scholarly journals Synchronous and opponent thermosensors use flexible cross-inhibition to orchestrate thermal homeostasis

2020 ◽  
Author(s):  
Luis Hernandez-Nunez ◽  
Alicia Chen ◽  
Gonzalo Budelli ◽  
Vincent Richter ◽  
Anna Rist ◽  
...  
Keyword(s):  
Body Temperature ◽  
Behavioral Analysis ◽  
Sensory Receptor ◽  
Directed Movement ◽  
Temperature Changes ◽  
Set Point ◽  
Temperature Homeostasis ◽  
Essential Function ◽  
Control Body ◽  
Cross Inhibition

Body temperature homeostasis is an essential function that relies upon the integration of the outputs from multiple classes of cooling- and warming-responsive cells. The computations that integrate these diverse outputs to control body temperature are not understood. Here we discover a new set of Warming Cells (WCs), and show that the outputs of these WCs and previously described Cooling Cells (CCs1) are combined in a cross-inhibition computation to drive thermal homeostasis in larval Drosophila. We find that WCs and CCs are opponent sensors that operate in synchrony above, below, and near the homeostatic set-point, with WCs consistently activated by warming and inhibited by cooling, and CCs the converse. Molecularly, these opponent sensors rely on overlapping combinations of Ionotropic Receptors to detect temperature changes: Ir68a, Ir93a, and Ir25a for WCs; Ir21a, Ir93a, and Ir25a for CCs. Using a combination of optogenetics, sensory receptor mutants, and quantitative behavioral analysis, we find that the larva uses flexible cross-inhibition of WC and CC outputs to locate and stay near the homeostatic set-point. Balanced cross-inhibition near the set-point suppresses any directed movement along temperature gradients. Above the set-point, WCs mediate avoidance to warming while cross-inhibiting avoidance to cooling. Below the set-point, CCs mediate avoidance to cooling while cross-inhibiting avoidance to warming. Our results demonstrate how flexible cross-inhibition between warming and cooling pathways can orchestrate homeostatic thermoregulation.

scholarly journals Contribution of thermal and nonthermal factors to the regulation of body temperature in humans

2006 ◽  
Vol 100 (6) ◽  
pp. 2065-2072 ◽  
Author(s):  
Igor B. Mekjavic ◽  
Ola Eiken
Keyword(s):  
Body Temperature ◽  
Temperature Regulation ◽  
Animal Experiments ◽  
Reciprocal Inhibition ◽  
Set Point ◽  
Neurophysiological Studies ◽  
Thermoregulatory System ◽  
Effector Pathways ◽  
Cross Inhibition ◽  
Inhibition Theory

The set point has been used to define the regulated level of body temperature, suggesting that displacements of core temperature from the set point initiate heat production (HP) and heat loss (HL) responses. Human and animal experiments have demonstrated that the responses of sweating and shivering do not coincide at a set point but rather establish a thermoeffector threshold zone. Neurophysiological studies have demonstrated that the sensor-to-effector pathways for HP and HL overlap and, in fact, mutually inhibit each other. This reciprocal inhibition theory, presumably reflecting the manner in which thermal factors contribute to homeothermy in humans, does not incorporate the effect of nonthermal factors on temperature regulation. The present review examines the actions of these nonthermal factors within the context of neuronal models of temperature regulation, suggesting that examination of these factors may provide further insights into the nature of temperature regulation. It is concluded that, although there is no evidence to doubt the existence of the HP and HL pathways reciprocally inhibiting one another, it appears that such a mechanism is of little consequence when comparing the effects of nonthermal factors on the thermoregulatory system, since most of these factors seem to exert their influence in the region after the reciprocal cross-inhibition. At any given moment, both thermal and several nonthermal factors will be acting on the thermoregulatory system. It may, therefore, not be appropriate to dismiss the contribution of either when discussing the regulation of body temperature in humans.

Core body temperature changes after sauna exposition in healthy subjects

2012 ◽  
Vol 26 (2) ◽  
Author(s):  
Joanna Pawlak ◽  
Paweł Zalewski ◽  
Jacek J. Klawe ◽  
Monika Zawadka ◽  
Anna Bitner ◽  
...  
Keyword(s):  
Body Temperature ◽  
Healthy Subjects ◽  
Core Body Temperature ◽  
Temperature Changes ◽  
Core Body

Ambient temperature effects on physiological traits of white-tailed deer

1975 ◽  
Vol 53 (6) ◽  
pp. 679-685 ◽  
Author(s):  
J. B. Holter ◽  
W. E. Urban Jr. ◽  
H. H. Hayes ◽  
H. Silver ◽  
H. R. Skutt
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Energy Expenditure ◽  
Ambient Temperature ◽  
Temperature Effects ◽  
Temperature Changes ◽  
Wind Chill ◽  
Ambient Temperatures ◽  
Energy Equilibrium ◽  
Body Energy

Six adult white-tailed deer (Odocoileus virginianus borealis) were exposed to 165 periods of 12 consecutive hours of controlled constant ambient temperature in an indirect respiration calorimeter. Temperatures among periods varied from 38 to 0 (summer) or to −20C (fall, winter, spring). Traits measured were energy expenditure (metabolic rate), proportion of time spent standing, heart rate, and body temperature, the latter two using telemetry. The deer used body posture extensively as a means of maintaining body energy equilibrium. Energy expenditure was increased at low ambient temperature to combat cold and to maintain relatively constant body temperature. Changes in heart rate paralleled changes in energy expenditure. In a limited number of comparisons, slight wind chill was combatted through behavioral means with no effect on energy expenditure. The reaction of deer to varying ambient temperatures was not the same in all seasons of the year.

On the Regulation of the Respiration in Reptiles

1961 ◽  
Vol 38 (2) ◽  
pp. 301-314 ◽  
Author(s):  
BODIL NIELSEN
Keyword(s):  
Steady State ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Temperature Interval ◽  
Normal Values ◽  
Pulmonary Ventilation ◽  
The Body ◽  
Respiratory Frequency ◽  
Temperature Changes ◽  
Instantaneous Increase

1. In two species of Lacerta (L. viridis and L. sicula) the effects on respiration of body temperature (changes in metabolic rate) and of CO2 added to the inspired air were studied. 2. Pulmonary ventilation increases when body temperature increases. The increase is brought about by an increase in respiratory frequency. No relationship is found between respiratory depth and temperature. 3. The rise in ventilation is provoked by the needs of metabolism and is not established for temperature regulating purposes (in the temperature interval 10°-35°C). 4. The ventilation per litre O2 consumed has a high numerical value (about 75, compared to about 20 in man). It varies with the body temperature and demonstrates that the inspired air is better utilized at the higher temperatures. 5. Pulmonary ventilation increases with increasing CO2 percentages in the inspired air between o and 3%. At further increases in the CO2 percentage (3-13.5%) it decreases again. 6. At each CO2 percentage the pulmonary ventilation reaches a steady state after some time (10-60 min.) and is then unchanged over prolonged periods (1 hr.). 7. The respiratory frequency in the steady state decreases with increasing CO2 percentages. The respiratory depth in the steady state increases with increasing CO2 percentages. This effect of CO2 breathing is not influenced by a change in body temperature from 20° to 30°C. 8. Respiration is periodically inhibited by CO2 percentages above 4%. This inhibition, causing a Cheyne-Stokes-like respiration, ceases after a certain time, proportional to the CO2 percentage (1 hr. at 8-13% CO2), and respiration becomes regular (steady state). Shift to room air breathing causes an instantaneous increase in frequency to well above the normal value followed by a gradual decrease to normal values. 9. The nature of the CO2 effect on respiratory frequency and respiratory depth is discussed, considering both chemoreceptor and humoral mechanisms.

TEMPERATURE REGULATION IN EXERCISE

PEDIATRICS ◽  
1963 ◽  
Vol 32 (4) ◽  
pp. 691-702
Author(s):  
Sid Robinson
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Heat Stroke ◽  
The Body ◽  
Physiological Regulation ◽  
Temperature Changes ◽  
Metabolic Heat ◽  
Warm Blood ◽  
Hot Environments ◽  
Large Increments

The central body temperature of a man rises gradually during the first half hour of a period of work to a higher level and this level is precisely maintained until the work is stopped; body temperature then slowly declines to the usual resting level. During prolonged work the temperature regulatory center in the hypothalamus appears to be reset at a level which is proportional to the intensity of the work and this setting is independent of environmental temperature changes ranging from cold to moderately warm. In hot environments the resistance to heat loss may be so great that all of the increased metabolic heat of work cannot be dissipated and the man's central temperature will rise above the thermostatic setting. If this condition of imbalance is continued long enough heat stroke will ensue. We have found that in a 3 mile race lasting only 14 minutes on a hot summer day a runner's rectal temperature may rise to 41.1°C., with heat stroke imminent. The physiological regulation of body temperature of men in warm environments and during the increased metabolic heat production of work is dependent on sweating to provide evaporative cooling of the skin, and on adjustments of cutaneous blood flow which determine the conductance of heat from the deeper tissues to the skin. The mechanisms of regulating these responses during work are complex and not entirely understood. Recent experiments carried out in this laboratory indicate that during work, sweating may be regulated by reflexes originating from thermal receptors in the veins draining warm blood from the muscles, summated with reflexes from the cutaneous thermal receptors, both acting through the hypothalamic center, the activity of which is increased in proportion to its own temperature. At the beginning of work the demand for blood flow to the muscles results in reflex vasoconstriction in the skin. As the body temperature rises the thermal demand predominates and the cutaneous vessels dilate, increasing heat conductance to the skin. Large increments in cardiac output and compensatory vasoconstriction in the abdominal viscera make these vascular adjustments in work possible without circulatory embarrassment.

scholarly journals Insulin-like growth factor 1 receptor regulates hypothermia during calorie restriction

2017 ◽  
Vol 114 (36) ◽  
pp. 9731-9736 ◽  
Author(s):  
Rigo Cintron-Colon ◽  
Manuel Sanchez-Alavez ◽  
William Nguyen ◽  
Simone Mori ◽  
Ruben Gonzalez-Rivera ◽  
...  
Keyword(s):  
Growth Factor ◽  
Body Temperature ◽  
Calorie Restriction ◽  
Core Body Temperature ◽  
Insulin Like Growth Factor ◽  
Hypothalamic Nuclei ◽  
The Central Nervous System ◽  
Temperature Homeostasis ◽  
Core Body ◽  
The Brain

When food resources are scarce, endothermic animals can lower core body temperature (Tb). This phenomenon is believed to be part of an adaptive mechanism that may have evolved to conserve energy until more food becomes available. Here, we found in the mouse that the insulin-like growth factor 1 receptor (IGF-1R) controls this response in the central nervous system. Pharmacological or genetic inhibition of IGF-1R enhanced the reduction of temperature and of energy expenditure during calorie restriction. Full blockade of IGF-1R affected female and male mice similarly. In contrast, genetic IGF-1R dosage was effective only in females, where it also induced transient and estrus-specific hypothermia in animals fed ad libitum. These effects were regulated in the brain, as only central, not peripheral, pharmacological activation of IGF-1R prevented hypothermia during calorie restriction. Targeted IGF-1R knockout selectively in forebrain neurons revealed that IGF signaling also modulates calorie restriction-dependent Tbregulation in regions rostral of the canonical hypothalamic nuclei involved in controlling body temperature. In aggregate, these data identify central IGF-1R as a mediator of the integration of nutrient and temperature homeostasis. They also show that calorie restriction, IGF-1R signaling, and body temperature, three of the main regulators of metabolism, aging, and longevity, are components of the same pathway.

scholarly journals The Impact of Central and Peripheral Cyclooxygenase Enzyme Inhibition on Exercise-Induced Elevations in Core Body Temperature

2017 ◽  
Vol 12 (5) ◽  
pp. 662-667 ◽  
Author(s):  
Matthijs T.W. Veltmeijer ◽  
Dineke Veeneman ◽  
Coen C.C.W. Bongers ◽  
Mihai G. Netea ◽  
Jos W. van der Meer ◽  
...  
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Skin Temperature ◽  
Core Body Temperature ◽  
Exercise Tests ◽  
Hypothalamic Temperature ◽  
Set Point ◽  
Exercise Induced ◽  
Core Body ◽  
The Impact

Purpose:Exercise increases core body temperature (TC) due to metabolic heat production. However, the exercise-induced release of inflammatory cytokines including interleukin-6 (IL-6) may also contribute to the rise in TC by increasing the hypothalamic temperature set point. This study investigated whether the exercise-induced increase in TC is partly caused by an altered hypothalamic temperature set point.Methods:Fifteen healthy, active men age 36 ± 14 y were recruited. Subjects performed submaximal treadmill exercise in 3 randomized test conditions: (1) 400 mg ibuprofen and 1000 mg acetaminophen (IBU/APAP), (2) 1000 mg acetaminophen (APAP), and (3) a control condition (CTRL). Acetaminophen and ibuprofen were used to block the effect of IL-6 at a central and peripheral level, respectively. TC, skin temperature, and heart rate were measured continuously during the submaximal exercise tests.Results:Baseline values of TC, skin temperature, and heart rate did not differ across conditions. Serum IL-6 concentrations increased in all 3 conditions. A significantly lower peak TC was observed in IBU/APAP (38.8°C ± 0.4°C) vs CTRL (39.2°C ± 0.5°C, P = .02) but not in APAP (38.9°C ± 0.4°C) vs CTRL. Similarly, a lower ΔTC was observed in IBU/APAP (1.7°C ± 0.3°C) vs CTRL (2.0°C ± 0.5°C, P < .02) but not in APAP (1.7°C ± 0.5°C) vs CTRL. No differences were observed in skin temperature and heart-rate responses across conditions.Conclusions:The combined administration of acetaminophen and ibuprofen resulted in an attenuated increase in TC during exercise compared with a CTRL. This observation suggests that a prostaglandin-E2-induced elevated hypothalamic temperature set point may contribute to the exercise-induced rise in TC.

scholarly journals Malignant catarrhal fever (Coryza gangraenosa bovum)

2008 ◽  
Vol 62 (1-2) ◽  
pp. 105-110
Author(s):  
Filip Spasojevic ◽  
Djordje Uzelac ◽  
Zlatko Milosavljevic ◽  
Ivan Vujanac
Keyword(s):  
Body Temperature ◽  
Blood Vessels ◽  
Medical Condition ◽  
Malignant Catarrhal Fever ◽  
Lethal Outcome ◽  
Cattle Farm ◽  
Temperature Changes ◽  
Progressive Loss ◽  
Loss Of Weight ◽  
Elevated Body Temperature

Malignant catarrhal fever is a disease of cattle and other ruminants, which most often has a lethal outcome. The disease occurs sporadically and is very difficult to control. At a private mini cattle farm, the occurrence of malignant catarrhal fever was suspected on the grounds of anaemnestic data and results of clinical examinations. The owner said that, in addition to cattle, he also breeds sheep in a separate facility, but said these animals had not been in contact with the diseased cow. In the course of the disease, the characteristic symptoms developed so that the clinical diagnosis set earlier was subsequently confirmed. In addition to constantly elevated body temperature, changes in the eyes were observed very soon (congested blood vessels and capillaries of the white sclera with keratitis on both sides). In addition to photofobia and a copious discharge from the nasal cavities, the discharge was at first seromucous and later became mucopurrulent. In the later course of the disease, there was progressive loss of weight and exhaustion of the animal. Since therapy included, in addition to other medicines, also a glucocorticosteroid preparation, the animal aborted its fetus on the fifth day. A pathological-anatomical examination did not reveal any changes on the fetus. In spite of the applied therapy, the medical condition deteriorated from day to day, and the animal expired on the eighth day of the disease.

scholarly journals Suhu Tubuh Bayi Prematur di Inkubator Dinding Tunggal dengan Inkubator Dinding Tunggal Disertai Sungkup

2019 ◽  
Vol 2 (2) ◽  
pp. 113-122
Author(s):  
Padila Padila ◽  
Ida Agustien
Keyword(s):  
Body Temperature ◽  
Preterm Infants ◽  
Premature Infants ◽  
Study Groups ◽  
Mean Value ◽  
Mean Body Temperature ◽  
Temperature Changes ◽  
Average Change ◽  
Descriptive Method

This study aims to compare the average change in body temperature in a single wall incubator with a single wall incubator with hood in preterm infants with hypothermia. The design of this study uses a comparative descriptive method. The results of the study in the group of preterm infants with hypothermia in a single wall incubator with a lid significantly increased mean body temperature changes with a mean value of 36.09 variance 0.152 while for preterm infants with hypothermia in a single wall incubator a mean value of 35.35 variance values 0.859 and obtained t count from the two study groups namely 2.551 and 1.717 t table. In conclusion, a single wall incubator with a lid increases body temperature in premature infants with hypothermia compared to a single wall incubator.   Keywords: Hypothermia, Incubator, Premature

scholarly journals Warm Compress on Lowering Body Temperature Among Hyperthermia Patients: A Literature Review

2021 ◽  
Vol 4 (3) ◽  
pp. 344-355
Author(s):  
Lilis Lismayanti ◽  
Andika Abdul Malik ◽  
Nida Siti Padilah ◽  
Fidya Anisa Firdaus ◽  
Henri Setiawan
Keyword(s):  
Body Temperature ◽  
Literature Review ◽  
Nursing Process ◽  
Inclusion Criteria ◽  
Temperature Changes ◽  
Human Body Temperature ◽  
Critical Appraisal Skills ◽  
Online Library ◽  
Positive Effect ◽  
Common Manifestation

Hyperthermia increased the core human body temperature above normal 36.7-37.5 °C, usually caused by infection, resulting in fever, and was the most common manifestation. One of the efforts that could be done to overcome the symptoms of hyperthermia was the application of warm compresses to the frontal, axillary, and dorsalis pedis. The study aimed to describe body temperature changes in hyperthermic patients after warm compress was applied. This study used a descriptive design with a literature review approach. Twelve articles were included in this review by six journal databases: PubMed, JSTOR, Wiley Online Library, Sage Journal, Taylor and Francis Online, and Google Scholar. The selection was carried out by assessing articles that met the inclusion criteria, including the publication range for 2008-2021, English and Indonesian languages ??, and open access to full-text pdf. The critical assessment was carried out by using the Critical Appraisal Skills Programmed instrument. The review results showed that the warm compress method had a positive effect in lowering body temperature in the nursing process in patients with hyperthermia. Based on the literature from the reviewed articles, it could be concluded that a warm compress intervention needed to be given to hyperthermic patients to lower the patient's body temperature whether they were undergoing treatment or not

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