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Neonatal hibernation

Rebecca L Polich, Brooke L Bodensteiner, Clare I M Adams, Fredric J Janzen
Maternal stressors can play an integral role in offspring development and ultimate behaviors in many vertebrates. Increased circulating stress avoidance hormones can be reflected in elevated concentrations in ova, thus providing a potential mechanism for maternal stress to be transmitted to offspring even in taxa without parental care. In this study, we assessed the potential impacts of augmented stress avoidance hormones on offspring development and anti-predator behaviors in a freshwater turtle, Chrysemys picta...
January 1, 2018: Physiology & Behavior
Michael J Gaudry, Kevin L Campbell
Uncoupling protein 1 (UCP1) permits non-shivering thermogenesis (NST) when highly expressed in brown adipose tissue (BAT) mitochondria. Exclusive to placental mammals, BAT has commonly been regarded to be advantageous for thermoregulation in hibernators, small-bodied species, and the neonates of larger species. While numerous regulatory control motifs associated with UCP1 transcription have been proposed for murid rodents, it remains unclear whether these are conserved across the eutherian mammal phylogeny and hence essential for UCP1 expression...
2017: Frontiers in Physiology
Richard W Hill
The neonates of many rodent species survive deep hypothermia (T b = 0-8 °C). In key respects, this hypothermia is more akin to hibernation than was thought during much of the twentieth century, indicating that studies of neonatal hypothermia may usefully supplement studies of hibernation in understanding evolved tissue adaptations to near-freezing T b. To clarify evolutionary diversity in neonatal survival of deep hypothermia, neonates of six species or strains were subjected to a standardized procedure: exposure for 2...
July 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
Eric T Hileman, Richard B King, John M Adamski, Thomas G Anton, Robyn L Bailey, Sarah J Baker, Nickolas D Bieser, Thomas A Bell, Kristin M Bissell, Danielle R Bradke, Henry Campa, Gary S Casper, Karen Cedar, Matthew D Cross, Brett A DeGregorio, Michael J Dreslik, Lisa J Faust, Daniel S Harvey, Robert W Hay, Benjamin C Jellen, Brent D Johnson, Glenn Johnson, Brooke D Kiel, Bruce A Kingsbury, Matthew J Kowalski, Yu Man Lee, Andrew M Lentini, John C Marshall, David Mauger, Jennifer A Moore, Rori A Paloski, Christopher A Phillips, Paul D Pratt, Thomas Preney, Kent A Prior, Andrew Promaine, Michael Redmer, Howard K Reinert, Jeremy D Rouse, Kevin T Shoemaker, Scott Sutton, Terry J VanDeWalle, Patrick J Weatherhead, Doug Wynn, Anne Yagi
Elucidating how life history traits vary geographically is important to understanding variation in population dynamics. Because many aspects of ectotherm life history are climate-dependent, geographic variation in climate is expected to have a large impact on population dynamics through effects on annual survival, body size, growth rate, age at first reproduction, size-fecundity relationship, and reproductive frequency. The Eastern Massasauga (Sistrurus catenatus) is a small, imperiled North American rattlesnake with a distribution centered on the Great Lakes region, where lake effects strongly influence local conditions...
2017: PloS One
Sefi J A Horesh, Jaim Sivan, Avi Rosenstrauch, Itay Tesler, A Allan Degen, Michael Kam
Sit-and-wait ambushing and active hunting are two strategies used by predators to capture prey. In snakes, hunting strategy is conserved phylogenetically; most species employ only one strategy. Active hunters encounter and capture more prey but invest more energy in hunting and have higher risks of being predated. This trade-off is important to small predators. The small Cerastes vipera employs both modes of hunting, which is unlike most viperids which use only sit-and wait ambushing. This species hibernates in October and emerges in April...
February 2017: Behavioural Processes
Lucas Francisco R do Nascimento, Lilian Cristina da Silveira, Laura Gabriela Nisembaum, Alison Colquhoun, Agusto S Abe, Carlos Alberto Mandarim-de-Lacerda, Silvia Cristina R de Souza
Seasonal plasticity in the small intestine of neonatal tegu lizards was investigated using morphometry and analysis of enzymes involved in supplying energy to the intestinal tissue. In the autumn, the intestinal mass (Mi) was 1.0% of body mass and the scaling exponent b=0.92 indicated that Mi was larger in smaller neonates. During arousal from dormancy Mi was 23% smaller; later in spring, Mi increased 60% in relation to the autumn and the exponent b=0.14 indicated that the recovery was disproportionate in smaller tegus...
May 2016: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
Yayong Wu, Jinzhong Fu, Bisong Yue, Yin Qi
Viviparous lizards living in cold climate of high altitude often exhibit atypical reproductive cycles, in which mating and fertilization occur synchronously and annually with parturition occurring at the end of the year. Nevertheless, detailed case studies on atypical reproductive cycles are few. Using anatomical data combined with behavioral observations, we examined the reproductive cycle of a common Asian agamid, Phrynocephalus vlangalii, from a high-elevation area in Sichuan, China. Male spermiation of P...
November 2015: Ecology and Evolution
Alessandra Mozzi, Diego Forni, Rachele Cagliani, Uberto Pozzoli, Jacopo Vertemara, Nereo Bresolin, Manuela Sironi
The albuminoid gene family comprises vitamin D-binding protein (GC), alpha-fetoprotein (AFP), afamin (AFM), and albumin (ALB). Albumin is the most abundant human serum protein, and, as the other family members, acts as a transporter of endogenous and exogenous substances including thyroxine, fatty acids, and drugs. Instead, the major cargo of GC is 25-hydroxyvitamin D. We performed an evolutionary study of albuminoid genes and we show that ALB evolved adaptively in mammals. Most positively selected sites are located within albumin-binding sites for fatty acids and thyroxine, as well as at the contact surface with neonatal Fc receptor...
2014: Genome Biology and Evolution
Matthias Rosenwald, Aliki Perdikari, Thomas Rülicke, Christian Wolfrum
Brown adipose tissue helps to maintain body temperature in hibernators, rodents and neonatal mammals by converting lipids and glucose into heat, thereby increasing energy expenditure. In addition to classical brown adipocytes, adult rodents-like adult humans-harbour brown-like adipocytes in the predominantly white adipose tissue. The formation of these brite (brown-in-white) adipocytes is a physiological response to chronic cold and their cellular origin is under debate. We show here that cold-induced formation of brite adipocytes in mice is reversed within 5 weeks of warm adaptation, but the brite adipocytes formed by cold stimulation are not eliminated...
June 2013: Nature Cell Biology
Aurélie Aïdam, Catherine Louise Michel, Xavier Bonnet
The impact of temperature during incubation and gestation has been tested in various reptiles; the postnatal period has been rarely investigated however. Three groups of newborn aspic vipers (Vipera aspis) were placed under contrasted thermal regimes during 7 months: (1) a cool 23°C constant regime, (2) a warm 28°C constant regime, and (3) an optimal regime with free-access to a wide range of temperatures. Later, all the snakes were placed under hibernation conditions (6°C) during 3 months. Finally all the snakes were placed in the optimal thermal regime during 2 additional months...
July 2013: Journal of Experimental Zoology. Part A, Ecological Genetics and Physiology
Matthias Keller, David P Enot, Mark P Hodson, Emeka I Igwe, Hans-Peter Deigner, Justin Dean, Hayde Bolouri, Henrik Hagberg, Carina Mallard
Prenatal inflammation is considered an important factor contributing to preterm birth and neonatal mortality and morbidity. The impact of prenatal inflammation on fetal bioenergetic status and the correlation of specific metabolites to inflammatory-induced developmental brain injury are unknown. We used a global metabolomics approach to examine plasma metabolites differentially regulated by intrauterine inflammation. Preterm-equivalent sheep fetuses were randomized to i.v. bolus infusion of either saline-vehicle or LPS...
2011: PloS One
Jung Yoon Bae, Jun Kanamune, Dong-Wook Han, Kazuaki Matsumura, Suong-Hyu Hyon
We investigated the hibernation effect of epigallocatechin-3-O-gallate (EGCG) on neonatal human tarsal fibroblasts (nHTFs) by analyzing the expression of cell cycle-related genes. EGCG application to culture media moderately inhibited the growth of nHTFs, and the removal of EGCG from culture media led to complete recovery of cell growth. EGCG resulted in a slight decrease in the cell population of the S and G(2)/M phases of cell cycle with concomitant increase in that of the G(0)/G(1) phase, but this cell cycle profile was restored to the initial level after EGCG removal...
2009: Cell Transplantation
Ruriko Iibuchi, Noriko Nakano, Tadashi Nakamura, Tadasu Urashima, Michito Shimozuru, Tetsuma Murase, Toshio Tsubota
Japanese black bears, Ursus thibetanus japonicus, have been classified as a vulnerable species so that data on reproduction are needed to maintain and/or extend their population. They are known to have a peculiar style of reproduction, giving birth to their neonates and raising them during denning, a period of complete fasting. In this study, we investigated the metabolic rate and milk composition of mother bears raising neonates, and the changes in body weight of the neonates under captive conditions. Seven female bears kept in dens were weighed once a month, and the amount of energy they used was calculated...
May 2009: Japanese Journal of Veterinary Research
H Schneider
In the dual ex vivo perfusion of an isolated human placental cotyledon it takes on average 20-30 min to set up stable perfusion circuits for the maternal and fetal vascular compartments. In vivo placental tissue of all species maintains a highly active metabolism and it continues to puzzle investigators how this tissue can survive 30 min of ischemia with more or less complete anoxia following expulsion of the organ from the uterus and do so without severe damage. There seem to be parallels between "depressed metabolism" seen in the fetus and the immature neonate in the peripartum period and survival strategies described in mammals with increased tolerance of severe hypoxia like hibernators in the state of torpor or deep sea diving turtles...
March 2009: Placenta
M G Abate, B Cadore, G Citerio
Therapeutic moderate hypothermia (32-34 degrees C) is currently recommended for patients with out-of-hospital cardiac arrest (OHCA) and for newborns exhibiting neonatal hypoxic/ischemic encephalopathy. Hypothermia as neuroprotective strategy has been extensively studied in other scenarios, mainly for traumatic brain injury. Despite a negative result reported by a multicenter trial conducted in 2001 by Clifton et al. regarding the use of hypothermia on head injury patients, several studies in both clinical and laboratory settings have continued to report positive outcomes with hypothermia use in neurocritical care...
July 2008: Minerva Anestesiologica
Ujas Shah, Harold Bien, Emilia Entcheva
Fast processes in cardiac electrophysiology are often studied at temperatures lower than physiological. Extrapolation of values is based on widely accepted Q10 (Arrhenius) model of temperature dependence (ratio of kinetic properties for a 10 degrees C change in temperature). In this study, we set out to quantify the temperature dependence of essential parameters that define spatiotemporal behavior of cardiac excitation. Additionally, we examined temperature's effects on restitution dynamics. We employed fast fluorescence imaging with voltage-and calcium-sensitive dyes in neonatal rat cardiomyocyte sheets...
2006: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Dominique Singer, Christian Mühlfeld
Mammalian birth is accompanied by profound changes in metabolic rate that can be described in terms of body size relationship (Kleiber's rule). Whereas the fetus, probably as an adaptation to the low intrauterine pO2, exhibits an "inappropriately" low, adult-like specific metabolic rate, the term neonate undergoes a rapid metabolic increase up to the level to be expected from body size. A similar, albeit slowed, "switching-on" of metabolic size allometry is found in human preterm neonates whereas animals that are normally born in a very immature state are able to retard or even suppress the postnatal metabolic increase in favor of weight gain and O2 supply...
December 2007: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
Gary C Packard, Mary J Packard
Painted turtles (Chrysemys picta) typically spend their first winter of life in a shallow, subterranean hibernaculum (the natal nest) where they seemingly withstand exposure to ice and cold by resisting freezing and becoming supercooled. However, turtles ingest soil and fragments of eggshell as they are hatching from their eggs, and the ingestate usually contains efficient nucleating agents that cause water to freeze at high subzero temperatures. Consequently, neonatal painted turtles have only a modest ability to undergo supercooling in the period immediately after hatching...
May 2006: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
Craig K R Willis, R Mark Brigham, Fritz Geiser
Many mammals save energy during food shortage or harsh weather using controlled reductions in body temperature and metabolism called torpor. However, torpor slows offspring growth, and reproductive individuals are thought to avoid using it because of reduced fitness resulting from delayed offspring development. We tested this hypothesis by investigating torpor during reproduction in hoary bats (Lasiurus cinereus, Vespertilionidae) in southern Canada. We recorded deep, prolonged torpor bouts, which meet the definition for hibernation, by pregnant females...
February 2006: Die Naturwissenschaften
Sandrine Meylan, Jean Clobert
Hormones are an important interface between genome and environment, because of their ability to modify the phenotype. More particularly, glucocorticoids are known to affect both morphological, physiological and behavioral traits. Many studies suggest that prenatal stress (associated with an elevation of corticosterone) has deleterious effects on offspring, an altered physiology resulting in retardation of fetal growth and higher percentage of dead neonates. In this study, we investigate the consequences of an artificial increase of corticosterone in pregnant female Lacerta vivipara on two important fitness components: growth and survival...
June 2005: Hormones and Behavior
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