Small mammals living in moderate or arctic climatic zones regularly experience seasonal changes i... more Small mammals living in moderate or arctic climatic zones regularly experience seasonal changes in temperature and food availability. Ambient temperatures during winter are well below the thermoneutral zone of small mammals (15–30°C), and food is available only as a fraction of food availability during summer. Despite such unfavorable conditions, small mammals exploit habitats close to or even beyond the arctic circle [18, 51, 55]. Winter can be considered as a seasonal bottleneck for small mammals, causing pressure for the evolution of seasonal acclimation. An entire scope of behavioral and physiological adjustments is used for seasonal acclimation, which may include cessation of reproduction, reduction of body mass, improvements of fur insulation, and the occurrence of daily torpor or hibernation in the winter season. These measures can be used to reduce individual energy requirements during winter [32, 108]. On the other hand, the low ambient temperature in winter also demands improvements in cold tolerance in small mammals when they remain active during winter. This can be achieved by better insulation of winter fur as well as improvements in their capacity for thermoregulatory heat production. Thermal insulation of fur largely depends of the thickness of the air layer trapped in the fur. Small mammals have only a small capacity to increase the thickness of their fur and therefore have only a very limited possibility of seasonal improvement of thermal insulation [29, 43]. They have to rely on their capacity for heat production in order to maintain a high body temperature. Seasonal acclimation therefore appears a difficult task where small mammals have to solve a rather paradoxical situation, they have to exploit measures for reduction of their individual energy expenses, and at the same time to create a greater potential of energy dissipation for thermoregulation.
... expenditure toward fall observed here and in several other hibernating species (Bailey 1965; ... more ... expenditure toward fall observed here and in several other hibernating species (Bailey 1965; Mrosovsky 1971; Ward and Armitage 1981) is generally accompanied by a reduction in food consump-tion (Fall 1971; Kilgore and Armitage ... Ludwig-Maximilian-Universitit, Munich. ...
Evolution and Ecophysiology of Torpor.- Hibernation by Echidnas in Mild Climates: Hints about the... more Evolution and Ecophysiology of Torpor.- Hibernation by Echidnas in Mild Climates: Hints about the Evolution of Endothermy.- Patterns of Hibernation of Echidnas in Tasmania.- Daily Heterothermy in Mammals: Coping with Unpredictable Environments.- Body Temperature and Metabolic Rate of a Hibernating Primate in Madagascar: Preliminary Results from a Field Study.- Heterothermy in Mousebirds: Evidence of Avian Proto-Torpor?.- Spontaneous Arousal in Reptiles? Body Temperature Ecology of Rosenberg's Goanna, Varanus rosenbergi.- Hibernation in the Extreme: Burrow and Body Temperatures, Metabolism, and Limits to Torpor Bout Length in Arctic Ground Squirrels.- Energetics of Hibernation in Woodchucks (Marmota monax).- Mechanisms of Social Thermoregulation in Hibernating Alpine Marmots (Marmota marmota).- Do Patterns of Torpor Differ between Free-ranging and Captive Mammals and Birds?.- Weather Patterns and Daily Torpor in Free-ranging Animals.- Role of Soil Temperature in Timing of Emergence from Hibernation in the Jumping Mouse, Zapus hudsonius.- Temperature Selection and Energy Expenditure in the Marsupial Hibernator Cercartetus nanus.- Torpor in the Carnivorous Marsupial Sminthopsis macroura: Effects of Food Quality and Quantity.- Parasite Adaptations to Hibernation in Alpine Marmots.- Physiological Mechanisms of Torpor.- Perspectives on Metabolic Suppression during Mammalian Hibernation and Daily Torpor.- Control of Cardiac and Ventilation Frequencies during Hibernation in Ground Squirrels.- Intermittent Ventilation in Hibernating Dormice - Is Ventilation always Necessary to Meet Metabolic Demands?.- Retention of Carbon Dioxide during Entrance into Torpor in Dormice.- Thermal Cycling of the Pulmonary Surfactant System in Small Heterothermic Mammals.- Anoxia Tolerance to Oxygen Necessity: Paradigm Shift in the Physiology of Survival of Apneic Deep Hypothermia in Neonatal Rodents.- The Effects of alpha-Tocopherol on Mammalian Torpor.- Essential Fatty Acids: Their Impact on Free-living Alpine Marmots (Marmota marmota).- Circadian Rhythms of Body Temperature in Laboratory and Field Marmots (Marmota flaviventris).- Circannual Rhythms in European Ground Squirrels during Nine Years of Entrainment.- Is Hibernation Facilitated by an Inhibition of Arousal ?.- The Djungarian Hamster is Sleep Deprived during Daily Torpor.- Neuropeptides and Neurotransmitters in the Suprachiasmatic Nucleus: Relationship with the Hibernation Process.- Ultrastructure of Organs and Tissues during Hibernation.- Temperature Modulation of Glucocorticoid-receptor Affinity in a Hibernator, the European Ground Squirrel, and a Non-Hibernator, the Rat.- Follicular Development and Hibernation in European Ground Squirrels.- Effects of Hetastarch on Rewarming after Prolonged Deep Hypothermia in Rats.- Biochemical and Molecular Mechanisms of Torpor.- Gene Expression and Protein Adaptations in Mammalian Hibernation.- Quantitative and Qualitative Changes in Gene Expression during Hibernation in Golden-mantled Ground Squirrels.- Genetic Control of Carbon Utilization during Hibernation: Mechanistic Considerations.- Cellular Response to Metabolic Stress in Hibernating Mammals.- Gluconeogenesis in Brain and Liver During Daily Torpor in Deer Mice (Peromyscus maniculatus).- Cardiac Cyclic Nucleotide Phosphodiesterase (PDE) Activity in the European Hamster during Hibernation.- Temperature Dependence of Coupled and Uncoupled Oxidations in Brain Synaptosomes from Hibernators and Non-Hibernators.- Endogenous Changes in Hibernation-Specific Protein in Chipmunk Cerebrospinal Fluid.- Opioid-like Hibernation Factors Provide Protection to the Ischemic Myocardium.- Energy Balance and Cold Adaptation.- Is there a Life in the Cold without UCP1? Uncoupling Proteins and Thermoregulatory Thermogenesis.- Viral Labeling of the CNS Origins of the Sympathetic Nervous System Innervation of Brown Adipose Tissue: Implications for Torpor and Hibernation Responses.- Mitochondrial Proton Conductance, Standard Metabolic Rate and Metabolic Depression.- Mitochondria in the Cold.- A Contribution of Acid-base Regulation to Metabolic Depression in Marine Ectotherms.- Leptin - Signals and Secretions from White Adipose Tissue.- Flexibility of Basal Metabolic Rate in Arctic Breeding Kittiwakes (Rissa tridactyla).- Relationships between Resting Metabolic Rate and Morphology in Lactating Mice: What Tissues are the Major Contributors to Resting Metabolism?.- Use of the EM-SCAN(R) to Determine Body Composition in Previously Frozen Specimens.- The Influence of Temperature and Season on Mitogen-Induced Proliferation of Ground Squirrel Lymphocytes.- Oestradiol and Progesterone Control Cytochrome c Oxidase Activity in Thermogenic Tissues.- Low Temperature Effects and Social Influences on Physiological Condition of Subadult Wild Rabbits.- Physico-chemical Model for Brain Ganglioside Function in Thermal Adaptation of Vertebrates.- Vertebrate Freeze Tolerance: Molecular Studies of Signal Transduction and Gene…
Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology, 1971
1. The ealorigenic response to noradrenaline (NA) is compared in seven species of mammals with em... more 1. The ealorigenic response to noradrenaline (NA) is compared in seven species of mammals with emphasis on species smaller than the rat (Clethrionomys glareolus, NMRI-mouse, Phodopus sungorus, Mesocricetus auratus, Glis glis, Meriones shawi, rabbit). There is a negative correlation between increase of oxygen consumption during the NA-test (x02) and body weight of the species investigated [Fig. 8; Eq. (3)]. 2. This relation holds if all mammals are injected with their specific NA-dose for maximal response [Fig. 2; Eq. (1) and (2)]. 3. In most mammals 20 miu after the injection of ~A the maximum of oxygen consumption is reached (NST-02). The relation between NST-O 2 and body weight (W=body weight in g) is described by the regression [Fig. 10; Eq. (4)]:
Small mammals living in moderate or arctic climatic zones regularly experience seasonal changes i... more Small mammals living in moderate or arctic climatic zones regularly experience seasonal changes in temperature and food availability. Ambient temperatures during winter are well below the thermoneutral zone of small mammals (15–30°C), and food is available only as a fraction of food availability during summer. Despite such unfavorable conditions, small mammals exploit habitats close to or even beyond the arctic circle [18, 51, 55]. Winter can be considered as a seasonal bottleneck for small mammals, causing pressure for the evolution of seasonal acclimation. An entire scope of behavioral and physiological adjustments is used for seasonal acclimation, which may include cessation of reproduction, reduction of body mass, improvements of fur insulation, and the occurrence of daily torpor or hibernation in the winter season. These measures can be used to reduce individual energy requirements during winter [32, 108]. On the other hand, the low ambient temperature in winter also demands improvements in cold tolerance in small mammals when they remain active during winter. This can be achieved by better insulation of winter fur as well as improvements in their capacity for thermoregulatory heat production. Thermal insulation of fur largely depends of the thickness of the air layer trapped in the fur. Small mammals have only a small capacity to increase the thickness of their fur and therefore have only a very limited possibility of seasonal improvement of thermal insulation [29, 43]. They have to rely on their capacity for heat production in order to maintain a high body temperature. Seasonal acclimation therefore appears a difficult task where small mammals have to solve a rather paradoxical situation, they have to exploit measures for reduction of their individual energy expenses, and at the same time to create a greater potential of energy dissipation for thermoregulation.
... expenditure toward fall observed here and in several other hibernating species (Bailey 1965; ... more ... expenditure toward fall observed here and in several other hibernating species (Bailey 1965; Mrosovsky 1971; Ward and Armitage 1981) is generally accompanied by a reduction in food consump-tion (Fall 1971; Kilgore and Armitage ... Ludwig-Maximilian-Universitit, Munich. ...
Evolution and Ecophysiology of Torpor.- Hibernation by Echidnas in Mild Climates: Hints about the... more Evolution and Ecophysiology of Torpor.- Hibernation by Echidnas in Mild Climates: Hints about the Evolution of Endothermy.- Patterns of Hibernation of Echidnas in Tasmania.- Daily Heterothermy in Mammals: Coping with Unpredictable Environments.- Body Temperature and Metabolic Rate of a Hibernating Primate in Madagascar: Preliminary Results from a Field Study.- Heterothermy in Mousebirds: Evidence of Avian Proto-Torpor?.- Spontaneous Arousal in Reptiles? Body Temperature Ecology of Rosenberg's Goanna, Varanus rosenbergi.- Hibernation in the Extreme: Burrow and Body Temperatures, Metabolism, and Limits to Torpor Bout Length in Arctic Ground Squirrels.- Energetics of Hibernation in Woodchucks (Marmota monax).- Mechanisms of Social Thermoregulation in Hibernating Alpine Marmots (Marmota marmota).- Do Patterns of Torpor Differ between Free-ranging and Captive Mammals and Birds?.- Weather Patterns and Daily Torpor in Free-ranging Animals.- Role of Soil Temperature in Timing of Emergence from Hibernation in the Jumping Mouse, Zapus hudsonius.- Temperature Selection and Energy Expenditure in the Marsupial Hibernator Cercartetus nanus.- Torpor in the Carnivorous Marsupial Sminthopsis macroura: Effects of Food Quality and Quantity.- Parasite Adaptations to Hibernation in Alpine Marmots.- Physiological Mechanisms of Torpor.- Perspectives on Metabolic Suppression during Mammalian Hibernation and Daily Torpor.- Control of Cardiac and Ventilation Frequencies during Hibernation in Ground Squirrels.- Intermittent Ventilation in Hibernating Dormice - Is Ventilation always Necessary to Meet Metabolic Demands?.- Retention of Carbon Dioxide during Entrance into Torpor in Dormice.- Thermal Cycling of the Pulmonary Surfactant System in Small Heterothermic Mammals.- Anoxia Tolerance to Oxygen Necessity: Paradigm Shift in the Physiology of Survival of Apneic Deep Hypothermia in Neonatal Rodents.- The Effects of alpha-Tocopherol on Mammalian Torpor.- Essential Fatty Acids: Their Impact on Free-living Alpine Marmots (Marmota marmota).- Circadian Rhythms of Body Temperature in Laboratory and Field Marmots (Marmota flaviventris).- Circannual Rhythms in European Ground Squirrels during Nine Years of Entrainment.- Is Hibernation Facilitated by an Inhibition of Arousal ?.- The Djungarian Hamster is Sleep Deprived during Daily Torpor.- Neuropeptides and Neurotransmitters in the Suprachiasmatic Nucleus: Relationship with the Hibernation Process.- Ultrastructure of Organs and Tissues during Hibernation.- Temperature Modulation of Glucocorticoid-receptor Affinity in a Hibernator, the European Ground Squirrel, and a Non-Hibernator, the Rat.- Follicular Development and Hibernation in European Ground Squirrels.- Effects of Hetastarch on Rewarming after Prolonged Deep Hypothermia in Rats.- Biochemical and Molecular Mechanisms of Torpor.- Gene Expression and Protein Adaptations in Mammalian Hibernation.- Quantitative and Qualitative Changes in Gene Expression during Hibernation in Golden-mantled Ground Squirrels.- Genetic Control of Carbon Utilization during Hibernation: Mechanistic Considerations.- Cellular Response to Metabolic Stress in Hibernating Mammals.- Gluconeogenesis in Brain and Liver During Daily Torpor in Deer Mice (Peromyscus maniculatus).- Cardiac Cyclic Nucleotide Phosphodiesterase (PDE) Activity in the European Hamster during Hibernation.- Temperature Dependence of Coupled and Uncoupled Oxidations in Brain Synaptosomes from Hibernators and Non-Hibernators.- Endogenous Changes in Hibernation-Specific Protein in Chipmunk Cerebrospinal Fluid.- Opioid-like Hibernation Factors Provide Protection to the Ischemic Myocardium.- Energy Balance and Cold Adaptation.- Is there a Life in the Cold without UCP1? Uncoupling Proteins and Thermoregulatory Thermogenesis.- Viral Labeling of the CNS Origins of the Sympathetic Nervous System Innervation of Brown Adipose Tissue: Implications for Torpor and Hibernation Responses.- Mitochondrial Proton Conductance, Standard Metabolic Rate and Metabolic Depression.- Mitochondria in the Cold.- A Contribution of Acid-base Regulation to Metabolic Depression in Marine Ectotherms.- Leptin - Signals and Secretions from White Adipose Tissue.- Flexibility of Basal Metabolic Rate in Arctic Breeding Kittiwakes (Rissa tridactyla).- Relationships between Resting Metabolic Rate and Morphology in Lactating Mice: What Tissues are the Major Contributors to Resting Metabolism?.- Use of the EM-SCAN(R) to Determine Body Composition in Previously Frozen Specimens.- The Influence of Temperature and Season on Mitogen-Induced Proliferation of Ground Squirrel Lymphocytes.- Oestradiol and Progesterone Control Cytochrome c Oxidase Activity in Thermogenic Tissues.- Low Temperature Effects and Social Influences on Physiological Condition of Subadult Wild Rabbits.- Physico-chemical Model for Brain Ganglioside Function in Thermal Adaptation of Vertebrates.- Vertebrate Freeze Tolerance: Molecular Studies of Signal Transduction and Gene…
Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology, 1971
1. The ealorigenic response to noradrenaline (NA) is compared in seven species of mammals with em... more 1. The ealorigenic response to noradrenaline (NA) is compared in seven species of mammals with emphasis on species smaller than the rat (Clethrionomys glareolus, NMRI-mouse, Phodopus sungorus, Mesocricetus auratus, Glis glis, Meriones shawi, rabbit). There is a negative correlation between increase of oxygen consumption during the NA-test (x02) and body weight of the species investigated [Fig. 8; Eq. (3)]. 2. This relation holds if all mammals are injected with their specific NA-dose for maximal response [Fig. 2; Eq. (1) and (2)]. 3. In most mammals 20 miu after the injection of ~A the maximum of oxygen consumption is reached (NST-02). The relation between NST-O 2 and body weight (W=body weight in g) is described by the regression [Fig. 10; Eq. (4)]:
Uploads
Papers by Gerhard Heldmaier