نتایج جستجو برای: hibernation

تعداد نتایج: 1799  

Journal: :American journal of physiology. Regulatory, integrative and comparative physiology 2003
Jérôme S Menet Patrick Vuillez Michel Saboureau Paul Pévet

The circadian clock of mammals, located in the suprachiasmatic nuclei (SCN) of the hypothalamus, has been demonstrated to integrate day length change from long (LP) to short photoperiod (SP). This photoperiodic change induces in Syrian hamsters a testicular regression through melatonin action, a phenomenon that is inhibited when hamsters have free access to a wheel. The intergeniculate leaflets...

Journal: :Behavioural brain research 2006
Maegan M Weltzin Huiwen W Zhao Kelly L Drew David J Bucci

Hibernation is a unique and highly regulated physiological state characterized by profound, albeit periodically reversible, depression in body temperature, metabolism, and consciousness. Hippocampal synapses undergo pronounced remodeling in concert with torpor and arousal. During hibernation, the number of postsynaptic densities, apical dendritic branches, and spine densities decreases substant...

Journal: :The Journal of experimental biology 2013
O Lynne Nelson Bryan C Rourke

Deep hibernators such as golden-mantled ground squirrels (Callospermophilus lateralis) have multiple challenges to cardiac function during low temperature torpor and subsequent arousals. As heart rates fall from over 300 beats min(-1) to less than 10, chamber dilation and reduced cardiac output could lead to congestive myopathy. We performed echocardiography on a cohort of individuals prior to ...

Journal: :American journal of physiology. Regulatory, integrative and comparative physiology 2013
Inge G Revsbech Hans Malte Ole Fröbert Alina Evans Stéphane Blanc Johan Josefsson Angela Fago

During winter hibernation, brown bears (Ursus arctos) reduce basal O(2) consumption rate to ∼25% compared with the active state, while body temperature decreases moderately (to ∼30°C), suggesting a temperature-independent component in their metabolic depression. To establish whether changes in O(2) consumption during hibernation correlate with changes in blood O(2) affinity, we took blood sampl...

Journal: :The Journal of biological chemistry 2016
Karen Gjesing Welinder Rasmus Hansen Michael Toft Overgaard Malene Brohus Mads Sønderkær Martin von Bergen Ulrike Rolle-Kampczyk Wolfgang Otto Tomas L Lindahl Karin Arinell Alina L Evans Jon E Swenson Inge G Revsbech Ole Frøbert

Brown bears (Ursus arctos) hibernate for 5-7 months without eating, drinking, urinating, and defecating at a metabolic rate of only 25% of the summer activity rate. Nonetheless, they emerge healthy and alert in spring. We quantified the biochemical adaptations for hibernation by comparing the proteome, metabolome, and hematological features of blood from hibernating and active free-ranging suba...

Journal: :General and comparative endocrinology 2004
DeeAnn M Reeder Nicole S Kosteczko Thomas H Kunz Eric P Widmaier

Baseline and stress-responsive glucocorticoid (GC) levels were characterized during the active period in free-ranging male and reproductive female little brown myotis (Myotis lucifugus). Bats were trapped and blood was sampled within 3 min of capture at two maternity sites during the summer and at one swarming site prior to hibernation in New England. Both GC hormones, cortisol and corticostero...

2013
Bethany T. Nelson Xunshan Ding Jamie Boney-Montoya Robert D. Gerard Steven A. Kliewer Matthew T. Andrews

Hibernation is a natural adaptation that allows certain mammals to survive physiological extremes that are lethal to humans. Near freezing body temperatures, heart rates of 3-10 beats per minute, absence of food consumption, and depressed metabolism are characteristic of hibernation torpor bouts that are periodically interrupted by brief interbout arousals (IBAs). The molecular basis of torpor ...

Journal: :Physiological and biochemical zoology : PBZ 2003
Kenneth B Armitage Brett C Woods

We investigated mechanisms of energy conservation during hibernation. The amount of time torpid was significantly less for groups of three young marmots than for marmots hibernating singly. Mean daily mass loss (DML; as mg d(-1) g(-1) immergence mass) averaged 1.33 for single marmots and 1.46 for grouped young. Animals were active 17.3% of the time, which used 82.4% of the energy, and were torp...

Journal: :The Journal of experimental biology 2012
Kristin A Jonasson Craig K R Willis

Hibernation physiology and energy expenditure have been relatively well studied in large captive hibernators, especially rodents, but data from smaller, free-ranging hibernators are sparse. We examined variation in the hibernation patterns of free-ranging little brown bats (Myotis lucifugus) using temperature-sensitive radio-transmitters. First, we aimed to test the hypothesis that age, sex and...

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