1
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Concetti C, Viskaitis P, Grujic N, Duss SN, Privitera M, Bohacek J, Peleg-Raibstein D, Burdakov D. Exploratory Rearing Is Governed by Hypothalamic Melanin-Concentrating Hormone Neurons According to Locus Ceruleus. J Neurosci 2024; 44:e0015242024. [PMID: 38575343 PMCID: PMC11112542 DOI: 10.1523/jneurosci.0015-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 03/20/2024] [Accepted: 03/25/2024] [Indexed: 04/06/2024] Open
Abstract
Information seeking, such as standing on tiptoes to look around in humans, is observed across animals and helps survival. Its rodent analog-unsupported rearing on hind legs-was a classic model in deciphering neural signals of cognition and is of intense renewed interest in preclinical modeling of neuropsychiatric states. Neural signals and circuits controlling this dedicated decision to seek information remain largely unknown. While studying subsecond timing of spontaneous behavioral acts and activity of melanin-concentrating hormone (MCH) neurons (MNs) in behaving male and female mice, we observed large MN activity spikes that aligned to unsupported rears. Complementary causal, loss and gain of function, analyses revealed specific control of rear frequency and duration by MNs and MCHR1 receptors. Activity in a key stress center of the brain-the locus ceruleus noradrenaline cells-rapidly inhibited MNs and required functional MCH receptors for its endogenous modulation of rearing. By defining a neural module that both tracks and controls rearing, these findings may facilitate further insights into biology of information seeking.
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Affiliation(s)
- Cristina Concetti
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Paulius Viskaitis
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Nikola Grujic
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Sian N Duss
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Mattia Privitera
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Johannes Bohacek
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Daria Peleg-Raibstein
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
| | - Denis Burdakov
- Department of Health Sciences and Technology, Neuroscience Center Zürich (ZNZ), Swiss Federal Institute of Technology (ETH Zürich), Zürich 8092, Switzerland
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2
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Narimatsu Y, Kato M, Iwakoshi-Ukena E, Moriwaki S, Ogasawara A, Furumitsu M, Ukena K. Neurosecretory Protein GM-Expressing Neurons Participate in Lipid Storage and Inflammation in Newly Developed Cre Driver Male Mice. Biomedicines 2023; 11:3230. [PMID: 38137451 PMCID: PMC10740756 DOI: 10.3390/biomedicines11123230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/04/2023] [Accepted: 12/04/2023] [Indexed: 12/24/2023] Open
Abstract
Obesity induces inflammation in the hypothalamus and adipose tissue, resulting in metabolic disorders. A novel hypothalamic neuropeptide, neurosecretory protein GM (NPGM), was previously identified in the hypothalamus of vertebrates. While NPGM plays an important role in lipid metabolism in chicks, its metabolic regulatory effects in mammals remain unclear. In this study, a novel Cre driver line, NPGM-Cre, was generated for cell-specific manipulation. Cre-dependent overexpression of Npgm led to fat accumulation without increased food consumption in male NPGM-Cre mice. Chemogenetic activation of NPGM neurons in the hypothalamus acutely promoted feeding behavior and chronically resulted in a transient increase in body mass gain. Furthermore, the ablated NPGM neurons exhibited a tendency to be glucose intolerant, with infiltration of proinflammatory macrophages into the adipose tissue. These results suggest that NPGM neurons may regulate lipid storage and inflammatory responses, thereby maintaining glucose homeostasis.
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Affiliation(s)
- Yuki Narimatsu
- Laboratory of Neurometabolism, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8521, Japan (E.I.-U.); (S.M.)
| | | | | | | | | | | | - Kazuyoshi Ukena
- Laboratory of Neurometabolism, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8521, Japan (E.I.-U.); (S.M.)
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3
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Concetti C, Peleg-Raibstein D, Burdakov D. Hypothalamic MCH Neurons: From Feeding to Cognitive Control. FUNCTION 2023; 5:zqad059. [PMID: 38020069 PMCID: PMC10667013 DOI: 10.1093/function/zqad059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/06/2023] [Accepted: 10/11/2023] [Indexed: 12/01/2023] Open
Abstract
Modern neuroscience is progressively elucidating that the classic view positing distinct brain regions responsible for survival, emotion, and cognitive functions is outdated. The hypothalamus demonstrates the interdependence of these roles, as it is traditionally known for fundamental survival functions like energy and electrolyte balance, but is now recognized to also play a crucial role in emotional and cognitive processes. This review focuses on lateral hypothalamic melanin-concentrating hormone (MCH) neurons, producing the neuropeptide MCH-a relatively understudied neuronal population with integrative functions related to homeostatic regulation and motivated behaviors, with widespread inputs and outputs throughout the entire central nervous system. Here, we review early findings and recent literature outlining their role in the regulation of energy balance, sleep, learning, and memory processes.
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Affiliation(s)
- Cristina Concetti
- Neurobehavioural Dynamics Laboratory, ETH Zürich, Schorenstrasse 16, Schwerzenbach 8603, Switzerland
| | - Daria Peleg-Raibstein
- Neurobehavioural Dynamics Laboratory, ETH Zürich, Schorenstrasse 16, Schwerzenbach 8603, Switzerland
| | - Denis Burdakov
- Neurobehavioural Dynamics Laboratory, ETH Zürich, Schorenstrasse 16, Schwerzenbach 8603, Switzerland
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4
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Fang LZ, Linehan V, Licursi M, Alberto CO, Power JL, Parsons MP, Hirasawa M. Prostaglandin E 2 activates melanin-concentrating hormone neurons to drive diet-induced obesity. Proc Natl Acad Sci U S A 2023; 120:e2302809120. [PMID: 37467285 PMCID: PMC10401019 DOI: 10.1073/pnas.2302809120] [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: 03/07/2023] [Accepted: 05/09/2023] [Indexed: 07/21/2023] Open
Abstract
Hypothalamic inflammation reduces appetite and body weight during inflammatory diseases, while promoting weight gain when induced by high-fat diet (HFD). How hypothalamic inflammation can induce opposite energy balance outcomes remains unclear. We found that prostaglandin E2 (PGE2), a key hypothalamic inflammatory mediator of sickness, also mediates diet-induced obesity (DIO) by activating appetite-promoting melanin-concentrating hormone (MCH) neurons in the hypothalamus in rats and mice. The effect of PGE2 on MCH neurons is excitatory at low concentrations while inhibitory at high concentrations, indicating that these neurons can bidirectionally respond to varying levels of inflammation. During prolonged HFD, endogenous PGE2 depolarizes MCH neurons through an EP2 receptor-mediated inhibition of the electrogenic Na+/K+-ATPase. Disrupting this mechanism by genetic deletion of EP2 receptors on MCH neurons is protective against DIO and liver steatosis in male and female mice. Thus, an inflammatory mediator can directly stimulate appetite-promoting neurons to exacerbate DIO and fatty liver.
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Affiliation(s)
- Lisa Z. Fang
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Victoria Linehan
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Maria Licursi
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Christian O. Alberto
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Jacob L. Power
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Matthew P. Parsons
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
| | - Michiru Hirasawa
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’sA1B 3V6, Canada
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5
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Beekly BG, Rupp A, Burgess CR, Elias CF. Fast neurotransmitter identity of MCH neurons: Do contents depend on context? Front Neuroendocrinol 2023; 70:101069. [PMID: 37149229 PMCID: PMC11190671 DOI: 10.1016/j.yfrne.2023.101069] [Citation(s) in RCA: 1] [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: 12/13/2022] [Revised: 04/07/2023] [Accepted: 04/29/2023] [Indexed: 05/08/2023]
Abstract
Hypothalamic melanin-concentrating hormone (MCH) neurons participate in many fundamental neuroendocrine processes. While some of their effects can be attributed to MCH itself, others appear to depend on co-released neurotransmitters. Historically, the subject of fast neurotransmitter co-release from MCH neurons has been contentious, with data to support MCH neurons releasing GABA, glutamate, both, and neither. Rather than assuming a position in that debate, this review considers the evidence for all sides and presents an alternative explanation: neurochemical identity, including classical neurotransmitter content, is subject to change. With an emphasis on the variability of experimental details, we posit that MCH neurons may release GABA and/or glutamate at different points according to environmental and contextual factors. Through the lens of the MCH system, we offer evidence that the field of neuroendocrinology would benefit from a more nuanced and dynamic interpretation of neurotransmitter identity.
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Affiliation(s)
- B G Beekly
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States; Elizabeth W. Caswell Diabetes Institute, University of Michigan, Ann Arbor, MI, United States.
| | - A Rupp
- Elizabeth W. Caswell Diabetes Institute, University of Michigan, Ann Arbor, MI, United States
| | - C R Burgess
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States; Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI, United States
| | - C F Elias
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States; Elizabeth W. Caswell Diabetes Institute, University of Michigan, Ann Arbor, MI, United States
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6
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Crosstalk between Melanin Concentrating Hormone and Endocrine Factors: Implications for Obesity. Int J Mol Sci 2022; 23:ijms23052436. [PMID: 35269579 PMCID: PMC8910548 DOI: 10.3390/ijms23052436] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 02/10/2022] [Accepted: 02/21/2022] [Indexed: 01/03/2023] Open
Abstract
Melanin-concentrating hormone (MCH) is a 19aa cyclic peptide exclusively expressed in the lateral hypothalamic area, which is an area of the brain involved in a large number of physiological functions and vital processes such as nutrient sensing, food intake, sleep-wake arousal, memory formation, and reproduction. However, the role of the lateral hypothalamic area in metabolic regulation stands out as the most relevant function. MCH regulates energy balance and glucose homeostasis by controlling food intake and peripheral lipid metabolism, energy expenditure, locomotor activity and brown adipose tissue thermogenesis. However, the MCH control of energy balance is a complex mechanism that involves the interaction of several neuroendocrine systems. The aim of the present work is to describe the current knowledge of the crosstalk of MCH with different endocrine factors. We also provide our view about the possible use of melanin-concentrating hormone receptor antagonists for the treatment of metabolic complications. In light of the data provided here and based on its actions and function, we believe that the MCH system emerges as an important target for the treatment of obesity and its comorbidities.
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7
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Hypothalamic melanin-concentrating hormone regulates hippocampus-dorsolateral septum activity. Nat Neurosci 2022; 25:61-71. [PMID: 34980924 PMCID: PMC8741735 DOI: 10.1038/s41593-021-00984-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 11/10/2021] [Indexed: 12/15/2022]
Abstract
Hypothalamic melanin-concentrating hormone (MCH) polypeptide contributes to regulating energy homeostasis, sleep, and memory, though the mechanistic bases of its effects are unknown. Here, in mice, we uncover the physiological mechanism underlying the functional role of MCH signaling in projections to the dorsolateral septum (dLS), a region involved in routing hippocampal firing rhythms and encoding spatial memory based on such rhythms. Firing activity within the dLS in response to dorsal CA3 (dCA3) excitation is limited by strong feed-forward inhibition (FFI). We find that MCH synchronizes dLS neuronal firing with its dCA3 inputs by enhancing GABA release, which subsequently reduces the FFI and augments dCA3 excitatory input strength, both via presynaptic mechanisms. At the functional level, our data reveal a role for MCH signaling in the dLS in facilitating spatial memory. These findings support a model in which peptidergic signaling within the dLS modulates dorsal hippocampal output and supports memory encoding.
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8
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Al-Massadi O, Dieguez C, Schneeberger M, López M, Schwaninger M, Prevot V, Nogueiras R. Multifaceted actions of melanin-concentrating hormone on mammalian energy homeostasis. Nat Rev Endocrinol 2021; 17:745-755. [PMID: 34608277 DOI: 10.1038/s41574-021-00559-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 12/12/2022]
Abstract
Melanin-concentrating hormone (MCH) is a small cyclic peptide expressed in all mammals, mainly in the hypothalamus. MCH acts as a robust integrator of several physiological functions and has crucial roles in the regulation of sleep-wake rhythms, feeding behaviour and metabolism. MCH signalling has a very broad endocrine context and is involved in physiological functions and emotional states associated with metabolism, such as reproduction, anxiety, depression, sleep and circadian rhythms. MCH mediates its functions through two receptors (MCHR1 and MCHR2), of which only MCHR1 is common to all mammals. Owing to the wide variety of MCH downstream signalling pathways, MCHR1 agonists and antagonists have great potential as tools for the directed management of energy balance disorders and associated metabolic complications, and translational strategies using these compounds hold promise for the development of novel treatments for obesity. This Review provides an overview of the numerous roles of MCH in energy and glucose homeostasis, as well as in regulation of the mesolimbic dopaminergic circuits that encode the hedonic component of food intake.
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Affiliation(s)
- Omar Al-Massadi
- Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago (CHUS/SERGAS), Santiago de Compostela, Spain.
- CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain.
| | - Carlos Dieguez
- CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Marc Schneeberger
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Miguel López
- CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain
| | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Vincent Prevot
- Univ. Lille, Inserm, CHU Lille, Lille Neuroscience and Cognition, Laboratory of Development and Plasticity of the Neuroendocrine Brain, UMR-S1172, EGID, Lille, France
| | - Ruben Nogueiras
- CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain.
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, Spain.
- Galician Agency of Innovation (GAIN), Xunta de Galicia, Santiago de Compostela, Spain.
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9
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Robles-Oteiza C, Ayeni D, Levy S, Homer RJ, Kaech SM, Politi K. Elevated murine HB-EGF confers sensitivity to diphtheria toxin in EGFR-mutant lung adenocarcinoma. Dis Model Mech 2021; 14:272093. [PMID: 34494649 PMCID: PMC8617309 DOI: 10.1242/dmm.049072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 08/31/2021] [Indexed: 12/11/2022] Open
Abstract
Conditional ablation of defined cell populations in vivo can be achieved using genetically engineered mice in which the human diphtheria toxin (DT) receptor (DTR) is placed under control of a murine tissue-specific promotor, such that delivery of DT selectively ablates cells expressing this high-affinity human DTR; cells expressing only the endogenous low-affinity mouse DTR are assumed to be unaffected. Surprisingly, we found that systemic administration of DT induced rapid regression of murine lung adenocarcinomas that express human mutant EGFR in the absence of a transgenic allele containing human DTR. DT enzymatic activity was required for tumor regression, and mutant EGFR-expressing tumor cells were the primary target of DT toxicity. In FVB mice, EGFR-mutant tumors upregulated expression of HBEGF, which is the DTR in mice and humans. HBEGF blockade with the enzymatically inactive DT mutant CRM197 partially abrogated tumor regression induced by DT. These results suggest that elevated expression of murine HBEGF, i.e. the low-affinity DTR, confers sensitivity to DT in EGFR-mutant tumors, demonstrating a biological effect of DT in mice lacking transgenic DTR alleles and highlighting a unique vulnerability of EGFR-mutant lung cancers.
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Affiliation(s)
| | - Deborah Ayeni
- Department of Pathology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Stellar Levy
- Yale Cancer Center, Yale School of Medicine, New Haven, CT 06510, USA
| | - Robert J Homer
- Department of Pathology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Susan M Kaech
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06510, USA.,NOMIS Center for Immunobiology and Microbial Pathogenesis, Salk Institute, La Jolla, CA 92037, USA
| | - Katerina Politi
- Department of Pathology, Yale School of Medicine, New Haven, CT 06510, USA.,Yale Cancer Center, Yale School of Medicine, New Haven, CT 06510, USA.,Department of Medicine (Section of Medical Oncology), Yale School of Medicine, New Haven, CT 06510, USA
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10
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Izawa S, Yoneshiro T, Kondoh K, Nakagiri S, Okamatsu-Ogura Y, Terao A, Minokoshi Y, Yamanaka A, Kimura K. Melanin-concentrating hormone-producing neurons in the hypothalamus regulate brown adipose tissue and thus contribute to energy expenditure. J Physiol 2021; 600:815-827. [PMID: 33899241 DOI: 10.1113/jp281241] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 04/20/2021] [Indexed: 12/17/2022] Open
Abstract
KEY POINTS Melanin-concentrating hormone (MCH) neuron-ablated mice exhibit increased energy expenditure and reduced fat weight. Increased brown adipose tissue (BAT) activity and locomotor activity-independent energy expenditure contributed to body weight reduction in MCH neuron-ablated mice. MCH neurons send inhibitory input to the medullary raphe nucleus to modulate BAT activity. ABSTRACT Hypothalamic melanin-concentrating hormone (MCH) peptide robustly affects energy homeostasis. However, it is unclear whether and how MCH-producing neurons, which contain and release a variety of neuropeptides/transmitters, regulate energy expenditure in the central nervous system and peripheral tissues. We thus examined the regulation of energy expenditure by MCH neurons, focusing on interscapular brown adipose tissue (BAT) activity. MCH neuron-ablated mice exhibited reduced body weight, increased oxygen consumption, and increased BAT activity, which improved locomotor activity-independent energy expenditure. Trans-neuronal retrograde tracing with the recombinant pseudorabies virus revealed that MCH neurons innervate BAT via the sympathetic premotor region in the medullary raphe nucleus (MRN). MRN neurons were activated by MCH neuron ablation. Therefore, endogenous MCH neuron activity negatively modulates energy expenditure via BAT inhibition. MRN neurons might receive inhibitory input from MCH neurons to suppress BAT activity.
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Affiliation(s)
- Shuntaro Izawa
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan.,Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, 464-8601, Japan.,Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.,JSPS Research Fellowship for Young Scientists, Tokyo, 102-0083, Japan
| | - Takeshi Yoneshiro
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan.,Division of Metabolic Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, 153-8904, Japan
| | - Kunio Kondoh
- Division of Endocrinology and Metabolism, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, 444-8585, Japan
| | - Shohei Nakagiri
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan
| | - Yuko Okamatsu-Ogura
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan
| | - Akira Terao
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan.,Department of Biology, School of Biological Sciences, Tokai University, Sapporo, 005-8601, Japan
| | - Yasuhiko Minokoshi
- Division of Endocrinology and Metabolism, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, 444-8585, Japan
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, 464-8601, Japan.,Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Kazuhiro Kimura
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan
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11
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Concetti C, Burdakov D. Orexin/Hypocretin and MCH Neurons: Cognitive and Motor Roles Beyond Arousal. Front Neurosci 2021; 15:639313. [PMID: 33828450 PMCID: PMC8019792 DOI: 10.3389/fnins.2021.639313] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/01/2021] [Indexed: 02/01/2023] Open
Abstract
The lateral hypothalamus (LH) is classically implicated in sleep-wake control. It is the main source of orexin/hypocretin and melanin-concentrating hormone (MCH) neuropeptides in the brain, which have been both implicated in arousal state switching. These neuropeptides are produced by non-overlapping LH neurons, which both project widely throughout the brain, where release of orexin and MCH activates specific postsynaptic G-protein-coupled receptors. Optogenetic manipulations of orexin and MCH neurons during sleep indicate that they promote awakening and REM sleep, respectively. However, recordings from orexin and MCH neurons in awake, moving animals suggest that they also act outside sleep/wake switching. Here, we review recent studies showing that both orexin and MCH neurons can rapidly (sub-second-timescale) change their firing when awake animals experience external stimuli, or during self-paced exploration of objects and places. However, the sensory-behavioral correlates of orexin and MCH neural activation can be quite different. Orexin neurons are generally more dynamic, with about 2/3rds of them activated before and during self-initiated running, and most activated by sensory stimulation across sensory modalities. MCH neurons are activated in a more select manner, for example upon self-paced investigation of novel objects and by certain other novel stimuli. We discuss optogenetic and chemogenetic manipulations of orexin and MCH neurons, which combined with pharmacological blockade of orexin and MCH receptors, imply that these rapid LH dynamics shape fundamental cognitive and motor processes due to orexin and MCH neuropeptide actions in the awake brain. Finally, we contemplate whether the awake control of psychomotor brain functions by orexin and MCH are distinct from their “arousal” effects.
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Affiliation(s)
- Cristina Concetti
- Department of Health Sciences and Technology, ETH Zürich, Zurich, Switzerland
| | - Denis Burdakov
- Department of Health Sciences and Technology, ETH Zürich, Zurich, Switzerland
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12
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Lee J, Raycraft L, Johnson AW. The dynamic regulation of appetitive behavior through lateral hypothalamic orexin and melanin concentrating hormone expressing cells. Physiol Behav 2020; 229:113234. [PMID: 33130035 DOI: 10.1016/j.physbeh.2020.113234] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 02/07/2023]
Abstract
The lateral hypothalamic area (LHA) is a heterogeneous brain structure extensively studied for its potent role in regulating energy balance. The anatomical and molecular diversity of the LHA permits the orchestration of responses to energy sensing cues from the brain and periphery. Two of the primary cell populations within the LHA associated with integration of this information are Orexin (ORX) and Melanin Concentrating Hormone (MCH). While both of these non-overlapping populations exhibit orexigenic properties, the activities of these two systems support feeding behavior through contrasting mechanisms. We describe the anatomical and functional properties as well as interaction with other neuropeptides and brain reward and hedonic systems. Specific outputs relating to arousal, food seeking, feeding, and metabolism are coordinated through these mechanisms. We then discuss how both the ORX and MCH systems harmonize in a divergent yet overall cooperative manner to orchestrate feeding behavior through transitions between various appetitive states, and thus offer novel insights into LHA allostatic control of appetite.
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Affiliation(s)
| | | | - Alexander W Johnson
- Department of Psychology; Neuroscience Program, Michigan State University, East Lansing.
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13
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Bandaru SS, Khanday MA, Ibrahim N, Naganuma F, Vetrivelan R. Sleep-Wake Control by Melanin-Concentrating Hormone (MCH) Neurons: a Review of Recent Findings. Curr Neurol Neurosci Rep 2020; 20:55. [PMID: 33006677 DOI: 10.1007/s11910-020-01075-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE OF THE REVIEW Melanin-concentrating hormone (MCH)-expressing neurons located in the lateral hypothalamus are considered as an integral component of sleep-wake circuitry. However, the precise role of MCH neurons in sleep-wake regulation has remained unclear, despite several years of research employing a wide range of techniques. We review recent data on this aspect, which are mostly inconsistent, and propose a novel role for MCH neurons in sleep regulation. RECENT FINDINGS While almost all studies using "gain-of-function" approaches show an increase in rapid eye movement sleep (or paradoxical sleep; PS), loss-of-function approaches have not shown reductions in PS. Similarly, the reported changes in wakefulness or non-rapid eye movement sleep (slow-wave sleep; SWS) with manipulation of the MCH system using conditional genetic methods are inconsistent. Currently available data do not support a role for MCH neurons in spontaneous sleep-wake but imply a crucial role for them in orchestrating sleep-wake responses to changes in external and internal environments.
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Affiliation(s)
- Sathyajit S Bandaru
- Department of Neurology, Beth Israel Deaconess Medical Center, 3 Blackfan Circle, Center for Life Science # 711, Boston, MA, USA
| | - Mudasir A Khanday
- Department of Neurology, Beth Israel Deaconess Medical Center, 3 Blackfan Circle, Center for Life Science # 711, Boston, MA, USA.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Nazifa Ibrahim
- Department of Neurology, Beth Israel Deaconess Medical Center, 3 Blackfan Circle, Center for Life Science # 711, Boston, MA, USA.,Department of Public Health Sciences, University of Massachusetts, Amherst, MA, USA
| | - Fumito Naganuma
- Department of Neurology, Beth Israel Deaconess Medical Center, 3 Blackfan Circle, Center for Life Science # 711, Boston, MA, USA.,Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Ramalingam Vetrivelan
- Department of Neurology, Beth Israel Deaconess Medical Center, 3 Blackfan Circle, Center for Life Science # 711, Boston, MA, USA. .,Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA.
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14
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Control of fear extinction by hypothalamic melanin-concentrating hormone-expressing neurons. Proc Natl Acad Sci U S A 2020; 117:22514-22521. [PMID: 32848057 PMCID: PMC7486764 DOI: 10.1073/pnas.2007993117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Learning to fear danger is essential for survival. However, overactive, relapsing fear behavior in the absence of danger is a hallmark of disabling anxiety disorders that affect millions of people. Its suppression is thus of great interest, but the necessary brain components remain incompletely identified. We studied fear suppression through a procedure in which, after acquiring fear of aversive events (fear learning), subjects were exposed to fear-eliciting cues without aversive events (safety learning), leading to suppression of fear behavior (fear extinction). Here we show that inappropriate, learning-resistant fear behavior results from disruption of brain components not previously implicated in this disorder: hypothalamic melanin-concentrating hormone-expressing neurons (MNs). Using real-time recordings of MNs across fear learning and extinction, we provide evidence that fear-inducing aversive events elevate MN activity. We find that optogenetic disruption of this MN activity profoundly impairs safety learning, abnormally slowing down fear extinction and exacerbating fear relapse. Importantly, we demonstrate that the MN disruption impairs neither fear learning nor related sensory responses, indicating that MNs differentially control safety and fear learning. Thus, we identify a neural substrate for inhibition of excessive fear behavior.
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15
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Flanigan ME, Aleyasin H, Li L, Burnett CJ, Chan KL, LeClair KB, Lucas EK, Matikainen-Ankney B, Durand-de Cuttoli R, Takahashi A, Menard C, Pfau ML, Golden SA, Bouchard S, Calipari ES, Nestler EJ, DiLeone RJ, Yamanaka A, Huntley GW, Clem RL, Russo SJ. Orexin signaling in GABAergic lateral habenula neurons modulates aggressive behavior in male mice. Nat Neurosci 2020; 23:638-650. [PMID: 32284606 PMCID: PMC7195257 DOI: 10.1038/s41593-020-0617-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 03/02/2020] [Indexed: 11/30/2022]
Abstract
Heightened aggression is characteristic of multiple neuropsychiatric disorders and can have various negative effects on patients, their families and the public. Recent studies in humans and animals have implicated brain reward circuits in aggression and suggest that, in subsets of aggressive individuals, domination of subordinate social targets is reinforcing. In this study, we showed that, in male mice, orexin neurons in the lateral hypothalamus activated a small population of glutamic acid decarboxylase 2 (GAD2)-expressing neurons in the lateral habenula (LHb) via orexin receptor 2 (OxR2) and that activation of these GAD2 neurons promoted male-male aggression and conditioned place preference for aggression-paired contexts. Moreover, LHb GAD2 neurons were inhibitory within the LHb and dampened the activity of the LHb as a whole. These results suggest that the orexin system is important for the regulation of inter-male aggressive behavior and provide the first functional evidence of a local inhibitory circuit within the LHb.
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Affiliation(s)
- Meghan E Flanigan
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Hossein Aleyasin
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Long Li
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - C Joseph Burnett
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Kenny L Chan
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Katherine B LeClair
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Elizabeth K Lucas
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC, USA
| | - Bridget Matikainen-Ankney
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Romain Durand-de Cuttoli
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Aki Takahashi
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Laboratory of Behavioral Neuroendocrinology, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Caroline Menard
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Psychiatry and Neuroscience, Faculty of Medicine and CERVO Brain Research Center, Université Laval, Ville de Québec, QC, Canada
| | - Madeline L Pfau
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sam A Golden
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Sylvain Bouchard
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Erin S Calipari
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Eric J Nestler
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ralph J DiLeone
- Department of Psychiatry, Yale University, New Haven, CT, USA
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - George W Huntley
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Roger L Clem
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Scott J Russo
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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16
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Rogers AA, Aiani LM, Blanpain LT, Yuxian S, Moore R, Willie JT. Deep brain stimulation of hypothalamus for narcolepsy-cataplexy in mice. Brain Stimul 2020; 13:1305-1316. [PMID: 32320748 DOI: 10.1016/j.brs.2020.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 03/25/2020] [Accepted: 04/08/2020] [Indexed: 10/24/2022] Open
Abstract
BACKGROUND Narcolepsy type 1 (NT1, narcolepsy with cataplexy) is a disabling neurological disorder caused by loss of excitatory orexin neurons from the hypothalamus and is characterized by decreased motivation, sleep-wake fragmentation, intrusion of rapid-eye-movement sleep (REMS) during wake, and abrupt loss of muscle tone, called cataplexy, in response to sudden emotions. OBJECTIVE We investigated whether subcortical stimulation, analogous to clinical deep brain stimulation (DBS), would ameliorate NT1 using a validated transgenic mouse model with postnatal orexin neuron degeneration. METHODS Using implanted electrodes in freely behaving mice, the immediate and prolonged effects of DBS were determined upon behavior using continuous video-electroencephalogram-electromyogram (video/EEG/EMG) and locomotor activity, and neural activation in brain sections, using immunohistochemical labeling of the immediate early gene product c-Fos. RESULTS Brief 10-s stimulation to the region of the lateral hypothalamus and zona incerta (LH/ZI) dose-responsively reversed established sleep and cataplexy episodes without negative sequelae. Continuous 3-h stimulation increased ambulation, improved sleep-wake consolidation, and ameliorated cataplexy. Brain c-Fos from mice sacrificed after 90 min of DBS revealed dose-responsive neural activation within wake-active nuclei of the basal forebrain, hypothalamus, thalamus, and ventral midbrain. CONCLUSION Acute and continuous LH/ZI DBS enhanced behavioral state control in a mouse model of NT1, supporting the feasibility of clinical DBS for NT1 and other sleep-wake disorders.
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Affiliation(s)
| | - Lauren M Aiani
- Department of Neurosurgery, Emory University, USA; Department of Neurology, Emory University, USA
| | | | - Sun Yuxian
- Department of Biostatistics and Bioinformatics, Emory University, USA
| | - Renee Moore
- Department of Biostatistics and Bioinformatics, Emory University, USA
| | - Jon T Willie
- Department of Neurosurgery, Emory University, USA; Department of Neurology, Emory University, USA.
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17
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Regan MD, Flynn-Evans EE, Griko YV, Kilduff TS, Rittenberger JC, Ruskin KJ, Buck CL. Shallow metabolic depression and human spaceflight: a feasible first step. J Appl Physiol (1985) 2020; 128:637-647. [PMID: 31999524 DOI: 10.1152/japplphysiol.00725.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Synthetic torpor is an induced state of deep metabolic depression (MD) in an organism that does not naturally employ regulated and reversible MD. If applied to spaceflight crewmembers, this metabolic state may theoretically mitigate numerous biological and logistical challenges of human spaceflight. These benefits have been the focus of numerous recent articles where, invariably, they are discussed in the context of hypothetical deep MD states in which the metabolism of crewmembers is profoundly depressed relative to basal rates. However, inducing these deep MD states in humans, particularly humans aboard spacecraft, is currently impossible. Here, we discuss shallow MD as a feasible first step toward synthetic torpor during spaceflight and summarize perspectives following a recent NASA-hosted workshop. We discuss methods to safely induce shallow MD (e.g., sleep and slow wave enhancement via acoustic and photoperiod stimulation; moderate sedation via dexmedetomidine), which we define as an ~20% depression of metabolic rate relative to basal levels. We also discuss different modes of shallow MD application (e.g., habitual versus targeted, whereby shallow MD is induced routinely throughout a mission or only under certain circumstances, respectively) and different spaceflight scenarios that would benefit from its use. Finally, we propose a multistep development plan toward the application of synthetic torpor to human spaceflight, highlighting shallow MD's role. As space agencies develop missions to send humans further into space than ever before, shallow MD has the potential to confer health benefits for crewmembers, reduce demands on spacecraft capacities, and serve as a testbed for deeper MD technologies.
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Affiliation(s)
- Matthew D Regan
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Erin E Flynn-Evans
- Fatigue Countermeasures Laboratory, Human Systems Integration Division, NASA Ames Research Center, Moffett Field, California
| | - Yuri V Griko
- Countermeasure Development Laboratory, Space Biosciences Division, NASA Ames Research Center, Moffett Field, California
| | - Thomas S Kilduff
- Biosciences Division, Center for Neuroscience, SRI International, Menlo Park, California
| | - Jon C Rittenberger
- Guthrie Robert Packer Hospital Emergency Medicine Program, Geisinger Commonwealth School of Medicine, Scranton, Pennsylvania
| | - Keith J Ruskin
- Department of Anesthesia and Critical Care, University of Chicago, Chicago, Illinois
| | - C Loren Buck
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
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18
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Dilsiz P, Aklan I, Sayar Atasoy N, Yavuz Y, Filiz G, Koksalar F, Ates T, Oncul M, Coban I, Ates Oz E, Cebecioglu U, Alp MI, Yilmaz B, Atasoy D. MCH Neuron Activity Is Sufficient for Reward and Reinforces Feeding. Neuroendocrinology 2020; 110:258-270. [PMID: 31154452 DOI: 10.1159/000501234] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 05/31/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND Melanin-concentrating hormone (MCH)-expressing neurons have been implicated in regulation of energy homeostasis and reward, yet the role of their electrical activity in short-term appetite and reward modulation has not been fully understood. OBJECTIVES We investigated short-term behavioral and physiological effects of MCH neuron activity manipulations. METHODS We used optogenetic and chemogenetic approaches in Pmch-cre transgenic mice to acutely stimulate/inhibit MCH neuronal activity while probing feeding, locomotor activity, anxiety-like behaviors, glucose homeostasis, and reward. RESULTS MCH neuron activity is neither required nor sufficient for short-term appetite unless stimulation is temporally paired with consumption. MCH neuronal activation does not affect short-term locomotor activity, but inhibition improves glucose tolerance and is mildly anxiolytic. Finally, using two different operant tasks, we showed that activation of MCH neurons alone is sufficient to induce reward. CONCLUSIONS Our results confirm diverse behavioral/physiological functions of MCH neurons and suggest a direct role in reward function.
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Affiliation(s)
- Pelin Dilsiz
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Iltan Aklan
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
- Department of Pharmacology, Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Nilufer Sayar Atasoy
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
- Department of Pharmacology, Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Yavuz Yavuz
- Department of Physiology, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Gizem Filiz
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Fulya Koksalar
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Tayfun Ates
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Merve Oncul
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Ilknur Coban
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Edanur Ates Oz
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Utku Cebecioglu
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Muhammed Ikbal Alp
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey
| | - Bayram Yilmaz
- Department of Physiology, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Deniz Atasoy
- Department of Physiology, School of Medicine, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey,
- Department of Pharmacology, Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA,
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The role of co-neurotransmitters in sleep and wake regulation. Mol Psychiatry 2019; 24:1284-1295. [PMID: 30377299 PMCID: PMC6491268 DOI: 10.1038/s41380-018-0291-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 09/17/2018] [Accepted: 10/08/2018] [Indexed: 12/11/2022]
Abstract
Sleep and wakefulness control in the mammalian brain requires the coordination of various discrete interconnected neurons. According to the most conventional sleep model, wake-promoting neurons (WPNs) and sleep-promoting neurons (SPNs) compete for network dominance, creating a systematic "switch" that results in either the sleep or awake state. WPNs and SPNs are ubiquitous in the brainstem and diencephalon, areas that together contain <1% of the neurons in the human brain. Interestingly, many of these WPNs and SPNs co-express and co-release various types of the neurotransmitters that often have opposing modulatory effects on the network. Co-transmission is often beneficial to structures with limited numbers of neurons because it provides increasing computational capability and flexibility. Moreover, co-transmission allows subcortical structures to bi-directionally control postsynaptic neurons, thus helping to orchestrate several complex physiological functions such as sleep. Here, we present an in-depth review of co-transmission in hypothalamic WPNs and SPNs and discuss its functional significance in the sleep-wake network.
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20
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Chee MJ, Hebert AJ, Briançon N, Flaherty SE, Pissios P, Maratos-Flier E. Conditional deletion of melanin-concentrating hormone receptor 1 from GABAergic neurons increases locomotor activity. Mol Metab 2019; 29:114-123. [PMID: 31668382 PMCID: PMC6745487 DOI: 10.1016/j.molmet.2019.08.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/23/2019] [Accepted: 08/25/2019] [Indexed: 12/28/2022] Open
Abstract
Objective Melanin-concentrating hormone (MCH) plays a key role in regulating energy balance. MCH acts via its receptor MCHR1, and MCHR1 deletion increases energy expenditure and locomotor activity, which is associated with a hyperdopaminergic state. Since MCHR1 expression is widespread, the neurons supporting the effects of MCH on energy expenditure are not clearly defined. There is a high density of MCHR1 neurons in the striatum, and these neurons are known to be GABAergic. We thus determined if MCH acts via this GABAergic neurocircuit to mediate energy balance. Methods We generated a Mchr1-flox mouse and crossed it with the Vgat-cre mouse to assess if MCHR1 deletion from GABAergic neurons expressing the vesicular GABA transporter (vGAT) in female Vgat-Mchr1-KO mice resulted in lower body weights or increased energy expenditure. Additionally, we determined if MCHR1-expressing neurons within the accumbens form part of the neural circuit underlying MCH-mediated energy balance by delivering an adeno-associated virus expressing Cre recombinase to the accumbens nucleus of Mchr1-flox mice. To evaluate if a dysregulated dopaminergic tone leads to their hyperactivity, we determined if the dopamine reuptake blocker GBR12909 prolonged the drug-induced locomotor activity in Vgat-Mchr1-KO mice. Furthermore, we also performed amperometry recordings to test whether MCHR1 deletion increases dopamine output within the accumbens and whether MCH can suppress dopamine release. Results Vgat-Mchr1-KO mice have lower body weight, increased energy expenditure, and increased locomotor activity. Similarly, restricting MCHR1 deletion to the accumbens nucleus also increased locomotor activity. Vgat-Mchr1-KO mice show increased and prolonged sensitivity to GBR12909-induced locomotor activity, and amperometry recordings revealed that GBR12909 elevated accumbens dopamine levels to twice that of controls, thus MCHR1 deletion may lead to a hyperdopaminergic state that mediates their observed hyperactivity. Consistent with the inhibitory effect of MCH, we found that MCH acutely suppresses dopamine release within the accumbens. Conclusions As with established models of systemic MCH or MCHR1 deletion, we found that MCHR1 deletion from GABAergic neurons, specifically those within the accumbens nucleus, also led to increased locomotor activity. A hyperdopaminergic state underlies this increased locomotor activity, and is consistent with our finding that MCH signaling within the accumbens nucleus suppresses dopamine release. In effect, MCHR1 deletion may disinhibit dopamine release leading to the observed hyperactivity. Generation of Mchr1-flox mouse enabled cre-mediated deletion of Mchr1. Mchr1 deletion at GABAergic neurons decreased body weight. Mchr1 deletion at GABAergic neurons increased locomotor activity. Mchr1 deletion increased dopaminergic tone in the mesolimbic accumbens circuitry. MCH suppressed dopamine release in the accumbens nucleus.
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Affiliation(s)
- Melissa J Chee
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada; Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
| | - Alex J Hebert
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada; Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Nadege Briançon
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Stephen E Flaherty
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Pavlos Pissios
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Eleftheria Maratos-Flier
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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21
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Ruedl C, Jung S. DTR-mediated conditional cell ablation-Progress and challenges. Eur J Immunol 2019; 48:1114-1119. [PMID: 29974950 DOI: 10.1002/eji.201847527] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 05/28/2018] [Indexed: 12/14/2022]
Abstract
Cell ablation is a valuable complement to mutagenesis for experimentally defining specific cell functions in physiology and pathophysiology in small animal models. One of the most popular ablation strategies involves transgenic expression of a primate diphtheria toxin receptor (DTR) on murine cells that are otherwise resistant to the bacterial exotoxin. The efforts of many laboratories using the DTR approach over the years have yielded numerous valuable insights into specific cell functions. Here, we will discuss the technical aspects of the DTR approach, including the strengths, pitfalls, and future strategies to overcome the shortcomings, highlighting a recent paper published in the European Journal of Immunology [El Hachem et al. Eur. J. Immunol. 2018 https://doi.org/10.1002/eji.201747351]. A particular focus will be given to the application of DTR approach to decipher in vivo functions of the murine myeloid cell compartment.
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Affiliation(s)
- Christiane Ruedl
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Steffen Jung
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel
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22
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Naganuma F, Bandaru SS, Absi G, Mahoney CE, Scammell TE, Vetrivelan R. Melanin-concentrating hormone neurons contribute to dysregulation of rapid eye movement sleep in narcolepsy. Neurobiol Dis 2018; 120:12-20. [PMID: 30149182 PMCID: PMC6195361 DOI: 10.1016/j.nbd.2018.08.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 08/02/2018] [Accepted: 08/23/2018] [Indexed: 12/22/2022] Open
Abstract
The lateral hypothalamus contains neurons producing orexins that promote wakefulness and suppress REM sleep as well as neurons producing melanin-concentrating hormone (MCH) that likely promote REM sleep. Narcolepsy with cataplexy is caused by selective loss of the orexin neurons, and the MCH neurons appear unaffected. As the orexin and MCH systems exert opposing effects on REM sleep, we hypothesized that imbalance in this REM sleep-regulating system due to activity in the MCH neurons may contribute to the striking REM sleep dysfunction characteristic of narcolepsy. To test this hypothesis, we chemogenetically activated the MCH neurons and pharmacologically blocked MCH signaling in a murine model of narcolepsy and studied the effects on sleep-wake behavior and cataplexy. To chemoactivate MCH neurons, we injected an adeno-associated viral vector containing the hM3Dq stimulatory DREADD into the lateral hypothalamus of orexin null mice that also express Cre recombinase in the MCH neurons (MCH-Cre::OX-KO mice) and into control MCH-Cre mice with normal orexin expression. In both lines of mice, activation of MCH neurons by clozapine-N-oxide (CNO) increased rapid eye movement (REM) sleep without altering other states. In mice lacking orexins, activation of the MCH neurons also increased abnormal intrusions of REM sleep manifest as cataplexy and short latency transitions into REM sleep (SLREM). Conversely, a MCH receptor 1 antagonist, SNAP 94847, almost completely eliminated SLREM and cataplexy in OX-KO mice. These findings affirm that MCH neurons promote REM sleep under normal circumstances, and their activity in mice lacking orexins likely triggers abnormal intrusions of REM sleep into non-REM sleep and wake, resulting in the SLREM and cataplexy characteristic of narcolepsy.
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Affiliation(s)
- Fumito Naganuma
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA; Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, 1-15-1, Fukumuro, Miyagino-ku, Sendai 983-8536, Japan
| | - Sathyajit S Bandaru
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA
| | - Gianna Absi
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA
| | - Carrie E Mahoney
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA
| | - Thomas E Scammell
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA
| | - Ramalingam Vetrivelan
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston MA-02215, USA.
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23
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Arrigoni E, Chee MJS, Fuller PM. To eat or to sleep: That is a lateral hypothalamic question. Neuropharmacology 2018; 154:34-49. [PMID: 30503993 DOI: 10.1016/j.neuropharm.2018.11.017] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/08/2018] [Accepted: 11/12/2018] [Indexed: 12/15/2022]
Abstract
The lateral hypothalamus (LH) is a functionally and anatomically complex brain region that is involved in the regulation of many behavioral and physiological processes including feeding, arousal, energy balance, stress, reward and motivated behaviors, pain perception, body temperature regulation, digestive functions and blood pressure. Despite noteworthy experimental efforts over the past decades, the circuit, cellular and synaptic bases by which these different processes are regulated by the LH remains incompletely understood. This knowledge gap links in large part to the high cellular heterogeneity of the LH. Fortunately, the rapid evolution of newer genetic and electrophysiological tools is now permitting the selective manipulation, typically genetically-driven, of discrete LH cell populations. This, in turn, permits not only assignment of function to discrete cell groups, but also reveals that considerable synergistic and antagonistic interactions exist between key LH cell populations that regulate feeding and arousal. For example, we now know that while LH melanin-concentrating hormone (MCH) and orexin/hypocretin neurons both function as sensors of the internal metabolic environment, their roles regulating sleep and arousal are actually opposing. Additional studies have uncovered similarly important roles for subpopulations of LH GABAergic cells in the regulation of both feeding and arousal. Herein we review the role of LH MCH, orexin/hypocretin and GABAergic cell populations in the regulation of energy homeostasis (including feeding) and sleep-wake and discuss how these three cell populations, and their subpopulations, may interact to optimize and coordinate metabolism, sleep and arousal. This article is part of the Special Issue entitled 'Hypothalamic Control of Homeostasis'.
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Affiliation(s)
- Elda Arrigoni
- Department of Neurology, Beth Israel Deaconess Medical Center, Division of Sleep Medicine, Harvard Medical School, Boston, MA, 02215, USA.
| | - Melissa J S Chee
- Department of Neuroscience, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Patrick M Fuller
- Department of Neurology, Beth Israel Deaconess Medical Center, Division of Sleep Medicine, Harvard Medical School, Boston, MA, 02215, USA
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24
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Latifi B, Adamantidis A, Bassetti C, Schmidt MH. Sleep-Wake Cycling and Energy Conservation: Role of Hypocretin and the Lateral Hypothalamus in Dynamic State-Dependent Resource Optimization. Front Neurol 2018; 9:790. [PMID: 30344503 PMCID: PMC6183196 DOI: 10.3389/fneur.2018.00790] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/31/2018] [Indexed: 12/23/2022] Open
Abstract
The hypocretin (Hcrt) system has been implicated in a wide range of physiological functions from sleep-wake regulation to cardiovascular, behavioral, metabolic, and thermoregulagtory control. These wide-ranging physiological effects have challenged the identification of a parsimonious function for Hcrt. A compelling hypothesis suggests that Hcrt plays a role in the integration of sleep-wake neurophysiology with energy metabolism. For example, Hcrt neurons promote waking and feeding, but are also sensors of energy balance. Loss of Hcrt function leads to an increase in REM sleep propensity, but a potential role for Hcrt linking energy balance with REM sleep expression has not been addressed. Here we examine a potential role for Hcrt and the lateral hypothalamus (LH) in state-dependent resource allocation as a means of optimizing resource utilization and, as a result, energy conservation. We review the energy allocation hypothesis of sleep and how state-dependent metabolic partitioning may contribute toward energy conservation, but with additional examination of how the loss of thermoregulatory function during REM sleep may impact resource optimization. Optimization of energy expenditures at the whole organism level necessitates a top-down network responsible for coordinating metabolic operations in a state-dependent manner across organ systems. In this context, we then specifically examine the potential role of the LH in regulating this output control, including the contribution from both Hcrt and melanin concentrating hormone (MCH) neurons among a diverse LH cell population. We propose that this hypothalamic integration system is responsible for global shifts in state-dependent resource allocations, ultimately promoting resource optimization and an energy conservation function of sleep-wake cycling.
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Affiliation(s)
- Blerina Latifi
- Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Antoine Adamantidis
- Department of Neurology, Center for Experimental Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.,Department of Biomedical Research, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Claudio Bassetti
- Department of Neurology, Center for Experimental Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Markus H Schmidt
- Department of Neurology, Center for Experimental Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.,Ohio Sleep Medicine Institute, Dublin, OH, United States
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25
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Naganuma F, Bandaru SS, Absi G, Chee MJ, Vetrivelan R. Melanin-concentrating hormone neurons promote rapid eye movement sleep independent of glutamate release. Brain Struct Funct 2018; 224:99-110. [PMID: 30284033 DOI: 10.1007/s00429-018-1766-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 09/27/2018] [Indexed: 12/20/2022]
Abstract
Neurons containing melanin-concentrating hormone (MCH) in the posterior lateral hypothalamus play an integral role in rapid eye movement sleep (REMs) regulation. As MCH neurons also contain a variety of other neuropeptides [e.g., cocaine- and amphetamine-regulated transcript (CART) and nesfatin-1] and neurotransmitters (e.g., glutamate), the specific neurotransmitter responsible for REMs regulation is not known. We hypothesized that glutamate, the primary fast-acting neurotransmitter in MCH neurons, is necessary for REMs regulation. To test this hypothesis, we deleted vesicular glutamate transporter (Vglut2; necessary for synaptic release of glutamate) specifically from MCH neurons by crossing MCH-Cre mice (expressing Cre recombinase in MCH neurons) with Vglut2flox/flox mice (expressing LoxP-modified alleles of Vglut2), and studied the amounts, architecture and diurnal variation of sleep-wake states during baseline conditions. We then activated the MCH neurons lacking glutamate neurotransmission using chemogenetic methods and tested whether these MCH neurons still promoted REMs. Our results indicate that glutamate in MCH neurons contributes to normal diurnal variability of REMs by regulating the levels of REMs during the dark period, but MCH neurons can promote REMs even in the absence of glutamate.
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Affiliation(s)
- Fumito Naganuma
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, 3 Blackfan Circle, Center for Life Science # 717, Boston, MA, 02215, USA
- Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, 1-15-1, Fukumuro, Miyagino-ku, Sendai, 983-8536, Japan
| | - Sathyajit S Bandaru
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, 3 Blackfan Circle, Center for Life Science # 717, Boston, MA, 02215, USA
| | - Gianna Absi
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, 3 Blackfan Circle, Center for Life Science # 717, Boston, MA, 02215, USA
| | - Melissa J Chee
- Department of Neuroscience, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Ramalingam Vetrivelan
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, 3 Blackfan Circle, Center for Life Science # 717, Boston, MA, 02215, USA.
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26
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Burdakov D. How orexin signals bias action: Hypothalamic and accumbal circuits. Brain Res 2018; 1731:145943. [PMID: 30205111 DOI: 10.1016/j.brainres.2018.09.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/01/2018] [Accepted: 09/06/2018] [Indexed: 01/04/2023]
Abstract
Survival-maximizing, well-timed actions are a key responsibility of the brain. Hypothalamic neurons containing neurotransmitters orexins/hypocretins are important players in this process. Individuals without orexin neurons display inappropriately-timed transitions between arousal states, and other behavioural abnormalities including increased risk-taking. Deciphering neural circuits through which orexin neurons control brain states and behavior thus illuminates brain mechanisms of context-appropriate actions. This review outlines and puts into broader context recent examples of orexin circuit analyses in the lateral hypothalamus (LH) and the nucleus accumbens (NAc), two brain regions clasically implicated in context-appropriate actions. In the LH, orexin neurons excite GAD65-expressing neurons. The LH(GAD65) neuron excitation induces elevated locomotor activity, while inhibition of LH(GAD65) neuron natural activity depresses voluntary locomotion. The orexin → LH(GAD65) circuit may therefore assist in creating the drive to run. In the NAc shell region, orexin axons excite D2 neurons (dopamine-inhibited neurons expressing dopamine type-2 receptor). NAc(D2) cell activation increases risk-avoidance behaviors, while NAc(D2) cell inhibition reduces risk-avoidance. The excitatory orexin → NAc(D2) circuit may thus assist in reducing risk-taking, and oppose the inhibitory VTA(dopamine) → NAc(D2) circuit during computation of risk appetite. Neural computation in these local and long-range orexin circuits may thus assist in generating risk-avoiding locomotor responses to stressors known to activate orexin neurons, such as body energy depletion or potential external threats. A model is proposed where orexin-opposing, inhibitory inputs acting on the orexin target neurons may context-specifically channel orexin-induced brain excitation towards particular sets of actions.
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Affiliation(s)
- Denis Burdakov
- Swiss Federal Institute of Technology/ETH Zürich, Switzerland.
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27
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Brown J, Sagante A, Mayer T, Wright A, Bugescu R, Fuller PM, Leinninger G. Lateral Hypothalamic Area Neurotensin Neurons Are Required for Control of Orexin Neurons and Energy Balance. Endocrinology 2018; 159:3158-3176. [PMID: 30010830 PMCID: PMC6669822 DOI: 10.1210/en.2018-00311] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 07/10/2018] [Indexed: 12/12/2022]
Abstract
The lateral hypothalamic area (LHA) is essential for motivated ingestive and locomotor behaviors that impact body weight, yet it remains unclear how the neurochemically defined subpopulations of LHA neurons contribute to energy balance. In particular, the role of the large population of LHA neurotensin (Nts) neurons has remained ambiguous due to the lack of methods to easily visualize and modulate these neurons. Because LHA Nts neurons are activated by leptin and other anorectic cues and they modulate dopamine or local LHA orexin neurons implicated in energy balance, they may have important, unappreciated roles for coordinating behaviors necessary for proper body weight. In this study, we genetically ablated or chemogenetically inhibited LHA Nts neurons in adult mice to determine their necessity for control of motivated behaviors and body weight. Genetic ablation of LHA Nts neurons resulted in profoundly increased adiposity compared with mice with intact LHA Nts neurons, as well as diminished locomotor activity, energy expenditure, and water intake. Complete loss of LHA Nts neurons also led to downregulation of orexin, revealing important cross-talk between the LHA Nts and orexin populations in maintenance of behavior and body weight. In contrast, chemogenetic inhibition of intact LHA Nts neurons did not disrupt orexin expression, but it suppressed locomotor activity and the adaptive response to leptin. Taken together, these data reveal the necessity of LHA Nts neurons and their activation for controlling energy balance, and that LHA Nts neurons influence behavior and body weight via orexin-dependent and orexin-independent mechanisms.
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Affiliation(s)
- Juliette Brown
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan
- Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan
| | - Andrew Sagante
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Thomas Mayer
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Anna Wright
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Raluca Bugescu
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Patrick M Fuller
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts
| | - Gina Leinninger
- Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan
- Department of Physiology, Michigan State University, East Lansing, Michigan
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28
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Luo SX, Huang J, Li Q, Mohammad H, Lee CY, Krishna K, Kok AMY, Tan YL, Lim JY, Li H, Yeow LY, Sun J, He M, Grandjean J, Sajikumar S, Han W, Fu Y. Regulation of feeding by somatostatin neurons in the tuberal nucleus. Science 2018; 361:76-81. [PMID: 29976824 DOI: 10.1126/science.aar4983] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 05/08/2018] [Indexed: 12/28/2022]
Abstract
The tuberal nucleus (TN) is a surprisingly understudied brain region. We found that somatostatin (SST) neurons in the TN, which is known to exhibit pathological or cytological changes in human neurodegenerative diseases, play a crucial role in regulating feeding in mice. GABAergic tuberal SST (TNSST) neurons were activated by hunger and by the hunger hormone, ghrelin. Activation of TNSST neurons promoted feeding, whereas inhibition reduced it via projections to the paraventricular nucleus and bed nucleus of the stria terminalis. Ablation of TNSST neurons reduced body weight gain and food intake. These findings reveal a previously unknown mechanism of feeding regulation that operates through orexigenic TNSST neurons, providing a new perspective for understanding appetite changes.
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Affiliation(s)
- Sarah Xinwei Luo
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667
| | - Ju Huang
- Discipline of Neuroscience and Department of Anatomy, Histology and Embryology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China 200025
| | - Qin Li
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667.,Center for Brain Science, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China 430071
| | - Hasan Mohammad
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667
| | - Chun-Yao Lee
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667
| | - Kumar Krishna
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
| | - Alison Maun-Yeng Kok
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667
| | - Yu Lin Tan
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667
| | - Joy Yi Lim
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667
| | - Hongyu Li
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667
| | - Ling Yun Yeow
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667
| | - Jingjing Sun
- Discipline of Neuroscience and Department of Anatomy, Histology and Embryology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China 200025
| | - Miao He
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China 200032
| | - Joanes Grandjean
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667
| | - Sreedharan Sajikumar
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
| | - Weiping Han
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667
| | - Yu Fu
- Singapore Bioimaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore 138667. .,Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
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29
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Abstract
In contrast to synaptic transmission, the mechanism of volume transmission-in which neurotransmitters or neuropeptides diffuse to many effector cells-is not extensively investigated, although it represents an important mode of neuronal communication. In this issue of Cell Metabolism, Noble et al. (2018) demonstrate how the orexigenic melanin-concentrating hormone (MCH) controls feeding behavior through cerebrospinal fluid (CSF) volume transmission.
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Affiliation(s)
- Hong Jiang
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Str. 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Jens C Brüning
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Str. 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany.
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30
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Schneeberger M, Tan K, Nectow AR, Parolari L, Caglar C, Azevedo E, Li Z, Domingos A, Friedman JM. Functional analysis reveals differential effects of glutamate and MCH neuropeptide in MCH neurons. Mol Metab 2018; 13:83-89. [PMID: 29843980 PMCID: PMC6026325 DOI: 10.1016/j.molmet.2018.05.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 04/25/2018] [Accepted: 05/03/2018] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES Melanin-concentrating hormone (MCH) neurons in the lateral hypothalamus (LH) regulate food intake and body weight, glucose metabolism and convey the reward value of sucrose. In this report, we set out to establish the respective roles of MCH and conventional neurotransmitters in these neurons. METHODS MCH neurons were profiled using Cre-dependent molecular profiling technologies (vTRAP). MCHCre mice crossed to Vglut2fl/flmice or to DTRfl/flwere used to identify the role of glutamate in MCH neurons. We assessed metabolic parameters such as body composition, glucose tolerance, or sucrose preference. RESULTS We found that nearly all MCH neurons in the LH are glutamatergic and that a loss of glutamatergic signaling from MCH neurons from a glutamate transporter (VGlut2) knockout leads to a reduced weight, hypophagia and hyperkinetic behavior with improved glucose tolerance and a loss of sucrose preference. These effects are indistinguishable from those seen after ablation of MCH neurons. These findings are in contrast to those seen in mice with a knockout of the MCH neuropeptide, which show normal glucose preference and do not have improved glucose tolerance. CONCLUSIONS Overall, these data show that the vast majority of MCH neurons are glutamatergic, and that glutamate and MCH signaling mediate partially overlapping functions by these neurons, presumably by activating partially overlapping postsynaptic populations. The diverse functional effects of MCH neurons are thus mediated by a composite of glutamate and MCH signaling.
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Affiliation(s)
- Marc Schneeberger
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Keith Tan
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA; A*Star Institute of Medical Biology, 1 Fusionopolis Way, #20-10 Connexis North Tower, Singapore, 138632, Singapore
| | - Alexander R Nectow
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA; Princeton Neuroscience institute, Princeton University, Princeton, NJ, 08544-2098, USA
| | - Luca Parolari
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Caner Caglar
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Estefania Azevedo
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Zhiying Li
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Ana Domingos
- Obesity Laboratory, Instituto Gulbenkian de Ciência, Oeiras, 2780-156, Portugal
| | - Jeffrey M Friedman
- Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA.
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31
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Fast and Slow Oscillations Recruit Molecularly-Distinct Subnetworks of Lateral Hypothalamic Neurons In Situ. eNeuro 2018; 5:eN-NWR-0012-18. [PMID: 29423437 PMCID: PMC5802337 DOI: 10.1523/eneuro.0012-18.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 01/25/2018] [Indexed: 12/17/2022] Open
Abstract
Electrical signals generated by molecularly-distinct classes of lateral hypothalamus (LH) neurons have distinct physiological consequences. For example, LH orexin neurons promote net body energy expenditure, while LH non-orexin neurons [VGAT, melanin-concentrating hormone (MCH)] drive net energy conservation. Appropriate switching between such physiologically-opposing LH outputs is traditionally thought to require cell-type-specific chemical modulation of LH firing. However, it was recently found that, in vivo, the LH neurons are also physiologically exposed to electrical oscillations of different frequency bands. The role of the different physiological oscillation frequencies in firing of orexin vs non-orexin LH neurons remains unknown. Here, we used brain-slice whole-cell patch-clamp technology to target precisely-defined oscillation waveforms to individual molecularly-defined classes LH cells (orexin, VGAT, MCH, GAD65), while measuring the action potential output of the cells. By modulating the frequency of sinusoidal oscillatory input, we found that high-frequency oscillations (γ, ≈30–200 Hz) preferentially silenced the action potential output orexinLH cells. In contrast, low frequencies (δ-θ, ≈0.5–7 Hz) similarly permitted outputs from different LH cell types. This differential control of orexin and non-orexin cells by oscillation frequency was mediated by cell-specific, impedance-unrelated resonance mechanisms. These results substantiate electrical oscillations as a novel input modality for cell-type-specific control of LH firing, which offers an unforeseen way to control specific cell ensembles within this highly heterogeneous neuronal cluster.
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32
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Blomeley C, Garau C, Burdakov D. Accumbal D2 cells orchestrate innate risk-avoidance according to orexin signals. Nat Neurosci 2018; 21:29-32. [PMID: 29180747 PMCID: PMC5983352 DOI: 10.1038/s41593-017-0023-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 10/22/2017] [Indexed: 11/08/2022]
Abstract
Excitation of accumbal D2 cells governs vital actions, including avoidance of learned risks, but the origins of this excitation and roles of D2 cells in innate risk-avoidance are unclear. Hypothalamic neurons producing orexins (also called hypocretins) enhance innate risk-avoidance via poorly understood neurocircuits. We describe a direct orexin→D2 excitatory circuit and show that D2 cell activity is necessary for orexin-dependent innate risk-avoidance in mice, thus revealing an unsuspected hypothalamus-accumbens interplay in action selection.
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33
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Xie Y, Kaufmann D, Moulton MJ, Panahi S, Gaynes JA, Watters HN, Zhou D, Xue HH, Fung CM, Levine EM, Letsou A, Brennan KC, Dorsky RI. Lef1-dependent hypothalamic neurogenesis inhibits anxiety. PLoS Biol 2017; 15:e2002257. [PMID: 28837622 PMCID: PMC5570277 DOI: 10.1371/journal.pbio.2002257] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 07/21/2017] [Indexed: 11/19/2022] Open
Abstract
While innate behaviors are conserved throughout the animal kingdom, it is unknown whether common signaling pathways regulate the development of neuronal populations mediating these behaviors in diverse organisms. Here, we demonstrate that the Wnt/ß-catenin effector Lef1 is required for the differentiation of anxiolytic hypothalamic neurons in zebrafish and mice, although the identity of Lef1-dependent genes and neurons differ between these 2 species. We further show that zebrafish and Drosophila have common Lef1-dependent gene expression in their respective neuroendocrine organs, consistent with a conserved pathway that has diverged in the mouse. Finally, orthologs of Lef1-dependent genes from both zebrafish and mouse show highly correlated hypothalamic expression in marmosets and humans, suggesting co-regulation of 2 parallel anxiolytic pathways in primates. These findings demonstrate that during evolution, a transcription factor can act through multiple mechanisms to generate a common behavioral output, and that Lef1 regulates circuit development that is fundamentally important for mediating anxiety in a wide variety of animal species.
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Affiliation(s)
- Yuanyuan Xie
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah, United States of America
| | - Dan Kaufmann
- Department of Neurology, University of Utah, Salt Lake City, Utah, United States of America
| | - Matthew J. Moulton
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
| | - Samin Panahi
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah, United States of America
| | - John A. Gaynes
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah, United States of America
| | - Harrison N. Watters
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah, United States of America
| | - Dingxi Zhou
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah, United States of America
- School of Life Sciences, Peking University, Beijing, China
| | - Hai-Hui Xue
- Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Camille M. Fung
- Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Edward M. Levine
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, United States of America
| | - Anthea Letsou
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
| | - K. C. Brennan
- Department of Neurology, University of Utah, Salt Lake City, Utah, United States of America
| | - Richard I. Dorsky
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah, United States of America
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Diniz GB, Bittencourt JC. The Melanin-Concentrating Hormone as an Integrative Peptide Driving Motivated Behaviors. Front Syst Neurosci 2017; 11:32. [PMID: 28611599 PMCID: PMC5447028 DOI: 10.3389/fnsys.2017.00032] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 05/04/2017] [Indexed: 12/14/2022] Open
Abstract
The melanin-concentrating hormone (MCH) is an important peptide implicated in the control of motivated behaviors. History, however, made this peptide first known for its participation in the control of skin pigmentation, from which its name derives. In addition to this peripheral role, MCH is strongly implicated in motivated behaviors, such as feeding, drinking, mating and, more recently, maternal behavior. It is suggested that MCH acts as an integrative peptide, converging sensory information and contributing to a general arousal of the organism. In this review, we will discuss the various aspects of energy homeostasis to which MCH has been associated to, focusing on the different inputs that feed the MCH peptidergic system with information regarding the homeostatic status of the organism and the exogenous sensory information that drives this system, as well as the outputs that allow MCH to act over a wide range of homeostatic and behavioral controls, highlighting the available morphological and hodological aspects that underlie these integrative actions. Besides the well-described role of MCH in feeding behavior, a prime example of hypothalamic-mediated integration, we will also examine those functions in which the participation of MCH has not yet been extensively characterized, including sexual, maternal, and defensive behaviors. We also evaluated the available data on the distribution of MCH and its function in the context of animals in their natural environment. Finally, we briefly comment on the evidence for MCH acting as a coordinator between different modalities of motivated behaviors, highlighting the most pressing open questions that are open for investigations and that could provide us with important insights about hypothalamic-dependent homeostatic integration.
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Affiliation(s)
- Giovanne B. Diniz
- Laboratory of Chemical Neuroanatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São PauloSão Paulo, Brazil
| | - Jackson C. Bittencourt
- Laboratory of Chemical Neuroanatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São PauloSão Paulo, Brazil
- Center for Neuroscience and Behavior, Institute of Psychology, University of São PauloSão Paulo, Brazil
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Orexin-driven GAD65 network of the lateral hypothalamus sets physical activity in mice. Proc Natl Acad Sci U S A 2017; 114:4525-4530. [PMID: 28396414 DOI: 10.1073/pnas.1619700114] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Damage to the lateral hypothalamus (LH) causes profound physical inactivity in mammals. Several molecularly distinct types of LH neurons have been identified, including orexin cells and glutamic acid decarboxylase 65 (GAD65) cells, but their interplay in orchestrating physical activity is not fully understood. Here, using optogenetic circuit analysis and cell type-specific deep-brain recordings in behaving mice, we show that orexin cell activation rapidly recruits GAD65LH neurons. We demonstrate that internally initiated GAD65LH cell bursts precede and accompany spontaneous running bouts, that selective chemogenetic silencing of natural GAD65LH cell activity depresses voluntary locomotion, and that GAD65LH cell overactivation leads to hyperlocomotion. These results thus identify a molecularly distinct, orexin-activated LH submodule that governs physical activity in mice.
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Levels of Cocaine- and Amphetamine-Regulated Transcript in Vagal Afferents in the Mouse Are Unaltered in Response to Metabolic Challenges. eNeuro 2016; 3:eN-FTR-0174-16. [PMID: 27822503 PMCID: PMC5088776 DOI: 10.1523/eneuro.0174-16.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/15/2016] [Accepted: 09/16/2016] [Indexed: 12/21/2022] Open
Abstract
Cocaine- and amphetamine-regulated transcript (CART) is one of the most abundant neuropeptides in vagal afferents, including those involved in regulating feeding. Recent observations indicate that metabolic challenges dramatically alter the neuropeptidergic profile of CART-producing vagal afferents. Here, using confocal microscopy, we reassessed the distribution and regulation of CART(55–102) immunoreactivity in vagal afferents of the male mouse in response to metabolic challenges, including fasting and high-fat-diet feeding. Importantly, the perikarya and axons of vagal C-fibers were labeled using mice expressing channelrodhopsin-2 (ChR2-YFP) in Nav1.8-Cre–expressing neurons. In these mice, approximately 82% of the nodose ganglion neurons were labeled with ChR2-YFP. Furthermore, ChR2-YFP–labeled axons could easily be identified in the dorsovagal complex. CART(55–102) immunoreactivity was observed in 55% of the ChR2-YFP–labeled neurons in the nodose ganglion and 22% of the ChR2-YFP–labeled varicosities within the area postrema of fed, fasted, and obese mice. The distribution of positive profiles was also identical across the full range of CART staining in fed, fasted, and obese mice. In contrast to previous studies, fasting did not induce melanin-concentrating hormone (MCH) immunoreactivity in vagal afferents. Moreover, prepro-MCH mRNA was undetectable in the nodose ganglion of fasted mice. In summary, this study showed that the perikarya and central terminals of vagal afferents are invariably enriched in CART and devoid of MCH.
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Vetrivelan R, Kong D, Ferrari LL, Arrigoni E, Madara JC, Bandaru SS, Lowell BB, Lu J, Saper CB. Melanin-concentrating hormone neurons specifically promote rapid eye movement sleep in mice. Neuroscience 2016; 336:102-113. [PMID: 27595887 DOI: 10.1016/j.neuroscience.2016.08.046] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 08/25/2016] [Accepted: 08/27/2016] [Indexed: 12/30/2022]
Abstract
Currently available evidence indicates that neurons containing melanin-concentrating hormone (MCH) in the lateral hypothalamus are critical modulators of sleep-wakefulness, but their precise role in this function is not clear. Studies employing optogenetic stimulation of MCH neurons have yielded inconsistent results, presumably due to differences in the optogenetic stimulation protocols, which do not approximate normal patterns of cell firing. In order to resolve this discrepancy, we (1) selectively activated the MCH neurons using a chemogenetic approach (Cre-dependent hM3Dq expression) and (2) selectively destroyed MCH neurons using a genetically targeted diphtheria toxin deletion method, and studied the changes in sleep-wake in mice. Our results indicate that selective activation of MCH neurons causes specific increases in rapid eye movement (REM) sleep without altering wake or non-REM (NREM) sleep. On the other hand, selective deletions of MCH neurons altered the diurnal rhythm of wake and REM sleep without altering their total amounts. These results indicate that activation of MCH neurons primarily drives REM sleep and their presence may be necessary for normal expression of diurnal variation of REM sleep and wake.
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Affiliation(s)
- Ramalingam Vetrivelan
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston, MA 02215, United States.
| | - Dong Kong
- Department of Neuroscience, Tufts University School of Medicine, Programs of Neuroscience and Cellular, Molecular and Development Biology, Tufts Sackler School of Graduate Biomedical Sciences, Boston, MA 02111, United States
| | - Loris L Ferrari
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston, MA 02215, United States
| | - Elda Arrigoni
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston, MA 02215, United States
| | - Joseph C Madara
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, United States
| | - Sathyajit S Bandaru
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston, MA 02215, United States
| | - Bradford B Lowell
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, United States
| | - Jun Lu
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston, MA 02215, United States
| | - Clifford B Saper
- Department of Neurology, Beth Israel Deaconess Medical Center and Division of Sleep Medicine, Harvard Medical School, Boston, MA 02215, United States.
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38
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MCH receptor deletion does not impair glucose-conditioned flavor preferences in mice. Physiol Behav 2016; 163:239-244. [PMID: 27195455 DOI: 10.1016/j.physbeh.2016.05.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 04/06/2016] [Accepted: 05/14/2016] [Indexed: 11/22/2022]
Abstract
The post-oral actions of glucose stimulate intake and condition flavor preferences in rodents. Hypothalamic melanin-concentrating hormone (MCH) neurons are implicated in sugar reward, and this study investigated their involvement in glucose preference conditioning in mice. In Exp. 1 MCH receptor 1 knockout (KO) and C57BL/6 wildtype (WT) mice learned to prefer 8% glucose over an initially more-preferred non-nutritive 0.1% sucralose+saccharin (S+S) solution. In contrast, the KO and WT mice preferred S+S to 8% fructose, which is consistent with this sugar's weak post-oral reinforcing action. In Exp. 2 KO and WT mice were trained to drink a flavored solution (CS+) paired with intragastric (IG) infusion of 16% glucose and a different flavored solution (CS-) paired with IG water. Both groups drank more CS+ than CS- in training and preferred the CS+ to CS- in a 2-bottle test. These results indicate that MCH receptor signaling is not required for flavor preferences conditioned by the post-oral actions of glucose. This contrasts with other findings implicating MCH signaling in other types of sugar reward processing.
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Awake dynamics and brain-wide direct inputs of hypothalamic MCH and orexin networks. Nat Commun 2016; 7:11395. [PMID: 27102565 PMCID: PMC4844703 DOI: 10.1038/ncomms11395] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 03/21/2016] [Indexed: 12/18/2022] Open
Abstract
The lateral hypothalamus (LH) controls energy balance. LH melanin-concentrating-hormone (MCH) and orexin/hypocretin (OH) neurons mediate energy accumulation and expenditure, respectively. MCH cells promote memory and appropriate stimulus-reward associations; their inactivation disrupts energy-optimal behaviour and causes weight loss. However, MCH cell dynamics during wakefulness are unknown, leaving it unclear if they differentially participate in brain activity during sensory processing. By fiberoptic recordings from molecularly defined populations of LH neurons in awake freely moving mice, we show that MCH neurons generate conditional population bursts. This MCH cell activity correlates with novelty exploration, is inhibited by stress and is inversely predicted by OH cell activity. Furthermore, we obtain brain-wide maps of monosynaptic inputs to MCH and OH cells, and demonstrate optogenetically that VGAT neurons in the amygdala and bed nucleus of stria terminalis inhibit MCH cells. These data reveal cell-type-specific LH dynamics during sensory integration, and identify direct neural controllers of MCH neurons. Hypothalamic neurons expressing melanin-concentrating-hormone (MCH) maintain body weight by orchestrating behaviour and metabolism, but little is known about their intrinsic regulation. Here, Gonzalez and colleagues reveal their behaviour-related dynamics during wakefulness, and map their brain-wide neural inputs.
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Petrenko V, Mihhailova J, Salmon P, Kiss JZ. Apoptotic neurons induce proliferative responses of progenitor cells in the postnatal neocortex. Exp Neurol 2015; 273:126-37. [PMID: 26291762 DOI: 10.1016/j.expneurol.2015.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 07/13/2015] [Accepted: 08/11/2015] [Indexed: 12/29/2022]
Abstract
Apoptotic cell death is the leading cause of neuronal loss after neonatal brain injury. Little is known about the intrinsic capacity of the immature cerebral cortex for replacing dead cells. Here we test the hypothesis that neuronal apoptosis is able to trigger compensatory proliferation in surrounding cells. In order to establish a "pure" apoptotic cell death model and to avoid the confounding effects of broken blood-brain barrier and inflammatory reactions, we used a diphtheria toxin (DT) and diphtheria toxin receptor (DTR) system to induce ablation of layer IV neurons in the rodent somatosensory cortex during the early postnatal period. We found that DT-triggered apoptosis is a slowly progressing event lasting about for 7 days. While dying cells expressed the morphological features of apoptosis, we could not detect immunoreactivity for activated caspase-3 in these cells. Microglia activation and proliferation represented the earliest cellular responses to apoptotic cell death. In addition, we found that induced apoptosis triggered a massive proliferation of undifferentiated progenitor cell pool including Sox2 as well as NG2 cells. The default differentiation pattern of proliferating progenitors appears to be the glial phenotype; we could not find evidence for newly generated neurons in response to apoptotic neuronal death. These results suggest that mitotically active progenitor populations are intrinsically capable to contribute to the repair process of injured cortical tissue and may represent a potential target for neuronal replacement strategies.
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Affiliation(s)
- Volodymyr Petrenko
- Department of Neurosciences, University of Geneva Medical School, CH-1211 Geneva 4, Switzerland
| | - Jevgenia Mihhailova
- Department of Neurosciences, University of Geneva Medical School, CH-1211 Geneva 4, Switzerland
| | - Patrick Salmon
- Department of Neurosciences, University of Geneva Medical School, CH-1211 Geneva 4, Switzerland
| | - Jozsef Z Kiss
- Department of Neurosciences, University of Geneva Medical School, CH-1211 Geneva 4, Switzerland.
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41
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Chee MJS, Douris N, Forrow AB, Monnard A, Lu S, Flaherty SE, Adams AC, Maratos-Flier E. Melanin-concentrating hormone is necessary for olanzapine-inhibited locomotor activity in male mice. Eur Neuropsychopharmacol 2015; 25:1808-16. [PMID: 26092201 PMCID: PMC4609648 DOI: 10.1016/j.euroneuro.2015.05.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 04/07/2015] [Accepted: 05/25/2015] [Indexed: 01/01/2023]
Abstract
Olanzapine (OLZ), an atypical antipsychotic, can be effective in treating patients with restricting type anorexia nervosa who exercise excessively. Clinical improvements include weight gain and reduced pathological hyperactivity. However the neuronal populations and mechanisms underlying OLZ actions are not known. We studied the effects of OLZ on hyperactivity using male mice lacking the hypothalamic neuropeptide melanin-concentrating hormone (MCHKO) that are lean and hyperactive. We compared the in vivo effects of systemic or intra-accumbens nucleus (Acb) OLZ administration on locomotor activity in WT and MCHKO littermates. Acute systemic OLZ treatment in WT mice significantly reduced locomotor activity, an effect that is substantially attenuated in MCHKO mice. Furthermore, OLZ infusion directly into the Acb of WT mice reduced locomotor activity, but not in MCHKO mice. To identify contributing neuronal mechanisms, we assessed the effect of OLZ treatment on Acb synaptic transmission ex vivo and in vitro. Intraperitoneal OLZ treatment reduced Acb GABAergic activity in WT but not MCHKO neurons. This effect was also seen in vitro by applying OLZ to acute brain slices. OLZ reduced the frequency and amplitude of GABAergic activity that was more robust in WT than MCHKO Acb. These findings indicate that OLZ reduced Acb GABAergic transmission and that MCH is necessary for the hypolocomotor effects of OLZ.
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Affiliation(s)
- Melissa J S Chee
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Nicholas Douris
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Avery B Forrow
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Arnaud Monnard
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Shuangyu Lu
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Stephen E Flaherty
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Andrew C Adams
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Eleftheria Maratos-Flier
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
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42
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Skrapits K, Kanti V, Savanyú Z, Maurnyi C, Szenci O, Horváth A, Borsay BÁ, Herczeg L, Liposits Z, Hrabovszky E. Lateral hypothalamic orexin and melanin-concentrating hormone neurons provide direct input to gonadotropin-releasing hormone neurons in the human. Front Cell Neurosci 2015; 9:348. [PMID: 26388735 PMCID: PMC4559643 DOI: 10.3389/fncel.2015.00348] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 08/20/2015] [Indexed: 12/03/2022] Open
Abstract
Hypophysiotropic projections of gonadotropin-releasing hormone (GnRH)-synthesizing neurons form the final common output way of the hypothalamus in the neuroendocrine control of reproduction. Several peptidergic neuronal systems of the medial hypothalamus innervate human GnRH cells and mediate crucially important hormonal and metabolic signals to the reproductive axis, whereas much less is known about the contribution of the lateral hypothalamic area to the afferent control of human GnRH neurons. Orexin (ORX)- and melanin-concentrating hormone (MCH)-synthesizing neurons of this region have been implicated in diverse behavioral and autonomic processes, including sleep and wakefulness, feeding and other functions. In the present immunohistochemical study, we addressed the anatomical connectivity of these neurons to human GnRH cells in post-mortem hypothalamic samples obtained from autopsies. We found that 38.9 ± 10.3% and 17.7 ± 3.3% of GnRH-immunoreactive (IR) perikarya in the infundibular nucleus of human male subjects received ORX-IR and MCH-IR contacts, respectively. On average, each 1 mm segment of GnRH dendrites received 7.3 ± 1.1 ORX-IR and 3.7 ± 0.5 MCH-IR axo-dendritic appositions. Overall, the axo-dendritic contacts dominated over the axo-somatic contacts and represented 80.5 ± 6.4% of ORX-IR and 76.7 ± 4.6% of MCH-IR inputs to GnRH cells. Based on functional evidence from studies of laboratory animals, the direct axo-somatic and axo-dendritic input from ORX and MCH neurons to the human GnRH neuronal system may convey critical metabolic and other homeostatic signals to the reproducive axis. In this study, we also report the generation and characterization of new antibodies for immunohistochemical detection of GnRH neurons in histological sections.
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Affiliation(s)
- Katalin Skrapits
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Vivien Kanti
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Zsófia Savanyú
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Csilla Maurnyi
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
| | - Ottó Szenci
- Department and Clinic for Production Animals, Faculty of Veterinary Science, Szent István University Üllő, Hungary ; MTA-SZIE Large Animal Clinical Research Group, Dóra major Üllő, Hungary
| | - András Horváth
- Department and Clinic for Production Animals, Faculty of Veterinary Science, Szent István University Üllő, Hungary
| | - Beáta Á Borsay
- Department of Forensic Medicine, Faculty of Medicine of the University of Debrecen Debrecen, Hungary
| | - László Herczeg
- Department of Forensic Medicine, Faculty of Medicine of the University of Debrecen Debrecen, Hungary
| | - Zsolt Liposits
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary ; Department of Neuroscience, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University Budapest, Hungary
| | - Erik Hrabovszky
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences Budapest, Hungary
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Sokolowski K, Esumi S, Hirata T, Kamal Y, Tran T, Lam A, Oboti L, Brighthaupt SC, Zaghlula M, Martinez J, Ghimbovschi S, Knoblach S, Pierani A, Tamamaki N, Shah NM, Jones KS, Corbin JG. Specification of select hypothalamic circuits and innate behaviors by the embryonic patterning gene dbx1. Neuron 2015; 86:403-16. [PMID: 25864637 DOI: 10.1016/j.neuron.2015.03.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 12/29/2014] [Accepted: 03/03/2015] [Indexed: 12/30/2022]
Abstract
The hypothalamus integrates information required for the production of a variety of innate behaviors such as feeding, mating, aggression, and predator avoidance. Despite an extensive knowledge of hypothalamic function, how embryonic genetic programs specify circuits that regulate these behaviors remains unknown. Here, we find that in the hypothalamus the developmentally regulated homeodomain-containing transcription factor Dbx1 is required for the generation of specific subclasses of neurons within the lateral hypothalamic area/zona incerta (LH) and the arcuate (Arc) nucleus. Consistent with this specific developmental role, Dbx1 hypothalamic-specific conditional-knockout mice display attenuated responses to predator odor and feeding stressors but do not display deficits in other innate behaviors such as mating or conspecific aggression. Thus, activity of a single developmentally regulated gene, Dbx1, is a shared requirement for the specification of hypothalamic nuclei governing a subset of innate behaviors. VIDEO ABSTRACT.
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Affiliation(s)
- Katie Sokolowski
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Shigeyuki Esumi
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA; Graduate School of Medical Sciences, Kumamoto University, 2-39-1 Kurokami, Chuo Ward, Kumamoto, Kumamoto Prefecture 860-0862, Japan
| | - Tsutomu Hirata
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Yasman Kamal
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Tuyen Tran
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Andrew Lam
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Livio Oboti
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Sherri-Chanelle Brighthaupt
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Manar Zaghlula
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Jennifer Martinez
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Svetlana Ghimbovschi
- Center for Genetic Medicine, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Susan Knoblach
- Center for Genetic Medicine, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
| | - Alessandra Pierani
- Institut Jacques Monod, Universite Paris Diderot, 15 rue Hélène Brion, 75013 Paris, France
| | - Nobuaki Tamamaki
- Graduate School of Medical Sciences, Kumamoto University, 2-39-1 Kurokami, Chuo Ward, Kumamoto, Kumamoto Prefecture 860-0862, Japan
| | - Nirao M Shah
- Department of Anatomy, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Kevin S Jones
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA; Department of Biology, Howard University, 415 College Street NW, Washington, DC 20059, USA
| | - Joshua G Corbin
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA.
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Ren H, Lu TY, McGraw TE, Accili D. Anorexia and impaired glucose metabolism in mice with hypothalamic ablation of Glut4 neurons. Diabetes 2015; 64:405-17. [PMID: 25187366 PMCID: PMC4303970 DOI: 10.2337/db14-0752] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The central nervous system (CNS) uses glucose independent of insulin. Nonetheless, insulin receptors and insulin-responsive glucose transporters (Glut4) often colocalize in neurons (Glut4 neurons) in anatomically and functionally distinct areas of the CNS. The apparent heterogeneity of Glut4 neurons has thus far thwarted attempts to understand their function. To answer this question, we used Cre-dependent, diphtheria toxin-mediated cell ablation to selectively remove basal hypothalamic Glut4 neurons and investigate the resulting phenotypes. After Glut4 neuron ablation, mice demonstrate altered hormone and nutrient signaling in the CNS. Accordingly, they exhibit negative energy balance phenotype characterized by reduced food intake and increased energy expenditure, without locomotor deficits or gross neuronal abnormalities. Glut4 neuron ablation affects orexigenic melanin-concentrating hormone neurons but has limited effect on neuropeptide Y/agouti-related protein and proopiomelanocortin neurons. The food intake phenotype can be partially normalized by GABA administration, suggesting that it arises from defective GABAergic transmission. Glut4 neuron-ablated mice show peripheral metabolic defects, including fasting hyperglycemia and glucose intolerance, decreased insulin levels, and elevated hepatic gluconeogenic genes. We conclude that Glut4 neurons integrate hormonal and nutritional cues and mediate CNS actions of insulin on energy balance and peripheral metabolism.
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Affiliation(s)
- Hongxia Ren
- Department of Medicine and Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, NY
| | - Taylor Y Lu
- Department of Medicine and Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, NY
| | - Timothy E McGraw
- Department of Biochemistry, Weill Cornell Medical College, New York, NY
| | - Domenico Accili
- Department of Medicine and Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, NY
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45
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Jennings JH, Ung RL, Resendez SL, Stamatakis AM, Taylor JG, Huang J, Veleta K, Kantak PA, Aita M, Shilling-Scrivo K, Ramakrishnan C, Deisseroth K, Otte S, Stuber GD. Visualizing hypothalamic network dynamics for appetitive and consummatory behaviors. Cell 2015; 160:516-27. [PMID: 25635459 PMCID: PMC4312416 DOI: 10.1016/j.cell.2014.12.026] [Citation(s) in RCA: 373] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 10/28/2014] [Accepted: 11/24/2014] [Indexed: 01/02/2023]
Abstract
Optimally orchestrating complex behavioral states, such as the pursuit and consumption of food, is critical for an organism's survival. The lateral hypothalamus (LH) is a neuroanatomical region essential for appetitive and consummatory behaviors, but whether individual neurons within the LH differentially contribute to these interconnected processes is unknown. Here, we show that selective optogenetic stimulation of a molecularly defined subset of LH GABAergic (Vgat-expressing) neurons enhances both appetitive and consummatory behaviors, whereas genetic ablation of these neurons reduced these phenotypes. Furthermore, this targeted LH subpopulation is distinct from cells containing the feeding-related neuropeptides, melanin-concentrating hormone (MCH), and orexin (Orx). Employing in vivo calcium imaging in freely behaving mice to record activity dynamics from hundreds of cells, we identified individual LH GABAergic neurons that preferentially encode aspects of either appetitive or consummatory behaviors, but rarely both. These tightly regulated, yet highly intertwined, behavioral processes are thus dissociable at the cellular level.
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Affiliation(s)
- Joshua H Jennings
- Departments of Psychiatry and Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA; Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Randall L Ung
- Departments of Psychiatry and Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA; Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Shanna L Resendez
- Departments of Psychiatry and Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Alice M Stamatakis
- Departments of Psychiatry and Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA; Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Johnathon G Taylor
- Departments of Psychiatry and Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Jonathan Huang
- Departments of Psychiatry and Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Katie Veleta
- Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Pranish A Kantak
- Departments of Psychiatry and Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Megumi Aita
- Departments of Psychiatry and Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kelson Shilling-Scrivo
- Departments of Psychiatry and Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Charu Ramakrishnan
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | | | - Garret D Stuber
- Departments of Psychiatry and Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA; Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC 27599, USA.
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Posttraining ablation of adult-generated olfactory granule cells degrades odor-reward memories. J Neurosci 2015; 34:15793-803. [PMID: 25411506 DOI: 10.1523/jneurosci.2336-13.2014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Proliferation of neural progenitor cells in the subventricular zone leads to the continuous generation of new olfactory granule cells (OGCs) throughout life. These cells synaptically integrate into olfactory bulb circuits after ∼2 weeks and transiently exhibit heightened plasticity and responses to novel odors. Although these observations suggest that adult-generated OGCs play important roles in olfactory-related memories, global suppression of olfactory neurogenesis does not typically prevent the formation of odor-reward memories, perhaps because residual OGCs can compensate. Here, we used a transgenic strategy to selectively ablate large numbers of adult-generated OGCs either before or after learning in mice. Consistent with previous studies, pretraining ablation of adult-generated OGCs did not prevent the formation of an odor-reward memory, presumably because existing OGCs can support memory formation in their absence. However, ablation of a similar cohort of adult-generated OGCs after training impaired subsequent memory expression, indicating that if these cells are available at the time of training, they play an essential role in subsequent expression of odor-reward memories. Memory impairment was associated with the loss of adult-generated OGCs that were >10 d in age and did not depend on the developmental stage in which they were generated, suggesting that, once sufficiently mature, OGCs generated during juvenility and adulthood play similar roles in the expression of odor-reward memories. Finally, ablation of adult-generated OGCs 1 month after training did not produce amnesia, indicating that adult-generated OGCs play a time-limited role in the expression of odor-reward memories.
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Wellhauser L, Gojska NM, Belsham DD. Delineating the regulation of energy homeostasis using hypothalamic cell models. Front Neuroendocrinol 2015; 36:130-49. [PMID: 25223866 DOI: 10.1016/j.yfrne.2014.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 08/28/2014] [Accepted: 09/02/2014] [Indexed: 12/27/2022]
Abstract
Attesting to its intimate peripheral connections, hypothalamic neurons integrate nutritional and hormonal cues to effectively manage energy homeostasis according to the overall status of the system. Extensive progress in the identification of essential transcriptional and post-translational mechanisms regulating the controlled expression and actions of hypothalamic neuropeptides has been identified through the use of animal and cell models. This review will introduce the basic techniques of hypothalamic investigation both in vivo and in vitro and will briefly highlight the key advantages and challenges of their use. Further emphasis will be place on the use of immortalized models of hypothalamic neurons for in vitro study of feeding regulation, with a particular focus on cell lines proving themselves most fruitful in deciphering fundamental basics of NPY/AgRP, Proglucagon, and POMC neuropeptide function.
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Affiliation(s)
- Leigh Wellhauser
- Department of Physiology, University of Toronto, Toronto, Ontario M5G 1A8, Canada
| | - Nicole M Gojska
- Department of Physiology, University of Toronto, Toronto, Ontario M5G 1A8, Canada
| | - Denise D Belsham
- Departments of Physiology, Medicine and OB/GYN, University of Toronto, Toronto, Ontario M5G 1A8, Canada; Division of Cellular and Molecular Biology, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario M5S 1A8, Canada.
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Kosse C, Gonzalez A, Burdakov D. Predictive models of glucose control: roles for glucose-sensing neurones. Acta Physiol (Oxf) 2015; 213:7-18. [PMID: 25131833 PMCID: PMC5767106 DOI: 10.1111/apha.12360] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 05/08/2014] [Accepted: 08/01/2014] [Indexed: 12/17/2022]
Abstract
The brain can be viewed as a sophisticated control module for stabilizing blood glucose. A review of classical behavioural evidence indicates that central circuits add predictive (feedforward/anticipatory) control to the reactive (feedback/compensatory) control by peripheral organs. The brain/cephalic control is constructed and engaged, via associative learning, by sensory cues predicting energy intake or expenditure (e.g. sight, smell, taste, sound). This allows rapidly measurable sensory information (rather than slowly generated internal feedback signals, e.g. digested nutrients) to control food selection, glucose supply for fight-or-flight responses or preparedness for digestion/absorption. Predictive control is therefore useful for preventing large glucose fluctuations. We review emerging roles in predictive control of two classes of widely projecting hypothalamic neurones, orexin/hypocretin (ORX) and melanin-concentrating hormone (MCH) cells. Evidence is cited that ORX neurones (i) are activated by sensory cues (e.g. taste, sound), (ii) drive hepatic production, and muscle uptake, of glucose, via sympathetic nerves, (iii) stimulate wakefulness and exploration via global brain projections and (iv) are glucose-inhibited. MCH neurones are (i) glucose-excited, (ii) innervate learning and reward centres to promote synaptic plasticity, learning and memory and (iii) are critical for learning associations useful for predictive control (e.g. using taste to predict nutrient value of food). This evidence is unified into a model for predictive glucose control. During associative learning, inputs from some glucose-excited neurones may promote connections between the 'fast' senses and reward circuits, constructing neural shortcuts for efficient action selection. In turn, glucose-inhibited neurones may engage locomotion/exploration and coordinate the required fuel supply. Feedback inhibition of the latter neurones by glucose would ensure that glucose fluxes they stimulate (from liver, into muscle) are balanced. Estimating nutrient challenges from indirect sensory cues may become more difficult when the cues become complex and variable (e.g. like human foods today). Consequent errors of predictive glucose control may contribute to obesity and diabetes.
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Affiliation(s)
- C. Kosse
- Division of Neurophysiology MRC National Institute for Medical Research London UK
| | - A. Gonzalez
- Division of Neurophysiology MRC National Institute for Medical Research London UK
| | - D. Burdakov
- Division of Neurophysiology MRC National Institute for Medical Research London UK
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Bisschop PH, Fliers E, Kalsbeek A. Autonomic Regulation of Hepatic Glucose Production. Compr Physiol 2014; 5:147-65. [DOI: 10.1002/cphy.c140009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Abstract
Uncoupling protein 2 (UCP2) is a mitochondrial anion carrier protein, which uncouples the oxidative phosphorylation from ATP production by dissipating the proton gradient generated across the mitochondrial inner membrane. UCP2 regulates not only mitochondrial ATP production, but also the generation of reactive oxygen species (ROS), considered important second-messenger signals within the cell. The importance of UCP2 was firstly reported in macrophages and pancreatic beta cells. However, several studies have revealed the important role of UCP2 in the Central Nervous System (CNS) in the regulation of homeostatic mechanisms including food intake, energy expenditure, glucose homeostasis and reward behaviors. The mechanisms by which central UCP2 affect these processes seem to be associated with synaptic and mitochondrial plasticity. In this review, we will describe recent findings on central UCP2 and discuss its role in CNS regulation of homeostasis.
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Affiliation(s)
- Chitoku Toda
- Departments of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA; Program in Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Sabrina Diano
- Departments of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA; Program in Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06520, USA; Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA.
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