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Kim JH, Chen W, Chao ES, Rivera A, Kaku HN, Jiang K, Lee D, Chen H, Vega JM, Chin TV, Jin K, Nguyen KT, Zou SS, Moin Z, Nguyen S, Xue 薛名杉 M. GABAergic/Glycinergic and Glutamatergic Neurons Mediate Distinct Neurodevelopmental Phenotypes of STXBP1 Encephalopathy. J Neurosci 2024; 44:e1806232024. [PMID: 38360746 PMCID: PMC10993039 DOI: 10.1523/jneurosci.1806-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 01/09/2024] [Accepted: 01/26/2024] [Indexed: 02/17/2024] Open
Abstract
An increasing number of pathogenic variants in presynaptic proteins involved in the synaptic vesicle cycle are being discovered in neurodevelopmental disorders. The clinical features of these synaptic vesicle cycle disorders are diverse, but the most prevalent phenotypes include intellectual disability, epilepsy, movement disorders, cerebral visual impairment, and psychiatric symptoms ( Verhage and Sørensen, 2020; Bonnycastle et al., 2021; John et al., 2021; Melland et al., 2021). Among this growing list of synaptic vesicle cycle disorders, the most frequent is STXBP1 encephalopathy caused by de novo heterozygous pathogenic variants in syntaxin-binding protein 1 (STXBP1, also known as MUNC18-1; Verhage and Sørensen, 2020; John et al., 2021). STXBP1 is an essential protein for presynaptic neurotransmitter release. Its haploinsufficiency is the main disease mechanism and impairs both excitatory and inhibitory neurotransmitter release. However, the disease pathogenesis and cellular origins of the broad spectrum of neurological phenotypes are poorly understood. Here we generate cell type-specific Stxbp1 haploinsufficient male and female mice and show that Stxbp1 haploinsufficiency in GABAergic/glycinergic neurons causes developmental delay, epilepsy, and motor, cognitive, and psychiatric deficits, recapitulating majority of the phenotypes observed in the constitutive Stxbp1 haploinsufficient mice and STXBP1 encephalopathy. In contrast, Stxbp1 haploinsufficiency in glutamatergic neurons results in a small subset of cognitive and seizure phenotypes distinct from those caused by Stxbp1 haploinsufficiency in GABAergic/glycinergic neurons. Thus, the contrasting roles of excitatory and inhibitory signaling reveal GABAergic/glycinergic dysfunction as a key disease mechanism of STXBP1 encephalopathy and suggest the possibility to selectively modulate disease phenotypes by targeting specific neurotransmitter systems.
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Affiliation(s)
- Joo Hyun Kim
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Wu Chen
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Eugene S Chao
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Armando Rivera
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Heet Naresh Kaku
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Kevin Jiang
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Dongwon Lee
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Hongmei Chen
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Jaimie M Vega
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Teresa V Chin
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Kevin Jin
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Kelly T Nguyen
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Sheldon S Zou
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Zain Moin
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Shawn Nguyen
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Mingshan Xue 薛名杉
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
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Onodera K, Tsuno Y, Hiraoka Y, Tanaka K, Maejima T, Mieda M. In vivo recording of the circadian calcium rhythm in Prokineticin 2 neurons of the suprachiasmatic nucleus. Sci Rep 2023; 13:16974. [PMID: 37813987 PMCID: PMC10562406 DOI: 10.1038/s41598-023-44282-5] [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: 05/15/2023] [Accepted: 10/05/2023] [Indexed: 10/11/2023] Open
Abstract
Prokineticin 2 (Prok2) is a small protein expressed in a subpopulation of neurons in the suprachiasmatic nucleus (SCN), the primary circadian pacemaker in mammals. Prok2 has been implicated as a candidate output molecule from the SCN to control multiple circadian rhythms. Genetic manipulation specific to Prok2-producing neurons would be a powerful approach to understanding their function. Here, we report the generation of Prok2-tTA knock-in mice expressing the tetracycline transactivator (tTA) specifically in Prok2 neurons and an application of these mice to in vivo recording of Ca2+ rhythms in these neurons. First, the specific and efficient expression of tTA in Prok2 neurons was verified by crossing the mice with EGFP reporter mice. Prok2-tTA mice were then used to express a fluorescent Ca2+ sensor protein to record the circadian Ca2+ rhythm in SCN Prok2 neurons in vivo. Ca2+ in these cells showed clear circadian rhythms in both light-dark and constant dark conditions, with their peaks around midday. Notably, the hours of high Ca2+ nearly coincided with the rest period of the behavioral rhythm. These observations fit well with the predicted function of Prok2 neurons as a candidate output pathway of the SCN by suppressing locomotor activity during both daytime and subjective daytime.
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Affiliation(s)
- Kaito Onodera
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, 920-8640, Japan
| | - Yusuke Tsuno
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, 920-8640, Japan
| | - Yuichi Hiraoka
- Laboratory of Molecular Neuroscience, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Takashi Maejima
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, 920-8640, Japan
| | - Michihiro Mieda
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, 920-8640, Japan.
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Davidson AJ, Beckner D, Bonnefont X. A Journey in the Brain's Clock: In Vivo Veritas? BIOLOGY 2023; 12:1136. [PMID: 37627020 PMCID: PMC10452196 DOI: 10.3390/biology12081136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 08/12/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023]
Abstract
The suprachiasmatic nuclei (SCN) of the hypothalamus contain the circadian pacemaker that coordinates mammalian rhythms in tune with the day-night cycle. Understanding the determinants of the intrinsic rhythmicity of this biological clock, its outputs, and resetting by environmental cues, has been a longstanding goal of the field. Integrated techniques of neurophysiology, including lesion studies and in vivo multi-unit electrophysiology, have been key to characterizing the rhythmic nature and outputs of the SCN in animal models. In parallel, reduced ex vivo and in vitro approaches have permitted us to unravel molecular, cellular, and multicellular mechanisms underlying the pacemaker properties of the SCN. New questions have emerged in recent years that will require combining investigation at a cell resolution within the physiological context of the living animal: What is the role of specific cell subpopulations in the SCN neural network? How do they integrate various external and internal inputs? What are the circuits involved in controlling other body rhythms? Here, we review what we have already learned about the SCN from in vivo studies, and how the recent development of new genetically encoded tools and cutting-edge imaging technology in neuroscience offers chronobiologists the opportunity to meet these challenges.
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Affiliation(s)
- Alec J. Davidson
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA;
| | - Delaney Beckner
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA;
| | - Xavier Bonnefont
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
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Gaspari S, Labouèbe G, Picard A, Berney X, Rodriguez Sanchez‐Archidona A, Thorens B. Tmem117 in AVP neurons regulates the counterregulatory response to hypoglycemia. EMBO Rep 2023; 24:e57344. [PMID: 37314252 PMCID: PMC10398655 DOI: 10.15252/embr.202357344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/21/2023] [Accepted: 05/31/2023] [Indexed: 06/15/2023] Open
Abstract
The counterregulatory response to hypoglycemia (CRR), which ensures a sufficient glucose supply to the brain, is an essential survival function. It is orchestrated by incompletely characterized glucose-sensing neurons, which trigger a coordinated autonomous and hormonal response that restores normoglycemia. Here, we investigate the role of hypothalamic Tmem117, identified in a genetic screen as a regulator of CRR. We show that Tmem117 is expressed in vasopressin magnocellular neurons of the hypothalamus. Tmem117 inactivation in these neurons increases hypoglycemia-induced vasopressin secretion leading to higher glucagon secretion in male mice, and this effect is estrus cycle phase dependent in female mice. Ex vivo electrophysiological analysis, in situ hybridization, and in vivo calcium imaging reveal that Tmem117 inactivation does not affect the glucose-sensing properties of vasopressin neurons but increases ER stress, ROS production, and intracellular calcium levels accompanied by increased vasopressin production and secretion. Thus, Tmem117 in vasopressin neurons is a physiological regulator of glucagon secretion, which highlights the role of these neurons in the coordinated response to hypoglycemia.
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Affiliation(s)
- Sevasti Gaspari
- Center for Integrative GenomicsUniversity of LausanneLausanneSwitzerland
| | - Gwenaël Labouèbe
- Center for Integrative GenomicsUniversity of LausanneLausanneSwitzerland
| | - Alexandre Picard
- Center for Integrative GenomicsUniversity of LausanneLausanneSwitzerland
| | - Xavier Berney
- Center for Integrative GenomicsUniversity of LausanneLausanneSwitzerland
| | | | - Bernard Thorens
- Center for Integrative GenomicsUniversity of LausanneLausanneSwitzerland
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Tsuno Y, Peng Y, Horike SI, Wang M, Matsui A, Yamagata K, Sugiyama M, Nakamura TJ, Daikoku T, Maejima T, Mieda M. In vivo recording of suprachiasmatic nucleus dynamics reveals a dominant role of arginine vasopressin neurons in circadian pacesetting. PLoS Biol 2023; 21:e3002281. [PMID: 37643163 PMCID: PMC10465001 DOI: 10.1371/journal.pbio.3002281] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 07/28/2023] [Indexed: 08/31/2023] Open
Abstract
The central circadian clock of the suprachiasmatic nucleus (SCN) is a network consisting of various types of neurons and glial cells. Individual cells have the autonomous molecular machinery of a cellular clock, but their intrinsic periods vary considerably. Here, we show that arginine vasopressin (AVP) neurons set the ensemble period of the SCN network in vivo to control the circadian behavior rhythm. Artificial lengthening of cellular periods by deleting casein kinase 1 delta (CK1δ) in the whole SCN lengthened the free-running period of behavior rhythm to an extent similar to CK1δ deletion specific to AVP neurons. However, in SCN slices, PER2::LUC reporter rhythms of these mice only partially and transiently recapitulated the period lengthening, showing a dissociation between the SCN shell and core with a period instability in the shell. In contrast, in vivo calcium rhythms of both AVP and vasoactive intestinal peptide (VIP) neurons in the SCN of freely moving mice demonstrated stably lengthened periods similar to the behavioral rhythm upon AVP neuron-specific CK1δ deletion, without changing the phase relationships between each other. Furthermore, optogenetic activation of AVP neurons acutely induced calcium increase in VIP neurons in vivo. These results indicate that AVP neurons regulate other SCN neurons, such as VIP neurons, in vivo and thus act as a primary determinant of the SCN ensemble period.
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Affiliation(s)
- Yusuke Tsuno
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Yubo Peng
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Shin-ichi Horike
- Division of Integrated Omics Research, Research Center for Experimental Modeling of Human Disease, Kanazawa University, Kanazawa, Japan
| | - Mohan Wang
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Ayako Matsui
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Kanato Yamagata
- Child Brain Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Mizuki Sugiyama
- Laboratory of Animal Physiology, School of Agriculture, Meiji University, Kawasaki, Japan
| | - Takahiro J. Nakamura
- Laboratory of Animal Physiology, School of Agriculture, Meiji University, Kawasaki, Japan
| | - Takiko Daikoku
- Division of Animal Disease Model, Research Center for Experimental Modeling of Human Disease, Kanazawa University, Kanazawa, Japan
| | - Takashi Maejima
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Michihiro Mieda
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
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Carmona-Alcocer V, Brown LS, Anchan A, Rohr KE, Evans JA. Developmental patterning of peptide transcription in the central circadian clock in both sexes. Front Neurosci 2023; 17:1177458. [PMID: 37274219 PMCID: PMC10235759 DOI: 10.3389/fnins.2023.1177458] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/21/2023] [Indexed: 06/06/2023] Open
Abstract
Introduction Neuropeptide signaling modulates the function of central clock neurons in the suprachiasmatic nucleus (SCN) during development and adulthood. Arginine vasopressin (AVP) and vasoactive intestinal peptide (VIP) are expressed early in SCN development, but the precise timing of transcriptional onset has been difficult to establish due to age-related changes in the rhythmic expression of each peptide. Methods To provide insight into spatial patterning of peptide transcription during SCN development, we used a transgenic approach to define the onset of Avp and Vip transcription. Avp-Cre or Vip-Cre males were crossed to Ai9+/+ females, producing offspring in which the fluorescent protein tdTomato (tdT) is expressed at the onset of Avp or Vip transcription. Spatial patterning of Avp-tdT and Vip-tdT expression was examined at critical developmental time points spanning mid-embryonic age to adulthood in both sexes. Results We find that Avp-tdT and Vip-tdT expression is initiated at different developmental time points in spatial subclusters of SCN neurons, with developmental patterning that differs by sex. Conclusions These data suggest that SCN neurons can be distinguished into further subtypes based on the developmental patterning of neuropeptide expression, which may contribute to regional and/or sex differences in cellular function in adulthood.
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Affiliation(s)
- Vania Carmona-Alcocer
- Department of Biomedical Science, Marquette University, Milwaukee, WI, United States
| | - Lindsey S. Brown
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Allston, MA, United States
| | - Aiesha Anchan
- Department of Biomedical Science, Marquette University, Milwaukee, WI, United States
| | - Kayla E. Rohr
- Department of Biomedical Science, Marquette University, Milwaukee, WI, United States
| | - Jennifer A. Evans
- Department of Biomedical Science, Marquette University, Milwaukee, WI, United States
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Bárez-López S, Scanlon L, Murphy D, Greenwood MP. Imaging the Hypothalamo-Neurohypophysial System. Neuroendocrinology 2023; 113:168-178. [PMID: 34438401 DOI: 10.1159/000519233] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/23/2021] [Indexed: 11/19/2022]
Abstract
The hypothalamo-neurohypophysial system (HNS) is a brain peptidergic neurosecretory apparatus which is composed of arginine vasopressin (AVP) and oxytocin (OXT) magnocellular neurones and their neuronal processes in the posterior pituitary (PP). In response to specific stimuli, AVP and OXT are secreted into the systemic circulation at the neurovascular interface of the PP, where they act as hormones, but they can also behave as neurotransmitters when released at the somatodendritic compartment or by axon collaterals to other brain regions. Because these peptides are crucial for several physiological processes, including fluid homoeostasis and reproduction, it is of great importance to map the HNS connectome in its entirety in order to understand its functions. In recent years, advances in imaging technologies have provided considerable new information about the HNS. These approaches include the use of reporter proteins under the control of specific promoters, viral tracers, brain-clearing methods, genetically encoded indicators, sniffer cells, mass spectrometry imaging, and spatially resolved transcriptomics. In this review, we illustrate how these latest approaches have enhanced our understanding of the structure and function of the HNS and how they might contribute further in the coming years.
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Affiliation(s)
- Soledad Bárez-López
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Liam Scanlon
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - David Murphy
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Michael Paul Greenwood
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
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Zheng H, López-Ferreras L, Krieger JP, Fasul S, Cea Salazar V, Valderrama Pena N, Skibicka KP, Rinaman L. A Cre-driver rat model for anatomical and functional analysis of glucagon (Gcg)-expressing cells in the brain and periphery. Mol Metab 2022; 66:101631. [PMID: 36368622 PMCID: PMC9677222 DOI: 10.1016/j.molmet.2022.101631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVE The glucagon gene (Gcg) encodes preproglucagon, which is cleaved to form glucagon-like peptide 1 (GLP1) and other mature signaling molecules implicated in metabolic functions. To date there are no transgenic rat models available for precise manipulation of GLP1-expressing cells in the brain and periphery. METHODS To visualize and manipulate Gcg-expressing cells in rats, CRISPR/Cas9 was used to express iCre under control of the Gcg promoter. Gcg-Cre rats were bred with tdTomato reporter rats to tag Gcg-expressing cells. Cre-dependent AAVs and RNAscope in situ hybridization were used to evaluate the specificity of iCre expression by GLP1 neurons in the caudal nucleus of the solitary tract (cNTS) and intermediate reticular nucleus (IRt), and by intestinal and pancreatic secretory cells. Food intake was assessed in heterozygous (Het) Gcg-Cre rats after chemogenetic stimulation of cNTS GLP1 neurons expressing an excitatory DREADD. RESULTS While genotype has minimal effect on body weight or composition in chow-fed Gcg-Cre rats, homozygous (Homo) rats have lower plasma glucose levels. In neonatal and adult Gcg-Cre/tdTom rats, reporter-labeled cells are present in the cNTS and IRt, and in additional brain regions (e.g., basolateral amygdala, piriform cortex) that lack detectable Gcg mRNA in adults but display transient developmental or persistently low Gcg expression. Compared to wildtype (WT) rats, hindbrain Gcg mRNA and GLP1 protein in brain and plasma are markedly reduced in Homo Gcg-Cre rats. Chemogenetic stimulation of cNTS GLP1 neurons reduced overnight chow intake in males but not females, the effect in males was blocked by antagonism of central GLP1 receptors, and hypophagia was enhanced when combined with a subthreshold dose of cholecystokinin-8 to stimulate gastrointestinal vagal afferents. CONCLUSIONS Gcg-Cre rats are a novel and valuable experimental tool for analyzing the development, anatomy, and function of Gcg-expressing cells in the brain and periphery. In addition, Homo Gcg-Cre rats are a unique model for assessing the role of Gcg-encoded proteins in glucose homeostasis and energy metabolism.
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Affiliation(s)
- Huiyuan Zheng
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Lorena López-Ferreras
- Institute of Neuroscience and Physiology, Department of Physiology/Metabolic Physiology, The Sahlgrenska Academy at University of Gothenburg, Sweden
| | - Jean-Phillipe Krieger
- Institute of Neuroscience and Physiology, Department of Physiology/Metabolic Physiology, The Sahlgrenska Academy at University of Gothenburg, Sweden
| | - Stephen Fasul
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Valentina Cea Salazar
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Natalia Valderrama Pena
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Karolina P. Skibicka
- Department of Nutritional Sciences, College of Health and Human Development, Huck Institute, The Pennsylvania State University, University Park, PA, USA,Institute of Neuroscience and Physiology, Department of Physiology/Metabolic Physiology, The Sahlgrenska Academy at University of Gothenburg, Sweden,Corresponding author. Department of Nutritional Sciences, Pennsylvania State University, 204 Chandlee Lab, University Park, PA 16802, USA
| | - Linda Rinaman
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA,Corresponding author. Department of Psychology, Program in Neuroscience, Florida State University, 1107 W. Call Street, Tallahassee, FL 32306, USA.
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Tonsfeldt KJ, Cui LJ, Lee J, Walbeek TJ, Brusman LE, Jin Y, Mieda M, Gorman MR, Mellon PL. Female fertility does not require Bmal1 in suprachiasmatic nucleus neurons expressing arginine vasopressin, vasoactive intestinal peptide, or neuromedin-S. Front Endocrinol (Lausanne) 2022; 13:956169. [PMID: 35992114 PMCID: PMC9389073 DOI: 10.3389/fendo.2022.956169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 07/06/2022] [Indexed: 01/27/2023] Open
Abstract
Disruptions to the circadian system alter reproductive capacity, particularly in females. Mice lacking the core circadian clock gene, Bmal1, are infertile and have evidence of neuroendocrine disruption including the absence of the preovulatory luteinizing hormone (LH) surge and enhanced responsiveness to exogenous kisspeptin. Here, we explore the role of Bmal1 in suprachiasmatic nucleus (SCN) neuron populations known to project to the neuroendocrine axis. We generated four mouse lines using Cre/Lox technology to create conditional deletion of Bmal1 in arginine vasopressin (Bmal1fl/fl:Avpcre ), vasoactive intestinal peptide (Bmal1fl/fl:Vipcre ), both (Bmal1fl/fl:Avpcre+Vipcre ), and neuromedin-s (Bmal1fl/fl:Nmscre ) neurons. We demonstrate that the loss of Bmal1 in these populations has substantial effects on home-cage circadian activity and temperature rhythms. Despite this, we found that female mice from these lines demonstrated normal estrus cycles, fecundity, kisspeptin responsiveness, and inducible LH surge. We found no evidence of reproductive disruption in constant darkness. Overall, our results indicate that while conditional Bmal1 knockout in AVP, VIP, or NMS neurons is sufficient to disrupted locomotor activity, this disruption is insufficient to recapitulate the neuroendocrine reproductive effects of the whole-body Bmal1 knockout.
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Affiliation(s)
- Karen J. Tonsfeldt
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
| | - Laura J. Cui
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Jinkwon Lee
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Thijs J. Walbeek
- Department of Psychology, University of California, San Diego, La Jolla, CA, United States
| | - Liza E. Brusman
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Ye Jin
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Michihiro Mieda
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Michael R. Gorman
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
- Department of Psychology, University of California, San Diego, La Jolla, CA, United States
| | - Pamela L. Mellon
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
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Enkephalin release from VIP interneurons in the hippocampal CA2/3a region mediates heterosynaptic plasticity and social memory. Mol Psychiatry 2022; 27:2879-2900. [PMID: 33990774 PMCID: PMC8590711 DOI: 10.1038/s41380-021-01124-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 03/23/2021] [Accepted: 04/13/2021] [Indexed: 12/22/2022]
Abstract
The hippocampus contains a diverse array of inhibitory interneurons that gate information flow through local cortico-hippocampal circuits to regulate memory storage. Although most studies of interneurons have focused on their role in fast synaptic inhibition mediated by GABA release, different classes of interneurons express unique sets of neuropeptides, many of which have been shown to exert powerful effects on neuronal function and memory when applied pharmacologically. However, relatively little is known about whether and how release of endogenous neuropeptides from inhibitory cells contributes to their behavioral role in regulating memory formation. Here we report that vasoactive intestinal peptide (VIP)-expressing interneurons participate in social memory storage by enhancing information transfer from hippocampal CA3 pyramidal neurons to CA2 pyramidal neurons. Notably, this action depends on release of the neuropeptide enkephalin from VIP neurons, causing long-term depression of feedforward inhibition onto CA2 pyramidal cells. Moreover, VIP neuron activity in the CA2 region is increased selectively during exploration of a novel conspecific. Our findings, thus, enhance our appreciation of how GABAergic neurons can regulate synaptic plasticity and mnemonic behavior by demonstrating that such actions can be mediated by release of a specific neuropeptide, rather than through classic fast inhibitory transmission.
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11
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Peng Y, Tsuno Y, Matsui A, Hiraoka Y, Tanaka K, Horike SI, Daikoku T, Mieda M. Cell Type-Specific Genetic Manipulation and Impaired Circadian Rhythms in ViptTA Knock-In Mice. Front Physiol 2022; 13:895633. [PMID: 35592033 PMCID: PMC9110775 DOI: 10.3389/fphys.2022.895633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 04/18/2022] [Indexed: 11/30/2022] Open
Abstract
The suprachiasmatic nucleus (SCN), the central circadian clock in mammals, is a neural network consisting of various types of GABAergic neurons, which can be differentiated by the co-expression of specific peptides such as vasoactive intestinal peptide (VIP) and arginine vasopressin (AVP). VIP has been considered as a critical factor for the circadian rhythmicity and synchronization of individual SCN neurons. However, the precise mechanisms of how VIP neurons regulate SCN circuits remain incompletely understood. Here, we generated ViptTA knock-in mice that express tetracycline transactivator (tTA) specifically in VIP neurons by inserting tTA sequence at the start codon of Vip gene. The specific and efficient expression of tTA in VIP neurons was verified using EGFP reporter mice. In addition, combined with Avp-Cre mice, ViptTA mice enabled us to simultaneously apply different genetic manipulations to VIP and AVP neurons in the SCN. Immunostaining showed that VIP is expressed at a slightly reduced level in heterozygous ViptTA mice but is completely absent in homozygous mice. Consistently, homozygous ViptTA mice showed impaired circadian behavioral rhythms similar to those of Vip knockout mice, such as attenuated rhythmicity and shortened circadian period. In contrast, heterozygous mice demonstrated normal circadian behavioral rhythms comparable to wild-type mice. These data suggest that ViptTA mice are a valuable genetic tool to express exogenous genes specifically in VIP neurons in both normal and VIP-deficient mice, facilitating the study of VIP neuronal roles in the SCN neural network.
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Affiliation(s)
- Yubo Peng
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Yusuke Tsuno
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Ayako Matsui
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Yuichi Hiraoka
- Laboratory of Molecular Neuroscience, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Shin-ichi Horike
- Division of Integrated Omics Research, Research Center for Experimental Modeling of Human Disease, Kanazawa University, Kanazawa, Japan
| | - Takiko Daikoku
- Division of Animal Disease Model, Research Center for Experimental Modeling of Human Disease, Kanazawa University, Kanazawa, Japan
| | - Michihiro Mieda
- Department of Integrative Neurophysiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
- *Correspondence: Michihiro Mieda,
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12
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Smith CB, van der Vinne V, McCartney E, Stowie AC, Leise TL, Martin-Burgos B, Molyneux PC, Garbutt LA, Brodsky MH, Davidson AJ, Harrington ME, Dallmann R, Weaver DR. Cell-Type-Specific Circadian Bioluminescence Rhythms in Dbp Reporter Mice. J Biol Rhythms 2022; 37:53-77. [PMID: 35023384 DOI: 10.1177/07487304211069452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Circadian rhythms are endogenously generated physiological and molecular rhythms with a cycle length of about 24 h. Bioluminescent reporters have been exceptionally useful for studying circadian rhythms in numerous species. Here, we report development of a reporter mouse generated by modification of a widely expressed and highly rhythmic gene encoding D-site albumin promoter binding protein (Dbp). In this line of mice, firefly luciferase is expressed from the Dbp locus in a Cre recombinase-dependent manner, allowing assessment of bioluminescence rhythms in specific cellular populations. A mouse line in which luciferase expression was Cre-independent was also generated. The Dbp reporter alleles do not alter Dbp gene expression rhythms in liver or circadian locomotor activity rhythms. In vivo and ex vivo studies show the utility of the reporter alleles for monitoring rhythmicity. Our studies reveal cell-type-specific characteristics of rhythms among neuronal populations within the suprachiasmatic nuclei ex vivo. In vivo studies show Dbp-driven bioluminescence rhythms in the liver of Albumin-Cre;DbpKI/+ "liver reporter" mice. After a shift of the lighting schedule, locomotor activity achieved the proper phase relationship with the new lighting cycle more rapidly than hepatic bioluminescence did. As previously shown, restricting food access to the daytime altered the phase of hepatic rhythmicity. Our model allowed assessment of the rate of recovery from misalignment once animals were provided with food ad libitum. These studies confirm the previously demonstrated circadian misalignment following environmental perturbations and reveal the utility of this model for minimally invasive, longitudinal monitoring of rhythmicity from specific mouse tissues.
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Affiliation(s)
- Ciearra B Smith
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts.,Graduate Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, Massachusetts
| | - Vincent van der Vinne
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts.,Department of Biology, Williams College, Williamstown, Massachusetts
| | | | - Adam C Stowie
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, Georgia
| | - Tanya L Leise
- Department of Mathematics & Statistics, Amherst College, Amherst, Massachusetts
| | | | | | - Lauren A Garbutt
- Division of Biomedical Sciences, Warwick Medical School, The University of Warwick, Coventry, UK
| | - Michael H Brodsky
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts
| | - Alec J Davidson
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, Georgia
| | | | - Robert Dallmann
- Division of Biomedical Sciences, Warwick Medical School, The University of Warwick, Coventry, UK
| | - David R Weaver
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts.,Graduate Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, Massachusetts.,NeuroNexus Institute, University of Massachusetts Chan Medical School, Worcester, Massachusetts
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13
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Bittman EL. Anatomical Methods to Study the Suprachiasmatic Nucleus. Methods Mol Biol 2022; 2482:191-210. [PMID: 35610428 PMCID: PMC10752494 DOI: 10.1007/978-1-0716-2249-0_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The mammalian suprachiasmatic nucleus (SCN) functions as a master circadian pacemaker. In order to examine mechanisms by which it keeps time, entrains to periodic environmental signals (zeitgebers), and regulates subordinate oscillators elsewhere in the brain and in the periphery, a variety of molecular methods have been applied. Multiple label immunocytochemistry and in situ hybridization provide anatomical insights that complement physiological approaches (such as ex vivo electrophysiology and luminometry) widely used to study the SCN.The anatomical methods require interpretation of data gathered from groups of individual animals sacrificed at different time points. This imposes constraints on the design of the experiments that aim to observe changes that occur with circadian phase in free-running conditions. It is essential in such experiments to account for differences in the periods of the subjects. Nevertheless, it is possible to resolve intracellular colocalization and regional expression of functionally important transcripts and/or their peptide products that serve as neuromodulators or neurotransmitters. Armed with these tools and others, understanding of the mechanisms by which the hypothalamic pacemaker regulates circadian function is progressing apace.
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Affiliation(s)
- Eric L Bittman
- Department of Biology and Program in Neuroscience & Behavior, University of Massachusetts, Amherst, MA, USA.
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14
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Rohr KE, Inda T, Evans JA. Vasopressin Resets the Central Circadian Clock in a Manner Influenced by Sex and Vasoactive Intestinal Polypeptide Signaling. Neuroendocrinology 2022; 112:904-916. [PMID: 34856551 PMCID: PMC9160207 DOI: 10.1159/000521286] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 12/01/2021] [Indexed: 01/03/2023]
Abstract
BACKGROUND/AIMS Circadian rhythms in behavior and physiology are programmed by the suprachiasmatic nucleus (SCN) of the hypothalamus. A subset of SCN neurons produce the neuropeptide arginine vasopressin (AVP), but it remains unclear whether AVP signaling influences the SCN clock directly. METHODS Here, we test that AVP signaling acting through V1A and V1B receptors influences molecular rhythms in SCN neurons. V1 receptor agonists were applied ex vivo to PERIOD2::LUCIFERASE SCN slices, allowing for real-time monitoring of changes in molecular clock function. RESULTS V1A/B agonists reset the phase of the SCN molecular clock in a time-dependent manner, with larger magnitude responses by the female SCN. Further, we found evidence that both Gαq and Gαs signaling pathways interact with V1A/B-induced SCN resetting, and that this response requires vasoactive intestinal polypeptide (VIP) signaling. CONCLUSIONS Collectively, this work indicates that AVP signaling resets SCN molecular rhythms in conjunction with VIP signaling and in a manner influenced by sex. This highlights the utility of studying clock function in both sexes and suggests that signal integration in central clock circuits regulates emergent properties important for the control of daily rhythms in behavior and physiology.
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Affiliation(s)
| | | | - Jennifer A. Evans
- Corresponding author: 560 N 16 St, Schroeder Complex, Room 446, Milwaukee, WI 53233, Phone: 414 288-5732, Fax: 414-288-6564,
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15
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Horie K, Inoue K, Nishimori K, Young LJ. Investigation of Oxtr-expressing Neurons Projecting to Nucleus Accumbens using Oxtr-ires-Cre Knock-in prairie Voles (Microtus ochrogaster). Neuroscience 2021; 448:312-324. [PMID: 33092784 DOI: 10.1016/j.neuroscience.2020.08.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/13/2020] [Accepted: 08/17/2020] [Indexed: 01/10/2023]
Abstract
Social bonds such as parent-infant attachment or pair bonds can be critical for mental and physical well-being. The monogamous prairie vole (Microtus ochrogaster) has proven useful for examining the neural substrates regulating social behaviors, including social bonding. Oxytocin (OXT) and oxytocin receptor (OXTR) play critical roles in alloparental care, pair bonding and consoling behavior in prairie voles. While OXTR in a few regions, such as the nucleus accumbnes (NAcc), prefrontal cortex (PFC) and anterior cingulate cortex (ACC), have been implicated in regulating these behaviors, the extent to which other OXT sensitive areas modulate social behaviors has not been investigated. The NAcc is a central hub for modulating OXTR dependent social behaviors. To identify neurons expressing Oxtr in prairie vole brain, we generated gene knock-in voles expressing Cre recombinase in tandem with Oxtr (Oxtr-ires-Cre) using CRISPR/Cas9 genome editing. We confirmed Oxtr and Cre mRNA co-localization in NAcc, validating this model. Next, we identified putative Oxtr-expressing neurons projecting to NAcc by infusing retrograde CRE-dependent EGFP AAV into NAcc and visualizing fluorescence. We found enhanced green fluorescent protein (EGFP) positive neurons in anterior olfactory nucleus, PFC, ACC, insular cortex (IC), paraventricular thalamus (PVT), basolateral amygdala (BLA), and posteromedial and posterolateral cortical amygdaloid area (PMCo, PLCo). The ACC to NAcc OXTR projection may represent a species-specific circuit since Oxtr-expressing neurons in the ACC of mice were reported not to project to the NAcc. This is the first delineation of Oxtr-expressing neural circuits in the prairie vole, and demonstrates the utility of this novel genetically modified organism for characterizing OXTR circuits involved in social behaviors.
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Affiliation(s)
- Kengo Horie
- Laboratory of Molecular Biology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-0845, Japan; Silvio O. Conte Center for Oxytocin and Social Cognition, Center for Translational Social Neuroscience, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, USA
| | - Kiyoshi Inoue
- Silvio O. Conte Center for Oxytocin and Social Cognition, Center for Translational Social Neuroscience, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, USA
| | - Katsuhiko Nishimori
- Laboratory of Molecular Biology, Department of Molecular and Cell Biology, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-0845, Japan.
| | - Larry J Young
- Silvio O. Conte Center for Oxytocin and Social Cognition, Center for Translational Social Neuroscience, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, USA; Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, 954 Gatewood Road, Atlanta, GA 30329, USA.
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16
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Rohr KE, Telega A, Savaglio A, Evans JA. Vasopressin regulates daily rhythms and circadian clock circuits in a manner influenced by sex. Horm Behav 2021; 127:104888. [PMID: 33202247 PMCID: PMC7855892 DOI: 10.1016/j.yhbeh.2020.104888] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/30/2020] [Accepted: 11/04/2020] [Indexed: 12/17/2022]
Abstract
Arginine vasopressin (AVP) is a neurohormone that alters cellular physiology through both endocrine and synaptic signaling. Circadian rhythms in AVP release and other biological processes are driven by the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. Loss of vasopressin signaling alters circadian behavior, but the basis of these effects remains unclear. Here we investigate the role of AVP signaling in circadian timekeeping by analyzing behavior and SCN function in a novel AVP-deficient mouse model. Consistent with previous work, loss of AVP signaling increases water consumption and accelerates recovery to simulated jetlag. We expand on these results to show that loss of AVP increases period, imprecision and plasticity of behavioral rhythms under constant darkness. Interestingly, the effect of AVP deficiency on circadian period was influenced by sex, with loss of AVP lengthening period in females but not males. Examining SCN function directly with ex vivo bioluminescence imaging of clock protein expression, we demonstrate that loss of AVP signaling modulates the period, precision, and phase relationships of SCN neurons in both sexes. This pattern of results suggests that there are likely sex differences in downstream targets of the SCN. Collectively, this work indicates that AVP signaling modulates circadian circuits in a manner influenced by sex, which provides new insight into sexual dimorphisms in the regulation of daily rhythms.
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Affiliation(s)
- Kayla E Rohr
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Adam Telega
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Alexandra Savaglio
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Jennifer A Evans
- Marquette University, Department of Biomedical Sciences, United States of America.
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17
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Shan Y, Abel JH, Li Y, Izumo M, Cox KH, Jeong B, Yoo SH, Olson DP, Doyle FJ, Takahashi JS. Dual-Color Single-Cell Imaging of the Suprachiasmatic Nucleus Reveals a Circadian Role in Network Synchrony. Neuron 2020; 108:164-179.e7. [PMID: 32768389 PMCID: PMC8265161 DOI: 10.1016/j.neuron.2020.07.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/17/2020] [Accepted: 07/10/2020] [Indexed: 01/08/2023]
Abstract
The suprachiasmatic nucleus (SCN) acts as a master pacemaker driving circadian behavior and physiology. Although the SCN is small, it is composed of many cell types, making it difficult to study the roles of particular cells. Here we develop bioluminescent circadian reporter mice that are Cre dependent, allowing the circadian properties of genetically defined populations of cells to be studied in real time. Using a Color-Switch PER2::LUCIFERASE reporter that switches from red PER2::LUCIFERASE to green PER2::LUCIFERASE upon Cre recombination, we assess circadian rhythms in two of the major classes of peptidergic neurons in the SCN: AVP (arginine vasopressin) and VIP (vasoactive intestinal polypeptide). Surprisingly, we find that circadian function in AVP neurons, not VIP neurons, is essential for autonomous network synchrony of the SCN and stability of circadian rhythmicity.
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Affiliation(s)
- Yongli Shan
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA
| | - John H Abel
- Department of Anesthesiology, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yan Li
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA
| | - Mariko Izumo
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA
| | - Kimberly H Cox
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA
| | - Byeongha Jeong
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA
| | - Seung-Hee Yoo
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA
| | - David P Olson
- Department of Pediatrics, Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Francis J Doyle
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA; Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Joseph S Takahashi
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA.
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18
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Suprachiasmatic VIP neurons are required for normal circadian rhythmicity and comprised of molecularly distinct subpopulations. Nat Commun 2020; 11:4410. [PMID: 32879310 PMCID: PMC7468160 DOI: 10.1038/s41467-020-17197-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 06/12/2020] [Indexed: 12/02/2022] Open
Abstract
The hypothalamic suprachiasmatic (SCN) clock contains several neurochemically defined cell groups that contribute to the genesis of circadian rhythms. Using cell-specific and genetically targeted approaches we have confirmed an indispensable role for vasoactive intestinal polypeptide-expressing SCN (SCNVIP) neurons, including their molecular clock, in generating the mammalian locomotor activity (LMA) circadian rhythm. Optogenetic-assisted circuit mapping revealed functional, di-synaptic connectivity between SCNVIP neurons and dorsomedial hypothalamic neurons, providing a circuit substrate by which SCNVIP neurons may regulate LMA rhythms. In vivo photometry revealed that while SCNVIP neurons are acutely responsive to light, their activity is otherwise behavioral state invariant. Single-nuclei RNA-sequencing revealed that SCNVIP neurons comprise two transcriptionally distinct subtypes, including putative pacemaker and non-pacemaker populations. Altogether, our work establishes necessity of SCNVIP neurons for the LMA circadian rhythm, elucidates organization of circadian outflow from and modulatory input to SCNVIP cells, and demonstrates a subpopulation-level molecular heterogeneity that suggests distinct functions for specific SCNVIP subtypes. Cell groups in the hypothalamic suprachiasmatic clock contribute to the genesis of circadian rhythms. The authors identified two populations of vasoactive intestinal polypeptide-expressing neurons in the suprachiasmatic nucleus which regulate locomotor circadian rhythm in mice.
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19
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Joye DAM, Rohr KE, Keller D, Inda T, Telega A, Pancholi H, Carmona-Alcocer V, Evans JA. Reduced VIP Expression Affects Circadian Clock Function in VIP-IRES-CRE Mice (JAX 010908). J Biol Rhythms 2020; 35:340-352. [PMID: 32460660 DOI: 10.1177/0748730420925573] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Circadian rhythms are programmed by the suprachiasmatic nucleus (SCN), which relies on neuropeptide signaling to maintain daily timekeeping. Vasoactive intestinal polypeptide (VIP) is critical for SCN function, but the precise role of VIP neurons in SCN circuits is not fully established. To interrogate their contribution to SCN circuits, VIP neurons can be manipulated specifically using the DNA-editing enzyme Cre recombinase. Although the Cre transgene is assumed to be inert by itself, we find that VIP expression is reduced in both heterozygous and homozygous adult VIP-IRES-Cre mice (JAX 010908). Compared with wild-type mice, homozygous VIP-Cre mice display faster reentrainment and shorter free-running period but do not become arrhythmic in constant darkness. Consistent with this phenotype, homozygous VIP-Cre mice display intact SCN PER2::LUC rhythms, albeit with altered period and network organization. We present evidence that the ability to sustain molecular rhythms in the VIP-Cre SCN is not due to residual VIP signaling; rather, arginine vasopressin signaling helps to sustain SCN function at both intracellular and intercellular levels in this model. This work establishes that the VIP-IRES-Cre transgene interferes with VIP expression but that loss of VIP can be mitigated by other neuropeptide signals to help sustain SCN function. Our findings have implications for studies employing this transgenic model and provide novel insight into neuropeptide signals that sustain daily timekeeping in the master clock.
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Affiliation(s)
- Deborah A M Joye
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Kayla E Rohr
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Danielle Keller
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Thomas Inda
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Adam Telega
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | - Harshida Pancholi
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
| | | | - Jennifer A Evans
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin
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20
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Paul S, Hanna L, Harding C, Hayter EA, Walmsley L, Bechtold DA, Brown TM. Output from VIP cells of the mammalian central clock regulates daily physiological rhythms. Nat Commun 2020; 11:1453. [PMID: 32193397 PMCID: PMC7081308 DOI: 10.1038/s41467-020-15277-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 02/29/2020] [Indexed: 12/27/2022] Open
Abstract
The suprachiasmatic nucleus (SCN) circadian clock is critical for optimising daily cycles in mammalian physiology and behaviour. The roles of the various SCN cell types in communicating timing information to downstream physiological systems remain incompletely understood, however. In particular, while vasoactive intestinal polypeptide (VIP) signalling is essential for SCN function and whole animal circadian rhythmicity, the specific contributions of VIP cell output to physiological control remains uncertain. Here we reveal a key role for SCN VIP cells in central clock output. Using multielectrode recording and optogenetic manipulations, we show that VIP neurons provide coordinated daily waves of GABAergic input to target cells across the paraventricular hypothalamus and ventral thalamus, supressing their activity during the mid to late day. Using chemogenetic manipulation, we further demonstrate specific roles for this circuitry in the daily control of heart rate and corticosterone secretion, collectively establishing SCN VIP cells as influential regulators of physiological timing. VIP-expressing neurons play a central role in circadian timekeeping within the mammalian central clock. Here the authors use opto- and chemogenetic approaches to show that VIP neuronal activity regulates rhythmic activity in downstream hypothalamic target neurons and their physiological functions.
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Affiliation(s)
- Sarika Paul
- Centre for Biological timing, Faculty of Biology Medicine & Health, University of Manchester, Manchester, UK
| | - Lydia Hanna
- Centre for Biological timing, Faculty of Biology Medicine & Health, University of Manchester, Manchester, UK.,School of Pharmacy, University of Reading, Reading, UK
| | - Court Harding
- Centre for Biological timing, Faculty of Biology Medicine & Health, University of Manchester, Manchester, UK
| | - Edward A Hayter
- Centre for Biological timing, Faculty of Biology Medicine & Health, University of Manchester, Manchester, UK
| | - Lauren Walmsley
- Centre for Biological timing, Faculty of Biology Medicine & Health, University of Manchester, Manchester, UK
| | - David A Bechtold
- Centre for Biological timing, Faculty of Biology Medicine & Health, University of Manchester, Manchester, UK
| | - Timothy M Brown
- Centre for Biological timing, Faculty of Biology Medicine & Health, University of Manchester, Manchester, UK.
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