Temperature: Multidisciplinary Biomedical Journal最新文献

{"title":"A cellular pathway controlling functional plasma membrane incorporation of the cold sensor TRPM8","authors":"J. Vriens, T. Voets","doi":"10.1080/23328940.2016.1200205","DOIUrl":"https://doi.org/10.1080/23328940.2016.1200205","url":null,"abstract":"The transient receptor potential melastatin 8 (TRPM8) plays a crucial part in cold detection by the somatosensory system. In heterologous expression systems, TRPM8 activity steeply increases upon cooling and in the presence of substances that are known to produce a cooling sensation, including menthol, and the ‘super-cooling agent’ icilin. TRPM8-deficient mice exhibited a striking deficit in avoiding cool temperatures (18–30 C). Moreover, whereas mild cooling can evoke analgesia in wild-type mice, cooling-induced analgesia was absent in TRPM8-deficient mice. Importantly, increased functional expression of TRPM8 contributes to pathological cold hypersensitivity and cold allodynia in various animal models of neuropathic and inflammatory pain. In recent years, important advances have been made in our knowledge about the biophysical properties of TRPM8. However, the knowledge about the trafficking mechanism that determine the abundance of TRPM8 at the plasma membrane is very sparse. Nevertheless, modulation of the number of active cold sensitive TRPM8 channels at the plasma membrane represents an important regulatory mechanism under normal and pathophysiological conditions. In this article we discuss our recent findings published in the article ’VAMP7 regulates constitutive membrane incorporation of the cold-activated channel’ in which we have uncovered a cellular pathway that controls functional plasma membrane incorporation of TRPM8, and thus regulates thermo-sensitivity in vivo. By the use of Total internal reflection fluorescence (TIRF) microscopy, in which only a thin layer of illumination above the interface is created and only fluorophores within this thin layer (»100–300 nm) in the sample are excited, we revealed that fluorescently tagged TRPM8 channels are located in a population of highly dynamic vesicular and tubular structures. By treatment of TRPM8-mCherry expressing cells with microtubuleor actindepolymerizing agents and additional TIRF Recovery after Photobleaching (TIRF-FRAP) experiments, we were able to show that TRPM8-positive structures use microtubules as principal track for rapid near-membrane intracellular movement. Further characterization of the mobile TRPM8-positive structures was done by co-expression of TRPM8-mCherry along with known markers of various cellular compartments tagged with GFP, and quantified by dual-color TIRFM to simultaneously monitor the movement of TRPM8-mCherry along with GFP-tagged marker proteins. These results showed strong dynamic co-localization of TRPM8 and the Lysosomal associated membrane protein 1 (LAMP1), which was also observed in neurites of TGN co-expressing TRPM8-mCherry and LAMP1-GFP (Fig. 1A). Although LAMP1 is typically associated with endo-lysosomal structures, additional TIR-FRAP experiments indicated that TRPM8and LAMP1-positive mobile vesicles transport TRPM8 from the cell center toward the plasma membrane via microtubules. The pool of mobile TRPM8-positive vesicles is a stable compar","PeriodicalId":22565,"journal":{"name":"Temperature: Multidisciplinary Biomedical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75090575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interactions in human performance: An individual and combined stressors approach","authors":"Alex B. Lloyd, G. Havenith","doi":"10.1080/23328940.2016.1189991","DOIUrl":"https://doi.org/10.1080/23328940.2016.1189991","url":null,"abstract":"In many clinical, ergonomic and sporting contexts, humans are exposed to environments that are suboptimal for physical and cognitive performance. This has prompted a substantial body research on the human response to heat, cold, hypoxia, noise, vibration, hypoand hyperbaria, as well as hyperand microgravity. However, working at environmental extremes can expose individuals to more than just a single stressor. Indeed, it is the combination of stressful factors which characterizes the ‘extreme’ nature of environments like high-altitude (e.g. hypobaric hypoxia, cold, solar radiation), deep-sea (e.g., hyperbaria, cold, inspiratory gas toxicity) and space (e.g. heat, cold, hypobaric normoxia, hyperand microgravity).","PeriodicalId":22565,"journal":{"name":"Temperature: Multidisciplinary Biomedical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86474514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hemodynamic responses upon the initiation of thermoregulatory behavior in young healthy adults.","authors":"Zachary J Schlader, Suman Sarker, Toby Mündel, Gregory L Coleman, Christopher L Chapman, James R Sackett, Blair D Johnson","doi":"10.1080/23328940.2016.1148938","DOIUrl":"10.1080/23328940.2016.1148938","url":null,"abstract":"<p><p>We tested the hypotheses that thermoregulatory behavior is initiated before changes in blood pressure and that skin blood flow upon the initiation of behavior is reflex mediated. Ten healthy young subjects moved between 40°C and 17°C rooms when they felt 'too warm' (W→C) or 'too cool' (C→W). Blood pressure, cardiac output, skin and rectal temperatures were measured. Changes in skin blood flow between locations were not different at 2 forearm locations. One was clamped at 34°C ensuring responses were reflex controlled. The temperature of the other was not clamped ensuring responses were potentially local and/or reflex controlled. Relative to pre-test Baseline, skin temperature was not different at C→W (33.5 ± 0.7°C, P = 0.24), but was higher at W→C (36.1 ± 0.5°C, P < 0.01). Rectal temperature was different from Baseline at C→W (-0.2 ± 0.1°C, P < 0.01) and W→C (-0.2 ± 0.1°C, P < 0.01). Blood pressure was different from Baseline at C→W (+7 ± 4 mmHg, P < 0.01) and W→C (-5 ± 5 mmHg, P < 0.01). Cardiac output was not different from Baseline at C→W (-0.1 ± 0.4 L/min, P = 0.56), but higher at W→C (0.4 ± 0.4 L/min, P < 0.01). Skin blood flow between locations was not different from Baseline at C→W (clamped: -6 ± 15 PU, not clamped: -3 ± 6 PU, P = 0.46) or W→C (clamped: +21 ± 23 PU, not clamped: +29 ± 15 PU, P = 0.26). These data indicate that the initiation of thermoregulatory behavior is preceded by moderate changes in blood pressure and that skin blood flow upon the initiation of this behavior is under reflex control.</p>","PeriodicalId":22565,"journal":{"name":"Temperature: Multidisciplinary Biomedical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4965002/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73066206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From science to practice: Development of a thermally-insulated ice slushy dispensing bottle that helps athletes “keep their cool” in hot temperatures","authors":"P. Laursen","doi":"10.1080/23328940.2016.1165786","DOIUrl":"https://doi.org/10.1080/23328940.2016.1165786","url":null,"abstract":"Like many of us, I love sport. I care deeply about athlete performance. It is my job to. That passion has enabled me to wear a number of hats in the arena. I’ve been an athlete (triathlon and cycling), a coach, a professor, and an applied sport scientist. Residing in this sometimes messy, often fun, middle-space, between research, theory and application, which do not always align, I’ve been able to make some observations, identify some problems, and foster some solutions. The topic of this editorial is a story about how I’ve assisted to bridge a small gap between science and practice, by mixing scientific understanding and ingenuity to alter athlete temperature. Last year I delivered two presentations in Paris on this topic, entitled: Keeping your cool: How fluid temperature affects thermal comfort and performance in the heat. My opening slide included the picture, shown as Figure 1. Here we have two of today’s world-best triathletes, Andrea Hewitt and Rachel Klamer, racing in the Gold Coast World Series Race in Australia (April 2015). In this race, it was 28 Celsius, with high humidity. To me, this picture speaks volumes about what’s really important when maximizing performance in hot environments. Consider the following question: what’s essential to these athletes when they have cold fluid in their hands? Are they thirsty and dehydrated, or is it more likely that their brain/body is overheating? If these athletes were thirsty, and fluid consumption mattered to their brain at that point, then surely they would be more interested in drinking that fluid; but clearly they are not. When it’s on, with metabolic heat production sky high, (as it is in most of the Olympic sports we deal with) it’s brain temperature, or perhaps more accurately the brain’s recognition of a body that’s overheating that matters. So let’s go back in time a bit and allow me to tell you the story about how I became involved in discovering the importance of fluid temperature for performance in the heat. While employed as a lecturer at Edith Cowen University (ECU) in Perth Australia, I enjoyed collaborating with Dr David Martin, an Australian Institute of Sport Senior Physiologist, in the area of precooling athletes before competition in the heat in order to improve performance. It was 2006, and the Beijing Olympics were at the forefront of our minds. We’d put our heads together previously for the Athens’ Games strategy where we had arrived at the position that the best precooling strategy possible, was a combining a plunge pool maneuver with an ice jacket to retain body coolness. Beijing, expected to be just as hot, was up next, and we were still searching for something effective and practical to keep athletes cool. Meanwhile, a sport scientist up in Darwin, named Matt Brearly, was doing some experimentation during his bike rides. Of course, it doesn’t get much hotter in Australia than this place. Very simply, he was looking at what happened to his performance times riding home","PeriodicalId":22565,"journal":{"name":"Temperature: Multidisciplinary Biomedical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88620633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regional brain responses in humans during body heating and cooling","authors":"M. Farrell","doi":"10.1080/23328940.2016.1174794","DOIUrl":"https://doi.org/10.1080/23328940.2016.1174794","url":null,"abstract":"ABSTRACT Functional brain imaging of responses to thermal challenge in humans provides a viable method to implicate widespread neuroanatomical regions in the processes of thermoregulation. Thus far, functional neuroimaging techniques have been used infrequently in humans to investigate thermoregulation, although preliminary outcomes have been informative and certainly encourage further forays into this field of enquiry. At this juncture, sustained regional brain activations in response to prolonged changes in body temperature are yet to be definitively characterized, but it would appear that thermoregulatory regions are widely distributed throughout the hemispheres of the human brain. Of those autonomic responses to thermal challenge investigated so far, the loci of associated brainstem responses in human are homologous with other species. However, human imaging studies have also implicated a wide range of forebrain regions in thermal sensations and autonomic responses that extend beyond outcomes reported in other species. There is considerable impetus to continue human functional neuroimaging of thermoregulatory responses because of the unique opportunities presented by the method to survey regions across the whole brain in compliant, conscious participants.","PeriodicalId":22565,"journal":{"name":"Temperature: Multidisciplinary Biomedical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89790633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"To drink or to pour: How should athletes use water to cool themselves?","authors":"N. Morris, O. Jay","doi":"10.1080/23328940.2016.1185206","DOIUrl":"https://doi.org/10.1080/23328940.2016.1185206","url":null,"abstract":"It’s almost that time again. With the 2016 summer Olympics in Rio just around the corner, the season of dreams is upon us. It’s the time when we watch seemingly real life super heroes push themselves to the limit, while bringing back early memories of when we wanted to be those athletes on TV that children look up to. At the Rio games, not only will these super humans compete against each other, they must also contend with the hot and balmy conditions. Some of us, during sporting activities, may be familiar with battling against our own minds and dealing with the oppressive force of the heat, when we would happily accept any measure that alleviates the discomfort of our exertions. With respect to endurance sports in the heat, this relief can come with sipping cool water, spraying our face with a cool mist, or wrapping an ice towel around our necks. The cover photo of this edition of Temperature illustrates a scenario of two elite triathletes, Andrea Hewitt (on the left) and Rachel Klamer (on the right), dousing themselves with water from their bottles in order to cope with both the internal heat they are producing through muscular contractions, and the external heat from the surrounding environment. We sometimes see athletes self-dousing with water, or have done it ourselves, in order to attain an immediate relief from the heat rather than taking the time to drink. But is this a smart move? Shouldn’t we just drink the water instead, or even better – drink iced water? To answer this question, we must consider how much heat we can lose to water in its various forms. The most straightforward way is to do so via conduction following the ingestion of cold water. The amount of heat lost is determined by the temperature difference between the ingested water and the body core, the volume of water drunk, and the specific heat capacity of water, i.e. the amount of heat energy needed to warm up 1 g of water by 1 C, which is 4.184 J/g/ C. We can dramatically increase the amount of heat lost to water by adding ice into the mix, as the amount of heat required to melt ice, known as the latent heat of fusion, is much greater than the specific heat capacity of water at 334 J/g. It is this much greater potential for heat loss that has led to the recent trend of athletes consuming ice slurry drinks, a mixture of shredded ice and water, before or during their athletic activities. Despite this improved potential for heat dissipation, melting ice is still a far cry from the amount of heat we can lose through the evaporation of water, as just one gram of evaporated water results in the liberation of a massive 2430 J of latent heat energy. To put these different cooling strategies into context, we can directly compare heat loss potential with a fixed volume of water (Fig. 1). Assuming a core body temperature of 38 C, drinking one glass (250 ml) of 1 C water would result in a net heat loss of 39 kJ. Whereas if the contents of that glass were changed to half-water and hal","PeriodicalId":22565,"journal":{"name":"Temperature: Multidisciplinary Biomedical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74488497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validation of an ingestible temperature data logging and telemetry system during exercise in the heat","authors":"Gavin Travers, D. Nichols, A. Farooq, S. Racinais, J. Périard","doi":"10.1080/23328940.2016.1171281","DOIUrl":"https://doi.org/10.1080/23328940.2016.1171281","url":null,"abstract":"ABSTRACT Aim: Intestinal temperature telemetry systems are promising monitoring and research tools in athletes. However, the additional equipment that must be carried to continuously record temperature data limits their use to training. The purpose of this study was to assess the validity and reliability of a new gastrointestinal temperature data logging and telemetry system (e-Celsius™) during water bath experimentation and exercise trials. Materials and Methods: Temperature readings of 23 pairs of e-Celsius (TeC) and VitalSense (TVS) ingestible capsules were compared to rectal thermistor responses (Trec) at 35, 38.5 and 42°C in a water bath. Devices were also assessed in vivo during steady-state cycling (n = 11) and intermittent running (n = 11) in hot conditions. Results: The water bath experiment showed TVS and TeC under-reported Trec (P<0.001). This underestimation of Trec also occurred during both cycling (mean bias vs TVS: 0.21°C, ICC: 0.84, 95% CI: 0.66–0.91; mean bias vs. TeC: 0.44°C, ICC: 0.68, 95% CI: 0.07–0.86, P<0.05) and running trials (mean bias vs. TVS: 0.15°C, ICC: 0.92, 95% CI: 0.83–0.96; mean bias vs. TeC: 0.25, ICC: 0.86, 95% CI: 0.61–0.94, P<0.05). However, calibrating the devices attenuated this difference during cycling and eliminated it during running. During recovery following cycling exercise, TeC and TVS were significantly lower than Trec despite calibration (P<0.01). Conclusion: These results indicate that both TeC and TVS under-report Trec during steady-state and intermittent exercise in the heat, with TeC predicting Trec with the least accuracy of the telemetry devices. It is therefore recommended to calibrate these devices at multiple temperatures prior to use.","PeriodicalId":22565,"journal":{"name":"Temperature: Multidisciplinary Biomedical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80794431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The link between autonomic and behavioral thermoregulation","authors":"B. Kingma","doi":"10.1080/23328940.2016.1168535","DOIUrl":"https://doi.org/10.1080/23328940.2016.1168535","url":null,"abstract":"The human thermoregulatory apparatus has both autonomic and behavioral mechanisms at its disposal. Behavioral mechanisms include changing of clothes, moving to warmer/cooler/shaded areas and changing the environment by operating windows or the thermostat. For autonomous thermoregulation the body relies on metabolic responses to increase heat production, and besides sweating also on cardiovascular responses to increase heat loss and modulation of body tissue insulation. In this edition of Temperature, Schlader et al. identify that the hypoor hypertensive load on the cardiovascular system that is a consequence of autonomous thermoregulation may cause health risks for people that have problems with their heart. This is exemplified by increased mortality during cold spells or heat waves in healthcompromised populations; but also mild thermal challenges can have long lasting effects on systolic blood pressure in older adults. Schlader et al. indicate that instead of undergoing these internal perturbations, the body may minimize the cardiovascular load by behavioral thermoregulation to counteract or even preemptively avoid the thermal challenge. In this particular paper Schlader et al. describe how thermoregulatory behavior, by moving from a cool to a warm environment and vice versa, is preceded by small changes in blood pressure and moderate changes in skin blood flow. Thermal behavior is thus successful in avoiding large internal cardiovascular perturbations in a healthy subpopulation. Noteworthy, behavior initiated with minimal changes to core temperature, and Schlader et al. conclude that distal skin temperature (i.e., fingertip) may be the primary auxiliary signal for the body to initiate cold-defensive behavior. Based on their data a similar conclusion may be drawn for heat-defensive behavior, however, Schlader et al. discuss possible limitations from the methodology and point out that face and neck skin may have a stronger influence on thermal sensation in warm conditions. All in all, the data shows the strong coupling of modest changes to skin temperature in relation to initiation of thermal behavior. Moreover the behavioral thermopreferendum may work out as a second line of defense (after skin blood flow) to minimize the metabolic and water expenditure for body temperature regulation. But what if the thermosensory pathway is impaired, such as in older adults or diabetics? Could a lack of thermoregulatory response add to cardiovascular problems in these populations? The work of Schlader et al. gives clear clues on how to proceed with this matter and the link between autonomous and behavioral thermoregulation may prove critical especially in those populations who have impaired autonomous means of regulating body temperature. For instance, monitoring of temperature and cardiovascular parameters with wearables may be used to inform individuals, or their medical professionals, that they should show thermoregulatory behavior in order to avoid advers","PeriodicalId":22565,"journal":{"name":"Temperature: Multidisciplinary Biomedical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81814788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A continent-wide analysis of the shade requirements of red and western grey kangaroos","authors":"J. Roberts, Graeme Coulson, A. Munn, Michael R. Kearney","doi":"10.1080/23328940.2016.1163452","DOIUrl":"https://doi.org/10.1080/23328940.2016.1163452","url":null,"abstract":"ABSTRACT Foraging time may be constrained by a suite of phenomena including weather, which can restrict a species' activity and energy intake. This is recognized as pivotal for many species whose distributions are known to correlate with climate, including kangaroos, although such impacts are rarely quantified. We explore how differences in shade seeking, a thermoregulatory behavior, of 2 closely-related kangaroo species, Macropus rufus (red kangaroos) and M. fuliginosus (western grey kangaroos), might reflect differences in their distributions across Australia. We observed foraging and shade-seeking behavior in the field and, together with local weather observations, calculated threshold radiant temperatures (based on solar and infrared radiant heat loads) over which the kangaroos retreated to shade. We apply these calculated tolerance thresholds to hourly microclimatic estimates derived from daily-gridded weather data to predict activity constraints across the Australian continent over a 10-year period. M. fuliginosus spent more time than M. rufus in the shade (7.6 ± 0.7 h versus 6.4 ± 0.9 h) and more time foraging (11.8 ± 0.5 h vs. 10.0 ± 0.6 h), although total time resting was equivalent (∼8.2 h). M. rufus tolerated 19°C higher radiant temperatures than M. fuliginosus (89°C versus 70°C radiant temperature). Across Australia, we predicted M. fuliginosus to be more restricted to shade than M. rufus, with higher absolute shade requirements farther north. These results corroborate previous findings that M. rufus is more adept at dealing with heat than M. fuliginosus and indicate that M. rufus is less dependent on shade on a continental scale.","PeriodicalId":22565,"journal":{"name":"Temperature: Multidisciplinary Biomedical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85126068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-thermal modulation of sudomotor function during static exercise and the impact of intensity and muscle-mass recruitment","authors":"C. Gordon, Joanne N. Caldwell, N. A. Taylor","doi":"10.1080/23328940.2016.1176102","DOIUrl":"https://doi.org/10.1080/23328940.2016.1176102","url":null,"abstract":"ABSTRACT Aim: Static muscle activation elicits intensity-dependent, non-thermal sweating that is presumably controlled by feedforward (central command) mechanisms. However, it is currently unknown how the size of the recruited muscle mass interacts with that mechanism. To investigate the possible muscle-size dependency of that non-thermal sweating, the recruitment of two muscle groups of significantly different size was investigated in individuals within whom steady-state thermal sweating had been established and clamped. Methods: Fourteen passively heated subjects (climate chamber and water-perfusion garment) performed 60-s, static handgrip and knee-extension activations at 30% and 50% of maximal voluntary force, plus a handgrip at 40% intensity (143.4 N) and a third knee extension at the same absolute force. Local sweating from four body segments (averaged to represent whole-body sudomotor activity), three deep-body and eight skin temperatures, heart rates and perceptions of physical effort were measured continuously, and analyzed over the final 30 s of exercise. Results: In the presence of thermal clamping and low-level, steady-state sweating, static muscle activation resulted in exercise-intensity dependent changes in the whole-body sudomotor response during these handgrip and knee-extension actions (P < 0.05). However, there was no evidence of a dependency on the size of the recruited muscle mass (P > 0.05), yet both dependencies were apparent for heart rate, and partially evident for the sensations of physical effort. Conclusion: These observations represent the first evidence that exercise-related sudomotor feedforward is not influenced by the size of the activated muscle mass, but is instead primarily dictated by the intensity of the exercise itself.","PeriodicalId":22565,"journal":{"name":"Temperature: Multidisciplinary Biomedical Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79206954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}