Reassessment of the cardio-respiratory stress response, using the king penguin as a model. (January 2015)

• Record Type: Journal Article
• Authors: Willener, Astrid S. T.; Halsey, Lewis G.; Strike, Siobhán; Enstipp, Manfred R.; Georges, Jean-Yves; Handrich, Yves
• Is Part Of: Stress. Volume 18:Number 1(2015:Jan.)
• Page Start: 115
• Page End: 120
• Publication Date: 2015-01
• Subjects: Stress (Physiology) -- Periodicals; 616.98
• DOI: 10.3109/10253890.2014.986451
• Languages: English
• ISSNs: 1025-3890

Abstract

<abstract> <title>Abstract</title> <p>Research in to short-term cardio-respiratory changes in animals in reaction to a psychological stressor typically describes increases in rate of oxygen consumption (<inline-formula><tex-math notation="TeX"><![CDATA[\def\newpage{\vfill \break } \nopagenumbers $ \dot V_{\rm O_2 } $ \newpage \end]]></tex-math></inline-formula>) and heart rate. Consequently, the broad consensus is that they represent a fundamental stressor response generalizable across adult species. However, movement levels can also change in the presence of a stressor, yet studies have not accounted for this possible confound on heart rate. Thus the direct effects of psychological stressors on the cardio-respiratory system are not resolved. We used an innovative experimental design employing accelerometers attached to king penguins (<italic>Aptenodytes patagonicus</italic>) to measure and thus account for movement levels in a sedentary yet free-to-move animal model during a repeated measures stress experiment. As with previous studies on other species, incubating king penguins (<italic>N</italic> = 6) exhibited significant increases in both <inline-formula><tex-math notation="TeX"><![CDATA[\def\newpage{\vfill \break } \nopagenumbers $ \dot V_{\rm O_2 } $ \newpage \end]]></tex-math></inline-formula> and heart rate when exposed to the stressor. However, movement levels, while still low, also increased in response to the stressor. Once this was accounted for by comparing periods of time during the control and stress conditions when movement levels were similar as recorded by the accelerometers, only <inline-formula><tex-math notation="TeX"><![CDATA[\def\newpage{\vfill \break } \nopagenumbers $ \dot V_{\rm O_2 } $ \newpage \end]]></tex-math></inline-formula> significantly increased; there was no change in heart rate. These findings offer evidence that changing movement levels have an important effect on the measured stress response and that the cardio-respiratory response <italic>per se</italic> to a psychological stressor (i.e. the response as a result of physiological changes directly attributable to the stressor) is an increase in <inline-formula><tex-math notation="TeX"><![CDATA[\def\newpage{\vfill \break } \nopagenumbers $ \dot V_{\rm O_2 } $ \newpage \end]]></tex-math></inline-formula> without an increase in heart rate.</p> </abstract>