William F Colmers

Biography

William F Colmers is a Professor belongs to the Department of Pharmacology from the university of Alberta.

Research Interest

My laboratory studies the biological role which Neuropeptide Y (NPY), and related signals play in different brain regions. We are funded by the Canadian Institutes of Health Research (CIHR) and the US National Institutes of Health (NIH). Energy Balance: Body weight and composition is controlled by a complex network of neurons in the brain, a large proportion of which are in the hypothalamus, ans which regulate the intake and expenditure of energy. Disorders of energy balance such as obesity and cachexia are widespread health problems. NPY injection into several regions of the hypothalamus causes a remarkable increase in food intake, even in fully-satiated animals. Continued treatment with NPY can result in obese animals. Obesity: We are examining the brain mechanisms by which NPY causes this increase, studying neurons in the paraventricular (PVN) and ventromedial (VMN) nuclei of the hypothalamus. NPY affects transmitter release onto some neurons, and inhibits neurons in other areas, especially ones that are sensitive to the fat hormone, leptin. Other chemical messengers that regulate energy balance also have actions on NPY-sensitive systems. We are now feeding rats a high-fat diet, switching them back to low fat food and examining the brain responses of those that stay fat and those that return to their normal weight. Cachexia: Patients with chronic diseases such as cancers or heart disease often lose large amounts of weight, further endangering their health and recovery. We are studying the brain in model systems to determine if the changes that happen in obesity are pushed in the opposite direction in cachexia Anxiety: NPY acts at two receptor populations, Y1 and Y2, that have opposite actions on animals' reactions to stress. Y1 receptors relax an animal and Y2 receptors make them anxious. We are studying the mechanisms by which this occurs.