The Hibernation Continuum: Physiological and Molecular Aspects of Metabolic Plasticity in Mammals

Physiology ◽  
2015 ◽  
Vol 30 (4) ◽  
pp. 273-281 ◽  
Author(s):  
Frank van Breukelen ◽  
Sandra L. Martin
Keyword(s):  
Phenotypic Plasticity ◽  
Body Temperature ◽  
Temperature Fluctuation ◽  
Metabolic Flexibility ◽  
Metabolic Depression ◽  
Metabolic Plasticity ◽  
Internal Milieu ◽  
The Face ◽  
Molecular Aspects ◽  
Physiological And Biochemical

Mammals are often considered to be masters of homeostasis, with the ability to maintain a constant internal milieu, despite marked changes in the environment; however, many species exhibit striking physiological and biochemical plasticity in the face of environmental fluctuations. Here, we review metabolic depression and body temperature fluctuation in mammals, with a focus on the extreme example of hibernation in small-bodied eutherian species. Careful exploitation of the phenotypic plasticity of mammals with metabolic flexibility may provide the key to unlocking the molecular secrets of orchestrating and surviving reversible metabolic depression in less plastic species, including humans.

scholarly journals The metabolic response of the Bradypus sloth to temperature

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5600 ◽  
Author(s):  
Rebecca Naomi Cliffe ◽  
David Michael Scantlebury ◽  
Sarah Jane Kennedy ◽  
Judy Avey-Arroyo ◽  
Daniel Mindich ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Energy Expenditure ◽  
High Power ◽  
Metabolic Response ◽  
Metabolic Responses ◽  
Metabolic Depression ◽  
Wide Range ◽  
Energetic Constraints ◽  
Power Costs

Poikilotherms and homeotherms have different, well-defined metabolic responses to ambient temperature (Ta), but both groups have high power costs at high temperatures. Sloths (Bradypus) are critically limited by rates of energy acquisition and it has previously been suggested that their unusual departure from homeothermy mitigates the associated costs. No studies, however, have examined how sloth body temperature and metabolic rate vary with Ta. Here we measured the oxygen consumption (VO2) of eight brown-throated sloths (B. variegatus) at variable Ta’s and found that VO2 indeed varied in an unusual manner with what appeared to be a reversal of the standard homeotherm pattern. Sloth VO2 increased with Ta, peaking in a metabolic plateau (nominal ‘thermally-active zone’ (TAZ)) before decreasing again at higher Ta values. We suggest that this pattern enables sloths to minimise energy expenditure over a wide range of conditions, which is likely to be crucial for survival in an animal that operates under severe energetic constraints. To our knowledge, this is the first evidence of a mammal provisionally invoking metabolic depression in response to increasing Ta’s, without entering into a state of torpor, aestivation or hibernation.

scholarly journals Increased Thermal Sensitivity of a Tropical Marine Gastropod Under Combined CO2 and Temperature Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Jay J. Minuti ◽  
Charlee A. Corra ◽  
Brian S. Helmuth ◽  
Bayden D. Russell
Keyword(s):  
Defense Mechanism ◽  
Thermal Sensitivity ◽  
Interactive Effects ◽  
Lethal Temperature ◽  
Weather Extremes ◽  
Short Term ◽  
Metabolic Plasticity ◽  
The Face ◽  
Metabolic Performance ◽  
Maximum Metabolic Rate

The ability of an organism to alter its physiology in response to environmental conditions offers a short-term defense mechanism in the face of weather extremes resulting from climate change. These often manifest as multiple, interacting drivers, especially pH and temperature. In particular, decreased pH can impose constraints on the biological mechanisms which define thermal limits by throwing off energetic equilibrium and diminishing physiological functions (e.g., in many marine ectotherms). For many species, however, we do not have a detailed understanding of these interactive effects, especially on short-term acclimation responses. Here, we investigated the metabolic plasticity of a tropical subtidal gastropod (Trochus maculatus) to increased levels of CO2 (700 ppm) and heating (+3°C), measuring metabolic performance (Q10 coefficient) and thermal sensitivity [temperature of maximum metabolic rate (TMMR), and upper lethal temperature (ULT)]. Individuals demonstrated metabolic acclimation in response to the stressors, with TMMR increasing by +4.1°C under higher temperatures, +2.7°C under elevated CO2, and +4.4°C under the combined stressors. In contrast, the ULT only increased marginally in response to heating (+0.3°C), but decreased by −2.3°C under CO2, and −8.7°C under combined stressors. Therefore, although phenotypic plasticity is evident with metabolic acclimation, acute lethal temperature limits seem to be less flexible during short-term acclimation.

Ventilatory and metabolic responses to hypoxia in the smallest simian primate, the pygmy marmoset

2002 ◽  
Vol 92 (1) ◽  
pp. 202-210 ◽  
Author(s):  
Glenn J. Tattersall ◽  
James L. Blank ◽  
Stephen C. Wood
Keyword(s):  
Body Temperature ◽  
Metabolic Response ◽  
World Monkey ◽  
Minute Ventilation ◽  
Metabolic Depression ◽  
Hypoxic Conditions ◽  
Pygmy Marmoset ◽  
Average Body Mass ◽  
Average Body ◽  
Ventilatory Response To Hypoxia

The pygmy marmoset ( Cebuella pygmaea) is the smallest New World Monkey (average body mass of 120–130 g). As such, it faces possible challenges to thermoregulation. Small mammals (e.g., rats) are well known to lower body temperature and metabolism in response to hypoxia; however, small primates have not been studied in this respect nor have, in general, the interactions between metabolism and ventilation. Because little is known about these responses in small primates, it seemed of great interest to assess the hypoxia-induced metabolic depression and drop in body temperature and the associated ventilatory requirements in this species under hypoxic conditions. Exposure to graded hypoxia (30 min at each of 18, 16, 14, 12, and 10% O2) caused body temperature to drop from the normoxic value of 39 to 37°C. This was accompanied by a marked metabolic depression (O2 consumption was ∼68% of the normoxic value, implying a suppression of metabolism greater than that predicted from a typical value of the effect of 10°C change on metabolism of 2–3 times). Minute ventilation declined in parallel to metabolism, maintaining a constant air-convection requirement during hypoxia; thus this species did not show the typical mammalian hyperventilation. Acute exposure to 10% O2 led to a similar overall decline in metabolism and body temperature and qualitative differences in the timing of these changes. The pygmy marmoset shares some similarities in its hypoxic metabolic response with other mammals of similar size yet appears to be unique in its much diminished ventilatory response to hypoxia.

Integration of silicon and secondary metabolites in plants: a significant association in stress tolerance

2020 ◽  
Vol 71 (21) ◽  
pp. 6758-6774 ◽  
Author(s):  
Mohammad Abass Ahanger ◽  
Javaid Akhter Bhat ◽  
Manzer H Siddiqui ◽  
Jörg Rinklebe ◽  
Parvaiz Ahmad
Keyword(s):  
Secondary Metabolites ◽  
Stress Tolerance ◽  
Secondary Metabolism ◽  
Abiotic Stresses ◽  
Current Knowledge ◽  
Pathogen Resistance ◽  
Molecular Aspects ◽  
Nitrogen Containing Compounds ◽  
Sessile Organisms ◽  
Physiological And Biochemical

Abstract As sessile organisms, plants are unable to avoid being subjected to environmental stresses that negatively affect their growth and productivity. Instead, they utilize various mechanisms at the morphological, physiological, and biochemical levels to alleviate the deleterious effects of such stresses. Amongst these, secondary metabolites produced by plants represent an important component of the defense system. Secondary metabolites, namely phenolics, terpenes, and nitrogen-containing compounds, have been extensively demonstrated to protect plants against multiple stresses, both biotic (herbivores and pathogenic microorganisms) and abiotic (e.g. drought, salinity, and heavy metals). The regulation of secondary metabolism by beneficial elements such as silicon (Si) is an important topic. Silicon-mediated alleviation of both biotic and abiotic stresses has been well documented in numerous plant species. Recently, many studies have demonstrated the involvement of Si in strengthening stress tolerance through the modulation of secondary metabolism. In this review, we discuss Si-mediated regulation of the synthesis, metabolism, and modification of secondary metabolites that lead to enhanced stress tolerance, with a focus on physiological, biochemical, and molecular aspects. Whilst mechanisms involved in Si-mediated regulation of pathogen resistance via secondary metabolism have been established in plants, they are largely unknown in the case of abiotic stresses, thus leaving an important gap in our current knowledge.

scholarly journals Body temperature fluctuation analysis in cirrhosis

2017 ◽  
Vol 38 (2) ◽  
pp. 378-379 ◽  
Author(s):  
Ali R. Mani ◽  
Roham Mazloom ◽  
Zahra Haddadian ◽  
Sara Montagnese
Keyword(s):  
Body Temperature ◽  
Temperature Fluctuation ◽  
Fluctuation Analysis

scholarly journals Phenotypic plasticity and evolution of thermal tolerance in two lineages of bacteria from temperate and hot environments

2020 ◽  
Author(s):  
Enrique Hurtado-Bautista ◽  
Laura F. Pérez-Sánchez ◽  
África Islas-Robles ◽  
Gustavo Santoyo ◽  
Gabriela Olmedo-Álvarez
Keyword(s):  
Phenotypic Plasticity ◽  
Heat Tolerance ◽  
Thermal Tolerance ◽  
Hot Spring ◽  
Negative Impact ◽  
Thermal Reaction ◽  
Physiological Limits ◽  
Evolutionary Changes ◽  
The Face ◽  
Life On Earth

AbstractDespite the crucial role of microorganisms to sustain life on Earth, there is little research on the evolution of thermal tolerance of bacteria in the face of the challenge that global warming poses. Phenotypic adaptation to a new environment requires plasticity to allow individuals to respond to selective forces, followed by adaptive evolution. We do not know to what extent phenotypic plasticity allows thermal tolerance evolution in bacteria at the border of their physiological limits. We analyzed growth and thermal reaction norms to temperature of strains of two bacterial lineages, Bacillus cereus sensu lato and Bacillus subtilis sensu lato, that evolved in two contrasting environments, a temperate lagoon (T) and a hot spring (H). Our results showed that despite co-occurrence of members of both lineages in the two contrasting environments, norms of reactions to temperature exhibited a similar pattern only within the lineages, suggesting fixed phenotypic plasticity. Additionally, within the B. cereus lineage, strains from the H environment showed only two to three °C more heat tolerance than strains from the T environment. The limited evolutionary changes towards an increase in heat tolerance in bacteria should alert us of the negative impact that climate change can have on all biological cycles in the planet.

scholarly journals Multi Patient Wireless Monitoring for Pandemic With Continuous Reading Analysis and Alert Generation For Affected Patient

2021 ◽  
pp. 546-552
Author(s):  
Dr. J. Jeba Johannah ◽  
Sivagnana Sowndarya R R ◽  
Tamilarasi. S
Keyword(s):  
Body Temperature ◽  
Web Application ◽  
Graphical Representation ◽  
Public Healthcare ◽  
The Novel ◽  
The Public ◽  
Wireless Monitoring ◽  
The Face ◽  
Temperature Levels ◽  
Multiple Patients

The public healthcare system of a country needs to deal with newer ailments and challenges arising due to change in lifestyle, food habits, etc. In addition, the novel requirements of the consumer healthcare market, facing among other issues, the strong demographic changes associated with the aging population put researchers in front of new and exciting challenges. The country’s healthcare infrastructure may not be enough in the face of an epidemic, especially COVID-19.To overcome these problems, in this project we use an oxidation sensor and a temperature sensor to record the readings of the blood oxidation levels and body temperature of the patient. The readings are then pushed to the cloud using a Wi-Fi module, the values are then fetched on the frontend web application. A web application using reacts is developed to give a live analysis to monitor and check the condition of multiple patients with a graphical representation of their oxidation and body temperature levels. The bio data of each patient specifically can be viewed by the doctor. When the condition of a patient is at an abnormal level the doctor is immediately alerted through a pop up in the web application. Thus, this project prevents the doctor from coming in direct contact with multiple patients preventing further spread of the virus.

Advanced in Rootstock Breeding of Nut Trees: Objectives and Strategies

2021 ◽  
Author(s):  
Kourosh Vahdati ◽  
Saadat Sarikhani ◽  
Mohammad Mehdi Arab ◽  
Charles A. Leslie ◽  
Abhaya M. Dandekar ◽  
...  
Keyword(s):  
Economic Returns ◽  
Long Distance ◽  
Economic Production ◽  
Environmental Interactions ◽  
Current Consumption ◽  
Production And Consumption ◽  
The Face ◽  
Molecular Aspects ◽  
Horticultural Practice ◽  
Rootstock Breeding

The production and consumption of nuts are increasing in the world due to strong economic returns and the nutritional value of their products. With the increasing role and importance given to nuts (i.e., walnuts, hazelnut, pistachio, pecan, almond) in a balanced and healthy diet and in the prevention of various diseases, breeding of the nuts species has also been stepped up. Most recent fruit breeding programs have focused on scion genetic improvement. However, the use of locally adapted grafted rootstocks also enhanced the productivity and quality of tree fruit crops. Grafting is an ancient horticultural practice use in nut crops to manipulate scion phenotype and productivity and overcome biotic and abiotic stresses. There are complex rootstock breeding objectives and physiological and molecular aspects of rootstock–scion interactions in nut crops. In this review, we provide an overview of these, considering the mechanisms involved in nutrient and water uptake, regulation of phytohormones, and rootstock influences on the scion molecular processes, including long-distance gene silencing and trans-grafting. Understanding the mechanisms resulting from rootstock × scion × environmental interactions will contribute to developing new rootstocks with resilience in the face of climate change, but also of the multitude of diseases and pests and of the possible increase of their aggressiveness. They will also have to offer the premises of economic production, respectively yield and the quality, according to multiple destinations of nuts in the current consumption and food industry, but also the increasing exigencies of the consumer market and the profile industry.

Effects of food deprivation on daily changes in body temperature and behavioral thermoregulation in rats

2000 ◽  
Vol 278 (1) ◽  
pp. R134-R139 ◽  
Author(s):  
Tamae Yoda ◽  
Larry I. Crawshaw ◽  
Kyoko Yoshida ◽  
Liu Su ◽  
Takayoshi Hosono ◽  
...  
Keyword(s):  
Body Temperature ◽  
Food Deprivation ◽  
Escape Behavior ◽  
The Body ◽  
Behavioral Thermoregulation ◽  
Cold Environments ◽  
The Face ◽  
Regulate Body Temperature ◽  
Behavioral Mechanisms ◽  
Escape Behaviors

Homeothermic animals regulate body temperature (Tb) by using both autonomic and behavioral mechanisms. In the latter process, animals seek out cooler or warmer places when they are exposed to excessively hot or cold environments. Thermoregulation is affected by the state of energy reserves in the body. In the present study, we examine the effects of 4-day food deprivation on circadian changes in Tb and on cold-escape and heat-escape behaviors in rats. Continuous measurement of Tb during food deprivation indicated that the peak Tb amplitude was not different from baseline values, but the trough amplitude continuously decreased after the onset of food deprivation. Cold-escape behavior was facilitated by food deprivation, whereas heat-escape behavior was unchanged. After the termination of food deprivation, the lowered Tb returned to normal on the first day. However, cold-escape behavior was still facilitated on the third day after food reintroduction. Autonomic and behavioral thermoregulatory effectors are modulated in the face of food shortage so as to maintain optimal performance during the active period, whereas increasing energy conservation occurs during the quiescent phase.

Sign in / Sign up

Export Citation Format

Share Document