Welcome to Dr. Mark Fry's obesity research page. Dr. Fry is a member of the Department of Biological Sciences, at the University of Manitoba, in Winnipeg Manitoba, Canada. His lab is located in room 472 of the Duff Roblin Building on the Fort Garry campus of University of Manitoba, and his office is located in room 469 of the Duff Roblin Building.
Mark Fry uses a number of techniques to investigate the role of specific areas of the brain and CNS, including the hypothalamus, subfornical organ, and area postrema, in development of obesity. His lab uses numerous cutting edge research tools including patch clamp electrophysiology, microarray, RNAseq, qPCR, and neuronal cell culture. His lab is interested in the action of specific molecules including ghrelin, neuropeptide y (NPY) and dopamine.
The main focus of the research carried out in the lab is to understand the physiology of hunger and appetite by investigating the neurons that regulate homeostasis. In particular, the lab is interested in understanding regulation of electrical activity in neurons from circuits that control hunger, appetite, thirst and other aspects of energy homeostasis. Neurons from regions called the sensory circumventricular organs (CVOs) are thought to be especially important for regulation of homeostasis because these specialized areas are are not protected by the blood-brain barrier. The neurons within CVOs are in direct contact with hormones in the circulation and are able to sense hunger-stimulating and satiety (hunger-ending) hormones in the bloodstream: some of these hormones include ghrelin and leptin.
Towards understanding the basic neural mechanisms that control hunger and appetite, our research particularly aims to understand roles of different ion channel proteins in the regulation of electrical excitability of neurons. Ion channels are proteins in neuronal cell membranes that undergo conformational changes to form a pore that allows charged ions such as Na+, Ca++, K+ and Cl- to flow into or out of the cell. These “ionic currents” are the basis of the neuronal action potential and neuronal communication within the CNS.
There is a large diversity of ion channels: dozens of ion channel gene families have been described, and many families have numerous isoforms. These isoforms exhibit only subtle structural differences, but often exhibit dramatic functional differences. Populations of neurons may express vastly different complements of these isoforms and the relationship between ion channel isoform expression and the patterns of neuronal electrical activity is only beginning to be understood. Acutely modulating neuronal ion channel properties by activating intracellular signaling pathways or by changing expression patterns of ion channels by disease or other stimulus can result in dramatic changes in neuronal function, and represents an exciting target for drugs that can modulate appetite and other physiological processes.