title: Repeated exposure to stressful conditions can have beneficial effects on survival.
abstract: Repeated exposure to stressful circumstances is generally thought to be associated with increased pathology and reduced longevity. However, growing lines of evidence suggest that the effects of environmental stressors on survival and longevity depend on a multitude of factors and, under some circumstances, might be positive rather than negative. Here, using the zebra finch (Taeniopygia guttata), we show that repeated exposure to stressful conditions (i.e. unpredictable food availability), which induced no changes in body mass, was associated with a decrease in mortality rate and an increase in the age of death. As expected, the treated birds responded to the unpredictable food supply by increasing baseline glucocorticoid stress hormone secretion and there were no signs of habituation of this hormonal response to the treatment across time. Importantly, and consistent with previous literature, the magnitude of hormone increase induced by the treatment was significant, but relatively mild, since the baseline glucocorticoid concentrations in the treated birds were substantially lower than the peak levels that occur during an acute stress response in this species. Taken together, these data demonstrate that protracted exposure to relatively mild stressful circumstances can have beneficial lifespan effects.
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK.
authors.forename: Valeria
authors.initials: V
authors.lastname: Marasco
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK.
authors.forename: Winnie
authors.initials: W
authors.lastname: Boner
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK.
authors.forename: Britt
authors.initials: B
authors.lastname: Heidinger
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK.
authors.forename: Kate
authors.initials: K
authors.lastname: Griffiths
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, UK. Electronic address: Pat.Monaghan@glasgow.ac.uk.
authors.forename: Pat
authors.initials: P
authors.lastname: Monaghan
mesh_terms: D000222:Adaptation, Physiological; D000375:Aging / Q000502:physiology / Q000523:psychology; D000818:Animals; D001717:Birds; D004435:Eating / Q000523:psychology*; D005508:Food Deprivation / Q000502:physiology*; D005938:Glucocorticoids / Q000378:metabolism*; D008017:Life Expectancy; D009026:Mortality; D013315:Stress, Psychological / Q000378:metabolism / Q000401:mortality / Q000503:physiopathology
chemical_list: D005938:Glucocorticoids
keywords: Chronic stress; Corticosterone; Glucocorticoids; HPA axis; Hormesis; Unpredictable food availability