scholarly journals Saliva cortisol responses to altered plasma PUFA patterns in guinea pigs

2018 ◽  
Vol 120 (11) ◽  
pp. 1240-1251 ◽  
Author(s):  
Matthias Nemeth ◽  
Eva Millesi ◽  
Karl-Heinz Wagner ◽  
Bernard Wallner
Keyword(s):  
Energy Balance ◽  
Hpa Axis ◽  
Stress Responses ◽  
Guinea Pigs ◽  
Physiological Stress ◽  
Peak Plasma ◽  
Dietary Pufa ◽  
Saliva Cortisol ◽  
Measurement Design ◽  
Hpa Axis Activity

AbstractPUFA modulate hypothalamic–pituitary–adrenal (HPA) axis activity and cortisol concentrations and therefore affect physiological stress responses and the regulation of energy balance in the short- and long-term. Especially dietary intake of n-3 PUFA and a lowered n-6:n-3 ratio are highly encouraged due to beneficial and diminishing effects on basal cortisol secretions. However, the time of such effects to occur and how plasma PUFA patterns affect cortisol concentrations in the short-term was rarely investigated. In order to address this, we supplemented forty male and forty female guinea pigs with diets high in the essential PUFA α-linolenic acid (ALA, 18 : 3n-3) and linoleic acid (LA, 18 : 2n-6) for 20 d. Saliva cortisol concentrations in relation to altering plasma PUFA patterns during this time span were analysed in a repeated measurement design both during basal conditions (individual housing) in 5-d intervals and during stressful social confrontations. We detected very fast plasma PUFA accumulation rates, corresponding to the major dietary PUFA, which resulted in plasma PUFA plateau phases after 10 d. ALA negatively and LA positively affected saliva cortisol concentrations throughout the study. A positive effect of the plasma n-6:n-3 ratio on saliva cortisol concentrations was detected during peak plasma PUFA accumulations and social confrontations, while no effects were detected in relation to plasma PUFA plateau phases. These results suggest that the plasma n-6:n-3 ratio diminishes HPA axis activity during altered physiological conditions only and highlights the importance of altering plasma PUFA patterns for HPA axis functions and the control of energy balance and physiological stress.

scholarly journals Non-invasive cortisol measurements as indicators of physiological stress responses in guinea pigs

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1590 ◽  
Author(s):  
Matthias Nemeth ◽  
Elisabeth Pschernig ◽  
Bernard Wallner ◽  
Eva Millesi
Keyword(s):  
Stress Responses ◽  
Environmental Conditions ◽  
Guinea Pigs ◽  
Acute Stress ◽  
Physiological Stress ◽  
Non Invasive ◽  
Biological Relevance ◽  
Saliva Cortisol ◽  
Cortisol Levels

Non-invasive measurements of glucocorticoid (GC) concentrations, including cortisol and corticosterone, serve as reliable indicators of adrenocortical activities and physiological stress loads in a variety of species. As an alternative to invasive analyses based on plasma, GC concentrations in saliva still represent single-point-of-time measurements, suitable for studying short-term or acute stress responses, whereas fecal GC metabolites (FGMs) reflect overall stress loads and stress responses after a species-specific time frame in the long-term. In our study species, the domestic guinea pig, GC measurements are commonly used to indicate stress responses to different environmental conditions, but the biological relevance of non-invasive measurements is widely unknown. We therefore established an experimental protocol based on the animals’ natural stress responses to different environmental conditions and compared GC levels in plasma, saliva, and fecal samples during non-stressful social isolations and stressful two-hour social confrontations with unfamiliar individuals. Plasma and saliva cortisol concentrations were significantly increased directly after the social confrontations, and plasma and saliva cortisol levels were strongly correlated. This demonstrates a high biological relevance of GC measurements in saliva. FGM levels measured 20 h afterwards, representing the reported mean gut passage time based on physiological validations, revealed that the overall stress load was not affected by the confrontations, but also no relations to plasma cortisol levels were detected. We therefore measured FGMs in two-hour intervals for 24 h after another social confrontation and detected significantly increased levels after four to twelve hours, reaching peak concentrations already after six hours. Our findings confirm that non-invasive GC measurements in guinea pigs are highly biologically relevant in indicating physiological stress responses compared to circulating levels in plasma in the short- and long-term. Our approach also underlines the importance of detailed investigations on how to use and interpret non-invasive measurements, including the determination of appropriate time points for sample collections.

Effects of prolonged exendin-4 administration on hypothalamic-pituitary-adrenal axis activity and water balance

2013 ◽  
Vol 304 (10) ◽  
pp. E1105-E1117 ◽  
Author(s):  
Manuel Gil-Lozano ◽  
Marina Romaní-Pérez ◽  
Verónica Outeiriño-Iglesias ◽  
Eva Vigo ◽  
Patricia L. Brubaker ◽  
...  
Keyword(s):  
Adrenal Gland ◽  
Hpa Axis ◽  
Stress Responses ◽  
Fold Increase ◽  
Acute Administration ◽  
Sprague Dawley ◽  
Hypothalamic Pituitary Adrenal ◽  
Sprague Dawley Rats ◽  
Glucagon Like Peptide 1 ◽  
Hpa Axis Activity

Exendin-4 (Ex-4) is a natural agonist of the glucagon-like peptide-1 (GLP-1) receptor, currently being used as a treatment for type 2 diabetes mellitus due to its insulinotropic properties. Previous studies have revealed that acute administration of both GLP-1 and, in particular, Ex-4 potently stimulates hypothalamic-pituitary-adrenal (HPA) axis activity. In this work, the effects of prolonged Ex-4 exposure on HPA function were explored. To this end, Sprague-Dawley rats were subjected to a daily regimen of two Ex-4 injections (5 μg/kg sc) for a minimum of 7 days. We found that subchronic Ex-4 administration produced a number of effects that resemble chronic stress situations, including hyperactivation of the HPA axis during the trough hours, disruption of glucocorticoid circadian secretion, hypertrophy of the adrenal gland, decreased adrenal gland sensitivity, impaired pituitary-adrenal stress responses, and reductions in both food intake and body weight. In addition, a threefold increase in diuresis was observed followed by a 1.5-fold increase in water intake; these latter effects were abolished by adrenalectomy. Together, these findings indicate that Ex-4 induces a profound dysregulation of HPA axis activity that may also affect renal function.

Limbic Pathways to Stress Control

2016 ◽  
Author(s):  
James P. Herman
Keyword(s):  
Neural Networks ◽  
Prefrontal Cortex ◽  
Stress Response ◽  
Hpa Axis ◽  
Stress Responses ◽  
Physiological Stress ◽  
Brain Regions ◽  
Subcortical Structures ◽  
Stress Control ◽  
Stress Activation

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.

scholarly journals TheKampoMedicine Yokukansan Decreases MicroRNA-18 Expression and Recovers Glucocorticoid Receptors Protein Expression in the Hypothalamus of Stressed Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Shoko Shimizu ◽  
Takashi Tanaka ◽  
Takashi Takeda ◽  
Masaya Tohyama ◽  
Shingo Miyata
Keyword(s):  
Hpa Axis ◽  
Stress Responses ◽  
Glucocorticoid Receptors ◽  
Psychological Symptoms ◽  
Plasma Corticosterone ◽  
Mrna Levels ◽  
Stress Exposure ◽  
Protein Levels ◽  
Hpa Axis Activity ◽  
The Brain

It is well known that glucocorticoid receptor (GR) signaling regulates the hypothalamic-pituitary-adrenal (HPA) axis, and GR expression level is associated with HPA axis activity. Recent studies revealed that microRNA- (miR-) 18 and/or 124a are candidate negative regulators of GR in the brain. TheKampomedicine Yokukansan (YKS) can affect psychological symptoms such as depression and anxiety that are associated with stress responses. In this study, we evaluated the effect of YKS on miR-18 and 124a and GR levels in mice exposed to stress. We found that YKS pretreatment normalized elevated plasma corticosterone levels in stress-exposed mice. In addition, GR mRNA levels were downregulated in the brain following stress exposure. While miR-124a expression levels were not altered in the hypothalamus of stress-exposed mice, miR-18 levels decreased in the hypothalamus of YKS-pretreated mice after stress exposure. Finally, GR protein levels in the paraventricular nucleus (PVN) of the hypothalamus after stress exposure recovered in YKS-pretreated mice. Collectively, these data suggest that YKS normalizes GR protein levels by regulating miR-18 expression in the hypothalamus, thus normalizing HPA axis activity following stress exposure.

scholarly journals M102. MEASURING PHYSIOLOGICAL RESPONSES ASSOCIATED WITH SOCIAL STRESS IN A VIRTUAL ENVIRONMENT AND ITS RELATIONSHIP WITH CHILDHOOD TRAUMA IN EARLY SCHIZOPHRENIA - A PILOT STUDY

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S174-S174
Author(s):  
Stéfan Du Plessis ◽  
Michelle Mckenzie ◽  
Ivan Crockart ◽  
Sanja Kilian ◽  
Frederika Scheffler ◽  
...  
Keyword(s):  
Childhood Trauma ◽  
Hpa Axis ◽  
Stress Responses ◽  
Social Stress ◽  
Physiological Stress ◽  
Stress Test ◽  
Stress Sensitivity ◽  
Childhood Trauma Questionnaire ◽  
The Relationship ◽  
Fear Of Heights

Abstract Background In lower to middle income countries (LMIC), the influences of environmental stress on neurobiological processes involved in the development of schizophrenia is of great importance. High levels of stress may contribute to an increased burden of schizophrenia, including profound functional impairment and disability, decreased productivity, and even elevated mortality. Stress in Schizophrenia has been associated with behavioral disturbances such as maladaptive coping styles as well as well-established physiological abnormalities in sensorimotor gating in the form of abnormal startle responses. In turn, childhood trauma exposure is known to affect physiological stress responses. Indeed, we have found childhood trauma to be associated with both white matter and hippocampal changes in schizophrenia. Few studies, however, have explored the relationship between Childhood trauma and stress responses in schizophrenia. In recent years Virtual Reality (VR) has undergone a resurgence as a viable method for studying fear related physiological stress responses in an ecologically valid manner. Here we aim to investigate the potential relationship between abnormal physiological stress responses in schizophrenia with early life adversity. Methods Physiological response data were collected while participants completed a VR paradigm based on the Trier stress test, a well-established social stressor that reliably elicits a stress response in participants in VR and HPA axis attenuation in schizophrenia. Data were also collected in a fear of heights environment, not associated with abnormalities in schizophrenia. Childhood trauma was assessed with the Childhood Trauma Questionnaire (CTQ). HPA axis stress responses during the course of the task were assessed using saliva cortisol samples collected at key points during the paradigms. Results Preliminary data of both the social anxiety and fear of heights scenario will be presented. We will focus specifically on the viability of using VR in a LMIC context. Discussion VR could prove to be a cost-effective tool to explore the relationship between childhood trauma, stress sensitivity and schizophrenia.

scholarly journals Stress activity is not predictive of coping style in North American red squirrels

2018 ◽  
Author(s):  
Sarah E. Westrick ◽  
Freya van Kesteren ◽  
Rupert Palme ◽  
Rudy Boonstra ◽  
Jeffery E. Lane ◽  
...  
Keyword(s):  
Stress Responses ◽  
North American ◽  
Physiological Stress ◽  
Coping Styles ◽  
Behavioral Responses ◽  
Laboratory Studies ◽  
Wild Populations ◽  
Red Squirrels ◽  
North American Red Squirrels ◽  
Hpa Axis Activity

AbstractIndividuals vary in their behavioral and physiological responses to environmental changes. These behavioral responses are often described as ‘coping styles’ along a proactive-reactive continuum. Studies in laboratory populations often, but not always, find that behavioral responses and physiological responses to stressors covary, where more proactive (more aggressive and active) individuals have a lower physiological stress response, specifically as measured by hypothalamic-pituitary-adrenal (HPA) axis activity. These studies support the possibility of hormonal pleiotropy underlying the presentation of behaviors that make up the proactive-reactive phenotype. However, recent research in wild populations is equivocal, with some studies reporting the same pattern as found in many controlled laboratory studies, whereas others do not. We tested the hypothesis that physiological and behavioral stress responses are correlated in wild adult North American red squirrels (Tamiasciurus hudsonicus). We used fecal cortisol metabolites (FCMs) as a non-invasive, integrated estimate of circulating glucocorticoids for our measurement of HPA axis activity. We found that FCM concentrations were not correlated with three measures of behavioral coping styles (activity, aggression, and docility) among individuals. This does not support the hypothesis that hormonal pleiotropy underlies a proactive-reactive continuum of coping styles. Instead, our results support the “two-tier” hypothesis that behavioral and physiological stress responses are independent and uncorrelated traits among individuals in wild populations that experience naturally varying environments rather than controlled environments. If also found in other studies, this may alter our predictions about the evolutionary consequences of behavioral and endocrine coping styles in free-living animals.Significance StatementIndividuals vary in how they respond to stressors through behavior and physiology, but we find the two responses are independent in wild animals. Many laboratory studies find links between the behavioral and physiological stress responses, however studies conducted with wild populations are less conclusive. In wild North American red squirrels, independence between the physiological response and behavioral response may allow adaptive responses to a changing environment without pleiotropic constraint.

scholarly journals Time-of-day-dependent adaptation of the HPA axis to predictable social defeat stress

2016 ◽  
Vol 231 (3) ◽  
pp. 209-221 ◽  
Author(s):  
C E Koch ◽  
M S Bartlang ◽  
J T Kiehn ◽  
L Lucke ◽  
N Naujokat ◽  
...  
Keyword(s):  
Hpa Axis ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Social Defeat ◽  
Time Of Day ◽  
Adaptive Responses ◽  
Social Defeat Stress ◽  
Flight Behaviour ◽  
Hpa Axis Activity ◽  
The Impact

In modern societies, the risk of developing a whole array of affective and somatic disorders is associated with the prevalence of frequent psychosocial stress. Therefore, a better understanding of adaptive stress responses and their underlying molecular mechanisms is of high clinical interest. In response to an acute stressor, each organism can either show passive freezing or active fight-or-flight behaviour, with activation of sympathetic nervous system and the hypothalamus–pituitary–adrenal (HPA) axis providing the necessary energy for the latter by releasing catecholamines and glucocorticoids (GC). Recent data suggest that stress responses are also regulated by the endogenous circadian clock. In consequence, the timing of stress may critically affect adaptive responses to and/or pathological effects of repetitive stressor exposure. In this article, we characterize the impact of predictable social defeat stress during daytime versus nighttime on bodyweight development and HPA axis activity in mice. While 19 days of social daytime stress led to a transient reduction in bodyweight without altering HPA axis activity at the predicted time of stressor exposure, more detrimental effects were seen in anticipation of nighttime stress. Repeated nighttime stressor exposure led to alterations in food metabolization and reduced HPA axis activity with lower circulating adrenocorticotropic hormone (ACTH) and GC concentrations at the time of predicted stressor exposure. Our data reveal a circadian gating of stress adaptation to predictable social defeat stress at the level of the HPA axis with impact on metabolic homeostasis underpinning the importance of timing for the body’s adaptability to repetitive stress.

Emotions and health: The impact of emotions, emotions regulation, music, and acculturation on health

2008 ◽  
Vol 16 (3) ◽  
pp. 112-115 ◽  
Author(s):  
Stephan Bongard ◽  
Volker Hodapp ◽  
Sonja Rohrmann
Keyword(s):  
Stress Responses ◽  
Physiological Stress ◽  
Anger Expression ◽  
Domain Specific ◽  
Cardiovascular Stress ◽  
Expression Behavior ◽  
Cardio Vascular ◽  
And Coping ◽  
Relationship Of ◽  
The Impact

Abstract. Our unit investigates the relationship of emotional processes (experience, expression, and coping), their physiological correlates and possible health outcomes. We study domain specific anger expression behavior and associated cardio-vascular loads and found e.g. that particularly an open anger expression at work is associated with greater blood pressure. Furthermore, we demonstrated that women may be predisposed for the development of certain mental disorders because of their higher disgust sensitivity. We also pointed out that the suppression of negative emotions leads to increased physiological stress responses which results in a higher risk for cardiovascular diseases. We could show that relaxation as well as music activity like singing in a choir causes increases in the local immune parameter immunoglobuline A. Finally, we are investigating connections between migrants’ strategy of acculturation and health and found e.g. elevated cardiovascular stress responses in migrants when they where highly adapted to the German culture.

Sign in / Sign up

Export Citation Format

Share Document