Effects of stimulus mode and ambient temperature on cerebral responses to local thermal stimulation: An EEG study

2017 ◽  
Vol 113 ◽  
pp. 17-22 ◽  
Author(s):  
Bin Lv ◽  
Chang Su ◽  
Lei Yang ◽  
Tongning Wu
2000 ◽  
Vol 279 (6) ◽  
pp. R2079-R2088 ◽  
Author(s):  
Hui Gong ◽  
Ronald Szymusiak ◽  
Janice King ◽  
Teresa Steininger ◽  
Dennis McGinty

Preoptic area (POA) neuronal activity promotes sleep, but the localization of critical sleep-active neurons is not completely known. Thermal stimulation of the POA also facilitates sleep. This study used the c-Fos protein immunostaining method to localize POA sleep-active neurons at control (22°C) and mildly elevated (31.5°C) ambient temperatures. At 22°C, after sleep, but not after waking, we found increased numbers of c-Fos immunoreactive neurons (IRNs) in both rostral and caudal parts of the median preoptic nucleus (MnPN) and in the ventrolateral preoptic area (VLPO). In animals sleeping at 31.5°C, significantly more Fos IRNs were found in the rostral MnPN compared with animals sleeping at 22°C. In VLPO, Fos IRN counts were no longer increased over waking levels after sleep at the elevated ambient temperature. Sleep-associated Fos IRNs were also found diffusely in the POA, but counts were lower than those made after waking. This study supports a hypothesis that the MnPN, as well as the VLPO, is part of the POA sleep-facilitating system and that the rostral MnPN may facilitate sleep, particularly at elevated ambient temperatures.


1992 ◽  
Vol 164 (1) ◽  
pp. 39-53
Author(s):  
TAKASHI TOMINAGA ◽  
YUTAKA NAITOH

1. The overall membrane potential response of the ciliate Paramecium caudatum to a rise in the temperature of its environment was depolarizing when the ambient temperature before stimulation (Te) was equal to or higher than the culture temperature (Tc), but hyperpolarizing when Te was lower than Tc. 2. The anterior region of the cell responded to a rise in temperature with a localized membrane depolarization. The posterior region was depolarized when Te was equal to or higher than Tc but hyperpolarized when Te was lower than Tc. The Te-dependent polarity reversal of the posterior response was responsible for the comparable reversal of the overall response. 3. The temperature at which the polarity reversal of the posterior response took place shifted according to Tc. This shift caused a comparable shift in the temperature at which polarity reversal occurred for the overall response. 4. The Te-dependent polarity reversal of the posterior response and its Tc-dependence are major causes of thermoaccumulation mediated by ciliary activity of Paramecium in regions with temperatures close to Tc


Author(s):  
S.W. French ◽  
N.C. Benson ◽  
C. Davis-Scibienski

Previous SEM studies of liver cytoskeletal elements have encountered technical difficulties such as variable metal coating and heat damage which occurs during metal deposition. The majority of studies involving evaluation of the cell cytoskeleton have been limited to cells which could be isolated, maintained in culture as a monolayer and thus easily extracted. Detergent extraction of excised tissue by immersion has often been unsatisfactory beyond the depth of several cells. These disadvantages have been avoided in the present study. Whole C3H mouse livers were perfused in situ with 0.5% Triton X-100 in a modified Jahn's buffer including protease inhibitors. Perfusion was continued for 1 to 2 hours at ambient temperature. The liver was then perfused with a 2% buffered gluteraldehyde solution. Liver samples including spontaneous tumors were then maintained in buffered gluteraldehyde for 2 hours. Samples were processed for SEM and TEM using the modified thicarbohydrazide procedure of Malich and Wilson, cryofractured, and critical point dried (CPD). Some samples were mechanically fractured after CPD.


Author(s):  
S. Mahajan

The evolution of dislocation channels in irradiated metals during deformation can be envisaged to occur in three stages: (i) formation of embryonic cluster free regions, (ii) growth of these regions into microscopically observable channels and (iii) termination of their growth due to the accumulation of dislocation damage. The first two stages are particularly intriguing, and we have attempted to follow the early stages of channel formation in polycrystalline molybdenum, irradiated to 5×1019 n. cm−2 (E > 1 Mev) at the reactor ambient temperature (∼ 60°C), using transmission electron microscopy. The irradiated samples were strained, at room temperature, up to the macroscopic yield point.Figure 1 illustrates the early stages of channel formation. The observations suggest that the cluster free regions, such as A, B and C, form in isolated packets, which could subsequently link-up to evolve a channel.


Author(s):  
Robert C. Rau

Previous work has shown that post-irradiation annealing, at temperatures near 1100°C, produces resolvable dislocation loops in tungsten irradiated to fast (E > 1 MeV) neutron fluences of about 4 x 1019 n/cm2 or greater. To crystallographically characterize these loops, tilting experiments were carried out in the electron microscope on a polycrystalline specimen which had been irradiated to 1.5 × 1021 n/cm2 at reactor ambient temperature (∼ 70°C), and subseouently annealed for 315 hours at 1100°C. This treatment produced large loops averaging 1000 Å in diameter, as shown in the micrographs of Fig. 1. The orientation of this grain was near (001), and tilting was carried out about axes near [100], [10] and [110].


Author(s):  
J. J. Laidler

The presence of three-dimensional voids in quenched metals has long been suspected, and voids have indeed been observed directly in a number of metals. These include aluminum, platinum, and copper, silver and gold. Attempts at the production of observable quenched-in defects in nickel have been generally unsuccessful, so the present work was initiated in order to establish the conditions under which such defects may be formed.Electron beam zone-melted polycrystalline nickel foils, 99.997% pure, were quenched from 1420°C in an evacuated chamber into a bath containing a silicone diffusion pump fluid . The pressure in the chamber at the quenching temperature was less than 10-5 Torr . With an oil quench such as this, the cooling rate is approximately 5,000°C/second above 400°C; below 400°C, the cooling curve has a long tail. Therefore, the quenched specimens are aged in place for several seconds at a temperature which continuously approaches the ambient temperature of the system.


2018 ◽  
Vol 24 (2) ◽  
Author(s):  
PIYUSH MISHRA ◽  
DEVENDRA KUMAR BHATT

Pasta was prepared by incorporation of Ocimum sanctum (Basil) for better textural and sensory properties. The pasta was incorporated with the leaf extract of Ocimum sanctum at different concentrations of control, 5, 10, and 15.The natural antioxidants present in the O. sanctum leaf powder that was incorporated in the fruit leather showed extended shelf-life over three months when compared with control, without any added preservative at ambient temperature. Also the nutritional stability of the product was studied under two flexible packages of polypropylene and polyester out of that the products packed in polypropylene showed better storage stability .


2018 ◽  
Vol 239 (3) ◽  
pp. 313-324 ◽  
Author(s):  
Lewin Small ◽  
Henry Gong ◽  
Christian Yassmin ◽  
Gregory J Cooney ◽  
Amanda E Brandon

One major factor affecting physiology often overlooked when comparing data from animal models and humans is the effect of ambient temperature. The majority of rodent housing is maintained at ~22°C, the thermoneutral temperature for lightly clothed humans. However, mice have a much higher thermoneutral temperature of ~30°C, consequently data collected at 22°C in mice could be influenced by animals being exposed to a chronic cold stress. The aim of this study was to investigate the effect of housing temperature on glucose homeostasis and energy metabolism of mice fed normal chow or a high-fat, obesogenic diet (HFD). Male C57BL/6J(Arc) mice were housed at standard temperature (22°C) or at thermoneutrality (29°C) and fed either chow or a 60% HFD for 13 weeks. The HFD increased fat mass and produced glucose intolerance as expected but this was not exacerbated in mice housed at thermoneutrality. Changing the ambient temperature, however, did alter energy expenditure, food intake, lipid content and glucose metabolism in skeletal muscle, liver and brown adipose tissue. Collectively, these findings demonstrate that mice regulate energy balance at different housing temperatures to maintain whole-body glucose tolerance and adiposity irrespective of the diet. Despite this, metabolic differences in individual tissues were apparent. In conclusion, dietary intervention in mice has a greater impact on adiposity and glucose metabolism than housing temperature although temperature is still a significant factor in regulating metabolic parameters in individual tissues.


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