scholarly journals Predation risk and the evolution of a vertebrate stress response: parallel evolution of stress reactivity and sexual dimorphism

2021 ◽  
Author(s):  
Jerker Vinterstare ◽  
Gustaf MO Ekelund Ugge ◽  
Kaj Hulthén ◽  
Alexander Hegg ◽  
Christer Brönmark ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Stress Response ◽  
Predation Risk ◽  
Stress Reactivity ◽  
Parallel Evolution

scholarly journals Procoagulant reactivity to laboratory acute mental stress in Africans and Caucasians, and its relation to depressive symptoms: The SABPA Study

2013 ◽  
Vol 110 (11) ◽  
pp. 977-986 ◽  
Author(s):  
Mark Hamer ◽  
Nico T. Malan ◽  
Kobus Scheepers ◽  
Muriel Meiring ◽  
Leonè Malan ◽  
...  
Keyword(s):  
Psychological Distress ◽  
Depressive Symptoms ◽  
Stress Response ◽  
Mental Stress ◽  
Stress Reactivity ◽  
General Health Questionnaire ◽  
Peripheral Resistance ◽  
Well Being ◽  
Health Questionnaire ◽  
D Dimer

SummaryThe risk of cardiovascular disease is dramatically increasing in Africans (black). The prothrombotic stress response contributes to atherothrombotic disease and is modulated by depressive symptoms. We examined coagulation reactivity to acute mental stress and its relation to psychological well-being in Africans relative to Caucasians (white). A total of 102 African and 165 Caucasian school teachers underwent the Stroop Color-Word Conflict test. Circulating levels of von Willebrand factor (VWF) antigen, fibrinogen, and D-dimer were measured before and after the Stroop. Cardiovascular reactivity measures were also obtained. All participants completed the Patient Health Questionnaire-9 and the General Health Questionnaire-28 for the assessment of depressive symptoms and total psychological distress, respectively. After controlling for covariates, resting levels of VWF, fibrinogen, and D-dimer were higher in Africans than in Caucasians (all p-values ≤0.006). Depressive symptoms and psychological distress were not significantly associated with resting coagulation measures. Stress reactivity in VWF (p<0.001) and fibrinogen (p=0.016), but not in D-dimer (p=0.27), were decreased in Africans relative to Caucasians with Africans showing greater reactivity of total peripheral resistance (p=0.017). Depressive symptoms, but not general psychological distress, were associated with greater VWF increase (p=0.029) and greater fibrinogen decrease (p=0.030) in Africans relative to Caucasians. In conclusion, Africans showed greater hypercoagulability at rest but diminished procoagulant reactivity to acute mental stress when compared with Caucasians. Ethnic differences in the vascular adrenergic stress response might partially explain this finding. Depressive symptoms were associated with exaggerated VWF reactivity in Africans relative to Caucasians. The clinical implications of these findings for Africans need further study.

scholarly journals Gonadal Steroids Negatively Modulate Oxidative Stress in CBA/Ca Female Mice Infected withP. bergheiANKA

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Néstor Aarón Mosqueda-Romo ◽  
Ana Laura Rodríguez-Morales ◽  
Fidel Orlando Buendía-González ◽  
Margarita Aguilar-Sánchez ◽  
Jorge Morales-Montor ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Superoxide Dismutase ◽  
Sexual Dimorphism ◽  
Stress Response ◽  
Glutathione Peroxidase ◽  
Oxidative Stress Response ◽  
Gonadal Steroids ◽  
Male Mice ◽  
Female Mice

We decreased the level of gonadal steroids in female and male mice by gonadectomy. We infected these mice withP. bergheiANKA and observed the subsequent impact on the oxidative stress response. Intact females developed lower levels of parasitaemia and lost weight faster than intact males. Gonadectomised female mice displayed increased levels of parasitaemia, increased body mass, and increased anaemia compared with their male counterparts. In addition, gonadectomised females exhibited lower specific catalase, superoxide dismutase, and glutathione peroxidase activities in their blood and spleen tissues compared with gonadectomised males. To further study the oxidative stress response inP. bergheiANKA-infected gonadectomised mice, nitric oxide levels were assessed in the blood and spleen, and MDA levels were assessed in the spleen. Intact, sham-operated, and gonadectomised female mice exhibited higher levels of nitric oxide in the blood and spleen compared with male mice. MDA levels were higher in all of the female groups. Finally, gonadectomy significantly increased the oxidative stress levels in females but not in males. These data suggest that differential oxidative stress is influenced by oestrogens that may contribute to sexual dimorphism in malaria.

scholarly journals The buffer effect of therapy dog exposure on stress reactivity in undergraduate students

2021 ◽  
Author(s):  
Alexandra J. Fiocco ◽  
Anastasia M. Hunse
Keyword(s):  
Stress Response ◽  
University Students ◽  
Undergraduate Students ◽  
Stress Reactivity ◽  
Physiological Stress ◽  
Electrodermal Activity ◽  
Management Program ◽  
Buffer Effect ◽  
Therapy Dog ◽  
Effect Of Therapy

Stress is an insidious health risk that is commonly reported among university students. While research suggests that dog exposure may facilitate recovery from a stress response, little is known about the buffer effect of dog exposure on the stress response to a future stressor. This study examined whether interaction with a therapy dog could reduce the strength of the physiological stress response when exposed to a subsequent stressor. Sixty-one university students were randomly assigned to either a therapy dog (TD, n = 31) or a no-dog control (C, n = 30) group. The stress response was measured by electrodermal activity (EDA) in response to the Paced Auditory Serial Addition Test (PASAT). Participants also completed questionnaires that assessed pet attitude, general stress levels, and affect. Analyses of covariance (ANCOVAs) showed that increase in EDA was significantly more pronounced in the C group than in the TD group (p < 0.01). Pet attitudes did not modulate the buffer effect of therapy dog exposure. Results suggest that therapy dog exposure may buffer the stress response in university students, which has implications for the promotion of a viable stress management program on university campuses. Keywords: stress; therapy dog; intervention; human-animal interaction

scholarly journals Maternal age and maternal environment affect stress reactivity and measures of social behaviour in laying hens

2021 ◽  
Author(s):  
Mariana R. L. V. Peixoto ◽  
Leanne Cooley ◽  
Tina M. Widowski
Keyword(s):  
Stress Response ◽  
Maternal Effects ◽  
Social Stress ◽  
Maternal Age ◽  
Stress Reactivity ◽  
Laying Hens ◽  
Maternal Environment ◽  
Positive Effects ◽  
The Subject ◽  
Commercial Breeder

Abstract Maternal effects can shape the phenotypes of offspring, but the extent to which a layer breeder’s experience can affect commercial laying hens remains unclear. We aimed to investigate the effects of maternal age and maternal environment on laying hens' behaviour and stress response. In our first experiment (E1), commercial hybrid hens were reared either in aviary or barren brooding cages, then housed in aviary, conventional cages or furnished (enriched) cages, thus forming different maternal housing treatments. Hens from each treatment were inseminated at three ages, and measures of response to manual restraint and social stress were assessed in offspring. In experiment 2 (E2), maternal age effects on offspring's stress response were further investigated using fertile eggs from commercial breeder flocks at three ages. In E1, maternal age affected struggling and corticosterone during manual restraint, feather pecking and pulling and comb wounds. Additionally, maternal rearing and housing in aviary systems showed positive effects on measures of behaviour and stress response in offspring. Effects of maternal age were not replicated in E2, possibly due to methodological differences or higher tolerance to maternal effects in commercial breeders. Overall, we recommend researchers start reporting parent stock's age to increase our understanding of the subject.

scholarly journals New Perspectives in the Model of Stress Response

2017 ◽  
pp. S173-S185 ◽  
Author(s):  
I. TONHAJZEROVA ◽  
M. MESTANIK
Keyword(s):  
Stress Response ◽  
Complex Analysis ◽  
Stress Reactivity ◽  
Developmental Trajectory ◽  
Biofeedback Training ◽  
Human Organism ◽  
Calibration Model ◽  
Promising Tool ◽  
Adaptive Calibration ◽  
As Stress

The reactions of human organism to changes of internal or external environment termed as stress response have been at the center of interest during recent decades. Several theories were designed to describe the regulatory mechanisms which maintain the stability of vital physiological functions under conditions of threat or other environmental challenges. However, most of the models of stress reactivity were focused on specific aspects of the regulatory outcomes – physiological (e.g. neuroendocrine), psychological or behavioral regulation. Recently, a novel complex theory based on evolutionary and developmental biology has been introduced. The Adaptive Calibration Model of stress response employs a broad range of the findings from previous theories of stress and analyzes the responsivity to stress with respect to interindividual differences as a consequence of conditional adaptation – the ability to modify developmental trajectory to match the conditions of the social and physical environment. This review summarizes the contributions of the most important models in the field of stress response and emphasizes the importance of complex analysis of the psycho-physiological mechanisms. Moreover, it outlines the implications for nonpharmacological treatment of stress-related disorders with the application of biofeedback training as a promising tool based on voluntary modification of neurophysiological functions.

scholarly journals Relaxed risk of predation drives parallel evolution of stickleback behaviour

2022 ◽  
Author(s):  
Antoine Fraimout ◽  
Elisa Päiviö ◽  
Juha Merilä
Keyword(s):  
Phenotypic Plasticity ◽  
Predation Risk ◽  
Parallel Evolution ◽  
Predation Pressure ◽  
Evolutionary Divergence ◽  
Pungitius Pungitius ◽  
Risk Of Predation ◽  
Selective Agents ◽  
Habitat Similarity ◽  
Evolution By Natural Selection

The occurrence of similar phenotypes in multiple independent populations (viz. parallel evolution) is a testimony of evolution by natural selection. Parallel evolution implies that populations share a common phenotypic response to a common selection pressure associated with habitat similarity. Examples of parallel evolution at the genetic and phenotypic levels are fairly common, but the driving selective agents often remain elusive. Similarly, the role of phenotypic plasticity in facilitating early stages of parallel evolution is unclear. We investigated whether the relaxation of predation pressure associated with the colonization of freshwater ponds by nine-spined sticklebacks (Pungitius pungitius) likely explains the divergence in complex behaviours between marine and pond populations, and whether this divergence is parallel. Using laboratory-raised individuals exposed to different levels of perceived predation risk, we calculated vectors of phenotypic divergence for four behavioural traits between habitats and predation risk treatments. We found a significant correlation between the directions of evolutionary divergence and phenotypic plasticity, suggesting that habitat divergence in behaviour is aligned with the response to relaxation of predation pressure. Finally, we show that this alignment is found across multiple pairs of populations, and that the relaxation of predation pressure has likely driven parallel evolution of behaviour in this species.

scholarly journals Effects of sugar and sweetener on the acute endocrine stress response in fasted women

2020 ◽  
Author(s):  
Maria Meier ◽  
Ulrike U. Bentele ◽  
Annika Benz ◽  
Bernadette Denk ◽  
Stephanie J. Dimitroff ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Stress Response ◽  
Stress Reactivity ◽  
Blood Glucose Concentration ◽  
Stress Test ◽  
Sweet Taste ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Endocrine Stress Response ◽  
Metabolic Properties

The endocrine stress response helps to maintain homeostasis at times of increased demand and supports survival through energy mobilization. Paradoxically, low blood glucose levels impede the endocrine stress response, yet increasing blood glucose levels through sugar consumption prior to stress restores it. This suggests that glucose availability may play a causal role in the endocrine stress response. However, sugar has other distinct properties beyond the raise of blood glucose concentration. Here, we investigated the potential role of sweetness in restoring the cortisol stress reactivity after fasting. N=152 women (mean(age)=21.53, sd(age)=2.61) participated in a psychosocial stress test for groups in the morning after an overnight fast. Prior to stress induction, participants either consumed a drink that contained a caloric sweetener (sugar, n=51), an equally sweet drink containing non-caloric sweetener (sweetener, n=46), or water (n=56). Salivary cortisol and blood glucose levels were assessed repeatedly. Former studies suggested that sugar load prior to stress leads to increased cortisol responses compared to water, and sweetener. The effects of the consumed drinks on cortisol trajectories were tested using multilevel mixed models. Unexpectedly, we found that sugar and sweetener each significantly increased cortisol stress reactivity compared to water. Indeed, sweetener lead to cortisol increases comparable to sugar. Changes in blood glucose levels after drink consumption were not significantly associated with stress-induced increases in cortisol. This suggests that not the metabolic properties of sugar, but properties of sweet taste prior to stress are critical to boost the endocrine stress response to stress.

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