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January 3 - Febuary 28, 2021

Meeting Abstract

P15-5  Sat Jan 2  Carbohydrate breakdown reflects wear-and-tear during a combined fast and chronic stress in house sparrows (Passer domesticus) Beattie, UK*; Ysrael, MC; Romero, LM; Tufts University, Medford, MA; Tufts University, Medford, MA; Tufts University, Medford, MA

One aspect of the Reactive Scope Model is wear-and-tear, which describes a decrease in an animals’ ability to cope with a stressor, typically because of a period of chronic or repeated stressors. With prolonged fasting, animals exhibit 3 phases of macromolecule breakdown for energy: phase I is primarily carbohydrate breakdown, phase II is primarily fat breakdown, and phase III is primarily protein breakdown. We investigated whether wear-and-tear due to chronic stress would accelerate a transition from phase II to phase III. We exposed house sparrows (Passer domesticus) to 3 weeks of daily fasts combined with intermittent repeated acute stressors to create chronic stress, followed by 2 weeks of daily fasts without stressors. In both a fed and fasted state, we used human point-of-care devices to measure glucose, β-hydroxybutyrate, and uric acid, which are indicative of carbohydrate, fat, and protein breakdown, respectively. We expected birds to be in phase II in a fasted state, but if wear-and-tear accumulated sufficiently, we hypothesized a shift to phase III. The birds did not exhibit a clear shift to phase III, however there was a pattern in carbohydrate breakdown that did not align with the hypothesis. In both a fasted and fed state, the birds increased carbohydrate breakdown throughout the experiment, suggesting wear-and-tear occurred, but was not sufficient to induce a shift to phase III. The birds also exhibited a significant decrease in weight, no change in corticosterone, and a transient decrease in neophobia with chronic stress. In conclusion, the birds appear to have experienced wear-and-tear, but our protocol was not sufficient to accelerate a transition to premature protein breakdown.