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https://www.readbyqxmd.com/read/28641050/thrifty-females-frisky-males-winter-energetics-of-hibernating-bats-from-a-cold-climate
#1
Zenon J Czenze, Kristin A Jonasson, Craig K R Willis
Mammalian hibernation consists of energy-saving torpor bouts (periods of controlled reduction in body temperature [Tb]) interspersed with brief arousals to normothermic Tb. Frequency and duration of torpor bouts and arousals can affect winter survival and are thought to be influenced by an optimization balancing the energetic benefits of prolonged torpor against the physiological and ecological costs (e.g., accumulation of metabolic wastes). Female little brown bats (Myotis lucifugus) spend their fat reserves more slowly than males during winter, presumably so they can emerge from hibernation in good condition to initiate pregnancy...
July 2017: Physiological and Biochemical Zoology: PBZ
https://www.readbyqxmd.com/read/28626157/protein-restriction-does-not-affect-body-temperature-pattern-in-female-mice
#2
Goro A Kato, Hiroki Shichijo, Toshihiro Takahashi, Akio Shinohara, Tetsuo Morita, Chihiro Koshimoto
Daily torpor is a physiological adaptation in mammals and birds characterized by a controlled reduction of metabolic rate and body temperature during the resting phase of circadian rhythms. In laboratory mice, daily torpor is induced by dietary caloric restriction. However, it is not known which nutrients are related to daily torpor expression. To determine whether dietary protein is a key factor in inducing daily torpor in mice, we fed mice a protein-restricted (PR) diet that included only one-quarter of the amount of protein but the same caloric level as a control (C) diet...
June 13, 2017: Experimental Animals
https://www.readbyqxmd.com/read/28622494/laryngeal-neuropathy-in-adult-goats-with-copper-deficiency
#3
R F A Sousa, V M Almeida, J E Neto, C W A Nascimento, G X Medeiros, R M T Medeiros, F Riet-Correa, F S Mendonça
The aim of this study was to elucidate the cause of a neurological syndrome characterized by stridor in adult goats with clinical signs of copper deficiency. The main clinical signs consisted of apathy, emaciation, pale mucous membranes, mucous nasal discharge, dyspnea, severe achromotrichia, diffuse alopecia, torpor, ataxia, and stridor. When the goats were forced to move, the stridor increased. In a herd of 194 Toggenburg goats, 10 adult goats with clinical signs of copper deficiency were removed from the herd and divided into 2 groups: group 1, which consisted of 4 nannies and 1 buck with stridor, and group 2, which consisted of 4 nannies and 1 buck without stridor...
July 2017: Veterinary Pathology
https://www.readbyqxmd.com/read/28620354/torpor-the-rise-and-fall-of-3-monoiodothyronamine-from-brain-to-gut-from-gut-to-brain
#4
REVIEW
Hartmut H Glossmann, Oliver M D Lutz
3-Monoiodothyronamine (T1AM), first isolated from rat brain, is reported to be an endogenous, rapidly acting metabolite of thyroxine. One of its numerous effects is the induction of a "torpor-like" state in experimental animals. A critical analysis of T1AM, to serve as an endogenous cryogen, is given. The proposed biosynthetic pathway for formation of T1AM, which includes deiodinases and ornithine decarboxylase in the upper intestinum, is an unusual one. To reach the brain via systemic circulation, enterohepatic recycling and passage through the liver may occur...
2017: Frontiers in Endocrinology
https://www.readbyqxmd.com/read/28614673/pseudogymnoascus-destructans-transcriptome-changes-during-white-nose-syndrome-infections
#5
Sophia M Reeder, Jonathan M Palmer, Jenni M Prokkola, Thomas M Lilley, DeeAnn M Reeder, Kenneth A Field
White nose syndrome (WNS) is caused by the psychrophilic fungus Pseudogymnoascus destructans that can grow in the environment saprotrophically or parasitically by infecting hibernating bats. Infections are pathological in many species of North American bats, disrupting hibernation and causing mortality. To determine what fungal pathways are involved in infection of living tissue, we examined fungal gene expression using RNA-Seq. We compared P. destructans gene expression when grown in culture to that during infection of a North American bat species, Myotis lucifugus, that shows high WNS mortality...
June 14, 2017: Virulence
https://www.readbyqxmd.com/read/28597237/energy-conserving-thermoregulatory-patterns-and-lower-disease-severity-in-a-bat-resistant-to-the-impacts-of-white-nose-syndrome
#6
Marianne S Moore, Kenneth A Field, Melissa J Behr, Gregory G Turner, Morgan E Furze, Daniel W F Stern, Paul R Allegra, Sarah A Bouboulis, Chelsey D Musante, Megan E Vodzak, Matthew E Biron, Melissa B Meierhofer, Winifred F Frick, Jeffrey T Foster, Daryl Howell, Joseph A Kath, Allen Kurta, Gerda Nordquist, Joseph S Johnson, Thomas M Lilley, Benjamin W Barrett, DeeAnn M Reeder
The devastating bat fungal disease, white-nose syndrome (WNS), does not appear to affect all species equally. To experimentally determine susceptibility differences between species, we exposed hibernating naïve little brown myotis (Myotis lucifugus) and big brown bats (Eptesicus fuscus) to the fungus that causes WNS, Pseudogymnoascus destructans (Pd). After hibernating under identical conditions, Pd lesions were significantly more prevalent and more severe in little brown myotis. This species difference in pathology correlates with susceptibility to WNS in the wild and suggests that survival is related to different host physiological responses...
June 8, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28588221/ketogenic-diet-induces-expression-of-the-muscle-circadian-gene-slc25a25-via-neural-pathway-that-might-be-involved-in-muscle-thermogenesis
#7
Reiko Nakao, Shigeki Shimba, Katsutaka Oishi
We recently found that the mRNA expression of Slc25a25, a Ca(2+)-sensitive ATP carrier in the inner mitochondrial membrane, fluctuates in a circadian manner in mouse skeletal muscle. We showed here that the circadian expression of muscle Slc25a25 was damped in Clock mutant, muscle-specific Bmal1-deficient, and global Bmal1-deficient mice. Furthermore, a ketogenic diet (KD) that induces time-of-day-dependent hypothermia (torpor), induced Slc25a25 mRNA expression in skeletal muscle. Hypothermia induced by KD did not affect thermogenic genes such as Sarcolipin and Pgc1a in muscles and Ucp1 in adipose tissues...
June 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28576823/heart-rate-dynamics-in-a-marsupial-hibernator
#8
Steven J Swoap, Gerhard Körtner, Fritz Geiser
The eastern pygmy-possum (Cercartetus nanus) is a small marsupial that can express spontaneous short bouts of torpor, as well as multi-day bouts of deep hibernation. To examine heart rate (HR) control at various stages of torpor in a marsupial hibernator, and to see whether HR variability differs from deep placental hibernators, we used radiotelemetry to measure ECG and Tb while measuring the rate of O2 consumption and ventilation. The HR and rate of O2 consumption during euthermia was at its minimum (321±34 bpm, 0...
June 2, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28551285/insights-into-the-unique-torpor-of-botrylloides-leachi-a-colonial-urochordate
#9
Yosef Hyams, Guy Paz, Claudette Rabinowitz, Baruch Rinkevich
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...
May 25, 2017: Developmental Biology
https://www.readbyqxmd.com/read/28515330/post-fire-recovery-of-torpor-and-activity-patterns-of-a-small-mammal
#10
Clare Stawski, Taylor Hume, Gerhard Körtner, Shannon E Currie, Julia Nowack, Fritz Geiser
To cope with the post-fire challenges of decreased availability of food and shelter, brown antechinus (Antechinus stuartii), a small marsupial mammal, increase the use of energy-conserving torpor and reduce activity. However, it is not known how long it takes for animals to resume pre-fire torpor and activity patterns during the recovery of burnt habitat. Therefore, we tested the hypothesis that antechinus will adjust torpor use and activity after a fire depending on vegetation recovery. We simultaneously quantified torpor and activity patterns for female antechinus from three adjacent areas: (i) the area of a management burn 1 year post-fire, (ii) an area that was burned 2 years prior, and (iii) a control area...
May 2017: Biology Letters
https://www.readbyqxmd.com/read/28484364/energy-homeostasis-in-monotremes
#11
REVIEW
Stewart C Nicol
In 1803, the French anatomist Étienne Geoffroy Saint-Hilaire decided that the newly described echidna and platypus should be placed in a separate order, the monotremes, intermediate between reptiles and mammals. The first physiological observations showed monotremes had low body temperatures and metabolic rates, and the consensus was that they were at a stage of physiological development intermediate between "higher mammals" and "lower vertebrates." Subsequent studies demonstrated that platypuses and echidnas are capable of close thermoregulation in the cold although less so under hot conditions...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28473298/maintenance-of-neural-activities-in-torpid-rhinolophus-ferrumequinum-bats-revealed-by-2d-gel-based-proteome-analysis
#12
Qiuyuan Yin, Yijian Zhang, Dong Dong, Ming Lei, Shuyi Zhang, Chen-Chung Liao, Yi-Hsuan Pan
Bats are the only mammals capable of self-powered flying. Many bat species hibernate in winter. A reversible control of cerebral activities is critical for bats to accommodate a repeated torpor-arousal cycle during hibernation. Little is known about the molecular mechanisms that regulate neuronal activities in torpid bats. In this study, Rhinolophus ferrumequinum bat brain proteins were fractionated, and their abundance in active and torpid states was compared. Results of 2D gel-based proteomics showed that 38% of identified proteins with a significant change in abundance are involved in synaptic vesicle recycling and cytoskeletal integrity...
August 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28452286/clock-gene-expression-in-the-suprachiasmatic-nucleus-of-hibernating-arctic-ground-squirrels
#13
Tomoko Ikeno, Cory T Williams, C Loren Buck, Brian M Barnes, Lily Yan
Most organisms have a circadian system, entrained to daily light-dark cycles, that regulates 24-h rhythms of physiology and behavior. It is unclear, however, how circadian systems function in animals that exhibit seasonal metabolic suppression, particularly when this coincides with the long-term absence of a day-night cycle. The arctic ground squirrel, Urocytellus parryii, is a medium-sized, semi-fossorial rodent that appears above-ground daily during its short active season in spring and summer before re-entering a constantly dark burrow for 6 to 9 months of hibernation...
June 2017: Journal of Biological Rhythms
https://www.readbyqxmd.com/read/28432393/more-functions-of-torpor-and-their-roles-in-a-changing-world
#14
Julia Nowack, Clare Stawski, Fritz Geiser
Increased winter survival by reducing energy expenditure in adult animals is often viewed as the primary function of torpor. However, torpor has many other functions that ultimately increase the survival of heterothermic mammals and birds. In this review, we summarize new findings revealing that animals use torpor to cope with the conditions during and after natural disasters, including fires, storms, and heat waves. Furthermore, we suggest that torpor, which also prolongs longevity and was likely crucial for survival of mammals during the time of the dinosaur extinctions, will be advantageous in a changing world...
April 21, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28432150/specialist-generalist-model-of-body-temperature-regulation-can-be-applied-on-the-intraspecific-level
#15
Anna S Przybylska, Jan S Boratyński, Michał S Wojciechowski, Małgorzata Jefimow
According to theoretical predictions endothermic homeotherms can be classified as either thermal specialists and thermal generalists. In high cost environments thermal specialists are supposed to be more prone to use facultative heterothermy than generalists. We tested this hypothesis on the intraspecific level using laboratory male mice (C57BL/cmdb) fasted under different thermal conditions (20 and 10°C), and for different time periods (12-48 h). We predicted that variability of body temperature (Tb) and time spent with Tb below normothermy increase with the increase of environmental demands (duration of fasting and cold)...
April 21, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28417150/torpor-patterns-in-common-hamsters-with-and-without-access-to-food-stores
#16
Carina Siutz, Eva Millesi
Hibernating species significantly reduce energy expenditure during winter by entering torpor. Nevertheless, the various benefits of hibernation might be counteracted by negative effects of torpor such as immune depression, oxidative stress, or neuronal impairment. Considering these trade-offs, adequate energy reserves could allow animals to reduce the time spent in torpor or the extent of metabolic depression. Common hamsters use food stores during hibernation and previously documented high individual variations in body temperature patterns during winter could, therefore, be related to differences in external energy reserves...
April 17, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28404741/avian-blastoderm-dormancy-arrests-cells-in-g2-and-suppresses-apoptosis
#17
Mee Hyun Ko, Young Sun Hwang, Jong Seop Rim, Ho Jae Han, Jae Yong Han
In most avian species, the early embryo suspends development when the ambient temperature is too low; the resultant dormant state is called cold torpor. However, very little is known about dormant avian embryos at the cellular level. To investigate the molecular processes that occur in the chicken blastoderm during cold torpor, we performed transcriptome analysis and investigated cellular responses in dormant embryos. In embryos stored at low temperature, we observed up-regulation of genes and proteins related to endoplasmic reticulum stress and stress-activated protein kinase signaling...
April 12, 2017: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
https://www.readbyqxmd.com/read/28402233/torpor-patterns-in-desert-hedgehogs-paraechinus-aethiopicus-represent-another-new-point-along-a-thermoregulatory-continuum
#18
Justin G Boyles, Nigel C Bennett, Osama B Mohammed, Abdulaziz N Alagaili
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 (Tb) in free-ranging desert hedgehogs (Paraechinus aethiopicus) across three seasons in the deserts of Saudi Arabia. Modal Tb's (35°-36.5°C) were slightly below normal for mammals but still warmer than those of other hedgehogs. The single maximum Tb recorded was 39.2°C, which is cooler than maximum Tb's recorded in most desert mammals...
July 2017: Physiological and Biochemical Zoology: PBZ
https://www.readbyqxmd.com/read/28396263/stable-isotope-analysis-of-co2-in-breath-indicates-metabolic-fuel-shifts-in-torpid-arctic-ground-squirrels
#19
Trixie N Lee, Melanie M Richter, Cory T Williams, Øivind Tøien, Brian M Barnes, Diane M O'Brien, C Loren Buck
Stable carbon isotope ratios (δ(13)C) in breath show promise as an indicator of immediate metabolic fuel utilization in animals because tissue lipids have a lower δ(13)C value than carbohydrates and proteins. Metabolic fuel consumption is often estimated using the respiratory exchange ratio (RER), which has lipid and carbohydrate boundaries, but does not differentiate between protein and mixed fuel catabolism at intermediate values. Because lipids have relatively low δ(13)C values, measurements of stable carbon isotopes in breath may help distinguish between catabolism of protein and mixed fuel that includes lipid...
July 2017: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
https://www.readbyqxmd.com/read/28391591/syrian-hamster-neuroplasticity-mechanisms-fail-as-temperature-declines-to-15%C3%A2-%C3%A2-c-but-histaminergic-neuromodulation-persists
#20
Jock S Hamilton, Sat M Chau, Kevin J Malins, Giancarlo G Ibanez, John M Horowitz, Barbara A Horwitz
Previous research suggests that hippocampal neurons in mammalian hibernators shift their major function from memory formation at euthermic brain temperatures (T b = ~37 °C) to modulation of hibernation bout duration as T b decreases. This role of hippocampal neurons during torpor is based in part on in vivo studies showing that histamine (HA) infused into ground squirrel hippocampi lengthened torpor bouts by ~50%. However, it was unclear if HA acted directly on hippocampal neurons or on downstream brain regions via HA spillover into lateral ventricles...
April 9, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
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