Modulation of the hypothalamic–pituitary–adrenal axis of an Arctic–breeding polygynandrous songbird, the Smith's longspur,
            <i>Calcarius pictus</i>

Meddle, Simone; Owen-Ashley, Noah T; Richardson, Matthew I; Wingfield, John C.

doi:10.1098/rspb.2003.2455

Cited by 63 publications

(31 citation statements)

References 34 publications

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“…Supporting this interpretation, changes in the release of ACTH have already been shovm to regulate corticosterone stress response in birds (Romero et aJ. 1998i3,1998¿, 1998q Romero and Wingfield 1998Meddle et al 2003;Romero 2006). For instance, Romero (2006) found that an experimental increase in circulating ACTH levels stimulates corticosterone secretion of bouse sparrows {Passer domestiats) during several life-history stages (molting, wintering, and breeding).…”

Section: Proximate Causes Of Corticosterone Release Modulationmentioning

confidence: 71%

“…Because pituitary adrenocorticotropic hormone (ACTH) controls adrenal corticosterone release, an attenuation of the corticosterone stress response could result from changes in the adrenal's sensitivity to ACTH Romero et al 1998/j. 19981', Sims andMeddle et al 2003;Romero 2006). In this study, we tested whether the adrenal's sensitivity to ACTH varied with body condition in brooding snow petrels.…”

Section: Introductionmentioning

confidence: 95%

“…Because corticosterone secretion is involved in the regulation of the tradeoff between reproduction and survival, ecophysiologists have suggested that the sensitivity of the HPA axis to stress could be a reliable measurement of parental investment in vertebrates (Wingfield et al 1995;Ricklefs and Wikelski 2002;Holberton and Wingfield 2003;Wilson and Holberton 2004). Indeed, a number of studies have effectively demonstrated that corticosterone secretion in response to a standardized stress protocol is modulated according to environmental conditions, physiological conditions, and life-history stages (Wingfield et al 1995;O'Reilly and Wingfield 2001;Meddle et al 2003;Moore and lessop 2003;Wingfield and Sapolsky 2003;Lendvai et al 2007).…”

Section: Introductionmentioning

confidence: 95%

See 2 more Smart Citations

What Factors Drive Prolactin and Corticosterone Responses to Stress in a Long‐Lived Bird Species (Snow PetrelPagodroma nivea)?

Angelier¹,

Moe²,

Blanc³

et al. 2009

Physiological and Biochemical Zoology

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Life-history theory predicts that individuals should adapt their parental investment to the costs and benefits of the current reproductive effort. This could be achieved by modulating the hormonal stress response, which may shift energy investment away from reproduction and redirect it toward survival. In birds, this stress response consists of a release of corticosterone that may be accompanied by a decrease in circulating prolactin, a hormone involved in the regulation of parental care. We lack data on the modulation of the prolactin stress response. In this study, we tested the hypothesis that individuals should modulate their prolactin stress response according to the fitness value of the current reproductive effort relative to the fitness value of future reproduction. Specifically, we examined the influence of breeding status (failed breeders vs. incubating birds) and body condition on prolactin and corticosterone stress responses in a long-lived species, the snow petrel Pagodroma nivea. When facing stressors, incubating birds had higher prolactin levels than failed breeders. However, we found no effect of body condition on the prolactin stress response. The corticosterone stress response was modulated according to body condition but was not affected by breeding status. We also performed an experiment using injections of adrenocorticotropic hormone (ACTH) and found that the modulation of the corticosterone stress response was probably associated with a reduction in ACTH release by the pituitary and a decrease in adrenal sensitivity to ACTH. In addition, we examined whether prolactin and corticosterone secretion were functionally linked. We found that these two hormonal stress responses were not correlated. Moreover, injection of ACTH did not affect prolactin levels, demonstrating that short-term variations in prolactin levels are not governed directly or indirectly by ACTH release. Thus, we suggest that the corticosterone and prolactin responses to short-term stressors are independent and may therefore mediate some specific components of parental investment in breeding birds. With mounting evidence, we suggest that examining both corticosterone and prolactin stress responses could be relevant to parental investment in vertebrates.

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Section: Proximate Causes Of Corticosterone Release Modulationmentioning

confidence: 71%

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 95%

See 1 more Smart Citation

What Factors Drive Prolactin and Corticosterone Responses to Stress in a Long‐Lived Bird Species (Snow PetrelPagodroma nivea)?

Angelier¹,

Moe²,

Blanc³

et al. 2009

Physiological and Biochemical Zoology

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“…Marra and Holberton (1998) and O'Reilly and found no effect of sex on baseline CORT or the stress response in migratory passerines or premigratory shorebirds, respectively. However, other studies have previously reported differences between male and female baseline CORT level (Meddle et al 2003), as well as differences in stress response (O'Reilly and Wingfield 2003;Jenni-Eiermann et al 2008). However, these studies focused primarily on the breeding season, where sex differences are thought to be related to differential parental investment.…”

Section: Discussionmentioning

confidence: 96%

Variation in Plasma Corticosterone in Migratory Songbirds: A Test of the Migration-Modulation Hypothesis

Wagner¹,

Green²,

Cooper³

et al. 2014

Physiological and Biochemical Zoology

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Physiological mechanisms underlying migration remain poorly understood, but recent attention has focused on the role of the glucocorticoid hormone corticosterone (CORT) as a key endocrine regulator of migration. The migration-modulation hypothesis (MMH) proposes that baseline plasma CORT levels are elevated in migratory birds to facilitate hyperphagia and lipogenesis and that further elevation of CORT in response to acute stress is suppressed. Consequently, CORT may be a poor indicator of individual condition or environmental variation in migratory birds. We tested the MMH by measuring baseline and stress-induced CORT in common yellowthroats (Geothlypis trichas) during fall migration over 2 consecutive years in the Revelstoke Reach drawdown zone, a migratory stopover site affected by local hydroelectric operations. Birds had low baseline CORT at initial capture (<5 ng/mL) and then showed a robust stress response, with CORT increasing to ca. 50 ng/mL within 10-20 min. Our data therefore do not support the MMH. Baseline CORT did not vary with body mass, time of capture, Julian day, or year, suggesting that variable flooding regimes did not affect baseline CORT. Individual variation in the rate of increase in CORT was correlated with Julian day, being higher later in the migration period. Our data suggest that plasma CORT can be a useful metric in migration studies.

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“…For example, in many studies morphological measurements are taken after the last sampling period, so that the only time birds are handled is when blood samples are taken (Wingfield et al 1992, Silverin et al 1997, Blas et al 2005. In contrast, sometimes morphological measurements are taken in between blood samples, when the birds would otherwise be in a cloth bag (Meddle et al 2003, Adams et al 2005. Similarly, occasionally birds are held in small cages in between sampling periods (e.g., Love et al 2005) rather than in cloth bags.…”

mentioning

confidence: 99%

Stress Responsiveness in Nestlings: A Comparison of Two Sampling Techniques

Dufty¹

2008

The Auk

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I compared the effects on plasma corticosterone levels of two methods of collecting blood samples during standardized capture and handling stress protocols. In one method, individual nestling American Kestrels (Falco sparverius) were bled at three time periods: when initially removed from the nest, and 15 and 30 min later. In the other method, siblings removed from a nest were bled once each, either at the time of removal, or 15 or 30 min later. I found that there was no difference between the two groups in plasma corticosterone levels at the first sampling period, but 15 and 30 min after capture the singly-bled birds had significantly higher plasma corticosterone levels than the multiply-bled nestlings. The results suggest that data from multiplybled birds underestimate actual circulating hormone levels. The underlying mechanism for this phenomenon is unknown, although it may involve hemodilution.Key words: American Kestrel, stress, corticosterone, hemodilution, nestlings Organisms experiencing stressors typically secrete glucocorticoids to maintain or restore homeostasis (Wingfield and Romero 2001). The pattern of corticosterone secretion in response to a standardized stressor frequently is used to compare how different organisms respond to disruptive events. For birds, the most common technique is to use capture and handling stress to activate the hypothalamic-pituitary-adrenal (HPA) axis, with the sensitivity of the axis to the stressor determined through repeated blood sampling followed by radioimmunoassay (RIA) of the blood samples for corticosterone. Birds are held in a cloth bag between sampling sessions. This protocol facilitates comparison of adrenal responsiveness within and among species, and the results of such studies have enhanced our understanding of how ecological factors modulate stress responses (Wingfield et al. 1998, Wingfield andRomero 2001).The importance of a standardized approach in collecting blood samples to measure adrenoresponsiveness has been acknowledged, either explicitly or implicitly, in myriad papers. However, subtle, but possibly important, procedural differences occur among studies that use this protocol. For example, in many studies morphological measurements are taken after the last sampling period, so that the only time birds are handled is when blood samples are taken (Wingfield et al. 1992, Silverin et al. 1997, Blas et al. 2005. In contrast, sometimes morphological measurements are taken in between blood samples, when the birds would otherwise be in a cloth bag (Meddle et al. 2003, Adams et al. 2005. Similarly, occasionally birds are held in small cages in between sampling periods (e.g., Love et al. 2005) rather than in cloth bags. Furthermore, different trapping methods may be utilized in the same investigation (e.g., Lynn et al. 2003). In addition, in most studies similar amounts of blood are removed at each sampling period, but in others the initial blood sample may be larger, if additional hematological measurements are performed (e.g., Clinchy et al. 2004)....

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Modulation of the hypothalamic–pituitary–adrenal axis of an Arctic–breeding polygynandrous songbird, the Smith's longspur, Calcarius pictus

Cited by 63 publications

References 34 publications

What Factors Drive Prolactin and Corticosterone Responses to Stress in a Long‐Lived Bird Species (Snow PetrelPagodroma nivea)?

What Factors Drive Prolactin and Corticosterone Responses to Stress in a Long‐Lived Bird Species (Snow PetrelPagodroma nivea)?

Variation in Plasma Corticosterone in Migratory Songbirds: A Test of the Migration-Modulation Hypothesis

Stress Responsiveness in Nestlings: A Comparison of Two Sampling Techniques

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