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Pesquisa : G07.110.232.889 [Categoria DeCS]
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  1 / 105 MEDLINE  
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[PMID]:29045417
[Au] Autor:Siutz C; Nemeth M; Wagner KH; Quint R; Ruf T; Millesi E
[Ad] Endereço:Department of Behavioural Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria.
[Ti] Título:Effects of food store quality on hibernation performance in common hamsters.
[So] Source:PLoS One;12(10):e0185913, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Hibernating animals can adjust torpor expression according to available energy reserves. Besides the quantity, the quality of energy reserves could play an important role for overwintering strategies. Common hamsters are food-storing hibernators and show high individual variation in hibernation performance, which might be related to the quality of food hoards in the hibernacula. In this study, we tested the effects of food stores high in fat content, particularly polyunsaturated fatty acids (PUFAs), on hibernation patterns under laboratory conditions. Control animals received standard rodent pellets only, while in the other group pellets were supplemented with sunflower seeds. We recorded body temperature during winter using subcutaneously implanted data loggers, documented total food consumption during winter, and analysed PUFA proportions in white adipose tissue (WAT) before and after the winter period. About half of the individuals in both groups hibernated and torpor expression did not differ between these animals. Among the high-fat group, however, individuals with high sunflower seeds intake strongly reduced the time spent in deep torpor. PUFA proportions in WAT decreased during winter in both groups and this decline was positively related to the time an individual spent in deep torpor. Sunflower seeds intake dampened the PUFA decline resulting in higher PUFA levels in animals of the high-fat group after winter. In conclusion, our results showed that common hamsters adjusted torpor expression and food intake in relation to the total energy of food reserves, underlining the importance of food hoard quality on hibernation performance.
[Mh] Termos MeSH primário: Ingestão de Alimentos/fisiologia
Hibernação/fisiologia
[Mh] Termos MeSH secundário: Tecido Adiposo Branco/metabolismo
Animais
Peso Corporal
Cricetinae
Dieta Hiperlipídica
Ácidos Graxos Insaturados/metabolismo
Feminino
Sementes
Fatores de Tempo
Torpor/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Fatty Acids, Unsaturated)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171019
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0185913


  2 / 105 MEDLINE  
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[PMID]:29023516
[Au] Autor:Cubuk C; Markowsky H; Herwig A
[Ad] Endereço:Zoologisches Institut, Universität Hamburg, Hamburg, Germany.
[Ti] Título:Hypothalamic control systems show differential gene expression during spontaneous daily torpor and fasting-induced torpor in the Djungarian hamster (Phodopus sungorus).
[So] Source:PLoS One;12(10):e0186299, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Djungarian hamsters are able to use spontaneous daily torpor (SDT) during the winter season as well as fasting-induced torpor (FIT) at any time of the year to cope with energetically challenging environmental conditions. Torpor is a state of severely reduced metabolism with a pronounced decrease in body temperature, which enables animals to decrease their individual energy requirements. Despite sharing common characteristics, such as reduced body mass before first torpor expression and depressed metabolism and body temperature during the torpid state, FIT and SDT differ in several physiological properties including torpor bout duration, minimal body temperature, fuel utilization and circadian organization. It remains unclear, whether SDT and FIT reflect the same phenomenon or two different physiological states. The hypothalamus has been suggested to play a key role in regulating energy balance and torpor. To uncover differences in molecular control mechanisms of torpor expression, we set out to investigate hypothalamic gene expression profiles of genes related to orexigenic (Agrp/Npy), circadian clock (Bmal1/Per1) and thyroid hormone (Dio2/Mct8) systems of animals undergoing SDT and FIT during different torpor stages. Orexigenic genes were mainly regulated during FIT and remained largely unaffected by SDT. Expression patterns of clock genes showed disturbed circadian clock rhythmicity in animals undergoing FIT, but not in animals undergoing SDT. During both, SDT and FIT, decreased Dio2 expression was detected, indicating reduced hypothalamic T3 availability in both types of torpor. Taken together, our results provide evidence that SDT and FIT also differ in certain central control mechanisms and support the observation that animals undergoing SDT are in energetical balance, whereas animals undergoing FIT display a negative energy balance. This should be carefully taken into account when interpreting data in torpor research, especially from animal models of fasting-induced hypometabolism such as mice.
[Mh] Termos MeSH primário: Hipotálamo/metabolismo
Phodopus/metabolismo
Torpor/fisiologia
[Mh] Termos MeSH secundário: Fatores de Transcrição ARNTL/genética
Fatores de Transcrição ARNTL/metabolismo
Proteína Relacionada com Agouti/genética
Proteína Relacionada com Agouti/metabolismo
Animais
Temperatura Corporal
Ritmo Circadiano/genética
Cricetinae
Metabolismo Energético
Jejum
Iodeto Peroxidase/genética
Iodeto Peroxidase/metabolismo
RNA/química
RNA/isolamento & purificação
RNA/metabolismo
RNA Mensageiro/metabolismo
Reação em Cadeia da Polimerase em Tempo Real
Análise de Sequência de DNA
Transcriptoma
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (ARNTL Transcription Factors); 0 (Agouti-Related Protein); 0 (RNA, Messenger); 63231-63-0 (RNA); EC 1.11.1.- (iodothyronine deiodinase type II); EC 1.11.1.8 (Iodide Peroxidase)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171024
[Lr] Data última revisão:
171024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171013
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0186299


  3 / 105 MEDLINE  
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[PMID]:28551285
[Au] Autor:Hyams Y; Paz G; Rabinowitz C; Rinkevich B
[Ad] Endereço:Israel Oceanographic and Limnological Research, National Institute of Oceanography, P.O. Box 8030, Tel Shikmona, Haifa 31080, Israel; Marine Biology Department, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa 31905, Israel. Electronic address: yo-chyams@hotmail.com.
[Ti] Título:Insights into the unique torpor of Botrylloides leachi, a colonial urochordate.
[So] Source:Dev Biol;428(1):101-117, 2017 08 01.
[Is] ISSN:1095-564X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Rough environmental conditions make the survival of many multi-cellular organisms almost impossible, enforcing behavioral, morphological, physiological and reproductive rejoinders that can cope with harsh times and hostile environments, frequently through down-regulation of metabolism into basal states of dormancy, or torpor. This study examines one of the most unique torpor strategies seen within the phylum Chordata, exhibited by the colonial urochordate Botrylloides leachi, which enters a state of hibernation or aestivation in response to thermal stress, during which all of its functional colonial units (zooids) are entirely absorbed and the colony survives as small remnants of the vasculature, lacking both feeding and reproduction organs. Tissue vestiges then regenerate fully functional colony when re-exposed to milder environmental conditions. The whole metamorphic cycle of hibernation and arousal was studied here and divided into seven major stages, during which the anatomical characteristics of the zooids, the blood cell populations and the expression patterns of some "stem cell" markers were monitored. The first two phases are associated with the shortening of the blastogenic cycles from the typical 7-day cycle to 3-5day long cycles and with the significant diminution of zooids, leaving a carpet of vasculature. During hibernation this colonial carpet is made of a twisted, opaque and condensed mass of vasculature, loaded with condensed masses of blood cells that possess two types of multicellular structures, the 20-50µm "morula-like" opaque balls of cells, and small single-layer epithelial spheres, "blastula-like" structures (50-80µm). Arousal from hibernation starts with the emergence of several clear tunic areas among the vasculature lacunae, which then turn into transparent buds that become progressively larger and opaque. This is followed by sluggish, newfangled cell movement within the vasculature, which increases in intensity and rate over time. A closer examination of the vasculature revealed dramatic vicissitudes in the blood cell constituency as hibernation progressed, which is manifested by the appearance of two novel cell types not recorded in regular colonies, the multinucleate cells (MNC) and storage cells, each with 2-3 distinct cell morphs. Using mixtures of pre-labeled where half stained with a florescent marker for membranes and half stained for DNA we recorded within 2-3 days from onset new MNC stained by both staining, attesting for the de novo formation of MNC through cells fusion. At the outset of hibernation we documented high expression levels of PIWI, PL-10 and PCNA in cells residing in cell islands (CIs), which are the specific stem cell niches found along the endostyle at the ventral side of the zooids. During hibernation, most of the PIWI / PL-10 /PCNA cells were the MNCs, now located in the newly shaped and dilated vasculature, where they increased in numbers. Also, most of the PCNA cells were identified as MNCs. We further documented that the Bl-PIWI RNA (in situ hybridization) and protein (immunohistochemistry) expressions documented during the hibernation/arousal processes diverged significantly from normal blastogenesis expressions. Counting PIWI blood cells at various blastogenic stages revealed a significant increase as the hibernation progressed, peaking in aroused colonies at an average of 30 PIWI cells/ampulla. The Pl-10 protein expression patterns in the zooids and buds changed as the hibernation progressed, similar to the PIWI and PCNA expressions. Considering the evolutionary perspectives to hibernation we propose linkages to the disposable-soma theory.
[Mh] Termos MeSH primário: Regeneração/fisiologia
Células-Tronco/fisiologia
Torpor/fisiologia
Urocordados/fisiologia
[Mh] Termos MeSH secundário: Animais
Proteínas Argonauta/metabolismo
RNA Helicases DEAD-box/metabolismo
Temperatura Alta
Antígeno Nuclear de Célula em Proliferação/metabolismo
Urocordados/citologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Argonaute Proteins); 0 (Proliferating Cell Nuclear Antigen); EC 3.6.4.13 (DEAD-box RNA Helicases)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171111
[Lr] Data última revisão:
171111
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170529
[St] Status:MEDLINE


  4 / 105 MEDLINE  
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[PMID]:28402233
[Au] Autor:Boyles JG; Bennett NC; Mohammed OB; Alagaili AN
[Ad] Endereço:1 Cooperative Wildlife Research Laboratory, Department of Zoology, Southern Illinois University, Carbondale, Illinois.
[Ti] Título:Torpor Patterns in Desert Hedgehogs (Paraechinus aethiopicus) Represent Another New Point along a Thermoregulatory Continuum.
[So] Source:Physiol Biochem Zool;90(4):445-452, 2017 Jul/Aug.
[Is] ISSN:1537-5293
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Documenting variation in thermoregulatory patterns across phylogenetically and geographically diverse taxa is key to understanding the evolution of endothermy and heterothermy in birds and mammals. We recorded body temperature (T ) in free-ranging desert hedgehogs (Paraechinus aethiopicus) across three seasons in the deserts of Saudi Arabia. Modal T 's (35°-36.5°C) were slightly below normal for mammals but still warmer than those of other hedgehogs. The single maximum T recorded was 39.2°C, which is cooler than maximum T 's recorded in most desert mammals. Desert hedgehogs commonly used torpor during winter and spring but never during summer. Torpor bouts occurred frequently but irregularly, and most lasted less than 24 h. Unlike daily heterotherms, desert hedgehogs did occasionally remain torpid for more than 24 h, including one bout of 101 h. Body temperatures during torpor were often within 2°-3°C of ambient temperature; however, we never recorded repeated bouts of long, predictable torpor punctuated by brief arousal periods similar to those common among seasonal hibernators. Thus, desert hedgehogs can be included on the ever-growing list of species that display torpor patterns intermediate to traditionally defined hibernators and daily heterotherms. Extant hedgehogs are a recent radiation within an ancient family, and the intermediate thermoregulatory pattern displayed by desert hedgehogs is unlike the deeper and more regular torpor seen in other hedgehogs, suggesting that this may be a derived-as opposed to ancestral-trait in this subfamily. We suggest that this family (Erinaceidae) and order (Eulipotyphla) may be important for understanding the evolution of thermoregulatory patterns among Laurasiatheria and mammals in general.
[Mh] Termos MeSH primário: Regulação da Temperatura Corporal/fisiologia
Clima Desértico
Ouriços-Cacheiros/fisiologia
Torpor/fisiologia
[Mh] Termos MeSH secundário: Animais
Feminino
Masculino
Estações do Ano
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170921
[Lr] Data última revisão:
170921
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170413
[St] Status:MEDLINE
[do] DOI:10.1086/691542


  5 / 105 MEDLINE  
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[PMID]:28356368
[Au] Autor:Douglas TK; Cooper CE; Withers PC
[Ad] Endereço:Department of Environment and Agriculture, Curtin University, Bentley, WA 6845, Australia.
[Ti] Título:Avian torpor or alternative thermoregulatory strategies for overwintering?
[So] Source:J Exp Biol;220(Pt 7):1341-1349, 2017 Apr 01.
[Is] ISSN:1477-9145
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:It is unclear whether torpor really is uncommon amongst passerine birds. We therefore examined body temperature and thermoregulatory strategies of an Austral passerine, the white-browed babbler ( ), which has characteristics related to a high probability of torpor use; it is a sedentary, insectivorous, cooperative breeding species, which we studied during winter in a temperate habitat. Wild, free-living babblers maintained normothermy overnight, even at sub-zero ambient temperatures, with a mean minimum body temperature of 38.5±0.04°C that was independent of minimum black bulb temperature. Physiological variables measured in the laboratory revealed that babblers had a low basal metabolic rate and evaporative water loss, but their body temperature and thermal conductance were typical of those of other birds and they had a typical endothermic response to low ambient temperature. Huddling yielded significant energy savings at low temperatures and a roost nest created a microclimate that buffered against low temperatures. Low basal energy requirements, communal roosting and the insulation of a roost nest confer sufficient energetic benefits, allowing babblers to meet energy requirements without resorting to heterothermia, even in their depauperate, low-productivity landscape, suggesting that passerine birds use alternatives to torpor to balance their energy budgets when possible.
[Mh] Termos MeSH primário: Regulação da Temperatura Corporal
Passeriformes/fisiologia
Torpor
[Mh] Termos MeSH secundário: Animais
Metabolismo Basal
Temperatura Corporal
Estações do Ano
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170908
[Lr] Data última revisão:
170908
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170331
[St] Status:MEDLINE
[do] DOI:10.1242/jeb.154633


  6 / 105 MEDLINE  
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[PMID]:28356365
[Au] Autor:Munro D; Treberg JR
[Ad] Endereço:Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada R3T 2N2.
[Ti] Título:A radical shift in perspective: mitochondria as regulators of reactive oxygen species.
[So] Source:J Exp Biol;220(Pt 7):1170-1180, 2017 Apr 01.
[Is] ISSN:1477-9145
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Mitochondria are widely recognized as a source of reactive oxygen species (ROS) in animal cells, where it is assumed that over-production of ROS leads to an overwhelmed antioxidant system and oxidative stress. In this Commentary, we describe a more nuanced model of mitochondrial ROS metabolism, where integration of ROS production with consumption by the mitochondrial antioxidant pathways may lead to the regulation of ROS levels. Superoxide and hydrogen peroxide (H O ) are the main ROS formed by mitochondria. However, superoxide, a free radical, is converted to the non-radical, membrane-permeant H O ; consequently, ROS may readily cross cellular compartments. By combining measurements of production and consumption of H O , it can be shown that isolated mitochondria can intrinsically approach a steady-state concentration of H O in the medium. The central hypothesis here is that mitochondria regulate the concentration of H O to a value set by the balance between production and consumption. In this context, the consumers of ROS are not simply a passive safeguard against oxidative stress; instead, they control the established steady-state concentration of H O By considering the response of rat skeletal muscle mitochondria to high levels of ADP, we demonstrate that H O production by mitochondria is far more sensitive to changes in mitochondrial energetics than is H O consumption; this concept is further extended to evaluate how the muscle mitochondrial H O balance should respond to changes in aerobic work load. We conclude by considering how differences in the ROS consumption pathways may lead to important distinctions amongst tissues, along with briefly examining implications for differing levels of activity, temperature change and metabolic depression.
[Mh] Termos MeSH primário: Peróxido de Hidrogênio/metabolismo
Mitocôndrias/metabolismo
Espécies Reativas de Oxigênio/metabolismo
[Mh] Termos MeSH secundário: Animais
Metabolismo Energético
Seres Humanos
Músculo Esquelético/metabolismo
Estresse Oxidativo
Consumo de Oxigênio
Torpor
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Reactive Oxygen Species); BBX060AN9V (Hydrogen Peroxide)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170908
[Lr] Data última revisão:
170908
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170331
[St] Status:MEDLINE
[do] DOI:10.1242/jeb.132142


  7 / 105 MEDLINE  
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[PMID]:28250178
[Au] Autor:Ayala-Berdon J; Vázquez-Fuerte R; Beamonte-Barrientos R; Schondube JE
[Ad] Endereço:Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Apartado Postal 27-3 (Xangari), Morelia, Michoacán 58089, México jorgeayalaberdon@gmail.com.
[Ti] Título:Effect of diet quality and ambient temperature on the use of torpor by two species of neotropical nectar-feeding bats.
[So] Source:J Exp Biol;220(Pt 5):920-929, 2017 Mar 01.
[Is] ISSN:1477-9145
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Neotropical bats use torpor as a strategy to save energy when they experience a low energy intake and/or low ambient temperature ( ). Digestive physiology limits the energy intake of several glossophaginid bats, and could play an important role in the onset of torpor in these tropical animals. We measured the effect that diet quality and had on the use of torpor by the nectar-feeding bats and Captive bats were fed with 5% (low) or 35% (high) sucrose solutions while exposed to two different (17.7 and 23.2°C; low and high ) in four different treatments: (1) high sucrose:high , (2) high sucrose:low , (3) low sucrose:high and (4) low sucrose:low We measured their energy intake, changes in body mass (Δ ) and skin temperature ( ) as response variables. Energy intake (in 10 h) was limited when both species fed on 5% sucrose, but body mass gain was only affected in Energy intake and had a negative effect on the minimum of both species, and Δ affected the time that used torpor. Both species remained normothermic on the high sucrose:high treatment, but used torpor on the other three treatments. Bats used torpor during their resting and activity periods. spent more time in torpor in the low sucrose high treatment, while used this strategy for longer periods of time in the high sucrose low treatment. We found that diet quality and played an important role in the use of torpor by nectar-feeding bats.
[Mh] Termos MeSH primário: Fenômenos Fisiológicos da Nutrição Animal
Quirópteros/fisiologia
Torpor
[Mh] Termos MeSH secundário: Animais
Temperatura Baixa
Dieta
Ingestão de Energia
Comportamento Alimentar
Masculino
Sacarose/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
57-50-1 (Sucrose)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170829
[Lr] Data última revisão:
170829
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170303
[St] Status:MEDLINE
[do] DOI:10.1242/jeb.142422


  8 / 105 MEDLINE  
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[PMID]:28210076
[Au] Autor:Sisa C; Turroni S; Amici R; Brigidi P; Candela M; Cerri M
[Ad] Endereço:Claudia Sisa, Roberto Amici, Matteo Cerri, Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy.
[Ti] Título:Potential role of the gut microbiota in synthetic torpor and therapeutic hypothermia.
[So] Source:World J Gastroenterol;23(3):406-413, 2017 Jan 21.
[Is] ISSN:2219-2840
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Therapeutic hypothermia is today used in several clinical settings, among them the gut related diseases that are influenced by ischemia/reperfusion injury. This perspective paved the way to the study of hibernation physiology, in natural hibernators, highlighting an unexpected importance of the gut microbial ecosystem in hibernation and torpor. In natural hibernators, intestinal microbes adaptively reorganize their structural configuration during torpor, and maintain a mutualistic configuration regardless of long periods of fasting and cold temperatures. This allows the gut microbiome to provide the host with metabolites, which are essential to keep the host immunological and metabolic homeostasis during hibernation. The emerging role of the gut microbiota in the hibernation process suggests the importance of maintaining a mutualistic gut microbiota configuration in the application of therapeutic hypothermia as well as in the development of new strategy such as the use of synthetic torpor in humans. The possible utilization of tailored probiotics to mold the gut ecosystem during therapeutic hypothermia can also be taken into consideration as new therapeutic strategy.
[Mh] Termos MeSH primário: Microbioma Gastrointestinal/fisiologia
Hipotermia Induzida
Enteropatias/terapia
Simbiose/fisiologia
Torpor/fisiologia
[Mh] Termos MeSH secundário: Animais
Microbioma Gastrointestinal/efeitos dos fármacos
Hibernação/fisiologia
Homeostase/fisiologia
Seres Humanos
Enteropatias/microbiologia
Intestinos/microbiologia
Probióticos/uso terapêutico
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170717
[Lr] Data última revisão:
170717
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170218
[St] Status:MEDLINE
[do] DOI:10.3748/wjg.v23.i3.406


  9 / 105 MEDLINE  
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[PMID]:28168294
[Au] Autor:Vyazovskiy VV; Palchykova S; Achermann P; Tobler I; Deboer T
[Ad] Endereço:Department of Physiology, Anatomy and Genetics, University of Oxford, OX1 3PT Oxford, UK.
[Ti] Título:Different Effects of Sleep Deprivation and Torpor on EEG Slow-Wave Characteristics in Djungarian Hamsters.
[So] Source:Cereb Cortex;27(2):950-961, 2017 Feb 01.
[Is] ISSN:1460-2199
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:It has been shown previously in Djungarian hamsters that the initial electroencephalography (EEG) slow-wave activity (power in the 0.5-4.0 Hz band; SWA) in non-rapid eye movement (NREM) sleep following an episode of daily torpor is consistently enhanced, similar to the SWA increase after sleep deprivation (SD). However, it is unknown whether the network mechanisms underlying the SWA increase after torpor and SD are similar. EEG slow waves recorded in the neocortex during sleep reflect synchronized transitions between periods of activity and silence among large neuronal populations. We therefore set out to investigate characteristics of individual cortical EEG slow waves recorded during NREM sleep after 4 h SD and during sleep after emergence from an episode of daily torpor in adult male Djungarian hamsters. We found that during the first hour after both SD and torpor, the SWA increase was associated with an increase in slow-wave incidence and amplitude. However, the slopes of single slow waves during NREM sleep were steeper in the first hour after SD but not after torpor, and, in contrast to sleep after SD, the magnitude of change in slopes after torpor was unrelated to the changes in SWA. Furthermore, slow-wave slopes decreased progressively within the first 2 h after SD, while a progressive increase in slow-wave slopes was apparent during the first 2 h after torpor. The data suggest that prolonged waking and torpor have different effects on cortical network activity underlying slow-wave characteristics, while resulting in a similar homeostatic sleep response of SWA. We suggest that sleep plays an important role in network homeostasis after both waking and torpor, consistent with a recovery function for both states.
[Mh] Termos MeSH primário: Córtex Cerebral/fisiopatologia
Privação do Sono/fisiopatologia
Sono/fisiologia
Torpor/fisiologia
[Mh] Termos MeSH secundário: Animais
Eletrodos Implantados
Eletroencefalografia
Eletromiografia
Homeostase/fisiologia
Masculino
Phodopus
Processamento de Sinais Assistido por Computador
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170425
[Lr] Data última revisão:
170425
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170208
[St] Status:MEDLINE
[do] DOI:10.1093/cercor/bhx020


  10 / 105 MEDLINE  
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[PMID]:28100803
[Au] Autor:Stawski C; Nowack J; Körtner G; Geiser F
[Ad] Endereço:Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia cstawsk2@une.edu.au.
[Ti] Título:A new cue for torpor induction: charcoal, ash and smoke.
[So] Source:J Exp Biol;220(Pt 2):220-226, 2017 Jan 15.
[Is] ISSN:1477-9145
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Recent work has shown that the use of torpor for energy conservation increases after forest fires in heterothermic mammals, probably in response to the reduction of food. However, the specific environmental cues for this increased torpor expression remain unknown. It is possible that smoke and the novel substrate of charcoal and ash act as signals for an impending period of starvation requiring torpor. We therefore tested the hypothesis that the combined cues of smoke, a charcoal/ash substrate and food shortage will enhance torpor expression in a small forest-dwelling marsupial, the yellow-footed antechinus (Antechinus flavipes), because like other animals that live in fire-prone habitats they must effectively respond to fires to ensure survival. Activity and body temperature patterns of individuals in outdoor aviaries were measured under natural environmental conditions. All individuals were strictly nocturnal, but diurnal activity was observed shortly after smoke exposure. Overall, torpor in females was longer and deeper than that in males. Interestingly, while both males and females increased daily torpor duration during food restriction by >2-fold as anticipated, a combination of food restriction and smoke exposure on a charcoal/ash substrate further increased daily torpor duration by ∼2-fold in both sexes. These data show that this combination of cues for torpor induction is stronger than food shortage on its own. Our study provides significant new information on how a small forest-dwelling mammal responds to fire cues during and immediately after a fire and identifies a new, not previously recognised, regulatory mechanism for thermal biology in mammals.
[Mh] Termos MeSH primário: Sinais (Psicologia)
Marsupiais/fisiologia
Torpor
[Mh] Termos MeSH secundário: Animais
Carvão Vegetal/análise
Feminino
Privação de Alimentos
Masculino
Fumaça/análise
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Smoke); 16291-96-6 (Charcoal)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170120
[St] Status:MEDLINE
[do] DOI:10.1242/jeb.146548



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