Adaptive and
Stress Physiology
,
,H0: Overview of the course
Learning outcomes – 6 credits
• The students have a profound knowledge of the physical and biochemical mechanisms
needed for adaptation to extreme and/or changing environmental parameters.
• Students know how animals and plants survive similar environmental challenges and can
explain the principal differences and similarities in their strategies.
• Students have a clear understanding of the physiological regulatory mechanisms involved at
the molecular, cellular and organismal level.
• The students are capable of gathering information on physiological adaptations to specific
environmental conditions and can use this information to prepare a written report.
• Students are also capable of setting up an experiment to illustrate such adaptations and to
report on these results.
Course content
General principles
• Adaptation and acclimation
• Conformers and regulators, temporal and regional avoidance
• Types of environmental factors (constant, predictable varying, unpredictable, biotic and
abiotic stress factors)
• Combinations of stress factors and cross-protection
Topics from animal adaptive and stress physiology
• Thermoregulation: poikilotherm/ectotherm, homeotherm/endotherm, coping with extreme
temperatures (chilling/freezing and heat), torpor, hibernation, diapause
• Hypoxic conditions: living at high altitude, living in the deep sea
• Birhythmicity: molecular clock, circadian, seasonal and tidal rhythms, migration
• Ageing: different theories of ageing, healthspan vs lifespan, cell-autonomous and cell-non-
autonomous aspects, environmental aspects
Topics from plant adaptive and stress physiology
• Water deficit: plant water status and acclimation and adaptations strategies
• Salt and heavy metal stress as more specific types of osmotic stress
• Chilling and freezing stress and heat stress
• Waterlogging and flooding (hypoxia) and oxidative stress
• Biotic interactions: symbioses and defense against pathogens and herbivores using
physical/chemical barriers, and induced responses, including innate immunity
The exam
• Oral exam: 17/20
o part animal: 8/20
o part plant: 9/20
Partial assessment: 3/20
, H1: GENERAL PRINCIPLES .................................................................................................................................................1
1.1 PRINCIPLES OF PHYSIOLOGY ................................................................................................................................................. 1
1.2 WHAT IS STRESS? .............................................................................................................................................................. 2
1.2.1 General adaptation syndrome (GAS) .................................................................................................................... 2
1.2.2 Physiological responses to stress .......................................................................................................................... 3
1.2.3 Neuro-adrenal responses ...................................................................................................................................... 4
1.2.4 Homeodynamics ................................................................................................................................................... 6
1.2.5 Stressors and dealing with them .......................................................................................................................... 6
........................................................................................................................................................................................9
PART 1: ANIMALS .............................................................................................................................................................9
H2: THERMAL STRESS.......................................................................................................................................................9
2.1 DETERMINANTS OF BODY HEAT AND TEMPERATURE ................................................................................................................ 10
2.1.1 General concepts about body heat and temperature ......................................................................................... 10
2.1.2 Heat balance equation and heat transfer mechanisms ...................................................................................... 11
2.2 GENERAL MECHANISMS OF HEAT TRANSFER........................................................................................................................... 12
2.3 GENERAL BIOCHEMISTRY AFFECTED BY TEMPERATURE ............................................................................................................. 14
2.3.1 Thermal effects on enzymatic activity ................................................................................................................ 14
2.3.2 Thermal effects on membranes and cellular structures...................................................................................... 16
2.3.3 Thermal induction of stress proteins .................................................................................................................. 19
2.4 PHYSIOLOGICAL CLASSIFICATION USING THERMAL BIOLOGY ....................................................................................................... 20
2.4.1 Thermal biology of heterotherms ....................................................................................................................... 21
2.4.2 Thermal biology of ectotherms ........................................................................................................................... 22
2.4.3 Thermal biology of endotherms.......................................................................................................................... 25
2.4.4 Costs & benefits of ectotherms vs endotherms .................................................................................................. 28
2.5 NEURONAL MECHANISMS OF TEMPERATURE CONTROL ............................................................................................................ 29
2.6 SPECIALIZED METABOLIC STATES .......................................................................................................................................... 30
H3: TIME ........................................................................................................................................................................ 31
3.1 BIOLOGICAL RHYTHMS ...................................................................................................................................................... 31
3.1.1 Clock-driven society vs biological timekeeping ................................................................................................... 31
3.1.2 Types of biological rhythms ................................................................................................................................ 31
3.1.3 Biological rhythms are endogenous ................................................................................................................... 31
3.2 CIRCADIAN RHYTHMS ....................................................................................................................................................... 32
3.2.1 Characteristics of a circadian rhythm ................................................................................................................. 32
3.2.2 Molecular basis of circadian clocks..................................................................................................................... 36
3.2.3 Circadian clock of Drosophila melanogaster ...................................................................................................... 38
3.2.4 Circadian clock in humans .................................................................................................................................. 40
3.3 AGING ........................................................................................................................................................................... 42
3.3.1 What is aging? .................................................................................................................................................... 42
3.3.2 Studying aging requires readouts ....................................................................................................................... 42
H4: OXYGEN STRESS ....................................................................................................................................................... 48
4.1 INTRODUCTION TO OXYGEN AND RESPIRATION ....................................................................................................................... 48
4.1.1 Composition of atmospheric air ......................................................................................................................... 48
4.1.2 The importance of oxygen for animal life ........................................................................................................... 48
4.1.3 Evolution of atmospheric oxygen ........................................................................................................................ 49
4.2 DIFFERENT RESPIRATORY SYSTEMS ....................................................................................................................................... 50
4.2.1 Diffusion-based respiration ................................................................................................................................ 50
4.2.2 Bulk flow systems................................................................................................................................................ 50
4.2.3 Cutaneous respiration (“skin breathing”) ........................................................................................................... 51
4.2.4 Specialized respiratory organs: gills and lungs ................................................................................................... 51
4.2.5 Capturing and releasing oxygen ......................................................................................................................... 52
4.3 OXYGEN TENSION AND CELLULAR RESPONSES ........................................................................................................................ 53
Stress Physiology
,
,H0: Overview of the course
Learning outcomes – 6 credits
• The students have a profound knowledge of the physical and biochemical mechanisms
needed for adaptation to extreme and/or changing environmental parameters.
• Students know how animals and plants survive similar environmental challenges and can
explain the principal differences and similarities in their strategies.
• Students have a clear understanding of the physiological regulatory mechanisms involved at
the molecular, cellular and organismal level.
• The students are capable of gathering information on physiological adaptations to specific
environmental conditions and can use this information to prepare a written report.
• Students are also capable of setting up an experiment to illustrate such adaptations and to
report on these results.
Course content
General principles
• Adaptation and acclimation
• Conformers and regulators, temporal and regional avoidance
• Types of environmental factors (constant, predictable varying, unpredictable, biotic and
abiotic stress factors)
• Combinations of stress factors and cross-protection
Topics from animal adaptive and stress physiology
• Thermoregulation: poikilotherm/ectotherm, homeotherm/endotherm, coping with extreme
temperatures (chilling/freezing and heat), torpor, hibernation, diapause
• Hypoxic conditions: living at high altitude, living in the deep sea
• Birhythmicity: molecular clock, circadian, seasonal and tidal rhythms, migration
• Ageing: different theories of ageing, healthspan vs lifespan, cell-autonomous and cell-non-
autonomous aspects, environmental aspects
Topics from plant adaptive and stress physiology
• Water deficit: plant water status and acclimation and adaptations strategies
• Salt and heavy metal stress as more specific types of osmotic stress
• Chilling and freezing stress and heat stress
• Waterlogging and flooding (hypoxia) and oxidative stress
• Biotic interactions: symbioses and defense against pathogens and herbivores using
physical/chemical barriers, and induced responses, including innate immunity
The exam
• Oral exam: 17/20
o part animal: 8/20
o part plant: 9/20
Partial assessment: 3/20
, H1: GENERAL PRINCIPLES .................................................................................................................................................1
1.1 PRINCIPLES OF PHYSIOLOGY ................................................................................................................................................. 1
1.2 WHAT IS STRESS? .............................................................................................................................................................. 2
1.2.1 General adaptation syndrome (GAS) .................................................................................................................... 2
1.2.2 Physiological responses to stress .......................................................................................................................... 3
1.2.3 Neuro-adrenal responses ...................................................................................................................................... 4
1.2.4 Homeodynamics ................................................................................................................................................... 6
1.2.5 Stressors and dealing with them .......................................................................................................................... 6
........................................................................................................................................................................................9
PART 1: ANIMALS .............................................................................................................................................................9
H2: THERMAL STRESS.......................................................................................................................................................9
2.1 DETERMINANTS OF BODY HEAT AND TEMPERATURE ................................................................................................................ 10
2.1.1 General concepts about body heat and temperature ......................................................................................... 10
2.1.2 Heat balance equation and heat transfer mechanisms ...................................................................................... 11
2.2 GENERAL MECHANISMS OF HEAT TRANSFER........................................................................................................................... 12
2.3 GENERAL BIOCHEMISTRY AFFECTED BY TEMPERATURE ............................................................................................................. 14
2.3.1 Thermal effects on enzymatic activity ................................................................................................................ 14
2.3.2 Thermal effects on membranes and cellular structures...................................................................................... 16
2.3.3 Thermal induction of stress proteins .................................................................................................................. 19
2.4 PHYSIOLOGICAL CLASSIFICATION USING THERMAL BIOLOGY ....................................................................................................... 20
2.4.1 Thermal biology of heterotherms ....................................................................................................................... 21
2.4.2 Thermal biology of ectotherms ........................................................................................................................... 22
2.4.3 Thermal biology of endotherms.......................................................................................................................... 25
2.4.4 Costs & benefits of ectotherms vs endotherms .................................................................................................. 28
2.5 NEURONAL MECHANISMS OF TEMPERATURE CONTROL ............................................................................................................ 29
2.6 SPECIALIZED METABOLIC STATES .......................................................................................................................................... 30
H3: TIME ........................................................................................................................................................................ 31
3.1 BIOLOGICAL RHYTHMS ...................................................................................................................................................... 31
3.1.1 Clock-driven society vs biological timekeeping ................................................................................................... 31
3.1.2 Types of biological rhythms ................................................................................................................................ 31
3.1.3 Biological rhythms are endogenous ................................................................................................................... 31
3.2 CIRCADIAN RHYTHMS ....................................................................................................................................................... 32
3.2.1 Characteristics of a circadian rhythm ................................................................................................................. 32
3.2.2 Molecular basis of circadian clocks..................................................................................................................... 36
3.2.3 Circadian clock of Drosophila melanogaster ...................................................................................................... 38
3.2.4 Circadian clock in humans .................................................................................................................................. 40
3.3 AGING ........................................................................................................................................................................... 42
3.3.1 What is aging? .................................................................................................................................................... 42
3.3.2 Studying aging requires readouts ....................................................................................................................... 42
H4: OXYGEN STRESS ....................................................................................................................................................... 48
4.1 INTRODUCTION TO OXYGEN AND RESPIRATION ....................................................................................................................... 48
4.1.1 Composition of atmospheric air ......................................................................................................................... 48
4.1.2 The importance of oxygen for animal life ........................................................................................................... 48
4.1.3 Evolution of atmospheric oxygen ........................................................................................................................ 49
4.2 DIFFERENT RESPIRATORY SYSTEMS ....................................................................................................................................... 50
4.2.1 Diffusion-based respiration ................................................................................................................................ 50
4.2.2 Bulk flow systems................................................................................................................................................ 50
4.2.3 Cutaneous respiration (“skin breathing”) ........................................................................................................... 51
4.2.4 Specialized respiratory organs: gills and lungs ................................................................................................... 51
4.2.5 Capturing and releasing oxygen ......................................................................................................................... 52
4.3 OXYGEN TENSION AND CELLULAR RESPONSES ........................................................................................................................ 53
