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Sur S, Sharma A. Understanding the role of temperature in seasonal timing: Effects on behavioural, physiological and molecular phenotypes. Mol Ecol 2024:e17447. [PMID: 38946196 DOI: 10.1111/mec.17447] [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: 09/30/2023] [Revised: 04/26/2024] [Accepted: 06/14/2024] [Indexed: 07/02/2024]
Abstract
Organisms adapt to daily and seasonal environmental changes to maximise their metabolic and reproductive fitness. For seasonally breeding animals, photoperiod is considered the most robust cue to drive these changes. It, however, does not explain the interannual variations in different seasonal phenotypes. Several studies have repeatedly shown the influence of ambient temperature on the timing of different seasonal physiologies including the timing of migration, reproduction and its associated behaviours, etc. In the present review, we have discussed the effects of changes in ambient temperature on different seasonal events in endotherms with a focus on migratory birds as they have evolved to draw benefits from distinct but largely predictable seasonal patterns of natural resources. We have further discussed the physiological and molecular mechanisms by which temperature affects seasonal timings. The primary brain area involved in detecting temperature changes is the hypothalamic preoptic area. This area receives thermal inputs via sensory neurons in the peripheral ganglia that measure changes in thermoregulatory tissues such as the skin and spinal cord. For the input signals, several thermal sensory TRP (transient receptor potential ion channels) channels have been identified across different classes of vertebrates. These channels are activated at specific thermal ranges. Once perceived, this information should activate an effector function. However, the link between temperature sensation and the effector pathways is not properly understood yet. Here, we have summarised the available information that may help us understand how temperature information is translated into seasonal timing.
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Affiliation(s)
- Sayantan Sur
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Aakansha Sharma
- Department of Zoology, University of Lucknow, Lucknow, India
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2
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Notley SR, Akerman AP, D'Souza AW, Meade RD, McCourt ER, McCormick JJ, Kenny GP. Dose-dependent nonthermal modulation of whole body heat exchange during dynamic exercise in humans. Am J Physiol Regul Integr Comp Physiol 2024; 326:R53-R65. [PMID: 37955132 DOI: 10.1152/ajpregu.00203.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/30/2023] [Accepted: 10/30/2023] [Indexed: 11/14/2023]
Abstract
To maintain heat balance during exercise, humans rely on skin blood flow and sweating to facilitate whole body dry and evaporative heat exchange. These responses are modulated by the rise in body temperature (thermal factors), as well as several nonthermal factors implicated in the cardiovascular response to exercise (i.e., central command, mechanoreceptors, and metaboreceptors). However, the way these nonthermal factors interact with thermal factors to maintain heat balance remains poorly understood. We therefore used direct calorimetry to quantify the effects of dose-dependent increases in the activation of these nonthermal stimuli on whole body dry and evaporative heat exchange during dynamic exercise. In a randomized crossover design, eight participants performed 45-min cycling at a fixed metabolic heat production (200 W/m2) in warm, dry conditions (30°C, 20% relative humidity) on four separate occasions, differing only in the level of lower-limb compression applied via bilateral thigh cuffs pressurized to 0, 30, 60, or 90 mmHg. This model provoked increments in nonthermal activation while ensuring the heat loss required to balance heat production was matched across trials. At end-exercise, dry heat loss was 2 W/m2 [1, 3] lower per 30-mmHg pressure increment (P = 0.006), whereas evaporative heat loss was elevated 5 W/m2 [3, 7] with each pressure increment (P < 0.001). Body heat storage and esophageal temperature did not differ across conditions (both P ≥ 0.600). Our findings indicate that the nonthermal factors engaged during exercise exert dose-dependent, opposing effects on whole body dry and evaporative heat exchange, which do not significantly alter heat balance.NEW & NOTEWORTHY To maintain heat balance during exercise, humans rely on skin blood flow and sweating to facilitate dry and evaporative heat exchange. These responses are modulated by body temperatures (thermal factors) and several nonthermal factors (e.g., central command, metaboreceptors), although the way thermal and nonthermal factors interact to regulate body temperature is poorly understood. We demonstrate that nonthermal factors exert dose-dependent, opposing effects on dry and evaporative heat loss, without altering heat storage during dynamic exercise.
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Affiliation(s)
- Sean R Notley
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Ashley P Akerman
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Andrew W D'Souza
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Robert D Meade
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Emma R McCourt
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - James J McCormick
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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3
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Keihani A, Mayeli A, Ferrarelli F. Circadian Rhythm Changes in Healthy Aging and Mild Cognitive Impairment. Adv Biol (Weinh) 2023; 7:e2200237. [PMID: 36403250 PMCID: PMC10199146 DOI: 10.1002/adbi.202200237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/01/2022] [Indexed: 11/21/2022]
Abstract
Disruptions in circadian rhythms can occur in healthy aging; however, these changes are more severe and pervasive in individuals with age-related and neurodegenerative diseases, such as dementia. Circadian rhythm alterations are also present in preclinical stages of dementia, for example, in patients with mild cognitive impairments (MCI); thus, providing a unique window of opportunity for early intervention in neurodegenerative disorders. Nonetheless, there is a lack of studies examining the association between relevant changes in circadian rhythms and their relationship with cognitive dysfunctions in MCI individuals. In this review, circadian system alterations occurring in MCI patients are examined compared to healthy aging individuals while also considering their association with MCI neurocognitive alterations. The main findings are that abnormal circadian changes in rest-activity, core body temperature, melatonin, and cortisol rhythms appear in the MCI stage and that these circadian rhythm disruptions are associated with some of the neurocognitive deficits observed in MCI patients. In addition, preliminary evidence indicates that interventions aimed at restoring regular circadian rhythms may prevent or halt the progress of neurodegenerative diseases and mitigate their related cognitive impairments. Future longitudinal studies with repeated follow-up assessments are needed to establish the translational potential of these findings in clinical practice.
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Affiliation(s)
- Ahmadreza Keihani
- Department of Psychiatry, University of Pittsburgh, 3501 Forbes Ave, Pittsburgh, PA, 15213, USA
| | - Ahmad Mayeli
- Department of Psychiatry, University of Pittsburgh, 3501 Forbes Ave, Pittsburgh, PA, 15213, USA
| | - Fabio Ferrarelli
- Department of Psychiatry, University of Pittsburgh, 3501 Forbes Ave, Pittsburgh, PA, 15213, USA
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Carrasco RA, Breen KM. Allostasis in Neuroendocrine Systems Controlling Reproduction. Endocrinology 2023; 164:bqad125. [PMID: 37586095 PMCID: PMC10461221 DOI: 10.1210/endocr/bqad125] [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: 05/30/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 08/18/2023]
Abstract
Allostasis provides a supporting role to the homeostatic control of biological variables in mammalian species. While the concept of homeostasis is related to the control of variables within a set point or range that are essential to life, allostasis refers to systems that facilitate adaptation to challenges that the organism faces and the new requirements for survival. Essential for such adaptation is the role played by the brain in eliciting neural and neuroendocrine responses. Reproductive function is fundamental for the survival of species but is costly in energetic terms and requires a synchrony with an ever-changing environment. Thus, in many species reproductive function is blocked or delayed over immediate challenges. This review will cover the physiological systems and neuroendocrine pathways that supply allostatic control over reproductive neuroendocrine systems. Light, hypoxia, temperature, nutrition, psychosocial, and immune mediators influence the neuroendocrine control of reproductive functions through pathways that are confluent at the paraventricular nucleus; however, understanding of the integrative responses to these stimuli has not been clarified. Likely, the ultimate consequence of these allostatic mechanisms is the modification of kisspeptin and gonadotropin-releasing hormone neuronal activity, thus compromising reproduction function in the short term, while preserving species survivability.
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Affiliation(s)
- Rodrigo A Carrasco
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, CA 92093-0674, USA
| | - Kellie M Breen
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, CA 92093-0674, USA
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Brioschi ML, Dalmaso Neto C, Toledo MD, Neves EB, Vargas JVC, Teixeira MJ. Infrared image method for possible COVID-19 detection through febrile and subfebrile people screening. J Therm Biol 2023; 112:103444. [PMID: 36796899 PMCID: PMC9794388 DOI: 10.1016/j.jtherbio.2022.103444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 11/30/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022]
Abstract
This study proposed an infrared image-based method for febrile and subfebrile people screening to comply with the society need for alternative, quick response, and effective methods for COVID-19 contagious people screening. The methodology consisted of: (i) Developing a method based on facial infrared imaging for possible COVID-19 early detection in people with and without fever (subfebrile state); (ii) Using 1206 emergency room (ER) patients to develop an algorithm for general application of the method, and (iii) Testing the method and algorithm effectiveness in 2558 cases (RT-qPCR tested for COVID-19) from 227,261 workers evaluations in five different countries. Artificial intelligence was used through a convolutional neural network (CNN) to develop the algorithm that took facial infrared images as input and classified the tested individuals in three groups: fever (high risk), subfebrile (medium risk), and no fever (low risk). The results showed that suspicious and confirmed COVID-19 (+) cases characterized by temperatures below the 37.5 °C fever threshold were identified. Also, average forehead and eye temperatures greater than 37.5 °C were not enough to detect fever similarly to the proposed CNN algorithm. Most RT-qPCR confirmed COVID-19 (+) cases found in the 2558 cases sample (17 cases/89.5%) belonged to the CNN selected subfebrile group. The COVID-19 (+) main risk factor was to be in the subfebrile group, in comparison to age, diabetes, high blood pressure, smoking and others. In sum, the proposed method was shown to be a potentially important new tool for COVID-19 (+) people screening for air travel and public places in general.
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Affiliation(s)
- Marcos Leal Brioschi
- Medical Thermology and Thermography Specialization, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, HCFMUSP, São Paulo, SP, 01246-903, Brazil
| | - Carlos Dalmaso Neto
- Medical Thermology and Thermography Specialization, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, HCFMUSP, São Paulo, SP, 01246-903, Brazil; Mechanical Engineering Post-Graduation Program, Mechanical Engineering Department, Universidade Federal do Paraná, UFPR, Curitiba, PR, 81531-980, Brazil.
| | - Marcos de Toledo
- Medical Thermology and Thermography Specialization, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, HCFMUSP, São Paulo, SP, 01246-903, Brazil
| | - Eduardo Borba Neves
- Biomedical Engineering Post-Graduation Program, Universidade Tecnológica Federal do Paraná, UTFPR, Curitiba, PR, 82590-300, Brazil
| | - José Viriato Coelho Vargas
- Mechanical Engineering Post-Graduation Program, Mechanical Engineering Department, Universidade Federal do Paraná, UFPR, Curitiba, PR, 81531-980, Brazil
| | - Manoel Jacobsen Teixeira
- Neurology and Neurosurgery Department, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - HCFMUSP, São Paulo, SP, 01246-903, Brazil
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6
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Ahmed SG, S.R. S. Analysis of human thermoregulatory mechanisms using 2-D computational model. J Therm Biol 2022; 110:103388. [DOI: 10.1016/j.jtherbio.2022.103388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/30/2022] [Accepted: 11/03/2022] [Indexed: 11/10/2022]
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Parkinson T, Zhang H, Arens E, He Y, de Dear R, Elson J, Parkinson A, Maranville C, Wang A. Predicting thermal pleasure experienced in dynamic environments from simulated cutaneous thermoreceptor activity. INDOOR AIR 2021; 31:2266-2280. [PMID: 34048603 DOI: 10.1111/ina.12859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/26/2021] [Accepted: 05/06/2021] [Indexed: 06/12/2023]
Abstract
Research into human thermal perception indoors has focused on "neutrality" under steady-state conditions. Recent interest in thermal alliesthesia has highlighted the hedonic dimension of our thermal world that has been largely overlooked by science. Here, we show the activity of sensory neurons can predict thermal pleasure under dynamic exposures. A numerical model of cutaneous thermoreceptors was applied to skin temperature measurements from 12 human subjects. A random forest model trained on simulated thermoreceptor impulses could classify pleasure responses (F1 score of 67%) with low false positives/negatives (4%). Accuracy increased (83%) when excluding the few extreme (dis)pleasure responses. Validation on an independent dataset confirmed model reliability. This is the first empirical demonstration of the relationship between thermoreceptors and pleasure arising from thermal stimuli. Insights into the neurophysiology of thermal perception can enhance the experience of built environments through designs that promote sensory excitation instead of neutrality.
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Affiliation(s)
- Thomas Parkinson
- Center for the Built Environment (CBE), University of California Berkeley, Berkeley, California, USA
| | - Hui Zhang
- Center for the Built Environment (CBE), University of California Berkeley, Berkeley, California, USA
| | - Ed Arens
- Center for the Built Environment (CBE), University of California Berkeley, Berkeley, California, USA
| | - Yingdong He
- Center for the Built Environment (CBE), University of California Berkeley, Berkeley, California, USA
| | - Richard de Dear
- Indoor Environmental Quality Lab, School of Architecture, Design and Planning, The University of Sydney, Sydney, NSW, Australia
| | - John Elson
- Ford Motor Company, Dearborn, Michigan, USA
| | - Alex Parkinson
- Department of Mathematics, Macquarie University, Sydney, NSW, Australia
| | | | - Andrew Wang
- Center for the Built Environment (CBE), University of California Berkeley, Berkeley, California, USA
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8
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Kamm GB, Boffi JC, Zuza K, Nencini S, Campos J, Schrenk-Siemens K, Sonntag I, Kabaoğlu B, El Hay MYA, Schwarz Y, Tappe-Theodor A, Bruns D, Acuna C, Kuner T, Siemens J. A synaptic temperature sensor for body cooling. Neuron 2021; 109:3283-3297.e11. [PMID: 34672983 DOI: 10.1016/j.neuron.2021.10.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/01/2021] [Accepted: 09/30/2021] [Indexed: 10/20/2022]
Abstract
Deep brain temperature detection by hypothalamic warm-sensitive neurons (WSNs) has been proposed to provide feedback information relevant for thermoregulation. WSNs increase their action potential firing rates upon warming, a property that has been presumed to rely on the composition of thermosensitive ion channels within WSNs. Here, we describe a synaptic mechanism that regulates temperature sensitivity of preoptic WSNs and body temperature. Experimentally induced warming of the mouse hypothalamic preoptic area in vivo triggers body cooling. TRPM2 ion channels facilitate this homeostatic response and, at the cellular level, enhance temperature responses of WSNs, thereby linking WSN function with thermoregulation for the first time. Rather than acting within WSNs, we-unexpectedly-find TRPM2 to temperature-dependently increase synaptic drive onto WSNs by disinhibition. Our data emphasize a network-based interoceptive paradigm that likely plays a key role in encoding body temperature and that may facilitate integration of diverse inputs into thermoregulatory pathways.
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Affiliation(s)
- Gretel B Kamm
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Juan C Boffi
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany; Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Kristina Zuza
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Sara Nencini
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Joaquin Campos
- Chica and Heinz Schaller Foundation, Institute for Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Katrin Schrenk-Siemens
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Ivo Sonntag
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Burçe Kabaoğlu
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Muad Y Abd El Hay
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Yvonne Schwarz
- Institute for Physiology, Center of Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Anke Tappe-Theodor
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Dieter Bruns
- Institute for Physiology, Center of Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Claudio Acuna
- Chica and Heinz Schaller Foundation, Institute for Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Thomas Kuner
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Jan Siemens
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany; Molecular Medicine Partnership Unit (MMPU), European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany.
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The Effect of Cold Exposure on Cognitive Performance in Healthy Adults: A Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18189725. [PMID: 34574649 PMCID: PMC8470111 DOI: 10.3390/ijerph18189725] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 09/10/2021] [Accepted: 09/11/2021] [Indexed: 01/08/2023]
Abstract
Several aspects of cognition can be affected after cold exposure, but contradictory results have been reported regarding affected cognitive domains. The aim of the current systematic review was to evaluate the effects of specific cold exposure on cognitive performance in healthy subjects. A systematic search was performed using MEDLINE (through PubMed), EMBASE (Scopus) and PsycINFO databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Inclusion criteria were healthy subjects exposed to a cold environment (either simulated or not) and cognitive performance related to cold exposure with an experimental design. The literature search identified 18 studies, eight studies investigated the effect of cold air exposure and ten the effect of cold water immersion on cognitive performance of healthy subjects. There were several differences among the studies (environmental temperature reached, time of exposure, timing, and type of cognitive test administration). Cold exposure induced in most of the experimental settings (15 of 18) an impairment of CP even before accidental hypothermia was established. The most investigated and affected cognitive domains were attention and processing speed, executive function, and memory. Gender differences and effects of repeated exposure and possible acclimation on cognitive performance need further studies to be confirmed.
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Norris AJ, Shaker JR, Cone AL, Ndiokho IB, Bruchas MR. Parabrachial opioidergic projections to preoptic hypothalamus mediate behavioral and physiological thermal defenses. eLife 2021; 10:60779. [PMID: 33667158 PMCID: PMC7935488 DOI: 10.7554/elife.60779] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 02/24/2021] [Indexed: 02/06/2023] Open
Abstract
Maintaining stable body temperature through environmental thermal stressors requires detection of temperature changes, relay of information, and coordination of physiological and behavioral responses. Studies have implicated areas in the preoptic area of the hypothalamus (POA) and the parabrachial nucleus (PBN) as nodes in the thermosensory neural circuitry and indicate that the opioid system within the POA is vital in regulating body temperature. In the present study we identify neurons projecting to the POA from PBN expressing the opioid peptides dynorphin and enkephalin. Using mouse models, we determine that warm-activated PBN neuronal populations overlap with both prodynorphin (Pdyn) and proenkephalin (Penk) expressing PBN populations. Here we report that in the PBN Prodynorphin (Pdyn) and Proenkephalin (Penk) mRNA expressing neurons are partially overlapping subsets of a glutamatergic population expressing Solute carrier family 17 (Slc17a6) (VGLUT2). Using optogenetic approaches we selectively activate projections in the POA from PBN Pdyn, Penk, and VGLUT2 expressing neurons. Our findings demonstrate that Pdyn, Penk, and VGLUT2 expressing PBN neurons are critical for physiological and behavioral heat defense.
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Affiliation(s)
- Aaron J Norris
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, United States
| | - Jordan R Shaker
- Medical Scientist Training Program, University of Washington, Seattle, United States
| | - Aaron L Cone
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, United States
| | - Imeh B Ndiokho
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, United States
| | - Michael R Bruchas
- Center for the Neurobiology of Addiction, Pain and Emotion, Departments of Anesthesiology and Pharmacology, University of Washington, Seattle, United States
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The Role of Thermosensitive Ion Channels in Mammalian Thermoregulation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:355-370. [DOI: 10.1007/978-981-16-4254-8_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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12
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Lubkowska A, Szymański S, Chudecka M. Neonatal thermal response to childbirth: Vaginal delivery vs. caesarean section. PLoS One 2020; 15:e0243453. [PMID: 33296407 PMCID: PMC7725314 DOI: 10.1371/journal.pone.0243453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 11/22/2020] [Indexed: 11/24/2022] Open
Abstract
Newborns, regardless of the method of termination of pregnancy, are exposed to the first exogenous stress factors during delivery. The purpose of the study was to evaluate the differences in newborns' thermal response to vaginal (VD) vs caesarean section (CS) delivery. The temperature was measured during the first minutes of life within 122 healthy full-term newborns, on the forehead, chest and upper-back by infrared camera (FLIR T1030sc HD). The lowest temperatures were recorded in the forehead of VD newborns (significantly difference with CS; p < 0.001), the warmest was the chest. A significant correlation was found between the duration of the second stage of natural childbirth and surface temperature and pO2 in the newborn blood. The temperatures of selected body surface areas correlate highly positively, regardless of the mode of delivery. In the case of healthy neonates, with normal birth weight and full-term, VD creates more favourable conditions stimulating the mechanisms of adaptation for a newborn than CS.
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Affiliation(s)
- Anna Lubkowska
- Chair and Department of Functional Diagnostics and Physical Medicine, Faculty of Health Sciences, Pomeranian Medical University, Szczecin, Poland
| | - Sławomir Szymański
- Department of Obstetrics and Pathology of Pregnancy, Pomeranian Medical University in Szczecin, Szczecin, Poland
| | - Monika Chudecka
- Institute of Physical Culture Sciences, Faculty of Physical Education and Health, University of Szczecin, Szczecin, Poland
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Bastías-Pérez M, Zagmutt S, Soler-Vázquez MC, Serra D, Mera P, Herrero L. Impact of Adaptive Thermogenesis in Mice on the Treatment of Obesity. Cells 2020; 9:E316. [PMID: 32012991 PMCID: PMC7072509 DOI: 10.3390/cells9020316] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/20/2020] [Accepted: 01/27/2020] [Indexed: 12/12/2022] Open
Abstract
Obesity and associated metabolic diseases have become a priority area of study due to the exponential increase in their prevalence and the corresponding health and economic impact. In the last decade, brown adipose tissue has become an attractive target to treat obesity. However, environmental variables such as temperature and the dynamics of energy expenditure could influence brown adipose tissue activity. Currently, most metabolic studies are carried out at a room temperature of 21 °C, which is considered a thermoneutral zone for adult humans. However, in mice this chronic cold temperature triggers an increase in their adaptive thermogenesis. In this review, we aim to cover important aspects related to the adaptation of animals to room temperature, the influence of housing and temperature on the development of metabolic phenotypes in experimental mice and their translation to human physiology. Mice studies performed in chronic cold or thermoneutral conditions allow us to better understand underlying physiological mechanisms for successful, reproducible translation into humans in the fight against obesity and metabolic diseases.
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Affiliation(s)
- Marianela Bastías-Pérez
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, E-08028 Barcelona, Spain
| | - Sebastián Zagmutt
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, E-08028 Barcelona, Spain
| | - M Carmen Soler-Vázquez
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, E-08028 Barcelona, Spain
| | - Dolors Serra
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, E-08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, E-28029 Madrid, Spain
| | - Paula Mera
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, E-08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, E-28029 Madrid, Spain
| | - Laura Herrero
- Department of Biochemistry and Physiology, School of Pharmacy and Food Sciences, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, E-08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, E-28029 Madrid, Spain
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Tan CL, Knight ZA. Regulation of Body Temperature by the Nervous System. Neuron 2019; 98:31-48. [PMID: 29621489 DOI: 10.1016/j.neuron.2018.02.022] [Citation(s) in RCA: 300] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 02/19/2018] [Accepted: 02/23/2018] [Indexed: 01/24/2023]
Abstract
The regulation of body temperature is one of the most critical functions of the nervous system. Here we review our current understanding of thermoregulation in mammals. We outline the molecules and cells that measure body temperature in the periphery, the neural pathways that communicate this information to the brain, and the central circuits that coordinate the homeostatic response. We also discuss some of the key unresolved issues in this field, including the following: the role of temperature sensing in the brain, the molecular identity of the warm sensor, the central representation of the labeled line for cold, and the neural substrates of thermoregulatory behavior. We suggest that approaches for molecularly defined circuit analysis will provide new insight into these topics in the near future.
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Affiliation(s)
- Chan Lek Tan
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94158
| | - Zachary A Knight
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94158; Kavli Center for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158.
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Mitchell D, Snelling EP, Hetem RS, Maloney SK, Strauss WM, Fuller A. Revisiting concepts of thermal physiology: Predicting responses of mammals to climate change. J Anim Ecol 2018; 87:956-973. [DOI: 10.1111/1365-2656.12818] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 01/17/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Duncan Mitchell
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
- School of Human Sciences; University of Western Australia; Crawley WA Australia
| | - Edward P. Snelling
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
| | - Robyn S. Hetem
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
- School of Animal, Plant and Environmental Sciences; Faculty of Science; University of the Witwatersrand; Johannesburg South Africa
| | - Shane K. Maloney
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
- School of Human Sciences; University of Western Australia; Crawley WA Australia
| | - Willem Maartin Strauss
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
- Department of Environmental Science; University of South Africa; Johannesburg South Africa
| | - Andrea Fuller
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
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Kalmár F. Innovative method and equipment for personalized ventilation. INDOOR AIR 2015; 25:297-306. [PMID: 24923841 DOI: 10.1111/ina.12138] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 06/06/2014] [Indexed: 06/03/2023]
Abstract
At the University of Debrecen, a new method and equipment for personalized ventilation has been developed. This equipment makes it possible to change the airflow direction during operation with a time frequency chosen by the user. The developed office desk with integrated air ducts and control system permits ventilation with 100% outdoor air, 100% recirculated air, or a mix of outdoor and recirculated air in a relative proportion set by the user. It was shown that better comfort can be assured in hot environments if the fresh airflow direction is variable. Analyzing the time step of airflow direction changing, it was found that women prefer smaller time steps and their votes related to thermal comfort sensation are higher than men's votes.
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Affiliation(s)
- F Kalmár
- Department of Building Services and Building Engineering, University of Debrecen, Debrecen, Hungary
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Todd G, Gordon CJ, Groeller H, Taylor NAS. Does intramuscular thermal feedback modulate eccrine sweating in exercising humans? Acta Physiol (Oxf) 2014; 212:86-96. [PMID: 24934867 DOI: 10.1111/apha.12327] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 04/30/2014] [Accepted: 06/10/2014] [Indexed: 11/27/2022]
Abstract
AIM Few investigators have considered the possibility that skeletal muscles might contain thermosensitive elements capable of modifying thermoeffector responses. In this experiment, the temporal relationships between dynamic changes in deep-body and intramuscular temperatures and eccrine sweat secretion were explored during rhythmical and reproducible variations in heat production. METHODS Eight subjects performed semi-recumbent cycling (25 °C) at a constant load to first establish whole-body thermal and sudomotor steady states (35 min), followed by a 24-min block of sinusoidal workload variations (three, 8-min periods) and then returning to steady-state cycling (20 min). Individual oesophageal, mean skin and intramuscular (vastus lateralis) temperatures were independently cross-correlated with simultaneously measured forehead sweat rates to evaluate the possible thermal modulation of sudomotor activity. RESULTS Both intramuscular and oesophageal temperatures showed strong correlations with sinusoidal variations in sweating with respective maximal cross-correlation coefficients of 0.807 (±0.044) and 0.845 (±0.035), but these were not different (P = 0.40). However, the phase delay between intramuscular temperature changes and sweat secretion was significantly shorter than the delay between oesophageal temperature and sweating [25.6 s (±12.6) vs. 46.9 s (±11.3); P = 0.03]. CONCLUSION The temporal coupling of eccrine sweating to intramuscular temperature, combined with a shorter phase delay, was consistent with the presence of thermosensitive elements within skeletal muscles that appear to participate in the modulation of thermal sweating.
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Affiliation(s)
- G. Todd
- Centre for Human and Applied Physiology; School of Medicine; University of Wollongong; Wollongong NSW Australia
| | - C. J. Gordon
- Centre for Human and Applied Physiology; School of Medicine; University of Wollongong; Wollongong NSW Australia
| | - H. Groeller
- Centre for Human and Applied Physiology; School of Medicine; University of Wollongong; Wollongong NSW Australia
| | - N. A. S. Taylor
- Centre for Human and Applied Physiology; School of Medicine; University of Wollongong; Wollongong NSW Australia
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Shafton AD, Kitchener P, McKinley MJ, McAllen RM. Reflex control of rat tail sympathetic nerve activity by abdominal temperature. Temperature (Austin) 2014; 1:37-41. [PMID: 27583279 PMCID: PMC4972510 DOI: 10.4161/temp.29597] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 06/16/2014] [Accepted: 06/16/2014] [Indexed: 01/15/2023] Open
Abstract
The thermoregulatory reflex effects of warming and cooling in the abdomen were investigated in 4 urethane-anesthetized Sprague-Dawley rats. Animals were shaved and surrounded by a water-perfused silastic jacket. Skin temperature under the jacket was recorded by thermocouples at 3 sites and brain temperature was monitored by a thermocouple inserted lateral to the hypothalamus. A heat exchanger made from an array of silicon tubes in parallel loops was placed through a ventral incision into the abdomen; it rested against the intestinal serosa and the temperature of this interface was monitored by a thermocouple. Few- or multi-unit postganglionic activity was recorded from sympathetic nerves supplying tail vessels (tail SNA). Intra-abdominal temperature was briefly lowered or raised between 35–41 °C by perfusing the heat exchanger with cold or warm water. Warming the abdomen inhibited tail SNA while cooling it excited tail SNA in all 4 animals. We also confirmed that cooling the trunk skin activated tail SNA. Multivariate analysis of tail SNA with respect to abdominal, brain and trunk skin temperatures revealed that all had highly significant independent inhibitory actions on tail SNA, but in these experiments abdominal temperature had the weakest and brain temperature the strongest effect. We conclude that abdominal temperature has a significant thermoregulatory action in the rat, but its influence on cutaneous vasomotor control appears to be weaker than that of skin or brain temperatures.
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Affiliation(s)
- Anthony D Shafton
- The Florey Institute of Neuroscience and Mental Health; University Of Melbourne; Melbourne, VIC Australia
| | - Peter Kitchener
- Department of Anatomy & Neuroscience; University Of Melbourne; Melbourne, VIC Australia
| | - Michael J McKinley
- The Florey Institute of Neuroscience and Mental Health; University Of Melbourne; Melbourne, VIC Australia; Department of Physiology; University Of Melbourne; Melbourne, VIC Australia
| | - Robin M McAllen
- The Florey Institute of Neuroscience and Mental Health; University Of Melbourne; Melbourne, VIC Australia; Department of Anatomy & Neuroscience; University Of Melbourne; Melbourne, VIC Australia
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Abstract
This review analyses whether skin temperature represents ambient temperature and serves as a feedforward signal for the thermoregulation system, or whether it is one of the body's temperatures and provides feedback. The body is covered mostly by hairy (non-glabrous) skin, which is typically insulated from the environment (with clothes in humans and with fur in non-human mammals). Thermal signals from hairy skin represent a temperature of the insulated superficial layer of the body and provide feedback to the thermoregulation system. It is explained that this feedback is auxiliary, both negative and positive, and that it reduces the system's response time and load error. Non-hairy (glabrous) skin covers specialized heat-exchange organs (e.g. the hand), which are also used to explore the environment. In thermoregulation, these organs are primarily effectors. Their main thermosensory-related role is to assess local temperatures of objects explored; these local temperatures are feedforward signals for various behaviours. Non-hairy skin also contributes to the feedback for thermoregulation, but this contribution is limited. Autonomic (physiological) thermoregulation does not use feedforward signals. Thermoregulatory behaviours use both feedback and feedforward signals. Implications of these principles to thermopharmacology, a new approach to achieving biological effects by blocking temperature signals with drugs, are discussed.
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Affiliation(s)
- A. A. Romanovsky
- Trauma Research Systemic Inflammation Laboratory (FeverLab) St. Joseph's Hospital and Medical Center Phoenix AZUSA
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Almeida MC, Hew-Butler T, Soriano RN, Rao S, Wang W, Wang J, Tamayo N, Oliveira DL, Nucci TB, Aryal P, Garami A, Bautista D, Gavva NR, Romanovsky AA. Pharmacological blockade of the cold receptor TRPM8 attenuates autonomic and behavioral cold defenses and decreases deep body temperature. J Neurosci 2012; 32:2086-99. [PMID: 22323721 PMCID: PMC3566779 DOI: 10.1523/jneurosci.5606-11.2012] [Citation(s) in RCA: 183] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 12/14/2011] [Indexed: 11/21/2022] Open
Abstract
We studied N-(2-aminoethyl)-N-(4-(benzyloxy)-3-methoxybenzyl)thiophene-2-carboxamide hydrochloride (M8-B), a selective and potent antagonist of the transient receptor potential melastatin-8 (TRPM8) channel. In vitro, M8-B blocked cold-induced and TRPM8-agonist-induced activation of rat, human, and murine TRPM8 channels, including those on primary sensory neurons. In vivo, M8-B decreased deep body temperature (T(b)) in Trpm8(+/+) mice and rats, but not in Trpm8(-/-) mice, thus suggesting an on-target action. Intravenous administration of M8-B was more effective in decreasing T(b) in rats than intrathecal or intracerebroventricular administration, indicating a peripheral action. M8-B attenuated cold-induced c-Fos expression in the lateral parabrachial nucleus, thus indicating a site of action within the cutaneous cooling neural pathway to thermoeffectors, presumably on sensory neurons. A low intravenous dose of M8-B did not affect T(b) at either a constantly high or a constantly low ambient temperature (T(a)), but the same dose readily decreased T(b) if rats were kept at a high T(a) during the M8-B infusion and transferred to a low T(a) immediately thereafter. These data suggest that both a successful delivery of M8-B to the skin (high cutaneous perfusion) and the activation of cutaneous TRPM8 channels (by cold) are required for the hypothermic action of M8-B. At tail-skin temperatures <23°C, the magnitude of the M8-B-induced decrease in T(b) was inversely related to skin temperature, thus suggesting that M8-B blocks thermal (cold) activation of TRPM8. M8-B affected all thermoeffectors studied (thermopreferendum, tail-skin vasoconstriction, and brown fat thermogenesis), thus suggesting that TRPM8 is a universal cold receptor in the thermoregulation system.
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Affiliation(s)
- M. Camila Almeida
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013
- Natural and Humanities Sciences Center, Federal University of ABC, Santo André, SP 09210-170, Brazil
| | - Tamara Hew-Butler
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013
| | - Renato N. Soriano
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013
| | | | | | | | - Nuria Tamayo
- Chemistry Research and Discovery, Amgen, Thousand Oaks, California 91320, and
| | - Daniela L. Oliveira
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013
| | - Tatiane B. Nucci
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013
| | - Prafulla Aryal
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720
| | - Andras Garami
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013
| | - Diana Bautista
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720
| | | | - Andrej A. Romanovsky
- Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013
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MARLIN DJ, SCOTT CM, SCHROTER RC, MILLS PC, HARRIS RC, HARRIS PATRICIAA, ORME CE, ROBERTS CA, MARR CELIAM, DYSON SUEJ, BARRELET F. Physiological responses in nonheat acclimated horses performing treadmill exercise in cool (20°C/40%RH), hot dry (30°C/40%RH) and hot humid (30°C/80%RH) conditions. Equine Vet J 2010. [DOI: 10.1111/j.2042-3306.1996.tb05034.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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23
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Romanovsky AA, Almeida MC, Garami A, Steiner AA, Norman MH, Morrison SF, Nakamura K, Burmeister JJ, Nucci TB. The transient receptor potential vanilloid-1 channel in thermoregulation: a thermosensor it is not. Pharmacol Rev 2009; 61:228-61. [PMID: 19749171 PMCID: PMC2763780 DOI: 10.1124/pr.109.001263] [Citation(s) in RCA: 198] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The development of antagonists of the transient receptor potential vanilloid-1 (TRPV1) channel as pain therapeutics has revealed that these compounds cause hyperthermia in humans. This undesirable on-target side effect has triggered a surge of interest in the role of TRPV1 in thermoregulation and revived the hypothesis that TRPV1 channels serve as thermosensors. We review literature data on the distribution of TRPV1 channels in the body and on thermoregulatory responses to TRPV1 agonists and antagonists. We propose that two principal populations of TRPV1-expressing cells have connections with efferent thermoeffector pathways: 1) first-order sensory (polymodal), glutamatergic dorsal-root (and possibly nodose) ganglia neurons that innervate the abdominal viscera and 2) higher-order sensory, glutamatergic neurons presumably located in the median preoptic hypothalamic nucleus. We further hypothesize that all thermoregulatory responses to TRPV1 agonists and antagonists and thermoregulatory manifestations of TRPV1 desensitization stem from primary actions on these two neuronal populations. Agonists act primarily centrally on population 2; antagonists act primarily peripherally on population 1. We analyze what roles TRPV1 might play in thermoregulation and conclude that this channel does not serve as a thermosensor, at least not under physiological conditions. In the hypothalamus, TRPV1 channels are inactive at common brain temperatures. In the abdomen, TRPV1 channels are tonically activated, but not by temperature. However, tonic activation of visceral TRPV1 by nonthermal factors suppresses autonomic cold-defense effectors and, consequently, body temperature. Blockade of this activation by TRPV1 antagonists disinhibits thermoeffectors and causes hyperthermia. Strategies for creating hyperthermia-free TRPV1 antagonists are outlined. The potential physiological and pathological significance of TRPV1-mediated thermoregulatory effects is discussed.
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Affiliation(s)
- Andrej A Romanovsky
- Systemic Inflammation Laboratory, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013, USA.
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25
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Westerterp-Plantenga MS, Wouters L, ten Hoor F. Deceleration in cumulative food intake curves, changes in body temperature and diet-induced thermogenesis. Physiol Behav 1990; 48:831-6. [PMID: 2087514 DOI: 10.1016/0031-9384(90)90235-v] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In order to assess the relationship between the shape of the cumulative food intake curve and a reflection of internal processes, eating behaviour, postprandial thermogenesis, and skin and core temperature of normal weight restrained and unrestrained eating women and of obese restrained eating women were recorded during four-course solid food lunches, eaten in a laboratory setting (respiration chamber) at a constant ambient temperature of 22 degrees C. The skin temperature (upper arm, upper leg, liver proximity) and core temperature were measured constantly from one hour prior to until two hours after the lunch. Normal weight unrestrained eaters displayed decelerated cumulative food intake curves and an increase in the liver temperature data of 0.8-1.5 degrees C, from the beginning of the meal onwards, remaining high until 60-90 minutes after the meal was consumed. The postprandial thermogenesis of normal weight unrestrained eaters was on average 8.1 +/- 1.3%, calculated over two and a half hours from the beginning of the meal. Overweight and normal weight restrained eaters displayed linear cumulative food intake curves, almost no changes in skin and core temperatures and a postprandial thermogenesis of 4.2 +/- 0.3% and 4.8 +/- 0.7%, calculated over two and a half hours from the beginning of the meal onwards. In conclusion, deceleration in cumulative food intake curves is positively correlated with a temperature increase in the skin in the proximity of the liver, and with postprandial thermogenesis.
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Werner J, Bienek A. Loss and restoration of preoptic thermoreactiveness after lesions of the rostral raphe nuclei. Exp Brain Res 1990; 80:429-35. [PMID: 2358054 DOI: 10.1007/bf00228170] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Preoptic neurons, extracellularly recorded in the rat's brain, were tested for their responses to thermal stimulation of the scrotal and abdominal skin before and after electrolytic lesions of about 1 mm3 in the area of the rostral raphe nuclei, nucleus raphe dorsalis and centralis (NRD/NRC). All analyzed neurons were of the switching type, i.e. they changed their firing rates to a higher or lower level when a threshold of the peripheral stimulation temperature was exceeded. When major parts of NRD or NRC were destroyed, the preoptic neurons no longer changed their firing rates after thermal stimulation, whereas transmission of noxious information in most cases was not impeded. Smaller lesions in NRD or NRC did not abolish the responses, but brought about essentially modified responses compared to those before the lesions. Lesions lateral to NRD or NRC had no effect. If the lesions were effective and the neurons could be observed for a longer period after the lesions, the response was restored in many cases. As the noxious response had often not been abolished and the lateral lesions were without any effect, it might be that the lesion effects and the restoration of responses involve short-term plasticity. However, temporary block of input to the neurons by unspecific effects cannot be excluded.
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Affiliation(s)
- J Werner
- Institut für Physiologie, Ruhr-Universität, Bochum, Federal Republic of Germany
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27
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Repeated exposures to cold and the relationship between skin and core temperatures in control of metabolic rate in the goat (Capra hircus). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1990; 96:245-52. [PMID: 1976469 DOI: 10.1016/0300-9629(90)90687-n] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
1. After 10-12 experiments in each of three goats, in which skin or core temperatures were lowered while the other temperatures remained sufficiently high to prevent metabolic rate from increasing, the core temperature threshold of shivering was lowered by 0.35 degrees C. 2. After 10-15 experiments, in which skin and core temperatures were simultaneously lowered to induce major increases of metabolic rate, no further change of threshold was observed, while the slope of metabolic rate over core temperature was reduced. 3. It is concluded that repeated cold exposures without manifest shivering can induce tolerance adaptation to cold.
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Abstract
Experiments were done to assess that fraction of the metabolic response to external cold exposure, which is attributable to skin temperature. In 5 conscious and closely clipped goats the metabolic rate was determined at various stable levels of skin temperature in the range from 13 to 41 degrees C, while core temperature was kept constant at 38.8 degrees C. Skin temperature was manipulated by a rapidly circulating shower bath, while core temperature was controlled by means of heat exchangers acting on arterial blood temperature in a chronic arteriovenous shunt. The metabolic response to skin temperature fell into two clearly discernible sections: a first zone with skin temperatures above 25-30 degrees C, within which the metabolic rate rose at a rate of -0.34 +/- 0.07 W/kg.degrees C with decreasing skin temperature, and a second zone with skin temperatures below 25-30 degrees C, within which the metabolic rate either plateaued or even grew smaller with further decreasing skin temperature. It is concluded that the relationship between skin temperature and metabolic rate does not directly reproduce the temperature-response curve of cutaneous cold receptors but also reflects a complex interaction of several factors, including an unspecific temperature effect on muscle metabolism.
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Affiliation(s)
- G Kuhnen
- Physiologisches Institut der Universität, Giessen, Federal Republic of Germany
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30
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Werner J. Functional mechanisms of temperature regulation, adaptation and fever: complementary system theoretical and experimental evidence. Pharmacol Ther 1988; 37:1-23. [PMID: 3289051 DOI: 10.1016/0163-7258(88)90016-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- J Werner
- Institut für Physiologie, Ruhr-Universität, Bochum, Federal Republic of Germany
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31
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Roth J, Zeisberger E, Schwandt HJ. Influence of increased catecholamine levels in blood plasma during cold-adaptation and intramuscular infusion on thresholds of thermoregulatory reactions in guinea-pigs. J Comp Physiol B 1988; 157:855-63. [PMID: 3351026 DOI: 10.1007/bf00691018] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Catecholamines and some of their metabolites were determined in urine and blood plasma of guinea-pigs before, during and after acclimation to a cold or warm environment. During adaptation to 5 degrees C the amounts of noradrenaline in plasma and 24-h urine samples continuously increased up to 600% compared with values obtained at an ambient temperature of 22 degrees C. Higher levels of dihydroxyphenylglycol and 3-methoxy-4-hydroxyphenylglycol further indicated an increased turnover of noradrenaline during cold adaptation. Acclimation to an ambient temperature of 28 degrees C reduced the peripheral release of noradrenaline in comparison to the release observed at 22 degrees C. Cold-induced increases in metabolic rate and electrical muscle activity both occur at a considerably lower mean body temperature in cold-than in warm-adapted guinea-pigs. The shift of thermoregulatory cold defence reactions to a lower mean body temperature could also be observed in warm-adapted animals after intramuscular infusion of noradrenaline in amounts comparable to those released during cold adaptation. It is concluded that high peripheral sympathetic activity directly or indirectly inhibits noradrenergic neurons in the lower brain stem that modulate the thermoregulatory control system by means of their afferents to the hypothalamus. As a consequence of this peripheral influence the thermoregulatory set point is shifted to a lower mean body temperature.
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Affiliation(s)
- J Roth
- Physiologisches Institut, Justus-Liebig-Universität, Giessen, Federal Republic of Germany
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32
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Brück K, Zeisberger E. Adaptive changes in thermoregulation and their neuropharmacological basis. Pharmacol Ther 1987; 35:163-215. [PMID: 3321099 DOI: 10.1016/0163-7258(87)90106-9] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Adaptive changes of the thermoregulatory system include morphological and functional modifications. The morphological modifications such as changes in body shape and insulation need time periods of months to years to develop, unless they are genetically fixed and appear seasonally. In general, they are preceded by functional modifications, including changes in capacity of the effector systems and changes in regulatory characteristics, which need much less time to develop. These early changes in regulatory characteristics, which can be defined as deviations in threshold and gain of the thermoregulatory responses, have been described and subdivided into short-term (minutes) and long-term (weeks) modifications. Evidence for the participation of monoaminergic brain stem systems in these modifications has been reviewed. On the basis of recent insights into the organization of the thermoregulatory system, and of evaluation of experimental evidence from electrophysiological, neuropharmacological, and neuroanatomical studies it can be concluded that these systems are involved in adaptive modifications. Receiving information from several sensory systems they seem to deliver additional modulatory signals, which may interfere with the processing of specific thermal information at several sites. Theoretically, the central monoamines may participate in the control of thermal input, in the central integration of thermal signals, and in modification of output signals to thermoregulatory effectors. Best documented is their modulatory action on thermosensitive and thermointegrative hypothalamic neurons. There, the monoamines 5-hydroxytryptamine and noradrenaline act as antagonists, which enhance or diminish the effects of thermal afferents mediated by other transmitters. Moreover, the antagonistic monoaminergic systems are interconnected and can influence each other at the level of lower brain stem. The activity in central monoaminergic systems can also be modified by neurohumoral feedback mechanisms from the periphery. By means of these interrelations the vegetative responses of the organism can be corrected and optimized. These interrelations can explain also some cross-adaptive changes in the thermoregulatory threshold for shivering evoked by nonthermal factors such as food intake or long-distance running.
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Affiliation(s)
- K Brück
- Justus-Liebig-University of Giessen, F.R.G
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Heath ME, Jessen C. Effects of skin temperature on cold defense after cutaneous denervation of the trunk. Pflugers Arch 1986; 407:175-7. [PMID: 3748778 DOI: 10.1007/bf00580672] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In intact goats the core temperature threshold below which heat production increases with falling core temperature, is inversely related to the temperature of the water bath in which they stand and is therefore assumed to be indicative of the central integration of signals from skin and core temperature receptors. The present study shows that a difference in core temperature thresholds for bath temperatures of 35 degrees C and 40 degrees C persisted after denervation of about two-thirds of the skin of the trunk and limbs. Also, for a given combination of skin and core temperatures, heat production was as great or greater after cutaneous denervation as before. It is concluded that, following denervation of the trunk and upper limbs, intact temperature receptors in the non-denervated skin of the legs and tail, and/or also in tissues between the skin and core, provide important and significant inputs to the temperature regulating system. But these inputs cannot explain fully the thermoregulatory responses observed unless it is assumed that the thermosensitivity of these tissues increased.
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