Biographical Information:

The primary focus of the Schaeffer lab is the study of muscle plasticity and its implications in organismal energy balance. Experimental approaches range from cell and molecular studies to measurements of physiological activity in the field. This very broad interest can best be divided into 2 more specific research programs.

One of these programs is to utilize the tools of molecular biology to investigate the roles of specific regulatory factors in the control of muscle phenotype in health and disease. Muscle phenotypic plasticity is important in the maintenance of normal metabolic regulation, best demonstrated by the loss of this trait in metabolic diseases such as the metabolic syndrome and diabetes. Although the dynamic regulation of muscle fuel uptake and oxidation is very well appreciated, there is considerable debate about whether loss of normal metabolic function is a causative agent or an outcome of disease. We study the interaction of activity and lipid metabolism in the regulation and maintenance of muscle function using genetically modified mouse and cell culture models.

Another program utilizes comparative physiology in an attempt to delineate the ways in which evolution has shaped muscle and energetic physiology in order to identify the common “design principles” or constraints that operate on animals (primarily tetrapods) in general. Much is known about the physiological responses of muscle to alterations in activity or demand in numerous mammalian species. How and to what extent this is true in other tetrapods (or in marsupials) remains under-investigated. Further, even in mammalian model species such as rats and mice, the control of acclimative responses is poorly understood. I propose (as have many before me) that by describing adaptations of muscle-metabolic physiology across evolutionary radiations, that both the events common to all species as well as unique adaptations will inform our understanding of muscle biology.