scholarly journals Tameness and stress physiology in a predator-naive island species confronted with novel predation threat

2006 ◽  
Vol 274 (1609) ◽  
pp. 577-582 ◽  
Author(s):  
Thomas Rödl ◽  
Silke Berger ◽  
L Michael Romero ◽  
Martin Wikelski

Tame behaviour, i.e. low wariness, in terrestrial island species is often attributed to low predation pressure. However, we know little about its physiological control and its flexibility in the face of predator introductions. Marine iguanas ( Amblyrhynchus cristatus ) on the Galápagos Islands are a good model to study the physiological correlates of low wariness. They have lived virtually without predation for 5–15 Myr until some populations were first confronted with feral cats and dogs some 150 years ago. We tested whether and to what extent marine iguanas can adjust their behaviour and endocrine stress response to novel predation threats. Here, we show that a corticosterone stress response to experimental chasing is absent in naive animals, but is quickly restored with experience. Initially, low wariness also increases with experience, but remains an order of magnitude too low to allow successful escape from introduced predators. Our data suggest that the ability of marine iguanas to cope with predator introductions is limited by narrow reaction norms for behavioural wariness rather than by constraints in the underlying physiological stress system. In general, we predict that island endemics show flexible physiological stress responses but are restricted by narrow behavioural plasticity.

Author(s):  
Renae Charalambous ◽  
Troy Simonato ◽  
Matthew Peel ◽  
Edward Narayan

Koalas (Phascolarctos cinereus) are one of Australia's most charismatic native small marsupial species. Unfortunately, populations of koalas are rapidly declining throughout Australia and they continue to face increasing pressure from a changing ecosystem. Negative stimulants in the environment can elicit stress responses through activation of the hypothalamic-pituitary-adrenal (HPA) axis. Depending on the duration of the negative stimulant, the stress response can lead to either acute or chronic side effects, and is shown through the activation of the neuroendocrine stress system and the release of glucocorticoids (e.g., cortisol). Wild koalas entering clinical care face novel stressors that can be out of a wildlife carer's control. In this pilot study, we monitored physiological stress in three wild koalas at a wildlife rehabilitation centre in New South Wales, Australia. Acute and chronic stress was indexed non-invasively, with faecal samples taken to evaluate acute stress, and fur samples taken to evaluate chronic stress. Sampling occurred sporadically over four months, from the start of September 2018 to the end of December 2018. Results attempt to understand the stress response of koalas to negative stimulants in the environment by comparing faecal glucocorticoids on days where a known stressor was recorded with days where no known stressor was recorded. Furthermore, variations in faecal and fur glucocorticoids were compared between the three koalas in this study. To our knowledge, this is the first evidence of stress tracking of wild rescued koalas in a sanctuary. We suggest that further monitoring of baseline, acute and chronic stress will be needed to better understand how koalas respond to negative stimulants associated with clinical care.


2005 ◽  
Vol 35 (2) ◽  
pp. 289-295 ◽  
Author(s):  
Luís Antônio Kioshi Aoki Inoue ◽  
Luís Orlando B. Afonso ◽  
George K. Iwama ◽  
Gilberto Moraes

Fish transport is one of the most stressful procedures in aquaculture facilities. The present work evaluated the stress response of matrinxã to transportation procedures, and the use of clove oil as an alternative to reduce the stress response to transport in matrinxã (Brycon cephalus). Clove oil solutions were tested in concentrations of 0, 1, 5 and 10 mg/L during matrinxã transportation in plastic bags, supplied with water and oxygen as the usual field procedures in Brazil. Clove oil reduced some of the physiological stress responses (plasma cortisol, glucose and ions) that we measured. The high energetic cost to matrinxã cope with the transport stress was clear by the decrease of liver glycogen after transport. Our results suggest that clove oil (5 mg/l) can mitigate the stress response in matrinxã subjected to transport.


2020 ◽  
pp. 101-118
Author(s):  
James M. Bjork ◽  
Nicholas D. Thomson

Stress is both a critical contributor and consequence of substance use disorder (SUD). First, exaggerated subjective stress responses are characteristic of affective symptomatology such as depression, bipolar disorder, generalized anxiety, and posttraumatic stress disorder (sometimes stemming from histories of abuse) that have been prognostic of development of addiction in longitudinal studies. Substance use is negatively reinforced in many at-risk and addicted individuals because it may acutely alleviate stress. Second, chronic administration of commonly abused substances alters physiological stress response systems, especially during acute withdrawal. Third, acute stress responses blunt the addicted individual’s frontocortically mediated behavioral repertoire (solution space) in favor of reflexive behavioral biases toward relief-based substance use. Therefore, acute stress responses are a strong trigger for relapse to substance use during extended recovery. These findings have collectively led to approaches to SUD relapse prevention that pharmacologically blunt components of the stress response, but these agents have not reliably shown success in human clinical trials. This chapter reviews these different relationships between stress and addiction and offers future avenues for additional research.


2013 ◽  
Vol 280 (1768) ◽  
pp. 20131444 ◽  
Author(s):  
Tim S. Jessop ◽  
Mike Letnic ◽  
Jonathan K. Webb ◽  
Tim Dempster

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.


2018 ◽  
Vol 61 (7) ◽  
pp. 1525-1543 ◽  
Author(s):  
Leah B. Helou ◽  
Clark A. Rosen ◽  
Wei Wang ◽  
Katherine Verdolini Abbott

Purpose Research suggests that abnormal levels of intrinsic laryngeal muscle (ILM) contraction is a potential causal factor in stress-induced voice disorders. This study seeks to characterize the ILM stress response in a cohort of vocally healthy women. Method The authors used an unblinded, nonrandomized, repeated-measures design. Forty vocally healthy female adults were subjected to a stressful speech preparation task. Measurements of heart rate, blood pressure, trapezius muscle (positive control) activation, and tibialis muscle (negative control) activation were obtained from 37 participants before and during stressor exposure, in a nonvoice and nonspeaking task paradigm, to confirm physiological stress response compared to baseline. Fine wire electromyography of the ILMs (posterior cricoarytenoid, thyroarytenoid/lateral cricoarytenoid muscle complex, and cricothyroid) was performed simultaneously so that the activity of these muscles could be measured prior to and during stressor exposure. Results The protocol successfully elicited the typical and expected physiological stress responses. Findings supported the hypothesis that, in some individuals, the ILMs significantly increase in activity during stress reactions compared to baseline, as do the control muscles. Conclusions This study characterizes ILM responses to psychological stress in vocally healthy participants. Some of the female adults in this study appeared to be “laryngeal stress responders,” as evidenced by increased activity of the ILMs during a silent (i.e., nonvocal, nonspeech) speech preparation task that they considered to be stressful.


Author(s):  
James P. Herman

Appropriate control of the HPA (hypothalamo-pituitary-adrenocortical axis) is required for adaptation to physiological and environmental challenges. Inadequate control is linked to numerous stress-related pathologies, including PTSD, highlighting its importance in linking physiological stress responses with behavioral coping strategies. This chapter highlights neurocircuit mechanisms underlying HPA axis adaptation and pathology. Control of the HPA stress response is mediated by the coordinated activity of numerous limbic brain regions, including the prefrontal cortex, hippocampus, and amygdala. In general, hippocampal output inhibits anticipatory HPA axis responses, whereas amygdala subnuclei participate in stress activation. The prefrontal cortex plays an important role in inhibition of context-dependent stress responses. These regions converge on subcortical structures that relay information to paraventricular nucleus corticotropin-releasing hormone neurons, controlling the magnitude and duration of HPA axis stress responses. The output of these neural networks determines the net effect on glucocorticoid secretion, both within the normal adaptive range and in pathological circumstances.


mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Kerrie L. May ◽  
Kelly M. Lehman ◽  
Angela M. Mitchell ◽  
Marcin Grabowicz

ABSTRACTGram-negative bacteria produce lipid-anchored lipoproteins that are trafficked to their outer membrane (OM). These lipoproteins are essential components in each of the molecular machines that build the OM, including the Bam machine that assembles β-barrel proteins and the Lpt pathway that transports lipopolysaccharide. Stress responses are known to monitor Bam and Lpt function, yet no stress system has been found that oversees the fundamental process of lipoprotein trafficking. We used genetic and chemical biology approaches to induce several different lipoprotein trafficking stresses inEscherichia coli. Our results identified the Cpx two-component system as a stress response for monitoring trafficking. Cpx is activated by trafficking defects and is required to protect the cell against the consequence of the resulting stress. The OM-targeted lipoprotein NlpE acts as a sensor that allows Cpx to gauge trafficking efficiency. We reveal that NlpE signals to Cpx while it is transiting the inner membrane (IM)en routeto the OM and that only a small highly conserved N-terminal domain is required for signaling. We propose that defective trafficking causes NlpE to accumulate in the IM, activating Cpx to mount a transcriptional response that protects cells. Furthermore, we reconcile this new role of NlpE in signaling trafficking defects with its previously proposed role in sensing copper (Cu) stress by demonstrating that Cu impairs acylation of lipoproteins and, consequently, their trafficking to the OM.IMPORTANCEThe outer membrane built by Gram-negative bacteria such asEscherichia coliforms a barrier that prevents antibiotics from entering the cell, limiting clinical options at a time of prevalent antibiotic resistance. Stress responses ensure that barrier integrity is continuously maintained. We have identified the Cpx signal transduction system as a stress response that monitors the trafficking of lipid-anchored lipoproteins to the outer membrane. These lipoproteins are needed by every machine that builds the outer membrane. Cpx monitors just one lipoprotein, NlpE, to detect the efficiency of lipoprotein trafficking in the cell. NlpE and Cpx were previously shown to play a role in resistance to copper. We show that copper blocks lipoprotein trafficking, reconciling old and new observations. Copper is an important element in innate immunity against pathogens, and our findings suggest that NlpE and Cpx helpE. colisurvive the assault of copper on a key outer membrane assembly pathway.


Author(s):  
Sue Boinski

Temperament is a complex behavioral trait that describes characteristic patterns of response to environmental, particularly social, conditions and perturbations. Disparities in the tendency to approach or avoid novelty or readiness to engage in aggressive interactions have been documented in comparisons between species (Christian 1970), subspecies (Gonzalez et al. 1981), populations within species (Champoux et al. 1994), inbred lines of laboratory animals (Scott and Fuller 1965), domesticated versus wild populations (Price 1984), and individuals within a species (Benus et al. 1992). Differences in physiological stress response systems (Selye 1937) are commonly identified as an important proximate mechanism underlying these temperament differences (Huntingford and Turner 1987, Kagan et al. 1988). Social systems of animals are perceived as emerging from relationships between individuals (Hinde 1983). Individual interactions, in turn, are hypothesized to reflect individual behavioral strategies which maximize inclusive fitness (Silk 1987). Selection on a physiological system, which can dramatically affect the pattern and outcomes of individual interactions, could produce evolutionary change in social organization and social behavior. Many workers explicitly suggest that temperament differences among primate species are adaptive in many instances, yet admit that the specific ecological and social selection pressures to which the neuroendocrine system is responding are often unclear (Thierry 1985, Clarke et al. 1988, Richard et al. 1989). Species-level comparisons have not offered many testable comparative models, probably because of confounding effects such as large phylogentic distances or uncertain phylogeny, inadequate knowledge of ecological and social conditions in the wild, drift, and convergent evolution. In short, little progress has been made toward understanding the evolution of stress-response patterns in primates. In this chapter I suggest that comparisons of geographically and genetically separated primate populations or subspecies may be an alternative and more successful approach to addressing the evolution of stress responses and the disparate social behaviors that result. Population and geographic comparisons are likely to be profitable for three reasons: (1) comparisons are less likely to be confounded by phylogenetic disparities (Arnold 1992), (2) the factors imposing different selective regimes among localities can perhaps be more readily identified, (3) hypothesis testing may be facilitated because populations suitable for testing a model will be easier to identify than new species.


2017 ◽  
Vol 11 (4) ◽  
pp. 685-692 ◽  
Author(s):  
Javad Razjouyan ◽  
Gurtej Singh Grewal ◽  
Talal K. Talal ◽  
David G. Armstrong ◽  
Joseph L. Mills ◽  
...  

Background: Poor healing is an important contributing factor to amputation among patients with diabetic foot ulcers (DFUs). Physiological stress may slow wound healing and increase susceptibility to infection. Objectives: The objective was to examine the association between heart rate variability (HRV) as an indicator of physiological stress response and healing speed (HealSpeed) among outpatients with active DFUs. Design and Methods: Ambulatory patients with diabetes with DFUs (n = 25, age: 59.3 ± 8.3 years) were recruited. HRV during pre–wound dressing was measured using a wearable sensor attached to participants’ chest. HRVs were quantified in both time and frequency domains to assess physiological stress response and vagal tone (relaxation). Change in wound size between two consecutive visits was used to estimate HealSpeed. Participants were then categorized into slow healing and fast healing groups. Between the two groups, comparisons were performed for demographic, clinical, and HRV derived parameters. Associations between different descriptors of HRV and HealSpeed were also assessed. Results: HealSpeed was significantly correlated with both vagal tone ( r = –.705, P = .001) and stress response ( r = .713, P = .001) extracted from frequency domain. No between-group differences were observed except those from HRV-derived parameters. Models based on HRVs were the highest predictors of slow/fast HealSpeed (AUC > 0.90), while models based on demographic and clinical information had poor classification performance (AUC = 0.44). Conclusion: This study confirms an association between stress/vagal tone and wound healing in patients with DFUs. In particular, it highlights the importance of vagal tone (relaxation) in expediting wound healing. It also demonstrates the feasibility of assessing physiological stress responses using wearable technology in outpatient clinic during routine clinic visits.


2009 ◽  
Vol 21 (1) ◽  
pp. 47-68 ◽  
Author(s):  
Laura R. Stroud ◽  
Elizabeth Foster ◽  
George D. Papandonatos ◽  
Kathryn Handwerger ◽  
Douglas A. Granger ◽  
...  

AbstractLittle is known about normative variation in stress response over the adolescent transition. This study examined neuroendocrine and cardiovascular responses to performance and peer rejection stressors over the adolescent transition in a normative sample. Participants were 82 healthy children (ages 7–12 years, n = 39, 22 females) and adolescents (ages 13–17, n = 43, 20 females) recruited through community postings. Following a habituation session, participants completed a performance (public speaking, mental arithmetic, mirror tracing) or peer rejection (exclusion challenges) stress session. Salivary cortisol, salivary alpha amylase (sAA), systolic and diastolic blood pressure (SBP, DBP), and heart rate were measured throughout. Adolescents showed significantly greater cortisol, sAA, SBP, and DBP stress response relative to children. Developmental differences were most pronounced in the performance stress session for cortisol and DBP and in the peer rejection session for sAA and SBP. Heightened physiological stress responses in typical adolescents may facilitate adaptation to new challenges of adolescence and adulthood. In high-risk adolescents, this normative shift may tip the balance toward stress response dysregulation associated with depression and other psychopathology. Specificity of physiological response by stressor type highlights the importance of a multisystem approach to the psychobiology of stress and may also have implications for understanding trajectories to psychopathology.


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