How Truly Conserved Is the “Well-Conserved” Vertebrate Stress Response?

Romero, L. Michael; Gormally, Brenna M. G.

doi:10.1093/icb/icz011

Cited by 73 publications

(49 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, Cort function and regulation have been shown to change inconsistently depending on the life‐history stage and the context of the stressor (Lattin, Bauer, de Bruijn, & Romero, 2012; Romero, 2002). In fact, a recent review has highlighted how the regulation of the acute stress response at multiple physiological scales—including Cort and heart rate—can be greatly influenced by internal and external conditions (Romero & Gormally, 2019), suggesting the stress response is dependent on the context.…”

Section: Introductionmentioning

confidence: 99%

Beyond corticosterone: The acute stress response increases DNA damage in house sparrows

et al. 2020

View full text Add to dashboard Cite

Although corticosterone (Cort) has been the predominant metric used to assess acute stress in birds, it does not always accurately reflect how an animal copes with a stressor. Downstream measurements may be more reliable. In the current study, we tested the hypothesis that acute increases in DNA damage could be used to assess stressor exposure. Studies have shown DNA damage increases in response to stress‐related hormones in vitro; however, this has not yet been thoroughly applied in wild animals. We exposed house sparrows (Passer domesticus) to a 30‐ or 120‐min restraint stressor and took blood samples at 0, 30, 60, and 120 min to measure Cort, DNA damage, and uric acid. Both treatments increased DNA damage and Cort, and decreased uric acid. It thus appears that DNA damage can reflect acute stressor exposure. To improve the usability of DNA damage as a metric for stress, we also tested the impacts of sample storage on DNA damage. Leaving red blood cells on ice for up to 24 hr, only slightly influenced DNA damage. Freezing blood samples for 1–4 weeks substantially increased DNA damage. These findings emphasize the importance of reducing variation between samples by assaying them together whenever possible. Overall, these results indicate that assessing DNA damage is a valid method of assessing acute stressor exposure that is suitable for both laboratory‐ and field‐based studies; however, additional research is needed on the molecular dynamics of nucleated red blood cells, including whether and how their DNA is repaired.

show abstract

Section: Introductionmentioning

confidence: 99%

Beyond corticosterone: The acute stress response increases DNA damage in house sparrows

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Evaluating the incidence and impacts of stress in wildlife is notoriously challenging ( Dickens et al , 2013 , Romero et al , 2019 ). Commonly used markers, such as circulating GCs, are extremely variable and do not fully capture the complexity of the physiological response ( MacDougall-Shackleton et al , 2019 , Romero et al , 2019).…”

Section: Introductionmentioning

confidence: 99%

A blubber gene expression index for evaluating stress in marine mammals

Busqueta

Crocker

Champagne

et al. 2020

Conservation Physiology

View full text Add to dashboard Cite

Evaluating the impacts of anthropogenic disturbance on free-ranging marine mammal populations, many of which are in decline, requires robust diagnostic markers of physiological stress and health. However, circulating levels of canonical ‘stress hormones’ such as glucocorticoids, which are commonly used to evaluate animal health, do not capture the complexity of species-specific responses and cannot be easily measured in large, fully aquatic marine mammals. Alternatively, expression of stress-responsive genes in hormone target tissues such as blubber, the specialized subcutaneous adipose tissue that can be manually or remotely sampled from many marine mammals, may be a more informative and sensitive indicator of recent (within 24 h) exposure to stressors. We previously identified genes that were upregulated in the inner blubber of juvenile northern elephant seals during experimental stimulation of the hypothalamic–pituitary–adrenal axis. In this study, we measured baseline expression levels of a subset of these genes in inner blubber of unmanipulated juvenile elephant seals of varying physiological states and correlated them with other stress markers (body condition index, corticosteroid and thyroid hormone levels). Expression of 10 genes, including those associated with lipid metabolism (ACSL1, HMGCS2, CDO1), redox homeostasis (GPX3), adipokine signaling (ADIPOQ), lipid droplet formation (PLIN1, CIDEA) and adipogenesis (DKK1, AZGP1, TGFBI), was described by three principal components and was associated with cortisol and thyroid hormone levels. Significantly, baseline gene expression levels were predictive of circulating hormone levels, suggesting that these markers may be potential indicators of exposure to stressors in marine mammal species that are inaccessible for blood sampling. A similar approach may be used to identify species-specific stress markers in other tissues that can be sampled by remote biopsy dart from free-ranging marine mammals, such as outer blubber and skin.

show abstract

“…negative feedback strength) are emerging as having greater value than single time point measurements (e.g. maximum titres) in predicting fitness [9], while establishing within-individual repeatability between acute stress responses is essential for determining response phenotypes [10].…”

Section: Introductionmentioning

confidence: 99%

Eye region surface temperature dynamics during acute stress relate to baseline glucocorticoids independently of environmental conditions

Jerem

Jenni-Eiermann

McKeegan

et al. 2019

Physiology & Behavior

View full text Add to dashboard Cite

Reactions to acute stressors are critical for survival. Yet, the challenges of assessing underlying physiological processes in the field limit our understanding of how variation in the acute stress response relates to fitness in free-living animals. Glucocorticoid secretion during acute stress can be measured from blood plasma concentrations, but each blood sample can only provide information for one point in time. Also, the number of samples that can be extracted from an individual in the field is usually limited to avoid compromising welfare. This restricts capacity for repeated assessment, and therefore temporal resolution of findings within- and between-acute stress responses - both of which are important for determining links between acute stress and fitness. Acute stress induces additional body surface temperature changes that can be measured non-invasively, and at high frequencies using thermal imaging, offering opportunities to overcome these limitations. But, this method's usefulness in the field depends on the extent that environmental conditions affect the body surface temperature response, which remains poorly understood. We assessed the relative importance of individual physiology (baseline glucocorticoid concentrations) and environmental conditions (air temperature and relative humidity) in determining the eye region surface temperature (Teye) response to acute stress, in wild blue tits (Cyanistes caeruleus) during trapping, handling and blood sampling. When controlling for between-individual baseline variation, Teye initially dropped rapidly below, and then recovered above baseline, before declining more slowly until the end of the test, 160 s after trap closure. One measure of the amplitude of this response – the size of the initial drop in Teye – was dependent on environmental conditions, but not baseline corticosterone. Whereas, two properties defining response dynamics – the timing of the initial drop, and the slope of the subsequent recovery – were related to baseline corticosterone concentrations, independently of environmental conditions. This suggests inferring the acute stress response using thermal imaging of Teye will be practical under fluctuating environmental conditions in the field.

show abstract

How Truly Conserved Is the “Well-Conserved” Vertebrate Stress Response?

Cited by 73 publications

References 50 publications

Beyond corticosterone: The acute stress response increases DNA damage in house sparrows

Beyond corticosterone: The acute stress response increases DNA damage in house sparrows

A blubber gene expression index for evaluating stress in marine mammals

Eye region surface temperature dynamics during acute stress relate to baseline glucocorticoids independently of environmental conditions

Contact Info

Product

Resources

About