI: 10.2174/1570159x18666200429013041] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/06/2020] [Accepted: 04/24/2020] [Indexed: 12/13/2022] Open
Abstract
All mammalian cells exhibit circadian rhythm in cellular metabolism and energetics. Autonomous cellular clocks are modulated by various pathways that are essential for robust time keeping. In addition to the canonical transcriptional translational feedback loop, several new pathways of circadian timekeeping - non-transcriptional oscillations, post-translational modifications, epigenetics and cellular signaling in the circadian clock - have been identified. The physiology of circadian rhythm is expansive, and its link to the neurodegeneration is multifactorial. Circadian rhythm disruption is prevelant in contamporary society where light-noise, shift-work, and transmeridian travel are commonplace, and is also reported from the early stages of Alzheimer's disease (AD). Circadian alignment by bright light therapy in conjunction with chronobiotics is beneficial for treating sundowning syndrome and other cognitive symptoms in advanced AD patients. We performed a comprehensive analysis of the clinical and translational reports to review the physiology of the circadian clock, delineate its dysfunction in AD, and unravel the dynamics of the vicious cycle between two pathologies. The review delineates the role of putative targets like clock proteins PER, CLOCK, BMAL1, ROR, and clock-controlled proteins like AVP, SIRT1, FOXO, and PK2 towards future approaches for management of AD. Furthermore, the role of circadian rhythm disruption in aging is delineated.
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Affiliation(s)
- Ashish Sharma
- Neuropharmacology Laboratory, School of Pharmaceutical Sciences, Shoolini University, Solan 173 212, Himachal Pradesh, India
| | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Medical Drive, 117 600, Singapore
| | - Murtaza M Tambuwala
- School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine, County, Londonderry, BT52 1SA, Northern Ireland, United Kingdom
| | - Alaa A A Aljabali
- Faculty of Pharmacy, Department of Pharmaceutical Sciences, Yarmouk University, Irbid 21163, Jordan
| | - Dinesh Kumar Chellappan
- Department of Life Sciences, School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, 57000, Malaysia
| | - Kamal Dua
- Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Rohit Goyal
- Neuropharmacology Laboratory, School of Pharmaceutical Sciences, Shoolini University, Solan 173 212, Himachal Pradesh, India
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24
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Joye DAM, Rohr KE, Keller D, Inda T, Telega A, Pancholi H, Carmona-Alcocer V, Evans JA. Reduced VIP Expression Affects Circadian Clock Function in VIP-IRES-CRE Mice (JAX 010908). J Biol Rhythms 2020; 35:340-352. [PMID: 32460660 DOI: 10.1177/0748730420925573] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Circadian rhythms are programmed by the suprachiasmatic nucleus (SCN), which relies on neuropeptide signaling to maintain daily timekeeping. Vasoactive intestinal polypeptide (VIP) is critical for SCN function, but the precise role of VIP neurons in SCN circuits is not fully established. To interrogate their contribution to SCN circuits, VIP neurons can be manipulated specifically using the DNA-editing enzyme Cre recombinase. Although the Cre transgene is assumed to be inert by itself, we find that VIP expression is reduced in both heterozygous and homozygous adult VIP-IRES-Cre mice (JAX 010908). Compared with wild-type mice, homozygous VIP-Cre mice display faster reentrainment and shorter free-running period but do not become arrhythmic in constant darkness. Consistent with this phenotype, homozygous VIP-Cre mice display intact SCN PER2::LUC rhythms, albeit with altered period and network organization. We present evidence that the ability to sustain molecular rhythms in the VIP-Cre SCN is not due to residual VIP signaling; rather, arginine vasopressin signaling helps to sustain SCN function at both intracellular and intercellular levels in this model. This work establishes that the VIP-IRES-Cre transgene interferes with VIP expression but that loss of VIP can be mitigated by other neuropeptide signals to help sustain SCN function. Our findings have implications for studies employing this transgenic model and provide novel insight into neuropeptide signals that sustain daily timekeeping in the master clock.
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Affiliation(s)
- Deborah A M Joye
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Kayla E Rohr
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Danielle Keller
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Thomas Inda
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Adam Telega
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Harshida Pancholi
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | | | - Jennifer A Evans
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
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25
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Moreno JP, Crowley SJ, Alfano CA, Thompson D. Physiological mechanisms underlying children's circannual growth patterns and their contributions to the obesity epidemic in elementary school age children. Obes Rev 2020; 21:e12973. [PMID: 31737994 PMCID: PMC7002188 DOI: 10.1111/obr.12973] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 10/18/2019] [Accepted: 10/18/2019] [Indexed: 12/20/2022]
Abstract
Several studies since the 1990s have demonstrated that children increase their body mass index at a faster rate during summer months compared with the school year, leading some to conclude that the out-of-school summer environment is responsible. Other studies, however, have suggested that seasonality may play a role in children's height and weight changes across the year. This article reviews evidence for seasonal differences in the rate of children's height and weight gain and proposes potential physiological mechanisms that may explain these seasonal variations.
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Affiliation(s)
- Jennette P Moreno
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Stephanie J Crowley
- Biological Rhythm Research Laboratory, Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, Illinois
| | - Candice A Alfano
- Sleep and Anxiety Center of Houston (SACH), Department of Psychology, University of Houston, Houston, Texas
| | - Debbe Thompson
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
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26
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Pilorz V, Astiz M, Heinen KO, Rawashdeh O, Oster H. The Concept of Coupling in the Mammalian Circadian Clock Network. J Mol Biol 2020; 432:3618-3638. [PMID: 31926953 DOI: 10.1016/j.jmb.2019.12.037] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/22/2019] [Accepted: 12/23/2019] [Indexed: 12/13/2022]
Abstract
The circadian clock network regulates daily rhythms in mammalian physiology and behavior to optimally adapt the organism to the 24-h day/night cycle. A central pacemaker, the hypothalamic suprachiasmatic nucleus (SCN), coordinates subordinate cellular oscillators in the brain, as well as in peripheral organs to align with each other and external time. Stability and coordination of this vast network of cellular oscillators is achieved through different levels of coupling. Although coupling at the molecular level and across the SCN is well established and believed to define its function as pacemaker structure, the notion of coupling in other tissues and across the whole system is less well understood. In this review, we describe the different levels of coupling in the mammalian circadian clock system - from molecules to the whole organism. We highlight recent advances in gaining knowledge of the complex organization and function of circadian network regulation and its significance for the generation of stable but plastic intrinsic 24-h rhythms.
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Affiliation(s)
- Violetta Pilorz
- University of Lübeck, Institute of Neurobiology, Center of Brain, Behavior and Metabolism, Marie-Curie-Strasse, 23562, Luebeck, Germany
| | - Mariana Astiz
- University of Lübeck, Institute of Neurobiology, Center of Brain, Behavior and Metabolism, Marie-Curie-Strasse, 23562, Luebeck, Germany
| | - Keno Ole Heinen
- University of Lübeck, Institute of Neurobiology, Center of Brain, Behavior and Metabolism, Marie-Curie-Strasse, 23562, Luebeck, Germany
| | - Oliver Rawashdeh
- The University of Queensland, School of Biomedical Sciences, Faculty of Medicine, St Lucia Qld, 4071, Australia
| | - Henrik Oster
- University of Lübeck, Institute of Neurobiology, Center of Brain, Behavior and Metabolism, Marie-Curie-Strasse, 23562, Luebeck, Germany.
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27
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Rohr KE, Pancholi H, Haider S, Karow C, Modert D, Raddatz NJ, Evans J. Seasonal plasticity in GABA A signaling is necessary for restoring phase synchrony in the master circadian clock network. eLife 2019; 8:49578. [PMID: 31746738 PMCID: PMC6867713 DOI: 10.7554/elife.49578] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 10/15/2019] [Indexed: 12/14/2022] Open
Abstract
Annual changes in the environment threaten survival, and numerous biological processes in mammals adjust to this challenge via seasonal encoding by the suprachiasmatic nucleus (SCN). To tune behavior according to day length, SCN neurons display unified rhythms with synchronous phasing when days are short, but will divide into two sub-clusters when days are long. The transition between SCN states is critical for maintaining behavioral responses to seasonal change, but the mechanisms regulating this form of neuroplasticity remain unclear. Here we identify that a switch in chloride transport and GABAA signaling is critical for maintaining state plasticity in the SCN network. Further, we reveal that blocking excitatory GABAA signaling locks the SCN into its long day state. Collectively, these data demonstrate that plasticity in GABAA signaling dictates how clock neurons interact to maintain environmental encoding. Further, this work highlights factors that may influence susceptibility to seasonal disorders in humans. In winter, as the days become shorter, millions of people find that their mood and energy levels start to drop. They crave carbohydrates, struggle with their weight, and find it harder to get out of bed in the mornings. These individuals are suffering from the ‘winter blues’ or seasonal affective disorder (SAD), and most find that their symptoms spontaneously improve in the spring when the days become longer again. Many also benefit from bright light therapy during the winter months, but not everyone responds fully to this treatment, so additional options are needed. The winter blues occur when the brain adjusts to changes in day length with the onset of winter. The brain region responsible for making this adjustment is the suprachiasmatic nucleus (SCN). The SCN is the master clock of the brain that coordinates the body’s circadian rhythms – the daily fluctuations in things like appetite, body temperature, sleep and wakefulness. But as well as being the brain’s clock, the SCN is also the brain’s calendar. In winter, when the days are short, SCN neurons coordinate their activity and fire in synchrony. But in summer, when the days are long, SCN neurons divide into two clusters, which fire at different times. By transitioning between these two states, the SCN helps the body adjust to seasonal changes in day length. Rohr, Pancholi et al. now provide new insight into the mechanism behind this process by showing that light alters the neurochemistry of the SCN. Exposing mice to long days causes a brain chemical called GABA to switch from inhibiting neurons in the SCN to activating them. Blocking this switch from inhibition to activation locks the SCN into its 'summer state'. Rohr, Pancholi et al. propose that this failure to transition to the winter state may be an interesting way to prevent the winter blues. While much remains to be learned about this process, these findings pave the way for better understanding the neurobiology of winter depression and how best to treat it.
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Affiliation(s)
- Kayla E Rohr
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Harshida Pancholi
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Shabi Haider
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Christopher Karow
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - David Modert
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Nicholas J Raddatz
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Jennifer Evans
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
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Foster S, Christiansen T, Antle MC. Modeling the Influence of Synaptic Plasticity on After-effects. J Biol Rhythms 2019; 34:645-657. [PMID: 31436125 DOI: 10.1177/0748730419871189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
While circadian rhythms in physiology and behavior demonstrate remarkable day-to-day precision, they are also able to exhibit plasticity in a variety of parameters and under a variety of conditions. After-effects are one type of plasticity in which exposure to non-24-h light-dark cycles (T-cycles) will alter the animal's free-running rhythm in subsequent constant conditions. We use a mathematical model to explore whether the concept of synaptic plasticity can explain the observation of after-effects. In this model, the SCN is composed of a set of individual oscillators randomly selected from a normally distributed population. Each cell receives input from a defined set of oscillators, and the overall period of a cell is a weighted average of its own period and that of its inputs. The influence that an input has on its target's period is determined by the proximity of the input cell's period to the imposed T-cycle period, such that cells with periods near T will have greater influence. Such an arrangement is able to duplicate the phenomenon of after-effects, with relatively few inputs per cell (~4-5) being required. When the variability of periods between oscillators is low, the system is quite robust and results in minimal after-effects, while systems with greater between-cell variability exhibit greater magnitude after-effects. T-cycles that produce maximal after-effects have periods within ~2.5 to 3 h of the population period. Overall, this model demonstrates that synaptic plasticity in the SCN network could contribute to plasticity of the circadian period.
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Affiliation(s)
- Semra Foster
- Department of Psychology, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Tom Christiansen
- Department of Psychology, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Michael C Antle
- Department of Psychology, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
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29
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Hannibal J, Norn THB, Georg B, Fahrenkrug J. Spatiotemporal expression pattern of PERIOD 1 and PERIOD 2 in the mouse SCN is dependent on VIP receptor 2 signaling. Eur J Neurosci 2019; 50:3115-3132. [PMID: 31211910 DOI: 10.1111/ejn.14482] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 04/29/2019] [Accepted: 05/21/2019] [Indexed: 11/29/2022]
Abstract
Neurons of the hypothalamic suprachiasmatic nucleus (SCN) express clock genes, which regulate their own transcription and generate daily output signals driving circadian rhythmic behavior and physiology. The neuropeptide VIP and its specific receptor, the VPAC2 receptor, are important for synchronization of clock neurons. In the present study, we characterized PER1 and PER2 expressing neurons in wild-type and VPAC2-deficient mice. We found evidence for distinct spatiotemporal circadian oscillation in the expression of the PER genes in two separate clusters of SCN neurons. In wild-type mice corresponding to the SCN shell and ventral core, high expression of PER was found at lights-off most likely representing an evening clock (E-clock). In another smaller cluster of neurons located in the central core of the SCN, PER expression peaks in antiphase at lights-on and could represent a morning clock (M-clock). BMAL1 immunoreactivity was found to be expressed in antiphase to PER in M and E neurons, respectively. PER was found in 98% of neurons expressing vasopressin (AVP) and in 92% of VIP neurons. The chemotype of M neurons was not identified. M but not E cells were responsive to long but not short photoperiods. The expression of the VPAC2 receptor was found in both M and E cells, and VPAC2-deficient mice displayed markedly blunted PER expression in both cell clusters of the SCN. Conclusion: These observations support the existence of M and E clocks involved in circadian and seasonal adaptation, which seem dependent on intact VIP/VPAC2 signaling in the SCN.
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Affiliation(s)
- Jens Hannibal
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Tania H B Norn
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Birgitte Georg
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jan Fahrenkrug
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark
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30
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Steady-State Pupil Size Varies with Circadian Phase and Sleep Homeostasis in Healthy Young Men. Clocks Sleep 2019; 1:240-258. [PMID: 33089167 PMCID: PMC7445830 DOI: 10.3390/clockssleep1020021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 05/07/2019] [Indexed: 11/16/2022] Open
Abstract
Pupil size informs about sympathovagal balance as well as cognitive and affective processes, and perception. It is also directly linked to phasic activity of the brainstem locus coeruleus, so that pupil measures have gained recent attention. Steady-state pupil size and its variability have been directly linked to sleep homeostasis and circadian phase, but results have been inconsistent. Here, we report robust changes in steady-state pupil size during 29 h of continuous wakefulness in healthy young men (N = 20; 18–30 years old) maintained in dim-light in strictly controlled constant routine conditions. These variations were associated with variations in motivation and sustained attention performance. Pupil size variability did not significantly change during the protocol. Yet, pupil size variability was linearly associated with subjective fatigue, sociability, and anguish. No associations were found between neither steady-state pupil size nor pupil size variability, and objective EEG measure of alertness and subjective sleepiness. Our data support therefore the notion that, compared with its variability, steady-state pupil size is strongly influenced by the concomitant changes in sleep need and circadian phase. In addition, steady-state pupil size appears to be related to motivation and attention, while its variability may be related to separate affective dimensions and subjective fatigue.
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31
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Harrison EM, Yablonsky AM, Powell AL, Ancoli-Israel S, Glickman GL. Reported light in the sleep environment: enhancement of the sleep diary. Nat Sci Sleep 2019; 11:11-26. [PMID: 30988646 PMCID: PMC6438264 DOI: 10.2147/nss.s193902] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Light is the primary synchronizing cue for the circadian timing system, capable of exerting robust physiological effects, even with very dim and/or brief photic exposure. Mammals, including humans, are particularly susceptible to light at night. As such, measures of light in the sleeping environment are critical for evaluating sleep health. Sleep diaries provide inexpensive measures of sleep, but do not typically include light information. METHODS Four questions probing visual perception of light in the bedtime and waking environments were added to the Consensus Sleep Diary for Morning administration. As part of a lighting intervention study, 18 hospital Labor and Delivery Department personnel completed the sleep diary for 1 week in each of two experimental conditions while wearing Actiwatch devices equipped with photosensors. Diary responses were evaluated against photosensor values from the beginning and end of each rest interval (n=194 rest intervals), as well as against sleep measures, utilizing linear mixed models. RESULTS Responses to light questions were related to actual light measures at bedtime, controlling for shift type and experimental condition. In addition, subjective light information at bedtime and waking was related to both objective and subjective sleep parameters, with data generally indicating poorer sleep with light in the sleeping environment. CONCLUSION Questions addressing perception of light in the sleeping environment may provide a crude yet affordable metric of relative photic intensity. Further, as responses relate to sleep outcomes, subjective light information may yield valuable insights regarding mechanisms and outcomes of clinical significance in sleep and circadian research.
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Affiliation(s)
| | - Abigail M Yablonsky
- Clinical Investigations Department, Naval Medical Center San Diego, San Diego, CA, USA
| | - Alexandra L Powell
- Center for Circadian Biology, University of California, San Diego, CA, USA,
| | - Sonia Ancoli-Israel
- Center for Circadian Biology, University of California, San Diego, CA, USA,
- Department of Psychiatry, University of California, San Diego, CA, USA
| | - Gena L Glickman
- Center for Circadian Biology, University of California, San Diego, CA, USA,
- Department of Psychiatry, Uniformed Services University, Bethesda, MD, USA
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32
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Murphy BA. Circadian and Circannual Regulation in the Horse: Internal Timing in an Elite Athlete. J Equine Vet Sci 2019; 76:14-24. [PMID: 31084748 DOI: 10.1016/j.jevs.2019.02.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 02/25/2019] [Indexed: 12/20/2022]
Abstract
Biological rhythms evolved to provide temporal coordination across all tissues and organs and allow synchronization of physiology with predictable environmental cycles. Most important of these are circadian and circannual rhythms, primarily regulated via photoperiod signals from the retina. Understanding the nature of physiological rhythms in horses is crucially important for equine management. Predominantly, they have been removed from exposure to their natural environmental stimuli; the seasonally changing photoperiod, continuous foraging and feeding activity, social herd interactions, and the continuous low-intensity exercise of a grassland dweller. These have been replaced in many cases with confined indoor housing, regimental feeding and exercise times, social isolation, and exposure to lighting that is often erratic and does not come close to mimicking the spectral composition of sunlight. Man has further altered seasonal timing cues through the use of artificial lighting programs that impact reproductive behavior, breeding efficiency, and the development of youngstock. Understanding how these new environmental cues (some stronger and some weaker) impact the internal physiology of the horse in the context of the natural endogenous rhythms that evolved over millennia is key to helping to improve equine health, welfare, and performance, now and into the future. This review provides an overview of the field, highlights the recent discoveries related to biological timing in horses, and discusses the implications that these findings may have for the production and management of the elite equine athlete.
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Affiliation(s)
- Barbara A Murphy
- School of Agriculture and Food Science, University College Dublin, Dublin, Ireland.
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33
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Ashraf H, Ahmad J, Hassan A, Ali A. Computational modeling and analysis of the impacts of sleep deprivation on glucose stimulated insulin secretion. Biosystems 2019; 179:1-14. [PMID: 30790613 DOI: 10.1016/j.biosystems.2019.02.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 01/02/2019] [Accepted: 02/13/2019] [Indexed: 01/12/2023]
Abstract
Circadian clock is an exquisite internal biological clock functioning in all living organisms. Lifestyle changes such as shift work or frequent travelling might result in malfunctioning of the central and consequently the peripheral clocks leading to different metabolic disorders. Disruptions in β cell clock have been found to be a potential reason behind β cell failure that makes a person prone towards developing type 2 diabetes (T2DM). In this study, a Petri net model for β cell circadian clock has been developed, followed by analysis of the negative impacts of sleep deprivation conditions on the process of glucose stimulated insulin secretion (GSIS) through misalignment of circadian clock. The analysis of structural properties of the Petri net model reveals robustness of the circadian system. The simulation results predict that sleep loss negatively affects the expression of circadian genes which eventually leads to impaired GSIS and β cell failure. These results suggest that sleep/wake cycle is a vital contributor for the entrainment of the circadian clock and normal functioning of β cell.
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Affiliation(s)
- Hufsah Ashraf
- Research Center for Modeling and Simulation (RCMS), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Jamil Ahmad
- Research Center for Modeling and Simulation (RCMS), National University of Sciences and Technology (NUST), Islamabad, Pakistan; Department of Computer Science and Information Technology, University of Malakand, Chakdara, Pakistan.
| | - Azka Hassan
- Research Center for Modeling and Simulation (RCMS), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Amjad Ali
- Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology (NUST), Islamabad, Pakistan
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34
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Tokuda IT, Ono D, Honma S, Honma KI, Herzel H. Coherency of circadian rhythms in the SCN is governed by the interplay of two coupling factors. PLoS Comput Biol 2018; 14:e1006607. [PMID: 30532130 PMCID: PMC6301697 DOI: 10.1371/journal.pcbi.1006607] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 12/20/2018] [Accepted: 10/30/2018] [Indexed: 01/05/2023] Open
Abstract
Circadian clocks are autonomous oscillators driving daily rhythms in physiology and behavior. In mammals, a network of coupled neurons in the suprachiasmatic nucleus (SCN) is entrained to environmental light-dark cycles and orchestrates the timing of peripheral organs. In each neuron, transcriptional feedbacks generate noisy oscillations. Coupling mediated by neuropeptides such as VIP and AVP lends precision and robustness to circadian rhythms. The detailed coupling mechanisms between SCN neurons are debated. We analyze organotypic SCN slices from neonatal and adult mice in wild-type and multiple knockout conditions. Different degrees of rhythmicity are quantified by pixel-level analysis of bioluminescence data. We use empirical orthogonal functions (EOFs) to characterize spatio-temporal patterns. Simulations of coupled stochastic single cell oscillators can reproduce the diversity of observed patterns. Our combination of data analysis and modeling provides deeper insight into the enormous complexity of the data: (1) Neonatal slices are typically stronger oscillators than adult slices pointing to developmental changes of coupling. (2) Wild-type slices are completely synchronized and exhibit specific spatio-temporal patterns of phases. (3) Some slices of Cry double knockouts obey impaired synchrony that can lead to co–existing rhythms (“splitting”). (4) The loss of VIP-coupling leads to desynchronized rhythms with few residual local clusters. Additional information was extracted from co–culturing slices with rhythmic neonatal wild-type SCNs. These co–culturing experiments were simulated using external forcing terms representing VIP and AVP signaling. The rescue of rhythmicity via co–culturing lead to surprising results, since a cocktail of AVP-antagonists improved synchrony. Our modeling suggests that these counter-intuitive observations are pointing to an antagonistic action of VIP and AVP coupling. Our systematic theoretical and experimental study shows that dual coupling mechanisms can explain the astonishing complexity of spatio-temporal patterns in SCN slices. The mammalian circadian clock is orchestrated by a network of coupled neurons. Brain slice preparations allow the analysis of coupling mechanisms mediated by neuropeptides. From bioluminescence recordings, we extract single cell characteristics such as period, amplitude and damping rate. Our data-based stochastic network model involves local coupling between cells and additional external forcing. Available experimental data guide our simulations with two distinct coupling and forcing mechanisms representing the neuropeptides VIP and AVP. We compare our simulations with experiments from neonatal and adult wild-type brain slices and multiple knockouts. Furthermore, we study co–culturing of slices with synchronized neonatal wild-type slices. The extreme complexity of the spatio-temporal patterns is quantified using empirical orthogonal functions (EOFs). The experimental reduction of AVP coupling leads to surprising observations. In double knockouts, inhibition of AVP signaling can improve synchrony, whereas, in triple knockouts, coherency is reduced. Our network modeling shows that these counter-intuitive observations can be explained by an antagonistic action of VIP and AVP signaling. The agreement of experiments and simulations suggests that quite complex spatio-temporal patterns can appear as emergent properties of oscillator networks with dual coupling mechanisms.
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Affiliation(s)
- Isao T. Tokuda
- Department of Mechanical Engineering, Ritsumeikan University, Shiga, Japan
- * E-mail: (ITT); (HH)
| | - Daisuke Ono
- Photonic Bioimaging Section, Research Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Sato Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Ken-Ichi Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Hanspeter Herzel
- Institute for Theoretical Biology, Charité and Humboldt University of Berlin, Berlin, Germany
- * E-mail: (ITT); (HH)
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35
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Carmona-Alcocer V, Rohr KE, Joye DAM, Evans JA. Circuit development in the master clock network of mammals. Eur J Neurosci 2018; 51:82-108. [PMID: 30402923 DOI: 10.1111/ejn.14259] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/08/2018] [Accepted: 10/31/2018] [Indexed: 12/24/2022]
Abstract
Daily rhythms are generated by the circadian timekeeping system, which is orchestrated by the master circadian clock in the suprachiasmatic nucleus (SCN) of mammals. Circadian timekeeping is endogenous and does not require exposure to external cues during development. Nevertheless, the circadian system is not fully formed at birth in many mammalian species and it is important to understand how SCN development can affect the function of the circadian system in adulthood. The purpose of the current review is to discuss the ontogeny of cellular and circuit function in the SCN, with a focus on work performed in model rodent species (i.e., mouse, rat, and hamster). Particular emphasis is placed on the spatial and temporal patterns of SCN development that may contribute to the function of the master clock during adulthood. Additional work aimed at decoding the mechanisms that guide circadian development is expected to provide a solid foundation upon which to better understand the sources and factors contributing to aberrant maturation of clock function.
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Affiliation(s)
| | - Kayla E Rohr
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Deborah A M Joye
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Jennifer A Evans
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
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36
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Collins B, Brown SA. Beyond the molecular clock. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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37
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Wehr TA. Bipolar mood cycles associated with lunar entrainment of a circadian rhythm. Transl Psychiatry 2018; 8:151. [PMID: 30104658 PMCID: PMC6089884 DOI: 10.1038/s41398-018-0203-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 05/15/2018] [Accepted: 06/15/2018] [Indexed: 12/15/2022] Open
Abstract
In bipolar disorder, episodes of depression and mania are associated with dramatic disturbances in sleep, which experiments show are likely to contribute to the pathogenesis of the episodes. A recent finding that 18 patients' manic-depressive cycles oscillated in synchrony with biweekly surges in amplitude of the moon's tides provided a clue to the cause of the sleep-disturbances. Analyses of one of the patients' sleep-wake cycles suggest that his mood cycles arose when a circadian rhythm that normally is entrained to dawn and controls the daily onset of wakefulness became entrained instead to 24.8-h recurrences of every second 12.4-h tidal cycle. The finding provides the basis for a comprehensive description of the pathogenesis and pathophysiology of the mood cycle.
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Affiliation(s)
- Thomas A. Wehr
- 0000 0004 0464 0574grid.416868.5Intramural Research Program, National Institute of Mental Health, Bethesda, MD USA
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38
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Pierre K, Rao RT, Hartmanshenn C, Androulakis IP. Modeling the Influence of Seasonal Differences in the HPA Axis on Synchronization of the Circadian Clock and Cell Cycle. Endocrinology 2018; 159:1808-1826. [PMID: 29444258 PMCID: PMC6044315 DOI: 10.1210/en.2017-03226] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 02/06/2018] [Indexed: 12/22/2022]
Abstract
Synchronization of biological functions to environmental signals enables organisms to anticipate and appropriately respond to daily external fluctuations and is critical to the maintenance of homeostasis. Misalignment of circadian rhythms with environmental cues is associated with adverse health outcomes. Cortisol, the downstream effector of hypothalamic-pituitary-adrenal (HPA) activity, facilitates synchronization of peripheral biological processes to the environment. Cortisol levels exhibit substantial seasonal rhythmicity, with peak levels occurring during the short-photoperiod winter months and reduced levels occurring in the long-photoperiod summer season. Seasonal changes in cortisol secretion could therefore alter its entraining capabilities, resulting in a season-dependent modification in the alignment of biological activities with the environment. We develop a mathematical model to investigate the influence of photoperiod-induced seasonal differences in the circadian rhythmicity of the HPA axis on the synchronization of the peripheral circadian clock and cell cycle in a heterogeneous cell population. Model simulations predict that the high-amplitude cortisol rhythms in winter result in the greatest entrainment of peripheral oscillators. Furthermore, simulations predict a circadian gating of the cell cycle with respect to the expression of peripheral clock genes. Seasonal differences in cortisol rhythmicity are also predicted to influence mitotic synchrony, with a high-amplitude winter rhythm resulting in the greatest synchrony and a shift in timing of the cell cycle phases, relative to summer. Our results highlight the primary interactions among the HPA axis, the peripheral circadian clock, and the cell cycle and thereby provide an improved understanding of the implications of circadian misalignment on the synchronization of peripheral regulatory processes.
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Affiliation(s)
- Kamau Pierre
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | - Rohit T Rao
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | - Clara Hartmanshenn
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | - Ioannis P Androulakis
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey
- Correspondence: Ioannis P. Androulakis, PhD, Biomedical Engineering Department, Rutgers University, 599 Taylor Road, Piscataway, New Jersey 08854. E-mail:
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Rao RT, Pierre KK, Schlesinger N, Androulakis IP. The Potential of Circadian Realignment in Rheumatoid Arthritis. Crit Rev Biomed Eng 2017; 44:177-191. [PMID: 28605351 DOI: 10.1615/critrevbiomedeng.2016018812] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this short review, we discuss evidence supporting the modulation of peripheral circadian systems as a therapeutic strategy for rheumatoid arthritis (RA). We first review the role of proinflammatory cytokines and oxidative stress, two of the primary mediators of chronic inflammation in RA, and their regulation by circadian clock machinery. We further highlight the role of environmental and metabolic signals in regulating the central and peripheral circadian clocks, with an emphasis on seasonal variations in photoperiod and rhythmic metabolic input, respectively. Finally, we hypothesize that the entrainment and realignment of peripheral clock rhythms have the ability to modulate these mediators, improving clinical outcomes in RA patients. Our discussion emphasizes the use of light therapy and time-restricted feeding for entraining peripheral clocks either via the entrainment of the central circadian clock in suprachiasmatic nuclei (SCN) or directly by uncoupling the peripheral circadian clocks from SCN. In doing so, we highlight the use of nonpharmacologic interventions as a potential strategy for improving clinical outcomes in chronic inflammatory conditions such as RA.
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Affiliation(s)
- Rohit T Rao
- Chemical & Biochemical Engineering Department, Rutgers University, Piscataway, New Jersey
| | - Kamau K Pierre
- Biomedical Engineering Department, Rutgers University, Piscataway, New Jersey
| | - Naomi Schlesinger
- Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
| | - Ioannis P Androulakis
- Chemical and Biochemical Engineering Department, Rutgers University, Piscataway, New Jersey; Biomedical Engineering Department, Rutgers University, Piscataway, New Jersey; Department of Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
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40
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Rao RT, Scherholz ML, Hartmanshenn C, Bae SA, Androulakis IP. On the analysis of complex biological supply chains: From Process Systems Engineering to Quantitative Systems Pharmacology. Comput Chem Eng 2017; 107:100-110. [PMID: 29353945 DOI: 10.1016/j.compchemeng.2017.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The use of models in biology has become particularly relevant as it enables investigators to develop a mechanistic framework for understanding the operating principles of living systems as well as in quantitatively predicting their response to both pathological perturbations and pharmacological interventions. This application has resulted in a synergistic convergence of systems biology and pharmacokinetic-pharmacodynamic modeling techniques that has led to the emergence of quantitative systems pharmacology (QSP). In this review, we discuss how the foundational principles of chemical process systems engineering inform the progressive development of more physiologically-based systems biology models.
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Affiliation(s)
- Rohit T Rao
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, NJ 08854
| | - Megerle L Scherholz
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, NJ 08854
| | - Clara Hartmanshenn
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, NJ 08854
| | - Seul-A Bae
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, NJ 08854
| | - Ioannis P Androulakis
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, NJ 08854.,Department of Biomedical Engineering, Rutgers The State University of New Jersey, 599 Taylor Road, Piscataway, NJ 08854
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41
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Kistenpfennig C, Nakayama M, Nihara R, Tomioka K, Helfrich-Förster C, Yoshii T. A Tug-of-War between Cryptochrome and the Visual System Allows the Adaptation of Evening Activity to Long Photoperiods in Drosophila melanogaster. J Biol Rhythms 2017; 33:24-34. [PMID: 29179610 DOI: 10.1177/0748730417738612] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In many animals, the circadian clock plays a role in adapting to the coming season by measuring day length. The mechanism for measuring day length and its neuronal circuits remains elusive, however. Under laboratory conditions, the fruit fly, Drosophila melanogaster, displays 2 activity peaks: one in the morning and one in the evening. These peaks appear to be regulated by 2 separate circadian oscillators (the morning and evening oscillators) that reside in different subsets of pacemaker clock neurons in the brain. The morning and evening activity peaks can flexibly change their phases to adapt to different photoperiods by tracking dawn and dusk, respectively. In this study, we found that cryptochrome (CRY) in the evening oscillators (the fifth small ventral lateral neuron [5th s-LNv] and the dorsal lateral neurons [LNds]) limits the ability of the evening peak to track dusk during long days. In contrast, light signaling from the external photoreceptors (compound eyes, ocelli, and Hofbauer-Buchner eyelets) increases the ability of the evening peak to track dusk. At the molecular level, CRY signaling dampens the amplitude of PAR-domain protein 1 (PDP1) oscillations in most clock neurons during long days, whereas signaling from the visual system increases these amplitudes. Thus, our results suggest that light inputs from the two major circadian photoreceptors, CRY and the visual system, have opposite effects on day length adaptation. Their tug-of-war appears to determine the precise phase adjustment of evening activity.
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Affiliation(s)
- Christa Kistenpfennig
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.,Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Am Hubland, Würzburg, Germany.,2. Oxitec Ltd, 71 Innovation Drive, Milton Park, Abingdon, OX14 4RQ, UK
| | - Mayumi Nakayama
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Ruri Nihara
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Kenji Tomioka
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Charlotte Helfrich-Förster
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Am Hubland, Würzburg, Germany
| | - Taishi Yoshii
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
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42
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Moran-Ramos S, Guerrero-Vargas NN, Mendez-Hernandez R, Basualdo MDC, Escobar C, Buijs RM. The suprachiasmatic nucleus drives day-night variations in postprandial triglyceride uptake into skeletal muscle and brown adipose tissue. Exp Physiol 2017; 102:1584-1595. [PMID: 29113012 DOI: 10.1113/ep086026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 09/26/2017] [Indexed: 12/23/2022]
Abstract
NEW FINDINGS What is the central question of this study? What are the factors influencing day-night variations in postprandial triglycerides? What is the main finding and its importance? Rats show low postprandial plasma triglyceride concentrations early in the active period that are attributable to a higher uptake by skeletal muscle and brown adipose tissue. We show that these day-night variations in uptake are driven by the suprachiasmatic nucleus, probably via a Rev-erbα-mediated mechanism and independent of locomotor activity. These findings highlight that the suprachiasmatic nucleus has a major role in day-night variations in plasma triglycerides and that disturbances in our biological clock might be an important risk factor contributing to development of postprandial hyperlipidaemia. Energy metabolism follows a diurnal pattern, mainly driven by the suprachiasmatic nucleus (SCN), and disruption of circadian regulation has been linked to metabolic abnormalities. Indeed, epidemiological evidence shows that night work is a risk factor for cardiovascular disease, and postprandial hyperlipidaemia is an important contributor. Therefore, the aim of this work was to investigate the factors that drive day-night variations in postprandial triglycerides (TGs). Intact and SCN-lesioned male Wistar rats were subjected to an oral fat challenge during the beginning of the rest phase (day) or the beginning of the active phase (night). The plasma TG profile was evaluated and tissue TG uptake assayed. After the fat challenge, intact rats showed lower postprandial plasma TG concentrations early in the night when compared with the day. However, no differences were observed in the rate of intestinal TG secretion between day and night. Instead, there was a higher uptake of TG by skeletal muscle and brown adipose tissue early in the active phase (night) when compared with the rest phase (day), and these variations were abolished in rats bearing bilateral SCN lesions. Rev-erbα gene expression suggests this as a possible mediator of the mechanism linking the SCN and day-night variations in TG uptake. These findings show that the SCN has a major role in day-night variations in plasma TGs by promoting TG uptake into skeletal muscle and brown adipose tissue. Consequently, disturbance of the biological clock might be an important risk factor contributing to the development of hyperlipidaemia.
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Affiliation(s)
- Sofía Moran-Ramos
- Department of Anatomy, Faculty of Medicine, Universidad Nacional Autonóma de México, Mexico City, Mexico
| | - Natali N Guerrero-Vargas
- Department of Anatomy, Faculty of Medicine, Universidad Nacional Autonóma de México, Mexico City, Mexico.,Department of Cell Biology and Physiology, Institute for Biomedical Research, Universidad Nacional Autonoma de Mexico, Mexico City, Mexico
| | - Rebeca Mendez-Hernandez
- Department of Cell Biology and Physiology, Institute for Biomedical Research, Universidad Nacional Autonoma de Mexico, Mexico City, Mexico
| | - Maria Del Carmen Basualdo
- Department of Cell Biology and Physiology, Institute for Biomedical Research, Universidad Nacional Autonoma de Mexico, Mexico City, Mexico
| | - Carolina Escobar
- Department of Anatomy, Faculty of Medicine, Universidad Nacional Autonóma de México, Mexico City, Mexico
| | - Ruud M Buijs
- Department of Cell Biology and Physiology, Institute for Biomedical Research, Universidad Nacional Autonoma de Mexico, Mexico City, Mexico
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43
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Brown TM. Using light to tell the time of day: sensory coding in the mammalian circadian visual network. ACTA ACUST UNITED AC 2017; 219:1779-92. [PMID: 27307539 PMCID: PMC4920240 DOI: 10.1242/jeb.132167] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 05/09/2016] [Indexed: 12/31/2022]
Abstract
Circadian clocks are a near-ubiquitous feature of biology, allowing organisms to optimise their physiology to make the most efficient use of resources and adjust behaviour to maximise survival over the solar day. To fulfil this role, circadian clocks require information about time in the external world. This is most reliably obtained by measuring the pronounced changes in illumination associated with the earth's rotation. In mammals, these changes are exclusively detected in the retina and are relayed by direct and indirect neural pathways to the master circadian clock in the hypothalamic suprachiasmatic nuclei. Recent work reveals a surprising level of complexity in this sensory control of the circadian system, including the participation of multiple photoreceptive pathways conveying distinct aspects of visual and/or time-of-day information. In this Review, I summarise these important recent advances, present hypotheses as to the functions and neural origins of these sensory signals, highlight key challenges for future research and discuss the implications of our current knowledge for animals and humans in the modern world.
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Affiliation(s)
- Timothy M Brown
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
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44
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Chew KS, Fernandez DC, Hattar S, Südhof TC, Martinelli DC. Anatomical and Behavioral Investigation of C1ql3 in the Mouse Suprachiasmatic Nucleus. J Biol Rhythms 2017; 32:222-236. [PMID: 28553739 PMCID: PMC5664174 DOI: 10.1177/0748730417704766] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Many biochemical, physiological, and behavioral processes such as glucose metabolism, body temperature, and sleep-wake cycles show regular daily rhythms. These circadian rhythms are adjusted to the environmental light-dark cycle by a central pacemaker located in the suprachiasmatic nucleus (SCN) in order for the processes to occur at appropriate times of day. Here, we investigated the expression and function of a synaptic organizing protein, C1QL3, in the SCN. We found that C1ql3 is robustly expressed in the SCN. C1ql3 knockout mice have a reduced density of excitatory synapses in the SCN. In addition, these mice exhibited less consolidated activity to the active portions of the day and period lengthening following a 15-minute phase-delaying light pulse. These data identify C1QL3 as a signaling molecule that is highly expressed in SCN neurons, where it contributes to the formation and/or maintenance of glutamatergic synapses and plays a role in circadian behaviors, which may include circadian aftereffects.
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Affiliation(s)
- Kylie S. Chew
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland
- Department of Biology, Stanford University School of Medicine, Stanford, California
| | - Diego C. Fernandez
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland
| | - Samer Hattar
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland
- The Solomon Snyder-Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Thomas C. Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California
- Howard Hughes Medical, Institute, Stanford University School of Medicine, Stanford, California
| | - David C. Martinelli
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut
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45
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Mendoza-Viveros L, Chiang CK, Ong JLK, Hegazi S, Cheng AH, Bouchard-Cannon P, Fana M, Lowden C, Zhang P, Bothorel B, Michniewicz MG, Magill ST, Holmes MM, Goodman RH, Simonneaux V, Figeys D, Cheng HYM. miR-132/212 Modulates Seasonal Adaptation and Dendritic Morphology of the Central Circadian Clock. Cell Rep 2017; 19:505-520. [PMID: 28423315 PMCID: PMC5864111 DOI: 10.1016/j.celrep.2017.03.057] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 01/11/2017] [Accepted: 03/17/2017] [Indexed: 02/04/2023] Open
Abstract
The central circadian pacemaker, the suprachiasmatic nucleus (SCN), encodes day length information by mechanisms that are not well understood. Here, we report that genetic ablation of miR-132/212 alters entrainment to different day lengths and non-24 hr day-night cycles, as well as photoperiodic regulation of Period2 expression in the SCN. SCN neurons from miR-132/212-deficient mice have significantly reduced dendritic spine density, along with altered methyl CpG-binding protein (MeCP2) rhythms. In Syrian hamsters, a model seasonal rodent, day length regulates spine density on SCN neurons in a melatonin-independent manner, as well as expression of miR-132, miR-212, and their direct target, MeCP2. Genetic disruption of Mecp2 fully restores the level of dendritic spines of miR-132/212-deficient SCN neurons. Our results reveal that, by regulating the dendritic structure of SCN neurons through a MeCP2-dependent mechanism, miR-132/212 affects the capacity of the SCN to encode seasonal time.
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Affiliation(s)
- Lucia Mendoza-Viveros
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada; Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada
| | - Cheng-Kang Chiang
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Jonathan L K Ong
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada
| | - Sara Hegazi
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada; Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada
| | - Arthur H Cheng
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada; Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada
| | - Pascale Bouchard-Cannon
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada; Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada
| | - Michael Fana
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada; Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada
| | - Christopher Lowden
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada; Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada
| | - Peng Zhang
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada
| | - Béatrice Bothorel
- Institut des Neurosciences Cellulaires et Intégratives, UPR CNRS 3212, Université de Strasbourg, 5 rue Blaise Pascal, 67084 Strasbourg, France
| | - Matthew G Michniewicz
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada
| | - Stephen T Magill
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Melissa M Holmes
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada; Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada
| | - Richard H Goodman
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239, USA
| | - Valérie Simonneaux
- Institut des Neurosciences Cellulaires et Intégratives, UPR CNRS 3212, Université de Strasbourg, 5 rue Blaise Pascal, 67084 Strasbourg, France
| | - Daniel Figeys
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada; Canadian Institute for Advanced Research, 180 Dundas Street West, Toronto, ON M5G 1Z8, Canada
| | - Hai-Ying M Cheng
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada; Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada.
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46
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Stothard ER, McHill AW, Depner CM, Birks BR, Moehlman TM, Ritchie HK, Guzzetti JR, Chinoy ED, LeBourgeois MK, Axelsson J, Wright KP. Circadian Entrainment to the Natural Light-Dark Cycle across Seasons and the Weekend. Curr Biol 2017; 27:508-513. [PMID: 28162893 DOI: 10.1016/j.cub.2016.12.041] [Citation(s) in RCA: 165] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/02/2016] [Accepted: 12/19/2016] [Indexed: 01/17/2023]
Abstract
Reduced exposure to daytime sunlight and increased exposure to electrical lighting at night leads to late circadian and sleep timing [1-3]. We have previously shown that exposure to a natural summer 14 hr 40 min:9 hr 20 min light-dark cycle entrains the human circadian clock to solar time, such that the internal biological night begins near sunset and ends near sunrise [1]. Here we show that the beginning of the biological night and sleep occur earlier after a week's exposure to a natural winter 9 hr 20 min:14 hr 40 min light-dark cycle as compared to the modern electrical lighting environment. Further, we find that the human circadian clock is sensitive to seasonal changes in the natural light-dark cycle, showing an expansion of the biological night in winter compared to summer, akin to that seen in non-humans [4-8]. We also show that circadian and sleep timing occur earlier after spending a weekend camping in a summer 14 hr 39 min:9 hr 21 min natural light-dark cycle compared to a typical weekend in the modern environment. Weekend exposure to natural light was sufficient to achieve ∼69% of the shift in circadian timing we previously reported after a week's exposure to natural light [1]. These findings provide evidence that the human circadian clock adapts to seasonal changes in the natural light-dark cycle and is timed later in the modern environment in both winter and summer. Further, we demonstrate that earlier circadian timing can be rapidly achieved through natural light exposure during a weekend spent camping.
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Affiliation(s)
- Ellen R Stothard
- Department of Integrative Physiology, Sleep and Chronobiology Laboratory, University of Colorado Boulder, Boulder, CO 80309-0354, USA
| | - Andrew W McHill
- Department of Integrative Physiology, Sleep and Chronobiology Laboratory, University of Colorado Boulder, Boulder, CO 80309-0354, USA
| | - Christopher M Depner
- Department of Integrative Physiology, Sleep and Chronobiology Laboratory, University of Colorado Boulder, Boulder, CO 80309-0354, USA
| | - Brian R Birks
- Department of Integrative Physiology, Sleep and Chronobiology Laboratory, University of Colorado Boulder, Boulder, CO 80309-0354, USA
| | - Thomas M Moehlman
- Department of Integrative Physiology, Sleep and Chronobiology Laboratory, University of Colorado Boulder, Boulder, CO 80309-0354, USA
| | - Hannah K Ritchie
- Department of Integrative Physiology, Sleep and Chronobiology Laboratory, University of Colorado Boulder, Boulder, CO 80309-0354, USA
| | - Jacob R Guzzetti
- Department of Integrative Physiology, Sleep and Chronobiology Laboratory, University of Colorado Boulder, Boulder, CO 80309-0354, USA
| | - Evan D Chinoy
- Department of Integrative Physiology, Sleep and Chronobiology Laboratory, University of Colorado Boulder, Boulder, CO 80309-0354, USA
| | - Monique K LeBourgeois
- Sleep and Development Laboratory, 1725 Pleasant Street, Clare Small 114, University of Colorado Boulder, Boulder, CO 80309-0354, USA
| | - John Axelsson
- Department of Clinical Neuroscience, Karolinska Institutet, K8, Psychology Axelsson, Nobels Väg 9, 17177, Stockholm, Sweden; Stress Research Institute, Stockholm University, 14419 Stockholm, Sweden
| | - Kenneth P Wright
- Department of Integrative Physiology, Sleep and Chronobiology Laboratory, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
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47
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Sharma A, Goyal R. Do Circadian Rhythms Draw the Patterns of Sustained Mental Vigor and Ailment? Drug Dev Res 2016; 77:469-473. [PMID: 27686062 DOI: 10.1002/ddr.21342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Preclinical Research Circadian rhythms are fundamental processes in all cells that coordinate a variety of cellular functions related to a specific time of the day. Disruption of circadian rhythms markedly impacts homeostasis. In this Commentary, we present data that disruption of circadian rhythm may lead to the pathogenesis of neurodegenerative states. In this context, we further argue that there is an urgent need of developing new generations of compounds, chronobiotics, to modulate the molecular substrates of circadian timing system. Chronobiotics conceptually offer an effective way for restoration and protection from the consequences of the circadian disruption. We also briefly discuss whether dysfunctional circadian rhythms are a major driver of aging. Drug Dev Res 77 : 469-473, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Ashish Sharma
- School of Pharmaceutical Sciences, Shoolini University, Solan, Himachal Pradesh, India
| | - Rohit Goyal
- School of Pharmaceutical Sciences, Shoolini University, Solan, Himachal Pradesh, India
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48
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Gu C, Tang M, Yang H. The synchronization of neuronal oscillators determined by the directed network structure of the suprachiasmatic nucleus under different photoperiods. Sci Rep 2016; 6:28878. [PMID: 27358024 PMCID: PMC4928114 DOI: 10.1038/srep28878] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 06/09/2016] [Indexed: 11/09/2022] Open
Abstract
The main function of the principal clock located in the suprachiasmatic nucleus (SCN) of mammals is synchronizing the body rhythms to the 24 h light-dark cycle. Additionally, the SCN is able to adapt to the photoperiod of the cycle which varies among seasons. Under the long photoperiod (LP), the synchronization degree of the SCN neurons is lower than that under the photoperiod (SP). In the present study, a potential explanation is given for this phenomenon. We propose that the asymmetrical coupling between the light-signal-sensitive part (the ventralateral part, abbreviation: VL) and the light-signal-insensitive part (the dorsalmedial part, abbreviation: DM) of the SCN plays a role in the synchronization degree, which is reflected by the ratio of the number of the directed links from the VL neurons to the DM neurons to the total links of both directions between the VL and the DM. The ratio is assumed to characterize the directed network structure under different photoperiods, which is larger under the SP and smaller under the LP. We found that with the larger ratio in the situation of the SP, the synchronization degree is higher. Our finding may shed new light on the asymmetrical coupling between the VL and the DM, and the network structure of the SCN.
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Affiliation(s)
- Changgui Gu
- Business School, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Ming Tang
- Web Sciences Center, University of Electronic Science and Technology of China, Chengdu 610054, China.,Big data research center, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Huijie Yang
- Business School, University of Shanghai for Science and Technology, Shanghai 200093, China
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49
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Pierre K, Schlesinger N, Androulakis IP. The role of the hypothalamic-pituitary-adrenal axis in modulating seasonal changes in immunity. Physiol Genomics 2016; 48:719-738. [PMID: 27341833 DOI: 10.1152/physiolgenomics.00006.2016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 06/23/2016] [Indexed: 12/21/2022] Open
Abstract
Seasonal changes in environmental conditions are accompanied by significant adjustment of multiple biological processes. In temperate regions, the day fraction, or photoperiod, is a robust environmental cue that synchronizes seasonal variations in neuroendocrine and metabolic function. In this work, we propose a semimechanistic mathematical model that considers the influence of seasonal photoperiod changes as well as cellular and molecular adaptations to investigate the seasonality of immune function. Our model predicts that the circadian rhythms of cortisol, our proinflammatory mediator, and its receptor exhibit seasonal differences in amplitude and phase, oscillating at higher amplitudes in the winter season with peak times occurring later in the day. Furthermore, the reduced photoperiod of winter coupled with seasonal alterations in physiological activity induces a more exacerbated immune response to acute stress, simulated in our studies as the administration of an acute dose of endotoxin. Our findings are therefore in accordance with experimental data that reflect the predominance of a proinflammatory state during the winter months. These changes in circadian rhythm dynamics may play a significant role in the seasonality of disease incidence and regulate the diurnal and seasonal variation of disease symptom severity.
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Affiliation(s)
- Kamau Pierre
- Biomedical Engineering Department, Rutgers University, Piscataway, New Jersey
| | - Naomi Schlesinger
- Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
| | - Ioannis P Androulakis
- Biomedical Engineering Department, Rutgers University, Piscataway, New Jersey; Chemical and Biochemical Engineering Department, Rutgers University, Piscataway, New Jersey; and Department of Surgery, Rutgers-Robert Wood Johnson Medical School, New Brunswick, New Jersey
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50
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Pévet P. Melatonin receptors as therapeutic targets in the suprachiasmatic nucleus. Expert Opin Ther Targets 2016; 20:1209-18. [DOI: 10.1080/14728222.2016.1179284] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Paul Pévet
- Institut des neurosciences cellulaires et Integratives, INCI UPR 3212, CNRS and the University of Strasbourg, Strasbourg, France
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