The main function of hibernation and daily torpor in heterothermic mammals and birds (i.e. species capable of expressing torpor) is to conserve energy and water and thus to survive during adverse environmental conditions or periods of food shortage no matter if they live in the arctic or the tropics. However, the reduced energy requirements also permit survival of bad weather during reproductio...

Introduction For cold-blooded or poikilothermic animals, winter presents challenges to survival. Since the body temperature (Tb) of poikilotherms is usually very close to that of their surrounding environment, the risk of death from freezing is very real when temperatures drop below 0°C. Food is also scare during the winter and some animals also have limited mobility because the cold can make m...

According to the expensive brain hypothesis, periodic energy level determines mass. However, various environmental and biological factors directly or indirectly relevant intake have not been well studied. Here, we systematically examined how body mass, hibernation, diurnally, substrate use, diet individually synergistically determine mass in a large dataset of more than 1000 species. We found t...

ON SEV-ZaAJ~ OCCASIONS the subject of Artificial Hibernation has been dtscussed before the Canadian Anaesthetists' Society by Dr. Fernando ]-Iudon of Quebec City. We thought, therefore, it would be of some interest to present a series of 42 climcal cases of which '22 were medical and 20 were surgic~d. From the concepts of Claude Berna~, Cannon, Reilly and Selye, Laborit evolved his technique of...

1. To examine the hypothesis that stimulation of immune function plays a role in periodic arousal from hibernation, bacterial growth during hibernation was estimated using a simple mathematical model of the general dynamics of bacterial abundance at body temperatures experienced during hibernation. 2. In the model, periodic arousals were important for animals infected with Salmonella at body te...

Heterothermic mammals tolerate severe hypoxia, as well as a variety of central nervous system insults, better than homeothermic mammals. Tolerance to hypoxia may stem from adaptations associated with the ability to survive hibernation and periodic arousal thermogenesis. Here, we review evidence and mechanisms of hypoxia tolerance during hibernation, euthermy and arousal in heterothermic mammals...

Synopsis The conquest of land has endowed air-breathers with the capability to utilize ventilation not only to acquire oxygen but also to control blood and intracellular acid-base state. Hypercapnic acidosis (resulting from ventilatory control and/or behavioral choice), thus, has become a universal component of hypometabolic states in air-breathers, with inhibitory and/or protective roles. Here...