Autoradiographic patterns of [14C]2-deoxyglucose uptake are described throughout the brains of hibernating and euthermic ground squirrels. Autoradiographs of the brains of hibernating animals are generally homogeneous in comparison to euthermic animals; hence, the relative 2-deoxyglucose uptake (RBDGU) of gray to white matter for the majority of the 85 neural structures examined decreases durin...

During hibernation at ambient temperatures (T(a)) above 0 degrees C, rodents typically maintain body temperature (T(b)) approximately 1 degrees C above T(a), reduce metabolic rate, and suspend or substantially reduce many physiological functions. We tested the extent to which the presence of an insulative pelage affects hibernation. T(b) was recorded telemetrically in golden-mantled ground squi...

Decreased physical activity in mammals increases bone turnover and uncouples bone formation from bone resorption, leading to hypercalcemia, hypercalcuria, bone loss and increased fracture risk. Black bears, however, are physically inactive for up to 6 months annually during hibernation without losing cortical or trabecular bone mass. Bears have been shown to preserve trabecular bone volume and ...

The Chinese brown frog (Rana dybowskii) is a special amphibian with one unique physiological phenomenon, which is that its oviduct expands prior to hibernation, instead of during the breeding period. In this study, we investigate the localization and expression level of PPARγ2, leptin and leptin receptor proteins in oviduct of Rana dybowskii during  breeding period and pre-hibernation. There we...

Disuse by bed rest, limb immobilization or space flight causes rapid bone loss by arresting bone formation and accelerating bone resorption. This net bone loss increases the risk of fracture upon remobilization. Bone loss also occurs in hibernating ground squirrels, golden hamsters, and little brown bats by arresting bone formation and accelerating bone resorption. There is some histological ev...

The Chinese soft-shelled turtle ( Pelodiscus sinensis ) is among the most primitive amphibians and reptiles in nature. On account of its environmental suitability unique hibernation habit, peculiar physiological phenomenon P. attracted attention researchers field marine science. present study aimed to investigate molecular mechanisms underlying periodic variation lipid droplet (LD) liver . Hist...

OBJECTIVE The physiology of hibernation is characterized by dramatic reductions of heart rate, respiration, metabolism, blood pressure and body temperature and by resistance to ventricular fibrillation. Gap junctions in the heart provide low resistance pathways, facilitating electrical and metabolic coupling between cardiac muscle cells for coordinated action of the heart and tissue homeostasis...

Hibernation (multiday torpor) and daily torpor in heterothermic mammals and birds are characterized by pronounced temporal reductions in body temperature, energy expenditure, water loss, and other physiological functions and are the most effective means for energy conservation available to endotherms. Hibernators express multiday torpor predominately throughout winter, which substantially enhan...

Body temperature drops dramatically during hibernation, but the heart retains the ability to contract and is resistant to induction of arrhythmia. Although adaptive changes in the heart prior to hibernation may be involved in the cold-resistant property, it remains unclear whether these changes are sufficient for maintaining cardiac pulsatility under an extreme hypothermic condition. We forcibl...

Electron immunocytochemistry was used to examine perivascular nerves of hamster mesenteric and renal arteries during hibernation and 2 h after arousal from hibernation. Vessels from cold-exposed but nonhibernating, and normothermic control hamsters were also examined. During hibernation the percentage of axon profiles in mesenteric and renal arteries that were immunopositive for markers of symp...