scholarly journals Modelling the emergence of rodent filial huddling from physiological huddling

2017 ◽  
Vol 4 (11) ◽  
pp. 170885 ◽  
Author(s):  
Stuart P. Wilson
Keyword(s):  
Simple Model ◽  
Associative Learning ◽  
Fat Tissue ◽  
Ambient Temperatures ◽  
Thermodynamic Entropy ◽  
Brown Adipose ◽  
Metabolic Costs ◽  
Social Ordering ◽  
Olfactory Preferences ◽  
Existing Data

Huddling behaviour in neonatal rodents reduces the metabolic costs of physiological thermoregulation. However, animals continue to huddle into adulthood, at ambient temperatures where they are able to sustain a basal metabolism in isolation from the huddle. This ‘filial huddling’ in older animals is known to be guided by olfactory rather than thermal cues. The present study aimed to test whether thermally rewarding contacts between young mice, experienced when thermogenesis in brown adipose fat tissue (BAT) is highest, could give rise to olfactory preferences that persist as filial huddling interactions in adults. To this end, a simple model was constructed to fit existing data on the development of mouse thermal physiology and behaviour. The form of the model that emerged yields a remarkable explanation for filial huddling; associative learning maintains huddling into adulthood via processes that reduce thermodynamic entropy from BAT metabolism and increase information about social ordering among littermates.

Energy intake and fur in summer- and winter-acclimated Siberian hamsters (Phodopus sungorus)

2001 ◽  
Vol 281 (2) ◽  
pp. R519-R527 ◽  
Author(s):  
Alexander S. Kauffman ◽  
Alessandra Cabrera ◽  
Irving Zucker
Keyword(s):  
Food Intake ◽  
Energy Intake ◽  
Ventral Surface ◽  
Phodopus Sungorus ◽  
Ambient Temperatures ◽  
Siberian Hamsters ◽  
Daily Food ◽  
Brown Adipose ◽  
Wide Range ◽  
The Impact

Few studies have directly addressed the impact of fur on seasonal changes in energy intake. The daily food intake of Siberian hamsters ( Phodopus sungorus) was measured under simulated summer and winter conditions in intact animals and those with varying amounts of pelage removed. Energy intake increased up to 44% above baseline control values for approximately 2–3 wk after complete shaving. Increases in food intake varied with condition and were greater in hamsters housed in short than long day lengths and at low (5°C) than moderate (23°C) ambient temperatures. Removal of 8 cm2 of dorsal fur, equivalent to 30% of the total dorsal fur surface, increased food intake, but removal of 4 cm2 had no effect. An 8-cm2 fur extirpation from the ventral surface did not increase food consumption. Food intake was not influenced differentially by fur removal from above brown adipose tissue hot spots. Fur plays a greater role in energy balance in winter- than summer-acclimated hamsters and conserves energy under a wide range of environmental conditions.

GDP binding to rat brown fat mitochondria: effects of thyroxine at different ambient temperatures

1981 ◽  
Vol 241 (3) ◽  
pp. C134-C139 ◽  
Author(s):  
U. Sundin
Keyword(s):  
Linear Increase ◽  
Reciprocal Relationship ◽  
Brown Fat ◽  
Hormone Activity ◽  
Ambient Temperatures ◽  
Heating Capacity ◽  
Brown Adipose ◽  
Induced Changes ◽  
Brown Fat Mitochondria

Reports on a reciprocal relationship between sympathetic-nerve and experimentally induced changes in thyroid-hormone activity called into question the proposed role of thyroxine in the changes seen in the brown fat after cold adaptation. Rats reared at +30, +22, and +5 degrees C received daily injections of thyroxine (1 mg/kg). After 3 wk of treatment, the thermogenic state of the tissue was assessed by measuring the capacity of the brown fat mitochondria to bind guanosine 5'-diphosphate (GDP). GDP-inhibited mitochondrial swelling, brown adipose tissue (BAT) wet weights, and mitochondrial yields were also measured. The control animals showed a linear increase in GDP binding between +30 and +5 degrees C. Thyroxine was found to lower the GDP binding markedly at +5 degrees C, less so at +22 degrees C, while no effect was evident at +30 degrees C. The values at +22 and +30 degrees C were identical. The other parameters studied all confirmed these results. The conclusion made is that the thyroxine-induced rise in basal metabolic rate lowers the critical temperature and reduces the demand for nonshivering thermogenesis. This is reflected in the reduced GDP binding and hence heating capacity of the brown fat mitochondria.

Characterization and regulation of cold-induced heat shock protein expression in mouse brown adipose tissue

1995 ◽  
Vol 269 (1) ◽  
pp. R38-R47 ◽  
Author(s):  
J. M. Matz ◽  
M. J. Blake ◽  
H. M. Tatelman ◽  
K. P. Lavoi ◽  
N. J. Holbrook
Keyword(s):  
Adipose Tissue ◽  
Heat Shock ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Elevated Temperatures ◽  
Uncoupling Protein ◽  
Hsp70 Expression ◽  
Mitochondrial Uncoupling ◽  
Ambient Temperatures ◽  
Brown Adipose

The accumulation of heat shock proteins (HSPs) after the exposure of cells or organisms to elevated temperatures is well established. It is also known that a variety of other environmental and cellular metabolic stressors can induce HSP synthesis. However, few studies have investigated the effect of cold temperature on HSP expression. Here we report that exposure of Institute of Cancer Research (ICR) mice to cold ambient temperatures results in a tissue-selective induction of HSPs in brown adipose tissue (BAT) coincident with the induction of mitochondrial uncoupling protein synthesis. Cold-induced HSP expression is associated with enhanced binding of heat shock transcription factors to DNA, similar to that which occurs after exposure of cells or tissues to heat and other metabolic stresses. Adrenergic receptor antagonists were found to block cold-induced HSP70 expression in BAT, whereas adrenergic agonists induced BAT HSP expression in the absence of cold exposure. These findings suggest that norepinephrine, released in response to cold exposure, induces HSP expression in BAT. Norepinephrine appears to initiate transcription of HSP genes after binding to BAT adrenergic receptors through, as yet, undetermined signal transduction pathways. Thermogenesis results from an increase in activity and synthesis of several metabolic enzymes in BAT of animals exposed to cold challenge. The concomitant increase in HSPs may function to facilitate the translocation and activity of the enzymes involved in this process.

scholarly journals Development of homeothermic endothermy is delayed in high-altitude native deer mice ( Peromyscus maniculatus)

2019 ◽  
Vol 286 (1907) ◽  
pp. 20190841 ◽  
Author(s):  
Cayleih E. Robertson ◽  
Glenn J. Tattersall ◽  
Grant B. McClelland
Keyword(s):  
High Altitude ◽  
Peromyscus Maniculatus ◽  
Common Garden ◽  
Deer Mice ◽  
Ambient Temperatures ◽  
Equivalent Age ◽  
Brown Adipose ◽  
Challenging Environment ◽  
Sympathetic Regulation ◽  
Saving Measure

Altricial mammals begin to independently thermoregulate during the first few weeks of postnatal development. In wild rodent populations, this is also a time of high mortality (50–95%), making the physiological systems that mature during this period potential targets for selection. High altitude (HA) is a particularly challenging environment for small endotherms owing to unremitting low O 2 and ambient temperatures. While superior thermogenic capacities have been demonstrated in adults of some HA species, it is unclear if selection has occurred to survive these unique challenges early in development. We used deer mice ( Peromyscus maniculatus ) native to high and low altitude (LA), and a strictly LA species ( Peromyscus leucopus ), raised under common garden conditions, to determine if postnatal onset of endothermy and maturation of brown adipose tissue (BAT) is affected by altitude ancestry. We found that the onset of endothermy corresponds with the maturation and activation of BAT at an equivalent age in LA natives, with 10-day-old pups able to thermoregulate in response to acute cold in both species. However, the onset of endothermy in HA pups was substantially delayed (by approx. 2 days), possibly driven by delayed sympathetic regulation of BAT. We suggest that this delay may be part of an evolved cost-saving measure to allow pups to maintain growth rates under the O 2 -limited conditions at HA.

scholarly journals Gqα/G11α deficiency in dorsomedial hypothalamus leads to obesity resulting from decreased energy expenditure and impaired sympathetic nerve activity

2020 ◽  
Author(s):  
Eric A. Wilson ◽  
Hui Sun ◽  
Zhenzhong Cui ◽  
Marshal T. Jahnke ◽  
Mritunjay Pandey ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Food Intake ◽  
Energy Expenditure ◽  
Energy Homeostasis ◽  
Dorsomedial Hypothalamus ◽  
Ambient Temperatures ◽  
Brown Adipose ◽  
Inhibit Food Intake ◽  
Specific Deletion

The G protein subunits Gqα and G11α (Gq/11α) couple receptors to phospholipase C, leading to increased intracellular calcium. In this study we investigated the consequences of Gq/11α deficiency in the dorsomedial hypothalamus (DMH), a critical site for the control of energy homeostasis. Mice with DMH-specific deletion of Gq/11α (DMHGq/11KO) were generated by stereotaxic injection of AAV-Cre-GFP into the DMH of Gqαflox/flox:G11α-/- mice. Compared to control mice that received DMH injection of AAV-GFP, DMHGq/11KO mice developed obesity associated with reduced energy expenditure without significant changes in food intake or physical activity. DMHGq/11KO mice showed no defects in the ability of the melanocortin agonist melanotan II to acutely stimulate energy expenditure or to inhibit food intake. At room temperature (22oC) DMHGq/11KO mice showed reduced sympathetic nervous system activity in brown adipose tissue (BAT) and heart, accompanied with decreased basal BAT Ucp1 gene expression and lower heart rates. These mice were cold intolerant when acutely exposed to cold (6oC for 5 hours) and had decreased cold-stimulated BAT Ucp1 gene expression. DMHGq/11KO mice also failed to adapt to gradually declining ambient temperatures and to develop adipocyte browning in inguinal white adipose tissue although their BAT Ucp1 was proportionally stimulated. Consistent with impaired cold-induced thermogenesis, the onset of obesity in DMHGq/11KO mice was significantly delayed when housed under thermoneutral conditions (30ºC). Thus, our results show that Gqα and G11α in the DMH are required for the control of energy homeostasis by stimulating energy expenditure and thermoregulation.

scholarly journals Taurine Stimulates Thermoregulatory Genes in Brown Fat Tissue and Muscle without an Influence on Inguinal White Fat Tissue in a High-Fat Diet-Induced Obese Mouse Model

Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 688 ◽  
Author(s):  
Kyoung Soo Kim ◽  
Hari Madhuri Doss ◽  
Hee-Jin Kim ◽  
Hyung-In Yang
Keyword(s):  
Adipose Tissue ◽  
Mouse Model ◽  
High Fat Diet ◽  
Fat Deposition ◽  
Chow Diet ◽  
Fat Tissue ◽  
High Fat ◽  
Taurine Supplementation ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose

This study was conducted to investigate if taurine supplementation stimulates the induction of thermogenic genes in fat tissues and muscles and decipher the mechanism by which taurine exerts its anti-obesity effect in a mildly obese ICR (CD-1®) mouse model. Three groups of ICR mice were fed a normal chow diet, a high-fat diet (HFD), or HFD supplemented with 2% taurine in drinking water for 28 weeks. The expression profiles of various genes were analyzed by real time PCR in interscapular brown adipose tissue (BAT), inguinal white adipose tissue (iWAT), and the quadriceps muscles of the experimental groups. Genes that are known to regulate thermogenesis like PGC-1α, UCP-1, Cox7a1, Cox8b, CIDE-A, and β1-, β2-, and β3-adrenergic receptors (β-ARs) were found to be differentially expressed in the three tissues. These genes were expressed at a very low level in iWAT as compared to BAT and muscle. Whereas, HFD increased the expression of these genes. Taurine supplementation stimulated the expression of UCP-1, Cox7a1, and Cox8b in BAT and only Cox7a1 in muscle, while there was a decrease in iWAT. In contrast, fat deposition-related genes, monoamine oxidases (MAO)-A, and -B, and lipin-1, were decreased by taurine supplementation only in iWAT and not in BAT or muscle. In conclusion, the potential anti-obesity effects of taurine may be partly due to upregulated thermogenesis in BAT, energy metabolism of muscle, and downregulated fat deposition in iWAT.

Cold-defense function of brown adipose tissue during sleep

1993 ◽  
Vol 265 (5) ◽  
pp. R1060-R1064 ◽  
Author(s):  
M. Calasso ◽  
E. Zantedeschi ◽  
P. L. Parmeggiani
Keyword(s):  
Adipose Tissue ◽  
Ambient Temperature ◽  
Brown Adipose Tissue ◽  
Nasal Mucosa ◽  
Interscapular Brown Adipose Tissue ◽  
Ambient Temperatures ◽  
Brown Adipose ◽  
Before And After ◽  
Defense Function

Rats with chronically implanted electroencephalograph scalp electrodes and thermistors were exposed to 24 and 4 degrees C ambient temperatures during the light hours before and after acclimation to 4 degrees C ambient temperature for 9 days. During synchronized sleep, deep interscapular temperature was higher at 4 degrees C than at 24 degrees C both before and after acclimation to cold. After ablation of brown adipose tissue, deep interscapular temperature was lower at 4 degrees C than at 24 degrees C during synchronized sleep. In the presence of brown adipose tissue, deep interscapular temperature decreased sharply during desynchronized sleep at 4 degrees C both before and after acclimation to cold. This decrease was subsequent to and correlated with an increase in the temperature of the nasal mucosa. The decrease in deep interscapular temperature during desynchronized sleep at 4 degrees C ambient temperature was markedly reduced by ablation of the interscapular brown adipose tissue.

Transcriptome of the subcutaneous adipose tissue in response to oral supplementation of type 2 Leprdb obese diabetic mice with niacin-bound chromium

2006 ◽  
Vol 27 (3) ◽  
pp. 370-379 ◽  
Author(s):  
Cameron Rink ◽  
Sashwati Roy ◽  
Savita Khanna ◽  
Trenton Rink ◽  
Debasis Bagchi ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Blood Glucose ◽  
Specific Gene ◽  
Oral Glucose ◽  
Diabetic Mice ◽  
Fat Tissue ◽  
Obesity And Diabetes ◽  
Brown Adipose

The effects of oral niacin-bound chromium (NBC) supplementation on the subcutaneous fat tissue of type 2 Lepr db obese diabetic mice were examined using high-density comprehensive mouse genome (45,101 probe sets) expression arrays. The influence of such supplementation on the plasma cardiovascular risk factors of these mice was also investigated. Supplementation of NBC had no significant effect on age-dependent weight gain in the Lepr db obese diabetic mice. However, NBC lowered total cholesterol (TC), TC-to-HDL ratio, LDL cholesterol, and triglyceride levels while increasing HDL cholesterol in the blood plasma. No effect of NBC supplementation was observed on fasting blood glucose levels. Oral glucose tolerance test revealed a significantly improved clearance of blood glucose between 1 and 2 h of glucose challenge in NBC-supplemented mice. Unbiased genome-wide interrogation demonstrated that NBC resulted in the upregulation of muscle-specific gene expression in the fat tissue. Genes encoding proteins involved in glycolysis, muscle contraction, muscle metabolism, and muscle development were specifically upregulated in response to NBC supplementation. Genes in the adipose tissue that were downregulated in response to NBC supplementation included cell death-inducing DNA fragmentation factor (CIDEA) and uncoupling protein-1, which represent key components involved in the thermogenic role of brown adipose tissue and tocopherol transfer protein, the primary carrier of α-tocopherol to adipose tissue. The observation that CIDEA-null mice are resistant to obesity and diabetes suggests that the inhibitory role of NBC on CIDEA expression was favorable. Further studies testing the molecular basis of NBC function and long-term outcomes are warranted.

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