1
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Mota CMD, Madden CJ. Neural circuits of long-term thermoregulatory adaptations to cold temperatures and metabolic demands. Nat Rev Neurosci 2024; 25:143-158. [PMID: 38316956 DOI: 10.1038/s41583-023-00785-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2023] [Indexed: 02/07/2024]
Abstract
The mammalian brain controls heat generation and heat loss mechanisms that regulate body temperature and energy metabolism. Thermoeffectors include brown adipose tissue, cutaneous blood flow and skeletal muscle, and metabolic energy sources include white adipose tissue. Neural and metabolic pathways modulating the activity and functional plasticity of these mechanisms contribute not only to the optimization of function during acute challenges, such as ambient temperature changes, infection and stress, but also to longitudinal adaptations to environmental and internal changes. Exposure of humans to repeated and seasonal cold ambient conditions leads to adaptations in thermoeffectors such as habituation of cutaneous vasoconstriction and shivering. In animals that undergo hibernation and torpor, neurally regulated metabolic and thermoregulatory adaptations enable survival during periods of significant reduction in metabolic rate. In addition, changes in diet can activate accessory neural pathways that alter thermoeffector activity. This knowledge may be harnessed for therapeutic purposes, including treatments for obesity and improved means of therapeutic hypothermia.
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Affiliation(s)
- Clarissa M D Mota
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, USA
| | - Christopher J Madden
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, USA.
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2
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Woodie LN, Melink LC, Alberto AJ, Burrows M, Fortin SM, Chan CC, Hayes MR, Lazar MA. Hindbrain REV-ERB nuclear receptors regulate sensitivity to diet-induced obesity and brown adipose tissue pathophysiology. Mol Metab 2024; 79:101861. [PMID: 38142970 PMCID: PMC10792761 DOI: 10.1016/j.molmet.2023.101861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 12/08/2023] [Accepted: 12/20/2023] [Indexed: 12/26/2023] Open
Abstract
OBJECTIVE The dorsal vagal complex (DVC) of the hindbrain is a major point of integration for central and peripheral signals that regulate a wide variety of metabolic functions to maintain energy balance. The REV-ERB nuclear receptors are important modulators of molecular metabolism, but their role in the DVC has yet to be established. METHODS Male REV-ERBα/β floxed mice received stereotaxic injections of a Cre expressing virus to the DVC to create the DVC REV-ERBα/β double knockout (DVC RDKO). Control littermates received stereotaxic injections to the DVC of a green fluorescent protein expressing virus. Animals were maintained on a normal chow diet or a 60% high-fat diet to observe the metabolic phenotype arising from DVC RDKO under healthy and metabolically stressed conditions. RESULTS DVC RDKO animals on high-fat diet exhibited increased weight gain compared to control animals maintained on the same diet. Increased weight gain in DVC RDKO animals was associated with decreased basal metabolic rate and dampened signature of brown adipose tissue activity. RDKO decreased gene expression of calcitonin receptor in the DVC and tyrosine hydroxylase in the brown adipose tissue. CONCLUSIONS These results suggest a previously unappreciated role of REV-ERB nuclear receptors in the DVC for maintaining energy balance and metabolic rate potentially through indirect sympathetic outflow to the brown adipose tissue.
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Affiliation(s)
- Lauren N Woodie
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lily C Melink
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ahren J Alberto
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michelle Burrows
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Samantha M Fortin
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Calvin C Chan
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew R Hayes
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism, and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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3
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Fozzato A, New LE, Griffiths JC, Patel B, Deuchars SA, Filippi BM. Manipulating mitochondrial dynamics in the NTS prevents diet-induced deficits in brown fat morphology and glucose uptake. Life Sci 2023; 328:121922. [PMID: 37423379 DOI: 10.1016/j.lfs.2023.121922] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 07/06/2023] [Accepted: 07/06/2023] [Indexed: 07/11/2023]
Abstract
AIMS Brown adipose tissue (BAT) can produce heat by metabolizing glucose and fatty acids. Activation of BAT is controlled by the central nervous system (CNS) through sympathetic innervation. Dysregulation of signalling molecules in selective CNS areas such as the nucleus of tractus solitarius (NTS) are linked with altered BAT activity, obesity and diabetes. High-fat diet (HFD)-feeding increases mitochondrial fragmentation in the NTS, triggering insulin resistance, hyperphagia and weight gain. Here we sought to determine whether changes in mitochondrial dynamics in the NTS can affect BAT glucose uptake. MAIN METHODS Rats received DVC stereotactic surgery for local brain administration of viruses that express mutated Drp1 genes. BAT glucose uptake was measured with PET/CT scans. Biochemical assays and immunohistochemistry determined altered levels of key signalling molecules and neural innervation of BAT. KEY FINDINGS We show that short-term HFD-feeding decreases BAT glucose uptake. However, inhibiting mitochondrial fragmentation in NTS-astrocytes of HFD-fed rats partially restores BAT glucose uptake accompanied by lower blood glucose and insulin levels. Tyrosine Hydroxylase (TH) revealed that rats with inhibited mitochondrial fragmentation in NTS astrocytes had higher levels of catecholaminergic innervation in BAT compared to HFD-fed rats, and did not exhibit HFD-dependent infiltration of enlarged white fat droplets in the BAT. In regular chow-fed rats, increasing mitochondrial fragmentation in the NTS-astrocytes reduced BAT glucose uptake, TH immune-positive boutons and β3-adrenergic receptor levels. SIGNIFICANCE Our data suggest that targeting mitochondrial dynamics in the NTS-astrocytes could be a beneficial strategy to increase glucose utilization and protect from developing obesity and diabetes.
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Affiliation(s)
- Arianna Fozzato
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Lauryn E New
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Joanne C Griffiths
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Bianca Patel
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Susan A Deuchars
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Beatrice M Filippi
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
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4
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Mota CMD, Madden CJ. High Fat Diet Suppresses Energy Expenditure Via Neurons in the Brainstem. Neuroscience 2023; 520:84-94. [PMID: 37054945 PMCID: PMC10200768 DOI: 10.1016/j.neuroscience.2023.04.006] [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] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 04/04/2023] [Indexed: 04/15/2023]
Abstract
Oxidation of fat by brown adipose tissue (BAT) contributes to energy balance and heat production. During cold exposure, BAT thermogenesis produces heat to warm the body. Obese subjects and rodents, however, show impaired BAT thermogenesis to the cold. Our previous studies suggest that vagal afferents synapsing in the nucleus tractus solitarius (NTS), tonically inhibit BAT thermogenesis to the cold in obese rats. NTS neurons send projections to the dorsal aspect of the lateral parabrachial nucleus (LPBd), which is a major integrative center that receives warm afferent inputs from the periphery and promotes inhibition of BAT thermogenesis. This study investigated the contribution of LPBd neurons in the impairment of BAT thermogenesis in rats fed a high-fat diet (HFD). By using a targeted dual viral vector approach, we found that chemogenetic activation of an NTS-LPB pathway inhibited BAT thermogenesis to the cold. We also found that the number of Fos-labelled neurons in the LPBd was higher in rats fed a HFD than in chow diet-fed rats after exposure to a cold ambient temperature. Nanoinjections of a GABAA receptor agonist into the LPBd area rescued BAT thermogenesis to the cold in HFD rats. These data reveal the LPBd as a critical brain area that tonically suppresses energy expenditure in obesity during skin cooling. These findings reveal novel effects of high-fat diets in the brain and in the control of metabolism and can contribute to the development of therapeutic approaches to regulate fat metabolism.
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Affiliation(s)
- Clarissa M D Mota
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, United States
| | - Christopher J Madden
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, United States.
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5
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Garami A, Steiner AA, Pakai E, Wanner SP, Almeida MC, Keringer P, Oliveira DL, Nakamura K, Morrison SF, Romanovsky AA. The neural pathway of the hyperthermic response to antagonists of the transient receptor potential vanilloid-1 channel. Temperature (Austin) 2023; 10:136-154. [PMID: 37187834 PMCID: PMC10177699 DOI: 10.1080/23328940.2023.2171671] [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: 10/22/2022] [Revised: 01/13/2023] [Accepted: 01/18/2023] [Indexed: 01/27/2023] Open
Abstract
We identified the neural pathway of the hyperthermic response to TRPV1 antagonists. We showed that hyperthermia induced by i.v. AMG0347, AMG 517, or AMG8163 did not occur in rats with abdominal sensory nerves desensitized by pretreatment with a low i.p. dose of resiniferatoxin (RTX, TRPV1 agonist). However, neither bilateral vagotomy nor bilateral transection of the greater splanchnic nerve attenuated AMG0347-induced hyperthermia. Yet, this hyperthermia was attenuated by bilateral high cervical transection of the spinal dorsolateral funiculus (DLF). To explain the extra-splanchnic, spinal mediation of TRPV1 antagonist-induced hyperthermia, we proposed that abdominal signals that drive this hyperthermia originate in skeletal muscles - not viscera. If so, in order to prevent TRPV1 antagonist-induced hyperthermia, the desensitization caused by i.p. RTX should spread into the abdominal-wall muscles. Indeed, we found that the local hypoperfusion response to capsaicin (TRPV1 agonist) in the abdominal-wall muscles was absent in i.p. RTX-desensitized rats. We then showed that the most upstream (lateral parabrachial, LPB) and the most downstream (rostral raphe pallidus) nuclei of the intrabrain pathway that controls autonomic cold defenses are also required for the hyperthermic response to i.v. AMG0347. Injection of muscimol (inhibitor of neuronal activity) into the LPB or injection of glycine (inhibitory neurotransmitter) into the raphe blocked the hyperthermic response to i.v. AMG0347, whereas i.v. AMG0347 increased the number of c-Fos cells in the raphe. We conclude that the neural pathway of TRPV1 antagonist-induced hyperthermia involves TRPV1-expressing sensory nerves in trunk muscles, the DLF, and the same LPB-raphe pathway that controls autonomic cold defenses.
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Affiliation(s)
- Andras Garami
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Alexandre A. Steiner
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
- Departamento de Imunologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, São Paulo, Brazil
| | - Eszter Pakai
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Samuel P. Wanner
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
| | - M. Camila Almeida
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
| | - Patrik Keringer
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Daniela L. Oliveira
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
| | - Kazuhiro Nakamura
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shaun F. Morrison
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, USA
| | - Andrej A. Romanovsky
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
- School of Molecular Sciences, University of Arizona, Tempe, AZ, USA
- Zharko Pharma, Inc., Olympia, WA, USA
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6
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Ma WX, Yuan PC, Zhang H, Kong LX, Lazarus M, Qu WM, Wang YQ, Huang ZL. Adenosine and P1 receptors: Key targets in the regulation of sleep, torpor, and hibernation. Front Pharmacol 2023; 14:1098976. [PMID: 36969831 PMCID: PMC10036772 DOI: 10.3389/fphar.2023.1098976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 02/27/2023] [Indexed: 03/12/2023] Open
Abstract
Graphical AbstractAdenosine mediates sleep, torpor and hibernation through P1 receptors. Recent reasearch has shown that P1 receptors play a vital role in the regulation of sleep-wake, torpor and hibernation-like states. In this review, we focus on the roles and neurobiological mechanisms of the CNS adenosine and P1 receptors in these three states. Among them, A1 and A2A receptors are key targets for sleep-wake regulation, A1Rs and A3Rs are very important for torpor induction, and activation of A1Rs is sufficient for hibernation-like state.
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Affiliation(s)
- Wei-Xiang Ma
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Ping-Chuan Yuan
- Anhui Provincial Engineering Research Center for Polysaccharide Drugs, Provincial Engineering Laboratory for Screening and Re-evaluation of Active Compounds of Herbal Medicines in Southern Anhui, School of Pharmacy, Wannan Medical College, Wuhu, China
| | - Hui Zhang
- Anhui Provincial Engineering Research Center for Polysaccharide Drugs, Provincial Engineering Laboratory for Screening and Re-evaluation of Active Compounds of Herbal Medicines in Southern Anhui, School of Pharmacy, Wannan Medical College, Wuhu, China
| | - Ling-Xi Kong
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Michael Lazarus
- International Institute for Integrative Sleep Medicine (WPI-IIIS) and Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Wei-Min Qu
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
- *Correspondence: Wei-Min Qu, ; Yi-Qun Wang, ; Zhi-Li Huang,
| | - Yi-Qun Wang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
- *Correspondence: Wei-Min Qu, ; Yi-Qun Wang, ; Zhi-Li Huang,
| | - Zhi-Li Huang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
- *Correspondence: Wei-Min Qu, ; Yi-Qun Wang, ; Zhi-Li Huang,
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Meng JJ, Shen JW, Li G, Ouyang CJ, Hu JX, Li ZS, Zhao H, Shi YM, Zhang M, Liu R, Chen JT, Ma YQ, Zhao H, Xue T. Light modulates glucose metabolism by a retina-hypothalamus-brown adipose tissue axis. Cell 2023; 186:398-412.e17. [PMID: 36669474 DOI: 10.1016/j.cell.2022.12.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 09/22/2022] [Accepted: 12/13/2022] [Indexed: 01/20/2023]
Abstract
Public health studies indicate that artificial light is a high-risk factor for metabolic disorders. However, the neural mechanism underlying metabolic modulation by light remains elusive. Here, we found that light can acutely decrease glucose tolerance (GT) in mice by activation of intrinsically photosensitive retinal ganglion cells (ipRGCs) innervating the hypothalamic supraoptic nucleus (SON). Vasopressin neurons in the SON project to the paraventricular nucleus, then to the GABAergic neurons in the solitary tract nucleus, and eventually to brown adipose tissue (BAT). Light activation of this neural circuit directly blocks adaptive thermogenesis in BAT, thereby decreasing GT. In humans, light also modulates GT at the temperature where BAT is active. Thus, our work unveils a retina-SON-BAT axis that mediates the effect of light on glucose metabolism, which may explain the connection between artificial light and metabolic dysregulation, suggesting a potential prevention and treatment strategy for managing glucose metabolic disorders.
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Affiliation(s)
- Jian-Jun Meng
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Jia-Wei Shen
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Guang Li
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Chang-Jie Ouyang
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Jia-Xi Hu
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Zi-Shuo Li
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Hang Zhao
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Yi-Ming Shi
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Mei Zhang
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Rong Liu
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Ju-Tao Chen
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Yu-Qian Ma
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Huan Zhao
- College of Biology, Food and Environment, Hefei University, Hefei 230601, China
| | - Tian Xue
- Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Brain Function and Disease, Biomedical Sciences and Health Laboratory of Anhui Province, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China; Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China.
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8
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Sun L, Aarnio R, Herre EA, Kärnä S, Palani S, Virtanen H, Liljenbäck H, Virta J, Honkaniemi A, Oikonen V, Han C, Laurila S, Bucci M, Helin S, Yatkin E, Nummenmaa L, Nuutila P, Tang J, Roivainen A. [ 11C]carfentanil PET imaging for studying the peripheral opioid system in vivo: effect of photoperiod on mu-opioid receptor availability in brown adipose tissue. Eur J Nucl Med Mol Imaging 2023; 50:266-274. [PMID: 36166079 PMCID: PMC9816189 DOI: 10.1007/s00259-022-05969-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/15/2022] [Indexed: 01/11/2023]
Abstract
PURPOSE Photoperiod determines the metabolic activity of brown adipose tissue (BAT) and affects the food intake and body mass of mammals. Sympathetic innervation of the BAT controls thermogenesis and facilitates physiological adaption to seasonal changes, but the exact mechanism remains elusive. Previous studies have shown that central opioid signaling regulates BAT thermogenesis, and that the expression of the brain mu-opioid receptor (MOR) varies seasonally. Therefore, it is important to know whether MOR expression in BAT shows seasonal variation. METHODS We determined the effect of photoperiod on BAT MOR availability using [11C]carfentanil positron emission tomography (PET). Adult rats (n = 9) were repeatedly imaged under various photoperiods in order to simulate seasonal changes. RESULTS Long photoperiod was associated with low MOR expression in BAT (β = - 0.04, 95% confidence interval: - 0.07, - 0.01), but not in muscles. We confirmed the expression of MOR in BAT and muscle using immunofluorescence staining. CONCLUSION Photoperiod affects MOR availability in BAT. Sympathetic innervation of BAT may influence thermogenesis via the peripheral MOR system. The present study supports the utility of [11C]carfentanil PET to study the peripheral MOR system.
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Affiliation(s)
- Lihua Sun
- Department of Nuclear Medicine, Huashan Hospital, Fudan University, Shanghai, China.
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland.
| | - Richard Aarnio
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Erika Atencio Herre
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Salli Kärnä
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Senthil Palani
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Helena Virtanen
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Heidi Liljenbäck
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
- Turku Center for Disease Modeling, University of Turku, 20520, Turku, Finland
| | - Jenni Virta
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Aake Honkaniemi
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Vesa Oikonen
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Chunlei Han
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Sanna Laurila
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
- Heart Center, Turku University Hospital, 20520, Turku, Finland
| | - Marco Bucci
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institute, 17177, Stockholm, Sweden
- Theme Inflammation and Aging, Karolinska University Hospital, 14186, Stockholm, Sweden
- Turku PET Centre, Åbo Akademi University, Turku, Finland
| | - Semi Helin
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
| | - Emrah Yatkin
- Central Animal Laboratory, University of Turku, 20520, Turku, Finland
| | - Lauri Nummenmaa
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
- Department of Psychology, University of Turku, 20520, Turku, Finland
| | - Pirjo Nuutila
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
- Department of Endocrinology, Turku University Hospital, 20520, Turku, Finland
- InFLAMES Research Flagship Center, University of Turku, 20520, Turku, Finland
| | - Jing Tang
- Research Program in Systems Oncology, Faculty of Medicine, University of Helsinki, 00014, Helsinki, Finland
| | - Anne Roivainen
- Turku PET Centre, University of Turku and Turku University Hospital, 20520, Turku, Finland
- Turku Center for Disease Modeling, University of Turku, 20520, Turku, Finland
- InFLAMES Research Flagship Center, University of Turku, 20520, Turku, Finland
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9
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Gonzalez IE, Ramirez-Matias J, Lu C, Pan W, Zhu A, Myers MG, Olson DP. Paraventricular Calcitonin Receptor-Expressing Neurons Modulate Energy Homeostasis in Male Mice. Endocrinology 2021; 162:6218079. [PMID: 33834205 PMCID: PMC8139622 DOI: 10.1210/endocr/bqab072] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Indexed: 12/29/2022]
Abstract
The paraventricular nucleus of the hypothalamus (PVH) is a heterogeneous collection of neurons that play important roles in modulating feeding and energy expenditure. Abnormal development or ablation of the PVH results in hyperphagic obesity and defects in energy expenditure whereas selective activation of defined PVH neuronal populations can suppress feeding and may promote energy expenditure. Here, we characterize the contribution of calcitonin receptor-expressing PVH neurons (CalcRPVH) to energy balance control. We used Cre-dependent viral tools delivered stereotaxically to the PVH of CalcR2Acre mice to activate, silence, and trace CalcRPVH neurons and determine their contribution to body weight regulation. Immunohistochemistry of fluorescently-labeled CalcRPVH neurons demonstrates that CalcRPVH neurons are largely distinct from several PVH neuronal populations involved in energy homeostasis; these neurons project to regions of the hindbrain that are implicated in energy balance control, including the nucleus of the solitary tract and the parabrachial nucleus. Acute activation of CalcRPVH neurons suppresses feeding without appreciably augmenting energy expenditure, whereas their silencing leads to obesity that may be due in part due to loss of PVH melanocortin-4 receptor signaling. These data show that CalcRPVH neurons are an essential component of energy balance neurocircuitry and their function is important for body weight maintenance. A thorough understanding of the mechanisms by which CalcRPVH neurons modulate energy balance might identify novel therapeutic targets for the treatment and prevention of obesity.
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MESH Headings
- Animals
- Eating/physiology
- Energy Metabolism/genetics
- Energy Metabolism/physiology
- Feeding Behavior/physiology
- Homeostasis/physiology
- Hypothalamus/metabolism
- Hypothalamus/physiology
- Male
- Mice
- Mice, Transgenic
- Neurons/metabolism
- Neurons/physiology
- Paraventricular Hypothalamic Nucleus/metabolism
- Paraventricular Hypothalamic Nucleus/physiology
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Receptor, Melanocortin, Type 4/physiology
- Receptors, Calcitonin/genetics
- Receptors, Calcitonin/metabolism
- Receptors, Calcitonin/physiology
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Affiliation(s)
- Ian E Gonzalez
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
- Division of Endocrinology, Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Julliana Ramirez-Matias
- College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, MI 48109, USA
| | - Chunxia Lu
- Division of Endocrinology, Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Warren Pan
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Allen Zhu
- Division of Endocrinology, Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Martin G Myers
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - David P Olson
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
- Division of Endocrinology, Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA
- Correspondence: David P. Olson, MD PhD, Department of Pediatrics, Division of Pediatric Endocrinology, Michigan Medicine, D1205 MPB / SPC 5718, Ann Arbor, MI 48109, USA.
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10
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Liu C, Lee CY, Asher G, Cao L, Terakoshi Y, Cao P, Kobayakawa R, Kobayakawa K, Sakurai K, Liu Q. Posterior subthalamic nucleus (PSTh) mediates innate fear-associated hypothermia in mice. Nat Commun 2021; 12:2648. [PMID: 33976193 PMCID: PMC8113537 DOI: 10.1038/s41467-021-22914-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 03/17/2021] [Indexed: 12/16/2022] Open
Abstract
The neural mechanisms of fear-associated thermoregulation remain unclear. Innate fear odor 2-methyl-2-thiazoline (2MT) elicits rapid hypothermia and elevated tail temperature, indicative of vasodilation-induced heat dissipation, in wild-type mice, but not in mice lacking Trpa1-the chemosensor for 2MT. Here we report that Trpa1-/- mice show diminished 2MT-evoked c-fos expression in the posterior subthalamic nucleus (PSTh), external lateral parabrachial subnucleus (PBel) and nucleus of the solitary tract (NTS). Whereas tetanus toxin light chain-mediated inactivation of NTS-projecting PSTh neurons suppress, optogenetic activation of direct PSTh-rostral NTS pathway induces hypothermia and tail vasodilation. Furthermore, selective opto-stimulation of 2MT-activated, PSTh-projecting PBel neurons by capturing activated neuronal ensembles (CANE) causes hypothermia. Conversely, chemogenetic suppression of vGlut2+ neurons in PBel or PSTh, or PSTh-projecting PBel neurons attenuates 2MT-evoked hypothermia and tail vasodilation. These studies identify PSTh as a major thermoregulatory hub that connects PBel to NTS to mediate 2MT-evoked innate fear-associated hypothermia and tail vasodilation.
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Affiliation(s)
- Can Liu
- Peking University-Tsinghua University-NIBS Joint Graduate Program, School of Life Sciences, Tsinghua University, Beijing, China
- National Institute of Biological Sciences (NIBS), Beijing, China
| | - Chia-Ying Lee
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Greg Asher
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Liqin Cao
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yuka Terakoshi
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Peng Cao
- National Institute of Biological Sciences (NIBS), Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research (TIMBR), Tsinghua University, Beijing, China
| | - Reiko Kobayakawa
- Department of Functional Neuroscience, Institute of Biomedical Science, Kansai Medical University, Osaka, Japan
| | - Ko Kobayakawa
- Department of Functional Neuroscience, Institute of Biomedical Science, Kansai Medical University, Osaka, Japan
| | - Katsuyasu Sakurai
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan.
| | - Qinghua Liu
- National Institute of Biological Sciences (NIBS), Beijing, China.
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan.
- Tsinghua Institute of Multidisciplinary Biomedical Research (TIMBR), Tsinghua University, Beijing, China.
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11
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Activation of Transient Receptor Potential Vanilloid 1 Channels in the Nucleus of the Solitary Tract and Activation of Dynorphin Input to the Median Preoptic Nucleus Contribute to Impaired BAT Thermogenesis in Diet-Induced Obesity. eNeuro 2021; 8:ENEURO.0048-21.2021. [PMID: 33707202 PMCID: PMC8174036 DOI: 10.1523/eneuro.0048-21.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 02/27/2021] [Indexed: 12/12/2022] Open
Abstract
The impairment of cold-evoked activation of brown adipose tissue (BAT) in rats fed a high-fat diet (HFD) requires the activity of a vagal afferent to the medial nucleus of the solitary tract (mNTS). We determined the role of transient receptor potential vanilloid 1 (TRPV1) activation in the mNTS, and of a dynorphin input to the median preoptic nucleus (MnPO) in the impaired BAT thermogenic response to cold in HFD-fed rats. The levels of some linoleic acid (LA) metabolites, which can act as endogenous TRPV1 agonists, were elevated in the NTS of HFD rats compared with chow-fed rats. In HFD rats, nanoinjections of the TRPV1 antagonist, capsazepine (CPZ) in the NTS rescued the impaired BAT sympathetic nerve activity (BAT SNA) and thermogenic responses to cold. In contrast, in chow-fed rats, cold-evoked BAT SNA and BAT thermogenesis were not changed by nanoinjections of CPZ into the NTS. Axon terminals of NTS neurons that project to the dorsal lateral parabrachial nucleus (LPBd) were closely apposed to LPBd neurons that project to the MnPO. Many of the neurons in the LPBd that expressed c-fos during cold challenge were dynorphinergic. In HFD rats, nanoinjections of the κ opioid receptor (KOR) antagonist, nor-binaltorphimine (nor-BNI), in the MnPO rescued the impaired BAT SNA and thermogenic responses to cold. These data suggest that HFD increases the content of endogenous ligands of TRPV1 in the NTS, which increases the drive to LPBd neurons that in turn release dynorphin in the MnPO to impair activation of BAT.
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12
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Cerri M, Amici R. Thermoregulation and Sleep: Functional Interaction and Central Nervous Control. Compr Physiol 2021; 11:1591-1604. [PMID: 33792906 DOI: 10.1002/cphy.c140012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Each of the wake-sleep states is characterized by specific changes in autonomic activity and bodily functions. The goal of such changes is not always clear. During non-rapid eye movement (NREM) sleep, the autonomic outflow and the activity of the endocrine system, the respiratory system, the cardiovascular system, and the thermoregulatory system seem to be directed at increasing energy saving. During rapid eye movement (REM) sleep, the goal of the specific autonomic and regulatory changes is unclear, since a large instability of autonomic activity and cardiorespiratory function is observed in concomitance with thermoregulatory changes, which are apparently non-functional to thermal homeostasis. Reciprocally, the activation of thermoregulatory responses under thermal challenges interferes with sleep occurrence. Such a double-edged and reciprocal interaction between sleep and thermoregulation may be favored by the fact that the central network controlling sleep overlaps in several parts with the central network controlling thermoregulation. The understanding of the central mechanism behind the interaction between sleep and thermoregulation may help to understand the functionality of thermoregulatory sleep-related changes and, ultimately, the function(s) of sleep. © 2021 American Physiological Society. Compr Physiol 11:1591-1604, 2021.
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Affiliation(s)
- Matteo Cerri
- Department of Biomedical and Neuromotor Sciences - Physiology, Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Roberto Amici
- Department of Biomedical and Neuromotor Sciences - Physiology, Alma Mater Studiorum - University of Bologna, Bologna, Italy
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13
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Van Schaik L, Kettle C, Green R, Irving HR, Rathner JA. Effects of Caffeine on Brown Adipose Tissue Thermogenesis and Metabolic Homeostasis: A Review. Front Neurosci 2021; 15:621356. [PMID: 33613184 PMCID: PMC7889509 DOI: 10.3389/fnins.2021.621356] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/11/2021] [Indexed: 12/11/2022] Open
Abstract
The impact of brown adipose tissue (BAT) metabolism on understanding energy balance in humans is a relatively new and exciting field of research. The pathogenesis of obesity can be largely explained by an imbalance between caloric intake and energy expenditure, but the underlying mechanisms are far more complex. Traditional non-selective sympathetic activators have been used to artificially elevate energy utilization, or suppress appetite, however undesirable side effects are apparent with the use of these pharmacological interventions. Understanding the role of BAT, in relation to human energy homeostasis has the potential to dramatically offset the energy imbalance associated with obesity. This review discusses paradoxical effects of caffeine on peripheral adenosine receptors and the possible role of adenosine in increasing metabolism is highlighted, with consideration to the potential of central rather than peripheral mechanisms for caffeine mediated BAT thermogenesis and energy expenditure. Research on the complex physiology of adipose tissue, the embryonic lineage and function of the different types of adipocytes is summarized. In addition, the effect of BAT on overall human metabolism and the extent of the associated increase in energy expenditure are discussed. The controversy surrounding the primary β-adrenoceptor involved in human BAT activation is examined, and suggestions as to the lack of translational findings from animal to human physiology and human in vitro to in vivo models are provided. This review compares and distinguishes human and rodent BAT effects, thus developing an understanding of human BAT thermogenesis to aid lifestyle interventions targeting obesity and metabolic syndrome. The focus of this review is on the effect of BAT thermogenesis on overall metabolism, and the potential therapeutic effects of caffeine in increasing metabolism via its effects on BAT.
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Affiliation(s)
- Lachlan Van Schaik
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Christine Kettle
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Rodney Green
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Helen R. Irving
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Joseph A. Rathner
- Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
- Department of Physiology, School of Biomedical Sciences, The University of Melbourne, Melbourne, VIC, Australia
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14
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Frare C, Jenkins ME, McClure KM, Drew KL. Seasonal decrease in thermogenesis and increase in vasoconstriction explain seasonal response to N 6 -cyclohexyladenosine-induced hibernation in the Arctic ground squirrel (Urocitellus parryii). J Neurochem 2019; 151:316-335. [PMID: 31273780 PMCID: PMC6819227 DOI: 10.1111/jnc.14814] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/12/2019] [Accepted: 07/01/2019] [Indexed: 01/07/2023]
Abstract
Hibernation is a seasonal phenomenon characterized by a drop in metabolic rate and body temperature. Adenosine A1 receptor agonists promote hibernation in different mammalian species, and the understanding of the mechanism inducing hibernation will inform clinical strategies to manipulate metabolic demand that are fundamental to conditions such as obesity, metabolic syndrome, and therapeutic hypothermia. Adenosine A1 receptor agonist-induced hibernation in Arctic ground squirrels is regulated by an endogenous circannual (seasonal) rhythm. This study aims to identify the neuronal mechanism underlying the seasonal difference in response to the adenosine A1 receptor agonist. Arctic ground squirrels were implanted with body temperature transmitters and housed at constant ambient temperature (2°C) and light cycle (4L:20D). We administered CHA (N6 -cyclohexyladenosine), an adenosine A1 receptor agonist in euthermic-summer phenotype and euthermic-winter phenotype and used cFos and phenotypic immunoreactivity to identify cell groups affected by season and treatment. We observed lower core and subcutaneous temperature in winter animals and CHA produced a hibernation-like response in winter, but not in summer. cFos-ir was greater in the median preoptic nucleus and the raphe pallidus in summer after CHA. CHA administration also resulted in enhanced cFos-ir in the nucleus tractus solitarius and decreased cFos-ir in the tuberomammillary nucleus in both seasons. In winter, cFos-ir was greater in the supraoptic nucleus and lower in the raphe pallidus than in summer. The seasonal decrease in the thermogenic response to CHA and the seasonal increase in vasoconstriction, assessed by subcutaneous temperature, reflect the endogenous seasonal modulation of the thermoregulatory systems necessary for CHA-induced hibernation. Cover Image for this issue: doi: 10.1111/jnc.14528.
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Affiliation(s)
- Carla Frare
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska, USA
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - Mackenzie E Jenkins
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - Kelsey M McClure
- Department of Veterinary Medicine, Colorado State University, Fort Collins, Colorado, USA
| | - Kelly L Drew
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska, USA
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, USA
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15
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Farmer DGS, Pracejus N, Dempsey B, Turner A, Bokiniec P, Paton JFR, Pickering AE, Burguet J, Andrey P, Goodchild AK, McAllen RM, McMullan S. On the presence and functional significance of sympathetic premotor neurons with collateralized spinal axons in the rat. J Physiol 2019; 597:3407-3423. [DOI: 10.1113/jp277661] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 04/23/2019] [Indexed: 11/08/2022] Open
Affiliation(s)
- David G. S. Farmer
- Florey Institute of Neuroscience and Mental Health University of Melbourne Parkville VIC Australia
| | - Natasha Pracejus
- Florey Institute of Neuroscience and Mental Health University of Melbourne Parkville VIC Australia
| | - Bowen Dempsey
- Neuroscience Paris‐Saclay Institute (Neuro‐PSI) CNRS Gif‐Sur‐Yvette France
| | - Anita Turner
- Faculty of Medicine & Health Science Macquarie University North Ryde NSW Australia
| | - Phillip Bokiniec
- Department of Neuroscience Max Delbrück Center for Molecular Medicine (MDC) Berlin‐Buch, Germany Neuroscience Research Center and Cluster of Excellence NeuroCure Charité‐Universitätsmedizin Berlin Germany
| | - Julian F. R. Paton
- Department of Physiology Faculty of Medical & Health Sciences University of Auckland Park Road Grafton Auckland New Zealand
| | - Anthony E. Pickering
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences University of Bristol Bristol UK
| | - Jasmine Burguet
- Institut Jean‐Pierre Bourgin INRA AgroParisTech CNRS Université Paris‐Saclay Versailles France
| | - Philippe Andrey
- Institut Jean‐Pierre Bourgin INRA AgroParisTech CNRS Université Paris‐Saclay Versailles France
| | - Ann K. Goodchild
- Faculty of Medicine & Health Science Macquarie University North Ryde NSW Australia
| | - Robin M. McAllen
- Florey Institute of Neuroscience and Mental Health University of Melbourne Parkville VIC Australia
| | - Simon McMullan
- Faculty of Medicine & Health Science Macquarie University North Ryde NSW Australia
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16
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Ferrucci M, Limanaqi F, Ryskalin L, Biagioni F, Busceti CL, Fornai F. The Effects of Amphetamine and Methamphetamine on the Release of Norepinephrine, Dopamine and Acetylcholine From the Brainstem Reticular Formation. Front Neuroanat 2019; 13:48. [PMID: 31133823 PMCID: PMC6524618 DOI: 10.3389/fnana.2019.00048] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/26/2019] [Indexed: 12/22/2022] Open
Abstract
Amphetamine (AMPH) and methamphetamine (METH) are widely abused psychostimulants, which produce a variety of psychomotor, autonomic and neurotoxic effects. The behavioral and neurotoxic effects of both compounds (from now on defined as AMPHs) stem from a fair molecular and anatomical specificity for catecholamine-containing neurons, which are placed in the brainstem reticular formation (RF). In fact, the structural cross-affinity joined with the presence of shared molecular targets between AMPHs and catecholamine provides the basis for a quite selective recruitment of brainstem catecholamine neurons following AMPHs administration. A great amount of investigations, commentary manuscripts and books reported a pivotal role of mesencephalic dopamine (DA)-containing neurons in producing behavioral and neurotoxic effects of AMPHs. Instead, the present review article focuses on catecholamine reticular neurons of the low brainstem. In fact, these nuclei add on DA mesencephalic cells to mediate the effects of AMPHs. Among these, we also include two pontine cholinergic nuclei. Finally, we discuss the conundrum of a mixed neuronal population, which extends from the pons to the periaqueductal gray (PAG). In this way, a number of reticular nuclei beyond classic DA mesencephalic cells are considered to extend the scenario underlying the neurobiology of AMPHs abuse. The mechanistic approach followed here to describe the action of AMPHs within the RF is rooted on the fine anatomy of this region of the brainstem. This is exemplified by a few medullary catecholamine neurons, which play a pivotal role compared with the bulk of peripheral sympathetic neurons in sustaining most of the cardiovascular effects induced by AMPHs.
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Affiliation(s)
- Michela Ferrucci
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Fiona Limanaqi
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Larisa Ryskalin
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | | | | | - Francesco Fornai
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- IRCCS Neuromed, Pozzilli, Italy
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17
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Conceição EPS, Madden CJ, Morrison SF. Neurons in the rat ventral lateral preoptic area are essential for the warm-evoked inhibition of brown adipose tissue and shivering thermogenesis. Acta Physiol (Oxf) 2019; 225:e13213. [PMID: 30365209 PMCID: PMC6686665 DOI: 10.1111/apha.13213] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 09/25/2018] [Accepted: 10/19/2018] [Indexed: 12/31/2022]
Abstract
AIM To determine the role of neurons in the ventral part of the lateral preoptic area (vLPO) in CNS thermoregulation. METHODS In vivo electrophysiological and neuropharmacological were used to evaluate the contribution of neurons in the vLPO to the regulation of brown adipose tissue (BAT) thermogenesis and muscle shivering in urethane/chloralose-anaesthetized rats. RESULTS Nanoinjections of NMDA targeting the medial preoptic area (MPA) and the vLPO suppressed the cold-evoked BAT sympathetic activity (SNA), reduced the BAT temperature (TBAT ), expired CO2 , mean arterial pressure (MAP), and heart rate. Inhibition of vLPO neurons with muscimol or AP5/CNQX elicited increases in BAT SNA, TBAT , tachycardia, and small elevations in MAP. The BAT thermogenesis evoked by AP5/CNQX in vLPO was inhibited by the activation of MPA neurons. The inhibition of BAT SNA by vLPO neurons does not require a GABAergic input to dorsomedial hypothalamus (DMH), but MPA provides a GABAergic input to DMH. The activation of vLPO neurons inhibits the BAT thermogenesis evoked by NMDA in the rostral raphe pallidus (rRPa), but not that after bicuculline in rRPa. The BAT thermogenesis elicited by vLPO inhibition is dependent on glutamatergic inputs to DMH and rRPa, but these excitatory inputs do not arise from MnPO neurons. The activation of neurons in the vLPO also inhibits cold- and prostaglandin-evoked muscle shivering, and vLPO inhibition is sufficient to evoke shivering. CONCLUSION The vLPO contains neurons that are required for the warm ambient-evoked inhibition of muscle shivering and of BAT thermogenesis, mediated through a direct or indirect GABAergic input to rRPa from vLPO.
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Affiliation(s)
- Ellen P S Conceição
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon
| | - Christopher J Madden
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon
| | - Shaun F Morrison
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon
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18
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Qin C, Li J, Tang K. The Paraventricular Nucleus of the Hypothalamus: Development, Function, and Human Diseases. Endocrinology 2018; 159:3458-3472. [PMID: 30052854 DOI: 10.1210/en.2018-00453] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 07/16/2018] [Indexed: 02/08/2023]
Abstract
The paraventricular nucleus of the hypothalamus (PVH), located in the ventral diencephalon adjacent to the third ventricle, is a highly conserved brain region present in species from zebrafish to humans. The PVH is composed of three main types of neurons, magnocellular, parvocellular, and long-projecting neurons, which play imperative roles in the regulation of energy balance and various endocrinological activities. In this review, we focus mainly on recent findings about the early development of the hypothalamus and the PVH, the functions of the PVH in the modulation of energy homeostasis and in the hypothalamus-pituitary system, and human diseases associated with the PVH, such as obesity, short stature, hypertension, and diabetes insipidus. Thus, the investigations of the PVH will benefit not only understanding of the development of the central nervous system but also the etiology of and therapy for human diseases.
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Affiliation(s)
- Cheng Qin
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, China
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi, China
| | - Jiaheng Li
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, China
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi, China
| | - Ke Tang
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi, China
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, Guangdong, China
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19
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Krieger JP, Santos da Conceição EP, Sanchez-Watts G, Arnold M, Pettersen KG, Mohammed M, Modica S, Lossel P, Morrison SF, Madden CJ, Watts AG, Langhans W, Lee SJ. Glucagon-like peptide-1 regulates brown adipose tissue thermogenesis via the gut-brain axis in rats. Am J Physiol Regul Integr Comp Physiol 2018; 315:R708-R720. [PMID: 29847161 DOI: 10.1152/ajpregu.00068.2018] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Endogenous intestinal glucagon-like peptide-1 (GLP-1) controls satiation and glucose metabolism via vagal afferent neurons (VANs). Recently, VANs have received increasing attention for their role in brown adipose tissue (BAT) thermogenesis. It is, however, unclear whether VAN GLP-1 receptor (GLP-1R) signaling affects BAT thermogenesis and energy expenditure (EE) and whether this VAN mechanism contributes to energy balance. First, we tested the effect of the GLP-1R agonist exendin-4 (Ex4, 0.3 μg/kg ip) on EE and BAT thermogenesis and whether these effects require VAN GLP-1R signaling using a rat model with a selective Glp1r knockdown (kd) in VANs. Second, we examined the role of VAN GLP-1R in energy balance during chronic high-fat diet (HFD) feeding in VAN Glp1r kd rats. Finally, we used viral transsynaptic tracers to identify the possible neuronal substrates of such a gut-BAT interaction. VAN Glp1r kd attenuated the acute suppressive effects of Ex4 on EE and BAT thermogenesis. Consistent with this finding, the VAN Glp1r kd increased EE and BAT activity, diminished body weight gain, and improved insulin sensitivity compared with HFD-fed controls. Anterograde transsynaptic viral tracing of VANs infected major hypothalamic and hindbrain areas involved in BAT sympathetic regulation. Moreover, retrograde tracing from BAT combined with laser capture microdissection revealed that a population of VANs expressing Glp1r is synaptically connected to the BAT. Our findings reveal a novel role of VAN GLP-1R signaling in the regulation of EE and BAT thermogenesis and imply that through this gut-brain-BAT connection, intestinal GLP-1 plays a role in HFD-induced metabolic syndrome.
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Affiliation(s)
- Jean-Philippe Krieger
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | | | - Graciela Sanchez-Watts
- Department of Biological Sciences, University of Southern California , Los Angeles, California
| | - Myrtha Arnold
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Klaus G Pettersen
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Mazher Mohammed
- Department of Neurological Surgery, Oregon Health and Science University , Portland, Oregon
| | - Salvatore Modica
- Translational Nutrition Biology Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Pius Lossel
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Shaun F Morrison
- Department of Neurological Surgery, Oregon Health and Science University , Portland, Oregon
| | - Christopher J Madden
- Department of Neurological Surgery, Oregon Health and Science University , Portland, Oregon
| | - Alan G Watts
- Department of Biological Sciences, University of Southern California , Los Angeles, California
| | - Wolfgang Langhans
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Shin J Lee
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
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20
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Zaretsky DV, Romanovsky AA, Zaretskaia MV, Molkov YI. Tissue oxidative metabolism can increase the difference between local temperature and arterial blood temperature by up to 1.3 oC: Implications for brain, brown adipose tissue, and muscle physiology. Temperature (Austin) 2018; 5:22-35. [PMID: 29687042 DOI: 10.1080/23328940.2018.1437311] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 02/02/2018] [Accepted: 02/02/2018] [Indexed: 10/18/2022] Open
Abstract
Tissue temperature increases, when oxidative metabolism is boosted. The source of nutrients and oxygen for this metabolism is the blood. The blood also cools down the tissue, and this is the only cooling mechanism, when direct dissipation of heat from the tissue to the environment is insignificant, e.g., in the brain. While this concept is relatively simple, it has not been described quantitatively. The purpose of the present work was to answer two questions: 1) to what extent can oxidative metabolism make the organ tissue warmer than the body core, and, 2) how quickly are changes in the local metabolism reflected in the temperature of the tissue? Our theoretical analysis demonstrates that, at equilibrium, given that heat exchange with the organ is provided by the blood, the temperature difference between the organ tissue and the arterial blood is proportional to the arteriovenous difference in oxygen content, does not depend on the blood flow, and cannot exceed 1.3oC. Unlike the equilibrium temperature difference, the rate of change of the local temperature, with respect to time, does depend on the blood flow. In organs with high perfusion rates, such as the brain and muscles, temperature changes occur on a time scale of a few minutes. In organs with low perfusion rates, such changes may have characteristic time constants of tens or hundreds of minutes. Our analysis explains, why arterial blood temperature is the main determinant of the temperature of tissues with limited heat exchange, such as the brain.
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Affiliation(s)
- Dmitry V Zaretsky
- Discovery and Translational Medicine Division, Intarcia Therapeutics, Research Triangle, NC 27709
| | - Andrej A Romanovsky
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013
| | - Maria V Zaretskaia
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Yaroslav I Molkov
- Department of Mathematics and Statistics and Neuroscience Institute, Georgia State University, GA 30303
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21
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Chechi K, van Marken Lichtenbelt W, Richard D. Brown and beige adipose tissues: phenotype and metabolic potential in mice and men. J Appl Physiol (1985) 2018; 124:482-496. [PMID: 28302705 PMCID: PMC5867364 DOI: 10.1152/japplphysiol.00021.2017] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/09/2017] [Accepted: 03/13/2017] [Indexed: 01/06/2023] Open
Abstract
With the recent rediscovery of brown fat in adult humans, our outlook on adipose tissue biology has undergone a paradigm shift. While we attempt to identify, recruit, and activate classic brown fat stores in humans, identification of beige fat has also raised the possibility of browning our white fat stores. Whether such transformation of human white fat depots can be achieved to enhance the whole body oxidative potential remains to be seen. Evidence to date, however, largely points toward a major oxidative role only for classic brown fat depots, at least in rodents. White fat stores seem to provide the main fuel for sustaining thermogenesis via lipolysis. Interestingly, molecular markers consistent with both classic brown and beige fat identity can be observed in human supraclavicular depot, thereby complicating the discussion on beige fat in humans. Here, we review the recent advances made in our understanding of brown and beige fat in humans and mice. We further provide an overview of their plausible physiological relevance to whole body energy metabolism.
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Affiliation(s)
- Kanta Chechi
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Ville de Québec, Quebec , Canada
| | - Wouter van Marken Lichtenbelt
- Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center , Maastricht , The Netherlands
| | - Denis Richard
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Ville de Québec, Quebec , Canada
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22
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Christie S, Wittert GA, Li H, Page AJ. Involvement of TRPV1 Channels in Energy Homeostasis. Front Endocrinol (Lausanne) 2018; 9:420. [PMID: 30108548 PMCID: PMC6079260 DOI: 10.3389/fendo.2018.00420] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 07/04/2018] [Indexed: 12/25/2022] Open
Abstract
The ion channel TRPV1 is involved in a wide range of processes including nociception, thermosensation and, more recently discovered, energy homeostasis. Tightly controlling energy homeostasis is important to maintain a healthy body weight, or to aid in weight loss by expending more energy than energy intake. TRPV1 may be involved in energy homeostasis, both in the control of food intake and energy expenditure. In the periphery, it is possible that TRPV1 can impact on appetite through control of appetite hormone levels or via modulation of gastrointestinal vagal afferent signaling. Further, TRPV1 may increase energy expenditure via heat production. Dietary supplementation with TRPV1 agonists, such as capsaicin, has yielded conflicting results with some studies indicating a reduction in food intake and increase in energy expenditure, and other studies indicating the converse. Nonetheless, it is increasingly apparent that TRPV1 may be dysregulated in obesity and contributing to the development of this disease. The mechanisms behind this dysregulation are currently unknown but interactions with other systems, such as the endocannabinoid systems, could be altered and therefore play a role in this dysregulation. Further, TRPV1 channels appear to be involved in pancreatic insulin secretion. Therefore, given its plausible involvement in regulation of energy and glucose homeostasis and its dysregulation in obesity, TRPV1 may be a target for weight loss therapy and diabetes. However, further research is required too fully elucidate TRPV1s role in these processes. The review provides an overview of current knowledge in this field and potential areas for development.
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Affiliation(s)
- Stewart Christie
- Vagal Afferent Research Group, Centre for Nutrition and Gastrointestinal Disease, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Gary A. Wittert
- Vagal Afferent Research Group, Centre for Nutrition and Gastrointestinal Disease, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Hui Li
- Vagal Afferent Research Group, Centre for Nutrition and Gastrointestinal Disease, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Amanda J. Page
- Vagal Afferent Research Group, Centre for Nutrition and Gastrointestinal Disease, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
- *Correspondence: Amanda J. Page
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23
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Morrison SF. Efferent neural pathways for the control of brown adipose tissue thermogenesis and shivering. HANDBOOK OF CLINICAL NEUROLOGY 2018; 156:281-303. [PMID: 30454595 DOI: 10.1016/b978-0-444-63912-7.00017-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The fundamental central neural circuits for thermoregulation orchestrate behavioral and autonomic repertoires that maintain body core temperature during thermal challenges that arise from either the ambient or the internal environment. This review summarizes our understanding of the neural pathways within the fundamental thermoregulatory reflex circuitry that comprise the efferent (i.e., beyond thermosensory) control of brown adipose tissue (BAT) and shivering thermogenesis: the motor neuron systems consisting of the BAT sympathetic preganglionic neurons and BAT sympathetic ganglion cells, and the alpha- and gamma-motoneurons; the premotor neurons in the region of the rostral raphe pallidus, and the thermogenesis-promoting neurons in the dorsomedial hypothalamus/dorsal hypothalamic area. Also included are inputs to, and neurochemical modulators of, these efferent neuronal populations that could influence their activity during thermoregulatory responses. Signals of metabolic status can be particularly significant for the energy-hungry thermoeffectors for heat production.
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Affiliation(s)
- Shaun F Morrison
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, United States.
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Conceição EPS, Madden CJ, Morrison SF. Tonic inhibition of brown adipose tissue sympathetic nerve activity via muscarinic acetylcholine receptors in the rostral raphe pallidus. J Physiol 2017; 595:7495-7508. [PMID: 29023733 DOI: 10.1113/jp275299] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 10/09/2017] [Indexed: 01/23/2023] Open
Abstract
KEY POINTS A tonically active, muscarinic cholinergic inhibition of rostral raphe pallidus (rRPa) neurons influences thermogenesis of brown adipose tissue (BAT) independent of ambient temperature conditions. The tonically active cholinergic input to rRPa originates caudal to the hypothalamus. Muscarinic acetylcholine receptor (mAChR) activation in rRPa contributes to the inhibition of BAT sympathetic nerve activity (SNA) evoked by activation of neurons in the rostral ventrolateral medulla (RVLM). The RVLM is not the sole source of the muscarinic cholinergic input to rRPa. Activation of GABA receptors in rRPa does not mediate the cholinergic inhibition of BAT SNA. ABSTRACT We sought to determine if body temperature and energy expenditure are influenced by a cholinergic input to neurons in the rostral raphe pallidus (rRPa), the site of sympathetic premotor neurons controlling thermogenesis of brown adipose tissue (BAT). Nanoinjections of the muscarinic acetylcholine receptor (mAChR) agonist, oxotremorine, or the cholinesterase inhibitor, neostigmine (NEOS), in the rRPa of anaesthetized rats decreased cold-evoked BAT sympathetic nerve activity (SNA, nadirs: -72 and -95%), BAT temperature (Tbat, -0.5 and -0.6°C), expired CO2 (Exp. CO2 , -0.3 and -0.5%) and heart rate (HR, -22 and -41 bpm). NEOS into rRPa reversed the increase in BAT SNA evoked by blockade of GABA receptors in rRPa. Nanoinjections of the mAChR antagonist, scopolamine (SCOP), in the rRPa of warm rats increased BAT SNA (peak: +1087%), Tbat (+1.8°C), Exp. CO2 (+0.7%), core temperature (Tcore, +0.5°C) and HR (+54 bpm). SCOP nanoinjections in rRPa produced similar activations of BAT during cold exposure, following a brain transection caudal to the hypothalamus, and during the blockade of glutamate receptors in rRPa. We conclude that a tonically active cholinergic input to the rRPa inhibits BAT SNA via activation of local mAChR. The inhibition of BAT SNA mediated by mAChR in rRPa does not depend on activation of GABA receptors in rRPa. The increase in BAT SNA following mAChR blockade in rRPa does not depend on the activity of neurons in the hypothalamus or on glutamate receptor activation in rRPa.
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Affiliation(s)
| | - Christopher J Madden
- Department of Neurological Surgery, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Shaun F Morrison
- Department of Neurological Surgery, Oregon Health & Science University, Portland, OR, 97239, USA
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Abstract
Brown and beige adipocytes arise from distinct developmental origins. Brown adipose tissue (BAT) develops embryonically from precursors that also give to skeletal muscle. Beige fat develops postnatally and is highly inducible. Beige fat recruitment is mediated by multiple mechanisms, including de novo beige adipogenesis and white-to-brown adipocyte transdifferentiaiton. Beige precursors reside around vasculatures, and proliferate and differentiate into beige adipocytes. PDGFRα+Ebf2+ precursors are restricted to beige lineage cells, while another PDGFRα+ subset gives rise to beige adipocytes, white adipocytes, or fibrogenic cells. White adipocytes can be reprogramed and transdifferentiated into beige adipocytes. Brown and beige adipocytes display many similar properties, including multilocular lipid droplets, dense mitochondria, and expression of UCP1. UCP1-mediated thermogenesis is a hallmark of brown/beige adipocytes, albeit UCP1-independent thermogenesis also occurs. Development, maintenance, and activation of BAT/beige fat are guided by genetic and epigenetic programs. Numerous transcriptional factors and coactivators act coordinately to promote BAT/beige fat thermogenesis. Epigenetic reprograming influences expression of brown/beige adipocyte-selective genes. BAT/beige fat is regulated by neuronal, hormonal, and immune mechanisms. Hypothalamic thermal circuits define the temperature setpoint that guides BAT/beige fat activity. Metabolic hormones, paracrine/autocrine factors, and various immune cells also play a critical role in regulating BAT/beige fat functions. BAT and beige fat defend temperature homeostasis, and regulate body weight and glucose and lipid metabolism. Obesity is associated with brown/beige fat deficiency, and reactivation of brown/beige fat provides metabolic health benefits in some patients. Pharmacological activation of BAT/beige fat may hold promise for combating metabolic diseases. © 2017 American Physiological Society. Compr Physiol 7:1281-1306, 2017.
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Affiliation(s)
- Liangyou Rui
- Department of Molecular and Integrative Physiology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
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26
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Choudhary RC, Jia X. Hypothalamic or Extrahypothalamic Modulation and Targeted Temperature Management After Brain Injury. Ther Hypothermia Temp Manag 2017; 7:125-133. [PMID: 28467285 PMCID: PMC5610405 DOI: 10.1089/ther.2017.0003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Targeted temperature management (TTM) has been recognized to protect tissue function and positively influence neurological outcomes after brain injury. While shivering during hypothermia nullifies the beneficial effect of TTM, traditionally, antishivering drugs or paralyzing agents have been used to reduce the shivering. The hypothalamic area of the brain helps in controlling cerebral temperature and body temperature through interactions between different brain areas. Thus, modulation of different brain areas either pharmacologically or by electrical stimulation may contribute in TTM; although, very few studies have shown that TTM might be achieved by activation and inhibition of neurons in the hypothalamic region. Recent studies have investigated potential pharmacological methods of inducing hypothermia for TTM by aiming to maintain the TTM and reduce the shivering effect without using antiparalytic drugs. Better survival and neurological outcome after brain injury have been reported after pharmacologically induced TTM. This review discusses the mechanisms and modulation of the hypothalamus with other brain areas that are involved in inducing hypothermia through which TTM may be achieved and provides therapeutic strategies for TTM after brain injury.
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Affiliation(s)
| | - Xiaofeng Jia
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, Maryland
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
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27
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Contreras C, Nogueiras R, Diéguez C, Rahmouni K, López M. Traveling from the hypothalamus to the adipose tissue: The thermogenic pathway. Redox Biol 2017; 12:854-863. [PMID: 28448947 PMCID: PMC5406580 DOI: 10.1016/j.redox.2017.04.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/08/2017] [Accepted: 04/11/2017] [Indexed: 01/13/2023] Open
Abstract
Brown adipose tissue (BAT) is a specialized tissue critical for non-shivering thermogenesis producing heat through mitochondrial uncoupling; whereas white adipose tissue (WAT) is responsible of energy storage in the form of triglycerides. Another type of fat has been described, the beige adipose tissue; this tissue emerges in existing WAT depots but with thermogenic ability, a phenomenon known as browning. Several peripheral signals relaying information about energy status act in the brain, particularly the hypothalamus, to regulate thermogenesis in BAT and browning of WAT. Different hypothalamic areas have the capacity to regulate the thermogenic process in brown and beige adipocytes through the sympathetic nervous system (SNS). This review discusses important concepts and discoveries about the central control of thermogenesis as a trip that starts in the hypothalamus, and taking the sympathetic roads to reach brown and beige fat to modulate thermogenic functions.
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Affiliation(s)
- Cristina Contreras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain.
| | - Rubén Nogueiras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain
| | - Carlos Diéguez
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa, Iowa City, Iowa 52242, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, USA
| | - Miguel López
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela 15706, Spain.
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28
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Conceição EPSD, Madden CJ, Morrison SF. Glycinergic inhibition of BAT sympathetic premotor neurons in rostral raphe pallidus. Am J Physiol Regul Integr Comp Physiol 2017; 312:R919-R926. [PMID: 28254751 DOI: 10.1152/ajpregu.00551.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 02/02/2017] [Accepted: 02/18/2017] [Indexed: 11/22/2022]
Abstract
The rostral raphe pallidus (rRPa) contains sympathetic premotor neurons controlling thermogenesis in brown adipose tissue (BAT). We sought to determine whether a tonic activation of glycineA receptors (GlyAR) in the rRPa contributes to the inhibitory regulation of BAT sympathetic nerve activity (SNA) and of cardiovascular parameters in anesthetized rats. Nanoinjection of the GlyAR antagonist, strychnine (STR), into the rRPa of intact rats increased BAT SNA (peak: +495%), BAT temperature (TBAT, +1.1°C), expired CO2, (+0.4%), core body temperature (TCORE, +0.2°C), mean arterial pressure (MAP, +4 mmHg), and heart rate (HR, +57 beats/min). STR into rRPa in rats with a postdorsomedial hypothalamus transection produced similar increases in BAT thermogenic and cardiovascular parameters. Glycine nanoinjection into the rRPa evoked a potent inhibition of the cooling-evoked increases in BAT SNA (nadir: -74%), TBAT (-0.2°C), TCORE (-0.2°C), expired CO2 (-0.2%), MAP (-8 mmHg), and HR (-22 beats/min) but had no effect on the increases in these variables evoked by STR nanoinjection into rRPa. Nanoinjection of GABA into the rRPa inhibited the STR-evoked BAT SNA (nadir: -86%) and reduced the expired CO2 (-0.4%). Blockade of glutamate receptors in rRPa reduced the STR-evoked increases in BAT SNA (nadir: -61%), TBAT (-0.5°C), expired CO2 (-0.3%), MAP (-9 mmHg), and HR (-33 beats/min). We conclude that a tonically active glycinergic input to the rRPa contributes to the inhibitory regulation of the discharge of BAT sympathetic premotor neurons and of BAT thermogenesis and energy expenditure.
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Affiliation(s)
| | - Christopher J Madden
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon
| | - Shaun F Morrison
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon
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29
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Nakamura Y, Yanagawa Y, Morrison SF, Nakamura K. Medullary Reticular Neurons Mediate Neuropeptide Y-Induced Metabolic Inhibition and Mastication. Cell Metab 2017; 25:322-334. [PMID: 28065829 PMCID: PMC5299028 DOI: 10.1016/j.cmet.2016.12.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/16/2016] [Accepted: 12/05/2016] [Indexed: 02/01/2023]
Abstract
Hypothalamic neuropeptide Y (NPY) elicits hunger responses to increase the chances of surviving starvation: an inhibition of metabolism and an increase in feeding. Here we elucidate a key central circuit mechanism through which hypothalamic NPY signals drive these hunger responses. GABAergic neurons in the intermediate and parvicellular reticular nuclei (IRt/PCRt) of the medulla oblongata, which are activated by NPY-triggered neural signaling from the hypothalamus, potentially through the nucleus tractus solitarius, mediate the NPY-induced inhibition of metabolic thermogenesis in brown adipose tissue (BAT) via their innervation of BAT sympathetic premotor neurons. Intriguingly, the GABAergic IRt/PCRt neurons innervating the BAT sympathetic premotor region also innervate the masticatory motor region, and stimulation of the IRt/PCRt elicits mastication and increases feeding as well as inhibits BAT thermogenesis. These results indicate that GABAergic IRt/PCRt neurons mediate hypothalamus-derived hunger signaling by coordinating both autonomic and feeding motor systems to reduce energy expenditure and to promote feeding.
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Affiliation(s)
- Yoshiko Nakamura
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan
| | - Shaun F Morrison
- Department of Neurological Surgery, Oregon Health & Science University, Portland, OR 97239, USA
| | - Kazuhiro Nakamura
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan.
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30
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Sabino JPJ, Soriano RN, Donatti AF, Fernandez RR, Kwiatkoski M, Francescato HD, Coimbra TM, Branco LG. Involvement of endogenous central hydrogen sulfide (H2S) in hypoxia-induced hypothermia in spontaneously hypertensive rats. Can J Physiol Pharmacol 2017; 95:157-162. [DOI: 10.1139/cjpp-2016-0033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Spontaneously hypertensive rats (SHR) display autonomic imbalance and abnormal body temperature (Tb) adjustments. Hydrogen sulfide (H2S) modulates hypoxia-induced hypothermia, but its role in SHR thermoregulation is unknown. We tested the hypothesis that SHR display peculiar thermoregulatory response to hypoxia and that endogenous H2S overproduced in the caudal nucleus of the solitary tract (NTS) of SHR modulates this response. SHR and Wistar rats were microinjected into the fourth ventricle with aminooxyacetate (AOA, H2S-synthezing enzyme inhibitor) or sodium sulfide (Na2S, H2S donor) and exposed to normoxia (21% inspired O2) or hypoxia (10% inspired O2, 30 min). Tb was continuously measured, and H2S production rate was assessed in caudal NTS homogenates. In both groups, AOA, Na2S, or saline (i.e., control; 1 μL) did not affect euthermia. Hypoxia caused similar decreases in Tb in both groups. AOA presented a longer latency to potentiate hypoxic hypothermia in SHR. Caudal NTS H2S production rate was higher in SHR. We suggest that increased bioavailability of H2S in the caudal NTS of SHR enables the adequate modulation of excitability of peripheral chemoreceptor-activated NTS neurons that ultimately induce suppression of brown adipose tissue thermogenesis, thus accounting for the normal hypoxic hypothermia.
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Affiliation(s)
- João Paulo J. Sabino
- Dental School of Ribeirão Preto, 14040-904, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Renato N. Soriano
- Division of Physiology and Biophysics, Department of Basic Life Sciences, Federal University of Juiz de Fora, 35020-220, Governador Valadares, MG, Brazil
| | - Alberto F. Donatti
- Dental School of Ribeirão Preto, 14040-904, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Marcelo Kwiatkoski
- Dental School of Ribeirão Preto, 14040-904, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Heloísa D.C. Francescato
- School of Medicine of Ribeirão Preto, 14040-904, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Terezila M. Coimbra
- School of Medicine of Ribeirão Preto, 14040-904, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Luiz G.S. Branco
- Dental School of Ribeirão Preto, 14040-904, University of São Paulo, Ribeirão Preto, SP, Brazil
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31
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Abstract
The homeostatic control of body temperature is essential for survival in mammals and is known to be regulated in part by temperature-sensitive neurons in the hypothalamus. However, the specific neural pathways and corresponding neural populations have not been fully elucidated. To identify these pathways, we used cFos staining to identify neurons that are activated by a thermal challenge and found induced expression in subsets of neurons within the ventral part of the lateral preoptic nucleus (vLPO) and the dorsal part of the dorsomedial hypothalamus (DMD). Activation of GABAergic neurons in the vLPO using optogenetics reduced body temperature, along with a decrease in physical activity. Optogenetic inhibition of these neurons resulted in fever-level hyperthermia. These GABAergic neurons project from the vLPO to the DMD and optogenetic stimulation of the nerve terminals in the DMD also reduced body temperature and activity. Electrophysiological recording revealed that the vLPO GABAergic neurons suppressed neural activity in DMD neurons, and fiber photometry of calcium transients revealed that DMD neurons were activated by cold. Accordingly, activation of DMD neurons using designer receptors exclusively activated by designer drugs (DREADDs) or optogenetics increased body temperature with a strong increase in energy expenditure and activity. Finally, optogenetic inhibition of DMD neurons triggered hypothermia, similar to stimulation of the GABAergic neurons in the vLPO. Thus, vLPO GABAergic neurons suppressed the thermogenic effect of DMD neurons. In aggregate, our data identify vLPO→DMD neural pathways that reduce core temperature in response to a thermal challenge, and we show that outputs from the DMD can induce activity-induced thermogenesis.
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32
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Madden CJ, Santos da Conceicao EP, Morrison SF. Vagal afferent activation decreases brown adipose tissue (BAT) sympathetic nerve activity and BAT thermogenesis. Temperature (Austin) 2016; 4:89-96. [PMID: 28349097 PMCID: PMC5356211 DOI: 10.1080/23328940.2016.1257407] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 11/02/2016] [Accepted: 11/02/2016] [Indexed: 02/08/2023] Open
Abstract
In urethane/α-chloralose anesthetized rats, electrical stimulation of cervical vagal afferent fibers inhibited the increases in brown adipose tissue sympathetic nerve activity and brown adipose tissue thermogenesis evoked by cold exposure, by nanoinjection of the GABAA receptor antagonist, bicuculline, in the dorsomedial hypothalamus, and by nanoinjection of N-methyl-D-aspartate in the rostral raphe pallidus. Vagus nerve stimulation-evoked inhibition of brown adipose tissue sympathetic nerve activity was prevented by blockade of ionotropic glutamate receptors in the termination site of vagal afferents in the nucleus of the solitary tract, and by nanoinjection of GABAA receptor antagonists in the rostral raphe pallidus. In conclusion, the brown adipose tissue sympathoinhibitory effect of cervical afferent vagal nerve stimulation is mediated by glutamatergic activation of second-order sensory neurons in the nucleus of the solitary tract and by a GABAergic inhibition of brown adipose tissue sympathetic premotor neurons in the rostral raphe pallidus, but does not require GABAergic inhibition of the brown adipose tissue sympathoexcitatory neurons in the dorsomedial hypothalamus.
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Affiliation(s)
- Christopher J Madden
- Department of Neurological Surgery, Oregon Health & Science University , Portland, OR, USA
| | | | - Shaun F Morrison
- Department of Neurological Surgery, Oregon Health & Science University , Portland, OR, USA
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Madden CJ, Morrison SF. A high-fat diet impairs cooling-evoked brown adipose tissue activation via a vagal afferent mechanism. Am J Physiol Endocrinol Metab 2016; 311:E287-92. [PMID: 27354235 PMCID: PMC5005966 DOI: 10.1152/ajpendo.00081.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/23/2016] [Indexed: 01/01/2023]
Abstract
In dramatic contrast to rats on a control diet, rats maintained on a high-fat diet (HFD) failed to activate brown adipose tissue (BAT) during cooling despite robust increases in their BAT activity following direct activation of their BAT sympathetic premotor neurons in the raphe pallidus. Cervical vagotomy or blockade of glutamate receptors in the nucleus of the tractus solitarii (NTS) reversed the HFD-induced inhibition of cold-evoked BAT activity. Thus, a HFD does not prevent rats from mounting a robust, centrally driven BAT thermogenesis; however, a HFD does alter a vagal afferent input to NTS neurons, thereby preventing the normal activation of BAT thermogenesis to cooling. These results, paralleling the absence of cooling-evoked glucose uptake in the BAT of obese humans, reveal a neural mechanism through which consumption of a HFD contributes to reduced energy expenditure and thus to weight gain.
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Affiliation(s)
- Christopher J Madden
- Department of Neurological Surgery, Oregon Health and Science University, Portland, Oregon
| | - Shaun F Morrison
- Department of Neurological Surgery, Oregon Health and Science University, Portland, Oregon
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Mokhtari M, Sistanizad M, Farasatinasab M. Antipyretic Effect of Clonidine in Intensive Care Unit Patients: A Nested Observational Study. J Clin Pharmacol 2016; 57:48-51. [PMID: 27264198 DOI: 10.1002/jcph.776] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/23/2016] [Accepted: 05/24/2016] [Indexed: 11/08/2022]
Abstract
Fever in the intensive care unit (ICU) is usually an adaptive response to infection or inflammation. Pharmacological intervention is often required in addition to addressing the underlying causes of fever. Animal studies have examined the antipyretic effect of clonidine; however, to our knowledge there are no clinical data available in humans. The observation of an antipyretic effect of clonidine was made during a single-center randomized control trial that was designed to study the effect of clonidine addition to the commonly used sedative agents in mechanically ventilated ICU patients. Forty patients 18 years or older on mechanical ventilation for 3 days or longer were randomized into 2 groups receiving clonidine and placebo. In addition to the usual sedation/analgesia, patients in the clonidine arm received enteral clonidine in doses of 0.1 mg 3 times a day (TID), which was increased to 0.2 mg TID if the hemodynamics remained stable. Vital signs, laboratory data, all cultures, and daily ICU events were recorded. The odds ratio of temperature higher than 38.3°C was 3.96 times higher in the placebo group, after adjustment for the illness severity and the time of follow-up (P = .049). A lower temperature (0.52°C) was observed in the clonidine group after adjustment for the time of follow-up (P = .006). Our report is the first of its kind in humans that demonstrates possible antipyretic properties of enteral clonidine in the critically ill intensive care unit patient.
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Affiliation(s)
- Majid Mokhtari
- Department of Medicine, Pulmonary and Critical Care Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Sistanizad
- Department of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Farasatinasab
- Department of Clinical Pharmacy, School of Pharmacy-International Campus, FCRDC, Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran
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Abstract
Central neural circuits orchestrate the behavioral and autonomic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response and behavioral states and in response to declining energy homeostasis. This review summarizes the central nervous system circuit mechanisms controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction regulating heat loss and shivering and brown adipose tissue for thermogenesis. The activation of these thermoeffectors is regulated by parallel but distinct efferent pathways within the central nervous system that share a common peripheral thermal sensory input. The model for the neural circuit mechanism underlying central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation, for elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation, and for the discovery of novel therapeutic approaches to modulating body temperature and energy homeostasis.
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Affiliation(s)
- Shaun F Morrison
- Department of Neurological Surgery, Oregon Health & Science University, Portland, OR, USA
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Morrison SF. Central neural control of thermoregulation and brown adipose tissue. Auton Neurosci 2016; 196:14-24. [PMID: 26924538 DOI: 10.1016/j.autneu.2016.02.010] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 02/05/2016] [Accepted: 02/19/2016] [Indexed: 12/26/2022]
Abstract
Central neural circuits orchestrate the homeostatic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response. This review summarizes the experimental underpinnings of our current model of the CNS pathways controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction controlling heat loss, and shivering and brown adipose tissue for thermogenesis. The activation of these effectors is regulated by parallel but distinct, effector-specific, core efferent pathways within the CNS that share a common peripheral thermal sensory input. Via the lateral parabrachial nucleus, skin thermal afferent input reaches the hypothalamic preoptic area to inhibit warm-sensitive, inhibitory output neurons which control heat production by inhibiting thermogenesis-promoting neurons in the dorsomedial hypothalamus that project to thermogenesis-controlling premotor neurons in the rostral ventromedial medulla, including the raphe pallidus, that descend to provide the excitation of spinal circuits necessary to drive thermogenic thermal effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus sympathetic premotor neurons controlling cutaneous vasoconstriction. The model proposed for central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation and elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation.
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Affiliation(s)
- Shaun F Morrison
- Department of Neurological Surgery, Oregon Health & Science University, Portland, OR 97239, Unites States.
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Martinez-Lopez N, Garcia-Macia M, Sahu S, Athonvarangkul D, Liebling E, Merlo P, Cecconi F, Schwartz GJ, Singh R. Autophagy in the CNS and Periphery Coordinate Lipophagy and Lipolysis in the Brown Adipose Tissue and Liver. Cell Metab 2016; 23:113-27. [PMID: 26698918 PMCID: PMC4715637 DOI: 10.1016/j.cmet.2015.10.008] [Citation(s) in RCA: 219] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 08/31/2015] [Accepted: 10/19/2015] [Indexed: 01/22/2023]
Abstract
The integrative physiology of inter-organ communication in lipophagy regulation is not well understood. Lipophagy and the cytosolic lipases ATGL and HSL contribute to lipid droplet (LD) mobilization; however, whether autophagy proteins engage with lipases to promote lipid utilization remains unknown. Here, we show that cold induces autophagy in proopiomelanocortin (POMC) neurons and activates lipophagy in brown adipose tissue (BAT) and liver in mice. Targeted activation of autophagy in POMC neurons via intra-hypothalamic rapamycin is sufficient to trigger lipid utilization in room temperature-housed mice. Conversely, inhibiting autophagy in POMC neurons or in peripheral tissues or denervating BAT blocks lipid utilization. Unexpectedly, the autophagosome marker LC3 is mechanistically coupled to ATGL-mediated lipolysis. ATGL exhibits LC3-interacting region (LIR) motifs, and mutating a single LIR motif on ATGL displaces ATGL from LD and disrupts lipolysis. Thus, cold-induced activation of central autophagy activates lipophagy and cytosolic lipases in a complementary manner to mediate lipolysis in peripheral tissues.
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Affiliation(s)
- Nuria Martinez-Lopez
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Marina Garcia-Macia
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Srabani Sahu
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Diana Athonvarangkul
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Emily Liebling
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Paola Merlo
- Department of Biology, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Francesco Cecconi
- Unit of Cell Stress and Survival, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark; Laboratory of Molecular Neuroembryology, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy; Department of Biology, University of Rome "Tor Vergata," 00133 Rome, Italy
| | - Gary J Schwartz
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rajat Singh
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Abstract
Although it has been known for more than a century that the brain controls overall energy balance and adiposity by regulating feeding behavior and energy expenditure, the roles for individual brain regions and neuronal subtypes were not fully understood until recently. This area of research is active, and as such our understanding of the central regulation of energy balance is continually being refined as new details emerge. Much of what we now know stems from the discoveries of leptin and the hypothalamic melanocortin system. Hypothalamic circuits play a crucial role in the control of feeding and energy expenditure, and within the hypothalamus, the arcuate nucleus (ARC) functions as a gateway for hormonal signals of energy balance, such as leptin. It is also well established that the ARC is a primary residence for hypothalamic melanocortinergic neurons. The paraventricular hypothalamic nucleus (PVH) receives direct melanocortin input, along with other integrated signals that affect energy balance, and mediates the majority of hypothalamic output to control both feeding and energy expenditure. Herein, we review in detail the structure and function of the ARC-PVH circuit in mediating leptin signaling and in regulating energy balance.
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Affiliation(s)
- Amy K Sutton
- Departments of Internal Medicine and Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48105;
- Division of Endocrinology, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan 48105;
| | - Martin G Myers
- Departments of Internal Medicine and Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48105;
| | - David P Olson
- Division of Endocrinology, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan 48105;
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El Bitar N, Pollin B, Huang G, Mouraux A, Le Bars D. The rostral ventromedial medulla control of cutaneous vasomotion of paws and tail in the rat: implication for pain studies. J Neurophysiol 2015; 115:773-89. [PMID: 26581872 DOI: 10.1152/jn.00695.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/13/2015] [Indexed: 11/22/2022] Open
Abstract
Thermal neutrality in rodents is achieved by large cyclic variations of the sympathetic drive of the vasomotion of the tail and paws, the most widely used target organs in current acute or chronic animal models of pain. Given the pivotal functional role of rostral ventromedial medulla (RVM) in nociception and rostral medullary raphe (rMR) in thermoregulation, two largely overlapping brain regions, we aimed at circumscribing the brainstem regions that are the source of premotor afferents to sympathetic preganglionic neurons that control the vasomotor tone of the tail and hind paws. A thermometric infrared camera recorded indirectly the vasomotor tone of the tail and hind paws. During the control period, the rat was maintained in vasoconstriction by preserving a stable, homogeneous, and constant surrounding temperature, slightly below the core temperature. The functional blockade of the RVM/rMR by the GABAA receptor agonist muscimol (0.5 nmol, 50 nl) elicited an extensive increase of the temperature of the paws and tail, associated with a slight decrease of blood pressure and heart rate. Both the increased heat loss through vasodilatation and the decrease heart-induced heat production elicited a remarkable reduction of the central temperature. The effective zones were circumscribed to the parts of the RVM/rMR facing the facial nucleus. They match very exactly the brain regions often described as specifically devoted to the control of nociception. Our data support and urge on the highest cautiousness regarding the interpretation of results aimed at studying the effects of any pharmacological manipulations of RVM/rMR with the usual tests of pain.
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Affiliation(s)
- Nabil El Bitar
- Sorbonne Universités, Université Pierre et Marie Curie, Faculté de Médecine, Paris, France; Neurosciences Paris-Seine, Institut National de la Santé et de la Recherche Médicale UMRS-1130, Centre National de la Recherche Scientifique UMR-8246, Paris, France; and
| | - Bernard Pollin
- Sorbonne Universités, Université Pierre et Marie Curie, Faculté de Médecine, Paris, France; Neurosciences Paris-Seine, Institut National de la Santé et de la Recherche Médicale UMRS-1130, Centre National de la Recherche Scientifique UMR-8246, Paris, France; and
| | - Gan Huang
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - André Mouraux
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - Daniel Le Bars
- Sorbonne Universités, Université Pierre et Marie Curie, Faculté de Médecine, Paris, France; Neurosciences Paris-Seine, Institut National de la Santé et de la Recherche Médicale UMRS-1130, Centre National de la Recherche Scientifique UMR-8246, Paris, France; and
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Abstract
Thermogenesis, the production of heat energy, in brown adipose tissue is a significant component of the homeostatic repertoire to maintain body temperature during the challenge of low environmental temperature in many species from mouse to man and plays a key role in elevating body temperature during the febrile response to infection. The sympathetic neural outflow determining brown adipose tissue (BAT) thermogenesis is regulated by neural networks in the CNS which increase BAT sympathetic nerve activity in response to cutaneous and deep body thermoreceptor signals. Many behavioral states, including wakefulness, immunologic responses, and stress, are characterized by elevations in core body temperature to which central command-driven BAT activation makes a significant contribution. Since energy consumption during BAT thermogenesis involves oxidation of lipid and glucose fuel molecules, the CNS network driving cold-defensive and behavioral state-related BAT activation is strongly influenced by signals reflecting the short- and long-term availability of the fuel molecules essential for BAT metabolism and, in turn, the regulation of BAT thermogenesis in response to metabolic signals can contribute to energy balance, regulation of body adipose stores and glucose utilization. This review summarizes our understanding of the functional organization and neurochemical influences within the CNS networks that modulate the level of BAT sympathetic nerve activity to produce the thermoregulatory and metabolic alterations in BAT thermogenesis and BAT energy expenditure that contribute to overall energy homeostasis and the autonomic support of behavior.
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Affiliation(s)
- Shaun F Morrison
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon
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41
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Differential metabolism of brown adipose tissue in newborn rabbits in relation to position in the litter huddle. J Therm Biol 2015; 51:33-41. [DOI: 10.1016/j.jtherbio.2015.03.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 12/20/2022]
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Shylo AV. Dynamics of the Electrographic Indices in Rats and Hamsters Recovering from Artificial and Natural Hypometabolic States. NEUROPHYSIOLOGY+ 2015. [DOI: 10.1007/s11062-015-9502-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The continuous rise in obesity is a major concern for future healthcare management. Many strategies to control body weight focus on a permanent modification of food intake with limited success in the long term. Metabolism or energy expenditure is the other side of the coin for the regulation of body weight, and strategies to enhance energy expenditure are a current focus for obesity treatment, especially since the (re)-discovery of the energy depleting brown adipose tissue in adult humans. Conversely, several human illnesses like neurodegenerative diseases, cancer, or autoimmune deficiency syndrome suffer from increased energy expenditure and severe weight loss. Thus, strategies to modulate energy expenditure to target weight gain or loss would improve life expectancies and quality of life in many human patients. The aim of this book chapter is to give an overview of our current understanding and recent progress in energy expenditure control with specific emphasis on central control mechanisms.
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Donatti AF, Soriano RN, Sabino JP, Branco LGS. Involvement of endogenous hydrogen sulfide (H2S) in the rostral ventrolateral medulla (RVLM) in hypoxia-induced hypothermia. Brain Res Bull 2014; 108:94-9. [PMID: 25262576 DOI: 10.1016/j.brainresbull.2014.08.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/01/2014] [Accepted: 08/28/2014] [Indexed: 01/06/2023]
Abstract
Hypoxia evokes a regulated decrease in deep body temperature (Tb). Hydrogen sulfide (H2S), a signaling molecule that belongs to the gasotransmitter family, has been demonstrated to participate in several brain-mediated responses. Rostral ventrolateral medulla (RVLM) is a brainstem region involved in thermoregulation. Recently, it has been shown that exogenous H2S modulates RVLM activity. In the present study, we investigated whether endogenously produced H2S in the RVLM plays a role in the control of hypoxia-induced hypothermia. Tb was measured before and after bilateral microinjection of aminooxyacetate (AOA, 0.2, 1 and 2 pmol/100 nl, a cystathionine β-synthase, CBS, inhibitor) or vehicle into the RVLM followed by a 60-min normoxia (21% inspired O2) or hypoxia (7% inspired O2) exposure. Microinjection of AOA or vehicle did not change Tb during normoxia. Exposure to hypoxia evoked a typical decrease in Tb. Microinjection of AOA (2 pmol) into the RVLM followed by hypoxia significantly attenuated the decrease in Tb. Thus, endogenous H2S in the RVLM seems to play no role in the maintenance of basal Tb, whereas during hypoxia this gas plays a cryogenic role. Moreover, RVLM homogenates of rats exposed to hypoxia exhibited a decreased rate of H2S production. Our data are consistent with the notion that during hypoxia H2S synthesis is diminished in the RVLM facilitating hypothermia.
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Affiliation(s)
- Alberto F Donatti
- Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, 14040-904 Ribeirão Preto, SP, Brazil
| | - Renato N Soriano
- Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, 14040-904 Ribeirão Preto, SP, Brazil
| | - João P Sabino
- Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, 14040-904 Ribeirão Preto, SP, Brazil
| | - Luiz G S Branco
- Department of Morphology, Physiology and Basic Pathology, Dental School of Ribeirão Preto, University of São Paulo, 14040-904 Ribeirão Preto, SP, Brazil.
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El-Chami M, Shaheen D, Ivers B, Syed Z, Badr MS, Lin HS, Mateika JH. Time of day affects chemoreflex sensitivity and the carbon dioxide reserve during NREM sleep in participants with sleep apnea. J Appl Physiol (1985) 2014; 117:1149-56. [PMID: 25213638 DOI: 10.1152/japplphysiol.00681.2014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Our investigation was designed to determine whether the time of day affects the carbon dioxide reserve and chemoreflex sensitivity during non-rapid eye movement (NREM) sleep. Ten healthy men with obstructive sleep apnea completed a constant routine protocol that consisted of sleep sessions in the evening (10 PM to 1 AM), morning (6 AM to 9 AM), and afternoon (2 PM to 5 PM). Between sleep sessions, the participants were awake. During each sleep session, core body temperature, baseline levels of carbon dioxide (PET(CO2)) and minute ventilation, as well as the PET(CO2) that demarcated the apneic threshold and hypocapnic ventilatory response, were measured. The nadir of core body temperature during sleep occurred in the morning and was accompanied by reductions in minute ventilation and PetCO2 compared with the evening and afternoon (minute ventilation: 5.3 ± 0.3 vs. 6.2 ± 0.2 vs. 6.1 ± 0.2 l/min, P < 0.02; PET(CO2): 39.7 ± 0.4 vs. 41.4 ± 0.6 vs. 40.4 ± 0.6 Torr, P < 0.02). The carbon dioxide reserve was reduced, and the hypocapnic ventilatory response increased in the morning compared with the evening and afternoon (carbon dioxide reserve: 2.1 ± 0.3 vs. 3.6 ± 0.5 vs. 3.5 ± 0.3 Torr, P < 0.002; hypocapnic ventilatory response: 2.3 ± 0.3 vs. 1.6 ± 0.2 vs. 1.8 ± 0.2 l·min(-1)·mmHg(-1), P < 0.001). We conclude that time of day affects chemoreflex properties during sleep, which may contribute to increases in breathing instability in the morning compared with other periods throughout the day/night cycle in individuals with sleep apnea.
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Affiliation(s)
- Mohamad El-Chami
- John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan; Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - David Shaheen
- John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan; Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Blake Ivers
- John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan; Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Ziauddin Syed
- John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan; Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - M Safwan Badr
- John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan; Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan; Department of Biomedical Engineering, Wayne State University Detroit, Michigan
| | - Ho-Sheng Lin
- John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan; Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan; Department of Otolaryngology-Head & Neck Surgery, Wayne State University School of Medicine and Karmanos Cancer Institute, Detroit, Michigan; and
| | - Jason H Mateika
- John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan; Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan; Department of Internal Medicine, Wayne State University School of Medicine, Detroit, Michigan;
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Whittle AJ, Walsh J, de Lecea L. Light and chemical control of neuronal circuits: possible applications in neurotherapy. Expert Rev Neurother 2014; 14:1007-17. [PMID: 25115180 DOI: 10.1586/14737175.2014.948850] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Millions of people worldwide suffer from diseases that result from a failure of central pathways to regulate behavioral and physiological processes. Advances in genetics and pharmacology have already allowed us to appreciate that rather than this dysregulation being systemic throughout the brain, it is usually rooted in specific subsets of dysfunctional cells within discrete neurological circuits. This article discusses the advent of opto- and chemogenetic tools and how they are providing the means to dissect these circuits with a degree of temporal and spatial sensitivity not previously possible. We also highlight the potential applications for treating disease and the key developments likely to have the greatest impact over the next 5 years.
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Affiliation(s)
- Andrew J Whittle
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
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Morrison SF, Madden CJ, Tupone D. Central neural regulation of brown adipose tissue thermogenesis and energy expenditure. Cell Metab 2014; 19:741-756. [PMID: 24630813 PMCID: PMC4016184 DOI: 10.1016/j.cmet.2014.02.007] [Citation(s) in RCA: 317] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Thermogenesis, the production of heat energy, is the specific, neurally regulated, metabolic function of brown adipose tissue (BAT) and contributes to the maintenance of body temperature during cold exposure and to the elevated core temperature during several behavioral states, including wakefulness, the acute phase response (fever), and stress. BAT energy expenditure requires metabolic fuel availability and contributes to energy balance. This review summarizes the functional organization and neurochemical influences within the CNS networks governing the level of BAT sympathetic nerve activity to produce the thermoregulatory and metabolically driven alterations in BAT thermogenesis and energy expenditure that contribute to overall energy homeostasis.
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Affiliation(s)
- Shaun F Morrison
- Department of Neurological Surgery Oregon Health & Science University Portland, OR, 97239 USA
| | - Christopher J Madden
- Department of Neurological Surgery Oregon Health & Science University Portland, OR, 97239 USA
| | - Domenico Tupone
- Department of Neurological Surgery Oregon Health & Science University Portland, OR, 97239 USA
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48
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Tupone D, Madden CJ, Morrison SF. Autonomic regulation of brown adipose tissue thermogenesis in health and disease: potential clinical applications for altering BAT thermogenesis. Front Neurosci 2014; 8:14. [PMID: 24570653 PMCID: PMC3916784 DOI: 10.3389/fnins.2014.00014] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 01/20/2014] [Indexed: 01/04/2023] Open
Abstract
From mouse to man, brown adipose tissue (BAT) is a significant source of thermogenesis contributing to the maintenance of the body temperature homeostasis during the challenge of low environmental temperature. In rodents, BAT thermogenesis also contributes to the febrile increase in core temperature during the immune response. BAT sympathetic nerve activity controlling BAT thermogenesis is regulated by CNS neural networks which respond reflexively to thermal afferent signals from cutaneous and body core thermoreceptors, as well as to alterations in the discharge of central neurons with intrinsic thermosensitivity. Superimposed on the core thermoregulatory circuit for the activation of BAT thermogenesis, is the permissive, modulatory influence of central neural networks controlling metabolic aspects of energy homeostasis. The recent confirmation of the presence of BAT in human and its function as an energy consuming organ have stimulated interest in the potential for the pharmacological activation of BAT to reduce adiposity in the obese. In contrast, the inhibition of BAT thermogenesis could facilitate the induction of therapeutic hypothermia for fever reduction or to improve outcomes in stroke or cardiac ischemia by reducing infarct size through a lowering of metabolic oxygen demand. This review summarizes the central circuits for the autonomic control of BAT thermogenesis and highlights the potential clinical relevance of the pharmacological inhibition or activation of BAT thermogenesis.
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Affiliation(s)
- Domenico Tupone
- Department of Neurological Surgery, Oregon Health and Science University Portland, OR, USA
| | - Christopher J Madden
- Department of Neurological Surgery, Oregon Health and Science University Portland, OR, USA
| | - Shaun F Morrison
- Department of Neurological Surgery, Oregon Health and Science University Portland, OR, USA
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Molkov YI, Zaretskaia MV, Zaretsky DV. Meth math: modeling temperature responses to methamphetamine. Am J Physiol Regul Integr Comp Physiol 2014; 306:R552-66. [PMID: 24500434 DOI: 10.1152/ajpregu.00365.2013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Methamphetamine (Meth) can evoke extreme hyperthermia, which correlates with neurotoxicity and death in laboratory animals and humans. The objective of this study was to uncover the mechanisms of a complex dose dependence of temperature responses to Meth by mathematical modeling of the neuronal circuitry. On the basis of previous studies, we composed an artificial neural network with the core comprising three sequentially connected nodes: excitatory, medullary, and sympathetic preganglionic neuronal (SPN). Meth directly stimulated the excitatory node, an inhibitory drive targeted the medullary node, and, in high doses, an additional excitatory drive affected the SPN node. All model parameters (weights of connections, sensitivities, and time constants) were subject to fitting experimental time series of temperature responses to 1, 3, 5, and 10 mg/kg Meth. Modeling suggested that the temperature response to the lowest dose of Meth, which caused an immediate and short hyperthermia, involves neuronal excitation at a supramedullary level. The delay in response after the intermediate doses of Meth is a result of neuronal inhibition at the medullary level. Finally, the rapid and robust increase in body temperature induced by the highest dose of Meth involves activation of high-dose excitatory drive. The impairment in the inhibitory mechanism can provoke a life-threatening temperature rise and makes it a plausible cause of fatal hyperthermia in Meth users. We expect that studying putative neuronal sites of Meth action and the neuromediators involved in a detailed model of this system may lead to more effective strategies for prevention and treatment of hyperthermia induced by amphetamine-like stimulants.
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Affiliation(s)
- Yaroslav I Molkov
- Department of Mathematical Sciences, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana; and
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Chechi K, Nedergaard J, Richard D. Brown adipose tissue as an anti-obesity tissue in humans. Obes Rev 2014; 15:92-106. [PMID: 24165204 DOI: 10.1111/obr.12116] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 09/06/2013] [Accepted: 09/07/2013] [Indexed: 12/27/2022]
Abstract
During the 11th Stock Conference held in Montreal, Quebec, Canada, world-leading experts came together to present and discuss recent developments made in the field of brown adipose tissue biology. Owing to the vast capacity of brown adipose tissue for burning food energy in the process of thermogenesis, and due to demonstrations of its presence in adult humans, there is tremendous interest in targeting brown adipose tissue as an anti-obesity tissue in humans. However, the future of such therapeutic approaches relies on our understanding of the origin, development, recruitment, activation and regulation of brown adipose tissue in humans. As reviewed here, the 11th Stock Conference was organized around these themes to discuss the recent progress made in each aspect, to identify gaps in our current understanding and to further provide a common groundwork that could support collaborative efforts aimed at a future therapy for obesity, based on brown adipose tissue thermogenesis.
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Affiliation(s)
- K Chechi
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec, Canada
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