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Inyushkin AN, Poletaev VS, Inyushkina EM, Kalberdin IS, Inyushkin AA. Irisin/BDNF signaling in the muscle-brain axis and circadian system: A review. J Biomed Res 2023; 38:1-16. [PMID: 38164079 PMCID: PMC10818175 DOI: 10.7555/jbr.37.20230133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 09/19/2023] [Accepted: 09/25/2023] [Indexed: 01/03/2024] Open
Abstract
In mammals, the timing of physiological, biochemical and behavioral processes over a 24-h period is controlled by circadian rhythms. To entrain the master clock located in the suprachiasmatic nucleus of the hypothalamus to a precise 24-h rhythm, environmental zeitgebers are used by the circadian system. This is done primarily by signals from the retina via the retinohypothalamic tract, but other cues like exercise, feeding, temperature, anxiety, and social events have also been shown to act as non-photic zeitgebers. The recently identified myokine irisin is proposed to serve as an entraining non-photic signal of exercise. Irisin is a product of cleavage and modification from its precursor membrane fibronectin type Ⅲ domain-containing protein 5 (FNDC5) in response to exercise. Apart from well-known peripheral effects, such as inducing the "browning" of white adipocytes, irisin can penetrate the blood-brain barrier and display the effects on the brain. Experimental data suggest that FNDC5/irisin mediates the positive effects of physical activity on brain functions. In several brain areas, irisin induces the production of brain-derived neurotrophic factor (BDNF). In the master clock, a significant role in gating photic stimuli in the retinohypothalamic synapse for BDNF is suggested. However, the brain receptor for irisin remains unknown. In the current review, the interactions of physical activity and the irisin/BDNF axis with the circadian system are reconceptualized.
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Affiliation(s)
- Alexey N. Inyushkin
- Department of Human & Animal Physiology, Samara National Research University, Samara 443011, Russia
| | - Vitalii S. Poletaev
- Department of Human & Animal Physiology, Samara National Research University, Samara 443011, Russia
| | - Elena M. Inyushkina
- Department of Human & Animal Physiology, Samara National Research University, Samara 443011, Russia
| | - Igor S. Kalberdin
- Department of Human & Animal Physiology, Samara National Research University, Samara 443011, Russia
| | - Andrey A. Inyushkin
- Department of Human & Animal Physiology, Samara National Research University, Samara 443011, Russia
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Rohr KE, Inda T, Evans JA. Vasopressin Resets the Central Circadian Clock in a Manner Influenced by Sex and Vasoactive Intestinal Polypeptide Signaling. Neuroendocrinology 2022; 112:904-916. [PMID: 34856551 PMCID: PMC9160207 DOI: 10.1159/000521286] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 12/01/2021] [Indexed: 01/03/2023]
Abstract
BACKGROUND/AIMS Circadian rhythms in behavior and physiology are programmed by the suprachiasmatic nucleus (SCN) of the hypothalamus. A subset of SCN neurons produce the neuropeptide arginine vasopressin (AVP), but it remains unclear whether AVP signaling influences the SCN clock directly. METHODS Here, we test that AVP signaling acting through V1A and V1B receptors influences molecular rhythms in SCN neurons. V1 receptor agonists were applied ex vivo to PERIOD2::LUCIFERASE SCN slices, allowing for real-time monitoring of changes in molecular clock function. RESULTS V1A/B agonists reset the phase of the SCN molecular clock in a time-dependent manner, with larger magnitude responses by the female SCN. Further, we found evidence that both Gαq and Gαs signaling pathways interact with V1A/B-induced SCN resetting, and that this response requires vasoactive intestinal polypeptide (VIP) signaling. CONCLUSIONS Collectively, this work indicates that AVP signaling resets SCN molecular rhythms in conjunction with VIP signaling and in a manner influenced by sex. This highlights the utility of studying clock function in both sexes and suggests that signal integration in central clock circuits regulates emergent properties important for the control of daily rhythms in behavior and physiology.
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Affiliation(s)
| | | | - Jennifer A. Evans
- Corresponding author: 560 N 16 St, Schroeder Complex, Room 446, Milwaukee, WI 53233, Phone: 414 288-5732, Fax: 414-288-6564,
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Joye DAM, Evans JA. Sex differences in daily timekeeping and circadian clock circuits. Semin Cell Dev Biol 2021; 126:45-55. [PMID: 33994299 DOI: 10.1016/j.semcdb.2021.04.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/24/2021] [Accepted: 04/29/2021] [Indexed: 11/19/2022]
Abstract
The circadian system regulates behavior and physiology in many ways important for health. Circadian rhythms are expressed by nearly every cell in the body, and this large system is coordinated by a central clock in the suprachiasmatic nucleus (SCN). Sex differences in daily rhythms are evident in humans and understanding how circadian function is modulated by biological sex is an important goal. This review highlights work examining effects of sex and gonadal hormones on daily rhythms, with a focus on behavior and SCN circuitry in animal models commonly used in pre-clinical studies. Many questions remain in this area of the field, which would benefit from further work investigating this topic.
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Affiliation(s)
- Deborah A M Joye
- Marquette University, Department of Biomedical Sciences, Milwaukee, WI, USA
| | - Jennifer A Evans
- Marquette University, Department of Biomedical Sciences, Milwaukee, WI, USA.
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Jha PK, Bouâouda H, Kalsbeek A, Challet E. Distinct feedback actions of behavioural arousal to the master circadian clock in nocturnal and diurnal mammals. Neurosci Biobehav Rev 2021; 123:48-60. [PMID: 33440199 DOI: 10.1016/j.neubiorev.2020.12.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 09/16/2020] [Accepted: 12/10/2020] [Indexed: 12/20/2022]
Abstract
The master clock in the suprachiasmatic nucleus (SCN) of the hypothalamus provides a temporal pattern of sleep and wake that - like many other behavioural and physiological rhythms - is oppositely phased in nocturnal and diurnal animals. The SCN primarily uses environmental light, perceived through the retina, to synchronize its endogenous circadian rhythms with the exact 24 h light/dark cycle of the outside world. The light responsiveness of the SCN is maximal during the night in both nocturnal and diurnal species. Behavioural arousal during the resting period not only perturbs sleep homeostasis, but also acts as a potent non-photic synchronizing cue. The feedback action of arousal on the SCN is mediated by processes involving several brain nuclei and neurotransmitters, which ultimately change the molecular functions of SCN pacemaker cells. Arousing stimuli during the sleeping period differentially affect the circadian system of nocturnal and diurnal species, as evidenced by the different circadian windows of sensitivity to behavioural arousal. In addition, arousing stimuli reduce and increase light resetting in nocturnal and diurnal species, respectively. It is important to address further question of circadian impairments associated with shift work and trans-meridian travel not only in the standard nocturnal laboratory animals but also in diurnal animal models.
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Affiliation(s)
- Pawan Kumar Jha
- Circadian Clocks and Metabolism Team, Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, France; Department of Endocrinology and Metabolism, Amsterdam University Medical Center (AUMC), University of Amsterdam, the Netherlands; Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands.
| | - Hanan Bouâouda
- Circadian Clocks and Metabolism Team, Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, France
| | - Andries Kalsbeek
- Department of Endocrinology and Metabolism, Amsterdam University Medical Center (AUMC), University of Amsterdam, the Netherlands; Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
| | - Etienne Challet
- Circadian Clocks and Metabolism Team, Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, France
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Ben-Hamouda N, Poirel VJ, Dispersyn G, Pévet P, Challet E, Pain L. Short-term propofol anaesthesia down-regulates clock genes expression in the master clock. Chronobiol Int 2018; 35:1735-1741. [DOI: 10.1080/07420528.2018.1499107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Nawfel Ben-Hamouda
- Institut des neurosciences cellulaires et integratives, Neurobiology of Rhythms, CNRS (UPR3212), Université de Strasbourg, Strasbourg, France
- Adult intensive Care Medicine and Burns, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Vincent-Joseph Poirel
- Institut des neurosciences cellulaires et integratives, Neurobiology of Rhythms, CNRS (UPR3212), Université de Strasbourg, Strasbourg, France
| | - Garance Dispersyn
- Institut des neurosciences cellulaires et integratives, Neurobiology of Rhythms, CNRS (UPR3212), Université de Strasbourg, Strasbourg, France
- Institut de recherche biomedicale des armees, Bretigny-sur-Orge, France
| | - Paul Pévet
- Institut des neurosciences cellulaires et integratives, Neurobiology of Rhythms, CNRS (UPR3212), Université de Strasbourg, Strasbourg, France
| | - Etienne Challet
- Institut des neurosciences cellulaires et integratives, Neurobiology of Rhythms, CNRS (UPR3212), Université de Strasbourg, Strasbourg, France
| | - Laure Pain
- Institut des neurosciences cellulaires et integratives, Neurobiology of Rhythms, CNRS (UPR3212), Université de Strasbourg, Strasbourg, France
- Anesthesiology, Hopitaux universitaires de Strasbourg, Strasbourg, France
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Melatonin Signal Transduction Pathways Require E-Box-Mediated Transcription of Per1 and Per2 to Reset the SCN Clock at Dusk. PLoS One 2016; 11:e0157824. [PMID: 27362940 PMCID: PMC4928778 DOI: 10.1371/journal.pone.0157824] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 06/06/2016] [Indexed: 12/12/2022] Open
Abstract
Melatonin is released from the pineal gland into the circulatory system at night in the absence of light, acting as “hormone of darkness” to the brain and body. Melatonin also can regulate circadian phasing of the suprachiasmatic nucleus (SCN). During the day-to-night transition, melatonin exposure advances intrinsic SCN neural activity rhythms via the melatonin type-2 (MT2) receptor and downstream activation of protein kinase C (PKC). The effects of melatonin on SCN phasing have not been linked to daily changes in the expression of core genes that constitute the molecular framework of the circadian clock. Using real-time RT-PCR, we found that melatonin induces an increase in the expression of two clock genes, Period 1 (Per1) and Period 2 (Per2). This effect occurs at CT 10, when melatonin advances SCN phase, but not at CT 6, when it does not. Using anti-sense oligodeoxynucleotides (α ODNs) to Per 1 and Per 2, as well as to E-box enhancer sequences in the promoters of these genes, we show that their specific induction is necessary for the phase-altering effects of melatonin on SCN neural activity rhythms in the rat. These effects of melatonin on Per1 and Per2 were mediated by PKC. This is unlike day-active non-photic signals that reset the SCN clock by non-PCK signal transduction mechanisms and by decreasing Per1 expression. Rather, this finding extends roles for Per1 and Per2, which are critical to photic phase-resetting, to a nonphotic zeitgeber, melatonin, and suggest that the regulation of these clock gene transcripts is required for clock resetting by diverse regulatory cues.
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Bouchard-Cannon P, Cheng HYM. Scheduled feeding alters the timing of the suprachiasmatic nucleus circadian clock in dexras1-deficient mice. Chronobiol Int 2012; 29:965-81. [PMID: 22928915 PMCID: PMC3707842 DOI: 10.3109/07420528.2012.707264] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Restricted feeding (RF) schedules are potent zeitgebers capable of entraining metabolic and hormonal rhythms in peripheral oscillators in anticipation of food. Behaviorally, this manifests in the form of food anticipatory activity (FAA) in the hours preceding food availability. Circadian rhythms of FAA are thought to be controlled by a food-entrainable oscillator (FEO) outside of the suprachiasmatic nucleus (SCN), the central circadian pacemaker in mammals. Although evidence suggests that the FEO and the SCN are capable of interacting functionally under RF conditions, the genetic basis of these interactions remains to be defined. In this study, using dexras1-deficient (dexras1(-/-)) mice, the authors examined whether Dexras1, a modulator of multiple inputs to the SCN, plays a role in regulating the effects of RF on activity rhythms and gene expression in the SCN. Daytime RF under 12L:12D or constant darkness (DD) resulted in potentiated (but less stable) FAA expression in dexras1(-/-) mice compared with wild-type (WT) controls. Under these conditions, the magnitude and phase of the SCN-driven activity component were greatly perturbed in the mutants. Restoration to ad libitum (AL) feeding revealed a stable phase displacement of the SCN-driven activity component of dexras1(-/-) mice by ~2 h in advance of the expected time. RF in the late night/early morning induced a long-lasting increase in the period of the SCN-driven activity component in the mutants but not the WT. At the molecular level, daytime RF advanced the rhythm of PER1, PER2, and pERK expression in the mutant SCN without having any effect in the WT. Collectively, these results indicate that the absence of Dexras1 sensitizes the SCN to perturbations resulting from restricted feeding.
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Bartoszewicz R, Barbacka-Surowiak G. Phase response curve of mouse locomotor activity rhythm under constant light after 8-OH-DPAT and dark pulses. BIOL RHYTHM RES 2010. [DOI: 10.1080/09291010903557203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Renata Bartoszewicz
- a Department of Neurophysiology and Chronobiology , Institute of Zoology, Jagiellonian University , Krakow
| | - Grażyna Barbacka-Surowiak
- a Department of Neurophysiology and Chronobiology , Institute of Zoology, Jagiellonian University , Krakow
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9
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10
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Legan SJ, Donoghue KM, Franklin KM, Duncan MJ. Phenobarbital blockade of the preovulatory luteinizing hormone surge: association with phase-advanced circadian clock and altered suprachiasmatic nucleus Period1 gene expression. Am J Physiol Regul Integr Comp Physiol 2009; 296:R1620-30. [PMID: 19297538 DOI: 10.1152/ajpregu.90914.2008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The suprachiasmatic nucleus (SCN) controls the timing of the preovulatory luteinizing hormone (LH) surge in laboratory rodents. Barbiturate administration during a critical period on proestrus delays the surge and prolongs the estrous cycle 1 day. Because a nonphotic timing signal (zeitgeber) during the critical period that phase advances activity rhythms can also induce the latter effect, we hypothesized that barbiturates delay the LH surge by phase-advancing its circadian timing signal beyond the critical period. In experiment 1, locomotor rhythms and estrous cycles were monitored in hamsters for 2-3 wk preinjection and postinjection of vehicle or phenobarbital and after transfer to darkness at zeitgeber time (ZT) 6 on proestrus. Phenobarbital delayed estrous cycles in five of seven hamsters, which exhibited phase shifts that averaged twofold greater than those exhibited by vehicle controls or phenobarbital-injected hamsters with normal cycles. Experiment 2 used a similar protocol, but injections were at ZT 5, and blood samples for LH determination were collected from 1200 to 1800 on proestrus and the next day via jugular cannulae inserted the day before proestrus. Phenobarbital delayed the LH surge 1 day in all six hamsters, but it occurred at an earlier circadian time, supporting the above hypothesis. Experiment 3 investigated whether phenobarbital, like other nonphotic zeitgebers, suppresses SCN Period1 and Period2 transcription. Two hours postinjection, phenobarbital decreased SCN expression of only Period1 mRNA, as determined by in situ hybridization. These results suggest that phenobarbital advances the SCN pacemaker, governing activity rhythms and hormone release in part by decreasing its Period1 gene expression.
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Affiliation(s)
- Sandra J Legan
- Department of Physiology, University of Kentucky Medical Center, Lexington, KY 40536-0298, USA.
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11
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Mendoza J, Pévet P, Challet E. Entrainment and coupling of the hamster suprachiasmatic clock by daily dark pulses. J Neurosci Res 2009; 87:758-65. [DOI: 10.1002/jnr.21887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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12
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Marston OJ, Williams RH, Canal MM, Samuels RE, Upton N, Piggins HD. Circadian and dark-pulse activation of orexin/hypocretin neurons. Mol Brain 2008; 1:19. [PMID: 19055781 PMCID: PMC2632999 DOI: 10.1186/1756-6606-1-19] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Accepted: 12/03/2008] [Indexed: 01/03/2024] Open
Abstract
Temporal control of brain and behavioral states emerges as a consequence of the interaction between circadian and homeostatic neural circuits. This interaction permits the daily rhythm of sleep and wake, regulated in parallel by circadian cues originating from the suprachiasmatic nuclei (SCN) and arousal-promoting signals arising from the orexin-containing neurons in the tuberal hypothalamus (TH). Intriguingly, the SCN circadian clock can be reset by arousal-promoting stimuli while activation of orexin/hypocretin neurons is believed to be under circadian control, suggesting the existence of a reciprocal relationship. Unfortunately, since orexin neurons are themselves activated by locomotor promoting cues, it is unclear how these two systems interact to regulate behavioral rhythms. Here mice were placed in conditions of constant light, which suppressed locomotor activity, but also revealed a highly pronounced circadian pattern in orexin neuronal activation. Significantly, activation of orexin neurons in the medial and lateral TH occurred prior to the onset of sustained wheel-running activity. Moreover, exposure to a 6 h dark pulse during the subjective day, a stimulus that promotes arousal and phase advances behavioral rhythms, activated neurons in the medial and lateral TH including those containing orexin. Concurrently, this stimulus suppressed SCN activity while activating cells in the median raphe. In contrast, dark pulse exposure during the subjective night did not reset SCN-controlled behavioral rhythms and caused a transient suppression of neuronal activation in the TH. Collectively these results demonstrate, for the first time, pronounced circadian control of orexin neuron activation and implicate recruitment of orexin cells in dark pulse resetting of the SCN circadian clock.
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Antle MC, Tse F, Koke SJ, Sterniczuk R, Hagel K. Non-photic phase shifting of the circadian clock: role of the extracellular signal-responsive kinases I/II/mitogen-activated protein kinase pathway. Eur J Neurosci 2008; 28:2511-8. [DOI: 10.1111/j.1460-9568.2008.06533.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Novak CM, Ehlen JC, Albers HE. Photic and nonphotic inputs to the diurnal circadian clock. BIOL RHYTHM RES 2008. [DOI: 10.1080/09291010701683482] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Mendoza J, Clesse D, Pévet P, Challet E. Serotonergic potentiation of dark pulse-induced phase-shifting effects at midday in hamsters. J Neurochem 2008; 106:1404-14. [PMID: 18498439 DOI: 10.1111/j.1471-4159.2008.05493.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In mammals, resetting of the suprachiasmatic clock (SCN) by behavioral activation or serotonin (5-HT) agonists is mimicked by dark pulses, presented during subjective day in constant light (LL). Because behavioral resetting may be mediated in part by 5-HT inputs to the SCN, here we determined whether 5-HT system can modulate dark-induced phase-shifts in Syrian hamsters housed in LL. Two hours of darkness at mid-subjective day (circadian time 6; CT-6) resulted in increased concentrations of 5-HT in the SCN tissue and induction of c-FOS expression in the raphe nuclei. Injections of the 5-HT(1A/7) agonist +8-OH-DPAT or dark pulses at CT-6 induced phase-advances of the wheel-running activity rhythm and down-regulated the expression of the clock genes Per1-2 and c-FOS in the SCN in a similar way. The combination of both treatments [+8-OH-DPAT + dark pulses], however, resulted in larger phase-advances, while associated molecular changes were not significantly modified, except for the gene Dbp, in comparison to +8-OH-DPAT or dark pulses alone. Dark resetting was blocked by pre-treatment with a 5-HT(7) antagonist, but not with a 5-HT(1A) antagonist. The additive phase-shifts of two different cues to reset the SCN clock open wide the gateway for non-photic shifting, leading to new strategies in chronotherapy.
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Affiliation(s)
- Jorge Mendoza
- Institut de Neurosciences Cellulaires et Intégratives, Département de Neurobiologie des Rythmes, CNRS et Université Louis Pasteur, Strasbourg, France.
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Serotonergic activation potentiates light resetting of the main circadian clock and alters clock gene expression in a diurnal rodent. Exp Neurol 2008; 210:501-13. [DOI: 10.1016/j.expneurol.2007.11.026] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 11/21/2007] [Accepted: 11/22/2007] [Indexed: 11/21/2022]
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Abstract
Daily rhythmicity, including timing of wakefulness and hormone secretion, is mainly controlled by a master clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN clockwork involves various clock genes, with specific temporal patterns of expression that are similar in nocturnal and diurnal species (e.g. the clock gene Per1 in the SCN peaks at midday in both categories). Timing of sensitivity to light is roughly similar, during nighttime, in diurnal and nocturnal species. Molecular mechanisms of photic resetting are also comparable in both species categories. By contrast, in animals housed in constant light, exposure to darkness can reset the SCN clock, mostly during the resting period, i.e. at opposite circadian times between diurnal and nocturnal species. Nonphotic stimuli, such as scheduled voluntary exercise, food shortage, exogenous melatonin, or serotonergic receptor activation, are also capable of shifting the master clock and/or modulating photic synchronization. Comparison between day- and night-active species allows classifications of nonphotic cues in two, arousal-independent and arousal-dependent, families of factors. Arousal-independent factors, such as melatonin (always secreted during nighttime, independently of daily activity pattern) or gamma-aminobutyric acid (GABA), have shifting effects at the same circadian times in both nocturnal and diurnal rodents. By contrast, arousal-dependent factors, such as serotonin (its cerebral levels follow activity pattern), induce phase shifts only during resting and have opposite modulating effects on photic resetting between diurnal and nocturnal species. Contrary to light and arousal-independent nonphotic cues, arousal-dependent nonphotic stimuli provide synchronizing feedback signals to the SCN clock in circadian antiphase between nocturnal and diurnal animals.
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Affiliation(s)
- Etienne Challet
- Department of Neurobiology of Rhythms, Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (UMR 7168/LC2), University Louis Pasteur, 5 rue Blaise Pascal, Strasbourg, France.
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Vansteensel MJ, Michel S, Meijer JH. Organization of cell and tissue circadian pacemakers: a comparison among species. ACTA ACUST UNITED AC 2007; 58:18-47. [PMID: 18061682 DOI: 10.1016/j.brainresrev.2007.10.009] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Revised: 10/15/2007] [Accepted: 10/19/2007] [Indexed: 10/22/2022]
Abstract
In most animal species, a circadian timing system has evolved as a strategy to cope with 24-hour rhythms in the environment. Circadian pacemakers are essential elements of the timing system and have been identified in anatomically discrete locations in animals ranging from insects to mammals. Rhythm generation occurs in single pacemaker neurons and is based on the interacting negative and positive molecular feedback loops. Rhythmicity in behavior and physiology is regulated by neuronal networks in which synchronization or coupling is required to produce coherent output signals. Coupling occurs among individual clock cells within an oscillating tissue, among functionally distinct subregions within the pacemaker, and between central pacemakers and the periphery. Recent evidence indicates that peripheral tissues can influence central pacemakers and contain autonomous circadian oscillators that contribute to the regulation of overt rhythmicity. The data discussed in this review describe coupling and synchronization mechanisms at the cell and tissue levels. By comparing the pacemaker systems of several multicellular animal species (Drosophila, cockroaches, crickets, snails, zebrafish and mammals), we will explore general organizational principles by which the circadian system regulates a 24-hour rhythmicity.
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Affiliation(s)
- Mariska J Vansteensel
- Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center, Postal zone S5-P, P.O. Box 9600, 2300 RC Leiden, The Netherlands
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Mendoza J, Revel FG, Pévet P, Challet E. Shedding light on circadian clock resetting by dark exposure: differential effects between diurnal and nocturnal rodents. Eur J Neurosci 2007; 25:3080-90. [PMID: 17561821 DOI: 10.1111/j.1460-9568.2007.05548.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The master circadian clock in mammals, located in the suprachiasmatic nuclei (SCN) of the hypothalamus, is entrained by light and behavioural stimulation. In addition, the SCN can be reset by dark pulses in nocturnal rodents under constant light conditions. Here, the shifting effects of a dark pulse on the SCN clock were detailed at both a behavioural and molecular level in a nocturnal rodent (Syrian hamster), and were compared to those of a diurnal rodent (Arvicanthis ansorgei). Four-hour dark pulses led to phase advances in the circadian rhythm of locomotor activity from subjective midday to dusk in hamsters, but from subjective dusk to midnight in Arvicanthis. Moreover, dark pulses had no resetting effect during the middle of the subjective night in hamsters, while such a dead shifting zone occurred during most of the subjective day in Arvicanthis. The behavioural phase advances in both hamsters and Arvicanthis were most often accompanied by marked downregulation of the clock genes Per1 and/or Per2 in the SCN, and also by changes in the transforming growth factor-alpha expression, a neuropeptide that suppresses daytime activity in nocturnal mammals. Despite that both hamsters and Arvicanthis showed dark-induced phase advances at circadian time-12, Per1 gene and its protein PER1 were downregulated in Arvicanthis but not in hamsters. Altogether these results show that dark resetting of the SCN is always associated with downregulation of Per1 and/or Per2 expression, and mostly occurs during resting. Thus, the circadian window of sensitivity to dark differs between nocturnal and diurnal rodents.
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Affiliation(s)
- Jorge Mendoza
- Institut de Neurosciences Cellulaires et Intégratives, Département de Neurobiologie des Rythmes UMR7168/LC2, CNRS et Université Louis Pasteur, 67084 Strasbourg Cedex, France.
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Challet E, Gourmelen S, Pevet P, Oberling P, Pain L. Reciprocal relationships between general (Propofol) anesthesia and circadian time in rats. Neuropsychopharmacology 2007; 32:728-35. [PMID: 16641940 DOI: 10.1038/sj.npp.1301081] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Several common postdischarge symptoms, such as sleep disorders, headache, drowsiness or general malaise, evoke disturbances of circadian rhythms due to jet lag (ie crossing time zones) or shift work rotation. Considering that general anesthesia is associated with numerous effects on the central nervous system, we hypothesized that it may also act on the circadian timing system. We first determined the effects of the circadian timing on general anesthesia. We observed that identical doses of propofol showed marked circadian fluctuations in duration of effects, with a peak at the middle of the resting period (ie 7 h after lights on). Then, we examined the effects of general anesthesia on circadian timing, by analysing stable free-running circadian rhythms (ie in constant environmental conditions), an experimental approach used widely in circadian biology. Free-running rats were housed in constant darkness and temperature to assess possible phase-shifting effects of propofol anesthesia according to the time of the day. When administered around (+/-2 h) the daily rest/activity transition point, a 30-min propofol anesthesia induced a 1-h phase advance in the free-running rest-activity rhythm, while anesthesia had no significant resetting effect at other times of the day. Anesthesia-induced hypothermia was not correlated with the phase-shifting effects of propofol anesthesia. From our results, anesthesia itself can reset circadian timing, and acts as a synchronizing cue for the circadian clock.
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Affiliation(s)
- Etienne Challet
- Department of Neurobiology of Rhythms, Institute of Cellular and Integrative Neurosciences, CNRS (UMR7168), University L. Pasteur, Strasbourg, France
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Novak CM, Ehlen JC, Paul KN, Fukuhara C, Albers HE. Light and GABAAreceptor activation alterPeriodmRNA levels in the SCN of diurnal Nile grass rats. Eur J Neurosci 2006; 24:2843-52. [PMID: 17156208 DOI: 10.1111/j.1460-9568.2006.05166.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We examined Period (Per) mRNA rhythms in the suprachiasmatic nucleus (SCN) of a diurnal rodent and assessed how phase-shifting stimuli acutely affect SCN Per mRNA using semiquantitative in situ hybridization. First, Per1 and Per2 varied rhythmically in the SCN over the course of one circadian cycle in constant darkness: Per1 mRNA was highest in the early to mid-subjective day, while Per2 mRNA levels peaked in the late subjective day. Second, acute light exposure in the early subjective night significantly increased both Per1 and Per2 mRNA. Third, Per2 but not Per1 levels decreased 1 and 2 h after injection of the gamma-aminobutyric acid (GABA)(A) receptor agonist muscimol into the SCN during the subjective day. Fourth, muscimol also reduced the light-induced Per2 in the early subjective night, but Per1 induction by light was not significantly affected. Consistent with previous studies, these data demonstrate that diurnal and nocturnal animals show very similar daily patterns of Per mRNA and light-induced Per increases in the SCN. As with light, muscimol alters circadian phase, and daytime phase alterations induced by muscimol are associated with significant decreases in Per2 mRNA. In diurnal animals, muscimol-induced decreases in Per are associated with phase delays rather than advances. The direction of the daytime phase shift may be determined by the relative suppression of Per1 vs. Per2 in SCN cells. As in nocturnal animals, changes in Per1 and Per2 mRNA by photic and non-photic stimuli appear to be associated with circadian phase alteration.
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Affiliation(s)
- Colleen M Novak
- Endocrine Research Unit, Mayo Clinic and Foundation, Rochester, MN, USA.
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22
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Canal MM, Piggins HD. Resetting of the hamster circadian system by dark pulses. Am J Physiol Regul Integr Comp Physiol 2005; 290:R785-92. [PMID: 16239370 DOI: 10.1152/ajpregu.00548.2005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Circadian rhythms of animals are reset by exposure to light as well as dark; however, although the parameters of photic entrainment are well characterized, the phase-shifting actions of dark pulses are poorly understood. Here, we determined the tonic and phasic effects of short (0.25 h), moderate (3 h), and long (6-9 h) duration dark pulses on the wheel-running rhythms of hamsters in constant light. Moderate- and long-duration dark pulses phase dependently reset behavioral rhythms, and the magnitude of these phase shifts increased as a function of the duration of the dark pulse. In contrast, the 0.25-h dark pulses failed to evoke consistent effects at any circadian phase tested. Interestingly, moderate- and long-dark pulses elevated locomotor activity (wheel-running) on the day of treatment. This induced wheel-running was highly correlated with phase shift magnitude when the pulse was given during the subjective day. This, together with the finding that animals pulsed during the subjective day are behaviorally active throughout the pulse, suggests that both locomotor activity and behavioral activation play an important role in the phase-resetting actions of dark pulses. We also found that the robustness of the wheel-running rhythm was weakened, and the amount of wheel-running decreased on the days after exposure to dark pulses; these effects were dependent on pulse duration. In summary, similarly to light, the resetting actions of dark pulses are dependent on both circadian phase and stimulus duration. However, dark pulses appear more complex stimuli, with both photic and nonphotic resetting properties.
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Affiliation(s)
- M M Canal
- Faculty of Life Sciences, The University of Manchester, 3.614 Stopford Bldg., Oxford Rd., M13 9PT Manchester, United Kingdom
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Coogan AN, Piggins HD. Dark pulse suppression of P-ERK and c-Fos in the hamster suprachiasmatic nuclei. Eur J Neurosci 2005; 22:158-68. [PMID: 16029205 DOI: 10.1111/j.1460-9568.2005.04193.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It is well-established that light pulses regulate components of the extracellular signal-regulated kinases I/II (ERK) cascade in the suprachiasmatic nuclei (SCN) circadian clock. These events are important for photic-resetting of the circadian clock. The SCN circadian clock is also reset by pulses of dark, but it is unknown if this stimulus alters the activity of ERK, the transcription factor Elk-1 or expression of the immediate early gene c-fos in the SCN. Using Syrian hamsters free-running in constant light, we determined the effects of dark pulses on these factors in the SCN. In constant light, levels of phosphorylated ERK (P-ERK) showed significant circadian variation in the Syrian hamster SCN, while levels of c-Fos or phosphorylated Elk-1 (P-Elk-1) did not. A 6-h dark pulse beginning at circadian time (CT) 8 down-regulated expression of P-ERK and c-Fos, but not P-Elk-1, in the SCN. Following termination of the pulse, levels of c-Fos increased above time-matched control values, while P-ERK expression did not. When given at the beginning of the subjective night (CT13), a 6-h dark pulse did not phase-shift behavioural rhythms and failed to alter the expression of c-Fos, P-ERK, or P-Elk-1 in the SCN. At the level of the visual thalamus, expression of c-Fos in the intergeniculate leaflet was higher during the subjective night as compared to the subjective day, although dark pulses had no robust effects on expression of c-Fos or P-ELK-1 in this structure. We conclude that dark-pulse resetting of the circadian clock is complex and involves both non-photic and photic components.
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Affiliation(s)
- Andrew N Coogan
- 3.614 Stopford Building, Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
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Abstract
In mammals, circadian rhythms are driven by a pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus. We measured the rhythm of arginine vasopressin release in rat organotypic SCN slices following application of tetrodotoxin (TTX) or N-methyl-D-aspartate (NMDA) at various times throughout the circadian cycle. TTX resets the clock in a manner similar to dark pulses. A 4-h application of TTX starting in mid subjective day, at around circadian time (CT) 7.0, induced phase advances, while TTX treatment started in early subjective morning, at about CT 2.0, induced phase delays. On the other hand, NMDA resets the clock in a manner similar to a light pulse; that is, NMDA treatment in the early evening induced phase delays while treatment in the late night induced phase advances. The data indicate that deprivation of neuronal firing changes the circadian rhythm.
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Affiliation(s)
- Takako Noguchi
- Department of Physiology, Dokkyo University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, Japan
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Vansteensel MJ, Magnone MC, van Oosterhout F, Baeriswyl S, Albrecht U, Albus H, Dahan A, Meijer JH. The opioid fentanyl affects light input, electrical activity andPergene expression in the hamster suprachiasmatic nuclei. Eur J Neurosci 2005; 21:2958-66. [PMID: 15978007 DOI: 10.1111/j.1460-9568.2005.04131.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The suprachiasmatic nuclei (SCN) contain a major circadian pacemaker, which is regulated by photic and nonphotic stimuli. Although enkephalins are present in the SCN, their role in phase regulation of the pacemaker is largely unknown. The opioid agonist fentanyl, a homologue of morphine, is an addictive drug that induces phase shifts of circadian rhythms in hamsters. We observed that these phase shifts are blocked by naloxone, which is a critical test for true opioid receptor involvement, and conclude that opioid receptors are the sole mediators of the actions of fentanyl on the circadian timing system. A strong interaction between opioids and light input was shown by the ability of fentanyl and light to completely block each other's phase shifts of behavioural activity rhythms. Neuronal ensemble recordings in vitro provide first evidence that SCN cells show direct responses to fentanyl and react with a suppression of firing rate. Moreover, we show that fentanyl induces a strong attenuation of light-induced Syrian hamster Period 1 (shPer1) gene expression during the night. During the subjective day, we found no evidence for a role of shPer1 in mediation of fentanyl-induced phase shifts. Based on the present results, however, we cannot exclude the involvement of shPer2. Our data indicate that opioids can strongly modify the photic responsiveness of the circadian pacemaker and may do so via direct effects on SCN electrical activity and regulation of Per genes. This suggests that the pathways regulating addictive behaviour and the circadian clock intersect.
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Affiliation(s)
- Mariska J Vansteensel
- Department of Neurophysiology, Leiden University Medical Centre, Wassenaarseweg 62, PO Box 9604, 2300 RC Leiden, the Netherlands
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