Simon J. Fisher, MD, PhD

Simon J. Fisher, MD, PhD

Associate Professor of Medicine and of Cell Biology and Physiology


Dr. Fisher received his MD and PhD from the University of Toronto Medical School where he studied diabetes physiology with Mladen Vranic (1989-97). He received his medicine and endocrinology clinical training at Harvard’s Beth Israel Deaconess Medical Center (1997-2003) where he also studied insulin signaling with Ron Kahn at the Joslin Diabetes Center. Named in Best Doctors in America, Dr. Fisher has received a Career Development award from the Juvenile Diabetes Research Foundation. Dr. Fisher joined the faculty in the Department of Medicine in 2003.

Research Interests

Diabetes and its complications represent an extraordinary research challenge. Novel research in the field of diabetes research suggests that inappropriate insulin action at target tissues not classically considered insulin sensitive may contribute to the pathologic metabolism characteristic of diabetes and obesity. The goals of our laboratory are to test the hypothesis and understand the mechanism by which insulin appears to act in the central nervous system to regulate nutrient metabolism within the brain and in key peripheral tissues (i.e., liver). Our laboratory utilizes techniques of molecular biology, physiology, biochemistry, pharmacology, neuroscience, and genetics in the breeding and characterization of transgenic and tissue specific knockout models . The overall laboratory objectives are to identify the systemic regulators of blood sugar levels associated with insulin action in the central nervous system , to categorize novel hypothalamic nuclei and fuel sensors that are the key mediators of insulin action to define their role in the pathophysiology of defective insulin action, to characterize the pathway by which insulin acts to increase the stress response to hypoglycemia (low blood sugar) , and to identify key mediators of tissue cross-talk in response to insulin action and their roles in the pathogenesis of insulin resistance, obesity, and diabetes.

Awards and Honors

2001-03 Juvenile Diabetes Foundation International, Postdoctoral Fellowship

2003 Award of Excellence – Internal Medicine, Partners HealthCare, Harvard/MGH/McLean

1997 Wightman Award for Internal Medicine, Faculty of Medicine, Univ. of Toronto

1995 Canadian Society for Clinical Investigation Trainee Award

1995 Best Presentation Award – Toronto Banting & Best Diabetes Center Meeting