0230 Using hair cortisol concentrations to assess the adrenocortical stress response in beef cattle administered corticotrophin-release hormone

Continued range expansion into physiologically challenging environments requires invasive species to maintain adaptive phenotypic performance. The adrenocortical stress response, governed in part by glucocorticoid hormones, influences physiological and behavioural responses of vertebrates to environmental stressors. However, any adaptive role of this response in invasive populations that are expanding into extreme environments is currently unclear. We experimentally manipulated the adrenocortical stress response of invasive cane toads ( Rhinella marina ) to investigate its effect on phenotypic performance and fitness at the species' range front in the Tanami Desert, Australia. Here, toads are vulnerable to overheating and dehydration during the annual hot–dry season and display elevated plasma corticosterone levels indicative of severe environmental stress. By comparing unmanipulated control toads with toads whose adrenocortical stress response was manipulated to increase acute physiological stress responsiveness, we found that control toads had significantly reduced daily evaporative water loss and higher survival relative to the experimental animals. The adrenocortical stress response hence appears essential in facilitating complex phenotypic performance and setting fitness trajectories of individuals from invasive species during range expansion.

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DEVELOPMENTAL STUDY OF PITUITARY-ADRENOCORTICAL RESPONSE IN MICE: PLASMA AND BRAIN CORTICOSTERONE DETERMINATION AFTER HISTAMINE STRESS

Journal of Endocrinology ◽

10.1677/joe.0.0600353 ◽

1974 ◽

Vol 60 (2) ◽

pp. 353-358 ◽

Cited By ~ 14

Author(s):

RYOKO KAKIHANA ◽

STEPHEN BLUM ◽

SEYMOUR KESSLER

Keyword(s):

Stress Response ◽

Subcutaneous Injection ◽

Plasma Corticosterone ◽

Developmental Study ◽

Histamine Dihydrochloride ◽

Adrenocortical Response ◽

Corticosterone Response ◽

Adrenocortical Stress Response ◽

Hybrid Mice ◽

The Brain

SUMMARY The development of the pituitary-adrenocortical stress response was studied in CBA/J × DBA/2J hybrid mice. On the basis of the plasma corticosterone response 15 min after a subcutaneous injection of histamine dihydrochloride (50 mg/kg), the first three neonatal weeks could be divided into stress-nonresponsive (3–211 days) and stress-responsive 16–21 days) periods. During the former period, corticosterone levels in the brains of the non-stressed control mice were 63% higher than those of comparable mice during the latter period. Histamine stress significantly increased corticosterone concentrations in the brain during both these periods, but the increase was much greater (88%) during the stress-responsive period than during the stress-nonresponsive period (29%).

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Maturation of the adrenocortical stress response: Neuroendocrine control mechanisms and the stress hyporesponsive period

Brain Research Reviews ◽

10.1016/0165-0173(86)90010-x ◽

1986 ◽

Vol 11 (1) ◽

pp. 65-76 ◽

Cited By ~ 664

Author(s):

Robert M. Sapolsky ◽

Michael J. Meaney

Keyword(s):

Stress Response ◽

Control Mechanisms ◽

Neuroendocrine Control ◽

Adrenocortical Stress Response

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