Presenter(s): Ali Eggling—Biology and Environmental Science
Co-Presenter(s): Sera Kaplow
Session: Prerecorded Poster Presentation
Black Bears (Ursus americanus) have the unique ability to preserve bone structure and strength over the course of hibernation . In other hibernating mammals, decreased load on the skeleton causes a loss of bone density . Parathyroid hormone (PTH) is a regulatory hormone secreted by the parathyroid gland . PTH has been identified as an important regulator in bone metabolism, controlling the coupling of osteoblast and osteoclast production while also regulating blood calcium levels . Abnormal secretion of this hormone is linked to osteoporosis and Paget’s disease, both of which cause a weakening in bone density . Theoretical modeling of PTH secretion cycling suggests that this hormone allows bears to maintain bone strength during hibernation . Our objective is to identify PTH secretion cycles and analyze their correlation with predicted optimal interval release . We predict that Ursus americanus optimize PTH release cycles by closely adhering to a theorized six hour secretion cycle during hibernation . Additionally, we believe that their PTH secretion cycle during hibernation differs from non-hibernating months of the year . We intend to test this by collecting blood samples from hibernating and non-hibernating populations of American black bears and measuring their serum PTH levels over both a daily period and throughout hibernation . This research is closely linked to medical research surrounding disuse osteoporosis, as well as environmental research concerned with identifying a baseline for the biological function of these bears moving into climate driven environmental pressures .