Our Research
Global change and increasing frequency of unpredictable events appear as major threat for the vast majority of animal kingdom. There is growing interest in how well behavioural and physiological flexibility can buffer organisms from environmental hazards. Key metabolic constraints imposed by environmental fluctuations include a reduction in food availability, changes in food quality, periods of coldness or of dryness.
The ability to save energy through behavioral and physiological responses, such as entering a state of hypometabolism possibly associated with hypothermia, and to allocate it into the different fitness components (survival, reproduction, growth), has great ecological relevance for animal species, and also implies important evolutionary aspects.
To date, the underlying regulatory mechanisms of such strategies are far from being entirely understood, and many aspects still remain to be investigated. So far, the vast majority of research in this area has been done with a focus on small, endothermic animals that have to maintain a high core body temperature but can also enter an hypometabolic state under certain environmental circumstances. More rarely these mechanisms are studied in large endotherms or in ectotherms, in which ambient temperature governs body temperature and metabolism.
Behavioral and hypometabolic responses, however, seem to be present in a large variety of animal species, and appear as a continuum of mechanisms for living at a low pace. Mechanisms of energy savings imply some important evolutionary aspects leading to contrasting strategies of energy management and allocation to different fitness components. In the context of global environmental changes, understanding how the physiological flexibility that enables organisms to cope with fluctuating environments during their lifetime can be continued in species populations, via some inherited mechanisms, constitutes a great avenue of research.
The research conducted in this group aims at understanding the regional and/or whole-body mechanisms of energy strategies used by animal species in the context of a constantly changing environment, as well as the ecological and evolutionary implications of such strategies for an individual’s life and for entire animal populations. The focus is on behavioural and hypometabolic responses and thermal tolerance that enable animal species to optimize energy allocation to fitness components. To this aim, we are developing an integrative approach from the whole organism down to cellular or molecular levels to unravel the adaptive mechanisms of small (e.g. hamsters, chipmunks, dormice) to large (e.g. bears, seals, and elephant seals) mammalian heterotherms under laboratory, semi-captive and free-ranging conditions.
To access the descriptions of various research projects, simply click on the pictures with the links below to be directed to the specific webpage of the selected project.
For prospective students:
To work on a project, please consider sending your application by including your CV and a personal statement reflecting your motivation. For graduate researchers, provide your undergraduate transcripts and evidence for your scholarly potential (e.g., Hornor thesis, peer-reviewed paper that you wrote, science-focused class paper, etc). For undergradute researchers, you must be a current NMU student, have sucessfully completed Human Anatomy & Physiology (BI 207 / BI 208) and - depending on the project topic - Introduction to Cell & Molecular Biology (BI 218) or Principles of Ecology (BI 210) or Principles of Evolution (BI 215), and obtain a referral from a Biology faculty member or teaching assistant (TA). Send your application to Dr Sylvain Giroud at sgiroud@nmu.edu with the subject line: Energetics Lab Application (student name).
Credit: A. Strijkstra
Metabolic Physiology
Following the concept of comparative physiology, we are studying the metabolic adaptations, notably those linked to lipid metabolism, of hibernating animals, as a biomimicry strategy to fuel new ideas for translational research. This biomimicry research is notably of great interest for biomedical applications, including treatments for cardiovascular diseases or metabolic disorders such as obesity in both animals and humans.
Evolutionary Physiology
Understanding the links between proximal physiological & behavioral mechanisms and ultimate evolutionary consequences is key in determining adaptive or maladaptive responses of animal species. This has even more relevance in the context of ever-increasing environmental aterations as both biotic and abiotic cues have the potential to shape evolutionary processes across individuals of same species as well as between animal species. This series of projects is attached to determine these interconnections between proximate causes and ultimate consequences within individuals and across species.
Credit: Wiki
Credit: Wiki
Thermoregulatory Adaptations
In endotherms, heat production notably occurs via non-shivering thermogenesis (NST). Besides uncoupling protein 1 in the brown adipose tissue, mammalian NST possibly involves an additional mechanism of heat generation in skeletal muscle. This series of projects aim at investigating the role and implication of muscle NST in enabling endothermic species to maintain a stable and high core body temperature independently of environmental influences.
Ecophysiology & Global Change
Climate change including global warming has been described as one of the most important stressors for individuals and whole ecosystems. There is an increasing demand for a more processed-based understanding of the interplay of the physiological responses and the environmental change experienced by animals in the wild. Anthrogenic influences also greatly affect adaptive reponses of wild species including hibernators, with notably a large impact of toxins and contaminants from human origins on the behavioral and physiological mechanisms involved in the hibernation phenotype and its phenology in a seasonal context.
Credit: J. Painer
Collaborators & Funding
