1
|
Dantas-Ferreira R, Ciocca D, Vuillez P, Dumont S, Boitard C, Rogner UC, Challet E. Deletion of the Clock Gene Bmal2 Leads to Alterations in Hypothalamic Clocks, Circadian Regulation of Feeding, and Energy Balance. J Neurosci 2024; 44:e1886232024. [PMID: 38531632 PMCID: PMC11079965 DOI: 10.1523/jneurosci.1886-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 02/02/2024] [Accepted: 02/08/2024] [Indexed: 03/28/2024] Open
Abstract
BMAL2 (ARNTL2) is a paralog of BMAL1 that can form heterodimers with the other circadian factors CLOCK and NPAS2 to activate transcription of clock and clock-controlled genes. To assess a possible role of Bmal2 in the circadian regulation of metabolism, we investigated daily variations of energy metabolism, feeding behavior, and locomotor behavior, as well as ability to anticipate restricted food access in male mice knock-out for Bmal2 (B2KO). While their amount of food intake and locomotor activity were normal compared with wild-type mice, B2KO mice displayed increased adiposity (1.5-fold higher) and fasted hyperinsulinemia (fourfold higher) and tended to have lower energy expenditure at night. Impairment of the master clock in the suprachiasmatic nuclei was evidenced by the shorter free-running period (-14 min/cycle) of B2KO mice compared with wild-type controls and by a loss of daily rhythmicity in expression of intracellular metabolic regulators (e.g., Lipoprotein lipase and Uncoupling protein 2). The circadian window of eating was longer in B2KO mice. The circadian patterns of food intake and meal numbers were bimodal in control mice but not in B2KO mice. In response to restricted feeding, food-anticipatory activity was almost prevented in B2KO mice, suggesting altered food clock that controls anticipation of food availability. In the mediobasal hypothalamus of B2KO mice, expression of genes coding orexigenic neuropeptides (including Neuropeptide y and Agouti-Related Peptide) was downregulated, while Lipoprotein lipase expression lost its rhythmicity. Together, these data highlight that BMAL2 has major impacts on brain regulation of metabolic rhythms, sleep-wake cycle, and food anticipation.
Collapse
Affiliation(s)
- Rosana Dantas-Ferreira
- Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, Strasbourg 67000, France
| | - Dominique Ciocca
- Chronobiotron, CNRS, University of Strasbourg, Strasbourg 67000, France
| | - Patrick Vuillez
- Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, Strasbourg 67000, France
| | - Stéphanie Dumont
- Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, Strasbourg 67000, France
| | - Christian Boitard
- Institut Cochin, CNRS, Institut National de la Santé et la Recherche Médicale (INSERM), Université Paris Cité, Paris 75014, France
| | - Ute C Rogner
- Institut Cochin, CNRS, Institut National de la Santé et la Recherche Médicale (INSERM), Université Paris Cité, Paris 75014, France
| | - Etienne Challet
- Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, Strasbourg 67000, France
| |
Collapse
|
2
|
Porta-de-la-Riva M, Morales-Curiel LF, Carolina Gonzalez A, Krieg M. Bioluminescence as a functional tool for visualizing and controlling neuronal activity in vivo. NEUROPHOTONICS 2024; 11:024203. [PMID: 38348359 PMCID: PMC10861157 DOI: 10.1117/1.nph.11.2.024203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 02/15/2024]
Abstract
The use of bioluminescence as a reporter for physiology in neuroscience is as old as the discovery of the calcium-dependent photon emission of aequorin. Over the years, luciferases have been largely replaced by fluorescent reporters, but recently, the field has seen a renaissance of bioluminescent probes, catalyzed by unique developments in imaging technology, bioengineering, and biochemistry to produce luciferases with previously unseen colors and intensity. This is not surprising as the advantages of bioluminescence make luciferases very attractive for noninvasive, longitudinal in vivo observations without the need of an excitation light source. Here, we review how the development of dedicated and specific sensor-luciferases afforded, among others, transcranial imaging of calcium and neurotransmitters, or cellular metabolites and physical quantities such as forces and membrane voltage. Further, the increased versatility and light output of luciferases have paved the way for a new field of functional bioluminescence optogenetics, in which the photon emission of the luciferase is coupled to the gating of a photosensor, e.g., a channelrhodopsin and we review how they have been successfully used to engineer synthetic neuronal connections. Finally, we provide a primer to consider important factors in setting up functional bioluminescence experiments, with a particular focus on the genetic model Caenorhabditis elegans, and discuss the leading challenges that the field needs to overcome to regain a competitive advantage over fluorescence modalities. Together, our paper caters to experienced users of bioluminescence as well as novices who would like to experience the advantages of luciferases in their own hand.
Collapse
Affiliation(s)
- Montserrat Porta-de-la-Riva
- ICFO—Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Luis-Felipe Morales-Curiel
- ICFO—Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Adriana Carolina Gonzalez
- ICFO—Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Michael Krieg
- ICFO—Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| |
Collapse
|
3
|
Oster H, Colwell CS. Editorial: Recent advances in sleep and circadian rhythms: the hypothalamus and its relationship with appetite. Front Neurosci 2024; 18:1385619. [PMID: 38486970 PMCID: PMC10937535 DOI: 10.3389/fnins.2024.1385619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 02/19/2024] [Indexed: 03/17/2024] Open
Affiliation(s)
- Henrik Oster
- Center of Brain, Behavior and Metabolism, Institute of Neurobiology, University of Lübeck, Lübeck, Germany
| | - Christopher S. Colwell
- UCLA Laboratory of Sleep and Circadian Medicine, Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
| |
Collapse
|
4
|
Dollish HK, Tsyglakova M, McClung CA. Circadian rhythms and mood disorders: Time to see the light. Neuron 2024; 112:25-40. [PMID: 37858331 PMCID: PMC10842077 DOI: 10.1016/j.neuron.2023.09.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/09/2023] [Accepted: 09/20/2023] [Indexed: 10/21/2023]
Abstract
The importance of time is ever prevalent in our world, and disruptions to the normal light/dark and sleep/wake cycle have now become the norm rather than the exception for a large part of it. All mood disorders, including seasonal affective disorder (SAD), major depressive disorder (MDD), and bipolar disorder (BD), are strongly associated with abnormal sleep and circadian rhythms in a variety of physiological processes. Environmental disruptions to normal sleep/wake patterns, light/dark changes, and seasonal changes can precipitate episodes. Moreover, treatments that target the circadian system have proven to be therapeutic in certain cases. This review will summarize much of our current knowledge of how these disorders associate with specific circadian phenotypes, as well as the neuronal mechanisms that link the circadian clock with mood regulation. We also discuss what has been learned from therapies that target circadian rhythms and how we may use current knowledge to develop more individually designed treatments.
Collapse
Affiliation(s)
- Hannah K Dollish
- Department of Psychiatry, University of Pittsburgh School of Medicine, 450 Technology Drive, Suite 223, Pittsburgh, PA 15219, USA
| | - Mariya Tsyglakova
- Department of Psychiatry, University of Pittsburgh School of Medicine, 450 Technology Drive, Suite 223, Pittsburgh, PA 15219, USA
| | - Colleen A McClung
- Department of Psychiatry, University of Pittsburgh School of Medicine, 450 Technology Drive, Suite 223, Pittsburgh, PA 15219, USA.
| |
Collapse
|
5
|
González-Vila A, Luengo-Mateos M, Silveira-Loureiro M, Garrido-Gil P, Ohinska N, González-Domínguez M, Labandeira-García JL, García-Cáceres C, López M, Barca-Mayo O. Astrocytic insulin receptor controls circadian behavior via dopamine signaling in a sexually dimorphic manner. Nat Commun 2023; 14:8175. [PMID: 38071352 PMCID: PMC10710518 DOI: 10.1038/s41467-023-44039-8] [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] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
Mammalian circadian clocks respond to feeding and light cues, adjusting internal rhythms with day/night cycles. Astrocytes serve as circadian timekeepers, driving daily physiological rhythms; however, it's unknown how they ensure precise cycle-to-cycle rhythmicity. This is critical for understanding why mistimed or erratic feeding, as in shift work, disrupts circadian physiology- a condition linked to type 2 diabetes and obesity. Here, we show that astrocytic insulin signaling sets the free-running period of locomotor activity in female mice and food entrainment in male mice. Additionally, ablating the insulin receptor in hypothalamic astrocytes alters cyclic energy homeostasis differently in male and female mice. Remarkably, the mutants exhibit altered dopamine metabolism, and the pharmacological modulation of dopaminergic signaling partially restores distinct circadian traits in both male and female mutant mice. Our findings highlight the role of astrocytic insulin-dopaminergic signaling in conveying time-of-feeding or lighting cues to the astrocyte clock, thus governing circadian behavior in a sex-specific manner.
Collapse
Affiliation(s)
- Antía González-Vila
- Circadian and Glial Biology Lab, Physiology Department, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
- NeurObesity Lab, Physiology Department, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
| | - María Luengo-Mateos
- Circadian and Glial Biology Lab, Physiology Department, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
| | - María Silveira-Loureiro
- Circadian and Glial Biology Lab, Physiology Department, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
- NeurObesity Lab, Physiology Department, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Pablo Garrido-Gil
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Department of Morphological Science, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
- Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Nataliia Ohinska
- Circadian and Glial Biology Lab, Physiology Department, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
- Horbachevsky Ternopil National Medical University, Ternopil, Ukraine
| | - Marco González-Domínguez
- Circadian and Glial Biology Lab, Physiology Department, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Jose Luis Labandeira-García
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Department of Morphological Science, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain
- Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Cristina García-Cáceres
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Munich & German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität, Ludwig-Maximilians-Universität München, 80336, Munich, Germany
| | - Miguel López
- NeurObesity Lab, Physiology Department, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain.
| | - Olga Barca-Mayo
- Circadian and Glial Biology Lab, Physiology Department, Molecular Medicine and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, Santiago de Compostela, Spain.
| |
Collapse
|
6
|
Sanetra AM, Palus-Chramiec K, Chrobok L, Jeczmien-Lazur JS, Klich JD, Lewandowski MH. Proglucagon signalling in the rat Dorsomedial Hypothalamus - Physiology and high-fat diet-mediated alterations. Mol Cell Neurosci 2023; 126:103873. [PMID: 37295578 DOI: 10.1016/j.mcn.2023.103873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/24/2023] [Accepted: 06/06/2023] [Indexed: 06/12/2023] Open
Abstract
A relatively new pharmacological target in obesity treatment has been the preproglucagon (PPG) signalling, predominantly with glucagon-like peptide (GLP) 1 receptor agonists. As far as the PPG role within the digestive system is well recognised, its actions in the brain remain understudied. Here, we investigated PPG signalling in the Dorsomedial Hypothalamus (DMH), a structure involved in feeding regulation and metabolism, using in situ hybridisation, electrophysiology, and immunohistochemistry. Our experiments were performed on animals fed both control, and high-fat diet (HFD), uncovering HFD-mediated alterations. First, sensitivity to exendin-4 (Exn4, a GLP1R agonist) was shown to increase under HFD, with a higher number of responsive neurons. The amplitude of the response to both Exn4 and oxyntomodulin (Oxm) was also altered, diminishing its relationship with the cells' spontaneous firing rate. Not only neuronal sensitivity, but also GLP1 presence, and therefore possibly release, was influenced by HFD. Immunofluorescent labelling of the GLP1 showed changes in its density depending on the metabolic state (fasted/fed), but this effect was eliminated by HFD feeding. Interestingly, these dietary differences were absent after a period of restricted feeding, allowing for an anticipation of the alternating metabolic states, which suggests possible prevention of such outcome.
Collapse
Affiliation(s)
- A M Sanetra
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland.
| | - K Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland
| | - L Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland; School of Physiology, Pharmacology, and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, UK
| | - J S Jeczmien-Lazur
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland
| | - J D Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland; Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle Street 10, 13125 Berlin, Germany
| | - M H Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland.
| |
Collapse
|
7
|
Luengo-Mateos M, González-Vila A, Vicente Dragano NR, Ohinska N, Silveira-Loureiro M, González-Domínguez M, Estévez-Salguero Á, Novelle-Rodríguez P, López M, Barca-Mayo O. Hypothalamic astrocytic-BMAL1 regulates energy homeostasis in a sex-dependent manner. Cell Rep 2023; 42:112949. [PMID: 37542717 DOI: 10.1016/j.celrep.2023.112949] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 06/12/2023] [Accepted: 07/20/2023] [Indexed: 08/07/2023] Open
Abstract
Here, we demonstrate that hypothalamic astrocytic BMAL1 computes cyclic metabolic information to optimize energetic resources in a sexually dimorphic manner. Knockdown of BMAL1 in female astrocytes leads to negative energy balance and alters basal metabolic cycles without affecting circadian locomotor activity. Thus, astrocytic BMAL1 contributes to the control of energy balance through the modulation of the metabolic rate, hepatic and white adipose tissue lipogenesis, and the activity of brown adipose tissue. Importantly, most of these alterations are specific to hypothalamic astrocytic BMAL1. Moreover, female mice with BMAL1 knockdown in astrocytes exhibited a "male-like" metabolic obese phenotype when fed a high-fat diet. Overall, our results suggest a sexually dimorphic effect of astrocytic BMAL1 on the regulation of energy homeostasis, which may be of interest in the physiopathology of obesity and related comorbidities.
Collapse
Affiliation(s)
- María Luengo-Mateos
- Physiology Department, Molecular Medicine, and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Antía González-Vila
- Physiology Department, Molecular Medicine, and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Nathalia Romanelli Vicente Dragano
- Physiology Department, Molecular Medicine, and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706 Santiago de Compostela, Spain
| | - Nataliia Ohinska
- Physiology Department, Molecular Medicine, and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; Horbachevsky Ternopil National Medical University, 46001 Ternopil, Ukraine
| | - María Silveira-Loureiro
- Physiology Department, Molecular Medicine, and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Marco González-Domínguez
- Physiology Department, Molecular Medicine, and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Ánxela Estévez-Salguero
- Physiology Department, Molecular Medicine, and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Paula Novelle-Rodríguez
- Physiology Department, Molecular Medicine, and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Miguel López
- Physiology Department, Molecular Medicine, and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706 Santiago de Compostela, Spain.
| | - Olga Barca-Mayo
- Physiology Department, Molecular Medicine, and Chronic Diseases Research Centre (CiMUS), University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
| |
Collapse
|
8
|
Makrygianni EA, Chrousos GP. Neural Progenitor Cells and the Hypothalamus. Cells 2023; 12:1822. [PMID: 37508487 PMCID: PMC10378393 DOI: 10.3390/cells12141822] [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: 03/02/2023] [Revised: 05/22/2023] [Accepted: 06/02/2023] [Indexed: 07/30/2023] Open
Abstract
Neural progenitor cells (NPCs) are multipotent neural stem cells (NSCs) capable of self-renewing and differentiating into neurons, astrocytes and oligodendrocytes. In the postnatal/adult brain, NPCs are primarily located in the subventricular zone (SVZ) of the lateral ventricles (LVs) and subgranular zone (SGZ) of the hippocampal dentate gyrus (DG). There is evidence that NPCs are also present in the postnatal/adult hypothalamus, a highly conserved brain region involved in the regulation of core homeostatic processes, such as feeding, metabolism, reproduction, neuroendocrine integration and autonomic output. In the rodent postnatal/adult hypothalamus, NPCs mainly comprise different subtypes of tanycytes lining the wall of the 3rd ventricle. In the postnatal/adult human hypothalamus, the neurogenic niche is constituted by tanycytes at the floor of the 3rd ventricle, ependymal cells and ribbon cells (showing a gap-and-ribbon organization similar to that in the SVZ), as well as suprachiasmatic cells. We speculate that in the postnatal/adult human hypothalamus, neurogenesis occurs in a highly complex, exquisitely sophisticated neurogenic niche consisting of at least four subniches; this structure has a key role in the regulation of extrahypothalamic neurogenesis, and hypothalamic and extrahypothalamic neural circuits, partly through the release of neurotransmitters, neuropeptides, extracellular vesicles (EVs) and non-coding RNAs (ncRNAs).
Collapse
Affiliation(s)
- Evanthia A Makrygianni
- University Research Institute of Maternal and Child Health & Precision Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - George P Chrousos
- University Research Institute of Maternal and Child Health & Precision Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece
| |
Collapse
|
9
|
Ahern J, Chrobok Ł, Champneys AR, Piggins HD. A new phase model of the spatiotemporal relationships between three circadian oscillators in the brainstem. Sci Rep 2023; 13:5480. [PMID: 37016055 PMCID: PMC10073201 DOI: 10.1038/s41598-023-32315-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/25/2023] [Indexed: 04/06/2023] Open
Abstract
Analysis of ex vivo Per2 bioluminescent rhythm previously recorded in the mouse dorsal vagal complex reveals a characteristic phase relationship between three distinct circadian oscillators. These signals represent core clock gene expression in the area postrema (AP), the nucleus of the solitary tract (NTS) and the ependymal cells surrounding the 4th ventricle (4Vep). Initially, the data suggests a consistent phasing in which the AP peaks first, followed shortly by the NTS, with the 4Vep peaking 8-9 h later. Wavelet analysis reveals that this pattern is not consistently maintained throughout a recording, however, the phase dynamics strongly imply that oscillator interactions are present. A simple phase model of the three oscillators is developed and it suggests that realistic phase dynamics occur between three model oscillators with coupling close to a synchronisation transition. The coupling topology suggests that the AP bidirectionally communicates phase information to the NTS and the 4Vep to synchronise the three structures. A comparison of the model with previous experimental manipulations demonstrates its feasibility to explain DVC circadian phasing. Finally, we show that simulating steadily decaying coupling improves the model's ability to capture experimental phase dynamics.
Collapse
Affiliation(s)
- Jake Ahern
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
- Engineering Mathematics, University of Bristol, Bristol, BS8 1TW, UK
| | - Łukasz Chrobok
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Alan R Champneys
- Engineering Mathematics, University of Bristol, Bristol, BS8 1TW, UK
| | - Hugh D Piggins
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, BS8 1TD, UK.
| |
Collapse
|
10
|
Sato RY, Yamanaka Y. Nonphotic entrainment of central and peripheral circadian clocks in mice by scheduled voluntary exercise under constant darkness. Am J Physiol Regul Integr Comp Physiol 2023; 324:R526-R535. [PMID: 36802951 DOI: 10.1152/ajpregu.00320.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
In mammals, the central circadian pacemaker in the suprachiasmatic nucleus (SCN) entrains to an environmental light-dark (LD) cycle and organizes the temporal order of circadian rhythms in physiology and behavior. Previously, some studies have demonstrated that scheduled exercise could entrain the free-running behavior rhythm in nocturnal rodents. However, it remains unknown whether entrainment by scheduled exercise alters the internal temporal order of the behavioral circadian rhythms or clock gene expression in the SCN, extra-SCN brain regions, and peripheral organs when mice are entrained to the scheduled exercise under constant darkness (DD). In the present study, we examined circadian rhythms in locomotor activity and clock gene Per1 expression by bioluminescence reporter (Per1-luc) in the SCN, arcuate nucleus (ARC), liver, and skeletal muscle of mice entrained to an LD cycle, mice free-running under DD, and mice entrained to daily exposure to a new cage with a running wheel (NCRW) under DD. All mice showed a steady-state entrainment of behavioral circadian rhythms to NCRW exposure under DD in parallel with shortening of the α when compared with that under DD. The temporal order of behavioral circadian rhythms and the Per1-luc rhythms in the SCN and peripheral tissues but not in the ARC were maintained in the mice entrained to the NCRW and LD cycles; in contrast, the temporal order was altered in the mice under DD. The present findings reveal that the SCN entrains to daily exercise, and daily exercise reorganizes the internal temporal order of behavioral circadian rhythms and clock gene expression in the SCN and peripheral tissues.
Collapse
Affiliation(s)
- Ren Y Sato
- Department of Education, Hokkaido University, Sapporo, Japan
- Department of Cellular Pharmacology, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Yujiro Yamanaka
- Laboratory of Life & Health Sciences, Graduate School of Education and Faculty of Education, Hokkaido University, Sapporo, Japan
- Research and Education Center for Brain Science, Hokkaido University, Sapporo, Japan
| |
Collapse
|
11
|
Wang X, Dong YT, Hu XM, Zhang JZ, Shi NR, Zuo YQ, Wang X. The circadian regulation of extracellular ATP. Purinergic Signal 2023; 19:283-295. [PMID: 35939197 PMCID: PMC9984637 DOI: 10.1007/s11302-022-09881-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 06/24/2022] [Indexed: 11/25/2022] Open
Abstract
Extracellular ATP is a potent signaling molecule released from various cells throughout the body and is intimately involved in the pathophysiological functions of the nervous system and immune system by activating P2 purinergic receptors. Recent increasingly studies showed that extracellular ATP exhibits circadian oscillation with an approximately 24-h periodicity, which participates in regulatory pathways of central oscillator suprachiasmatic nucleus and peripheral oscillator bladder, respectively. Oscillators modulate the protein expression of ATP release channels and ectonucleotidase activity through clock genes; indeed, real-time alterations of ATP release and degradation determine outcomes of temporal character on extracellular ATP rhythm. The regulatory pathways on extracellular ATP rhythm are different in central and peripheral systems. In this review, we summarize the circadian rhythm of extracellular ATP and discuss several circadian regulatory pathways in different organs via ATP release and degradation, to provide a new understanding for purinergic signaling in the regulatory mechanism of circadian rhythm and a potential target to research the circadian regulation of extracellular ATP in other circadian oscillators.
Collapse
Affiliation(s)
- Xin Wang
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, 37 Shi-er Qiao Road, Chengdu, 610075 China
| | - Yu-Ting Dong
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, 37 Shi-er Qiao Road, Chengdu, 610075 China
| | - Xiu-Ming Hu
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, 37 Shi-er Qiao Road, Chengdu, 610075 China
| | - Ji-Zhou Zhang
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, 37 Shi-er Qiao Road, Chengdu, 610075 China
| | - Nan-Rui Shi
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, 37 Shi-er Qiao Road, Chengdu, 610075 China
| | - Yan-Qin Zuo
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, 37 Shi-er Qiao Road, Chengdu, 610075 China
| | - Xu Wang
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, 37 Shi-er Qiao Road, Chengdu, 610075 China
| |
Collapse
|
12
|
Hitrec T, Petit C, Cryer E, Muir C, Tal N, Fustin JM, Hughes AT, Piggins HD. Timed exercise stabilizes behavioral rhythms but not molecular programs in the brain's suprachiasmatic clock. iScience 2023; 26:106002. [PMID: 36866044 PMCID: PMC9971895 DOI: 10.1016/j.isci.2023.106002] [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: 09/06/2022] [Revised: 11/25/2022] [Accepted: 01/13/2023] [Indexed: 01/20/2023] Open
Abstract
Timed daily access to a running-wheel (scheduled voluntary exercise; SVE) synchronizes rodent circadian rhythms and promotes stable, 24h rhythms in animals with genetically targeted impairment of neuropeptide signaling (Vipr2 -/- mice). Here we used RNA-seq and/or qRT-PCR to assess how this neuropeptide signaling impairment as well as SVE shapes molecular programs in the brain clock (suprachiasmatic nuclei; SCN) and peripheral tissues (liver and lung). Compared to Vipr2 +/+ animals, the SCN transcriptome of Vipr2 -/- mice showed extensive dysregulation which included core clock components, transcription factors, and neurochemicals. Furthermore, although SVE stabilized behavioral rhythms in these animals, the SCN transcriptome remained dysregulated. The molecular programs in the lung and liver of Vipr2 -/- mice were partially intact, although their response to SVE differed to that of these peripheral tissues in the Vipr2 +/+ mice. These findings highlight that SVE can correct behavioral abnormalities in circadian rhythms without causing large scale alterations to the SCN transcriptome.
Collapse
Affiliation(s)
- Timna Hitrec
- School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Cheryl Petit
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PT, UK
| | - Emily Cryer
- School of Biological Sciences, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | - Charlotte Muir
- School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Natalie Tal
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PT, UK
| | - Jean-Michel Fustin
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PT, UK
| | - Alun T.L. Hughes
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PT, UK,School of Biological and Environmental Sciences, Faculty of Science, Liverpool John Moores University, Liverpool L3 3AF, UK,Corresponding author
| | - Hugh D. Piggins
- School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK,School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester M13 9PT, UK,Corresponding author
| |
Collapse
|
13
|
Sanetra AM, Palus-Chramiec K, Chrobok L, Jeczmien-Lazur JS, Gawron E, Klich JD, Pradel K, Lewandowski MH. High-Fat-Diet-Evoked Disruption of the Rat Dorsomedial Hypothalamic Clock Can Be Prevented by Restricted Nighttime Feeding. Nutrients 2022; 14:nu14235034. [PMID: 36501063 PMCID: PMC9735604 DOI: 10.3390/nu14235034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/21/2022] [Accepted: 11/24/2022] [Indexed: 11/29/2022] Open
Abstract
Obesity is a growing health problem for modern society; therefore, it has become extremely important to study not only its negative implications but also its developmental mechanism. Its links to disrupted circadian rhythmicity are indisputable but are still not well studied on the cellular level. Circadian food intake and metabolism are controlled by a set of brain structures referred to as the food-entrainable oscillator, among which the dorsomedial hypothalamus (DMH) seems to be especially heavily affected by diet-induced obesity. In this study, we evaluated the effects of a short-term high-fat diet (HFD) on the physiology of the male rat DMH, with special attention to its day/night changes. Using immunofluorescence and electrophysiology we found that both cFos immunoreactivity and electrical activity rhythms become disrupted after as few as 4 weeks of HFD consumption, so before the onset of excessive weight gain. This indicates that the DMH impairment is a possible factor in obesity development. The DMH cellular activity under an HFD became increased during the non-active daytime, which coincides with a disrupted rhythm in food intake. In order to explore the relationship between them, a separate group of rats underwent time-restricted feeding with access to food only during the nighttime. Such an approach completely abolished the disruptive effects of the HFD on the DMH clock, confirming its dependence on the feeding schedule of the animal. The presented data highlight the importance of a temporally regulated feeding pattern on the physiology of the hypothalamic center for food intake and metabolism regulation, and propose time-restricted feeding as a possible prevention of the circadian dysregulation observed under an HFD.
Collapse
Affiliation(s)
- Anna Magdalena Sanetra
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland
- Correspondence: (A.M.S.); (M.H.L.); Tel.: +48-12-664-53-56 (A.M.S.); +48-12-664-53-73 (M.H.L.)
| | - Katarzyna Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland
| | - Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, UK
| | - Jagoda Stanislawa Jeczmien-Lazur
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland
| | - Emilia Gawron
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland
| | - Jasmin Daniela Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland
| | - Marian Henryk Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland
- Correspondence: (A.M.S.); (M.H.L.); Tel.: +48-12-664-53-56 (A.M.S.); +48-12-664-53-73 (M.H.L.)
| |
Collapse
|
14
|
Areshidze DA, Kozlova MA, Makartseva LA, Chernov IA, Sinelnikov MY, Kirillov YA. Influence of constant lightning on liver health: an experimental study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:83686-83697. [PMID: 35771326 DOI: 10.1007/s11356-022-21655-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
Light pollution has become a serious problem in many urbanized areas of the world. The impact of prolonged exposure to light and consequent disruption of natural circadian rhythms has significant health implications. The current study was undertaken to evaluate the effect of prolonged exposure to light, simulating urban light pollution, on liver health. In order to evaluate the effect of prolonged exposure to light, we examined the morphofunctional state, immunohistochemical and micromorphometric parameters of rat liver in normal conditions and following prolonged lighting exposure. Our results show that nocturnal light disruption triggers a cell death in the liver within 3 weeks (necrosis and apoptosis of hepatocytes) and stimulates a change in normal cellular karyometric parameters. At the same time, intracellular regeneration takes place within the organ, which manifests through hepatocyte hypertrophy. Under the influence of constant illumination, the circadian rhythms (CRs) of the size of hepatocytes and their nuclei are restructured, and the rhythm of the nuclear-cytoplasmic ratio is destroyed. The destruction of the CR of expression of p53 and Ki-67 also occurs against the background of the rearrangement of the daily rhythmicity of Per2 and Bmal1. The revealed changes in the morphofunctional state of the liver under the influence of light pollution indicate that a violation of normal illumination regimes is a potent factor leading to significant structural changes in the liver.
Collapse
Affiliation(s)
- David A Areshidze
- A.P. Avtsyn Research Institute of Human Morphology, Moscow, Russian Federation
| | - Maria A Kozlova
- A.P. Avtsyn Research Institute of Human Morphology, Moscow, Russian Federation
| | | | - Igor A Chernov
- Tyumen State Medical University, Tyumen, Russian Federation
| | - Mikhail Y Sinelnikov
- A.P. Avtsyn Research Institute of Human Morphology, Moscow, Russian Federation.
- Sechenov University, Moscow, Russian Federation.
| | - Yuri A Kirillov
- A.P. Avtsyn Research Institute of Human Morphology, Moscow, Russian Federation
| |
Collapse
|
15
|
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.
Collapse
|
16
|
Tang Q, Assali DR, Güler AD, Steele AD. Dopamine systems and biological rhythms: Let's get a move on. Front Integr Neurosci 2022; 16:957193. [PMID: 35965599 PMCID: PMC9364481 DOI: 10.3389/fnint.2022.957193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 07/06/2022] [Indexed: 02/05/2023] Open
Abstract
How dopamine signaling regulates biological rhythms is an area of emerging interest. Here we review experiments focused on delineating dopamine signaling in the suprachiasmatic nucleus, nucleus accumbens, and dorsal striatum to mediate a range of biological rhythms including photoentrainment, activity cycles, rest phase eating of palatable food, diet-induced obesity, and food anticipatory activity. Enthusiasm for causal roles for dopamine in the regulation of circadian rhythms, particularly those associated with food and other rewarding events, is warranted. However, determining that there is rhythmic gene expression in dopamine neurons and target structures does not mean that they are bona fide circadian pacemakers. Given that dopamine has such a profound role in promoting voluntary movements, interpretation of circadian phenotypes associated with locomotor activity must be differentiated at the molecular and behavioral levels. Here we review our current understanding of dopamine signaling in relation to biological rhythms and suggest future experiments that are aimed at teasing apart the roles of dopamine subpopulations and dopamine receptor expressing neurons in causally mediating biological rhythms, particularly in relation to feeding, reward, and activity.
Collapse
Affiliation(s)
- Qijun Tang
- Department of Biology, University of Virginia, Charlottesville, VA, United States
| | - Dina R. Assali
- Department of Biological Sciences, California State Polytechnic University Pomona, Pomona, CA, United States
| | - Ali D. Güler
- Department of Biology, University of Virginia, Charlottesville, VA, United States
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, United States
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Andrew D. Steele
- Department of Biological Sciences, California State Polytechnic University Pomona, Pomona, CA, United States
| |
Collapse
|
17
|
Buel SM, Debopadhaya S, De los Santos H, Edwards KM, David AM, Dao UH, Bennett KP, Hurley JM. The PAICE suite reveals circadian posttranscriptional timing of noncoding RNAs and spliceosome components in Mus musculus macrophages. G3 (BETHESDA, MD.) 2022; 12:6649694. [PMID: 35876788 PMCID: PMC9434326 DOI: 10.1093/g3journal/jkac176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 06/27/2022] [Indexed: 01/07/2023]
Abstract
Circadian rhythms broadly regulate physiological functions by tuning oscillations in the levels of mRNAs and proteins to the 24-h day/night cycle. Globally assessing which mRNAs and proteins are timed by the clock necessitates accurate recognition of oscillations in RNA and protein data, particularly in large omics data sets. Tools that employ fixed-amplitude models have previously been used to positive effect. However, the recognition of amplitude change in circadian oscillations required a new generation of analytical software to enhance the identification of these oscillations. To address this gap, we created the Pipeline for Amplitude Integration of Circadian Exploration suite. Here, we demonstrate the Pipeline for Amplitude Integration of Circadian Exploration suite's increased utility to detect circadian trends through the joint modeling of the Mus musculus macrophage transcriptome and proteome. Our enhanced detection confirmed extensive circadian posttranscriptional regulation in macrophages but highlighted that some of the reported discrepancy between mRNA and protein oscillations was due to noise in data. We further applied the Pipeline for Amplitude Integration of Circadian Exploration suite to investigate the circadian timing of noncoding RNAs, documenting extensive circadian timing of long noncoding RNAs and small nuclear RNAs, which control the recognition of mRNA in the spliceosome complex. By tracking oscillating spliceosome complex proteins using the PAICE suite, we noted that the clock broadly regulates the spliceosome, particularly the major spliceosome complex. As most of the above-noted rhythms had damped amplitude changes in their oscillations, this work highlights the importance of the PAICE suite in the thorough enumeration of oscillations in omics-scale datasets.
Collapse
Affiliation(s)
| | | | | | - Kaelyn M Edwards
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Alexandra M David
- Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Uyen H Dao
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Kristin P Bennett
- Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA,Department of Computer Science, Rensselaer Polytechnic Institute, Troy, NY 12180, USA,Institute for Data Exploration and Applications, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Jennifer M Hurley
- Corresponding author: Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| |
Collapse
|
18
|
Palus-Chramiec K, Sanetra AM, Lewandowski MH. Day/night Changes in the Dorsomedial Hypothalamus Firing Responses to Ghrelin are Modulated by High-fat Diet. Neuroscience 2022; 494:167-177. [PMID: 35569641 DOI: 10.1016/j.neuroscience.2022.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 05/02/2022] [Accepted: 05/05/2022] [Indexed: 02/06/2023]
Abstract
Dorsomedial hypothalamus (DMH) is a part of the feeding center involved in food intake and regulation of the metabolism. DMH neurons express many receptors for different metabolic cues which can modulate its network and influence animals' behaviour. One of the metabolic peptides deliveredto this structure is ghrelin, the only well-known hunger signal, produced mainly in the stomach. Diet-induced obesity is a physiological model of obesity widely used in research. Here we investigated how time-of-day and high-fat diet (HFD) affect neuronal networks and the sensitivity to the metabolic information received by the DMH. Our results indicate that even a short period of HFD (2-3 weeks) consumption can cause dysregulation of the DMH neuronal network, manifested as a disruption of the day/night pattern of basal activity and altered sensitivity to incoming information. We showed for the first time a day/night pattern of sensitivity to ghrelin in the DMH, with a higher level during the behaviorally active phase of animals. This day/night rhythm of sensitivity to ghrelin was reversed in HFD group, causing a stronger effect during the non-active phase. After prolongation of the HFD consumption to 7-8 weeks we observed an increase in the responsiveness to ghrelin, than during the short-term diet.
Collapse
Affiliation(s)
- K Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland.
| | - A M Sanetra
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland.
| | - M H Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387 Krakow, Poland.
| |
Collapse
|
19
|
Pradel K, Drwięga G, Chrobok L, Błasiak T. Racing and Pacing in the Reward System: A Multi-Clock Circadian Control Over Dopaminergic Signalling. Front Physiol 2022; 13:932378. [PMID: 35812323 PMCID: PMC9259884 DOI: 10.3389/fphys.2022.932378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/07/2022] [Indexed: 11/27/2022] Open
Abstract
Level of motivation, responsiveness to rewards and punishment, invigoration of exploratory behaviours, and motor performance are subject to daily fluctuations that emerge from circadian rhythms in neuronal activity of the midbrain’s dopaminergic system. While endogenous circadian rhythms are weak in the ventral tegmental area and substantia nigra pars compacta, daily changes in expression of core clock genes, ion channels, neurotransmitter receptors, dopamine-synthesising enzymes, and dopamine transporters, accompanied by changes in electrical activity, are readily observed in these nuclei. These processes cause dopamine levels released in structures innervated by midbrain dopaminergic neurons (e.g., the striatum) to oscillate in a circadian fashion. Additionally, growing evidence show that the master circadian clock located in the suprachiasmatic nucleus of the hypothalamus (SCN) rhythmically influences the activity of the dopaminergic system through various intermediate targets. Thus, circadian changes in the activity of the dopaminergic system and concomitant dopamine release observed on a daily scale are likely to be generated both intrinsically and entrained by the master clock. Previous studies have shown that the information about the value and salience of stimuli perceived by the animal is encoded in the neuronal activity of brain structures innervating midbrain dopaminergic centres. Some of these structures themselves are relatively autonomous oscillators, while others exhibit a weak endogenous circadian rhythm synchronised by the SCN. Here, we place the dopaminergic system as a hub in the extensive network of extra-SCN circadian oscillators and discuss the possible consequences of its daily entrainment for animal physiology and behaviour.
Collapse
Affiliation(s)
- Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Gniewosz Drwięga
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Lukasz Chrobok
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Bristol, United Kingdom
- *Correspondence: Lukasz Chrobok, ; Tomasz Błasiak,
| | - Tomasz Błasiak
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
- *Correspondence: Lukasz Chrobok, ; Tomasz Błasiak,
| |
Collapse
|
20
|
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.
Collapse
|
21
|
Young CJ, Lyons D, Piggins HD. Circadian Influences on the Habenula and Their Potential Contribution to Neuropsychiatric Disorders. Front Behav Neurosci 2022; 15:815700. [PMID: 35153695 PMCID: PMC8831701 DOI: 10.3389/fnbeh.2021.815700] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/27/2021] [Indexed: 12/13/2022] Open
Abstract
The neural circadian system consists of the master circadian clock in the hypothalamic suprachiasmatic nuclei (SCN) communicating time of day cues to the rest of the body including other brain areas that also rhythmically express circadian clock genes. Over the past 16 years, evidence has emerged to indicate that the habenula of the epithalamus is a candidate extra-SCN circadian oscillator. When isolated from the SCN, the habenula sustains rhythms in clock gene expression and neuronal activity, with the lateral habenula expressing more robust rhythms than the adjacent medial habenula. The lateral habenula is responsive to putative SCN output factors as well as light information conveyed to the perihabenula area. Neuronal activity in the lateral habenula is altered in depression and intriguingly disruptions in circadian rhythms can elevate risk of developing mental health disorders including depression. In this review, we will principally focus on how circadian and light signals affect the lateral habenula and evaluate the possibility that alteration in these influences contribute to mental health disorders.
Collapse
|
22
|
Chrobok L, Pradel K, Janik ME, Sanetra AM, Bubka M, Myung J, Ridla Rahim A, Klich JD, Jeczmien-Lazur JS, Palus-Chramiec K, Lewandowski MH. Intrinsic circadian timekeeping properties of the thalamic lateral geniculate nucleus. J Neurosci Res 2021; 99:3306-3324. [PMID: 34758124 DOI: 10.1002/jnr.24973] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 09/07/2021] [Accepted: 09/17/2021] [Indexed: 01/08/2023]
Abstract
Circadian rhythmicity in mammals is sustained by the central brain clock-the suprachiasmatic nucleus of the hypothalamus (SCN), entrained to the ambient light-dark conditions through a dense retinal input. However, recent discoveries of autonomous clock gene expression cast doubt on the supremacy of the SCN and suggest circadian timekeeping mechanisms devolve to local brain clocks. Here, we use a combination of molecular, electrophysiological, and optogenetic tools to evaluate intrinsic clock properties of the main retinorecipient thalamic center-the lateral geniculate nucleus (LGN) in male rats and mice. We identify the dorsolateral geniculate nucleus as a slave oscillator, which exhibits core clock gene expression exclusively in vivo. Additionally, we provide compelling evidence for intrinsic clock gene expression accompanied by circadian variation in neuronal activity in the intergeniculate leaflet and ventrolateral geniculate nucleus (VLG). Finally, our optogenetic experiments propose the VLG as a light-entrainable oscillator, whose phase may be advanced by retinal input at the beginning of the projected night. Altogether, this study for the first time demonstrates autonomous timekeeping mechanisms shaping circadian physiology of the LGN.
Collapse
Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Marcelina Elzbieta Janik
- Department of Glycoconjugate Biochemistry, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Anna Magdalena Sanetra
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Monika Bubka
- Department of Glycoconjugate Biochemistry, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jihwan Myung
- Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, Taipei, Taiwan.,Brain and Consciousness Research Centre, Taipei Medical University-Shuang Ho Hospital, Ministry of Health and Welfare, New Taipei City, Taiwan
| | - Amalia Ridla Rahim
- Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, Taipei, Taiwan.,Brain and Consciousness Research Centre, Taipei Medical University-Shuang Ho Hospital, Ministry of Health and Welfare, New Taipei City, Taiwan
| | - Jasmin Daniela Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jagoda Stanislawa Jeczmien-Lazur
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Katarzyna Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Marian Henryk Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| |
Collapse
|
23
|
Jones JR, Chaturvedi S, Granados-Fuentes D, Herzog ED. Circadian neurons in the paraventricular nucleus entrain and sustain daily rhythms in glucocorticoids. Nat Commun 2021; 12:5763. [PMID: 34599158 PMCID: PMC8486846 DOI: 10.1038/s41467-021-25959-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 09/02/2021] [Indexed: 02/08/2023] Open
Abstract
Signals from the central circadian pacemaker, the suprachiasmatic nucleus (SCN), must be decoded to generate daily rhythms in hormone release. Here, we hypothesized that the SCN entrains rhythms in the paraventricular nucleus (PVN) to time the daily release of corticosterone. In vivo recording revealed a critical circuit from SCN vasoactive intestinal peptide (SCNVIP)-producing neurons to PVN corticotropin-releasing hormone (PVNCRH)-producing neurons. PVNCRH neurons peak in clock gene expression around midday and in calcium activity about three hours later. Loss of the clock gene Bmal1 in CRH neurons results in arrhythmic PVNCRH calcium activity and dramatically reduces the amplitude and precision of daily corticosterone release. SCNVIP activation reduces (and inactivation increases) corticosterone release and PVNCRH calcium activity, and daily SCNVIP activation entrains PVN clock gene rhythms by inhibiting PVNCRH neurons. We conclude that daily corticosterone release depends on coordinated clock gene and neuronal activity rhythms in both SCNVIP and PVNCRH neurons.
Collapse
Affiliation(s)
- Jeff R Jones
- Department of Biology, Washington University, St. Louis, St. Louis, MO, USA
- Department of Biology, Texas A&M University, College Station, College Station, TX, USA
| | - Sneha Chaturvedi
- Department of Biology, Washington University, St. Louis, St. Louis, MO, USA
| | | | - Erik D Herzog
- Department of Biology, Washington University, St. Louis, St. Louis, MO, USA.
| |
Collapse
|
24
|
Chrobok L, Jeczmien-Lazur JS, Bubka M, Pradel K, Klekocinska A, Klich JD, Ridla Rahim A, Myung J, Kepczynski M, Lewandowski MH. Daily coordination of orexinergic gating in the rat superior colliculus-Implications for intrinsic clock activities in the visual system. FASEB J 2021; 35:e21930. [PMID: 34533886 DOI: 10.1096/fj.202100779rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 08/24/2021] [Accepted: 08/31/2021] [Indexed: 01/07/2023]
Abstract
The orexinergic system delivers excitation for multiple brain centers to facilitate behavioral arousal, with its malfunction resulting in narcolepsy, somnolence, and notably, visual hallucinations. Since the circadian clock underlies the daily arousal, a timed coordination is expected between the orexin system and its target subcortical visual system, including the superior colliculus (SC). Here, we use a combination of electrophysiological, immunohistochemical, and molecular approaches across 24 h, together with the neuronal tract-tracing methods to investigate the daily coordination between the orexin system and the rodent SC. Higher orexinergic input was found to occur nocturnally in the superficial layers of the SC, in time for nocturnal silencing of spontaneous firing in this visual brain area. We identify autonomous daily and circadian expression of clock genes in the SC, which may underlie these day-night changes. Additionally, we establish the lateral hypothalamic origin of the orexin innervation to the SC and that the SC neurons robustly respond to orexin A via OX2 receptor in both excitatory and GABAA receptor-dependent inhibitory manners. Together, our evidence elucidates the combination of intrinsic and extrinsic clock mechanisms that shape the daily function of the visual layers of the SC.
Collapse
Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jagoda Stanislawa Jeczmien-Lazur
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Monika Bubka
- Department of Glycoconjugate Biochemistry, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Aleksandra Klekocinska
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jasmin Daniela Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Amalia Ridla Rahim
- Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, Taipei, Taiwan
| | - Jihwan Myung
- Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, Taipei, Taiwan.,Brain and Consciousness Research Centre, Taipei Medical University-Shuang Ho Hospital, Ministry of Health and Welfare, New Taipei City, Taiwan
| | - Mariusz Kepczynski
- Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University in Krakow, Krakow, Poland
| | - Marian Henryk Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| |
Collapse
|
25
|
Adlanmerini M, Nguyen HC, Krusen BM, Teng CW, Geisler CE, Peed LC, Carpenter BJ, Hayes MR, Lazar MA. Hypothalamic REV-ERB nuclear receptors control diurnal food intake and leptin sensitivity in diet-induced obese mice. J Clin Invest 2021; 131:140424. [PMID: 33021965 DOI: 10.1172/jci140424] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 09/29/2020] [Indexed: 12/15/2022] Open
Abstract
Obesity occurs when energy expenditure is outweighed by energy intake. Tuberal hypothalamic nuclei, including the arcuate nucleus (ARC), ventromedial nucleus (VMH), and dorsomedial nucleus (DMH), control food intake and energy expenditure. Here we report that, in contrast with females, male mice lacking circadian nuclear receptors REV-ERBα and -β in the tuberal hypothalamus (HDKO mice) gained excessive weight on an obesogenic high-fat diet due to both decreased energy expenditure and increased food intake during the light phase. Moreover, rebound food intake after fasting was markedly increased in HDKO mice. Integrative transcriptomic and cistromic analyses revealed that such disruption in feeding behavior was due to perturbed REV-ERB-dependent leptin signaling in the ARC. Indeed, in vivo leptin sensitivity was impaired in HDKO mice on an obesogenic diet in a diurnal manner. Thus, REV-ERBs play a crucial role in hypothalamic control of food intake and diurnal leptin sensitivity in diet-induced obesity.
Collapse
Affiliation(s)
- Marine Adlanmerini
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Hoang Cb Nguyen
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Brianna M Krusen
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Clare W Teng
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Caroline E Geisler
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Lindsey C Peed
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Bryce J Carpenter
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| | - Matthew R Hayes
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine.,Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine
| |
Collapse
|
26
|
Chrobok L, Klich JD, Sanetra AM, Jeczmien-Lazur JS, Pradel K, Palus-Chramiec K, Kepczynski M, Piggins HD, Lewandowski MH. Rhythmic neuronal activities of the rat nucleus of the solitary tract are impaired by high-fat diet - implications for daily control of satiety. J Physiol 2021; 600:751-767. [PMID: 34490628 DOI: 10.1113/jp281838] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Temporal partitioning of daily food intake is crucial for survival and involves the integration of internal circadian states and external influences such as the light-dark cycle and dietary composition. These intrinsic and extrinsic factors are interdependent with misalignment of circadian rhythms promoting body weight gain, while consumption of a calorie-dense diet elevates the risk of obesity and blunts circadian rhythms. Recently, we defined the circadian properties of the dorsal vagal complex of the brainstem, a structure implicated in the control of food intake and autonomic tone, but whether and how 24 h rhythms in this area are influenced by diet remains unresolved. Here we focused on a key structure of this complex, the nucleus of the solitary tract (NTS). We used a combination of immunohistochemical and electrophysiological approaches together with daily monitoring of body weight and food intake to interrogate how the neuronal rhythms of the NTS are affected by a high-fat diet. We report that short-term consumption of a high-fat diet increases food intake during the day and blunts NTS daily rhythms in neuronal discharge. Additionally, we found that a high-fat diet dampens NTS responsiveness to metabolic neuropeptides, and decreases orexin immunoreactive fibres in this structure. These alterations occur without prominent body weight gain, suggesting that a high-fat diet acts initially to reduce activity in the NTS to disinhibit mechanisms that suppress daytime feeding. KEY POINTS: The dorsal vagal complex of the rodent hindbrain possesses intrinsic circadian timekeeping mechanisms In particular, the nucleus of the solitary tract (NTS) is a robust circadian oscillator, independent of the master suprachiasmatic clock Here, we reveal that rat NTS neurons display timed daily rhythms in their neuronal activity and responsiveness to ingestive cues These daily rhythms are blunted or eliminated by a short-term high-fat diet, together with increased consumption of calories during the behaviourally quiescent day Our results help us better understand the circadian control of satiety by the brainstem and its malfunctioning under a high-fat diet.
Collapse
Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jasmin D Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Anna M Sanetra
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jagoda S Jeczmien-Lazur
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Katarzyna Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Mariusz Kepczynski
- Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University in Krakow, Krakow, Poland
| | - Hugh D Piggins
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Marian H Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| |
Collapse
|
27
|
Quintela T, Furtado A, Duarte AC, Gonçalves I, Myung J, Santos CRA. The role of circadian rhythm in choroid plexus functions. Prog Neurobiol 2021; 205:102129. [PMID: 34343629 DOI: 10.1016/j.pneurobio.2021.102129] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 07/22/2021] [Accepted: 07/28/2021] [Indexed: 12/17/2022]
Abstract
For several years, a great effort has been devoted to understand how circadian oscillations in physiological processes are determined by the circadian clock system. This system is composed by the master clock at the suprachiasmatic nucleus which sets the pace and tunes peripheral clocks in several organs. It was recently demonstrated that the choroid plexus epithelial cells that compose the blood-cerebrospinal fluid barrier hold a circadian clock which might control their multiple functions with implications for the maintenance of brain homeostasis. However, the choroid plexus activities regulated by its inner clock are still largely unknown. In this review, we propose that several choroid plexus functions might be regulated by the circadian clock, alike in other tissues. We provide evidences that the timing of cerebrospinal fluid secretion, clearance of amyloid-beta peptides and xenobiotics, and the barrier function of the blood-cerebrospinal fluid barrier are regulated by the circadian clock. These data, highlight that the circadian regulation of the blood-cerebrospinal fluid barrier must be taken into consideration for enhancing drug delivery to central nervous system disorders.
Collapse
Affiliation(s)
- Telma Quintela
- CICS-UBI - Health Sciences Research Center, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal.
| | - André Furtado
- CICS-UBI - Health Sciences Research Center, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Ana C Duarte
- CICS-UBI - Health Sciences Research Center, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Isabel Gonçalves
- CICS-UBI - Health Sciences Research Center, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Jihwan Myung
- Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, No. 172-1 Sec. 2 Keelung Road, Da'an District, Taipei 106, Taiwan; Brain and Consciousness Research Centre, Shuang Ho Hospital, Ministry of Health and Welfare, No. 291 Zhongzheng Road, Zhonghe District, New Taipei City 235, Taiwan
| | - Cecília R A Santos
- CICS-UBI - Health Sciences Research Center, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| |
Collapse
|
28
|
|
29
|
Buijink MR, Michel S. A multi-level assessment of the bidirectional relationship between aging and the circadian clock. J Neurochem 2021; 157:73-94. [PMID: 33370457 PMCID: PMC8048448 DOI: 10.1111/jnc.15286] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/23/2020] [Accepted: 12/23/2020] [Indexed: 12/15/2022]
Abstract
The daily temporal order of physiological processes and behavior contribute to the wellbeing of many organisms including humans. The central circadian clock, which coordinates the timing within our body, is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. Like in other parts of the brain, aging impairs the SCN function, which in turn promotes the development and progression of aging-related diseases. We here review the impact of aging on the different levels of the circadian clock machinery-from molecules to organs-with a focus on the role of the SCN. We find that the molecular clock is less effected by aging compared to other cellular components of the clock. Proper rhythmic regulation of intracellular signaling, ion channels and neuronal excitability of SCN neurons are greatly disturbed in aging. This suggests a disconnection between the molecular clock and the electrophysiology of these cells. The neuronal network of the SCN is able to compensate for some of these cellular deficits. However, it still results in a clear reduction in the amplitude of the SCN electrical rhythm, suggesting a weakening of the output timing signal. Consequently, other brain areas and organs not only show aging-related deficits in their own local clocks, but also receive a weaker systemic timing signal. The negative spiral completes with the weakening of positive feedback from the periphery to the SCN. Consequently, chronotherapeutic interventions should aim at strengthening overall synchrony in the circadian system using life-style and/or pharmacological approaches.
Collapse
Affiliation(s)
- M. Renate Buijink
- Department of Cellular and Chemical BiologyLaboratory for NeurophysiologyLeiden University Medical CenterLeidenthe Netherlands
| | - Stephan Michel
- Department of Cellular and Chemical BiologyLaboratory for NeurophysiologyLeiden University Medical CenterLeidenthe Netherlands
| |
Collapse
|
30
|
Page AJ. Gastrointestinal Vagal Afferents and Food Intake: Relevance of Circadian Rhythms. Nutrients 2021; 13:nu13030844. [PMID: 33807524 PMCID: PMC7998414 DOI: 10.3390/nu13030844] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/25/2021] [Accepted: 03/03/2021] [Indexed: 01/20/2023] Open
Abstract
Gastrointestinal vagal afferents (VAs) play an important role in food intake regulation, providing the brain with information on the amount and nutrient composition of a meal. This is processed, eventually leading to meal termination. The response of gastric VAs, to food-related stimuli, is under circadian control and fluctuates depending on the time of day. These rhythms are highly correlated with meal size, with a nadir in VA sensitivity and increase in meal size during the dark phase and a peak in sensitivity and decrease in meal size during the light phase in mice. These rhythms are disrupted in diet-induced obesity and simulated shift work conditions and associated with disrupted food intake patterns. In diet-induced obesity the dampened responses during the light phase are not simply reversed by reverting back to a normal diet. However, time restricted feeding prevents loss of diurnal rhythms in VA signalling in high fat diet-fed mice and, therefore, provides a potential strategy to reset diurnal rhythms in VA signalling to a pre-obese phenotype. This review discusses the role of the circadian system in the regulation of gastrointestinal VA signals and the impact of factors, such as diet-induced obesity and shift work, on these rhythms.
Collapse
Affiliation(s)
- Amanda J. Page
- Adelaide Medical School, University of Adelaide, Adelaide, SA 5000, Australia; ; Tel.: +61-8-8128-4840
- Nutrition, Diabetes and Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institution (SAHMRI), Adelaide, SA 5000, Australia
| |
Collapse
|
31
|
Chrobok L, Wojcik M, Klich JD, Pradel K, Lewandowski MH, Piggins HD. Phasic Neuronal Firing in the Rodent Nucleus of the Solitary Tract ex vivo. Front Physiol 2021; 12:638695. [PMID: 33762969 PMCID: PMC7982836 DOI: 10.3389/fphys.2021.638695] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/10/2021] [Indexed: 02/02/2023] Open
Abstract
Phasic pattern of neuronal activity has been previously described in detail for magnocellular vasopressin neurons in the hypothalamic paraventricular and supraoptic nuclei. This characteristic bistable pattern consists of alternating periods of electrical silence and elevated neuronal firing, implicated in neuropeptide release. Here, with the use of multi-electrode array recordings ex vivo, we aimed to study the firing pattern of neurons in the nucleus of the solitary tract (NTS) - the brainstem hub for homeostatic, cardio-vascular, and metabolic processes. Our recordings from the mouse and rat hindbrain slices reveal the phasic activity pattern to be displayed by a subset of neurons in the dorsomedial NTS subjacent to the area postrema (AP), with the inter-spike interval distribution closely resembling that reported for phasic magnocellular vasopressin cells. Additionally, we provide interspecies comparison, showing higher phasic frequency and firing rate of phasic NTS cells in mice compared to rats. Further, we describe daily changes in their firing rate and pattern, peaking at the middle of the night. Last, we reveal these phasic cells to be sensitive to α 2 adrenergic receptors activation and to respond to electrical stimulation of the AP. This study provides a comprehensive description of the phasic neuronal activity in the rodent NTS and identifies it as a potential downstream target of the AP noradrenergic system.
Collapse
Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland.,Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Michal Wojcik
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Jasmin Daniela Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Marian Henryk Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Hugh David Piggins
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
32
|
Van Drunen R, Eckel-Mahan K. Circadian Rhythms of the Hypothalamus: From Function to Physiology. Clocks Sleep 2021; 3:189-226. [PMID: 33668705 PMCID: PMC7931002 DOI: 10.3390/clockssleep3010012] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/11/2021] [Accepted: 02/18/2021] [Indexed: 12/13/2022] Open
Abstract
The nearly ubiquitous expression of endogenous 24 h oscillations known as circadian rhythms regulate the timing of physiological functions in the body. These intrinsic rhythms are sensitive to external cues, known as zeitgebers, which entrain the internal biological processes to the daily environmental changes in light, temperature, and food availability. Light directly entrains the master clock, the suprachiasmatic nucleus (SCN) which lies in the hypothalamus of the brain and is responsible for synchronizing internal rhythms. However, recent evidence underscores the importance of other hypothalamic nuclei in regulating several essential rhythmic biological functions. These extra-SCN hypothalamic nuclei also express circadian rhythms, suggesting distinct regions that oscillate either semi-autonomously or independent of SCN innervation. Concurrently, the extra-SCN hypothalamic nuclei are also sensitized to fluctuations in nutrient and hormonal signals. Thus, food intake acts as another powerful entrainer for the hypothalamic oscillators' mediation of energy homeostasis. Ablation studies and genetic mouse models with perturbed extra-SCN hypothalamic nuclei function reveal their critical downstream involvement in an array of functions including metabolism, thermogenesis, food consumption, thirst, mood and sleep. Large epidemiological studies of individuals whose internal circadian cycle is chronically disrupted reveal that disruption of our internal clock is associated with an increased risk of obesity and several neurological diseases and disorders. In this review, we discuss the profound role of the extra-SCN hypothalamic nuclei in rhythmically regulating and coordinating body wide functions.
Collapse
Affiliation(s)
- Rachel Van Drunen
- MD Anderson UTHealth School Graduate School of Biomedical Sciences, Houston TX 77030, USA;
- Brown Foundation Institute of Molecular Medicine University of Texas McGovern Medical School, Houston, TX 77030, USA
| | - Kristin Eckel-Mahan
- MD Anderson UTHealth School Graduate School of Biomedical Sciences, Houston TX 77030, USA;
- Brown Foundation Institute of Molecular Medicine University of Texas McGovern Medical School, Houston, TX 77030, USA
| |
Collapse
|
33
|
Gopalakrishnan S, Kannan NN. Only time will tell: the interplay between circadian clock and metabolism. Chronobiol Int 2020; 38:149-167. [PMID: 33345624 DOI: 10.1080/07420528.2020.1842436] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In most organisms ranging from cyanobacteria to humans, the endogenous timekeeping system temporally coordinates the behavioral, physiological, and metabolic processes with a periodicity close to 24 h. The timing of these daily rhythms is orchestrated by the synchronized oscillations of both the central pacemaker in the brain and the peripheral clocks located across multiple organs and tissues. A growing body of evidence suggests that the central circadian clock and peripheral clocks residing in the metabolically active tissues are incredibly well coordinated to confer coherent metabolic homeostasis. The interplay between nutrient metabolism and circadian rhythms can occur at various levels supported by the molecular clock network, multiple systemic mechanisms, and the neuroendocrine signaling pathways. While studies suggest the reciprocal regulation between circadian clock and metabolism, it is important to understand the precise mechanisms and the underlying pathways involved in the cross-talk among circadian oscillators and diverse metabolic networks. In addition to the internal synchronization of the metabolic rhythms, feeding time is considered as a potential external synchronization cue that fine tunes the timing of the circadian rhythms in metabolic peripheral clocks. A deeper understanding of how the timing of food intake and the diet composition drive the tissue-specific metabolic rhythms across the body is concomitantly important to develop novel therapeutic strategies for the metabolic disorders arising from circadian misalignment. This review summarizes the recent advancements in the circadian clock regulation of nutrient metabolism and discusses the current understanding of the metabolic feedback signals that link energy metabolism with the circadian clock.
Collapse
Affiliation(s)
- Swetha Gopalakrishnan
- Chronobiology Laboratory, School of Biology, Indian Institute of Science Education and Research (IISER) , Thiruvananthapuram, India
| | - Nisha N Kannan
- Chronobiology Laboratory, School of Biology, Indian Institute of Science Education and Research (IISER) , Thiruvananthapuram, India
| |
Collapse
|
34
|
Flanagan A, Bechtold DA, Pot GK, Johnston JD. Chrono-nutrition: From molecular and neuronal mechanisms to human epidemiology and timed feeding patterns. J Neurochem 2020; 157:53-72. [PMID: 33222161 DOI: 10.1111/jnc.15246] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 02/06/2023]
Abstract
The circadian timing system governs daily biological rhythms, synchronising physiology and behaviour to the temporal world. External time cues, including the light-dark cycle and timing of food intake, provide daily signals for entrainment of the central, master circadian clock in the hypothalamic suprachiasmatic nuclei (SCN), and of metabolic rhythms in peripheral tissues, respectively. Chrono-nutrition is an emerging field building on the relationship between temporal eating patterns, circadian rhythms, and metabolic health. Evidence from both animal and human research demonstrates adverse metabolic consequences of circadian disruption. Conversely, a growing body of evidence indicates that aligning food intake to periods of the day when circadian rhythms in metabolic processes are optimised for nutrition may be effective for improving metabolic health. Circadian rhythms in glucose and lipid homeostasis, insulin responsiveness and sensitivity, energy expenditure, and postprandial metabolism, may favour eating patterns characterised by earlier temporal distribution of energy. This review details the molecular basis for metabolic clocks, the regulation of feeding behaviour, and the evidence for meal timing as an entraining signal for the circadian system in animal models. The epidemiology of temporal eating patterns in humans is examined, together with evidence from human intervention studies investigating the metabolic effects of morning compared to evening energy intake, and emerging chrono-nutrition interventions such as time-restricted feeding. Chrono-nutrition may have therapeutic application for individuals with and at-risk of metabolic disease and convey health benefits within the general population.
Collapse
Affiliation(s)
- Alan Flanagan
- Section of Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK.,Section of Metabolic Medicine, Food and Macronutrients, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - David A Bechtold
- Division of Diabetes, Endocrinology & Gastroenterology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Gerda K Pot
- Department of Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,Nutrition and Health Department, Louis Bolk Instituut, Bunnik, the Netherlands
| | - Jonathan D Johnston
- Section of Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| |
Collapse
|
35
|
Sorrell J, Yates E, Rivir M, Woods SC, Hogenesch JB, Perez-Tilve D. The central melanocortin system mediates the benefits of time-restricted feeding on energy balance. Physiol Behav 2020; 227:113132. [DOI: 10.1016/j.physbeh.2020.113132] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/06/2020] [Accepted: 08/07/2020] [Indexed: 12/28/2022]
|
36
|
Bell BJ, Wang AA, Kim DW, Xiong J, Blackshaw S, Wu MN. Characterization of mWake expression in the murine brain. J Comp Neurol 2020; 529:1954-1987. [PMID: 33140455 DOI: 10.1002/cne.25066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 01/24/2023]
Abstract
Structure-function analyses of the mammalian brain have historically relied on anatomically-based approaches. In these investigations, physical, chemical, or electrolytic lesions of anatomical structures are applied, and the resulting behavioral or physiological responses assayed. An alternative approach is to focus on the expression pattern of a molecule whose function has been characterized and then use genetic intersectional methods to optogenetically or chemogenetically manipulate distinct circuits. We previously identified WIDE AWAKE (WAKE) in Drosophila, a clock output molecule that mediates the temporal regulation of sleep onset and sleep maintenance. More recently, we have studied the mouse homolog, mWAKE/ANKFN1, and our data suggest that its basic role in the circadian regulation of arousal is conserved. Here, we perform a systematic analysis of the expression pattern of mWake mRNA, protein, and cells throughout the adult mouse brain. We find that mWAKE labels neurons in a restricted, but distributed manner, in multiple regions of the hypothalamus (including the suprachiasmatic nucleus, dorsomedial hypothalamus, and tuberomammillary nucleus region), the limbic system, sensory processing nuclei, and additional specific brainstem, subcortical, and cortical areas. Interestingly, mWAKE is also observed in non-neuronal ependymal cells. In addition, to describe the molecular identities and clustering of mWake+ cells, we provide detailed analyses of single cell RNA sequencing data from the hypothalamus, a region with particularly significant mWAKE expression. These findings lay the groundwork for future studies into the potential role of mWAKE+ cells in the rhythmic control of diverse behaviors and physiological processes.
Collapse
Affiliation(s)
- Benjamin J Bell
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Annette A Wang
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Dong Won Kim
- Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jiali Xiong
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University, Baltimore, Maryland, USA
| | - Seth Blackshaw
- Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, USA
| | - Mark N Wu
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, USA
| |
Collapse
|
37
|
Bedont JL, Iascone DM, Sehgal A. The Lineage Before Time: Circadian and Nonclassical Clock Influences on Development. Annu Rev Cell Dev Biol 2020; 36:469-509. [PMID: 33021821 PMCID: PMC10826104 DOI: 10.1146/annurev-cellbio-100818-125454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Diverse factors including metabolism, chromatin remodeling, and mitotic kinetics influence development at the cellular level. These factors are well known to interact with the circadian transcriptional-translational feedback loop (TTFL) after its emergence. What is only recently becoming clear, however, is how metabolism, mitosis, and epigenetics may become organized in a coordinated cyclical precursor signaling module in pluripotent cells prior to the onset of TTFL cycling. We propose that both the precursor module and the TTFL module constrain cellular identity when they are active during development, and that the emergence of these modules themselves is a key lineage marker. Here we review the component pathways underlying these ideas; how proliferation, specification, and differentiation decisions in both developmental and adult stem cell populations are or are not regulated by the classical TTFL; and emerging evidence that we propose implies a primordial clock that precedes the classical TTFL and influences early developmental decisions.
Collapse
Affiliation(s)
- Joseph Lewis Bedont
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
| | - Daniel Maxim Iascone
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
| | - Amita Sehgal
- Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
- The Howard Hughes Medical Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| |
Collapse
|
38
|
Harding C, Bechtold DA, Brown TM. Suprachiasmatic nucleus-dependent and independent outputs driving rhythmic activity in hypothalamic and thalamic neurons. BMC Biol 2020; 18:134. [PMID: 32998726 PMCID: PMC7528611 DOI: 10.1186/s12915-020-00871-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/17/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Daily variations in mammalian physiology are under control of a central clock in the suprachiasmatic nucleus (SCN). SCN timing signals are essential for coordinating cellular clocks and associated circadian variations in cell and tissue function across the body; however, direct SCN projections primarily target a restricted set of hypothalamic and thalamic nuclei involved in physiological and behavioural control. The role of the SCN in driving rhythmic activity in these targets remains largely unclear. Here, we address this issue via multielectrode recording and manipulations of SCN output in adult mouse brain slices. RESULTS Electrical stimulation identifies cells across the midline hypothalamus and ventral thalamus that receive inhibitory input from the SCN and/or excitatory input from the retina. Optogenetic manipulations confirm that SCN outputs arise from both VIP and, more frequently, non-VIP expressing cells and that both SCN and retinal projections almost exclusively target GABAergic downstream neurons. The majority of midline hypothalamic and ventral thalamic neurons exhibit circadian variation in firing and those receiving inhibitory SCN projections consistently exhibit peak activity during epochs when SCN output is low. Physical removal of the SCN confirms that neuronal rhythms in ~ 20% of the recorded neurons rely on central clock input but also reveals many neurons that can express circadian variation in firing independent of any SCN input. CONCLUSIONS We identify cell populations across the midline hypothalamus and ventral thalamus exhibiting SCN-dependent and independent rhythms in neural activity, providing new insight into the mechanisms by which the circadian system generates daily physiological rhythms.
Collapse
Affiliation(s)
- Court Harding
- Centre for Biological Timing, Faculty of Medicine, Biology and Health, University of Manchester, Manchester, UK
| | - David A Bechtold
- Centre for Biological Timing, Faculty of Medicine, Biology and Health, University of Manchester, Manchester, UK
| | - Timothy M Brown
- Centre for Biological Timing, Faculty of Medicine, Biology and Health, University of Manchester, Manchester, UK.
| |
Collapse
|
39
|
Abstract
While neurons and circuits are almost unequivocally considered to be the computational units and actuators of behavior, a complete understanding of the nervous system must incorporate glial cells. Far beyond a copious but passive substrate, glial influence is inextricable from neuronal physiology, whether during developmental guidance and synaptic shaping or through the trophic support, neurotransmitter and ion homeostasis, cytokine signaling and immune function, and debris engulfment contributions that this class provides throughout an organism's life. With such essential functions, among a growing literature of nuanced roles, it follows that glia are consequential to behavior in adult animals, with novel genetic tools allowing for the investigation of these phenomena in living organisms. We discuss here the relevance of glia for maintaining circadian rhythms and also for serving functions of sleep.
Collapse
Affiliation(s)
- Gregory Artiushin
- Chronobiology and Sleep Institute, Perelman School of Medicine, and Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
| | - Amita Sehgal
- Chronobiology and Sleep Institute, Perelman School of Medicine, and Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
| |
Collapse
|
40
|
Northeast RC, Vyazovskiy VV, Bechtold DA. Eat, sleep, repeat: the role of the circadian system in balancing sleep-wake control with metabolic need. CURRENT OPINION IN PHYSIOLOGY 2020; 15:183-191. [PMID: 32617440 PMCID: PMC7323618 DOI: 10.1016/j.cophys.2020.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Feeding and sleep are behaviours fundamental to survival, and as such are subject to powerful homeostatic control. Of course, these are mutually exclusive behaviours, and therefore require coordinated temporal organisation to ensure that both energy demands and sleep need are met. Under optimal conditions, foraging/feeding and sleep can be simply partitioned to appropriate phases of the circadian cycle so that they are in suitable alignment with the external environment. However, under conditions of negative energy balance, increased foraging activity must be balanced against sleep requirements and energy conservation. In mammals and many other species, neural circuits that regulate sleep and energy balance are intimately and reciprocally linked. Here, we examine this circuitry, discuss how homeostatic regulation and temporal patterning of sleep are modulated by altered food availability, and describe the role of circadian system in adaptation to metabolic stress.
Collapse
Affiliation(s)
- Rebecca C Northeast
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - David A Bechtold
- Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| |
Collapse
|
41
|
Chrobok L, Northeast RC, Myung J, Cunningham PS, Petit C, Piggins HD. Timekeeping in the hindbrain: a multi-oscillatory circadian centre in the mouse dorsal vagal complex. Commun Biol 2020; 3:225. [PMID: 32385329 PMCID: PMC7210107 DOI: 10.1038/s42003-020-0960-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/21/2020] [Indexed: 02/06/2023] Open
Abstract
Metabolic and cardiovascular processes controlled by the hindbrain exhibit 24 h rhythms, but the extent to which the hindbrain possesses endogenous circadian timekeeping is unresolved. Here we provide compelling evidence that genetic, neuronal, and vascular activities of the brainstem’s dorsal vagal complex are subject to intrinsic circadian control with a crucial role for the connection between its components in regulating their rhythmic properties. Robust 24 h variation in clock gene expression in vivo and neuronal firing ex vivo were observed in the area postrema (AP) and nucleus of the solitary tract (NTS), together with enhanced nocturnal responsiveness to metabolic cues. Unexpectedly, we also find functional and molecular evidence for increased penetration of blood borne molecules into the NTS at night. Our findings reveal that the hindbrain houses a local network complex of neuronal and non-neuronal autonomous circadian oscillators, with clear implications for understanding local temporal control of physiology in the brainstem. Lukasz Chrobok, Rebecca Northeast et al. show circadian variation in clock gene expression and neuronal firing within the area postrema and the nucleus of the solitary tract in mice. These regions also exhibit variation in metabolic processes and blood-brain barrier permeability across the 24 hour cycle suggesting the presence of circadian oscillators within the dorsal vagal complex.
Collapse
Affiliation(s)
- Lukasz Chrobok
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK.,Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387, Krakow, Poland
| | - Rebecca C Northeast
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Jihwan Myung
- Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, No.172-1 Sec. 2 Keelung Road, Da'an District, Taipei, 106, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, No. 250, Wu-Hsing Street, Taipei, 110, Taiwan.,Brain and Consciousness Research Centre, Taipei Medical University-Shuang Ho Hospital, Ministry of Health and Welfare, No. 291 Zhongzheng Road, Zhonghe District, New Taipei City, 235, Taiwan
| | - Peter S Cunningham
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Cheryl Petit
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Hugh D Piggins
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK. .,School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, BS8 1TD, UK.
| |
Collapse
|
42
|
Begemann K, Neumann A, Oster H. Regulation and function of extra-SCN circadian oscillators in the brain. Acta Physiol (Oxf) 2020; 229:e13446. [PMID: 31965726 DOI: 10.1111/apha.13446] [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: 10/29/2019] [Revised: 01/14/2020] [Accepted: 01/16/2020] [Indexed: 12/12/2022]
Abstract
Most organisms evolved endogenous, so called circadian clocks as internal timekeeping mechanisms allowing them to adapt to recurring changes in environmental demands brought about by 24-hour rhythms such as the light-dark cycle, temperature variations or changes in humidity. The mammalian circadian clock system is based on cellular oscillators found in all tissues of the body that are organized in a hierarchical fashion. A master pacemaker located in the suprachiasmatic nucleus (SCN) synchronizes peripheral tissue clocks and extra-SCN oscillators in the brain with each other and with external time. Different time cues (so called Zeitgebers) such as light, food intake, activity and hormonal signals reset the clock system through the SCN or by direct action at the tissue clock level. While most studies on non-SCN clocks so far have focused on peripheral tissues, several extra-SCN central oscillators were characterized in terms of circadian rhythm regulation and output. Some of them are directly innervated by the SCN pacemaker, while others receive indirect input from the SCN via other neural circuits or extra-brain structures. The specific physiological function of these non-SCN brain oscillators as well as their role in the regulation of the circadian clock network remains understudied. In this review we summarize our current knowledge about the regulation and function of extra-SCN circadian oscillators in different brain regions and devise experimental approaches enabling us to unravel the organization of the circadian clock network in the central nervous system.
Collapse
Affiliation(s)
| | | | - Henrik Oster
- Institute of Neurobiology University of Lübeck Lübeck Germany
| |
Collapse
|
43
|
Abstract
Feeding schedules entrain circadian clocks in multiple brain regions and most peripheral organs and tissues, thereby synchronizing daily rhythms of foraging behavior and physiology with times of day when food is most likely to be found. Entrainment of peripheral clocks to mealtime is accomplished by multiple feeding-related signals, including absorbed nutrients and metabolic hormones, acting in parallel or in series in a tissue-specific fashion. Less is known about the signals that synchronize circadian clocks in the brain with feeding time, some of which are presumed to generate the circadian rhythms of food-anticipatory activity that emerge when food is restricted to a fixed daily mealtime. In this commentary, I consider the possibility that food-anticipatory activity rhythms are driven or entrained by circulating ghrelin, ketone bodies or insulin. While evidence supports the potential of these signals to participate in the induction or amount of food-anticipatory behavior, it falls short of establishing either a necessary or sufficient role or accounting for circadian properties of anticipatory rhythms. The availability of multiple, circulating signals by which circadian oscillators in many brain regions might entrain to mealtime has supported a view that food-anticipatory rhythms of behavior are mediated by a broadly distributed system of clocks. The evidence, however, does not rule out the possibility that multiple peripheral and central food-entrained oscillators and feeding-related signals converge on circadian oscillators in a defined location which ultimately set the phase and gate the expression of anticipatory activity rhythms. A candidate location is the dorsal striatum, a core component of the neural system which mediates reward, motivation and action and which contains circadian oscillators entrainable by food and dopaminergic drugs. Systemic metabolic signals, such as ghrelin, ketones and insulin, may participate in circadian food anticipation to the extent that they modulate dopamine afferents to circadian clocks in this area.
Collapse
Affiliation(s)
- Ralph E Mistlberger
- Department of Psychology, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A2S6, Canada
| |
Collapse
|
44
|
Tsang AH, Koch CE, Kiehn JT, Schmidt CX, Oster H. An adipokine feedback regulating diurnal food intake rhythms in mice. eLife 2020; 9:55388. [PMID: 32644041 PMCID: PMC7375813 DOI: 10.7554/elife.55388] [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: 01/23/2020] [Accepted: 07/08/2020] [Indexed: 12/15/2022] Open
Abstract
Endogenous circadian clocks have evolved to anticipate 24 hr rhythms in environmental demands. Recent studies suggest that circadian rhythm disruption is a major risk factor for the development of metabolic disorders in humans. Conversely, alterations in energy state can disrupt circadian rhythms of behavior and physiology, creating a vicious circle of metabolic dysfunction. How peripheral energy state affects diurnal food intake, however, is still poorly understood. We here show that the adipokine adiponectin (ADIPOQ) regulates diurnal feeding rhythms through clocks in energy regulatory centers of the mediobasal hypothalamus (MBH). Adipoq-deficient mice show increased rest phase food intake associated with disrupted transcript rhythms of clock and appetite-regulating genes in the MBH. ADIPOQ regulates MBH clocks via AdipoR1-mediated upregulation of the core clock gene Bmal1. BMAL1, in turn, controls expression of orexigenic neuropeptide expression in the MBH. Together, these data reveal a systemic metabolic circuit to regulate central circadian clocks and energy intake.
Collapse
Affiliation(s)
- Anthony H Tsang
- Circadian Rhythms Group, Max Planck Institute for Biophysical ChemistryGöttingenGermany,Institute of Neurobiology, University of LübeckLübeckGermany
| | | | | | | | - Henrik Oster
- Circadian Rhythms Group, Max Planck Institute for Biophysical ChemistryGöttingenGermany,Institute of Neurobiology, University of LübeckLübeckGermany
| |
Collapse
|
45
|
Northeast RC, Chrobok L, Hughes ATL, Petit C, Piggins HD. Keeping time in the lamina terminalis: Novel oscillator properties of forebrain sensory circumventricular organs. FASEB J 2019; 34:974-987. [PMID: 31914667 PMCID: PMC6972491 DOI: 10.1096/fj.201901111r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/19/2019] [Accepted: 10/15/2019] [Indexed: 12/11/2022]
Abstract
Drinking behavior and osmotic regulatory mechanisms exhibit clear daily variation which is necessary for achieving the homeostatic osmolality. In mammals, the master clock in the brain's suprachiasmatic nuclei has long been held as the main driver of circadian (24 h) rhythms in physiology and behavior. However, rhythmic clock gene expression in other brain sites raises the possibility of local circadian control of neural activity and function. The subfornical organ (SFO) and the organum vasculosum laminae terminalis (OVLT) are two sensory circumventricular organs (sCVOs) that play key roles in the central control of thirst and water homeostasis, but the extent to which they are subject to intrinsic circadian control remains undefined. Using a combination of ex vivo bioluminescence and in vivo gene expression, we report for the first time that the SFO contains an unexpectedly robust autonomous clock with unusual spatiotemporal characteristics in core and noncore clock gene expression. Furthermore, putative single-cell oscillators in the SFO and OVLT are strongly rhythmic and require action potential-dependent communication to maintain synchrony. Our results reveal that these thirst-controlling sCVOs possess intrinsic circadian timekeeping properties and raise the possibility that these contribute to daily regulation of drinking behavior.
Collapse
Affiliation(s)
- Rebecca C Northeast
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Lukasz Chrobok
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Alun T L Hughes
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Cheryl Petit
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Hugh D Piggins
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| |
Collapse
|
46
|
Mendoza J. Food intake and addictive-like eating behaviors: Time to think about the circadian clock(s). Neurosci Biobehav Rev 2019; 106:122-132. [DOI: 10.1016/j.neubiorev.2018.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 06/25/2018] [Accepted: 07/03/2018] [Indexed: 12/25/2022]
|
47
|
Abstract
Feeding, which is essential for all animals, is regulated by homeostatic mechanisms. In addition, food consumption is temporally coordinated by the brain over the circadian (~24 h) cycle. A network of circadian clocks set daily windows during which food consumption can occur. These daily windows mostly overlap with the active phase. Brain clocks that ensure the circadian control of food intake include a master light-entrainable clock in the suprachiasmatic nuclei of the hypothalamus and secondary clocks in hypothalamic and brainstem regions. Metabolic hormones, circulating nutrients and visceral neural inputs transmit rhythmic cues that permit (via close and reciprocal molecular interactions that link metabolic processes and circadian clockwork) brain and peripheral organs to be synchronized to feeding time. As a consequence of these complex interactions, growing evidence shows that chronodisruption and mistimed eating have deleterious effects on metabolic health. Conversely, eating, even eating an unbalanced diet, during the normal active phase reduces metabolic disturbances. Therefore, in addition to energy intake and dietary composition, appropriately timed meal patterns are critical to prevent circadian desynchronization and limit metabolic risks. This Review provides insight into the dual modulation of food intake by homeostatic and circadian processes, describes the mechanisms regulating feeding time and highlights the beneficial effects of correctly timed eating, as opposed to the negative metabolic consequences of mistimed eating.
Collapse
Affiliation(s)
- Etienne Challet
- Circadian clocks and metabolism team, Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, Strasbourg, France.
| |
Collapse
|
48
|
Myung J, Wu MY, Lee CY, Rahim AR, Truong VH, Wu D, Piggins HD, Wu MS. The Kidney Clock Contributes to Timekeeping by the Master Circadian Clock. Int J Mol Sci 2019; 20:ijms20112765. [PMID: 31195684 PMCID: PMC6600447 DOI: 10.3390/ijms20112765] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 06/01/2019] [Accepted: 06/03/2019] [Indexed: 01/11/2023] Open
Abstract
The kidney harbors one of the strongest circadian clocks in the body. Kidney failure has long been known to cause circadian sleep disturbances. Using an adenine-induced model of chronic kidney disease (CKD) in mice, we probe the possibility that such sleep disturbances originate from aberrant circadian rhythms in kidney. Under the CKD condition, mice developed unstable behavioral circadian rhythms. When observed in isolation in vitro, the pacing of the master clock, the suprachiasmatic nucleus (SCN), remained uncompromised, while the kidney clock became a less robust circadian oscillator with a longer period. We find this analogous to the silencing of a strong slave clock in the brain, the choroid plexus, which alters the pacing of the SCN. We propose that the kidney also contributes to overall circadian timekeeping at the whole-body level, through bottom-up feedback in the hierarchical structure of the mammalian circadian clocks.
Collapse
Affiliation(s)
- Jihwan Myung
- Graduate Institute of Mind, Brain and Consciousness, Taipei Medical University, Taipei 11031, Taiwan.
- Brain and Consciousness Research Center, Taipei Medical University-Shuang Ho Hospital, New Taipei City 23561, Taiwan.
- Laboratory of Braintime, Taipei Medical University, Taipei 11031 & Shuang Ho Hospital, New Taipei City 23561, Taiwan.
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Okinawa 904-0495, Japan.
| | - Mei-Yi Wu
- Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taipei 11031, Taiwan.
- Division of Nephrology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei 10672, Taiwan.
| | - Chun-Ya Lee
- Laboratory of Braintime, Taipei Medical University, Taipei 11031 & Shuang Ho Hospital, New Taipei City 23561, Taiwan.
- Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taipei 11031, Taiwan.
| | - Amalia Ridla Rahim
- Graduate Institute of Mind, Brain and Consciousness, Taipei Medical University, Taipei 11031, Taiwan.
- Brain and Consciousness Research Center, Taipei Medical University-Shuang Ho Hospital, New Taipei City 23561, Taiwan.
- Laboratory of Braintime, Taipei Medical University, Taipei 11031 & Shuang Ho Hospital, New Taipei City 23561, Taiwan.
| | - Vuong Hung Truong
- Graduate Institute of Mind, Brain and Consciousness, Taipei Medical University, Taipei 11031, Taiwan.
- Brain and Consciousness Research Center, Taipei Medical University-Shuang Ho Hospital, New Taipei City 23561, Taiwan.
- Laboratory of Braintime, Taipei Medical University, Taipei 11031 & Shuang Ho Hospital, New Taipei City 23561, Taiwan.
| | - Dean Wu
- Department of Neurology, Shuang Ho Hospital, New Taipei City 23561, Taiwan.
- Department of Neurology, Taipei Medical University, Taipei 11031, Taiwan.
| | - Hugh David Piggins
- School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK.
| | - Mai-Szu Wu
- Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taipei 11031, Taiwan.
- Division of Nephrology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
| |
Collapse
|
49
|
Mendoza J. Eating Rewards the Gears of the Clock. Trends Endocrinol Metab 2019; 30:299-311. [PMID: 30935670 DOI: 10.1016/j.tem.2019.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 02/26/2019] [Accepted: 03/07/2019] [Indexed: 12/18/2022]
Abstract
Eating behavior is regulated by metabolic and hedonic brain networks, which interact with each other to balance the physiological regulation of hunger and satiety. The daily balance of this regulation is controlled by the central circadian clock. Importantly, metabolic and reward properties of food impact the functioning of circadian clocks, altering the oscillatory activity of the molecular clockwork and circadian rhythms. However, when feeding (metabolic or reward) is timed, the whole circadian system is entrained. Furthermore, besides synchronizing the clock, the timing of both metabolic and reward eating might be crucial for health, to improve circadian physiology, as well as to treat metabolic (e.g., diabetes, obesity) and neurological diseases (e.g., mental, neurodegenerative).
Collapse
Affiliation(s)
- Jorge Mendoza
- Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique, CNRS UPR-3212, 8 allée du Général Rouvillois, 67000 Strasbourg, France.
| |
Collapse
|
50
|
Abstract
OBJECTIVE The goal of this narrative review is to provide an overview of migraine pathophysiology, with an emphasis on the role of calcitonin gene-related peptide (CGRP) within the context of the trigeminovascular system. BACKGROUND Migraine is a prevalent and disabling neurological disease that is characterized in part by intense, throbbing, and unilateral headaches. Despite recent advances in understanding its pathophysiology, migraine still represents an unmet medical need, as it is often underrecognized and undertreated. Although CGRP has been known to play a pivotal role in migraine for the last 2 decades, this has now received more interest spurred by the early clinical successes of drugs that block CGRP signaling in the trigeminovascular system. DESIGN This narrative review presents an update on the role of CGRP within the trigeminovascular system. PubMed searches were used to find recent (ie, 2016 to November 2018) published articles presenting new study results. Review articles are also included not as primary references but to bring these to the attention of the reader. Original research is referenced in describing the core of the narrative, and review articles are used to support ancillary points. RESULTS The trigeminal ganglion neurons provide the connection between the periphery, stemming from the interface between the primary afferent fibers of the trigeminal ganglion and the meningeal vasculature and the central terminals in the trigeminal nucleus caudalis. The neuropeptide CGRP is abundant in trigeminal ganglion neurons, and is released from the peripheral nerve and central nerve terminals as well as being secreted within the trigeminal ganglion. Release of CGRP from the peripheral terminals initiates a cascade of events that include increased synthesis of nitric oxide and sensitization of the trigeminal nerves. Secreted CGRP in the trigeminal ganglion interacts with adjacent neurons and satellite glial cells to perpetuate peripheral sensitization, and can drive central sensitization of the second-order neurons. A shift in central sensitization from activity-dependent to activity-independent central sensitization may indicate a mechanism driving the progression of episodic migraine to chronic migraine. The pathophysiology of cluster headache is much more obscure than that of migraine, but emerging evidence suggests that it may also involve hypersensitivity of the trigeminovascular system. Ongoing clinical studies with therapies targeted at CGRP will provide additional, valuable insights into the pathophysiology of this disorder. CONCLUSIONS CGRP plays an essential role in the pathophysiology of migraine. Treatments that interfere with the functioning of CGRP in the peripheral trigeminal system are effective against migraine. Blocking sensitization of the trigeminal nerve by attenuating CGRP activity in the periphery may be sufficient to block a migraine attack. Additionally, the potential exists that this therapeutic strategy may also alleviate cluster headache as well.
Collapse
Affiliation(s)
- Smriti Iyengar
- Eli Lilly and CompanyIndianapolisINUSA
- Present address:
Indiana University School of MedicineIndianapolisINUSA
| | | | | | | |
Collapse
|