151
|
Ono D, Honma S, Nakajima Y, Kuroda S, Enoki R, Honma KI. Dissociation of Per1 and Bmal1 circadian rhythms in the suprachiasmatic nucleus in parallel with behavioral outputs. Proc Natl Acad Sci U S A 2017; 114:E3699-E3708. [PMID: 28416676 PMCID: PMC5422828 DOI: 10.1073/pnas.1613374114] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The temporal order of physiology and behavior in mammals is primarily regulated by the circadian pacemaker located in the hypothalamic suprachiasmatic nucleus (SCN). Taking advantage of bioluminescence reporters, we monitored the circadian rhythms of the expression of clock genes Per1 and Bmal1 in the SCN of freely moving mice and found that the rate of phase shifts induced by a single light pulse was different in the two rhythms. The Per1-luc rhythm was phase-delayed instantaneously by the light presented at the subjective evening in parallel with the activity onset of behavioral rhythm, whereas the Bmal1-ELuc rhythm was phase-delayed gradually, similar to the activity offset. The dissociation was confirmed in cultured SCN slices of mice carrying both Per1-luc and Bmal1-ELuc reporters. The two rhythms in a single SCN slice showed significantly different periods in a long-term (3 wk) culture and were internally desynchronized. Regional specificity in the SCN was not detected for the period of Per1-luc and Bmal1-ELuc rhythms. Furthermore, neither is synchronized with circadian intracellular Ca2+ rhythms monitored by a calcium indicator, GCaMP6s, or with firing rhythms monitored on a multielectrode array dish, although the coupling between the circadian firing and Ca2+ rhythms persisted during culture. These findings indicate that the expressions of two key clock genes, Per1 and Bmal1, in the SCN are regulated in such a way that they may adopt different phases and free-running periods relative to each other and are respectively associated with the expression of activity onset and offset.
Collapse
Affiliation(s)
- Daisuke Ono
- Photonic Bioimaging Section, Research Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan;
| | - Sato Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan;
| | - Yoshihiro Nakajima
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | - Shigeru Kuroda
- Research Institute for Electronic Science, Hokkaido University, Sapporo, 001-0020, Japan
| | - Ryosuke Enoki
- Photonic Bioimaging Section, Research Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Ken-Ichi Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
| |
Collapse
|
152
|
Serotonin neurons in the dorsal raphe mediate the anticataplectic action of orexin neurons by reducing amygdala activity. Proc Natl Acad Sci U S A 2017; 114:E3526-E3535. [PMID: 28396432 DOI: 10.1073/pnas.1614552114] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Narcolepsy is a sleep disorder caused by the loss of orexin (hypocretin)-producing neurons and marked by excessive daytime sleepiness and a sudden weakening of muscle tone, or cataplexy, often triggered by strong emotions. In a mouse model for narcolepsy, we previously demonstrated that serotonin neurons of the dorsal raphe nucleus (DRN) mediate the suppression of cataplexy-like episodes (CLEs) by orexin neurons. Using an optogenetic tool, in this paper we show that the acute activation of DRN serotonin neuron terminals in the amygdala, but not in nuclei involved in regulating rapid eye-movement sleep and atonia, suppressed CLEs. Not only did stimulating serotonin nerve terminals reduce amygdala activity, but the chemogenetic inhibition of the amygdala using designer receptors exclusively activated by designer drugs also drastically decreased CLEs, whereas chemogenetic activation increased them. Moreover, the optogenetic inhibition of serotonin nerve terminals in the amygdala blocked the anticataplectic effects of orexin signaling in DRN serotonin neurons. Taken together, the results suggest that DRN serotonin neurons, as a downstream target of orexin neurons, inhibit cataplexy by reducing the activity of amygdala as a center for emotional processing.
Collapse
|
153
|
Yang JJ, Cheng RC, Cheng PC, Wang YC, Huang RC. K ATP Channels Mediate Differential Metabolic Responses to Glucose Shortage of the Dorsomedial and Ventrolateral Oscillators in the Central Clock. Sci Rep 2017; 7:640. [PMID: 28377630 PMCID: PMC5428822 DOI: 10.1038/s41598-017-00699-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/08/2017] [Indexed: 12/29/2022] Open
Abstract
The suprachiasmatic nucleus (SCN) central clock comprises two coupled oscillators, with light entraining the retinorecipient vasoactive intestinal peptide (VIP)-positive ventrolateral oscillator, which then entrains the arginine vasopressin (AVP)-positive dorsomedial oscillator. While glucose availability is known to alter photic entrainment, it is unclear how the SCN neurones respond to metabolic regulation and whether the two oscillators respond differently. Here we show that the ATP-sensitive K+ (KATP) channel mediates differential responses to glucose shortage of the two oscillators. RT-PCR and electrophysiological results suggested the presence of Kir6.2/SUR1 KATP channels in the SCN neurones. Immunostaining revealed preferential distribution of Kir6.2 in the dorsomedial subregion and selective colocalization with AVP. Whole cell recordings with ATP-free pipette solution indicated larger tolbutamide-induced depolarisation and tolbutamide-sensitive conductance in dorsal SCN (dSCN) than ventral SCN (vSCN) neurones. Tolbutamide-sensitive conductance was low under perforated patch conditions but markedly enhanced by cyanide inhibition of mitochondrial respiration. Glucoprivation produced a larger steady-state inhibition in dSCN than vSCN neurones, and importantly hypoglycemia via opening KATP channels selectively inhibited the KATP-expressing neurones. Our results suggest that the AVP-SCN oscillator may act as a glucose sensor to respond to glucose shortage while sparing the VIP-SCN oscillator to remain in synch with external light-dark cycle.
Collapse
Affiliation(s)
- Jyh-Jeen Yang
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Tao-Yuan, 33305, Taiwan
| | - Ruo-Ciao Cheng
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Tao-Yuan, 33305, Taiwan
| | - Pi-Cheng Cheng
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Tao-Yuan, 33305, Taiwan
| | - Yi-Chi Wang
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Tao-Yuan, 33305, Taiwan
| | - Rong-Chi Huang
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Tao-Yuan, 33305, Taiwan. .,Healthy Aging Research Center, Chang Gung University, Tao-Yuan, 33305, Taiwan. .,Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou Medical Center, Tao-Yuan, 33305, Taiwan.
| |
Collapse
|
154
|
Tso CF, Simon T, Greenlaw AC, Puri T, Mieda M, Herzog ED. Astrocytes Regulate Daily Rhythms in the Suprachiasmatic Nucleus and Behavior. Curr Biol 2017; 27:1055-1061. [PMID: 28343966 DOI: 10.1016/j.cub.2017.02.037] [Citation(s) in RCA: 196] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 02/09/2017] [Accepted: 02/15/2017] [Indexed: 12/30/2022]
Abstract
Astrocytes are active partners in neural information processing [1, 2]. However, the roles of astrocytes in regulating behavior remain unclear [3, 4]. Because astrocytes have persistent circadian clock gene expression and ATP release in vitro [5-8], we hypothesized that they regulate daily rhythms in neurons and behavior. Here, we demonstrated that daily rhythms in astrocytes within the mammalian master circadian pacemaker, the suprachiasmatic nucleus (SCN), determine the period of wheel-running activity. Ablating the essential clock gene Bmal1 specifically in SCN astrocytes lengthened the circadian period of clock gene expression in the SCN and in locomotor behavior. Similarly, excision of the short-period CK1ε tau mutation specifically from SCN astrocytes resulted in lengthened rhythms in the SCN and behavior. These results indicate that astrocytes within the SCN communicate to neurons to determine circadian rhythms in physiology and in rest activity.
Collapse
Affiliation(s)
- Chak Foon Tso
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63108, USA
| | - Tatiana Simon
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63108, USA
| | - Alison C Greenlaw
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63108, USA
| | - Tanvi Puri
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63108, USA
| | - Michihiro Mieda
- Department of Molecular Neuroscience and Integrative Physiology, Kanazawa University, 920-1192 Ishikawa, Japan
| | - Erik D Herzog
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63108, USA.
| |
Collapse
|
155
|
Synchronous circadian voltage rhythms with asynchronous calcium rhythms in the suprachiasmatic nucleus. Proc Natl Acad Sci U S A 2017; 114:E2476-E2485. [PMID: 28270612 DOI: 10.1073/pnas.1616815114] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The suprachiasmatic nucleus (SCN), the master circadian clock, contains a network composed of multiple types of neurons which are thought to form a hierarchical and multioscillator system. The molecular clock machinery in SCN neurons drives membrane excitability and sends time cue signals to various brain regions and peripheral organs. However, how and at what time of the day these neurons transmit output signals remain largely unknown. Here, we successfully visualized circadian voltage rhythms optically for many days using a genetically encoded voltage sensor, ArcLightD. Unexpectedly, the voltage rhythms are synchronized across the entire SCN network of cultured slices, whereas simultaneously recorded Ca2+ rhythms are topologically specific to the dorsal and ventral regions. We further found that the temporal order of these two rhythms is cell-type specific: The Ca2+ rhythms phase-lead the voltage rhythms in AVP neurons but Ca2+ and voltage rhythms are nearly in phase in VIP neurons. We confirmed that circadian firing rhythms are also synchronous and are coupled with the voltage rhythms. These results indicate that SCN networks with asynchronous Ca2+ rhythms produce coherent voltage rhythms.
Collapse
|
156
|
Mieda M, Hasegawa E, Kessaris N, Sakurai T. Fine-Tuning Circadian Rhythms: The Importance of Bmal1 Expression in the Ventral Forebrain. Front Neurosci 2017; 11:55. [PMID: 28232786 PMCID: PMC5299009 DOI: 10.3389/fnins.2017.00055] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/25/2017] [Indexed: 01/02/2023] Open
Abstract
Although, the suprachiasmatic nucleus (SCN) of the hypothalamus acts as the central clock in mammals, the circadian expression of clock genes has been demonstrated not only in the SCN, but also in peripheral tissues and brain regions outside the SCN. However, the physiological roles of extra-SCN circadian clocks in the brain remain largely elusive. In response, we generated Nkx2.1-Bmal1−/− mice in which Bmal1, an essential clock component, was genetically deleted specifically in the ventral forebrain, including the preoptic area, nucleus of the diagonal band, and most of the hypothalamus except the SCN. In these mice, as expected, PER2::LUC oscillation was drastically attenuated in the explants of mediobasal hypothalamus, whereas it was maintained in those of the SCN. Although, Nkx2.1-Bmal1−/− mice were rhythmic and nocturnal, they showed altered patterns of locomotor activity during the night in a 12:12-h light:dark cycle and during subjective night in constant darkness. Control mice were more active during the first half than the second half of the dark phase or subjective night, whereas Nkx2.1-Bmal1−/− mice showed the opposite pattern of locomotor activity. Temporal patterns of sleep-wakefulness and feeding also changed accordingly. Such results suggest that along with mechanisms in the SCN, local Bmal1–dependent clocks in the ventral forebrain are critical for generating precise temporal patterns of circadian behaviors.
Collapse
Affiliation(s)
- Michihiro Mieda
- Department of Molecular Neuroscience and Integrative Physiology, Graduate School of Medical Sciences, Kanazawa University Kanazawa, Japan
| | - Emi Hasegawa
- Department of Molecular Neuroscience and Integrative Physiology, Graduate School of Medical Sciences, Kanazawa University Kanazawa, Japan
| | - Nicoletta Kessaris
- Department of Cell and Developmental Biology, Wolfson Institute for Biomedical Research, University College London London, UK
| | - Takeshi Sakurai
- Department of Molecular Neuroscience and Integrative Physiology, Graduate School of Medical Sciences, Kanazawa University Kanazawa, Japan
| |
Collapse
|
157
|
Enoki R, Ono D, Kuroda S, Honma S, Honma KI. Dual origins of the intracellular circadian calcium rhythm in the suprachiasmatic nucleus. Sci Rep 2017; 7:41733. [PMID: 28155916 PMCID: PMC5290527 DOI: 10.1038/srep41733] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 01/03/2017] [Indexed: 12/01/2022] Open
Abstract
In mammals, the master circadian clock is located in the suprachiasmatic nucleus (SCN), where most neurons show circadian rhythms of intracellular Ca2+ levels. However, the origin of these Ca2+ rhythms remains largely unknown. In this study, we successfully monitored the intracellular circadian Ca2+ rhythms together with the circadian PER2 and firing rhythms in a single SCN slice ex vivo, which enabled us to explore the origins. The phase relation between the circadian PER2 and Ca2+ rhythms, but not between the circadian PER2 and firing rhythms, was significantly altered in Cry1/Cry2 double knockout mice, which display a loss of intercellular synchronization in the SCN. In addition, in Cry1/Cry2 double knockout mice, circadian Ca2+ rhythms were abolished in the dorsolateral SCN, but were maintained in the majority of the ventromedial SCN. These findings indicate that intracellular circadian Ca2+ rhythms are composed of an exogenous and endogenous component involving PER2 expression.
Collapse
Affiliation(s)
- Ryosuke Enoki
- Photonic Bioimaging Section, Research Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, N15 W7, Kita-ku, Sapporo, 060-8638, Japan.,Department of Chronomedicine, Hokkaido University Graduate School of Medicine, N15 W7, Kita-ku, Sapporo, 060-8638, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
| | - Daisuke Ono
- Photonic Bioimaging Section, Research Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, N15 W7, Kita-ku, Sapporo, 060-8638, Japan
| | - Shigeru Kuroda
- Mathematical and Physical Ethology Laboratory, Research Institute for Electrical Science, Hokkaido University, N20 W10, Kita-ku, Sapporo, Japan
| | - Sato Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, N15 W7, Kita-ku, Sapporo, 060-8638, Japan
| | - Ken-Ichi Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, N15 W7, Kita-ku, Sapporo, 060-8638, Japan
| |
Collapse
|
158
|
Tashiro T. Improvement of a patient's circadian rhythm sleep disorders by aripiprazole was associated with stabilization of his bipolar illness. J Sleep Res 2017; 26:247-250. [DOI: 10.1111/jsr.12496] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/09/2016] [Indexed: 01/28/2023]
Affiliation(s)
- Tetsuo Tashiro
- Tashiro Clinic; Akita-heal Medical Corporation; Akita City Akita Japan
| |
Collapse
|
159
|
Herzog ED, Hermanstyne T, Smyllie NJ, Hastings MH. Regulating the Suprachiasmatic Nucleus (SCN) Circadian Clockwork: Interplay between Cell-Autonomous and Circuit-Level Mechanisms. Cold Spring Harb Perspect Biol 2017; 9:9/1/a027706. [PMID: 28049647 DOI: 10.1101/cshperspect.a027706] [Citation(s) in RCA: 169] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The suprachiasmatic nucleus (SCN) is the principal circadian clock of the brain, directing daily cycles of behavior and physiology. SCN neurons contain a cell-autonomous transcription-based clockwork but, in turn, circuit-level interactions synchronize the 20,000 or so SCN neurons into a robust and coherent daily timer. Synchronization requires neuropeptide signaling, regulated by a reciprocal interdependence between the molecular clockwork and rhythmic electrical activity, which in turn depends on a daytime Na+ drive and nighttime K+ drag. Recent studies exploiting intersectional genetics have started to identify the pacemaking roles of particular neuronal groups in the SCN. They support the idea that timekeeping involves nonlinear and hierarchical computations that create and incorporate timing information through the interactions between key groups of neurons within the SCN circuit. The field is now poised to elucidate these computations, their underlying cellular mechanisms, and how the SCN clock interacts with subordinate circadian clocks across the brain to determine the timing and efficiency of the sleep-wake cycle, and how perturbations of this coherence contribute to neurological and psychiatric illness.
Collapse
Affiliation(s)
- Erik D Herzog
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri 63130-4899
| | - Tracey Hermanstyne
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri 63130-4899
| | - Nicola J Smyllie
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Michael H Hastings
- Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| |
Collapse
|
160
|
Chernysheva MP, Nozdrachev AD. Neuroendocrine hypothalamus as a homeostat of endogenous time. J EVOL BIOCHEM PHYS+ 2017. [DOI: 10.1134/s002209301701001x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
161
|
Park J, Zhu H, O'Sullivan S, Ogunnaike BA, Weaver DR, Schwaber JS, Vadigepalli R. Single-Cell Transcriptional Analysis Reveals Novel Neuronal Phenotypes and Interaction Networks Involved in the Central Circadian Clock. Front Neurosci 2016; 10:481. [PMID: 27826225 PMCID: PMC5079116 DOI: 10.3389/fnins.2016.00481] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 10/07/2016] [Indexed: 12/31/2022] Open
Abstract
Single-cell heterogeneity confounds efforts to understand how a population of cells organizes into cellular networks that underlie tissue-level function. This complexity is prominent in the mammalian suprachiasmatic nucleus (SCN). Here, individual neurons exhibit a remarkable amount of asynchronous behavior and transcriptional heterogeneity. However, SCN neurons are able to generate precisely coordinated synaptic and molecular outputs that synchronize the body to a common circadian cycle by organizing into cellular networks. To understand this emergent cellular network property, it is important to reconcile single-neuron heterogeneity with network organization. In light of recent studies suggesting that transcriptionally heterogeneous cells organize into distinct cellular phenotypes, we characterized the transcriptional, spatial, and functional organization of 352 SCN neurons from mice experiencing phase-shifts in their circadian cycle. Using the community structure detection method and multivariate analytical techniques, we identified previously undescribed neuronal phenotypes that are likely to participate in regulatory networks with known SCN cell types. Based on the newly discovered neuronal phenotypes, we developed a data-driven neuronal network structure in which multiple cell types interact through known synaptic and paracrine signaling mechanisms. These results provide a basis from which to interpret the functional variability of SCN neurons and describe methodologies toward understanding how a population of heterogeneous single cells organizes into cellular networks that underlie tissue-level function.
Collapse
Affiliation(s)
- James Park
- Department of Pathology, Anatomy and Cell Biology, Daniel Baugh Institute for Functional Genomics and Computational Biology, Sidney Kimmel Medical College, Thomas Jefferson UniversityPhiladelphia, PA, USA; Department of Chemical and Biomolecular Engineering, University of DelawareNewark, NJ, USA
| | - Haisun Zhu
- Department of Pathology, Anatomy and Cell Biology, Daniel Baugh Institute for Functional Genomics and Computational Biology, Sidney Kimmel Medical College, Thomas Jefferson University Philadelphia, PA, USA
| | - Sean O'Sullivan
- Department of Pathology, Anatomy and Cell Biology, Daniel Baugh Institute for Functional Genomics and Computational Biology, Sidney Kimmel Medical College, Thomas Jefferson University Philadelphia, PA, USA
| | - Babatunde A Ogunnaike
- Department of Chemical and Biomolecular Engineering, University of Delaware Newark, NJ, USA
| | - David R Weaver
- Department of Neurobiology, University of Massachusetts Medical School Worcester, MA, USA
| | - James S Schwaber
- Department of Pathology, Anatomy and Cell Biology, Daniel Baugh Institute for Functional Genomics and Computational Biology, Sidney Kimmel Medical College, Thomas Jefferson UniversityPhiladelphia, PA, USA; Department of Chemical and Biomolecular Engineering, University of DelawareNewark, NJ, USA
| | - Rajanikanth Vadigepalli
- Department of Pathology, Anatomy and Cell Biology, Daniel Baugh Institute for Functional Genomics and Computational Biology, Sidney Kimmel Medical College, Thomas Jefferson UniversityPhiladelphia, PA, USA; Department of Chemical and Biomolecular Engineering, University of DelawareNewark, NJ, USA
| |
Collapse
|
162
|
Qu Z, Zhang H, Huang M, Shi G, Liu Z, Xie P, Li H, Wang W, Xu G, Zhang Y, Yang L, Huang G, Takahashi JS, Zhang WJ, Xu Y. Loss of ZBTB20 impairs circadian output and leads to unimodal behavioral rhythms. eLife 2016; 5:e17171. [PMID: 27657167 PMCID: PMC5033604 DOI: 10.7554/elife.17171] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 09/01/2016] [Indexed: 12/15/2022] Open
Abstract
Many animals display morning and evening bimodal activities in the day/night cycle. However, little is known regarding the potential components involved in the regulation of bimodal behavioral rhythms in mammals. Here, we identified that the zinc finger protein gene Zbtb20 plays a crucial role in the regulation of bimodal activities in mice. Depletion of Zbtb20 in nerve system resulted in the loss of early evening activity, but the increase of morning activity. We found that Zbtb20-deficient mice exhibited a pronounced decrease in the expression of Prokr2 and resembled phenotypes of Prok2 and Prokr2-knockout mice. Injection of adeno-associated virus-double-floxed Prokr2 in suprachiasmatic nucleus could partly restore evening activity in Nestin-Cre; Zbtb20fl/fl (NS-ZB20KO) mice. Furthermore, loss of Zbtb20 in Foxg1 loci, but intact in the suprachiasmatic nucleus, was not responsible for the unimodal activity of NS-ZB20KO mice. Our study provides evidence that ZBTB20-mediated PROKR2 signaling is critical for the evening behavioral rhythms.
Collapse
Affiliation(s)
- Zhipeng Qu
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Hai Zhang
- Department of Pathophysiology, Second Military Medical University, Shanghai, China
| | - Moli Huang
- Cambridge-Suda Genomic Research Center, Soochow University, Suzhou, China
| | - Guangsen Shi
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Zhiwei Liu
- Cambridge-Suda Genomic Research Center, Soochow University, Suzhou, China
| | - Pancheng Xie
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Hui Li
- Department of Pathophysiology, Second Military Medical University, Shanghai, China
| | - Wei Wang
- Cambridge-Suda Genomic Research Center, Soochow University, Suzhou, China
| | - Guoqiang Xu
- College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Yang Zhang
- Cambridge-Suda Genomic Research Center, Soochow University, Suzhou, China
| | - Ling Yang
- Cambridge-Suda Genomic Research Center, Soochow University, Suzhou, China
| | - Guocun Huang
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, United States
| | - Joseph S Takahashi
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, United States
| | - Weiping J Zhang
- Department of Pathophysiology, Second Military Medical University, Shanghai, China
| | - Ying Xu
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
- Cambridge-Suda Genomic Research Center, Soochow University, Suzhou, China
| |
Collapse
|
163
|
Ono D, Honma S, Honma KI. Differential roles of AVP and VIP signaling in the postnatal changes of neural networks for coherent circadian rhythms in the SCN. SCIENCE ADVANCES 2016; 2:e1600960. [PMID: 27626074 PMCID: PMC5017821 DOI: 10.1126/sciadv.1600960] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Accepted: 08/09/2016] [Indexed: 06/01/2023]
Abstract
The suprachiasmatic nucleus (SCN) is the site of the master circadian clock in mammals. The SCN neural network plays a critical role in expressing the tissue-level circadian rhythm. Previously, we demonstrated postnatal changes in the SCN network in mice, in which the clock gene products CRYPTOCHROMES (CRYs) are involved. Here, we show that vasoactive intestinal polypeptide (VIP) signaling is essential for the tissue-level circadian PER2::LUC rhythm in the neonatal SCN of CRY double-deficient mice (Cry1,2 (-/-) ). VIP and arginine vasopressin (AVP) signaling showed redundancy in expressing the tissue-level circadian rhythm in the SCN. AVP synthesis was significantly attenuated in the Cry1,2 (-/-) SCN, which contributes to aperiodicity in the adult mice together with an attenuation of VIP signaling as a natural process of ontogeny. The SCN network consists of multiple clusters of cellular circadian rhythms that are differentially integrated by AVP and VIP signaling, depending on the postnatal period.
Collapse
Affiliation(s)
- Daisuke Ono
- Photonic Bioimaging Section, Research Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Sato Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Ken-ichi Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| |
Collapse
|
164
|
Mieda M, Okamoto H, Sakurai T. Manipulating the Cellular Circadian Period of Arginine Vasopressin Neurons Alters the Behavioral Circadian Period. Curr Biol 2016; 26:2535-2542. [PMID: 27568590 DOI: 10.1016/j.cub.2016.07.022] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/19/2016] [Accepted: 07/12/2016] [Indexed: 11/24/2022]
Abstract
As the central pacemaker in mammals, the circadian clock in the suprachiasmatic nucleus (SCN) of the hypothalamus is a heterogeneous structure consisting of multiple types of GABAergic neurons with distinct chemical identities [1, 2]. Although individual cells have a cellular clock driven by autoregulatory transcriptional/translational feedback loops of clock genes, interneuronal communication among SCN clock neurons is likely essential for the SCN to generate a highly robust, coherent circadian rhythm [1]. However, neuronal mechanisms that determine circadian period length remain unclear. The SCN is composed of two subdivisions: a ventral core region containing vasoactive intestinal peptide (VIP)-producing neurons and a dorsal shell region characterized by arginine vasopressin (AVP)-producing neurons. Here we examined whether AVP neurons act as pacemaker cells that regulate the circadian period of behavior rhythm in mice. The deletion of casein kinase 1 delta (CK1δ) specific to AVP neurons, which was expected to lengthen the period of cellular clocks [3-6], lengthened the free-running period of circadian behavior as well. Conversely, the overexpression of CK1δ specific to SCN AVP neurons shortened the free-running period. PER2::LUC imaging in slices confirmed that cellular circadian periods of the SCN shell were lengthened in mice without CK1δ in AVP neurons. Thus, AVP neurons may be an essential component of circadian pacemaker cells in the SCN. Remarkably, the alteration of the shell-core phase relationship in the SCN of these mice did not impair the generation per se of circadian behavior rhythm, thereby underscoring the robustness of the SCN network.
Collapse
Affiliation(s)
- Michihiro Mieda
- Department of Molecular Neuroscience and Integrative Physiology, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan.
| | - Hitoshi Okamoto
- Laboratory for Developmental Gene Regulation, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Takeshi Sakurai
- Department of Molecular Neuroscience and Integrative Physiology, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| |
Collapse
|
165
|
Unique food-entrained circadian rhythm in cysteine414-alanine mutant mCRY1 transgenic mice. Sleep Biol Rhythms 2016; 14:261-269. [PMID: 27441028 PMCID: PMC4932127 DOI: 10.1007/s41105-016-0050-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 01/07/2016] [Indexed: 11/05/2022]
Abstract
Food availability is a potent environmental cue that directs circadian locomotor activity in rodents. Daily scheduled restricted feeding (RF), in which the food available time is restricted for several hours each day, elicits anticipatory activity. This food-anticipatory activity (FAA) is controlled by a food-entrainable oscillator (FEO) that is distinct from the suprachiasmatic nucleus (SCN), the master pacemaker in mammals. In an earlier report, we described generation of transgenic (Tg) mice ubiquitously overexpressing cysteine414-alanine mutant mCRY1. The Tg mice displayed long locomotor free-running periods (approximately 28 h) with rhythm splitting. Furthermore, their locomotor activity immediately re-adjusted to the advance of light–dark cycles (LD), suggesting some disorder in the coupling of SCN neurons. The present study examined the restricted feeding cycle (RF)-induced entrainment of locomotor activity in Tg mice in various light conditions. In LD, wild-type controls showed both FAA and LD-entrained activities. In Tg mice, almost all activity was eventually consolidated to a single bout before the feeding time. The result suggests a possibility that in Tg mice the feeding cycle dominates the LD cycle as an entrainment agent. In constant darkness (DD), wild-type mice exhibited robust free-run activity and FAA during RF. For Tg mice, only the rhythm entrained to RF was observed in DD. Furthermore, after returning to free feeding, the free-run started from the RF-entrained phase. These results suggest that the SCN of Tg mice is entrainable to RF and that the mCRY1 mutation alters the sensitivity of SCN to the cycle of nonphotic zeitgebers.
Collapse
|
166
|
Evans JA. Collective timekeeping among cells of the master circadian clock. J Endocrinol 2016; 230:R27-49. [PMID: 27154335 PMCID: PMC4938744 DOI: 10.1530/joe-16-0054] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/06/2016] [Indexed: 01/09/2023]
Abstract
The suprachiasmatic nucleus (SCN) of the anterior hypothalamus is the master circadian clock that coordinates daily rhythms in behavior and physiology in mammals. Like other hypothalamic nuclei, the SCN displays an impressive array of distinct cell types characterized by differences in neurotransmitter and neuropeptide expression. Individual SCN neurons and glia are able to display self-sustained circadian rhythms in cellular function that are regulated at the molecular level by a 24h transcriptional-translational feedback loop. Remarkably, SCN cells are able to harmonize with one another to sustain coherent rhythms at the tissue level. Mechanisms of cellular communication in the SCN network are not completely understood, but recent progress has provided insight into the functional roles of several SCN signaling factors. This review discusses SCN organization, how intercellular communication is critical for maintaining network function, and the signaling mechanisms that play a role in this process. Despite recent progress, our understanding of SCN circuitry and coupling is far from complete. Further work is needed to map SCN circuitry fully and define the signaling mechanisms that allow for collective timekeeping in the SCN network.
Collapse
Affiliation(s)
- Jennifer A Evans
- Department of Biomedical SciencesMarquette University, Milwaukee, WI, USA
| |
Collapse
|
167
|
Pauls SD, Honma KI, Honma S, Silver R. Deconstructing Circadian Rhythmicity with Models and Manipulations. Trends Neurosci 2016; 39:405-419. [PMID: 27090429 DOI: 10.1016/j.tins.2016.03.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 03/15/2016] [Accepted: 03/18/2016] [Indexed: 01/15/2023]
Abstract
A master brain clock, localized to the hypothalamic suprachiasmatic nucleus (SCN), coordinates daily rhythms of physiology and behavior. Within the SCN, interconnected individual neurons are oscillators that, as an ensemble, function to send a coherent timing signal to the brain and body. However, individually, these neurons display different amplitudes, periods, and phases of oscillation. The dynamic properties of the SCN have been characterized over several spatial levels of analysis, from proteins to cells to tissues, and over several temporal ranges, from milliseconds to weeks. Modeling tools guide empirical research in this complex and multiscale spatiotemporal environment. Given that the SCN is a prototypical example of oscillating neural systems, principles of its organization hold promise as general prototypes of rhythms in other frequencies.
Collapse
Affiliation(s)
- Scott D Pauls
- Mathematics Department, Dartmouth College, Hanover, NH, USA
| | - Ken-Ichi Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Sato Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Rae Silver
- Neuroscience Program, Barnard College, New York, NY, USA; Department of Psychology, Columbia University, New York, NY, USA; Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA.
| |
Collapse
|
168
|
Kehrl JH. The impact of RGS and other G-protein regulatory proteins on Gαi-mediated signaling in immunity. Biochem Pharmacol 2016; 114:40-52. [PMID: 27071343 DOI: 10.1016/j.bcp.2016.04.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 04/08/2016] [Indexed: 01/30/2023]
Abstract
Leukocyte chemoattractant receptors are members of the G-protein coupled receptor (GPCR) family. Signaling downstream of these receptors directs the localization, positioning and homeostatic trafficking of leukocytes; as well as their recruitment to, and their retention at, inflammatory sites. Ligand induced changes in the molecular conformation of chemoattractant receptors results in the engagement of heterotrimeric G-proteins, which promotes α subunits to undergo GTP/GDP exchange. This results in the functional release of βγ subunits from the heterotrimers, thereby activating downstream effector molecules, which initiate leukocyte polarization, gradient sensing, and directional migration. Pertussis toxin ADP ribosylates Gαi subunits and prevents chemoattractant receptors from triggering Gαi nucleotide exchange. The use of pertussis toxin revealed the essential importance of Gαi subunit nucleotide exchange for chemoattractant receptor signaling. More recent studies have identified a range of regulatory mechanisms that target these receptors and their associated heterotrimeric G-proteins, thereby helping to control the magnitude, kinetics, and duration of signaling. A failure in these regulatory pathways can lead to impaired receptor signaling and immunopathology. The analysis of mice with targeted deletions of Gαi isoforms as well as some of these G-protein regulatory proteins is providing insights into their roles in chemoattractant receptor signaling.
Collapse
Affiliation(s)
- John H Kehrl
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 2089, United States.
| |
Collapse
|
169
|
Foppen E, Tan AAT, Ackermans MT, Fliers E, Kalsbeek A. Suprachiasmatic Nucleus Neuropeptides and Their Control of Endogenous Glucose Production. J Neuroendocrinol 2016; 28. [PMID: 26791158 DOI: 10.1111/jne.12365] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 01/11/2016] [Accepted: 01/14/2016] [Indexed: 12/21/2022]
Abstract
Defective control of endogenous glucose production is an important factor responsible for hyperglycaemia in the diabetic individual. During the past decade, progressively more evidence has appeared indicating a strong and potentially causal relationship between disturbances of the circadian system and defects of metabolic regulation, including glucose metabolism. The detrimental effects of disturbed circadian rhythms may have their origin in disturbances of the molecular clock mechanisms in peripheral organs, such as the pancreas and liver, or in the central brain clock in the hypothalamic suprachiasmatic nuclei (SCN). To assess the role of SCN output per se on glucose metabolism, we investigated (i) the effect of several SCN neurotransmitters on endogenous glucose production and (ii) the effect of SCN neuronal activity on hepatic and systemic insulin sensitivity. We show that silencing of SCN neuronal activity results in decreased hepatic insulin sensitivity and increased peripheral insulin sensitivity. Furthermore, both oxytocin neurones in the paraventricular nucleus of the hypothalamus (PVN) and orexin neurones in the lateral hypothalamus may be important targets for the SCN control of glucose metabolism. These data further highlight the role of the central clock in the pathophysiology of insulin resistance.
Collapse
Affiliation(s)
- E Foppen
- Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - A A T Tan
- Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - M T Ackermans
- Department of Clinical Chemistry, Laboratory of Endocrinology, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - E Fliers
- Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
| | - A Kalsbeek
- Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
- Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience (NIN), An Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, The Netherlands
| |
Collapse
|
170
|
Temporally chimeric mice reveal flexibility of circadian period-setting in the suprachiasmatic nucleus. Proc Natl Acad Sci U S A 2016; 113:3657-62. [PMID: 26966234 PMCID: PMC4822582 DOI: 10.1073/pnas.1511351113] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The suprachiasmatic nucleus (SCN) is the principal circadian clock of the mammalian brain. To function effectively, SCN neurons must operate as a synchronized circuit. How cell-autonomous and circuit-level circadian mechanisms interact to achieve this is unclear. Here, we used intersectional genetics to create temporally chimeric mice where both 24-h and 20-h clock neurons were present in the SCN, in different cell populations. The 24-h dopamine receptor-positive cells set the speed of the SCN, imposing their cell-autonomous 24-h period on all cells in the circuit. Exposure to a 20-h lighting cycle, however, inverted this dominance, reprograming the circuit to 20 h. These results show how robust circuit-level signaling underlies complex, nonlinear computations of circadian period that also exhibit a remarkable level of plasticity. The suprachiasmatic nucleus (SCN) is the master circadian clock controlling daily behavior in mammals. It consists of a heterogeneous network of neurons, in which cell-autonomous molecular feedback loops determine the period and amplitude of circadian oscillations of individual cells. In contrast, circuit-level properties of coherence, synchrony, and ensemble period are determined by intercellular signals and are embodied in a circadian wave of gene expression that progresses daily across the SCN. How cell-autonomous and circuit-level mechanisms interact in timekeeping is poorly understood. To explore this interaction, we used intersectional genetics to create temporally chimeric mice with SCN containing dopamine 1a receptor (Drd1a) cells with an intrinsic period of 24 h alongside non-Drd1a cells with 20-h clocks. Recording of circadian behavior in vivo alongside cellular molecular pacemaking in SCN slices in vitro demonstrated that such chimeric circuits form robust and resilient circadian clocks. It also showed that the computation of ensemble period is nonlinear. Moreover, the chimeric circuit sustained a wave of gene expression comparable to that of nonchimeric SCN, demonstrating that this circuit-level property is independent of differences in cell-intrinsic periods. The relative dominance of 24-h Drd1a and 20-h non-Drd1a neurons in setting ensemble period could be switched by exposure to resonant or nonresonant 24-h or 20-h lighting cycles. The chimeric circuit therefore reveals unanticipated principles of circuit-level operation underlying the emergent plasticity, resilience, and robustness of the SCN clock. The spontaneous and light-driven flexibility of period observed in chimeric mice provides a new perspective on the concept of SCN pacemaker cells.
Collapse
|
171
|
de Assis LVM, Moraes MN, da Silveira Cruz-Machado S, Castrucci AML. The effect of white light on normal and malignant murine melanocytes: A link between opsins, clock genes, and melanogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1119-33. [PMID: 26947915 DOI: 10.1016/j.bbamcr.2016.03.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 02/29/2016] [Accepted: 03/02/2016] [Indexed: 11/26/2022]
Abstract
The skin possesses a photosensitive system comprised of opsins whose function is not fully understood, and clock genes which exert an important regulatory role in skin biology. Here, we evaluated the presence of opsins in normal (Melan-a cells) and malignant (B16-F10 cells) murine melanocytes. Both cell lines express Opn2, Opn4--for the first time reported in these cell types--as well as S-opsin. OPN4 protein was found in a small area capping the cell nuclei of B16-F10 cells kept in constant dark (DD); twenty-four hours after the white light pulse (WLP), OPN4 was found in the cell membrane. Despite the fact that B16-F10 cells expressed less Opn2 and Opn4 than Melan-a cells, our data indicate that the malignant melanocytes exhibited increased photoresponsiveness. The clock gene machinery is also severely downregulated in B16-F10 cells as compared to Melan-a cells. Per1, Per2, and Bmal1 expression increased in B16-F10 cells in response to WLP. Although no response in clock gene expression to WLP was observed in Melan-a cells, gene correlational data suggest a minor effect of WLP. In contrast to opsins and clock genes, melanogenesis is significantly upregulated in malignant melanocytes in comparison to Melan-a cells. Tyrosinase expression increased after WLP only in B16-F10 cells; however no increase in melanin content after WLP was seen in either cell line. Our findings may prove useful in the treatment and the development of new pharmacological approaches of depigmentation diseases and skin cancer.
Collapse
Affiliation(s)
- L V M de Assis
- Laboratory of Comparative Physiology of Pigmentation, Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - M N Moraes
- Laboratory of Comparative Physiology of Pigmentation, Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - S da Silveira Cruz-Machado
- Laboratory of Chronopharmacology, Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - A M L Castrucci
- Laboratory of Comparative Physiology of Pigmentation, Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil.
| |
Collapse
|
172
|
Rhythmic expression of cryptochrome induces the circadian clock of arrhythmic suprachiasmatic nuclei through arginine vasopressin signaling. Proc Natl Acad Sci U S A 2016; 113:2732-7. [PMID: 26903624 DOI: 10.1073/pnas.1519044113] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Circadian rhythms in mammals are coordinated by the suprachiasmatic nucleus (SCN). SCN neurons define circadian time using transcriptional/posttranslational feedback loops (TTFL) in which expression of Cryptochrome (Cry) and Period (Per) genes is inhibited by their protein products. Loss of Cry1 and Cry2 stops the SCN clock, whereas individual deletions accelerate and decelerate it, respectively. At the circuit level, neuronal interactions synchronize cellular TTFLs, creating a spatiotemporal wave of gene expression across the SCN that is lost in Cry1/2-deficient SCN. To interrogate the properties of CRY proteins required for circadian function, we expressed CRY in SCN of Cry-deficient mice using adeno-associated virus (AAV). Expression of CRY1::EGFP or CRY2::EGFP under a minimal Cry1 promoter was circadian and rapidly induced PER2-dependent bioluminescence rhythms in previously arrhythmic Cry1/2-deficient SCN, with periods appropriate to each isoform. CRY1::EGFP appropriately lengthened the behavioral period in Cry1-deficient mice. Thus, determination of specific circadian periods reflects properties of the respective proteins, independently of their phase of expression. Phase of CRY1::EGFP expression was critical, however, because constitutive or phase-delayed promoters failed to sustain coherent rhythms. At the circuit level, CRY1::EGFP induced the spatiotemporal wave of PER2 expression in Cry1/2-deficient SCN. This was dependent on the neuropeptide arginine vasopressin (AVP) because it was prevented by pharmacological blockade of AVP receptors. Thus, our genetic complementation assay reveals acute, protein-specific induction of cell-autonomous and network-level circadian rhythmicity in SCN never previously exposed to CRY. Specifically, Cry expression must be circadian and appropriately phased to support rhythms, and AVP receptor signaling is required to impose circuit-level circadian function.
Collapse
|
173
|
Jeong B, Hong JH, Kim H, Choe HK, Kim K, Lee KJ. Multi-stability of circadian phase wave within early postnatal suprachiasmatic nucleus. Sci Rep 2016; 6:21463. [PMID: 26891917 PMCID: PMC4759822 DOI: 10.1038/srep21463] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/20/2016] [Indexed: 11/09/2022] Open
Abstract
The suprachiasmatic nucleus (SCN) is a group of cells that functions as a biological master clock. In different SCN cells, oscillations of biochemical markers such as the expression-level of clock genes, are not synchronized but instead form slow circadian phase waves propagating over the whole cell population spatio-temporal struc- ture is a fixed property set by the anatomy of a given SCN. Here, we show that this is not the case in early postnatal SCN. Earlier studies presumed that their Based on bioluminescence imaging experiments with Per2-Luciferase mice SCN cultures which guided computer simulations of a realistic model of the SCN, we demonstrate that the wave is not unique but can be in various modes including phase- coherent oscillation, crescent-shaped wave, and most notably, a rotating pinwheel wave that conceptually resembles a wall clock with a rotating hand. Furthermore, mode transitions can be induced by a pulse of 38.5 °C temperature perturbation. Importantly, the waves support a significantly different period, suggesting that neither a spatially-fixed phase ordering nor a specialized pacemaker having a fixed period exist in these studied SCNs. These results lead to new important questions of what the observed multi-stability means for the proper function of an SCN and its arrhythmia.
Collapse
Affiliation(s)
- Byeongha Jeong
- Department of Physics, Korea University, Seoul, 136-713, Korea
| | - Jin Hee Hong
- Department of Physics, Korea University, Seoul, 136-713, Korea
| | - Hyun Kim
- Department of Physics, Korea University, Seoul, 136-713, Korea
| | - Han Kyoung Choe
- School of Biological Sciences, Seoul National University, Seoul 151-742, Korea
| | - Kyungjin Kim
- School of Biological Sciences, Seoul National University, Seoul 151-742, Korea
| | - Kyoung J Lee
- Department of Physics, Korea University, Seoul, 136-713, Korea
| |
Collapse
|
174
|
Evans JA, Gorman MR. In synch but not in step: Circadian clock circuits regulating plasticity in daily rhythms. Neuroscience 2016; 320:259-80. [PMID: 26861419 DOI: 10.1016/j.neuroscience.2016.01.072] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 01/26/2016] [Accepted: 01/27/2016] [Indexed: 11/16/2022]
Abstract
The suprachiasmatic nucleus (SCN) is a network of neural oscillators that program daily rhythms in mammalian behavior and physiology. Over the last decade much has been learned about how SCN clock neurons coordinate together in time and space to form a cohesive population. Despite this insight, much remains unknown about how SCN neurons communicate with one another to produce emergent properties of the network. Here we review the current understanding of communication among SCN clock cells and highlight a collection of formal assays where changes in SCN interactions provide for plasticity in the waveform of circadian rhythms in behavior. Future studies that pair analytical behavioral assays with modern neuroscience techniques have the potential to provide deeper insight into SCN circuit mechanisms.
Collapse
Affiliation(s)
- J A Evans
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA.
| | - M R Gorman
- Department of Psychology, University of San Diego, La Jolla, CA, USA
| |
Collapse
|
175
|
Burton KJ, Li X, Li B, Cheng MY, Urbanski HF, Zhou QY. Expression of prokineticin 2 and its receptor in the macaque monkey brain. Chronobiol Int 2016; 33:191-9. [PMID: 26818846 PMCID: PMC4959799 DOI: 10.3109/07420528.2015.1125361] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Prokineticin 2 (PK2) has been indicated as an output signaling molecule for the suprachiasmatic nucleus (SCN) circadian clock. Most of these studies were performed with nocturnal animals, particularly mice and rats. In the current study, the PK2 and its receptor, PKR2, was cloned from a species of diurnal macaque monkey. The macaque monkey PK2 and PKR2 were found to be highly homologous to that of other mammalian species. The mRNA expression of PK2 and PKR2 in the macaque brain was examined by in situ hybridization. The expression patterns of PK2 and PKR2 in the macaque brain were found to be quite similar to that of the mouse brain. Particularly, PK2 mRNA was shown to oscillate in the SCN of the macaque brain in the same phase and with similar amplitude with that of nocturnal mouse brain. PKR2 expression was also detected in known primary SCN targets, including the midline thalamic and hypothalamic nuclei. In addition, we detected the expression of PKR2 mRNA in the dorsal raphe nucleus (DR) of both macaque and mouse brains. As a likely SCN to dorsal raphe projection has previously been indicated, the expression of PKR2 in the raphe nuclei of both macaque and mouse brain signifies a possible role of DR as a previously unrecognized primary SCN projection target.
Collapse
Affiliation(s)
- Katherine J. Burton
- Department of Pharmacology, University of California, Irvine, Irvine, CA, USA
| | - Xiaohan Li
- Department of Pharmacology, University of California, Irvine, Irvine, CA, USA
| | - Baoan Li
- Department of Pharmacology, University of California, Irvine, Irvine, CA, USA
| | - Michelle Y. Cheng
- Department of Pharmacology, University of California, Irvine, Irvine, CA, USA
| | - Henryk F. Urbanski
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA
| | - Qun-Yong Zhou
- Department of Pharmacology, University of California, Irvine, Irvine, CA, USA
| |
Collapse
|
176
|
Yamaguchi Y, Okada K, Mizuno T, Ota T, Yamada H, Doi M, Kobayashi M, Tei H, Shigeyoshi Y, Okamura H. Real-Time Recording of Circadian Per1 and Per2 Expression in the Suprachiasmatic Nucleus of Freely Moving Rats. J Biol Rhythms 2015; 31:108-11. [PMID: 26656624 DOI: 10.1177/0748730415621412] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Measuring real-time gene activity in the brains of freely moving animals presents a challenging issue in neuroscience research. Circadian gene expression in neurons of the suprachiasmatic nucleus (SCN), a small nucleus in the hypothalamus, is reflected in behavioral rhythmicity. Cellular oscillatory gene expression is generated by a transcription-translation feedback loop of clock genes including 2 oscillatory genes, Per1 and Per2. Here we have succeeded in real-time monitoring of Per1 and Per2 transcription separately by detecting the bioluminescence of luciferase (luc) reporters using a plastic optical fiber inserted into the SCN of freely moving rats. Per1-luc and Per2-luc rhythms peaked in the middle and late subjective day, respectively, which was confirmed by quantitative PCR-based measurements of SCN tissue samples. Studies of in vivo transcriptional states of clock genes in freely moving animals should improve our understanding of how clock gene expression is reflected in behavior.
Collapse
Affiliation(s)
- Yoshiaki Yamaguchi
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama, Japan
| | - Kazuki Okada
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Takanobu Mizuno
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Takumi Ota
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Hiroyuki Yamada
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Masao Doi
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama, Japan
| | - Masaki Kobayashi
- Department of Electronics and Intelligent Systems, Tohoku Institute of Technology, Sendai, Japan
| | - Hajime Tei
- Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Yasufumi Shigeyoshi
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kinki University, Ohno-Higashi, Osaka-Sayama, Osaka, Japan
| | - Hitoshi Okamura
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama, Japan
| |
Collapse
|
177
|
Yoshikawa T, Nakajima Y, Yamada Y, Enoki R, Watanabe K, Yamazaki M, Sakimura K, Honma S, Honma KI. Spatiotemporal profiles of arginine vasopressin transcription in cultured suprachiasmatic nucleus. Eur J Neurosci 2015; 42:2678-89. [DOI: 10.1111/ejn.13061] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 08/21/2015] [Accepted: 08/27/2015] [Indexed: 01/18/2023]
Affiliation(s)
- Tomoko Yoshikawa
- Photonic Bioimaging Section; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
| | - Yoshihiro Nakajima
- Health Research Institute; National Institute of Advanced Industrial Science and Technology (AIST); Kagawa 761-0395 Japan
| | - Yoshiko Yamada
- Photonic Bioimaging Section; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
| | - Ryosuke Enoki
- Photonic Bioimaging Section; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Precursory Research for Embryonic Science and Technology (PRESTO); Japan Science and Technology Agency (JST); Saitama 332-0012 Japan
| | - Kazuto Watanabe
- Department of Regulatory Physiology; Dokkyo Medical University School of Medicine; Tochigi 321-0293 Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata 951-8585 Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata 951-8585 Japan
| | - Sato Honma
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
| | - Ken-ichi Honma
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
| |
Collapse
|
178
|
Hughes ATL, Croft CL, Samuels RE, Myung J, Takumi T, Piggins HD. Constant light enhances synchrony among circadian clock cells and promotes behavioral rhythms in VPAC2-signaling deficient mice. Sci Rep 2015; 5:14044. [PMID: 26370467 PMCID: PMC4642707 DOI: 10.1038/srep14044] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/14/2015] [Indexed: 12/22/2022] Open
Abstract
Individual neurons in the suprachiasmatic nuclei (SCN) contain an intracellular molecular clock and use intercellular signaling to synchronize their timekeeping activities so that the SCN can coordinate brain physiology and behavior. The neuropeptide vasoactive intestinal polypeptide (VIP) and its VPAC2 receptor form a key component of intercellular signaling systems in the SCN and critically control cellular coupling. Targeted mutations in either the intracellular clock or intercellular neuropeptide signaling mechanisms, such as VIP-VPAC2 signaling, can lead to desynchronization of SCN neuronal clocks and loss of behavioral rhythms. An important goal in chronobiology is to develop interventions to correct deficiencies in circadian timekeeping. Here we show that extended exposure to constant light promotes synchrony among SCN clock cells and the expression of ~24 h rhythms in behavior in mice in which intercellular signaling is disrupted through loss of VIP-VPAC2 signaling. This study highlights the importance of SCN synchrony for the expression of rhythms in behavior and reveals how non-invasive manipulations in the external environment can be used to overcome neurochemical communication deficits in this important brain system.
Collapse
Affiliation(s)
- Alun T L Hughes
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - Cara L Croft
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - Rayna E Samuels
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - Jihwan Myung
- RIKEN Brain Science Institute, Wako, Saitama, Japan
| | - Toru Takumi
- RIKEN Brain Science Institute, Wako, Saitama, Japan
| | - Hugh D Piggins
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| |
Collapse
|
179
|
Husse J, Eichele G, Oster H. Synchronization of the mammalian circadian timing system: Light can control peripheral clocks independently of the SCN clock: alternate routes of entrainment optimize the alignment of the body's circadian clock network with external time. Bioessays 2015; 37:1119-28. [PMID: 26252253 PMCID: PMC5054915 DOI: 10.1002/bies.201500026] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A vast network of cellular circadian clocks regulates 24-hour rhythms of behavior and physiology in mammals. Complex environments are characterized by multiple, and often conflicting time signals demanding flexible mechanisms of adaptation of endogenous rhythms to external time. Traditionally this process of circadian entrainment has been conceptualized in a hierarchical scheme with a light-reset master pacemaker residing in the hypothalamus that subsequently aligns subordinate peripheral clocks with each other and with external time. Here we review new experiments using conditional mouse genetics suggesting that resetting of the circadian system occurs in a more "federated" and tissue-specific fashion, which allows for increased noise resistance and plasticity of circadian timekeeping under natural conditions.
Collapse
Affiliation(s)
- Jana Husse
- Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Gregor Eichele
- Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Henrik Oster
- Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
| |
Collapse
|
180
|
Loh DH, Kudo T, Colwell CS. Short circuiting the circadian system with a new generation of precision tools. Neuron 2015; 85:895-8. [PMID: 25741718 DOI: 10.1016/j.neuron.2015.02.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Circadian behavior in mammals is coordinated by neurons within the suprachiasmatic nucleus (SCN). In this issue, Lee et al. (2015) and Mieda et al. (2015) applied state-of-the-art genetic tools to dissect the microcircuits within the SCN generating circadian rhythmic behavior.
Collapse
Affiliation(s)
- Dawn H Loh
- Laboratory of Circadian and Sleep Medicine, Department of Psychiatry, Semel Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Takashi Kudo
- Laboratory of Circadian and Sleep Medicine, Department of Psychiatry, Semel Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Christopher S Colwell
- Laboratory of Circadian and Sleep Medicine, Department of Psychiatry, Semel Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA.
| |
Collapse
|